Frog Skin Antimicrobial Peptide 3-13 and Its Analogs Alleviate Atherosclerosis Cholesterol Accumulation in Foam Cells via PPARγ Signaling Pathway

Atherosclerosis (AS), a major contributor to cardiovascular disease, hypertension, and stroke, is associated with significant morbidity and mortality. Antimicrobial peptides (AMPs) 3-13, W3R6, and chensinin-1b were engineered based on the sequence of chensinin-1, originally isolated from the skin secretion of Rana chensinensis. This study investigated their therapeutic potential in ApoE-/- AS mice and THP-1-derived foam cells, focusing on the regulation of cholesterol metabolism. AMP 3-13 markedly reduced body weight gain, aortic root plaque formation, and plasma cholesterol levels in ApoE-/- mice. Transcriptomic analysis revealed that AMP 3-13 significantly altered gene expression related to cholesterol metabolism and the PPAR signaling pathway. Specifically, AMP 3-13 upregulated PPARγ, ABCA1, and ABCG1, while downregulating CD36 in aortic root plaques. In THP-1-derived foam cells, AMP 3-13 and its analogs activated the PPARγ–ABCA1/ABCG1 axis, enhancing cholesterol efflux. Concurrently, they inhibited CD36 expression by competing with PPARγ for promoter binding, thereby reducing ox-LDL uptake. These findings suggested that AMP 3-13 and its analogs represented promising therapeutic agents for AS through their ability to reduce cholesterol accumulation in foam cell.