Novel role of the serine protease inhibitor elafin in gluten-related disorders.
OBJECTIVE
Elafin, an endogenous serine protease inhibitor, modulates colonic inflammation. We investigated the role of elafin in celiac disease (CD) using human small intestinal tissues and in vitro assays of gliadin deamidation. We also investigated the potential beneficial effects of elafin in a mouse model of gluten sensitivity.


METHODS
Epithelial elafin expression in the small intestine of patients with active CD, treated CD, and controls without CD was determined by immunofluorescence. Interaction of elafin with human tissue transglutaminase-2 (TG-2) was investigated in vitro. The 33-mer peptide, a highly immunogenic gliadin peptide, was incubated with TG-2 and elafin at different concentrations. The degree of deamidation of the 33-mer peptide was analyzed by liquid chromatography-mass spectrometry. Elafin was delivered to the intestine of gluten-sensitive mice using a recombinant Lactococcus lactis vector. Small intestinal barrier function, inflammation, proteolytic activity, and zonula occludens-1 (ZO-1) expression were assessed.


RESULTS
Elafin expression in the small intestinal epithelium was lower in patients with active CD compared with control patients. In vitro, elafin significantly slowed the kinetics of the deamidation of the 33-mer peptide to its more immunogenic form. Treatment of gluten-sensitive mice with elafin delivered by the L. lactis vector normalized inflammation, improved permeability, and maintained ZO-1 expression.


CONCLUSIONS
The decreased elafin expression in the small intestine of patients with active CD, the reduction of 33-mer peptide deamidation by elafin, coupled to the barrier enhancing and anti-inflammatory effects observed in gluten-sensitive mice, suggest that this molecule may have pathophysiological and therapeutic importance in gluten-related disorders.
Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Canada.
Heather J
HJ
Galipeau
Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Canada.
Michelle
M
Wiepjes
1] INSERM, U1043, Toulouse, France [2] CNRS, U5282, Toulouse, France [3] Université de Toulouse, Université Paul Sabatier, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France.
Jean-Paul
JP
Motta
Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland.
Jessica D
JD
Schulz
Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Canada.
Jennifer
J
Jury
Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Canada.
Jane M
JM
Natividad
Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Canada.
Ines
I
Pinto-Sanchez
Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Canada.
Daniel
D
Sinclair
1] INSERM, U1043, Toulouse, France [2] CNRS, U5282, Toulouse, France [3] Université de Toulouse, Université Paul Sabatier, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France.
Perrine
P
Rousset
Commensal and Probiotics-Host Interactions Laboratory, UMR1319 Micalis, INRA, Jouy-en-Josas, France.
Rebeca
R
Martin-Rosique
Commensal and Probiotics-Host Interactions Laboratory, UMR1319 Micalis, INRA, Jouy-en-Josas, France.
Luis
L
Bermudez-Humaran
Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland.
Jean Christophe
JC
Leroux
Division of Gastroenterology and Hepatology, Department of Immunology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Joseph A
JA
Murray
Hospital de Gastroenterología Dr. Carlos Bonorino Udaondo, Buenos Aires, Argentina.
Edgardo
E
Smecuol
Hospital de Gastroenterología Dr. Carlos Bonorino Udaondo, Buenos Aires, Argentina.
Julio C
JC
Bai
1] INSERM, U1043, Toulouse, France [2] CNRS, U5282, Toulouse, France [3] Université de Toulouse, Université Paul Sabatier, Centre de Physiopathologie de Toulouse Purpan (CPTP), Toulouse, France.
Nathalie
N
Vergnolle
Commensal and Probiotics-Host Interactions Laboratory, UMR1319 Micalis, INRA, Jouy-en-Josas, France.
Philippe
P
Langella
Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Canada.
Elena F
EF
Verdu
D000328:Adult; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D002446:Celiac Disease / Q000178:diet therapy / Q000378:metabolism*; D002853:Chromatography, Liquid; D003641:Deamination; D055050:Diet, Gluten-Free; D053492:Elafin / Q000378:metabolism*; D005260:Female; D019204:GTP-Binding Proteins / Q000378:metabolism; D005903:Gliadin / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D007421:Intestine, Small / Q000378:metabolism*; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D016688:Mice, Inbred NOD; D008875:Middle Aged; D010539:Permeability; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases / Q000378:metabolism; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
D015415:Biomarkers; D053492:Elafin; C000717608:TGM2 protein, human; C569043:Tjp1 protein, mouse; D062826:Zonula Occludens-1 Protein; D005903:Gliadin; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins