Abstract: FR-PO386
THOC5-Dependent Posttranscriptional Control Maintains Vascular Smooth Muscle Cells Homeostasis Against CKD-Related Vascular Calcification
Session Information
- Hypertension and CVD: Basic
November 03, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Hypertension and CVD
- 1601 Hypertension and CVD: Basic
Authors
- He, Fan, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
- Cheng, Anying, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
- Wang, Yuyao, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
- Li, Qing, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
- Lv, Yongman, Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei, China
Background
Modulation of the vascular smooth muscle cell (VSMC) osteogenic transition plays a fundamental role in CKD-associated VC. Despite transcriptional control mechanisms of VSMC osteogenic transition having been extensively studied, posttranscriptional regulation is still awaiting elucidation. In the present study, we explore the mechanism of THOC5-dependent VSMCs osteochondrogenic switching.
Methods
Von Kossa staining and immunohistochemistry staining were used to detect calcification and expression of THOC5 respectively. Thoc5 shRNA and Thoc5 overexpression lentivirus were used to modulate the expression of Thoc5. RNA-Seq combined with RIP-Seq was used to explore the target mRNAs that directly bind to THOC5, and FISH was used to confirm its subcellular localization.
Results
Immunohistochemical staining showed significantly increased THOC5 expression in the calcified artery of CKD patients. Besides, calcification-induced increase of THOC5 expression was found in both in vivo and in vitro calcification models. The overexpression of Thoc5 relieves the calcification and osteogenic differentiation of VSMCs significantly in vitro, which is mainly manifested by the reduction of calcium ion deposition and the decreased expression of osteogenic markers. Furthermore, RNA-Seq revealed that THOC5 overexpression in osteogenic-induced VSMCs closely resembled the gene expression changes induced on TGF-β treatments in cultured VSMCs. RIP-Seq was selected to detect target genes of THOC5. It was found that THOC5 directly interacts with Guanylate exchange factors (GEFs) mRNAs, and is required for their export. Thereby THOC5 maintaining RhoA GTPase activation contributes to increasing the expression of VSMCs contraction marker, which maintains the contraction phenotype of VSMCs. ROCK (Rho-kinase) inhibitor reversed the protective role of THOC5 on VC.
Conclusion
Our data introduce the binding of THOC5 to GEFs as a novel mechanism contributing to maintaining VSMCs homeostasis and imply THOC5 as a potential intervention node for vascular calcification diseases.
Funding
- Government Support – Non-U.S.