黄芪对高血压大鼠血管重构中内质网应激反应的影响

目的研究黄芪对高血压大鼠血管重构中内质网应激反应(ERS)的影响,并探讨其血管保护的分子机制。方法将140只大鼠分为对照组、模型组、干预组。采用腹主动脉狭窄术建立高血压大鼠模型,干预组大鼠腹腔注射黄芪注射液8 g/(kg·d)。各组术后1、2、4、6周时采用鼠尾动脉测压法测量大鼠血压,测量血管肌层厚度、Western blot检测CRT和caspase-12的表达、TUNEL法检测血管平滑肌细胞(VSMC)凋亡率。结果模型组术后VSMC形态改变,血压、动脉血管壁肌层厚度和VSMC凋亡率可时间依赖性增大,ERS分子CRT在术后1、2周表达显著升高,4、6周表达降低,而caspase-12分子2周以后表达才升高,且随时间推迟,这种高表达越显著。黄芪干预对比模型组,VSMC形态有一定改善,血压、血管壁肌层厚度和VSMC凋亡率均显著降低,6周时降低幅度最大,同时黄芪能抑制CRT的早期高表达,能抑制caspase-12的高表达,这种抑制作用随着时间的推迟越明显。结论黄芪对高血压大鼠有一定降压作用,可改善血管重构,其机制可能与其调节ERS保护性和促凋亡因子有关。     

疱疹病毒与内质网应激

内质网是分泌型蛋白和膜蛋白折叠及翻译后修饰的主要场所.病毒感染所引起的宿主细胞内环境的改变可使细胞或病毒的未折叠和/或错误折叠蛋白在内质网中大量聚集,使内质网处于生理功能紊乱的应激状态.为了缓解这种应激压力,细胞会启动未折叠蛋白反应(UPR),并通过一系列分子的信号转导维持内质网稳态;同时病毒也会通过对UPR的精密调控...     

Polystyrene nanoplastics aggravates lipopolysaccharide-induced apoptosis in mouse kidney cells by regulating IRE1/XBP1 endoplasmic reticulum stress pathway via oxidative stress

Nanoplastics (NPs) pollution poses a huge threat to the ecosystem and has become one of the environmental pollutants that have attracted much attention. There is increasing evidence that both oxidative stress and endoplasmic reticulum stress (ERS) are associated with polystyrene nanoplastics (PS-NPs) exposure. Lipopolysaccharide (LPS) has been shown to induce apoptotic damage in various tissues, but whether PS-NPs can aggravate LPS-induced apoptosis in mouse kidneys through oxidative stress-regulated inositol-requiring enzyme 1 (IRE1)/X-box binding protein 1 (XBP1) ERS pathway remains unclear. In this study, based on the establishment of in vitro and in vivo PS-NPs and LPS exposure models alone and in combination in mice and HEK293 cells, the effects and mechanisms of PS-NPs on LPS-induced renal cell apoptosis were investigated. The results showed that PS-NPs could aggravate LPS-induced apoptosis. PS-NPs/LPS can induce ERS through oxidative stress, activate the IRE1/XBP1 pathway, and promote the expression of apoptosis markers (Caspase-3 and Caspase-12). Kidney oxidative stress, ERS, and apoptosis in PS-NPs + LPS combined exposure group were more severe than those in the single exposure group. Interestingly, 4-phenylbutyric acid-treated HEK293 cells inhibited the expression of the IRE1/XBP1 ERS pathway and apoptotic factors in the PS-NPs + LPS combined exposure group. N-acetyl-L-cysteine effectively blocked the activation of the IRE1/XBP1 ERS pathway, suggesting that PS-NPs-induced oxidative stress is an early event that triggers ERS. Collectively, these results confirmed that PS-NPs aggravated LPS-induced apoptosis through the oxidative stress-induced IRE1/XBP1 ERS pathway. Our study provides new insights into the health threats of PS-NPs exposed to mammals and humans.     

Endoplasmic reticulum stress-mediated apoptosis is activated in vascular calcification

Apoptosis of vascular smooth muscle cells plays an important role in vascular calcification (VC). However, the potential mechanism remains poorly understood. Previous studies showed that apoptosis mediated by endoplasmic reticulum stress (ERS) participates in several diseases with VC. We prepared two rat models of calcification, vitamin D₃ plus nicotine (VDN) and rapid calcification (RC), to investigate whether ERS-mediated apoptosis is activated in VC. TUNEL staining and cleaved caspase 3 protein levels illustrated enhanced apoptosis in calcification groups. Western blot analysis revealed the ERS hallmarks GRP78 and GRP94 increased by 43.9% and 91.7%, respectively, in the VDN group and GRP78 elevated by 84.0% in the RC group (all P < 0.05) as compared with controls. Moreover, two molecules of ERS-induced apoptosis, caspase 12 and C/EBP homologous protein, were up-regulated nearly 3-fold (P < 0.05) in the VDN group and 10-fold (P < 0.01) in the RC group. Our results indicated that ERS-induced apoptosis may be involved in VC, and amelioration of ERS could be a novel strategy to prevent and treat the related diseases.     

内质网应激与糖尿病动脉粥样硬化

动脉粥样硬化是糖尿病常见的并发症,80%的糖尿病患者死于动脉粥样硬化。近年来内质网应激在糖尿病动脉粥样硬化发生、发展过程中的作用受到了广泛关注。本文就内质网应激及其在糖尿病促发动脉粥样硬化中的作用机制作一概述。     

内质网应激的细胞效应分子机制

内质网应激（endoplasmic reticulum stress,ERs）是内质网腔内错误折叠蛋白聚积的一种适应性反应,适度ERs通过激活未折叠蛋白反应起适应性的细胞保护作用,而过高和持久的ERs则通过诱导转录因子CHOP表达、激活caspase-12和c—Jun氨基末端激酶（JNK）等导致细胞凋亡。近年来,越来越多的研究提示内质网应激是神经退行性病变、2型糖尿病以及肥胖等疾病发生过程中的重要环节。对内质网应激的细胞效应分子机制进行综述。随着对ERs机制理解的深入,有可能会发现新的分子标志物或新的诊疗策略。     

Hydrogen alleviates hyperoxic acute lung injury related endoplasmic reticulum stress in rats through upregulation of SIRT1

Hyperoxic acute lung injury (HALI) is a major clinical problem for patients undergoing supplemental oxygen therapy. Currently in clinical settings there exist no effective means of prevention or treatment methods. Our previous study found that: hydrogen could reduce HALI, as well as oxidative stress. This research will further explore the mechanism underlying the protective effect of hydrogen on oxygen toxicity. Rats were randomly assigned into three experimental groups and were exposed in a oxygen chamber for 60 continuous hours: 100% balanced air (control); 100% oxygen (HALI); 100% oxygen with hydrogen treatment (HALI?+?HRS). We examined lung function by wet to dry ratio of lung, lung pleural effusion and cell apoptosis. We also detected endoplasmic reticulum stress (ERS) by examining the expression of CHOP, GRP78 and XBP1. We further investigated the role of Sirtuin 1 (SIRT1) in HALI, which contributes to cellular regulation including ERS, by examining its expression after hydrogen treatment with SIRT1 inhibitor. Hydrogen could significantly reduce HALI by reducing lung edema and apoptosis, inhibiting the elevating of ERS and increased SIRT1 expression. By inhibition of SIRT1 expression, the effect of hydrogen on prevention of HALI is significantly weakened, the inhibition of the ERS was also reversed. Our findings indicate that hydrogen could reduce HALI related ERS and the mechanism of hydrogen may be associated with upregulation of SIRT1, this study reveals the molecular mechanisms underlying the protective effect of hydrogen, which provides a new theoretical basis for clinical application of hydrogen.     

瑞舒伐他汀对同型半胱氨酸诱导的小鼠血管平滑肌细胞去分化和内质网应激的影响及其机制研究

目的：探讨瑞舒伐他汀（Rsv）对同型半胱氨酸（Hcy）诱导的小鼠血管平滑肌细胞（VSMCs）去分化及内质网应激（ERS）的影响。方法：Hcy和不同浓度瑞舒伐他汀（0.1,1.0,10 μmol/L）干预VSMCs,48 h后检测细胞骨架及表型蛋白（α-SMA）、钙调节蛋白（calponin）和骨桥蛋白（OPN）变化,并检测ERS相关mRNA （Herpud1,XBP1s和GRP78）在不同时间点的水平;再在Hcy及Rsv干预基础上给予ERS抑制剂4-苯基丁酸（4-PBA）或诱导剂衣霉素来调控细胞ERS水平,检测细胞增殖、迁移和表型蛋白表达,明确ERS在Rsv表型保护中的作用;在Hcy及Rsv干预基础上给予雷帕霉素靶蛋白（mTOR）-P70S6激酶（P70S6K）信号抑制剂雷帕霉素或激活剂磷脂酸,检测mTOR-P70S6K磷酸化和ERS水平,明确mTOR-P70S6通路在Rsv调控ERS中的作用。结果：与Hcy组相比,Hcy+中Rsv组（1 μmol/L）和Hcy+高Rsv组（10 μmol/L）细胞骨架极性明显增强,α-SMA、calponin表达升高,而OPN及ERS相关mRNA水平显著降低（P<0.01）;与Hcy组比较,Hcy+Rsv组和Hcy+4-PBA组增殖、迁移水平降低（P<0.01）,收缩蛋白表达增强,但衣霉素干预则逆转了Rsv的上述作用;与Hcy组相比,Hcy+Rsv组和Hcy+雷帕霉素组的mTOR-P70S6K磷酸化及ERS水平降低（P<0.01）,但磷脂酸干预抑制了Rsv对mTOR-P70S6K通路和ERS的影响。结论：瑞舒伐他汀可能通过mTOR-P70S6K通路抑制ERS水平,抑制Hcy诱导的小鼠VSMCs去分化改变。     

内质网应激与心血管疾病研究概述

内质网应激是继死亡受体信号途径和线粒体途径之后新近发现的一条细胞凋亡通路,适度的应激可通过未折叠蛋白反应(UPR)产生细胞保护作用,但当应激过强或长时间不缓解时则会触发CHOP、ASK1/JNK及Caspases等通路诱导细胞凋亡。近年来研究发现内质网应激参与多种心血管疾病的发生发展,通过对相关通路的干预可以产生心肌细胞的保护作用,这有望成为防治心脏疾病的新靶点。     

IGL-1 solution reduces endoplasmic reticulum stress and apoptosis in rat liver transplantation

Injury due to cold ischemia reperfusion (I/R) is a major cause of primary graft non-function following liver transplantation. We postulated that I/R-induced cellular damage during liver transplantation might affect the secretory pathway, particularly at the endoplasmic reticulum (ER). We examined the involvement of ER stress in organ preservation, and compared cold storage in University of Wisconsin (UW) solution and in Institute Georges Lopez-1 (IGL-1) solution. In one group of rats, livers were preserved in UW solution for 8 h at 4 °C, and then orthotopic liver transplantation was performed according to Kamada''s cuff technique. In another group, livers were preserved in IGL-1 solution. The effect of each preservation solution on the induction of ER stress, hepatic injury, mitochondrial damage and cell death was evaluated. As expected, we found increased ER stress after liver transplantation. IGL-1 solution significantly attenuated ER damage by reducing the activation of three pathways of unfolded protein response and their effector molecules caspase-12, C/EBP homologous protein-10, X-box-binding protein 1, tumor necrosis factor-associated factor 2 and eukaryotic translation initiation factor 2. This attenuation of ER stress was associated with a reduction in hepatic injury and cell death. Our results show that IGL-1 solution may be a useful means to circumvent excessive ER stress reactions associated with liver transplantation, and may optimize graft quality.