Abstract
Identifying the early gene program induced by GnRH would help understand how GnRH-activated signaling pathways modulate gonadotrope secretory response. We previously analyzed GnRH-induced early genes in LβT2 cells, however these lack GnRH self-potentiation, a physiological attribute of gonadotropes. To minimize cellular heterogeneity, rat primary pituitary cultures were enriched for gonadotropes by 40-60% using a sedimentation gradient. Given the limited number of gonadotropes, RNA was amplified prior to microarray analysis. Thirty-three genes were up-regulated 40. min after GnRH stimulation. Real-time PCR confirmed regulation of several transcripts including fosB, c-fos, egr-2 and rap1b, a small GTPase and member of the Ras family. GnRH stimulated rap1b gene expression in gonadotropes, measured by a sensitive single cell assay. Immunocytochemistry revealed increased Rap1 protein in GnRH-stimulated gonadotropes. These data establish rap1b as a novel gene rapidly induced by GnRH and a candidate to modulate gonadotropin secretion in rat gonadotropes.
Original language | English (US) |
---|---|
Pages (from-to) | 10-19 |
Number of pages | 10 |
Journal | Molecular and Cellular Endocrinology |
Volume | 350 |
Issue number | 1 |
DOIs | |
State | Published - Mar 5 2012 |
Keywords
- Early gene
- GnRH
- Gonadotrope enrichment
- Rap1b
- Rat primary pituitary cultures
- Single-cell gene expression
ASJC Scopus subject areas
- Endocrinology
- Molecular Biology
- Biochemistry