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)

The regulation of the expression of the human corticotropin-releasing-hormone gene (hCRH) was studied in a mouse anterior pituitary cell line (AtT20) after transiently transfection with a chimeric gene containing the hCRH gene promoter fused to the bacterial chloramphenicol acetyltransferase (CAT) gene. Expression of the chimeric hCRH-CAT gene in AtT20 cells was enhanced by the cAMP analog (8-bromo-cAMP) about 5-fold but not by phorbol 12-myristate-13-acetate. The cAMP phosphodiesterase inhibitor isobutylmethylxanthine also strongly stimulated 15-fold the expression of the chimeric hCRH-CAT gene. Coincubation of cAMP analog and isobutylmethylxanthine resulted in a moderate 2-fold synergistic enhancement of CAT activity. Sequence comparison of the hCRH gene revealed a core sequence for a cAMP responsive element 5'-TGACGTCA-3' at -221 relative to the cap site. This regulatory element also confers cAMP inducibility on a heterologous promoter when placed upstream of the thymidine kinase promoter from herpes simplex virus. Finally, treatment with 0.5 microM dexamethasone reduced CAT activity about 2.0-fold in cAMP-stimulated cells. This result suggests that cAMP and glucocorticoids coordinately control hCRH gene expression.
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PMID:Glucocorticoid repression of 3',5'-cyclic-adenosine monophosphate-dependent human corticotropin-releasing-hormone gene promoter activity in a transfected mouse anterior pituitary cell line. 169 84

Infection of lymphocytes with Newcastle disease virus induces the cells to synthesize immunoreactive (ir) adrenocorticotropin (ACTH) and endorphins. The irACTH is synthesized de novo, and common properties of lymphocyte and pituitary ACTH include: antigenicity, bioactivity, molecular weight, and retention time on reverse phase high-pressure liquid chromatography. The irACTH appears to be active in vivo because a rise in serum corticosterone levels in hypophysectomized mice corresponds with spleen cell production of irACTH. Furthermore, preliminary experiments showed that B cell depletion blocked the normal rise in serum corticosterone levels after herpes simplex virus infection of intact mice. It seems that a similar system operates in vivo in humans. Typhoid vaccine, which induces lymphocyte-derived irACTH production in vitro, caused a time-dependent increase in the number of irACTH-positive lymphocytes in both hypopituitarism and normal short children. A rise in serum cortisol levels was seen in one patient with hypopituitarism and all normal patients. The above regulatory circuit also seems able to act in the reverse direction. Pituitary ACTH and alpha-endorphin can behave like lymphokines by being immunosuppressive at 0.5 microM in an in vitro antibody synthesis system. Further, lymphocytes were shown to have high-affinity receptors for both of these hormones. Thus, it appears that the immune and neuroendocrine systems have the ability to signal each other through common or related peptide hormones and receptors.
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PMID:A complete regulatory loop between the immune and neuroendocrine systems. 257 15

Herpes simplex viruses (HSV) remain latent in sensory and peripheral ganglia and can be reactivated to cause recurrent HSV infections. Recent evidence has suggested that stress can induce an immunosuppressive state and increase the frequency and severity of recurrent herpes infections. Because macrophages play a central role in the host defense against HSV, the effects of stress-related neuroendocrine hormones on macrophage-HSV interactions were examined. Norepinephrine and epinephrine blocked the capacity of recombinant interferon-gamma (IFN-gamma) to activate murine macrophages to a cytotoxic state capable of selectively killing HSV-infected cells. In contrast, ACTH, dopamine, serotonin, and beta-endorphin had no effect. The suppression of IFN-gamma-induced, macrophage-mediated lysis of HSV-infected cells occurred concomitantly with a marked increase in macrophage intracellular cyclic AMP levels. Moreover, exogenous administration of dibutyryl cyclic AMP blocked induction of macrophage-mediated cytotoxicity, suggesting that the neurohormones were modulating macrophage function via an adrenergic receptor-mediated system. These findings demonstrate that selective stress-related neurohormones modify the cytolytic activity of macrophages against virus-infected cells and suggest a possible neuroendocrine-immunologic basis for the recurrence of HSV infection.
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PMID:Neuroendocrine hormones suppress macrophage-mediated lysis of herpes simplex virus-infected cells. 300 Nov 83

We report results indicating that expression and hormonally controlled negative regulation of the human pro-opiomelanocortin (POMC) gene in mouse fibroblasts can be accomplished by the placement nearby of a simian virus 40 enhancer sequence. Expression resulting from correctly initiated transcription required the enhancer in cis both in cells stably transfected with the POMC gene and in a transient expression assay with constructs that fused that POMC promoter region to the protein-coding region of the herpes simplex virus thymidine kinase (TK) gene. Negative regulation of POMC transcription by glucocorticoids was demonstrated in transiently infected cells by assaying for TK activity encoded by the POMC-TK fusion constructs and by quantitative S1 nuclease mapping. The sequences responsible for such regulation were shown to be contained within a DNA segment that extends 670 base pairs upstream from the cap site for POMC mRNA.
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PMID:Hormonally mediated negative regulation of human pro-opiomelanocortin gene expression after transfection into mouse L cells. 301 28

Using HeLa whole cell extracts, we have demonstrated that transcription in vitro of the cloned human and bovine corticotropin/beta-lipotropin precursor genes is initiated accurately and efficiently. DNA sequences required for promoter function have been assessed by using a series of 5'-deletion mutants of a fusion gene that contains the 5'-flanking sequence and capping site of the human corticotropin/beta-lipotropin precursor gene and the structural sequence of the herpes simplex virus thymidine kinase gene. The results obtained have shown that the region between 22 base pairs and 35 base pairs upstream from the capping site is essential for the correct and efficient transcriptional initiation in vitro. Thus, the 'TATA box' present in this region seems to be the main promoter element for transcription of the human corticotropin/beta-lipotropin precursor gene in the HeLa cell-free system. We have also developed a transcription system in vitro from the corticotropin-producing mouse pituitary tumor cell line AtT-20 in culture. Deletion mapping of the fusion gene promoter has indicated that the 'TATA box' region is required for the accurate and efficient transcriptional initiation in this system as well. Characteristic of this system is that the deletion of the sequence lying between 53 base pairs and 59 base pairs upstream from the capping site increases the transcriptional efficiency. Because this effect is observed in the AtT-20 cell-free system, but hardly in the HeLa cell-free system, it seems reasonable to assume that the interaction of this upstream sequence with some factor(s) in the AtT-20 cell extract is responsible for the modulation of transcription of the human corticotropin/beta-lipotropin precursor gene.
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PMID:Sequence requirement for transcription in vitro of the human corticotropin/beta-lipotropin precursor gene. 630 52

The cloned human corticotropin-beta-lipotropin precursor gene, when joined with an SV40 vector and introduced into COS monkey cells, is transcribed from its own promoter. The DNA sequences required for promoter function have been identified by using 5' deletion mutants of the fusion gene AT which contains the 5'-flanking sequence and capping site of the human corticotropin-beta-lipotropin precursor gene and the structural sequence of the herpes simplex virus thymidine kinase gene. The deletion of the sequence located between 53 and 59 bp upstream of the capping site enhances the transcription approximately 3-fold, while the deletion of the TATA box region abolishes the transcription.
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PMID:DNA sequences required for transcription in vivo of the human corticotropin-beta-lipotropin precursor gene. 632 75

We have produced and characterized lines of transgenic mice expressing a fusion gene composed of the pituitary expression-specific promoter region of the POMC gene, driving the herpes simplex viral-1 thymidine kinase. Adult mice were treated with the antiherpes agent ganciclovir at 70 mg/kg body weight (ip, twice daily for 10-12 days). Approximately 98% of the pituitary intermediate lobe melanotropes and anterior lobe corticotropes were ablated as determined by immunocytochemistry and RIA specific for the POMC-derived peptides, ACTH, beta-endorophin, and alpha-MSH. The number of lactotropes, somatotropes, thyrotropes, and gonadotropes was not altered compared with controls, indicating that in the adult pituitary, POMC products are not required to maintain the distribution of cell types. As expected, plasma corticosterone levels were substantially decreased after POMC cell ablation. In situ hybridization studies showed that the mouse ACTH receptor was expressed uniformly throughout the adrenal cortex, and RNase protection assays revealed that the ACTH receptor mRNA decreased after pituitary POMC cell ablation. Additionally, RNase protection assays showed that pituitary POMC cell ablation resulted in the decrease of adrenal p450c11 beta transcripts while p450c11AS (aldosterone synthase) mRNA levels remained constant. These data demonstrate differential regulation of steroid pathway-specific enzymes by POMC products. Our results also suggest that the thymidine kinase cell obliteration technique may not be dependent on cell division as a prerequisite for cytotoxicity, thus supporting the idea that targeted molecular ablation using cell- and tissue-specific promoter sequences to drive viral thymidine kinase expression can be refined further to study other nonmitotic cells.
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PMID:Targeted ablation of pituitary pre-proopiomelanocortin cells by herpes simplex virus-1 thymidine kinase differentially regulates mRNAs encoding the adrenocorticotropin receptor and aldosterone synthase in the mouse adrenal gland. 747 75

The introduction of small mutations instead of null alleles into the mouse genome has broad applications to the study of protein structure-function relationships and the creation of animal models of human genetic diseases. To test a simple mutational strategy we designed a targeting vector for the mouse proopiomelanocortin (POMC) gene containing a single nucleotide insertion that converts the initial tyrosine codon of beta-endorphin 1-31 to a premature translational termination codon and introduces a unique Hpal endonuclease restriction site. The targeting vector also contains a neo cassette immediately 3' to the last POMC exon and a herpes simplex virus thymidine kinase cassette to allow positive and negative selection. Homologous recombination occurred at a frequency of 1/30 clones of electroporated embryonic stem cells selected in G418 and gancyclovir. 10/11 clones identified initially by a polymerase chain reaction (PCR) strategy had the predicted structure without evidence of concatemer formation by Southern blot analysis. We used a combination of Hpa I digestion of PCR amplified fragments and direct nucleotide sequencing to further confirm that the point mutation was retained in 9/10 clones. The POMC gene was transcriptionally silent in embryonic stem cells and the targeted allele was not activated by the downstream phosphoglycerate kinase-1 promoter that transcribed the neo gene. Under the electroporation conditions used, we have demonstrated that a point mutation can be introduced with high efficiency and precision into the POMC gene using a replacement type vector containing a retained selectable marker without affecting expression of the allele in the embryonic stem cells. A similar strategy may be useful for a wide range of genes.
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PMID:Introduction of a point mutation into the mouse genome by homologous recombination in embryonic stem cells using a replacement type vector with a selectable marker. 839 2

A 49-year-old man with herpes simplex encephalitis at age 22 was admitted with hypotension (90/60 mm Hg) and hypothermia (33.7 degrees C). His blood pressure was 80-90/50-60 mm Hg, with temperatures averaging 35 degrees C, for at least 3 years before admission. Evaluation of his hypothermia and hypotension revealed a low free triiodothyronine, low normal thyrotropin, luteinizing hormone < 2 mIU/L, follicle stimulating hormone <3 mIU/L, and low testosterone of 1.39 ng/dL. A baseline cortisol of 13.9 microg/dL was stimulated to 41.8 microg/dL with corticotropin, indicating he had partial anterior hypopituitarism with an intact pituitary-adrenal axis. Posterior pituitary function was normal. MRI revealed a "bright" posterior pituitary on a T1-weighted image, further indicating a normal posterior pituitary. Extensive decreased T1-weighting on MRI in the right and left temporal lobes was consistent with encephalomalacia. With thyroid hormone replacement, his blood pressure increased to 110/70 mm Hg with a temperature of 37 degrees C.
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PMID:Post-herpes encephalitic anterior pituitary insufficiency with hypothermia and hypotension. 1106 53

The demonstration of preproenkephalin A gene expression in rat dorsal root ganglia has raised the question of the physiological role of met-enkephalin-containing primary afferent fibres. Recently, we showed that systemic infection with a recombinant Herpes simplex virus encoding preproenkephalin A (HSVLatEnk1) yielded a marked increase in the density of met-enkephalin-like material synthesising neurons in rat dorsal root ganglia. This study further investigated the synthesis, transport and release of met-enkephalin-like material in the central and/or peripheral processes of primary afferent fibres in HSVLatEnk1-infected and control rats. In controls, dorsal root ganglia neurons containing met-enkephalin-like material were scarce and only a few positively labelled processes were seen at the peripheral output of the dorsal root ganglia. Met-enkephalin-like material accumulated at the proximal side of ligatured sciatic nerve, but not in ligatured L4-L5 dorsal roots. In HSVLatEnk1-infected rats with numerous somas and fibres stained for met-enkephalin-like material in dorsal root ganglia, met-enkephalin immunoreactive material largely accumulated at the proximal side of the ligatured sciatic nerve and few positively stained fibres were also observed in ligatured dorsal roots. Electrical stimulation of L4-L5 dorsal roots attached to a dorsal slice of the lumbar enlargement produced an overflow of met-enkephalin-like material which was approximately 70% higher in HSVLatEnk1-infected rats compared to controls. At the periphery, subcutaneous microdialysis showed higher basal levels of met-enkephalin-like material in the interstitial fluid of hindpaw plantar area in HSVLatEnk1-infected rats, and electrical stimulation of the ipsilateral sciatic nerve resulted in an approximately three-fold-higher overflow of this material than in control rats. These data demonstrated that met-enkephalin synthesised in dorsal root ganglion of both control and preproenkephalin A overexpressing rats is preferentially transported into the peripheral processes of primary afferent fibres where the peptide reaches a releasable compartment, thus providing a neuronal source of peripheral met-enkephalin.
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PMID:Met-enkephalin is preferentially transported into the peripheral processes of primary afferent fibres in both control and HSV1-driven proenkephalin A overexpressing rats. 1130 Dec 14


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