High-intensity interval training (treadmill) effects in myokines and endoplasmic reticulum stress of calf muscles in obese mice / Efectos del entrenamiento interválico de alta intensidad (trotadora) en miocinas y estrés del retículo endoplasmático de los músculos surales en ratones obesos

SUMMARY: Obesity is commonly associated with chronic tissue inflammation and skeletal muscle dysfunction. The study aimed to investigate the effects of High-Intensity Interval training (HIIT) on myokines and endoplasmic reticulum (ER) stress of diet- induced obese (DIO) mice. Three-month-old C57BL/6 male mice were fed a control (C) diet (n=20) or a high-fat (HF) diet (n=20) for 16 weeks. Then, half of the groups underwent HIIT (treadmill running) for an additional four weeks. HIIT increased calf muscles' contribution to BW (+24 %) and reduced weight gain in HF/HIIT than in HF (-120 %). Intramuscular fat accumulation was observed in HF and HF/ HIIT. Peak velocity was higher in HF/HIIT compared to HF (+26 %). Plasma insulin did not change, but glycemia was lower in HF/HIIT than in HF (-30 %). Fndc5 (+418 %) and Irisin (+72 %) were higher in HF/HIIT than in HF. Muscle Fgf21 was higher in HF/HIIT compared to HF (+30 %). In addition, NfKb (-53 %) and Tnfa (-63 %) were lower in HF/HIIT than in HF. However, Il1b (-86 %), Il6 (- 48 %), Il7 (-76 %), and Il15 (-21 %) were lower in HF/HIIT than in HF. Finally, HIIT reduced ER stress in HF/HIIT compared to HF: Atf4, -61 %; Chop, -61 %; Gadd45, -95 %. In conclusion, HIIT leads to weight loss and avoids muscle depletion. HIIT improves blood glucose, Irisin-Fndc5, and peak velocity. In addition, HIIT mitigates muscle inflammation and ER stress.

La obesidad es asociada comúnmente con inflamación tisular crónica y disfunción del músculo esquelético. El estudio tuvo como objetivo investigar los efectos del entrenamiento de intervalos de alta intensidad (HIIT) en las mioquinas y el estrés del retículo endoplásmico (ER) de ratones obesos inducidos por dieta (DIO). Se alimentó a ratones macho C57BL/6 de tres meses de edad con una dieta control (C) (n=20) o una dieta rica en grasas (HF) (n=20) durante 16 semanas. Luego, la mitad de los grupos se sometieron a HIIT (carrera en una trotadora) durante cuatro semanas más. HIIT aumentó la contribución de los músculos de la pantorrilla al BW (+24 %) y redujo el aumento de peso en HF/HIIT en HF (-120 %). Se observó acumulación de grasa intramuscular en HF y HF/HIIT. La velocidad máxima fue mayor en HF/HIIT en comparación con HF (+26 %). La insulina plasmática no cambió, pero la glucemia fue menor en HF/HIIT que en HF (-30 %). Fndc5 (+418 %) e Irisin (+72 %) fueron mayores en HF/HIIT que en HF. El Fgf21 muscular fue mayor en HF/ HIIT en comparación con HF (+30 %). Además, NfKb (-53 %) y Tnfa (-63 %) fueron menores en HF/HIIT que en HF. Sin embar- go, Il1b (-86 %), Il6 (-48 %), Il7 (-76 %) e Il15 (-21 %) fueron más bajos en HF/HIIT que en HF. Finalmente, HIIT redujo el estrés de RE en HF/HIIT en comparación con HF: Atf4, -61 %; Picar, - 61 %; Gadd45, -95 %. En conclusión, HIIT conduce a la pérdida de peso y evita el agotamiento muscular. HIIT mejora la glucosa en sangre, Irisin-Fndc5 y la velocidad máxima. Además, HIIT mitiga la inflamación muscular y el estrés ER.

Study on improvement mechanism of caudatin on liver injury in rats / 中国药房

OBJECTIVE To investigate the improvement mechanism of caudatin on liver injury of rats. METHODS SD rats were randomly divided into blank group， model group， caudatin low-dose and high-dose groups （25， 50 mg/kg）， with 6 rats in each group. Diethylnitrosamine （DEN） was injected intraperitoneally three times per week for eight weeks to establish liver injury model of rats. At 5th week of modeling， the rats received relevant medicine or 0.5% sodium carboxymethylcellulose intragastrically for 4 weeks. The levels of liver function indexes [alanine transaminase （ALT）， aspartate transaminase （AST）， total protein （TP） and total bilirubin （TBI）] and inflammatory factors [interleukin （IL-6）， tumor necrosis factor α （TNF-α）， IL-1β] in serum were detected； the histopathological morphological changes of rat liver were observed； the positive protein expressions of nuclear factor κB （NF-κB） and 78 kDa glucose regulatory protein （Grp78） in liver tissue were also determined； the expressions of endoplasmic reticulum stress-related protein Grp78， C/EBP homologous protein （CHOP）， activating transcription factor 6 （ATF6） and inositol requiring enzyme 1α （IRE1α） and the level of protein kinase R-like endoplasmic reticulum kinase robertluoyi@126.com （PERK） in liver tissue were detected. RESULTS Compared with blank group， serum levels of ALT， AST， TBI， IL-6， TNF-α and IL-1β and positive expressions of NF-κB and Grp78 in liver tissue as well as protein expressions of Grp78， CHOP， ATF6 and IRE1α， PERK protein phosphorylation level were all increased significantly in model group （P＜0.05）， while the serum level of TP was decreased significantly （P＜0.05）. The disordered structure of liver lobule， swollen liver cells， unclear intercellular boundary were observed and accompanied by inflammatory cell infiltration. Compared with model group， most of the above indexes were significantly reversed in caudatin groups （P＜0.05）； the structure of hepatic lobule was relatively complete and clear， the cells were arranged orderly， and the infiltration of inflammatory cells was also reduced. CONCLUSIONS Caudatin has a significant improvement effect against DEN-induced liver injury in rats， the mechanism of which may be associated with inhibiting endoplasmic reticulum stress and inflammatory reaction.

Pin1 aggravates renal injury induced by ischemia and reperfusion in rats via Nrf2/HO-1 mediated endoplasmic reticulum stress

Purpose: To investigate the role of peptidyl-prolyl cis/trans isomerase 1 (Pin1) on renal ischemia-reperfusion (I/R) injury and underlying mechanism. Methods: By establishing the in vitro and in vivo models of renal I/R, the role of Pin1 was explored by using molecular assays. Results: In renal I/R, endogenous Pin1 level was up-regulated in I/R-impaired kidney. Suppression of Pin1 with juglone afforded protection against I/R-mediated kidney dysfunction, and reduced I/R-induced endoplasmic reticulum (ER) stress in vivo. Consistent with the in vivo results, repression of Pin1 with juglone or gene knockdown with si-Pin1 conferred cytoprotection and restricted hypoxia/reoxygenation (H/R)-driven ER stress in HK-2 cells. Simultaneously, further study uncovered that Nrf-2/HO-1 signals was the association between Pin1 and ER stress in response to renal I/R. In addition, Nrf-2/HO-1 signal pathway was inactivated after kidney exposed to I/R, as indicated by the down-regulation of Nrf-2/HO-1 levels. Furthermore, inhibition of Pin1 remarkably rescued the inactivation ofNrf-2/HO-1. Conclusions: Pin1 modulated I/R-mediated kidney injury in ER stress manner dependent on Nrf2-HO-1 pathway in I/R injury.

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.

Effect of cell migration-inducing hyaluronidase 1 on biological function of gallbladder cancer GBC-SD cells and its mechanism / 中华肝胆外科杂志

Objective:To investigate the effect of cell migration-inducing hyaluronidase 1 (CEMIP) on biological function of gallbladder cancer GBC-SD cells and its possible mechanism.Methods:The expression of CEMIP in biliary epithelial cell line HIBEC and gallbladder cancer cell line NOZ and GBC-SD was detected by Western blot. GBC-SD cells in logarithmic growth phase were divided into blank control group, negative control group (transfection with nonsense siRNA), siCEMIP-1 group (transfection with siCEMIP-1) and siCEMIP-2 group (transfection with siCEMIP-2). The expression of CEMIP and binding immunoglobulin protein (Bip) and calreticulin (CRT) in GBC-SD cells was detected by Western blot after culturing for 48h in blank control group, negative control group, siCEMIP-1 and siCEMIP-2 group. The relative survival rate was determined by CCK-8 assay. The wound healing rate and apoptotic rate was detected by wound healing assay and flow cytometry. The migration and invasion abilities were evaluated by Transwell chamber assay. Twelve 5-week-old BALB/c-nude mice were selected and divided into control group and experimental group (6 mice in each group). GBC-SD cells and GBC-SD cells with silenced CEMIP were subcutaneously injected into the right armpit (forelimb) of the two groups of mice, respectively. The volume and weight of transplanted tumor were compared 33 days later.Results:Compared with HIBEC cells, the relative protein level of CEMIP in gallbladder cancer GBC-SD cells [(0.750±0.034) vs. (0.120±0.002)] and NOZ cells [(0.690±0.013) vs. (0.120±0.002)] was significantly higher ( P<0.05). Compared with blank control group and negative control group, the relative protein level of CEMIP, Bip and CRT in siCEMIP-1 group and siCEMIP-2 group was significantly lower ( P<0.05). Compared with blank control group and negative control group, the relative survival rate and wound healing rate and number of migration cells and invading cells in siCEMIP-1 group and siCEMIP-2 group were also significantly lower ( P<0.05). While the apoptotic rate in siCEMIP-1 group and siCEMIP-2 group were higher than that in blank control group and negative control group ( P<0.05). Compared with control group, the average tumor volume [(543.6±114.7) vs. (801.5±256.3) mm 3] and tumor weight [(0.453±0.093) vs. (0.728±0.278) g ] of the experimental group was significantly decreased ( P<0.05). Conclusions:CEMIP was up-regulated in gallbladder cancer cell line GBC-SD and NOZ. Silencing CEMIP inhibited cell proliferation, wound healing rate, migration and invasion, and promoted apoptosis in gallbladder cancer GBC-SD cells, which may be related to the inhibition of endoplasmic reticulum chaperone Bip and CRT expression.

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.

Estradiol inhibits differentiation of mouse macrophage into a pro-inflammatory phenotype by upregulating the IRE1α-XBP1 signaling axis / 南方医科大学学报

OBJECTIVE@#To explore the mechanism by which estradiol modulates the immunophenotype of macrophages through the endoplasmic reticulum stress pathway.@*METHODS@#Peritoneal macrophages isolated from C57 mice were cultured in the presence of 60 ng/mL interferon-γ (IFN-γ) followed by treatment with estradiol (1.0 nmol/L) alone, estradiol with estrogen receptor antagonist (Acolbifene, 4 nmol/L), estradiol with IRE1α inhibitor (4 μ 8 C), or estradiol with IRE1α agonist. After the treatments, the expression levels of MHC-Ⅱ, iNOS and endoplasmic reticulum stress marker proteins IRE1α, eIF2α and ATF6 in the macrophages were detected with Western blotting, and the mRNA levels of TGF-β, IL-6, IL-10 and TNF-α were detected with RT-PCR.@*RESULTS@#Estrogen treatment of the macrophages significantly decreased the expressions of M1-related proteins MHC-Ⅱ (P=0.021) and iNOS (P < 0.001) and the mRNA expressions of TNF-α (P=0.003) and IL-6 (P=0.004), increased the mRNA expression of TGF-β (P=0.002) and IL-10 (P=0.008), and up-regulated the protein expressions of IRE1α (P < 0.001) and its downstream transcription factor XBP-1 (P < 0.001). Addition of the estrogen inhibitor obviously blocked the effect of estrogen. Compared with estrogen treatment alone, combined treatment of the macrophages with estrogen and the IRE1α inhibitor 4 μ 8 C significantly up-regulated the protein expressions of MHC-Ⅱ (P=0.002) and iNOS (P=0.003) and the mRNA expressions of TNF-α (P=0.003) and IL-6 (P=0.024), and obviously down-regulated the mRNA expression of TGF-β (P < 0.001) and IL-10 (P < 0.001); these changes were not observed in cells treated with estrogen and the IRE1α agonist.@*CONCLUSION@#Estrogen can inhibit the differentiation of murine macrophages into a pro-inflammatory phenotype by up-regulating the IRE1α-XBP-1 signaling axis, thereby producing an inhibitory effect on inflammatory response.

HSP90α exacerbates house dust mite-induced asthmatic airway inflammation by upregulating endoplasmic reticulum stress in bronchial epithelial cells / 南方医科大学学报

OBJECTIVE@#To explore the role of heat shock protein 90α (HSP90α) and endoplasmic reticulum (ER) stress pathway in allergic airway inflammation induced by house dust mite (HDM) in bronchial epithelial cells.@*METHODS@#A HDM- induced asthmatic cell model was established in human bronchial epithelial (HBE) cells by exposure to a concentration gradient (200, 400 and 800 U/mL) of HDM for 24 h. To test the effect of siHSP90α and HSP90 inhibitor 17-AAG on HDM-induced asthmatic inflammation, HBE cells were transfected with siHSP90α (50 nmol, 12 h) or pretreated with 17-AAG (900 nmol, 6 h) prior to HDM exposure (800 U/mL) for 24 h, and the changes in the expression of HSP90α and ER stress markers were assessed. We also tested the effect of nasal drip of 17-AAG, HDM, or their combination on airway inflammation and ER stress in C57BL/6 mice.@*RESULTS@#In HBE cells, HDM exposure significantly up-regulated the expression of HSP90α protein (P=0.011) and ER stress markers XBP-1 (P=0.044), ATF-6α (P=0.030) and GRP-78 (P=0.027). Knocking down HSP90α and treatment with 17-AAG both significantly inhibited HDM-induced upregulation of XBP-1 (P=0.008). In C57BL/6 mice, treatment with 17-AAG obviously improved HDM-induced airway inflammation and significantly reduced the number of inflammatory cells in the airway (P=0.014) and lowered the levels of IL-4 (P=0.030) and IL-5 (P=0.035) in alveolar lavage fluid. Immunohistochemical staining showed that the expressions of XBP-1 and GRP-78 in airway epithelial cells decreased significantly after the treatment of 17-AAG.@*CONCLUSIONS@#HSP90α promotes HDM-induced airway allergic inflammation possibly by upregulating ER stress pathway in bronchial epithelial cells.

Catalpol improves non-alcoholic fatty liver and lipid-lowering mechanism through endoplasmic reticulum stress-mediated PERK-eIF2α signaling pathway / 中华内分泌代谢杂志

Objective:To investigate effect and underlying lipid-lowering mechanisms of catalpol in non-alcoholic fatty liver disease(NAFLD).Methods:In vivo model of NAFLD was established with high-fat diet-fed ICR mice for 8 weeks. Low(50 mg/kg), medium(150 mg/kg), and high(300 mg/kg) doses of catalpol were administered, and the body weight, liver weight, hepatic index, and biochemical parameters of the mice were analyzed. Free fatty acid-induced LO2 in human hepatocytes to establish NAFLD cell model. Quantitative realtime PCR reaction to detect fatty acid synthesis-related gene levels. Western blotting assay was adopted to analyze proteins in the endoplasmic reticulum stress(ERS)-mediated protein kinase RNA-like endoplasmic reticulum kinase(PERK)-eukaryotic translation initiation factor 2α(eIF2α) signaling pathway. Results:Compared with model mice, body weight [(39.43±1.84)g, (34.01±1.83)g, (32.28±1.11)g vs(42.17±1.37)g, all P<0.001], liver weight [(1.03±0.06)g, (0.79±0.05)g, (0.64±0.04)g vs(1.30±0.13)g, P<0.01 or P<0.001], and liver index [(2.60±0.09)%, (2.32±0.09)%, (1.99±0.11)% vs(3.07±0.30)%, P<0.05 or P<0.001] were reduced in low, medium, and high doses of catapol model. Medium and high doses of catalpol diminished total cholesterol, triglyceride, low density lipoprotein-cholesterol, aspartate aminotransferase, and alanine aminotransferase( P<0.01 or P<0.001), increased high density lipoprotein-cholesterol( P<0.01 or P<0.001). In the cell model, elevated levels of both fatty acid synthesis genes and PERK-eIF2α pathway proteins were attenuated by catalase, and this attenuation was reversed by signaling pathway agonists. Conclusion:The Chinese herb catalpol may play a role in improving NALFD by regulating the ERS-mediated PERK-eIF2α signaling pathway.

Research progress of endoplasmic reticulum targeting drug delivery system for anti-tumor immunotherapy / 药学学报

Endoplasmic reticulum (ER), a multifunctional organelle in eukaryotic cells, is responsible for protein synthesis and intracellular signal transduction, which dominates cell function, survival, and apoptosis. Disequilibrium of ER homeostasis may induce ER stress, which closely intertwines with tumor occurrence and progress. A few clinical-used drugs (such as anthraquinones and oxaliplatin) can mediate the immunogenic cell death of tumor cells through excessive ER stress, and sequentially stimulate anti-tumor immune responses as well as long-term immune memory. However, these drugs often exhibit poor targeting ability and extremely low ER accumulation in tumor cells, limiting their clinical efficacy. Therefore, the researches of ER-targeted delivery of these drugs will significantly benefit the efficient and precise anti-tumor immunotherapy. In this review, we introduce the relationship between ER and tumor immunity, and summarize the ER targeting strategies for anti-tumor immunotherapy in recent years. Furthermore, we discuss the problems of existing ER targeting strategies and look into its broad prospects of application.

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.

Study of endoplasmic reticulum stress in human dental pulp cells induced by oxygen-glucose deprivation culture in vitro / 口腔疾病防治

Objective@#Oxygen-glucose deprivation (OGD) is used to mimic ischemia in vitro to observe whether endoplasmic reticulum (ER) stress is involved in human dental pulp cells (hDPCs) after OGD and to better understand the regulatory mechanism of hDPCs in ischemia.@*Methods@# hDPCs were cultured in glucose-free DMEM and hypoxia (volume fraction 2% O2) to establish an hDPCs OGD model in vitro, which mimics hDPCs ischemia in vitro. hDPCs were divided into a control group (normal culture) and an experimental group (OGD 0 h, 2 h, 4 h and 8 h groups). After pretreatment with OGD for 0, 2, 4 and 8 h, hDPC viability was measured by methylthiazol tetrazolium (MTT) assay. qRT-PCR was used to detect the mRNA expression of ER stress markers [splicing x-box binding protein1 (sXBP1), activating transcription Factor 4 (ATF4) and C/EBP homologous protein (chop)]. Western blot was used to detect the protein expression of ER stress markers [phosphorylated RNA-activated protein kinase-like ER-resident kinase (p-perk) and phosphorylated eukaryotic initiation factor-2α (p-eIF2α)]. @*Results@#Compared with OGD 0 h group, cell viability of hDPCs decreased when exposed to OGD treatment for 2 h, 4 h and 8 h. Compared with the control group, mRNA expressions of ER stress makers (sXBP1, ATF4 and chop) and the protein expressions of ER stress protein markers (p-perk andp-eIF2α) increased in OGD treatment cells after 4 h were higher in OGD cells. The differences were statistically significant (P<0.05).@*Conclusion@#The results indicate that ER stress response is involved in hDPCs in OGD treatment.

Regulation of Nrf2 signaling factor in cadmium combined with bacitracin induced endoplasmic reticulum stress in testes and ovaries of rats / 中国职业医学

@#Objective To investigate the effect of acute exposure to cadmium combined with bacitracin on the endoplasmic reticulum stress (ERS) in testes and ovaries of rats and its regulation by nuclear factor erythroid-2-related factor 2 (Nrf2). Methods According to the 4×2 factorial design model, 48 specific pathogen free adult SD rats were divided into four groups: the control group and the low-, medium- and high- dose cadmium chloride exposure groups. Each group was further divided into with- or without bacitracin combined subgroup. There were six rats in each subgroup with 3 males and 3 females. The low-, medium- and high- dose groups were intraperitoneally injected with 5, 10, 20 mg/kg body weight of cadmium chloride solution, respectively. The control group was intraperitoneally injected with the same amount of 0.9% sodium chloride solution. Among them, rats in the bacitracin combined subgroup were given a one-time intraperitoneal injection of bacitracin at a dose of 20 mg/kg body weight two hours before cadmium chloride exposure. After 48 hours, the rats were sacrificed. The mRNA expression of glucose regulated protein78 kD (Grp78), protein kinase R-like endoplasmic reticulum kinase (Perk), Nrf2 in testes and ovaries of rats was determined using quantitative real-time polymerase chain reaction. The protein expression of GRP78, PERK, NRF2 was determined using Western blotting. Results The mRNA expression of Grp78, Perk, Nrf2 and the protein expression of GRP78, PERK, NRF2 in testes and ovaries of rats in the no bacitracin combined subgroups of the three dose groups showed different degrees of up-regulated changes compared with the no bacitracin combined subgroup of the control group (all P<0.05). Among them, the expression of the three kinds of mRNAs and proteins in the testes and ovaries of rats in the no bacitracin combined subgroups of the high-dose group was up-regulated (all P<0.05), and most of them were higher than those in the no bacitracin combined subgroups of the low- and medium-dose groups (all P<0.05). The expression of most of the three kinds of mRNAs and proteins in testes of rats showed different degrees of down-regulated changes (all P<0.05), but the expression of the three kinds of mRNAs and proteins showed different degrees of up-regulated changes in ovaries (all P<0.05) in the bacitracin combined subgroups of the three doses groups than that in the bacitracin combined subgroups of the control group, and especially in the bacitracin combined subgroups of the high-dose subgroup. The expression of the three kinds of mRNAs and proteins in testes and ovaries of rats in the bacitracin combined subgroups of the three doses groups showed different degrees of changes (all P<0.05) compared with the no bacitracin combined subgroup in the same group, and the expression in the bacitracin combined subgroups of the medium- and high-dose groups showed mainly down-regulated changes (all P<0.05). Conclusion Acute exposure to cadmium can induce different degrees of ERS, activate PERK/NRF2 signaling pathway, and improve the toxicity to testis and ovary. Bacitracin can inhibit cadmium-induced ERS, thereby inhibiting the activation of PERK/NRF2 signaling pathway, and enhancing the synergistic effect of cadmium on testis and ovary toxicity. The higher the exposure dose of cadmium, the more obvious the inhibitory effect.

Broussonetiae Fructus Protects Against APAP-induced Liver Injury in Mice by Inhibiting Endoplasmic Reticulum Stress Pathway / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of Broussonetiae Fructus （BF） in preventing and treating drug-induced liver injury （DILI） induced by acetaminophen （APAP） through the endoplasmic reticulum stress pathway. MethodSixty C57BL/6N mice were randomly divided into normal group， model group， silybin group （3.4 g·kg-1）， and high-， medium- and low-dose BF groups （3.0， 1.5， 0.75 g·kg-1）， with 10 mice in each group. The DILI model was induced by intragastric administration of APAP at 800 mg·kg-1， and drugs were administered simultaneously for 10 consecutive days. The serum contents or activities of alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， total bilirubin （TBIL）， and direct bilirubin （DBIL） were measured. Hematoxylin-eosin（HE） staining was performed to observe the pathological changes in liver tissues. The morphological changes in liver mitochondria were observed by transmission electron microscopy. The activities or content of superoxide dismutase （SOD）， malondialdehyde （MDA）， total antioxidant capacity （T-AOC）， glutathione （GSH）， glutathione disulfide （GSSG）， glutathione peroxidase （GSH-Px）， and adenosine triphosphate （ATP） in the serum and liver tissues were detected by the colorimetric method. The expression of reactive oxygen species （ROS） in liver tissues was detected by immunofluorescence. The gene expression of glucose-regulated protein 78 （GRP78）， CCAAT/enhancer-binding protein homologous protein （CHOP）， and c-Jun N-terminal kinase （JNK） in liver tissues was detected by Real-time quantitative polymerase chain reaction （PCR）. ResultCompared with the normal group， the model group showed increased serum activities or content of ALT， AST， TBIL， and DBIL （P<0.01）， increased MDA and GSSG contents （P<0.01）， decreased contents or activities of SOD， T-AOC， GSH， GSH-Px， and ATP （P<0.01）， swollen hepatocytes with inflammatory infiltration and lamellar necrosis， swollen and broken mitochondria of hepatocytes， and increased mRNA expression of GRP78， CHOP， and JNK （P<0.01）. Compared with the model group， the groups with drug intervention showed decreased serum content or activities of ALT， AST， TBIL， and DBIL （P<0.05， P<0.01）， reduced MDA and GSSG contents（P<0.05， P<0.01）， and increased contents or activities of SOD， T-AOC， GSH， GSH-Px， and ATP （P<0.05， P<0.01）， improved swollen hepatocytes， inflammatory infiltration， and lamellar necrosis， recovered bilayer membrane structure in mitochondria of hepatocytes， and decreased mRNA expression of GRP78， CHOP， and JNK （P<0.05， P<0.01）. ConclusionBF has preventive and therapeutic effects on APAP-induced DILI mice， and the mechanism may be related to the reduction of endoplasmic reticulum stress and oxidative stress level in vivo.

Stimuli-responsive nano vehicle enhances cancer immunotherapy by coordinating mitochondria-targeted immunogenic cell death and PD-L1 blockade

Induction of immunogenic cell death promotes antitumor immunity against cancer. However, majority of clinically-approved drugs are unable to elicit sufficient ICD. Here, our study revealed that mitochondria-targeted delivery of doxorubicin (DOX) massively amplified ICD via substantial generation of reactive oxygen species (ROS) after mitochondrial damage. The underlying mechanism behind increased ICD was further demonstrated to be ascribed to two pathways: (1) ROS elevated endoplasmic reticulum (ER) stress, leading to surface exposure of calreticulin; (2) ROS promoted release of various mitochondria-associated damage molecules including mitochondrial transcription factor A. Nevertheless, adaptive upregulation of PD-L1 was found after such ICD-inducing treatment. To overcome such immunosuppressive feedback, we developed a tumor stimuli-responsive nano vehicle to simultaneously exert mitochondrial targeted ICD induction and PD-L1 blockade. The nano vehicle was self-assembled from ICD-inducing copolymer and PD-L1 blocking copolymer, and possessed long-circulating property which contributed to better tumor accumulation and mitochondrial targeting. As a result, the nano vehicle remarkably activated antitumor immune responses and exhibited robust antitumor efficacy in both immunogenic and non-immunogenic tumor mouse models.

The substitution of SERCA2 redox cysteine 674 promotes pulmonary vascular remodeling by activating IRE1α/XBP1s pathway

Pulmonary hypertension (PH) is a life-threatening disease characterized by pulmonary vascular remodeling, in which hyperproliferation of pulmonary artery smooth muscle cells (PASMCs) plays an important role. The cysteine 674 (C674) in the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2 (SERCA2) is the critical redox regulatory cysteine to regulate SERCA2 activity. Heterozygous SERCA2 C674S knock-in mice (SKI), where one copy of C674 was substituted by serine to represent partial C674 oxidative inactivation, developed significant pulmonary vascular remodeling resembling human PH, and their right ventricular systolic pressure modestly increased with age. In PASMCs, substitution of C674 activated inositol requiring enzyme 1 alpha (IRE1α) and spliced X-box binding protein 1 (XBP1s) pathway, accelerated cell cycle and cell proliferation, which reversed by IRE1α/XBP1s pathway inhibitor 4μ8C. In addition, suppressing the IRE1α/XBP1s pathway prevented pulmonary vascular remodeling caused by substitution of C674. Similar to SERCA2a, SERCA2b is also important to restrict the proliferation of PASMCs. Our study articulates the causal effect of C674 oxidative inactivation on the development of pulmonary vascular remodeling and PH, emphasizing the importance of C674 in restricting PASMC proliferation to maintain pulmonary vascular homeostasis. Moreover, the IRE1α/XBP1s pathway and SERCA2 might be potential targets for PH therapy.

Effect of wheat-grain moxibustion on the expression of Beclin-1/GRP78 in spinal dorsal horn in rats with cervical spondylotic radiculopathy / 中国针灸

OBJECTIVE@#To observe the effect of wheat-grain moxibustion at "Dazhui" (GV 14) on the expressions of Beclin-1 and GRP78 in spinal dorsal horn in rats with cervical spondylotic radiculopathy (CSR), and to explore the possible analgesic mechanism of wheat-grain moxibustion for CSR.@*METHODS@#A total of 48 SD rats were randomly divided into a sham operation group, a model group, a wheat-grain moxibustion group and a wheat-grain moxibustion+3-MA group, 12 rats in each group. The CSR model was prepared by spinal cord insertion method. Three days after modeling, the rats in the model group were intraperitoneally injected with 1 mL of 0.9% sodium chloride solution; the rats in the wheat-grain moxibustion group were treated with wheat-grain moxibustion at "Dazhui" (GV 14, 6 cones per time) on the basis of the model group; the rats in the wheat-grain moxibustion+3-MA group were intraperitoneally injected with 3-MA solution and wheat-grain moxibustion at "Dazhui" (GV 14, 6 cones per time). The three groups were intervened for 7 days, once a day. The gait score and mechanical pain threshold were observed before treatment and 7 days into treatment; after the treatment, the expressions of mRNA and protein of Beclin-1 in spinal dorsal horn were detected by real-time fluorescence quantitative PCR and immunohistochemistry; the expression of GRP78 protein in spinal dorsal horn was detected by Western blot method; the autophagosomes and ultrastructure in spinal dorsal horn neurons were observed by electron microscope.@*RESULTS@#After the treatment, compared with the sham operation group, in the model group, the gait score was increased and the mechanical pain threshold was decreased (P<0.01), and the expression of GRP78 protein in spinal dorsal horn was increased (P<0.01). Compared with the model group and the wheat-grain moxibustion+3-MA group, in the wheat-grain moxibustion group, the gait score was decreased and mechanical pain threshold was increased (P<0.01), and the expression of GRP78 protein in spinal dorsal horn was decreased, and the expressions of mRNA and protein of Beclin-1 were increased (P<0.01). Under electron microscope, the ultrastructure of spinal dorsal horn neurons in the wheat-grain moxibustion group was not significantly damaged, and its structure was basically close to normal, and the number of autophagosomes was more than the other three groups.@*CONCLUSION@#Wheat-grain moxibustion at "Dazhui" (GV 14) has analgesic effect on CSR rats. The mechanism may be related to moderately up-regulate the expression of Beclin-1, enhance autophagy and reduce endoplasmic reticulum stress.

Effect of moxibustion at "oppositely-located points" on neurogenic bladder after spinal cord injury and endoplasmic reticulum stress pathway in rats / 中国针灸

OBJECTIVE@#To observe the effect of moxibustion at oppositely-located points "Mingmen" (GV 4) and "Shenque" (CV 8) on the motor function of the hind limbs and bladder function in rats with neurogenic bladder after suprasacral spinal cord injury (SCI), so as to explore the effect of this therapy on bladder tissue apoptosis mediated by endoplasmic reticulum stress pathway.@*METHODS@#Twenty-eight female Wistar rats were randomly divided into a sham-operation group (8 rats) and a model establishment group (20 rats). Using the modified Allen's method, the spinal cord of T10 segment was injured to establish a neurogenic bladder model in the model establishment group. Sixteen rats were modeled successfully and then divided into a model group (8 rats) and a moxibustion group (8 rats). In the moxibustion group, 2 h after consciousness regaining from modeling anesthesia, moxibustion was exerted at "Shenque" (CV 8) and "Mingmen" (GV 4), 2 cones at each acupoint in one intervention. The intervention was administered once every two days and 5-time intervention was required totally. After intervention, Basso, Beattie and Bresnahan locomotor rating scale (BBB) score for the motor function of the hind limbs, and the urodynamics indexes (maximum bladder capacity, urine leakage pressure and bladder compliance) were compared among groups. HE staining method was adopted to observe the morphological changes of bladder tissue. With Western blot method and real-time PCR assay, the protein and mRNA expressions of the endoplasmic reticulum stress-related genes (glucose- regulated protein 78 [GRP78], activating transcription factor 4 [ATF4] and cysteinyl aspartate specific proteinase-12 [Caspase-12]) were determined.@*RESULTS@#The transitional epithelial cells were arranged irregularly, the bladder wall was getting thinner, and the cellular vacuolar degeneration and neutrophil infiltration were found in the model group. Whereas, compared with the model group, in the moxibustion group, the arrangement of transitional epithelial cells was clear and continuous in layers, the cellular vacuolar degeneration was mild and the infiltration presented in a small amount of neutrophil granulocytes. Compared with the sham-operation group, in the model group, the BBB score was reduced (P<0.01), the maximum bladder capacity and bladder compliance were increased (P<0.01), and the protein expression levels of GRP78, ATF4 and Caspase-12, as well as mRNA expressions were all increased (P<0.01). In comparison with the model group, in the moxibustion group, BBB score was increased (P<0.01), the maximum bladder capacity and bladder compliance were decreased (P<0.01), and the protein and mRNA expression levels of GRP78, ATF4 and Caspase-12 were all decreased (P<0.01).@*CONCLUSION@#Moxibustion at the "oppositely-located points" improves the urination function, alleviate urine retention in neurogenic bladder rats after spinal cord injury. The underlying mechanism may be related to the down-regulation of the expressions of GRP78, ATF4 and Caspase-12 in the endoplasmic reticulum stress pathway of the bladder tissues, and thus to alleviate the apoptosis of bladder tissue.

Effects of N-acetylcysteine on endoplasmic reticulum stress and oxidative stress in cerebral micro-vascular endothelial cells / 中华行为医学与脑科学杂志

Objective:To investigate the effect of N-acetylcysteine (NAC) on endoplasmic reticulum stress (ERS) and oxidative stress(OS) induced by tunicamycin (Tm) and its mechanism.Methods:Mouse derived brain microvascular endothelial cells cultured in vitro were divided into control group (normal cell culture), TM group (cells were intervened with 5 μg/mL Tm for 24 h), NAC + TM group (cells were pretreated with 1 mmol/L NAC for 1 h, then were intervened with 5 μg/mL Tm for 24 h) and NAC group (cells were intervened with 1 mmol/L NAC for 24 h) according to different intervention methods.CCK-8 and FITC-Annexin V/PI were used to detect the survival rate and apoptosis rate of cells.Western blot was used to detect the expression of GRP78、CHOP、p-eNOS and caspase-12 protein. Laser confocal microcopy was used to detect the expression of ROS, and colorimetry was used to detect the activity of MDA and SOD.Results:There were significant differences in apoptosis rate and survival rate among the four groups ( F=62.57, 35.00, both P<0.05). The apoptosis rate of TM group ((25.49±1.55)%) was higher than that of Control group ((13.76±1.48)%)( P<0.01), while the apoptosis rate of NAC+ TM group ((17.65±1.00)%) was lower than that of TM group ( P<0.01). The survival rate of TM group ((66.33±5.69)%) was lower than that of Control group ((100.00±2.12)%)( P<0.01), while the survival rate of NAC+ TM group ((85.67±4.04)%) was higher than that of TM group ( P<0.01). Western blot showed that there were significant differences in the expression levels of GRP78、CHOP and p-eNOS among the four groups ( F=32.39, 68.66, 13.12, all P<0.01). The expression levels of GRP78 and CHOP protein in TM group were higher than those of Control group (both P<0.05), while the expression level of p-eNOS was lower than that of Control group ( P<0.01). The expression levels of GRP78 and CHOP protein in NAC+ TM group were lower than those of TM group (both P<0.05), while the expression level of p-eNOS was higher than that of TM group ( P<0.01). There was no significant difference in the expression level of caspase-12 protein among the four groups ( F=0.33, P>0.05). Laser confocal showed that there was significant difference in the average fluorescence intensity of ROS among the four groups ( F=77.66, P<0.01). The average fluorescence intensity of ROS in TM group (32.67±1.53) was higher than that in Control group (12.67±2.08) and NAC+ TM group (18.33±1.53) (both P<0.01). Colorimetry showed that there were significant differences in the activity of SOD and the concentration of MDA among the four groups ( F=40.53, 34.99, both P<0.01). The results of colorimetry showed that the activity of SOD in TM group((41.60±1.53)U/mg) was lower than that in Control group((65.39±4.60)U/mg) and NAC+ TM group((58.72±1.64)U/mg)(both P<0.01). The concentration of MDA in TM((2.27±0.11)μmol/mg) group was higher than that in Control group((1.39±0.13)μmol/mg) and NAC+ TM group((1.44±0.11)μmol/mg) (both P<0.01). Conclusion:NAC can reduce Tm-induced apoptosis of cerebral micro-vascular endothelial cells, which may be related to its inhibition of ERS/ OS-related pathways.

The role of podocyte autophagy and endoplasmic reticulum stress in diabetic kidney disease / 中华危重病急救医学

Diabetic kidney disease (DKD) is one of the serious complications of diabetes mellitus, and it has become the leading cause of chronic renal failure in China. Podocytes are highly differentiated epithelial cells and are the important part of the glomerular filtration barrier. Apoptosis and shedding of podocytes, foot process fusion and decreased expression of slit membrane proteins can lead to proteinuria, which in turn affects the progression of DKD. Autophagy is an important process for eukaryotic cells to degrade cytoplasmic proteins and organelles,the increase of autophagy level helps to reduce podocytes damage. Endoplasmic reticulum stress (ERS) is the accumulation of misfolded proteins in cells. It allows the cells into stress state, and may be able to regulate cell damage in both directions. Autophagy and ERS are regulated by multiple signaling pathways and are considered to be closely related to the occurrence and development of DKD. This article explained some pathways and the role of podocyte autophagy and ERS in DKD, and the interaction between podocyte autophagy and ERS, which providing some potential targets for the treatment of DKD by interfering with podocyte autophagy and ERS.