title: Metformin and male reproduction: effects on Sertoli cell metabolism.
abstract: OBJECTIVE
  Metformin is commonly used to treat type 2 diabetes (T2D). While new clinical applications have been ascribed to metformin, including treatment of anovulatory infertility, its effects on male reproduction have not been investigated. The Sertoli cell (SC) is crucial for germ cell development, exerting metabolic control of spermatogenesis, therefore, we investigated the effects of metformin on SC metabolism.
  
  
  METHODS
  Rat SCs were cultured in the absence and presence of metformin (5, 50 and 500 μM). mRNA and protein levels of glucose transporters (GLUT1 and GLUT3), phosphofructokinase 1 (PFK 1), lactate dehydrogenase (LDH) and monocarboxylate transporter 4 (MCT4) were determined by quantitative PCR and Western blot respectively. LDH activity was assessed and metabolite production/consumption determined by (1) H-NMR.
  
  
  RESULTS
  Metformin (50 μM) decreased mRNA and protein levels of GLUT1, GLUT3, MCT4 and PFK 1 but did not affect LDH mRNA or protein levels. However, although glucose consumption was maintained in metformin-treated cells, LDH activity, lactate and alanine production were increased, indicating an enhanced glycolytic flux. No metabolic cytotoxicity was detected in SCs exposed to supra-pharmacological concentration of metformin.
  
  
  CONCLUSIONS
  Our results indicate that metformin: (i) decreases mRNA and protein levels of glycolysis-related transporters in SCs but increases their activity; and (ii) stimulates alanine production, which induces antioxidant activity and maintains the NADH/NAD(+) equilibrium. The increased lactate in metformin-treated SCs provides nutritional support and has an anti-apoptotic effect in developing germ cells. Thus, metformin can be considered as a suitable antidiabetic drug for male patients of reproductive age with T2D.
authors.affiliation: CICS-UBI - Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal.
authors.forename: M G
authors.initials: MG
authors.lastname: Alves
authors.forename: A D
authors.initials: AD
authors.lastname: Martins
authors.forename: C V
authors.initials: CV
authors.lastname: Vaz
authors.forename: S
authors.initials: S
authors.lastname: Correia
authors.forename: P I
authors.initials: PI
authors.lastname: Moreira
authors.forename: P F
authors.initials: PF
authors.lastname: Oliveira
authors.forename: S
authors.initials: S
authors.lastname: Socorro
mesh_terms: D000409:Alanine / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D051272:Glucose Transporter Type 1 / Q000235:genetics / Q000378:metabolism; D051274:Glucose Transporter Type 3 / Q000235:genetics / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D008687:Metformin / Q000494:pharmacology*; D027501:Monocarboxylic Acid Transporters / Q000235:genetics / Q000378:metabolism; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D010732:Phosphofructokinase-1 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012098:Reproduction; D012708:Sertoli Cells / Q000187:drug effects* / Q000378:metabolism
chemical_list: D051272:Glucose Transporter Type 1; D051274:Glucose Transporter Type 3; D007004:Hypoglycemic Agents; D027501:Monocarboxylic Acid Transporters; D009124:Muscle Proteins; D012333:RNA, Messenger; C516342:Slc16a3 protein, rat; C495679:Slc2a1 protein, rat; C495690:Slc2a3 protein, rat; D019344:Lactic Acid; D008687:Metformin; D007770:L-Lactate Dehydrogenase; D010732:Phosphofructokinase-1; D000409:Alanine
keywords: Sertoli; glycolysis; male reproductive function; metabolism; metformin