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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the transforming growth factor-beta (TGF-beta) superfamily is the largest family of secreted growth factors, surprisingly few downstream target genes in their signaling pathways have been identified. Likewise, the identities of oocyte-derived secreted factors, which regulate important oocyte-somatic cell interactions, remain largely unknown. For example, oocytes are known to secrete paracrine growth factor(s) which are necessary for cumulus expansion, induction of hyaluronic acid synthesis, and suppression of LH receptor (LHR) mRNA synthesis. Our previous studies demonstrated that absence of the TGF-beta family member, growth differentiation factor-9 (GDF-9), blocks ovarian folliculogenesis at the primary follicle stage leading to infertility. In the present study, we demonstrate that mouse GDF-9 protein is expressed in all oocytes beginning at the type 3a follicle stage including antral follicles. To explore the biological functions of GDF-9 in the later stages of folliculogenesis and cumulus expansion, we produced mature, glycosylated, recombinant mouse GDF-9 using a Chinese hamster ovary cell expression system. A granulosa cell culture system was established to determine the role of GDF-9 in the regulation of several key ovarian gene products using semiquantitative RT-PCR. We find that recombinant GDF-9 induces hyaluronan synthase 2 (HAS2), cyclooxygenase 2 (COX-2), and steroidogenic acute regulator protein (StAR) mRNA synthesis but suppresses urokinase plasminogen activator (uPA) and LHR mRNA synthesis. Consistent with the induction of StAR mRNA by GDF-9, recombinant GDF-9 increases granulosa cell progesterone synthesis in the absence of FSH. Since induction of HAS2 and suppression of the protease uPA in cumulus cells are key events in the production of the hyaluronic acid-rich extracellular matrix which is produced during cumulus expansion, we determined whether GDF-9 could mimic this process. Using oocytectomized cumulus cell-oocyte complexes, we show that recombinant GDF-9 induces cumulus expansion in vitro. These studies demonstrate that GDF-9 can bind to receptors on granulosa cells to regulate the expression of a number of gene products. Thus, in addition to playing a critical function as a growth and differentiation factor during early folliculogenesis, GDF-9 functions as an oocyte-secreted paracrine factor to regulate several key granulosa cell enzymes involved in cumulus expansion and maintenance of an optimal oocyte microenvironment, processes which are essential for normal ovulation, fertilization, and female reproduction.
Mol Endocrinol 1999 Jun
PMID:Paracrine actions of growth differentiation factor-9 in the mammalian ovary. 1037

Altered PRL levels are associated with infertility in women. Molecular targets at which PRL elicits these effects have yet to be determined. These studies demonstrate transcriptional regulation by PRL of the gene encoding the final enzymatic step in progesterone biosynthesis: 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase (3beta-HSD). A 9/9 match with the consensus Stat5 response element was identified at -110 to -118 in the human Type II 3beta-HSD promoter. 3beta-HSD chloramphenicol acetyltransferase (CAT) reporter constructs containing either an intact or mutated Stat5 element were tested for PRL activation. Expression vectors for Stat5 and the PRL receptor were cotransfected with a -300 --> +45 3beta-HSD CAT reporter construct into HeLa cells, which resulted in a 21-fold increase in reporter activity in the presence of PRL. Promoter activity showed an increased response with a stepwise elevation of transfected Stat5 expression or by treatment with increasing concentrations of PRL (max, 250 ng/ml). This effect was dramatically reduced when the putative Stat5 response element was removed by 5'-deletion of the promoter or by the introduction of a 3-bp mutation into critical nucleotides in the element. Furthermore, 32P-labeled promoter fragments containing the Stat5 element were shifted in electrophoretic mobility shift assay experiments using nuclear extracts from cells treated with PRL, and this complex was supershifted with antibodies to Stat5. These results demonstrate that PRL has the ability to regulate expression of a key human enzyme gene (type II 3beta-HSD) in the progesterone biosynthetic pathway, which is essential for maintaining pregnancy.
Mol Endocrinol 1999 Jul
PMID:Stat5-mediated regulation of the human type II 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase gene: activation by prolactin. 1040 60

Gonadotrophins are fundamental to the mechanisms regulating follicle status and development. Follicles in the ovary are either quiescent or committed to one of two pathways: growth or atresia. The requirement for gonadotrophins by the follicles varies with development: committed follicles grow independently of gonadotrophins (primarily FSH) until the late preantral stage when antrum formation is contingent upon FSH. The involvement of estrogen in regulating gonadotrophin secretion is well documented and while evidence for a local regulatory role of estrogen in the ovary mounts, an obligatory role for estrogen in the folliculogenic process has not been established. The availability of a wide range of gene-disrupted mice termed 'knockouts', is providing information relevant to the study of folliculogenesis. Mice deficient in either estrogen or estrogen receptors, are infertile primarily due to either a block in folliculogenesis prior to antrum formation or as a consequence of failing to ovulate. Blocking estrogen stimulated, post-receptor molecules such as cyclin D2, severely retards granulosa cell proliferation and leads to infertility, although the contribution of estrogen in this model is not so clear given that FSH also stimulates cyclin D2. Similar problems dissociating the roles of FSH and estrogen are evident with the FSH deficient animal models. Nevertheless, estrogen is clearly an important and probably obligatory regulator of folliculogenesis, especially in the post antral stage. The exact points in the folliculogenic process where estrogen exerts its principal effects remains to be elucidated.
Mol Cell Endocrinol 1999 May 25
PMID:The role of estrogen in folliculogenesis. 1041 20

Mutations in gonadotropin genes are extremely rare. Only one case of inactivating human luteinizing hormone (LH) beta mutation exists in the literature, a male with absence of Leydig cells, lack of spontaneous puberty and infertility. A total of four cases of inactivating mutation of the follicle-stimulating hormone beta (FSHbeta) gene (two female and two male) are known. The phenotype of the women was primary amenorrhea and absence of follicular maturation, the men were azoospermic. In addition, a common genetic variant (v) of LH was recently discovered. It is caused by two point mutations in the LH beta-subunit gene, resulting in amino acid alterations: Trp8 --> Arg and Ile15 --> Thr. In addition, the latter change introduces an extra glycosylation signal for oligosaccharide attachment to Asn13. The v-LHbeta allele has a carrier frequency ranging from 0 to > 50% in various populations. The variant LH molecule has increased intrinsic bioactivity in vitro, but decreased circulatory half-life in vivo, and the v-LHbeta promoter is about 50% more active in cell line transfections than that of wild-type (wt) LH. These differences in LH synthesis and action in individuals homo- or heterozygous for the v-LH allele are reflected by altered disposition to pathologies of pituitary-gonadal function, such as delayed puberty, polycystic ovarian syndrome and infertility.
Mol Cell Endocrinol 1999 May 25
PMID:Mutations and polymorphisms in gonadotropin genes. 1041 23

Some pathologies of the pituitary-gonadal function have recently been found to be due to mutations of the gonadotropin or gonadotropin receptor genes. Although these conditions are extremely rare, they are very informative, by elucidating some less well characterized facets of normal gonadotropin function and the molecular pathogenesis of disturbances in sexual differentiation and fertility. In contrast, there is a common polymorphism in the Luteinizing Hormone (LH) beta-subunit gene, where two point mutations cause two alterations in the amino acid sequence (Trp8 --> Arg and Ile15 --> Thr) and introduce an extra glycosylation signal to Asn13. The carriers of this variant gene are largely healthy, but certain mild differences in their gonadal function have been found, as reflected by alterations in gonadal steroidogenesis, pubertal development and predisposition to diseases such as infertility, polycystic ovarian syndrome, and breast and prostatic cancer. The purpose of this chapter is to review the current knowledge of the occurrence, special functional features and clinical correlates of this LH variant.
J Steroid Biochem Mol Biol
PMID:Alterations in gonadal steroidogenesis in individuals expressing a common genetic variant of luteinizing hormone. 1041 3

Proper evaluation of male infertility includes a careful history, physical examination, semen analysis, and karyotyping. Molecular cytogenetic analysis may also be necessary to further delineate the karyotype. Following the above approach, we found an apparently unique 8;22 translocation in a male patient with infertility but few other phenotypic manifestations. Delineating the exact genetic basis of infertility is important in view of the most recent advances in reproductive technology such as in vitro fertilization and intracytoplasmic sperm injection. Patients utilizing these emerging techniques need to be properly counseled as to their risks of transmitting these chromosomal abnormalities to their offspring.
Exp Mol Pathol 1999 Sep
PMID:Male infertility associated with a unique 8;22 translocation. 1049 93

In bovine oviduct cells 17beta-oestradiol can induce the synthesis of leukaemia inhibitory factor (LIF), a glycoprotein essential for embryo implantation. Therefore substances which are structurally similar to 17beta-oestradiol and possess oestrogenic activity may also modulate LIF synthesis and influence the reproductive process. We used primary cultures of bovine and human oviduct cells (epithelial cells:fibroblasts 1:1) to compare the effects of 17beta-oestradiol, phyto-oestrogens (genistein, biochanin A, daidzein, formononetin, and equol) and xeno-oestrogens [polychlorinated biphenyls (PCB): trichlorobiphenyl, 4-hydroxy-trichlorobiphenyl and 4-hydroxy-dichlorobiphenyl] on LIF synthesis. Immunoreactive LIF-enzyme-linked immunosorbent assay was used to determine the concentration of LIF in the culture medium. Similar to 17beta-oestradiol, genistein (0.02-2 micromol/l) induced LIF synthesis in bovine oviduct cells in a concentration-dependent manner. Equol, biochanin A and daidzein (2 micromol/l), 4-hydroxy-trichlorobiphenyl and 4-hydroxy-dichlorobiphenyl (0.01-10 micromol/l) but not formononetin (2 micromol/l) also induced LIF synthesis in bovine cells. Phyto-oestrogens and xeno-oestrogens also induced LIF synthesis in human oviduct cells (P < 0.05). The stimulatory effects of PCB, phyto-oestrogens and 17beta-oestradiol were blocked by ICI 182,780 (1 micromol/l). Moreover, 17beta-oestradiol, 4-hydroxy-trichlorobiphenyl, 4-hydroxy-dichlorobiphenyl, genistein, tamoxifen and ICI 182,780 displaced [(3)H]17beta-oestradiol from cytosolic oestrogen receptors in bovine oviduct cells. These results suggest that phyto-oestrogens and PCB mimic the effects of oestradiol in inducing LIF synthesis by bovine and human oviduct cells and that these stimulatory effects are oestrogen receptor-mediated. Environmental oestrogens act as endocrine modulators/disrupters and may induce deleterious effects on the reproductive process by influencing LIF synthesis in a non-cyclic fashion leading to tubal infertility.
Mol Hum Reprod 1999 Oct
PMID:Xeno-oestrogens and phyto-oestrogens induce the synthesis of leukaemia inhibitory factor by human and bovine oviduct cells. 1050 16

Patients with hypogonadotropic hypogonadism (HH) present with delayed puberty, infertility, and low serum gonadotropins. The molecular basis for most cases of HH is unknown, but single gene mutations have been described for some hypothalamic and pituitary genes. Kallmann syndrome due to KAL gene mutations and adrenal hypoplasia congenita/HH caused by AHC gene mutations are both X-linked recessive disorders. Mutations in the gonadotropin releasing hormone receptor, leptin, and the leptin receptor cause autosomal recessive HH. In addition, isolated deficiencies of follicle stimulating hormone and luteinizing hormone in the corresponding specific beta-subunit genes and PROP1 gene mutations represent pituitary deficiency states, resulting in a phenotype of HH. Despite these remarkable advances in our understanding of human HH, the cause of approximately 90% remains unknown.
Mol Genet Metab 1999 Oct
PMID:The molecular basis of human hypogonadotropic hypogonadism. 1052 69

Brucella abortus is a facultative intracellular pathogen that causes abortion and infertility in domestic animals and a severe debilitating febrile illness in humans. The mechanisms that this highly successful intracellular pathogen uses to adapt to, and survive within, the harsh intracellular environment of the host macrophage are presently unknown. Maintenance of the stationary phase growth state has been proposed to be critical for the virulence of several mammalian pathogens, but analysis of this relationship for the brucellae has not been undertaken. In order to evaluate this relationship, we examined the in vitro and in vivo characteristics of an isogenic hfq mutant constructed from virulent Brucella abortus 2308. In Escherichia coli, the hfq gene product is an RNA-binding protein that participates in the regulation of stationary phase stress resistance, at least partly by enhancing translation of the stationary phase-specific sigma factor RpoS. As expected, the Brucella abortus hfq mutant, designated Hfq3, showed increased sensitivity to H2O2, and decreased survival under acidic conditions (pH 4.0), during stationary phase growth compared with 2308. Hfq3 was also less able to withstand prolonged starvation than 2308. The Brucella abortus hfq mutant, unlike its parental strain 2308, fails to replicate in cultured murine macrophages, and is rapidly cleared from the spleens and livers of experimentally infected BALB/c mice. These findings suggest that the Brucella abortus hfq gene product makes an essential contribution to pathogenesis in mice, probably by allowing the brucellae to adapt appropriately to the harsh environmental conditions encountered within the host macrophage.
Mol Microbiol 1999 Nov
PMID:The Brucella abortus host factor I (HF-I) protein contributes to stress resistance during stationary phase and is a major determinant of virulence in mice. 1056 9

The herpes simplex virus transactivator protein VP16 is frequently used to regulate gene expression in several experimental systems, including transgenic mice. It has been suggested that high levels of VP16 expression in mice may be lethal. In order to systematically address this issue, we linked the VP16 gene to promoters that are active early and in a variety of tissues throughout development, such as the human beta-actin promoter or the rat nestin gene enhancer. VP16 expression was assayed using a LacZ reporter gene linked to a VP16-responsive immediate early gene promoter. We show here that expression of VP16 at high levels is detrimental to pre-implantation development. By culturing embryos in vitro, we demonstrate that this effect is exerted at the transition from the 2-cell to the 4-cell stage, reducing survival to the blastocyst stage dramatically. On the other hand, transgenic mice expressing VP16 transgenes at postimplantation stages are viable. These results suggest a differential sensitivity to VP16 expression in different cell types and stages of development. The reduction of embryo survival by VP16 implicates herpes virus infection as a potential cause of infertility.
Mol Reprod Dev 2000 Jan
PMID:Herpes simplex virus transcriptional activator VP16 is detrimental to preimplantation development in mice. 1060 72


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