TGFB1 and atrial fibrillation: MIAT knockdown significantly alleviates atrial fibrillation and reduces atrial fibrillation-induced atrial fibrosis by targeting miRNA-133A-3p and inhibiting fibrosis-related gene expression of collagen I, collagen III, connective tissue growth factor, and TGF-β1.214 Costantino et al.215 demonstrated that in diet-induced obese mouse hearts, AP-1 transcription factor directly bound to the PPARγpromoter, which resulted in activation of PPARγand increased transcription of Fas, Cd36, Lpl and Plin5.