ANGIOTENSIN-CONVERTING ENZYME AND KININASE-II-LIKE ACTIVITIES IN CULTURED VALVULAR INTERSTITIAL-CELLS OF THE RAT-HEART
ANGIOTENSIN-CONVERTING ENZYME AND KININASE-II-LIKE ACTIVITIES IN CULTURED VALVULAR INTERSTITIAL-CELLS OF THE RAT-HEART
复制标题
DOI：
10.1016/0008-6363(96)88547-6
复制
发表时间：
1995-01-01
影响因子：
10.8
通讯作者：
WEBER, KT
中科院分区：
文献类型：
--
作者：
KATWA, LC;RATAJSKA, A;WEBER, KT
目的：血管紧张素转换酶（ACE）在高胶原更新的细胞部位（如心脏瓣膜）的功能尚不确定。本研究的目的是评估血管紧张素转换酶和激酶-II样活性和胶原蛋白周转培养的成年大鼠心脏瓣膜间质细胞。研究方法：通过免疫标记（罗丹明鬼笔环肽、结蛋白和Griffonia simplicifolia凝集素）确定瓣膜间质细胞表型，并通过逆转录-聚合酶链反应分析、ACE单克隆抗体和体外放射自显影分别确认ACE mRNA和蛋白的存在。用高效液相色谱法分析血管紧张素转换酶（ACE）和类激酶Ⅱ活性。用免疫印迹结合法检测瓣膜间质细胞膜血管紧张素Ⅱ（AT）和缓激肽受体。分别用酶联免疫吸附法和酶谱法测定瓣膜间质细胞培养液中I型胶原和胶原酶的含量。用北方印迹法和原位杂交法检测培养的瓣膜间质细胞I型胶原mRNA的表达。结果如下：在完整的瓣膜间质细胞或其细胞膜中，我们发现：（1）肌动蛋白微丝，但不显示结蛋白或凝集素标记;（2）ACE mRNA表达和结合活性;（3）血管紧张素I转化为血管紧张素II，这一过程可被50 μ M赖诺普利完全抑制，而激酶-II样活性超过ACE活性，赖诺普利不抑制;（4）瓣膜间质细胞膜制备物中的AT和缓激肽受体;（5）I型胶原mRNA表达和胶原酶活性;和（6）血管紧张素II。诱导I型胶原合成和mRNA表达增加。结论：培养的瓣膜间质细胞代表一种非内皮、非平滑肌细胞类型，表达ACE和I型胶原mRNA。血管紧张素转换酶和激酶-II样活动在瓣膜间质细胞可能参与调节肽，影响胶原周转。血管紧张素II刺激这些细胞中I型胶原合成和mRNA表达。
Objective: The function of angiotensin converting enzyme (ACE) at cell sites of high collagen turnover, such as heart valves, is uncertain. The aim of this study was to assess ACE and kininase-II-like activities and collagen turnover in cultured valvular interstitial cells of the adult rat heart. Methods: The valvular interstitial cell phenotype was determined by immunolabelling (rhodamine phalloidin, desmin, and Griffonia simplicifolia lectin), and the presence of ACE mRNA and protein was confirmed by reverse transcriptase-polymerase chain reaction analysis, ACE monoclonal antibody and in vitro autoradiography, respectively. ACE and kininase-II-like activities in valvular interstitial cells were analysed by high performance liquid chromatography. Angiotensin II (AT,) and bradykinin receptors in valvular interstitial cell membranes were examined by western immunoblotting and binding assay. Type I collagen and collagenase in valvular interstitial cell culture media were determined by ELISA and zymography, respectively. Type I collagen mRNA expression in cultured valvular interstitial cells was determined by northern blot analysis and in situ hybridisation. Results: In intact valvular interstitial cells or their cell membrane we found: (1) actin microfilaments, but not desmin or lectin labelling; (2) ACE mRNA expression and binding activity; (3) conversion of angiotensin I to angiotensin II, which was completely inhibited by 50 mu M lisinopril, while kininase-II-like activity exceeded ACE activity and was not inhibited by lisinopril; (4) AT, and bradykinin receptors in valvular interstitial cell membrane preparations; (5) type I collagen mRNA expression and collagenase activity; and (6) angiotensin II. induced increase in type I collagen synthesis and mRNA expression. Conclusions: Cultured valvular interstitial cells represent a nonendothelial, non-smooth-muscle cell type that expresses mRNA for ACE and type I collagen. ACE and kininase-II-like activities in valvular interstitial cells may be involved in the regulation of peptides that influence collagen turnover. Angiotensin II stimulates type I collagen synthesis and mRNA expression in these cells.