CCAAT/Enhancer-Binding Protein Alpha Is a Novel Regulator of Vascular Smooth Muscle Cell Osteochondrogenic Transition and Vascular Calcification

Pengyuan Chen; Wanzi Hong; Ziying Chen; Flora Gordillo-Martinez; Siying Wang; Hualin Fan; Yuanhui Liu; Yining Dai; Bo Wang; Lei Jiang; Hongjiao Yu; PengCheng He

doi:10.3389/fphys.2022.755371

CCAAT/Enhancer-Binding Protein Alpha Is a Novel Regulator of Vascular Smooth Muscle Cell Osteochondrogenic Transition and Vascular Calcification

Front Physiol. 2022 Feb 28:13:755371. doi: 10.3389/fphys.2022.755371. eCollection 2022.

Authors

Pengyuan Chen^{1

2}, Wanzi Hong^{2

3}, Ziying Chen⁴, Flora Gordillo-Martinez⁵, Siying Wang², Hualin Fan³, Yuanhui Liu⁶, Yining Dai⁶, Bo Wang⁶, Lei Jiang^{3

6}, Hongjiao Yu⁷, PengCheng He^{3

6

8}

Affiliations

¹ Department of Cardiology, Guangdong Provincial People's Hospital's Nanhai Hospital, The Second Hospital of Nanhai District Foshan City, Foshan, China.
² Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
³ School of Medicine, Guangdong Provincial People's Hospital, South China University of Technology, Guangzhou, China.
⁴ Department of Pathology, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, Qingyuan, China.
⁵ Institute of Science and Environment, University of Saint Joseph, Macao, Macao SAR, China.
⁶ Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
⁷ Department of Biochemistry and Molecular Biology, Guangzhou Medical University-Guangzhou Institutes of Biomedicine and Health Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, China.
⁸ School of Medicine, The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China.

Abstract

Aims: Vascular calcification is a common clinical complication of chronic kidney disease (CKD), atherosclerosis (AS), and diabetes, which is associated with increased cardiovascular morbidity and mortality in patients. The transdifferentiation of vascular smooth muscle cells (VSMCs) to an osteochondrogenic phenotype is a crucial step during vascular calcification. The transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα) plays an important role in regulating cell proliferation and differentiation, but whether it regulates the calcification of arteries and VSMCs remains unclear. Therefore, this study aims to understand the role of C/EBPα in the regulation of vascular calcification.

Methods and results: Both mRNA and protein expression levels of C/EBPα were significantly increased in calcified arteries from mice treated with a high dose of vitamin D3 (vD3). Upregulation of C/EBPα was also observed in the high phosphate- and calcium-induced VSMC calcification process. The siRNA-mediated knockdown of C/EBPα significantly attenuated VSMC calcification in vitro. Moreover, C/EBPα depletion in VSMCs significantly reduced the mRNA expression of the osteochondrogenic genes, e.g., sex-determining region Y-box 9 (Sox9). C/EBPα overexpression can induce SOX9 overexpression. Similar changes in the protein expression of SOX9 were also observed in VSMCs after C/EBPα depletion or overexpression. In addition, silencing of Sox9 expression significantly inhibited the phosphate- and calcium-induced VSMC calcification in vitro.

Conclusion: Findings in this study indicate that C/EBPα is a key regulator of the osteochondrogenic transdifferentiation of VSMCs and vascular calcification, which may represent a novel therapeutic target for vascular calcification.

Keywords: CCAAT/enhancer-binding protein alpha; calcium deposition; osteogenic differentiation; vascular calcification; vascular smooth muscle cells.