Kai Strothmann | PubMed Health

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↗

PubMed2003

Gene expression profiling of mouse Sertoli cell lines.

The proliferation and differentiation of Sertoli cells is regulated by follicle-stimulating hormone (FSH). The molecular events following FSH stimulation are only partially known. To investigate FSH action in Sertoli cells, we established two novel FSH-responsive mouse Sertoli-cell-derived lines expressing human wild-type (WT) FSH receptor (FSHR) or overexpressing mutated (Asp567Gly) constitutively active FSHR (MUT). Gene expression profiling with commercially available cDNA arrays, including 588 mouse genes, revealed 146 genes expressed in both cell lines. Compared with the expression pattern of WT cells, 20 genes were identified as being either up- or down-regulated (>two-fold) in the MUT cells. We observed a strong differential expression of factors involved in cellular proliferation, e.g. cyclin D2 (repressed to nearly undetectable levels), proliferating cell nuclear antigen (2.5-fold repression) and Eps-8 (six-fold repression), and in genes involved in cellular differentiation, e.g. cytokeratin-18 (13-fold induction). The cDNA array results for six representative genes were confirmed by Northern blotting, which also included the parental SK-11 cell line devoid of FSHR expression. We found no further acute FSH- or forskolin-induced change in expression levels after 3-h stimulations, suggesting that the observed differences between the two cell lines is a consequence of mild, chronically increased, cAMP production in MUT cells. These results provide a platform for the further investigation of selected candidate genes in primary cultures and/or in vivo.

Animals↗