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Same Precursor (same + precursor)
Selected AbstractsA decade of hypocretins: past, present and future of the neurobiology of arousalACTA PHYSIOLOGICA, Issue 3 2010L. De Lecea Abstract In 1998, two groups independently identified the hypocretins, also known as orexins, as two hypothalamic peptides derived from the same precursor expressed in a few thousand neurones restricted to the perifornical area. A decade later, an amazing set of discoveries has demonstrated a key role for this neurotransmitter system in arousal and beyond. Here I review some of the experiments that led to these discoveries and the implications in the neurobiology of the hypothalamus and our understanding of brain arousal. [source] Hypocretin (orexin) in the rat pineal gland: a central transmitter with effects on noradrenaline-induced release of melatoninEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2001Jens D. Mikkelsen Abstract Hypocretin-1 (HCRT-1) and hypocretin 2 (HCRT-2), also known as orexin-A and orexin-B, are two neuropeptides derived from the same precursor. Hypocretinergic neurons have been found exclusively in the hypothalamic dorsolateral area. These neurons are implicated in sleep and feeding through activation of specific G-protein-coupled orexin-1 and orexin-2 receptor (OR-R1 and OR-R2). The purpose of this study was to determine the existence of the HCRT peptides in the central input of the rat pineal gland. Further, OR-R1 and OR-R2 expression was determined in the pineal gland and the effect of HCRT-2 on melatonin synthesis and secretion was analysed in dissociated rat pinealocytes. A large contingent of HCRT-positive nerve fibres and terminals were observed in the epithalamus, many of which entered into the pineal parenchyma. A significant number of nerve fibres endowed with positive boutons were identified in the pineal stalk, though the number of positive fibres decreased along the extension of the stalk. So far, no positive fibres have been found in the superficial pineal gland. RT-PCR analysis revealed the expression of OR-R2 mRNA, whereas OR-R1-receptor mRNA was not detected. When tested alone, HCRT-2 had no effect on secretion of melatonin from cultured rat pinealocytes. However, HCRT-2 partially inhibited (by a maximum of 30%) the ,-adrenergic-induced melatonin secretion. The same effect was seen on activation of N-acetyltransferase activity. The distribution and the large number of HCRT-positive fibres together with the effect on noradrenaline-mediated melatonin release through specific receptors suggests that these peptides may be significant central transmitters in pineal function, probably mediating homeostatic signals to the pineal gland. [source] Identification of proNeuropeptide FFA peptides processed in neuronal and non-neuronal cells and in nervous tissueFEBS JOURNAL, Issue 20 2003Elisabeth Bonnard Peptides which should be generated from the neuropeptide FF (NPFF) precursor were identified in a neuronal (human neuroblastoma SH-SY5Y) cell line and in COS-7 cells after transient transfection of the human proNPFFA cDNA and were compared with those detected in the mouse spinal cord. After reverse-phase high performance liquid chromatography of soluble material, NPFF-related peptides were immunodetected with antisera raised against NPFF and identified by using on-line capillary liquid chromatography/nanospray ion trap tandem mass spectrometry. Neuronal and non-neuronal cells generated different peptides from the same precursor. In addition to NPFF, SQA-NPFF (Ser-Gln-Ala-Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-amide) and NPAF were identified in the human neuroblastoma while only NPFF was clearly identified in COS-7 cells. In mouse, in addition to previously detected NPFF and NPSF, SPA-NPFF (Ser-Pro-Ala-Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-amide), the homologous peptide of SQA-NPFF, were characterized. These data on intracellular processing of proNeuropeptide FFA are discussed in regard to the known enzymatic processing mechanisms. [source] The Tissue-Specific Processing of Pro-OpiomelanocortinJOURNAL OF NEUROENDOCRINOLOGY, Issue 6 2008A. B. Bicknell It is just over 30 years since the definitive identification of the adrenocorticotrophin (ACTH) precursor, pro-opiomelanocotin (POMC). Although first characterised in the anterior and intermediate lobes of the pituitary, POMC is also expressed in a number of both central and peripheral tissues including the skin, central nervous tissue and placenta. Following synthesis, POMC undergoes extensive post-translational processing producing not only ACTH, but also a number of other biologically active peptides. The extent and pattern of this processing is tissue-specific, the end result being the tissue dependent production of different combinations of peptides from the same precursor. These peptides have a diverse range of biological roles ranging from pigmentation to adrenal function to the regulation of feeding. This level of complexity has resulted in POMC becoming the archetypal model for prohormone processing, illustrating how a single protein combined with post-translational modification can have a diverse number of roles. [source] Two tachykinin-like peptides from skin secretions of Danio rerioJOURNAL OF PEPTIDE SCIENCE, Issue 2 2010Xuhua Mi Abstract Tachykinin perform multiple physiological functions such as smoothing muscle contraction, vasodilation, inflammation, the processing of nerve signal, neuroprotection and neurodegeneration. Two novel tachykinin-like peptides named tachykinin-DR1 and -DR2 were identified from skin secretions of Danio rerio in current work. Their amino acid sequences were determined as SKSQHFHGLM-NH2 and NKGEIFVGLM-NH2, respectively. They share a conserved FXGLM-NH2C -terminal consensus motif. By cDNA cloning, the precursor encoding both tachykinin-DR1 and -DR2 was screened from the skin cDNA library of D. rerio. Tachykinin-DR1 and -DR2 share the same precursor, which is composed of 108 amino acid (aa) residues. Regarding the biological activity, tachykinin-DRs could induce the contraction of isolated strips of guinea pig ileum just like other tackykinins. To our best knowledge, this is the first report of tachykinin from fish skin. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd. [source] Pleomorphic lobular carcinoma of the breast: role of comprehensive molecular pathology in characterization of an entityTHE JOURNAL OF PATHOLOGY, Issue 1 2005Jorge S Reis-Filho Abstract Immunohistochemical analysis of E-cadherin has changed the way lobular neoplasia is perceived. It has helped to classify difficult cases of carcinoma in situ with indeterminate features and led to the identification of new variants of lobular carcinoma. Pleomorphic lobular carcinoma (PLC) and pleomorphic lobular carcinoma in situ (PLCIS), recently described variants of invasive and in situ classic lobular carcinoma, are reported to be associated with more aggressive clinical behaviour. Although PLC/PLCIS show morphological features of classic lobular neoplasia and lack E-cadherin expression, it is still unclear whether these lesions evolve through the same genetic pathway as lobular carcinomas or are high-grade ductal neoplasms that have lost E-cadherin. Here we have analysed a case of extensive PLCIS and invasive PLC associated with areas of E-cadherin-negative carcinoma in situ with indeterminate features, using immunohistochemistry, chromogenic in situ hybridization, high-resolution comparative genomic hybridization (CGH) and array-based CGH. We observed that all lesions lacked E-cadherin and ,-catenin and showed gain of 1q and loss of 16q, features that are typical of lobular carcinomas but are not seen in high-grade ductal lesions. In addition, amplifications of c-myc and HER2 were detected in the pleomorphic components, which may account for the high-grade features in this case and the reported aggressive clinical behaviour of these lesions. Taken together, these data suggest that at least some PLCs may evolve from the same precursor or through the same genetic pathway as classic lobular carcinomas. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] | ||||||||||||||||