Hormonal regulation of messenger ribonucleic acid expression for steroidogenic factor-1, steroidogenic acute regulatory protein, and cytochrome P450 side-chain cleavage in bovine luteal cells

Citation
R. Mamluk et al., Hormonal regulation of messenger ribonucleic acid expression for steroidogenic factor-1, steroidogenic acute regulatory protein, and cytochrome P450 side-chain cleavage in bovine luteal cells, BIOL REPROD, 60(3), 1999, pp. 628-634
Citations number
45
Categorie Soggetti
da verificare
Journal title
BIOLOGY OF REPRODUCTION
ISSN journal
00063363 → ACNP
Volume
60
Issue
3
Year of publication
1999
Pages
628 - 634
Database
ISI
SICI code
0006-3363(199903)60:3<628:HROMRA>2.0.ZU;2-P
Abstract
To examine hormonal regulation of genes pertinent to luteal steroidogenesis , bovine theca and granulosa cells derived from preovulatory follicles were cultured with various combinations of forskolin and insulin. On Day 8 of c ulture, progesterone production was measured, and mRNA levels of steroidoge nic factor-1 (SF-1), cytochrome P450 side-chain cleavage enzyme (P450(scc)) , and steroidogenic acute regulatory protein (StAR) were determined by mean s of semiquantitative reverse transcription-polymerase chain reaction. Nota bly, the combination of forskolin plus insulin stimulated progesterone prod uction in luteinized theca cells. This was probably a result of a synergist ic interaction between forskolin and insulin, observed on both StAR and P45 0,,, mRNA levels. However, in luteinized granulosa cells (LGC), forskolin a nd insulin each independently were able to up-regulate the levels of P450(s cc) and StAR mRNA levels, respectively. Moreover, insulin alone was suffici ent to maintain the high steady-state levels of StAR mRNA in LGC. Both insu lin and insulin-like growth factor I enhanced StAR gene expression in LGC. SF-1 was constitutively expressed in bovine luteal cells; its amounts did n ot vary between the two luteal cell types or with hormonal treatments. In summary, this study demonstrates a distinct, cell-type specific regulati on of StAR and P450(scc) mRNA in the two bovine luteal cell types.