Icariin Improves D-Gal-Induced Sertoli Cell Dysfunction by Activating Autophagy-Lysosomal-Mitochondrial Pathway

Epimedium brevicornu Maxim (Yinyanghuo) is widely used to treat reproductive disorders. Icariin (ICA), the main active ingredient of Epimedium brevicornu Maxim, can alleviate age-related testicular dysfunction and Sertoli cell injury. However, whether ICA can regulate the autophagic activity of Sertoli cells and thus improve cell function remains unclear. The present study aimed to evaluate the protective effects of ICA on mitochondrial biogenesis, lysosome biogenesis, and autophagic activity in D-Galactose (D-gal)-induced Sertoli cell. TM4 cells were pretreated with ICA and then exposed to D-gal. After treatment, Sertoli cell viability was detected. Oxidative stress, apoptosis, mitochondrial biogenesis, lysosomal biogenesis, and autophagy-related protein and mRNA levels were analyzed. Sertoli cells were stained with Lyso-Tracker and Mito-Tracker to visualize lysosomes and mitochondria. ICA treatment significantly increased the Sertoli cell viability and protected against D-gal-induced oxidative stress. Meanwhile, ICA treatment significantly increased the expression levels of TFEB and LAMP2 proteins and promoted lysosomal biogenesis. Moreover, ICA treatment increased the expression of PINK1, Parkin, ATG5, ULK1, and LC3-II proteins, activated autophagic activity, and thus improved Sertoli cell function and increased GDNF and Claudin5 protein levels. ICA treatment could alleviate oxidative stress, increase mitochondrial biogenesis, and improve Sertoli cell function by activating autophagy and promoting lysosomal biogenesis.