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Objective To study the β-adrenergic receptors ( adrenergic receptor , AR ) - adenylate cyclase ( adenylate cyclase , AC ) - cyclic adenosine monophosphate (cyclic adenosine monophosphate, cAMP) signaling pathway in vascular smooth muscle cells (vascular smooth muscle cell VSMC) proliferation and mitochondrial fusion protein expression ( mitofusin2 , in Mfn2 ) and its downstream signaling molecules . Methods Cultured rat VSMC, treated with different concentrations (5μM , 10 μM , 25μM , 50 μM) , isoproterenol (isoprenaline, ISO) treated with cell counting , water-soluble methyl thiazolyl tetrazolium salt ( WST- 1 ) observed by ISO VSMC proliferation ; different concentrations (5μM, 10μM, 25μM, 50μM) blessing Secretary Colin ( forskolin , FSK ) treatment of VSMC and Western blot detection handled in two ways Mfn2, phosphorylation of Raf-1 (p- Raf-1) and phosphorylated ERK1 / 2 ( p -ERK1 / 2 ) expression of affect ; small interfering RNA (small interfering RNA, siRNA) silencing Mfn2, Western blot observed in each group in Mfn2 p- ERK1 / 2 changes . The results of cell counting and WST-1 display , ISO inhibit VSMC proliferation in a concentration - dependent manner ; Western blot results show that ISO and forskolin can raise Mfn2 expression in a concentration - dependent increase of p-Raf-1 and p- ERK1 / 2 expression showed a concentration -dependent reduction in Mfn2 silencing antagonized the ISO mediated 's p-ERK1 / 2 inhibition . Conclusion 1 , cellular level confirmed that excited βAR able to inhibit the proliferation of VSMC ; βAR - AC- cAMP signaling pathway is upregulated Mfn2 expression by suppression Ras-Raf-ERK/MAPK signaling pathway to inhibit the proliferation of VSMC , indicating that βAR-AC-cAMP signaling pathway is the Mfn2 a upstream signal conditioning path .
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