title: Oxytocin opposes effects of bacterial endotoxin on ER-stress signaling in Caco2BB gut cells.
abstract: BACKGROUND
  The neuropeptide neuromodulator and hormone oxytocin (OT) activates signaling pathways involved in mRNA translation in response to endoplasmic reticulum stress and reduces inflammation associated with experimental colitis in rats. The anti-inflammatory effects of OT may serve a vital role in the development, survival and function of newborn-type enterocytes during microbial gut colonization, which coincides with the milk suckling period when OT receptor expression peaks in the gut. Furthermore, mice deficient in the OT receptor have abnormal gut structure and function, underscoring OT's developmental importance.
  
  
  METHODS
  We tested the effect of OT upon lipopolysaccharide (LPS)-induced markers of the inflammatory response in Caco2BB gut cells in vitro using automated immunocapillary electrophoresis.
  
  
  RESULTS
  We demonstrate that OT suppresses NF-κB signaling and presumably inflammatory transcriptional programs, which are unleashed by LPS through the modulation of IκB. We show that OT counteracts LPS-elicited silencing of the unfolded protein response, a pathway limiting endoplasmic reticulum stress by suppressing protein translation. OT selectively activates dsRNA-activated kinase (PKR), X-box binding protein 1 (XBP1), immunoglobulin binding protein (BiP), A20 (TNFα-induced protein 3) and inositol requiring enzyme 1a (IRE1a). OT inactivates eukaryotic translation initiation factor 2a (eIF2a) without significant activation of protein kinase RNA-like endoplasmic reticulum kinase (PERK).
  
  
  CONCLUSIONS
  Mild, preemptive stimulation of endoplasmic reticulum stress sensors by OT may precondition newborn enterocytes to resist apoptosis associated with inflammation and may support their differentiation and development by modulating cellular metabolism.
  
  
  CONCLUSIONS
  OT may protect enterocytes and other cell types, such as neurons, from stress-related complications during postnatal development.
authors.affiliation: Division of Developmental Neuroscience, New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032, USA. Electronic address: bk2348@columbia.edu.
authors.forename: Benjamin Y
authors.initials: BY
authors.lastname: Klein
authors.affiliation: Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032, USA; Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY 10032, USA; Department of Psychiatry, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Hadassah
authors.initials: H
authors.lastname: Tamir
authors.affiliation: Center for Infection and Immunology, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Hirschberg
authors.affiliation: Division of Developmental Neuroscience, New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Ludwig
authors.affiliation: EB Sciences, Oakland, CA 94611, USA.
authors.forename: Sara B
authors.initials: SB
authors.lastname: Glickstein
authors.affiliation: Division of Developmental Neuroscience, New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032, USA; Department of Psychiatry, Columbia University Medical Center, New York, NY 10032, USA; Department of Pediatrics, Columbia University Medical Center, New York, NY 10032, USA.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Myers
authors.affiliation: Division of Developmental Neuroscience, New York State Psychiatric Institute, Columbia University Medical Center, New York, NY 10032, USA; Department of Pathology & Cell Biology, Columbia University Medical Center, New York, NY 10032, USA; Department of Psychiatry, Columbia University Medical Center, New York, NY 10032, USA; Department of Pediatrics, Columbia University Medical Center, New York, NY 10032, USA. Electronic address: mgw13@columbia.edu.
authors.forename: Martha G
authors.initials: MG
authors.lastname: Welch
mesh_terms: D018938:Caco-2 Cells; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects*; D020895:Enterocytes / Q000187:drug effects*; D006360:Heat-Shock Proteins / Q000032:analysis*; D006801:Humans; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors*; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000502:physiology; D010121:Oxytocin / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects*; D056811:Unfolded Protein Response
chemical_list: D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; D010121:Oxytocin
keywords: Enterocytes; Eukaryotic requiring enzyme 1a, A20; Inositol requiring enzyme 1a; Unfolded protein response; X-box binding protein 1