Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.10.2 (focal adhesion kinase)
 44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The rat luteal 20alpha-hydroxysteroid dehydrogenase plays a key role at catabolizing progesterone and at decreasing the level of this steroid secreted by the ovaries. Throughout pregnancy and before parturition neither the mRNA nor the protein for this enzyme could be detected. In this investigation we set to examine whether PRL and PRL-like hormone from placental origin silence the expression of this gene and whether PRL action involves tyrosine kinase activity and/or de novo protein synthesis. The results revealed that PRL and PRL-like hormone from rat placental origin (rPL-1 and rPL-2), but not rat growth hormone, caused a rapid and profound inhibition of 20alpha-HSD mRNA expression in highly luteinized granulosa cells. Immunoprecipition and western blot analysis indicate that PRL-R associates with JAK2 and Stat5, and this association is increased within 30 seconds with PRL treatment. Although both JAK2 and Stat5 were phosphorylated on tyrosine upon PRL treatment, the PRL mediated inhibition of 20alpha-HSD was not reversed by either tyrosine kinase inhibitors, AG18 and genistein, but was largely reversed by the protein synthesis inhibitor cycloheximide. In summary, results of this investigation indicate that although PRL can activate the JAK2/Stat5 system in the corpus luteum, the down regulation of 20alpha-HSD mRNA by PRL does not appear to involve tyrosine kinase activity but depends on de novo synthesis of protein(s).
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PMID:Prolactin-mediated inhibition of 20alpha-hydroxysteroid dehydrogenase gene expression and the tyrosine kinase system. 920 1

The primary culture of rat luteal cells and their long-term maintenance have been difficult. Low cellular yields have limited the possibility for the study of gene regulation in luteal cells. The goal of this study was to develop a cell line to serve as a model by which to study the expression and regulation of various genes specific to luteal cells. We attempted to develop a luteal cell line by transformation of large luteal cells through infection with a temperature-sensitive simian virus (SV-40 tsA209) mutant that has a temperature-sensitive mutation required for the maintenance of cell transformation. We report here the successful establishment of such a cell line, designated GG-CL cells. Large luteal cells were purified to homogeneity by flow cytometry from corpora lutea of day 14 pregnant rats, cultured for 24 h, and then infected with the SV-40 tsA209 mutant virus. Transformed cells were maintained at the permissive temperature (33 C) until colonies were identified. Several colonies of transformed cells were isolated and passaged. They multiplied at 33 C and formed multilayers. At the nonpermissive temperature (40 C), cells reverted to the normal differentiated phenotype similar to the primary luteal cells in culture. To determine whether GG-CL cells express the genes found in normal luteal cells, messenger RNA (mRNA) expression was examined by either Northern analysis or RT-PCR with primers specific to each mRNA. GG-CL cells were found to express receptors for interleukin-6 and glucocorticoid, as well as the newly discovered estrogen receptor-beta (ER-beta) and the orphan nuclear receptor nur 77. No receptors for ER-alpha, progesterone, LH, or PRL could be detected. This cell line also expressed 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD), but not cholesterol side-chain cleavage cytochrome P450 (P450scc), 3beta-hydroxysteroid dehydrogenase, or aromatase cytochrome P450 (P450arom). Although the cells did not express the PRL receptor, they did express Janus kinase (JAK2) and signal transducers and activators of transcription (Stat5b), and, when transfected with the PRL receptor, they responded to PRL with a marked inhibition in 20alpha-HSD mRNA expression. In addition, estradiol enhanced ER-beta expression in a dose-dependent manner whereas cAMP stimulation caused a marked and rapid increase in the expression of the orphan receptor nur 77. In summary, a temperature-sensitive cell line was successfully established from the large luteal cells of rat corpora lutea. These cells express key genes encoding enzymes and receptors inherent to this defined luteal cell population and respond to stimulation by PRL, estradiol, and cAMP.
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PMID:Establishment and characterization of a simian virus 40-transformed temperature-sensitive rat luteal cell line. 952 80

Although the main role of prolactin (PRL) in pregnant rodents is to sustain progesterone production by the corpus luteum, progesterone treatment of PRL or PRL receptor (PRL-R) null mice is unable to prevent fetal loss. We have previously shown that the rat decidua is a site of PRL production and action. In this report, we examined the hypothesis, using PRL null mice and rat decidual cell culture, that the absence of this hormone leads to the expression in the decidua of genes detrimental to pregnancy. The results show that decidual growth is normal in PRL null mice treated with PRL, progesterone, or their combination. However, the decidua of mice treated with progesterone starts expressing IL-6 and 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD), two proteins absent from the decidua of wild-type mice and involved, respectively, in inflammation and progesterone catabolism. The expression of both IL-6 and 20alpha-HSD is prevented by PRL treatment. Our results further suggest that PRL inhibition of 20alpha-HSD expression is at the level of transcription and that decidual PRL (dPRL) inhibits 20alpha-HSD promoter activity. Inhibitors of Janus kinase 2 (Jak2) but not other kinases prevent dPRL down-regulation of the 20alpha-HSD promoter. Furthermore, cotransfection of the 20alpha-HSD promoter with expression vectors of constitutively active PRL-R, Jak2, or signal transducer and activator of transcription 5b (Stat5b) leads to substantial inhibition of promoter activity. Taken together, our investigation provides an explanation for the inability of progesterone to sustain pregnancy in PRL null mice and suggests that dPRL plays an important role in pregnancy by repressing the expression of IL-6 and 20alpha-HSD in the decidua. The study also demonstrates that PRL signals through the Jak2/Stat5 pathway to down-regulate 20alpha-HSD expression in the decidua.
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PMID:Decidual prolactin silences the expression of genes detrimental to pregnancy. 1725