Corticotropin-releasing hormone (Crh), a 41-residue polypeptide, activates two G-protein-coupled receptors, Crhr1 and Crhr2, causing (among other transductional events) phosphorylation of the transcription factor Creb. The physiologic role of these receptors is only partially understood. Here we report that male, but not female, Crhr2-deficient mice exhibit enhanced anxious behaviour in several tests of anxiety in contrast to mice lacking Crhr1. The enhanced anxiety of Crhr2-deficient mice is not due to changes in hypothalamic-pituitary-adrenal (HPA) axis activity, but rather reflects impaired responses in specific brain regions involved in emotional and autonomic function, as monitored by a reduction of Creb phosphorylation in male, but not female, Crhr2-/- mice. We propose that Crhr2 predominantly mediates a central anxiolytic response, opposing the general anxiogenic effect of Crh mediated by Crhr1. Neither male nor female Crhr2-deficient mice show alterations of baseline feeding behaviour. Both respond with increased edema formation in response to thermal exposure, however, indicating that in contrast to its central role in anxiety, the peripheral role of Crhr2 in vascular permeability is independent of gender.

Corticotropin-releasing factor (CRF) mediates many critical aspects of the physiological response to stress. These effects are elicited by binding to specific highaffinity receptors, which are coupled to guanine nucleotide stimulatory factor (Gs)-response pathways. Recently, a gene encoding a receptor for CRF, expressed in pituitary and the central nervous system (PC-CRF receptor), was isolated and characterized. Here we report the identification and characterization of a second, distinct CRF receptor that is expressed primarily in heart and skeletal muscle and exhibits a specific ligand preference and antagonist sensitivity compared with the PC-CRF receptor. We refer to this second receptor as the heart/muscle (HM)-CRF receptor.Corticotropin-releasing factor (CRF) (1) is a member of a family of peptides from different species that act as agonists of the CRF receptor. These peptides include the frog skin peptide, sauvagine (2), and the teleost fish urophysis peptide, urotensin I (3). CRF is a 41-amino acid hypothalamic neuropeptide that plays a central role in coordinating the communications between endocrine, nervous, and immune systems to achieve homeostasis in response to environmental adversities (4, 5). The peptide was originally characterized in the hypothalamo-hypophyseal system but was later found to be widely distributed throughout the central nervous system (CNS), where it appeared to function as a neurotransmitter or neuromodulator (6). In the CNS, CRF initiates the hypothalamic-pituitary-adrenal axis by stimulating the release of adrenocorticotropin (ACTH) and ,B-endorphin from the anterior pituitary. ACTH stimulates adrenal cortex to secrete corticosteroids that, in turn, elicit a wide range of biological responses and exert negative feedback on the hypothalamus and pituitary (4, 5, 7). Both sauvagine and urotensin I have been shown to stimulate the hypothalamic-pituitary-adrenal axis after i.v. administration (8). Intracerebroventricular administration of CRF provokes stress-like responses including activation of the sympathetic nervous system, resulting in an elevation of plasma epinephrine, norepinephrine, and glucose, which results in increased heart rate and mean arterial blood pressure (9, 10). Outside the CNS, CRF immunoreactivity is detectable in multiple peripheral organs, including placenta, adrenal medulla, pancreas, lung, stomach, duodenum, and liver (4, 5). i.v. administration of CRF, sauvagine, and urotensin I has been shown to elicit peripheral systemic responses, including vasodilation (11).CRF functions by binding to a membrane-bound receptor that is coupled to the guanine nucleotide stimulatory factor (G,) signaling protein, resulting in increased intracellular cAMP levels (12,13 (23), and growth hormonereleasing factor ]. The PC-CRF receptor mRNA was found to be most highly expressed in the cerebellum and pituitary and found at lower levels in other brain areas, intestine, and testes. This receptor is undetectable in other tissues examined, including heart and skeletal mus...

Anti-mucin1 (MUC1) antibodies have long been used clinically in cancer diagnosis and therapy and specific bindings of some of them are known to be dependent on the differential glycosylation of MUC1. However, a systematic comparison of the binding specificities of anti-MUC1 antibodies was not previously conducted. Here, a total of 20 glycopeptides including the tandem repeat unit of MUC1, APPAHGVTSAPDTRPAPGSTAPPAHGV with GalNAc (Tn-antigen), Galβ1-3GalNAc (T-antigen), NeuAcα2-3Galβ1-3GalNAc (sialyl-T-antigen), or NeuAcα2-6GalNAc (sialyl-Tn-antigen) at each threonine or serine residue were prepared by a combination of chemical glycopeptide synthesis and enzymatic extension of carbohydrate chains. These glycopeptides were tested by the enzyme-linked immunosorbent assay (ELISA) for their capacity to bind 13 monoclonal antibodies (mAbs) known to be specific for MUC1. The results indicated that anti-MUC1 mAbs have diverse specificities but can be classified into a few characteristic groups based on their binding pattern toward glycopeptides in some cases having a specific glycan at unique glycosylation sites. Because the clinical significance of some of these antibodies was already established, the structural features identified by these antibodies as revealed in the present study should provide useful information relevant to their further clinical use and the biological understanding of MUC1.

SummarySHRSP5/Dmcr is a newly established substrain of stroke-prone spontaneously hypertensive rat (SHRSP). Recently, high-fat and high-cholesterol (HFC) diet-fed SHRSP5/Dmcr has been reported as a novel rat model of developing hepatic lesions similar to human non-alcoholic steatohepatitis (NASH). The aim of this study was to investigate the detailed pathological conditions induced by HFC diet in SHRSP5/Dmcr rats using molecular biological methods and morphometric analysis. SHRSP5/Dmcr rats at 6 weeks of age were fed on either HFC diet or stroke-prone (SP) diet for 2, 4, 6, 8 and 16 weeks and histopathological changes in the liver, blood chemistry and mRNA expression levels in the liver were investigated. As evidenced by the histopathological examination of the liver of the SHRSP5/Dmcr rats, hepatic steatosis and lobular inflammation were present, with gradual increasing severity from 2 weeks after the introduction of the HFC diet. Partial hepatic fibrosis was detected at 6 weeks and spread over the entire region of the liver with more severe bridging formation by 16 weeks. The degrees of NASH-like hepatic lesions such as steatosis (the size distribution of lipid droplets), inflammation and fibrosis were quantified by morphometric analysis. Eosinophilic inclusion bodies encountered in the hepatocytes had immunoreactivity with Cox-4 and double-membrane walls, identified as mega-mitochondria. Serum ALT and bilirubins, and the mRNA expression levels related to fibrosis were closely correlated with hepatic histopathological changes. The clear feeding time-dependent progression of NASH-like hepatic lesion in HFC diet-fed SHRSP5/Dmcr rats reinforced the conclusion that this strain might be a useful model of NASH and of inflammatory fibrotic liver disease.