Search Results (764)

Ferroptosis, a regulated form of cell death characterized by lipid peroxidation and iron accumulation, is increasingly recognized for its role in disease pathogenesis. The unfolded protein response (UPR) has been implicated in both endoplasmic reticulum (ER) stress and ferroptosis-mediated cell fate decisions; yet, the specific mechanism remains poorly understood. In this study, we demonstrated that ER stress induced by tunicamycin and ferroptosis triggered by erastin both activate the UPR, leading to the induction of ferroptotic cell death. This cell death was mitigated by the application of chemical chaperones and a ferroptosis inhibitor. Among the three arms of the UPR, the PERK-eIF2α-ATF4 signaling axis was identified as a crucial mediator in this process. Mechanistically, the ATF4-driven induction of DDIT4 plays a pivotal role, facilitating ferroptosis via the inhibition of the mTORC1 pathway. Furthermore, acetaminophen (APAP)-induced hepatotoxicity was investigated as a model of eIF2α-ATF4-mediated ferroptosis. Our findings reveal that the inhibition of eIF2α-ATF4 or ferroptosis protects against APAP-induced liver damage, underscoring the therapeutic potential of targeting these pathways. Overall, this study not only clarifies the intricate role of the PERK-eIF2α-ATF4 axis in ER-stress-and erastin-induced ferroptosis but also extends these findings to a clinically relevant model, providing a foundation for potential therapeutic interventions in conditions characterized by dysregulated ferroptosis and ER stress. Full article

Equine follicle-stimulating hormone receptor (eFSHR) contains four extracellular N-linked glycosylation sites, which play important roles in agonist-induced signal transduction. Glycosylation regulates G protein-coupled receptor mechanisms by influencing folding, ligand binding, signaling, trafficking, and internalization. Here, we examined whether the glycosylated sites in eFSHR are necessary for cyclic adenosine monophosphate (cAMP) signal transduction and the phosphate extracellular signal-regulated kinase 1/2 (pERK1/2) response. We constructed mutants (N191Q, N199Q, N268Q, and N293Q) of the four N-linked glycosylation sites in eFSHR using site-directed mutagenesis. In wild-type (wt) eFSHR, the cAMP response gradually increased dose-dependently, displaying a strong response at the EC₅₀ and Rmax. Two mutants (N191Q and N199Q) considerably decreased the cAMP response. Both EC₅₀ values were approximately 0.46- and 0.44-fold compared to that of the eFSHR-wt, whereas Rmax levels were 0.29- and 0.45-fold compared to eFSHR-wt because of high-ligand treatment. Specifically, the EC₅₀ and Rmax values in the N268Q mutant were increased 1.23- and 1.46-fold, respectively, by eFSHR-wt. pERK1/2 activity in eFSHR-wt cells was rapid, peaked within 5 min, consistently sustained until 15 min, and then sharply decreased. pERK1/2 activity in the N191Q mutant showed a pattern similar to that of the wild type, despite impaired cAMP responsiveness. The N199Q mutant showed low pERK1/2 activity at 5 and 15 min. Interestingly, pERK1/2 activity in the N268Q and N298Q mutants was similar to that of eFSHR-wt at 5 min, but neither mutant showed any signaling at 15 min, despite displaying high cAMP responsiveness. Overall, eFSHR N-linked glycosylation sites can signal to pERK1/2 via PKA and the other signals, dependent on G protein coupling and β-arrestin-dependent recruitment. Our results provide strong evidence for a new paradigm in which cAMP signaling is not activated, yet pERK1/2 cascade remains strongly induced. Full article

Drilling fluids are vital in oil and gas well operations, ensuring borehole stability, cutting removal, and pressure control. However, fluid loss into formations during drilling can compromise formation integrity, alter permeability, and risk groundwater contamination. Water-based drilling fluids (WBDFs) are favored for their environmental and cost-effective benefits but often require additives to address filtration and rheological limitations. This study explored the feasibility of using vegetable waste, including pumpkin peel (PP), courgette peel (CP), and butternut squash peel (BSP) in fine (75 μm) and very fine (10 μm) particle sizes as biodegradable WBDF additives. Waste vegetable peels were processed using ball milling and characterized via FTIR, TGA, and EDX. WBDFs, prepared per API SPEC 13A with 3 wt% of added additives, were tested for rheological and filtration properties. Results highlighted that very fine pumpkin peel powder (PP_10) was the most effective additive, reducing fluid loss and filter cake thickness by 43.5% and 50%, respectively. PP_10 WBDF maintained mud density, achieved a pH of 10.52 (preventing corrosion), and enhanced rheological properties, including a 50% rise in plastic viscosity and a 44.2% increase in gel strength. These findings demonstrate the remarkable potential of biodegradable vegetable peels as sustainable WBDF additives. Full article

Background: Sparstolonin B (SsnB), a natural compound with anti-inflammatory and anti-proliferative properties, was investigated for its effects on cell viability, apoptosis, and inflammatory pathways in human colorectal cancer cells (HCT-116) and healthy human fibroblasts (BJ). Phorbol 12-myristate 13-acetate (PMA), a tumor promoter and inflammatory activator, was used to stimulate proliferation and inflammatory pathways. Methods: HCT-116 and BJ cells were treated with SsnB (3.125–50 μM) or PMA (1–10 nM) for 12–18 h. Cell viability was assessed using MTT analysis, while apoptosis was evaluated through cleaved caspase-3 staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and flow cytometry. Proliferation was analyzed through proliferating cell nuclear antigen (PCNA) staining. Toll-like receptor (TLR) signaling, cytokine expression, and sphingolipid levels were measured using immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and mass spectrometry, respectively. Results: SsnB reduced HCT-116 cell viability in a dose- and time-dependent manner with minimal effects on BJ cells. SsnB (25 μM, 12 h) decreased HCT-116 viability 0.6-fold, while PMA (10 nM, 12 h) increased it 2-fold (p < 0.01). No significant change was observed in BJ cells. PCNA fluorescence staining increased 2-fold with PMA and decreased 0.4-fold with SsnB (p < 0.001). PMA upregulated TLR2 and TLR4 mRNA and protein levels, with MyD88, p-ERK, and pNF-κB fluorescence increasing 2.1-, 1.5-, and 1.7-fold, respectively (p < 0.001). PMA elevated TNF-α, IL-1β, and IL-6 levels (p < 0.01). SsnB suppressed PMA-induced effects and promoted apoptosis, increasing cleaved caspase-3 levels by 1.5-fold and TUNEL staining by 1.9-fold (p < 0.01). Flow cytometry confirmed a significant increase in early and late apoptotic cells in the SsnB group. SsnB also increased ceramide (C18, C20, C22, and C24) levels (1.3- to 2.5-fold, p < 0.01) while reducing PMA-induced S1P and C1P increases (p < 0.01). Conclusions: SsnB selectively inhibits proliferation, induces apoptosis, and modulates inflammatory and sphingolipid pathways in colorectal cancer cells, with minimal toxicity to healthy fibroblasts, supporting its potential as a targeted therapeutic agent. Full article

Benzo(a)pyrene (B(a)P) and pyrene, the most prominent subtypes of polycyclic aromatic hydrocarbons (PAHs), contaminate environments as organic pollutants. They adversely affect body systems, including degeneration of the central nervous system. This study investigated the in vitro toxic effects of B(a)P and pyrene on proliferation, endoplasmic reticulum (ER) stress induction, and autophagy in human astrocytes using U-87 MG human astrocytoma cells as a model. Both B(a)P and pyrene were toxic to U-87 MG cells in a concentration-dependent manner. Astrocytic proliferation was interfered with, enhancing S-phase cell cycle arrest. B(a)P promoted the presence of autophagic vesicles and the expression of autophagic markers LC3, beclin-1, and p62, suggesting activated autophagy. B(a)P enhanced the expression of ER stress markers BiP, PERK, and IRE1. ER stress appeared to be correlated with autophagy induction, as demonstrated by experiments using chloroquine, an autophagy inhibitor. Pyrene enhanced the expression of autophagic markers and ER stress primarily via PERK activation, although autophagic vesicles were not observed. The study demonstrates that B(a)P enhances ER stress-mediated autophagy more evidently than pyrene and affected toxicity to astrocytes. These results provide a basis for understanding the toxic effects of the main PAH substances affecting astrocytes. Full article

Equine chorionic gonadotropin (eCG) hormone, comprising highly glycosylated α- and β-subunits, elicits responses similar to follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in non-equid species. This study aimed to establish a mass production of recombinant eCG (rec-eCG) using CHO DG44 cells. Single-chain rec-eCG β/α was expressed in CHO DG44 cells. FSH- and LH-like activities were evaluated in CHO-K1 and HEK 293 cells expressing the equine LH/CG receptor (eLH/CGR), rat LH/CGR (rLH/CGR), and rFSHR. pERK1/2 activation and β-arrestin 2 recruitment were assessed in PathHunter CHO-K1 cells. The expression from one, among nine isolates, peaked at 364–470 IU/mL on days 9 and 11. The molecular weight of rec-eCG β/α ranged from 40 to 47 kDa, with two distinct bands. PNGase F treatment reduced the molecular weight by 8–10 kDa, indicating N-glycosylation. Rec-eCG β/α demonstrated dose-responsive cAMP activity in cells expressing eLH/CGR, with enhanced potency in rLH/CGR and rFSHR. Phospho-ERK1/2 activation peaked at 5 min before declining rapidly. β-arrestin 2 recruitment was receptor-mediated in cells expressing hFSHR and hLH/CGR. This study provides insights into the mechanisms underlying eCG’s FSH- and LH-like activities. Stable CHO DG44 cells can produce large quantities of rec-eCG. eCG activates pERK1/2 signaling via the PKA/cAMP pathway and facilitates β-arrestin 2 recruitment. Full article

Methylglyoxal (MGO), a by-product of glycolysis, plays a significant role in cellular metabolism, particularly under stress conditions. However, MGO is a potent glycotoxin, and its accumulation has been linked to the development of several pathological conditions due to oxidative stress, including diabetes mellitus and neurodegenerative diseases. This paper focuses on the biochemical mechanisms by which MGO contributes to oxidative stress, particularly through the formation of advanced glycation end products (AGEs), its interactions with antioxidant systems, and its involvement in chronic diseases like diabetes, neurodegeneration, and cardiovascular disorders. MGO exerts its effects through multiple signaling pathways, including NF-κB, MAPK, and Nrf2, which induce oxidative stress. Additionally, MGO triggers apoptosis primarily via intrinsic and extrinsic pathways, while endoplasmic reticulum (ER) stress is mediated through PERK-eIF2α and IRE1-JNK signaling. Moreover, the activation of inflammatory pathways, particularly through RAGE and NF-κB, plays a crucial role in the pathogenesis of these conditions. This study points out the connection between oxidative and carbonyl stress due to increased MGO formation, and it should be an incentive to search for a marker that could have prognostic significance or could be a targeted therapeutic intervention in various diseases. Full article

Background: Crohn’s disease (CD) is an inflammatory bowel disease marked by an abnormal immune response and excessive pro-inflammatory cytokines, leading to impaired protein processing and endoplasmic reticulum (ER) stress. This stress, caused by the accumulation of misfolded proteins, triggers the unfolded protein response (UPR) through IRE1/Xbp-1, PERK/eIF2α, and ATF6 pathways, which are linked to intestinal inflammation. This study aimed to investigate ER stress in CD patients’ intestinal mucosa and evaluate phenylbutyrate (PBA) as an ER stress inhibitor. Methods: Colon biopsies from CD patients and controls were cultured under five conditions, including 4-PBA treatments. Real-time PCR, cytokine level, and immunohistochemistry were performed. Results: Immunohistochemistry revealed that ER stress was activated in CD patients’ intestinal epithelial cells and lamina propria cells. PERK/eIF2α, but not IRE1/Xbp-1 or ATF6, was upregulated in CD patients compared to controls. UPR-related genes (STC2, CALR, HSPA5, HSP90B1) were also elevated in CD patients. PBA treatment significantly reduced ER stress and UPR markers while decreasing apoptotic markers like DDIT3. Pro-inflammatory cytokines, such as IL-1β, IL-6, IL-17, TNF- α, and sCD40L, were significantly reduced after PBA treatment. Conclusion: ER stress and UPR pathways are activated in CD colonic mucosa, and PBA reduces these markers, suggesting potential therapeutic benefits for CD-related inflammation. Full article

The type I protein kinase PERK is an endoplasmic reticulum (ER) transmembrane protein that plays a multifaceted role in cancer development and progression, influencing tumor growth, metastasis, and cellular stress responses. The activation of PERK represents one of the three signaling pathways induced during the unfolded protein response (UPR), which is triggered, in particular, in tumor cells that constitutively experience various intracellular and extracellular stresses that impair protein folding within the ER. PERK activation can lead to both pro-survival and proapoptotic outcomes, depending on the cellular context and the extent of ER stress. It helps the reprogramming of the gene expression in cancer cells, thereby ensuring survival in the face of oncogenic stress, such as replicative stress and DNA damage, and also microenvironmental challenges, including hypoxia, angiogenesis, and metastasis. Consequently, PERK contributes to tumor initiation, transformation, adaptation to the microenvironment, and chemoresistance. However, sustained PERK activation in cells can also impair cell proliferation and promote apoptotic death by various interconnected processes, including mitochondrial dysfunction, translational inhibition, the accumulation of various cellular stresses, and the specific induction of multifunctional proapoptotic factors, such as CHOP. The dual role of PERK in promoting both tumor progression and suppression makes it a complex target for therapeutic interventions. A comprehensive understanding of the intricacies of PERK pathway activation and their impact is essential for the development of effective therapeutic strategies, particularly in diseases like cancer, where the ER stress response is deregulated in most, if not all, of the solid and liquid tumors. This article provides an overview of the knowledge acquired from the study of animal models of cancer and tumor cell lines cultured in vitro on PERK’s intracellular functions and their impact on cancer cells and their microenvironment, thus highlighting potential new therapeutic avenues that could target this protein. Full article

This study examined the impact of males’ facial and vocal attractiveness, as well as social interest in females’ decision-making in a trust game. The results showed that trustees with attractive faces or expressing positive social interest were more likely to receive initial investments. Trustees with attractive voices also received more initial investments than unattractive ones in most conditions, except when they had attractive faces and positive interest. Moreover, participants reinvest in trustees with attractive faces or voices, even if they withheld repayment. However, trustees with positive interest would receive more reinvestment only when they reciprocated. In addition, trusters expressing positive social interest were expected to invest and earn repayment at higher rates. Nonetheless, trusters with attractive faces (or voices) were only expected to invest at higher rates when they had attractive voices (or faces) and negative interest. These findings suggest that beauty premium is modulated by participants’ roles, such that the effect of beauty would be stronger when participants encounter trustees rather than trusters. Positive social interest is a perk in most conditions, except when trustees withheld repayment. Full article

Pigment epithelium-derived factor (PEDF) is a multifunctional soluble glycoprotein, primarily known for its potent anti-angiogenic properties. In recent years, its ability to counteract cell proliferation and motility has generated interest in PEDF as a potential tumor suppressor. In the intrahepatic Cholangiocarcinoma (iCCA), PEDF, Thrombospondin 1 (THBS1), and Thrombospondin 2 (THBS2) are expressed and released into the tumor microenvironment (TME), where they promote lymphangiogenesis at the expense of the neoangiogenic program, aiding the dissemination of cancer cells via lymphatic vessels. Recently, we demonstrated that THBS1 and THBS2 directly affect iCCA cells, exacerbating their malignant behavior, while the direct role of PEDF remains to be elucidated. In this study, through a cell-based assay and molecular analysis, we investigate the direct function of PEDF on two well-established iCCA cell lines. Our results show that PEDF affects cancer cell motility in a paracrine manner, reducing their migratory and invasive capabilities. Notably, our data suggest that the PEDF-induced inhibition of motility in iCCA cells occurs through the MAPK/ERK signaling pathway, as indicated by the reduced phosphorylation of ERK1/2. Overall, this study provides the first evidence of PEDF acting as a tumor suppressor in iCCA. Full article

Scour near various offshore structures (monopile, caisson foundation and jacket structure) was studied by performing laboratory flume tests and numerical solutions with a semi-empirical model (SEDSCOUR) and a sophisticated 2DV model (SUSTIM2DV). The laboratory test results show that the maximum free scour depth around a monopile without bed protection is slightly higher than the pile diameter. The maximum scour consisting of pile scour and global scour around an open jacket structure standing on four piles is much lower than the scour near the other structures (monopile and caisson). The maximum scour depth along a circular caisson foundation is found to be related to the base diameter of the structure. The main cause of the scour near these types of structures is the increase in the velocity along the flanks of the structure. Six cases have been used for validation: two laboratory cases (A and B) and four field cases (C, D, E and F). The measured scour values of the new physical model tests with the monopile and the open jacket structure presented in this paper are in reasonably good agreement with other laboratory and field scour data from the literature. The semi-empirical SEDSCOUR model proposed in this paper can be used for the reliable prediction of free scour and global scour near monopiles and jacket structures in a sandy bed (even with a small percentage of mud, up to 30%). The maximum scour depth along a large-scale caisson structure is more difficult to predict because the scour depth depends on the precise geometry and dimensions of the structure and the prevailing flow and sediment conditions. A detailed 2DV model with a fine horizontal grid (2 m) along a stream tube following the contour of the caisson is explored for scour predictions. The 2DV model simulates the flow and sediment transport at 50 to 100 points over the depth along the stream tube and can be run on a time-scale of 1 year. Full article

Objectives: Perfusion strategy is crucial for the outcome of neonatal aortic arch surgery. This study investigates Whole-Body Perfusion to potentially improve postoperative outcomes for neonates, addressing a significant gap in current research. Methods: Retrospective analysis was conducted for neonates receiving aortic arch reconstruction in our institution: 33 patients were treated with Antegrade Cerebral Perfusion (ACP, 2014–2017) and 61 patients with Whole-Body Perfusion (WBP, 2017–2022). After strict Propensity Score Matching, 20 patients were analyzed in each group. WBP consists of ACP and Lower Body Perfusion (LBP), achieved through a femoral arterial sheath. Results: Patients with WBP had a shorter time on Cardiopulmonary Bypass (86.65 ± 25.47 vs. 172.95 ± 60.12 min) and Cross-Clamp time (46.70 ± 18.48 vs. 91.30 ± 40.10 min) (p ≤ 0.001). Lactate at the time of reperfusion and after 24 h was lower in the WBP group (1.73 ± 0.63 vs. 4.29 ± 1.61, p < 0.001; 1.45 ± 0.57 vs. 2.09 ± 0.96 mmol/L, p = 0.026). Patients with WBP needed significantly fewer intraoperative transfusions of Red Blood Cells, Fresh Frozen Plasma and Platelets (p ≤ 0.001). WBP patients had a shorter time on ventilator (5.15 ± 4.05 vs. 10.00 ± 8.72 days, p = 0.01) and a higher urine output after 24 h (200.85 ± 100.87 vs. 118.10 ± 82.33 mL, p = 0.002). Conclusions: Patients treated with WBP received significantly fewer intraoperative transfusions and had a shorter time on extracorporeal circulation and ventilator. Furthermore, there was a trend for reduced multiorgan dysfunction. Full article

Chemotherapy-induced peripheral neuropathy and the accompanying affective disorders are serious side effects, and their resolution is not guaranteed. Oxidative stress and elevated levels of Nod-like receptor protein 3 (NLRP3) have been detected in the peripheral and central nervous systems of animals with neuropathic pain provoked by several antineoplastic drugs, such as paclitaxel (PTX). Several studies have further indicated that NLRP3 inflammasome inhibition could be an approach for treating chronic pain, but its impact on the anxiodepressive-like behaviors and memory deficits related to PTX-provoked neuropathy has not yet been investigated. MCC950 is a potent and specific inhibitor of the NLRP3 pathway that acts through inhibiting NLRP3 activation and inflammasome formation. We hypothesized that the administration of MCC950 could alleviate the affective and cognitive disorders accompanying PTX-provoked neuropathy. Using male C57BL/6 mice, we assessed the effects of MCC950 on the mechanical and thermal allodynia, anxiodepressive-like behavior, and memory deficits incited by this taxane. The results indicated that the intraperitoneal administration of 10 mg/kg of MCC950 twice daily for three consecutive days fully reversed the PTX-induced mechanical and thermal allodynia. This treatment also completely attenuated the anxiolytic (p < 0.004) and depressive-like behaviors (p < 0.022) and memory deficits (novel object recognition test; p < 0.0018) incited by PTX. These actions were mainly achieved through blocking NLRP3 inflammasome activation in the sciatic nerve, amygdala, and hippocampus, and oxidative stress in the amygdala and hippocampus. MCC950 also normalized the p-ERK 1/2 overexpression in the sciatic nerve and apoptotic responses in the sciatic nerve and the amygdala. This study suggests that MCC950 might be a promising treatment for PTX-induced mental illnesses and neuropathy. Full article