舌癌细胞迁移过程中RhoA和蛋白激酶A的作用

目的：研究RhoA和蛋白激酶A（protein kinase A，PKA）在舌癌细胞迁移过程中的作用。方法：采用Boyden趋化小室、细胞黏附试验和划痕法测定细胞的迁移能力，观察RhoA激动剂溶血磷脂酸（lysophosphatidic acid，LPA）及PKA激动剂cAMP对人舌癌细胞Tca8113的迁移作用。数据以SPSS10．0统计软件包进行t检验。结果：加入1μmol／L LPA和3μmol／L LPA后，细胞迁移数与对照组相比显著增加（P〈0．01），舌癌细胞的迁移能力显著增强。不同浓度LPA组细胞与先用100μmol／L cAMP或200μmol／L cAMP处理后再加入LPA组比较，各组在包被Matrigel或Fn基质表面上的黏附情况存在剂量依赖关系。经cAMP处理后，舌癌细胞在基质表面的黏附显著降低，且随着浓度的增加，其抑制作用更加显著。结论：RhoA的活化可以促进Tea8113细胞的迁移，而cAMP通过激活PKA，抑制LPA引起的RhoA活化．进而抑制细胞的迁移能力。     

Cellular and subcellular localization of the small G protein RhoA in the human and rat embryonic and adult kidney

Rho proteins, a subgroup of the Ras GTPase superfamily, control many cellular processes and morphogenetic events by acting as signaling molecules in the transduction pathways of various receptors. Among the "Rho-dependent" receptors are the extracellular matrix- and growth factor-binding sites; these are particularly involved in the modulation of renal development since they control the epithelial-mesenchymal interactions that drive kidney organogenesis. The present study has addressed the immunohistochemical localization of RhoA in developing and adult kidneys of rats and humans because: a) Rho proteins are known to have a morphogenetic role, b) data in the literature on expression of Rho GTPases during mammalian histogenesis and organogenesis are scarce, and c) their involvement in the transduction pathways of receptors is implicated in kidney development. In particular, RhoA peptide was found to be localized in the mesonephric duct and vesicles in both rats and humans; metanephric anlagen were mainly stained in ampullar-derived cells. Periglomerular tubules of fetal and adult kidneys as well as collecting ducts of adult kidneys showed intense staining. Therefore, the present study provides new information on the distribution patterns of RhoA during early stages of mammalian kidney development suggesting that this signaling molecule may take part in epithelial-mesenchymal induction processes that control kidney organogenesis. RhoA expression in adult structures may be linked with renewal of renal epithelial cells and the maintenance of their morphology and polarity.     

RhoA在子痫前期患者胎盘中的表达

目的:检测正常晚期妊娠和子痫前期患者胎盘RhoA的表达,探讨RhoA在子痫前期发病中的作用。方法:用免疫组织化学SP法及RT-PCR检测40例子痫前期和20例正常晚期妊娠胎盘RhoA蛋白及其mRNA的表达。结果:RhoA主要在滋养细胞表达。轻度子痫前期组和重度子痫前期组RhoA蛋白及mRNA均高于正常晚期妊娠组,差异有统计学意义(P<0.05)。结论:子痫前期患者胎盘RhoA的高表达可能与子痫前期的发病有一定的关系。     

FTY720-P 对破骨细胞 EphA2-EphrinA2双向信号通路作用的研究

目的探讨 FTY720-P 对破骨细胞 EphA2-EphrinA2 双向信号通路的影响。方法取小鼠巨噬细胞 RAW264.7，采用地塞米松及 1α，25-二羟维生素 D₃ 诱导分化为破骨细胞，并行抗酒石酸酸性磷酸酶（tartrate resistant acid phosphatase，TRAP）染色鉴定。将诱导培养的破骨细胞分为两组，实验组给予 400 ng/mL 的 FTY720-P 处理，对照组不给予 FTY720-P。培养 48 h 后，取细胞行实时荧光定量 PCR 检测、Western blot 检测以及免疫荧光染色观察，分析细胞中 EphA2、EphrinA2、RhoA，以及骨重建相关蛋白 BMP-2 及 TGF-β₁ 的表达。 结果经 TRAP 染色鉴定，RAW264.7 细胞成功诱导成为破骨细胞。培养 48 h 后，与对照组相比，实验组 EphA2 及 EphrinA2 mRNA 及蛋白相对表达量均明显降低（P<0.05），RhoA 蛋白相对表达量也明显降低（P<0.05）；BMP-2 及 TGF-β₁ mRNA 相对表达量明显增高（P<0.05），蛋白表达增强。 结论FTY720-P 能通过影响破骨细胞 EphA2-EphrinA2 双向信号通路之间的传导下调 RhoA，并促进 TGF-β₁ 和 BMP-2 表达，最终影响破骨细胞的破骨作用。     

RhoA/ROCK信号通路与动脉粥样硬化关系的研究进展

动脉粥样硬化是一种常见的全身性血管疾病,同时也是多种急性心血管疾病的病理基础。而急性心血管疾病的死亡率高,严重危害人们的生命健康。近年来,越来越多的研究表明RhoA/ROCK信号通路与动脉粥样硬化的形成有密切联系。抑制RhoA/ROCK信号通路可以通过稳定血管内皮功能、抑制血管平滑肌细胞增殖和迁移、抑制血管钙化、调控炎症细胞聚集以及抑制血小板增殖变形来延缓或抑制动脉粥样硬化的形成。     

急性肺损伤中炎症因子 IL-8与 RhoA 的相关性研究

目的：探讨油酸型急性肺损伤模型中IL‐8与RhoA的相关性。方法建立大鼠油酸急性肺损伤模型,检测各组大鼠肺湿／干重比及肺泡灌洗液（BALF）中中性粒细胞比例,比较肺组织病理学改变;采用聚合酶链反应检测肺组织匀浆RhoA表达,酶联免疫吸附法（ELISA ）测定大鼠IL‐8的变化。结果肺W／D损伤组在2、6、12、24 h均较正常组明显升高,并且损伤组2 h比值最高;损伤组各时间点BALF中中性粒细胞计数比例明显高于正常组,24 h中性粒细胞细胞比例达峰值;损伤组个时间点血浆及BALF中IL‐8较正常组明显升高,两者具有相关性;损伤组各时间点RhoA的表达明显高于正常组。结论油酸型急性肺损伤大鼠中存在RhoA的高表达,RhoA表达增加可致IL‐8的表达增加,进而引起炎症细胞浸润。     

RhoA/ROCK pathway regulates hypoxia-induced myocardial cell apoptosis

Objective:To observe the regulatory effects of RhoA/ROCK pathway on the apoptosis of cardiac myocyte induced by anoxia and its mechanism.Methods:The model of cardiac myocyte anoxia was established.The beat pulsations and apoptosis rales after 1 h,3 h,6 h,9 h and 12 h of anoxia were recorded and the expressions of RhoA,ROCK1/2,p-PI3 K,p-AKT and caspae-3 were detected,too.The apoptosis and the expressions of related proteins were detected after RNAi of RhoA and the inhibition of ROCK by Y-27632.Results:The beat pulsations after 1 h,3 h,6 h.9h and 12 h decreased gradually but the apoptosis rates increased gradually,and the expressions of RhoA,ROCK1/2,p-P13 K,p-AKT and caspase-3 were increasing along with the increasing duration of anoxia.The apoptotic rales after 1 h,3 h,6 h.9 h and 12 h of anoxia were(4.36±0.98)%,(8.36±2.12)%,(15.32±3.62)%,(18.68±4.83)%and(24.56±6.22)%.respectively and decreased more significantly than control group in different time points of anoxia(P0.05).and the expressions of RhoA,ROCK1/2,p-PI3 K,p-AKT and caspase-3 decreased significantly(P0.05).The apoptosis rate and the expressions of RhoA,ROCK1/2,p-PI3 K,p-AKT and caspase-3 decreased significantly(P0.05) after the inhibition of ROCK by Y-27632(P0.05).Conclusions:RhoA/ROCK pathway plays a critical role in the regulation of the apoptosis of cardiac myocyte induced by anoxia,which may be accompanied by regulating the activity of PI3K/AKT/Caspase-3 pathway.     

基于RhoA/ROCK-1通路研究针刺干预SHR脑保护作用机制

[目的] 明确自发性高血压大鼠（SHR）脑损害与RhoA、ROCK-1的相关性,探讨针刺干预SHR脑保护的Rho通路机制。[方法] 将SHR随机分为模型对照组、太冲穴组,WKY大鼠设为正常对照组。太冲穴组针刺干预4周,其余两组在干预期内给予相同程度、相同时长的抓取。观测各组大鼠收缩压、舒张压、平均动脉压的改变;苏木精-伊红（HE）染色观察脑组织形态学改变;蛋白免疫印迹（Western blot）法测定各组大鼠脑组织中RhoA、ROCK-1的表达水平。[结果] 在干预周期内,正常对照组收缩压、舒张压、平均压均处于正常血压范围内。与正常对照组比较,模型对照组收缩压、舒张压、平均压均较高,且有随着周龄增加而增高的趋势。与模型对照组相比,太冲穴组可有效降低收缩压,有降低舒张压、平均压的趋势。模型对照组较正常对照组脑组织细胞排列紊乱,细胞坏死及间质水肿程度加重,RhoA、ROCK-1表达升高;太冲穴组与模型对照组比较,脑细胞排列规则,细胞坏死及间质水肿消失,RhoA、ROCK-1表达下降。[结论] 针刺太冲穴能有效降低SHR血压,改善脑损害,其机制可能与抑制RhoA/ROCK-1信号通路表达相关。