Paeoniflorin protects HUVECs from AGE-BSA-induced injury via an autophagic pathway by acting on the RAGE

The aim of our study was to investigate the protective effects of Paeoniflorin (PF) against injury induced by AGE-modified bovine serum albumin (AGE-BSA) in human umbilical vein endothelial cells (HUVECs), and to examine the underlying mechanisms of these effects. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to determine cell viability. Protein expression levels were determined by western blotting. For function-blocking experiments, we used small interfering RNA molecules (siRNA) for function-blocking experiments. At 6 h, we found that 100 μg/mL AGE-BSA reduced the viability of HUVECs. However, pretreatment with PF restored cell viability in a dose-dependent manner. AGE-BSA increased the levels of microtubule-associated protein light chain 3-II (LC3-II) and the receptor for advanced glycation end products (RAGE). Expression of p62 protein was also increased, but not at a statistically significant level. Pretreatment with PF further increased levels of LC3-II and RAGE, but reduced the expression of p62. In cells transfected with Atg5 and RAGE siRNA, cell viability and expression of LC3-II decreased in both the AGE-BSA and PF + AGE-BSA treatments. PF can protect HUVECs from AGE-BSA-induced injury by upregulating autophagy and promoting the completion of autophagy flux. RAGE plays an important role in this autophagic protection effect.     

The role of C/EBP-α expression in human liver and liver fibrosis and its relationship with autophagy

Aim: To investigate the expression of CCAAT enhancer binding protein-α (C/EBP-α) in normal human liver and liver fibrosis and its probable association with autophagy. Methods: Double label immunohistochemistry was used to detect the location of C/EBP-α in hepatocytes and hepatic stellate cells (HSCs). The expression of C/EBP-α, Atg5, and Atg6 was also evaluated by immunohistochemistry in paraffin sections of human liver. HSC-T6 cells were treated with rapamycin and 3-methyladenine (3MA) to induce or inhibit autophagy, and the expression of C/EBP-α protein was detected by Western blotting. Results: Double label immunohistochemistry showed that C/EBP-α was predominantly located in hepatocytes and that its expression was significantly decreased in fibrosis compared with normal liver. Atg5 expression was increased in fibrosis but was located primarily in liver septa and peri-vascular areas, which was consistent with the distribution of HSCs. In contrast, Atg6 was not expressed in normal or fibrotic liver. Treatment of HSC-T6 cells in culture with rapamycin or 3MA decreased or increased C/EBP-α expression, respectively, as shown by Western blotting. Conclusion: C/EBP-α was primarily expressed in hepatocytes in normal liver, but its expression decreased significantly in liver fibrosis. Autophagy might play a role in liver fibrosis through its association with C/EBP-α, but this hypothesis warrants further investigation.     

Beclin 1 and p62 expression in non-small cell lung cancer: relation with malignant behaviors and clinical outcome

Autophagy plays a complicated role in tumorigenesis in a variety of cancers. Recently, many studies report that some autophagy-related markers could be detected in several types of human tumors. However, fewer studies have been conducted to evaluate the relationship between autophagy and lung cancer, especially in non-small cell lung cancer (NSCLC). In this study, the expression levels of autophagy-related markers Beclin 1 and p62 were detected by Western blot analysis and cell immunofluorescence staining in three human NSCLC cell lines A549, H1299 and HCC827. Then, tissue microarray and immunohistochemical staining were used to determine Beclin 1 and p62 expression in 104 NSCLC specimens collected from patients. Beclin 1 and p62 were observed to primarily distribute in the cytoplasm of the cells. Beclin 1 was expressed more predominantly in male and heavy-smoker and its expression was significantly correlated with the differentiation and lymph node metastasis. p62 expression was negatively correlated with TNM stage and lymph node metastasis. Univariate Cox regression analysis revealed that low expression of Beclin 1 and high expression of p62 were significantly associated with shorter survival. Meanwhile, multivariate Cox regression analysis indicated that Beclin 1 and p62 were independent risk factors related to overall survival for patients with NSCLC. Collectively, our study suggests that Beclin 1 and p62 could serve as potential indicators for the prognosis of patients with NSCLC.     

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     

Mir-30a抑制自噬及上皮细胞间质化增强肺腺癌细胞对克唑替尼的敏感性

目的探索上调肺腺癌细胞中Mir-30a的表达水平能否增强细胞对克唑替尼的敏感性,观察细胞增殖率的变化及克唑替尼IC50等的变化,并探索相关的机制。方法使用Lipofectamine2000携带Mir-30a对H3122细胞进行瞬时转染,并与克唑替尼共同作用。将肺腺癌H3122细胞分为对照组、克唑替尼与联合组。MTT法检测各组细胞增殖率变化,Transwell检测细胞侵袭性。Western blot检测ALK、c-MET、Beclin-1、E-cadherin及Vimentin蛋白的表达。结果在H3122细胞中Mir-30a转染与克唑替尼共同作用较克唑替尼单独作用有更显著的细胞杀伤作用。转染后的细胞较单独应用克唑替尼组侵袭力减弱。转染与克唑替尼联合组Beclin1、ALK、c-MET及Vimentin的蛋白的表达有明显下降,E-cadherin稍有增强。结论 Mir-30a增强肺腺癌细胞对克唑替尼的敏感性,可能与过量表达的Mir-30a抑制癌细胞的自噬及上皮细胞间质化相关。     

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。