Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Retinoblastoma protein (RB) is a tumor suppressor gene product involved in embryogenesis and cell cycle progression. One of the major mechanisms leading to RB dysfunction is complex formation with viral oncoproteins using the common RB binding motif Leu X Cys X Glu (LXCXE) which has also been identified in cellular ligands, e.g., RBP-1 and RBP-2. p107, a cellular protein with RB sequence homology, has been shown to bind to the same viral oncoproteins associating with RB and is therefore thought to contribute to cell cycle regulation. It has recently been suggested that insulin stimulates gene transcription through direct association with an, as yet, unidentified intracellular transcription factor. Due to the central roles of RB and p107 in coupling external growth signals with the progression of the cell cycle clock, we have hypothesized that these two proteins might be candidates for mediating the effects of insulin on DNA. We report here the identification of a region in the B-chain of human insulin that has the sequence LXCXE. Based on this finding we predict that the insulin B-chain may interact with RB and/or p107. Since we have also identified sequences hydropathically related to LXCXE in insulin-like growth factor I (IGF-I) and II (IGF-II), but not in relaxin, nerve growth factor, epidermal growth factor, glucagon or beta-endorphin, we further propose that both IGF-I and -II may assemble with RB and/or p107, too. Moreover, binding sites on RB and p107 identical with those suggested for viral oncoproteins and cellular ligands are predicted for insulin/IGF-I/IGF-II by using the hydropathic complementarity approach.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Proposed interaction between insulin and retinoblastoma protein. 133 81

To assess whether neuroendocrine dysfunction is present in children with acquired immunodeficiency syndrome (AIDS) and growth failure, we evaluated the thyroid, adrenal, and growth hormone-insulin-like growth factor I (IGF-1) axes in nine children with AIDS and failure to thrive. Basal thyroid-stimulating hormone, free thyroxine, and triiodothyronine levels were normal in eight of the nine children and indicated primary hypothyroidism in one child; thyroxine levels were elevated in four and normal in five children. Thyroxine-binding globulin levels were elevated in all children. Serial measurements of thyroid-stimulating hormone, made hourly from 2 to 6 pm and from 10 pm to 2 am, revealed a flat diurnal rhythm of thyroid-stimulating hormone in six children, which may indicate early central hypothyroidism, and a normal nocturnal rise in the remaining three children. Basal plasma corticotropin and aldosterone levels were normal in all children, plasma renin levels were normal in three and elevated in six children, and cortisol levels were normal or elevated in all children. Corticotropin-stimulated cortisol levels exceeded 500 nmol/L (18 micrograms/dl) in all children except one, who was receiving treatment with ketoconazole. Thus adrenocortical function appeared to be grossly intact. The peak growth hormone responses to provocative testing was normal (greater than 7 ng/ml) in eight children and low in one child. The plasma level of insulin-like growth factor I was normal in eight of the nine children and low in one child. We conclude that growth failure in children with AIDS does not usually result from a recognized endocrine cause and that adrenal function is usually normal. However, endocrine deficiency may contribute to morbidity in some children with AIDS.
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PMID:Growth and neuroendocrine dysfunction in children with acquired immunodeficiency syndrome. 201 47

GRF promotes follicular maturation and ovulation when administered with FSH in the treatment of infertility. Such actions could be mediated by stimulation of GH secretion and insulin-like growth factor I production, but the known actions of the structurally related hormone, vasoactive intestinal peptide (VIP), on granulosa cell function suggested that GRF may also act directly on the ovary to stimulate follicular development. Radioligand binding and activation studies, performed in granulosa cells from immature estrogen-treated rats, revealed a common receptor for VIP and rat (r) GRF in the ovary. Specific binding of [125I]VIP to granulosa cells was saturable and dependent on time and temperature. The relative potencies of VIP-related peptides for inhibition of radioligand binding were: VIP greater than rGRF greater than peptide histidine isoleucinamide greater than [His1,Nle27] human GRF(1-32)NH2 greater than secretin. In binding studies with the potent GRF agonist, [125I] [His1,Nle27]GRF(1-32)NH2, relative potencies were: rGRF(1-43)OH greater than [His1,Nle27]human GRF(1-32)NH2 greater than VIP greater than peptide histidine isoleucinamide greater than secretin. Glucagon and gastric inhibitory peptide, other peptides of the glucagon superfamily, and unrelated peptides including CRF and beta-endorphin, did not inhibit binding of either radioligand to ovarian receptors. In cultured granulosa cells, rGRF and VIP stimulated cAMP formation, consistent with coupling of their receptors to the adenylate cyclase system, and potentiated FSH-induced cAMP production. Both peptides also amplified FSH-induced progesterone biosynthesis, aromatase activity, and LH receptor formation. These observations demonstrate that rGRF is a potent cAMP-mediated agonist in the rat ovary and acts on a common VIP/GRF receptor in maturing granulosa cells. It is likely that the potentiating effect of administered GRF on gonadotropin-stimulated follicular development in vivo is in part mediated by direct actions of the peptide on the VIP/GRF receptor. Also, since GRF is present in the gonads, it is possible that the locally-produced peptide promotes follicular maturation by paracrine modulation of the stimulatory action of FSH on granulosa cell function.
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PMID:Receptor-mediated actions of growth hormone releasing factor on granulosa cell differentiation. 217 7

Pretreatment of bovine adrenocortical cells with increasing concentrations of insulin-like growth factor I (IGF-I) for 3 days resulted in a dose dependent (ED50 congruent to 5 ng/ml) increment in Corticotropin (ACTH) receptors. Moreover, IGF-I pretreatment potentiated the effects of maximal active concentration of ACTH (10(-9) M) on its own receptors. Whereas ACTH (10(-9) M) or IGF-I (50 ng/ml) alone induced a 3- and 2.5-fold increase respectively in ACTH receptors, there was a 7.5 fold increase in the presence of the two peptides. This synergism between ACTH and IGF-I was also observed for the ACTH-induced cortisol response with an increase of 9-, 3- and 20-fold for cells pretreated with ACTH, IGF-I and the two peptides, respectively. However, the effects of both peptides on ACTH-induced cAMP production was only additive. The present results show that ACTH and IGF-I are potent stimulating factors on bovine adrenal cell differentiated functions and that the effects of both peptides are synergistic.
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PMID:Synergistic effects of corticotropin and insulin-like growth factor I on corticotropin receptors and corticotropin responsiveness in cultured bovine adrenocortical cells. 248 Jan 25

The role of insulin-like growth factor I (IGF-I) on the specific function of several steroidogenic cells has been recently reported. Since IGF-I is produced by several tissues, we have investigated whether bovine adrenal cells secrete this peptide. Purification of conditioned medium from adrenal cells incubated with [35S]methionine through affinity chromatography (monoclonal anti-IGF-I antibody), high pressure liquid chromatography, and polyacrylamide gel electrophoresis revealed a single band of similar Mr as pure recombinant IGF-I. Moreover, the purified adrenal-secreted IGF-I displaced bound 125I-IGF-I to its adrenal receptors, and pretreatment of adrenal cells with the purified peptide enhanced the acute corticotropin (ACTH)-induced cAMP production as recombinant IGF-I. The basal secretion of IGF-I (6 +/- 1 ng/48 h/10(6) cells) was stimulated 3-, 4.5-, and 9.5-fold by fibroblast growth factor, angiotensin II (A-II), and ACTH, respectively, but not by growth hormone. The stimulatory effects of A-II and ACTH were dose-dependent (ED50 congruent to 2.5 x 10(-8) and 1.5 x 10(-10) M, respectively), and the effects of both hormones were additive. Glucocorticoids were not the mediators of the effect of the two hormones on IGF-I secretion, since inhibition of their steroidogenic action by aminoglutethimide did not significantly modify IGF-I secretion. An immunoreactive IGF-I material was also secreted by mouse adrenal tumor cell line Y-1, but the stimulatory effect of ACTH was only 2-fold, and there was no effect of A-II. Since bovine adrenal cells contain specific IGF-I receptors and this peptide is required for the maintenance of some adrenal cell-specific function, the present data suggest that IGF-I may act in an autocrine fashion to stimulate adrenal cell differentiation stimulated by ACTH and A-II.
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PMID:Hormonal regulation of insulin-like growth factor I secretion by bovine adrenal cells. 254 Jan 65

Among the large number of immediate early genes, nuclear proto-oncogenes of the Fos and Jun families, have been postulated to be involved in the long-term effects of several growth factors on cell differentiation and/or multiplication. Since adrenal cell differentiated functions appear to be regulated by specific hormones and growth factors, the effects of these factors on proto-oncogene mRNA levels were analysed in bovine adrenal fasciculata cells (BAC) in culture. Corticotropin (ACTH) and insulin-like growth factor I increased c-fos and jun-B mRNA, but had no effect on c-jun mRNA and these early changes were associated with a later increase in BAC specific function [ACTH receptors, cytochrome P450 17 alpha) and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD)] and an enhanced steroidogenic responsiveness to both ACTH and angiotensin-II (A-II). On the other hand, A-II increased the three proto-oncogene (c-fos, c-jun and jun-B) mRNAs, induced a decrease of P450 17 alpha and 3 beta-HSD and caused a marked homologous and heterologous (ACTH) densitization. Transforming growth factor beta 1 which only increased jun-B mRNA, markedly reduced BAC differentiated functions and the steroidogenic responsiveness to both ACTH and A-II. Thus, it is postulated that the proto-oncoproteins encoded by the immediate early genes may play a role in the long-term effects of peptide hormones and growth factors on BAC differentiated functions.
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PMID:Peptide hormone and growth factor regulation of nuclear proto-oncogenes and specific functions in adrenal cells. 791 7

Adrenal cell-differentiated functions and, therefore, their steroidogenic capacity can be regulated in an opposite direction by insulin-like growth factor I (IGF-I) and transforming growth factor-beta 1 (TGF beta 1). The enhanced steroidogenic responsiveness of bovine and ovine adrenal cells treated with IGF-I can be explained by its positive effects on the number of corticotropin (ACTH) and angiotensin II (A-II) receptors associated with an increase in the alpha s and alpha i subunits of G proteins but also by its effects on several steps of the steroidogenic pathway. In contrast, TGF beta 1 is a potent inhibitor of differentiated functions of both bovine and ovine adrenal cells. TGF beta 1 reduces ACTH and A-II receptor number, inhibits cAMP formation, and decreases several steroidogenic enzyme activities. The physiological role of these peptides in adrenal cells is strengthened by the fact that both are synthetized and secreted by these cells and that their secretion can be regulated by the specific hormones, ACTH and A-II.
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PMID:Regulation of adrenal cell-differentiated functions by growth factors. 795 33

Basal cortisol levels and cortisol responses to dexamethasone (DXM) and corticotropin were studied in relation to serum levels of sex hormone-binding globulin (SHBG), testosterone (T), free T, estradiol (E2), insulin-like growth factor I (IGF-I), high-density lipoprotein cholesterol (HDLC), triglycerides (TG), and insulin in 30 men. SHBG was positively correlated to age (P < .01), HDLC (P < .05), and total T (P < .05) and negatively correlated to TG (P < .02) and insulin (P < .001). SHBG was inversely related to corticosteroid-binding globulin (P < .05), but was not significantly associated with IGF-I. Free T was positively related to TG (P < .05), insulin (P < .01), total T (P < .001), and basal (P < .01) and free cortisol (P < .05). Corticotropin-stimulated cortisol responses were negatively associated with SHBG (P < .001) and positively associated with insulin (P < .01). Multiple linear regression analyses with SHBG as the dependent variable indicated that cortisol response alone explained 34.0% and together with age 46.2% of the variation of SHBG levels. Only insulin and age, but not cortisol response, remained significant predictors of SHBG concentrations when entered simultaneously into the mathematical model; this model explained 55.1% of the variation of SHBG levels. Thus, in addition to insulin and age, cortisol reserves and secretion seem to have significant associations with serum SHBG and free T concentrations.
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PMID:Serum sex hormone-binding globulin, cardiovascular risk factors, and adrenal cortisol responses to dexamethasone and corticotropin. 839 55

The effects of various neuropeptides on human plasma cells were studied. Of the various neuropeptides tested, vasoactive intestinal peptide (VIP) enhanced Ig production and growth in human plasma cell lines, IM-9 and AF-10, and in plasma cells generated in vivo (four out of four patients with plasma cell leukemia) and in vitro. In contrast, other neuropeptides (neuropeptide Y, somatostatin, substance P, peptide YY, neurokinin A, calcitonin gene-related peptide, chole-cystokinin octapeptide, and beta-endorphin) were ineffective. Moreover, VIP-induced enhancement was specifically blocked by VIP receptor antagonist. Among the various cytokines, IL-6, GH, and insulin-like growth factor I (IGF-I) also enhanced Ig production and thymidine uptake in plasma cells. However, VIP-induced enhancement was not mediated by IL-6, GH, or IGF-I because antibodies to these cytokines failed to block VIP-induced enhancement. Phorbol 12,13 dibutyrate enhanced Ig production and thymidine uptake in plasma cells, and the Phorbol 12,13 dibutyrate-induced enhancement was blocked by H7 (a protein kinase C inhibitor) but not by H8 (a protein kinase A inhibitor). Similarly, VIP-induced enhancement was blocked by H7 but not by H8. Collectively, VIP enhances plasma cell responses via mechanisms that may involve protein kinase C.
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PMID:Vasoactive intestinal peptide enhances immunoglobulin production and growth in human plasma cells via mechanisms that may involve protein kinase C. 876 69

To evaluate the late-effects of allogeneic bone marrow transplantation (BMT) on endocrine function 20 adults (10 females, 10 males) with hematological malignancies were studied after a mean of 3.2 years (range 1.0-10.0) following BMT. The mean age of patients at the time of BMT was 39 years. Dynamic tests of the hypothalamic-pituitary axis included growth hormone releasing hormone (GHRH), gonadotropin releasing hormone (GnRH) and thyrotropin releasing hormone (TRH) stimulations with measurements of serum growth hormone (GH), follicle stimulating hormone (FSH), luteinizing hormone (LH), thyrotropin (TSH) and prolactin (PRL) responses. Adrenal function was assessed with the adrenocorticotropin (ACTH) test. Five patients (25%) had a subnormal GH response to GHRH stimulation, but all had a normal serum insulin-like growth factor I (IGF-I) value. There was an inverse nonlinear relationship between the body mass index (BMI; kg/m2) and GH response but no relation between the GH response and total body irradiation (TBI), intrathecal treatment or occurrence of graft-versus-host disease. In females, serum FSH and LH basal levels and responses to GnRH, in spite of oestrogen substitution therapy in 9/10 patients, indicated ovarian failure and early menopause. Most responses to GnRH were delayed. All males had elevated serum basal FSH levels indicating damage in seminiferous tubulus and infertility. Serum basal LH was elevated only in four males but testosterone values were all within normal limits. However, the mean free androgen index (FAI) was in the low normal range, and two subjects had abnormally low FAI. Serum free thyroxine (fT4) levels were normal in all but one, but an exaggerated TSH response to TRH occurred in seven patients (35%). Four of them had received TBI and one total nodal irradiation suggesting radiation-induced damage to the thyroid gland. In 19 of the 20 patients, adrenal function judged with ACTH test was normal. We conclude that functional impairments of the hypothalamus-pituitary-gonad/thyroid axis are common while disturbances in GH, adrenal and prolactin occur less often in patients after intensive treatment and BMT. Typically, the target organ is more commonly affected than the hypothalamus-pituitary axis. In spite of normal serum testosterone and LH values, serum FAI may reveal androgen deficiency.
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PMID:Long-term effects of allogeneic bone marrow transplantation (BMT) on pituitary, gonad, thyroid and adrenal function in adults. 972 67


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