title: Coenzyme Q-dependent mitochondrial respiratory chain activity in granulosa cells is reduced with aging.
abstract: OBJECTIVE
  To examine coenzyme Q10 (CoQ10)-dependent mitochondrial respiratory chain (MRC) activity in granulosa cells (GC) with aging and examine the effect of in vitro CoQ supplementation.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Hospital laboratory.
  
  
  METHODS
  Ten younger (<32 years) and 10 older (>39 years) patients undergoing in vitro fertilization (IVF) treatment.
  
  
  METHODS
  Measurement of succinate-cytochrome c reductase (MRC complex II + III) activity in the presence and absence of CoQ1 (a soluble CoQ analog).
  
  
  METHODS
  MRC enzymatic activity in human GC via complex II + III measured in GC homogenate by spectrophotometry and compared with CoQ in dependent MRC complex II and citrate synthase (CS).
  
  
  RESULTS
  Complex II + III activity was 1.9 times higher in young patients compared with older patients (18.3 ± 5.8 and 9.6 ± 3 nmol/min/mg, respectively) whereas II and CS were not statistically significantly different. Increased II + III activity in the presence CoQ1 was observed in both groups but was statistically significantly higher in the older patients, reaching similar levels. Compared with baseline (II + III + Q/II + III), the increase was 2.47 times higher in older patients compared with young patients (6.5 ± 2.0 and 2.62 ± 0.83, respectively).
  
  
  CONCLUSIONS
  Coenzyme Q10-dependent MRC activity in GC reduces with aging. This reduction is diminished upon in vitro CoQ1 supplementation, indicating that CoQ10 deficit is the underlying cause for the mitochondrial dysfunction. The results show that functional CoQ10 status can be assessed by measuring complex II + III activity in GC and might provide a useful monitoring tool for future clinical studies of oral CoQ10 supplementation to older patients undergoing IVF treatment.
authors.affiliation: Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel. Electronic address: assaf.benmeir@gmail.com.
authors.forename: Assaf
authors.initials: A
authors.lastname: Ben-Meir
authors.affiliation: Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
authors.forename: Shlomi
authors.initials: S
authors.lastname: Yahalomi
authors.affiliation: Monique and Jacques Roboh Department of Genetic Research and Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
authors.forename: Brit
authors.initials: B
authors.lastname: Moshe
authors.affiliation: Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
authors.forename: Yoel
authors.initials: Y
authors.lastname: Shufaro
authors.affiliation: Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Reubinoff
authors.affiliation: Monique and Jacques Roboh Department of Genetic Research and Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
authors.forename: Ann
authors.initials: A
authors.lastname: Saada
mesh_terms: D000328:Adult; D000367:Age Factors; D000375:Aging / Q000378:metabolism*; D015536:Down-Regulation; D004579:Electron Transport; D042963:Electron Transport Complex II / Q000378:metabolism*; D014450:Electron Transport Complex III / Q000378:metabolism*; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology*; D014451:Ubiquinone / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D014451:Ubiquinone; D042963:Electron Transport Complex II; D014450:Electron Transport Complex III
keywords: Coenzyme Q10; granulosa cells; mitochondria; reproductive aging