茶多酚对卵巢癌SKOV3细胞自噬水平的影响及相关机制研究

目的研究茶多酚(EGCG)对人卵巢癌SKOV3细胞自噬水平的影响及相关机制。方法用EGCG处理SKOV3细胞,Western blot检测自噬相关蛋白LC3-II及蛋白激酶B(PKB)信号通路相应蛋白表达变化。结果 EGCG处理SKOV3细胞后,自噬相关蛋白LC3-II表达上调,并呈一定的时间浓度依赖性。EGCG处理SKOV3细胞后,AKT的磷酸化水平下调,AKT激活剂胰岛素样生长因子1(IGF-1)预处理后,自噬相关蛋白LC3-II高表达被抑制。结论 EGCG通过AKT介导的信号通路诱导SKOV3细胞自噬水平升高。     

Autophagy Activity in Pulmonary Metastatic Tumor Tissues from Colorectal Cancer: A Pilot Study

Purpose

Autophagy has been reported to be involved in treatment failure in tumor. We aimed to evaluate autophagy activity in tumor tissue and compare them between the recurrence and non-recurrence groups.

Materials and Methods

We analyzed expressions of autophagy-related proteins in tumor tissues which were obtained from pulmonary metastases of colorectal cancer patients by Western blot. We also analyzed autophagosomes by transmission electron microscopy.

Results

Tumor tissues from recurrence group showed increased levels of LC3B-II, decreased levels of p62/SQSTM1, and also a marked accumulation of autophagosomes compared with tissues from non-recurrence group.

Conclusion

The present study suggests that autophagy may be associated with treatment failure of metastatic colorectal cancer.     

Xenophagy in Helicobacter pylori‐ and Epstein–Barr virus‐induced gastric cancer

Helicobacter pylori and Epstein–Barr virus (EBV) account for roughly 80% and 10%, respectively, of gastric carcinomas worldwide. Autophagy is an evolutionarily conserved and intricately regulated cellular process that involves the sequestration of cytoplasmic proteins and organelles into double‐membrane autophagosomes that eventually fuse with lysosomes for degradation of the engulfed content. Emerging evidence indicates that xenophagy, a form of selective autophagy, plays a crucial role in the pathogenesis of H. pylori‐ and EBV‐induced gastric cancer. Xenophagy specifically recognizes intracellular H. pylori and EBV and physically targets these pathogens to the autophagosomal–lysosomal pathway for degradation. In this connection, H. pylori or EBV‐induced dysregulation of autophagy may be causally linked to gastric tumourigenesis and therefore can be exploited as therapeutic targets. This review will discuss how H. pylori and EBV infection activate autophagy and how these pathogens evade recognition and degradation by the autophagic pathway. Elucidating the molecular aspects of H. pylori‐ and EBV‐induced autophagy will help us better understand the pathogenesis of gastric cancer and promote the development of autophagy modulators as antimicrobial agents. Published by John Wiley & Sons, Ltd     

香草扶正合剂对Lewis肺癌模型小鼠癌细胞自噬的影响

[目的]探讨香草扶正合剂(Xiangcao Fuzheng Mixture,XCFZ)的抑瘤作用及其机制。[方法]建立Lewis肺癌小鼠移植瘤模型,随机分为模型组,XCFZ低、中、高剂量组,顺铂组(阳性对照组),并设置空白组。模型组以双蒸水0.2mL·d-1灌胃,XCFZ低、中、高剂量组分别以XCFZ低、中、高剂量0.2mL·d-1灌胃,XCFZ低、中、高剂量浓度分别为0.93g·mL-1、1.86g·mL-1、3.72g·mL-1;顺铂组以0.64mg·mL-1的顺铂溶液0.1mL·(2d)-1腹腔注射,同时以双蒸水0.2mL·d-1灌胃。每天固定时间给药,给药14d。称取小鼠体质量、瘤质量和去瘤后体质量,并计算抑瘤率,常规石蜡切片观察肿瘤组织病理改变,透射电镜观察瘤组织自噬小体,Western blot检测瘤组织自噬相关基因Beclin1、自噬相关蛋白5(autophagy related 5,Atg5)、微管相关蛋白1轻链3-β(microtubule associated protein 1 light chain 3-β,LC3b)蛋白表达水平,实时荧光定量PCR技术(Real-time quantitative PCR,RT-qPCR)检测瘤组织Beclin1、Atg5、LC3b、Unc-51样自噬激活激酶1(Unc-51 like autophagy activating kinase 1,ULK1)、B细胞淋巴瘤-2(B-cell lymphoma-2,Bcl-2)、Bcl-2相关X蛋白(Bcl-2 associated X protein,Bax)mRNA表达水平。[结果]与模型组比较,各给药组瘤质量降低(P＜0.01)。顺铂组抑瘤率最高,其次为XCFZ中剂量组。与模型组比较,XCFZ中剂量可升高小鼠去瘤后体质量(P＜0.05),增加肿瘤组织Atg5、Beclin1、LC3b蛋白及Atg5、Beclin1、LC3b、ULK1 mRNA表达水平,并升高Bax/Bcl-2 mRNA比值(P＜0.05,P＜0.01)。与顺铂组比较,XCFZ中剂量可升高小鼠去瘤后体质量(P＜0.01),增加肿瘤组织Atg5、LC3b蛋白及Beclin1 mRNA表达水平(P＜0.05,P＜0.01,P＜0.05)。[结论]XCFZ对肺癌小鼠模型肿瘤生长具有抑制作用,其抑瘤作用可能与自噬诱导相关;或与增加自噬相关蛋白Beclin1、Atg5表达,引发凋亡相关。     

自噬与神经性疼痛

神经性疼痛是由外周和中枢神经元突触可塑性介导的疼痛超敏反应,由于神经细胞受体、酶、离子 通道的复杂变化,神经性疼痛的治疗仍是全世界健康问题的重大挑战。神经系统中,自噬对神经元的生存和动态平衡是至关重要的,其所需基因的特异性消耗,足以导致神经元的死亡,自噬功能障碍是神经病理性疼痛的基础。该文讨论神经病理性疼痛发生过程中自噬的可能作用机制,以及可用于治疗神经病理性疼痛的潜在 靶点。     

Novel insights on the role of CD8+ T cells and cytotoxic responses during Helicobacter pylori infection

Helicobacter pylori chronically persists in 50% of the human population and causes serious gastric and duodenal pathologies in 15% of infected people. Research on the immune response to the infection has mainly focused on the induction of CD4+ T cell responses. Human studies emphasize the potential clinical relevance of CD8+ cytotoxic T lymphocytes, however this cell type has barely been reported in studies employing mouse or gerbil models. Traditionally characterized as an extracellular bacterium, H. pylori has been identified inside epithelial and immune cells. Similarly to other intracellular bacteria, H. pylori infection of macrophages can alter autophagy and phagosome processing. A novel animal model of H. pylori infection demonstrates for the first time the induction of cytotoxic CD8+ T cell responses in pigs and localization of intracellular H. pylori within lymphoid aggregates. Here, we discuss novel mechanisms of host-H. pylori interactions that could lead to the induction of cytotoxic responses.     

脑缺血再灌注不同时间对大鼠海马神经元自噬及PI3K/mTOR通路的影响

目的：探讨脑缺血再灌注不同时间对大鼠海马神经元自噬及PI3K/mTOR通路的影响。方法：72只大鼠随机分为假手术组、脑缺血再灌注组（分别再灌0、6、12、24、36 h）,每组12只。采用四血管阻断法建立大鼠全脑缺血再灌注损伤模型。神经功能缺损评分评价大鼠海马神经功能,HE染色检测大鼠海马神经细胞损伤,透射电镜下观察海马神经元内自噬小体,Western blot检测Beclin-1、LC3 II、p62、p-PI3K、p-Akt及p-mTOR蛋白表达。结果：与假手术组比,随着脑缺血再灌注的时间延长,脑缺血再灌注大鼠神经功能缺损评分、脑梗死面积、自噬小体数量均增加（均P＜0.05）;随着脑缺血再灌注的时间延长,大鼠海马组织自噬相关蛋白Beclin-1和LC3 II表达显著上调、p62表达下调（P＜0.05）;PI3K/mTOR通路相关蛋白p-PI3K、p-Akt、p-mTOR表达显著下调（P＜0.05）。结论：脑缺血再灌注可增强大鼠海马神经元自噬,抑制PI3K/mTOR信号通路。     

Pathophysiologic mechanisms in diabetic kidney disease: A focus on current and future therapeutic targets

Diabetic kidney disease (DKD) is the primary cause of chronic kidney disease around the globe and is one of the main complications in patients with type 1 and 2 diabetes. The standard treatment for DKD is drugs controlling hyperglycemia and high blood pressure. Renin angiotensin aldosterone system blockade and sodium glucose cotransporter 2 (SGLT2) inhibition have yielded promising results in DKD, but many diabetic patients on such treatments nevertheless continue to develop DKD, leading to kidney failure and cardiovascular comorbidities. New therapeutic options are urgently required. We review here the promising therapeutic avenues based on insights into the mechanisms of DKD that have recently emerged, including mineralocorticoid receptor antagonists, SGLT2 inhibitors, glucagon-like peptide-1 receptor agonist, endothelin receptor A inhibition, anti-inflammatory agents, autophagy activators and epigenetic remodelling. The involvement of several molecular mechanisms in DKD pathogenesis, together with the genetic and epigenetic variability of this condition, makes it difficult to target this heterogeneous patient population with a single drug. Personalized medicine, taking into account the genetic and mechanistic variability, may therefore improve renal and cardiovascular protection in diabetic patients with DKD.