Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0003128 (anovulation)
 1,718 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Polycystic ovary syndrome, characterized by hyperandrogenism and chronic anovulation, is frequently associated with insulin resistance. Ample evidence implicates a role for insulin in the genesis of ovarian hyperandrogenism. The objective of this study was to begin to define the intracellular signaling pathway(s) that mediates insulin regulation of 17alpha-hydroxylase activity in human ovarian theca cells. Third-passage theca cells, isolated from the ovaries of regularly cycling premenopausal women, were used. Insulin alone had no effect on 17alpha-hydroxylase activity or CYP17 mRNA expression but required costimulation with forskolin. At the insulin concentration used (10 ng/ml), a neutralizing antibody to the insulin receptor (but not an antibody to the type I IGF receptor) blocked the insulin stimulation of 17alpha-hydroxylase activity, demonstrating that the effects were mediated by the insulin receptor. Insulin stimulated both phosphatidylinositol-3-kinase (PI3-kinase) and extracellular signal-regulated kinase-1/2 (MAPK) pathways. Specific inhibition of MAPK kinase (MEK) with PD98059 or I0126 did not decrease the 17alpha-hydroxylase activity stimulated by forskolin or forskolin plus insulin. In contrast, the PI3-kinase inhibitor LY294002 completely blocked insulin-stimulated 17alpha-hydroxylase activity. Our data demonstrate that insulin stimulates PI3-kinase and extracellular signal-regulated kinase-1/2 activities in human theca cells, but only PI3-kinase mediates the insulin augmentation of forskolin-stimulated 17alpha-hydroxylase activity.
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PMID:Insulin augmentation of 17alpha-hydroxylase activity is mediated by phosphatidyl inositol 3-kinase but not extracellular signal-regulated kinase-1/2 in human ovarian theca cells. 1451 32

The polycystic ovary syndrome (PCOS) is a heterogeneous multifactorial endocrine metabolic disorder with genetic predisposition affecting 6% of women in the reproductive age. This syndrome is characterized by the presence of oligo-anovulation, hyperandrogenism and polycystic ovaries. Several genes have been postulated as responsible for the etiology of this disorder. Among these genes are those encoding the enzymes involved in the ovarian androgen biosynthesis. Two of the candidate genes are the CYP17 and the CYP11alpha, encoding the 17-alpha-hydroxylase (P45017alpha) and the cholesterol side chain cleavage (P450scc) respectively. The polymorphisms of these genes are linked to the development of an hyperandrogenic phenotype. The aim of this work was to analyze the allelic frequencies of such polymorphisms in a cohort of women with PCOS and to compare them with those of healthy women. Furthermore, the correlation between each allelic variant and the corresponding hyperandrogenic phenotype was also assessed. Therefore, 65 patients and 58 age matched healthy controls were analyzed. The serum levels of testosterone and the frequency of each polymorphism were determined. When the PCOS population was analyzed, a significant statistical difference was found when relating the group with the highest androgenemia level with the presence of A2/A2 genotype of CYP 17 gene, and a higher level of circulating androgen was found in PCO women carrying the 216- allele of CYP11alpha gene (that did not reach statistical significance). Our results suggest that both alleles play a minor role in the development of PCOS and could be a genetic risk marker of the hyperandrogenic phenotype.
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PMID:[Polymorphism in CYP11alpha and CYP17 genes and the etiology of hyperandrogenism in patients with polycystic ovary syndrome]. 1849 61

Polycystic ovary syndrome (PCOS), characterized by increased ovarian androgen biosynthesis, anovulation, and infertility, affects 5-7% of reproductive-age women. Genome-wide association studies identified PCOS candidate loci that were replicated in subsequent reports, including DENND1A, which encodes a protein associated with clathrin-coated pits where cell-surface receptors reside. However, these studies provided no information about functional roles for DENND1A in the pathogenesis of PCOS. DENND1A protein was located in the cytoplasm as well as nuclei of theca cells, suggesting a possible role in gene regulation. DENND1A immunostaining was more intense in the theca of PCOS ovaries. Using theca cells isolated and propagated from normal cycling and PCOS women, we found that DENND1A variant 2 (DENND1A.V2) protein and mRNA levels are increased in PCOS theca cells. Exosomal DENND1A.V2 RNA was significantly elevated in urine from PCOS women compared with normal cycling women. Forced overexpression of DENND1A.V2 in normal theca cells resulted in a PCOS phenotype of augmented CYP17A1 and CYP11A1 gene transcription, mRNA abundance, and androgen biosynthesis. Knock-down of DENND1A.V2 in PCOS theca cells reduced androgen biosynthesis and CYP17A1 and CYP11A1 gene transcription. An IgG specific to DENND1A.V2 also reduced androgen biosynthesis and CYP17 and CYP11A1 mRNA when added to the medium of cultured PCOS theca cells. We conclude that the PCOS candidate gene, DENND1A, plays a key role in the hyperandrogenemia associated with PCOS. These observations have both diagnostic and therapeutic implications for this common disorder.
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PMID:Overexpression of a DENND1A isoform produces a polycystic ovary syndrome theca phenotype. 2470 93