细胞自噬的调控与自噬程序性死亡的研究进展

自噬(autophagy)是一种溶酶体依赖性降解途径,涉及细胞内长寿蛋白和受损伤细胞器的降解,其既是细胞保守的自我防御机制,又是一种程序性细胞死亡机制(PCD),与机体的多种疾病有密切关系.自噬具有独特的形态改变和特有的调控通路,自噬的调控涉及到多种机制、如翻译后修饰等.凋亡是研究最清楚的程序性细胞死亡机制,凋亡与细胞自噬程序性死亡之间存在着复杂的关系.对哺乳动物细胞自噬的分子调控机制,自噬程序性细胞死亡过程及其与凋亡的关系等方面进行探讨很有意义.     

细胞自噬的形态学特征和功能意义

目的 自噬是细胞受到刺激后吞噬自身的细胞质或细胞器,最终将吞噬物在溶酶体内降解的过程.按吞噬物进入溶酶体的途径,自噬可分为巨自噬、微自噬和分子伴侣介导的自噬3类.在巨自噬,自噬前体包裹细胞质或细胞器后形成自噬体,继而自噬体与溶酶体结合形成自噬溶酶体,自噬体内容物被降解.在微自噬,溶酶体膜凹陷,直接吞噬细胞质、细胞器或细胞核,形成自噬体,然后被溶酶体酶降解.分子伴侣介导的自噬是通过溶酶体膜的受体将细胞质内的蛋白质转运入溶酶体.自噬从酵母至哺乳动物细胞均很保守,对于耐受饥饿和缺血,清除衰老细胞器,清除细菌和异物,维持细胞活性和延长寿命等起着重要作用.自噬活动受自噬基因的调控,自噬基因缺失或功能障碍时可导致某些疾病的发生.深入认识自噬过程以及由此产生的自噬体等结构及其功能有助于探讨自噬对于人体生理和病理作用的机制.本文综述了自噬的形态学特征及其功能意义.     

自噬与免疫相关性自噬的研究进展

自噬是细胞内的长寿命蛋白和大分子蛋白成分利用溶酶体进行降解的过程,是真核细胞所特有的分解代谢途径,在能量代谢循环、促进细胞存活中都起到相当重要的作用。随着生命科学领域相互交叉学科的迅速发展,自噬在免疫、炎症、肿瘤等方面的地位也越来越多地受到人们的关注,而自噬与炎症感染、机体免疫及自身免疫反应之间的联系也逐渐成为了研究的焦点。研究发现,通过自噬诱导适度的机体免疫对稳定生物体的正常机能状态具有非常重要的生理意义。本文对自噬与免疫相关性自噬方面的研究进展进行综述。     

自噬的分子机制与病理生理意义

自噬是以细胞质空泡化为特征的溶酶体依赖性的降解途径。自噬可以降解胞质内受损的结构,并产生氨基酸、游离脂肪酸等物质以供蛋白质和能量的合成,使细胞能够适应缺氧和饥饿等环境。自噬的过程受一系列复杂的信号分子的调控,调控机制的失效与肿瘤、神经退行性疾病、衰老等有重要的联系。     

线粒体自噬在器官纤维化疾病中作用的研究进展

线粒体自噬是一种选择性降解细胞中损伤或多余线粒体的特异性自噬现象,使细胞在应激损伤时能够维持线粒体数量和质量的稳定,从而维持细胞的正常表型和功能。其分子机制途径较为复杂,主要涉及PINK1/Parkin途径、NIX和BNIP3、FUNDC1等。线粒体自噬的异常与多种疾病密切相关,而调节不同阶段线粒体自噬分子机制在疾病发展中的作用已被重视。现就近年线粒体自噬在多种器官纤维化病变中的研究进展综述如下。     

细胞自噬机制开启疾病治疗新途径

自噬是指细胞内细胞器和蛋白质等在溶酶体被降解及其降解产物被重新利用的过程。日本科学家大隅良典(Yoshinori Ohsumi)发现了15个自噬相关基因并阐述了自噬机制,获得2016年诺贝尔生理学与医学奖。他的开创性研究成果为探讨细胞自噬的生理和病理作用奠定了重要基础,并为通过调节细胞自噬治疗疾病开辟了新途径。自噬是一种普遍性细胞反应,正常情况下细胞自噬水平很低,受生理或病理性刺激后自噬水平显著升高。自噬相关基因缺失或自噬功能障碍时可导致某些疾病的发生。近来,人们试图通过激活或抑制细胞自噬预防和治疗自噬障碍相关性疾病。     

人巨细胞病毒感染与细胞自噬的关系

人巨细胞病毒与宿主共同进化的漫长过程中,为促进自身的增殖和感染,HCMV也进化出多种策略利用或抵消自噬的影响。自噬是进化上高度保守的细胞降解途径,通过回收细胞质、细胞器和蛋白质以维持细胞内稳态。同时它也可以作为细胞防御机制,直接包裹降解病原体或通过促进先天性和适应性免疫以对抗多种病原体的侵袭。本文将对近年来有关HCMV与自噬关系的研究作一综述。     

肾癌中细胞自噬的作用及自噬调节剂在肾癌治疗中的研究进展

细胞自噬是细胞体内的一种“自我吞噬”的分解代谢过程,通过将细胞内衰老的细胞器、受损蛋白和其他细胞成分包裹于自噬溶酶体中,从而实现能量供应和物质的循环利用。研究表明,细胞自噬与肾癌的发生、发展和转归密切相关,其不仅参与肾癌的发生,而且在肾癌发展的不同阶段分别起促进或抑制的双重作用。有针对性地靶向调节不同阶段肾癌的自噬水平可能是治疗肾癌的新策略。该文对细胞自噬的发生过程及其在肾癌发展进程中的作用进行综述,并探讨自噬调节剂(自噬抑制剂/诱导剂)在肾癌治疗中的潜在作用。     

miR-30a通过靶向调控Beclin-1、ATG5影响食管癌细胞自噬及增殖过程北大核心CSCD

目的:探究miR-30a通过靶向调控Beclin-1、ATG5表达对食管癌细胞自噬及增殖过程的影响。方法:靶基因预测、双荧光素酶报告实验验证miR-30a对Beclin-1、ATG5的靶向调控作用。GEO、Human Protein Atlas和GEPIA在线分析TCGA数据库和GTEx项目中食管癌组织及癌旁组织miR-30a、Beclin-1、ATG5表达、患者预后生存期。免疫组化检测45例食管癌及癌旁组织标本Beclin-1、ATG5表达,并分析Beclin-1、ATG5表达与患者临床病理参数的关系。采用脂质体LipofectamineTM3000将靶向Beclin-1、ATG5的miR-30a-mimic转染至Eca-109细胞,体外常规培养并分为3组:未转染组(control组)、转染无义RNA的阴性对照组(mimic NC组)、转染miR-30a-mimic的干扰组(miR-30a组)。MTT和克隆形成实验测定细胞增殖活力;qRT-PCR检测miR-30a、Beclin-1、ATG5 mRNA表达;划痕实验检测细胞迁移能力;Transwell小室实验检测细胞迁移和侵袭;Western blot检测Beclin-1、ATG5、LC3Ⅱ、p62蛋白表达。透射电镜观察细胞自噬泡形成情况。结果:生信分析结果显示,食管癌组织中miR-30a表达高于正常组织,Beclin-1、ATG5表达低于正常组织,且预后生存期与miR-30a表达呈负相关,与Beclin-1、ATG5表达呈正相关(P<0.05)。与control组和mimic NC组相比,miR-30a组细胞增殖、迁移和侵袭能力、p62蛋白表达明显升高,Beclin-1、ATG5、LC3Ⅱ表达、细胞自噬活力明显降低(P<0.05)。而control组与mimic NC组上述指标差异无统计学意义(P>0.05)。结论:miR-30a靶向调控Beclin-1、ATG5表达;Beclin-1、ATG5在食管癌组织和细胞中表达均降低,具有肿瘤抑制基因作用,可能通过抑制癌细胞增殖、迁移和侵袭、促进自噬发挥抑癌作用,为通过靶向调控自噬途径治疗食管癌提供了新思路。     

Expression of autophagy related proteins in invasive lobular carcinoma: comparison to invasive ductal carcinoma

The aim of this study is to compare the expression of autophagy related proteins in invasive lobular carcinoma (ILC) with that of autophagy related proteins in invasive ductal carcinoma (IDC), and to determinate its implication. Tissue microarray containing 114 ILC and 692 IDC was constructed, and immunohistochemistry was performed for autophagy related protein (beclin-1, LC3A, LC3B, p62) and Ki-67. No significant difference in expression of autophagy-related proteins between pleomorphic type (n = 12) and classic type (n = 102) of ILC was observed, whereas ILC and IDC showed distinguished features that tumoral beclin-1, stromal LC3A, tumoral LC3B, tumoral p62 were highly expressed in IDC and tumoral BNIP3 was highly expressed in ILC (P < 0.001). Beclin-1 expression was correlated with ER negativity (P = 0.016) and TNBC type (P = 0.024). BNIP3 expression was correlated with ER positivity (p = 0.040). Using multivariate Cox analysis, shorter overall survival was associated with tumoral beclin-1 positivity (hazard ratio: 21.19, 95% CI: 1.098-409.1, P = 0.043). In conclusion, ILC and IDC showed different expression pattern of autophagy-related proteins in tumor and stroma that demonstrated by higher expression of tumoral beclin-1, stromal LC3A, tumoral LC3B, tumoral p62 in IDC, and higher expression of tumoral BNIP3 in ILC.     

晚期食管癌患者食管内支架置入术的整体护理

目的：初步探讨整体护理对晚期食管癌患者食管内支架置入术后患者的临床效果。方法采用回顾性研究的方法,回顾2013年6月~2014年6月成功为20例晚期食管Ca患者在胃镜下行食管支架置入术后的整体护理。结果20例患者全部置入成功,术后2h可进流食,术后2w再进行吞咽苦难分级。未发生大出血穿孔等近期并发症,随访6~12个月,均未发生支架变形、移位及食物嵌塞等远期并发症。结论通过全方位的整体护理,晚期食管癌患者食管内支架置入术后能有效防治可能发生的并发症,值得推广应用。     

线粒体自噬对结直肠癌的影响

线粒体是细胞新陈代谢和生长发育过程中重要的细胞器,能够为细胞的生命活动提供能量和底物.当细胞处于恶劣环境时,线粒体通过自噬清除不需要或损伤的线粒体来减轻负荷,补充营养物质,适应恶劣的环境.线粒体自噬对维持细胞生存,抵御环境压力,衰老和凋亡过程起着重要作用.线粒体自噬的异常将导致多种疾病,如:神经退行性变、心脏病、糖尿病以及肿瘤等.随着人们生活习惯的改变,结直肠癌的发病率和死亡率逐年增加,成为中国最常见的恶性肿瘤之一,结直肠癌与线粒体自噬的研究也成为该领域的研究热点.明确线粒体自噬对结直肠癌的作用,有助于进一步了解结直肠癌的发病机制,并为结直肠癌的诊断和治疗提供新的方向和思路.因此,本文将着重阐述线粒体自噬的发生机制及其与结直肠癌的关系.     

食管癌穿孔的手术治疗

目的:对33例食管癌穿孔的患者的手术治疗进行疗效分析。方法:其中食管癌切除同时纵隔穿孔区域周围组织切除26例;不同方式肺切除4例,支气管膜部楔形切除1例,单纯探查2例。结果:30例近期疗效满意,生存期均在6月以上,1例手术后33天死亡。结论:食管癌穿孔的患者应首先手术治疗且疗效肯定。     

Expression of IAP family proteins in esophageal cancer

Members of the inhibitor of apoptosis protein (IAP) family, including survivin, have been reported to be expressed in many tumors. However, their expression in esophageal cancer has not been clarified completely. We investigated the expression of mRNA for IAP family proteins in samples from esophageal cancers and their adjacent normal mucosa tissues by real-time quantitative RT-PCR. The survivin expression in esophageal cancer was significantly higher than that in normal mucosa (P < 0.05). Other IAP family proteins including cIAP1, cIAP2, NAIP and XIAP tended to show stronger expression in cancer tissue than normal mucosa, although the differences were not significant. As to the histological type of tumor, poorly differentiated squamous cell carcinomas exhibited significantly higher level of expression than well-differentiated carcinomas (P < 0.05). The proportion of apoptotic cells of cancer tissue inversely correlated with the intensity of survivin expression (P < 0.05). Immunohistochemical staining demonstrated cytoplasmic as well as nuclear expression of survivin in esophageal cancer, and further, in situ hybridization analysis demonstrated cytoplasmic expression of mRNA for survivin. The results suggest that the expression of IAP family proteins, especially survivin, may be associated with the biological character of esophageal cancer, such as apoptosis.     

食管癌及癌旁组织中端粒酶活性检测及其意义

目的探讨食管癌及癌旁组织中端粒酶活性检测的意义.方法采用PCR技术为基础的TRAP法检测了39例食管癌及癌旁组织端粒酶活性.结果39例食管癌组织中34例端粒酶活性阳性,阳性率为87.2%,癌旁组织中3例阳性,阳性率为7.7%,9例食管良性组织中1例阳性,阳性率为11.1%.食管癌与相应癌旁组织和良性食管组织端粒酶阳性检测率相比,差异有显著性意义(p<0.01).伴有淋巴结转移的25例食管癌端粒酶阳性检测率为96.0%,显著高于未伴有淋巴结转移的阳性率(71.4%),两者差异有显著性意义(p<0.05).结论端粒酶激活与食管癌发生发展有关,对端粒酶活性进行检测对食管癌的诊断和判断预后有重要价值.     

CT判断食管癌外侵程度与手术病理结果对比研究

目的：探讨CT判断食管癌外侵程度与手术病理结果的一致性。方法：经手术病理证实的食管癌患者226例，与术前CT资料进行对比分析。结果：CT判断食管癌外侵敏感性80．6％，特异性97．9％，阳性预测值86．2％，阴性预测值96．9％，准确性95．5％，假阴性6例，假阳性5例，食管壁厚度＞2cm时肿瘤外侵率达92．0％。结论：CT判断食管癌外侵基本可靠，对治疗方案的制订有价值，对手术的难度估计有帮助，术前CT检查是必要的。     

The effect and mechanism of miR-210 in down-regulating the autophagy of lung cancer cells

This project aims to investigate the roles of miR-210 in autophagy of lung cancer cells and the related mechanism. The expressions of miR-210 and ATG7 in 30 cancer tissues and the adjacent tissues in patients with lung cancer were compared using RT-qPCR methods, Western Blot assay was carried out to test the expression of ATG7 in protein. Moreover, the dual luciferase reporter gene assay system was used to confirm ATG7 is a target gene of miR-210. Furthermore, lung cancer cell line A549 was transfected with either miR-210 mimics or inhibitors and RT-qPCR methods was used to detect the expression of miR-210 and ATG7. Next, MTT assay was used to examine the effect of miR-210 on the growth of the lung cancer cells, and finally, the expression of autophagy related genes, ATG7, LC3-II/LC3-I and Beclin-1 were detected by Western Blot and ICC assay. We observed that miR-210 was significantly increased and ATG7 was markedly decreased in cancer tissue of patients with lung cancer compared with normal tissue. Moreover, results of dual luciferase reporter assay indicated that ATG7 is a direct target of miR-210. Next, transfection of miR-210 mimics in lung cancer cells induced significant increase in cell proliferation, and transfection of miR-210 inhibitors lead to inhibited cell proliferation. Furthermore, over-expression of miR-210 induced marked decrease in the expression of ATG7, LC3-II/LC3-I and Beclin-1, while transfection of miR-210 inhibitors induced significant increase in the expression of ATG7, LC3-II/LC3-I and beclin-1. Our results suggested that miR-210 plays a great role in autophagy of lung cancer cell by targeting ATG7.