Mesothelial cell proliferation and apoptosis

Mesothelial cells line the pleural and peritoneal surfaces, where under normal conditions they proliferate and undergo cell death at a slow rate, thereby maintaining a constant number of cells. These tightly regulated processes are disrupted in malignancy. By developing a better understanding of the mechanisms that regulate cell proliferation and apoptosis in mesothelial and mesothelioma cells, we may be able to develop more effective therapeutic agents that target specific steps in these pathways to induce apoptosis more efficiently. This paper reviews our current knowledge of the signaling pathways involved in the regulation of mesothelial cell proliferation and apoptosis. The latest advancements in identifying proteins that play key roles in the resistance to apoptosis are highlighted.     

急性白血病患者Bcl—2,Bax基因mRNA表达的临床意义

目的：探讨Bcl-2,Bax基因mRNA表达与急性白血病（AL）预后及多药耐药性的关系。方法：应用逆转录－聚合酶链反应（RT－PCR）方法测定55例初始AL患者及20例正常人的Bcl-2,Bax,mdr-1基因mRNA基因mRNA水平的表达,并用读胶仪进行定量分析。结果：Bcl-2,Bax基因在AL患者广泛表达,Bcl-2平均表达水平明显高于正常对照（P＜0．05）。Bax表达和Bax/Bcl-2比值和正常对照组之间无显著差异。Bax/Bcl-2比值（P＜0．01）比值是决定AL化疗敏感的重要指标,与AL预后密切相关,是影响CR率和总生存期的危险因素。Bxl-2,Bax基因表达和mdr-1表达两者无相关关系,联合Bax/Bcl-2比值和mdr-1表达将AL患者分为高,中,低危组,CR分别为11．9％（1／9）、60．7％（17．28）、100％（18／18）,三组有显著性差异（P＜0．05）。结论：Bax/Bcl-2比值是决定AL化疗敏感的重要指标,是影响CR率和总生存期的危险因素。结合mdr-1表达可做为AL患者判断预后的指标之一。     

脑出血病人神经元凋亡及Bcl-2、Bax表达与中风闭脱证的研究

目的观察脑出血病人血肿周围组织神经元凋亡和凋亡相关基因Bcl-2、Bax蛋白的表达及其与中风闭脱证的关系.方法采用TUNEL法、免疫组织化学法分别检测脑出血病人血肿周围组织凋亡神经元和Bcl-2、Bax蛋白表达水平.结果血肿周围组织细胞凋亡率及Bcl-2、Bax蛋白表达明显高于正常对照组,差异有统计学意义(P<0.01);Bcl-2蛋白表达与细胞凋亡率呈负相关(P<0.01),Bax蛋白表达及Bax/Bcl-2与细胞凋亡率呈正相关(P均<0.01).闭、脱证之间细胞凋亡率及Bcl -2、Bax蛋白阳性率、Bax/Bcl-2有统计学意义(P<0.05或P<0.01),脱证细胞凋亡率、Bax 、Bax/ Bcl-2大于闭证,Bcl-2小于闭证.结论细胞凋亡机制参与了脑出血后继发性神经元损伤.细胞凋亡率及Bcl-2、Bax蛋白表达对中风闭脱证微观辨证有一定的帮助.     

Bcl‐2 overexpression in hepatic stellate cell line CFSC‐2G,induces a pro‐fibrotic state

Background and Aim: Development of hepatic fibrosis is a complex process that involves oxidative stress (OS) and an altered balance between pro‐ and anti‐apoptotic molecules. Since Bcl‐2 overexpression preserves viability against OS, our objective was to address the effect of Bcl‐2 overexpression in the hepatic stellate cells (HSC) cell‐line CFSC‐2G under acetaldehyde and H₂O₂ challenge, and explore if it protects these cells against OS, induces replicative senescence and/or modify extracellular matrix (ECM) remodeling potential. Methods: To induce Bcl‐2 overexpression, HSC cell line CFSC‐2G was transfected by lipofection technique. Green fluorescent protein‐only CFSC‐2G cells were used as a control. Cell survival after H₂O₂ treatment and total protein oxidation were assessed. To determine cell cycle arrest, proliferation‐rate, DNA synthesis and senescence were assessed. Matrix metalloproteinases (MMP), tissue‐inhibitor of MMP (TIMP), transglutaminases (TG) and smooth muscle a‐actin (α‐SMA) were evaluated by western blot in response to acetaldehyde treatment as markers of ECM remodeling capacity in addition to transforming growth factor‐β (TGF‐β) mRNA. Results: Cells overexpressing Bcl‐2 survived ≈ 20% more than control cells when exposed to H₂O₂ and ≈ 35% proteins were protected from oxidation, but Bcl‐2 did not slow proliferation or induced senescence. Bcl‐2 overexpression did not change α‐SMA levels, but it increased TIMP‐1 (55%), tissue transglutaminases (tTG) (25%) and TGF‐β mRNA (49%), when exposed to acetaldehyde, while MMP‐13 content decreased (47%). Conclusions: Bcl‐2 overexpression protected HSC against oxidative stress but it did not induce replicative senescence. It increased TIMP‐1, tTG and TGF‐β mRNA levels and decreased MMP‐13 content, suggesting that Bcl‐2 overexpression may play a key role in the progression of fibrosis in chronic liver diseases.     

黄芪当归合剂对大鼠缺血性急性肾损伤的保护研究

目的:探讨黄芪当归合剂对实验性缺血性肾损伤大鼠肾小管上皮细胞凋亡的保护作用.方法:建立大鼠实验性缺血性急性肾损伤模型,在缺血30 min再灌注不同时间点检测血尿素氮(BUN)、血肌酐(SCr)和尿液中N-乙酰-β-D-氨基葡萄糖酐酶(NAG).同时取肾组织,苏木素-伊红(HE)染色,光镜下观察细胞形态学变化.免疫组织化学方法检测Bcl-2和Bax基因的蛋白表达,观察黄芪当归合剂对上述表达的影响.结果:缺血性急性肾损伤时肾脏存在明显的细胞凋亡;Bcl-2和Bax基因的蛋白表达主要在近曲肾小管和远曲肾小管,肾小球很少;肾脏缺血性损伤时Bcl-2基因表达增加,Bax基因表达中量增加,Bcl-2/Bax比率升高.与缺血/再灌注组比较,黄芪当归合剂组Bax表达明显增加,Bcl-2/Bax比率降低,肾脏损伤亦减轻.结论:黄芪当归合剂对急性肾损伤具有显著的保护作用,其机制可能与其降低Bcl-2/Bax比率有关.     

乳腺癌组织bcl—2和p53蛋白表达相对定量测定及相关性和预后关系

目的探讨ｂｃｌ２和ｐ５３蛋白定量指标与乳腺癌临床病理参数的关系及预后价值。方法应用图象分析仪对６０例乳腺癌组织进行ｂｃｌ２、ｐ５３和雌孕激素受体免疫组化及酶联亲和法定量测定。结果（１）ｂｃｌ２蛋白定量高值组，乳腺癌组织学分级低，患者生存期长，生存率高（Ｐ＜０．０５）。（２）ｐ５３蛋白表达及定量高值组，组织学分级高，患者生存期短、生存率低（Ｐ＜０．０５）。（３）ｂｃｌ与ｐ５３呈负相关（Ｐ＜０．０５）。（４）ｂｃｌ２与雌孕激素受体间有显著正相关性（Ｐ＜０．００１）。结论定量检测ｂｃｌ２和ｐ５３蛋白对评估乳腺癌分化程度及判断预后具一定价值。ｂｃｌ２与ｐ５３在乳腺癌发生发展中有不同生物学作用。ｂｃｌ２对乳腺癌患者内分泌治疗有重要参考价值     

Melatonin‐induced calbindin‐D9k expression reduces hydrogen peroxide‐mediated cell death in rat pituitary GH3 cells

Abstract: In this study, we investigated whether calbindin‐D9k (CaBP‐9k) expression was regulated by melatonin during hydrogen peroxide (H₂O₂)‐induced cell death in rat pituitary GH3 cells. CaBP‐9k expression was increased by melatonin in a dose‐ and time‐dependent manner, indicating that CaBP‐9k expression is regulated by melatonin. Cell survival was increased approximately 27–30% where H₂O₂‐treated cells (0.25 or 0.5 mm ) were also incubated with 1 mm melatonin, when compared with H₂O₂ alone or H₂O₂ plus 0.5 mm melatonin. This result was consistent with 4,6‐diamidino‐2‐phenylindole staining. CaBP‐9k expression was also augmented by co‐treatment with H₂O₂ and 1 mm melatonin, suggesting a functional relationship between increased cell death and melatonin‐induced CaBP‐9k expression during H₂O₂‐mediated apoptosis. Bcl‐2‐associated protein expression increased following treatment with H₂O₂ alone, whereas Bcl‐2 expression was elevated following treatment with melatonin alone, or H₂O₂ plus melatonin. The expression of p53 was depressed by treatment with melatonin alone, or co‐treatment with H₂O₂ plus melatonin. These results correlated with CaBP‐9k expression levels and activation of the mitogen‐activated protein kinase/extracellular signal‐regulated kinase signaling pathway. Knockdown of CaBP‐9k expression using a small inhibitory RNA resulted in an elevation of H₂O₂‐induced cell death, whereas cell survival was increased in cells that overexpressed CaBP‐9k, providing additional evidence that the induction of CaBP‐9k expression may be associated with survival signaling during H₂O₂‐mediated oxidative cell death. CaBP‐9k appears to interact with p53, suggesting a possible role for this interaction in cell proliferation and cell cycle progression.     

雌激素对脑缺血时Bcl-2蛋白表达影响及神经保护作用的研究

目的 :研究雌激素对缺血性脑损害的神经保护作用是否与 Bcl 2蛋白的表达有关。方法 :采用大鼠大脑中动脉闭塞制成局灶性脑缺血模型。在缺血 2小时、再灌注 2 2小时后立即断头取脑 ,应用 TTC染色和免疫组织化学方法 ,观察脑梗死体积及 Bcl 2蛋白的表达。结果 :(1)雌激素用药组较手术对照组脑梗死体积显著缩小 (P<0 .0 5 ) ;(2 ) Bcl 2蛋白的表达较手术对照组明显增强 (P<0 .0 5 )。结论 :雌激素上调大鼠脑缺血时Bcl 2的表达很可能是其具有神经保护作用的机制之一。