自噬与沉默信息调节因子蛋白家族对心肌缺血/再灌注的影响

背景自噬是一种细胞本体的降解过程.它以溶酶体的方式参与或老化非正常的细胞蛋白及细胞本身的降解.许多研究证实自噬水平在心肌缺血/再灌注(ischemia/reperfusion,I/R)中增高,但对于自噬在再灌注中的作用,现在争议较大.同时有研究证实新发现的与长寿相关的沉默信息调节因子蛋白(silent information regulator protein,Sirt)家族可能参与了自噬对I/R的调节.目的了解Sirt家族、自噬及I/R这三者间的联系.内容对自噬的基本过程,自噬的分子机制,自噬在心肌I/R中的作用,自噬与Sirt家族的关系作一综述.趋向促进对自噬的深入了解,期望对Sirt家族在心肌保护方面的作用提供新的认识.     

沉默信息调节蛋白1在心肌缺血/再灌注中的保护作用

背景 沉默信息调节蛋白1 (silent information regulator protein 1,Sirt1)是尼克酰胺腺嘌呤二核苷酸(nicotinamide adenine dinucleotide,NAD)依赖的第3类组蛋白/非组蛋白去乙酰酶,参与细胞内多种生物功能的调节.Sirt1不仅在抗衰老中发挥重要作用,同样在心肌缺血/再灌注( ischemia/reperfusion,I/R)时保护受损细胞.目的 对Sirt1在心肌I/R中的保护机制以及几种激活Sirt1活性的方法进行综述. 内容 Sirt1能使活性氧清除剂产生增加、抗心肌细胞凋亡、促进细胞内自噬、减轻炎症反应、促进胞内正常线粒体合成等而减轻I/R的心肌细胞损伤.通过多种方法提高I/R时Sirt1的活性,是减轻损伤的重要措施. 趋向 随着Sin1在心肌I/R中的作用机制不断被揭示,其将成为缓解心肌I/R损伤的重要靶点.     

Cbl suppresses B cell receptor-mediated phospholipase C (PLC)-gamma2 activation by regulating B cell linker protein-PLC-gamma2 binding

Accumulating evidence indicates that the Cbl protein plays a negative role in immune receptor signaling; however, the mode of Cbl action in B cell receptor (BCR) signaling still remains unclear. DT40 B cells deficient in Cbl showed enhanced BCR-mediated phospholipase C (PLC)-gamma2 activation, thereby leading to increased apoptosis. A possible explanation for the involvement of Cbl in PLC-gamma2 activation was provided by findings that Cbl interacts via its Src homology 2 (SH2) domain with B cell linker protein (BLNK) after BCR ligation. BLNK is a critical adaptor molecule for PLC-gamma2 tyrosine phosphorylation through its binding to the PLC-gamma2 SH2 domains. As a consequence of the interaction between Cbl and BLNK, the BCR-induced recruitment of PLC-gamma2 to BLNK and the subsequent PLC-gamma2 tyrosine phosphorylation were inhibited. Thus, our data suggest that Cbl negatively regulates the PLC-gamma2 pathway by inhibiting the association of PLC-gamma2 with BLNK.     

Differential gene expression identifies subgroups of renal cell carcinoma

Clear cell carcinoma of the kidney, the most common subtype of renal cell cancer, displays different biological behavior in different patients. This heterogeneity cannot be recognized by light microscopy. In this study, gene expression in 16 clear cell renal cell carcinoma samples and 17 non-malignant tissue types comprising 539 samples was determined using oligonucleotide microarrays representing approximately 40,000 known genes and ESTs. Differences in gene expression were quantified as the fold change in gene expression between the various sets of samples. A set of genes was identified that was overexpressed in the renal cell carcinoma samples compared with the normal kidney samples. Principle component analysis of the set of renal cell carcinomas using this set of genes overexpressed in renal cell cancer revealed the existence of 2 major subgroups among the renal carcinomas. A series of principle component analyses of the set of renal cell carcinomas using different gene sets composed of genes involved in different metabolic pathways also revealed the same 2 major subgroups of the renal cell cancers. Eisen clustering using the same genes also revealed the same 2 major renal cell cancer subsets. Review of the pathology suggested that these 2 subgroups differed in pathologic grade. Genes differentially expressed between the 2 renal cell cancer subsets were identified. Examination of gene expression in each renal cell cancer subset and the pool of renal cell carcinoma samples compared with that in 17 different normal tissues revealed genes specifically overexpressed in renal cell cancer compared with these normal tissues. The authors conclude that gene expression patterns may be useful in helping to further classify subtypes of renal cell carcinoma that may have clinical significance. In addition, the genes identified as overexpressed in each set of clear cell renal cell carcinomas compared with normal tissues may represent useful targets for therapy.     

SIRT1与眼科疾病的研究进展

沉默信息调节因子相关酶1(sirtuin type1,SIRT1)是一种细胞代谢辅酶NAD⁺依赖的Ⅲ类组蛋白去乙酰化酶,通过转录调控,参与基因转录、能量代谢以及细胞衰老过程的调节,具有延长生物寿命和延缓多种年龄相关性疾病发展的作用,在抗衰老研究领域备受关注。近年的研究显示SIRT1在眼科多种疾病的发病机制中占有重要的地位,尤其是眼表疾病、青光眼、白内障、葡萄膜炎以及眼底病等,针对SIRT1活性的促进可能成为眼科新型药物的治疗靶点。本文将对SIRT1与眼科疾病的研究报道进行综述。     

电针“内关”穴对心肌缺血大鼠心肌氯离子通道相关基因表达的影响

目的:观察电针"内关"穴对心肌缺血大鼠心肌氯离子通道调控基因表达的影响,探讨经穴效应特异性的作用机制。方法:SD大鼠随机分为正常对照组10只,模型组、内关穴组、列缺穴组、非经非穴组各15只。皮下注射异丙肾上腺素建立心肌缺血模型。内关穴组取"内关"穴,列缺穴组取"列缺"穴、非经非穴组取"天枢"与"神阙"连线中点进行电针治疗,每日治疗1次,治疗7d。Western blot法和Real time-PCR法分别检测心肌组织蛋白激酶C(PKC)和氯离子通道基因囊性纤维化跨膜传导调节因子(CFTR)及钙激活氯通道(CLCa 1)的基因表达。结果:与正常对照组比较,模型组大鼠心肌PKC、CLCa l、CFTR表达升高(P0.05)。与模型组比较,内关穴组、列缺穴组及非经非穴组大鼠心肌PKC表达明显下降(P0.05),内关穴组和列缺穴组与非经非穴组比较PKC表达下降(P0.05)。与模型组比较,内关穴组、列缺穴组及非经非穴组心肌CLCa l基因表达显著降低(P0.05),列缺穴组、非经非穴组与内关穴组比较显著升高(P0.05),列缺穴组与非经非穴组比较显著下降(P0.05)。与模型组比较,内关穴组、列缺穴组CFTR基因表达显著下降(P0.05),列缺穴组、非经非穴组与内关穴组比较显著升高(P0.05),而列缺穴组与非经非穴组比较显著下降(P0.05)。结论:电针不同穴位对心肌缺血大鼠心肌PKC、CFTR、CLCa 1的表达有不同的影响,"内关"穴具有特异性效应。     

片仔癀防治大鼠非酒精性脂肪肝的探讨

目的: 观察片仔癀对非酒精性脂肪肝模型大鼠的防治作用,并探讨其防治作用的相关机制。 方法: 将48只Wistar雄性大鼠随机平均分为正常组、模型组、舒降之辛伐他片组、片仔癀低、中、高剂量组6个组,采用高脂饲料制备大鼠非酒精性脂肪肝模型,同时分别灌服舒降之辛伐他片(0.003 g ·kg^-1 ·d^-1)和不同剂量的片仔癀(0.5,1,2 g ·kg^-1 ·d^-1)进行干预。实验4周后结束,收集标本用生化分析仪检测肝功能天门冬氨酸氨基转移酶(AST),丙氨酸氨基转移酶(ALT),白蛋白(Alb),总胆红素(TBIL),γ-谷氨酰胺转肽酶(γ-GT)和血脂胆固醇(TCH),甘油三酯(TG),低密度脂蛋白(LDL),高密度脂蛋白(HDL)水平,做肝脏组织病理学观察,并用RT-PCR检测法尼醇X受体(FXR),靶基因小异二聚体伴侣(SHP)和固醇调节元件结合蛋白-1c (SREBP-1c) mRNA表达情况。 结果: 与正常组比较,模型组AST,ALT,γ-GT水平明显升高,LDL明显升高(P<0.01),肝细胞脂肪变性,肝细胞坏死和炎症细胞浸润,FXR,SHP mRNA表达明显降低(P<0.01),SREBP-1c mRNA的表达升高;与模型组比较,片仔癀低、中剂量组能不同程度地降低AST,ALT,γ-GT水平(P<0.05,P<0.01);明显降低TG含量(P<0.05);能明显改善肝细胞脂肪变性,减少肝细胞坏死和炎症细胞浸润;提高FXR,SHP mRNA的表达,降低SREBP-1c mRNA的表达(P<0.05,P<0.01)。 结论: 片仔癀能够一定程度上改善脂肪肝的肝功能,降低血脂,其机制可能是通过FXR-SHP-SREBP-1c通路调节血脂起作用,其中以低、中剂量组疗效相对较好。     

Developmental programing of thirst and sodium appetite

Thirst and sodium appetite are the sensations responsible for the motivated behaviors of water and salt intake, respectively, and both are essential responses for the maintenance of hydromineral homeostasis in animals. These sensations and their related behaviors develop very early in the postnatal period in animals. Many studies have demonstrated several pre- and postnatal stimuli that are responsible for the developmental programing of thirst and sodium appetite and, consequently, the pattern of water and salt intake in adulthood in need-free or need-induced conditions. The literature systematically reports the involvement of dietary changes, hydromineral and cardiovascular challenges, renin–angiotensin system and steroid hormone disturbances, and lifestyle in these developmental factors. Therefore, this review will address how pre- and postnatal challenges can program lifelong thirst and sodium appetite in animals and humans, as well as which neuroendocrine substrates are involved. In addition, the possible epigenetic molecular mechanisms responsible for the developmental programing of drinking behavior, the clinical implications of hydromineral disturbances during pre- and postnatal periods, and the developmental origins of adult hydromineral behavior will be discussed.     

A multicenter,randomized, observation-controlled clinical trial to evaluate the efficacy and safety of thymalfasin adjuvant therapy in patients with HBV-related HCC after curative resection – first announcement of the protocol

Hepatocellular carcinoma (HCC), the third leading cause of cancer-related death worldwide, is a disease of immune microenvironment. Chronic Hepatitis B virus (HBV) infection, also an immune-related disease, is the major etiological factor for HCC especially in Asia. As an immune regulator, which has pleiotropic activities on T cells, nature killer cells and dendritic cells and so on, the efficacy of thymalfasin on HCC patients has been proven by several pilot studies as an adjuvant therapy. Combination of thymalfasin significantly improved survival and prolonged the time to tumor recurrence in patients who received transcatheter arterial chemoembolization after tumor resection. An improvement in patients’ immunity has also been demonstrated. However, there is no large-scale randomized controlled study so far in resectable HCC patients. To confirm the role of thymalfasin adjuvant therapy in patients with HBV-related HCC after curative resection, a large-scale multicenter randomized controlled trial has been planned in China to investigate the effect of thymalfasin (1.6 mg twice a week for 12 months) on 2-year recurrence-free survival rate and tumor immune microenvironment. Here is the first announcement of the study protocol (ClinialTrials.gov Identifier: NCT02281266).