Pachymic acid alleviates secondary lymphedema through the modulation of EETs level and the inhibition of lymphatic fibrosis.

Abstract

OBJECTIVE: This study evaluated the lymphangiogenesis-promoting and antifibrotic effects of PA, a natural component derived from Poria cocos, and to explore its mechanisms to mitigate lymphedema progression. METHODS: Tubule formation, spheroid sprouting, cell scratch and transwell assays approaches were used to assess the effects of TGF-β1 and PA on LECs tube formation and migratory capacity. A lymphedema tail loop mouse model was constructed, with tail volume measurements, H&E staining, Masson staining, immunofluorescence, and Western blotting to compare fibrosis and lymphatic vessel neogenesis under PA-treated and untreated conditions. RNA sequencing was employed for transcriptomic analysis, while immunofluorescence and Western blotting were used to investigate the role of the AA-EETs-DHETs pathway in PA-mediated lymphatic repair and the associated mitigation of fibrosis. RESULTS: Functionally, it enhanced LECs tube formation, sprouting, and migration, while reducing collagen III and α-SMA deposition in both TGF-β1-induced fibrosis and mouse models, alleviating the fibrotic microenvironment. Mechanistically, PA exerted its effects by modulating the AA-CYP2C8/CYP2J2-EETs-sEH-DHETs metabolic pathway, thereby increasing EETs level. CONCLUSIONS: PA promotes lymphangiogenesis and alleviates LECs fibrosis by increasing EETs level, highlighting its potential as a novel therapeutic target for lymphedema.