Knockdown of Sucla2 decreases the viability of mouse spermatocytes by inducing apoptosis through injury of the mitochondrial function of cells.

INTRODUCTION Sucla2, a β subunit of succinyl coenzyme A synthase, is located in the mitochondrial matrix. Sucla2 catalyzes the reversible synthesis of succinate and adenosine triphosphate (ATP) in the tricarboxylic acid cycle. Sucla2 expression was found to be correlated with the capacitation of boar spermatozoa. We have previously reported that Sucla2 was decreased in the testes of rats with spermatogenesis failure after exposure to endocrine disruptor BDE47. Yet, the expression model of Sucla2 in spermatogenesis and the function of Sucla2 in spermatogenic cells are still unclear. Our objective was to explore the localization of Sucla2 during mouse spermatogenesis and its function in the mouse spermatocyte line (GC2). MATERIAL AND METHODS The localization of Sucla2 in the mouse testis was explored through immunohistochemistry (IHC). Sucla2 was knocked down in GC2 cells and its expression was detected by Western blot (WB) to verify the efficiency of the siRNA transfection. Mitochondrial membrane potential (MMP), apoptosis and ROS of GC2 were detected by flow cytometry. ATP production was measured by the luminometric method and the presence of Bcl2 of GC2 was detected by WB. RESULTS Sucla2 is highly expressed in all germ cells but not in interstitial cells. Coarse Sucla2 signals are found in spermatocytes in stages VII–XII of mouse spermatogenesis. In GC2 cells, knockdown of Sucla2 decreased cell viability and MMP, induced apoptosis of GC2 cells, decreased ATP production, and Bcl2 expression, and increased ROS levels. CONCLUSIONS Sucla2 is related to the developmental stages of mouse spermatogenesis. Knockdown of Sucla2 decreases the viability of mouse spermatocytes by inducing apoptosis via decreased mitochondrial function of the cells