[Platelet derived growth factor-BB regulates phenotype transformation of pulmonary artery smooth muscle cells via...

Objective: To investigate whether platelet-derived growth factor-BB (PDGF-BB) can regulate phenotypic transformation of pulmonary artery smooth muscle cells (PASMCs) via SIRT3 affecting glycolytic pathway. Methods: The PASMCs were isolated from Sprague Dawley rats. PASMCs were divided into 3 groups by using 2-deoxyglucose (2-DG), an inhibitor of the glycolytic pathway: normal control group, PDGF-BB group(30 ng/ml) and PDGF-BB (30 ng/ml)+2-DG (10 mmol/L) group. In lentivirus-mediated overexpression assay, cells were divided into control group, PDGF-BB group(30 ng/ml), PDGF-BB+deacetylase sirtuin-3 (SIRT3) overexpression group and PDGF-BB+empty vector group. The expression levels of phenotype related index such as α-smooth muscle actin (α-SMA), smooth muscle myosin heavy chain (SM-MHC), calponin, vimentin were detected by qRT-PCR and Western blot. Meanwhile, the expression of α-SMA was detected by cellular immunofluorescence staining. EDU staining was used to detect the proliferation of PASMCs. The expression of SIRT3 was detected by Western blot. The expressions of glucose transporter 1 and aerobic glycolytic enzymes were detected by qRT-PCR and Western blot in lentivirus-mediated overexpression assay. Results: (1) PDGF-BB affects PASMCs phenotypic transformation through glycolytic pathway: compared with normal control group, PDGF-BB significantly decreased the expressions of contractile phenotype markers such as α-SMA, SM-MHC, calponin mRNA and protein (all P<0.05), but it increased the expressions of the synthetic phenotype marker vimentin mRNA and protein (both P<0.05). Cellular immunofluorescence assay showed that PDGF-BB significantly decreased the number of α-SMA positive cells, while 2-DG reversed the process. (2) PDGF-BB promoted cell proliferation through glycolytic pathway: the proliferation of PASMCs was significantly higher in PDGF-BB group than in control group (P<0.05), and which could be significantly reduced by 2-DG (P<0.05). (3) PDGF-BB inhibited the expression of SIRT3 protein in PASMCs: the expression of SIRT3 protein in PDGF-BB group was lower than that in control group (P<0.05). (4) PDGF-BB affected glycolytic pathway through SIRT3:compared with the control group, PDGF-BB significantly increased the expression levels of glucose transporter 1 (Glut1), hexokinase 2 (HK2) and 6-phosphfructo-2-kinase 3 (PFKFB3) mRNA (all P<0.05), which was reserved by over-expression of SIRT3. There were no significant difference in mRNA expression levels between PDGF-BB group and PDGF-BB+empty vector group (P>0.05).Compared with the control group, PDGF-BB significantly increased the expression levels of Glut1, HK2 and PFKFB3 protein(all P<0.05), which was reserved by over-expression of SIRT3. There were no significant differences in protein expression levels between PDGF-BB group and PDGF-BB+empty vector group (all P>0.05). Conclusion: PDGF-BB regulates phenotypic transformation of PASMCs via SIRT3 affecting glycolytic pathway.