Human chorionic gonadotropin stimulation of relaxin secretion by luteinized human granulosa cells*†*Presented in part at the Society for Gynecologic Investigation, San Diego, California, March 15 to 18, 1989.†Supported by National Institutes of Health grant HD22338, Bethesda, Maryland.

1992 ◽  
Vol 58 (2) ◽  
pp. 314-320 ◽  
Author(s):  
Carol L. Gagliardi ◽  
Laura T. Goldsmith ◽  
Maria Saketos ◽  
Gerson Weiss ◽  
Cecilia L. Schmidt
Keyword(s):  
Chorionic Gonadotropin ◽  
Granulosa Cells ◽  
Human Chorionic Gonadotropin ◽  
San Diego ◽  
National Institutes Of Health ◽  
Human Granulosa Cells ◽  
Gonadotropin Stimulation ◽  
Stimulation Of

scholarly journals Insulin and Human Chorionic Gonadotropin Cause a Shift in the Balance of Sterol Regulatory Element-Binding Protein (SREBP) Isoforms Toward the SREBP-1c Isoform in Cultures of Human Granulosa Cells

2005 ◽  
Vol 90 (6) ◽  
pp. 3738-3746 ◽  
Author(s):  
Malcolm C. Richardson ◽  
Iain T. Cameron ◽  
Chantal D. Simonis ◽  
Madhab C. Das ◽  
Tessa E. Hodge ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Chorionic Gonadotropin ◽  
Granulosa Cells ◽  
Human Chorionic Gonadotropin ◽  
Binding Protein ◽  
Regulatory Element ◽  
Human Granulosa Cells ◽  
Igf Binding ◽  
Sterol Regulatory Element ◽  
Igf Binding Protein

The isoforms of sterol regulatory element-binding proteins (SREBP) (1a, 1c, and 2) are key transcriptional regulators of lipid biosynthesis. We examined their regulation by gonadotropin and insulin in human granulosa cells. After removal of leukocytes, granulosa cells were exposed to hormonal additions for 16 h starting on d 2 of culture. Progesterone, lactate, and IGF binding protein-1 were measured in culture medium and cellular mRNA measured by competitive RT-PCR. Addition of human chorionic gonadotropin (hCG) (100 ng/ml) stimulated progesterone production (7.0-fold, P < 0.001 vs. control), whereas lactate was increased by hCG (1.6-fold, P < 0.001) and insulin (1.4-fold, P < 0.001; 1000 ng/ml). Insulin decreased IGF binding protein-1 production by 85% (P < 0.001). There were no significant effects on the expression of SREBP-1a but significant increases in mRNA for SREBP-1c with insulin (6.3-fold), hCG (10.4-fold) and in combination (15.2-fold; P < 0.01 for all comparisons). No consistent effects on SREBP-2 were observed. The expression of mRNA for fatty acid synthase, a target gene for SREBP-1c, was increased by hCG (24-fold, P = 0.006) and insulin (19-fold, P = 0.024), which also increased the level of cellular, total fatty acid (1.34-fold; P = 0.03). Thus, hCG and insulin cause a switch toward expression of the SREBP-1c isoform with consequent effects on fatty acid synthesis. We suggest that high circulating insulin, associated with clinically defined insulin resistance, may up-regulate SREBP-1c expression in the ovary.

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