不要低估血管平滑肌细胞在动脉粥样硬化斑块形成中的作用

血管内皮细胞、平滑肌细胞(SMC)和巨噬细胞共同参与动脉粥样硬化(As)斑块形成。近年研究表明,SMC来源的细胞占As斑块中细胞总数的70%以上。As斑块中的SMC通过自分泌细胞因子促进自身的增殖、迁移和炎症反应,通过旁分泌激活单核/巨噬细胞并将其募集到As损伤部位,同时通过其细胞膜表面表达的脂蛋白受体摄取脂质形成泡沫细胞。SMC在As斑块形成中扮演十分重要的角色,应进一步深化对SMC在As发生发展中的作用及作用机制的研究。     

巨噬细胞增殖和凋亡与动脉粥样硬化

动脉粥样硬化（As）是一种由动脉壁脂质沉积所引发的一种病理生理过程,与巨噬细胞介导的慢性炎性反应高度相关。As早期,巨噬细胞通过吞噬作用清除斑块中修饰脂蛋白、细胞碎片和死亡细胞,限制斑块生长。随着病程进展,斑块中巨噬细胞凋亡增多且清除功能下降,引起继发性细胞坏死和炎性反应,促成不稳定斑块形成。巨噬细胞增殖和凋亡与As发生发展密切相关。本文主要针对巨噬细胞增殖和凋亡对As发生发展的影响做一综述,为As防治提供理论依据。     

阿托伐他汀减轻巨噬细胞内质网应激及其介导的细胞凋亡

目的 探讨阿托伐他汀对7-酮胆固醇（7-KC）诱导的巨噬细胞内质网应激及细胞凋亡的影响。方法 AopE-/-小鼠左肾动脉和左颈总动脉联合部分结扎建立颈动脉易损斑块模型。采用HE染色方法观察斑块病理学改变,用免疫荧光结合激光扫描共聚焦显微镜技术检测斑块中内质网应激(ER stress)相关蛋白CHOP及磷酸化PERK（p-PERK）的表达。体外培养小鼠巨噬细胞RAW264.7,给予7-KC、H2O2或联合阿托伐他汀处理后,蛋白质免疫印迹方法（Western blot）测定ER stress相关蛋白CHOP、p-PERK 、XBP-1s及凋亡相关蛋白cleaved caspase-3的表达。结果 AopE-/-小鼠颈动脉易损斑块局部ER stress相关蛋白CHOP的表达及PERK磷酸化水平明显上调;7-KC可诱导小鼠巨噬细胞ER stress,进而诱导细胞凋亡;同时,氧化应激诱导剂H2O2也可通过诱导小鼠巨噬细胞ER stress介导细胞凋亡;而阿托伐他汀可抑制7-KC和H2O2诱导的巨噬细胞ER stress及其介导的细胞凋亡。结论 ER stress可能参与AS易损斑块的形成;阿托伐他汀可通过减少细胞内氧化应激的水平,减轻巨噬细胞ER stress,从而抑制细胞凋亡。     

凝集素样氧化低密度脂蛋白受体1对动脉粥样硬化血管细胞作用的研究进展

<正>动脉粥样硬化性血管疾病是一种主要累及大中肌性动脉的慢性疾病,其主要组织学特征是富含脂质的粥样斑块,其中胆固醇的低密度脂蛋白(LDL)进入易发生动脉粥样硬化的动脉内膜中,同时伴随单核细胞黏附于管腔的内皮细胞上。单核细胞受炎性内皮细胞释放的促炎因子趋化,而进入内膜下并分化为巨噬细胞~([1])。巨噬细胞吞噬氧化低密度脂蛋白(ox-LDL)后不能利用脂质,最终转变成泡沫细胞。巨噬细胞活化后,可释放促炎细胞因子、增加活性氧产生、促进氧化应激进展~([2])。巨噬细胞可通过一些清道夫受体(SR),     

巨噬细胞自噬在动脉粥样硬化中作用的研究进展

动脉粥样硬化(As)所致心脑血管疾病在全球的罹患率及致死率名居前列,严重威胁人类健康。血脂紊乱和氧化炎症等状态使血管内膜下巨噬细胞对胆固醇的多进少出,导致胞内积聚大量脂滴(LDs),演变为泡沫细胞,成为As斑块形成的中心环节。自噬是细胞一种保护性物质降解途径,基础性自噬有利于细胞的物质代谢平衡,但自噬缺陷或异常则使细胞清除能力下降,引发代谢应激、氧化、炎症及细胞死亡等,与As斑块发生发展密切相关。本文就巨噬细胞自噬在胆固醇代谢、炎症、氧化应激、凋亡等方面的作用作一综述。     

内质网应激与心血管疾病的研究进展

内质网(ER)是真核细胞最主要的膜性结构,是细胞内重要生理过程发生的关键细胞器。在多种内外因素的作用下,ER的稳态受到破坏,导致蛋白质加工运输受阻,未折叠蛋白或错误折叠蛋白在ER腔内聚集,形成内质网应激(ERS),并触发未折叠蛋白反应(UPR)。适度的ERS通过UPR信号通路减少蛋白质合成、促进蛋白质降解、增加协助蛋白质折叠的分子伴侣,最终缓解ER压力。但是,如果ERS过强或持续时间过长,超过细胞的自身调节能力时,UPR可启动细胞凋亡,亦可导致疾病。大量研究表明,ERS与多种心血管疾病(CVD)的发生发展密切相关。该综述主要阐述UPR在几种常见CVD中的研究进展和靶向UPR作为CVD的潜在治疗方法。     

细胞胆固醇流出通路研究进展

动脉粥样硬化的形成是动脉壁内泡沫细胞逐渐沉积的慢性炎症过程。循环中的氧化脂质特别是氧化型低密度脂蛋白胆固醇,以及一些体液因子、细胞因子均可引起单核巨噬细胞表面的清道夫受体表达增加,单核巨噬细胞吞噬大量含胆固醇的脂质,胆固醇流出减少,形成泡沫细胞,并在内皮下聚集,从而促进动脉粥样硬化的发生。     

神经导向因子Netrin-1调节单核巨噬细胞迁移与动脉粥样斑块关系的研究进展

动脉粥样硬化是动脉壁的一种慢性炎症性疾病,单核巨噬细胞在其发生发展中起着关键作用。动脉粥样斑块中单核巨噬细胞迁移能力受损,滞留于斑块内,增加了斑块不稳定性,加速动脉粥样硬化病变的进展。目前研究表明动脉粥样斑块中巨噬细胞分泌的神经导向因子Netrin-1通过与巨噬细胞表面相应受体结合,可以抑制巨噬细胞迁出斑块,促进动脉粥样硬化的进展。但在动脉粥样硬化形成初期,血管内皮细胞表达的Netrin-1却被发现对动脉粥样硬化起到保护作用。     

未折叠蛋白反应与2型糖尿病胰岛β细胞凋亡

内质网(ER)是细胞内蛋白质合成、折叠的重要场所,对应激极为敏感.多种因素均可导致ER功能发生改变,统称为内质网应激(ERS).ERS可以启动细胞内一系列适应性反应,即未折叠蛋白反应(UPR),以恢复细胞内环境的稳态.但持久和(或)剧烈的ERS将启动细胞凋亡程序.胰岛β细胞具有高度发达的ER,使其对2型糖尿病长期高血糖和游离脂肪酸所致的应激更为敏感.大量的研究表明,作为ERS组成部分之一的UPR在β细胞凋亡中起重要作用.现综述UPR导致2型糖尿病胰岛β细胞凋亡的具体机制.     

炎症反应在易损斑块中的作用及其机制研究进展

炎症反应在易损斑块的形成和进展中发挥重要作用,同时调控血管局部病变及全身炎症状态。一些促炎性细胞和炎症因子使斑块纤维帽的抗张强度降低,坏死脂质内核增大,血管机械稳定性丧失和斑块破裂;另一方面,炎症反应的激活和代谢紊乱也会引起内皮功能不全、斑块侵蚀进而导致血栓形成。该过程主要由巨噬细胞和淋巴细胞等多种炎症细胞参与,并受到多种因素调控,包括胆固醇结晶和脂质递质、血管剪切力、血管新生及斑块内出血等。此外,机体还存在一些抑炎性分子,能避免易损斑块向破裂或侵蚀进展。促炎和抗炎反应的平衡影响急性冠状动脉事件的发生。因此,以炎症反应为靶点,筛选出有易损斑块的患者并干预,或可减少急性冠状动脉事件的发生和改善预后,具有重要临床价值。     

The role of endoplasmic reticulum stress in the progression of atherosclerosis

Prolonged activation of the endoplasmic reticulum (ER) stress pathway known as the unfolded protein response (UPR) can lead to cell pathology and subsequent tissue dysfunction. There is now ample evidence that the UPR is chronically activated in atherosclerotic lesional cells, particularly advanced lesional macrophages and endothelial cells. The stressors in advanced lesions that can lead to prolonged activation of the UPR include oxidative stress, oxysterols, and high levels of intracellular cholesterol and saturated fatty acids. Importantly, these arterial wall stressors may be especially prominent in the settings of obesity, insulin resistance, and diabetes, all of which promote the clinical progression of atherosclerosis. In the case of macrophages, prolonged ER stress triggers apoptosis, which in turn leads to plaque necrosis if the apoptotic cells are not rapidly cleared. ER stress-induced endothelial cell apoptosis may also contribute to plaque progression. Another potentially important proatherogenic effect of prolonged ER stress is activation of inflammatory pathways in macrophages and, perhaps in response to atheroprone shear stress, endothelial cells. Although exciting work over the last decade has begun to shed light on the mechanisms and in vivo relevance of ER stress-driven atherosclerosis, much more work is needed to fully understand this area and to enable an informed approach to therapeutic translation.     

内质网应激与心血管疾病

内质网(endoplasmic reticulum,ER)是细胞内蛋白质折叠、Ca2+储存和脂质生物合成的重要部位。氧化应激、缺血、Ca2+稳态的失衡都可以引起ER内非折叠蛋白的聚集,通过ER内的分子伴侣激活非折叠蛋白反应（unfolded protein response,UPR)可促进细胞的生存,但是过度ER应激(endoplasmic reticulum stress,ERS)可以诱导凋亡信号起始,通过线粒体依赖或者非线粒体依赖途径导致细胞死亡。因此,近年来ER被认为是决定细胞生存与凋亡的重要器官。最近研究提示,ERS在多种心血管疾病的病生理机制中起着重要作用,包括心功能不全及缺血性心脏疾病等。对这些疾病分子机制的进一步认识,将有助于开发新的靶向药物并治疗疾病。本文将对ERS和其与心血管疾病的关系进行综述。     

Acinar cell injury induced by inadequate unfolded protein response in acute pancreatitis

Acute pancreatitis (AP) is an inflammatory disorder of pancreatic tissue initiated in injured acinar cells. Severe AP remains a significant challenge due to the lack of effective treatment. The widely-accepted autodigestion theory of AP is now facing challenges, since inhibiting protease activation has negligible effectiveness for AP treatment despite numerous efforts. Furthermore, accumulating evidence supports a new concept that malfunction of a self-protective mechanism, the unfolded protein response(UPR), is the driving force behind the pathogenesis of AP. The UPR is induced by endoplasmic reticulum(ER) stress, a disturbance frequently found in acinar cells, to prevent the aggravation of ER stress that can otherwise lead to cell injury. In addition, the UPR's signaling pathways control NFκB activation and autophagy flux, and these dysregulations cause acinar cell inflammatory injury in AP, but with poorly understood mechanisms. We therefore summarize the protective role of the UPR in AP, propose mechanistic models of how inadequate UPR could promote NFκB's pro-inflammatory activity and impair autophagy's protective function in acinar cells, and discuss its relevance to current AP treatment. We hope that insight provided in this review will help facilitate the research and management of AP.     

Melatonin and endoplasmic reticulum stress: relation to autophagy and apoptosis

Endoplasmic reticulum (ER) is a dynamic organelle that participates in a number of cellular functions by controlling lipid metabolism, calcium stores, and proteostasis. Under stressful situations, the ER environment is compromised, and protein maturation is impaired; this causes misfolded proteins to accumulate and a characteristic stress response named unfolded protein response (UPR). UPR protects cells from stress and contributes to cellular homeostasis re‐establishment; however, during prolonged ER stress, UPR activation promotes cell death. ER stressors can modulate autophagy which in turn, depending of the situation, induces cell survival or death. Interactions of different autophagy‐ and apoptosis‐related proteins and also common signaling pathways have been found, suggesting an interplay between these cellular processes, although their dynamic features are still unknown. A number of pathologies including metabolic, neurodegenerative and cardiovascular diseases, cancer, inflammation, and viral infections are associated with ER stress, leading to a growing interest in targeting components of the UPR as a therapeutic strategy. Melatonin has a variety of antioxidant, anti‐inflammatory, and antitumor effects. As such, it modulates apoptosis and autophagy in cancer cells, neurodegeneration and the development of liver diseases as well as other pathologies. Here, we review the effects of melatonin on the main ER stress mechanisms, focusing on its ability to regulate the autophagic and apoptotic processes. As the number of studies that have analyzed ER stress modulation by this indole remains limited, further research is necessary for a better understanding of the crosstalk between ER stress, autophagy, and apoptosis and to clearly delineate the mechanisms by which melatonin modulates these responses.     

内质网应激在肝脏疾病中的研究进展

内质网应激（ERS）是指由于某种原因使内质网中未折叠或错误折叠的蛋白质聚集导致内质网结构、功能紊乱的病理过程。适度的ERS通过激活未折叠蛋白质反应（UPR）对细胞起保护作用,而强烈或持久的ERS则会诱导细胞凋亡。近年来诸多研究显示EBS是多种肝脏疾病发生、发展过程中的重要环节。本文就ERS在肝脏疾病中的研究进展作一综述。     

Implications of ER Stress,the Unfolded Protein Response,and Pro‐ and Anti‐Apoptotic Protein Fingerprints in Human Monocyte‐Derived Dendritic Cells Treated With Alcohol

Background: Dendritic cells (DCs) are responsible for the activation of T cells and B cells. There is accumulating evidence that psychoactive substances such as alcohol can affect immune responses. We hypothesize that this occurs by modulating changes in proteins triggering a process known as unfolded protein response (UPR). This process protects cells from the toxic effects of misfolded proteins responsible for causing endoplasmic reticulum (ER) stress. Although much is known about ER stress, little is understood about the consequences of ethanol use on DC’s protein expression. Methods: In this study, we investigated alterations in the proteins of human monocyte‐derived dendritic cells (MDDC) treated with 0.1% of alcohol by two‐dimensional (2D) gel electrophoresis followed by liquid chromatography–tandem mass spectrometry, protein identification, and confirmation at the gene expression level by qRT‐PCR. Results: Proteomes of related samples demonstrated 32 differentially expressed proteins that had a 2‐fold or greater change in expression (18 spots were up‐regulated and 14 were down‐regulated), compared to the control cultures (untreated cells). Alcohol significantly changed the expression of several components of the UPR stress‐induced pathways that include chaperones, ER stress, antioxidant enzymes, proteases, alcohol dehydrogenase, cytoskeletal and apoptosis‐regulating proteins. qRT‐PCR analyses highlighted the enhanced expression of UPR and antioxidant genes that increased (18 hours) with alcohol treatment. Conclusion: Results of these analyses provide insights into alcohol mechanisms of regulating DC and suggest that alcohol induced specifically the UPR in DC. We speculate that activation of a UPR by alcohol may protect the DC from oxidant injury but may lead to the development of alcohol‐related diseases.     

Stress hypERactivation in the β-cell

In pancreatic β-cells, the endoplasmic reticulum (ER) is the crucial site for insulin biosynthesis, as this is where the protein-folding machinery for secretory proteins is localized. Perturbations to ER function of the β-cell, such as a high demand for insulin secretion, can lead to an imbalance in protein homeostasis and lead to ER stress. This stress can be mitigated by an adaptive, cellular response, the unfolded protein response (UPR). UPR activation is vital to the survival of β-cells, as these cells represent one of the most susceptible tissues for ER stress, due to their highly secretory function. However, in some cases, this response is not sufficient to relieve stress, leading to apoptosis and contributing to the pathogenesis of diabetes. Recent evidence shows that ER stress plays a significant role in both type 1 and type 2 diabetes. In this review, we outline the mechanisms of ER stress-mediated β-cell death and focus on the role of ER stress in various forms of diabetes, particularly a genetic form of diabetes called Wolfram syndrome.