Research advances in endoplasmic reticulum stress in methamphetamine use disorder / 重庆医学

Methamphetamine use disorder is an ongoing global public health problem with complex mechanisms involving multiple neural circuits and neurotransmitters in the brain,and there are currently no effective drugs and methods to treat it.This article reviews the role of endoplasmic reticulum stress in meth-amphetamine use disorder and discusses the treatment strategies that can be used to mitigate the methamphet-amine-induced neurotoxic damage,which will contribute to the exploration of methamphetamine use disorder mechanisms and the development of new target drugs.

Research Progress of Endoplasmic Reticulum Stress PERK-eIF2α-AFT4-CHOP Signaling Pathway in Hematological Malignancies / 肿瘤防治研究

The biosynthesis and maturation of proteins are primarily regulated by the endoplasmic reticulum in its physiological state. Thus, the disruption of physiological homeostasis initiates the buildup of unfolded and misfolded proteins in the endoplasmic reticulum, resulting in endoplasmic reticulum stress (ERS) and unfolded protein response (UPR). One of the important pathways by which UPR maintains intracellular homeostasis under ERS is activating protein kinase R-like endoplasmic reticulum kinase (PERK). The activation of the PERK pathway stimulates eukaryotic translation initiation factor 2 subunit-α (eIF2α) phosphorylation and the selective translation of active transcription factor 4 (ATF4), and PERK induces cell apoptosis by directly binding to the promoter of pro-apoptotic transcription factor C/EBP homologous protein (CHOP). This signaling pathway is also one of the important mechanisms by which UPR participates in the regulation of hematological malignancies and immune cells in a tumor microenvironment. This article provides an overview of advancements in research into the PERK-eIF2α-ATF4-CHOP signaling pathway in hematological malignancies and the potential therapeutic benefits of targeting this signaling pathway.

Progress of unfolded protein response in acute respiratory distress syndrome / 国际儿科学杂志

Acute respiratory distress syndrome(ARDS)is a severe respiratory disease in children and the pathogenesis is not fully defined.It is mainly related to various mechanisms of lung injury such as inflammation and autophagy.In recent years, studies have found that, endoplasmic reticulum stress(ERS)can aggravate lung injury in ARDS, in which protein homeostasis imbalance can induce activation of the unfolded protein response(UPR).The UPR reconstructs homeostasis by mediating transmembrane protein-related signaling pathways, while continuous excessive ERS will promote apoptosis and autophagy.This review summarizes the progress of the signaling pathway of UPR related to lung injury and its inflammatory effect in ARDS.

Crosstalk between activating transcription factor 6 and the inositol-requiring enzyme 1 - X-box binding protein 1 pathway in oxygen-glucose deprivation/reoxygenation-injured HT22 cells / 中华危重病急救医学

Objective:To study the crosstalk between the activating transcription factor 6 (ATF6) and inositol-requiring enzyme 1 (IRE1) - X-box binding protein 1 (XBP1) pathway in oxygen-glucose deprivation/reoxygenation (OGD/R)-injured mouse hippocampal neuronal cell line HT22.Methods:The OGD/R-injured HT22 cell model was used to observe the changes of the indicators of endoplasmic reticulum stress (ERS), cell viability, and apoptosis at different OGD/R time points (0, 3, 6, 12, and 24 hours). HT22 cells in the logarithmic growth phase were randomized into blank control group, control+ATF6 activator (AA147) group, control+IRE1 inhibitor (4μ8c) group, OGD/R model group, OGD/R+AA147 group and OGD/R+4μ8c group (10 μmol/L AA147 or 16 μmol/L 4μ8c was given during the whole process in the AA147 group and 4μ8c group). Western blotting was used to detect the expression of ERS-related proteins [glucose-regulated protein 78 (GRP78), phosphorylated-inositol-requiring enzyme 1 (p-IRE1), and phosphorylated-eukaryotic translation initiation factor-2α (p-eIF2α)], and apoptosis-related proteins (Bcl-2, Bax, caspase-3, and cleaved caspase-3). The mRNA of ERS-related genes, and ATF6 [homocysteine-inducible, endoplasmic reticulum stress-inducible, ubiquitin-like domain member 1 (Herpud1), protein disulfide isomerase associated 4 (Pdia4) and Sel-1 suppressor of lin-12-like (Sel1L)] and spliced XBP1 [XBP1s, include DnaJ heat shock protein family member B9 (Erdj4), Sec24 related gene family, member D (Sec24d) and signal sequence receptor, gamma (Ssr3)] induced transcriptional response-related genes were measured by real-time quantitative polymerase chain reaction (RT-qPCR). A cell counting kit-8 (CCK-8) assay was used to detect the viability of HT22 cells. Immunofluorescence was utilized to test the expression of cleaved caspase-3.Results:Compared with the blank control group, the expression of ERS-related proteins p-IRE1 and p-eIF2α were significantly increased at 12 hours and 3 hours following OGD/R, respectively (p-IRE1/β-actin: 2.09±0.10 vs. 1.00±0.00, p-eIF2α/β-actin: 1.39±0.11 vs. 1.00±0.00, both P < 0.01). The mRNA expressions of ERS-related genes [ATF6, XBP1s, unspliced XBP1 (XBP1u), activating transcription factor 4 (ATF4), CCAAT/EBP homologous protein (CHOP)] were also upregulated in different OGD/R timepoint in HT22 cells, which indicated ERS was activated in OGD/R-stimulated HT22 cells. Compared with the OGD/R model group, the expression of protein p-IRE1 was not changed, but the mRNA of XBP1s and XBP1u were obviously downregulated in the OGD/R+AA147 group [XBP1s (2 -ΔΔCt): 0.76 (0.71, 0.92) vs. 1.13 (1.03, 1.29), XBP1u (2 -ΔΔCt): 0.29±0.05 vs. 0.52±0.04, both P < 0.01], whereas the expressions of XBP1s-induced transcriptional response downstream genes did not change significantly. Compared with the OGD/R model group, the protein of short-form ATF6 (sATF6) and GRP78 were not changed after administration of 4μ8c, neither was the mRNA expression of ATF6-induced transcriptional response-related genes. These results showed that the mRNA expression of XBP1s and XBP1u were inhibited by AA147-induced activation of ATF6, but no crosstalk was observed between the transcriptional response induced by ATF6 and XBP1s. Compared with the blank control group, the cell viability decreased significantly at OGD/R 3 hours [(44.64±5.12) % vs. (99.13±5.76) %, P < 0.01], the ratios of apoptosis-related proteins Bax/Bcl-2 and cleaved caspase-3/caspase-3 were significantly increased at OGD/R 3 hours and OGD 0 hour, respectively (Bax/Bcl-2: 6.15±1.65 vs. 1.00±0.00, cleaved caspase-3/caspase-3: 17.48±2.75 vs. 1.00±0.00, both P < 0.01), which indicated that apoptosis was activated in OGD/R-treated HT22 cells. Compared with the OGD/R model group, the cell viability decreased significantly [(36.52±17.78)% vs. (69.90±9.43)%, P < 0.01], and the ratios of Bax/Bcl-2 and cleaved caspase-3/caspase-3 were significantly upregulated in the OGD/R+AA147 group in HT22 cells (Bax/Bcl-2: 2.06±0.31 vs. 1.10±0.25, cleaved caspase-3/caspase-3: 3.35±0.59 vs. 0.55±0.09, both P < 0.01). Conclusion:Under our experimental conditions, no obvious crosstalk between the transcriptional response induced by ATF6 and XBP1s was observed, while ATF6 activation induced by AA147 suppressed mRNA expression of XBP1s and XBP1u and promoted cell death in OGD/R-treated HT22 cells.

Research progress in the role of endoplasmic reticu-lum stress in cerebral ischemia-reperfusion injury / 中国药理学与毒理学杂志

During cerebral ischemia-reperfusion injury(CIRI),endoplasmic reticulum stress(ERS)leads to the development and progression of a series of deleterious physiological responses such as oxidative stress,dis-turbed calcium ion homeostasis,inflammation,apoptosis and autophagy.The unfolded protein response(UPR)is the main pathway activated by ERS,which regulates the expression of related factors within the endoplasmic reticu-lum(ER)and reduces protein translation levels.Prolonged and intense ERS may lead to cell death.Excessive ERS induces apoptosis mediated by C/EBP homologous pro-tein(CHOP),caspase-12 and c-Jun N-terminal kinase(JNK),thereby exacerbating brain damage.The thresh-old for the transition from adaptive mechanisms to apop-totic mechanisms during ERS depends on multiple fac-tors,including the cell status and environment,signaling pathway activity status,cumulative cascade,and the dose and time of ERS inducers.Further research is needed to completely elucidate the mechanism of ERS.Although the factors associated with the PERK and ATF6 path-ways are less extensively studied,their regulators still exist.Deficiency of protein tyrosine phosphatase 1B(PTP1B)leads to increased phosphorylation of PERK-eIF2α,while regulation of the proteasome and regulation of the XBP1 target gene WFS1 may also affect ATF6 sta-bility.In addition,differences in the structure,gene expres-sion,and metabolism of different types of neurons,as well as in their internal environment,may lead to differ-ences in their response to and impact on ERS.Differenc-es in UPR signaling pathways occur in hippocampal neurons and medial thalamic cells,and Purkinje cells and pyramidal cells may be more sensitive to ERS than other types of neurons.Our group's previous study found that ERS induced apoptosis in neurons after the onset of CIRI by regulating proteins such as GRP78,CHOP and caspase-12,but the effects of UPR activation on different cells need to be further investigated.

Research progress on effect of unfolded protein response in heat stroke / 解放军医学杂志

Heat stroke(HS)is a serious life-threatening disease caused by heat injury and characterized by a core body temperature>40℃with central nervous system dysfunction and multi-organ failure.The main pathophysiological manifestations of HS are the thermal acute phase response and thermoregulatory imbalance.Proteins are particularly sensitive to heat,and the thermal environment can cause massive protein denaturation,resulting in the deposition of unfolded and misfolded proteins in the cytoplasm,causing cellular dysfunction and even death.The unfolded protein response(UPR),mainly divided into the endoplasmic reticulum UPR and the mitochondrial UPR,is an important physiological process that helps proteins to fold correctly or degrade irretrievably denatured proteins.This paper summarizes the regulatory mechanisms of UPR,the relationship between UPR and severe diseases,as well as the relationship between HS and UPR to provide new ideas for the treatment of HS.

The mechanism of down-regulation of HPSE alleviating myocardial ischemia-reperfusion injury in rats / 实用医学杂志

Objective To explore the effects of heparinase(HPSE)on myocardial apoptosis,inflamma-tory response and oxidative damage in myocardial ischemia reperfusion(MI/R)rats.Methods Sixty SD rats were randomly assigned(1∶1∶1∶1)tocontrol group,I/R group,I/R+shRNA-NC group and I/R+Heparanase-shRNA group.The control group was only threaded without ligation after thoracotomy,and the MI/R model was prepared by ligation of the left anterior descending branch of coronary artery.The western blot assay(WB)was used to detect heart function and markers of heart damage in each group.HE staining and TUNEL staining were used to observe the myocardial pathology.The expression of apoptosis-related proteins(Caspase-3,Bax,Bcl-2)and UPRmt marker proteins(LonP1,HSP70)were detected by WB.The contents of superoxide dismutase(SOD)and malondi-aldehyde(MDA)were detected by kit.The levels of interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in peripheral blood were detected by enzyme-linked immunosorbent assay(ELISA).Results HE staining results showed that the myocardium,epimyma and myocardial fibers were intact and normal in control group.However,the myocardial fibers were bent,myoglobin was dissolved,myocardial muscle nucleus was pyknotic and dissolved,and muscle bundle membrane was ruptured in I/R group and I/R+shRNA-NC group.The epimyocardium was intact in I/R+Heparanase-shRNA group.Moreover,the myocardial fiber bending was significantly improved in I/R+Heparanase-shRNA group.Additionally,compared with the control group,the expression levels of CK-MB,cTnI,Mb,Caspase-3 protein,Bax protein,MDA,IL-6,TNF-α and HSP70 in I/R group were significantly increased.And the difference was statistically significant.Furthermore,the expression levels of HR,LVEF,LVWT,Bcl-2 protein,SOD and LonP1 protein were significantly decreased.Additionally,compared with the I/R+shRNA-NC group,the expression levels of CK-MB,cTnI,Mb,Caspase-3 protein,Bax protein,MDA,IL-6 and TNF-α in I/R+ Heparanase-shRNA group were significantly decreased.And the difference was statistically significant.However,the expression levels of HR,LVEF,LVWT,Bcl-2 protein,SOD,LonP1 and HSP70 were significantly increased.And the difference was statistically significant.Conclusion Down-regulation of HPSE alleviates myocardial injury in ischemia-reperfusion rats by inhibiting oxidative stress,inflammation,and apoptosis.The mechanism may be related to the inhibition of UPRmt signaling pathway.

Recent advance of Marinesco-Sj?gren syndrome / 中华神经医学杂志

Marinesco-Sj?gren syndrome (MSS), also known as hereditary ataxia-dwarf-mental retardation syndrome, is a rare autosomal recessive ataxia syndrome. This article reviews the recent advance in clinic characteristics, pathogenic gene mutation sites, pathogenesis and clinic diagnosis and treatment of MSS, in order to improve clinicians' understanding of the disease and diagnosis and treatment level, and reduce the missed diagnosis and misdiagnosis of the disease.

Research progress of IRE1α inhibitors / 药学学报

Inositol requiring enzyme 1 alpha (IRE1α), a widespread transmembrane protein in mammals, is an endoplasmic reticulum stress (ER stress) receptor. Among the three signaling pathways of the unfolded protein response (UPR), the IRE1α pathway is the most conservative. And there is a growing body of evidence that the occurrence and development of tumors is closely related to the over-expression of IRE1α. Therefore, the study of the IRE1α inhibitors is of great significance to the discovery of new anti-tumor drugs and has been attracting more and more attention. In the hope of providing ideas for the research of targeting IRE1α for cancer therapy, this paper reviewed the data of representative IRE1α inhibitors, including inhibitory activity, the mechanism of action, structural characteristics, and so on.

Effects of high-fat diet on testicular germ cell apoptosis in mice through endoplasmic reticulum stress / 中国药理学通报

Aim To study the effects of high-fat diet on testicular germ cell apoptosis in mice through endoplasmic reticulum stress. Methods C57BL/6J male mice were assigned into normal group and high-fat diet group randomly, with six mice in each group. The mice in normal group or high-fat diet group were fed with regular or high-fat diet continuously for five months. The mice were weighed, anesthetized, and euthanized to collect testicular and epididymal tissue for analysis. The testicular tissue was weighed and their indices were calculated. Epididymal tissue was collected for semen analysis. The morphological alterations of testicular tissue were observed using hematoxylin-eosin ( HE ) staining. The apoptosis of germ cells was detected by TUNEL staining and the apoptotic indices were calculated. The expression levels of apoptosis and endoplasmic reticulum stress-related proteins in testicular tissue were detected by Western blot. The protein expression and localization of GRP78 in testicular tissue were further detected by immunofluorescence. Results The results showed that compared to the normal group, the high-fat diet group had a significant increase in body weight, a significant decrease in testicular index, sperm concentration, and sperm vability, loose arrangement of germ cells, significant thinning of the seminiferous epithelium, no significant change in the diameter of seminiferous tubules, a significant increase in germ cell apoptosis , with an increased apoptosis index, and significant increase in expression of Bax and cleaved-caspase-12,and a significant decrease in Bcl-2 protein expression. The expression levels of GRP78 , p-IREl, XBP1, and ATF6a proteins were significantly up-regulated, while p-PERK, p-eIF2a, ATF4 protein expression showed no significant changes. Immunofluorescence results further showed a significant increase in the expression of GRP78 protein in the testicular tissue,with no significant changes in the expression location. Conclusions High-fat diet can induce the apoptosis of mouse testicular germ cells, and the mechanism may be related to the activation of endoplasmic reticulum stress IRE1 and ATF6 signaling pathway.

Endoplasmic reticulum stress in the pathogenesis of age-related macular degeneration / 国际眼科杂志(Guoji Yanke Zazhi)

@#Age-related macular degeneration(ARMD)is a main cause of irreversible visual impairment in the elderly. The major pathological features are drusen formation, macular pigment disorder, geographic atrophy and abnormal neovascularization. Retinal pigment epithelium(RPE)function is impaired in ARMD. Endoplasmic reticulum(ER)is an organelle in eukaryotes responsible for protein synthesis, modification, integration and quality control. ER also participates in the maintenance of calcium homeostasis and lipid biosynthesis. Stimuli from the external and internal environment may trigger ER stress and therefore activate the intracellular signal transduction pathway-the unfolded protein response(UPR), to restore cell homeostasis. However, prolonged ER stress may lead to apoptosis. The pathogenesis of ARMD has not been fully elucidated, nevertheless, compelling evidence demonstrates that ER stress is involved. In this article, we summarize recent advances in UPR pathways, as well as the role of ER stress in the physiological function of RPE and in the pathogenesis of ARMD.

The expression of oxidative stress genes related to myocardial ischemia reperfusion injury in patients with ST-elevation myocardial infarction / 世界急诊医学杂志（英文）

@#BACKGROUND: We aimed to investigate the gene expression of myocardial ischemia/reperfusion injury (MIRI) in patients with acute ST-elevation myocardial infarction (STEMI) using stress and toxicity pathway gene chip technology and try to determine the underlying mechanism. METHODS: The mononuclear cells were separated by ficoll centrifugation, and plasma total antioxidant capacity (T-AOC) was determined by the ferric reducing ability of plasma (FRAP) assay. The expression of toxic oxidative stress genes was determined and verified by oligo gene chip and quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, gene ontology (GO) enrichment analysis was performed on DAVID website to analyze the potential mechanism further. RESULTS: The total numbers of white blood cells (WBC) and neutrophils (N) in the peripheral blood of STEMI patients (the AMI group) were significantly higher than those in the control group (WBC: 11.67±4.85 ×109/L vs. 6.41±0.72 ×109/L, P<0.05; N: 9.27±4.75 ×109/L vs. 3.89±0.81 ×109/ L, P<0.05), and WBCs were significantly associated with creatine kinase-myocardial band (CK-MB) on the first day (Y=8.945+0.018X, P<0.05). In addition, the T-AOC was significantly lower in the AMI group comparing to the control group (12.80±1.79 U/mL vs. 20.48±2.55 U/mL, P<0.05). According to the gene analysis, eight up-regulated differentially expressed genes (DEGs) included GADD45A, PRDX2, HSPD1, DNAJB1, DNAJB2, RAD50, TNFSF6, and TRADD. Four down-regulated DEGs contained CCNG1, CAT, CYP1A1, and ATM. TNFSF6 and CYP1A1 were detected by polymerase chain reaction (PCR) to verify the expression at different time points, and the results showed that TNFSF6 was up-regulated and CYP1A1 was down-regulated as the total expression. GO and kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis suggested that the oxidative stress genes mediate MIRI via various ways such as unfolded protein response (UPR) and apoptosis. CONCLUSIONS: WBCs, especially neutrophils, were the critical cells that mediating reperfusion injury. MIRI was regulated by various genes, including oxidative metabolic stress, heat shock, DNA damage and repair, and apoptosis-related genes. The underlying pathway may be associated with UPR and apoptosis, which may be the novel therapeutic target.

Romidepsin (FK228) improves the survival of allogeneic skin grafts through downregulating the production of donor-specific antibody via suppressing the IRE1α-XBP1 pathway / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Antibody-mediated rejection (AMR) is one of the major causes of graft loss after transplantation. Recently, the regulation of B cell differentiation and the prevention of donor-specific antibody (DSA) production have gained increased attention in transplant research. Herein, we established a secondary allogeneic in vivo skin transplant model to study the effects of romidepsin (FK228) on DSA. The survival of grafted skins was monitored daily. The serum levels of DSA and the number of relevant immunocytes in the recipient spleens were evaluated by flow cytometry. Then, we isolated and purified B cells from B6 mouse spleens in vitro by magnetic bead sorting. The B cells were cultured with interleukin-4 (IL-4) and anti-clusters of differentiation 40 (CD40) antibody with or without FK228 treatment. The immunoglobulin G1 (IgG1) and IgM levels in the supernatant were evaluated by enzyme-linked immunosorbent assay (ELISA). Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and western blotting were conducted to determine the corresponding levels of messenger RNA (mRNA) and protein expression in cultured cells and the recipient spleens. The results showed that FK228 significantly improved the survival of allogeneic skin grafts. Moreover, FK228 inhibited DSA production in the serum along with the suppression of histone deacetylase 1 (HADC1) and HDAC2 and the upregulation of the acetylation of histones H2A and H3. It also inhibited the differentiation of B cells to plasma cells, decreased the transcription of positive regulatory domain-containing 1 (Prdm1) and X-box-binding protein 1 (Xbp1), and decreased the expression of phosphorylated inositol-requiring enzyme 1 α (p-IRE1α), XBP1, and B lymphocyte-induced maturation protein-1 (Blimp-1). In conclusion, FK228 could decrease the production of antibodies by B cells via inhibition of the IRE1α-XBP1 signaling pathway. Thus, FK228 is considered as a promising therapeutic agent for the clinical treatment of AMR.

Research progress of the unfolded protein response-activating transcription factor 6 pathway in ischemia-reperfusion injury post cardiac arrest / 中华危重病急救医学

Ischemia/reperfusion (I/R) caused by cardiac arrest (CA) and subsequent cardiopulmonary resuscitation (CPR) was the primary cause of post-cardiac arrest syndrome (PCAS), including post-cardiac arrest myocardial dysfunction and post-cardiac arrest brain injury. Disturbance of endoplasmic reticulum proteostasis, so-called endoplasmic reticulum stress (ERS) was one of the pathological changes induced by I/R injury. The unfolded protein response (UPR) was an adaptive response triggered by ERS in cells. Modulating the UPR arms to alleviate ERS to promote cell survival was promising for attenuating I/R injury. Activating the activating transcription factor6 (ATF6) signaling pathway, one of the arms of the UPR, confers protection against I/R injury in multiple tissues by restoring endoplasmic reticulum proteostasis and reducing oxygen free radicals. This article reviewed the structural characteristics and biological function of ATF6 and focused on its essential role in cardiac and cerebral I/R injury as well as potential therapeutic targets, hoping to provide new ideas for the effective treatment of PCAS.

Regulation effect of endoplasmic reticulum stress and unfolded protein response activation on skeletal muscle fiber immune behavior / 解剖学报

Objective To investigate the regulatory effects of activated endoplasmic reticulum stress（ERS） and unfolded protein response（UPR） on the immune behavior of the stressed muscle fibers in inflammatory environments induced by interferon-γ（IFN-γ）. Methods The myogenic precursor cells（MPCs） of C57 BL/6 mice cultured in vitro were differentiated into multinucleated myogenic tubes by horse serum and then to set up: 1. Control group; 2. IFN-γ group; 3. Tunicamycin group; 4. Thapsigargin group; 5. IFN-γ and 4-phenylbutyrate（4-PBA） combined treatment group; 6. IFN-γ, TG and 4-PBA combined treatment group; 7. IFN-γ and 4μ8 c combined treatment group; 8. IFN-γ, TG and 4μ8 c combined treatment group; 9. IFN-γ and GSK2606414 combined treatment group; 10. IFN-γ, TG and GSK2606414 combined treatment group. The level of myokines gene was detected by Real-time PCR. The expression of UPR key molecules including eukaryotic intiatio factor 2α（eIF2α）, inositol requrring enzyme 1α（IRE1α） and activating transcription factor 6（ATF6） in muscle fibers was observed by immunofluorescence. Western blotting was used to detect immune molecules related to muscle cells, myokines and key molecules of UPR. Luminex analyzed the levels of pro-inflammatory myokines in muscle fibers. Results The expression of H-2 Kb, H2-Ea, Toll like receptor 3（TLR3）, p-eIF2α and p-IRE1α were up-regulated in IFN-γ induced inflammatory environment. The expression of H-2 Kb, H2-Ea, TLR3 and myokines in the group with UPR inhibitor 4-PBA was down-regulated compared with IFN-γ group, and the expression of these molecules in the group with IRE1α specific inhibitor 4μ8 c was down-regulated compared with the IFN-γ group. The addition of protein kinase R-like endoplasmic eticulum（PERK） specific inhibitor GSK2606414 showed no significant change. Conclusion In IFN-γ induced inflammatory environment, the UPR-IRE1α pathway activates and inhibits the synthesis of muscle fiber immune-related molecules, which further inhibits the muscle fiber mediated immune response and facilitates muscle regeneration.

Exploring Pathogenic Mechanisms of Non-alcoholic Fatty Liver Disease Based on Mitochondrial Dysfunction and Endoplasmic Reticulum Stress / 胃肠病学

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease caused by abnormal accumulation of fat in the hepatocytes. Its prevalence is rising globally and has become the most common cause of chronic liver disease worldwide. The pathogenesis of NAFLD is multifaceted, involving insulin resistance, genetic and epigenetic factors, chronic systemic inflammation, mitochondrial dysfunction, endoplasmic reticulum stress, diet, gut microbiota, and other significant contributors. This article primarily delves into the mechanisms of mitochondrial dysfunction and endoplasmic reticulum stress in the development of NAFLD, aiming to provide new insights and therapeutic strategies for NAFLD.

Flurochloridone-induced apoptosis via IRE1α-JNK signaling pathway in mice testicular cells and TM4 cells / 环境与职业医学

Background Flurochloridone (FLC) can induce apoptosis in Sertoli cells, but the specific mechanism remains unknown. Objective To investigate the testicular cell apoptosis in mice as well as apoptosis and activation of endoplasmic reticulum stress in TM4 cell line induced by FLC through in vivo and in vitro study designs respectively, and study the role of inosital-requiring enzyme 1α (IRE1α)-c-Jun N-terminal kinase (JNK) signaling pathway in the process of FLC-induced apoptosis in TM4 cells through intervention study design. Methods Testicular tissues were collected from male C57BL/6 mice which were treated with 3, 15, 75, and 375 mg·（kg·d）−1 FLC by oral perfusion for 28 d. Apoptosis was observed by TUNEL staining, and the levels of apoptosis-related proteins were detected by Western blotting, including B-cell lymphoma-2 (Bcl-2), Bcl-2 interacting mediator of cell death (Bim), and Bcl-2 associated X protein (Bax). In the in vitro study, TM4 cells were treated with different concentrations of FLC (40, 80, and 160 μmol·L−1) for 6 h, then apoptosis rate was detected by flow cytometry, and the levels of apoptosis-related proteins (Bcl-2, Bim, and Bax) and endoplasmic reticulum stress-related proteins [glucose regulated protein 78 (GRP78), phosphorylated-protein kinase R like endoplasmic reticulum kinase (p-PERK), activating transcription factor 6 (ATF6), phosphorylated-inosital-requiring enzyme 1α (p-IRE1α), and phosphorylated-JNK (p-JNK)] were measured by Western blotting. In the intervention study, TM4 cells were pretreated with IRE1α phosphorylation inhibitor 4μ8C and JNK phosphorylation inhibitor SP600125 for 6 h, then treated with 160 μmol·L−1 FLC for 6 h. The levels of apoptosis-related proteins and endoplasmic reticulum stress-related proteins were measured by Western blotting, and cell viability was detected by cell counting kit-8. Results After the male C57BL/6 mice orally exposed to FLC for 28 d, apoptosis occurred in the seminiferous tubule. The protein expression level of Bcl-2, apoptosis inhibitor, was decreased in the 75 and 375 mg·(kg·d)−1 groups (P<0.05), and the protein expression levels of Bim and Bax, apoptosis promoters, were increased in the 75 and 375 mg·(kg·d)−1 groups respectively (P<0.05). The percentages of apoptotic cells in the 0, 40, 80, and 160 μmol·L−1 FLC groups were 2.7%±0.2%, 4.8%±1.3%, 9.4%±0.3%, and 13.2%±0.2%, respectively, increased significantly compared with the control group (P<0.05). The protein expression level of Bcl-2 also was decreased in the 160 μmol·L−1 FLC group (P<0.05), while the levels of Bim and Bax were increased in both of the 80 and 160 μmol·L−1 groups (P<0.05). The expression levels of endoplasmic reticulum stress-related proteins (GRP78, p-PERK, ATF6, p-IRE1α, and p-JNK) were increased (P<0.05) or showed a rising trend in TM4 cells. Pre-treatment with 4μ8C (25 and 50 μmol·L−1) and SP600125 (10 and 20 μmol·L−1) significantly down-regulated the protein expression levels of GRP78, p-IRE1α, p-JNK, and Bax induced by FLC (P<0.05) or in a downward trend. Both of the inhibitors alleviated the decreased cell viability induced by FLC (P<0.05) or in alleviating fashion. Conclusion FLC could induce apoptosis in mice testis and TM4 cell apoptosis through activating endoplasmic reticulum stress and IRE1α-JNK signaling pathway.

The role of endoplasmic reticulum stress in hepatic insulin resistance caused by intermittent hypoxia / 安徽医科大学学报

Objective @#To investigate the role of endoplasmic reticulum stress in hepatic insulin resistance induced by intermittent hypoxia in rats．@*Methods @#Twenty-four SD rats were randomly divided into control group ( NC group) and intermittent hypoxia group ( CIH group) ．The NC group was placed in a normoxia environment for 12 weeks，and the CIH group was given intermittent hypoxia for 8 weeks，and then returned to normoxia until the 12th week．In both groups，fasting blood glucose (FBG) ，fasting insulin (FINS) ，and liver inositol-requiring enzyme- 1 α(IRE1 α) ，X-box binding protein 1s(XBP1s) ，forkhead box transcription factor O1 (FoxO1) ，activating transcription factor-6(ATF6) ，cAMP-response element binding protein( CREB) ，CREB-regulated transcription coacti- vator-2( CRTC2) ，double-stranded RNA-dependent protein kinase-like ER kinase ( PERK) ，eukaryotic initiation factor 2 α(eIF2 α) ，protein kinase B ( AKT) ，phosphoenolpyruvate carboxykinase ( PEPCK) ，glucose-6-phosphat- ase( G6Pase) mRNA were measured at baseline，week 8，and week 12 .@*Results @#There was no significant differ- ence in each observation index between the two groups at baseline ; at 8 weeks，the levels of FBG，FINS and the mRNA levels of IRE1α , XBP1s，ATF6，PERK，eIF2 α , PEPCK and G6Pase in the CIH group were higher than those in the NC group (P＜0. 05) ，while the mRNA levels of CREB，CRTC2 and AKT were lower than those in the NC group (P＜0. 05) ; at 12 weeks，there was no significant difference in each observation index between the two groups．Pearson correlation analysis showed(8th week of intermittent hypoxia group) : homeostasis model as- sessment-insulin resistance(HOMA-IR) was positively correlated with FoxO1，CREB，CRTC2 and PERK，eIF2 α mRNA levels (r = 0. 172，0. 595，0. 183，0. 702，0. 608 ; P＜0. 05) while it was negatively correlated with IRE1α , XBP1s，ATF6，AKT mRNA levels (r = －0. 422 ，－0. 327 ，－0. 309 ，－0. 399 ; P＜0. 05) ．@*Conclusion @#Intermittent hypoxia can lead to insulin resistance，and endoplasmic reticulum stress may mediate this effect.

The changes of mitochondrial unfolded protein response in epileptic hippocampal neurons and the effect of mitochondria-targeted antioxidant Mito-TEMPO / 中风与神经疾病杂志

@#Objective To investigate the changes of mitochondrial unfolded protein response (mtUPR) in hippocampus of lithium-pilocarpine induced seizures and the effect of mitochondria-targeted antioxidant. Methods Lithium chloride and pilocarpine were used to elicit status epilepticus in rats, and the rats were further treated with mitochondria-targeted antioxidant Mito-TEMPO. Adult male Wistar rats were randomly divided into control group, PILO group, Mito-TEMPO group and PILO +Mito-TEMPO group. Nissl staining was used to observe the damage of hippocampal neurons, electron transmission microscopy was used to observe the ultrastructure of mitochondria, ROS production of mitochondria was detected by reactive oxygen species fluorescent probe (DCFDA), and mitochondrial membrane potential was detected by Rhoda.mine123 staining. The expressions of mitochondrial heat shock protein HSP60, protease LONP1 and mitochondrial protease CLpP were detected by Western blot. Results (1) Compared with CON group, the ultrastructure of hippocampal neuronal mitochondria in PILO group was seriously damaged, mitochondrial ROS production was increased, and mitochondrial membrane potential was decreased. (2) Compared with the CON group, the expressions of HSP60 , Lonp1 and CLpP in the PILO group were increased. (3) Compared with the PILO group, the damage of mitochondrial ultrastructure was alleviated in the PILO+Mito-TEMPO group, the production of mitochondrial ROS was significantly reduced, and the mitochondrial membrane potential was increased. (4) Compared with the PILO group, the expressions of HSP60, LONP1 and CLpP in the hippocampal neurons of the PILO+Mito-TEMPO group were decreased. Conclusion The mtUPR is significantly activated in hippocampal neurons in epilepsy, and Mito-TEMPO may play a protective role in hippocampal mitochondrial injury in epilepsy regulating mtUPR.

Role and research progress of endoplasmic reticulum stress in anti -tumor therapy / 中国药理学通报

In the process of tumor occurrence, development and metastasis, the stress environment experienced by tumor cells such as hypoxia, low glucose, acidosis, can cause tumor cells to undergo endoplasmic reticulum stress (E R S). In order to restore cell homeostasis, ERS initiates the unfolded protein response (U P R). But when ERS exceeds the survival ability of cells, it will mediate cell apoptosis. This article expounds the role of ERS in anti-tumor therapy and its research progress mainly from the two aspects of inhibition of UPR mediated promote survival pathways and induction of ERS mediated death pathways, in order to understand the relationship between ERS-related pathways and anti-tumor treatments, hoping to provide new ideas for tumor treatment.