An orally active matrix metalloproteinase inhibitor, ONO-4817, reduces dextran sulfate sodium-induced colitis in mice

The proteolytic activity in inflammatory bowel disease: insight from gut microbiota

Inflammatory bowel disease (IBD) is a chronic, recurrent inflammatory disease caused by the destruction of the intestinal mucosal epithelium that affects a growing number of people worldwide. Although the etiology of IBD is complex and still elucidated, the role of dysbiosis and dysregulated proteolysis is well recognized. Various studies observed altered composition and diversity of gut microbiota, as well as increased proteolytic activity (PA) in serum, plasma, colonic mucosa, and fecal supernatant of IBD compared to healthy individuals. The imbalance of intestinal microecology and intestinal protein hydrolysis were gradually considered to be closely related to IBD. Notably, the pivotal role of intestinal microbiota in maintaining proteolytic balance received increasing attention. In summary, we have speculated a mesmerizing story, regarding the hidden role of PA and microbiota-derived PA hidden in IBD. Most importantly, we provided the diagnosis and therapeutic targets for IBD as well as the formulation of new treatment strategies for other digestive diseases and protease-related diseases.

Transabdominal ultrasound alleviates LPS-induced neuroinflammation by modulation of TLR4/NF-κB signaling and tight junction protein expression

AIM

Inflammatory bowel disease (IBD) may be a risk factor in the development of brain inflammation. It has been demonstrated noninvasive neuromodulation through sub-organ ultrasound stimulation. The purpose of this study was to investigate whether abdominal low-intensity pulsed ultrasound (LIPUS) alleviates lipopolysaccharide (LPS)-induced cortical inflammation via inhibition of colonic inflammation.

MATERIALS AND METHODS

Colonic and cortical inflammation was induced in mice by LPS (0.75 mg/kg, i.p. injection) for 7 days, followed by application of LIPUS (0.5 and 1.0 W/cm²) to the abdominal area for 6 days. Biological samples were collected for Western blot analysis, gelatin zymography, colon length measurement, and histological evaluation.

KEY FINDINGS

LIPUS treatment significantly attenuated LPS-induced increases in IL-6, IL-1β, COX-2, and cleaved caspase-3 expression in the colon and cortex of mice. Moreover, LIPUS significantly increased the levels of tight junction proteins in the epithelial barrier in the mouse colon and cortex with LPS-induced inflammation. Compared to the group treated only with LPS, the LIPUS-treated groups showed decreased muscle thickness and increased crypt length and colon length. Furthermore, LIPUS treatment reduced inflammation by inhibiting the LPS-induced activation of TLR4/NF-κB inflammatory signaling in the brain.

SIGNIFICANCE

We found that LIPUS alleviated LPS-induced colonic and cortical inflammation through abdominal stimulation of mice. These results suggest that abdominal LIPUS stimulation may be a novel therapeutic strategy against neuroinflammation via enhancement of tight junction protein levels and inhibition of inflammatory responses in the colon.

Chalcones and Gastrointestinal Cancers: Experimental Evidence

Colorectal (CRC) and gastric cancers (GC) are the most common digestive tract cancers with a high incidence rate worldwide. The current treatment including surgery, chemotherapy or radiotherapy has several limitations such as drug toxicity, cancer recurrence or drug resistance and thus it is a great challenge to discover an effective and safe therapy for CRC and GC. In the last decade, numerous phytochemicals and their synthetic analogs have attracted attention due to their anticancer effect and low organ toxicity. Chalcones, plant-derived polyphenols, received marked attention due to their biological activities as well as for relatively easy structural manipulation and synthesis of new chalcone derivatives. In this study, we discuss the mechanisms by which chalcones in both in vitro and in vivo conditions suppress cancer cell proliferation or cancer formation.

Meroterpenoid-Rich Ethanoic Extract of Sargassum macrocarpum Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice

Colitis is a colon mucosal disorder characterized by intestinal damage and inflammation. This current study aimed to evaluate the effect of meroterpenoid-rich ethanoic extract of a brown algae, Sargassum macrocarpum (MES) on dextran sulfate sodium (DSS)-induced colitis in mice and explore the possible mechanisms. Mice were given 4% DSS in drinking water for 7 days to induce colitis, followed by 3 days of regular water. MES (12 mg/kg body weight) or celecoxib (10 mg/kg body weight) was administrated orally to mice on a daily basis during these 10 days. Both MES and celecoxib supplementations significantly attenuated DSS-induced weight loss, shortening of colon length, elevated myeloperoxidase activity as well as histomorphological changes of colon. MES and celecoxib reduced the inflammation level of colon tissue, as indicated by its suppression on a panel of pro-inflammatory cytokines, including interleukin (IL)-1β, IL-17, tumor necrosis factor α, and interferon γ, and a group of inflammatory proteins, including intracellular adhesion molecule 1, vascular adhesion molecule 1, matrix metalloproteinase (MMP)-2, MMP-9, MMP-13, and inducible nitric oxidase. In addition, their administration down-regulated pro-inflammatory cytokines in serum. Moreover, the supplementation of MES suppressed the DSS-induced hyperactivation of Akt, JNK, and NF-κB signaling pathways. Taken together, our results demonstrate that MES ameliorates DSS-induced colitis in mice, suggesting that MES may have therapeutic implications for the treatment of colitis.

IL-6 deficiency promotes colitis by recruiting Ly6Chi monocytes into inflamed colon tissues in a CCL2-CCR2-dependent manner

Interleukin 6 (IL-6) is a pleiotropic cytokine that is elevated in inflammatory bowel disease. However, the role of IL-6 deficiency in colitis is not well-defined. Some IL-6 and IL-6 receptor antagonists are associated with severe gastrointestinal immune adverse effects, but the mechanisms of the effects are not clear. This study aimed to investigate the effect of IL-6 in ulcerative colitis in Il6^-/- mice. Results indicated that physiological deficiency of IL-6 promoted the development of colitis. Moreover, IL-6 deficiency significantly increased the mRNA levels of monocytes chemokine Ccl2 and its receptor Ccr2 in colon tissues. Similarly, the percentage of Ly6C^high monocytes and neutrophils were increased in the colon of Il6^-/- mice. Intestinal crypts more strongly increased the migration of Il6^-/- macrophages than wild-type ones. Moreover, Il6^-/- macrophages promoted the migration of neutrophils. Most importantly, RS102895, an antagonist of CCR2, diminished chemotaxis of macrophages and inhibited colitis in Il6^-/- mice. Collectively, these results indicate that Il6^-/- macrophages migrate to inflamed colon tissues and recruit neutrophils, thereby promoting the effect of Il6^-/- on colitis. This study expands our understanding on the effect of IL-6 deficiency in colitis and the development of gastrointestinal immune adverse effects.

New Perspectives in the Study of Intestinal Inflammation: Focus on the Resolution of Inflammation

Inflammation is an essential physiological process that is directed to the protection of the organism against invading pathogens or tissue trauma. Most of the existing knowledge related to inflammation is focused on the factors and mechanisms that drive the induction phase of this process. However, since the recognition that the resolution of the inflammation is an active and tightly regulated process, increasing evidence has shown the relevance of this process for the development of chronic inflammatory diseases, such as inflammatory bowel disease. For that reason, with this review, we aimed to summarize the most recent and interesting information related to the resolution process in the context of intestinal inflammation. We discussed the advances in the understanding of the pro-resolution at intestine level, as well as the new mediators with pro-resolutive actions that could be interesting from a therapeutic point of view.

Dietary Grape Seed Meal Bioactive Compounds Alleviate Epithelial Dysfunctions and Attenuates Inflammation in Colon of DSS-Treated Piglets

Inflammatory Bowel Diseases (IBD) are chronic inflammations associated with progressive degradation of intestinal epithelium and impairment of the local innate immune response. Restoring of epithelial integrity and of the mucosal barrier function, together with modulation of inflammatory and innate immune markers, represent targets for alternative strategies in IBD. The aim of our study was to evaluate the effects of a diet including 8% grape seed meal (GSM), rich in bioactive compounds (polyphenols, polyunsaturated fatty acids (PUFAs), fiber) on the markers of colonic epithelial integrity, mucosal barrier function, pro-inflammatory, and innate immunity in DSS-treated piglets used as animal models of intestinal inflammation. Our results have demonstrated the beneficial effects of bioactive compounds from dietary GSM, exerted at three complementary levels: (a) restoration of the epithelial integrity and mucosal barrier reinforcement by modulation of claudins, Occludin (OCCL) and Zonula-1 (ZO-1) tight junction genes and proteins, myosin IXB (MYO9B) and protein tyrosine phosphatase (PTPN) tight junction regulators and mucin-2 (MUC2) gene; (b) reduction of pro-inflammatory MMP-2 (matrix metalloproteinase-2) and MMP-9 (matrix metalloproteinase-9) genes and activities; and (c) suppression of the innate immune TLR-2 (Toll-like receptor-2) and TLR-4 (Toll-like receptor-4) genes and attenuation of the expression of MyD88 (Myeloid Differentiation Primary Response 88)/MD-2 (Myeloid differentiation factor-2) signaling molecules. These beneficial effects of GSM could further attenuate the transition of chronic colitis to carcinogenesis, by modulating the in-depth signaling mediators belonging to the Wnt pathway.

MMP inhibitors attenuate doxorubicin cardiotoxicity by preventing intracellular and extracellular matrix remodelling

AIMS

Heart failure is a major complication in cancer treatment due to the cardiotoxic effects of anticancer drugs, especially from the anthracyclines such as doxorubicin (DXR). DXR enhances oxidative stress and stimulates matrix metalloproteinase-2 (MMP-2) in cardiomyocytes. We investigated whether MMP inhibitors protect against DXR cardiotoxicity given the role of MMP-2 in proteolyzing sarcomeric proteins in the heart and remodelling the extracellular matrix.

METHODS AND RESULTS

Eight-week-old male C57BL/6J mice were treated with DXR weekly with or without MMP inhibitors doxycycline or ONO-4817 by daily oral gavage for 4 weeks. Echocardiography was used to determine cardiac function and left ventricular remodelling before and after treatment. MMP inhibitors ameliorated DXR-induced systolic and diastolic dysfunction by reducing the loss in left ventricular ejection fraction, fractional shortening, and E'/A'. MMP inhibitors attenuated adverse left ventricular remodelling, reduced cardiomyocyte dropout, and prevented myocardial fibrosis. DXR increased myocardial MMP-2 activity in part also by upregulating N-terminal truncated MMP-2. Immunogold transmission electron microscopy showed that DXR elevated MMP-2 levels within the sarcomere and mitochondria which were associated with myofilament lysis, mitochondrial degeneration, and T-tubule distention. DXR-induced myofilament lysis was associated with increased titin proteolysis in the heart which was prevented by ONO-4817. DXR also increased the level and activity of MMP-2 in human embryonic stem cell-derived cardiomyocytes, which was reduced by ONO-4817.

CONCLUSIONS

MMP-2 activation is an early event in DXR cardiotoxicity and contributes to myofilament lysis by proteolyzing cardiac titin. Two orally available MMP inhibitors ameliorated DXR cardiotoxicity by attenuating intracellular and extracellular matrix remodelling, suggesting their use may be a potential prophylactic strategy to prevent heart injury during chemotherapy.

Thymopentin ameliorates dextran sulfate sodium-induced colitis by triggering the production of IL-22 in both innate and adaptive lymphocytes

Background: Ulcerative colitis (UC) is a chronic inflammatory gastrointestinal disease, notoriously challenging to treat. Previous studies have found a positive correlation between thymic atrophy and colitis severity. It was, therefore, worthwhile to investigate the effect of thymopentin (TP5), a synthetic pentapeptide corresponding to the active domain of the thymopoietin, on colitis. Methods: Dextran sulfate sodium (DSS)-induced colitis mice were treated with TP5 by subcutaneous injection. Body weight, colon length, colon weight, immune organ index, disease activity index (DAI) score, and the peripheral blood profile were examined. The immune cells of the spleen and colon were analyzed by flow cytometry. Histology was performed on isolated colon tissues for cytokine analysis. Bacterial DNA was extracted from mouse colonic feces to assess the intestinal microbiota. Intestinal lamina propria mononuclear cells (LPMCs), HCT116, CT26, and splenocytes were cultured and treated with TP5. Results: TP5 treatment increased the body weight and colon length, decreased the DAI score, and restored colon architecture of colitic mice. TP5 also decreased the infiltration of immune cells and expression levels of pro-inflammatory cytokines such as IL-6. Importantly, the damaged thymus and compromised lymphocytes in peripheral blood were significantly restored by TP5. Also, the production of IL-22, both in innate and adaptive lymphoid cells, was triggered by TP5. Given the critical role of IL-22 in mucosal host defense, we tested the effect of TP5 on mucus barrier and gut microbiota and found that the number of goblet cells and the level of Mucin-2 expression were restored, and the composition of the gut microbiome was normalized after TP5 treatment. The critical role of IL-22 in the protective effect of TP5 on colitis was further confirmed by administering the anti-IL-22 antibody (αIL-22), which completely abolished the effect of TP5. Furthermore, TP5 significantly increased the expression level of retinoic acid receptor-related orphan receptor γ (RORγt), a transcription factor for IL-22. Consistent with this, RORγt inhibitor abrogated the upregulation of IL-22 induced by TP5. Conclusion: TP5 exerts a protective effect on DSS-induced colitis by triggering the production of IL-22 in both innate and adaptive lymphocytes. This study delineates TP5 as an immunomodulator that may be a potential drug for the treatment of UC.

Protective Effect of Spirulina platensis Extract against Dextran-Sulfate-Sodium-Induced Ulcerative Colitis in Rats

Inflammatory bowel disease is a multifactorial inflammatory condition. This study aimed to test the protective effects of Spirulina platensis against ulcerative colitis (UC). UC was induced in thirty-six male Wistar rats by adding dextran sulfate sodium (DSS) to their drinking water, while a control group received only drinking water. UC rats were equally-divided into six groups that received a single oral daily dose of vehicle (DSS), sulfasalazine (SSZ, 50 mg/kg/day), chloroform or the hydroalcoholic extracts of Spirulina platensis (100 or 200 mg/kg/day) for 15 days, and then blood and colon samples were harvested for determination of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), erythrocyte sedimentation rate (ESR), myeloperoxidase (MPO), and histopathology. At the end of the study, compared to time-matched controls, UC rats showed increased TNF-α (1.64-fold), IL-6 (5.73-fold), ESR (3.18-fold), and MPO (1.61-fold), along with loss of body weight (24.73%) and disease activity index (1.767 ± 0.216 vs. 0 ± 0), p < 0.001. These effects were prevented by SSZ treatment (p < 0.001 vs. DSS). The hydroalcoholic extract of Spirulina platensis dose-dependently modulated all DSS-induced inflammatory changes. However, the chloroform extract significantly lowered only IL-6 and ESR, but not TNF-α or MPO levels. The protective effects of the hydroalcoholic extract of Spirulina platensis against experimental UC involved mitigation of DSS-induced inflammation.

A20 ameliorates inflammatory bowel disease in mice via inhibiting NF-κB and STAT3 activation

A20 is a zinc finger protein that effectively inhibits the activation of nuclear factor (NF)-κB to downregulate the expression of tumor necrosis factor-α, interleukin (IL)-1β, and IL-17. A20 also plays a crucial role as a feedback inhibitor of the inflammatory response. Due to its inhibitory role, A20 may be useful in regulating diseases resulting from chronic inflammation and excessive pro-inflammatory cytokine production, such as colitis. Patients with colitis produce high levels of pro-inflammatory cytokines in the intestine. Therefore, this study aimed to investigate whether A20 improves experimental colitis by reducing high levels of inflammation in the intestine. An A20 overexpression vector was administered to mice by intrarectal injection after colitis induction. Histological analysis by immunohistochemistry was used to score sections of the intestine. Confocal laser scanning microscopy was used to identify the expression of IL-17 and forkhead box p (FOXP) 3 protein in spleen tissues. Protein expression induced by STAT3 and NF-κB signaling was analyzed by western blot. We found that A20 reduced the colitis activity index score and the histological score of the intestine. A20 also decreased inflammatory cytokine levels in the intestine and increased colon length. Additionally, A20 overexpression downregulated the activation of NF-kB and STAT3. A20 also reduced IL-17 expression in CD4⁺ T cells from spleen sections. In contrast, A20 overexpression enhanced the expression of FOXP3 in CD4⁺ T cells. These results suggest that A20 may inhibit the progression of colitis by decreasing inflammation via inhibition of NF-κB, phosphorylated STAT3, and IL-17.

The indane diastereoisomers, PH2 and PH5: divergence between their effects in delayed-type hypersensitivity models and a model of colitis

OBJECTIVES

Compounds PH2 and PH5 are distereoisomers of novel indane compounds, synthesised as analogues of secondary metabolites of the fern, Onychium. In this study, we compare their effects on a variety of inflammatory models.

METHODS

In an effort to extend our knowledge of their anti-inflammatory profile, we have investigated their activity in two models of delayed-type hypersensitivity (DTH); the methylated bovine serum albumin model (mBSA) and the oxazolone contact hypersensitivity (CHS) model, on IL2 release from Jurkat cells and in the dextran sulphate sodium (DSS) murine model of inflammatory bowel disease.

KEY FINDINGS

Both diastereoisomers are equipotent in reducing paw swelling in the mBSA model and in inhibiting interleukin (IL) 2 release from Jurkat cells. They are equally ineffective in the oxazolone contact hypersensitivity model (CHS). Only the diastereoisomer, PH5, protects against DSS-induced colitis and of its two enantiomers, only the S,S-enantiomer, PH22, possesses this activity. PH2 is ineffective in the DSS model.

CONCLUSIONS

The results suggest that the beneficial effect of PH5, and its enantiomer PH22, in the DSS model is a consequence of an action on a target specific to the colitis model. The implications of such data suggest an unknown target in this disease model that may be exploited to therapeutic advantage.

Coenzyme Q10 Inhibits Th17 and STAT3 Signaling Pathways to Ameliorate Colitis in Mice

Coenzyme Q10 (CoQ10) is a powerful antioxidant substance synthesized in the body. The current study aimed to determine whether CoQ10 suppresses inflammation and inhibits p-STAT3 expression in an experimental colitis mouse model. The mice were orally fed with CoQ10 once a day for 13 days. Histological analysis of the colons was performed by immunohistochemistry. Expression of IL-17, FOXP3, p53, AMPK, and mTOR and activation of p-STAT3 and p-STAT5 in lymph node and spleen tissues were detected by confocal microscopy of stained tissue sections. The relative mRNA expression was measured with real-time PCR, and protein levels were examined by western blot. CoQ10 reduced the disease activity index score and the colon histological score. It also reduced inflammatory mediators in the colon and increased the colon length. The expression of IL-17 and p-STAT3 was decreased with CoQ10 treatment. In contrast, CoQ10 treatment increased the expression of p-AMPK and FOXP3. Expression of anti-inflammatory cytokines was shown to increase in colitis mice treated with CoQ10. These results suggested that CoQ10 may reduce the severity of colitis and suppress inflammation through the inhibition of p-STAT3 and IL-17. These results support the use of CoQ10 as a potential targeted therapy for the treatment of colitis.

Inhibition of matrix metalloproteinase-9 by a barbiturate-nitrate hybrid ameliorates dextran sulphate sodium-induced colitis: effect on inflammation-related genes

BACKGROUND AND PURPOSE

Matrix metalloproteinase-9 (MMP-9) is up-regulated in ulcerative colitis and implicated in the pathology of the disease. In this study, we have examined the effects of a barbiturate-based MMP inhibitor incorporating a nitric oxide donor/mimetic group (dinitrate-barbiturate) on the intestinal injury induced by dextran sulphate sodium (DSS).

EXPERIMENTAL APPROACH

In vivo experiments were carried out using male Wistar rats given 5% DSS ad libitum in drinking water. The dinitrate-barbiturate, non-nitrate equivalent, nitrate side chains alone or vehicle were administered rectally, twice daily. MMP-9 release was measured by gelatin zymography, and analysis of gene expression was carried out using RT-qPCR. TaqMan low density arrays were used to evaluate the expression of 91 inflammatory genes in the rat colon.

KEY RESULTS

The dinitrate-barbiturate inhibited the induction and activity of MMP-9 during DSS colitis in the rat. This occurred in association with significant reductions in the colitic response to DSS as assessed by an established clinical disease activity index and a pathological colitis grade score. The compound modified expression rates of numerous inflammation-related genes in the colon.

CONCLUSIONS AND IMPLICATIONS

This study demonstrated the efficacy of the dinitrate-barbiturate in DSS-induced colitis. Therefore, barbiturate-nitrate hybrids may be developed as a promising anti-inflammatory approach to the treatment of inflammatory bowel disease.

Heparin improves BMSC cell therapy: Anticoagulant treatment by heparin improves the safety and therapeutic effect of bone marrow-derived mesenchymal stem cell cytotherapy

Systemic infusion of bone marrow-derived mesenchymal stem cells (BMSCs) has become a promising strategy for disease treatment and tissue regeneration. Strategies to enhance the efficiency of BMSC cell therapy are crucial to promote its clinical application. Here, we aimed to improve BMSC cell therapy by inhibiting the BMSC-induced coagulation reaction. Intravenous injection of gradient BMSCs into mice showed that BMSCs were not fully compatible with blood. Large doses of BMSCs induced a series of symptoms of respiratory failure and heart failure. Histological and homeostasis analysis confirmed that large doses of BMSCs induced disseminated intravascular thrombosis, exhaustion of platelets and coagulation factors, and prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT). Similar to mouse BMSCs, goat and human BMSCs also induced coagulation reactions in vitro and in vivo. The coagulation was induced mostly by tissue factor, the overexpression of which enhanced the procoagulant activity of BMSCs during in vitro culture. Notably, clinical doses of BMSCs in cell therapy also induced mild and reversible coagulation, which increased BMSC lung embolism and clearance. Anticoagulation treatment by heparin (400 U/kg) prevented BMSC-induced coagulation and the acute adverse effects of large-dose BMSCs infusion efficiently. Importantly, heparin treatment led to decreased BMSC lung embolism and enhanced migration and maintenance of BMSCs to target organs in cell therapy. Based on an experimental colitis model, we confirmed that heparin treatment enhanced the effect of BMSC therapy efficiently to reduce mortality, prevent weight loss, suppress inflammation reaction and alleviate tissue injury. In conclusion, BMSCs possess procoagulant activity that could induce disseminated coagulation and thrombosis in recipients. Anticoagulation treatment by heparin is a practical strategy to improve both the safety and therapeutic effect of BMSC therapy.

Knockdown of MicroRNA Let-7a Improves the Functionality of Bone Marrow-Derived Mesenchymal Stem Cells in Immunotherapy

Bone marrow-derived mesenchymal stem cells (MSCs) have been recently used in clinical treatment of inflammatory diseases. Practical strategies improving the immunosuppressive property of MSCs are urgently needed for MSC immunotherapy. In this study, we aimed to develop a microRNA-based strategy to improve MSC immunotherapy. Bioinformatic analysis revealed that let-7a targeted the 3' UTR of mRNA of Fas and FasL, both of which are essential for MSCs to induce T cell apoptosis. Knockdown of let-7a by specific inhibitor doubled Fas and Fas ligand (FasL) protein levels in MSCs. Because Fas attracts T cell migration and FasL induces T cell apoptosis, knockdown of let-7a significantly promoted MSC-induced T cell migration and apoptosis in vitro and in vivo. Importantly, MSCs knocked down of let-7a were more efficient to reduce the mortality, prevent the weight loss, suppress the inflammation reaction, and alleviate the tissue lesion of experimental colitis and graft-versus-host disease (GVHD) mouse models. In conclusion, knockdown of let-7a significantly improved the therapeutic effect of MSC cytotherapy on inflammatory bowel diseases and GVHD. With high safety and convenience, knockdown of let-7a is a potential strategy to improve MSC therapy for inflammatory diseases in clinic.

Melatonin Treatment Improves Mesenchymal Stem Cells Therapy by Preserving Stemness during Long-term In Vitro Expansion

Mesenchymal stem cells (MSCs) are promising candidates for tissue regeneration and disease treatment. However, long-term in vitro passaging leads to stemness loss of MSCs, resulting in failure of MSCs therapy. Here, we report a melatonin-based strategy to improve cell therapy of in vitro cultured MSCs. Among four small molecules with anti-aging and stem cell-protection properties (rapamycin, resveratrol, quercetin and melatonin), colony forming, proliferation, and osteogenic differentiation assay showed that melatonin was the most efficient to preserve self-renewal and differentiation properties of rat bone marrow MSCs (BMMSCs) after long-term passaging. Functional assays confirmed melatonin treatment did not affect the colony forming, proliferation and osteogenic differentiation of BMMSCs cultured for 1 or 4 passages, but largely prevented the decline of self-renew and differentiation capacity of BMMSCs cultured for 15 passages in vitro. Furthermore, heterotopic osteogenesis assay, critical size calvarial defects repair assay, osteoporosis treatment and experimental colitis therapy assay strongly certified that melatonin preserved the therapeutic effect of long-term passaged BMMSCs on bone regeneration and immunotherapy in vivo. Mechanistically, melatonin functioned by activating antioxidant defense system, inhibiting the pathway of cell senescence, and preserving the expression of gene governing the stemness. Taken together, our findings showed that melatonin treatment efficiently prevented the dysfunction and therapeutic failure of BMMSCs after long-term passaging, providing a practical strategy to improve the application of BMMSCs in tissue engineering and cytotherapy.

Matrix Metalloproteinases in Non-Neoplastic Disorders

The matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases belonging to the metzincin superfamily. There are at least 23 members of MMPs ever reported in human, and they and their substrates are widely expressed in many tissues. Recent growing evidence has established that MMP not only can degrade a variety of components of extracellular matrix, but also can cleave and activate various non-matrix proteins, including cytokines, chemokines and growth factors, contributing to both physiological and pathological processes. In normal conditions, MMP expression and activity are tightly regulated via interactions between their activators and inhibitors. Imbalance among these factors, however, results in dysregulated MMP activity, which causes tissue destruction and functional alteration or local inflammation, leading to the development of diverse diseases, such as cardiovascular disease, arthritis, neurodegenerative disease, as well as cancer. This article focuses on the accumulated evidence supporting a wide range of roles of MMPs in various non-neoplastic diseases and provides an outlook on the therapeutic potential of inhibiting MMP action.

MMP-19 deficiency causes aggravation of colitis due to defects in innate immune cell function

Matrix metalloproteinases (MMPs) are potential biomarkers for disease activity in inflammatory bowel disease (IBD). However, clinical trials targeting MMPs have not succeeded, likely due to poor understanding of the biological functions of individual MMPs. Here, we explore the role of MMP-19 in IBD pathology. Using a DSS-induced model of colitis, we show evidence for increased susceptibility of Mmp-19-deficient (Mmp-19(-/-)) mice to colitis. Absence of MMP-19 leads to significant disease progression, with reduced survival rates, severe tissue destruction, and elevated levels of pro-inflammatory modulators in the colon and plasma, and failure to resolve inflammation. There was a striking delay in neutrophil infiltration into the colon of Mmp-19(-/-) mice during the acute colitis, leading to persistent inflammation and poor recovery; this was rescued by reconstitution of irradiated Mmp-19(-/-) mice with wild-type bone marrow. Additionally, Mmp-19-deficient macrophages exhibited decreased migration in vivo and in vitro and the mucosal barrier appeared compromised. Finally, chemokine fractalkine (CX3CL1) was identified as a novel substrate of MMP-19, suggesting a link between insufficient processing of CX3CL1 and cell recruitment in the Mmp-19(-/-) mice. MMP-19 proves to be a critical factor in balanced host response to colonic pathogens, and for orchestrating appropriate innate immune response in colitis.

Selenium-Containing Phycocyanin from Se-Enriched Spirulina platensis Reduces Inflammation in Dextran Sulfate Sodium-Induced Colitis by Inhibiting NF-κB Activation

Selenium (Se) plays an important role in fine-tuning immune responses. Inflammatory bowel disease (IBD) involves hyperresponsive immunity of the digestive tract, and a low Se level might aggravate IBD progression; however, the beneficial effects of natural Se-enriched diets on IBD remain unknown. Previously, we developed high-yield Se-enriched Spirulina platensis (Se-SP) as an excellent organic nutritional Se source. Here we prepared Se-containing phycocyanin (Se-PC) from Se-SP and observed that Se-PC administration effectively reduced the extent of colitis in mouse induced by dextran sulfate sodium. Supplementation with Se-PC resulted in significant protective effects, including mitigation of body weight loss, bloody diarrhea, and colonic inflammatory damage. The anti-inflammatory effects of Se-PC supplementation were found to involve modulation of cytokines, including IL-6, TNF-α, MCP-1, and IL-10. Mechanistically, Se-PC inhibited the activation of macrophages by suppressing the nuclear translocation of NF-κB, which is involved in the transcription of these pro-inflammatory cytokines. These results together suggest potential benefits of Se-PC as a functional Se supplement to reduce the symptoms of IBD.

Expressions of Matrix Metalloproteinases (MMP-2, MMP-7, and MMP-9) and Their Inhibitors (TIMP-1, TIMP-2) in Inflammatory Bowel Diseases

Crohn's disease (CD) and ulcerative colitis (UC) belong to a group of inflammatory bowel diseases (IBD). The aim of our study was to evaluate the expression of MMP-2, MMP-7, MMP-9, TIMP-1, and TIMP-2 in ulcerative colitis and Crohn's disease. The study group comprised 34 patients with UC and 10 patients with CD. Evaluation of MMP-2, MMP-7, MMP-9, TIMP-1, and TIMP-2 expression in tissue samples was performed using immunohistochemistry. The overexpression of MMP-9 and TIMP-1 was dominant in both the glandular epithelium and inflammatory infiltration in UC patients. In contrast, in CD subjects the positive expression of MMP-2 and TIMP-1 was in glandular tubes while mainly MMP-7 and TIMP-2 expression was in inflammatory infiltration. Metalloproteinases' expression was associated with the presence of erosions, architectural tissue changes, and inflammatory infiltration in the lamina propria of UC patients. The expression of metalloproteinase inhibitors correlated with the presence of eosinophils and neutrophils in UC and granulomas in CD patients. Our studies indicate that the overexpression of metalloproteinases and weaker expression of their inhibitors may determine the development of IBD. It appears that MMP-2, MMP-7, and MMP-9 may be a potential therapeutic target and the use of their inhibitors may significantly reduce UC progression.

A New Signaling Pathway for HCV Inhibition by Estrogen: GPR30 Activation Leads to Cleavage of Occludin by MMP-9

Poor outcome in response to hepatitis C virus, including higher viral load, hepatocellular carcinoma and cirrhosis, is more associated with men and postmenopausal women than with premenopausal women and women receiving hormone replacement therapy, suggesting that β-estradiol plays an innate role in preventing viral infection and liver disease. Consequently, most research in the field has concluded that estrogen affects HCV replication through viral interactions with estrogen receptor-α. Previously, estrogen-like antagonists, including Tamoxifen, were shown to reduce HCV RNA production and prevent viral entry, although the authors did not identify host factors involved. Estrogen can act alternatively through the membrane-bound G-protein-coupled estrogen receptor, GPR30. Here, human hepatoma Huh7.5 cells were infected with HCV J6/JFH-1 and treated with estrogen or Tamoxifen, resulting in a marked decrease in detectable virus. The effect was mimicked by G1, a GPR30-specific agonist, and was reversed by the GPR30-specific antagonist, G15. While previous studies have demonstrated that estrogen down-regulated occludin in cervical cancer cells, its action on liver cells was unknown. Occludin is a tight junction protein and HCV receptor and here we report that activation and cellular export of MMP-9 led to the cleavage of occludin upon estrogen treatment of liver cells. This is the first report of the cleavage of an HCV receptor in response to estrogen. We also identify the occludin cleavage site in extracellular Domain D; the motif required for HCV entry and spread. This pathway gives new insight into a novel innate antiviral pathway and the suboptimal environment that estrogen provides for the proliferation of the virus. It may also explain the disparate host-virus responses to HCV demonstrated by the two sexes. Moreover, these data suggest that hormone replacement therapy may have beneficial antiviral enhancement properties for HCV-infected postmenopausal women and show promise for new antiviral treatments for both men and women.

Apigenin supplementation protects the development of dextran sulfate sodium-induced murine experimental colitis by inhibiting canonical and non-canonical inflammasome signaling pathways

The present study was designed to elucidate the protective effects of dietary apigenin (API) enrichment in a chronic colitis model induced by DSS in mice. Inflammatory mediators and the possible role of canonical and non-canonical NLRP3 inflammasome signaling pathways in the beneficial effects of API under chronic inflammatory conditions were also explored. Six-week-old mice were randomized in four dietary groups: sham and control groups received standard diet (SD), and other two groups were fed with API at 0.1%. After 30days, all groups except sham received 3% DSS in drinking water for 5days followed by a regime of 21days of water. Our results revealed that dietary API supplementation decreased the macroscopic and microscopic damage signs of colitis; also, it was capable to down-regulate mPGES, COX-2 and iNOS enzyme colonic expressions and to decrease serum matrix metalloproteinase (MMP-3) levels. Similarly, API diet reduced IL-1β and TNF-α proinflammatory cytokine secretions in primary LPS-stimulated splenocytes. Furthermore, we demonstrated that API anti-inflammatory activity was related with an inhibition of both canonical and non-canonical NLRP3 inflammasome pathways by decreasing proinflammatory IL-1β and IL-18 cytokine levels as a consequence of regulation of cleaved caspase-1 and caspase-11 enzymes. We conclude that API supplement might provide a basis for developing a new dietary strategy for the prevention of chronic ulcerative colitis.

Matrix metalloproteinase inhibitors prevent sepsis-induced refractoriness to vasoconstrictors in the cecal ligation and puncture model in rats

Previous studies have shown that the loss of contractility in aortas from lipopolysaccharide (LPS)-treated rats is related to intracellular activation of matrix metalloproteinase (MMPs). However, the role of MMPs in the vascular refractoriness to vasoconstrictors has not been investigated in a model of polymicrobial sepsis. We evaluated the effects of the oral administration of the MMP inhibitors doxycycline or ONO-4817 in the in vitro vascular reactivity of aortic rings from rats subjected to the cecal ligation and puncture (CLP) model of sepsis. Both doxycycline and ONO-4817 did not change vascular responses in sham-operated rats, but fully prevented hyporeactivity to KCl, phenylephrine and angiotensin II in vessels from CLP rats. This protective effect was not associated with changes in hematological parameters or blood nitrate and nitrite. The refractoriness to contractile agents was accompanied by enhanced activity of MMP-2 in aorta from CLP rats, which was abrogated by MMP inhibitors. CLP-induced sepsis did not impair the levels of MMP-2 in aorta, but significantly reduced calponin-1, a regulatory protein of vascular contraction. In addition, augmented levels of TIMP-1 were found in vessels from CLP rats. All these differences were prevented by either doxycycline or ONO-4817. Our study shows, for the first time in the CLP rat model of sepsis, that the vascular refractoriness to different contractile agents induced by polymicrobial sepsis is associated with increased activity of MMP-2 and reduced amounts of calponin-1 in the aorta. These findings reinforce the importance of the enhanced activity of MMPs for vascular failure in septic shock.

Inhibition of plasmin protects against colitis in mice by suppressing matrix metalloproteinase 9-mediated cytokine release from myeloid cells

BACKGROUND & AIMS

Activated proteases such as plasmin and matrix metalloproteinases (MMPs) are activated in intestinal tissues of patients with active inflammatory bowel diseases. We investigated the effect of plasmin on the progression of acute colitis.

METHODS

Colitis was induced in Mmp9(-/-), Plg(-/-), and C57BL/6 (control) mice by the administration of dextran sulfate sodium, trinitrobenzene sulfonic acid, or CD40 antibody. Plasmin was inhibited in control mice by intraperitoneal injection of YO-2, which blocks its active site. Mucosal and blood samples were collected and analyzed by reverse-transcription polymerase chain reaction and immunohistochemical analyses, as well as for mucosal inflammation and levels of cytokines and chemokines.

RESULTS

Circulating levels of plasmin were increased in mice with colitis, compared with controls. Colitis did not develop in control mice injected with YO-2 or in Plg(-/-) mice. Colons from these mice had reduced infiltration of Gr1+ neutrophils and F4/80+ macrophages, and reduced levels of inflammatory cytokines and chemokines. Colonic inflammation and colitis induction required activation of endogenous MMP9. After colitis induction, mice given YO-2, Plg(-/-) mice, and Mmp9(-/-) mice had reduced serum levels of tumor necrosis factor and C-X-C motif chemokine ligand 5, compared with control mice.

CONCLUSIONS

In mice, plasmin induces a feedback mechanism in which activation of the fibrinolytic system promotes the development of colitis via activation of MMP9 or proteolytic enzymes. The proteolytic environment stimulates the influx of myeloid cells into the colonic epithelium and the production of tumor necrosis factor and C-X-C motif chemokine ligand 5. In turn, myeloid CD11b+ cells release the urokinase plasminogen activator, which accelerates plasmin production. Disruption of the plasmin-induced chronic inflammatory circuit therefore might be a strategy for colitis treatment.

Olmesartan decreased levels of IL-1β and TNF-α, down-regulated MMP-2, MMP-9, COX-2, RANK/RANKL and up-regulated SOCs-1 in an intestinal mucositis model

Methotrexate (MTX) is a pro-oxidant compound that depletes dihydrofolate pools and is widely used in the treatment of leukaemia and other malignancies. The efficacy of methotrexate is often limited by mucositis and intestinal injury, which are major causes of morbidity in children and adults. The aim of this study was to evaluate the effect of olmesartan (OLM), an angiotensin II receptor antagonist, on an Intestinal Mucositis Model (IMM) induced by MTX in Wistar rats. IMM was induced via intraperitoneal (i.p.) administration of MTX (7 mg/kg) for three consecutive days. The animals were pre-treated with oral OLM at 0.5, 1 or 5 mg/kg or with vehicle 30 min prior to exposure to MTX. Small intestinal homogenates were assayed for levels of the IL-1β, IL-10 and TNF-α cytokines, malondialdehyde and myeloperoxidase activity. Additionally, immunohistochemical analyses of MMP-2, MMP-9, COX-2, RANK/RANKL and SOCS-1 and confocal microscopy analysis of SOCS-1 expression were performed. Treatment with MTX + OLM (5 mg/kg) resulted in a reduction of mucosal inflammatory infiltration, ulcerations, vasodilatation and haemorrhagic areas (p<0.05) as well as reduced concentrations of MPO (p<0.001) and the pro-inflammatory cytokines IL-1β (p<0.001) and TNF-a (p<0.01), and increase anti-inflammatory cytocine IL-10 (p<0.05). Additionally, the combined treatment reduced expression of MMP-2, MMP-9, COX-2, RANK and RANKL(p<0.05) and increased cytoplasmic expression of SOCS-1 (p<0.05). Our findings confirm the involvement of OLM in reducing the inflammatory response through increased immunosuppressive signalling in an IMM. We also suggest that the beneficial effect of olmesartan treatment is specifically exerted during the damage through blocking inflammatory cytocines.

Selective gelatinase inhibition reduces apoptosis and pro-inflammatory immune cell responses in Campylobacter jejuni-infected gnotobiotic IL-10 deficient mice

Increased levels of the matrix metalloproteinases-2 and -9 (also referred to gelatinase-A and -B, respectively) can be detected in intestinal inflammation. We have recently shown that selective gelatinase blockage by the synthetic compound RO28-2653 ameliorates acute murine ileitis and colitis. We here investigated whether RO28-2653 exerts anti-inflammatory effects in acute Campylobacter jejuni-induced enterocolitis of gnotobiotic IL-10(-/-) mice generated following antibiotic treatment. Mice were perorally infected with C. jejuni (day 0) and either treated with RO28-2653 (75 mg/kg body weight/day) or placebo from day 1 until day 6 post infection (p.i.) by gavage. Irrespective of the treatment, infected mice displayed comparable pathogen loads within the gastrointestinal tract. Following RO28-2653 administration, however, infected mice exhibited less severe symptoms such as bloody diarrhea as compared to placebo controls. Furthermore, less distinct apoptosis but higher numbers of proliferating cells could be detected in the colon of RO28-2653-treated as compared to placebo-treated mice at day 7 p.i. Remarkably, gelatinase blockage resulted in lower numbers of T- and B-lymphocytes as well as macrophages and monocytes in the colonic mucosa of C. jejuni-infected gnotobiotic IL-10(-/-) mice. Taken together, synthetic gelatinase inhibition exerts anti-inflammatory effects in experimental campylobacteriosis.

Role of vitamin D derivatives in intestinal tissue of patients with inflammatory bowel diseases

BACKGROUND AND AIM

The adhesion molecule expression and matrix metalloproteinases (MMPs) are proposed to be major factors for intestinal injury mediated by T cells in (IBD) and are up-regulated in intestinal mucosa of IBD patients. To investigate the effect of vitamin D derivatives on adhesion molecules and MMPs in colonic biopsies of IBD patients.

METHODS

Biopsies from inflamed and non-inflamed tract of terminal ileum and colon and PBMC from the same IBD patients were cultured with or without vitamin D derivatives. MMP activity and adhesion molecule levels were determined.

RESULTS

1,25(OH)2D3 and ZK 191784 significantly decrease ICAM-1 protein levels in the biopsies obtained only from the inflamed region of intestine of UC patients, while MAdCAM-1 levels decrease in the presence of 1,25(OH)2D3 in the non-inflamed region, and, in the presence of ZK, in the inflamed one. In CD patients 1,25(OH)2D3 and ZK decrease ICAM-1 and MAdCAM-1 in the biopsies obtained from the non-inflamed and inflamed regions, with the exception of ICAM-1 in the inflamed region in the presence of 1,25(OH)2D3. The expression of MMP-9, MMP-2, and MMP-3 decreases in the presence of vitamin D derivatives in UC and CD with the exception of 1,25(OH)2D3 that does not affect the levels of MMP-9 and MMP-2 in CD. Vitamin D derivatives always affect MMP-9, MMP-2 and ICAM-1 in PBMC of UC and CD patients.

CONCLUSIONS

Based on the increased expression of ICAM-1, MAdCAM-1 and MMP-2,-9,-3 in IBD, our study suggests that vitamin D derivatives may be effective in the management of these diseases.

The impact of Toll-like-receptor-9 on intestinal microbiota composition and extra-intestinal sequelae in experimental Toxoplasma gondii induced ileitis

Background

Following peroral Toxoplasma (T.) gondii infection, susceptible mice develop acute ileitis due to a microbiota-dependent Th1 type immunopathology. Toll-like-receptor (TLR)-9 is known to recognize bacterial DNA and mediates intestinal inflammation, but its impact on intestinal microbiota composition and extra-intestinal sequelae following T. gondii infection has not yet been elucidated.

Methods and results

Seven days following peroral infection (p.i.) with 100 cysts of T. gondii ME49 strain, TLR-9^-/- and wildtype (WT) mice suffered from comparable ileitis, whereas ileal parasitic loads as well as IFN-γ and nitric oxide levels were higher in TLR-9^-/- compared to WT mice. Locally, TLR-9^-/- mice exhibited increased ileal CD3+, but not FOXP3+ cell numbers at day 7 p.i.; in mesenteric lymph nodes IFN-γ-producing CD4+ cell numbers and TNF-α and IFN-γ concentrations were also increased in TLR-9^-/- compared to WT mice. T. gondii DNA levels, however, did not differ in mice of either genotype. Differences in intestinal microbiota were rather subtle except for bifidobacteria that were virtually absent in both, naïve and T. gondii infected TLR-9^-/-, but not WT mice. Extra-intestinally, TLR-9^-/- mice displayed less distinct systemic immune responses as indicated by lower serum IL-6, and splenic TNF-α and IFN-γ levels as compared to WT mice despite higher translocation rates of intestinal bacteria to extra-intestinal compartments such as liver, spleen, kidney, and cardiac blood. Most importantly, brains were also affected in this inflammatory scenario as early as day 7 p.i. Remarkably, TLR-9^-/- mice exhibited more pronounced inflammatory infiltrates with higher numbers of F4/80+ macrophages and microglia in the cortex and meninges as compared to WT mice, whereas T. gondii DNA levels did not differ.

Conclusion

We here show that TLR-9 is not required for the development of T. gondii induced ileitis but mediates distinct inflammatory changes in intestinal and extra-intestinal compartments including the brain.

Collagen degradation and neutrophilic infiltration: a vicious circle in inflammatory bowel disease

OBJECTIVE

Proline-glycine-proline (PGP) has been shown to have chemotactic effects on neutrophils via CXCR2 in several lung diseases. PGP is derived from collagen by the combined action of matrix metalloproteinase (MMP) 8 and/or MMP9 and prolyl endopeptidase (PE). We investigated the role of PGP in inflammatory bowel disease (IBD).

DESIGN

In intestinal tissue from patients with IBD and mice with dextran sodium sulfate (DSS)-induced colitis, MMP8, MMP9 and PE were evaluated by ELISA, immunoblot and immunohistochemistry. Peripheral blood polymorphonuclear cell (PMN) supernatants were also analysed accordingly and incubated with collagen to assess PGP generation ex vivo. PGP levels were measured by mass spectrometry, and PGP neutralisation was achieved with a PGP antagonist and PGP antibodies.

RESULTS

In the intestine of patients with IBD, MMP8 and MMP9 levels were elevated, while PE was expressed at similar levels to control tissue. PGP levels were increased in intestinal tissue of patients with IBD. Similar results were obtained in intestine from DSS-treated mice. PMN supernatants from patients with IBD were far more capable of generating PGP from collagen ex vivo than healthy controls. Furthermore, PGP neutralisation during DSS-induced colitis led to a significant reduction in neutrophil infiltration in the intestine.

CONCLUSIONS

The proteolytic cascade that generates PGP from collagen, as well as the tripeptide itself, is present in the intestine of patients with IBD and mice with DSS-induced colitis. PGP neutralisation in DSS-treated mice showed the importance of PGP-guided neutrophilic infiltration in the intestine and indicates a vicious circle in neutrophilic inflammation in IBD.

A review of the use of melatonin in ulcerative colitis: experimental evidence and new approaches

: Ulcerative colitis (UC), an inflammatory bowel disease, affects many people across the globe, and its prevalence is increasing steadily. Inflammation and oxidative stress play a vital role in the perpetuation of inflammatory process and the subsequent DNA damage associated with the development of UC. UC induces not only local but also systemic damage, which involves the perturbation of multiple molecular pathways. Furthermore, UC leads to an increased risk of colorectal cancer, the third most common malignancy in humans. Most of the drugs used for the treatment of UC are unsatisfactory because they are generally mono-targeted, relatively ineffective and unaffordable for many people. Thus, agents that can target multiple molecular pathways and are less expensive have enormous potential to treat UC. Melatonin has beneficial effects against UC in experimental and clinical studies because of its ability to modulate several molecular pathways of inflammation, oxidative stress, fibrosis, and cellular injury. However, many novel targets are yet to be explored on which melatonin may act to exert its favorable effects in UC. It is time to explore improved intervention strategies with melatonin in UC on the basis of studies investigating different molecular targets using proteomic and genomic approaches. This review identifies various molecular targets for melatonin with the intent of providing novel strategies for combating UC and the associated extraintestinal manifestations of this debilitating disease.

Administration of reconstituted polyphenol oil bodies efficiently suppresses dendritic cell inflammatory pathways and acute intestinal inflammation

Polyphenols are natural compounds capable of interfering with the inflammatory pathways of several in vitro model systems. In this study, we developed a stable and effective strategy to administer polyphenols to treat in vivo models of acute intestinal inflammation. The in vitro suppressive properties of several polyphenols were first tested and compared for dendritic cells (DCs) production of inflammatory cytokines. A combination of the polyphenols, quercetin and piperine, were then encapsulated into reconstituted oil bodies (OBs) in order to increase their stability. Our results showed that administration of low dose reconstituted polyphenol OBs inhibited LPS-mediated inflammatory cytokine secretion, including IL-6, IL-23, and IL-12, while increasing IL-10 and IL-1Rα production. Mice treated with the polyphenol-containing reconstituted OBs (ROBs) were partially protected from dextran sodium sulfate (DSS)-induced colitis and associated weight loss, while mortality and inflammatory scores revealed an overall anti-inflammatory effect that was likely mediated by impaired DC immune responses. Our study indicates that the administration of reconstituted quercetin and piperine-containing OBs may represent an effective and potent anti-inflammatory strategy to treat acute intestinal inflammation.

Oral delivery of IL-27 recombinant bacteria attenuates immune colitis in mice

BACKGROUND & AIMS

Treatment of inflammatory bowel disease would benefit from specific targeting of therapeutics to the intestine. We developed a strategy for localized delivery of the immunosuppressive cytokine interleukin (IL)-27, which is synthesized actively in situ by the food-grade bacterium Lactococcus lactis (LL-IL-27), and tested its ability to reduce colitis in mice.

METHODS

The 2 genes encoding mouse IL-27 were synthesized with optimal codon use for L lactis and joined with a linker; a signal sequence was added to allow for product secretion. The construct was introduced into L lactis. Colitis was induced via transfer of CD4(+)CD45RB(hi) T cells into Rag(-/-) mice to induce colitis; 7.5 weeks later, LL-IL-27 was administered to mice via gavage. Intestinal tissues were collected and analyzed.

RESULTS

LL-IL-27 administration protected mice from T-cell transfer-induced enterocolitis and death. LL-IL-27 reduced disease activity scores, pathology features of large and small bowel, and levels of inflammatory cytokines in colonic tissue. LL-IL-27 also reduced the numbers of CD4(+) and IL-17(+) T cells in gut-associated lymphoid tissue. The effects of LL-IL-27 required production of IL-10 by the transferred T cells. LL-IL-27 was more effective than either LL-IL-10 or systemic administration of recombinant IL-27 in reducing colitis in mice. LL-IL-27 also reduced colitis in mice after administration of dextran sodium sulfate.

CONCLUSIONS

LL-IL-27 reduces colitis in mice by increasing the production of IL-10. Mucosal delivery of LL-IL-27 could be a more effective and safer therapy for inflammatory bowel disease.

Ethanol extract of Cordyceps militaris grown on germinated soybeans attenuates dextran-sodium-sulfate- (DSS-) induced colitis by suppressing the expression of matrix metalloproteinases and inflammatory mediators

The effect of Cordyceps militaris (CM) grown on germinated soybeans (GSC) in the inflammatory bowel disease (IBD) model was studied. To demonstrate the preventive effect of GSC extract in a dextran-sodium-sulfate- (DSS-) induced acute colitis mouse model, GSC was administered 2 days before DSS coadministration. GSC significantly suppressed DSS-induced disease activity index (DAI) as well as histopathological scores, compared to control or CM-treated group. To elucidate the anti-IBD activity of GSC, we checked the level of matrix metalloproteinases (MMPs) and inflammatory mediators. GSC extract decreased the level of MMP-3 and -9 mRNAs and p53 proteins. The level and activity of LPS-induced MMP-9 were reduced in GSC-treated RAW264.7 cells. It also attenuated the level of inducible nitric oxide synthase (iNOS) and tumor necrosis factor- (TNF-) α mRNAs both in colon tissue and in macrophage cells. These results suggest that GSC can be applied as a protective agent against IBDs.

Systemic infusion of bone marrow-derived mesenchymal stem cells for treatment of experimental colitis in mice

BACKGROUND AND AIMS

The anti-inflammatory and reparative properties of mesenchymal stem cells (MSCs) make them a promising tool for treating immune-mediated and inflammatory disorders. However, whether MSCs can be used for treatment of inflammatory bowel disease (IBD) still remains unclear. In this study, a dextran sulfate sodium (DSS)-induced mouse colitis model was used to test the hypothesis that infused bone marrow-derived MSCs could exert anti-inflammatory effects against experimental colitis.

METHODS

DSS-induced colitis mice were injected with 1 × 10(6) MSCs [in phosphate-buffered saline (PBS)] via the tail vein. Control colitis mice received PBS alone. To trace the injected cells in vivo, MSCs were labeled with chloromethyl-benzamidodialkylcarbocyanine (CM-DiI). On day 15 of the experiment, the colon was sectioned and examined for histopathological changes. Pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β] in the inflamed colon were analyzed by real-time reverse-transcription polymerase chain reaction (RT-PCR). Serum values of TNF-α in mice were evaluated quantitatively by enzyme-linked immunosorbent assay (ELISA) analysis.

RESULTS

DSS-induced colitis showed symptoms similar to ulcerative colitis in humans, including body weight loss, bloody diarrhea, mucosal ulceration, and shortening of the colon. Bone marrow-derived MSCs significantly ameliorated the clinical and histopathologic severity of DSS colitis compared with non-MSC control. Pro-inflammatory cytokines in both the inflamed colon (TNF-α, IL-1β) and serum (TNF-α) were downregulated in MSC-treated mice in contrast to control. CM-DiI-labeled MSCs accumulated in inflamed regions of the colon, mainly in the submucosa.

CONCLUSIONS

Systemic infusion of bone marrow-derived MSCs may exert therapeutic efficacy on acute DSS-induced colitis in mice through their anti-inflammatory effects, which demonstrates the feasibility of using bone marrow-derived MSCs to treat IBD.

The synthetic hydroxyproline-containing collagen analogue (Gly-Pro-Hyp)10 ameliorates acute DSS colitis

In experimental models of and humans with intestinal inflammation, increased levels of the matrix-degrading gelatinases MMP-2 and -9 in inflamed tissues can be detected. The synthetic collagen analogue (Gly-Pro-Hyp)10, (GPO)10, has been identified as a relevant binding structure for proMMP-2/-9 and promotes enzymatic activity of proMMP-2. Since targeted MMP strategies might offer promising anti-inflammatory treatment options, we for the first time studied in vivo actions exerted by (GPO)10 applying an acute dextrane sulfate sodium (DSS) induced colitis model. Seven-day intraperitoneal (GPO)10 treatment ameliorated clinical symptoms and histopathological colonic changes as compared to placebo controls with severe colitis. (GPO)10-treated mice displayed a diminished influx of neutrophils, and T- and B-lymphocytes into their colonic mucosa whereas numbers of regulatory T-cells and regenerative cells were higher as compared to placebo controls. Furthermore, IL-6 secretion was down-regulated in ex vivo colonic biopsies derived from (GPO)10-treated mice whereas higher concentrations of the anti-inflammatory cytokine IL-10 in extra-intestinal compartments such as MLN and spleen could be detected. Strikingly, influx of inflammatory cells into lungs was abolished following (GPO)10 application. We therefore propose (GPO)10 as a promising effective and safe treatment option of intestinal and extra-intestinal inflammatory conditions in humans.

The distinct roles of MMP-2 and MMP-9 in acute DSS colitis

Expression of gelatinases A and B, also referred to matrixmetalloproteinases (MMP)-2 and -9, respectively, is increased in inflamed tissues of experimental intestinal inflammation and humans with inflammatory bowel disease (IBDs). Given that we recently reported that treatment with the selective gelatinase inhibitor RO28-2653 ameliorates acute dextrane sulfate sodium (DSS) colitis, we asked whether gelatinase A or B expression is pivotal in mediating large intestinal inflammation. Results from our study reveal that symptoms of acute DSS colitis as well as histopathological colonic changes were ameliorated in MMP-2-, but not MMP-9-deficient mice, and were paralleled by a diminished influx of immune cells. In MMP-2-deficient mice, we observed lower expression of pro-inflammatory cytokines including interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and IL-6 in colonic biopsies and less overgrowth of the colonic lumen by potentially pro-inflammatory enterobacteria from the commensal gut microbiota. We conclude that rather MMP-2 than MMP-9 is causative for the establishment of DSS colitis in mice. The discrepancy of these data to prior reports might be due to substantial differences in the intestinal microbiota composition of the mice bred at different animal facilities impacting susceptibility to inflammatory stimuli. Consequently, a detailed survey of the gut microbiota should be implemented in immunological/inflammatory studies in the future in order to allow comparison of data from different facilities.

Selective gelatinase blockage ameliorates acute DSS colitis

In the experimental models of intestinal inflammation and humans with inflammatory bowel diseases (IBD), increased levels of the matrix metalloproteinases (MMPs), MMP-2 and -9 (also referred to as gelatinase A and B, respectively), in inflamed tissue sites can be detected. In the presented study, we investigated potential beneficial effects exerted by doxycycline nonselectively blocking MMPs and the selective gelatinase inhibitor RO28-2653 in acute DSS colitis. Treatment with either compound for 8 days ameliorated clinical colitis pathology with a superior outcome in RO28-2653-treated animals. As compared to placebo controls, histopathological changes in the colon were less distinct following MMP blockage and IL-6 secretion in ex vivo biopsies was downregulated, paralleled by a diminished influx of pro-inflammatory immune cells and lack of overgrowth of the colonic lumen by potentially pro-inflammatory Escherichia coli of the commensal colon flora. We conclude that selective gelatinase inhibition not only exerts beneficial effects by disrupting the vicious cycle of positive feedback between immune cell stimulation and MMP induction but also prevents overgrowth of the colonic lumen by pro-inflammatory E. coli despite a lack of direct anti-bacterial properties, thus unaffecting the commensal gut microbiota. These findings put RO28-2653 into a center stage for development of intervention strategies in human IBD.

Novel application of proton pump inhibitor for the prevention of colitis-induced colorectal carcinogenesis beyond acid suppression

Colitis-associated cancers arise in the setting of chronic inflammation wherein an "inflammation-dysplasia-carcinoma" sequence prevails. Based on our previous findings in which the proton pump inhibitor could impose significant levels of anti-inflammatory, antiangiogenic, and selective apoptosis induction beyond gastric acid suppression, we investigated whether omeprazole could prevent the development of colitis-associated cancer in a mouse model induced by repeated bouts of colitis. Omeprazole, 10 mg/kg, was given i.p. all through the experimental periods for colitis-associated carcinogenesis. Molecular changes regarding inflammation and carcinogenesis were compared between control groups and colitis-associated cancer groups treated with omeprazole in addition to chemopreventive outcome. Nine of 12 (75.0%) mice in the control group developed multiple colorectal tumors, whereas tumors were noted in only 3 of 12 (25.0%) mice treated with daily injections of omeprazole. The cancer-preventive results of omeprazole treatment was based on significant decreases in the levels of nitric oxide, thiobarbituric acid-reactive substance, and interleukin-6 accompanied with attenuated expressions of tumor necrosis factor-alpha, inducible nitric oxide synthase, and cyclooxygenase-2. The expressions of matrix metalloproteinase (MMP)-9, MMP-11, and MT1-MMMP were significantly decreased in mice treated with omeprazole in accordance with significant decreases in the number of beta-catenin-accumulated crypts. A significant induction of apoptosis was observed in tumor tissue treated with omeprazole. Omeprazole could block the trophic effect of gastrin in colon epithelial cells. The significant anti-inflammatory, antioxidative, and antimutagenic activities of omeprazole played a cancer-preventive role against colitis-induced carcinogenesis, and our novel in vivo evidence is suggestive of chemopreventive action independent of gastric acid suppression.

Stromelysin-1 and macrophage metalloelastase expression in the intestinal mucosa of Crohn's disease patients treated with infliximab

BACKGROUND AND AIMS

The mechanism by which anti-tumor necrosis factor (TNF)-alpha therapy promotes rapid closure of fistulas and mucosal wound healing in Crohn's disease (CD) remains unclear. An ex-vivo model of gut T-cell mediated injury indicated that TNF-alpha blockade prevents tissue damage concomitant with matrix metalloproteinase (MMP) inhibition. We, therefore, hypothesized that the chimeric anti-TNF-alpha antibody infliximab facilitates wound healing in CD by downregulating tissue degrading MMPs. We focused on MMP-3 (stromelysin-1) and MMP-12 (macrophage metalloelastase) as these two enzymes have been linked to connective tissue destruction in CD.

METHODS

Endoscopic biopsies were taken from 10 CD patients immediately before and after 10 weeks of treatment with infliximab. Before treatment, biopsies were taken from macroscopically inflamed areas, and after treatment were collected from the same locations as before treatment. The degree of mucosal damage was assessed by using a histological scoring system. MMP transcripts were detected by in-situ hybridization on paraffin sections. MMP proteins were determined by immunoblotting on mucosal homogenates.

RESULTS

Six out of 10 patients had a clinical response to infliximab. MMP-3 and MMP-12 transcripts and proteins, which were highly expressed in CD inflamed mucosa, decreased after treatment in those patients who responded to infliximab. MMP-3 and MMP-12 downregulation was accompanied by a concomitant improvement of the histologic score. No change in MMP expression was found in nonresponders.

CONCLUSION

The downregulation of tissue degrading MMPs in CD mucosa may explain the wound repair capacity of infliximab in healing fistulas and ulcers.

Effect of a matrix metalloproteinase sequestering biomaterial on Caco-2 epithelial cell barrier integrity in vitro

A novel matrix metalloproteinase sequestering biomaterial (MI Theramer beads) restored the epithelial barrier in a double chamber in vitro test system after disruption by Cytochalasin D and the secretion of the metalloproteinase MMP-2. MI beads are chemically modified (hydroxamated) poly(methacrylic acid-co-methyl methacrylate). We are exploring the utility of this material in inflammatory bowel disease (IBD), in which one manifestation is a compromised intestinal epithelial barrier. In a first step towards this goal we incubated MI beads (or polymethyl methacrylate control beads) with Caco-2 epithelial cells and mesenchymal 3T3 fibroblasts on two sides of a Matrigel((R))-coated filter and used Cytochalasin D (Cyto D) to activate MMP-2 (secreted by the 3T3 cells), disrupt actin filaments of Caco-2 cells and render the epithelial barrier leaky, as measured by dextran fluorescein equilibration. Addition of MI beads to Cyto D-treated cells inhibited active MMP-2 and prevented equilibration of dextran fluorescein. This study is the first step in showing a potential benefit to local (as opposed to systemic) inhibition of metalloproteinases in IBD or other intestinal inflammatory diseases.

Minocycline attenuates experimental colitis in mice by blocking expression of inducible nitric oxide synthase and matrix metalloproteinases

In addition to its antimicrobial activity, minocycline exerts anti-inflammatory effects in several disease models. However, whether minocycline affects the pathogenesis of inflammatory bowel disease has not been determined. We investigated the effects of minocycline on experimental colitis and its underlying mechanisms. Acute and chronic colitis were induced in mice by treatment with dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS), and the effect of minocycline on colonic injury was assessed clinically and histologically. Prophylactic and therapeutic treatment of mice with minocycline significantly diminished mortality rate and attenuated the severity of DSS-induced acute colitis. Mechanistically, minocycline administration suppressed inducible nitric oxide synthase (iNOS) expression and nitrotyrosine production, inhibited proinflammatory cytokine expression, repressed the elevated mRNA expression of matrix metalloproteinases (MMPs) 2, 3, 9, and 13, diminished the apoptotic index in colonic tissues, and inhibited nitric oxide production in the serum of mice with DSS-induced acute colitis. In DSS-induced chronic colitis, minocycline treatment also reduced body weight loss, improved colonic histology, and blocked expression of iNOS, proinflammatory cytokines, and MMPs from colonic tissues. Similarly, minocycline could ameliorate the severity of TNBS-induced acute colitis in mice by decreasing mortality rate and inhibiting proinflammatory cytokine expression in colonic tissues. These results demonstrate that minocycline protects mice against DSS- and TNBS-induced colitis, probably via inhibition of iNOS and MMP expression in intestinal tissues. Therefore, minocycline is a potential remedy for human inflammatory bowel diseases.

Spontaneous and cytokine induced expression and activity of matrix metalloproteinases in human colonic epithelium

Matrix metalloproteinases (MMPs) have been implicated in tissue damage associated with inflammatory bowel disease (IBD).As the role of the intestinal epithelium in this process is unknown, we determined MMP expression and enzyme activity in human colonic epithelial cells (CEC). MMP mRNA expression was assessed by reverse transcription-polymerase chain reaction in HT-29 and DLD-1 cells and in CEC isolated from biopsies from IBD and control patients. Total MMP activity in the cells was measured by a functional assay, based on degradation of a fluorescent synthetic peptide containing the specific bond for MMP cleavage. HT-29 and DLD-1 expressed several MMPs and levels of MMP-3, -10 and -13 mRNA expression were increased significantly by tumour necrosis factor (TNF)-alpha exposure. Transcripts of MMP-1, -3, -7, -9, -10 and -12 were detected in CECs and all, except MMP12, at significantly increased levels in cells from inflamed IBD mucosa. MMP-2 and -8 mRNA were expressed inconsistently and MMP-11, -13 and -14 mRNA undetectable. Proteolytic MMP activity was detected in CEC supernatants and the level was increased significantly in inflamed IBD epithelium. The enzyme activity was inhibited strongly by a specific MMP inhibitor (GM 6001). A significant TNF-alpha-mediated increase in MMP enzyme activity was also detected in HT-29 cells in vitro. In conclusion, the expression of several MMPs as well as the level of functional MMPactivity is increased in CEC from patients with active IBD. The results suggest that MMPs released by the intestinal epithelium may be involved in the pathogenesis of IBD by promoting local mucosal damage.

Matrix metalloproteinase-9-mediated tissue injury overrides the protective effect of matrix metalloproteinase-2 during colitis

Matrix metalloproteinases (MMP) play an important role in pathogenesis of inflammatory bowel disease (IBD). Two known gelatinases, MMP-2 and MMP-9, are upregulated during IBD. Epithelial-derived MMP-9 is an important mediator of tissue injury in colitis, whereas MMP-2 protects against tissue damage and maintains gut barrier function. It has been suggested that developing strategies to block MMP-9 activity in the gut might be of benefit to IBD. However, given that MMP-2 and MMP-9 are structurally similar, such approaches would also likely inhibit MMP-2. Thus, to gain insight into outcome of inhibiting both MMP-2 and MMP-9, MMP-2(-/-)/MMP-9(-/-) double knockout mice (dKO) lacking both MMP-2 and MMP-9 were used in this study. Three models of murine colitis were used: dextran sodium sulfate (DSS), Salmonella typhimurium (S.T.), and trinitrobenzene sulfonic acid (TNBS). Our data demonstrate that MMP-2 and MMP-9 activities were highly upregulated in wild-type (WT) mice treated with DSS, S.T., or TNBS whereas dKO mice were resistant to the development of colitis. WT mice had extensive inflammation and tissue damage compared with dKO mice as suggested by histological assessment and myeloperoxidase activity. In conclusion, these results suggest an overriding role of MMP-9 in mediating tissue injury compared with the protective role of MMP-2 in development of colitis. Thus inhibition of MMP-9 may be beneficial in treatment of colitis even if resulting in inhibition of MMP-2.

Matrix metalloproteinase-9 derived from polymorphonuclear neutrophils increases gut barrier dysfunction and bacterial translocation in rat severe acute pancreatitis

BACKGROUND

The role of polymorphonuclear neutrophil granulocytes (PMNs) and the PMN-derived protease, which is called matrix metalloproteinase-9 (MMP-9), for the gut barrier dysfunction in severe acute pancreatitis (SAP) has not yet been clarified. The aim of this study was to evaluate the effects of PMNs and MMP-9 on gut barrier dysfunction in rat SAP.

METHODS

SAP was induced by the injection of 5% sodium taurocholate, and anti-rat PMN serum or BB-94 were administered 48 h and 24 h, respectively, before the induction of acute pancreatitis. Twenty-four hours after the induction of acute pancreatitis, the gut barrier dysfunction and the incidence of bacterial translocation (BT) and PMN transmigration were investigated by bacterial, histologic, and biochemical (MPO) analysis. Inhibition of MMP-9 was achieved by depletion of PMNs or inhibition of MMP-activity by a broad-spectrum MMP inhibitor and confirmed by zymography. In addition, reactive oxygen species were evaluated by spin trap assay.

RESULTS

The mucosal injury and the infiltration of PMNs into the gut tissue of rats with SAP were significantly increased in comparison with rats treated with anti-rat PMN serum or BB-94. The levels of MMP-9 and reactive oxygen species in the gut of rats with SAP were significantly higher than those of the rats treated with anti-rat PMN serum or BB-94. Pretreatment with anti-rat PMN serum or BB-94 reduced the incidence of BT in SAP.

CONCLUSION

The incidence of BT in SAP was prevented by the depletion of PMNs or less pronounced by the injection of the MMP inhibitor BB-94. PMNs play an important pathophysiologic role in the occurrence of BT, and MMP-9 is involved in both BT and PMN transmigration in rat SAP.

Matrix metalloproteinase-9 and metalloproteinase-2 activity and expression is reduced by melatonin during experimental colitis

Matrix metalloproteinases (MMPs) are associated with matrix turnover in both physiological and pathological conditions. Several data indicate that MMPs play an important role in the pathogenesis of colitis. Various evidence has documented that the pineal secretory product melatonin exerts an important anti-inflammatory effect in different experimental models including colitis. However, no reports are available on the relationship between the activity and expression of MMPs and anti-inflammatory effect of melatonin. The aim of the present study was to evaluate whether melatonin prevents the experimental colitis in rats by regulating MMP-9 and MMP-2 activity and expression. Colitis was induced by intracolonic instillation of dinitrobenzene sulphonic acid (DNBS). Four days after DNBS administration, colon TNF-alpha production was associated with colon damage. Biochemical methods and zymography were used to analyse MMP-9 and MMP-2 activities in colon tissues from DNBS-injured rats. Our studies reveal that melatonin prevented colon injury and lipid peroxidation in rats at 4 days after DNBS-induced colitis. Melatonin also reduced proMMP-9 and MMP-2 activities that were induced in the colon tissues by DNBS administration. Reduced MMP-9 and MMP-2 activities were associated with reduced expression of TNF-alpha. We conclude that melatonin's ability to reduce DNBS-induced colon injury in rats is related to a reduction in proMMP-9 and MMP-2 activities and expression.