7157

TP53

BCC7|LFS1|P53|TRP53;tumor protein p53;TP53;tumor protein p53

antigen NY-CO-13|cellular tumor antigen p53|p53 tumor suppressor|phosphoprotein p53|transformation-related protein 53

17p13.1

protein-coding

Count: P53 knockout; 22059

Chronic hypoxia induces pulmonary arterial remodeling, resulting in pulmonary hypertension and right ventricular hypertrophy. hypoxia has been implicated as a physiological stimulus for p53 induction and hypoxia-inducible factor-1alpha (HIF-1alpha). However, the subcellular interactions between hypoxic exposure and expression of p53 and HIF-1alpha remain unclear. To examine the role of p53 and HIF-1alpha expression on hypoxia-induced pulmonary arterial remodeling, wild-type (WT) and p53 knockout (p53KO) mice were exposed to either normoxia or hypoxia for 8 wk. Following chronic hypoxia, both genotypes demonstrated elevated right ventricular pressures, right ventricular hypertrophy as measured by the ratio of the right ventricle to the left ventricle plus septum weights, and vascular remodeling. However, the right ventricular systolic pressures, the ratio of the right ventricle to the left ventricle plus septum weights, and the medial wall thickness of small vessels were significantly greater in the p53KO mice than in the WT mice. The p53KO mice had lower levels of p21 and miR34a expression, and higher levels of HIF-1alpha, VEGF, and PDGF expression than WT mice following chronic hypoxic exposure. This was associated with a higher proliferating cell nuclear antigen expression of pulmonary artery in p53KO mice. We conclude that p53 plays a critical role in the mitigation of hypoxia-induced small pulmonary arterial remodeling. By interacting with p21 and HIF-1alpha, p53 may suppress hypoxic pulmonary arterial remodeling and pulmonary arterial smooth muscle cell proliferation under hypoxia.