//9 Impact of Gender on the Pathogenesis of Crohn s Disease Theresa T. Pizarro Department of Pathology, CWRU Gender Differences in Autoimmune Diseases n Autoimmune diseases affect ~.7-. million people n Disproportionate occurrence (~%) in female population n Magnitude of gender bias is disease specific n Hashimoto s thyroiditis (:, female: male ratio) Lupus (:, female: male ratio) Chronic active hepatitis Sjogren s syndrome (7:, female: male ratio) Primary biliary cirrhosis Rheumatoid arthritis (:, female: male ratio) Multiple sclerosis (:, female: male ratio) Diabetes mellitis type (:, female: male ratio) n Currently, pathogenic mechanism(s) underlying gender bias in autoimmunity is unknown
//9 Gender Differences in IBD (Crohn s disease) n Effects of hormonal surges during pregnancy and post-partum appear to impact symptom activity in CD (Crohn et al., NY State J. Med. 9) n Increased incidence of CD in Turner s Syndrome patients (Price, J. Med. Genet. 979) n Susceptibility locus on ChrX that may be associated with a genetic predisposition to CD (Vermeire et al., Gastroenterol. ) n Slight increase in incidence of CD in females compared to males (.:, female: male ratio) (Hanauer et al., Inflamm. Bowel Dis. ) n Female CD patients more likely to experience severe disease manifestations and lower health-related quality of life (Saibeni et al., Hepatogastroenterol. ) n High-frequency TLR haplotypes (located on ChrX locus) are associated with both UC and CD in females (Saruta et al., IBD Journal 9) Gender Differences in Animal Models of IBD n Treatment with a highly selective orally active estrogen receptor (Erb) ligand treated Th-mediated colitis (Verdu et al., Am. J. Physiol. ) n Presence of an X-linked susceptibility loci in the /YitFc mouse strain (Kozaiwa et al., Gastroenterol. ) n Deletion of the X-linked immunodeficiency gene, Wiskott- Aldrich Syndrome protein (WASP), results in Th-mediated colitis (Nguyen et al., Gastroenterol. 7)
//9 Features of the /YitFc () mouse model of experimental Crohn s disease n Spontaneous ileitis without chemical, genetic or immunologic manipulation n % penetrance by wks; persistence of phenotype up to wks of age n Closely resembles human CD for disease location and histologic features n Disease mediated by both Th and Th cytokines n Responsive to standard CD therapies (i.e. steroids, anti-tnf) Histologic features of mouse strain n Segmental, discontinuous inflammation n Villous blunting, infiltration of PMNs, mononuclear cells in LP and submucosa n Apthous inflammatory lesions n Transmural inflammation n Granulomas n Cryptitis, Crypt microabscesses n Basal plasmacytolysis Kosiewicz, et al., J. Clin. Invest.
//9 Early & severe ileal inflammation in - females week- Male week- Female Total Inflammatory Index Male Female 7 9 Age (weeks) Villous Distortion Score 7 9 Active Inflammatory Score 7 9 Chronic Inflammatory Score 7 9 Age (weeks) Age (weeks) Age (weeks) Suggestive QTL by analysis of extreme phenotypes Chr Chr Chr 9 Chr X DXMit7 D9Mit DMit9 DMit Sugawara, et al., Gastroenterol. PPARg E-cadherin a/b-defensins Kozaiwa, et al., Gastroenterol. b-catenin JAM-C cingulin-like IL- MyD IL-R claudin- FoxP
//9 Human Chr X Mouse Chr X Xp.. Foxp A. Foxp (.cm) Xq.-q Cldn IRAK (9. cm) A 7. NEMO Xq IRAK NEMO F Cldn Epithelial permeability is increased in mice and occurs prior to the onset of inflammation A Small Intestine (Lactulose/Mannitol FE)..7....7 AKR B Ileal Inflammatory Score AKR C Ileum MPO Activity (U/mg tissue) AKR Colon (Sucralose FE)....9.. 9 Age (weeks) Colon Inflammatory Score 9 Age (weeks) Colon MPO Activ ity (U/mg tissue) 9 Age (weeks) Olson, et al., J. Exp. Med.,
//9 Altered epithelial TJ protein in young, uninflamed compared to control AKR ILEUM COLON claudin- mrna Expression mrna Expression mrna Expression.... AKR claudin- claudin- claudin- claudin- #... claudin- claudin- claudin- claudin- # Olson, et al., J. Exp. Med., occludin occludin Total Ileal Inflammation. Inflammatory Score..... Lactulose:Mannitol FE Ratio.......... native Small Intestinal Permeability Chr 7 (cont.) Chr PPARg Chr Chr 9 Chr X E-cadherin b-catenin claudin- a/b-defensins JAM-C FoxP cingulin-like IL- MyD IL-R
//9 What is the mechanism(s) for the differential response to estrogens in male vs female mice? Impact of ER isotypes in males vs females Role of Tregs in the manifestation of ileitis No significant difference in serum estrogen levels comparing vs AKR (control) females Circulating E is not responsible for modulating ileitis Disease may be due to differential expression of ER isotypes 7
//9 Differential expression of ER isotypes on MLN cells from and control mice ER-α Actin AKR F M F M ERa/Actin Ratio P<. vs. other experimental groups ER-β Actin ERḇ / Actin Ratio F M M F AKR P<. vs. other experimental groups Characterization of MLN Treg (FoxP) subsets Mouse X- chromosome A. FoxP (.cm) A A. A. A A A A 7. A 7. B C C D E E F F F F Rivera-Nieves, et al., Gastroenterol. FACS characterization of male vs. female Tregs
//9 Overview: distinct populations of Treg cells Naïve T Natural Tregs Other T cells populations TGF-β, IL- FoxP Th Figure from Walker Lucy SK, Immunol cell biol, 7; : - 7 Recently described Folate receptor marker; FR was included for characterizing distinct populations of Treg; in addition to traditional marker, FoxP Sakaguchi et al,immunity; 7 High population of MLN ntregs exist in males vs females FoxP hi A. Male Female AKR Male. ±.7. ±.. ±. AKR Female. ±.7 CDCD FRhi.7 ±.. ±.. ±.7. ±.7 CDCD Natural Tregs CDFoxphi higher in males Putative effector T cells, CDFoxPlo and CDFRlo cells higher in -F 9
//9 ERβ agonist influences MLN Treg marker expression FoxP/Actin 9 FoxP IL- (Pg/ml) PPT IL- P<. vs. other experimental groups DPN CTRL M F M F AKR M F M F AKR M F M F AKR P<. vs. other experimental groups TGF-b (Pg/ml) 7 M F M F TGF-β M F M F M F M F PPT DPN CTRL M F M F M F M F M F M F AKR AKR AKR -F Tregs are functionally more active than -F males females AKR males AKR females M M M Treg suppression activity = fold difference of percent divided T- effector cells (alone) : Teffector + Treg In co-culture experiment, ratio of T-effector: Treg used was : M= 7 h M= 9 h M= h
//9 Summary of Potential Pathogenic Mechanisms Underlying Gender Bias in Crohn s Disease Immunological factors Environmental Factors Genetic Factors Loss of Selftolerance Direct immune system towards Th/Th responses Dysfunctional regulatory mechanisms Crohn s Disease Sex hormones (androgens, estrogens) ChrX plays role? fetal-maternal microchimerism confer susceptibility?