Testosterone regulation on quiescin sulfhydryl oxidase 2 synthesis in the epididymis.

The epididymis is an androgen-responsive organ, whose structure and functions are modulated by the coordination between androgen and epididymal cues. Highly-regulated molecular interaction within the epididymis is required to support viable sperm development necessary for subsequent fertilization. In the present study, we extended our earlier findings on a promising epididymal protein, quiescin sulfhydryl oxidase 2 (QSOX2), and demonstrated a positive correlation between testosterone and QSOX2 protein synthesis through use of loss- and restore-of-function animal models. Moreover, based on transcriptomic analyses and 2-dimensional culture system, we determined that an additional polarized effect of glutamate is indispensable for the regulatory action of testosterone on QSOX2 synthesis. In conclusion, we propose non-canonical testosterone signaling supports epididymal QSOX2 protein synthesis, providing a novel perspective on the regulation of sperm maturation within the epididymis.