Growth characteristics and functions of rat vascular adventitia fibroblast subpopulations

AIM: To observe in vitro monoclonal culture, proliferation characteristics and vascular functions of SD rat thoracic aorta adventitial fibroblasts. METHODS: Vascular adventitial fibroblasts were individually expanded using cloning rings. Phenotypic characteristics of the cells were identified by RT-PCR. The growth ability of the cells was determined by methyl thiazolyl tetrazolium (MTT) assay. Fluorescent quantitative PCR was used to detect the mRNA expression of preproendothelin-1 (preproET-1) induced by angiotensinⅡ (AngⅡ) and treated with AngⅡ receptor antagonist losartan and PD-123319. RESULTS: Spindle cells and round cells were isolated using cloning rings.The amplified PCR products of von Willebrand factor, CD8, desmin and myosin heavy chain was not expressed in both cells. For spindle cells, the exponential phase of growth was from the 2nd day to the 4th day after passage. For round cells, the exponential phase of growth was from the 3rd day to the 5th day after passage. The concentration dependence (0~1 000 nmol/L) of AngⅡ was observed to significantly increase the expression of preproET-1 mRNA in the round cells (P<0.01), and AngⅡ had no significant effect on the mRNA expression of preproET-1 in the spindle cells. Losartan blocked the AngⅡ-induced mRNA expression of preproET-1 in the round cells, and had no significant effect on the mRNA expression of preproET-1 in the spindle cells. CONCLUSION: Rat vascular adventitial fibroblasts can be isolated using cloning rings, and 2 different phenotypic cells are obtained. AngⅡ significantly increases the mRNA expression of preproET-1 in the round cell subpopulation, suggesting that the 2 subpopulations may play different roles in vascular remodeling and reparative process.