Activity of SHIP, Which Prevents Expression of Interleukin 1β, Is Reduced in Patients With Crohn's Disease.
OBJECTIVE
Crohn's disease (CD) is associated with a dysregulated immune response to commensal micro-organisms in the intestine. Mice deficient in inositol polyphosphate 5'-phosphatase D (INPP5D, also known as SHIP) develop intestinal inflammation resembling that of patients with CD. SHIP is a negative regulator of PI3Kp110α activity. We investigated mechanisms of intestinal inflammation in Inpp5d(-/-) mice (SHIP-null mice), and SHIP levels and activity in intestinal tissues of subjects with CD.


METHODS
We collected intestines from SHIP-null mice, as well as Inpp5d(+/+) mice (controls), and measured levels of cytokines of the interleukin 1 (IL1) family (IL1α, IL1β, IL1ra, and IL6) by enzyme-linked immunosorbent assay. Macrophages were isolated from lamina propria cells of mice, IL1β production was measured, and mechanisms of increased IL1β production were investigated. Macrophages were incubated with pan-phosphatidylinositol 3-kinase inhibitors or PI3Kp110α-specific inhibitors. Some mice were given an antagonist of the IL1 receptor; macrophages were depleted from ilea of mice using clodronate-containing liposomes. We obtained ileal biopsies from sites of inflammation and peripheral blood mononuclear cells (PBMCs) from treatment-naïve subjects with CD or without CD (controls), and measured SHIP levels and activity. PBMCs were incubated with lipopolysaccharide and adenosine triphosphate, and levels of IL1β production were measured.


RESULTS
Inflamed intestinal tissues and intestinal macrophages from SHIP-null mice produced higher levels of IL1B and IL18 than intestinal tissues from control mice. We found PI3Kp110α to be required for macrophage transcription of Il1b. Macrophage depletion or injection of an IL1 receptor antagonist reduced ileal inflammation in SHIP-null mice. Inflamed ileal tissues and PBMCs from patients with CD had lower levels of SHIP protein than controls (P < .0001 and P < .0002, respectively). There was an inverse correlation between levels of SHIP activity in PBMCs and induction of IL1β production by lipopolysaccharide and adenosine triphosphate (R(2) = .88).


CONCLUSIONS
Macrophages from SHIP-deficient mice have increased PI3Kp110α-mediated transcription of Il1b, which contributes to spontaneous ileal inflammation. SHIP levels and activity are lower in intestinal tissues and peripheral blood samples from patients with CD than controls. There is an inverse correlation between SHIP activity and induction of IL1β production by lipopolysaccharide and adenosine triphosphate in PBMCs. Strategies to reduce IL1B might be developed to treat patients with CD found to have low SHIP activity.
Division of Gastroenterology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Eyler N
EN
Ngoh
Division of Gastroenterology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Shelley B
SB
Weisser
Division of Gastroenterology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Young
Y
Lo
Division of Gastroenterology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Lisa K
LK
Kozicky
Division of Gastroenterology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Roger
R
Jen
Division of Gastroenterology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Hayley K
HK
Brugger
Division of Gastroenterology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Susan C
SC
Menzies
Division of Gastroenterology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Keith W
KW
McLarren
Department of Surgery, Child & Family Research Institute, and University of British Columbia, Vancouver, British Columbia, Canada.
Dominika
D
Nackiewicz
Department of Molecular Cell Biology, Vrije Universiteit, Amsterdam, Netherlands.
Nico
N
van Rooijen
Division of Gastroenterology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Kevan
K
Jacobson
Department of Surgery, Child & Family Research Institute, and University of British Columbia, Vancouver, British Columbia, Canada.
Jan A
JA
Ehses
Division of Allergy and Immunology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, and the University of British Columbia, Vancouver, British Columbia, Canada.
Stuart E
SE
Turvey
Division of Gastroenterology, Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address: laurasly@mail.ubc.ca.
Laura M
LM
Sly
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D002478:Cells, Cultured; D058534:Class I Phosphatidylinositol 3-Kinases; D003424:Crohn Disease / Q000175:diagnosis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D004195:Disease Models, Animal; D006801:Humans; D007079:Ileitis / Q000175:diagnosis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D007082:Ileum / Q000201:enzymology* / Q000276:immunology / Q000473:pathology; D000072181:Inositol Polyphosphate 5-Phosphatases; D020382:Interleukin-18 / Q000378:metabolism; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000201:enzymology / Q000276:immunology; D008264:Macrophages / Q000201:enzymology* / Q000276:immunology / Q000473:pathology; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010744:Phosphoric Monoester Hydrolases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D014158:Transcription, Genetic; D015854:Up-Regulation
D000893:Anti-Inflammatory Agents; D058534:Class I Phosphatidylinositol 3-Kinases; D000072181:Inositol Polyphosphate 5-Phosphatases; D020382:Interleukin-18; D053583:Interleukin-1beta; D019869:Phosphatidylinositol 3-Kinases; D000072183:Phosphatidylinositol-3,4,5-Trisphosphate 5-Phosphatases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010744:Phosphoric Monoester Hydrolases; D047428:Protein Kinase Inhibitors; D017472:Receptors, Interleukin-1; C508585:IL1B protein, human; C587672:IL1B protein, mouse; C546639:Pik3ca protein, mouse; C000606430:INPP5D protein, human; C000606433:Inpp5d protein, mouse
Inflammatory; PI3Kp110α; Phosphatidylinositol; Signal Transduction