模拟失重大鼠胸主动脉收缩功能的变化可能与Rho激酶改变有关

目的:观察模拟失重大鼠胸主动脉收缩功能的变化及Rho相关的蛋白激酶（Rho-associated protein kinase,ROCK）表达的改变,并探讨二者之间的关系。方法: 以尾部悬吊4周建立模拟失重大鼠模型并观察模拟失重对胸主动脉的主要生理的影响。采用离体血管环功能实验检测大鼠胸主动脉的收缩反应性变化;通过蛋白印迹技术检测大鼠胸主动脉ROCK II蛋白的表达。结果: 与对照组相比,悬吊组氯化钾、苯肾上腺素诱导的大鼠胸主动脉收缩功能均明显增强（P<0.05）。用ROCK特异性抑制剂Y-27632孵育1 h后,两组胸主动脉的收缩反应均显著降低至同一水平,两组间无统计学差异。蛋白印迹结果显示,悬吊组ROCK II的表达增加。结论: ROCK表达的改变可能在模拟失重大鼠胸主动脉收缩功能增强中发挥重要作用,去除ROCK的作用可消除模拟失重大鼠与正常大鼠胸主动脉收缩功能的差异。     

吡格列酮对糖尿病大鼠冠状动脉RhoA/ROCK信号通路的影响

目的 观察糖尿病（DM）大鼠和正常大鼠冠状动脉RhoA及Rho激酶（ROCK）表达水平及PPAR-γ激动剂吡格列酮（PIO）对糖尿病大鼠糖脂代谢及冠状动脉组织RhoA及ROCK表达水平的影响.方法 30只雄性Sprague-Dawley大鼠随机分为3组,对照组予普通饮食;DM组给予高果糖饮食＋链脲佐菌素（25 mg/kg）造模,PIO干预组在糖尿病组基础上给予吡格列酮10 mg·kg-1 ·d-1干预.4周后采血检测血糖、血脂及胰岛素水平,分离冠状动脉采用Western Blot法测定各组大鼠冠状动脉组织中RhoA、ROCK1、ROCK2蛋白表达水平.结果 吡格列酮可显著降低DM大鼠胆固醇、三酰甘油及空腹胰岛素水平（均为P ＜0.05）.与对照组比较,DM组RhoA（F =5.131,P=0.019）、ROCK2蛋白表达水平升高（F=6.953,P=0.011）,ROCK1蛋白表达水平差异无统计学意义.给予PIO干预后ROCK2蛋白表达水平明显降低,差异具有统计学意义（F =4.323,P=0.045）.结论 PIO可显著改善糖尿病大鼠胰岛素抵抗状态,降低TC及TG水平.糖尿病大鼠冠状动脉RhoA/ROCK蛋白表达增加,吡格列酮可显著降低糖尿病大鼠冠状动脉组织ROCK2蛋白表达水平.     

MCU介导的线粒体Ca2+稳态失调参与模拟失重引起的大鼠脑动脉平滑肌细胞凋亡

目的 观察线粒体钙单向转运体（mitochondrial Ca2+ uniporter, MCU）在模拟失重引起大鼠脑动脉平滑肌细胞凋亡中的作用。 方法 采用尾吊大鼠方法建立模拟失重模型,实验大鼠分为对照（Control, CON）组和尾吊（tail suspension, SUS）组。造模成功后,分离脑动脉血管,取病理切片行TUNEL染色及细胞色素C免疫荧光染色检测平滑肌细胞凋亡水平,蛋白免疫印迹实验检测凋亡相关蛋白及MCU蛋白表达水平,最后急性分离脑动脉平滑肌细胞,分别采用Rhod-2 AM、mitoSOX染色检测细胞线粒体内Ca2+水平和活性氧簇（reactive oxygen species,ROS）水平。 结果 与对照组比较,尾吊组模拟失重大鼠基底动脉平滑肌细胞TUNEL阳性率显著增加（P < 0.05）,细胞色素C入核率显著增加（P < 0.05）,促凋亡蛋白cleaved caspas-9、cleaved caspas-3、Bax表达显著增加（P < 0.05）,抑制凋亡蛋白Bcl-2显著降低（P < 0.05）;同时,MCU蛋白表达水平下调（P < 0.05）;此外,尾吊组大鼠脑动脉平滑肌细胞线粒体内Ca2+浓度下降（P < 0.05）及ROS水平增加（P < 0.05）。 结论 模拟失重引起大鼠脑动脉平滑肌细胞凋亡,同时MCU表达降低,提示MCU可能参与了模拟失重引起的脑动脉平滑肌细胞凋亡这一病理过程。     

过氧亚硝酸盐对糖尿病大鼠血管收缩功能的影响的研究

目的 观察过氧亚硝酸盐对糖尿病大鼠胸主动脉血管收缩功能的影响.方法 雄性SD大鼠30只,大鼠随机分为3组：对照组、糖尿病组和糖尿病＋尿酸盐孵育（过氧亚硝酸盐清除剂）组.以去除内皮的大鼠胸主动脉作为实验标本.分别检测各组血管收缩功能、RhoA/ROCK表达水平和硝基酪氨酸表达水平的差异.结果 糖尿病组血管的收缩反应增强.糖尿病组与尿酸盐孵育组相比,RhoA mRNA表达水平升高.糖尿病组血管ROCK的蛋白表达水平显著升高.糖尿病组血管硝基酪氨酸表达水平显著升高.结论 过氧亚硝酸盐导致糖尿病大鼠胸主动脉血管ROCK蛋白表达水平增加及血管收缩反应增强.     

柴胡疏肝散对抑郁症模型大鼠海马单胺氧化酶与乙酰胆碱酯酶活性的影响

目的 观察柴胡疏肝散对大鼠大脑海马乙酰胆碱酯酶(AChE)与单胺氧化酶(MAO)活性的影响.方法 选取60只4～5月龄的SD大鼠随机分为正常组、模型组、氟西汀组和中药组,共4组,每组15只.利用孤养结合慢性轻度不可预见性应激刺激制造抑郁症模型.21 d后,采用敞箱实验、糖水消耗量检测和体重检测等指标评定大鼠行为学改变,并用免疫组织化学染色法观察大鼠大脑海马区AChE的蛋白表达变化,利用比色法检测大鼠大脑海马区MAO活性.结果 与正常组相比,模型组水平运动得分、垂直运动得分、体重和糖水偏爱度均明显降低(P<0.01),与模型组比较,氟西汀组和中药组水平运动得分、垂直运动得分、糖水偏爱度与体重均明显升高(P<0.05～0.001);免疫组化结果显示,与正常组相比,模型组海马区AChE的蛋白表达均明显升高(P<0.05),与模型组相比,氟西汀组和中药组大鼠海马区AChE的蛋白表达均明显降低(P<0.05);比色法结果显示,与正常组相比,模型组海马区MAO活性明显升高(P<0.05),与模型组相比,氟西汀组、中药组海马区MAO活性明显下降(P<0.05).结论 柴胡疏肝散抗抑郁症的作用可能与其降低大脑组织海马区AChE蛋白表达和MAO活性有关.     

去势对大鼠肠系膜小动脉的血管功能影响及其机制研究

目的本研究观察雄激素缺乏对大鼠肠系膜小动脉舒缩功能的影响,以及其是否涉及Rho/Rho激酶（ROCK）信号通路。方法用离体血管张力法检测24周龄对照和去势大鼠的肠系膜小动脉收缩和舒张反应。结果 1）去势组大鼠的肠系膜小动脉对苯肾上腺素（PE）收缩反应较对照组无差异;2）去势组与对照组比较对低浓度（0.01μM）的乙酰胆碱（ACh）、硝普钠（SNP）舒张反应增强（23%±5%vs.5%±3%,28%±7%vs.9%±3%,respectively,P〈0.05）,高度浓度时（10μM）无差别;3）预孵育ROCK抑制剂（Y-27632,1μM）后,较抑制前对照组对PE收缩反应降低（Emax99%±4%vs134%±8%,P〈0.01）,去势组未有改变;两组对ACh反应较抑制前均无差异,两组对浓度依赖的Y-27632舒张反应也无差异。结论去势不影响大鼠肠系膜小动脉的收缩功能,但减弱了其对ROCK的敏感性;去势可增强大鼠肠系膜动脉的内皮和非内皮依赖性舒张,与ROCK无关。     

短期模拟失重可引起大鼠视交叉上核中枢时钟基因的表达异常

目的 探讨1周模拟失重对大鼠生物钟中枢时钟基因表达影响。 方法 采用尾悬吊后肢去负荷模型模拟太空微重力环境，48只雄性SD大鼠随机均分为对照（control，CON）组和尾悬吊（tail-suspension，SUS）组。两组大鼠在相同的光照环境下（08:00～20:00）饲养。蛋白印迹实验检测大鼠视交叉上核（suprachiasmatic nucleus，SCN）内时钟基因（Per2，Bmal1）以及钙通道Ca_v1.2蛋白在不同时间点的表达水平，同时采用实时定量PCR技术检测不同时间点SCN中Per2，Bmal1的转录水平。 结果 与CON组相比，短期模拟失重引起大鼠SCN中时钟基因Per2和Bmal1 mRNA转录和蛋白表达下降（P<0.05），且波动幅度发生显著降低。此外，与对照组相比，模拟失重使得SUS组大鼠SCN中Ca_v1.2蛋白表达发生了明显上升（P<0.05）。 结论 短期模拟失重可引起大鼠时钟基因表达异常，这可能是模拟失重引起机体发生病理性改变的机制之一，也为重力变化信号直接转化为时间节律信号提供了直接的证据。     

ROCK1在大鼠脑缺血再灌注致细胞凋亡中的作用

目的探讨脑缺血再灌注环境下Rho相关的卷曲螺旋蛋白激酶(ROCK)1在细胞凋亡中的作用及可能的机制。方法Zea-longa改良线栓法制作大脑中动脉闭塞(MCAO)大鼠模型,腹腔注射ROCK1抑制剂法舒地尔(Fasudil),荧光定量PCR技术检测ROCK1、bax、bcl-2、caspase-3 mRNA含量,Western印迹技术检测ROCK1、ERK1/2、p ERK1/2蛋白表达水平。结果缺血脑组织细胞bax、caspase-3、ROCK1的mRNA表达量1 d开始逐渐升高,3 d表达至高峰,7 d后回落;bcl-2基因正相反,与正常组相比差异有统计学意义(P<0.05)。ROCK1蛋白表达与mRNA水平一致,ERK1/2蛋白含量没有明显改变,p ERK1/2蛋白变化趋势与ROCK1一致。ROCK1被抑制后,Bax mRNA含量升高,bcl-2、caspase-3 mRNA含量下降(P<0.05)。ERK1/2蛋白未发生明显变化,p ERK1/2蛋白表达量明显升高。结论 ROCK1可能参与了缺血致脑细胞凋亡的过程,其机制可能是通过ERK1/2作为ROCK1下游信号分子共同调节缺血脑组织细胞凋亡。     

模拟失重大鼠胸主动脉平滑肌细胞凋亡的变化及间断性人工重力对抗的影响

目的:观察模拟失重大鼠胸主动脉平滑肌细胞凋亡的变化及间断性人工重力对其影响。方法: 将27只SD大鼠随机分为3组（每组9只）,即对照组(CON)、模拟失重组(SUS)及站立对抗组(STD)。以尾部悬吊大鼠模拟失重3周,同期每天悬吊23 h、站立1 h模拟间断性人工重力对抗的效果。用TUNEL染色法检测SUS组、同步对照(CON)组及STD组大鼠胸主动脉平滑肌细胞的凋亡情况;用Western blot法检测各组大鼠胸主动脉组织中Bad、FasL及Caspase-3蛋白表达的变化。结果: 与CON组比较,SUS组大鼠胸主动脉平滑肌细胞TUNEL染色阳性的细胞明显减少(P<0.01);STD组TUNEL染色阳性的细胞较CON组及SUS组显著增加（P<0.01）。SUS组Bad的表达较CON组和STD组显著减少（P<0.05）,STD组Bad的表达较CON组有增加的趋势,但无统计学差异。SUS组FasL及Caspase-3的表达较CON组显著降低(P<0.05);STD组FasL及Caspase-3的表达较CON组及SUS组显著增高(P<0.01)。结论: 模拟失重可减少大鼠胸主动脉平滑肌细胞凋亡,每日1 h的-Gx对抗可使胸主动脉平滑肌细胞的凋亡增加,提示血管组织平滑肌细胞的凋亡在失重引起的动脉血管适应性重构中可能发挥重要作用。     

缺氧诱导因子-1α在老年性痴呆模型鼠海马中的表达

目的 观察老年性痴呆(AD)大鼠行为学、海马神经细胞凋亡率及缺氧诱导因子(HIF)-1α表达水平的变化.方法 侧脑室注射Aβ25～35构建AD大鼠模型,Morris水迷宫实验测试大鼠空间学习记忆能力,流式细胞术检测海马神经细胞凋亡率, Western印迹技术检测大鼠海马HIF-1α蛋白的表达.结果 Morris水迷宫实验结果显示AD组大鼠平均逃避潜伏期显著延长(P<0.05),流式细胞分析结果显示,AD组海马神经细胞凋亡百分率较正常对照组显著升高(P<0.05),Western印迹检测结果显示,AD组海马神经细胞HIF-1α蛋白表达水平较正常对照组显著升高(P<0.05).结论 侧脑室注射Aβ25～35成功构建AD大鼠模型并上调海马神经细胞HIF-1α水平表达.     

The role of the RhoA/Rho-kinase signaling pathway in renal vascular reactivity in endothelial nitric oxide synthase null mice

BACKGROUND: Smooth muscle contraction is regulated by the small GTPase RhoA and its target, Rho-kinase and recent evidence indicates that nitric oxide (NO) causes vasodilation through inhibition of the RhoA/Rho-kinase (ROCK) signaling pathway. AIM: This study tested the hypothesis that the enhanced renal vascular tone and systemic hypertension in endothelial nitric oxide synthase (eNOS) null mice is due to disinhibition of the ROCK signaling pathway. METHODS: Systolic blood pressure (SBP) was measured by tail-cuff plethysmography and the isolated Krebs-perfused kidney preparation was used to evaluate renal vascular responses in C57BL/6 (wild type, WT) and eNOS knockout (KO) mice treated with Y-27632, a ROCK inhibitor. RESULTS: Compared with the WT mice, Rho kinase activity was higher in eNOS KO mice (37 +/- 8%, P < 0.05) as was SBP (33 +/- 4%, P < 0.05), basal renal perfusion pressure (31 +/- 4%, P < 0.05) and renal vascular resistance (35 +/- 4%, P < 0.05). Y-27632 abolished these differences. Vasoconstriction elicited by angiotensin II (Ang II) or phenylephrine (PE), G-protein-coupled receptor (GPCR) agonists, but not that elicited by arachidonic acid or KCl, was greater in eNOS KO mice. Y-27632 eliminated the amplified vasoconstriction elicited by Ang II or phenylephrine but to a greater extent in eNOS KO mice. Similarly, responses elicited by guanosine 5'-gamma-thiotriphosphate (GTPgammaS), a non-hydrolyzable GTP analog, or sodium tetrafluoride (NaF4), an activator of G-proteins, was greater in eNOS KO mice, 53 +/- 14 and 50 +/- 3%, respectively. Y-27632 normalized the difference. Y-27632 also elicited a dose-dependent renal vasodilation that was greater in eNOS KO mice. CONCLUSIONS: These results show that the ROCK signaling pathway is amplified in the eNOS KO mouse kidney and that the enhanced renal vascular tone and selective increase in reactivity to GPCR agonists supports a role for ROCK in the hypertension and vascular dysfunction in the eNOS KO mice.     

Different Effect of Rho Kinase Inhibition on Calcium Signaling in Rat Isolated Large and Small Arteries

In addition to its role in the regulation of artery contraction, Rho kinase (ROCK) was reported to be involved in the cytosolic calcium response to vasoconstrictor agonists in rat aorta and superior mesenteric artery (SMA). However, it remains to be determined whether ROCK also contributes to calcium signaling in resistance arteries, which play a major role in blood pressure regulation. The investigation of the effect of ROCK inhibition on the calcium and contractile responses of rat resistance mesenteric artery (RMA), in comparison with aorta and SMA, indicated that the calcium response to noradrenaline was inhibited by the ROCK inhibitor Y-27632 in aorta and SMA but not in RMA. The effect of Y-27632 on the calcium signal was unaffected by cytochalasin-D. ROCK activation in noradrenaline-stimulated arteries was confirmed by the inhibition of myosin light chain phosphorylation by Y-27632. Moreover, noradrenaline-induced calcium signaling was similarly inhibited by nimodipine in aorta, SMA and RMA, but nimodipine sensitivity of the contraction increased from the aorta to the RMA, suggesting that the contraction was controlled by different sources of calcium. In pressurized RMA, Y-27632 and H-1152 depressed pressure-induced calcium responses and abolished myogenic contraction. These results stress the important differences in calcium signaling between conductance and resistance arteries.     

Involvement of Rho kinase (ROCK) in sepsis-induced acute lung injury

Indirect acute lung injury is associated with high morbidity and mortality. We investigated the link between Rho kinase (ROCK) activation and apoptotic cell death in sepsis induced acute lung injury. This hypothesis was tested by administering a specific, selective inhibitor of ROCK (Y-27632) to rats subjected to cecal ligation and puncture (CLP). Rats were randomly divided into 4 groups as; sham-operated, sham + Y-27632, CLP and CLP + Y-27632. Twenty-four hours later, each experiment was terminated and lungs analyzed. Histopathology was assessed by hematoxylin-eosin staining and the presence of apoptosis was evaluated through the TUNEL assay. Pulmonary activity of caspase 3 and ROCK 1 & 2 were measured by western blot. Interstitial edema, severely damaged pulmonary architecture with massive infiltration of the inflammatory cells and an increase in lung tissue TBARS levels as well as 3-NT to total tyrosine ratios were observed in untreated CLP animals. Pretreatment of animals with Y-27632, reduced lung injury in the CLP induced septic rats in each of these parameters of lung injury (p<0.05). Western immunoblot revealed active caspase cleavage and increased expression of active fragment of ROCK 1 & 2 in the CLP group. TUNEL assay showed an increase in percentage of apoptotic cells when comparing the CLP group with the CLP + Y-27632 group. These results suggest an important role of Rho kinase in sepsis induced lung injury by a mechanism that might be related to oxidative and/or nitrosative stress mediated caspase cleavage leading to apoptosis.     

Inhibition of intrahepatic metastasis of human hepatocellular carcinoma by Rho-associated protein kinase inhibitor Y-27632

Intrahepatic metastasis is one of the most important prognostic factors for patients with hepatocellular carcinoma (HCC). Cell motility mediated by Rho- and p160 Rho-associated coiledcoil forming protein kinase (p160ROCK) signaling pathways has recently been shown to play a critical role in intrahepatic metastasis in human HCC. Furthermore, the stable introduction of dominant-negative p160ROCK into Li7 cells resulted in a reduced metastatic rate in mice with severe combined immunodeficiency (SCID). To investigate whether the specific p160ROCK inhibitor, Y-27632, could also inhibit intrahepatic metastasis, the effect of Y-27632 on the cell motility and intrahepatic metastasis of Li7 was investigated. Y-27632 markedly blocked actin reorganization and motility of Li7 cells mediated by lysophosphatidic acid (LPA). Y-27632 was administered continuously into the peritoneal cavity using a micro-osmotic pump, together with orthotopic implantation of Li7 cells into the liver of SCID mice. Phosphate-buffered saline (PBS) alone was administered as the control. The incidence of mice with metastatic nodules decreased in the Y-27632-treated group. The primary tumor volume at the site of injection was smaller in the Y-27632-treated group compared with the control group, but the difference was not statistically significant. Histologically, control tumors showed infiltrative growth into the sinusoidal area at the tumor boundary, whereas Y-27632-treated tumors showed expansive growth and low invasiveness. These findings confirm the importance of the Rho/p160ROCK signaling pathway in intrahepatic metastasis of human HCC, and indicate that Y-27632 may be useful for the prevention of intrahepatic metastasis of human HCC.     

Comparison of inhibitory effects of Y-27632, a Rho kinase inhibitor, in strips of small and large mesenteric arteries from spontaneously hypertensive and normotensive Wistar-Kyoto rats.

Since Y-27632, a specific inhibitor of Rho kinase, decreases the blood pressure in spontaneously hypertensive rats (SHR), it is suggested that Rho kinase is involved in the pathophysiology of hypertension. However, the effects of Y-27632 on isolated resistance arteries have never been determined. This study aimed to examine the possible role of the Rho/Rho kinase pathway during arterial contraction in isolated resistance arteries from SHR. The profile of arterial relaxant effects of Y-27632 was compared in endothelium-denuded strips of small and large mesenteric arteries from 13-week-old SHR and normotensive Wistar-Kyoto rats (WKY). The addition of 10(-6) mol/l norepinephrine (NE) to the strips of small arteries caused an initial peak followed by a tonic contraction in both strains. There was no difference between the two strains in either the initial peak or the tonic contraction. The addition of Y-27632 (0.3-3 micromol/l) to the tonic contraction of these strips caused a concentration-dependent relaxation in both strains. The relaxation was greater in SHR than in WKY. Similar results were observed in strips of large arteries. The relaxant effects of Y-27632 were greater in the large artery than in the small artery. Y-27632 also induced a concentration-dependent relaxation in strips precontracted with 65.9 mmol/l K+ depolarization. In both arteries, this relaxation was greater in SHR. The relaxant effects of Y-27632 were greater in the K+-contracted strips than in the NE-contracted strips. We conclude that Y-27632 shows the greater relaxant effects on the SHR arteries, and the effects are more evident in the large artery and in the K+-contracted strips.     

高糖通过Rho/ROCK信号通路诱导人肾小球系膜细胞的炎症反应及纤维化

目的 探讨Rho/ROCK信号通路在高糖诱导的人肾小球系膜细胞(HMCs)炎症反应及纤维化中的作用.方法 将传代培养的HMCs同步化后分组:(1)正常糖浓度对照组(NG,5.5 mmol/L葡萄糖);(2)高糖组(HG,30 mmol/L葡萄糖);(3)甘露醇渗透压对照组(Man,5.5 mmol/L葡萄糖+24.5 mmol/L甘露醇);(4)NG+Y-27632(10 μmmol/L)组;(5)HG+Y-27632(10 μmmol/L)组,培养12、24、36、48、72 h后收集上清及细胞,用Western印迹检测RhoA蛋白的活化,用实时PCR检测细胞中RhoA、ROCK-Ⅰ、结缔组织生长因子(CTGF)、肿瘤坏死因子α(TNF-α)mRNA浓度的变化,用ELISA方法检测上清中纤维连接蛋白(FN)、CTGF、TNF-α的蛋白含量.结果 (1)高糖刺激HMCs的RhoA活化,于30 min即可出现活性升高,1 h达到高峰,之后活化的RhoA表达逐渐下降(P=0.02).(2)高糖培养下的HMCsRhoA、ROCK-Ⅰ、CTGF、TNF-α mRNA的表达较NG组明显升高(P＜0.05),并有一定的时间依赖性,Man组与NG组相比差异无统计学意义(P＞0.05).(3)经Y-27632预处理后,在正常糖和高糖浓度培养24 h或48 h后,NG+Y-27632组和HG+Y-27632组与未处理组相比RhoA、ROCK-Ⅰ、CTGF、TNF-α mRNA的表达明显下降(P＜0.01).(4)高糖呈时间依赖方式增加HMCs的FN、CTGF、TNF-α分泌(P＜0.05).(5)经Y-27632预处理,继续培养12、24、36、48、72 h后NG组和HG组中FN、CTGF、TNF-α蛋白的分泌较处理前明显降低(P＜0.05).结论 高糖可通过Rho/ROCK信号通路介导HMCs的炎症反应和纤维化,抑制此通路可作为减缓糖尿病肾病发生发展的潜在靶点.

Abstract：

Objective To investigate the role of Rho/ROCK signaling pathway in the process of human mesangial cells (HMCs) inflammation and fibrosis induced by high glucose. Methods Synchronized HMCs were divided into following groups: ( 1 ) Normal glucose control group ( NG, 5.5 mmol/L glucose); ( 2 ) High glucose group ( HG, 30 mmol/L glucose); (3) Mannitol group( Man,5.5 mmol/L glucose+ 24.5 mmol/L mannitol); (4) NG +Y-27632 group( 10 μ mmol/L Y-27632 ); ( 5 ) HG Y-27632 group ( 10 μmmol/L Y-27632 ). The supernatant and cells were collected at 0,12,24,36,48, and 72 h. Western blot was used to detect the active RhoA and total RhoA,while RhoA, ROCK-Ⅰ, CTGF, and TNF-α mRNA expressions were determined with realtime PGR method in the cells, then ELISA method was used to check protein levels of FN, CTGF, and TNF-α in the supernatant. Results ( 1 ) RhoA activation was stimulated after treatment for with 30 mmol/L glucose, peaked at 1 h, and then decreased ( P = 0. 02). (2) RhoA, ROCK-Ⅰ, CTGF, and TNF-α mRNA expressions in HMC cultured under high glucose were higher than those in the normal group ( P ＜ 0.05 ), and there was certain time-dependence. Besides, there was no statistical significance between Man and NG groups( P＞0. 05 ). ( 3 ) After Y-27632 pretreatment and being cultured with normal glucose and high glucose for24 h or48 h, RhoA, ROCK-Ⅰ, CTGF, and TNF-α mRNA expressions were significantly decreased ( P＜0.01 ) as compared with groups without treatment. (4) High glucose increased FN, CTGF,and TNF-α protein secretion of HMC in a time-dependent manner( P＜0. 05 ). ( 5 ) After Y-27632 pretreatment and being cultured with normal and high glucose for 12,24,36,48,72 h, FN, CTGF, and TNF-α protein secretions were significantly reduced( P＜0.05 ). Conclusion Rho/ROCK signaling pathway may mediate inflammation and fibrosis induced by high glucose in HMCs, supporting a potential role for inhibitors of Rho/ROCK in the treatment of diabetic nephropathy.     

Blockade of Rho/Rho-associated coiled coil-forming kinase signaling can prevent progression of hepatocellular carcinoma in matrix metalloproteinase-dependent manner

Aim:  There is growing evidence that the Rho/Rho-associated coiled coil-forming kinase (ROCK) signaling pathway is upregulated in tumors and plays a key role in cancer invasion and metastasis. Our aim was to test the anticancer effects of Rho/ROCK inhibitor, Y-27632, including possible mechanisms in a highly-metastasizing hepatocellular carcinoma (HCC) mouse model on its secretion of matrix metalloproteinase (MMP) and tumor progression.
Methods:  Following orthotopic implantation of CBO140C12 HCC tumor fragments into the liver of mice, the mice were randomly assigned to a Y-27632-treated group or control group. After treatment for 4 weeks, specimens were obtained to evaluate tumor size, metastases, and immunohistochemical findings. In vitro , we examined the effects of Y-27632 and RhoC siRNA on MMP-2 and -9 expressions, invasiveness, and apoptosis in cultured tumor cells.
Results:  Both RhoA and RhoC were upregulated in HCC-bearing livers, and Y-27632 significantly inhibited not only tumor growth and intrahepatic metastasis ( P  < 0.05), but also tumoral MMP-9 expression. Moreover, Y-27632 treatment resulted in large necrotic areas in tumors. In vitro , Y-27632 and RhoC siRNA reduced MMP-2 and -9 expressions, as well as the chemotactic migration of tumor cells dose-dependently, and increased apoptosis eight times.
Conclusion:  Y-27632 suppresses progression and limits the intrahepatic metastasis of established HCC. This could be linked to the decreased MMP expression and induction of apoptosis in tumor cells. Rho signaling may prove to be a productive target in anticancer therapy.     

Attenuated noradrenaline-induced contraction of pulmonary arteries from rats treated with monocrotaline: role of rho kinase

Noradrenaline-induced pulmonary artery contraction was reduced in monocrotaline-treated rats. The possibility that this could be due to alterations in the rho kinase pathway was examined in this study. A combination of nifedipine (10(-6) M) and thapsigargin (10(-6) M) attenuated noradrenaline-induced contraction significantly more in artery segments from monocrotaline-treated rats than in artery segments from control rats indicating a reduced role for calcium sensitization in artery segments from monocrotaline-treated rats. In artery segments permeabilized with ionomycin, CaCl(2) (1.25 mmol/l) produced significantly greater contraction in monocrotaline treated rats compared with control rats. Addition of noradrenaline (10(-5) M) to the bath produced further contractions in both groups. However, noradrenaline-induced contraction was less in monocrotaline-treated rats compared with controls. Y-27632 concentration dependently relaxed ring segments of pulmonary artery pre-contracted with noradrenaline (10(-5)M). The pIC(50) values were 6.46+/- 0.09 (n=5) 5.81+/- 0.06 (n=5) in control and pulmonary hypertensive rings, respectively. The maximum relaxation to Y-27632 was significantly higher in monocrotaline-treated rats. ROCK II was the predominant isoform of rho kinase expressed in the pulmonary artery. The level of expression was increased in rats treated with monocrotaline. These results would suggest that while basal rho kinase activity was elevated in monocrotaline-induced pulmonary hypertension, noradrenaline-induced contraction was attenuated, suggesting poor coupling of the receptor activation to rho kinase activation.