Common 677C→T mutation of the 5,10-methylenetetrahydrofolate reductase gene affects follicular estradiol synthesis
Received 14 March 2007; received in revised form 5 November 2007; accepted 5 November 2007. published online 13 February 2008.
Objective
To investigate the influence of the 5,10-methylenetetrahydrofolate reductase 677C→T mutation on the E2 synthesis in human granulosa cells (GCs).
Design
In vitro cell culture study.
Setting
Research laboratory of a university hospital.
Patient(s)
Follicular fluids (n = 139) and GCs (n = 66) were obtained from patients undergoing controlled ovarian hyperstimulation for IVF with or without ICSI.
Intervention(s)
Granulosa cells were cultured for a total of 5 days. On day 3, the cells either were stimulated with recombinant (r-) FSH or r-LH (80 IU/L for 48 h) or were sham stimulated.
Main Outcome Measure(s)
Estradiol and protein content were measured in the pooled follicular fluids of each individual. At the end of each GC-culturing period, the concentrations of E2 were measured in the supernatants of triplicate cultures by immunoassays. The 5,10-methylenetetrahydrofolate reductase 677C→T genotype was determined by RFLP analysis.
Result(s)
The E2-protein ratio of homozygous T/T carriers was significantly lower compared with that of homozygous C/C individuals. Furthermore, basal and r-FSH– as well as r-LH–stimulated E2 synthesis of GC obtained from homozygous T/T patients was significantly reduced, compared with GC from heterozygous C/T and homozygous C/C subjects.
Conclusion(s)
Decreased E2 in follicular fluid and decreased E2 synthesis of GC from homozygous T/T individuals suggest that reduced follicular E2 is a result of impaired E2 production of human GC.
aDepartment of Obstetrics and Gynecology, Division of Endocrinology and Reproductive Medicine, Grosshadern, Ludwig Maximilians-University, Munich, Germany
bDepartment of Clinical Chemistry, Grosshadern, Ludwig Maximilians-University, Munich, Germany
cCentre for Reproductive Medicine, Munich, Germany
Reprint requests: Christian J. Thaler, M.D., Department of Obstetrics and Gynecology, Division of Endocrinology and Reproductive Medicine, Grosshadern, Ludwig-Maximilians-University, Marchioninistrasse 15, D-81377 Munich, Germany (FAX: 49-89-7095-7588).
Authors S.H. and R.P. contributed equally to the work and both should be considered to be the first author.
Supported by the Department of Obstetrics and Gynecology, Grosshadern, Ludwig-Maximilians-University, Munich, Germany.
Presented at the 56th National Congress of Gynecology and Obstetrics, Berlin, Germany, September 19–22, 2006.
ABSTRACT