Microfibril-Associated Protein-3-Like Regulates TGFβ-Induced EMT Process via TNFR2/p38 MAPK Pathway in Endothelial Cells

Abdominal aortic inflammation (AAI) is a major arterial vasculitis characterized by chronic inflammation and fibrosis. Endothelial cells transform into mesenchymal cells (EMT) is one of the significant mechanisms of vasculitis fibrosis. Despite its importance, the molecular mechanism of EMT in AAI remains poorly understood. In this study, we induced AAI in mice through intraperitoneal injection of tumor necrosis factor-alpha (TNFα). To analyze protein expression, we performed Western blotting. Additionally, we extracted RNA using the nanomagnetic bead method to investigate the expression of functionally related genes. We conducted cell migration and invasion assays using scratch and Transwell techniques. Western blot analysis revealed the upregulation of microfibril-associated protein-3-like (MFAP3L) and tumor necrosis factor (TNF) receptor 2 (TNFR2), along with p38 signaling pathway activation. Notably, MFAP3L expression played a crucial role in the transforming growth factor-beta (TGFβ)-induced EMT process in endothelial cells. Furthermore, we identified that MFAP3L-mediated EMT relied on both TNFR2 expression and the activity of the TNFR2/p38 signaling pathway.