Maimendong decoction modulates the PINK1/Parkin signaling pathway alleviates type 2 alveolar epithelial cells senescence and enhances mitochondrial autophagy to offer potential therapeutic effects for idiopathic pulmonary fibrosis

Abstract

Ethnopharmacological relevance

Maimendong decoction (MMDD) originates from the ancient Chinese medical text Synopsis of the Golden Chamber and is a well-established remedy for treating lung diseases. It has demonstrated efficacy in the long-term clinical management of idiopathic pulmonary fibrosis (IPF); however, its underlying mechanisms remain unclear.

Aim of the study

This study investigates whether MMDD alleviates IPF by reducing type 2 alveolar epithelial cell (AEC2) senescence and enhancing mitochondrial autophagy. It also explores whether these effects are mediated through the PTEN-induced putative kinase 1 (PINK1)/Parkinson juvenile disease protein 2 (Parkin) pathway.

Materials and methods

An IPF mouse model was established with bleomycin (BLM). Mice were administered MMDD, pirfenidone (PFD), or saline for 7 or 28 days. Body weight, lung coefficient, and lung appearance were monitored, and lung tissue pathology was assessed. The expression levels of p53, p21, p16, SA-β-gal activity, and senescence-associated secretory phenotype (SASP) markers were measured. Ultrastructural changes in AEC2 mitochondria were analyzed using transmission electron microscopy. Protein levels of autophagy markers sequestosome-1 and light chain 3 were assessed. The protein levels of PINK1, Parkin, and phosphorylated Parkin were further assessed using network pharmacology analysis and molecular docking technology.

Results

MMDD alleviated BLM-induced IPF by improving body weight, lung appearance, and histopathological features. It reduced AEC2 senescence markers, including p53, p21, p16, SA-β-gal, and SASP, while enhancing mitochondrial autophagy and repairing mitochondrial damage. Network pharmacology and molecular docking identified PINK1 as a major target, and Western blot (WB) analysis confirmed that MMDD regulates the PINK1/Parkin signaling pathway in the treatment of IPF.

Conclusions

MMDD regulates the PINK1/Parkin signaling pathway, alleviates AEC2 senescence, and enhances mitochondrial autophagy, providing significant therapeutic potential for IPF treatment.