[The effect of survivin expression on the apoptosis and proliferation of hypoxic human pulmonary arterial smooth muscle cells].

Objective: Survivin is a new member of the inhibitor of apoptosis (IAP) family of proteins, which is also the strongest inhibitor of apoptosis.It inhibits apoptosis and promotes cell proliferation. This study aims to explore the effect of survivin expression on the apoptosis and proliferation of hypoxic human pulmonary arterial smooth muscle cells (HPASMCs).

Methods: HPASMCs were divided randomly into 6 groups:Normoxia (N group):cultured under normoxia;Normoxia+YM155(NY group):cultured under normoxia with YM155, a selective survivin inhibitor, for 24 h;Hypoxia(H group):cultured under hypoxia for 24 h;Hypoxia+1 nmol/L YM155 (HY1 group):cultured under hypoxia with 1 nmol/L YM155 for 24 h; Hypoxia+10 nmol/L YM155 (HY10 group):cultured under hypoxia with 10 nmol/L YM155 for 24 h;Hypoxia+100 nmol/L YM155 (HY100 group):cultured under hypoxia with 100 nmol/L YM155 for 24 h. The mRNA and protein expressions of survivin were measured by real time PCR and Western Blot respectively. Cell proliferation was determined using a Cell Counting Kit-8 (CCK-8). Apoptosis was detected with a TUNEL test.

Results: The mRNA and protein expressions of survivin were observed in the H group (17 086 ± 1 044, 0.837 ± 0.027), but not in the N group (1, 0.016 ± 0.06) . The cell proliferation in H group ( 1.44 ± 0.12) was significantly increased compared with that of the N group (0.99 ± 0.07, q = 6.484, P < 0.05). The apoptosis in the H group (0.61 ± 0.50) was significantly decreased compared with that in the N group (2.68 ± 1.36, q = 3.532, P < 0.05). As compared with the H group, the survivin mRNA, survivin protein and cell proliferation in hypoxia plus 1 nmol/L, 10 nmol/L, 100 nmol/L YM155 groups (8 074 ± 2 135, 5 614 ± 709, 1 382 ± 347,0.382 ± 0.041,0.281 ± 0.025,0.021 ± 0.002, 1.318 ± 0.067, 1.168 ± 0.071,0.845 ± 0.129, q = 8.59, 11.14, 15.53, 20.26, 24.77, 36.36, 2.58, 3.98, 8.73, all P < 0.05) significant decreased , but the apoptosis in hypoxia plus 1 nmol/L, 10 nmol/L, 100 nmol/L YM155 groups (5.52 ± 1.71, 6.66 ± 1.49, 7.97 ± 1.93, q = 6.014, 7.413, 9.023, all P < 0.05) enhanced in a dose-dependent manner.

Conclusions: Survivin was expressed in hypoxic HPASMCs, but not in normal HPASMCs. Treatment with the survivin inhibitor YM155 led to decreased proliferation and enhanced apoptosis in hypoxic HPASMCs. Survivin might be a significant target for human hypoxic pulmonary hypertension.