Impairment Of Intestinal Epithelial Barrier Research Articles

Oral d-ribose causes depressive-like behavior by altering glycerophospholipid metabolism via the gut-brain axis

Our previous work has shown that d-ribose (RIB)-induced depressive-like behaviors in mice. However, the relationship between variations in RIB levels and depression as well as potential RIB participation in depressive disorder is yet unknown. Here, a reanalysis of metabonomics data from depressed patients and depression model rats is performed to clarify whether the increased RIB level is positively correlated with the severity of depression. Moreover, we characterize intestinal epithelial barrier damage, gut microbial composition and function, and microbiota-gut-brain metabolic signatures in RIB-fed mice using colonic histomorphology, 16 S rRNA gene sequencing, and untargeted metabolomics analysis. The results show that RIB caused intestinal epithelial barrier impairment and microbiota-gut-brain axis dysbiosis. These microbial and metabolic modules are consistently enriched in peripheral (fecal, colon wall, and serum) and central (hippocampus) glycerophospholipid metabolism. In addition, three differential genera (Lachnospiraceae_UCG-006, Turicibacter, and Akkermansia) and two types of glycerophospholipids (phosphatidylcholine and phosphatidylethanolamine) have greater contributions to the overall correlations between differential genera and glycerophospholipids. These findings suggest that the disturbances of gut microbiota by RIB may contribute to the onset of depressive-like behaviors via regulating glycerophospholipid metabolism, and providing new insight for understanding the function of microbiota-gut-brain axis in depression.

Curcumin suppresses the Wnt/β-catenin signaling pathway by inhibiting NKD2 methylation to ameliorate intestinal ischemia/reperfusion injury.

Intestinal ischemia/reperfusion (I/R) injury is a life-threatening condition with no effective treatment currently available. Curcumin (CCM), a polyphenol compound in Curcuma Longa, reportedly has positive effects against intestinal I/R injury. However, the mechanism underlying the protective effect of CCM against intestinal I/R injury has not been fully clarified. To determine whether the protective effect of CCM was mediated by epigenetic effects on Wnt/β-catenin signaling, the effect of CCM was examined in vivo and in vitro. An intestinal I/R model was established in Sprague-Dawley (SD) rats with superior mesenteric artery occlusion, and Caco-2 cells were subjected to hypoxia/reoxygenation (H/R) for in vivo simulation of I/R. The results showed that CCM significantly reduced inflammatory, cell apoptosis, and oxidative stress induced by I/R insult in vivo and in vitro. Western blot analysis showed that CCM preconditioning reduced the protein levels of β-catenin, p-GSK3β, and cyclin-D1 and increased the protein level of GSK3β compared with the I/R group. Overexpressing β-catenin aggravated H/R injury, and knocking down β-catenin relieved H/R injury by improving intestinal permeability and reducing the cell apoptosis. Moreover, Naked cuticle homolog 2(NKD2) mRNA and protein levels were upregulated in the CCM-pretreated group. 5-aza-2'-deoxycytidine (5-AZA) treatment improved intestinal epithelial barrier impairment induced by H/R. Besides, the protein levels of total β-catenin, phosphor-β-catenin and cyclin-D1 were reduced after overexpressing NKD2 in Caco-2 cells following H/R insult. In conclusion, Our study suggests that CCM could attenuate intestinal I/R injury in vitro and in vivo by suppressing the Wnt/β-catenin signaling pathway via inhibition of NKD2 methylation.

Baicalin mitigates hypertension-linked alterations in the intestinal lymphatic vasculature in part through preserving the functional barrier integrity of lymphatic endothelial cells

Intestinal epithelial barrier impairment serves as an important link between hypertension and systemic inflammation. However, it remains unknown if hypertension is associated with lymphatic alterations in the intestine. Our previous work has demonstrated that baicalin, a naturally occurring anti-inflammatory flavonoid, attenuates intestinal epithelial barrier impairment and inflammation in spontaneously hypertensive rats. The impact of baicalin on hypertension-associated intestinal lymphatic alterations, if present, remains to be investigated too. To address these questions, in vivo and in vitro studies were performed in angiotensin II (ang II)-induced hypertensive mice and ang II-stimulated lymphatic endothelial cells, respectively. The results revealed that ang II infusion led to pronounced dilation of the lacteals and expansion of the lymphatic vasculature in the submucosal layer and muscularis externa in the ilium. Meanwhile, the intestinal lymphatics are overtly leaky in the ang II-infused mice. Although losartan, an ang II type 1 receptor blocker, normalized the blood pressure, it failed to mitigate hypertension-linked intestinal lymphatic alterations. However, baicalin treatment protected against intestinal lymphatic alterations, preserved intestinal epithelial barrier integrity and lowered the serum level of Il6 in the ang II-infused mice. Furthermore, baicalin directly antagonized ang II-induced proliferation, migration, decline in the barrier function and disruption of the tight junction integrity in lymphatic endothelial cells. In conclusion, the work here suggests that intestinal lymphatic alterations may serve as a new component of hypertension-linked leaky gut pathologies. Most importantly, baicalin attenuates hypertension-associated intestinal lymphatic alterations in part by directly counteracting ang II-induced functional barrier impairment in lymphatic endothelial cells.

Interleukin-37 exacerbates experimental colitis in an intestinal microbiome-dependent fashion.

Background: Inflammatory bowel disease (IBD) involves complicated crosstalk between host immunity and the gut microbiome, whereas the mechanics of how they govern intestinal inflammation remain poorly understood. In this study, we investigated the contribution of environmental factors to shaping gut microbiota composition in colitis mice that were transgenic for human IL-37, a natural anti-inflammatory cytokine possessing pathogenic and protective functions related to microbiota alterations.Methods: Mice transgenic expressing human IL-37 (IL-37tg) were housed under conventional and specific pathogen-free (SPF) conditions to develop a mouse model of dextran sulfate sodium (DSS)-induced colitis. 16S ribosomal RNA sequencing was used for analyzing fecal microbial communities. The efficacy of microbiota in the development of colitis in IL-37tg mice was investigated after antibiotic treatment and fecal microbiota transplantation (FMT). The mechanism by which IL-37 worsened colitis was studied by evaluating intestinal epithelial barrier function, immune cell infiltration, the expression of diverse cytokines and chemokines, as well as activated signaling pathways.Results: We found that IL-37 overexpression aggravated DSS-induced colitis in conventional mice but protected against colitis in SPF mice. These conflicting results from IL-37tg colitis mice are ascribed to a dysbiosis of the gut microbiota in which detrimental bacteria increased in IL-37tg conventional mice. We further identified that the outcome of IL-37-caused colon inflammation is strongly related to intestinal epithelial barrier impairment caused by pathogenic bacteria, neutrophils, and NK cells recruitment in colon lamina propria and mesenteric lymph node to enhance inflammatory responses in IL-37tg conventional mice.Conclusions: The immunoregulatory properties of IL-37 are detrimental in the face of dysbiosis of the intestinal microbiota, which contributes to exacerbated IBD occurrences that are uncontrollable by the immune system, suggesting that depleting gut pathogenic bacteria or maintaining intestinal microbial and immune homeostasis could be a promising therapeutic strategy for IBD.

Renovation of Intestinal Barrier by Polydatin in Experimentally Induced Ulcerative Colitis: Comparative Ultrastructural Study with L-Carnosine

Ulcerative colitis (UC) is a chronic inflammatory bowel disease associated with intestinal epithelial barrier impairment. Polydatin (PD), a natural product isolated from Polygonum cuspidatum, is known to have an anti-inflammatory, antioxidant, and antiapoptotic effect. We attempted to compare the protective impact of PD pretreatment on alterations to the intestinal epithelial barrier and the colonic wall’s ultrastructure accompanying ulcerative colitis to other conventional drugs in practice, primarily L-carnosine, which has not been addressed before. The rats were divided into 5 groups; 3 of them were treated with sulphasalazine (500 mg/kg), L-carnosine (30 mg/kg), and PD (45 mg/kg). All groups were administered their respective drugs 3 days before the UC was induced by acetic acid intra-rectally, and the treatment was continued until the 11th day. The disease activity index (DAI) was estimated, and a macroscopic scoring was established for the harvested colonic tissue. The tissues were extracted and processed for hematoxylin and eosin staining, caspase-3 immunohistochemical staining, electron microscopy, and biochemical analysis evaluating proinflammatory markers (IL-1β, TNF-α, and IL-6), myeloperoxidase (MPO), oxidative stress, and lipid peroxidation. Histopathological examination of colonic tissue showed that PD pretreatment effectively restored mucosal epithelial cells, intercellular tight junctions, goblet cells, and maintained the intestinal epithelial and endothelial barriers. PD suppressed MPO, proinflammatory markers, and malondialdehyde but enhanced superoxide dismutase and glutathione levels. It also hampered apoptosis, as evidenced by a reduction in caspase-3 expression. PD showed a significantly better response in preserving the intestinal epithelial barrier against acetic acid-induced colitis as compared to sulphasalazine and L-carnosine. These findings demonstrate the therapeutic role of PD for patients with UC.

Administration of Lactobacillus reuteri Combined with Clostridium butyricum Attenuates Cisplatin-Induced Renal Damage by Gut Microbiota Reconstitution, Increasing Butyric Acid Production, and Suppressing Renal Inflammation.

Cisplatin-induced nephrotoxicity is associated with gut microbiota disturbance. The present study aimed to investigate whether supplementation of Lactobacillus reuteri and Clostridium butyricum (LCs) had a protective effect on cisplatin-induced nephrotoxicity through reconstruction of gut microbiota. Wistar rats were given different treatments: control, cisplatin (Cis), cisplatin + C. butyricum and L. reuteri (Cis+LCs), and C. butyricum and L. reuteri (LCs). We observed that cisplatin-treated rats supplemented with LCs exhibited significantly decreased renal inflammation (KIM-1, F4/80, and MPO), oxidative stress, fibrosis (collagen IV, fibronectin, and a-SMA), apoptosis, concentration of blood endotoxin and indoxyl sulfate, and increased fecal butyric acid production compared with those without supplementation. In addition, LCs improved the cisplatin-induced microbiome dysbiosis by maintaining a healthy gut microbiota structure and diversity; depleting Escherichia-Shigella and the Enterobacteriaceae family; and enriching probiotic Bifidobacterium, Ruminococcaceae, Ruminiclostridium_9, and Oscillibacter. Moreover, the LCs intervention alleviated the cisplatin-induced intestinal epithelial barrier impairment. This study indicated LCs probiotic serves as a mediator of the gut–kidney axis in cisplatin-induced nephrotoxicity to restore the intestinal microbiota composition, thereby suppressing uremic toxin production and enhancing butyrate production. Furthermore, the renoprotective effect of LCs is partially mediated by increasing the anti-inflammatory effects and maintaining the integrity of the intestinal barrier.

Plumericin Protects against Experimental Inflammatory Bowel Disease by Restoring Intestinal Barrier Function and Reducing Apoptosis.

Intestinal epithelial barrier impairment plays a key pathogenic role in inflammatory bowel diseases (IBDs). In particular, together with oxidative stress, intestinal epithelial barrier alteration is considered as upstream event in ulcerative colitis (UC). In order to identify new products of natural origin with a potential activity for UC treatment, this study evaluated the effects of plumericin, a spirolactone iridoid, present as one of the main bioactive components in the bark of Himatanthus sucuuba (Woodson). Plumericin was evaluated for its ability to improve barrier function and to reduce apoptotic parameters during inflammation, both in intestinal epithelial cells (IEC-6), and in an animal experimental model of 2, 4, 6-dinitrobenzene sulfonic acid (DNBS)-induced colitis. Our results indicated that plumericin increased the expression of adhesion molecules, enhanced IEC-6 cells actin cytoskeleton rearrangement, and promoted their motility. Moreover, plumericin reduced apoptotic parameters in IEC-6. These results were confirmed in vivo. Plumericin reduced the activity of myeloperoxidase, inhibited the expression of ICAM-1, P-selectin, and the formation of PAR, and reduced apoptosis parameters in mice colitis induced by DNBS. These results support a pharmacological potential of plumericin in the treatment of UC, due to its ability to improve the structural integrity of the intestinal epithelium and its barrier function.

Ascorbate exacerbates iron toxicity on intestinal barrier function against Salmonella infection

Ascorbic acid is often used to enhance iron absorption in nutritional interventions, but it produces pro-oxidant effects in the presence of iron. This study aimed to evaluate ascorbate’s role in iron toxicity on intestinal resistance against foodborne pathogens during iron supplementation/fortification. In polarized Caco-2 cell monolayers, compared to the iron-alone treatment, the iron-ascorbate co-treatment caused more than 2-fold increase in adhesion, invasion and translocation of Salmonella enterica serovar Typhimurium. According to 3-(4,5-dimethylthiazol-2-yl)−2,5-diphenyltetrazolium bromide assay, lactate dehydrogenase release and transepithelial electrical resistance, the iron-ascorbate co-treatment resulted in reduced cell viability and increased impairment of cell membrane and paracellular permeability compared to the iron-alone treatment. Butylated hydroxytoluene protected cells against these prooxidant toxicities of ascorbate. Ascorbate completely restored iron-induced intracellular oxidant burst and depletion of cytosolic antioxidant reserve, according to dichlorodihydrofluorescein fluorescence and intracellular reduced glutathione levels. In Salmonella-infected C57BL/6 mice, iron-ascorbate co-supplementation resulted in greater loss of body weight and appetite, lower survival rate, shorter colon length, heavier intestinal microvilli damage, and more intestinal pathogen colonization and translocation than the iron-alone supplementation. Overall, ascorbate would exacerbate iron toxicity on intestinal resistance against Salmonella infection through pro-oxidant impairment of intestinal epithelial barrier from extracellular side and/or by facilitating intestinal pathogen colonization.

Dietary fructose-induced gut dysbiosis promotes mouse hippocampal neuroinflammation: a benefit of short-chain fatty acids

BackgroundWestern-style diets arouse neuroinflammation and impair emotional and cognitive behavior in humans and animals. Our previous study showed that a high-fructose diet caused the hippocampal neuroinflammatory response and neuronal loss in animals, but the underlying mechanisms remained elusive. Here, alterations in the gut microbiota and intestinal epithelial barrier were investigated as the causes of hippocampal neuroinflammation induced by high-fructose diet.ResultsA high-fructose diet caused the hippocampal neuroinflammatory response, reactive gliosis, and neuronal loss in C57BL/6N mice. Depletion of the gut microbiota using broad-spectrum antibiotics suppressed the hippocampal neuroinflammatory response in fructose-fed mice, but these animals still exhibited neuronal loss. Gut microbiota compositional alteration, short-chain fatty acids (SCFAs) reduction, intestinal epithelial barrier impairment, NOD-like receptor family pyrin domain-containing 6 (NLRP6) inflammasome dysfunction, high levels of serum endotoxin, and FITC-dextran were observed in fructose-fed mice. Of note, SCFAs, as well as pioglitazone (a selective peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist), shaped the gut microbiota and ameliorated intestinal epithelial barrier impairment and NLRP6 inflammasome dysfunction in fructose-fed mice. Moreover, SCFAs-mediated NLRP6 inflammasome activation was inhibited by histamine (a bacterial metabolite) in ex vivo colonic explants and suppressed in murine CT26 colon carcinoma cells transfected with NLRP6 siRNA. However, pioglitazone and GW9662 (a PPAR-γ antagonist) exerted no impact on SCFAs-mediated NLRP6 inflammasome activation in ex vivo colonic explants, suggesting that SCFAs may stimulate NLRP6 inflammasome independently of PPAR-γ activation. SCFAs and pioglitazone prevented fructose-induced hippocampal neuroinflammatory response and neuronal loss in mice. Additionally, SCFAs activated colonic NLRP6 inflammasome and increased DCX+ newborn neurons in the hippocampal DG of control mice.ConclusionsOur findings reveal that gut dysbiosis is a critical factor for a high-fructose diet-induced hippocampal neuroinflammation in C57BL/6N mice possibly mediated by impairing intestinal epithelial barrier. Mechanistically, the defective colonic NLRP6 inflammasome is responsible for intestinal epithelial barrier impairment. SCFAs can stimulate NLRP6 inflammasome and ameliorate the impairment of intestinal epithelial barrier, resulting in the protection against a high-fructose diet-induced hippocampal neuroinflammation and neuronal loss. This study addresses a gap in the understanding of neuronal injury associated with Western-style diets. A new intervention strategy for reducing the risk of neurodegenerative diseases through SCFAs supplementation or dietary fiber consumption is emphasized.

The effects of lower thoracic epidural blockade on intestinal epithelial barrier and activation of enteric glial cells in rats with hemorrhagic shock and resuscitation

Objective To investigate the effects of lower thoracic epidural blockade on integrity of intestinal epithelial barrier(IEB) and activation of enteric glial cell(EGC) in rats with hemorrhagic shock and resuscitation. Methods Seventy-two SD rats with epidural catheterization according to a modified method described by Bahar et al. were randomly divided into four groups with 18 in each group: sham group(group S), control group(group C), normal saline group(group N) and thoracic epidural blockade group(group T). In group S, rats were just received vascular cannulation, whereas the rats in other groups were subjected to hemorrhagic shock and resuscitation with normal saline according to the modified method described by Wiggers. Thirty minutes before bleeding, either 0.075% ropivacaine(group T) or normal saline(group N) 100 μl/kg was infused through thoracic epidural catheters. The survival rates of rats in 72 h after resuscitation were evaluated. The MAP and HR were monitored after vascular cannulation(T0), 30 min after epidural infusion(T1), 30 min of shock(T2), 60 min of shock(T3), 30 min and 60 min after resuscitation(T4 and T5 respectively). Arterial blood samples were collected for blood gas analysis at T0, T3 and T5. At 3 h following resuscitation, the severity of intestinal edema, the pathological changes of intestinal mucosa, and the function of IEB were evaluated by wet/dry ratio(W/D), Chiu's score, and lipopolysaccharide(LPS) concentrations in the portal vein, respectively. The expression of Occludin and glial fibrillary acidic protein(GFAP), a marker of EGCs, were determined by western blot. Results Compared with group C and group N, the survival rates and median survival time of group T were significantly promoted (P<0.05), While MAP and HR decreased at T4 and T5, the levels of pH and lactic acid at T3 and T5 were alleviated (P<0.05). Besides these, in group T, the levels of W/D, Chiu's score and LPS were decreased while the expression of Occludin and GFAP were increased significantly in comparison with group C and group N(P<0.05). Conclusions Lower thoracic epidural blockade attenuates IEB impairment induced by hemorrhagic shock and resuscitation in rats, alleviating internal environment disturbance and thus promoting survival rates after resuscitation, whose mechanism is related to activation of EGC. Key words: Thoracic epidural blockade; Hemorrhagic shock; Resuscitation; Intestinal epithelial barrier; Enteric glial cell

Metformin Improves Ileal Epithelial Barrier Function in Interleukin-10 Deficient Mice.

Background and aimsThe impairment of intestinal epithelial barrier is the main etiologic factor of inflammatory bowel disease. The proper intestinal epithelial proliferation and differentiation is crucial for maintaining intestinal integrity. Metformin is a common anti-diabetic drug. The objective is to evaluate the protective effects of metformin on ileal epithelial barrier integrity using interleukin-10 deficient (IL10KO) mice.MethodsWild-type and IL10KO mice were fed with/without metformin for 6 weeks and then ileum was collected for analyses. The mediatory role of AMP-activated protein kinase (AMPK) was further examined by gain and loss of function study in vitro.ResultsCompared to wild-type mice, IL10KO mice had increased proliferation, reduced goblet cell and Paneth cell lineage differentiation in the ileum tissue, which was accompanied with increased crypt expansion. Metformin supplementation mitigated intestinal cell proliferation, restored villus/crypt ratio, increased goblet cell and Paneth cell differentiation and improved barrier function. In addition, metformin supplementation in IL10KO mice suppressed macrophage pro-inflammatory activity as indicated by reduced M1 macrophage abundance and decreased pro-inflammatory cytokine IL-1β, TNF-α and IFN-γ expressions. As a target of metformin, AMPK phosphorylation was enhanced in mice treated with metformin, regardless of mouse genotypes. In correlation, the mRNA level of differentiation regulator including bmp4, bmpr2 and math1 were also increased in IL10KO mice supplemented with metformin, which likely explains the enhanced epithelial differentiation in IL10KO mice with metformin. Consistently, in Caco-2 cells, metformin promoted claudin-3 and E-cadherin assembly and mitigated TNF-α-induced fragmentation of tight junction proteins. Gain and loss of function assay also demonstrated AMPK was correlated with epithelial differentiation and proliferation.ConclusionsMetformin supplementation promotes secretory cell lineage differentiation, suppresses inflammation and improves epithelial barrier function in IL10KO mice likely through activation of AMPK, showing its beneficial effects on gut epithelial.

Faecalibacterium prausnitzii prevents physiological damages in a chronic low-grade inflammation murine model.

BackgroundThe human gut houses one of the most complex and abundant ecosystems composed of up to 1013-1014 microorganisms. The importance of this intestinal microbiota is highlighted when a disruption of the intestinal ecosystem equilibrium appears (a phenomenon called dysbiosis) leading to an illness status, such as inflammatory bowel diseases (IBD). Indeed, the reduction of the commensal bacterium Faecalibacterium prausnitzii (one of the most prevalent intestinal bacterial species in healthy adults) has been correlated with several diseases, including IBD, and most importantly, it has been shown that this bacterium has anti-inflammatory and protective effects in pre-clinical models of colitis. Some dysbiosis disorders are characterized by functional and physiological alterations. Here, we report the beneficial effects of F. prausnitzii in the physiological changes induced by a chronic low-grade inflammation in a murine model. Chronic low-grade inflammation and gut dysfunction were induced in mice by two episodes of dinitro-benzene sulfonic acid (DNBS) instillations. Markers of inflammation, gut permeability, colonic serotonin and cytokine levels were studied. The effects of F. prausnitzii strain A2-165 and its culture supernatant (SN) were then investigated.ResultsNo significant differences were observed in classical inflammation markers confirming that inflammation was subclinical. However, gut permeability, colonic serotonin levels and the colonic levels of the cytokines IL-6, INF-γ, IL-4 and IL-22 were higher in DNBS-treated than in untreated mice. Importantly, mice treated with either F. prausnitzii or its SN exhibited significant decreases in intestinal permeability, tissue cytokines and serotonin levels.ConclusionsOur results show that F. prausnitzii and its SN had beneficial effects on intestinal epithelial barrier impairment in a chronic low-grade inflammation model. These observations confirm the potential of this bacterium as a novel probiotic treatment in the management of gut dysfunction and low-grade inflammation.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-015-0400-1) contains supplementary material, which is available to authorized users.

Stress disrupts intestinal mucus barrier in rats via mucin O-glycosylation shift: prevention by a probiotic treatment.

Despite well-known intestinal epithelial barrier impairment and visceral hypersensitivity in irritable bowel syndrome (IBS) patients and IBS-like models, structural and physical changes in the mucus layer remain poorly understood. Using a water avoidance stress (WAS) model, we aimed at evaluating whether 1) WAS modified gut permeability, visceral sensitivity, mucin expression, biochemical structure of O-glycans, and related mucus physical properties, and 2) whether Lactobacillus farciminis treatment prevented these alterations. Wistar rats received orally L. farciminis or vehicle for 14 days; at day 10, they were submitted to either sham or 4-day WAS. Intestinal paracellular permeability and visceral sensitivity were measured in vivo. The number of goblet cells and Muc2 expression were evaluated by histology and immunohistochemistry, respectively. Mucosal adhesion of L. farciminis was determined ex situ. The mucin O-glycosylation profile was obtained by mass spectrometry. Surface imaging of intestinal mucus was performed at nanoscale by atomic force microscopy. WAS induced gut hyperpermeability and visceral hypersensitivity but did not modify either the number of intestinal goblet cells or Muc2 expression. In contrast, O-glycosylation of mucins was strongly affected, with the appearance of elongated polylactosaminic chain containing O-glycan structures, associated with flattening and loss of the mucus layer cohesive properties. L. farciminis bound to intestinal Muc2 and prevented WAS-induced functional alterations and changes in mucin O-glycosylation and mucus physical properties. WAS-induced functional changes were associated with mucus alterations resulting from a shift in O-glycosylation rather than from changes in mucin expression. L. farciminis treatment prevented these alterations, conferring epithelial and mucus barrier strengthening.

Matrix metalloproteinase 13 modulates intestinal epithelial barrier integrity in inflammatory diseases by activating TNF

Several pathological processes, such as sepsis and inflammatory bowel disease (IBD), are associated with impairment of intestinal epithelial barrier. Here, we investigated the role of matrix metalloproteinase MMP13 in these diseases. We observed that MMP13−/− mice display a strong protection in LPS- and caecal ligation and puncture-induced sepsis. We could attribute this protection to reduced LPS-induced goblet cell depletion, endoplasmic reticulum stress, permeability and tight junction destabilization in the gut of MMP13−/− mice compared to MMP13+/+ mice. Both in vitro and in vivo, we found that MMP13 is able to cleave pro-TNF into bioactive TNF. By LC-MS/MS, we identified three MMP13 cleavage sites, which proves that MMP13 is an alternative TNF sheddase next to the TNF converting enzyme TACE. Similarly, we found that the same mechanism was responsible for the observed protection of the MMP13−/− mice in a mouse model of DSS-induced colitis. We identified MMP13 as an important mediator in sepsis and IBD via the shedding of TNF. Hence, we propose MMP13 as a novel drug target for diseases in which damage to the gut is essential.