Root of Prunus persica (taoshugen) ameliorated renal fibrosis by inhibiting TGF-β signaling via upregulating Pmepa1 in mice with unilateral ureter obstruction

Abstract

Ethnopharmacological relevance

Various parts of Prunus persica (L.) Batsch (peach) exhibit medicinal properties and are utilized in traditional Chinese medicine (TCM) for therapeutic purposes. Notably, the root of P. persica, referred to as “taoshugen” in Chinese, is utilized by experienced TCM practitioners for the treatment of liver cirrhosis, suggesting its potential efficacy in mitigating organ fibrosis.

Aim of the study

The study aimed to investigate the potential protective role of the water extract of taoshugen (WE-TSG) against chronic kidney disease-associated renal fibrosis and the underlying mechanisms.

Materials and methods

The chemical composition of WE-TSG was characterized using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The anti-renal fibrosis efficacy of WE-TSG was evaluated in vitro using TGF-β1-stimulated renal tubular TCMK1 cells and in vivo using a murine model of unilateral ureter obstruction (UUO). The underlying mechanisms were elucidated using RNA-seq and CRISPR/Cas9-mediated loss of function of candidate genes. The activity of TGF-β signaling and the extent of fibrosis were determined by luciferase reporter assays, histology, immunohistochemistry, RT-PCR, and Western blot.

Results

LC-MS/MS analysis identified 14 major compounds in WE-TSG, primarily flavonoids and organooxygen compounds. In TCMK1 cells, WE-TSG significantly inhibited the activity of TGF-β-responsive luciferase reporters, CAGA-luc and CTGF-luc, and dose-dependently (3.125, 6.25, and 12.5 μg/mL) suppressed TGF-β1-induced Smad2/3 phosphorylation (p-Smad2/3) and fibrotic gene (fibronectin, Col1a1, and Ctgf) expression, without affecting total Smad2/3 protein levels. In vivo, oral administration of WE-TSG (1.4 and 2.8 g/kg) attenuated structural abnormalities, collagen deposition, and fibrotic gene (fibronectin, Col1a1, and α-SMA) expression, alongside reduced TGF-β signaling activity (TGF-β1 and p-Smad2/3) in the kidney tissues of UUO mice. RNA-seq in TCMK1 cells identified that Pmepa1, a negative-feedback regulator of TGF-β signaling, was significantly upregulated upon WE-TSG pretreatment. Importantly, knockout of Pmepa1 abolished the anti-TGF-β signaling and anti-fibrosis effects of WE-TSG in TGF-β1-stimulated TCMK1 cells. Moreover, kidney-targeted Pmepa1 knockdown also abrogated the anti-renal fibrosis role of WE-TSG in UUO mice.

Conclusions

Our findings demonstrate that WE-TSG inhibits TGF-β signaling and attenuates UUO-induced renal fibrosis by promoting Pmepa1 expression, highlighting the potential of herbal medicine taoshugen in the clinical treatment of CKD.