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)

Recent experimental findings involve corticotropin-releasing hormone (CRH) in the cellular response to noxious stimuli and possibly apoptosis. The aim of the present work was to examine the effect of CRH on apoptosis and the Fas/Fas ligand system in an in vitro model, the PC12 rat pheochromocytoma cell line, which is widely used in the study of apoptosis and at the same time expresses the CRH/CRH receptor system. We have found the following. CRH induced Fas ligand production and apoptosis. These effects were mediated by the CRH type 1 receptor because its antagonist antalarmin blocked CRH-induced apoptosis and Fas ligand expression. CRH activated p38 mitogen-activated protein kinase, which was found to be essential for CRH-induced apoptosis and Fas ligand production. CRH also promoted a rapid and transient activation of ERK1/2, which, however, was not necessary for either CRH-induced apoptosis or Fas ligand production. Thus, CRH promotes PC12 apoptosis via the CRH type 1 receptor, which induces Fas ligand production via activation of p38.
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PMID:Corticotropin-releasing hormone induces Fas ligand production and apoptosis in PC12 cells via activation of p38 mitogen-activated protein kinase. 1179 Jul 88

Bovine cumulus-oocyte complexes (COCs) and mural granulosa cells express the mRNA coding for the micro-opioid receptor. The addition of beta-endorphin (beta-end) to oocytes cultured in hormonally-supplemented in vitro maturation (IVM) medium had no effect on the rates of oocytes reaching the metaphase II (MII) stage, but significantly decreased the maturation rate (P < 0.05) and arrested oocytes at metaphase I (MI) after culture in hormone-free medium (P < 0.001). Naloxone (Nx) reverted this inhibitory effect of beta-end. Moreover, Nx "per se" showed a dose-dependent dual effect. When added at high concentration (10 x (-3) M), it significantly reduced the rate of oocytes in MII (P < 0.001), thus increasing the rate of oocytes arrested in MI. However, Nx added at low concentration (10 x (-8) M) significantly increased oocyte maturation (P < 0.001). High concentration of Nx induced an increase in both intracellular calcium concentration ([Ca(2+)](i)) and in the activity of the mitogen-activated protein kinase (MAPK) also called extracellular-regulated kinase (ERK) in cumulus cells of bovine COCs. Blocking the rise in [Ca(2+)](i) with the calcium chelator acetoxymethylester-derived form of bis (o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM) reversed the Nx-dependent inhibition of meiotic maturation observed at high Nx concentrations. Whereas blocking ERK with the MAPK/ERK kinase (MEK) inhibitor, PD98059, had no effect on this process. Therefore, we concluded that the mocro-opioid receptor, by inducing [Ca(2+)](i) increase, participates in the cumulus-oocyte coupled signaling associated with oocyte maturation.
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PMID:Effects of beta-endorphin and Naloxone on in vitro maturation of bovine oocytes. 1220 31

We have previously demonstrated that corticotropin-releasing hormone (CRH) receptor 1 (CRH-R1) is functionally expressed in rat microglia. In the present study, we show that CRH, acting on CRH-R1, promoted cell proliferation and tumour necrosis factor-alpha (TNF-alpha) release in cultured rat microglia. Exogenous CRH resulted in an increase in BrdU incorporation compared with control cells, which was observed in a range of concentrations of CRH between 10 and 500 nm, with a maximal response at 50 nm. The effect of CRH on BrdU incorporation was inhibited by a CRH antagonist astressin but not by a cAMP-dependent protein kinase inhibitor H89. Exposure of microglial cells to CRH resulted in a transient and rapid increase in TNF-alpha release in a dose-dependent manner. In the presence of astressin, the effects of CRH on TNF-alpha release were attenuated. CRH effects on TNF-alpha release were also inhibited by specific inhibitors of MEK, the upstream kinase of the extracellular signal-regulated protein kinase (ERK) (PD98059) or p38 mitogen-activated protein kinase (SB203580), but not by H89. Furthermore, CRH induced rapid phosphorylation of ERK and p38 kinases. Astressin, PD98059, and SB230580 were able to inhibit CRH-induced kinase phosphorylation. These results suggest that CRH induces cell proliferation and TNF-alpha release in cultured microglia via MAP kinase signalling pathways, thereby providing insight into the interactions between CRH and inflammatory mediators.
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PMID:Corticotropin-releasing hormone induces proliferation and TNF-alpha release in cultured rat microglia via MAP kinase signalling pathways. 1248 15

Steroid hormone biosynthesis in the adrenal cortex is controlled by adrenocorticotropin (ACTH), which increases intracellular cAMP, resulting in the activation of cAMP-dependent protein kinase(PKA) and subsequent increase in steroidogenic gene transcription. We have found that a dual-specificity phosphatase is essential for conveying ACTH/cAMP-stimulated transcription of several steroidogenic genes in the human adrenal cortex. In the present study, the role of mitogen-activated protein kinase phosphatase-1 (MKP-1), a nuclear dual-specificity phosphatase, in the transcriptional activation of human CYP17 (hCYP17) in H295R human adrenocortical cells is established. Stimulation of H295R cells with dibutyryl-cAMP (Bt(2)cAMP) induces MKP-1 mRNA and protein expression within 30 min of exposure. In transient-transfection studies, transcriptional activity of an hCYP17 promoter-reporter construct was increased by Bt(2)cAMP and by overexpression of PKA or MKP-1. Furthermore, PKA phosphorylated an MKP-1-glutathione S-transferase fusion protein in in vitro assays and Bt(2)cAMP increased (32)P associated with MKP-1 that was immunoprecipitated from H295R cells. Finally, silencing MKP-1 expression using antisense oligonucleotides attenuated cAMP-stimulated hCYP17 expression, whereas silencing of ERK1/2 increased hCYP17 expression. These findings demonstrate integral roles for MKP-1 and ERK1/2 via regulation of the phosphorylation state of steroidogenic factor-1 (SF-1) in mediating ACTH/cAMP-dependent transcription of hCYP17, thereby maintaining the balance between transcriptional activation and repression.
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PMID:CAMP-dependent protein kinase enhances CYP17 transcription via MKP-1 activation in H295R human adrenocortical cells. 1250 19

Steroid hormone biosynthesis in the adrenal cortex is controlled by the peptide hormone adrenocorticotropin (ACTH), which acts to increase intracellular cAMP, resulting in the activation of cAMP-dependent protein kinase (PKA) and subsequent increase in steroidogenic gene transcription. We have identified three proteins interacting with the human CYP17 cAMP responsive sequence (CRS): steroidogenic factor 1 (SF-1), p54nrb, and polypyrimidine tract-binding protein-associated splicing factor (PSF). Nuclear extracts isolated from cAMP stimulated of H295R cells showed cAMP-inducible binding to the human CYP17 (hCYP17) CRS. This cAMP-inducible binding was dependent on a dual-specificity phosphatase (DSP). DSP activity was subsequently shown to be is essential for conveying ACTH/cAMP-stimulated transcription of several steroidogenic genes in the human adrenal cortex. We report here that the transactivation potential of SF-1 is also dependent on phosphatase activity; suggesting that SF-1 is dephosphorylated in response to ACTH/cAMP stimulation. Finally, we demonstrate a role for mitogen-activated protein kinase phosphatase 1 (MKP-1), a nuclear DSP, in conveying SF-1-dependent transcription of an hCYP17 promoter-reporter construct in the H295R human adrenocortical cell line. We conclude that a DSP, possibly MKP-1, is essential for enhancing hCYP17 transcription in the adrenal cortex by desphosphorylating of SF-1, thereby increasing the binding affinity of SF-1, p54nrb, and PSF for the hCYP17 promoter.
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PMID:Transcriptional complexes at the CYP17 CRS. 1253 Jun 62

Opioids have previously been shown to affect proliferation and differentiation in various neural cell types. In the present study, cultured rat adult hippocampal progenitors (AHPs) were shown to release beta-endorphin. Membrane preparations of AHPs were found to bind [125I]beta-endorphin, and immunoreactivity for mu- and delta-opioid receptors (MORs and DORs), but not for kappa-opioid receptors (KORs), was found on cells in culture. Both DNA content and [3H]thymidine incorporation were reduced after a 48-h incubation with 100 microM naloxone, 10 micro m naltrindole or 10 microM beta-funaltrexamine, but not nor-binaltorphimine, suggesting proliferative actions of endogenous opioids against MORs and DORs on AHPs. Furthermore, analysis of gene and protein expression after incubation with MOR and DOR antagonists for 48 h using RT-PCR and Western blotting suggested decreased signalling through the mitogen-activated protein kinase (MAPK) pathway and lowered levels of genes and proteins that are important in cell cycling. Cultures were incubated with naloxone (10 or 100 microM) for 10 days to study the effects on differentiation. This resulted in an approximately threefold increase in neurogenesis, a threefold decrease in astrogliogenesis and a 50% decrease in oligodendrogenesis. In conclusion, this study suggests that reduced signalling through MORs and DORs decreases proliferation in rat AHPs, increases the number of in vitro-generated neurons and reduces the number of astrocytes and oligodendrocytes in culture.
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PMID:Mu- and delta-opioid receptor antagonists decrease proliferation and increase neurogenesis in cultures of rat adult hippocampal progenitors. 1267 Mar 4

Tpit (Tbx19) is a transcription factor belonging to the T-box family, and it is essential for late differentiation of pituitary pro-opiomelanocortin (POMC)-expressing corticotroph and melanotroph cells. Tpit is also required, both in humans and mice, for cell-specific expression of the POMC gene in cooperation with the homeoprotein Pitx1. Despite their important roles as developmental regulators, the molecular mechanisms underpinning the functions of T-box factors in general, and of Tpit in particular, are still poorly defined. We now report that Tpit functions as an activator of transcription by recruiting SRC/p160 co-activators to its cognate DNA target in the POMC promoter, the Tpit/Pitx-RE. We also show that Tpit is a mediator of hormone signaling and that the Tpit/Pitx-RE is responsive to signals elicited by hypothalamic corticotropin-releasing hormone. These signals are mediated by the cAMP-dependent protein kinase and mitogen-activated protein kinase pathways, and activation of cAMP-dependent protein kinase also enhances Tpit and SRC-dependent transcription. We have previously shown that corticotropin-releasing hormone action is also exerted at the POMC promoter through the orphan nuclear receptor NGFI-B and its recruitment of SRC co-activators. Given that Tpit exhibits transcriptional synergy with NGFI-B, our results suggest that Tpit, along with NGFI-B and SRC-2, is part of a transcription regulatory complex assembled on the POMC promoter in response to hormonal stimulation.
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PMID:The T-box factor Tpit recruits SRC/p160 co-activators and mediates hormone action. 1297 Mar 70

Urocortin (UCN), a member of the Corticotropin-Releasing Factor (CRF) family of peptides is a well described cardioprotective agent. UCN is able to bind to two types of G-protein coupled receptors: CRF receptor type 1 (CRFR1) and CRF receptor type 2 (CRFR2), whereas, two homologues of UCN, stresscopin (SCP) or also known as urocortin III (UCNIII) and stresscopin related peptide (SRP), or urocortin II (UCNII), bind exclusively and with high affinity to CRFR2, we hypothesised that they will exhibit more pronounced cardioprotective effects than UCN. We show for the first time that SCP is expressed in rat cardiomyocytes and that the levels of SRP and SCP are increased by hypoxic stress. All three peptides have potent cardioprotective effects in cells exposed to hypoxia/reoxygenation. When used at 10(-8) M they increased the amount of live cells by 25% when added prior to hypoxia, and by 20% when UCN and SCP were added at the onset of reoxygenation. In addition, the peptides are equally are more potent antiapoptotic factors than UCN. The antiapoptotic effects of SCP were more pronounced than SRP and UCN at a concentration of 10(-10) M. Furthermore, SCP and SRP protect cardiomyocytes better than UCN at concentrations up to and including 10(-10) M and reduced the amount of TUNEL positive cells almost by half at concentrations of 10(-12) to 10(-10) M. More importantly, we demonstrate that SCP and SRP are able to protect cardiomyocytes even if they are administered after the hypoxic insult and prior to reoxygenation. In this case SCP was more potent than UCN and SRP at 10(-12) M and both SCP and SRP exhibited higher protection at 10(-8) M compared to UCN. Cardioprotection of cardiomyocytes by 10(-8) M of peptides was abolished when treated with 50 microM LY294002 or 100 microM PD98059, but not by 10 microM SB203580 prior to the hypoxic insult. Transfection of dominant negative Akt and MEK1 also blocked protection by the peptides, whereas dominant negative MEKK6 had no effects, demonstrating that SCP and SRP, like UCN, require activation of p42/44 Mitogen activated protein kinase and Akt/Protein Kinase B in order to produce their cardioprotective effects. In addition, we showed that SCP and UCN are potent activators of the p42/44 MAPK pathway, with SRP able to induce phosphorylation of p42/44 MAPK as well, albeit not as pronounced.
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PMID:Protective effects of the urocortin homologues stresscopin (SCP) and stresscopin-related peptide (SRP) against hypoxia/reoxygenation injury in rat neonatal cardiomyocytes. 1451 39

The melanocortin 4 receptor (MC4-R) is a Galpha s-coupled receptor known to increase cAMP production following agonist stimulation. We demonstrate that the mitogen-activated protein kinases p42 (ERK2) and p44 (ERK1) are also activated by MC4-R following treatment with the MC4-R agonist NDP-alpha-MSH in stably transfected CHO-K1 cells. This time- and dose-dependent response is abolished by the MC4-R antagonist SHU-9119. p42/p44 MAPK activation is blocked by the phosphatidylinositol 3-kinase (PI3K) inhibitors wortmannin and LY294002 but not by the protein kinase A (PKA) inhibitor Rp-cAMPS, indicating that that signal activating the p42/p44 MAPK pathway is conveyed through inositol triphosphate.
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PMID:Activation of MAP kinase by MC4-R through PI3 kinase. 1517 28

Stress induces tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH) gene expression in sympathetic ganglia and adrenal medulla (AM). However, distinct molecular mechanisms appear to regulate these genes in these locations. The elevation of TH mRNA in response to single immobilization stress (IMO) in AM is robust, but transient, while the induction of TH and DBH mRNAs in sympathetic ganglia is slower and more long lasting. Injections of adrenocorticotropic hormone (ACTH) elicited induction of TH and DBH gene expression in rat sympathetic ganglia, but not in AM. The superior cervical (SCG) and stellate (StG) ganglia, but not AM, were found to express mRNA for the MC-2 receptor, the major ACTH responsive receptor in adrenal cortex. IMO led to increase in MC-2 receptor mRNA levels in SCG. Thus, ACTH, via the MC-2 receptor, may be directly involved in the stress-elicited regulation of norepinephrine biosynthesis in sympathetic ganglia. The signaling pathways triggered by IMO differed in these locations. In AM, IMO triggered activation of the MAP kinase, JNK, and induction of AP1 factors, Egr1 and phosphorylation of CREB. In contrast in the SCG, with IMO we did not observe changes in JNK and little binding to the AP1 motif of the TH promoter. However, there was an increase in CREB binding to the CRE site of the TH promoter. The results reveal differential mechanisms of regulation of catecholamine biosynthetic enzymes by stress in two components of the sympathoadrenal system and should provide basis for possible selective pharmacologic interventions.
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PMID:Molecular regulation of gene expression of catecholamine biosynthetic enzymes by stress: sympathetic ganglia versus adrenal medulla. 1524 Mar 92


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