Regulation and Function of Urocortins and their Receptors

Summary

Principal Investigator: Aditi Bhargava
Abstract: PROJECT SUMMARY/ABSTRACT The corticotropin-releasing factor (CRF) family of neuropeptides (CRF and urocortins [Ucn] 1-3) and their receptors (CRFR1, CRFR2) are essential mediators of stress in the central nervous system. Therefore a systemic inhibition of their function is not an attractive therapeutic model. Components of this peptide/receptor family are prominently expressed within the intestine, where their local functions remain to be defined. Our preliminary data from CRFR2 heterozygous mice suggests that perturbation of the CRFR2 system renders the mice more susceptible to sudden stress and immune challenges. Our results suggest that new treatments for intestinal inflammatory diseases may require either antagonists or agonists of CRF receptors, depending upon the affected intestinal region and the type of inflammatory disease. A striking feature we observed during colitis was reciprocal changes in mRNA and protein levels of Ucn ligands and their receptors. These differential changes can alter Ucn-induced trafficking of receptors from and to the plasma membrane. However, the molecular mechanisms of this divergent trafficking to recycling or degradatory pathways remain unexplored. Thus, our hypothesis is that Ucn isoforms, differentially signaling through CRF receptors, govern intestinal inflammation at the molecular, cellular and organ levels. The aims of this proposal are to: Specific Aim 1. To define the systemic role of the Ucn/CRFR system in intestinal inflammation. We will use pharmacological and genetic approaches to define the systemic role of the Ucn/CRFR system in intestinal inflammation. We will determine if CRFR2 knockout and heterozygous mice exhibit differential sensitivity to inflammation and agonist treatment as compared with their wild type littermates. We will determine alterations in colitis severity by measuring changes in body weight gain, mortality, histological damage, and fluid leak. Specific Aim 2. To define the contributions of colon-specific Ucns and CRFRs in intestinal inflammation using RNA interference (RNAi). To determine the colon-specific role of the Ucn/CRFR system, we will establish the use RNAi to knockdown expression of Ucns and CRFR2 locally in the colon. We will determine the spatial and temporal effects of RNAi in the colon, and assess whether colon-specific knockdown of Ucns and CRFRs is sufficient to ameliorate or exacerbate colitis, using end points defined in Specific Aim 1. Specific Aim 3. To define the mechanism and function of Ucn1-induced trafficking of CRFR1. We will examine the influence of Ucn1 stimulation on the subcellular localization of CRFR1 using confocal microscopy and immunofluorescence. We will explore the ability of the adaptor/scaffolding proteins ([unreadable]-arrestins and dynamin) to desensitize and resensitize CRFRs. We will assess Ucn1 regulation of CRFR1 activity by measuring Ucn1-stimulated intracellular Ca2+ mobilization. Thus, manipulation of the urocortins and their receptors provides an effective starting point for understanding their GI functions, which could contribute to the development of new treatments for inflammatory bowel disease.
Funding Period: 2009-04-01 - 2014-03-31
more information: NIH RePORT

Top Publications

  1. pmc Local secretion of urocortin 1 promotes microvascular permeability during lipopolysaccharide-induced inflammation
    Elizabeth L Cureton
    Department of Surgery, University of California, San Francisco, San Francisco, California 94143, USA
    Endocrinology 150:5428-37. 2009
  2. pmc Corticotropin-releasing factor receptor 2 mediates sex-specific cellular stress responses
    Eric Kubat
    Department of Surgery, University of California San Francisco, San Francisco, California 94143, USA
    Mol Med 19:212-22. 2013
  3. pmc Local injection of dsRNA targeting calcitonin receptor-like receptor (CLR) ameliorates Clostridium difficile toxin A-induced ileitis
    Aditi Bhargava
    Department of Surgery, University of California, San Francisco, CA 94143 0660, USA
    Proc Natl Acad Sci U S A 110:731-6. 2013
  4. pmc Plasma membrane calcium ATPase regulates bone mass by fine-tuning osteoclast differentiation and survival
    Hyung Joon Kim
    Department of Cell and Developmental Biology, BK21 Program and Dental Research Institute, Seoul National University, Seoul 110 749, Korea
    J Cell Biol 199:1145-58. 2012
  5. pmc Rosiglitazone improves survival and hastens recovery from pancreatic inflammation in obese mice
    Maria Pini
    Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, United States of America
    PLoS ONE 7:e40944. 2012
  6. pmc Localization of calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 1 (RAMP1) in human gastrointestinal tract
    Graeme S Cottrell
    Department of Surgery, Center for Neurobiology of Digestive Diseases, University of California San Francisco, San Francisco, CA 94143 0660, United States
    Peptides 35:202-11. 2012
  7. pmc Role of IL-6 in the resolution of pancreatitis in obese mice
    Maria Pini
    Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
    J Leukoc Biol 91:957-66. 2012
  8. pmc Endothelin-converting enzyme-1 actions determine differential trafficking and signaling of corticotropin-releasing factor receptor 1 at high agonist concentrations
    Burcu Hasdemir
    Department of Surgery, Center for Neurobiology of Digestive Diseases, University of California, San Francisco, San Francisco, California 94143, USA
    Mol Endocrinol 26:681-95. 2012
  9. pmc Transient gastric irritation in the neonatal rats leads to changes in hypothalamic CRF expression, depression- and anxiety-like behavior as adults
    Liansheng Liu
    Division of Gastroenterology and Hepatology, Stanford University Medical Center, Stanford, California, United States of America
    PLoS ONE 6:e19498. 2011
  10. pmc Urocortin 1 modulates immunosignaling in a rat model of colitis via corticotropin-releasing factor receptor 2
    Jen Chang
    Dept of Surgery, Univ of California, San Francisco, 94143 0660, USA
    Am J Physiol Gastrointest Liver Physiol 300:G884-94. 2011

Detail Information

Publications15

  1. pmc Local secretion of urocortin 1 promotes microvascular permeability during lipopolysaccharide-induced inflammation
    Elizabeth L Cureton
    Department of Surgery, University of California, San Francisco, San Francisco, California 94143, USA
    Endocrinology 150:5428-37. 2009
    ..Ucn1's effect on L(p) is partially mediated by the CRH-R(2) receptor and acts independently of the c-JUN N-terminal kinase signal transduction pathway...
  2. pmc Corticotropin-releasing factor receptor 2 mediates sex-specific cellular stress responses
    Eric Kubat
    Department of Surgery, University of California San Francisco, San Francisco, California 94143, USA
    Mol Med 19:212-22. 2013
    ..Our results demonstrate the importance of identifying sex-specific pathogenic mechanisms and their value in designing effective therapeutics...
  3. pmc Local injection of dsRNA targeting calcitonin receptor-like receptor (CLR) ameliorates Clostridium difficile toxin A-induced ileitis
    Aditi Bhargava
    Department of Surgery, University of California, San Francisco, CA 94143 0660, USA
    Proc Natl Acad Sci U S A 110:731-6. 2013
    ..difficile infection...
  4. pmc Plasma membrane calcium ATPase regulates bone mass by fine-tuning osteoclast differentiation and survival
    Hyung Joon Kim
    Department of Cell and Developmental Biology, BK21 Program and Dental Research Institute, Seoul National University, Seoul 110 749, Korea
    J Cell Biol 199:1145-58. 2012
    ..Thus, our results suggest that PMCAs play important roles for the regulation of bone homeostasis in both mice and humans by modulating Ca(2+) signaling in osteoclasts...
  5. pmc Rosiglitazone improves survival and hastens recovery from pancreatic inflammation in obese mice
    Maria Pini
    Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, Illinois, United States of America
    PLoS ONE 7:e40944. 2012
    ..However, RGZ worsens selective parameters of AP severity in LFD mice...
  6. pmc Localization of calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 1 (RAMP1) in human gastrointestinal tract
    Graeme S Cottrell
    Department of Surgery, Center for Neurobiology of Digestive Diseases, University of California San Francisco, San Francisco, CA 94143 0660, United States
    Peptides 35:202-11. 2012
    ..Thus, CGRP and IMD appear to be released locally, where they can mediate their effect on their receptors regulating diverse functions such as inflammation, pain and motility...
  7. pmc Role of IL-6 in the resolution of pancreatitis in obese mice
    Maria Pini
    Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
    J Leukoc Biol 91:957-66. 2012
    ....
  8. pmc Endothelin-converting enzyme-1 actions determine differential trafficking and signaling of corticotropin-releasing factor receptor 1 at high agonist concentrations
    Burcu Hasdemir
    Department of Surgery, Center for Neurobiology of Digestive Diseases, University of California, San Francisco, San Francisco, California 94143, USA
    Mol Endocrinol 26:681-95. 2012
    ....
  9. pmc Transient gastric irritation in the neonatal rats leads to changes in hypothalamic CRF expression, depression- and anxiety-like behavior as adults
    Liansheng Liu
    Division of Gastroenterology and Hepatology, Stanford University Medical Center, Stanford, California, United States of America
    PLoS ONE 6:e19498. 2011
    ..We hypothesized that psychological morbidity in these conditions may result from gastrointestinal problems, rather than causing them...
  10. pmc Urocortin 1 modulates immunosignaling in a rat model of colitis via corticotropin-releasing factor receptor 2
    Jen Chang
    Dept of Surgery, Univ of California, San Francisco, 94143 0660, USA
    Am J Physiol Gastrointest Liver Physiol 300:G884-94. 2011
    ..Thus we conclude that local CRF(2) and pERK1/2 activation is pivotal for macroscopic spread of colitis and resolution of edema. Elimination of CRF(2), but not CRF(1), results in uncoordinated immune and pERK1/2 signaling responses...
  11. ncbi Contrasting effects of ERK on tight junction integrity in differentiated and under-differentiated Caco-2 cell monolayers
    Sudhir Aggarwal
    Department of Physiology, University of Tennessee Health Sciences Center, Memphis, TN 38163, USA
    Biochem J 433:51-63. 2011
    ....
  12. pmc Expression and role of serum and glucocorticoid-regulated kinase 2 in the regulation of Na+/H+ exchanger 3 in the mammalian kidney
    Alan C Pao
    Div of Nephrology, Dept of Medicine, Stanford Univ, 780 Welch Rd, Suite 106, Palo Alto, CA 94304, USA
    Am J Physiol Renal Physiol 299:F1496-506. 2010
    ....
  13. pmc c-Jun NH2-terminal kinase-2 mediates osmotic stress-induced tight junction disruption in the intestinal epithelium
    G Samak
    Department of Physiology, University of Tennessee Health Science Center, Memphis, 38163, USA
    Am J Physiol Gastrointest Liver Physiol 299:G572-84. 2010
    ..These results reveal the role of JNK2 in the mechanism of osmotic stress-induced TJ disruption in the intestinal epithelium...
  14. pmc Urocortin 3 expression at baseline and during inflammation in the colon: corticotropin releasing factor receptors cross-talk
    Shilpi Mahajan
    Department of Surgery, University of California, San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143, USA
    Peptides 54:58-66. 2014
    ..Thus, our results suggest that a balanced and coordinated expression of CRF receptors is required for proper regulation of Ucn3 at baseline and during inflammation. ..