Hepatoma-derived growth factor enhances osteoblastic transformation of rat aortic vascular smooth muscle cells in vitro

• Published in: Life sciences (1973) 2020-09, Vol.256, p.117964, Article 117964
• Main Authors: Cheng, Cheng-I, Chang, Huoy-Rou, Tai, Ming-Hong, Chou, Ming-Huei, Chen, Guan-Ting, Chen, Po-Han, Kao, Ying-Hsien
• Format: Article
• Language: English
• Subjects: 1-Phosphatidylinositol 3-kinase; Actin; AKT protein; Alkaline phosphatase; Aorta; Arteriosclerosis; Biomedical materials; Calcification; Calcification (ectopic); Calcium; Cbfa-1 protein; Cell migration; Cell proliferation; Conversion; Gene silencing; Genetic transformation; Growth factors; Hepatoma; MAP kinase; Markers; Muscles; NF-κB protein; Osteoblasts; Osteogenic factor; Osteopontin; Phosphatase; Phosphorylation; Regulators; RNA-mediated interference; Signal transduction; Signaling; Signaling transduction; siRNA; Smooth muscle; Synergism; Transformations; Vascular calcification; Vascular remodeling; Western blotting
• ISSN: 0024-3205; 1879-0631
• DOI: 10.1016/j.lfs.2020.117964

Vascular smooth muscle cells (VSMCs) are important regulators of vascular functions and their conversion to osteoblasts is a key to development of vascular calcification. This study aimed to characterize in vitro effect of hepatoma-derived growth factor (HDGF) on phenotypic conversion of cultured aortic VSMCs into osteoblast-like cells. Cell proliferation and migration assays were used to examine cell behaviors. Western blotting, alkaline phosphatase activity and calcium staining were used to evaluate osteoblastic marker expression and function, respectively. Recombinant HDGF treatment enhanced VSMC growth and motility. Treatment of osteogenic medium (OM) increased expression of not only HDGF but also osteoblastic markers, including Runx2 and osteopontin (OPN), while VSMC marker α-smooth muscle actin (α-SMA) declined. Coincidentally, HDGF and OM treatment alone stimulated signaling activities in both PI3K/Akt and MAPK pathways. Conversely, inhibition of Akt and p38 significantly blocked the OM-upregulated HDGF, Runx2, and OPN expression and NF-κB phosphorylation, but did not reversed the α-SMA downregulation, implicating the involvement of Akt and p38 activities in the osteoblastic transformation of VSMCs. Small interfering RNA-mediated HDGF gene silencing effectively prevented the Runx2 and OPN upregulation, alkaline phosphatase activation, and calcium deposition, but did not affect the α-SMA levels in the transformed cells, supporting the involvement of HDGF in regulation of Runx2 and OPN expression. In conclusion, in synergism with other osteogenic factor, HDGF may promote the progression of osteobastic transformation of VSMCs via Akt and p38 signaling pathways and contribute to vascular calcification in arteriosclerosis. HDGF (PubChem CID:); LY294002 (PubChem CID: 3973); PD98059 (PubChem CID: 4713); SB203580 (PubChem CID: 176155); SB431542 (PubChem CID: 4521392); SP600125 (PubChem CID: 8515); Wortmannin (PubChem CID: 312145).