TY - JOUR
T1 - Regulation of Cholesterol Side-Chain Cleavage Cytochrome P450 in Mouse Testis Leydig Cell Line I-10
AU - Chen, Chis Tsong
AU - Guo, Ing Cherng
AU - Chung, Bon Chu
AU - Chen, Chi Tsong
AU - Chung, Bon Chu
PY - 1995/9
Y1 - 1995/9
N2 - We have characterized regulation of steroidogenesis in a mouse testis Leydig cell line, I-10. Progesterone secretion was increased in a time- and dose-dependent fashion by 8-Br-cAMP treatment. The amount of cholesterol side-chain cleavage enzyme (P450scc), the first and rate-limiting enzyme for the synthesis of steroids, as detected by immunoblotting, was also increased. The calcium ionophore A23187 decreased the amount of P450scc, but it did not interfere with cAMP stimulation of the accumulation of P450scc. This regulation of P450scc expression by cAMP and A23187 is at the post-transcriptional level because the amount of P450scc mRNA was not affected by either treatment. This result was further confirmed by direct measurement of transcription in the presence or absence of forskolin treatment. I-10, however, supported cAMP-dependent transcriptional activation of the exogenous gene, as shown by the increased expression of a reporter gene under the control of the −600 to −2,500 fragment of the P450scc gene. The ability for transcriptional activation of the exogenous but not endogenous P450scc gene makes I-10 a unique steroidogenic cell line.
AB - We have characterized regulation of steroidogenesis in a mouse testis Leydig cell line, I-10. Progesterone secretion was increased in a time- and dose-dependent fashion by 8-Br-cAMP treatment. The amount of cholesterol side-chain cleavage enzyme (P450scc), the first and rate-limiting enzyme for the synthesis of steroids, as detected by immunoblotting, was also increased. The calcium ionophore A23187 decreased the amount of P450scc, but it did not interfere with cAMP stimulation of the accumulation of P450scc. This regulation of P450scc expression by cAMP and A23187 is at the post-transcriptional level because the amount of P450scc mRNA was not affected by either treatment. This result was further confirmed by direct measurement of transcription in the presence or absence of forskolin treatment. I-10, however, supported cAMP-dependent transcriptional activation of the exogenous gene, as shown by the increased expression of a reporter gene under the control of the −600 to −2,500 fragment of the P450scc gene. The ability for transcriptional activation of the exogenous but not endogenous P450scc gene makes I-10 a unique steroidogenic cell line.
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U2 - 10.1089/dna.1995.14.803
DO - 10.1089/dna.1995.14.803
M3 - Article
C2 - 7669257
AN - SCOPUS:0029028799
VL - 14
SP - 803
EP - 810
JO - DNA and Cell Biology
JF - DNA and Cell Biology
SN - 1044-5498
IS - 9
ER -