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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Superovulatory responses in cattle are known to be highly variable. In the present study, a recombinant porcine follicle stimulating hormone (rpFSH) produced in baculovirus-insect cells was utilised to evaluate the role of this recombinant FSH in control of the ovulatory process. Immature hypophysectomised rats were implanted with oestrogen pellet (10 mg diethylstilbestrol) and then primed with pregnant mare serum gonadotropin (PMSG, 17.5 IU, sc). Fifty-two hours later, 100 microg rpFSH or saline was injected (sc) to induce ovulation. All rats that received rpFSH ovulated with about eight ova rat(-1), whereas none of the control animals did. Ovulation induced by rpFSH was associated with an increase in the ovarian activity and message levels of tissue-type plasminogen activator (tPA), a protease important in the preovulatory degradation of the follicle wall. Furthermore, addition of rpFSH to the cultured rat granulosa cells resulted in a significant increase in tPA enzyme activity. These results demonstrate that rpFSH produced in baculovirus-insect cells has biological potency in ovulation as well as gene expression of tPA, providing a large advantage of this massive expression system in the reproduction of domestic animals.
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PMID:Recombinant porcine follicle stimulating hormone produced in baculovirus-insect cells induces rat ovulation in vivo and gene expression of tissue plasminogen activator in vitro. 955 1

FSH is the main regulator of Sertoli cell function. Nevertheless, several other effectors such as catecholamines can also stimulate these cells through the adenylyl cyclase transduction pathway. However, the expression of beta adrenergic receptors in Sertoli cells is a subject of controversy. The aim of the present study was to determine if there are physiologically functional beta adrenergic receptors in Sertoli cells and to which subtype(s) they belong. In freshly isolated Sertoli cells, isoproterenol, a non selective beta-adrenergic agonist, was found to stimulate cAMP production and tissue-type plasminogen activator secretion. Specific transcripts for the beta1 and beta2, but not beta3, subtypes were detected by RT-PCR analysis. Beta2 transcripts were the form expressed predominantly in Sertoli cells. Binding experiments carried out on freshly isolated and on cytospined Sertoli cells indicated that in both conditions, [125I]iodocyanopindolol binding was inhibited by a non-selective and a 2 selective antagonist, whereas a beta1 selective antagonist had no effect. Scatchard analysis of beta2 specific inhibition revealed a dissociation constant of 0.3 nM and a receptor density of 14000 sites per cell. In freshly isolated Sertoli cells, we observed that cAMP and tissue-type plasminogen activator were stimulated by isoproterenol and a beta2 selective agonist, but not by beta1 or beta3 selective agonists. Accordingly, the isoproterenol-stimulated tissue-type plasminogen activator responses were abolished by the beta2 selective antagonist only. In cultured Sertoli cells, the trend was the same: tissue-type plasminogen activator and transferrin secretions were increased by isoproterenol and beta2 but not by beta1 or beta3 selective agonists. We conclude that freshly isolated Sertoli cells express beta2 adrenergic receptors which are functionally coupled to adenylyl cyclase and that these characteristics are preserved in cell culture. For the tested parameters, catecholamines and FSH effects were similar, but response magnitudes were systematically lower with beta agonists than with FSH. As norepinephrine is normally present in physiologically-relevant amounts in the interstitial fluid, it can be suspected to play a role in the regulation of Sertoli cell function.
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PMID:Beta2 adrenergic receptors mediate cAMP, tissue-type plasminogen activator and transferrin production in rat Sertoli cells. 978 5

FSH is synthesized and secreted by the anterior pituitary gland in multiple molecular forms; the release of these isoforms depends on the endocrine status of the donor at the time of sample collection. In the present study, we analysed the possibility that the FSH charge isoforms may exert differential effects at the target cell. Seven FSH isoform mixes were isolated from pooled anterior pituitary glycoprotein extracts by high resolution chromatofocusing, followed by affinity chromatography, which removed nearly 90% of the LH that co-eluted with the FSH isoforms during chromatofocusing. The isoforms (isoform I, pH >7.10; II, pH range 6.60-6.20; III, pH 5. 47-5.10; IV, pH 5.03-4.60; V, pH 4.76-4.12; VI, pH 4.05-3.82 and VII, pH <3.80) were then tested for their capacity to stimulate cAMP release, androgen aromatization and tissue-type plasminogen activator (tPA) enzyme activity and cytochrome P450 aromatase, tPA and inhibin alpha-subunit mRNA production by rat granulosa cells in culture. cAMP and oestradiol production were determined by RIA, tPA enzyme activity by SDS-PAGE and zymography and all mRNAs by northern blot hybridization analysis and semiquantitative RT-PCR. All isoforms, with the exception of isoform I, stimulated synthesis and release of cAMP, oestrogen and tPA enzyme activity in a dose-dependent manner; the potency of the less acidic isoforms (pH 6. 60-4.60) was greater than that exhibited by the more acidic/sialylated analogs (pH 4.76 to <3.80; potencies II>III>IV>V>VII>VI). A similar trend was observed in terms of cytochrome P450 aromatase and tPA mRNA production. In contrast, when FSH-stimulated production of alpha-inhibin mRNA was analysed, isoforms V-VII were significantly more potent (two- to threefold) than the less acidic/sialylated counterparts (II-IV). In contrast to isoforms II-VII (which behaved as FSH agonists), isoform I (elution pH >7.10) completely blocked P450 aromatase and tPA mRNA expression, without altering that of a constitutively expressed gene (glyceraldehyde-3-phosphate dehydrogenase). These results show for the first time that the naturally occurring human FSH isoforms may exhibit differential or even unique effects at the target cell level.
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PMID:Differential effects of the charge variants of human follicle-stimulating hormone. 1081 Feb 83

During the preovulatory period, cumulus cells (CCs) form a hyaluronan-protein extracellular matrix (cumulus expansion) that positively influences oocyte fertilization. Degradation of this matrix and CC-oocyte complex (COC) dissociation occurs within a few hours of ovulation and parallels the aging of oocytes. Modulation of CC proteolytic activity by gonadotropins and oocyte soluble factors has been hypothesized to determine such cumulus matrix changes. In the present study, we investigated plasminogen activator (PA) synthesis by COCs during the expansion and disassembly processes. Our results show that the secretion of tissue type PA and urokinase type PA (uPA) by oocytes and CCs, respectively, does not change significantly during expansion but dramatically increases thereafter. Compact COCs were isolated from immature mice, primed 48 h earlier with 5 IU PMSGs, and were induced to expand in vitro with 100 ng/ml FSH in the presence of 1% FCS. Full expansion was achieved at 16 h, when hyaluronan synthesis ceased. Release of hyaluronan and CCs from the COC matrix began between 18 and 20 h of culture, which indicates that matrix degradation started at this time. PA activities in culture media were determined by SDS-PAGE, followed by a zymography at various time intervals between 4 and 32 h of culture. Secreted tissue type PA and uPA activity abruptly increased between 16 and 20 h after FSH stimulation. Slot blot hybridization of CC messenger RNA showed that uPA messenger RNA levels correlated with the increase in uPA activity. Similar temporal patterns of PA synthesis and matrix degradation were found in COCs induced to expand in vivo by injection of 5 IU human CG into PMSG-primed mice. Cultures of CCs, both in the presence and absence of oocytes, revealed that uPA synthesis is repressed in FSH-stimulated CCs by an oocyte-soluble factor for the first 16 h of culture, whereas CC responsiveness to this factor is lost thereafter. In conclusion, the data show that a sophisticated interplay between oocyte and CCs causes the two cell types to simultaneously secrete PA activity after ovulation. The fact that matrix degradation parallels PA production strongly supports the hypothesis that these enzymes may destabilize the expanded COC matrix.
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PMID:Control of mouse cumulus cell-oocyte complex integrity before and after ovulation: plasminogen activator synthesis and matrix degradation. 1141 25

A Continuous Flow Electrophoresis System (CFES) was used on Space Shuttle flight STS-8 to separate specific secretory cells from suspensions of cultured primary human embryonic kidney cells and rat pituitary cells. The objectives were to isolate the subfractions of kidney cells that produce the largest amounts of urokinase (plasminogen activator), and to isolate the subfractions of rat pituitary cells that secrete growth hormone, prolactin, and other hormones. Kidney cells were separated into more than 32 fractions in each of two electrophoretic runs. Electrophoretic mobility distributions in flight experiments were spread more than the ground controls. Multiple assay methods confirmed that all cultured kidney cell fractions produced some urokinase, and five to six fractions produced significantly more urokinase than the other fractions. Several fractions also produced tissue plasminogen activator. The pituitary cells were separated into 48 fractions in each of the two electrophoretic runs, and the amounts of growth hormone (GH) and prolactin (PRL) released into the medium for each cell fraction were determined. Cell fractions were grouped into eight mobility classes and immunocytochemically assayed for the presence of GH, PRL, ACTH, LH, TSH, and FSH. The patterns of hormone distribution indicate that the specialized cells producing GH and PRL are isolatable due to the differences in electrophoretic mobilities.
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PMID:Electrophoretic separation of kidney and pituitary cells on STS-8. 1154 4

Gonadotropins are synthesized and released in different molecular forms. In this article, we present evidence that the glycosylation variants of human pituitary FSH exhibit differential and divergent effects at the target cell level and that less sialylated, short-lived variants may exert significant effects in in vivo conditions. Less acidic/sialylated glycoforms (elution pH value 6.60-4.60 as disclosed by high resolution chromatofocusing of anterior glycoprotein extracts), induced higher cAMP release, estrogen production and tissue-type plasminogen activator (tPA) enzyme activity as well as cytochrome P450 aromatase and tPA mRNA expression in cultured rat granulosa cells than the more acidic analogs (pH<4.76). By contrast, the more acidic/sialylated glycoforms induced higher alpha-inhibin subunit mRNA expression than their less acidic counterparts. In cumulus enclosed oocytes isolated from mice ovaries, addition of less acidic isoforms induced resumption of meiosis more efficiently than the more acidic analogs. Interestingly, the least acidic isoform (pH>7.10) behave as a strong antagonist of several FSH-mediated effects. Assessment of the in vivo effects of the isoforms on granulosa cell proliferation in follicles from immature rats, revealed that short-lived isoforms were equally or even more efficient than their more acidic counterparts in maintaining granulosa cell proliferation when administered immediately after hypophysectomy. These results show that the naturally occurring human FSH isoforms may exhibit differential or even unique effects at the target cell level and that factors other than the metabolic clearance rate of the molecule (including receptor-binding affinity and capability of the ligand to activate its receptor and trigger intracellular signaling) also play an important role in determining the net in vivo effects of a particular FSH variant.
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PMID:Assessment of the in vitro and in vivo biological activities of the human follicle-stimulating isohormones. 1190 Aug 95

We evaluated the association of hemostatic factors with insulin resistance in relation to reproductive hormones including FSH, estradiol, testosterone, and SHBG. SHBG was used to calculate the free estradiol index and free androgen index. We studied 3,200 women, aged 42-52 yr, in the Study of Women's Health Across the Nation, a prospective multiethnic study of the menopausal transition. We measured the hemostatic factors, fibrinogen, factor VIIc, tissue plasminogen activator (t-PA), and plasminogen activator inhibitor type 1 (PAI-1), as well as glucose and insulin to calculate insulin resistance. After adjustment for body mass index, site, and ethnicity, SHBG was correlated with PAI-1 (partial r = -0.30) and t-PA (partial r = -0.12). Although testosterone was associated with t-PA (partial r = 0.13) and PAI-1 (partial r = 0.07), free androgen index was strongly correlated with t-PA (partial r = 0.18) and PAI-1 (partial r = 0.26). SHBG modified the association of hemostatic factors with insulin resistance. Women with greater insulin resistance had lower SHBG and higher PAI-1. Estrogen measures were not associated with insulin resistance. The influence of sex hormones on hemostatic factors and insulin resistance is poorly understood. SHBG, which influences the amount of bioavailable hormone, significantly modified the association of PAI-1 and t-PA with insulin resistance. The longitudinal Study of Women's Health Across the Nation will help us discern whether this interaction contributes to heart disease and diabetes among postmenopausal women.
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PMID:Insulin resistance, hemostatic factors, and hormone interactions in pre- and perimenopausal women: SWAN. 1455 72

During ovarian follicle growth, there is expansion of the basal lamina and changes in the follicular extracellular matrix (ECM) that are mediated in part by proteolytic enzyme cascades regulated by tissue-type plasminogen activator (tPA) and urokinase plasminogen activator (uPA). One PA inhibitor, serine protease inhibitor-E2 (SERPINE2) is expressed in granulosa but not theca cells, and expression changes with follicle development. In this study, we hypothesized that PA and SERPINE2 expression/secretion by granulosa cells are regulated by FSH and growth factors. SERPINE2 mRNA and protein levels, tPA gene expression and uPA secretion were stimulated by FSH. Insulin-like growth factor-I stimulated SERPINE2 secretion and uPA activity, and decreased secreted tPA activity and gene expression. Bone morphogenetic protein-7 increased SERPINE2 secretion and expression and tPA secretion. In contrast, fibroblast growth factor-2 inhibited tPA secretion and SERPINE2 secretion and expression. Epidermal growth factor inhibited SERPINE2 secretion and expression, but increased secreted tPA activity. Estradiol and SERPINE2 secretion were highly positively correlated, but estradiol did not alter SERPINE2 expression. These data demonstrate that SERPINE2 expression and protein secretion are regulated by FSH and growth factors in non-luteinizing bovine granulosa cells. As estradiol is a known marker of follicle health, and SERPINE2 is an anti-apoptotic factor, we propose that SERPINE2 is involved in the regulation of atresia in bovine follicles.
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PMID:Regulation of serine protease inhibitor-E2 and plasminogen activator expression and secretion by follicle stimulating hormone and growth factors in non-luteinizing bovine granulosa cells in vitro. 1680 68

Our previous studies have demonstrated that tissue type plasminogen activator (tPA) might be involved in matrix degradation of blood-testis barrier in rat. In this study, we have further investigated the effect of testosterone (T) on tPA production in rat Sertoli cells. Our results showed that Sertoli cells isolated from rat testes at various ages in vitro secreted tPA in an age-dependent manner. The tPA activity was detected on day 20 after birth, and reached maximum on day 60. The Sertoli cells isolated from the testes on day 20 were then cultured in the presence or absence of testosterone, FSH, and forskolin, the tPA activities were upregulated by T, FSH and forskolin. Addition of H89 or U0126, both inhibited the testosterone-, FSH-, and forskolin-induced tPA expression. It is suggested that FSH- and testosterone-stimulated tPA expression in Sertoli cells may be via PKA and ERK signal transduction. Furthermore, we have observed that testosterone stimulated tPA secretion at all the stages of spermatogenesis (II-VI, VII-VIII, IX-XII and XIII-I), the highest stimulation of tPA activity was observed at stages VII-VIII. This study further suggests that testosterone-induced tPA activity in the Sertoli cells might be related to the function of blood-testis barrier opening and/or closing.
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PMID:Testosterone upregulation of tissue type plasminogen activator expression in Sertoli cells : tPA expression in Sertoli cells. 1799 6

We have analyzed a possible role of mitogen-activated protein kinase (MAPK) and activator protein-1 (AP-1) in the regulation of FSH-induced tissue type plasminogen activator (tPA) production in granulosa cells (GCs) prepared from DES-treated immature rats; Treatment of the cells in the presence of FSH with MAPK inhibitors, such as UO126 or SB203580, significantly decreased the FSH-induced tPA production, suggesting that multiple signaling pathways may be involved in FSH-regulated tPA expression. We further examined possible signaling action involved in FSH-activated ERK1/2 and p38 MAPK on tPA production, and observed that FSH receptor occupancy led to both ERK1/2 and p38 MAPK phosphorylation. Such action might be through a protein kinase A-dependent pathway because the observed activation was destroyed by the addition of its specific inhibitor H89 to the culture. The inhibition of ERK1/2 and p38 MAPK activation by their specific inhibitors remarkably reduced FSH-induced tPA mRNA and its protein production. We further examined whether AP-1 located in the tPA promoter is involved in FSH-regulated tPA production, and demonstrated that FSH significantly stimulated AP-1 expression, whereas inclusion of H89, UO126, or SB20358 in the culture significantly decreased FSH-induced AP-1 expression. In summary, FSH-induced ERK1/2 and p38 MAPK activation is capable of regulating tPA production in cultured primary GCs, and that the transcript factor AP-1 may be important in the regulation of FSH-induced tPA expression.
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PMID:Mitogen-activated protein kinase regulates FSH-induced expression of tissue-type plasminogen activator through an activator protein 1 response element. 1898 62


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