The renal cell carcinoma lysis by a specific cytotoxic T cell clone is independent of the Fas/Fas-L cytotoxic pathway

The expression of Fas antigen at the surface of renal cell carcinoma and the susceptibility to Fas-mediated lysis by a tumor specific CTL clone were investigated. Renal cell carcinoma cell lines expressed Fas antigen and were susceptible to apoptosis mediated by antibodies to Fas/APO1. Using RT-PCR, we further showed that these cell lines expressed mRNA for Fas deleted transmembrane region, corresponding to a soluble form of Fas/APO-1. To investigate the role of the Fas/FasL pathway in the cytotoxic response against RCC cells, we analyzed the induction of Fas-L on a tumor specific T cell clone (CTL 8C2), previously generated against one RCC cell line. Fas-L expression on CTL 8C2 was detected by RT-PCR after stimulation with autologous tumor cells. However, the cytotoxic activity of CTL 8C2 was completely abolished when EGTA was added, suggesting that the cytolysis was mainly mediated by a Ca++-dependent pathway, perforin/granzyme-based.     

新生大鼠缺氧缺血时脑皮质Fas-L的变化

目的: 探讨缺氧缺血脑损伤时脑皮质Fas-L蛋白表达的变化.方法: 建立新生儿缺氧缺血性脑损伤(HIBD)动物模型并设假手术组作为对照,根据检测需要,在缺氧、缺血后24 h,3 d,7 d应用免疫组织化学SP法测定脑皮质Fas-L蛋白表达情况.结果: 左脑皮质Fas-L蛋白表达阳性率假手术组、实验组24 h依次为8.04±3.50,120.20±6.10 ; 3 d依次为8.20±3.10,87.6±5.90; 7 d依次为8.01±2.80,8.32±2.90.实验组与假手术组比较,在第7天时,差异无显著性(P＞0.05);24 h,3 d时明显增多,差异显著(P＜0.05).结论: 新生大鼠HIBD后24 h,3 d,7 d结扎侧脑皮质,Fas-L蛋白开始表达增高,后降低.     

辛伐他汀对单肾切除糖尿病老龄鼠肾组织Fas/Fas-L基因表达的影响

目的:探讨辛伐他汀对单肾切除糖尿病老龄SD大鼠肾脏凋亡相关基因Fas/Fas-L表达的影响.方法:单肾切除老龄SD大鼠分为肾切除对照组(C组)、糖尿病模型组(D组)、糖尿病辛伐他汀治疗组(S组).12周后采用原位末端标记法检测各组肾组织细胞凋亡指数,使用实时荧光定量PCR和免疫荧光法,从转录和翻译水平观察各组大鼠肾皮质中凋亡相关基因Fas及Fas-L的变化规律.结果:D组相对C组细胞凋亡指数、Fas及Fas-L的蛋白表达水平和相对应的mRNA拷贝数均明显增高,S组相对D组减弱(P<0.05),Fas、Fas-L蛋白主要在肾小管表达.结论:Fas及Fas-L系统与DN发生发展相关,辛伐他汀可在分子水平调控Fas及Fas-L基因的转录和翻译,抑制细胞凋亡,发挥肾脏保护作用.     

Upregulation of osteoblast apoptosis by malignant plasma cells: a role in myeloma bone disease

Typical features of multiple myeloma (MM) are osteolytic lesions and severely affected bone regeneration. This study of 53 MM patients demonstrates an enhancement of osteoblast cytotoxicity by malignant myeloma cells via the upregulation of apoptogenic receptors, including Fas ligand (Fas-L) and tumour-necrosis-factor-related apoptosis inducing ligand (TRAIL). Both were significantly increased in the marrow myeloma cells of patients with extensive osteolytic lesions in a fashion similar to the highly malignant human myeloma cell line MCC-2. Osteoblasts from these subjects over-expressed Fas and death receptor (DR) 4/5 and underwent dramatic apoptosis when co-cultured with either MCC-2 or autologous myeloma cells. In osteoblast and myeloma cell co-cultures, monocyte chemoattractant protein 1 (MCP-1) mRNA was upregulated in osteoblasts from patients with severe bone disease in parallel with increased CC-chemokine receptor R2 (CCR2) expression, the ligand of MCP-1, in the myeloma cells. This chemokine was shown to activate malignant cell migration in vitro. An upregulation of ICAM-1 expression occurred in osteoblasts from patients with active skeleton disease. This upregulation appeared to be an effect of malignant plasma cell contact, as MCC-2 co-culture greatly enhanced ICAM-1 production by resting osteoblasts from patients without skeleton involvement. Our results suggest that osteoblasts in active myeloma are functionally exhausted and promptly undergo apoptosis in the presence of myeloma cells from patients with severe bone disease. It is suggested that this cytotoxic effect plays a pivotal role in the pathogenesis of defective bone repair.     

Effect of Acanthopanax giraldii Harms Var.Hispidus Hoo polysaccharides on the human gastric cancer cell line SGC-7901 and its possible mechanism

Objective To study the inhibitory effect of Acanthopanax giraldii Harms Var.Hispidus Hoo polysaccharides (AGP) onSGC-7901 gastric cancer cells and its possible mechanism. Methods Cell doubling time analysis, colony forming assay and MTT assay were adopted to study the inhibitory effect and its characteristics. We also analyzed the amount of protein expressed by oncogenes, antioncogenes and cell factors using flow cytometric analysis.Results AGP inhibited the proliferation of SGC-7901 cells and cell colony forming ability. AGP did not inhibit the viability and function of lymphocytes of peripheral blood in healthy subjects and human embryonic tenocytes, except for the highest dosage of AGP ( P &lt;0. 05), which slightly inhibited the viability and function of the two types of normal cells. AGP inhibited the viability and function of SGC-7901 cells, except for the lowest dosages of AGPⅠ and AGPⅢ. There was a dose-effect relationship between the dosage of the AGP andSGC-7901 cells.The effect of the AGP at the molecular level was associated with the low protein expression of the c-myc and bcl-2 genes and the high protein expression of the p53, bax, fas and fas-L genes, as well as the cell factor TGFβ(1).The inhibitory effect of AGP was weaker than that of CDDP, but was stronger than that ofVitamine C. Conclusions Acanthopanax giraldii Harms Var.Hispidus Hoopolysaccharides selectively inhibited the proliferation, the colony forming ability, and the viability and function of human gastric cancer cells through the low protein expression of c-myc, bcl-2 and the high protein expression of p53, fas, fas-L and the cell factor TGFβ(1). The different inhibitory characteristics on the normal cells and cancer cells are possibly caused by gene and the cell factor expressions.     

长期饮酒大鼠缺血脑组织中Fas—L抗原表达及细胞凋亡的动态研究

目的研究长期饮酒大鼠局灶性脑缺血后Fas-L抗原和细胞凋亡在各时间段的表达。方法7.2%酒精代水自由饮用12周的大鼠用线拴法制备局灶性脑缺血模型,在缺血后不同时间(1,3,6 h)分别以免疫组织化学方法和TUNEL法动态检测Fas-L抗原表达和细胞凋亡情况。结果长期饮酒组大鼠缺血1 h,Fas-L抗原和凋亡细胞呈阳性,3 h达高峰,6 h减少。结论长期饮酒大鼠在脑缺血后Fas-L的阳性表达和细胞凋亡比正常大鼠脑缺血明显,且促使凋亡细胞迅速坏死。     

Mechanisms and biomarkers of immune quiescence in kidney transplantation

This review discusses the current understanding of biomarkers of immune quiescence based on reviews of published literature in kidney transplant operational tolerance and mechanistic studies based on a better characterization of the stable, well-functioning renal allograft.     

二黄糖肾康对糖尿病肾病大鼠肾脏细胞凋亡及PI3 K/AKT信号转导系统的影响

目的 观察二黄糖肾康对糖尿病肾病(DN)大鼠细胞凋亡及PI3 K/AKT信号转导系统的影响. 方法 SD大鼠单侧肾切除加腹腔注射链脲佐菌素(STZ)复制DN模型,每日二黄糖肾康灌胃,8 w后流式细胞术检测细胞凋亡数目及调控因子Bax、Bcl-2、Fas、Fas-L的蛋白表达,采用Western 印迹方法检测细胞内磷酸化Akt蛋白质的表达.结果 二黄糖肾康明显减少DN大鼠肾脏皮质细胞凋亡数目,降低Bax、Fas、Fas-L的的蛋白表达,增加Bcl-2的蛋白表达,激活PI3 K/AKT信号通路.结论 二黄糖肾康能有效降低肾脏细胞凋亡,激活PI3 K/AKT信号通路.