SphK1/S1P Mediates PDGF-Induced Pulmonary Arterial Smooth Muscle Cell Proliferation via miR-21/BMPRII/Id1 Signaling Pathway

• Main Authors: Fangwei Li, Jian Wang, Yanting Zhu, Lu Liu, Wei Feng, Wenhua Shi, Qingting Wang, Qianqian Zhang, Limin Chai, Manxiang Li
• Format: Article
• Language: English
• Published: Cell Physiol Biochem Press GmbH & Co KG 2018-11-01
• Series: Cellular Physiology and Biochemistry
• Subjects: SphK1; S1P; PDGF; Pulmonary Arterial Smooth Muscle Cell; Proliferation; miR-21; BMPRII; Id1
• Online Access: https://www.karger.com/Article/FullText/495243

Background/Aims: The underlying molecular mechanisms involved in sphingosine kinase 1 (SphK1)/sphingosine 1-phosphate (S1P) mediation of platelet-derived growth factor (PDGF)-induced pulmonary arterial smooth muscle cell (PASMC) proliferation are still unclear, and the present study aims to address this issue. Methods: Small interfering RNA (siRNA) and microRNA inhibitor transfection was performed to block the expression of SphK1, bone morphogenetic protein receptor II (BMPRII) and microRNA-21 (miR-21). Gene expression levels of SphK1, BMPRII and inhibitor of DNA binding 1 (Id1) were detected by immunoblotting, miR-21 expression level was examined with qRT-PCR, and S1P production was measured by ELISA. Additionally, PASMC proliferation was determined by BrdU incorporation assay. Results: Our results indicated that PDGF increased the expression of SphK1 protein and S1P production, up-regulated miR-21 expression, reduced BMPRII and Id1 expression, and promoted PASMCs proliferation. Pre-silencing of SphK1 with siRNA reversed PDGF-induced S1P production, miR-21 up-regulation, BMPRII and Id1 down-regulation, as well as PASMC proliferation. Pre-inhibition of miR-21 also blocked BMPRII and Id1 down-regulation as well as PASMC proliferation caused by PDGF. Knockdown of BMPRII down-regulated Id1 expression in PASMCs. We further found that inhibition of PI3K/Akt and ERK signaling pathways, particularly ERK cascade, suppressed PDGF-induced above changes. Conclusion: Our study indicates that SphK1/S1P pathway plays an important role in PDGF-induced PASMC proliferation via miR-21/BMPRII/Id1 axis and targeting against SphK1/S1P axis might be a novel strategy in the prevention and treatment of pulmonary arterial hypertension (PAH).