Expression of matrix metalloproteinases-2 and -9 in intestinal tissue of patients with inflammatory bowel diseases

Perspectives on the extracellular matrix in inflammatory bowel disease and bowel decellularization protocols

The extracellular matrix (ECM) is a non-cellular three-dimensional structure present in all tissues that is essential for the intestinal maintenance, function and structure, as well as for providing physical support for tissue integrity and elasticity. ECM enables the regulation of various processes involved in tissue homeostasis, being vital for healing, growth, migration and cell differentiation. Structurally, ECM is composed of water, polysaccharides and proteins, such as collagen fibers and proteoglycans, which are specifically arranged for each tissue. In pathological scenarios, such as inflammatory bowel disease (IBD), the deposition and remodeling of the ECM can be altered in relation to the homeostatic composition. IBD, such as Ulcerative colitis and Crohn’s disease, can be differentiated according to ECM alterations, such as circulating levels of collagen, laminin and vimentin neoepitopes. In this context, ECM presents particularities in both physiological and pathological processes, however, exploring methods of tissue decellularization is emerging as a promising frontier for new therapeutic interventions and clinical protocols, promoting the development of new approaches to intestinal diseases.

How the Western Diet Thwarts the Epigenetic Efforts of Gut Microbes in Ulcerative Colitis and Its Association with Colorectal Cancer

Ulcerative colitis (UC) is an autoimmune disease in which the immune system attacks the colon, leading to ulcer development, loss of colon function, and bloody diarrhea. The human gut ecosystem consists of almost 2000 different species of bacteria, forming a bioreactor fueled by dietary micronutrients to produce bioreactive compounds, which are absorbed by our body and signal to distant organs. Studies have shown that the Western diet, with fewer short-chain fatty acids (SCFAs), can alter the gut microbiome composition and cause the host's epigenetic reprogramming. Additionally, overproduction of H2S from the gut microbiome due to changes in diet patterns can further activate pro-inflammatory signaling pathways in UC. This review discusses how the Western diet affects the microbiome's function and alters the host's physiological homeostasis and susceptibility to UC. This article also covers the epidemiology, prognosis, pathophysiology, and current treatment strategies for UC, and how they are linked to colorectal cancer.

Matrix metalloproteinases in intestinal fibrosis

Intestinal fibrosis is a common complication in patients with inflammatory bowel disease [IBD], in particular Crohn's disease [CD]. Unfortunately, at present intestinal fibrosis is not yet preventable, and cannot be treated by interventions other than surgical removal. Intestinal fibrosis is characterized by excessive accumulation of extracellular matrix [ECM], which is caused by activated fibroblasts and smooth muscle cells. Accumulation of ECM results from an imbalanced production and degradation of ECM. ECM degradation is mainly performed by matrix metalloproteinases [MMPs], enzymes that are counteracted by tissue inhibitors of MMPs [TIMPs]. In IBD patients, MMP activity [together with other protease activities] is increased. At the same time, CD patients have a generally lower MMP activity compared to ulcerative colitis patients, who usually do not develop intestinal strictures or fibrosis. The exact regulation and role[s] of these MMPs in fibrosis are far from understood. Here, we review the current literature about ECM remodelling by MMPs in intestinal fibrosis and their potential role as biomarkers for disease progression or druggable targets.

Activatable Probes for Ratiometric Imaging of Endogenous Biomarkers In Vivo

Dynamic variations in the concentration and abnormal distribution of endogenous biomarkers are strongly associated with multiple physiological and pathological states. Therefore, it is crucial to design imaging systems capable of real-time detection of dynamic changes in biomarkers for the accurate diagnosis and effective treatment of diseases. Recently, ratiometric imaging has emerged as a widely used technique for sensing and imaging of biomarkers due to its advantage of circumventing the limitations inherent to conventional intensity-dependent signal readout methods while also providing built-in self-calibration for signal correction. Here, the recent progress of ratiometric probes and their applications in sensing and imaging of biomarkers are outlined. Ratiometric probes are classified according to their imaging mechanisms, and ratiometric photoacoustic imaging, ratiometric optical imaging including photoluminescence imaging and self-luminescence imaging, ratiometric magnetic resonance imaging, and dual-modal ratiometric imaging are discussed. The applications of ratiometric probes in the sensing and imaging of biomarkers such as pH, reactive oxygen species (ROS), reactive nitrogen species (RNS), glutathione (GSH), gas molecules, enzymes, metal ions, and hypoxia are discussed in detail. Additionally, this Review presents an overview of challenges faced in this field along with future research directions.

The Leptospermum scoparium (Mānuka)-Specific Nectar and Honey Compound 3,6,7-Trimethyllumazine (LepteridineTM) That Inhibits Matrix Metalloproteinase 9 (MMP-9) Activity

3,6,7-trimethyllumazine (Lepteridine™) is a newly discovered natural pteridine derivative unique to Mānuka (Leptospermum scoparium) nectar and honey, with no previously reported biological activity. Pteridine derivative-based medicines, such as methotrexate, are used to treat auto-immune and inflammatory diseases, and Mānuka honey reportedly possesses anti-inflammatory properties and is used topically as a wound dressing. MMP-9 is a potential candidate protein target as it is upregulated in recalcitrant wounds and intestinal inflammation. Using gelatin zymography, 40 μg/mL LepteridineTM inhibited the gelatinase activities of both pro- (22%, p < 0.0001) and activated (59%, p < 0.01) MMP-9 forms. By comparison, LepteridineTM exerted modest (~10%) inhibition against a chromogenic peptide substrate and no effect against a fluorogenic peptide substrate. These findings suggest that LepteridineTM may not interact within the catalytic domain of MMP-9 and exerts a negligible effect on the active site hydrolysis of small soluble peptide substrates. Instead, the findings implicate fibronectin II domain interactions by LepteridineTM which impair gelatinase activity, possibly through perturbed tethering of MMP-9 to the gelatin matrix. Molecular modelling analyses were equivocal over interactions at the S1' pocket versus the fibronectin II domain, while molecular dynamic calculations indicated rapid exchange kinetics. No significant degradation of synthetic or natural LepteridineTM in Mānuka honey occurred during simulated gastrointestinal digestion. MMP-9 regulates skin and gastrointestinal inflammatory responses and extracellular matrix remodelling. These results potentially implicate LepteridineTM bioactivity in Mānuka honey's reported beneficial effects on wound healing via topical application and anti-inflammatory actions in gastrointestinal disorder models via oral consumption.

Serine proteases and metalloproteases are highly increased in irritable bowel syndrome Tunisian patients

Serine proteases are involved in many biological processes and are associated with irritable bowel syndrome (IBS) pathology. An increase in serine protease activity has been widely reported in IBS patients. While most of the studies focused on host proteases, the contribution of microbial proteases are poorly studied. In the present study, we report the analysis of proteolytic activities in fecal samples from the first Tunisian cohort of IBS-M patients and healthy individuals. We demonstrated, for the first time, that metalloproteases activities were fourfold higher in fecal samples of IBS patients compared to controls. Of interest, the functional characterization of serine protease activities revealed a 50-fold increase in trypsin-like activities and a threefold in both elastase- and cathepsin G-like activities. Remarkably, we also showed a fourfold increase in proteinase 3-like activity in the case of IBS. This study also provides insight into the alteration of gut microbiota and its potential role in proteolytic modulation in IBS. Our results stressed the impact of the disequilibrium of serine proteases, metalloproteases and gut microbiota in IBS and the need of the further characterization of these targets to set out new therapeutic approaches.

Crohn's Disease: Basic Characteristics of the Disease, Diagnostic Methods, the Role of Biomarkers, and Analysis of Metalloproteinases: A Review

Crohn's disease is a chronic inflammatory bowel disease that affects the ileum and/or large intestine. At the same time, it can also affect any other part of the human body, i.e., from the mouth to the anus. In Crohn's disease, the physiology and functioning of the epithelial barrier are inhibited due to the correlation of various factors, such as the environment, genetic susceptibility or intestinal microbiota. The symptoms are very troublesome and cause a significant reduction in quality of life, sometimes occurring with paralyzing permanent damage to the digestive tract, requiring enteral or parenteral nutrition throughout life. In order to make a proper and accurate diagnosis, an appropriately selected diagnostic path in a given clinical entity is necessary. Standard diagnostic methods are: laboratory examination, histopathological examination, endoscopic examination, X-ray, computed tomography, ultrasound examination and magnetic resonance imaging. Medical biology and the analysis of metalloproteinases have also proved helpful in diagnosing changes occurring as a result of Crohn's disease. Here we provide a thorough review of the latest reports on Crohn's disease and its genetic conditions, symptoms, morphology, diagnosis (including the analysis of Crohn's disease biomarkers, i.e., metalloproteinases) and treatment.

Key elements determining the intestinal region-specific environment of enteric neurons in type 1 diabetes

Diabetes, as a metabolic disorder, is accompanied with several gastrointestinal (GI) symptoms, like abdominal pain, gastroparesis, diarrhoea or constipation. Serious and complex enteric nervous system damage is confirmed in the background of these diabetic motility complaints. The anatomical length of the GI tract, as well as genetic, developmental, structural and functional differences between its segments contribute to the distinct, intestinal region-specific effects of hyperglycemia. These observations support and highlight the importance of a regional approach in diabetes-related enteric neuropathy. Intestinal large and microvessels are essential for the blood supply of enteric ganglia. Bidirectional morpho-functional linkage exists between enteric neurons and enteroglia, however, there is also a reciprocal communication between enteric neurons and immune cells on which intestinal microbial composition has crucial influence. From this point of view, it is more appropriate to say that enteric neurons partake in multidirectional communication and interact with these key players of the intestinal wall. These interplays may differ from segment to segment, thus, the microenvironment of enteric neurons could be considered strictly regional. The goal of this review is to summarize the main tissue components and molecular factors, such as enteric glia cells, interstitial cells of Cajal, gut vasculature, intestinal epithelium, gut microbiota, immune cells, enteroendocrine cells, pro-oxidants, antioxidant molecules and extracellular matrix, which create and determine a gut region-dependent neuronal environment in diabetes.

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.

Identification of diagnostic biomarks and immune cell infiltration in ulcerative colitis

We aimed to explore diagnostic biomarks and immune cell infiltration characteristics in ulcerative colitis (UC). We used the dataset GSE38713 as the training set and dataset GSE94648 as the test set. A total of 402 differentially expressed genes (DEGs) were obtained from GSE38713. Annotating, visualizing, and integrating discovery of these differential genes was performed using Gene Ontology (GO), Kyoto Gene and Genome Encyclopedia Pathway (KEGG), and Gene Set Enrichment Analysis (GSEA). Protein-protein interaction networks were constructed from the STRING database, and protein functional modules were identified using the CytoHubba plugin of Cytoscape. Random forest and LASSO regression were used to screen for UC-related diagnostic markers, and ROC curves were generated to validate their diagnostic value. The composition of 22 immune cells was analyzed, and the immune cell infiltration in UC was analyzed using CIBERSORT. Results: Seven diagnostic markers associated with UC were identified: TLCD3A, KLF9, EFNA1, NAAA,WDR4, CKAP4, and CHRNA1. Immune cell infiltration assessment revealed that macrophages M1, activated dendritic cells, and neutrophil cells infiltrated relatively more compared to normal control samples. Our results suggest a new functional feature of UC and suggest potential biomarkers for UC through comprehensive analysis of integrated gene expression data.

Donepezil halts acetic acid-induced experimental colitis in rats and its associated cognitive impairment through regulating inflammatory/oxidative/apoptotic cascades: An add-on to its anti-dementia activity

Ulcerative colitis (UC) is a persistent inflammatory bowel disease (IBD) that is regarded as a risk factor for cognitive impairment. Donepezil (DON), a centrally acting acetylcholinesterase inhibitor (AChEI), is approved for the management of Alzheimer's disease (AD). We aimed to scrutinize the impact of DON on acetic acid (AA)-induced UC in rats and to evaluate its ability to attenuate inflammatory response, oxidative strain, and apoptosis in this model and its associated cognitive deficits. Rats were categorized into: normal, DON, AA, and AA + DON groups. DON (5 mg/kg/day) was administered orally for 14 days either alone or beginning with the day of UC induction. Colitis was evoked by a single transrectal injection of 1 ml of 4 % acetic acid. Results revealed that DON significantly improved the behavioral abnormalities with the mitigation of inflammation, apoptosis, and histopathological changes in the hippocampi of the colitis group. Moreover, DON significantly alleviated the macroscopic and microscopic changes associated with colitis. Interestingly, DON inhibited pro-inflammatory cytokines via suppression of AA-induced activation of nuclear factor kappa-B (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) in the colon, along with serum IL-1β. DON inhibited colon lipid peroxidation, restored the antioxidants with a significant amelioration of the degree of neutrophil infiltration, and repressed colitis-induced matrix metalloproteinases-9 (MMP-9) production. Furthermore, DON decreased the Bax/Bcl-2 ratio and caspase-3 protein expressions. Eventually, in lipopolysaccharide (LPS)-treated RAW 264.7 macrophage cells, DON suppressed nitric oxide (NO) release, demonstrating the ability of DON to significantly curtail inflammation in immune cells. Taken together, DON ameliorated experimental colitis and its linked cognitive dysfunction, possibly via its antioxidant effect and modulation of pro-inflammatory cytokines and apoptosis. Thereby, DON could be a therapeutic nominee for UC and associated neurological disorders.

The immunomodulatory role of matrix metalloproteinases in colitis-associated cancer

Matrix metalloproteinases (MMPs) are an important class of enzymes in the body that function through the extracellular matrix (ECM). They are involved in diverse pathophysiological processes, such as tumor invasion and metastasis, cardiovascular diseases, arthritis, periodontal disease, osteogenesis imperfecta, and diseases of the central nervous system. MMPs participate in the occurrence and development of numerous cancers and are closely related to immunity. In the present study, we review the immunomodulatory role of MMPs in colitis-associated cancer (CAC) and discuss relevant clinical applications. We analyze more than 300 pharmacological studies retrieved from PubMed and the Web of Science, related to MMPs, cancer, colitis, CAC, and immunomodulation. Key MMPs that interfere with pathological processes in CAC such as MMP-2, MMP-3, MMP-7, MMP-9, MMP-10, MMP-12, and MMP-13, as well as their corresponding mechanisms are elaborated. MMPs are involved in cell proliferation, cell differentiation, angiogenesis, ECM remodeling, and the inflammatory response in CAC. They also affect the immune system by modulating differentiation and immune activity of immune cells, recruitment of macrophages, and recruitment of neutrophils. Herein we describe the immunomodulatory role of MMPs in CAC to facilitate treatment of this special type of colon cancer, which is preceded by detectable inflammatory bowel disease in clinical populations.

Inflammatory Bowel Disease-Associated Gut Commensals Degrade Components of the Extracellular Matrix

Extracellular matrix (ECM) remodeling has emerged as a key feature of inflammatory bowel disease (IBD), and ECM fragments have been proposed as markers of clinical disease severity. Recent studies report increased protease activity in the gut microbiota of IBD patients. Nonetheless, the relationship between gut microbiota and ECM remodeling has remained unexplored. We hypothesized that members of the human gut microbiome could degrade the host ECM and that bacteria-driven remodeling, in turn, could enhance colonic inflammation. Through a variety of in vitro assays, we first confirmed that multiple bacterial species found in the human gut are capable of degrading specific ECM components. Clinical stool samples obtained from ulcerative colitis patients also exhibited higher levels of proteolytic activity in vitro, compared to those of their healthy counterparts. Furthermore, culture supernatants from bacteria species that are capable of degrading human ECM accelerated inflammation in dextran sodium sulfate (DSS)-induced colitis. Finally, we identified several of the bacterial proteases and carbohydrate degrading enzymes (CAZymes) that are potentially responsible for ECM degradation in vitro. Some of these protease families and CAZymes were also found in increased abundance in a metagenomic cohort of IBD. These results demonstrate that some commensal bacteria in the gut are indeed capable of degrading components of human ECM in vitro and suggest that this proteolytic activity may be involved in the progression of IBD. A better understanding of the relationship between nonpathogenic gut microbes, host ECM, and inflammation could be crucial to elucidating some of the mechanisms underlying host-bacteria interactions in IBD and beyond. IMPORTANCE Healthy gut epithelial cells form a barrier that keeps bacteria and other substances from entering the blood or tissues of the body. Those cells sit on scaffolding that maintains the structure of the gut and informs our immune system about the integrity of this barrier. In patients with inflammatory bowel disease (IBD), breaks are formed in this cellular barrier, and bacteria gain access to the underlying tissue and scaffolding. In our study, we discovered that bacteria that normally reside in the gut can modify and disassemble the underlying scaffolding. Additionally, we discovered that changes to this scaffolding affect the onset of IBD in mouse models of colitis as well as the abilities of these mice to recover. We propose that this new information will reveal how breaks in the gut wall lead to IBD and will open up new avenues by which to treat patients with IBD.

Elucidating the Role of Innate and Adaptive Immune Responses in the Pathogenesis of Canine Chronic Inflammatory Enteropathy-A Search for Potential Biomarkers

Simple Summary

Canine chronic inflammatory enteropathy (CIE) is a chronic disease affecting the small or large intestine and, in some cases, the stomach of dogs. This gastrointestinal disorder is common and is characterized by recurrent vomiting, diarrhea, and weight loss in affected dogs. The pathogenesis of IBD is not completely understood. Similar to human IBD, potential disease factors include genetics, environmental exposures, and dysregulation of the microbiota and the immune response. Some important components of the innate and adaptive immune response involved in CIE pathogenesis have been described. However, the immunopathogenesis of the disease has not been fully elucidated. In this review, we summarized the literature associated with the different cell types and molecules involved in the immunopathogenesis of CIE, with the aim of advancing the search for biomarkers with possible diagnostic, prognostic, or therapeutic utility.

Abstract

Canine chronic inflammatory enteropathy (CIE) is one of the most common chronic gastrointestinal diseases affecting dogs worldwide. Genetic and environmental factors, as well as intestinal microbiota and dysregulated host immune responses, participate in this multifactorial disease. Despite advances explaining the immunological and molecular mechanisms involved in CIE development, the exact pathogenesis is still unknown. This review compiles the latest reports and advances that describe the main molecular and cellular mechanisms of both the innate and adaptive immune responses involved in canine CIE pathogenesis. Future studies should focus research on the characterization of the immunopathogenesis of canine CIE in order to advance the establishment of biomarkers and molecular targets of diagnostic, prognostic, or therapeutic utility.

Matrix Metalloproteinases and Their Inhibitors in Pulmonary Fibrosis: EMMPRIN/CD147 Comes into Play

Pulmonary fibrosis (PF) is characterized by aberrant extracellular matrix (ECM) deposition, activation of fibroblasts to myofibroblasts and parenchymal disorganization, which have an impact on the biomechanical traits of the lung. In this context, the balance between matrix metalloproteinases (MMPs) and their tissue inhibitors of metalloproteinases (TIMPs) is lost. Interestingly, several MMPs are overexpressed during PF and exhibit a clear profibrotic role (MMP-2, -3, -8, -11, -12 and -28), but a few are antifibrotic (MMP-19), have both profibrotic and antifibrotic capacity (MMP7), or execute an unclear (MMP-1, -9, -10, -13, -14) or unknown function. TIMPs are also overexpressed in PF; hence, the modulation and function of MMPs and TIMP are more complex than expected. EMMPRIN/CD147 (also known as basigin) is a transmembrane glycoprotein from the immunoglobulin superfamily (IgSF) that was first described to induce MMP activity in fibroblasts. It also interacts with other molecules to execute non-related MMP aactions well-described in cancer progression, migration, and invasion. Emerging evidence strongly suggests that CD147 plays a key role in PF not only by MMP induction but also by stimulating fibroblast myofibroblast transition. In this review, we study the structure and function of MMPs, TIMPs and CD147 in PF and their complex crosstalk between them.

The Future of Precision Medicine to Predict Outcomes and Control Tissue Remodeling in Inflammatory Bowel Disease

Inflammatory bowel disease is characterized by significant interindividual heterogeneity. With a wider selection of pharmacologic and nonpharmacologic interventions available and in advanced developmental stages, a priority for the coming decade is to determine accurate methods of predicting treatment response and disease course. Precision medicine strategies will allow tailoring of preventative and therapeutic decisions to individual patient needs. In this review, we consider the future of precision medicine in inflammatory bowel disease. We discuss the critical need to extend from research focused on short-term symptomatic response to integrative multi-omic systems biology strategies to identify and validate biomarkers that underpin precision approaches. Crucially, the international community has collective responsibility to provide well-phenotyped and -curated longitudinal datasets for scientific discovery and validation. Research must also study broader aspects of the immune response, including components of the extracellular matrix, to better understand biological pathways initiating and perpetuating tissue fibrosis and longer-term disease complications.

Investigate the genetic mechanisms of diabetic kidney disease complicated with inflammatory bowel disease through data mining and bioinformatic analysis

BACKGROUND

Patients with diabetic kidney disease (DKD) often have gastrointestinal dysfunction such as inflammatory bowel disease (IBD). This study aims to investigate the genetic mechanism leading to IBD in DKD patients through data mining and bioinformatics analysis.

METHODS

The disease-related genes of DKD and IBD were searched from the five databases of OMIM, GeneCards, PharmGkb, TTD, and DrugBank, and the intersection part of the two diseases were taken to obtain the risk genes of DKD complicated with IBD. A protein-protein interaction (PPI) network analysis was performed on risk genes, and three topological parameters of degree, betweenness, and closeness of nodes in the network were used to identify key risk genes. Finally, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed on the risk genes to explore the related mechanism of DKD merging IBD.

RESULTS

This study identified 495 risk genes for DKD complicated with IBD. After constructing a protein-protein interaction network and screening for three times, six key risk genes were obtained, including matrix metalloproteinase 2 (MMP2), hepatocyte growth factor (HGF), fibroblast growth factor 2 (FGF2), interleukin (IL)-18, IL-13, and C-C motif chemokine ligand 5 (CCL5). Based on GO enrichment analysis, we found that DKD genes complicated with IBD were associated with 3,646 biological processes such as inflammatory response regulation, 121 cellular components such as cytoplasmic vesicles, and 276 molecular functions such as G-protein-coupled receptor binding. Based on KEGG enrichment analysis, we found that the risk genes of DKD combined with IBD were associated with 181 pathways, such as the PI3K-Akt signaling pathway, advanced glycation end product-receptor for AGE (AGE-RAGE) signaling pathway and hypoxia-inducible factor (HIF)-1 signaling pathway.

CONCLUSION

There is a genetic mechanism for the complication of IBD in patients with CKD. Oxidative stress, chronic inflammatory response, and immune dysfunction were possible mechanisms for DKD complicated with IBD.

Serum matrix metalloproteinase-9 concentration as a marker of disease activity in patients with inflammatory bowel disease

BACKGROUND AND AIM

Diagnosing inflammatory bowel disease (IBD), determining the appropriate treatment and follow-up of patients rely mainly on endoscopy and biopsy. Finding a sensitive, specific, cost-effective and less-invasive biomarker is the focus of much of the current research in this field. The aim was to investigate the relation between serum matrix metalloproteinase-9 (MMP-9) levels and disease activity in patients with IBD, correlating with clinical and endoscopic indices of disease activity and with treatment received.

PATIENTS AND METHODS

Sixty patients (30 with ulcerative colitis, 30 with Crohn's disease) and 20 controls were included. Serum MMP-9 levels were measured for all patients and controls by ELISA. Clinical activity was determined by partial Mayo score for patients with ulcerative colitis and Crohn's Disease Activity Index for patients with Crohn's disease, and endoscopic activity was assessed using Ulcerative Colitis Endoscopic Index of Severity for patients with ulcerative colitis and Simple Endoscopic Score of Crohn's disease for patients with Crohn's disease.

RESULTS

Serum MMP-9 was higher in patients with active ulcerative colitis than in patients with inactive disease and the control group. Serum MMP-9 was also higher in patients with active Crohn's disease than in patients with inactive disease and the control group. In both ulcerative colitis and Crohn's disease groups, there was a significant difference between serum MMP-9 levels in patients receiving conventional treatment and those on biological treatment, with lower levels of the marker detected in the sera of patients subgroups receiving biologics.

CONCLUSION

Serum MMP-9 can be used to differentiate between active and inactive IBD (including both ulcerative colitis and Crohn's disease).

Interplay between Extracellular Matrix and Neutrophils in Diseases

The extracellular matrix (ECM) is a highly dynamic and complex network structure, which exists in almost all tissues and is the microenvironment that cells rely on for survival. ECM interacts with cells to regulate diverse functions, including differentiation, proliferation, and migration. Neutrophils are the most abundant immune cells in circulation and play key roles in orchestrating a complex series of events during inflammation. Neutrophils can also mediate ECM remodeling by providing specific matrix-remodeling enzymes (such as neutrophil elastase and metalloproteinases), generating neutrophil extracellular traps, and releasing exosomes. In turn, ECM can remodel the inflammatory microenvironment by regulating the function of neutrophils, which drives disease progression. Both the presence of ECM and the interplay between neutrophils and their extracellular matrices are considered an important and outstanding mechanistic aspect of inflammation. In this review, the importance of ECM will be considered, together with the discussion of recent advances in understanding the underlying mechanisms of the intricate interplay between ECM and neutrophils. A better comprehension of immune cell-matrix reciprocal dependence has exciting implications for the development of new therapeutic options for neutrophil-associated infectious and inflammatory diseases.

Clinicopathological and bacteriological studies on lamb bacterial enteritis and monitoring the oregano oil and vitamins A,D3,E effect on its treatment

Objective:

The objective of the study was to assess the effect of A,D₃,E (I/M) and oregano oil extract 15% on some clinicopathological parameters during lamb bacterial enteritis treatment.

Materials and Methods:

Sixty Barki lambs, 20 apparently healthy (control group) and, 40 suffered from bacterial enteritis [enteric group (EG)], were subdivided into four treated groups (TGs): antibiotic group (AG), antibiotic + A,D₃,E group (A + A,D₃,E), antibiotic + oregano oil (AOG), and oregano group (OG). Fecal swabs were collected from EG then aseptically cultured, isolated, phenotypically identified, genotypically confirmed, and sequenced by PCR 16srRNA. Paper disk diffusion test was used for estimation of oregano oil extract 15% antibacterial activity. After blood sample aspiration from all animals, they were clinicopathologically and statistically analyzed.

Results:

Escherichia coli, followed by Salmonella species and then Klebsiella species, was the main causative agents of lamb diarrhea and were susceptible to oregano oil extract 15%. A + A,D₃,E and AOG showed significant (p < 0.05) enhancement of some clinicopathological parameters more than AG or OG. Matrix metalloproteinases (MMP-2 and MMP-9) and total antioxidant capacity (TAC), yielded area under the curve, sensitivity, negative predictive value as 1, 100% and 100% respectively, were determined in both EG and TGs.

Conclusion:

Oregano oil extract 15% has good antibacterial properties against enteric bacteria in vitro and in vivo. The combination between antibiotic and antioxidant vitamins or oregano plant extract of 15% has a good impact on some clinicopathological alterations in lamb bacterial enteritis treatment. TAC, MMP-9, and MMP-2 may be good markers for the disease and its treatment follow-up.

Matrix Metalloproteinase-9 (MMP-9) induced disruption of intestinal epithelial tight junction barrier is mediated by NF-κB activation

BACKGROUND

Matrix Metalloproteinase-9 (MMP-9) has been shown to play a key role in mediating inflammation and tissue damage in inflammatory bowel disease (IBD). In patients with IBD, the intestinal tight junction (TJ) barrier is compromised as characterized by an increase in intestinal permeability. MMP-9 is elevated in intestinal tissue, serum and stool of patients with IBD. Previous studies from our laboratory showed that MMP-9 causes an increase in intestinal epithelial TJ permeability and that the MMP-9 induced increase in intestinal permeability is an important pathogenic factor contributing to the development of intestinal inflammation in IBD. However, the intracellular mechanisms that mediate the MMP-9 modulation of intestinal barrier function remain unclear.

AIMS

The main aim of this study was to further elucidate the molecular mechanisms involved in MMP-9 induced increase in intestinal epithelial TJ permeability using Caco-2 monolayers as an in-vitro model system.

RESULTS

MMP-9 induced increase in Caco-2 TJ permeability was associated with activation and cytoplasmic-to-nuclear translocation of NF-κB p65. Knocking-down NF-κB p65 by siRNA transfection prevented the MMP-9 induced expression of the NF-κB target gene IL-8, myosin light chain kinase (MLCK) protein expression, and subsequently prevented the increase in Caco-2 TJ permeability. In addition, the effect of MMP-9 on Caco-2 intestinal epithelial TJ barrier function was not mediated by apoptosis or necrosis.

CONCLUSION

Our data show that the MMP-9 induced disruption of Caco-2 intestinal epithelial TJ barrier function is regulated by NF-κB pathway activation of MLCK.

Role of Matrix Metalloproteinases in Angiogenesis and Its Implications in Asthma

Asthma is a chronic airway disorder associated with aberrant inflammatory and remodeling responses. Angiogenesis and associated vascular remodeling are one of the pathological hallmarks of asthma. The mechanisms underlying angiogenesis in asthmatic airways and its clinical relevance represent a relatively nascent field in asthma when compared to other airway remodeling features. Matrix metalloproteinases (MMPs) are proteases that play an important role in both physiological and pathological conditions. In addition to facilitating extracellular matrix turnover, these proteolytic enzymes cleave bioactive molecules, thereby regulating cell signaling. MMPs have been implicated in the pathogenesis of asthma by interacting with both the airway inflammatory cells and the resident structural cells. MMPs also cover a broad range of angiogenic functions, from the degradation of the vascular basement membrane and extracellular matrix remodeling to the release of a variety of angiogenic mediators and growth factors. This review focuses on the contribution of MMPs and the regulatory role exerted by them in angiogenesis and vascular remodeling in asthma as well as addresses their potential as therapeutic targets in ameliorating angiogenesis in asthma.

89Zr-pro-MMP-9 F(ab')2 detects colitis induced intestinal and kidney fibrosis

Intestinal fibrosis is a common complication of inflammatory bowel disease but remains difficult to detect. Matrix metalloproteases (MMPs) have key roles in fibrosis and are therefore potential targets for fibrosis detection. We determined whether immunoPET of F(ab′)₂ antibody fragments targeting MMPs detects colitis induced colonic fibrosis. Mice were administered 2% dextran sulfate sodium treated water for 1 cycle (inflamed) or 3 cycles (fibrotic), or were untreated (control). Colonic and kidney collagen, innate cytokine, MMPs and fecal MPO concentrations were analyzed by multiplex/ELISA. α-pro-MMP-9 F(ab′)₂ fragments were engineered and conjugated to ⁸⁹Zr for PET imaging, ex-vivo Cherenkov analysis and bio-distribution. Colonic innate cytokine concentrations and fecal myeloperoxidase were increased in inflamed mice but not fibrotic mice, while collagen concentrations were increased in fibrotic mice. MMPs were increased in inflamed mice, but only pro-MMP-9 remained increased in fibrotic mice. ⁸⁹Zr-pro-MMP-9 F(ab′)₂ uptake was increased in the intestine but also in the kidney of fibrotic mice, where collagen and pro-MMP-9 concentrations were increased. ⁸⁹Zr-pro-MMP-9 F(ab′)₂ detects colitis induced intestinal fibrosis and associated kidney fibrosis.

Composites of yeast glucan particles and curcumin lead to improvement of dextran sulfate sodium-induced acute bowel inflammation in rats

The goal of this work was to assess the usability of yeast glucan particles (GPs) as carriers for curcumin and determine the beneficial effect of a pharmacological composite of curcumin in GPs on dextran sulfate sodium induced colitis in rats. The assessment of the anti-inflammatory effect of particular substances was evaluated on the basis of the calculated disease activity index and by assessment of cytokines and enzymes from the gut tissue - tumor necrosis factor α (TNF-α), transforming growth factor β1, interleukin (IL)-1β, IL-6, IL-10, IL-17, catalase, superoxide dismutase 2, myeloperoxidase (MPO), and matrix metalloproteinase 9. Composites of GPs with incorporated curcumin showed promising results with the capability to lower symptoms of colitis and significantly decrease the production of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, and the activity of MPO, as well. The anti-inflammatory effect of the composites was greater than those of pure GPs or curcumin.

Activities of matrix metalloproteinase-2, matrix metalloproteinase-9, and serine proteases in samples of the colorectal mucosa of Miniature Dachshunds with inflammatory colorectal polyps

OBJECTIVE

To investigate the activities of gelatinases (matrix metalloproteinase [MMP]-2 and MMP-9) and serine proteases in the colorectal mucosa of Miniature Dachshunds (MDs) with inflammatory colorectal polyps (ICRPs).

ANIMALS

15 MDs with ICRPs and 5 dogs with non-ICRP-related large bowel diarrhea (controls).

PROCEDURES

Zymographic methods were used to evaluate the activities of MMP-2, MMP-9, latent forms of MMP-2 and MMP-9 (pro-MMP-2 and pro-MMP-9), and serine proteases in inflamed and noninflamed tissue samples from MDs with ICRPs and in noninflamed tissue samples from control dogs. The associations of serine protease activities with MMP-2 or MMP-9 activity were also analyzed.

RESULTS

Activities of pro-MMP-2 and pro-MMP-9 were detected in most tissue samples, regardless of the tissue type, whereas activities of MMP-2 and MMP-9 were not detected in control tissue samples. In the inflamed tissue samples from MDs with ICRPs, the activities of MMP-2, pro-MMP-9, and MMP-9 were significantly higher than those in the noninflamed tissue samples from those dogs. Serine protease activities were significantly higher in the inflamed and noninflamed tissue samples from MDs with ICRP, compared with findings for control tissue samples. A weak correlation was detected between serine protease activities and MMP-9 activity.

CONCLUSIONS AND CLINICAL RELEVANCE

Study results suggested that gelatinase and serine protease activities are upregulated in the colorectal mucosa of MDs with ICRPs, possibly contributing to the pathogenesis of this disease through the functions of these enzymes in degradation of extracellular matrix and promotion of inflammatory cell migration and inflammatory responses.

Matrix metalloproteinases cleave membrane-bound PD-L1 on CD90+ (myo-)fibroblasts in Crohn's disease and regulate Th1/Th17 cell responses

Increased T helper (Th)1/Th17 immune responses are a hallmark of Crohn's disease (CD) immunopathogenesis. CD90+ (myo-)fibroblasts (MFs) are abundant cells in the normal (N) intestinal mucosa contributing to mucosal tolerance via suppression of Th1 cell activity through cell surface membrane-bound PD-L1 (mPD-L1). CD-MFs have a decreased level of mPD-L1. Consequently, mPD-L1-mediated suppression of Th1 cells by CD-MFs is decreased, yet the mechanism responsible for the reduction in mPDL-1 is unknown. Increased expression of matrix metalloproteinases (MMPs) has been reported in CD. Herein we observed that when compared to N- and ulcerative colitis (UC)-MFs, CD-MFs increase in LPS-inducible levels of MMP-7 and -9 with a significant increase in both basal and inducible MMP-10. A similar pattern of MMP expression was observed in the CD-inflamed mucosa. Treatment of N-MFs with a combination of recombinant human MMP-7, -9 and -10 significantly decreased mPD-L1. In contrast, inhibition of MMP activity with MMP inhibitors or anti-MMP-10 neutralizing antibodies restores mPD-L1 on CD-MFs. CD-MFs demonstrated reduced capacity to suppress Th1 and Th17 responses from activated CD4+ T cells. By contrast, supplementation of the CD-MF:T-cell co-cultures with MMP inhibitors or anti-MMP neutralizing antibodies restored the CD-MF-mediated suppression. Our data suggest that (i) increased MMP-10 expression by CD-MFs and concomitant cleavage of PD-L1 from the surface of CD-MFs are likely to be one of the factors contributing to the decrease of mPD-L1-mediated suppression of Th1/Th17 cells in CD; and (ii) MMPs are likely to have a significant role in the intestinal mucosal immune responses.

Extracellular Matrix Fragments of the Basement Membrane and the Interstitial Matrix Are Serological Markers of Intestinal Tissue Remodeling and Disease Activity in Dextran Sulfate Sodium Colitis

BACKGROUND

Chronic intestinal inflammation results in tissue damage partly caused by an increase in matrix metalloproteinases (MMP) activity causing degradation of extracellular matrix (ECM) proteins. We studied intestinal tissue remodeling by quantifying ECM protein fragments in serum in dextran sulfate sodium (DSS)-induced colitis, to investigate ECM protein fragments as serological biomarkers of intestinal tissue remodeling and disease activity.

METHODS

Male Sprague-Dawley rats received 5% DSS in drinking water for 5 days followed by 11 days with regular water. Disease activity index (DAI) was scored daily. Serum was collected on day 0, 6, 7, and 16. ELISAs were used to quantify MMP-derived remodeling fragments of basement membrane type IV collagen (C4M and PRO-C4) and interstitial matrix type III collagen (C3M and rPRO-C3).

RESULTS

In DSS rats, serum levels relative to baseline of C4M, PRO-C4, and C3M were elevated (P < 0.01; P < 0.001; P < 0.001) at day 7, which declined at day 16. Levels of rPRO-C3 were lower in DSS rats at day 7 and increased to normal levels at day 16. The ratio between C3M and rPRO-C3 showed an overall degradation (P < 0.0001) of collagen type III in DSS rats at day 7, which correlated to the DAI (r² = 0.5588, P < 0.0001).

CONCLUSION

Our data suggest that remodeling of the basement membrane (C4M and PRO-C4) and the interstitial matrix (C3M and rPRO-C3) increased during DSS-induced colitis and declined with reversal of the disease. Thus, serological biochemical biomarkers of the ECM reflect tissue remodeling and could be studied as markers of disease activity in IBD.

Serum MMP-9: a novel biomarker for prediction of clinical relapse in patients with quiescent Crohn's disease, a post hoc analysis

BACKGROUND

Matrix metalloproteinase-9 (MMP-9) is a novel marker of intestinal inflammation. The aim of this study was to assess if serum MMP-9 levels predict clinical flare in patients with quiescent Crohn's disease (CD).

METHODS

This study was a post hoc analysis of a prospective observational study in which quiescent CD patients were included and followed until clinical relapse or the end of a 2-year follow-up period. Serial C-reactive protein (CRP) and fecal calprotectin (FC) levels were measured, and the patients underwent repeated capsule endoscopies (CEs) every 6 months. Small bowel inflammation was quantified by Lewis score (LS) for CE. A baseline magnetic resonance enterography was also performed, and MaRIA score was calculated. Serum MMP-9 levels in baseline blood samples were quantified by ELISA.

RESULTS

Out of 58 eligible enrolled patients, 16 had a flare. Higher levels of baseline MMP-9 were found in patients who developed subsequent symptomatic flare compared with patients who did not [median 661 ng/ml, 25-75 interquartile range (IQR; 478.2-1441.3) versus 525.5 ng/ ml (339-662.7), respectively, p = 0.01]. Patients with serum MMP-9 levels of 945 ng/ ml or higher were at increased risk for relapse within 24 months [area under the curve (AUC) of 0.72 [95% confidence interval (CI): 0.56-0.88]; hazard ratio 8.1 (95% CI 3.0-21.9, p < 0.001)]. Serum MMP-9 concentrations showed weak and moderate correlation to baseline LS and FC, respectively (r = 0.31, p = 0.02; r = 0.46, p < 0.001). No correlation was found between serum MMP-9 to CRP and MaRIA score.

CONCLUSIONS

Serum MMP-9 may be a promising biomarker for prediction of clinical flare in CD patients with quiescent disease.

The intestinal tissue homeostasis - the role of extracellular matrix remodeling in inflammatory bowel disease

Introduction: Extracellular matrix (ECM) remodeling of the intestinal tissue is important in inflammatory bowel disease (IBD) due to the extensive mucosal remodeling. There are still gaps in our knowledge as to how ECM remodeling is related to intestinal epithelium homeostasis and healing of the intestinal mucosa.Areas covered: The aim of this review is to highlight the importance of the ECM in relation to the pathogenesis of IBD, while addressing basement membrane and interstitial matrix remodeling, and the processes of wound healing of the intestinal tissue in IBD.Expert opinion: In IBD, basement membrane remodeling may reflect the integrity of the intestinal epithelial-cell homeostasis. The interstitial matrix remodeling is associated with deep inflammation such as the transmural inflammation as seen in fistulas and intestinal fibrosis leading to fibrostenotic strictures, in patients with CD. The interplay between wound healing processes and ECM remodeling also affects the tissue homeostasis in IBD. The interstitial matrix, produced by fibroblasts, holds a very different biology as compared to the epithelial basement membrane in IBD. In combination with integration of wound healing, quantifying the interplay between damage and repair to these sub compartments may provide essential information in IBD patient profiling, mucosal healing and disease management.

Challenge to the Intestinal Mucosa During Sepsis

Sepsis is a complex of life-threating organ dysfunction in critically ill patients, with a primary infectious cause or through secondary infection of damaged tissues. The systemic consequences of sepsis have been intensively examined and evidences of local alterations and repercussions in the intestinal mucosal compartment is gradually defining gut-associated changes during sepsis. In the present review, we focus on sepsis-induced dysfunction of the intestinal barrier, consisting of an increased permeability of the epithelial lining, which may facilitate bacterial translocation. We discuss disturbances in intestinal vascular tonus and perfusion and coagulopathies with respect to their proposed underlying molecular mechanisms. The consequences of enzymatic responses by pancreatic proteases, intestinal alkaline phosphatases, and several matrix metalloproteases are also described. We conclude our insight with a discussion on novel therapeutic interventions derived from crucial aspects of the gut mucosal dynamics during sepsis.

Diagnostic Markers for Nonspecific Inflammatory Bowel Diseases

The nonspecific inflammatory bowel diseases (IBD) represent a heterogeneous group of chronic inflammatory disorders of the gastrointestinal tract, and Leśniowski-Crohn's disease (CD) and ulcerative colitis (UC) are among the two major clinical forms. Despite the great progress in understanding the pathogenesis of these diseases, their etiology remains unclear. Genetic, immune, and environmental factors are thought to play a key role. The correct diagnosis of nonspecific inflammatory bowel diseases as well as the determination of disease activity, risk stratification, and prediction of response to therapy still relies on a multidisciplinary approach based on clinical, laboratory, endoscopic, and histologic examination. However, considerable effort has been devoted to the development of an accurate panel of noninvasive biomarkers that have increased diagnostic sensitivity and specificity. Laboratory biomarkers useful in differentiating IBD with functional disorders and in evaluating disease activity, prognosis, and treatment selection for IBD are presented in this study.

Identification of matrix metalloproteinase-2 and -9 activities within the intestinal mucosa of dogs with chronic enteropathies

BACKGROUND

Matrix metalloproteinases (MMPs) 2 and 9 are zinc- and calcium-dependent endopeptidases involved in the breakdown and reconstitution of extracellular matrix under both physiological and pathological conditions. Mucosal MMP-2 and -9 activities have been reported to be upregulated in the intestine of humans with inflammatory bowel disease (IBD), and in animal models of IBD. However, their involvement in the pathogenesis of canine chronic enteropathies (CE) is unknown. This study investigated mucosal pro- and active MMP-2 and -9 activities in dogs with CE and healthy dogs using gelatin zymography, and also to determine the association of their activities in dogs with CE with the canine IBD activity index (CIBDAI), histopathologic findings, the clinical outcome, and hypoalbuminemia. Intestinal mucosal samples from duodenum, ileum, colon, and cecum were collected from 40 dogs with CE and 18 healthy Beagle dogs.

RESULTS

In dogs with CE, the number of samples positive for mucosal pro- and active MMP-2 was significantly higher in the duodenum (P < 0.0001 and P = 0.011, respectively), ileum (P = 0.002 and P = 0.018, respectively), and colon (P < 0.0001 and P = 0.002, respectively), compared with healthy controls. Mucosal pro-MMP-9-positive samples in the duodenum and colon were significantly more frequent in dogs with CE than in healthy dogs (P = 0.0004 and P = 0.001, respectively). Despite the presence of mucosal samples positive for active MMP-9 in the intestinal segments of dogs with CE, the difference compared to healthy controls did not reach statistical significance. None of the intestinal mucosal samples in healthy dogs showed gelatinolytic activity corresponding to the control bands of active MMP-2 and -9. Mucosal active MMP-9 activities displayed a significant positive association with the severity of neutrophil infiltration in the duodenum (P = 00.040), eosinophils in the cecum (P = 00.037), and the CIBDAI score for ileum samples (P = 0.023). There was no significant association of pro- and active MMP-2 and -9 levels with the clinical outcome or hypoalbuminemia.

CONCLUSIONS

This study is the first to demonstrate upregulation of mucosal pro- and active MMP-2 and pro-MMP-9 in the intestine of dogs with CE compared to healthy dogs. The results provide supporting evidence for the possible involvement of MMP-2 and -9 in the pathogenesis of canine CE.

Extracellular matrix remodeling and TGF-β1/Smad signaling in diabetic colon mucosa

Diabetes is associated with metabolic and functional alterations in the gut. Using an experimental model of streptozotocin (STZ)-induced diabetes in rodents, we analyzed the extracellular matrix (ECM) and TGF-β/Smad signaling in the colon mucosa. Male rats were divided into normal control, diabetic and insulin treated diabetic groups during 4 and 9 weeks. Sirius red staining showed marked increase in the extracellular matrix deposition in diabetic mucosa. High levels of fibrillar collagen (I and III) and fibronectin mRNAs were also detected with an imbalance between MMPs/TIMPs activities. Moreover, an increased mesenchymal cell proliferation together with an enhanced expression of myofibroblasts markers vimentin and α-SMA were observed. TGF-β/Smad signaling-related genes were determined using RT-PCR, Western blotting, and immunohistochemistry. Diabetic rats showed a significant up-regulation of TGF-β1, TGF-β receptors and the effectors p-Smad2/3 in the mucosa compared with control rats. Insulin treatment attenuated the stimulating effect of diabetes on colon ECM deposition and TGF-β/Smad signaling. In conclusion, the overall results showed a deregulation of the TGFβ1 pathway associated with the appearance of myofibroblasts and the accumulation of ECM in the mucosa of diabetic colon. These data provide the first in vivo evidence that TGF-β1/Smad is a key component of intestinal tissue remodeling in diabetes.

Differential intestinal anti-inflammatory effects of Lactobacillus fermentum and Lactobacillus salivarius in DSS mouse colitis: impact on microRNAs expression and microbiota composition

SCOPE

To compare the intestinal anti-inflammatory effects of two probiotics Lactobacillus fermentum and Lactobacillus salivarius in mouse colitis, focusing on their impact on selected miRNAs and microbiota composition.

METHODS AND RESULTS

Male C57BL/6J mice were randomly assigned to four groups (n = 10): non-colitic, DSS colitic and two colitic groups treated with probiotics (5 × 10⁸ CFU/mouse/day). Both probiotics ameliorated macroscopic colonic damage. They improved the colonic expression of markers involved in the immune response, and the expression of miR-155 and miR-223. L. fermentum also restored miR-150 and miR-143 expression, also linked to the preservation of the intestinal barrier function. Besides, these beneficial effects were associated with the amelioration of the microbiota dysbiosis and a recovery of the SCFAs- and lactic acid-producing bacterial populations, although only L. fermentum improved Chao richness, Pielou evenness and Shannon diversity. Moreover, L. fermentum also restored the Treg cell population in MLNs and the Th1/Th2 cytokine balance.

CONCLUSION

Both probiotics exerted intestinal anti-inflammatory effects in DSS-mouse colitis, maybe due to their ability to restore the intestinal microbiota homeostasis and modulate the immune response. L. fermentum showed a greater beneficial effect compared to L. salivarius, which makes it more interesting for future studies.

Serum Cyclophilin A Correlates with Increased Tissue MMP-9 in Patients with Ulcerative Colitis, but Not with Crohn's Disease

BACKGROUND

Cyclophilin A (CyPA) is an immunomodulatory protein, high expression of which correlates with poor outcome of patients with inflammatory diseases. However, its role in inflammatory bowel disease (IBD) has not been studied.

AIM

This study analyzes the correlation between cyclophilin A, matrix metalloproteinase (MMP)-9, and tissue inhibitor of MMP (TIMP)/MMP-9 complexes in the inflamed and non-inflamed colon mucosa of UC and CD patients.

METHODS

Serum and biopsy specimens from inflamed and non-inflamed colonic mucosa of 38 patients with IBD (19 with UC and 19 with CD) and 16 controls were included in our study. We measured serum and tissue level of CyPA, and tissue level of TNF-α, MMP-9, TIMP-1/MMP-9, and TIMP-2/MMP-9 using ELISA method.

RESULTS

Our results indicated that serum, but not tissue CyPA is increased in UC, rather than in CD patients, compared to the control. The increase correlated with higher tissue concentration of MMP-9 and TNF-α, especially in the UC group. Moreover, we observed significantly higher level of TIMP-1/MMP-9 in UC and CD group, which overlapped with the change in MMP-9. There was no change in TIMP-2/MMP-9 in the analyzed groups.

CONCLUSION

The current study suggests that serum CyPA may be an independent additional marker of IBD, especially of UC. Higher CyPA level may be followed by increased MMP-9 in those patients. However, further studies are necessary to verify the role of CyPA in IBD development.

Novel Biomarkers and the Future Potential of Biomarkers in Inflammatory Bowel Disease

There is increasing importance placed upon noninvasive assessment of gut inflammation. These tools are likely to be the key in differentiating intestinal inflammatory disease from functional disorders and in monitoring the response to intervention in individuals with known inflammatory conditions. Although various noninvasive markers are currently available, they have limitations and do not provide ideal utility. This review focuses on emerging markers of gut inflammation, highlighting the potential of specific markers.

The Impact of Therapeutic Antibodies on the Management of Digestive Diseases: History, Current Practice, and Future Directions

The development of therapeutic antibodies represents a revolutionary change in medical therapy for digestive diseases. Beginning with the initial studies that confirmed the pathogenicity of cytokines in inflammatory bowel disease, the development and application of therapeutic antibodies brought challenges and insights into their potential and optimal use. Infliximab was the first biological drug approved for use in Crohn's disease and ulcerative colitis. The lessons learned from infliximab include the importance of immunogenicity and the influence of pharmacokinetics on disease response and outcomes. Building on this foundation, other therapeutic antibodies achieved approval for inflammatory bowel disease and many more are in development for several digestive diseases. In this review, we reflect on the history of therapeutic antibodies and discuss current practice and future directions for the field.

Biochemical characterization and structure determination of a potent, selective antibody inhibitor of human MMP9

Matrix metalloproteinase 9 (MMP9) is a member of a large family of proteases that are secreted as inactive zymogens. It is a key regulator of the extracellular matrix, involved in the degradation of various extracellular matrix proteins. MMP9 plays a pathological role in a variety of inflammatory and oncology disorders and has long been considered an attractive therapeutic target. GS-5745, a potent, highly selective humanized monoclonal antibody inhibitor of MMP9, has shown promise in treating ulcerative colitis and gastric cancer. Here we describe the crystal structure of GS-5745·MMP9 complex and biochemical studies to elucidate the mechanism of inhibition of MMP9 by GS-5745. GS-5745 binds MMP9 distal to the active site, near the junction between the prodomain and catalytic domain, and inhibits MMP9 by two mechanisms. Binding to pro-MMP9 prevents MMP9 activation, whereas binding to active MMP9 allosterically inhibits activity.

Expression of inositol-requiring enzyme 1β is downregulated in colorectal cancer

The endoplasmic reticulum stress inositol-requiring enzyme (IRE) 1α/X-box binding protein (XBP) 1 signaling pathway is involved in the tumorigenesis of breast and prostate cancer. Mucin 2 (MUC2) protects colon tissues from the formation of tumors. In human colorectal cancer (CRC) the role of IRE1α, and its analogue, IRE1β, has yet to be elucidated. In the present study, the expression levels of IRE1α, IRE1β, un-spliced XBP1u, spliced XBP1s and MUC2 in surgically resected cancerous and adjacent non-cancerous tissues from patients with CRC were investigated. The IRE1α, IRE1β, XBP1u, XBP1s and MUC2 mRNA expression levels were determined using reverse transcription-quantitative polymerase chain reaction, and the protein expression levels were detected using immunohistochemistry and western blotting. The association between the expression levels of IRE1α, IRE1β and MUC2 and the clinicopathological features of patients with CRC was subsequently analyzed. The mRNA expression levels of IRE1β and MUC2 were decreased by ~2.1 and ~4.5-fold in CRC tissues, respectively, as compared with the adjacent normal tissues. The protein expression levels of IRE1β and MUC2 were decreased by ~8.0 and ~2.0-fold in the CRC tissues, respectively. IRE1β mRNA expression levels were positively correlated with MUC2 mRNA expression levels. IRE1β expression levels were revealed to be significantly associated with lymph node metastasis, tumor stage and histological differentiation. However, IRE1α, XBP1u and XBP1s mRNA and IRE1α protein expression levels were not observed to significantly differ between cancerous tissues and the adjacent normal tissues. The results indicated that the expression of IRE1β, but not IRE1α, may protect colon tissue from developing CRC by inducing MUC2 expression. Therefore, decreased IRE1β expression levels may be associated with the development of CRC through the inhibition of MUC2 expression.

Serotonin-Exacerbated DSS-Induced Colitis Is Associated with Increase in MMP-3 and MMP-9 Expression in the Mouse Colon

Background. 5-HT enhances dextran sulfate sodium- (DSS-) induced colitis and is involved in inflammatory bowel disease (IBD). Matrix metalloproteinases (MMPs) play roles in the process of intestinal inflammation. Aims. To examine whether 5-HT induces MMPs expression in mouse colon to enhance DSS-induced colitis. Materials and Methods. C57BL/6J (B6) mice were treated with either low-dose (1.0 mg/kg) or high-dose (2.0 mg/kg) 5-HT by enema, low-dose (1.0%) or high-dose (2.5%) DSS, or combined low-dose (1.0%) DSS and (1.0 mg/kg) 5-HT. Mouse colitis was analyzed. MMPs and tissue inhibitors of MMPs (TIMPs) mRNA were measured by real-time quantitative RT-PCR in mouse colon and in human Caco-2 cells and neutrophils. MMP-3 and MMP-9 protein levels were quantified from immunohistochemistry (IHC) images of mouse colons. Results. 5-HT exacerbated DSS-induced colitis, low-dose 5-HT induces both MMP-3 and MMP-9, and high-dose 5-HT only increased MMP-3 mRNA expression in mouse colon. Mouse colon MMP-3 and MMP-9 protein levels were also elevated by 5-HT treatment. The MMP-2, TIMP-1, and TIMP-2 mRNA levels were increased in the inflamed colon. 5-HT induced MMP-3 and MMP-9 mRNA expression in Caco-2 and human neutrophils, respectively, in vitro. Conclusion. 5-HT induced MMP-3 and MMP-9 expression in mouse colon; these elevated MMPs may contribute to DSS-induced colitis.

Randomised clinical trial: a phase 1, dose-ranging study of the anti-matrix metalloproteinase-9 monoclonal antibody GS-5745 versus placebo for ulcerative colitis

BACKGROUND

Matrix metalloproteinase-9 is a proteolytic enzyme whose expression is increased in ulcerative colitis.

AIM

To evaluate the safety and efficacy of GS-5745, a fully humanised anti-matrix metalloproteinase-9 monoclonal antibody, in moderately-to-severely active ulcerative colitis.

METHODS

We randomised 74 patients with ulcerative colitis to treatment with single or multiple ascending intravenous or subcutaneous doses of GS-5745 or placebo. Multiple-dose cohorts received either IV infusions (0.3, 1.0, 2.5 or 5.0 mg/kg GS-5745 or placebo) every 2 weeks (three total IV infusions) or five weekly SC injections (150 mg GS-5745 or placebo). The primary outcomes were the safety, tolerability and pharmacokinetics of escalating single and multiple doses of GS-5745. Exploratory analyses in the multiple-dose cohorts included clinical response (≥3 points or 30% decrease from baseline in Mayo Clinic score and ≥1 point decrease in the rectal bleeding subscore or a rectal bleeding subscore ≤1) and clinical remission (a complete Mayo Clinic score ≤2 with no subscore >1) at Day 36. Biological effects associated with a clinical response to GS-5745 were explored using histological and molecular approaches.

RESULTS

Twenty-three of the 42 patients (55%) receiving multiple doses of GS-5745 had adverse events, compared with 5/8 patients (63%) receiving placebo. GS-5745 showed target-mediated drug disposition, approximately dose-proportional increases in maximum plasma concentration and more than dose-proportional increases in the area under the plasma drug concentration-time curve. Clinical response occurred in 18/42 patients (43%) receiving GS-5745 compared with 1/8 patients (13%) receiving placebo. Clinical remission occurred in 6/42 patients (14%) receiving GS-5745 and 0/8 (0%) receiving placebo. Patients with a clinical response to GS-5745 had reductions in matrix metalloproteinase-9 tissue levels (mean 48.9% decrease from baseline compared with a mean 18.5% increase in nonresponders, P = 0.008) significant improvements in histopathology scores (confirmed with three separate histological disease activity indices), as well as changes in colonic gene expression that were consistent with reduced inflammation.

CONCLUSION

This phase 1 trial provides preliminary evidence for the safety and therapeutic potential of GS-5745 in the treatment of ulcerative colitis.

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.

Combined Effects of ACE and MMP-3 Polymorphisms On Migraine Development

Migraine is a primary headache disorder which involves both genetic and environmental components. Since angiotensin-converting enzyme (ACE) and matrix metalloproteinase (MMP) share the same homology, we investigated whether the MMP-3 and ACE I/D gene variants are involved in migraine risk and whether the ACE variant might act in combination with the MMP-3 genetic variant in patients with migraine. This is the first study to evaluate the association between MMP-3 and ACE polymorphisms, and migraine. Genotypes were determined by polymerase chain reaction. The frequencies of 5A5A genotypes of the MMP-3 and D allele of ACE were significantly elevated, but II genotypes of the ACE and 6A allele of MMP-3 significantly decreased in all patients. The combined DD/5A5A and ID/5A5A genotypes increased the risk of migraine. Individuals who were homozygous for the deletion (D) allele showed increased ACE activity. Subjects with the 5A5A genotype and/or D allele or with the combined DD/5A5A or ID/5A5A might be more susceptible to migraine development. In contrast, subjects with the II and/or 6A6A genotypes may be protected from migraine development. The greater activity of the 5A5A and DD genotypes might result in vascular reactivity that is more pronounced in migraine. Taken together, our data suggest that numerous genes may influence ACE activity. Discovery of new genes might better clarify the pathogenesis of migraine and open an avenue to therapeutic strategies against migraine.

Role of the protein annexin A1 on the efficacy of anti-TNF treatment in a murine model of acute colitis

TNF-α is involved in the mechanisms that initiate inflammatory bowel diseases (IBDs). Anti-TNF-α drugs, such as infliximab (IFX), cause non-responsiveness and side effects, indicating the need to investigate alternative therapies for these diseases. The anti-inflammatory protein, annexin A1 (AnxA1), has been associated with the protection of the gastrointestinal mucosa. To further address the role of endogenous AnxA1 on the TNF-α blockade efficacy in a murine model, we assessed colitis induced by Dextran Sulfate Sodium (DSS) in wild-type (WT) and AnxA1(-/-) Balb/c mice treated with IFX. We consistently observed endogenous AnxA1 prevented clinical and physiological manifestations of experimental colitis treated with IFX, additionally the manifestation of the disease was observed earlier in AnxA1(-)(/-) mice. Rectal bleeding, diarrhea, histological score, epithelial damages and collagen degradation caused by DSS were prevented following IFX treatment only in WT mice. IL-6 increased during colitis in WT and AnxA1(-)(/-) mice, decreasing under IFX treatment in WT. The influx of neutrophils and TNF-α secretion were largely elevated in AnxA1(-)(/-) mice when compared to WT mice. In the group WT/DSS+IFX, phagocytes were more susceptible to apoptosis following treatment with IFX. Endogenous expression of AnxA1 increased after DSS and decreased with IFX treatment, demonstrating an attenuated inflammatory response. The data indicate that AnxA1 contributes to the establishment of intestinal homeostasis after blocking of TNF-α was used as a treatment of IBD, constituting a key molecule in the mechanism of action and a potential biomarker of therapeutic efficacy.

Decreased Fibrogenesis After Treatment with Pirfenidone in a Newly Developed Mouse Model of Intestinal Fibrosis

BACKGROUND

Fibrosis as a common problem in patients with Crohn's disease is a result of an imbalance toward excessive tissue repair. At present, there is no specific treatment option. Pirfenidone is approved for the treatment of idiopathic pulmonary fibrosis with both antifibrotic and anti-inflammatory effects. We subsequently investigated the impact of pirfenidone treatment on development of fibrosis in a new mouse model of intestinal fibrosis.

METHODS

Small bowel resections from donor mice were transplanted subcutaneously into the neck of recipients. Animals received either pirfenidone (100 mg/kg, three times daily, orally) or vehicle.

RESULTS

After administration of pirfenidone, a significantly decreased collagen layer thickness was revealed as compared to vehicle (9.7 ± 1.0 versus 13.5 ± 1.5 µm, respectively, **P < 0.001). Transforming growth factor-β and matrix metalloproteinase-9 were significantly decreased after treatment with pirfenidone as confirmed by real-time PCR (0.42 ± 0.13 versus 1.00 ± 0.21 and 0.46 ± 0.24 versus 1.00 ± 0.62 mRNA expression level relative to GAPDH, respectively, *P < 0.05). Significantly decreased transforming growth factor-β after administration of pirfenidone was confirmed by Western blotting.

CONCLUSION

In our mouse model, intestinal fibrosis can be reliably induced and is developed within 7 days. Pirfenidone partially prevented the development of fibrosis, making it a potential treatment option against Crohn's disease-associated fibrosis.

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.

The Gastric Mucosa from Patients Infected with CagA+ or VacA+ Helicobacter pylori Has a Lower Level of Dual Oxidase-2 Expression than Uninfected or Infected with CagA-/VacA- H. pylori

BACKGROUND

Helicobacter pylori (H. pylori) is a well-recognized gastroduodenal pathogen and class I carcinogen. Dual oxidase-2 (DUOX2), a member of NADPH oxidase family, has several critical physiological functions, including thyroid hormone biosynthesis and host mucosal defense.

AIM

To investigate the effect of H. pylori infection on DUOX2 gene expression in human stomach.

MATERIALS AND METHODS

The biopsies were obtained from patients who underwent endoscopic diagnosis. The patient serum was assayed for two virulence factors of H. pylori, CagA IgG and VacA. The inflammation in gastric mucosa was analyzed with histology. Real-time quantitative PCR was used to detect the expression of three members of NADPH oxidase, NOX1, NOX2, and DUOX2, as well as lactoperoxidase (LPO) in the gastric mucosa. NOX2, DUOX2, and myeloperoxidase (MPO) protein levels were quantified by Western blots or immunohistochemistry.

RESULTS

The H. pylori-infected gastric mucosa had more severe inflammation than uninfected samples. However, the expression of DUOX2 mRNA and protein was lower in gastric mucosa of patients with H. pylori infection compared to the uninfected. Among the H. pylori-infected patients, those having CagA IgG or VacA in the serum had lower DUOX2 expression levels than those infected with H. pylori without either virulence factor. The NOX2 and MPO levels were higher in those patients infected with H. pylori irrespective of the virulence factors than those uninfected patients. NOX1 and LPO mRNA were undetectable in the gastric mucosa.

CONCLUSION

CagA+ or VacA+ H. pylori in the stomach of patients may suppress DUOX2 expression to promote its own survival. Increased NOX2 could not eliminate H. pylori infection.