C/EBP beta-Lin28a Positive Feedback Loop Mediated by C/EBP beta Hypomethylation Promotes the Proliferation and Migration of Vascular Smooth Muscle Cells in Restenosis

Background: The main reason for restenosis (RS) after percutaneous transluminal angioplasty is the excessive proliferation and migration of vascular smooth muscle cells (VSMCs) . C/EBPβ plays an important role in the process of vascular remodeling. However, the role of C/EBPβ in RS has not been clarified. Methods: The type 2 diabetes rat models of RS and atherosclerosis (AS) were established to detect the difference in DNA methylation and expression levels of C/EBPβ. Simultaneously, the effect of C/EBPβ on the proliferation and migration of VSMCs was clarified by regulating C/EBPβ and Lin28a in vitro. The effect of decitabine, a demethylating agent, on the expression of C/EBPβ and Lin28a, and the further regulation of VSMCs proliferation and migration was confirmed. Results: C/EBPβ was highly expressed and had a lower methylation level in RS compared with AS. In vitro C/EBPβ overexpression facilitated the proliferation and migration of VSMCs with increased expression of Lin28a. Conversely, C/EBPβ knockdown resulted in opposite effects. Chromatin immunoprecipitation assays further demonstrated that C/EBPβ could directly bind to the promoter of Lin28a. Furthermore, increased expression of C/EBPβ and enhanced proliferation and migration of VSMCs were observed after decitabine treatment. And mechanical stretch promoted the expression of C/EBPβ and Lin28a. Additionally, C/EBPβ expression increased following the overexpression of Lin28a. The reversed result was found in the Lin28a knockdown cells. Conclusion: Our results have demonstrated that C/EBPβ expression is regulated partly by DNA methylation. Meanwhile, as a transcription factor, C/EBPβ promotes the transcription of Lin28a and enhances the proliferation and migration of VSMCs through a positive feedback loop between the two. Our study suggests C/EBPβ-Lin28a axis is a driver of the RS progression, providing a promising therapeutic strategy for RS. Disclosure S.Jiang: n/a. L.Liao: None. J.Dong: None. X.Zhou: n/a. Q.Zhang: None. S.Guo: None. Q.Sheng: None. X.Li: None. R.Zhang: None. C.Xu: None. P.Gong: None. Funding National Natural Science Foundation of China Grants (81800732,81670757,82170824) , Shandong Provincial Medicine and Health Science and Technology Development Program (No.202103060766) and Shandong Provincial Hospital Research incubation Fund (No.2021FY059)