VDAC1, as a downstream molecule of MLKL, participates in OGD/R-induced necroptosis by inducing mitochondrial damage.

Ischemia-reperfusion (I/R) injury constitutes a significant risk factor for a range of diseases, including ischemic stroke, myocardial infarction, and trauma. Following the restoration of blood flow post-tissue ischemia, oxidative stress can lead to various forms of cell death, including necrosis, apoptosis, autophagy, and necroptosis. Recent evidence has highlighted the crucial role of mitochondrial dysfunction in I/R injury. Nevertheless, there remains much to be explored regarding the molecular signaling network governing cell death under conditions of oxidative stress. Voltage-dependent anion channel 1 (VDAC1), a major component in the outer mitochondrial membrane, is closely involved in the regulation of cell death. In a cellular model of oxygen-glucose deprivation and reoxygenation (OGD/R), which effectively simulates I/R injury in vitro, our study reveals that OGD/R induces VDAC1 oligomerization, consequently exacerbating cell death. Furthermore, we have revealed the translocation of mixed lineage kinase domain-like protein (MLKL) to the mitochondria, where it interacts with VDAC1 following OGD/R injury, leading to an increased mitochondrial membrane permeability. Notably, the inhibition of MLKL by necrosulfonamide hinders the binding of MLKL to VDAC1, primarily by affecting the membrane translocation of MLKL, and reduces OGD/R-induced VDAC1 oligomerization. Collectively, our findings provide preliminary evidence of the functional association between MLKL and VDAC1 in the regulation of necroptosis.

Insight into Crosstalk Between Mitophagy and Apoptosis/Necroptosis: Mechanisms and Clinical Applications in Ischemic Stroke.

Ischemic stroke is a serious cerebrovascular disease with high morbidity and mortality. As a result of ischemia-reperfusion, a cascade of pathophysiological responses is triggered by the imbalance in metabolic supply and demand, resulting in cell loss. These cellular injuries follow various molecular mechanisms solely or in combination with this disorder. Mitochondria play a driving role in the pathophysiological processes of ischemic stroke. Once ischemic stroke occurs, damaged cells would respond to such stress through mitophagy. Mitophagy is known as a conservatively selective autophagy, contributing to the removal of excessive protein aggregates and damaged intracellular components, as well as aging mitochondria. Moderate mitophagy may exert neuroprotection against stroke. Several pathways associated with the mitochondrial network collectively contribute to recovering the homeostasis of the neurovascular unit. However, excessive mitophagy would also promote ischemia-reperfusion injury. Therefore, mitophagy is a double-edged sword, which suggests that maximizing the benefits of mitophagy is one of the direction of future efforts. This review emphasized the role of mitophagy in ischemic stroke, and highlighted the crosstalk between mitophagy and apoptosis/necroptosis.

Do pyroptosis, apoptosis, and necroptosis (PANoptosis) exist in cerebral ischemia? Evidence from cell and rodent studies.

Some scholars have recently developed the concept of PANoptosis in the study of infectious diseases where pyroptosis, apoptosis and necroptosis act in consort in a multimeric protein complex, PANoptosome. This allows all the components of PANoptosis to be regulated simultaneously. PANoptosis provides a new way to study the regulation of cell death, in that different types of cell death may be regulated at the same time. To test whether PANoptosis exists in diseases other than infectious diseases, we chose cerebral ischemia/reperfusion injury as the research model, collected articles researching cerebral ischemia/reperfusion from three major databases, obtained the original research data from these articles by bibliometrics, data mining and other methods, then integrated and analyzed these data. We selected papers that investigated at least two of the components of PANoptosis to check its occurrence in ischemia/reperfusion. In the cell model simulating ischemic brain injury, pyroptosis, apoptosis and necroptosis occur together and this phenomenon exists widely in different passage cell lines or primary neurons. Pyroptosis, apoptosis and necroptosis also occurred in rat and mouse models of ischemia/reperfusion injury. This confirms that PANoptosis is observed in ischemic brain injury and indicates that PANoptosis can be a target in the regulation of various central nervous system diseases.

Long-term effects of immunosuppression treatment on IgA nephropathy: a systematic review and meta-analysis.

BACKGROUND: Immunoglobulin A (IgA) nephropathy is an immune complex-mediated glomerulonephritis; however, the role of immunosuppression is still controversial, and there is a lack of studies on the long-term efficacy of immunosuppressive drugs in the treatment of the disease. We conducted a meta-analysis to examine the long-term effects of immunosuppressive drugs. METHODS: To identify random control trial articles on immunosuppressive drugs in the treatment of IgA nephropathy with a follow-up time >3 years, the following databases were searched: MEDLINE (1946 to August 2021), EMBASE (2000 to August 2021), PubMed (2000 to August 2021), and Cochrane library (2000 to August 2021). After screening, the Cochrane Handbook of Systematic Reviews of Interventions was used to examine the bias of the studies, Stata16.0 software was used for the analysis, and forest plots were used to present the results. RESULTS: A total of 744 patients from 7 studies were included in the study. The results of the meta-analysis showed that the long-term renal function integrity rate in the experimental group treated with immunosuppressive drugs was higher than that in the control group treated with placebos [risk ratio (RR) =1.10, 95% confidence interval (CI): 1.00, 1.22, Z=1.978, P=0.048], the efficacy of immunosuppressive drugs during the 3-6-year follow-up period (RR =1.07, 95% CI: 0.92, 1.23, Z=0.864, P=0.388) was similar to that of immunosuppressive drugs during the 8-10-year follow-up period (RR =1.14, 95% CI: 1.00, 1.30, Z=1.909, P=0.056), the efficacy of immunosuppressive drug therapy alone (RR =1.11, 95% CI: 1.00, 1.24, Z=1.914, P=0.056) was similar to that of immunosuppressive combination drug therapy (RR =1.07, 95% CI: 0.84, 1.35, Z=0.549, P=0.583), and the adverse reactions in the immunosuppressive drug group were higher than those in the placebo group (RR =1.59, 95% CI: 1.38, 1.85, Z=6.230, P=0.000). DISCUSSION: The use of immunosuppressive drugs can improve the long-term effects of IgA nephropathy treatment, but consideration should be given to the increase of adverse reactions during treatment.

The Role of HSP90α in Methamphetamine/Hyperthermia-Induced Necroptosis in Rat Striatal Neurons.

Methamphetamine (METH) is one of the most widely abused synthetic drugs in the world. The users generally present hyperthermia (HT) and psychiatric symptoms. However, the mechanisms involved in METH/HT-induced neurotoxicity remain elusive. Here, we investigated the role of heat shock protein 90 alpha (HSP90α) in METH/HT (39.5°C)-induced necroptosis in rat striatal neurons and an in vivo rat model. METH treatment increased core body temperature and up-regulated LDH activity and the molecular expression of canonical necroptotic factors in the striatum of rats. METH and HT can induce necroptosis in primary cultures of striatal neurons. The expression of HSP90α increased following METH/HT injuries. The specific inhibitor of HSP90α, geldanamycin (GA), and HSP90α shRNA attenuated the METH/HT-induced upregulation of receptor-interacting protein 3 (RIP3), phosphorylated RIP3, mixed lineage kinase domain-like protein (MLKL), and phosphorylated MLKL. The inhibition of HSP90α protected the primary cultures of striatal neurons from METH/HT-induced necroptosis. In conclusion, HSP90α plays an important role in METH/HT-induced neuronal necroptosis and the HSP90α-RIP3 pathway is a promising therapeutic target for METH/HT-induced neurotoxicity in the striatum.

Research trends, hot spots and prospects for necroptosis in the field of neuroscience.

There are two types of cell death-apoptosis and necrosis. Apoptosis is cell death regulated by cell signaling pathways, while necrosis has until recently been considered a passive mechanism of cell death caused by environmental pressures. However, recent studies show that necrosis can also be regulated by specific cell signaling pathways. This mode of death, termed necroptosis, has been found to be related to the occurrence and development of many diseases. We used bibliometrics to analyze the global output of literature on necroptosis in the field of neuroscience published in the period 2007-2019 to identify research hotspots and prospects. We included 145 necroptosis-related publications and 2239 references published in the Web of Science during 2007-2019. Visualization analysis revealed that the number of publications related to necroptosis has increased year by year, reaching a peak in 2019. China is the country with the largest number of publications. Key word and literature analyses demonstrated that mitochondrial function change, stroke, ischemia/reperfusion and neuroinflammation are likely the research hotspots and future directions of necroptosis research in the nervous system. The relationship between immune response-related factors, damage-associated molecular patterns, pathogen-associated molecular patterns and necroptosis may become a potential research hotspot in the future. Taken together, our findings suggest that although the inherent limitations of bibliometrics may affect the accuracy of the literature-based prediction of research hotspots, the results obtained from the included publications can provide a reference for the study of necroptosis in the field of neuroscience.