Treprostinil inhibits plateletderived growth factorinduced proliferation of pulmonary artery smooth muscle cells via down regulating phosphorylation of Erk
WANG Qian1, LV Ji-yang2, WANG Yan1, SHI Wei-Qun1, LV Jin-quan1
(1. Department of Pediatrics, 2. Deparment of General Surgery, Affiliated Hospital of Jiangsu University, Zhenjiang Jiangsu 212001,China)
Abstract:Objective: To study the effect of Treprostinil(Trep) on the proliferation of pulmonary artery smooth cells(PASMCs) induced by plateletderived growth factor (PDGF) and potential underlying mechanisms. Methods: Rat PASMCs were isolated and cultured. The experiment included two stages. In the first stage, the cells were divided into 4 groups: control group 1(C1), PD98059 group, PDGF group 1(P1) and PDGF+ PD98059 group; the second stage was also divided into 4 groups: control group 2(C2), Trep group, PDGF group 2(P2) and PDGF+Trep group. PD98059 group was treated with 50 μmol·L-1 PD98059,Trep group was treated with 5 μmol·L-1 Trep,PDGF group 1,2(P1 and P2) were treated with 20 μg·L-1 PDGF, PDGF+ PD98059 was treated with 50 μmol·L-1 PD98059+ 20 μg·L-1 PDGF, and PDGF+Trep group was treated with 5 μmol·L-1 Trep + 20 μg·L-1 PDGF. After 24 hours, MTT assay was used to evaluate the proliferation activity; the morphology of the cells was observed under microscope; the expression of proliferating cell nuclear antigen(PCNA), p-Erk1/2 and t-Erk1/2 in each group was determined by Western blotting. Results: Phase 1: Cell density, cell proliferation activity, PCNA expression and p-Erk/t-Erk ratio in PDGF group were significantly higher than those in control group(P<0.05). Cell proliferation activity, PCNA expression and p-Erk/t-Erk ratio in PDGF+PD98059 group were significantly lower than those in PDGF group(P<0.05). Phase 2: Compared with control group, PDGF group showed higher cell density, cell proliferation activity, intracellular PCNA expression and p-Erk/t-Erk ratio. Compared with PDGF group, PDGF+Trep group showed higher cell density, cell proliferation activity, PCNA expression and p-Erk/t-Erk ratio(P<0.05). Conclusion: Trep could inhibit PDGF-induced rat PASMCs proliferation in vitro, which is associated with down-regulation of Erk1/2 phosphorylation.
[Key words]Treprostinil; pulmonary artery smooth muscle cells; Erk; proliferating cell nuclear antigen(PCNA)