Search Results (604)

In 2022, human breast cancer (HBC) and canine mammary tumors (CMTs) remained the most prevalent malignant tumors worldwide, with high recurrence and lethality rates, posing a significant threat to human and dog health. The development of breast cancer involves multiple signaling pathways, highlighting the need for effective inhibitory drugs that target key proteins in these pathways. This article reviews the dysregulation of the EGFR, PI3K/AKT/mTOR, Hippo, pyroptosis, and PD-1/PD-L1 signaling pathways in HBC and CMT, as well as the corresponding drugs used to inhibit tumor growth, with the aim of providing theoretical support for the development of more efficient drugs. Full article

Besides various infectious and inflammatory complications, recent studies also indicated the significance of NLRP3 inflammasome in cancer progression and therapy. NLRP3-mediated immune response and pyroptosis could be helpful or harmful in the progression of cancer, and also depend on the nature of the tumor microenvironment. The activation of NLRP3 inflammasome could increase immune surveillance and the efficacy of immunotherapy. It can also lead to the removal of tumor cells by the recruitment of phagocytic macrophages, T-lymphocytes, and other immune cells to the tumor site. On the other hand, NLRP3 activation can also be harmful, as chronic inflammation driven by NLRP3 supports tumor progression by creating an environment that facilitates cancer cell proliferation, migration, invasion, and metastasis. The release of pro-inflammatory cytokines such as IL-1β and IL-18 can promote tumor growth and angiogenesis, while sustained inflammation may lead to immune suppression, hindering effective anti-tumor responses. In this review article, we discuss the role of NLRP3 inflammasome-mediated inflammatory response in the pathophysiology of various cancer types; understanding this role is essential for the development of innovative therapeutic strategies for cancer growth and spread. Full article

Extremely premature infants are at significant risk for developing bronchopulmonary dysplasia (BPD) and neurodevelopmental impairment (NDI). Although BPD is a predictor of poor neurodevelopmental outcomes, it is currently unknown how BPD contributes to brain injury and long-term NDI in pre-term infants. Extracellular vesicles (EVs) are small, membrane-bound structures released from cells into the surrounding environment. EVs are involved in inter-organ communication in diverse pathological processes. Inflammasomes are large, multiprotein complexes that are part of the innate immune system and are responsible for triggering inflammatory responses and cell death. Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is pivotal in inflammasome assembly and activating inflammatory caspase-1. Activated caspase-1 cleaves gasdermin D (GSDMD) to release a 30 kD N-terminal domain that can form membrane pores, leading to lytic cell death, also known as pyroptosis. Activated caspase-1 can also cleave pro-IL-1β and pro-IL-18 to their active forms, which can be rapidly released through the GSDMD pores to induce inflammation. Recent evidence has emerged that activation of inflammasomes is associated with neonatal lung and brain injury, and inhibition of inflammasomes reduces hyperoxia-induced neonatal lung and brain injury. Additionally, multiple studies have demonstrated that hyperoxia stimulates the release of lung-derived EVs that contain inflammasome cargos. Adoptive transfer of these EVs into the circulation of normal neonatal mice and rats induces brain inflammatory injury. This review focuses on EV–inflammasomes’ roles in mediating lung-to-brain crosstalk via EV-dependent and EV-independent mechanisms critical in BPD, brain injury, and NDI pathogenesis. EV–inflammasomes will be discussed as potential therapeutic targets for neonatal lung and brain injury. Full article

Programmed cell death, especially programmed necrosis such as necroptosis, ferroptosis, and pyroptosis, has attracted significant attention recently. Traditionally, necrosis was thought to occur accidentally without signaling pathways, but recent discoveries have revealed that molecular pathways regulate certain forms of necrosis, similar to apoptosis. Accumulating evidence indicates that programmed necrosis is involved in the development of various diseases, including myocardial ischemia–reperfusion injury (MIRI). MIRI occurs when blood flow and oxygen return to an ischemic area, causing excessive production of reactive oxygen species. While this reperfusion is critical for treating myocardial infarction, it inevitably causes cellular damage via oxidative stress. Furthermore, this cellular damage triggers multiple forms of cardiomyocyte death, which is the primary cause of inflammation, cardiac tissue remodeling, and ensuing heart failure. Therefore, understanding the molecular mechanisms of various forms of cell death in MIRI is crucial for therapeutic target discovery. Developing therapeutic strategies to inhibit multiple cell death pathways simultaneously could provide effective protection against MIRI. In this paper, we review the fundamental molecular pathways and MIRI-specific mechanisms of apoptosis, necroptosis, ferroptosis, and pyroptosis. Additionally, we suggest that the simultaneous suppression of multiple cell death pathways could be an effective therapy and identify potential therapeutic targets for implementing this strategy. Full article

Endoplasmic reticulum stress (ERS) can activate pyroptosis through CHOP and TXNIP; however, the correlation between this process and the formation of kidney stones has not been reported. The purpose is to investigate the effects of calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) on ERS and pyroptosis in HK-2 cells and to explore the formation mechanism of calcium oxalate stones. HK-2 cells were injured by 3 μm COM and COD. COM and COD significantly upregulated the expression levels of GRP78, CHOP, TXNIP, and pyroptosis-related proteins (NLRP3, caspase-1, GSDMD-N, and IL-1β). Fluorescence colocalization revealed that COM induced pyroptosis by inducing the interaction between TXNIP and NLRP3. Both COM and COD crystals can induce ERS and pyroptosis in HK-2 cells. COM induces the interaction with NLRP3 by the upregulation of CHOP and TXNIP and then promotes pyroptosis, while COD only promotes pyroptosis by the upregulation of CHOP. The cytotoxicity and the ability of COM to promote crystal adhesion and aggregation are higher than COD, suggesting that COM is more dangerous for calcium oxalate kidney stone formation. Full article

Polystyrene nanoplastics (PS-NPs), a pervasive component of plastic pollution, have emerged as a significant environmental and health threat due to their microscopic size and bioaccumulative properties. This review systematically explores the biological effects and mechanisms of PS-NPs on cellular systems, encompassing oxidative stress, mitochondrial dysfunction, DNA damage, inflammation, and disruptions in autophagy. Notably, PS-NPs induce multiple forms of cell death, including apoptosis, ferroptosis, necroptosis, and pyroptosis, mediated through distinct yet interconnected molecular pathways. The review also highlights various factors that influence the cytotoxicity of PS-NPs, such as particle size, surface modifications, co-exposure with other pollutants, and protein corona formation. These complex interactions underscore the extensive and potentially hazardous impacts of PS-NPs on cellular health. The findings presented here emphasize the need for continued research on the mechanisms underlying PS-NP toxicity and the development of effective strategies for mitigating their effects, thereby informing regulatory frameworks aimed at minimizing environmental and biological risks. Full article

Quercetin is a natural polyphenolic flavonoid widely found in plants, fruits, and vegetables, and has been reported to play pharmacological roles in numerous pathogenic conditions. The anti-inflammatory effects of quercetin in various inflammatory conditions and diseases have been well-documented. However, its regulatory role in noncanonical inflammasome activation has not yet been demonstrated. This study investigated the anti-inflammatory effects of quercetin in caspase-11 noncanonical inflammasome-activated inflammatory responses in macrophages and a mouse model of acute lethal sepsis. Quercetin protected J774A.1 macrophages from lipopolysaccharide (LPS)-induced cell death and caspase-11 noncanonical inflammasome-induced pyroptosis. It significantly decreased the production and mRNA expression of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-18, and IL-6, but not tumor necrosis factor (TNF)-α, and inflammatory molecules, such as nitric oxide (NO) and inducible NO synthase in caspase-11 noncanonical inflammasome-activated J774A.1 cells. Mechanistically, quercetin strongly suppressed the autoproteolysis and secretion of caspase-11 and the proteolysis of gasdermin D in caspase-11 noncanonical inflammasome-activated J774A.1 cells. However, quercetin did not inhibit the direct binding of caspase-11 to LPS. In vivo, the study revealed that quercetin increased the survival rate of mice with acute lethal sepsis and decreased serum levels of pro-inflammatory cytokines without causing significant toxicity. In conclusion, this study highlights quercetin-mediated anti-inflammatory action in inflammatory responses and acute lethal sepsis through a novel mechanism that targets the caspase-11 noncanonical inflammasome in macrophages, suggesting quercetin as a promising anti-inflammatory agent in natural medicine. Full article

The mammalian target of rapamycin (mTOR), a serine/threonine kinase, promotes cell growth and inhibits autophagy. The following two complexes contain mTOR: mTORC1 with the regulatory associated protein of mTOR (RAPTOR) and mTORC2 with the rapamycin-insensitive companion of mTOR (RICTOR). The phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR signaling pathway is important in the intervertebral disk, which is the largest avascular, hypoxic, low-nutrient organ in the body. To examine gene-silencing therapeutic approaches targeting PI3K/Akt/mTOR signaling in degenerative disk cells, an in vitro comparative study was designed between small interfering RNA (siRNA)-mediated RNA interference (RNAi) and clustered regularly interspaced short palindromic repeat (CRISPR)–CRISPR-associated protein 9 (Cas9) gene editing. Surgically obtained human disk nucleus pulposus cells were transfected with a siRNA or CRISPR–Cas9 plasmid targeting mTOR, RAPTOR, or RICTOR. Both of the approaches specifically suppressed target protein expression; however, the 24-h transfection efficiency differed by 53.8–60.3% for RNAi and 88.1–89.3% for CRISPR–Cas9 (p < 0.0001). Targeting mTOR, RAPTOR, and RICTOR all induced autophagy and inhibited apoptosis, senescence, pyroptosis, and matrix catabolism, with the most prominent effects observed with RAPTOR CRISPR–Cas9. In the time-course analysis, the 168-h suppression ratio of RAPTOR protein expression was 83.2% by CRISPR–Cas9 but only 8.8% by RNAi. While RNAi facilitates transient gene knockdown, CRISPR–Cas9 provides extensive gene knockout. Our findings suggest that RAPTOR/mTORC1 is a potential therapeutic target for degenerative disk disease. Full article

Background: Dengue virus (DENV) is the most widespread mosquito-borne virus, which can cause dengue fever with mild symptoms, or progress to fatal dengue hemorrhagic fever and dengue shock syndrome. As the main target cells of DENV, macrophages are responsible for the innate immune response against the virus. Methods: In this study, we investigated the role of pyroptosis in the pathogenic mechanism of dengue fever by examining the level of pyroptosis in DENV-1-infected macrophages and further screened differentially expressed microRNAs by high-throughput sequencing to predict microRNAs that could affect the pyroptosis of the macrophage. Results: Macrophages infected with DENV-1 were induced with decreased cell viability, decreased release of lactate dehydrogenase and IL-1β, activation of NLRP3 inflammasome and caspase-1, cleavage of GSDMD to produce an N-terminal fragment bound to cell membrane, and finally induced macrophage pyroptosis. MicroRNA expression profiles were obtained by sequencing macrophages from all periods of DENV-1 infection and comparing with the negative control. Sixty-three microRNAs differentially expressed in both the early and later stages of infection were also identified. In particular, miR-223-3p, miR-148a-3p, miR-125a-5p, miR-146a-5p and miR-34a-5p were recognized as small molecules that may be involved in the regulation of inflammation. Conclusions: In summary, this study aimed to understand the pathogenic mechanism of DENV through relevant molecular mechanisms and provide new targets for dengue-specific therapy. Full article

In pediatric and intensive care units, propofol is widely used for general anesthesia and sedation procedures as a short-acting anesthetic. Multiple studies have revealed that propofol causes hippocampal injury and cognitive dysfunction in developing animals. As is known, GM1, a type of ganglioside, plays a crucial role in promoting nervous system development. Consequently, this study explored whether GM1 mitigated neurological injury caused by propofol during developmental stages and investigated its underlying mechanisms. Seven-day-old SD rats or PC12 cells were used in this study for histopathological analyses, a Morris water maze test, a lactate dehydrogenase release assay, Western blotting, and an ELISA. Furthermore, LY294002 was employed to explore the potential neuroprotective effect of GM1 via the PI3K/AKT signaling cascade. The results indicated that GM1 exerted a protective effect against hippocampal morphological damage and pyroptosis as well as behavioral abnormalities following propofol exposure by increasing p-PI3K and p-AKT expression while decreasing p-p65 expression in developing rats. Nevertheless, the inhibitor LY294002, which targets the PI3K/AKT cascade, attenuated the beneficial effects of GM1. Our study provides evidence that GM1 confers neuroprotection and attenuates propofol-induced developmental neurotoxicity, potentially involving the PI3K/AKT/NF-κB signaling cascade. Full article

Cytomegaloviruses, species-specific members of the betaherpesviruses, encode an impressive array of immune evasion strategies committed to the manipulation of the host immune system enabling these viruses to remain for life in a stand-off with host innate and adaptive immune mechanisms. Even though they are species-restricted, cytomegaloviruses are distributed across a wide range of different mammalian species in which they cause systemic infection involving many different cell types. Regulated, or programmed cell death has a recognized potential to eliminate infected cells prior to completion of viral replication and release of progeny. Cell death also naturally terminates replication during the final stages of replication. Over the past two decades, the host defense potential of known programmed cell death pathways (apoptosis, necroptosis, and pyroptosis), as well as a novel mitochondrial serine protease pathway have been defined through studies of cytomegalovirus-encoded cell death suppressors. Such virus-encoded inhibitors prevent virus-induced, cytokine-induced, and stress-induced death of infected cells while also moderating inflammation. By evading cell death and consequent inflammation as well as innate and adaptive immune clearance, cytomegaloviruses represent successful pathogens that become a critical disease threat when the host immune system is compromised. This review will discuss cell death programs acquired for mammalian host defense against cytomegaloviruses and enumerate the range of modulatory strategies this type of virus employs to balance host defense in favor of lifelong persistence. Full article

A shared hallmark of age-related neurodegenerative diseases is the chronic activation of innate immune cells, which actively contributes to the neurodegenerative process. In Alzheimer’s disease, this inflammatory milieu exacerbates both amyloid and tau pathology. A similar abnormal inflammatory response has been reported in Parkinson’s disease, with elevated levels of cytokines and other inflammatory intermediates derived from activated glial cells, which promote the progressive loss of nigral dopaminergic neurons. Understanding the causes that support this aberrant inflammatory response has become a topic of growing interest and research in neurodegeneration, with high translational potential. It has been postulated that the phenotypic shift of immune cells towards a proinflammatory state combined with the presence of immunogenic cell death fuels a vicious cycle in which mitochondrial dysfunction plays a central role. Mitochondria and mitochondria-generated reactive oxygen species are downstream effectors of different inflammatory signaling pathways, including inflammasomes. Dysfunctional mitochondria are also recognized as important producers of damage-associated molecular patterns, which can amplify the immune response. Here, we review the major findings highlighting the role of mitochondria as a checkpoint of neuroinflammation and immunogenic cell deaths in neurodegenerative diseases. The knowledge of these processes may help to find new druggable targets to modulate the inflammatory response. Full article

Background: Pyroptosis, an inflammatory cell death, is involved in the progression of atherosclerosis. Pyroptosis in endothelial cells (ECs) and its underlying mechanisms in atherosclerosis are poorly understood. Here, we investigated the role of a caspase-4/5-NF-κB pathway in pyroptosis in palmitic acid (PA)-stimulated ECs and EVs as players in pyroptosis. Methods: Human umbilical vein endothelial cells (HUVECs) were cultured in an endothelial cell medium, treated with Ox-LDL, PA, caspase-4/5 inhibitor, NF-κB inhibitor, and sEV release inhibitor for 24 h, respectively. The cytotoxicity of PA was determined using an MTT assay, cell migration using a scratch-wound-healing assay, cell morphology using bright field microscopy, and lipid deposition using oil red O staining. The mRNA and protein expression of GSDM-D, CASP4, CASP5, NF-κB, NLRP3, IL-1β, and IL-18 were determined with RT-PCR and Western blot. Immunofluorescence was used to determine NLRP3 and ICAM-1 expressions. Extracellular vesicles (EVs) were isolated using an exosome isolation kit and were characterized by Western blot and scanning electron microscopy. Results: PA stimulation significantly changed the morphology of the HUVECs characterized by cell swelling, plasma membrane rupture, and increased LDH release, which are features of pyroptosis. PA significantly increased lipid accumulation and reduced cell migration. PA also triggered inflammation and endothelial dysfunction, as evidenced by NLRP3 activation, upregulation of ICAM-1 (endothelial activation marker), and pyroptotic markers (NLRP3, GSDM-D, IL-1β, IL-18). Inhibition of caspase-4/5 (Ac-FLTD-CMK) and NF-κB (trifluoroacetate salt (TFA)) resulted in a significant reduction in LDH release and expression of caspase-4/5, NF-κB, and gasdermin D (GSDM-D) in PA-treated HUVECs. Furthermore, GW4869, an exosome release inhibitor, markedly reduced LDH release in PA-stimulated HUVECs. EVs derived from PA-treated HUVECs exacerbated pyroptosis, as indicated by significantly increased LDH release and augmented expression of GSDM-D, NF-κB. Conclusions: The present study revealed that inflammatory, non-canonical caspase-4/5-NF-κB signaling may be one of the crucial mechanistic pathways associated with pyroptosis in ECs, and pyroptotic EVs facilitated pyroptosis in normal ECs during atherosclerosis. Full article

Inflammation assumes a vital role in the pathogenesis of depression and in antidepressant treatment. Paeoniflorin (PF), a monoterpene glycoside analog possessing anti-inflammatory attributes, exhibits therapeutic efficacy on depression-like behavior in mice. The objective of this study was to evaluate the antidepressant effects of PF on depression elicited by the chronic unpredictable mild stress (CUMS) model and the precise neural sequence associated with the inflammatory process. In this study, we established an in vivo mouse model induced by CUMS and an in vitro BV2 cell model induced by LPS+ATP. The mechanism of PF for depression was assessed by the SIRT1 selective inhibitor EX-527. The findings demonstrated that PF significantly alleviated the damage of BV2 cells treated with LPS and ATP, inhibited the generation of ROS, up-regulated the expression of SIRT1 mRNA, and down-regulated the expression of nuclear NF-κB, p65, NLRP3, Caspase-1 and GSDMD-N in vitro. In vivo, PF mitigated the depressive-like behavior induced by CUMS, reduced the number of neurons, and decreased the secretion of pro-inflammatory factors IL-1β, IL-6, and TNF-α in the hippocampus. Immunohistochemical results indicated that PF attenuated CUMS-induced hyperactivation of microglia. Moreover, the expression level of SIRT1 in the hippocampus was augmented, while the protein levels of NF-κB, p65, NLRP3, Caspase-1, IL-1β and GSDMD-N were diminished after PF treatment. Additionally, the selective inhibition of SIRT1 attenuated the therapeutic effect of PF on depression. These results imply that PF possesses antidepressant properties that rely on SIRT1 signaling to regulate NLRP3 inflammasome inactivation. Full article

Microplastics (MPs) represent an emerging pollutant capable of entering the human body through the respiratory and digestive systems, thereby posing significant health risks. Systemic lupus erythematosus (SLE) is a complex autoimmune disease that affects multiple organ systems, often presenting with polyarticular joint manifestations. Despite its relevance, there is currently limited research on the impact of MPs on lupus arthritis. This study aims to investigate the effects of MPs on joint inflammation in SLE. MRL/lpr mice exhibit SLE similar to that of humans. We administered either 0.5 mg/kg or 5 mg/kg of MPs to 8-week-old female MRL/lpr mice via oral ingestion. Our findings indicate that exposure to MPs can lead to synovial damage, adversely affecting the morphology and function of the knee joint, along with increased oxidative stress, apoptosis, synovial fibrosis, and the secretion of inflammatory cytokines. Notably, MPs significantly enhanced synovial cell pyroptosis by upregulating the expression of NLRP3, CASPASE-1, GSDMD, IL-1β, and IL-18. Mechanistic analyses further demonstrated that MPs exposure activates the NF-κB and NRF2/KEAP1 signaling pathways. Overall, our in vivo findings suggest that MPs exposure promotes synovial cell pyroptosis through increased oxidative stress and NF-κB signaling, thereby disrupting the structure and function of synovial tissue. This research provides new insights into the synovial damage associated with MPs exposure. Full article