Mast Cell Tryptase Promotes Inflammatory Bowel Disease–Induced Intestinal Fibrosis

Abstract Background Intestinal fibrosis is the final pathological outcome of chronic intestinal inflammation without specific therapeutic drugs, which leads to ileus and surgical intervention. Intestinal fibrosis is characterized by excessive deposition of extracellular matrix (ECM). The role of mast cells (MCs), which are members of the sentinel immune cell population, is unknown in intestinal fibrosis. Methods In this study, we analyzed changes in MCs, tryptase proteins, and ECM components in human fibrotic and control patient intestines. We constructed dextran sodium sulfate–induced intestinal fibrosis models using wild-type mice, MC-reconstituted mice, and MC-deficient mice to explore the role of MCs and tryptase in intestinal fibrosis. The roles and mechanisms of MCs and tryptase on fibroblasts were evaluated using human MCs (HMC-1 and LAD-2), commercial tryptase proteins, human colon fibroblasts (CCD-18Co fibroblasts), the tryptase inhibitor APC366, and the protease-activated receptor-2 (PAR-2) antagonist ENMD-1068. Results Regardless of whether the colon was a human colon or a mouse colon, the fibrotic intestinal tissue had increased MC infiltration and a higher expression of ECM proteins or genes than that of the control group. The dextran sodium sulfate–induced intestinal fibrosis in MC-deficient mice was alleviated compared with that in wild-type mice. After MC reconstruction in MC-deficient mice, the alleviating effect disappeared. Tryptase, as a content stored in MC granules, was released into fibrotic intestinal tissues in the form of degranulation, resulting in an increased expression of tryptase. Compared with the control group, the tryptase inhibition group (the APC366 group) had reduced intestinal fibrosis. The CCD-18Co fibroblasts, when cocultured with MCs or treated with tryptase proteins, were activated to differentiate into myofibroblasts and secrete more ECM proteins (such as collagen and fibronectin). The underlying mechanism of fibroblast activation by tryptase was the activation of the PAR-2/Akt/mTOR pathway. Conclusions We found that MC tryptase promotes inflammatory bowel disease–induced intestinal fibrosis. The underlying mechanism is that tryptase promotes the differentiation of fibroblasts into fibrotic-phenotype myofibroblasts by activating the PAR-2/Akt/ mTOR pathway of fibroblasts.

Download Full-text

Role of Epithelial-to-Mesenchymal Transition in Inflammatory Bowel Disease

Journal of Crohn s and Colitis ◽

10.1093/ecco-jcc/jjy201 ◽

2018 ◽

Vol 13 (5) ◽

pp. 659-668 ◽

Cited By ~ 9

Author(s):

Sara Lovisa ◽

Giannicola Genovese ◽

Silvio Danese

Keyword(s):

Inflammatory Bowel Disease ◽

Wound Healing ◽

Bowel Disease ◽

Molecular Mechanisms ◽

Epithelial To Mesenchymal Transition ◽

Clinical Manifestations ◽

Mesenchymal Transition ◽

Intestinal Fibrosis ◽

Inflammatory Bowel

Abstract Intestinal fibrosis is an inevitable complication in patients with inflammatory bowel disease [IBD], occurring in its two major clinical manifestations: ulcerative colitis and Crohn’s disease. Fibrosis represents the final outcome of the host reaction to persistent inflammation, which triggers a prolonged wound healing response resulting in the excessive deposition of extracellular matrix, eventually leading to intestinal dysfunction. The process of epithelial-to-mesenchymal transition [EMT] represents an embryonic program relaunched during wound healing, fibrosis and cancer. Here we discuss the initial observations and the most recent findings highlighting the role of EMT in IBD-associated intestinal fibrosis and fistulae formation. In addition, we briefly review knowledge on the cognate process of endothelial-to-mesenchymal transition [EndMT]. Understanding EMT functionality and the molecular mechanisms underlying the activation of this mesenchymal programme will permit designing new therapeutic strategies to halt the fibrogenic response in the intestine.

Download Full-text

A4 THE CIRCADIAN TIMING OF INFLAMMATORY BOWEL DISEASE

Journal of the Canadian Association of Gastroenterology ◽

10.1093/jcag/gwab002.003 ◽

2021 ◽

Vol 4 (Supplement_1) ◽

pp. 4-5

Author(s):

Z Taleb ◽

K Stokes ◽

H Wang ◽

S M Collins ◽

W I Khan ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Circadian Clock ◽

Bowel Disease ◽

Mutant Mice ◽

Intestinal Epithelial ◽

Wild Type ◽

Colon Tissue ◽

Rhythmic Expression ◽

Inflammatory Bowel

Abstract Background The circadian clock is a highly conserved molecular pacemaker found in nearly every cell of the body. It consists of the genes BMAL1 and CLOCK that positively regulate CRY and PER, their negative regulators, resulting in a transcription/translation feedback loop that has a 24 hour cycle. This core clock mechanism drives the rhythmic expression of over 40% of the genome in a tissue-specific manner and therefore imposes 24 hour rhythms on many physiological processes. Shift work, which causes disruptions to the natural 24 hour physiological rhythms, has been shown to lead to an increased incidence of inflammatory bowel disease (IBD). Aims This study aims to characterize daily rhythms in inflammation and regeneration of the colon upon induction of acute colitis. We also aim to investigate the intestinal epithelial-specific effects of circadian clock disruption on overall disease progression. We hypothesize that the absence of a functional circadian clock eliminates proliferation rhythms of intestinal epithelial cells and disrupts the rhythms of inflammatory cytokines, thereby increasing the pathogenesis of IBD. Methods We tested the role of the clock in IBD using BMAL1+/+ (wild type) and BMAL1-/- (null mutant) mice. We also investigated the effects of the circadian clock specific to intestinal epithelial tissue using Vil+/+;BMAL1flox/flox (control) and VilCre/+;BMAL1flox/flox (conditional intestinal epithelial mutant) mice. Dextran Sulfate Sodium (DSS) was applied to induce acute colitis. Results We observed significantly decreased survival of BMAL1 circadian clock mutant mice when given colitis. A histology analysis indicates increased lesioning and overall inflammation in BMAL1-/- colon tissue. Disease activity and cytokine analyses reveal time-dependent severity in inflammatory response that is worse in BMAL1-/- mice. To test the circadian rhythms in intestinal regeneration of mice with IBD, we performed a 24 hour analysis comparing epithelial cell proliferation and cell death in colon tissue. We observed rhythmic expression of phosphor-histone H3 (a mitosis marker) in wild type mice which is eliminated in the BMAL1-/- lacking a circadian clock. Cell death which was measured by caspase 3 did not exhibit any differences between genotypes. Based on these results, we conclude that the loss of clock function leads to impaired regeneration during IBD, in part due to decreased and arrhythmic cell proliferation. Preliminary results in our VilCre/+;BMAL1flox/flox conditional intestinal epithelial mutant mice indicate that some of these effects may be epithelial-specific. Conclusions Our results support a critical role of the circadian clock in inflammatory bowel disease development. These data highlight that the circadian clock affects the regenerative abilities of intestinal epithelial cells. Funding Agencies CIHRChron’s and Colitis Canada, Ontario, University of Windsor

Download Full-text

Lactose Intolerance Assessed by Analysis of Genetic Polymorphism, Breath Test and Symptoms in Patients with Inflammatory Bowel Disease

Nutrients ◽

10.3390/nu13041290 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1290

Author(s):

Olga Maria Nardone ◽

Francesco Manfellotto ◽

Caterina D’Onofrio ◽

Alba Rocco ◽

Giovanni Annona ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Bowel Disease ◽

Breath Test ◽

Lactose Intolerance ◽

Intermediate Phenotype ◽

Control Group ◽

Nucleotide Polymorphisms ◽

Wild Type ◽

Hydrogen Breath Test ◽

Inflammatory Bowel

Many patients with inflammatory bowel disease (IBD) restrict dairy products to control their symptoms. The aim of the study was to investigate the prevalence of lactose intolerance assessed with hydrogen breath test (H-BT) in IBD patients in clinical remission compared to a sex, age and BMI matched control population. We further detected the prevalence of three single nucleotide polymorphisms of the lactase (LCT) gene: the lactase non persistence LCT-13910 CC (wildtype) and the intermediate phenotype LCT-22018 CT and LCT-13910 AG; finally, we assess the correlation between genotype and H-BT. A total of 54 IBD patients and 69 control who underwent clinical evaluation, H-BT and genetic test were enrolled. H-BT was positive in 64.8% IBD patients and 62.3% control (p = 0.3). The wild-type genotype was found in 85.2% IBD patients while CT-22018, AG-13910 and CT-22018/AG-13910 polymorphisms were found in 9.3%, 1.8% and 3.7%. In the control group, the wild-type genotype, CT-22018, AG-13910 and CT-22018/AG-13910 polymorphisms were found in 87%, 5.8%, 5.8% and 1.4% of cases, respectively. Therefore, the wild-type and polymorphisms’ prevalence did not differ between IBD population and control group (85.2% vs. 87%, p = 0.1) (14.8% vs. 13%, p = 0.7). The correlation between positive H-BT and genetic analysis showed that the wild-type genotype was associated with higher rate of lactose intolerance in the total population (OR 5.31, 95%CI 1.73–16.29, p = 0.003) and in the IBD (OR 7.61, 95%CI 1.36–42.7, p = 0.02). The prevalence of lactose intolerance in IBD patients did not differ from that of control. Despite suggestive symptoms, about 1/3 of IBD patients are not lactose intolerant, thus not needing “a priori” elimination diet. This may encourage a rationale and balanced dietary management in IBD.

Download Full-text

Role of Mast Cells in Inflammatory Bowel Disease and Inflammation-Associated Colorectal Neoplasia in IL-10-Deficient Mice

PLoS ONE ◽

10.1371/journal.pone.0012220 ◽

2010 ◽

Vol 5 (8) ◽

pp. e12220 ◽

Cited By ~ 42

Author(s):

Maciej Chichlowski ◽

Greg S. Westwood ◽

Soman N. Abraham ◽

Laura P. Hale

Keyword(s):

Inflammatory Bowel Disease ◽

Mast Cells ◽

Bowel Disease ◽

Colorectal Neoplasia ◽

Inflammatory Bowel ◽

Deficient Mice

Download Full-text

Helicobacter-induced inflammatory bowel disease in IL-10- and T cell-deficient mice

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.2001.281.3.g764 ◽

2001 ◽

Vol 281 (3) ◽

pp. G764-G778 ◽

Cited By ~ 101

Author(s):

Andrew Burich ◽

Robert Hershberg ◽

Kim Waggie ◽

Weiping Zeng ◽

Thea Brabb ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

T Cells ◽

T Cell ◽

T Lymphocytes ◽

Bowel Disease ◽

Wild Type ◽

Immunodeficient Mice ◽

Inflammatory Bowel ◽

Rag 1

Inflammatory bowel disease (IBD) is thought to result from a dysregulated mucosal immune response to luminal microbial antigens, with T lymphocytes mediating the colonic pathology. Infection with Helicobacter spp has been reported to cause IBD in immunodeficient mice, some of which lack T lymphocytes. To further understand the role of T cells and microbial antigens in triggering IBD, we infected interleukin (IL)-10−/−, recombinase-activating gene (Rag)1−/−, T-cell receptor (TCR)-α−/−, TCR-β−/−, and wild-type mice with Helicobacter hepaticus or Helicobacter bilis and compared the histopathological IBD phenotype. IL-10−/−mice developed severe diffuse IBD with either H. bilis or H. hepaticus, whereas Rag1−/−, TCR-α−/−, TCR-β−/−, and wild-type mice showed different susceptibilities to Helicobacter spp infection. Proinflammatory cytokine mRNA expression was increased in the colons of Helicobacter-infected IL-10−/−and TCR-α−/−mice with IBD. These results confirm and extend the role of Helicobacter as a useful tool for investigating microbial-induced IBD and show the importance, but not strict dependence, of T cells in the development of bacterial-induced IBD.

Download Full-text

GPR4 Deficiency Alleviates Intestinal Inflammation in a Mouse Model of Inflammatory Bowel Disease

10.1101/059014 ◽

2016 ◽

Author(s):

Edward J. Sanderlin ◽

Nancy R. Leffler ◽

Kvin Lertpiriyapong ◽

Qi Cai ◽

Heng Hong ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Mouse Model ◽

Bowel Disease ◽

Intestinal Inflammation ◽

Vascular Endothelial Cells ◽

Leukocyte Adhesion ◽

Lymphoid Follicle ◽

Wild Type ◽

Inflammatory Bowel ◽

Deficient Mice

AbstractGPR4 is a proton-sensing G protein-coupled receptor that can be activated by extracellular acidosis. It has recently been demonstrated that activation of GPR4 by acidosis increases the expression of numerous inflammatory and stress response genes in vascular endothelial cells (ECs) and also augments EC-leukocyte adhesion. Inhibition of GPR4 by siRNA or small molecule inhibitors reduces endothelial cell inflammation. As acidotic tissue microenvironments exist in many types of inflammatory disorders, including inflammatory bowel disease (IBD), we examined the role of GPR4 in IBD using a dextran sulfate sodium (DSS)-induced colitis mouse model. We observed that GPR4 mRNA expression was increased in mouse and human IBD tissues when compared to control intestinal tissues. To determine the function of GPR4 in IBD, wild-type and GPR4-deficient mice were treated with 3% DSS for 7 days to induce acute colitis. Our results showed that the severity of colitis was decreased in GPR4-deficient DSS-treated mice in comparison to wild-type DSS-treated mice. Clinical parameters, macroscopic disease indicators, and histopathological features were less severe in the DSS-treated GPR4-deficient mice than the DSS-treated wild-type mice. Inflammatory gene expression, leukocyte infiltration, and isolated lymphoid follicle (ILF) formation were reduced in intestinal tissues of DSS-treated GPR4-null mice. Collectively, our results suggest GPR4 provides a pro-inflammatory role in IBD as the absence of GPR4 ameliorates intestinal inflammation in the acute DSS-induced IBD mouse model.

Download Full-text

Protective effects of guggulsterone against colitis are associated with the suppression of TREM-1 and modulation of macrophages

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00027.2018 ◽

2018 ◽

Vol 315 (1) ◽

pp. G128-G139 ◽

Cited By ~ 7

Author(s):

Xiumei Che ◽

Ki Cheong Park ◽

Soo Jung Park ◽

You Hyun Kang ◽

Hyun A Jin ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Bowel Disease ◽

Myeloid Cells ◽

Trinitrobenzene Sulfonic Acid ◽

Toll Like Receptor ◽

Wild Type ◽

Toll Like Receptor 4 ◽

Inflammatory Bowel ◽

Deficient Mice ◽

M2 Phenotype

Triggering receptor expressed on myeloid cells 1 (TREM-1)-expressing intestinal macrophages are significantly increased in the colons of patients with inflammatory bowel disease (IBD). We focused here on the effects of guggulsterone on macrophage modulation in colitis as a potential therapeutic molecule in human IBD and explore the underlying mechanisms. Gene expression in macrophages was examined and wound-healing assay using HT-29 cells was performed. Colitis in wild-type and IL-10-, Toll-like receptor 4 (TLR4)-, and myeloid differentiation primary response 88 (MyD88)-deficient mice was induced via the administration of 2,4,6-trinitrobenzene sulfonic acid (TNBS) into the colon. In both in vitro and in vivo experiments, guggulsterone suppressed intestinal inflammation amplified by TREM-1 stimulation, in which the suppression of NF-κB, activating protein-1, and proteasome pathways was involved. In the TNBS-induced colitis model, guggulsterone reduced disease activity index scores and TREM-1 expression, stimulated IL-10 production, and improved survival in wild-type mice. These effects were not observed in IL-10-, TLR4-, and MyD88-deficient mice. Guggulsterone also suppressed M1 polarization, yet induced the M2 phenotype in macrophages from IBD patients as well as from mice. These findings indicate that guggulsterone blocks the hyperactivation of macrophages via TREM-1 suppression and induces M2 polarization via IL-10 mediated by the TLR4 signaling pathway. Furthermore, this study provides a new rationale for the therapeutic potential of guggulsterone in the treatment of IBD. NEW & NOTEWORTHY We found that guggulsterone attenuates triggering receptor expressed on myeloid cells 1 (TREM-1)-mediated hyperactivation of macrophages and polarizes macrophages toward the M2 phenotype. This was mediated by IL-10 and partly Toll-like receptor 4 signaling pathways. Overall, these data support that guggulsterone as a natural plant sterol modulates macrophage phenotypes in colitis, which may be of novel therapeutic importance in inflammatory bowel disease treatment.

Download Full-text

P621 Lactose intolerance assessed by analysis of genetic polymorphism, breath test and symptoms in patients with inflammatory bowel disease

Journal of Crohn s and Colitis ◽

10.1093/ecco-jcc/jjab076.741 ◽

2021 ◽

Vol 15 (Supplement_1) ◽

pp. S561-S562

Author(s):

O M Nardone ◽

F Manfellotto ◽

C D’Onofrio ◽

A Rocco ◽

G Annona ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

General Population ◽

Bowel Disease ◽

Clinical Remission ◽

Breath Test ◽

Lactose Intolerance ◽

Control Group ◽

Wild Type ◽

Significant Difference ◽

Inflammatory Bowel

Abstract Background Many patients with inflammatory bowel disease (IBD) make restriction of dairy products to control their symptoms. We aimed to investigate the prevalence of lactose intolerance assessed with hydrogen breath test (H-BT) in IBD patients in clinical remission with symptoms suggestive for lactose intolerance, compared to a sex- age- and BMI-matched control population. We further detected the prevalence of three single nucleotide polymorphisms of the lactase (LCT) gene: the lactase non persistence LCT-13910CC (genetic wildtype) and the intermediate phenotype LCT-22018AG, LCT-13910CT and we assess the correlation between genotype and H-BT Methods We performed a prospective study enrolling IBD patients in clinical remission: Crohn disease (CD) activity index CDAI<150 for CD and pMayo score≤1 for ulcerative colitis (UC) and controls. All of them underwent clinical evaluation, H-BT and genetic test analysing lactase gene polymorphisms located on chromosome 2. Statistical analysis was performed using chi-square, Student’s t-test and ANOVA. Results A total of 54 IBD patients and 69 matched controls were enrolled. H-BT was positive in 35(64.8%) IBD patients and 43 (62.3%) controls (p=0.3). No significant difference in lactose intolerance rate, assessed by H-BT and symptoms,was found between CD and UC patients (p =0.8). The wild-type genotype was found in 46 (85.2%) IBD patients , CT22018, AG13910 and CT22018/AG13910 polymorphisms were found in 9.3%, 1.8% and 3.7% respectively. While in the control group, the wild-type genotype, CT22018, AG13910 and CT22018/AG13910 polymorphisms were found in 87%, 5.8%, 5.8% and 1.4% of cases, respectively. The wild type and polymorphisms’ prevalence did not differ between IBD population and control group (85.2%vs 87%, p=0.1) (14.8% vs 13%, p=0.7) [Fig.1] and between CD and UC (p>0.05) [Fig.2]. The correlation between positive H-BT and genetic analysis showed that the wild-type genotype was associated with higher rate of lactose intolerance in the total population (OR 5.31, 95%CI 1.73–16.29, p=0.003) and in the IBD population (OR 7.61, 95%CI 1.36–42.7, p=0.02), even thought not in the control group (OR 4, 95%CI 0.90–17.68, p=0.07) Fig.1 Fig.2 Conclusion The prevalence of lactose intolerance in IBD is high but not dissimilar from that of the general population. The prevalence of the wild-type genotype in patients with IBD does not differ from the general population and it correlates with higher rate of lactose intolerance assessed with H-BT. Despite suggestive symptoms, about 1/3 of IBD patients is not lactose intolerant, not needing elimination diet. These can lead to promote a rationale and balanced dietary management in IBD and thereby preventing the occurrence of calcium phosphate metabolism disorders.

Download Full-text

Knockout ofMkp-1exacerbates colitis inIl-10-deficient mice

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00018.2012 ◽

2012 ◽

Vol 302 (11) ◽

pp. G1322-G1335 ◽

Cited By ~ 17

Author(s):

Ranyia Matta ◽

John A. Barnard ◽

Lyn M. Wancket ◽

Jing Yan ◽

Jianjing Xue ◽

...

Keyword(s):

Inflammatory Bowel Disease ◽

Immune Responses ◽

Rectal Prolapse ◽

Bowel Disease ◽

Negative Regulator ◽

Inflammatory Bowel ◽

Mucosal Immune Responses ◽

Deficient Mice ◽

Severe Colitis

Il-10-deficient mice develop colitis associated with exaggerated Th1/Th17 responses and are a valuable model of inflammatory bowel disease. Mkp-1 is a major negative regulator of MAPKs, and its expression is enhanced by IL-10. To understand the role of Mkp-1 in the regulation of intestinal mucosal immune responses, we studied the effect of Mkp-1 deletion on the pathogenesis of colitis in Il-10−/−mice. We found that knockout of Mkp-1 on an Il-10−/−background accelerated the development of colitis. Compared with Il-10−/−mice, colitis not only appeared earlier but also was more severe in Il-10−/−/ Mkp-1−/−mice. Il-10−/−mice exhibited a mild intestinal inflammation in the specific pathogen-free environment, and rectal prolapse rarely appeared before 6 mo of age. In contrast, the majority of Il-10−/−/ Mkp-1−/−mice developed severe colitis rapidly and presented with rectal prolapse after only 2–3 mo. The colon of Il-10−/−/ Mkp-1−/−mice showed diffuse transmural chronic inflammation and mucosal hyperplasia, with significantly more proliferating crypt epithelial cells than those of Il-10−/−mice. In addition to the severe colitis, Il-10−/−/ Mkp-1−/−mice also developed conjunctivitis and blepharitis. The colon of Il-10−/−/ Mkp-1−/−mice contained significantly higher levels of proinflammatory cytokines and exhibited greater MAPK activities than did the colon of Il-10−/−mice. Splenocytes and lymphocytes from Il-10−/−/ Mkp-1−/−mice produced higher levels of Th1 cytokines ex vivo upon activation than did cells from Il-10−/−mice. Our studies support a pivotal role of Mkp-1 as a negative regulator of mucosal immune responses and highlight its protective function against inflammatory bowel disease.

Download Full-text

The Multiple Faces of Integrin–ECM Interactions in Inflammatory Bowel Disease

International Journal of Molecular Sciences ◽

10.3390/ijms221910439 ◽

2021 ◽

Vol 22 (19) ◽

pp. 10439

Author(s):

Valentina Garlatti ◽

Sara Lovisa ◽

Silvio Danese ◽

Stefania Vetrano

Keyword(s):

Inflammatory Bowel Disease ◽

Extracellular Matrix ◽

Bowel Disease ◽

Great Promise ◽

Matrix Remodeling ◽

Independent Manner ◽

Damage Site ◽

Intestinal Fibrosis ◽

Inflammatory Bowel

Inflammatory Bowel Disease (IBD) comprises a series of chronic and relapsing intestinal diseases, with Crohn’s disease and ulcerative colitis being the most common. The abundant and uncontrolled deposition of extracellular matrix, namely fibrosis, is one of the major hallmarks of IBD and is responsible for the progressive narrowing and closure of the intestine, defined as stenosis. Although fibrosis is usually considered the product of chronic inflammation, the substantial failure of anti-inflammatory therapies to target and reduce fibrosis in IBD suggests that fibrosis might be sustained in an inflammation-independent manner. Pharmacological therapies targeting integrins have recently shown great promise in the treatment of IBD. The efficacy of these therapies mainly relies on their capacity to target the integrin-mediated recruitment and functionality of the immune cells at the damage site. However, by nature, integrins also act as mechanosensitive molecules involved in the intracellular transduction of signals and modifications originating from the extracellular matrix. Therefore, understanding integrin signaling in the context of IBD may offer important insights into mechanisms of matrix remodeling, which are uncoupled from inflammation and could underlie the onset and persistency of intestinal fibrosis. In this review, we present the currently available knowledge on the role of integrins in the etiopathogenesis of IBD, highlighting their role in the context of immune-dependent and independent mechanisms.

Download Full-text