The role of hypertension-related gene in aortic vascular smooth muscle cells from mice and rats

Objective To study the role of hypertension-related gene (HRG-1) in cardiovascular disea se.Methods The expression of HRG-1 was analyzed with RT-PCR and Northern blotting.Va scular smooth muscle cell (VSMC) proliferation was measured with (3) H-TdR inco rporation and was confirmed with histological analysis.Results Northern blot analysis showed that HRG-1 mRNA was expressed not only in VSMC, b ut als o in various rat tissues (heart, brain, lung, kidney, and liver).In addition, the expression of HRG-1 mRNA in heart, brain, kidney and liver of spontaneously hypertensive rat (SHR) was lower than that in the same tissues of Wistar-Kyoto rat (WKY).Semi-quantitative RT-PCR and histological analysis showed that the expression of HRG-1 mRNA in ApoE-knockout mice and in animal models of rest enosis was decreased and neointimal formation was observed in both models.ET, AII, and IL-1 stimulating VSMC proliferation reduced the expression of HRG-1 m RNA of VSMC.Atrial natriuretic factor (ANF), calcitonin gene-related peptide and adrenomedullin, inhibited VSMC proliferation and elevated the expression of HRG-1 mRNA.These effects could be blocked or attenuated by their correspondin g antagonists or antibodies.Conclusion HRG-1 is a gene related to VSMC proliferation.It may play an important role i n several occlusive cardiovascular diseases including atherosclerosis, restenosi s and hypertension.