内质网应激在UCH-L1抑制剂诱导细胞凋亡中的作用

目的探讨内质网应激(ERS)在泛素羧基末端水解酶-1(UCH-L1)抑制剂导致的细胞损伤过程中的作用。方法采用50μmol/L的UCH-L1抑制剂处理人神经母细胞瘤SK-N-SH细胞。于处理前(对照组)和处理后不同时间点(2、4、6、12、24h),分别采用MTT比色法和Western blotting法检测细胞活力和ERS相关蛋白Bip/Grp78、Xbp-1、p-eIF2α及其促凋亡转录因子CHOP/Gadd153的表达。结果MTT比色法检测发现,50μmol/LUCH-L1抑制剂处理后4h,SK-N-SH细胞活力下降43.1%(P<0.05),且随处理时间的延长继续呈现显著下降趋势(P<0.01)。Western blotting检测显示,经50μmol/LUCH-L1抑制剂处理后,SK-N-SH细胞ERS相关蛋白Bip/Grp78、p-eIF2α和Xbp-1表达分别于处理后2、4、6h时显著增加;转录因子CHOP/Gadd153表达则在处理后2h和4h时略有增加,6h后达到高峰。结论在UCH-L1抑制剂诱导的细胞凋亡过程中,ERS是导致细胞损伤的路径之一。     

大鼠肝细胞线粒体周围内质网的体视觉分析

目的：D直细胞与其周围内质网的结构关系,方法：使用钻占石刀对肝组织进行连续切片,电镜下观察线粒体及其周围内质网的三维结构。对肝细胞细胞器,特别是线粒体及其周围内质网进行体视学分析。结果：几乎所有的线粒体都在内质网的包绕下工作,在整个肝细胞内有26％的RER的32％的SER贴附近线粒体的周围。结论：肝细胞线粒体通常在内质网在包绕下执行生理功能,二者是结构和功能紧密联系的整体。     

内质网应激在三种常见精神疾病中的研究进展

精神疾病常常表现为慢性病程,具有反复发作、慢性迁延及致残的特点,是严重影响人类健康的疾病之一.近年来精神疾病的患病率逐年升高,给社会带来了严重的疾病负担.但是,目前大部分精神疾病的发病机制尚未完全阐明.不断增加的研究证据表明,内质网应激(ERS)与精神疾病的发生发展有着密切联系,这些疾病以精神分裂症、双相障碍及抑郁障碍这三种常见精神疾病为代表.同时,研究也发现一些相关药物可能通过靶向ERS而发挥作用,提示ERS可能是精神疾病的潜在作用靶点.因此,未来深入探讨ERS在精神疾病中的具体作用机制,可为精神疾病的治疗提供新的思路.     

柴胡皂苷 A通过抑制内质网应激信号通路减轻乌头碱中毒大鼠脑组织细胞凋亡的机制分析

目的探讨柴胡皂苷 A对乌头碱中毒大鼠脑组织细胞凋亡、内质网应激信号通路的影响。方法自 2018年 10月至2019年 7月,选取购自武汉大学中南医院动物实验中心 SPF级健康雄性 SD大鼠 100只,随机数字表法分为对照组、模型组、干预组 1、干预组 2、干预组 3,每组各 20只。采取乌头碱( 20 μg/kg)尾静脉注射制备乌头碱中毒大鼠模型,干预组 1、干预组 2、干预组 3分别注射不同剂量的胡皂苷 A(5 mg·kg.1 ·d.1、10 mg·kg.1 ·d.1、20 mg·kg.1 ·d.1),模型组与对照组注射等剂量的生理盐水。观察各组大鼠干预后 12 h、24 h脑组织的凋亡情况以及内质网应激信号通路相关蛋白水平变化。结果干预 12 h、24 h后,型组超氧化物歧化酶( SOD)活性低于对照组,丙二醛( MDA)、肿瘤坏死因子 -α(TNF-α)、白细胞介素 -6(IL-6)水平高于对照组,模模型组 B细胞淋巴瘤 -2(Bcl-2)蛋白表达［( 0.29±0.05)、(0.18±0.0)］低于对照组［( 0.84±0.07)、(0.86±0.06)］模型组凋亡率［(34.24±2.11)%、(54.65±4.68)%］、 Bcl相关 X蛋白( Bax)蛋白表达［(1.25±0.06)、(1.39±0.05)］、 CCAAT/增强子结合,蛋白同源蛋白( CHOP)蛋白表达［(0.98±0.08)、(1.26±0.06)］、葡萄糖调节蛋白 78(GRP78)蛋白表达［(1.45±0.08)、(1.62±0.07)］高于对照组［凋亡率( 2.33±1.03)%、(2.42±1.15)%,Bax蛋白表达( 0.33±0.06)、(0.35±0.07), CHOP蛋白表达( 0.54±0.06)、(0.53±0.05), GRP78蛋白表达( 0.68±0.06)、(0.69±0.06)］差异有统计学意义( P<0.05)。干预 12 h、24 h后,干预组 1、干预组 2、干预组 3的 SOD活性、 Bcl-2蛋白表达高于模型组, MDA、T,NF-α、IL-6含量、凋亡率和 Bax、CHOP、GRP78蛋白表达低于模型组(P<0.05)。结论柴胡皂苷 A可以降低乌头碱中毒大鼠脑组织凋亡及脑组织氧化应激反应,可能与抑制内质网应激信号通路有关。     

Endoplasmic stress-inducing variants in carboxyl ester lipase and pancreatic cancer risk

BackgroundEndoplasmic reticulum (ER) stress-inducing variants in several pancreatic secretory enzymes have been associated with pancreatic disease. Multiple variants in CEL, encoding carboxyl ester lipase, are known to cause maturity-onset diabetes of the young (MODY8) but have not been implicated in pancreatic cancer risk.MethodsThe prevalence of ER stress-inducing variants in the CEL gene was compared among pancreatic cancer cases vs. controls. Variants were identified by next-generation sequencing and confirmed by Sanger sequencing. Variants of uncertain significance (VUS) were assessed for their effect on the secretion of CEL protein and variants with reduced protein secretion were evaluated to determine if they induced endoplasmic reticulum stress.ResultsER stress-inducing CEL variants were found in 34 of 986 cases with sporadic pancreatic ductal adenocarcinoma, and 21 of 1045 controls (P = 0.055). Most of the variants were either the CEL-HYB1 variant, the I488T variant, or the combined CEL-HYB1/I488T variant; one case had a MODY8 variant.ConclusionThis case/control analysis finds ER stress-inducing CEL variants are not associated with an increased likelihood of having pancreatic cancer.     

Chaperone therapy for molecular pathology in lysosomal diseases

In lysosomal diseases, enzyme deficiency is caused by misfolding of mutant enzyme protein with abnormal steric structure that is expressed by gene mutation. Chaperone therapy is a new molecular therapeutic approach primarily for lysosomal diseases. The misfolded mutant enzyme is digested rapidly or aggregated to induce endoplasmic reticulum stress. As a result, the catalytic activity is lost. The following sequence of events results in chaperone therapy to achieve correction of molecular pathology. An orally administered low molecular competitive inhibitor (chaperone) is absorbed into the bloodstream and reaches the target cells and tissues. The mutant enzyme is stabilized by the chaperone and subjected to normal enzyme protein folding (proteostasis). The first chaperone drug was developed for Fabry disease and is currently available in medical practice. At present three types of chaperones are available: competitive chaperone with enzyme inhibitory bioactivity (exogenous), non-competitive (or allosteric) chaperone without inhibitory bioactivity (exogenous), and molecular chaperone (heat shock protein; endogenous). The third endogenous chaperone would be directed to overexpression or activated by an exogenous low-molecular inducer. This new molecular therapeutic approach, utilizing the three types of chaperone, is expected to apply to a variety of diseases, genetic or non-genetic, and neurological or non-neurological, in addition to lysosomal diseases.     

miRNA-125b Signaling Ameliorates Liver Injury Against Obstructive Jaundice-Induced Excessive Fibrosis in Experimental Rats

PurposeMultiple pathways are involved in inducing liver fibrosis, which can damage the integrity of liver. Among them, miR-125b has been found to exert an activating action on hepatic stellate cells. Endoplasmic reticulum stress and autophagy lead to liver disorders. Here, we evaluated the therapeutic influence of miR-125b on the endoplasmic reticulum function in injured livers submitted to bile duct ligation.Materials and MethodsFor inducing injury, bile duct ligation was done on miR-125b transgenic rats (miR-125b-Tg) in wild type rats. The rat T-6 cells received transfection of miR-125b mimic and Tunicamycin. Protein expressions were observed by western blot analysis.ResultsCompared to wild type rats, liver-injured rats showed significant impairment of liver function as assessed by the total bilirubin levels. The miR-125b-Tg rats showed decrease in activity of aspartate transaminase and alanine transaminase. Liver tissues of miR-125b-Tg rats showed weaker fibrotic matrix formation. Upregulation of miR-125b decreased the bile duct ligation-mediated hepatic disturbances for the expressions of endoplasmic reticulum kinase, inositol-requiring kinase 1alpha, sXBP1, CHOP, LC3, p62, ULK, and caspase-3/-8/-9. T-6 cells transfected with miR-125b mimic and treated with Tunicamycin caused decrease in levels of cleaved caspase-3, sXBP1, CHOP, and LC3. The miR-125b signaling showed protective effect on the liver tissues subjected to injury and fibrosis histopathology.ConclusionThis study demonstrates a novel insight into the miR125b-mediated stabilization of endoplasmic reticulum integrity, which slows the progression of injury-induced hepatic deterioration.