X Wang1, L Xue, L Tong. 1. Department of Cardiovascular Research, First Hospital Beijing Medical University, Beijing 100034.
Abstract
OBJECTIVE: To study the effects of vasoactive peptides [adrenomedullin (Adm), C-type natriuretic peptide (CNP), calcitonin gene related peptide (CGRP), somatostatin(SST) and parathyroid hormone-related protein] on homocysteine (Hcy)-induced proliferation of cultured rabbit vascular smooth muscle cell (VSMC). METHODS: Techniques of cell culture, 3H-thymidine incorporation, nuclei, membrane and cytosol fractions were isolated by differential centrifugation and PKC activity was measured. RESULTS: Hcy significantly stimulated DNA synthesis of VSMC. Adm, CNP, CGRP, SST, and PTHrP had no effect on basal 3H-TdR incorporation, but they could inhibit Hcy-induced 3H-TdR incorporation in dose-dependent manner. PKC inhibitor (H7 and Stauroporine) could inhibit VSMC proliferation induced by Hcy with reduction of 3H-TdR incorporation by 50% (P < 0.01) and 56% (P < 0.01), respectively. PKC was found to be distributed equally in nuclear fraction and membrane particulate, and higher in cytosol fraction in untreated VSMC. Treatment of VSMC with 10(-4) mol/L Hcy resulted in a significant increase in membrane-associated PKC combined with a loss of enzyme activity in the cytosol and nuclear fractions. Adm, CNP, CGRP and PTHrP altered the distribution of PKC activity induced by Hcy. CONCLUSION: Adm, CNP, CGRP and PTHrP inhibited VSMC proliferation possibly through PKC pathway.
OBJECTIVE: To study the effects of vasoactive peptides [adrenomedullin (Adm), C-type natriuretic peptide (CNP), calcitonin gene related peptide (CGRP), somatostatin(SST) and parathyroid hormone-related protein] on homocysteine (Hcy)-induced proliferation of cultured rabbit vascular smooth muscle cell (VSMC). METHODS: Techniques of cell culture, 3H-thymidine incorporation, nuclei, membrane and cytosol fractions were isolated by differential centrifugation and PKC activity was measured. RESULTS:Hcy significantly stimulated DNA synthesis of VSMC. Adm, CNP, CGRP, SST, and PTHrP had no effect on basal 3H-TdR incorporation, but they could inhibit Hcy-induced 3H-TdR incorporation in dose-dependent manner. PKC inhibitor (H7 and Stauroporine) could inhibit VSMC proliferation induced by Hcy with reduction of 3H-TdR incorporation by 50% (P < 0.01) and 56% (P < 0.01), respectively. PKC was found to be distributed equally in nuclear fraction and membrane particulate, and higher in cytosol fraction in untreated VSMC. Treatment of VSMC with 10(-4) mol/L Hcy resulted in a significant increase in membrane-associated PKC combined with a loss of enzyme activity in the cytosol and nuclear fractions. Adm, CNP, CGRP and PTHrP altered the distribution of PKC activity induced by Hcy. CONCLUSION:Adm, CNP, CGRP and PTHrP inhibited VSMC proliferation possibly through PKC pathway.
Authors: Ryan T Dackor; Kimberly Fritz-Six; William P Dunworth; Carrie L Gibbons; Oliver Smithies; Kathleen M Caron Journal: Mol Cell Biol Date: 2006-04 Impact factor: 4.272