Abstract

The mechanisms through which sperm manage their energy metabolism are poorly understood. The present study provides biochemical and morphological evidence that mitochondrial citrate carrier (CIC) is present in ejaculated human sperm and is restricted to the midpiece. The inhibition of CIC with the specific substrate analog 1,2,3-benzenetricarboxylate resulted in the reduction of cholesterol efflux, protein tyrosine phosphorylation, phospho-AKT, phospho-p60src, hyperactivated motility and acrosome reaction, suggesting a role for this mitochondrial carrier in sperm physiology. Furthermore, inhibition of CIC by 1,2,3-benzenetricarboxylate resulted in a reduction of glucose-stimulated insulin secretion and autocrine insulin secretion by sperm. Remarkably, blocking CIC also reduced glucose-6-phosphate dehydrogenase activity, probably in accordance with its regulation on insulin secretion. Capacitation and glucose metabolism were stimulated by glucose as well as citrate, the specific substrate of CIC, implying a similar action because glucose and citrate both induced insulin secretion by sperm. In the present finding, we discovered a new site of action for CIC in the regulation of metabolism, and it may be assumed that CIC works with other factors in the regulation of sperm energy metabolism to sustain capacitation process and acrosome reaction.

Autore Pugliese

• Capobianco Loredana

Tutti gli autori

• A.R.C. Cappello , C. Guido , A. Santoro , M. Santoro , L. Capobianco , D. Montanaro , A. Madeo , S. Andò , V. Dolce and Aquila S.

Titolo volume/Rivista

ENDOCRINOLOGY

Anno di pubblicazione

2012

ISSN

0013-7227

ISBN

Non Disponibile

Numero di citazioni Wos

16

Ultimo Aggiornamento Citazioni

28/04/2018

Numero di citazioni Scopus

19

Ultimo Aggiornamento Citazioni

28/04/2018

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile