Gonadotropin regulation of genes differentially expressed in response to PKCζ inhibitor during ovulation in the rat

AimsThe aim of the present study was to characterize genes regulated by protein kinase C (PKC)ζ inhibitor in the preovulatory granulosa cells following LH stimulation in the rat ovary.Main methodsAnnealing control primer (ACP)-based polymerase chain reaction (PCR) method was used to identify differentially expressed genes in granulosa cells of preovulatory follicles cultured in the presence of luteinizing hormone (LH) and myristoylated PKCζ pseudosubstrate peptide or a similarly sized control peptide.Key findingsAmong the 16 genes identified, five (testin, glypican-4, retrovirus SC1, aminolevulinic acid synthase 1 and serum-inducible kinase) experienced rapid and transient stimulation of gene expression upon exposure to human chorionic gonadotropin (hCG) in the ovary of immature rats primed with pregnant mare's serum gonadotropin (PMSG). In situ hybridization analysis revealed that hCG administration induced expression of these five genes in granulosa cells of preovulatory follicles. The Western analysis showed that the protein levels of testin and serum-inducible kinase were also increased by hCG. Expression of the eleven remaining genes in the ovary remained high at 24–72 h following hCG treatment.SignificanceThe present data demonstrate the gonadotropin stimulation of genes differentially expressed by PKCζ inhibitor, implicating that PKCζ pathway possibly plays a role in controlling the ovulation process.