Yinchenhao decoction attenuates obstructive jaundice-induced liver injury and hepatocyte apoptosis by suppressing protein kinase RNA-like endoplasmic reticulum kinase-induced pathway

BACKGROUND Chronic biliary obstruction results in ischemia and hypoxia of hepatocytes,and leads to apoptosis.Apoptosis is very important in regulating the homeostasis of the hepatobiliary system.Endoplasmic reticulum(ER)stress is one of the signaling pathways that induce apoptosis.Moreover,the protein kinase RNA-like endoplasmic reticulum kinase(PERK)-induced apoptotic pathway is the main way;but its role in liver injury remains unclear.Yinchenhao decoction(YCHD)is a traditional Chinese medicine formula that alleviates liver injury and apoptosis,yet its mechanism is unknown.We undertook this study to investigate the effects of YCHD on the expression of ER stress proteins and hepatocyte apoptosis in rats with obstructive jaundice(OJ).AIM To investigate whether YCHD can attenuate OJ-induced liver injury and hepatocyte apoptosis by inhibiting the PERK-CCAAT/enhancer-binding protein homologous protein(CHOP)-growth arrest and DNA damage-inducible protein 34(GADD34)pathway and B cell lymphoma/leukemia-2 related X protein(Bax)/B cell lymphoma/leukemia-2(Bcl-2)ratio.METHODS For in vivo experiments,30 rats were divided into three groups:control group,OJ model group,and YCHD-treated group.Blood was collected to detect the indicators of liver function,and liver tissues were used for histological analysis.For in vitro experiments,30 rats were divided into three groups:G1,G2,and G3.The rats in group G1 had their bile duct exposed without ligation,the rats in group G2 underwent total bile duct ligation,and the rats in group G3 were given a gavage of YCHD.According to the serum pharmacology,serum was extracted and centrifuged from the rat blood to cultivate the BRL-3A cells.Terminal deoxynucleotidyl transferase mediated dUTP nick end-labelling(TUNEL)assay was used to detect BRL-3A hepatocyte apoptosis.Alanine aminotransferase(ALT)and aspartate transaminase(AST)levels in the medium were detected.Western blot and quantitative real-time polymerase chain reaction(qRT-PCR)analyses were used to detect protein and gene expression levels of PERK,CHOP,GADD34,Bax,and Bcl-2 in the liver tissues and BRL-3A cells.RESULTS Biochemical assays and haematoxylin and eosin staining suggested severe liver function injury and liver tissue structure damage in the OJ model group.The TUNEL assay showed that massive BRL-3A rat hepatocyte apoptosis was induced by OJ.Elevated ALT and AST levels in the medium also demonstrated that hepatocytes could be destroyed by OJ.Western blot or qRT-PCR analyses showed that the protein and mRNA expression levels of PERK,CHOP,and GADD34 were significantly increased both in the rat liver tissue and BRL-3A rat hepatocytes by OJ.The Bax and Bcl-2 levels were increased,and the Bax/Bcl-2 ratio was also increased.When YCHD was used,the PERK,CHOP,GADD34,and Bax levels quickly decreased,while the Bcl-2 levels increased,and the Bax/Bcl-2 ratio decreased.CONCLUSION OJ-induced liver injury and hepatocyte apoptosis are associated with the activation of the PERK-CHOP-GADD34 pathway and increased Bax/Bcl-2 ratio.YCHD can attenuate these changes.

Prostaglandin E1 protects hepatocytes against endoplasmic reticulum stress-induced apoptosis via protein kinase A-dependent induction of glucose-regulated protein 78 expression

AIM To investigate the protective effect of prostaglandin E1(PGE1) against endoplasmic reticulum(ER) stressinduced hepatocyte apoptosis, and to explore its underlying mechanisms.METHODS Thapsigargin(TG) was used to induce ER stress in the human hepatic cell line L02 and hepatocarcinomaderived cell line Hep G2. To evaluate the effects of PGE1 on TG-induced apoptosis, PGE1 was used an hour prior to TG treatment. Activation of unfolded protein response signaling pathways were detected by western blotting and quantitative real-time RTPCR. Apoptotic index and cell viability of L02 cells and Hep G2 cells were determined with flow cytometry and MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2 H-tetrazolium] assay. RESULTS Pretreatment with 1 μmol/L PGE1 protected against TG-induced apoptosis in both L02 cells and Hep G2 cells. PGE1 enhanced the TG-induced expression of C/EBP homologous protein(CHOP), glucose-regulated protein(GRP) 78 and spliced X box-binding protein 1 at 6 h. However, it attenuated their expressions after 24 h. PGE1 alone induced protein and m RNA expressions of GRP78; PGE1 also induced protein expression of DNA damage-inducible gene 34 and inhibited the expressions of phospho-PKR-like ER kinase, phosphoeukaryotic initiation factor 2α and CHOP. Treatment with protein kinase A(PKA)-inhibitor H89 or KT5720 blocked PGE1-induced up-regulation of GRP78. Further, the cytoprotective effect of PGE1 on hepatocytes was not observed after blockade of GRP78 expression by H89 or small interfering RNA specifically targeted against human GRP78.CONCLUSION Our study demonstrates that PGE1 protects against ER stress-induced hepatocyte apoptosis via PKA pathwaydependent induction of GRP78 expression.

1-methyl-4-phenylpyridinium ion induces endoplasmic reticulum stress through glycogen synthase kinase-3 beta activation in PC12 cells

1-methyl-4-phenylpyridinium ion （MPP^＋） induces endoplasmic reticulum stress and activates caspase-12 in PC12 cells, leading to neuronal apoptosis. However, the underlying molecular mechanism remains unknown. The present study investigated the regulatory effects of nerve growth factor （Akt activator） and lithium chloride （glycogen synthase kinase-3β inhibitor） on the endoplasmic reticulum stress signaling pathway. The results revealed that MPP＋ induced expression of Bip and C/EBP homologous protein. The upregulation of Bip and C/EBP homologous protein, as well as the decreased pro-caspase-12 level induced by MPP^＋ were inhibited by pretreatment of the nerve growth factor or lithium chloride. These results suggest that the phosphatidylinositol 3 kinase-Aktglycogen synthase kinase-3β pathway is involved in MPP-induced endoplasmic reticulum stress.

Expression of casein kinase genes in glioma cell line U87: Effect of hypoxia and glucose or glutamine deprivation

The endoplasmic reticulum-nuclei-1 (ERN1) sensing and signaling enzyme mediates a set of complex intracellular signaling events known as the unfolded protein response. We have studied the effect of hypoxia and ischemic conditions (glucose or glutamine deprivation) on the expression of several casein kinase-1 and -2 genes in glioma U87 cells and its subline with suppressed function of ERN1. It was shown that blockade of ERN1, the key endoplasmic reticulum stress sensor, leads to an increase in the expression levels of casein kinase-1G2, -1E, -2B and NUCKS1 mRNA, but suppresses casein kinase-1A1, -1D and -2A1. Moreover, the expression levels of casein kinase-1A1, -1D and 1G3 as well as casein kinase-2A1 and -2A2 mRNAs are significantly increased under glutamine dep- rivation conditions both in control and ERN1- deficient glioma cells. At the same time, casein kinase-1E, -2B and NUCKS1 mRNA expression levels are also increased under this condition, but only in cells with suppressed function of ERN1. The expression level of NUCKS1 mRNA, however, is decreased both in control glioma cells and in genetically modified cells, but casein kinase-1G2—only in control U87 cells. Cell exposure to glucose deprivation conditions enhances the expression levels of casein kinase- 1D, 1G3, -1E and -2A1 in both types of glioma cells used, but casein kinase-2B expression levels increase only in cells with suppressed function of ERN1. Hypoxia induces or suppresses the expression of most of the studied genes mainly in ERN1-knockdown cells only. Results of this study show that hypoxia as well as glutamine and glucose deprivation conditions change the expression level most of casein kinase genes and that these effects are dependent on ERN1 signaling enzyme function.

Neuroprotective effects of Activin A on endoplasmic reticulum stress-mediated apoptotic and autophagic PC12 cell death

Activin A, a member of the transforming growth factor-beta superfamily, plays a neuroprotective role in multiple neurological diseases. Endoplasmic reticulum（ER） stress-mediated apoptotic and autophagic cell death is implicated in a wide range of diseases, including cerebral ischemia and neurodegenerative diseases. Thapsigargin was used to induce PC12 cell death, and Activin A was used for intervention. Our results showed that Activin A significantly inhibited morphological changes in thapsigargin-induced apoptotic cells, and the expression of apoptosis-associated proteins [cleaved-caspase-12, C/EBP homologous protein（CHOP） and cleaved-caspase-3] and biomarkers of autophagy（Beclin-1 and light chain 3）, and downregulated the expression of thapsigargin-induced ER stress-associated proteins [inositol requiring enzyme-1（IRE1）, tumor necrosis factor receptor-associated factor 2（TRAF2）, apoptosis signal-regulating kinase 1（ASK1）, c-Jun N-terminal kinase（JNK） and p38]. The inhibition of thapsigargin-induced cell death was concentration-dependent. These findings suggest that administration of Activin A protects PC12 cells against ER stress-mediated apoptotic and autophagic cell death by inhibiting the activation of the IRE1-TRAF2-ASK1-JNK/p38 cascade.

Role of endoplasmic reticulum stress in the loss of retinal ganglion cells in diabetic retinopathy

Endoplasmic reticulum stress is closely involved in the early stage of diabetic retinopathy. In the present study, a streptozotocin-induced diabetic animal model was given an intraperitoneal injection of tauroursodeoxycholic acid. Results from immunofluorescent co-localization experiments showed that both caspase-12 protein and c-Jun N-terminal kinase 1 phosphorylation levels significantly in- creased, which was associated with retinal ganglion cell death in diabetic retinas. The C/ERB ho- mologous protein pathway directly contributed to glial reactivity, and was subsequently responsible for neuronal loss and vascular abnormalities in diabetic retinopathy. Our experimental findings in- dicate that endoplasmic reticulum stress plays an important role in diabetes-induced retinal neu- ronal loss and vascular abnormalities, and that inhibiting the activation of the endoplasmic reticulum stress pathway provides effective protection against diabetic retinopathy.

Neuroprotective role of edaravone and the effects of endoplasmic reticulum stress in an adult rat model of focal cerebral ischemia/reperfusion

BACKGROUND： Endoplasmic reticulum （ER） stress impairs ER functions and leads to the accumulation of unfolded or misfolded proteins in the ER lumen. ER stress-induced cell death plays an important role in cerebral ischemia. Edaravon （3-methyl-1-phenyl-2-pyrazolin-5-one） is a potent and novel scavenger of free radicals that inhibit delayed neuronal death, as demonstrated by in vitro and animal studies. However, its effect on ER stress and induced neuronal apoptosis in a rat model of brief middle cerebral artery occlusion remains unclear. OBJECTIVE： To explore the effects of edaravone on the expression of ER stress-related factors and neuronal apoptosis, based on the hypothesis that edaravone influences ER stress in a rat model of cerebral ischemia/reperfusion. DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Laboratory of Department of Neurology, Xiangya Hospital and the Department of Laboratory Animals, Xiangya Medical College, Central South University in China from June 2005 to May 2006. MATERIALS： Edaravone was purchased from Simcere Pharmaceutical Group, China. METHODS： A total of 216 adult, male, Sprague Dawley rats were randomly assigned to sham-surgery, model and edaravone groups, with 72 rats in each group, Brief middle cerebral artery occlusion was established in the model and edaravone groups. In addition, the edaravone group rats were injected with 3 mg/kg edaravone through the tail vein. MAIN OUTCOME MEASURES： RNA-dependent protein kinase-like endoplasmic reticulum eukaryotic translation initiation factor 2a kinase （PERK） and C/EBP homology protein （CHOP） mRNA expression in the ischemic parietal cortex was determined by reverse transcriptionpolymerase chain reaction; phosphorylated PERK and CHOP protein expression was detected by immunohistochemistry; neuronal apoptosis was detected by TdT-mediated-dUTP nick end labeling. RESULTS： Neurological deficit scores were significantly reduced in the edaravone group compared to the model group at 12, 24, and 72 hours following reperfusion （P〈 0.05）. In addition, PERK and CHOP mRNA as well as phosphorylated PERK and CHOP protein expression were significantly reduced in the edaravone group compared to the model group at 1,3, and 6 hours following reperfusion （P 〈 0.05, P 〈 0.01）. CHOP mRNA expression was decreased in the edaravone group compared to the model group at 3, 6, 12, and 24 hours following reperfusion （P〈 0.01）, while CHOP protein expression was less than the model group at 6, 12, and 24 hours following reperfusion （P 〈 0.05）. CONCLUSION： Edaravone treatment resulted in decreased PERK and CHOP expression following ischemia/reperfusion, as well as reduced neuronal apoptosis. Edaravone exhibited a neuroprotective role by inhibiting endoplasmic reticulum stress.

Neuroprotective effects of atorvastatin against cerebral ischemia/reperfusion injury through the inhibition of endoplasmic reticulum stress

Cerebral ischemia triggers secondary ischemia/reperfusion injury and endoplasmic reticulum stress initiates cell apoptosis. However, the regulatory mechanism of the signaling pathway remains unclear. We hypothesize that the regulatory mechanisms are mediated by the protein kinase-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α in the endoplasmic reticulum stress signaling pathway. To verify this hypothesis, we occluded the middle cerebral artery in rats to establish focal cerebral ischemia/reperfusion model. Results showed that the expression levels of protein kinase-like endoplasmic reticulum kinase and caspase-3, as well as the phosphorylation of eukaryotic initiation factor 2α, were increased after ischemia/reperfusion. Administration of atorvastatin decreased the expression of protein kinase-like endoplasmic reticulum kinase, caspase-3 and phosphorylated eukaryotic initiation factor 2α, reduced the infarct volume and improved ultrastructure in the rat brain. After salubrinal, the specific inhibitor of phosphorylated eukaryotic initiation factor 2α was given into the rats intragastrically, the expression levels of caspase-3 and phosphorylated eukaryotic initiation factor 2α in the were decreased, a reduction of the infarct volume and less ultrastructural damage were observed than the untreated, ischemic brain. However, salubrinal had no impact on the expression of protein kinase-like endoplasmic reticulum kinase. Experimental findings indicate that atorvastatin inhibits endoplasmic reticulum stress and exerts neuroprotective effects. The underlying mechanisms of attenuating ischemia/reperfusion injury are associated with the protein kinase-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α/caspase-3 pathway.

低浓度氟化钠对人牙髓细胞的成骨/成牙本质分化的影响

目的探讨低浓度氟化钠对人牙髓细胞(human dental pulp cells,hDPCs)成骨/成牙本质分化的影响。方法本研究已通过单位伦理委员会审查批准。原代培养hDPCs,采用MTT法检测不同浓度氟化钠对hDPCs增殖的影响;选取合适浓度的氟化钠加入成骨/成牙本质分化诱导培养液中,对hDPCs进行体外诱导,通过茜素红染色检测hDPCs成骨/成牙本质分化能力的变化,RT⁃qPCR检测分化相关基因的mRNA表达;同时通过RT⁃qPCR和Western blot检测hDPCs成骨/成牙本质分化过程中内质网应激相关基因的表达。结果低浓度氟化钠(0.1 mmol/L)在体外可刺激hDPCs增殖,高浓度氟化钠(5~10 mmol/L)可抑制hDPCs增殖(P<0.05)。选取0.1 mmol/L氟化钠体外混合成骨/成牙本质分化诱导培养后hDPCs的茜素红染色增加,成骨/成牙本质分化相关基因牙本质涎磷蛋白(dentin sialophosphoprotein,DSPP)、骨涎蛋白(bone sialoprotein,BSP)和骨钙蛋白(osteocalcin,OCN)mRNA表达水平升高(P<0.05)。同时在此过程中RT⁃qPCR检测出mRNA水平hDPCs内质网应激相关基因:剪切x盒结合蛋白1(splicing x⁃box binding protein⁃1,sXBP1)、葡萄糖调节蛋白78(glucose⁃regulated protein 78,GRP78)以及活化转录因子4(activating transcription factor 4,ATF4)表达升高(P<0.05);Western blot检测出氟化钠混合成骨/成牙本质分化培养后细胞磷酸化真核起始因子⁃2α(phosphorylated eukary⁃otic initiation factor⁃2α,p⁃eIF2α)、磷酸化蛋白激酶样内质网激酶(phosphorylated the RNA⁃activated protein kinase⁃like ER⁃resident kinase,p⁃PERK)和ATF4蛋白表达增加(P<0.05)。结论低剂量氟化钠促进人牙髓细胞的成骨/成牙本质分化并伴有内质网应激水平的升高。

The Role and Mechanism of Unfolded Protein Response Pathway in Tumor Drug Resistance

In the process of tumor proliferation and metastasis,tumor cells encounter hypoxia,low glucose,acidosis,and other stressful environments.These conditions prompt tumor cells to generate endoplasmic reticulum stress(ERS).As a signal mechanism that mitigates ERS in eukaryotic cells,the unfolded protein response(UPR)pathway can activate cells and tissues,regulating pathological activities in various cells,and maintaining ER homeostasis.It forms the most crucial adaptive and defensive mechanism for cells.However,under the continuous influence of chemotherapy drugs,the quantity of unfolded proteins and erroneous proteins produced by tumor cells significantly increases,surpassing the normal regulatory range of UPR.Consequently,ERS fails to function properly,fostering tumor cell proliferation and the development of drug resistance.This review delves into the study of three UPR pathways(PERK,IRE1,and ATF6),elucidating the mechanisms of drug resistance and research progress in the signal transduction pathway of UPR related to cancers.It provides a profound understanding of the role and relationship between UPR and anti-tumor drugs,offering a new direction for effective clinical treatment.

慢性疼痛中内质网应激机制的研究进展

慢性疼痛作为公共卫生难题,其发病机制复杂,涉及脊髓神经元兴奋、胶质细胞激活及受体活化等。药物治疗虽能缓解疼痛,但不良反应限制了其应用。研究表明,内质网应激在慢性疼痛中扮演关键角色,通过影响疼痛感受器敏感性、调控伤害信号传递、触发炎症反应及神经可塑性改变,加剧疼痛并促进其发展。本文综述了内质网蛋白激酶样内切割酶(PKR-like endoplasmic reticulum kinase,PERK)、内质网应激调节因子1α (inositol-requiring enzyme 1α, IRE1α)和激活转录因子6 (activating transcription factor 6, ATF6)等通路在内质网应激与慢性疼痛中的具体机制,旨在为其深入研究和临床应用提供科学支撑,并探讨尚未解决的问题及未来发展方向。

A novel mechanism of PHB2-mediated mitophagy participating in the development of Parkinson's disease

Endoplasmic reticulum stress and mitochondrial dysfunction play important roles in Parkinson s disease,but the regulato ry mechanism remains elusive.Prohibitin-2(PHB2)is a newly discove red autophagy receptor in the mitochondrial inner membrane,and its role in Parkinson’s disease remains unclear.Protein kinase R(PKR)-like endoplasmic reticulum kinase(PERK)is a factor that regulates cell fate during endoplasmic reticulum stress.Parkin is regulated by PERK and is a target of the unfolded protein response.It is unclear whether PERK regulates PHB2-mediated mitophagy thro ugh Parkin.In this study,we established a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced mouse model of Parkinson’s disease.We used adeno-associated virus to knockdown PHB2 expression.Our res ults showed that loss of dopaminergic neurons and motor deficits were aggravated in the MPTP-induced mouse model of Parkinson’s disease.Ove rexpression of PHB2 inhibited these abnormalities.We also established a 1-methyl-4-phenylpyridine(MPP+)-induced SH-SY5Y cell model of Parkinson’s disease.We found that ove rexpression of Parkin increased co-localization of PHB2 and microtubule-associated protein 1 light chain 3,and promoted mitophagy.In addition,MPP+regulated Parkin involvement in PHB2-mediated mitophagy through phosphorylation of PERK.These findings suggest that PHB2 participates in the development of Parkinson’s disease by intera cting with endoplasmic reticulum stress and Parkin.

基于糖原合成酶激酶-3β及内质网应激探讨Renalase抗肾脏纤维化的作用机制

目的 探讨糖原合成酶激酶-3β(GSK-3β)在Renalase抗肾脏纤维化过程中的作用及其可能的机制。方法 选用C57BL/6小鼠,予以下分组:(1)Sham+Ad-β-gal组;(2)Sham+Ad-Renalase组;(3)UUO+Ad-β-gal组;(4)UUO+Ad-Renalas组。观察GSK-3β表达的变化,其中UUO组为单侧输尿管结扎致肾脏纤维化模型组,Sham组为假手术对照组,Ad-Renalase为过表达Renalase腺病毒,Ad-β-gal为对照腺病毒。然后应用病毒转染技术上调(UUO+Ad-Renalase+AAV-GSK-3β组)及下调(UUO+Ad-Renalase+Ad-GSK-3β-RNAi组)GSK-3β后观察Renalase抗纤维化作用的变化。结果 与假手术(Sham)组相比,UUO组GSK-3β表达增加;与UUO+Ad-β-gal组相比,UUO+Ad-Renalase组纤维组织沉积减少、纤维化标志蛋白Col-Ⅰ和FN表达下降的同时GSK-3β表达下调;当上调GSK-3β后,Renalase抗纤维化作用被抵消,而当下调GSK-3β后,与UUO+Ad-Renalase组相比,UUO+Ad-Renalase+Ad-GSK-3β-RNAi组纤维化没有进一步改善。同时观察到与Sham组相比,UUO组内质网应激激活明显,过表达Renalase后,内质网应激被抑制。当加入内质网应激激动剂TM后,与UUO+Ad-Renalase组相比,UUO+Ad-Renalase+TM组纤维化加重,GSK-3β表达升高;但无论GSK-3β升高或者降低,内质网应激均无明显变化。结论 本研究证实在单侧输尿管结扎致肾脏纤维化过程中,Renalase通过抑制内质网应激下调GSK-3β表达从而延缓肾脏纤维化。

内质网应激介导巨噬细胞极化分子机制研究进展

内质网(ER)是维持细胞内Ca 2+稳态、折叠新合成的分泌蛋白和膜蛋白以及蛋白质翻译后修饰的重要细胞器。ER腔内错误折叠与未折叠蛋白聚集,可激活内质网应激(ERS),进而激活蛋白激酶R样内质网激酶(PERK)、需肌醇酶1α(IRE-1α)和活化转录因子6(ATF6)三个不同的下游信号通路影响细胞的存活、分化和表型转换。近年来研究表明ERS下游信号级联反应与诱导巨噬细胞向促炎性M1型极化(IFN-γ和LPS)和抗炎性M2型极化(IL-4和IL-10)的信号通路之间存在密切相互作用,但两者之间的具体分子机制错综复杂。文中总结了ERS介导巨噬细胞极化的主要机制,重点讨论了ERS的三个不同下游信号影响巨噬细胞极化的分子机制。

内质网应激头颈部鳞状细胞癌细胞通过外泌体miR⁃26a⁃5p调控PTEN/AKT通路促进巨噬细胞PD⁃L1表达

目的探讨内质网应激(endoplasmic reticulum stress,ERS)的头颈部鳞状细胞癌(head and neck squa⁃mous cell carcinoma,HNSCC)细胞分泌的外泌体miRNA表达变化对巨噬细胞的影响机制。方法本研究已通过单位伦理委员会审查批准。通过蛋白质免疫印迹(Western blot,WB)和实时荧光定量PCR实验(RT⁃qPCR)检测HNSCC肿瘤组织及癌旁组织ERS相关蛋白,包括蛋白激酶R样内质网激酶(protein kinase R⁃like endoplas⁃mic reticulum kinase,PERK)和葡萄糖调节蛋白78(glucose⁃regulated protein 78,GRP78)的表达水平;以500 U/mL干扰素⁃γ(interferon⁃γ,IFN⁃γ)处理人喉鳞癌细胞系HN4细胞48 h,诱发HN4细胞产生内质网应激反应,收集HN4细胞分泌的外泌体,通过生物信息学分析鉴定外泌体的miRNA种类,预测miRNA的靶基因,将巨噬细胞转染miRNA、与收集的外泌体共培养、并敲低巨噬细胞PTEN表达,以WB和RT⁃qPCR检测外泌体miRNA调控的下游信号通路蛋白酪氨酸磷酸酶(phosphate and tension homology deleted on chromsome ten,PTEN)/蛋白激酶B(protein kinase B,AKT)及程序性死亡受体⁃1配体(programmed death receptor ligand 1,PD⁃L1)表达变化。结果HNSCC肿瘤组织相比癌旁组织ERS相关蛋白表达水平升高(P<0.05);RNA测序及实验验证表明ERS的HN4细胞分泌的外泌体miR⁃26a⁃5p表达上调(P<0.05);PTEN是miR⁃26a⁃5p的靶基因,miR⁃26a⁃5p升高巨噬细胞PD⁃L1表达水平,并下调PTEN表达(P<0.05);巨噬细胞与ERS外泌体共培养,miR⁃26a⁃5p和PD⁃L1表达上升,PTEN表达下降,p⁃AKT表达升高(P<0.05);敲低巨噬细胞PTEN表达,PD⁃L1表达上升(P<0.01)。结论ERS的HNSCC细胞通过外泌体miR⁃26a⁃5p调控PTEN/AKT通路及PD⁃L1的表达。

下调GSK3β通过抑制ITPR1-GRP75-VDAC1复合体功能减轻衰老肾小管上皮细胞缺氧/复氧损伤

目的探讨糖原合成酶激酶3β(GSK3β)对衰老小鼠原代肾小管上皮细胞(RTEC)缺氧/复氧(H/R)损伤的影响及其调控机制。方法将RTEC分成为Young组即正常生长的年轻RTEC、Old组即使用Etoposide诱导的衰老RTEC、Old+Ad-shNC+H/R组即使用Etoposide诱导衰老再转染腺病毒阴性对照(AdshNC)后进行H/R处理,Old+Ad-shGSK3β+H/R组即使用Etoposide诱导衰老后再转染靶向沉默GSK3β的短发夹RNA腺病毒(Ad-shGSK3β)后进行H/R处理。采用流式细胞术检测各组细胞凋亡水平和线粒体活性氧水平,采用免疫荧光染色法检测各组钙离子水平,采用蛋白质印迹法检测各组GSK3β、线粒体相关的内质网膜(MAM)相关蛋白肌醇1,4,5-三磷酸受体1(ITPR1)、电压依赖性阴离子通道1(VDAC1)、葡萄糖调节蛋白75(GRP75)表达及磷酸化水平,采用免疫共沉淀分析GSK3β与MAM相关蛋白的相互作用。结果与Young组比较,Old组细胞凋亡水平、线粒体活性氧水平及线粒体钙离子水平均较高;与Old组比较,Old+AdshNC+H/R组细胞凋亡水平、线粒体活性氧水平及线粒体钙离子水平均较高;与Old+Ad-shNC+H/R组比较,Old+Ad-shGSK3β+H/R组细胞凋亡水平、线粒体活性氧水平及线粒体钙离子水平均较低,差异均有统计学意义(均为P<0.05)。与Young组比较,Old组ITPR1、GRP75和GSK3β总蛋白表达增多,ITPR1和GRP75磷酸化水平升高,而VDAC1总蛋白和磷酸化水平均下降;与Old组比较,Old+Ad-shNC+H/R组GSK3β蛋白表达不变,ITPR1和GRP75总蛋白和磷酸化水平升高,VDAC1总蛋白表达不变,磷酸化水平增高;与Old+AdshNC+H/R组比较,Old+Ad-shGSK3β+H/R组GSK3β蛋白表达减少,ITPR1、GRP75和VDAC1总蛋白表达不变,磷酸化水平均下降。免疫共沉淀结果显示,GSK3β能够与ITPR1、GRP75和VDAC1蛋白发生相互作用。结论GSK3β在衰老RTEC中表达升高,抑制GSK3β表达能够降低ITPR1-GRP75-VDAC1复合体磷酸化水平,限制线粒体钙离子超负荷,保护线粒体功能,减少再灌注时细胞损伤。

内质网磷酸化修饰与肺结核感染后免疫反应的相关性研究

目的:观察内质网(ER)磷酸化修饰与肺结核感染后免疫反应的相关性。方法:在这项观察性研究中,我们招募了2021年1月至2023年6月间在本院接受治疗的成年结核病患者(n=19)和没有结核病症状并接触过的家庭接触者(健康接触者)(n=20)。所有患者在开始治疗前采集血样,并对这些血样进行了结核分枝杆菌特异性T细胞应答、细胞因子产生以及磷酸化的蛋白激酶样内质网激酶(PERK)和转录激活因子3(STAT3)表达的特征分析。结果:与健康接触者相比,结核病患者的PPD刺激的全血样品中IL-17、IL-22水平显著降低(P<0.05),和IL-6、IL-10水平显著增加(P<0.05)。与健康接触者相比,结核病患者的自发IL-10、IL-6和IFN-γ浓度更高(P<0.05)。在没有IL-6体外刺激的情况下,与健康接触者相比,结核病患者的CD4^(+)T细胞中的PERK水平显著更高(P<0.001)。加入IL-6导致健康接触者CD4^(+)T细胞中PERK水平较没有IL-6体外刺激健康接触者CD4^(+)T细胞显著增加(P<0.01)。与健康接触者相比,结核病患者的CD4^(+)T细胞具有更高的STAT3蛋白表达(P<0.05)。在所有供体和结核病患者中,CD4^(+)T细胞中PERK和STAT3表达之间呈显著正相关性(rho=0.571、0.503,均P<0.05)。仅在结核病患者中观察到CD40L/IL-2共表达T细胞和CD40L/IFN-γ共表达T细胞比例与STAT3表达呈负相关(rho=-0.481、-0.705,P<0.001)。结论:本研究提供了关于ER磷酸化修饰相关PERK/STAT3信号通路可能驱动结核病患者中的免疫抑制/抗T细胞反应的证据。

活性氧簇/p38丝裂原活化蛋白激酶级联反应对大鼠肾结石形成的影响及机制

目的探讨活性氧簇(ROS)/p38 MAPK级联反应对大鼠肾结石(KS)形成的影响及机制。方法50只SD大鼠随机分为对照组(正常喂养)、N-乙酰半胱氨酸(NAC)组(腹腔注射200 mg/kg NAC)、KS组(构建草酸钙KS模型)、KS+NAC组(构建草酸钙KS模型后腹腔注射200 mg/kg NAC)、KS+NAC+衣霉素(TM)组(构建草酸钙KS模型后腹腔注射200 mg/kg NAC与1 mg/kg TM),每组10只。给药结束4周后,测量大鼠24 h尿量与尿草酸(Ox),全自动生化仪检测血清肌酐(Cr)、尿素氮(BUN)、尿酸(UA)水平,HE染色和Von Kossa染色观察肾组织病理学变化及晶体沉积情况,TUNEL染色检测肾组织细胞凋亡,试剂盒测定肾组织超氧化物歧化酶(SOD)活性与丙二醛(MDA)含量,二氢乙锭(DHE)荧光探针检测肾组织ROS水平,免疫组织化学染色检测肾组织微管相关蛋白1轻链3B(LC3B)与葡萄糖调节蛋白78(GRP78)的表达,Western blotting测定肾组织p-p38 MAPK/p38 MAPK与LC3Ⅱ/LC3Ⅰ、Beclin1、GRP78和CCAAT/增强子结合蛋白同源蛋白(CHOP)水平。结果与KS组比较,KS+NAC组Ox、血清BUN、Cr、UA水平降低(P<0.05),肾小管扩张程度减轻,草酸钙结晶减少,TUNEL阳性细胞率减少(P<0.05),SOD活性升高,MDA含量减少(P<0.05),ROS水平降低(P<0.05),LC3B与GRP78阳性染色水平降低(P<0.05),p-p38 MAPK/p38 MAPK、LC3Ⅱ/LC3Ⅰ、Beclin1、GRP78及CHOP蛋白相对表达量均下调(P<0.05);与KS+NAC组比较,KS+NAC+TM组Ox、血清BUN、Cr、UA水平升高(P<0.05),肾小管扩张明显、草酸钙结晶增多,TUNEL阳性细胞率增加(P<0.05),SOD活性降低而MDA含量增加(P<0.05),ROS水平升高(P<0.05),LC3B与GRP78阳性染色水平升高(P<0.05),同时,p-p38 MAPK/p38 MAPK、LC3Ⅱ/LC3Ⅰ、Beclin1、GRP78、CHOP蛋白相对表达量均上调(P<0.05)。结论ROS/p38 MAPK级联反应参与大鼠KS形成,其作用与其激活内质网应激介导的自噬途径有关。

p38 MAPK通路调控自噬-内质网应激途径介导草酸钙肾结石形成的机制研究

目的 探究p38 MAPK通路对大鼠草酸钙(CaOx)肾结石形成的影响及其作用机制,为肾结石的治疗选择提供新的思路。方法 将40只大鼠分为对照组、SB203580组、CaOx组、SB203580+CaOx组,每组10只,CaOx组和SB203580+CaOx组以1%乙二醇与1%氯化铵配制的混合液灌胃建立CaOx肾结石模型,对照组和SB203580组以饮用水灌胃;造模后,SB203580组和SB203580+CaOx组腹腔注入剂量为5 mg/kg的SB203580,1次/d,连续注射14 d,对照组和CaOx组腹腔注入等体积生理盐水。称量大鼠肾脏质量并计算肾脏系数,全自动生化分析仪检测血清中血清尿素氮(BUN)和血肌酐(SCr)水平,酶联免疫吸附法(ELISA)测定尿液中中性粒细胞明胶酶相关脂质运载蛋白(NGAL)和肾损伤分子-1(KIM-1)水平,钙盐染色(Von Kossa)观察黑色晶体沉积及组织损伤情况,原位末端标记法(TUNEL)观察肾小管细胞凋亡情况,免疫组化染色检测自噬标记物表达,实时荧光定量聚合酶链反应(RT-qPCR)与蛋白质印迹(Western blotting)测定自噬及内质网应激途径相关分子表达。结果 与CaOx组比较,SB203580+CaOx组大鼠造模后体质量较高(P<0.05),肾脏质量、肾脏系数、BUN、SCr、NGAL、KIM-1水平均较低(P<0.05),肾脏组织病理损伤减轻且黑色结晶明显减少,TUNEL阳性细胞比例、LC3B与Beclin-1阳性表达面积占比、LC3B、Beclin-1、CHOP、GRP78 mRNA表达、LC3-Ⅱ/LC3-Ⅰ蛋白比值、Beclin-1、CHOP、GRP78蛋白表达均下调(P<0.05),p62 mRNA和蛋白表达上调(P<0.05)。结论 p38 MAPK通路参与大鼠CaOx肾结石形成,抑制该通路能够减少肾结石形成,该作用可能与其调控自噬-内质网应激有关。

Non-ionizing radiofrequency field induces unfolded protein response (UPR) in endoplasmic reticulum of mouse neuronal cells

Objective:To examine whether exposure of mouse neuronal cells to radiofrequency fields used in mobile communication devices can induce stress in endoplasmic reticulum(ER)and activate unfolded protein response(UPR).Methods:HT22 mouse hippocampus neuronal cells were exposed to continuous wave 900 MHz radiofrequency fields(RF)at 120μW/cm2 power intensity for 4 h/d for 5 consecutive days.The positive control cells were irradiated with 4 Gy of 60Coγ-rays at a dose rate of 0.5 Gy/min(GR).Twenty-four hours after the last exposure,cells were collected,and the expressions of sensor transmembrane proteins were detected using Western blot analysis.Results:The expression levels of Ire1,PERK,p-IRE1 and p-PERK,GRP78 and CHOP proteins were detected.There were no statistically significant differences in the expression levels of IRE1 and PERK proteins in control(CT),sham(SH)-,RF-and GR-exposed cells(P<0.05).The phosphorylated protein levels of p-IRE1 and p-PERK were significantly increased in cells exposed to RF and GR(P<0.05).The expression levels of GRP78 and CHOP were significantly increased in RF-and GR-exposed cells compared to CT and SH-exposed cells(P<0.05).Cells treated with 1μg/ml TM for 24 h showed significantly increased expression levels of GRP78 and CHOP proteins compared to controls(P<0.05).In the presence of 2 mmol/L PBA,TM-induced increased levels of GRP78 and CHOP proteins were reduced(P<0.05).Conclusions:The exposure of non-ionizing 900 MHz RF was able to cause stress in HT22 mouse neuronal cells and activated UPR in ER.Since UPR plays an important role in both cell survival(when UPR is mitigated)and apoptosis/death(under unresolvable stress conditions),further studies are required to determine the fate of the cells exposed to RF.