Participation of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase isoform 3 and pyruvate dehydrogenase complex in the regulation of lactate production by FSH and bFGF in rat Sertoli cells

RIERA MARÍA FERNANDA; REGUEIRA, MARIANA; GALARDO MARÍA NOEL LUJÁN; PELLIZZARI ELIANA HERMINIA; CIGORRAGA SELVA BEATRIZ; MERONI SILVINA BEATRIZ

San Diego

Congreso; The 97th Annual Meeting of the Endocrine Society & Expo (ENDO2015); 2015

Endocrine Society

Sertoli cells (SC) actively metabolize glucose and the majority of it is converted to lactate. Spermatocytes and spermatids are unable to use glucose and they do prefer lactate as an energy source. In this context, it is widely accepted that one of the most important SC nurse functions is to provide lactate for germ cells and that the mechanisms that regulate its production may be relevant to the maintenance of spermatogenesis.The availability of pyruvate, which is converted into lactate, might be regulated by FSH and bFGF in SC to ensure lactate supply to germ cells. The aim of this study was to analyze two possible mechanisms which may be involved in pyruvate availability. Firstly, regulation of the expression of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase isoform 3 (PFKFB3) responsible for fructose-2-6-biphosphate (Fru2,6P2) production. Fru2,6P2 is an allosteric regulator of phosphofructokinase 1, the rate limiting step in glycolysis, which increases glycolytic flux. Secondly, negative regulation of pyruvate dehydrogenase complex (PDC) activity by phosphorylation, which will increase pyruvate availability as a consequence of a lower conversion of pyruvate to acetyl-CoA. Cultures of SC obtained from 20-day-old rats were incubated for 48 h without (basal) or with FSH (100 ng/ml) or bFGF (30 ng/ml). Lactate levels were determined in conditioned media. Cell extracts were utilized to evaluate phosphorylated PDC (P-PDC) levels by Western blot and mRNA levels by RQPCR. Results are expressed as mean±SD (n=3). Analysis of PFKFB3 expression showed that FSH increased PFKFB3 mRNA levels (2.1±0.32*; *p