摘要
目的高血压引起的血管重塑与生物机械力的异常增加有关。为了探讨细胞外生物机械力是如何被细胞感受并被转导为细胞内的生物化学信号、最终导致细胞的病理生理反应。方法被分离的大鼠主动脉血管平滑肌细胞种植在底部为橡胶薄膜的细胞培养板上进行体外培养,细胞达80%融合后给予生物机械力刺激不同时间(60/min,15%伸张度)。受刺激后的细胞被收集后通过蛋白印迹(Western blot)方法进行蛋白激酶CβⅡ在细胞内转膜和蛋白激酶CβⅡ蛋白磷酸化分析。此外,受刺激后的细胞用氚标胸腺嘧啶核苷酸标记6 h并进行同位素计数。结果平滑肌细胞在静息状态下蛋白激酶CβⅡ在胞浆和胞膜的分布各占50%,受机械力刺激后蛋白激酶CβⅡ在胞浆和胞膜的分布为20%和80%,呈现出了机械力诱导的蛋白激酶CβⅡ明显地由胞浆向胞膜转位。蛋白激酶CβⅡ磷酸化分析显示:平滑肌细胞受机械力刺激后蛋白激酶CβⅡ能快速磷酸化,并呈现明显的时间依赖性。蛋白激酶CβⅡ磷酸化在受机械力刺激后2 min时达峰值,随后逐渐减弱,而未受机械力刺激的细胞则没有蛋白激酶CβⅡ磷酸化发生。氚标胸腺嘧啶核苷酸掺入实验结果发现,机械力刺激可明显促进细胞DNA合成增加。结论生物机械力可快速激活细胞蛋白激酶CβⅡ,导致蛋白激酶CβⅡ在细胞内转位和磷酸化,最终引起血管平滑肌细胞增殖。该研究对于理解高血压及其相关的心脑血管疾病发生的分子机制和提供对该疾病的防治方法将是非常有用的。
Aim Hypertension-induced cardiovascular remodeling is associated with abnormally increased biomechanical stress. To explore how the cantiovascular cells sense and convert the extracellular mechanical stress into intracellular biochemical signals leading to finally pathophysiological responses. Methods When rat vascular smooth muscle cells cultivated on a flexible membrane were subjected to cyclic strain stress （60 cycles/min, 15% elongation） at various time points, translocation and phosphotylation of protein kinase C （PKC）βⅡ were observed as detected by Western blot analysis. In addition,the stretched vascular smooth muscle cells were labeled using ^3H-thymidine for 6h and then harvested for ^3H-thymidine-labcled cell count. Results Equal distribution of PKCβⅡ was observed in cytosole and membrane of the quiescent vascular smooth muscle cells, respectively. While vascular smooth muscle cells were subjected to mechanical stress, induction of translecation of PKCβⅡ was observed as distributed by 20.9% in the cytosole and 79.1% in the membrane,implying that mechanical stress induced PKCβⅡ translocation from cytosole to membrane. Concomitantly, mechanical forces evoked rapid activation of PKCβⅡ in a time dependent manner showing that phosphorylation of PKCβⅡ peaked at 2min and declined after then in response to mechanical stress, while no phosphorylation of PKCβⅡ occurred in the untreated cells. In addition, mechanical forces significantly induced increase of DNA synthesis of vascular smooth muscle ceils as demonstrated by incorporation of [^3H]-thymidine compared to no treated cells. Conclusion Mechanical stress significantly induced translocation and phosphorylation of PKCβⅡ in the vascular smooth muscle cells leading to increased vascular smooth muscle cell proliferation. This data will he useful for understanding the molecular mechanisms of hypertension and its related cantiovascular diseases, and providing approaches of prevention and treatment of this disease.
出处
《中国动脉硬化杂志》
CAS
CSCD
2005年第5期553-556,共4页
Chinese Journal of Arteriosclerosis
基金
中山大学留学回国人员科研启动基金(1130001)
中山大学基础医学院留学回国人员科研启动基金(20041130-100)资助
作者简介
李朝红,副教授,硕士研究生导师。1997年7月毕业于中山医科大学（现中山大学医学院）．获医学博士学位；1998年5月～2000年7月在奥地利科学院老年病研究所从事博士后研究。主要从事生物机械力（高血压）与血管重塑机制的研究。2001年1月作为高级科学家应邀去美国宾州州立大学进行学术研究-对高血压与心脏重塑机制进行了，深入探讨。2004年11月回国工作；联系电话020-87331447，传真020-87331451。E-mail为lichaohongzq@yahoo．com。
谢富康，教授，博士研究生导师,专门从事组织工程和神经发育生物学研究。
徐清波，教授，博士研究生导师，专门从事心血管疾病的病理学分子机制研究。
