摘要
目的:在离体钙化的血管平滑肌细胞上,观察内皮素受体阻断剂对血管平滑肌细胞(VSMCs)钙化的影响,探讨内皮素(ET)促进细胞钙化的信号转导和分子机制。方法:β-磷酸甘油制备钙化VSMCs;通过细胞钙含量,[45Ca2+]摄取,碱性磷酸酶活性测定,判断钙化程度,[3H]-胸腺嘧啶([3H]-TdR)和[3H]-亮氨酸([3H]-Leu)掺入测定细胞DNA合成,竞争性定量RT-PCR测定VSMCs骨桥蛋白(OPN)mRNA水平,放射免疫法测定培养上清ET含量。结果:与正常对照VSMCs相比,钙化VSMCs内钙含量,[45Ca2+]摄入及碱性磷酸酶活性分别增加119%、174%和7倍(P<0.01),OPN表达增加86%;细胞生长活跃,[3H]-TdR和[3H]-Leu分别增加71%和35%;钙化细胞培养基中内皮素含量较对照组增加35%(P<0.05)。而钙化加内皮素受体阻断剂BQ123组明显减轻VSMCs钙化程度,钙含量,[45Ca2+]摄入及碱性磷酸酶活性分别较钙化组降低33%、37%、40%(均P<0.01),OPN表达明显下调25%;细胞增殖活性明显降低。结论:BQ123可减轻VSMCs钙化程度,表明ET促进VSMCs钙化主要是通过内皮素A型受体(ET-A)途经。
AIM： To observe the effect of endothelin receptor antagonist （BQ123） on calcification in rat vascular smooth muscle cells （VSMCs） in vitro. METHODS： Calcification of cultured rat VSMCs was produced by incubation with β - glycerophosphate. Calcium content, Ca^2＋ deposition and alkaline phosphatase activity were analyzed to estimate the extent of calcification. The DNA synthesis was detected by [^3H ] - TdR and [^3H ] - Leu incorporation. Osteopontin （OPN） mRNA was measured by competitive quantitative RT -PCR. Content of ET was measured by radioimmunoassay （RIA）. RESULTS： The results showed that compared with the control, the content of calcium, [^45 Ca^2＋ ] uptake and alkaline phosphatases activities in calcified VSMCs increased by 118% , 174% and 7 - fold （ all P 〈 0. 01 ） , respectively. The expression of OPN mRNA in calcified VSMCs was up - regulated by 86% （ P 〈 0.01 ）. The calcified VSMCs grew rapidly, in which [^3H] - TdR and [^3H] - Leu were elevated by 71% and 35%. The content of ET in calcified VSMCs medium was increased by 35% as compared with control. Furthermore, calcified VSMCs plus BQ123 groups obviously relieved degree of calcification, of which calcium content, Ca^2＋ deposition and alkaline phosphatase activities were 33% , 37% , 40% lower than those in calcified VSMCs （ P 〈 0. 01 ） , respectively. The expression of OPN mRNA was downregulated by 25% （P 〈 0. 01 ） and significantly inhibited VSMCs proliferation. CONCLUSION： BQ123 reduces VSMCs calcification, suggesting that ET promotes calcification in VSMCs mainly by ET/ ETA receptor pathway.
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
2008年第9期1690-1693,共4页
Chinese Journal of Pathophysiology
基金
国家自然科学基金资助项目(No.30470693)
湖北省教育厅重点项目(No.2004D008)
郧阳医学院基础医学院中青年科技创新团队(No.2005CXZ02)
