Adenovirus vector expressing mouse oncostatin M induces acute-phase proteins and TIMP-1 expression in vivo in mice.

Mouse oncostatin M (MuOSM) regulates the production of acute-phase proteins by hepatocytes as well as tissue inhibitor of metalloproteinases-1 (TIMP-1) production by fibroblasts in vitro. We have generated an adenovirus (Ad) encoding MuOSM and tested the effects of administration of recombinant AdMuOSM to mice in vivo. On intramuscular injection, AdMuOSM (5 X 10(7) plaque-forming units, pfu) induced an increase in serum levels of interleukin-6 (IL-6) as well as the acute-phase proteins serum amyloid A (SAP) and alpha1-acid glycoprotein (AGP) at day 1. SAP and AGP concentrations were elevated to greater levels at day 3 and decreased to near control levels at day 7. Intratracheal treatment with AdMuOSM induced TIMP-1 mRNA levels (as assessed by Northern blots) that corresponded to the presence of transgene MuOSM mRNA levels. TIMP-1 was elevated at day 1 and day 3 and less consistently at day 7 after administration. Intraperitoneal treatment with AdMuOSM also resulted in elevation of TIMP-1 mRNA in lung tissue. These results show that AdMuOSM can induce both local and systemic effects and demonstrate in vivo effects of OSM that are consistent with in vitro studies on acute-phase protein and TIMP-1 expression.     

Murine oncostatin M stimulates mouse synovial fibroblasts in vitro and induces inflammation and destruction in mouse joints in vivo

Oncostatin M (OSM) is a multifunctional cytokine, a member of the interleukin-6/leukemia inhibitory factor (IL-6/LIF) family, that can regulate a number of connective-tissue cell types in vitro including cartilage and synovial tissue-derived fibroblasts, however its role in joint inflammation in vivo is not clear. We have analyzed murine OSM (muOSM) activity in vitro and in vivo in mouse joint tissue, to determine the potential role of this cytokine in local joint inflammation and pathology. The effects of muOSM and other IL-6/LIF cytokines on mouse synovial fibroblast cultures were assessed in vitro and showed induction of monocyte chemotactic protein-1, interleukin-6, and tissue inhibitor metalloproteinase-1, as well as enhancement of colony growth in soft agarose culture. Other IL-6/LIF cytokines including IL-6, LIF, or cardiotrophin-1, did not have such effects when tested at relatively high concentrations (20 ng/ml). To assess effects of muOSM in articular joints in vivo, we used recombinant adenovirus expressing muOSM cDNA (AdmuOSM) and injected purified recombinant virus (10(6) to 10(8) pfu) intra-articularly into the knees of various mouse strains. Histological analysis revealed dramatic alterations in the synovium but not in synovium of knees treated with the control virus Ad-dl70 or knees treated with Adm-IL-6 encoding biologically active murine IL-6. AdmuOSM effects were characterized by increases in the synovial cell proliferation, infiltration of mononuclear cells, and increases in extracellular matrix deposition that were evident at day 4, but much more marked at days 7, 14, and 21 after administration. The synovium took on characteristics similar to pannus and appeared to contact and invade cartilage. Collectively, these results provide good evidence that OSM regulates synovial fibroblast function differently than other IL-6-type cytokines, and can induce a proliferative invasive phenotype of synovium in vivo in mice on overexpression. We suggest that OSM may contribute to pathology in arthritis.     

Oncostatin M overexpression induces skin inflammation but is not required in the mouse model of imiquimod‐induced psoriasis‐like inflammation

Oncostatin M (OSM) has been reported to be overexpressed in psoriasis skin lesions and to exert proinflammatory effects in vitro on human keratinocytes. Here, we report the proinflammatory role of OSM in vivo in a mouse model of skin inflammation induced by intradermal injection of murine OSM‐encoding adenovirus (AdOSM) and compare with that induced by IL‐6 injection. Here, we show that OSM potently regulates the expression of genes involved in skin inflammation and epidermal differentiation in murine primary keratinocytes. In vivo, intradermal injection of AdOSM in mouse ears provoked robust skin inflammation with epidermal thickening and keratinocyte proliferation, while minimal effect was observed after AdIL‐6 injection. OSM overexpression in the skin increased the expression of the S100A8/9 antimicrobial peptides, CXCL3, CCL2, CCL5, CCL20, and Th1/Th2 cytokines, in correlation with neutrophil and macrophage infiltration. In contrast, OSM downregulated the expression of epidermal differentiation genes, such as cytokeratin‐10 or filaggrin. Collectively, these results support the proinflammatory role of OSM when it is overexpressed in the skin. However, OSM expression was not required in the murine model of psoriasis induced by topical application of imiquimod, as demonstrated by the inflammatory phenotype of OSM‐deficient mice or wild‐type mice treated with anti‐OSM antibodies.     

Inhibition of dextran sulphate sodium (DSS)-induced colitis in mice by intracolonically administered antibodies against adhesion molecules (endothelial leucocyte adhesion molecule-1 (ELAM-1) or intercellular adhesion molecule-1 (ICAM-1)).

We examined the effect of intracolonic administration of anti-adhesion molecule antibodies on DSS-induced colitis in mice. Immunohistochemical staining in mice with colitis showed increased expression of ELAM-1 and ICAM-1 on endothelial cells of vessels in the lamina propria and submucosa at sites of inflamed lesions. Intracolonic administration of anti-ELAM-1 or anti-ICAM-1 antibody decreased bloody stools, anaemia, and histologically evident damage, as well as myeloperoxidase activity and IL-1beta content. We concluded that adhesion molecule expression is important in the development of DSS-induced colitis in mice and that intracolonic administration of anti-adhesion molecule antibodies, especially anti-ELAM-1 antibody, effectively inhibits the colonic inflammation. Intracolonic administration of anti-adhesion molecule antibodies may show therapeutic promise in ulcerative colitis.     

Suppressive effect of berberine on experimental dextran sulfate sodium-induced colitis

The anti-inflammatory effect of berberine was evaluated in murine model of acute experimental colitis induced by dextran sulfate sodium (DSS). Berberine, given orally at 40, 20, 10?mg/kg for 10 days, ameliorated all the supposed inflammatory symptoms of the induced colitis, such as body weightloss, blood hemoglobin reduction, high myeloperoxidase levels, and malondialdehyde content-inflamed mucosa. Furthermore, the cytokine production of splenic lymphocytes was analyzed. The results showed the IFN-γ and IL-12 were increased, but IL-4 and IL-10 were decreased in DSS-induced colitis,when those were compared with the normal control. But the administration of berberine to DSS-induced colitis mice showed lower production of IFN-γ and IL-12 and higher production of IL-4 and IL-10 than the DSS-induced colitis mice. The results suggest that the protective effects of berberine against the DSS-induced colitis may be associated with the regulation of cytokine production.     

Suppressive effect of berberine on experimental dextran sulfate sodium-induced colitis

The anti-inflammatory effect of berberine was evaluated in murine model of acute experimental colitis induced by dextran sulfate sodium (DSS). Berberine, given orally at 40, 20, 10?mg/kg for 10 days, ameliorated all the supposed inflammatory symptoms of the induced colitis, such as body weightloss, blood hemoglobin reduction, high myeloperoxidase levels, and malondialdehyde content-inflamed mucosa. Furthermore, the cytokine production of splenic lymphocytes was analyzed. The results showed the IFN-γ and IL-12 were increased, but IL-4 and IL-10 were decreased in DSS-induced colitis,when those were compared with the normal control. But the administration of berberine to DSS-induced colitis mice showed lower production of IFN-γ and IL-12 and higher production of IL-4 and IL-10 than the DSS-induced colitis mice. The results suggest that the protective effects of berberine against the DSS-induced colitis may be associated with the regulation of cytokine production.     

Adenoviral gene transfer of interleukin-1 in combination with oncostatin M induces significant joint damage in a murine model

Oncostatin M (OSM) is an interleukin (IL)-6 family cytokine that we have previously shown can synergize with a number of proinflammatory cytokines to promote the release of collagen from cartilage in explant culture. However, the effects of this potent cytokine combination in vivo are not known. Using adenoviral gene transfer, we have overexpressed murine IL-1 (AdmIL-1) and murine OSM (AdmOSM) intraarticularly in the knees of C57BL/6 mice. Histological analyses indicated marked synovial hyperplasia and inflammatory cell infiltration for both AdmIL-1 and AdmOSM but not in control joints. This inflammation was even more pronounced for the AdmIL-1+AdmOSM combination with evidence of cartilage and bone destruction. Significant loss of both proteoglycan and collagen was also seen for this combination, and immunohistochemistry revealed an increased expression of matrix metalloproteinases (MMPs) with decreased tissue inhibitor of metalloproteinases (TIMPs) in both articular cartilage and synovium. Similar expression profiles for MMPs/TIMPs were found in IL-1+OSM-stimulated human articular chondrocytes. Taken together, these data confirm that, in vivo, OSM can exacerbate the effects of IL-1 resulting in inflammation and tissue destruction characteristic of that seen in rheumatoid arthritis. We provide further evidence to implicate the up-regulation of MMPs as a key factor in joint pathology.     

携带小鼠白细胞介素-12 siRNA基因重组腺病毒载体的构建及其在树突状细胞中的表达

目的:构建载有白细胞介素-12干扰RNA(IL-12si RNA)基因的,能在树突状细胞(DC)表达的重组腺病毒载体,为免疫耐受提供基础。方法:将IL-12p35si RNA和IL-12p40si RNAcDNA克隆于腺病毒穿梭质粒pShuttle2,得到重组质粒,并与腺病毒骨架质粒BD Adeno-XTM体外连接后代共转化大肠杆菌DH5α菌株,重组腺病毒质粒经过293细胞的包装扩增及氯化铯(CsCl)纯化,生成带有IL-12p35和IL-12p40si RNA基因的重组腺病毒载体,感染DC细胞。结果:经形态学、病毒DNA酶切、聚合酶链反应(PCR)和逆转录(RT)等方法的鉴定,证实了载体构建的正确性;经测定,病毒滴度为2.5×1010efu/ml。结论:成功构建带有IL-12p35si RNA和IL-12p40si RNAcDNA的重组腺病毒载体,其所携带的载体能够转染小鼠DC并干扰其在DC中表达,为进一步的研究奠定了基础。     

Chronic experimental colitis induced by dextran sulphate sodium (DSS) is characterized by Th1 and Th2 cytokines

Oral administration of DSS has been reported to induce an acute and chronic colitis in mice. The aim of our study was to evaluate if the chronic phase of DSS-induced colitis was characterized by a Th1/Th2 response and how this would relate to mucosal regeneration. Swiss Webster mice were fed 5% DSS in their drinking water for 7 days, followed by 2–5 weeks consumption of water. Control mice received only water. The animals were killed at 3 and 6 weeks after induction. Their colons were isolated for histology and immunohistochemistry, using specific MoAbs for T and B cells, macrophages, interferon-gamma (IFN-γ), IL-4 and IL-5. Colons were scored for inflammation, damage and regeneration. Two weeks after stopping DSS the colonic epithelium had only partially healed. Total colitis scores were still increased, especially in the distal colon, which was due to more inflammation, damage and less regeneration. In areas of incomplete colonic healing the basal parts of the lamina propria contained macrophages and CD4⁺ T cells. These CD4⁺ T cells showed a focal increase of IFN-γ and IL-4 staining compared with control animals. These findings were still observed 5 weeks after stopping DSS in some mice, albeit less extensive. Chronic DSS-induced colitis is characterized by focal epithelial regeneration and a Th1 as well as Th2 cytokine profile. We postulate that chronic immune activation mediated by both populations of Th cells can interfere with colonic healing and can play a role in the pathogenesis of chronic colitis.     

Increased lymphocyte trafficking to colonic microvessels is dependent on MAdCAM-1 and C-C chemokine mLARC/CCL20 in DSS-induced mice colitis

Although enhanced lymphocyte trafficking is associated with colitis formation, little information about its regulation is available. The aim of this study was to examine how the murine liver and activation-regulated chemokine (mLARC/CCL20) contributes to lymphocyte recruitment in concert with vascular adhesion molecules in murine chronic experimental colitis. T and B lymphocytes isolated from the spleen were fluorescence-labelled and administered to recipient mice. Lymphocyte adhesion to microvessels of the colonic mucosa and submucosa was observed with an intravital microscope. To induce colitis, the mice received two cycles of treatment with 2% dextran sodium sulphate (DSS). In some of the experiments antibodies against the adhesion molecules or anti-mLARC/CCL20 were administered, or CC chemokine receptor 6 (CCR6) of the lymphocytes was desensitized with excess amounts of mLARC/CCL20. Significant increases in T and B cell adhesion to the microvessels of the DSS-treated mucosa and submucosa were observed. In chronic colitis, the accumulation of lymphocytes was significantly inhibited by anti-mucosal addressin cell adhesion molecule (MAdCAM)-1 mAb, but not by anti-vascular cell adhesion molecule-1. In DSS-treated colonic tissue, the expression of mLARC/CCL20 was significantly increased, the blocking of mLARC/CCL20 by monoclonal antibody or the desensitization of CCR6 with mLARC/CCL20 significantly attenuated the DSS-induced T and B cell accumulation. However, the combination of blocking CCR6 with MAdCAM-1 did not further inhibit these accumulations. These results suggest that in chronic DSS-induced colitis, both MAdCAM-1 and mLARC/CCL20 may play important roles in T and B lymphocyte adhesion in the inflamed colon under flow conditions.     

Reduced intestinal inflammation induced by dextran sodium sulfate in interleukin-6-deficient mice

Interleukin-6 (IL-6) is a multifunctional cytokine secreted by various cells, and is involved in the acute phase response and the immune response through T and B cell activation. To further define the role of IL-6 in intestinal inflammation, we studied the effects of dextran sulfate sodium (DSS) administration in mice with targeted deletions of the IL-6 gene. Acute colitis was induced in female IL-6-/- and IL-6+/+ mice by giving 4.5% DSS orally in drinking water for 8 days. The colonic mucosal injury and inflammation was evaluated based on survival rate, body-weight changes, total colon length and histological findings. Colonic mRNA expression for tumor necrosis factor (TNF)-alpha, IL-6, IL-10 and inducible nitric oxide synthase (iNOS) was measured by RT-PCR. Colonic IL-6 mRNA levels of wild-type mice continued to increase throughout the study period. At each assessment, colonic injury was significantly attenuated in DSS-treated IL-6-/- mice compared with DSS-treated IL-6+/+ mice. Histological study also showed a reduced infiltration of inflammatory cells, especially neutrophils, and mucosal cell disruption in DSS-treated IL-6-/- mice compared with DSS-treated IL-6+/+ mice. In the colons of DSS-treated IL-6-/- mice, the expression of both TNF-alpha mRNA and iNOS mRNA was reduced on day 5. In contrast, IL-10 mRNA expression was enhanced compared with DSS-treated IL-6+/+ mice. In conclusion, DSS-induced inflammation appears to be significantly inhibited in IL-6-/- mice compared to wild-type mice. These data suggest that persistent and marked blockade of IL-6 bioactivity provides some beneficial effects on intestinal inflammation.     

Adenoviral transfer of murine oncostatin M elicits periosteal bone apposition in knee joints of mice,despite synovial inflammation and up-regulated expression of interleukin-6 and receptor activator of nuclear factor-kappa B ligand

Oncostatin M (OSM) has been described as a bone-remodeling factor either stimulating osteoblast activity or osteoclast formation in vitro. To elucidate the in vivo effect of OSM on bone remodeling, we injected an adenoviral vector encoding murine OSM in knee joints of mice. OSM strongly induced interleukin (IL)-6 gene expression, a known mediator of osteoclast development. We investigated the OSM effect in wild-type and IL-6-deficient mice and found a similar degree of OSM-induced joint inflammation. Within the first week of inflammation, the periosteum along the femur and tibia increased in cell number and stained positive for the osteoblast marker alkaline phosphatase. At these sites bone apposition occurred in both strains as demonstrated by Goldner and Von Kossa staining. In vitro OSM enhanced the effect of bone morphogenetic protein-2 on osteoblast differentiation. Immunohistochemistry demonstrated expression of receptor activator of nuclear factor-kappa B ligand (RANKL) and its receptor, receptor activator of nuclear factor-kappa B (RANK), in the periosteum but osteoclasts were not detected at sites of bone apposition. Induced mRNA expression for the receptor activator of nuclear factor-kappa B ligand inhibitor osteoprotegerin probably controlled osteoclast development during OSM overexpression. Our results show that OSM favors bone apposition at periosteal sites instead of resorption in vivo. This effect was not dependent on or inhibited by IL-6.     

Tapeworm infection reduces epithelial ion transport abnormalities in murine dextran sulfate sodium-induced colitis

The rat tapeworm Hymenolepis diminuta was used to test the hypothesis that helminth infection could modulate murine colitis. Mice were infected with five H. diminuta cysticercoids, and colitis was evoked via free access to 4% (wt/vol) dextran sulfate sodium (DSS)-containing drinking water for 5 days. BALB/c mice were either infected with H. diminuta and 7 days later exposed to DSS (prophylactic strategy) or started on DSS and infected with H. diminuta 48 h later (treatment strategy). Naive and H. diminuta-only-infected mice served as controls. On autopsy, colonic segments were processed for histological examination and myeloperoxidase (MPO) measurement or mounted in Ussing chambers for assessment of epithelial ion transport. Cytokines (gamma interferon [IFN-gamma], interleukin 12 [IL-12], and IL-10) were measured in serum and colonic tissue homogenates. DSS treatment resulted in reduced ion responses (indicated by short-circuit current [Isc]) to electrical nerve stimulation, the cholinergic agonist carbachol, and the adenylate cyclase activator forskolin compared to controls. H. diminuta infection, either prophylactic or therapeutic, caused a significant (P < 0.05) amelioration of these DSS-induced irregularities in stimulated ion transport. In contrast, the histopathology (i.e., mixed immune cell infiltrate, edema, and ulcerative damage) and elevated MPO levels that accompany DSS colitis were unaffected by concomitant H. diminuta infection. Similarly, there were no significant differences in levels of IFN-gamma, IL-12, or IL-10 in serum or tissue from any of the treatment groups at the time of autopsy. We suggest that abolishment of colitis-induced epithelial ion transport abnormalities by H. diminuta infection provides proof-of-principle data and speculate that helminth therapy may provide relief of disease symptoms in colitis.     

Fucoidan derived from Cladosiphon okamuranus Tokida ameliorates murine chronic colitis through the down-regulation of interleukin-6 production on colonic epithelial cells

Our previous study indicated that the interleukin (IL)-6/STAT-3 signal was up-regulated in inflammatory bowel disease (IBD) in both humans and animal models. We also discovered phosphorylated STAT-3 in the nucleus of the colonic epithelial cells in IBD mice. Intestinal epithelial cells (IEC) have been shown to secrete IL-6. Therefore, the secretion of IL-6 from IEC may be one of the mechanisms of STAT-3 phosphorylation in IEC during the pathogenesis of IBD, and inhibition of IL-6 production by IEC may be beneficial in preventing IBD. We examined the preventative effect of various types of fucoidans on IL-6 production in a lipopolysaccharide (LPS)-stimulated murine colonic epithelial cells line, CMT-93, in vitro. We also determined in vivo the effect of fucoidans on murine chronic colitis induced with dextran sodium sulphate. Among fucoidans, those from Cladosiphon okamuranus Tokida and Kjellmaniella crassifolia inhibited IL-6 production in CMT-93 cells with the down-regulation of NF-kappaB nuclear translocation. Analysis of the effect of fucoidan on murine colitis in vivo showed that the disease activity index and myeloperoxidase activity decreased in mice fed Cladosiphon fucoidan, but not Fucus fucoidan. Cytokine profiles in colonic lamina propria indicated that the synthesis of interferon (IFN)-gamma and IL-6 decreased and that of IL-10 and transforming growth factor (TGF)-beta increased in mice fed Cladosiphon fucoidan, compared with mice fed a standard diet or Fucus fucoidan. The levels of IL-6 mRNA in colonic epithelial cells was lower in colitis-induced Balb/c mice fed Cladosiphon fucoidan than those fed a standard diet. Fucoidan improves murine chronic colitis by down-regulating the synthesis of IL-6 in the colonic epithelial cells. Fucoidan derived from C. o. Tokida may be useful as a dietary substance for the patients with inflammatory bowel disease.     

Regulatory T-cell depletion in the gut caused by integrin β7 deficiency exacerbates DSS colitis by evoking aberrant innate immunity

Integrin α₄β₇ controls lymphocyte trafficking into the gut and has essential roles in inflammatory bowel disease (IBD). The α₄β₇-blocking antibody vedolizumab is approved for IBD treatment; however, high dose of vedolizumab aggravates colitis in a small percentage of patients. Herein, we show that integrin β₇ deficiency results in colonic regulatory T (Treg) cell depletion and exacerbates dextran sulfate sodium (DSS) colitis by evoking aberrant innate immunity. In DSS-treated β₇-deficient mice, the loss of colonic Treg cells induces excessive macrophage infiltration in the colon via upregulation of colonic epithelial intercellular adhesion molecule 1 and increases proinflammatory cytokine expression, thereby exacerbating DSS-induced colitis. Moreover, reconstitution of the colonic Treg cell population in β₇-deficient mice suppresses aberrant innate immune response in the colon and attenuates DSS colitis. Thus, integrin α₄β₇ is essential for suppression of DSS colitis as it regulates the colonic Treg cell population and innate immunity.     

T-Cell Activation and Differentiation Are Regulated by TNF During Murine DBA/2 → B6D2F1 Intestinal Graft-Versus-Host Disease

Administration of a tumor necrosis factor (TNF) inhibitor-encoding adenoviral vector decreases the severity of colonic inflammation in a DBA/2B6D2F1 murine model of colonic graft-versus-host disease (GVHD). The present studies evaluated the effect of TNF blockade on the splenic and colonic T-cell responses. cDNA encoding an artificial fusion protein consisting of the extracellular domain of the human 55-kDa receptor for TNF fused to a mouse IgG heavy chain was subcloned into an E1a-deficient adenoviral vector. Following transfer of DBA/2 T cells and bone marrow cells into irradiated B6D2F1 mice, the mice then received either the control adenovirus or the TNF inhibitor-encoding adenovirus. Splenic and colonic lymphocytes were isolated, stained with anti-H-2^b, anti-H-2^d, anti-CD3, anti-CD4, anti-CD8, and anti-CD45RB antibodies, and analyzed by flow cytometry. Splenic and colonic lymphocyte cytokine profiles also were assessed. More colonic T cells of donor origin were isolated from the control adenovirus recipients than from recipients of the TNF inhibitor encoding adenovirus (P = .027). Fewer CD4⁺ and CD8⁺ T cells were observed in colon but not in the spleen in the TNF inhibitor recipients. Fewer CD45RB^low(memory) T cells were observed in the CD4⁺ colonic lymphocytes isolated from the TNF inhibitor recipients than from controls. Importantly, lower levels of interleukin-2(IL-2) and interferon-gamma (INF-) but not of IL-4 were observed in the lamina propria lymphocyte RNA isolated from the TNF inhibitor recipients. Infiltration and expansion of donor T cells and T-cell activation in the colon appear to be regulated by TNF during murine DBA/2 B6D2F1 gut GVHD.     

The free radical scavengers edaravone and tempol suppress experimental dextran sulfate sodium-induced colitis in mice

Recent studies have suggested that the enhanced release of reactive oxygen species (ROS) plays an important role in the pathogenesis of clinical inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn's disease. In the present study, we investigated the effects of the free radical scavengers edaravone and tempol in the development of experimental dextran sulfate sodium (DSS)-induced colitis in mice. Male BALB/cA mice were fed 4% (w/w of diet) DSS in standard powder chow for 8 days. Edaravone, tempol, or vehicle saline were then injected subcutaneously twice per day. After the experimental period, the colonic length, histological damage score, and mucosal myeloperoxidase (MPO) and serum interleukin-6 (IL-6) levels were measured. Edaravone (15 mg/kg/day) and tempol (5-15 mg/kg/day) suppressed the colonic shortening and the damage score. In particular, tempol at 15 mg/kg/day significantly attenuated the colonic shortening and damage score. Edaravone and tempol suppressed the serum IL-6 levels, and significantly suppressed the increased colonic MPO levels. These results strongly support the involvement of ROS in the pathogenesis of DSS-induced colitis. A clinical effect for edaravone and tempol in IBD patients is strongly expected.     

Non-hematopoietic STAT6 induces epithelial tight junction dysfunction and promotes intestinal inflammation and tumorigenesis

Enhanced gut permeability due to dysregulated epithelial tight junction is often associated with inflammatory bowel diseases (IBD), which have a greater risk for developing colorectal cancer. STAT6 activation was detected in inflamed colonic epithelium of active IBD patients, suggesting a role of epithelial STAT6 in colitis development. Here, we demonstrated that non-hematopoietic STAT6, but not hematopoietic STAT6, triggered DSS-induced colitis and subsequent tumorigenesis. This could be due to the enhancing-effect of STAT6 on gut permeability and microbiota translocation via interruption of epithelial tight junction integrity. Mechanistically, long-myosin light-chain kinase (MLCK1) was identified as a target of STAT6, leading to epithelial tight junction dysfunction and microbiota-driven colitis. Furthermore, neutralization of IL-13, which was primarily derived from type 2 innate lymphoid cells (ILC2) in a microbiota-dependent way, inhibited epithelial STAT6 activation and improved gut permeability and DSS-induced colitis. Importantly, pharmacological inhibition of STAT6 reduces murine intestinal tumor formation, and tumoral p-STAT6 levels positively correlated to the clinical stage and poor prognosis of human colorectal cancer. Thus, our study reveals a direct role of STAT6 in the disruption of epithelial tight junction integrity and colitis development, and suggests STAT6 as a potential therapeutic and prophylactic target for IBD and colitis-associated cancer.