hCG-induced ER stress-mediated apoptosis

It has been reported that Leydig cells, which produce testosterone in response to human chorionic gonadotropin (hCG), express key steroidogenic enzymes for the regulation of testosterone synthesis.

Interestingly, although Leydig cells produce and secrete testosterone in response to LH/hCG, repetitive hCG injection into mice has been shown to elicit a similar or lower testosterone level than that of control.

These observations showed that repeated and/or excessive hCG treatment seems to heavily damage steroidogenesis in Leydig cells. However, functional changes in the endoplasmic reticulum (ER) during steroidogenic enzyme expression in Leydig cells have not been demonstrated upon prolonged hCG treatment.

In this study, Park et al. analyzed whether hCG induces ER stress via three unfolded protein response (IRE1, PERK, and ATF6) pathways in mouse Leydig tumor (mLTC-1) cells and the testis.

These findings suggest that hCG-induced ER stress plays important roles in steroidogenic enzyme expression via modulation of the ATF6 pathway as well as ER stress-mediated apoptosis in Leydig cells.

Read full article at Park et al. (2013) Journal of Molecular Endocrinology 50 151-166 DOI: 10.1530/JME-12-0195