Cadmium exposure causes mouse spermatogonia apoptosis via inducing endoplasmic reticulum stress

Abstract

Abstract Cadmium (Cd), which can cause testicular germ cell apoptosis, is a well-recognized male reproductive toxicant, but the underlying mechanism still needs investigation. To detect Cd toxicity on testicular germ cell, we treated mouse spermatogonia with CdCl2 in vitro and investigated the responses from cells at both RNA and protein levels. After treating mouse-derived spermatogonia cell line GC-1 spg cells with 20 µM CdCl2 for 24h, cell apoptosis was measured by TUNEL and flow cytometry assay. After then, the expressions of key genes and protein biomarkers involved in endoplasmic reticulum (ER) stress were detected by qPCR and western blot, respectively. Finally, untargeted metabolomics was performed to compare metabolic differences, and Illumina RNA sequencing was conducted to screen differentially expressed genes (DEGs). Our results indicated that Cd exposure caused cell apoptosis, DEGs were involved in several apoptosis-related pathways. Cd exposure apparently elevated the mRNA and protein expressions levels of both GRP78 and ATF6α, and disrupted the expression of many types of metabolites, especially for amino acids. Taken together, our study uncovers the pathway of Cd toxicity on mouse spermatogonia, provides deep understanding on Cd-induced testicular toxicity.