Biomedical subjects

Alain Wunsch

Publications and source records attributed to Alain Wunsch.

3 recordsLinked to original sources

PubMed2005

Single-nucleotide polymorphisms in the promoter region influence the expression of the human follicle-stimulating hormone receptor.

OBJECTIVE: To characterize novel single-nucleotide polymorphisms (SNPs) in the human FSH receptor (FSHR) promoter region. DESIGN: Retrospective and basic research study. SETTING: University hospital. PATIENTS: Women (202 from Germany and 55 from Indonesia) with male or tubal factor infertility undergoing controlled ovarian stimulation for IVF treatment. INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): Frequency, distribution, and correlation with clinical data of the SNPs. Dual luciferase assays and electrophoretic mobility shift assays (EMSA). RESULT(S): We identified two SNPs and three mutations in the promoter region of the human FSHR which could be allocated to positions -29, -37, -114, -123, and -138 upstream of the translational initiation codon. One SNP showed a high incidence (-29: 44%, n = 202), but no correlation with basal FSH serum levels or ovarian response with the SNP at position -29 was found. Luciferase reporter assays, using pGL3 vector constructs, showed that mutations at positions -37 and -138 lead to significantly higher promoter activity. EMSA indicate that putative binding sites for transcription factors are affected by the SNPs. CONCLUSIONS: The newly identified SNPs do not seem to influence clinical parameters substantially, but modulate expression of the FSHR via changes in transcription factor binding sites.

Analysis of Variance↗

PubMed2004

Epidermal growth factor receptor pathway substrate 8 (Eps8) expression in maturing testis.

AIM: Although epidermal growth factor receptors are expressed in the testes, whether they signal through epidermal growth factor receptor pathway substrate 8 (Eps8) is unknown. Here we evaluated the expression pattern of Eps8 in the maturing testis. METHODS: The expression of Eps8 was analysed by Northern blotting, immunocytochemistry and Western blotting in primary Sertoli cell cultures and in testicular tissue of rodents. RESULTS: Eps8 is specifically expressed in gonocytes, Leydig and Sertoli cells of the neonatal rats and in Leydig and Sertoli cells of the adult rats and mice. Although gonocytes express Eps8, no signal was found in prepubertal or mature spermatogonia and the expression level of Eps8 in Sertoli cells increases with age. No regulation of Eps8 expression in primary immature rat Sertoli cells by Follicle stimulating hormone (FSH) was detected by Western blotting. CONCLUSION: Eps8 seems to be involved in the growth factor-controlled regulation of cell proliferation and differentiation in the seminiferous epithelium. Eps8 is a possible marker for gonocytes and in Sertoli cells it could be involved in crosstalk with other growth factor pathways.

Adaptor Proteins, Signal Transducing↗

PubMedDate not supplied

Follicle-stimulating hormone receptor gene haplotype distribution in normozoospermic and azoospermic men.

The human follicle-stimulating hormone (FSH) receptor (FSHR) gene possesses single nucleotide polymorphisms (SNP) in exon 10, which influence serum FSH levels in women, but not in men. In the present study we extend our previous investigation and for the first time analyze a novel, common SNP at position -29 of the FSHR core promoter in men. The SNP in codon 680 was analyzed in 438 men with nonobstructive azoospermia and in 304 controls. The SNP in codon 307 and at position -29 was analyzed in 345 men with nonobstructive azoospermia and 186 controls. SNPs were determined by allelic discrimination. No significant difference in the frequency of the polymorphism at position 680 and serum FSH levels was found. At position -29 (A/G) the A(-29) allele was less frequent than the G(-29) allele both in controls (25% vs 75%) and in patients (30% vs 70%) (P not significant). Together the three SNPs form four discrete haplotypes (A-Thr-Asn, G-Thr-Asn, A-Ala-Ser, and G-Ala-Ser) occurring in 10 combinations. A statistically significant difference in the allelic distribution between controls and azoospermic men was found (P < .05 by chi2 test). The A-Ala-Ser allele was more frequent in patients (9.1%) than in controls (5.4%), whereas the G-Thr-Asn allele was less frequent in patients (33.1%) than in controls (40.6%) (P < .01 by Fisher's exact test). No significant correlation between serum FSH levels and FSHR allele was found. We conclude that the FSHR haplotype does not associate with different serum FSH levels but it is differently distributed in normal and azoospermic men. The A-Ala-Ser and the G-Thr-Asn allele might represent genetic factors contributing to phenotypic expression of severe spermatogenetic impairment.

Follicle Stimulating Hormone↗