AIM: To assess corticotropin-releasing factor receptor 2 (CRF 2 ) expression in the colon of healthy subjects and patients with ulcerative colitis (UC). METHODS: We examined CRF2 gene and protein expression in the dis...AIM: To assess corticotropin-releasing factor receptor 2 (CRF 2 ) expression in the colon of healthy subjects and patients with ulcerative colitis (UC). METHODS: We examined CRF2 gene and protein expression in the distal/sigmoid colonic mucosal biopsies from healthy subjects and patients with UC (active or disease in remission), human immunodeficiency virus (HIV) and functional bowel disease (FBD) by reverse transcriptionpolymerase chain reaction and immunofluorescence. RESULTS: Gene expression of CRF2 was demonstrated in the normal human colonic biopsies, but not in the human colorectal adenocarcinoma cell line Caco2. Receptor protein localization showed immunoreactive CRF 2 receptors in the lamina propria and in the epithelial cells of the distal/sigmoid biopsy samples. Interestingly, CRF 2 immunoreactivity was no longer observed in epithelial cells of patients with mild-moderately active UC and disease in remission, while receptor protein expression did not change in the lamina propria. No differences in CRF 2 expression profile were observed in distal/sigmoid intestinal biopsies from HIV infection and FBD patients, showing no signs of inflammation. CONCLUSION: The down-regulation of the CRF2 receptor in the distal/sigmoid biopsies of UC patients is indicative of change in CRF 2 signalling associated with the process of inflammation.展开更多
AIM To measure exogenous corticotropin-releasing factor(CRF)-induced motility of the isolated rat colon and to demonstrate the effect of pharmacologic inhibition on CRF-induced motility. METHODS The isolated vascularl...AIM To measure exogenous corticotropin-releasing factor(CRF)-induced motility of the isolated rat colon and to demonstrate the effect of pharmacologic inhibition on CRF-induced motility. METHODS The isolated vascularly-perfused rat colon was used. Luminal pressure was monitored via microtip catheter pressure transducers in the proximal and distal colon. At first, exogenous CRF was administered in a stepwise manner and the concentration of CRF yielding maximal colonic motility was selected. After recording basal colonic motility, hexamethonium, phentolamine, propranolol, atropine and tetrodotoxin were infused into the isolated colon. Initially, only the test drug was infused; then, CRF was added. The motility index was expressed as percentage change over basal level. RESULTS Administration of 1.4, 14.4, 144 and 288 pmol/L CRF progressively increased colonic motility in the proximal and distal colon. Infusion of atropine or tetrodotoxin reduced CRF-induced motility of both the proximal and distal colon, whereas hexamethonium, phentolamine and propranolol had no effect.CONCLUSION CRF-induced colonic motility appears to be mediated by local cholinergic signaling via muscarinic receptors. Muscarinic receptors are potential targets for counteracting CRF-induced colonic hypermotility.展开更多
EAE （experimental autoimmune encephalomyelitis） is an established, inducible animal model employed in the study of MS （multiple sclerosis） characterized by inflammation, BBB （blood brain barrier） malfunction, de...EAE （experimental autoimmune encephalomyelitis） is an established, inducible animal model employed in the study of MS （multiple sclerosis） characterized by inflammation, BBB （blood brain barrier） malfunction, demyelination and neuronal disruption. CRF （corticotropin releasing factor） is a neuropeptide critically associated with immune function, BBB permeability, and the hypothalamic-pituitary-adrenal axis. Potential CRF targets in the brain include astrocytes, as well as endothelial cells of cerebral microvessels, since they have been reported to express CRFR （CRF receptors）. Further, both of these cell types function critically in regulating BBB permeability. CRF-BP （CRF binding protein） is also expressed in both neurons and glial cells. Changes in the cortical CRF system could be a contributing factor to the BBB disruption associated with MS/EAE and has been suggested to play a protective role against cytokine-induced inflammation. The current study assessed alterations associated with the C57BL/6 mouse model of EAE in the cortical CRF system and correlated these events with changes to the microvascular unit. Immunohistochemical confocal microscopy was used to analyze the distribution of CRF, CRF-BP, and CRFR in the mouse cerebral cortex. The authors observed a reduction in detectable CRF immunofluorescence in the EAE motor cortex, an increase in CRFBP immunoreactivity in EAE astrocytes and a concurrent reduction in astrocytic CRFR immunofluorescence. Staining techniques were used to visualize astrocytes/microvessels to document alterations in BBB integrity. Changes in the CRF system were associated with a modification of the blood brain barrier as manifested by a poorly defined astrocytic barrier in EAE microvessels. Evidence suggests that manipulation of CRF signaling pathways offers an intriguing target for interventional therapies designed to modify BBB permeability that may be beneficial for treating disease states such as MS.展开更多
基金Supported by Grants-in-Aid for Scientific Research(C)from the Ministry of Education,Culture,Sports,Science,and Tech-nology of Japanthe Foundation for the Promotion of Can-cer Research and Mitsui Life Social Welfare Foundation
文摘AIM: To examine whether commensal bacteria are a contributing cause of stress-related mucosal inflammation.
基金Supported by The National Institute of Diabetes and Digestive and Kidney Diseases R01 grant DK-57238Center Grant DK-41301 (Clinical core)+1 种基金Veteran Administration Research Career Scientist Award (YT)NIH DK-78676 (MM)
文摘AIM: To assess corticotropin-releasing factor receptor 2 (CRF 2 ) expression in the colon of healthy subjects and patients with ulcerative colitis (UC). METHODS: We examined CRF2 gene and protein expression in the distal/sigmoid colonic mucosal biopsies from healthy subjects and patients with UC (active or disease in remission), human immunodeficiency virus (HIV) and functional bowel disease (FBD) by reverse transcriptionpolymerase chain reaction and immunofluorescence. RESULTS: Gene expression of CRF2 was demonstrated in the normal human colonic biopsies, but not in the human colorectal adenocarcinoma cell line Caco2. Receptor protein localization showed immunoreactive CRF 2 receptors in the lamina propria and in the epithelial cells of the distal/sigmoid biopsy samples. Interestingly, CRF 2 immunoreactivity was no longer observed in epithelial cells of patients with mild-moderately active UC and disease in remission, while receptor protein expression did not change in the lamina propria. No differences in CRF 2 expression profile were observed in distal/sigmoid intestinal biopsies from HIV infection and FBD patients, showing no signs of inflammation. CONCLUSION: The down-regulation of the CRF2 receptor in the distal/sigmoid biopsies of UC patients is indicative of change in CRF 2 signalling associated with the process of inflammation.
文摘AIM To measure exogenous corticotropin-releasing factor(CRF)-induced motility of the isolated rat colon and to demonstrate the effect of pharmacologic inhibition on CRF-induced motility. METHODS The isolated vascularly-perfused rat colon was used. Luminal pressure was monitored via microtip catheter pressure transducers in the proximal and distal colon. At first, exogenous CRF was administered in a stepwise manner and the concentration of CRF yielding maximal colonic motility was selected. After recording basal colonic motility, hexamethonium, phentolamine, propranolol, atropine and tetrodotoxin were infused into the isolated colon. Initially, only the test drug was infused; then, CRF was added. The motility index was expressed as percentage change over basal level. RESULTS Administration of 1.4, 14.4, 144 and 288 pmol/L CRF progressively increased colonic motility in the proximal and distal colon. Infusion of atropine or tetrodotoxin reduced CRF-induced motility of both the proximal and distal colon, whereas hexamethonium, phentolamine and propranolol had no effect.CONCLUSION CRF-induced colonic motility appears to be mediated by local cholinergic signaling via muscarinic receptors. Muscarinic receptors are potential targets for counteracting CRF-induced colonic hypermotility.
文摘EAE （experimental autoimmune encephalomyelitis） is an established, inducible animal model employed in the study of MS （multiple sclerosis） characterized by inflammation, BBB （blood brain barrier） malfunction, demyelination and neuronal disruption. CRF （corticotropin releasing factor） is a neuropeptide critically associated with immune function, BBB permeability, and the hypothalamic-pituitary-adrenal axis. Potential CRF targets in the brain include astrocytes, as well as endothelial cells of cerebral microvessels, since they have been reported to express CRFR （CRF receptors）. Further, both of these cell types function critically in regulating BBB permeability. CRF-BP （CRF binding protein） is also expressed in both neurons and glial cells. Changes in the cortical CRF system could be a contributing factor to the BBB disruption associated with MS/EAE and has been suggested to play a protective role against cytokine-induced inflammation. The current study assessed alterations associated with the C57BL/6 mouse model of EAE in the cortical CRF system and correlated these events with changes to the microvascular unit. Immunohistochemical confocal microscopy was used to analyze the distribution of CRF, CRF-BP, and CRFR in the mouse cerebral cortex. The authors observed a reduction in detectable CRF immunofluorescence in the EAE motor cortex, an increase in CRFBP immunoreactivity in EAE astrocytes and a concurrent reduction in astrocytic CRFR immunofluorescence. Staining techniques were used to visualize astrocytes/microvessels to document alterations in BBB integrity. Changes in the CRF system were associated with a modification of the blood brain barrier as manifested by a poorly defined astrocytic barrier in EAE microvessels. Evidence suggests that manipulation of CRF signaling pathways offers an intriguing target for interventional therapies designed to modify BBB permeability that may be beneficial for treating disease states such as MS.
