Sterol Regulatory Element Binding Protein (SREBP)-1 is a novel regulator of the Transforming Growth Factor (TGF)-β receptor I (TβRI) through exosomal secretion
SREBP inhibition decreases cell surface expression of TGFβ receptor I in kidney mesangial cells. SREBP does not regulate receptor transcription or its proteasomal/lysosomal degradation. SREBP-1 serves as a novel cell surface retention factor for the TGFβ type I receptor. Profibrotic responses to TGFβ are prevented by SREBP inhibition. Targeting SREBP may serve as a novel therapy for fibrotic kidney disease.