Activation of AMP-Activated Protein Kinase Regulates Proliferation of Rat Sertoli Cells.

RIERA M FERNANDA; GALARDO MARÍA N; AGNELLO ANA C; PELLIZZARI ELIANA H; MERONI SILVINA B; CIGORRAGA SELVA B

Washington DC

Congreso; 91st Annual Meeting Endo 2009; 2009

The Endocrine Society

Sertoli cells (SC) provide the structural and nutritional support for germ cell development. Considering that each SC is able to support a limited number of germ cells, the final number of SC reached during the proliferative periods determines sperm production capacity in adulthood. Hence, the importance of clarifying the molecular mechanisms involved in cessation of SC proliferation. The protein kinase activated by AMP (AMPK) is a serine/threonine protein kinase that has been involved in sensing cell energy levels and in down-regulating cell proliferation. In this context, it has been observed that activation of AMPK by 5-aminoimidazole-4-carboxamide-1-b-D-ribofuranoside (AICAR) inhibits proliferation of various cell lines. The aim of this work was to analyze the participation of AMPK in the regulation of SC proliferation. Mitotically active SC were isolated from 8-day-old rats and cultured in chemically defined medium. Cultures were stimulated with AICAR (1mM) in the absence or presence of FSH (100ng/ml) for variable periods of time. AMPK activation by Western blot using a specific antibody against phosphorylated AMPK (P-AMPK), the number of SC by a cell proliferation assay (MTS) and the mRNA levels of the cell cycle inhibitor p19INK4d by Northern blot, were evaluated. As expected, AICAR treatment increased the levels of P-AMPK under basal and FSH-stimulated conditions. While AICAR did not modify cell viability evaluated by Trypan blue exclusion, it produced a decrease in FSH-stimulated SC mitosis. AICAR also promoted a 2.4±0.6-fold increment (mean±SD, n=3, p