[Up-regulation of connexin 43 (Cx43) by angiotensin II promotes the proliferation and migration of human pulmonary artery smooth muscle cells].

Objective To explore the role of Cx43 in the proliferation and migration of human pulmonary arterial smooth muscle cells (HPASMCs) induced by angiotensin II (Ang II). Methods HPASMCs were cultured in vitro and randomly divided into four groups: control group, Ang II group, Ang II combined with DMSO group, and Ang II combined with candesartan group, and cells were collected in logarithmic growth phase. Cell viability was detected by CCK-8 assay; the migration ability of HPASMCs were measured by wound-healing and TranswellTM assay. The protein levels of Cx43, osteopontin (OPN), proliferating cell nuclear antigen (PCNA), SMAD2 and SMAD3 in HPASMCs were detected by Western blot analysis. Results Compared with the control group, the expression of OPN and PCNA proteins significantly went up in Ang II group, and the cell proliferation and migration ability increased. The cell proliferation and migration ability of the Ang II combined with candesartan group were significantly lower than that in the Ang II group. Compared with the control group, the Cx43 protein and its phosphorylation level increased significantly in the Ang II group, and the protein expression of SMAD2 and SMAD3 increased, while the expression of each protein in the Ang II combined with candesartan group was significantly lower than those in the Ang II group. Conclusion Ang II up-regulates the expression of Cx43 protein to promote the proliferation and migration of HPASMCs, which may be related to the activation of SMAD2/3 signaling pathway.