International Journal of Molecular Sciences

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Open AccessCorrection

Zhou, T.B., et al., Correction: All-Trans Retinoic Acid Treatment Is Associated with Prohibitin Expression in Renal Interstitial Fibrosis Rats. Int. J. Mol. Sci. 2012, 13, 2769-2782.

by Tian-Biao Zhou, Yuan-Han Qin, Zheng-Yi Li, Hui-Ling Xu, Yan-Jun Zhao and Feng-Ying Lei

Int. J. Mol. Sci. 2012, 13(12), 17295; https://doi.org/10.3390/ijms131217295 - 18 Dec 2012

Cited by 1 | Viewed by 5314

Abstract

The authors wish to change Figure 2 of the paper published in IJMS [1]. The positions of H₁ and H₂ in the previous article were reversed. These errors have been amended in an amended version of the manuscript, which is available [...] Read more.

The authors wish to change Figure 2 of the paper published in IJMS [1]. The positions of H₁ and H₂ in the previous article were reversed. These errors have been amended in an amended version of the manuscript, which is available from the International Journal of Molecular Sciences website. The authors and publisher apologize for the inconvenience. [...] Full article

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Open AccessCorrection

Lech, M., et al., Quantitative Expression of C-Type Lectin Receptors in Humans and Mice. Int. J. Mol. Sci. 2012, 13, 10113-10131.

by Maciej Lech, Heni Eka Susanti, Christoph Römmele, Regina Gröbmayr, Roman Günthner and Hans-Joachim Anders

Int. J. Mol. Sci. 2012, 13(12), 17294; https://doi.org/10.3390/ijms131217294 - 18 Dec 2012

Viewed by 4915

Abstract

The authors wish to add this correction on their paper published in IJMS [1]. Galectin-1 was misclassified as a C-type lectin. Galectin-1 belongs to the family of the S-type lectins, i.e., the galectins. These errors have been amended in an amended version [...] Read more.

The authors wish to add this correction on their paper published in IJMS [1]. Galectin-1 was misclassified as a C-type lectin. Galectin-1 belongs to the family of the S-type lectins, i.e., the galectins. These errors have been amended in an amended version of the manuscript, which is available from the International Journal of Molecular Sciences website. The authors and publisher apologize for the inconvenience. [...] Full article

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Open AccessCorrection

Kasprzak, M.M., et al., Correction: Effect of Enzymatic Treatment of Different Starch Sources on the in Vitro Rate and Extent of Starch Digestion. Int. J. Mol. Sci. 2012, 13, 929-942.

by Mirosław Marek Kasprzak, Helle Nygaard Lærke, Flemming Hofmann Larsen, Knud Erik Bach Knudsen, Sven Pedersen and Anne Skov Jørgensen

Int. J. Mol. Sci. 2012, 13(12), 17292-17293; https://doi.org/10.3390/ijms131217292 - 18 Dec 2012

Cited by 3 | Viewed by 5501

Abstract

The authors wish to change the description of preparation of samples at Experimental Section on their paper published in IJMS [1]. [...] Full article

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Open AccessCorrection

Zarogouldis, P., et al., Vectors for Inhaled Gene Therapy in Lung Cancer. Application for Nano Oncology and Safety of Bio Nanotechnology. Int. J. Mol. Sci. 2012, 13, 10828-10862

by Paul Zarogoulidis, Nikos K. Karamanos, Konstantinos Porpodis, Kalliopi Domvri, Haidong Huang, Wolfgang Hohenforst-Schmidt, Eugene P. Goldberg and Konstantinos Zarogoulidis

Int. J. Mol. Sci. 2012, 13(12), 17290-17291; https://doi.org/10.3390/ijms131217290 - 18 Dec 2012

Cited by 3 | Viewed by 5671

Abstract

The authors wish to add this correction on their paper published in IJMS [1]. The first author’s name is misspelled and the correct name is Paul Zarogoulidis. In addition, the 6th author’s name is incorrect and should be corrected to Wolfgang Hohenforst-Schmidt. These [...] Read more.

The authors wish to add this correction on their paper published in IJMS [1]. The first author’s name is misspelled and the correct name is Paul Zarogoulidis. In addition, the 6th author’s name is incorrect and should be corrected to Wolfgang Hohenforst-Schmidt. These errors have been amended in an amended version of the manuscript, which is available from the International Journal of Molecular Sciences website. The authors and publisher apologize for the inconvenience. [...] Full article

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Open AccessArticle

Optimization of Synthesis, Characterization and Cytotoxic Activity of Seleno-Capparis spionosa L. Polysaccharide

by Yu-Bin Ji, Fang Dong, Lang Lang, Ling-Wen Zhang, Jing Miao, Zhen-Feng Liu, Li-Na Jin and Ying Hao

Int. J. Mol. Sci. 2012, 13(12), 17275-17289; https://doi.org/10.3390/ijms131217275 - 17 Dec 2012

Cited by 23 | Viewed by 6258

Abstract

In this study, an experiment was designed to optimize the synthesis of seleno-Capparis spionosa L. polysaccharide (Se-CSPS) by response surface methodology. Three independent variables (reaction time, reaction temperature and ratio of Na₂SeO₃ to CSPS) were tested. Furthermore, the thermal [...] Read more.

In this study, an experiment was designed to optimize the synthesis of seleno-Capparis spionosa L. polysaccharide (Se-CSPS) by response surface methodology. Three independent variables (reaction time, reaction temperature and ratio of Na₂SeO₃ to CSPS) were tested. Furthermore, the thermal stability, particle size, shape and cytotoxic activity of Se-CSPS in vitro were investigated. The optimum reaction conditions were obtained shown as follows: reaction time 7.5 h, reaction temperature 71 °C, and ratio of Na₂SeO₃ to CSPS 0.9 g/g. Under these conditions, the Se content in Se-CSPS reached 5.547 mg/g, which was close to the predicted value (5.518 mg/g) by the model. The thermal stability, particle size and shape of Se-CSPS were significantly different from those of CSPS. Additionally, a MTT assay indicated that the Se-CSPS could inhibit the proliferation of human gastric cancer SGC-7901 cells in a dose-dependent manner. Full article

(This article belongs to the Section Green Chemistry)

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Open AccessReview

Prodrugs of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs), More Than Meets the Eye: A Critical Review

by Amjad M. Qandil

Int. J. Mol. Sci. 2012, 13(12), 17244-17274; https://doi.org/10.3390/ijms131217244 - 17 Dec 2012

Cited by 116 | Viewed by 19273

Abstract

The design and the synthesis of prodrugs for nonsteroidal anti-inflammatory drugs (NSAIDs) have been given much attention by medicinal chemists, especially in the last decade. As a therapeutic group, NSAIDs are among the most widely used prescribed and over the counter (OTC) medications. [...] Read more.

The design and the synthesis of prodrugs for nonsteroidal anti-inflammatory drugs (NSAIDs) have been given much attention by medicinal chemists, especially in the last decade. As a therapeutic group, NSAIDs are among the most widely used prescribed and over the counter (OTC) medications. The rich literature about potential NSAID prodrugs clearly shows a shift from alkyl, aryalkyl or aryl esters with the sole role of masking the carboxylic acid group, to more elaborate conjugates that contain carefully chosen groups to serve specific purposes, such as enhancement of water solubility and dissolution, nitric oxide release, hydrogen sulfide release, antioxidant activity, anticholinergic and acetylcholinesterase inhibitory (AChEI) activity and site-specific targeting and delivery. This review will focus on NSAID prodrugs that have been designed or were, later, found to possess intrinsic pharmacological activity as an intact chemical entity. Such intrinsic activity might augment the anti-inflammatory activity of the NSAID, reduce its side effects or transform the potential therapeutic use from classical anti-inflammatory action to something else. Reports discussed in this review will be those of NO-NSAIDs, anticholinergic and AChEI-NSAIDs, Phospho-NSAIDs and some miscellaneous agents. In most cases, this review will cover literature dealing with these NSAID prodrugs from the year 2006 and later. Older literature will be used when necessary, e.g., to explain the chemical and biological mechanisms of action. Full article

(This article belongs to the Section Biochemistry)

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Open AccessArticle

Analysis of the Endoplasmic Reticulum Subproteome in the Livers of Type 2 Diabetic Mice

by Edmond Changkyun Park, Gun-Hwa Kim, Sung-Ho Yun, Hye Li Lim, Yeonhee Hong, Sang-Oh Kwon, Joseph Kwon, Young-Ho Chung and Seung Il Kim

Int. J. Mol. Sci. 2012, 13(12), 17230-17243; https://doi.org/10.3390/ijms131217230 - 17 Dec 2012

Cited by 7 | Viewed by 6814

Abstract

Type 2 diabetes is a chronic metabolic disease that results from insulin resistance in the liver, muscle, and adipose tissue and relative insulin deficiency. The endoplasmic reticulum (ER) plays a crucial role in the regulation of the cellular response to insulin. Recently, ER [...] Read more.

Type 2 diabetes is a chronic metabolic disease that results from insulin resistance in the liver, muscle, and adipose tissue and relative insulin deficiency. The endoplasmic reticulum (ER) plays a crucial role in the regulation of the cellular response to insulin. Recently, ER stress has been known to reduce the insulin sensitivity of the liver and lead to type 2 diabetes. However, detailed mechanisms of ER stress response that leads to type 2 diabetes remains unknown. To obtain a global view of ER function in type 2 diabetic liver and identify proteins that may be responsible for hepatic ER stress and insulin resistance, we performed proteomics analysis of mouse liver ER using nano UPLC-MS^E. A total of 1584 proteins were identified in control C57 and type 2 diabetic db/db mice livers. Comparison of the rER and sER proteomes from normal mice showed that proteins involved in protein synthesis and metabolic process were enriched in the rER, while those associated with transport and cellular homeostasis were localized to the sER. In addition, proteins involved in protein folding and ER stress were found only in the rER. In the livers of db/db mice, however, the functions of the rER and sER were severely disrupted, including the capacity to resolve ER stress. These results provide new insight into the research on hepatic insulin resistance and type 2 diabetes and are suggestive of the potential use of the differentially expressed hepatic ER proteins as biomarkers for hepatic insulin resistance and type 2 diabetes. Full article

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Physiological measurements in db/db mice. (A) Body weight of C57 control and db/db mice at 10 weeks; (B) Intraperitoneal glucose tolerance test (IPGTT) was performed by injecting 1 g/kg glucose intraperitoneally into indicated mice. Data are shown as means ± SD. p-Values were determined by Student’s t-test. *p < 0.001, **p < 0.005, and ***p < 0.05 versus C57 control mice; (C) Liver sections were prepared from C57BL/6J and db/db mice, and sections were stained with hematoxylin-eosin. Full article ">
Subcellular fractionation of mouse liver. (A) Flow diagram for the subcelluar fractionation. P, pellet; S, supernatant; SG, sucrose gradient; (B) Immunoblot assessment of the subcellular fractionation. Calnexin and KDEL are ER markers, MS604 is a mitochondria marker, and GAPDH is a cytosol marker. Full article ">
Venn diagrams showing the distribution of the unique ER proteins identified in C57 control and db/db mice livers. (A) Control mice livers; (B) db/db mice livers; (C) rER fraction; (D) sER fraction. Full article ">
Functional distribution of proteins among unique proteins of the rER and sER using Gene Ontology (GO) annotation with the hypergeometric test. (A) C57 control mice livers; (B) db/db mice livers. Unique proteins showing that the expression levels are higher at least 1.5-fold in each fraction were used for analysis (for C57 rER, 214 proteins; C57 sER, 166 proteins; db/db rER 148 proteins; db/db sER, 121 proteins). Proteins showing that the expression is higher or lower at least 5-fold are considered as exclusively expressed proteins in the indicated fraction. The degree of enrichment or depletion of identified proteins in a given function category is represented as −log(p). Full article ">
Proteins associated with ER stress. (A) Functional distribution of proteins involved in ER stress using Gene Ontology (GO) annotation with the hypergeometric test. Unique proteins showing that the expression levels are higher at least 1.5-fold in each fraction were used for analysis. The degree of enrichment or depletion of identified proteins in a given function category is represented as −log(p); (B) Protein network analysis. IPA-determined network of identified proteins in the rER that may be involved in ER stress signaling. Red, up-regulated in db/db mouse liver; green, down-regulated in db/db mouse liver. Full article ">

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Open AccessReview

X-Ray Repair Cross Complementing Protein 1 in Base Excision Repair

by Audun Hanssen-Bauer, Karin Solvang-Garten, Mansour Akbari and Marit Otterlei

Int. J. Mol. Sci. 2012, 13(12), 17210-17229; https://doi.org/10.3390/ijms131217210 - 17 Dec 2012

Cited by 46 | Viewed by 10696

Abstract

X-ray Repair Cross Complementing protein 1 (XRCC1) acts as a scaffolding protein in the converging base excision repair (BER) and single strand break repair (SSBR) pathways. XRCC1 also interacts with itself and rapidly accumulates at sites of DNA damage. XRCC1 can thus mediate [...] Read more.

X-ray Repair Cross Complementing protein 1 (XRCC1) acts as a scaffolding protein in the converging base excision repair (BER) and single strand break repair (SSBR) pathways. XRCC1 also interacts with itself and rapidly accumulates at sites of DNA damage. XRCC1 can thus mediate the assembly of large multiprotein DNA repair complexes as well as facilitate the recruitment of DNA repair proteins to sites of DNA damage. Moreover, XRCC1 is present in constitutive DNA repair complexes, some of which associate with the replication machinery. Because of the critical role of XRCC1 in DNA repair, its common variants Arg194Trp, Arg280His and Arg399Gln have been extensively studied. However, the prevalence of these variants varies strongly in different populations, and their functional influence on DNA repair and disease remains elusive. Here we present the current knowledge about the role of XRCC1 and its variants in BER and human disease/cancer. Full article

(This article belongs to the Special Issue DNA Damage and Repair in Degenerative Diseases)

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Base lesions and BER summary. (A) Base lesions: Typical sites of oxidation (red arrow marked O), alkylation (brown arrow marked (A) and spontaneous hydrolysis (blue arrow marked H) within adenine, guanine, thymine and cytosine; (B) Base Excision Repair: 1 to 5 major steps and enzymes/enzymatic activities. Full article ">
XRCC1 map. (A) Approximate XRCC1 protein interacting regions; (B) XRCC1 domains; (C) Known XRCC1 Ser/Thr phosphorylations and XRCC1 interacting kinases (Chk2: Thr284, DNA-PKcs: Ser371, CK2: cluster of six residues from Ser475 to Ser523, possibly more); (D) The three most prevalent XRCC1 variants. Full article ">
Scaffold protein interactions in BER. Common and separate interactions of XRCC1 and PCNA with enzymes involved in BER. Full article ">
A model of BER multiprotein complexes. (1) Classic BER/SSBR: At endogenous or low levels of induced DNA damage. Not dependent upon PARP1 and PARylation. Represents XRCC1-foci observed in untreated cells. Contain XRCC1 core-complex, APE1 and PARPs. Other proteins (X); (2) DNA repair at higher levels of DNA damage: Higher levels of DNA damage including strand breaks recruits PARPs followed by extensive PARylation. This is important both for signalling of damage, recruitment of repair factors and chromatin remodelling, and therefore the repair rate. These XRCC1-foci contain in addition to the core-complex, DNA repair proteins known to be involved replication and LP BER such as POLδ, FEN-1, PCNA and more (X); (3) Replication associated BER: Pre-replicative repair of single strand breaks and base damages prior to replication likely includes the UNG2 DNA glycosylase, and possibly MPG, in addition to the core-complex. Rapid removal of misincorporated bases by the DNA glycosylases UNG2 and MYH prior to rapid repair of abasic sites by the XRCC1 core complex on both leading and lagging strand. However, presence of FEN1, POLδ, and LIG1 on the lagging strand possibly also enables LP BER by “UNG2 associated complexes” [<a href="#b15-ijms-13-17210" class="html-bibr">15</a>]. This figure is adapted from [<a href="#b16-ijms-13-17210" class="html-bibr">16</a>]. Full article ">

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Open AccessArticle

Virtual Screening of Specific Insulin-Like Growth Factor 1 Receptor (IGF1R) Inhibitors from the National Cancer Institute (NCI) Molecular Database

by Cong Fan, Yan-Xin Huang, Yong-Li Bao, Lu-Guo Sun, Yin Wu, Chun-Lei Yu, Yu Zhang, Zhen-Bo Song, Li-Hua Zheng, Ying Sun, Guan-Nan Wang and Yu-Xin Li

Int. J. Mol. Sci. 2012, 13(12), 17185-17209; https://doi.org/10.3390/ijms131217185 - 14 Dec 2012

Cited by 4 | Viewed by 7657

Abstract

Insulin-like growth factor 1 receptor (IGF1R) is an attractive drug target for cancer therapy and research on IGF1R inhibitors has had success in clinical trials. A particular challenge in the development of specific IGF1R inhibitors is interference from insulin receptor (IR), which has [...] Read more.

Insulin-like growth factor 1 receptor (IGF1R) is an attractive drug target for cancer therapy and research on IGF1R inhibitors has had success in clinical trials. A particular challenge in the development of specific IGF1R inhibitors is interference from insulin receptor (IR), which has a nearly identical sequence. A few potent inhibitors that are selective for IGF1R have been discovered experimentally with the aid of computational methods. However, studies on the rapid identification of IGF1R-selective inhibitors using virtual screening and confidence-level inspections of ligands that show different interactions with IGF1R and IR in docking analysis are rare. In this study, we established virtual screening and binding-mode prediction workflows based on benchmark results of IGF1R and several kinase receptors with IGF1R-like structures. We used comprehensive analysis of the known complexes of IGF1R and IR with their binding ligands to screen specific IGF1R inhibitors. Using these workflows, 17 of 139,735 compounds in the NCI (National Cancer Institute) database were identified as potential specific inhibitors of IGF1R. Calculations of the potential of mean force (PMF) with GROMACS were further conducted for three of the identified compounds to assess their binding affinity differences towards IGF1R and IR. Full article

(This article belongs to the Section Physical Chemistry, Theoretical and Computational Chemistry)

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Open AccessReview

Nitric Oxide in Skeletal Muscle: Role on Mitochondrial Biogenesis and Function

by Celia Harumi Tengan, Gabriela Silva Rodrigues and Rosely Oliveira Godinho

Int. J. Mol. Sci. 2012, 13(12), 17160-17184; https://doi.org/10.3390/ijms131217160 - 14 Dec 2012

Cited by 92 | Viewed by 18526

Abstract

Nitric oxide (NO) has been implicated in several cellular processes as a signaling molecule and also as a source of reactive nitrogen species (RNS). NO is produced by three isoenzymes called nitric oxide synthases (NOS), all present in skeletal muscle. While neuronal NOS [...] Read more.

Nitric oxide (NO) has been implicated in several cellular processes as a signaling molecule and also as a source of reactive nitrogen species (RNS). NO is produced by three isoenzymes called nitric oxide synthases (NOS), all present in skeletal muscle. While neuronal NOS (nNOS) and endothelial NOS (eNOS) are isoforms constitutively expressed, inducible NOS (iNOS) is mainly expressed during inflammatory responses. Recent studies have demonstrated that NO is also involved in the mitochondrial biogenesis pathway, having PGC-1α as the main signaling molecule. Increased NO synthesis has been demonstrated in the sarcolemma of skeletal muscle fiber and NO can also reversibly inhibit cytochrome c oxidase (Complex IV of the respiratory chain). Investigation on cultured skeletal myotubes treated with NO donors, NO precursors or NOS inhibitors have also showed a bimodal effect of NO that depends on the concentration used. The present review will discuss the new insights on NO roles on mitochondrial biogenesis and function in skeletal muscle. We will also focus on potential therapeutic strategies based on NO precursors or analogs to treat patients with myopathies and mitochondrial deficiency. Full article

(This article belongs to the Special Issue Advances in Free Radicals in Biology and Medicine)

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Schematic diagram illustrating the organization of human nitric oxide synthases. (a) Schematic figure showing the dimeric conformation of nitric oxide synthases (NOS) with both subunits attached at the oxygenase domains (green); (b) Main structure differences between the three types of NOS isoforms. PDZ domain is typically present in neuronal NOS (nNOS), the presence of myristoylation (Myr) and palmitoylation (Palm) sites are specific to endothelial NOS (eNOS). All isoforms the oxygenase domain contains binding sites for l-arginine (Arg), Heme and tetrahydrobiopterin (BH4) while the reductase domain binds to calmodulin (CAM), FMN, FAD and NADPH. iNOS = induced NOS. Full article ">
The influence of NO on mitochondrial respiratory chain. The main site of inhibition of respiratory chain by NO is at complex IV (cytochrome c oxidase) by competition with oxygen. NO can also inhibits the electron transport chain at complex I (NADH dehydrogenase) and III (ubiquinol cytochrome c oxido reductase). The disturbance in the electron transport chain favors the formation of superoxide anions (O2−). The reaction between superoxide anions and NO, results in formation of peroxynitrite (ONOO−) inducing macromolecular damage and cell death. Full article ">
Schematic diagram illustrating the major NO pathways in the activation of mitochondrial biogenesis. Intracellular calcium release activates calcium/calmodulin kinase II (CaMK) triggering sequential activation of NOS and guanylate cyclase (GC) to generate cyclic GMP, which in turn activates protein kinase A (PKA). PKA phosphorylates CREB1 allowing its nuclear translocation and activation of the PGC-1 gene (peroxisome proliferator-activated receptor gamma co-activator 1), a co-activator for NRF-1 (nuclear respiratory factor-1), a transcription factors for mitochondrial biogenesis. The NOS-dependent induction of mitochondrial biogenesis also involves activation of AMP-activated kinase (AMPK), allowing phosphorylation of PGC-1. Full article ">

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Open AccessArticle

Aptamer-Based Molecular Recognition of Lysergamine, Metergoline and Small Ergot Alkaloids

by Elsa Rouah-Martin, Jaytry Mehta, Bieke Van Dorst, Sarah De Saeger, Peter Dubruel, Bert U. W. Maes, Filip Lemiere, Erik Goormaghtigh, Devin Daems, Wouter Herrebout, François Van Hove, Ronny Blust and Johan Robbens

Int. J. Mol. Sci. 2012, 13(12), 17138-17159; https://doi.org/10.3390/ijms131217138 - 14 Dec 2012

Cited by 20 | Viewed by 10087

Abstract

Ergot alkaloids are mycotoxins produced by fungi of the genus Claviceps, which infect cereal crops and grasses. The uptake of ergot alkaloid contaminated cereal products can be lethal to humans and animals. For food safety assessment, analytical techniques are currently used to [...] Read more.

Ergot alkaloids are mycotoxins produced by fungi of the genus Claviceps, which infect cereal crops and grasses. The uptake of ergot alkaloid contaminated cereal products can be lethal to humans and animals. For food safety assessment, analytical techniques are currently used to determine the presence of ergot alkaloids in food and feed samples. However, the number of samples which can be analyzed is limited, due to the cost of the equipment and the need for skilled personnel. In order to compensate for the lack of rapid tests for the detection of ergot alkaloids, the aim of this study was to develop a specific recognition element for ergot alkaloids, which could be further applied to produce a colorimetric reaction in the presence of these toxins. As recognition elements, single-stranded DNA ligands were selected by using an iterative selection procedure named SELEX, i.e., Systematic Evolution of Ligands by EXponential enrichment. After several selection cycles, the resulting aptamers were cloned and sequenced. A surface plasmon resonance analysis enabled determination of the dissociation constants of the complexes of aptamers and lysergamine. Dissociation constants in the nanomolar range were obtained with three selected aptamers. One of the selected aptamers, having a dissociation constant of 44 nM, was linked to gold nanoparticles and it was possible to produce a colorimetric reaction in the presence of lysergamine. This system could also be applied to small ergot alkaloids in an ergot contaminated flour sample. Full article

(This article belongs to the Section Molecular Recognition)

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Open AccessReview

Natural Biomolecules and Protein Aggregation: Emerging Strategies against Amyloidogenesis

by Antonella Sgarbossa

Int. J. Mol. Sci. 2012, 13(12), 17121-17137; https://doi.org/10.3390/ijms131217121 - 14 Dec 2012

Cited by 58 | Viewed by 11830

Abstract

Biomolecular self-assembly is a fundamental process in all organisms. As primary components of the life molecular machinery, proteins have a vast array of resources available to them for self-assembly in a functional structure. Protein self-assembly, however, can also occur in an aberrant way, [...] Read more.

Biomolecular self-assembly is a fundamental process in all organisms. As primary components of the life molecular machinery, proteins have a vast array of resources available to them for self-assembly in a functional structure. Protein self-assembly, however, can also occur in an aberrant way, giving rise to non-native aggregated structures responsible for severe, progressive human diseases that have a serious social impact. Different neurodegenerative disorders, like Huntington’s, Alzheimer’s, and spongiform encephalopathy diseases, have in common the presence of insoluble protein aggregates, generally termed “amyloid,” that share several physicochemical features: a fibrillar morphology, a predominantly beta-sheet secondary structure, birefringence upon staining with the dye Congo red, insolubility in common solvents and detergents, and protease resistance. Conformational constrains, hydrophobic and stacking interactions can play a key role in the fibrillogenesis process and protein–protein and peptide–peptide interactions—resulting in self-assembly phenomena of peptides yielding fibrils—that can be modulated and influenced by natural biomolecules. Small organic molecules, which possess both hydrophilic and hydrophobic moieties able to bind to peptide/protein molecules through hydrogen bonds and hydrophobic and aromatic interactions, are potential candidates against amyloidogenesis. In this review some significant case examples will be critically discussed. Full article

(This article belongs to the Special Issue Molecular Self-Assembly 2012)

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Open AccessArticle

High Density Lipoprotein Protects Mesenchymal Stem Cells from Oxidative Stress-Induced Apoptosis via Activation of the PI3K/Akt Pathway and Suppression of Reactive Oxygen Species

by Jianfeng Xu, Juying Qian, Xinxing Xie, Li Lin, Yunzeng Zou, Mingqiang Fu, Zheyong Huang, Guoping Zhang, Yangang Su and Junbo Ge

Int. J. Mol. Sci. 2012, 13(12), 17104-17120; https://doi.org/10.3390/ijms131217104 - 13 Dec 2012

Cited by 70 | Viewed by 9207

Abstract

The therapeutic effect of transplantation of mesenchymal stem cells (MSCs) in myocardial infarction (MI) appears to be limited by poor cell viability in the injured tissue, which is a consequence of oxidative stress and pro-apoptotic factors. High density lipoprotein (HDL) reverses cholesterol transport [...] Read more.

The therapeutic effect of transplantation of mesenchymal stem cells (MSCs) in myocardial infarction (MI) appears to be limited by poor cell viability in the injured tissue, which is a consequence of oxidative stress and pro-apoptotic factors. High density lipoprotein (HDL) reverses cholesterol transport and has anti-oxidative and anti-apoptotic properties. We, therefore, investigated whether HDL could protect MSCs from oxidative stress-induced apoptosis. MSCs derived from the bone marrow of rats were pre-incubated with or without HDL, and then were exposed to hydrogen peroxide (H₂O₂) in vitro, or were transplanted into experimentally infarcted hearts of rats in vivo. Pre-incubation of MSCs with HDL increased cell viability, reduced apoptotic indices and resulted in parallel decreases in reactive oxygen species (ROS) in comparison with control MSCs. Each of the beneficial effects of HDL on MSCs was attenuated by inhibiting the PI3K/Akt pathway. Preconditioning with HDL resulted in higher MSC survival rates, improved cardiac remodeling and better myocardial function than in the MSC control group. Collectively, these results suggest that HDL may protect against H₂O₂-induced apoptosis in MSCs through activation of a PI3K/Akt pathway, and by suppressing the production of ROS. Full article

(This article belongs to the Section Biochemistry)

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Open AccessReview

Plant Glandular Trichomes as Targets for Breeding or Engineering of Resistance to Herbivores

by Joris J. Glas, Bernardus C. J. Schimmel, Juan M. Alba, Rocío Escobar-Bravo, Robert C. Schuurink and Merijn R. Kant

Int. J. Mol. Sci. 2012, 13(12), 17077-17103; https://doi.org/10.3390/ijms131217077 - 12 Dec 2012

Cited by 413 | Viewed by 30003

Abstract

Glandular trichomes are specialized hairs found on the surface of about 30% of all vascular plants and are responsible for a significant portion of a plant’s secondary chemistry. Glandular trichomes are an important source of essential oils, i.e., natural fragrances or products [...] Read more.

Glandular trichomes are specialized hairs found on the surface of about 30% of all vascular plants and are responsible for a significant portion of a plant’s secondary chemistry. Glandular trichomes are an important source of essential oils, i.e., natural fragrances or products that can be used by the pharmaceutical industry, although many of these substances have evolved to provide the plant with protection against herbivores and pathogens. The storage compartment of glandular trichomes usually is located on the tip of the hair and is part of the glandular cell, or cells, which are metabolically active. Trichomes and their exudates can be harvested relatively easily, and this has permitted a detailed study of their metabolites, as well as the genes and proteins responsible for them. This knowledge now assists classical breeding programs, as well as targeted genetic engineering, aimed to optimize trichome density and physiology to facilitate customization of essential oil production or to tune biocide activity to enhance crop protection. We will provide an overview of the metabolic diversity found within plant glandular trichomes, with the emphasis on those of the Solanaceae, and of the tools available to manipulate their activities for enhancing the plant’s resistance to pests. Full article

(This article belongs to the Special Issue Green Biocides)

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Open AccessArticle

Plant Regeneration and Somatic Embryogenesis from Immature Embryos Derived through Interspecific Hybridization among Different Carica Species

by Md. Abul Kalam Azad, Md. Golam Rabbani and Latifah Amin

Int. J. Mol. Sci. 2012, 13(12), 17065-17076; https://doi.org/10.3390/ijms131217065 - 12 Dec 2012

Cited by 10 | Viewed by 7339

Abstract

Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild [...] Read more.

Plant regeneration and somatic embryogenesis through interspecific hybridization among different Carica species were studied for the development of a papaya ringspot virus-resistant variety. The maximum fruit sets were recorded from the cross of the native variety C. papaya cv. Shahi with the wild species C. cauliflora. The highest hybrid embryos were recorded at 90 days after pollination and the embryos were aborted at 150 days after pollination. The immature hybrid embryos were used for plant regeneration and somatic embryogenesis. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora showed the highest percentage of germination, as well as plant regeneration on growth regulators free culture medium after 7 days pre-incubation on half-strength MS medium supplemented with 0.2 mg/L BAP, 0.5 mg/L NAA and 60 g/L sucrose. The 90-day-old hybrid embryos from the cross of C. papaya cv. Shahi × C. cauliflora produced maximum callus, as well as somatic embryos when cultured on half-strength MS medium containing 5 mg/L 2,4-D, 100 mg/L glutamine, 100 mg/L casein hydrolysate and 60 g/L sucrose. The somatic embryos were transferred into half-strength MS medium containing 0.5 mg/L BAP and 0.2 mg/L NAA and 60 g/L sucrose for maturation. The highest number of regenerated plants per hybrid embryo (10.33) was recorded from the cross of C. papaya cv. Shahi × C. cauliflora. Isoenzyme and dendrogram cluster analysis using UPGMA of the regenerated F₁ plantlets confirmed the presence of the hybrid plantlets. Full article

(This article belongs to the Section Biochemistry)

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The somatic embryogenesis of immature zygotic hybrid embryos derived from the crosses of C. papaya cv. Shahi × C. cauliflora (a) Immature zygotic hybrid embryos from obtained at 90 days after pollination; (b) Profuse callus of immature hybrid embryos after culturing; (c) Mature somatic embryos; (d) Germinated somatic embryos; (e) Hybrid plant in the culture tube and (f) Acclimatized to ex vitro condition hybrid plant. Full article ">
Isoenzyme analysis of Glutamate Oxaloacetate Transminase (GOT) of different Carica species and their hybrids. (Lane 1 = C. papaya cv. Shahi, lane 2 = C. papaya cv. Ranchi, lane 3 = C. cauliflora, lane 4 = C. goudotiana, lane 5 = hybrid of C. papaya cv. Shahi × C. cauliflora, lane 6 = hybrid of C. papaya cv. Ranchi × C. cauliflora, lane 7 = hybrid of C. papaya cv. Shahi × C. goudotiana, lane 8 = hybrid of C. papaya cv. Ranchi × C. goudotiana. Full article ">
Zymogram of (GOT) isoenzyme of different Carica species and their hybrids. (Lane 1 = C. papaya cv. Shahi, lane 2 = C. papaya cv. Ranchi, lane 3 = C. cauliflora, lane 4 = C. goudotiana, lane 5 = hybrid of C. papaya cv. Shahi × C. cauliflora, lane 6 = hybrid of C. papaya cv. Ranchi × C. cauliflora, lane 7 = hybrid of C. papaya cv. Shahi × C. goudotiana, lane 8 = hybrid of C. papaya cv. Ranchi × C. goudotiana. Full article ">
Dendrogram cluster analysis using UPGMA showing the relationship among the parents and their hybrids of different Carica species from GOT isoenzyme data (CPS = C. papaya cv. Shahi, CPR = C. papaya cv. Ranchi, CC = C. cauliflora, CG = C. goudotiana). Full article ">

2024 KiB

Open AccessArticle

Anti-Legionella dumoffii Activity of Galleria mellonella Defensin and Apolipophorin III

by Marta Palusińska-Szysz, Agnieszka Zdybicka-Barabas, Bożena Pawlikowska-Pawlęga, Pawel Mak and Małgorzata Cytryńska

Int. J. Mol. Sci. 2012, 13(12), 17048-17064; https://doi.org/10.3390/ijms131217048 - 12 Dec 2012

Cited by 29 | Viewed by 8354

Abstract

The gram-negative bacterium Legionella dumoffii is, beside Legionella pneumophila, an etiological agent of Legionnaires’ disease, an atypical form of pneumonia. The aim of this study was to determine the antimicrobial activity of Galleria mellonella defense polypeptides against L. dumoffii. The extract [...] Read more.

The gram-negative bacterium Legionella dumoffii is, beside Legionella pneumophila, an etiological agent of Legionnaires’ disease, an atypical form of pneumonia. The aim of this study was to determine the antimicrobial activity of Galleria mellonella defense polypeptides against L. dumoffii. The extract of immune hemolymph, containing a mixture of defense peptides and proteins, exhibited a dose-dependent bactericidal effect on L. dumoffii. The bacterium appeared sensitive to a main component of the hemolymph extract, apolipophorin III, as well as to a defense peptide, Galleria defensin, used at the concentrations 0.4 mg/mL and 40 μg/mL, respectively. L. dumoffii cells cultured in the presence of choline were more susceptible to both defense factors analyzed. A transmission electron microscopy study of bacterial cells demonstrated that Galleria defensin and apolipophorin III induced irreversible cell wall damage and strong intracellular alterations, i.e., increased vacuolization, cytoplasm condensation and the appearance of electron-white spaces in electron micrographs. Our findings suggest that insects, such as G. mellonella, with their great diversity of antimicrobial factors, can serve as a rich source of compounds for the testing of Legionella susceptibility to defense-related peptides and proteins. Full article

(This article belongs to the Special Issue Phospholipids: Molecular Sciences 2012)

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Growth inhibition of L. dumoffii by G. mellonella immune hemolymph extract. The bacteria were incubated with the extract at the concentrations 0.4–3.3 mg/mL (total protein) for 1 h, as described in the Experimental Section. Next, the cells were seeded on the agar plates, and the growing colonies were counted. Survival of the untreated cells was regarded as 100% (C; control). Statistical significance: * p < 0.05; ** p < 0.01. Full article ">
The effects of G. mellonella apoLp-III and defensin on L. dumoffii survival and influence of choline supplementation on the activity of the antimicrobial factors. The bacteria cultured on the non-supplemented (black bars) and choline-supplemented (grey bars) medium were exposed to Galleria defensin (40 μg/mL) or apoLp-III (0.4 mg/mL), as described in the Experimental Section. After seeding of the bacteria on the agar plates, the growing colonies were counted. Survival of the untreated cells was regarded as 100% (C; control). The results are given as mean ± SD from three independent experiments. Statistical significance: ** p < 0.01; *** p < 0.001. Full article ">
The influence of the extract of G. mellonella immune hemolymph on L. dumoffii cell morphology. The cells growing on the non-supplemented (A–C,F–I) and choline-supplemented (D,E,J–K) agar medium were exposed to G. mellonella hemolymph extract (F–I,J,K) or left untreated (A–C,D,E). Then, the cells were prepared for TEM analysis as described in the Experimental Section. (A) one big bacterium in longitudinal section; vacuoles are visible inside the cell (arrowheads); the outer and inner membrane is distinguishable in the cell envelope; (B) a fragment of the bacterium with a visible internal membrane (arrows); IM, inner membrane; OM, outer membrane; (C) a portion of the bacterium with a peptidoglycan-like layer (denoted as PG); outer and inner membranes are seen; (D,E) cells cultured on the choline-supplemented medium with a typical appearance; (F) cells showing cell wall damage and a periplasmatic space (arrows); (G) bacteria with cell wall damage (arrows) and dense cytoplasm with vacuoles (arrowhead); (H) enlarged view of a bacterium with strong cell envelope damage and cytoplasm condensation; the rest of the cells exhibit cell wall damage and presence of vacuoles (arrowhead); (I) many bacterial cells demonstrating loose attachment of the cell membrane (arrows); and (J,K) cells cultured on choline exposed to the extract with visible deterioration of the cell wall. Full article ">
The influence of the extract of G. mellonella immune hemolymph on L. dumoffii cell morphology. The cells growing on the non-supplemented (A–C,F–I) and choline-supplemented (D,E,J–K) agar medium were exposed to G. mellonella hemolymph extract (F–I,J,K) or left untreated (A–C,D,E). Then, the cells were prepared for TEM analysis as described in the Experimental Section. (A) one big bacterium in longitudinal section; vacuoles are visible inside the cell (arrowheads); the outer and inner membrane is distinguishable in the cell envelope; (B) a fragment of the bacterium with a visible internal membrane (arrows); IM, inner membrane; OM, outer membrane; (C) a portion of the bacterium with a peptidoglycan-like layer (denoted as PG); outer and inner membranes are seen; (D,E) cells cultured on the choline-supplemented medium with a typical appearance; (F) cells showing cell wall damage and a periplasmatic space (arrows); (G) bacteria with cell wall damage (arrows) and dense cytoplasm with vacuoles (arrowhead); (H) enlarged view of a bacterium with strong cell envelope damage and cytoplasm condensation; the rest of the cells exhibit cell wall damage and presence of vacuoles (arrowhead); (I) many bacterial cells demonstrating loose attachment of the cell membrane (arrows); and (J,K) cells cultured on choline exposed to the extract with visible deterioration of the cell wall. Full article ">
The influence of defensin and apolipophorin III isolated from G. mellonella hemolymph on the ultrastructure of L. dumoffii cells. The cells grown on the non-supplemented (A–C,G,H) and choline-supplemented (D–F,I–K) medium were incubated in the presence of apoLp-III (A–F) or Galleria defensin (G–K). Then the cells were prepared for TEM analysis as described in the Experimental Section. (A,B) cells showing condensed cytoplasm, regions with decreased electron density and the presence of vacuoles (arrowhead); (C) a fragment of the bacterium with a group of visible vacuoles and dark, dense cytoplasm; (D,E) cells with vacuolization features (arrowheads) and cell envelope damage (arrow); (F) bacteria with cell wall distortion (arrow) and a widened periplasmatic space; (G) cells with electron-white spaces (EWS), membrane deterioration (arrows), and condensed content (arrowheads); (H) irreversible cell wall damage visible in bacteria (arrows) together with dense areas of cytoplasm or entire cytoplasm of the whole cells (arrowheads); (I) bacteria demonstrating loss of cell wall integrity, vacuolization of cytoplasm (arrowheads), cell shrinkage; and (J,K) cells showing cell wall damage (arrows), electron-white spaces (EWS), presence of small vacuoles (arrowheads). Full article ">
The influence of defensin and apolipophorin III isolated from G. mellonella hemolymph on the ultrastructure of L. dumoffii cells. The cells grown on the non-supplemented (A–C,G,H) and choline-supplemented (D–F,I–K) medium were incubated in the presence of apoLp-III (A–F) or Galleria defensin (G–K). Then the cells were prepared for TEM analysis as described in the Experimental Section. (A,B) cells showing condensed cytoplasm, regions with decreased electron density and the presence of vacuoles (arrowhead); (C) a fragment of the bacterium with a group of visible vacuoles and dark, dense cytoplasm; (D,E) cells with vacuolization features (arrowheads) and cell envelope damage (arrow); (F) bacteria with cell wall distortion (arrow) and a widened periplasmatic space; (G) cells with electron-white spaces (EWS), membrane deterioration (arrows), and condensed content (arrowheads); (H) irreversible cell wall damage visible in bacteria (arrows) together with dense areas of cytoplasm or entire cytoplasm of the whole cells (arrowheads); (I) bacteria demonstrating loss of cell wall integrity, vacuolization of cytoplasm (arrowheads), cell shrinkage; and (J,K) cells showing cell wall damage (arrows), electron-white spaces (EWS), presence of small vacuoles (arrowheads). Full article ">

1072 KiB

Open AccessReview

Organic Solar Cells: Understanding the Role of Förster Resonance Energy Transfer

by Krishna Feron, Warwick J. Belcher, Christopher J. Fell and Paul C. Dastoor

Int. J. Mol. Sci. 2012, 13(12), 17019-17047; https://doi.org/10.3390/ijms131217019 - 12 Dec 2012

Cited by 110 | Viewed by 15823

Abstract

Organic solar cells have the potential to become a low-cost sustainable energy source. Understanding the photoconversion mechanism is key to the design of efficient organic solar cells. In this review, we discuss the processes involved in the photo-electron conversion mechanism, which may be [...] Read more.

Organic solar cells have the potential to become a low-cost sustainable energy source. Understanding the photoconversion mechanism is key to the design of efficient organic solar cells. In this review, we discuss the processes involved in the photo-electron conversion mechanism, which may be subdivided into exciton harvesting, exciton transport, exciton dissociation, charge transport and extraction stages. In particular, we focus on the role of energy transfer as described by F¨orster resonance energy transfer (FRET) theory in the photoconversion mechanism. FRET plays a major role in exciton transport, harvesting and dissociation. The spectral absorption range of organic solar cells may be extended using sensitizers that efficiently transfer absorbed energy to the photoactive materials. The limitations of F¨orster theory to accurately calculate energy transfer rates are discussed. Energy transfer is the first step of an efficient two-step exciton dissociation process and may also be used to preferentially transport excitons to the heterointerface, where efficient exciton dissociation may occur. However, FRET also competes with charge transfer at the heterointerface turning it in a potential loss mechanism. An energy cascade comprising both energy transfer and charge transfer may aid in separating charges and is briefly discussed. Considering the extent to which the photo-electron conversion efficiency is governed by energy transfer, optimisation of this process offers the prospect of improved organic photovoltaic performance and thus aids in realising the potential of organic solar cells. Full article

(This article belongs to the Special Issue Förster Resonance Energy Transfer (FRET))

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262 KiB

Open AccessArticle

Effects of Schizonepetin on Activity and mRNA Expression of Cytochrome P450 Enzymes in Rats

by Beihua Bao, Ting Geng, Yudan Cao, Weifeng Yao, Li Zhang and Anwei Ding

Int. J. Mol. Sci. 2012, 13(12), 17006-17018; https://doi.org/10.3390/ijms131217006 - 12 Dec 2012

Cited by 12 | Viewed by 6395

Abstract

The aim of this study was to find out whether Schizonepetin influences the pharmacokinetics of the main substrates drugs of CYP1A2, CYP3A1/2, CYP2E1, CYP2C19 and CYP2D6 in rats; the influence on the levels of CYP mRNA was also studied. Phenacetin, dapsone, chlorzoxazone, omeprazole [...] Read more.

The aim of this study was to find out whether Schizonepetin influences the pharmacokinetics of the main substrates drugs of CYP1A2, CYP3A1/2, CYP2E1, CYP2C19 and CYP2D6 in rats; the influence on the levels of CYP mRNA was also studied. Phenacetin, dapsone, chlorzoxazone, omeprazole and metoprolol were selected as probe substrates for CYP1A2, CYP3A1/2, CYP2E1, CYP2C19 and CYP2D6 respectively. HPLC methods were employed for the determination of these substrates in plasma and the pharmacokinetic parameters were calculated. Real-time RT-PCR was used to determine the effects of Schizonepetin on the mRNA expression of CYP3A1, CYP1A2 and CYP2E1 in the rat liver. After the rats were orally administrated with Schizonepetin once a day for seven consecutive days, there were significant differences in plasma concentration of phenacetin, dapsone, chlorzoxazone and metoprolol, but not omeprazole, as compared with pre-administration. In addition, Schizonepetin induced the expression of CYP3A1, CYP1A and CYP2E1 at dosages of 24 and 48 mg/kg. Our results indicated that Schizonepetin had significant induction effects on CYP3A1/2 and inhibition effects on CYP1A2, CYP2E1 or CYP2D6 as oriented from the pharmacokinetic profiles of the substrates. Moreover, in the mRNA expression levels, Schizonepetin could induce the mRNA expression of CYP3A1, CYP1A and CYP2E1. In conclusion, co-administration of some CYP substrates with Schizonepetin may lead to an undesirable herb-drug interaction. Full article

(This article belongs to the Section Biochemistry)

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792 KiB

Open AccessReview

Intelligent Design of Nano-Scale Molecular Imaging Agents

by Sung Bae Kim, Mitsuru Hattori and Takeaki Ozawa

Int. J. Mol. Sci. 2012, 13(12), 16986-17005; https://doi.org/10.3390/ijms131216986 - 12 Dec 2012

Cited by 7 | Viewed by 8726

Abstract

Visual representation and quantification of biological processes at the cellular and subcellular levels within living subjects are gaining great interest in life science to address frontier issues in pathology and physiology. As intact living subjects do not emit any optical signature, visual representation [...] Read more.

Visual representation and quantification of biological processes at the cellular and subcellular levels within living subjects are gaining great interest in life science to address frontier issues in pathology and physiology. As intact living subjects do not emit any optical signature, visual representation usually exploits nano-scale imaging agents as the source of image contrast. Many imaging agents have been developed for this purpose, some of which exert nonspecific, passive, and physical interaction with a target. Current research interest in molecular imaging has mainly shifted to fabrication of smartly integrated, specific, and versatile agents that emit fluorescence or luminescence as an optical readout. These agents include luminescent quantum dots (QDs), biofunctional antibodies, and multifunctional nanoparticles. Furthermore, genetically encoded nano-imaging agents embedding fluorescent proteins or luciferases are now gaining popularity. These agents are generated by integrative design of the components, such as luciferase, flexible linker, and receptor to exert a specific on–off switching in the complex context of living subjects. In the present review, we provide an overview of the basic concepts, smart design, and practical contribution of recent nano-scale imaging agents, especially with respect to genetically encoded imaging agents. Full article

(This article belongs to the Special Issue Bioactive Nanoparticles 2012)

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382 KiB

Open AccessArticle

Increased Insulin Sensitivity and Distorted Mitochondrial Adaptations during Muscle Unloading

by Zhengtang Qi, Yuan Zhang, Wei Guo, Liu Ji and Shuzhe Ding

Int. J. Mol. Sci. 2012, 13(12), 16971-16985; https://doi.org/10.3390/ijms131216971 - 11 Dec 2012

Cited by 13 | Viewed by 6958

Abstract

We aimed to further investigate mitochondrial adaptations to muscle disuse and the consequent metabolic disorders. Male rats were submitted to hindlimb unloading (HU) for three weeks. Interestingly, HU increased insulin sensitivity index (ISI) and decreased blood level of triglyceride and insulin. In skeletal [...] Read more.

We aimed to further investigate mitochondrial adaptations to muscle disuse and the consequent metabolic disorders. Male rats were submitted to hindlimb unloading (HU) for three weeks. Interestingly, HU increased insulin sensitivity index (ISI) and decreased blood level of triglyceride and insulin. In skeletal muscle, HU decreased expression of pyruvate dehydrogenase kinase 4 (PDK4) and its protein level in mitochondria. HU decreased mtDNA content and mitochondrial biogenesis biomarkers. Dynamin-related protein (Drp1) in mitochondria and Mfn2 mRNA level were decreased significantly by HU. Our findings provide more extensive insight into mitochondrial adaptations to muscle disuse, involving the shift of fuel utilization towards glucose, the decreased mitochondrial biogenesis and the distorted mitochondrial dynamics. Full article

(This article belongs to the Special Issue Advances in Free Radicals in Biology and Medicine)

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Body mass (A), muscle relative weight (B) and blood parameters (C) in rats subjected to 21-day hindlimb unloading(HU). TG, triglyceride; TC, total cholesterol; HDLc, high-density lipoprotein cholesterol; ISI, insulin sensitivity index (= 1/(FPG × FINS)). Values are means ± SE. n = 8~10 for each group. *p < 0.05, **p < 0.01 vs. control rats. Full article ">
Body mass (A), muscle relative weight (B) and blood parameters (C) in rats subjected to 21-day hindlimb unloading(HU). TG, triglyceride; TC, total cholesterol; HDLc, high-density lipoprotein cholesterol; ISI, insulin sensitivity index (= 1/(FPG × FINS)). Values are means ± SE. n = 8~10 for each group. *p < 0.05, **p < 0.01 vs. control rats. Full article ">
Mitochondrial DNA content (A), Cytochrome c content (B) and oxidative damage (C) in skeletal muscle subjected to 21-day hindlimb unloading (HU). Real-time PCR was used to determine mtDNA content in gastrocnemius, relative to the endogenous control β-actin. ATPase6 was used as mtDNA marker, and β-actin was used as a nuclear DNA marker. Values are means ± SE. n = 6 for each group. * p < 0.05, ** p < 0.01 vs. control rats. Full article ">
Mitochondrial DNA content (A), Cytochrome c content (B) and oxidative damage (C) in skeletal muscle subjected to 21-day hindlimb unloading (HU). Real-time PCR was used to determine mtDNA content in gastrocnemius, relative to the endogenous control β-actin. ATPase6 was used as mtDNA marker, and β-actin was used as a nuclear DNA marker. Values are means ± SE. n = 6 for each group. * p < 0.05, ** p < 0.01 vs. control rats. Full article ">
mRNA quantification of proteins and regulators controlling fuel utilization (A), mitochondrial biogenesis (B) and dynamics (C) in skeletal muscle subjected to 21-day hindlimb unloading (HU). Real-time PCR was used to determine expression of genes in gastrocnemius from HU and control rats, relative to the endogenous control β-actin. Values are means ± SE. n = 6 for each group. * p < 0.05, ** p < 0.01 vs. control rats. Full article ">
mRNA quantification of proteins and regulators controlling fuel utilization (A), mitochondrial biogenesis (B) and dynamics (C) in skeletal muscle subjected to 21-day hindlimb unloading (HU). Real-time PCR was used to determine expression of genes in gastrocnemius from HU and control rats, relative to the endogenous control β-actin. Values are means ± SE. n = 6 for each group. * p < 0.05, ** p < 0.01 vs. control rats. Full article ">
Western blot analysis and densitometric ratios of PDK4, CPT-1β, Drp1 and Mfn2 in mitochondrial fractions. Western blot analysis was used to determine the level of proteins in mitochondrial fractions extracted from gastrocnemius, relative to the endogenous VDAC1 (mitochondrial). Values are means ± SE (A). Western blots (B) are representative from one rat from each group. n = 4 for each group. * p < 0.05 vs. control rats. Full article ">

748 KiB

Open AccessArticle

Effects of Sesamin on Streptozotocin (STZ)-Induced NIT-1 Pancreatic β-Cell Damage

by Hong Lei, Juncheng Han, Qin Wang, Shuzhen Guo, Hanju Sun and Xiaoxiang Zhang

Int. J. Mol. Sci. 2012, 13(12), 16961-16970; https://doi.org/10.3390/ijms131216961 - 11 Dec 2012

Cited by 33 | Viewed by 7208

Abstract

The protective effect of sesamin (SES) from sesame meal on NIT-1 pancreatic β-cells damaged by streptozotocin (STZ) in vitro was investigated. The cell viability, insulin secretion, the activity of superoxide dismutase(SOD), glutathione peroxidase (GSHpx) and the content of reduced glutathione (GSH) increased significantly [...] Read more.

The protective effect of sesamin (SES) from sesame meal on NIT-1 pancreatic β-cells damaged by streptozotocin (STZ) in vitro was investigated. The cell viability, insulin secretion, the activity of superoxide dismutase(SOD), glutathione peroxidase (GSHpx) and the content of reduced glutathione (GSH) increased significantly when incubated with SES (400, 200 µg mL⁻¹). The content of malondialdehyde (MDA), nitric oxide (NO) production, and the activity of NO synthase (NOS), inducible NOS (iNOS), decreased significantly when incubated with SES. The destructive changes of NIT-1 cells were ameliorated when treated with SES under microscopic observation. These data suggested that SES had obvious protective effect on NIT-1 pancreatic β-cells damaged by STZ, which might be related to its effects of decreasing levels of β-cell-destroying factors such as oxidative stress and NO synthesis. Full article

(This article belongs to the Section Biochemistry)

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1148 KiB

Open AccessArticle

Oxidative Stress Mediated-Alterations of the MicroRNA Expression Profile in Mouse Hippocampal Neurons

by Shunjiang Xu, Rui Zhang, Jingya Niu, Dongsheng Cui, Bing Xie, Binggui Zhang, Kang Lu, Wenjun Yu, Xueyi Wang and Qingfu Zhang

Int. J. Mol. Sci. 2012, 13(12), 16945-16960; https://doi.org/10.3390/ijms131216945 - 11 Dec 2012

Cited by 71 | Viewed by 8430

Abstract

Oxidative stress plays a critical role in the etiology and pathogenesis of neurodegenerative disorders, and the molecular mechanisms that control the neuron response to ROS have been extensively studied. However, the oxidative stress-effect on miRNA expression in hippocampal neurons has not been investigated, [...] Read more.

Oxidative stress plays a critical role in the etiology and pathogenesis of neurodegenerative disorders, and the molecular mechanisms that control the neuron response to ROS have been extensively studied. However, the oxidative stress-effect on miRNA expression in hippocampal neurons has not been investigated, and little is known on the effect of ROS-modulated miRNAs on cell function. In this study, H₂O₂ was used to stimulate the mouse primary hippocampal neurons to develop an oxidative stress cell model. The alterations of miRNAs expression were detected by microarray analysis and five miRNAs were validated by real-time RT-PCR. The bioinformatic analysis of deregulated miRNAs was performed to determine their potential roles in the pathogenesis of neurological disorders. We found that H₂O₂ mediated a total of 101 deregulated miRNAs, which mainly took part in the regulation of the MAPK pathway. Among them, miR-135b and miR-708 were up-regulated significantly and their targets were predicted to be involved in DNA recombination, protein ubiquitination, protein autophosphorylation and development of neurons. These results demonstrated that oxidative stress alters the miRNA expression profile of hippocampal neurons, and the deregulated miRNAs might play a potential role in the pathogenesis of neurodegenerative diseases, such as Alzheimer’s disease (AD). Full article

(This article belongs to the Section Biochemistry)

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The effect of H2O2 on the cell viability of mouse primary hippocampal neurons. (a) Primary hippocampal neurons grown for 7 DIV were immunostained for MAP-2; (b) Cell viability was assessed at 24 h after stimulation with different concentrations (0, 100, 200, 400 and 800 μmol/L) of H2O2 by MTT assay. * p < 0.05 versus control. Full article ">
The apoptosis percentage of primary hippocampal neurons induced by H2O2. Cells were stained with TUNEL and Hoechst 33258 after stimulation with 200 μmol/L H2O2 for 24 h. (a) Morphological apoptosis was determined by TUNEL assay. Green-stained cells were TUNEL-positive cells (I). All nuclei were stained with Hoechst 33258 (II). The merge of I and II is III (200×); (b) The ratio of TUNEL-positive primary hippocampal neurons to the total cells. * p < 0.01 versus control. All data were expressed as mean ± SD of three experiments. The images shown are representative images. Full article ">
The death percentage of primary hippocampal neurons induced by H2O2. Cells were stained with PI and Hoechst 33258 after stimulation with 200 μmol/L H2O2 for 24 h. (a) Morphological cell death was determined by PI staining. Red stained cells were PI-positive cells (I). All nuclei were stained with Hoechst 33258 (II). The merge of I and II is III (200×); (b) The ratio of PI -positive primary hippocampal neurons to the total cells. * p < 0.01 versus control. The images shown are representative images. Full article ">
Real-time quantification of chosen miRNAs in primary hippocampal neurons exposure to H2O2 (200 μmol/L) for 6 h. T-test p-value significance: ** p < 0.01, * p < 0.05. Expression was normalized to snoRNA U6. Three replicates of each qRT-PCR were performed. Full article ">

440 KiB

Open AccessReview

DNA Damage and Repair in Atherosclerosis: Current Insights and Future Perspectives

by Tiziana Cervelli, Andrea Borghini, Alvaro Galli and Maria Grazia Andreassi

Int. J. Mol. Sci. 2012, 13(12), 16929-16944; https://doi.org/10.3390/ijms131216929 - 11 Dec 2012

Cited by 56 | Viewed by 15231

Abstract

Atherosclerosis is the leading cause of morbidity and mortality among Western populations. Over the past two decades, considerable evidence has supported a crucial role for DNA damage in the development and progression of atherosclerosis. These findings support the concept that the prolonged exposure [...] Read more.

Atherosclerosis is the leading cause of morbidity and mortality among Western populations. Over the past two decades, considerable evidence has supported a crucial role for DNA damage in the development and progression of atherosclerosis. These findings support the concept that the prolonged exposure to risk factors (e.g., dyslipidemia, smoking and diabetes mellitus) leading to reactive oxygen species are major stimuli for DNA damage within the plaque. Genomic instability at the cellular level can directly affect vascular function, leading to cell cycle arrest, apoptosis and premature vascular senescence. The purpose of this paper is to review current knowledge on the role of DNA damage and DNA repair systems in atherosclerosis, as well as to discuss the cellular response to DNA damage in order to shed light on possible strategies for prevention and treatment. Full article

(This article belongs to the Special Issue DNA Damage and Repair in Degenerative Diseases)

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1018 KiB

Open AccessArticle

Evaporation Rate of Water as a Function of a Magnetic Field and Field Gradient

by Yun-Zhu Guo, Da-Chuan Yin, Hui-Ling Cao, Jian-Yu Shi, Chen-Yan Zhang, Yong-Ming Liu, Huan-Huan Huang, Yue Liu, Yan Wang, Wei-Hong Guo, Ai-Rong Qian and Peng Shang

Int. J. Mol. Sci. 2012, 13(12), 16916-16928; https://doi.org/10.3390/ijms131216916 - 11 Dec 2012

Cited by 85 | Viewed by 9316

Abstract

The effect of magnetic fields on water is still a highly controversial topic despite the vast amount of research devoted to this topic in past decades. Enhanced water evaporation in a magnetic field, however, is less disputed. The underlying mechanism for this phenomenon [...] Read more.

The effect of magnetic fields on water is still a highly controversial topic despite the vast amount of research devoted to this topic in past decades. Enhanced water evaporation in a magnetic field, however, is less disputed. The underlying mechanism for this phenomenon has been investigated in previous studies. In this paper, we present an investigation of the evaporation of water in a large gradient magnetic field. The evaporation of pure water at simulated gravity positions (0 gravity level (ab. g), 1 g, 1.56 g and 1.96 g) in a superconducting magnet was compared with that in the absence of the magnetic field. The results showed that the evaporation of water was indeed faster in the magnetic field than in the absence of the magnetic field. Furthermore, the amount of water evaporation differed depending on the position of the sample within the magnetic field. In particular, the evaporation at 0 g was clearly faster than that at other positions. The results are discussed from the point of view of the evaporation surface area of the water/air interface and the convection induced by the magnetization force due to the difference in the magnetic susceptibility of water vapor and the surrounding air. Full article

(This article belongs to the Section Physical Chemistry, Theoretical and Computational Chemistry)

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653 KiB

Open AccessArticle

Electrochemical Characterization of Escherichia coli Adaptive Response Protein AidB

by Michael J. Hamill, Marco Jost, Cintyu Wong, Nicholas C. Bene, Catherine L. Drennan and Sean J. Elliott

Int. J. Mol. Sci. 2012, 13(12), 16899-16915; https://doi.org/10.3390/ijms131216899 - 11 Dec 2012

Cited by 5 | Viewed by 8968

Abstract

When exposed to known DNA-damaging alkylating agents, Escherichia coli cells increase production of four DNA repair enzymes: Ada, AlkA, AlkB, and AidB. The role of three enzymes (Ada, AlkA, and AlkB) in repairing DNA lesions has been well characterized, while the function of [...] Read more.

When exposed to known DNA-damaging alkylating agents, Escherichia coli cells increase production of four DNA repair enzymes: Ada, AlkA, AlkB, and AidB. The role of three enzymes (Ada, AlkA, and AlkB) in repairing DNA lesions has been well characterized, while the function of AidB is poorly understood. AidB has a distinct cofactor that is potentially related to the elusive role of AidB in adaptive response: a redox active flavin adenine dinucleotide (FAD). In this study, we report the thermodynamic redox properties of the AidB flavin for the first time, both for free protein and in the presence of potential substrates. We find that the midpoint reduction potential of the AidB flavin is within a biologically relevant window for redox chemistry at −181 mV, that AidB significantly stabilizes the flavin semiquinone, and that small molecule binding perturbs the observed reduction potential. Our electrochemical results combined with structural analysis allow for fresh comparisons between AidB and the homologous acyl-coenzyme A dehydrogenase (ACAD) family of enzymes. AidB exhibits several discrepancies from ACADs that suggest a novel catalytic mechanism distinct from that of the ACAD family enzymes. Full article

(This article belongs to the Special Issue Flavins)

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Complete anaerobic reduction of AidB using the xanthine/xanthine oxidase method. (A) Representative spectra of the three redox states observed for AidB: oxidized (solid line), anionic semiquinone (dashed line), and reduced (dotted line); (B) Reduction of AidB in the presence of the redox dye PS (maximum absorbance at 520 nm), showing spectra collected every ~5 min. Full article ">
Simultaneous reduction of the AidB anionic semiquinone and PS. The visible absorbance spectra for the anionic semiquinone (monitored at 406 nm) and PS (monitored at 555 nm) decrease during their reduction. Inset: Plot of log [ox]/[red] for PS vs. log [sq]/[red] for AidB, used to calculate the midpoint potential with respect to the reference value of PS (−283 mV, pH 8). Full article ">
Maximum proportion of semiquinone formed by AidB during reduction is determined by plotting absorbance values at 365 nm vs. 440 nm. The linear fits, shown as dashed lines, are used to determine the theoretical absorbance of complete semiquinone formation. Full article ">
Midpoint reduction potential (Em) of AidB lowers as a function of isovaleryl-CoA (IVCoA) concentration. The dotted line is the fit to <a href="#FD4" class="html-disp-formula">equation 4</a> to determine Kdapp. Full article ">
Midpoint reduction potential (Em) of AidB at various NaCl concentrations. Full article ">
Model of the docking between AidB and the human ETF. (A) Side-by-side views of the AidB-ETF docking model (left) and the MCAD-ETF complex structure (right), shown in the same orientation. For the docking, the crystal structure of AidB (PDB ID: 3U33 [<a href="#b21-ijms-13-16899" class="html-bibr">21</a>]) was superimposed onto the MCAD-ETF complex structure (PDB ID: 1T9G [<a href="#b29-ijms-13-16899" class="html-bibr">29</a>]). All structures are shown in ribbon representation, with the ETF in red, AidB protomers in yellow and orange, and MCAD protomers in dark and light green. Only one dimer is shown both for the AidB tetramer and the MCAD tetramer, the second dimer is omitted for clarity in both cases. Transparent surfaces are shown around all proteins in red (ETF), yellow (AidB) and green (MCAD). Bound FAD-cofactors of AidB and MCAD are shown in ball-and-stick representation with carbon atoms in light green and orange, respectively. The ETF recognition loop is shown in purple and interacting hydrophobic residues of AidB and MCAD are shown as orange and green spheres, respectively; (B) Wall-eyed stereo view of the ETF recognition loop interactions. The docking was generated in the same fashion as in (A). The recognition loop is shown in purple ribbons, with Leu195 shown as sticks. MCAD residues from the MCAD-ETF complex structure that are interacting with the recognition loop are shown with pale green carbons. AidB residues near the putative location of ETF Leu195 are shown with yellow carbons. The axes of the recognition loop helix, MCAD helix C, and the corresponding AidB helix are shown and colored by dipole moment from blue (positive) to red (negative); (C) Multiple sequence alignment of ETFs from different organisms. The residue that inserts into the hydrophobic pocket of partner proteins is highlighted in yellow. Other conserved residues are shown in blue. Ec, E. coli (protein YdiQ); Bs, Bacillus subtillis; Mme, Methylophilus methylotrophus; Mb, Mycobacterium bovus; Pd, Paracoccus denitrificans; Ca, Clostridium acetobutylicum; At, Arabidopsis thaliana; Hs, Homo sapiens; Mmu, Mus musculus; Bb, Bos bovus. Full article ">
Model of the docking between AidB and the human ETF. (A) Side-by-side views of the AidB-ETF docking model (left) and the MCAD-ETF complex structure (right), shown in the same orientation. For the docking, the crystal structure of AidB (PDB ID: 3U33 [<a href="#b21-ijms-13-16899" class="html-bibr">21</a>]) was superimposed onto the MCAD-ETF complex structure (PDB ID: 1T9G [<a href="#b29-ijms-13-16899" class="html-bibr">29</a>]). All structures are shown in ribbon representation, with the ETF in red, AidB protomers in yellow and orange, and MCAD protomers in dark and light green. Only one dimer is shown both for the AidB tetramer and the MCAD tetramer, the second dimer is omitted for clarity in both cases. Transparent surfaces are shown around all proteins in red (ETF), yellow (AidB) and green (MCAD). Bound FAD-cofactors of AidB and MCAD are shown in ball-and-stick representation with carbon atoms in light green and orange, respectively. The ETF recognition loop is shown in purple and interacting hydrophobic residues of AidB and MCAD are shown as orange and green spheres, respectively; (B) Wall-eyed stereo view of the ETF recognition loop interactions. The docking was generated in the same fashion as in (A). The recognition loop is shown in purple ribbons, with Leu195 shown as sticks. MCAD residues from the MCAD-ETF complex structure that are interacting with the recognition loop are shown with pale green carbons. AidB residues near the putative location of ETF Leu195 are shown with yellow carbons. The axes of the recognition loop helix, MCAD helix C, and the corresponding AidB helix are shown and colored by dipole moment from blue (positive) to red (negative); (C) Multiple sequence alignment of ETFs from different organisms. The residue that inserts into the hydrophobic pocket of partner proteins is highlighted in yellow. Other conserved residues are shown in blue. Ec, E. coli (protein YdiQ); Bs, Bacillus subtillis; Mme, Methylophilus methylotrophus; Mb, Mycobacterium bovus; Pd, Paracoccus denitrificans; Ca, Clostridium acetobutylicum; At, Arabidopsis thaliana; Hs, Homo sapiens; Mmu, Mus musculus; Bb, Bos bovus. Full article ">
Generic mechanism for dehydrogenation of a substrate by an acyl-coenzyme A dehydrogenase. Full article ">

1119 KiB

Open AccessArticle

Bacterial Over-Expression and Purification of the 3'phosphoadenosine 5'phosphosulfate (PAPS) Reductase Domain of Human FAD Synthase: Functional Characterization and Homology Modeling

by Angelica Miccolis, Michele Galluccio, Teresa Anna Giancaspero, Cesare Indiveri and Maria Barile

Int. J. Mol. Sci. 2012, 13(12), 16880-16898; https://doi.org/10.3390/ijms131216880 - 11 Dec 2012

Cited by 23 | Viewed by 6298

Abstract

FAD synthase (FADS, EC 2.7.7.2) is a key enzyme in the metabolic pathway that converts riboflavin into the redox cofactor, FAD. Human FADS is organized in two domains: -the 3'phosphoadenosine 5'phosphosulfate (PAPS) reductase domain, similar to yeast Fad1p, at the C-terminus, and [...] Read more.

FAD synthase (FADS, EC 2.7.7.2) is a key enzyme in the metabolic pathway that converts riboflavin into the redox cofactor, FAD. Human FADS is organized in two domains: -the 3'phosphoadenosine 5'phosphosulfate (PAPS) reductase domain, similar to yeast Fad1p, at the C-terminus, and -the resembling molybdopterin-binding domain at the N-terminus. To understand whether the PAPS reductase domain of hFADS is sufficient to catalyze FAD synthesis, per se, and to investigate the role of the molybdopterin-binding domain, a soluble “truncated” form of hFADS lacking the N-terminal domain (Δ_1-328-hFADS) has been over-produced and purified to homogeneity as a recombinant His-tagged protein. The recombinant Δ_1-328-hFADS binds one mole of FAD product very tightly as the wild-type enzyme. Under turnover conditions, it catalyzes FAD assembly from ATP and FMN and, at a much lower rate, FAD pyrophosphorolytic hydrolysis. The Δ_1-328-hFADS enzyme shows a slight, but not significant, change of K_m values (0.24 and 6.23 µM for FMN and ATP, respectively) and of k_cat (4.2 × 10⁻² s⁻¹) compared to wild-type protein in the forward direction. These results demonstrate that the molybdopterin-binding domain is not strictly required for catalysis. Its regulatory role is discussed in light of changes in divalent cations sensitivity of the Δ_1-328-hFADS versus wild-type protein. Full article

(This article belongs to the Special Issue Flavins)

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200 KiB

Open AccessReview

UBE4B: A Promising Regulatory Molecule in Neuronal Death and Survival

by Rami Abou Zeinab, Hong Wu, Consolato Sergi and Roger Leng

Int. J. Mol. Sci. 2012, 13(12), 16865-16879; https://doi.org/10.3390/ijms131216865 - 10 Dec 2012

Cited by 8 | Viewed by 6373

Abstract

Neuronal survival and death of neurons are considered a fundamental mechanism in the regulation of the nervous system during early development of the system and in adulthood. Defects in this mechanism are highly problematic and are associated with many neurodegenerative diseases. Because neuronal [...] Read more.

Neuronal survival and death of neurons are considered a fundamental mechanism in the regulation of the nervous system during early development of the system and in adulthood. Defects in this mechanism are highly problematic and are associated with many neurodegenerative diseases. Because neuronal programmed death is apoptotic in nature, indicating that apoptosis is a key regulatory process, the p53 family members (p53, p73, p63) act as checkpoints in neurons due to their role in apoptosis. The complexity of this system is due to the existence of different naturally occurring isoforms that have different functions from the wild types (WT), varying from apoptotic to anti-apoptotic effects. In this review, we focus on the role of UBE4B (known as Ube4b or Ufd2a in mouse), an E3/E4 ligase that triggers substrate polyubiquitination, as a master regulatory ligase associated with the p53 family WT proteins and isoforms in regulating neuronal survival. UBE4B is also associated with other pathways independent of the p53 family, such as polyglutamine aggregation and Wallerian degeneration, both of which are critical in neurodegenerative diseases. Many of the hypotheses presented here are gateways to understanding the programmed death/survival of neurons regulated by UBE4B in normal physiology, and a means of introducing potential therapeutic approaches with implications in treating several neurodegenerative diseases. Full article

(This article belongs to the Special Issue DNA Damage and Repair in Degenerative Diseases)

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177 KiB

Open AccessReview

DNA Damage Due to Oxidative Stress in Chronic Obstructive Pulmonary Disease (COPD)

by Eirini Neofytou, Eleni G. Tzortzaki, Argiro Chatziantoniou and Nikolaos M. Siafakas

Int. J. Mol. Sci. 2012, 13(12), 16853-16864; https://doi.org/10.3390/ijms131216853 - 10 Dec 2012

Cited by 56 | Viewed by 15412

Abstract

According to the American Thorasic Society (ATS)/European Respiratory Society (ERS) Statement, chronic obstructive pulmonary disease (COPD) is defined as a preventable and treatable disease with a strong genetic component, characterized by airflow limitation that is not fully reversible, but is usually progressive and [...] Read more.

According to the American Thorasic Society (ATS)/European Respiratory Society (ERS) Statement, chronic obstructive pulmonary disease (COPD) is defined as a preventable and treatable disease with a strong genetic component, characterized by airflow limitation that is not fully reversible, but is usually progressive and associated with an enhanced inflammatory response of the lung to noxious particles or gases. The main features of COPD are chronic inflammation of the airways and progressive destruction of lung parenchyma and alveolar structure. The pathogenesis of COPD is complex due to the interactions of several mechanisms, such as inflammation, proteolytic/antiproteolytic imbalance, oxidative stress, DNA damage, apoptosis, enhanced senescence of the structural cells and defective repair processes. This review focuses on the effects of oxidative DNA damage and the consequent immune responses in COPD. In susceptible individuals, cigarette smoke injures the airway epithelium generating the release of endogenous intracellular molecules or danger-associated molecular patterns from stressed or dying cells. These signals are captured by antigen presenting cells and are transferred to the lymphoid tissue, generating an adaptive immune response and enhancing chronic inflammation. Full article

(This article belongs to the Special Issue DNA Damage and Repair in Degenerative Diseases)

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Graphical abstract

616 KiB

Open AccessArticle

Changes in Molecular Characteristics of Cereal Carbohydrates after Processing and Digestion

by Mirosław Marek Kasprzak, Helle Nygaard Lærke and Knud Erik Bach Knudsen

Int. J. Mol. Sci. 2012, 13(12), 16833-16852; https://doi.org/10.3390/ijms131216833 - 10 Dec 2012

Cited by 19 | Viewed by 7282

Abstract

Different extraction, purification and digestion methods were used to investigate the molecular properties of carbohydrates in arabinoxylan and β-glucan concentrates, dietary fiber (DF) rich breads and ileum content of bread fed pigs. The breads studied were: a low DF wheat bread (WF), whole [...] Read more.

Different extraction, purification and digestion methods were used to investigate the molecular properties of carbohydrates in arabinoxylan and β-glucan concentrates, dietary fiber (DF) rich breads and ileum content of bread fed pigs. The breads studied were: a low DF wheat bread (WF), whole meal rye bread (GR), rye bread with kernels (RK), wheat bread supplemented with wheat arabinoxylan concentrate (AX) and wheat bread supplemented with oat β-glucan concentrate (BG). The weight average molecular weight (M_w) of extractable carbohydrates in β-glucan concentrate decreased eight-fold after inclusion in the BG bread when exposed to in vitro digestion, while the M_w of purified extractable carbohydrates in AX bread was reduced two-fold, and remained almost unaffected until reaching the terminal ileum of pigs. Similarly, the M_w of purified extractable carbohydrates in GR and RK bread was not significantly changed in the ileum. The AX bread resulted in the highest concentration of dissolved arabinoxylan in the ileum among all the breads that caused a substantial increased in ileal AX viscosity. Nevertheless, for none of the breads, the M_w of extractable carbohydrates was related neither to the bread extract nor ileal viscosity. Full article

(This article belongs to the Section Biochemistry)

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Overview of extraction, purification and sampling from fiber concentrates, bread extracts, and in vitro and in vivo digested bread for molecular weight determination. Full article ">
Size exclusion chromatography with RALLS (green), LALLS (black) and intrinsic viscosity (blue) signal of alkaline extracts of fiber concentrates (procedure A). Full article ">
Size exclusion chromatography with RALLS (green), LALLS (black) and intrinsic viscosity (blue) signal of extracts of water extracted (procedure B), in vitro digested (procedure C), in vivo digested (procedure D) and lichenase treated in vitro digested (procedure E) and lichenase treated in vivo digested (procedure F) WF and GR breads. Full article ">
Size exclusion chromatography with RALLS (green), LALLS (black) and intrinsic viscosity (blue) signal of extracts of water extracted (procedure B), in vitro digested (procedure C), in vivo digested (procedure D) and lichenase treated in vitro digested (procedure E) and lichenase treated in vivo digested (procedure F) RK and AX breads. Full article ">
Size exclusion chromatography with RALLS (green), LALLS (black) and intrinsic viscosity (blue) signal of extracts of water extracted (procedure B), in vitro digested (procedure C), and in vivo digested (procedure D) BG bread. Full article ">

1357 KiB

Open AccessArticle

Turn-On Fluorescent Chemosensor for Hg²⁺ Based on Multivalent Rhodamine Ligands

by Xuemei Wang, Mudassir Iqbal, Jurriaan Huskens and Willem Verboom

Int. J. Mol. Sci. 2012, 13(12), 16822-16832; https://doi.org/10.3390/ijms131216822 - 7 Dec 2012

Cited by 14 | Viewed by 7671

Abstract

Rhodamine-based fluorescent chemosensors 1 and 2 exhibit selective fluorescence enhancement to Fe³⁺ and Hg²⁺ over other metal ions at 580 nm in CH₃CN/H₂O (3/1, v/v) solution. Bis(rhodamine) chemosensor 1, under optimized conditions (CH [...] Read more.

Rhodamine-based fluorescent chemosensors 1 and 2 exhibit selective fluorescence enhancement to Fe³⁺ and Hg²⁺ over other metal ions at 580 nm in CH₃CN/H₂O (3/1, v/v) solution. Bis(rhodamine) chemosensor 1, under optimized conditions (CH₃CN/HEPES buffer (0.02 M, pH = 7.0) (95/5, v/v)), shows a high selectivity and sensitivity to Hg²⁺, with a linear working range of 0–50 μM, a wide pH span of 4–10, and a detection limit of 0.4 μM Hg²⁺. Full article

(This article belongs to the Special Issue Molecular Self-Assembly 2012)

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Int. J. Mol. Sci., Volume 13, Issue 12 (December 2012) – 109 articles , Pages 15496-17295

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