Increased incidence of urinary matrix metalloproteinases as predictors of disease in pediatric patients with inflammatory bowel disease

Ameliorative effects of androstenediol against acetic acid-induced colitis in male wistar rats via inhibiting TLR4-mediated PI3K/Akt and NF-κB pathways through estrogen receptor β activation

5-androstenediol (ADIOL) functions as a selective estrogen receptor β (ERβ) ligand with a protective effect against many diseases. So, we conducted a novel insight into its role in acetic acid (AA)-induced colitis and investigated its effect on TLR4-Mediated PI3K/Akt and NF-κB Pathways and the potential role of ERβ as contributing mechanisms.

METHODS

Rats were randomized into 5 Groups; Control, Colitis, Colitis + mesalazine (MLZ), Colitis + ADIOL, and Colitis + ADIOL + PHTPP (ER-β antagonist). The colitis was induced through a rectal enema of acetic acid (AA) on the 8th day. At the end of treatment, colons were collected for macroscopic assessment. Tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), nuclear factor kappa b (NF-κB), toll-like receptor (TLR4), and phosphorylated Protein kinase B (pAKT) were measured. Besides, Gene expression of interleukin-1beta (IL-1β), metalloproteases 9 (Mmp9), inositol 3 phosphate kinase (PI3K), Neutrophil gelatinase-associated lipocalin (NGAL), ERβ and NLRP6 were assessed. Histopathological and immunohistochemical studies were also investigated.

RESULTS

Compared to the untreated AA group, the disease activity index (DAI) and macroscopic assessment indicators significantly decreased with ADIOL injections. Indeed, ADIOL significantly decreased colonic tissue levels of MDA, TLR4, pAKT, and NF-κB immunostainig while increased SOD activity and β catenin immunostainig. ADIOL mitigated the high genetic expressions of IL1β, NGAL, MMP9, and PI3K while increased ERβ and NLRP6 gene expression. Also, the pathological changes detected in AA groups were markedly ameliorated with ADIOL. The specific ERβ antagonist, PHTPP, largely diminished these protective effects of ADIOL.

CONCLUSION

ADIOL could be beneficial against AA-induced colitis mostly through activating ERβ.

Serum TGF-β1 and CD14 Predicts Response to Anti-TNF-α Therapy in IBD

Background

Tumor necrosis factor-alpha (TNF-α) agonists revolutionized therapeutic algorithms in inflammatory bowel disease (IBD) management. However, approximately every third IBD patient does not respond to this therapy in the long term, which delays efficient control of the intestinal inflammation.

Methods

We analyzed the power of serum biomarkers to predict the failure of anti-TNF-α. We collected serum of 38 IBD patients at therapy prescription and 38 weeks later and analyzed them with relation to therapy response (no-, partial-, and full response). We used enzyme-linked immunosorbent assay to quantify 16 biomarkers related to gut barrier (intestinal fatty acid-binding protein, liver fatty acid-binding protein, trefoil factor 3, and interleukin (IL)-33), microbial translocation, immune system regulation (TNF-α, CD14, lipopolysaccharide-binding protein, mannan-binding lectin, IL-18, transforming growth factor-β1 (TGF-β1), osteoprotegerin (OPG), insulin-like growth factor 2 (IGF-2), endocrine-gland-derived vascular endothelial growth factor), and matrix metalloproteinase system (MMP-9, MMP-14, and tissue inhibitors of metalloproteinase-1).

Results

We found that future full-responders have different biomarker profiles than non-responders, while partial-responders cannot be distinguished from either group. When future non-responders were compared to responders, their baseline contained significantly more TGF-β1, less CD14, and increased level of MMP-9, and concentration of these factors could predict non-responders with high accuracy (AUC = 0.938). Interestingly, during the 38 weeks, levels of MMP-9 decreased in all patients, irrespective of the outcome, while OPG, IGF-2, and TGF-β1 were higher in non-responders compared to full-responders both at the beginning and the end of the treatment.

Conclusions

The TGF-β1 and CD14 can distinguish non-responders from responders. The changes in biomarker dynamics during the therapy suggest that growth factors (such as OPG, IGF-2, and TGF-β) are not markedly influenced by the treatment and that anti-TNF-α therapy decreases MMP-9 without influencing the treatment outcome.

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.

Inflammatory bowel disease biomarkers

Inflammatory bowel disease (IBD) is characterized as chronic inflammation in the gastrointestinal tract, which includes two main subtypes, Crohn's disease and ulcerative colitis. Endoscopy combined with biopsy is the most effective way to establish IBD diagnosis and disease management. Imaging techniques have also been developed to monitor IBD. Although effective, the methods are expensive and invasive, which leads to pain and discomfort. Alternative noninvasive biomarkers are being explored as tools for IBD prognosis and disease management. This review focuses on novel biomarkers that have emerged in recent years. These serological biomarkers and microRNAs could potentially be used for disease management in IBD, thereby decreasing patient discomfort and morbidity.

Expression of MMP-2, MMP-7, MMP-9, and TIMP-1 by Inflamed Mucosa in the Initial Diagnosis of Ulcerative Colitis as a Response Marker for Conventional Medical Treatment

INTRODUCTION

Experimental and clinical data involve matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs) in the pathogenesis of inflammatory bowel diseases. However, the impact of MMPs/TIMPs expression by inflamed mucosa on medical response therapy has scarcely been investigated.

METHODS

The expression of MMP-2, MMP-7, MMP-9, and TIMP-1 was determined by immunohistochemical analysis in inflamed mucosa samples at diagnosis in 82 patients with ulcerative colitis (UC; 22 never-treated with corticosteroids, 28 nonresponders, and 32 responders to corticosteroid therapy) and 15 patients with acute diverticulitis (AD). The global expression (score value) of each factor was analyzed by computer-generated image analysis.

RESULTS

UC samples showed higher MMP-2 and MMP-9 expression but lower TIMP-1 expression than the AD samples (p < 0.0001, for all). High MMP-9 and TIMP-1 scores were significantly associated with no need for corticosteroid treatment (p < 0.001 and p = 0.017, respectively); whereas higher score in the MMP-7 expression was significantly associated with nonresponse to corticosteroid therapy (p = 0.037). In addition, in this latter UC subgroup, MMP-7 correlated positively with the younger age of the patients and with the extension of the disease (p = 0.030 and p = 0.010, respectively).

CONCLUSION

Our results suggest the relevance of MMPs and TIMPs for predicting treatment response to both 5-aminosalicylates and corticosteroids in UC.

Involvement of MIR-126 and MMP9 in the Pathogenesis of Intra-Abdominal Fistulizing Crohn’s Disease: A Brief Research Report

Background

Intra-abdominal fistulas are complications that affect a significant proportion of Crohn’s disease patients, often requiring surgery. The aim of the present work was to correlate the occurrence of intestinal fistulization to the clinico-pathological features of these patients and to the plasma levels of MMP9, a gelatinase involved in the pathophysiology of fistula formation, and of miR-126, appearing to modulate MMP9 expression.

Methods

In a series of 31 consecutive Crohn’s patients admitted to surgery due to therapeutic failure and/or complicated disease, we identified nine cases of abdominal fistulas, mainly entero-enteric fistulas. MMP9 protein was determined in plasma and at the intestinal level using immunometric assays. Circulating miR-126 was also measured in all plasma samples by real-time PCR.

Results

Comparing patients with and without intra-abdominal fistulas, we did not observe differences in terms of age, gender, disease location and duration, number of previous surgeries and pre-biologic medications. However, cases with intra-abdominal fistulas had a significantly higher CDAI (p < 0.0001) and a significantly lower circulating miR-126 (p < 0.05). Patients with intra-abdominal fistulas had also a significantly higher amount of circulating MMP9 (p < 0.0001) and this data was correlated with an increased expression of MMP9 protein in the mucosa and with reduced levels of circulating miR-126. Receiver operating characteristic (ROC) analysis pointed out the ability of circulating MMP9 to discriminate patients with and without intra-abdominal fistulas.

Conclusions

These data confirm that circulating MMP9 can be used for the identification of cases with intra-abdominal fistulas and suggest that miR-126 may be also involved in the pathogenesis of this complication and that it may be further investigated as a new therapeutic strategy or for monitoring therapeutic response in these patients.

Are Matrix Metalloproteinase-9 and Tissue Inhibitor of Metalloproteinase-1 Useful as Markers in Diagnostic Management of Children with Newly Diagnosed Ulcerative Colitis?

Matrix Metaloproteinase-9 (MMP-9) and Tissue Inhibitor of Metaloproteinase-1 (TIMP-1), enzymes involved in tissue remodelling, have been previously reported to be overexpressed in the colonic mucosa of patients with Ulcerative colitis (UC). The aim of this study was to determine the relation of MMP-9 and TIMP-1 with UC phenotypes, the disease activity index and routinely tested inflammatory markers in newly diagnosed paediatric patients. The study group comprised 35 children diagnosed with UC and 20 control groups. Serum and faecal concentrations of MMP-9 and TIMP-1 were estimated using enzyme-like immunosorbent assay kits and correlated to the disease activity index (Paediatric Ulcerative Colitis Activity Index, PUCAI), UC phenotype (Paris Classification), inflammatory markers and endoscopic score (Mayo score). Children with UC presented with significantly higher serum and faecal concentrations of studied markers compared to the control group. Both serums, MMP-9 and TIMP-1, were higher in children with more extended and severe lesions in the colon. Furthermore, serum MMP-9 correlated with the Mayo score, Paris classification and C-reactive protein (CRP) levels. Serum TIMP-1 showed correlation with PUCAI, Paris Classification, CRP levels and the erythrocyte sedimentation rate. Serum and faecal levels of MMP-9 and TIMP-1 are useful in discriminating UC patients and non-invasive assessments of disease phenotypes. It seemed that simultaneous measurement of these proteins in combination with other common markers of inflammation could be applied in clinical practice.

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).

Potential Roles of Exosomal lncRNAs in the Intestinal Mucosal Immune Barrier

The intestinal mucosal immune barrier protects the host from the invasion of foreign pathogenic microorganisms. Immune cells and cytokines in the intestinal mucosa maintain local and systemic homeostasis by participating in natural and adaptive immunity. Deficiency of the intestinal mucosal immune barrier is associated with a variety of intestinal illnesses. Exosomes are phospholipid bilayer nanovesicles that allow cell-cell communication by secreting physiologically active substances including proteins, lipids, transcription factors, mRNAs, micro-RNAs (miRNAs), and long noncoding RNAs (lncRNAs). Exosomal lncRNAs are involved in immune cell differentiation and the modulation of the immune response. This review briefly introduces the potential role of exosomal lncRNAs in the intestinal mucosal immune barrier and discusses their relevance to intestinal illnesses.

Anti-Metastatic and Anti-Inflammatory Effects of Matrix Metalloproteinase Inhibition by Ginsenosides

Matrix metalloproteinases (MMPs) are proteolytic enzymes which cleave extracellular matrix (ECM) and other substrates. They are deeply involved in both cancer metastasis and human chronic inflammatory diseases such as osteoarthritis and Crohn’s disease. Regulation of MMPs is closely associated with signaling molecules, especially mitogen-activated protein kinases (MAPKs), including three representative kinases, extracellular signal regulated kinases (ERK), p38 and c-Jun N-terminal kinases (JNK). Ginseng (Panax sp.) is a plant which has been traditionally used for medicinal applications. Ginsenosides are major metabolites which have potentials to treat various human diseases. In this review, the pharmacological effects of ginsenosides have been rigorously investigated; these include anti-metastatic and anti-inflammatory activities of ginsenosides associated with suppression of MMPs via regulation of various signaling pathways. This will highlight the importance of MMPs as therapeutic targets for anti-metastatic and anti-inflammatory drug development based on ginsenosides.

Cell-free DNA promotes malignant transformation in non-tumor cells

Cell-free DNA is present in different biological fluids and when released by tumor cells may contribute to pro-tumor events such as malignant transformation of cells adjacent to the tumor and metastasis. Thus, this study analyzed the effect of tumor cell-free DNA, isolated from the blood of prostate cancer patients, on non-tumor prostate cell lines (RWPE-1 and PNT-2). To achieve this, we performed cell-free DNA quantification and characterization assays, evaluation of gene and miRNA expression profiling focused on cancer progression and EMT, and metabolomics by mass spectrometry and cellular migration. The results showed that tumor-free cell DNA was able to alter the gene expression of MMP9 and CD44, alter the expression profile of nine miRNAs, and increased the tryptophan consumption and cell migration rates in non-tumor cells. Therefore, tumor cell-free DNA was capable of altering the receptor cell phenotype, triggering events related to malignant transformation in these cells, and can thus be considered a potential target for cancer diagnosis and therapy.

Usefulness of metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in clinical characterisation of children with newly diagnosed Crohn's disease

AIM

The aim of this study was to determine the relation of non-invasive markers representing gut mucosal damage (metalloproteinase-9 (MMP-9)) and remodelling (tissue inhibitor of metalloproteinase-1 (TIMP-1)) with Crohn's disease (CD) phenotype, disease activity scores (clinical and endoscopic) and radiological evaluation of the ileum in newly diagnosed children.

METHODS

Serum and faecal MMP-9 and TIMP-1 concentrations were determined with the sandwich enzyme-linked immunoassay technique. The performance of each marker with reference to the Paris classification, disease activity scores and magnetic resonance enterography results was assessed using non-parametric tests.

RESULTS

A total of 32 children with CD demonstrated higher levels of serum and faecal MMP-9 and TIMP-1 compared with a control group including children without gastrointestinal inflammatory disease (all P < 0.05). Only the serum MMP-9 concentration was significantly higher in children with L3 (ileocolonic) compared with children with L1 (distal ileum). The serum TIMP-1 level was significantly higher in patients with an magnetic resonance enterography-detected ileum involvement longer than 51 mm and in children with severe disease activity compared with other patients. The serum MMP-9 level was lower in patients with stenosis combined with prestenotic dilation compared with children without stenosis.

CONCLUSION

Increased serum and faecal MMP-9 and TIMP-1 concentrations are some reliable markers of inflammation in newly diagnosed children with CD, but without facilitating clear phenotyping of the disease.

Long Non-Coding RNA GAS5 and Intestinal MMP2 and MMP9 Expression: A Translational Study in Pediatric Patients with IBD

Background: The long non-coding RNA (lncRNA) growth arrest–specific transcript 5 (GAS5) seems to be involved in the regulation of mediators of tissue injury, in particular matrix metalloproteinases (MMPs), implicated in the pathogenesis of inflammatory bowel disease (IBD). We investigated the role of GAS5 in regulating MMP2 and MMP9 expression in pediatric patients with IBD and in vitro. Methods: In total, 25 IBD patients were enrolled: For each patient paired inflamed and non-inflamed biopsies were collected. RNA was extracted and GAS5, MMP2, and MMP9 were quantified by TaqMan assay. The expression of GAS5 and MMPs was also determined in the human monocytic THP1 cells differentiated into macrophages and stimulated with lipopolysaccharide (LPS). The function of GAS5 was assessed by overexpressing the lncRNA and evaluating the MMPs levels. Results: Real-time PCR results demonstrated a downregulation of GAS5 and an upregulation of both MMPs in inflamed tissues. In vitro data confirmed the trend observed in patients for the three genes: The stimulation with LPS promoted a downregulation of GAS5 while an increase of MMPs was observed. Overexpression experiments showed that higher levels of GAS5 lead to a decrease of both enzymes. Conclusion: These results provide new information about the role of GAS5 in IBD: The lncRNA could mediate tissue damage by modulating the expression of MMPs.

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.

Cellular and Molecular Effects of High-Molecular-Weight Heparin on Matrix Metalloproteinase 9 Expression

Blood sampling with different anticoagulants alters matrix metalloproteinase (MMP-) 9 expression, thus influencing its concentration and diagnostic validity. Here, we aimed to evaluate the effects of different anticoagulants on MMP-9 regulation. MMP-9 expression was assessed in response to ethylenediaminetetraacetic acid, citrate, and high-/low-molecular-weight heparin (HMWH, LMWH) in co-culture experiments using THP-1, Jurkat, and HT cells (representing monocytes, T, and B cells). Triple and double cell line co-culture experiments revealed that HMWH treatment of THP-1 and Jurkat led to a significant MMP-9 induction, whereas other anticoagulants and cell type combinations had no effect. Supernatant of HMWH-treated Jurkat cells also induced MMP-9 in THP-1 suggesting monocytes as MMP-9 producers. HMWH-induced cytokine/chemokine secretion was assessed in co-culture supernatant, and the influence of cytokines/chemokines on MMP-9 production was analyzed. These experiments revealed that Jurkat-derived IL-16 and soluble intercellular adhesion molecule (sICAM-) 1 are able to induce MMP-9 and IL-8 production by THP-1. As a consequence, the increased MMP-9 expression found in HMWH blood samples may be influenced by HMWH-dependent secretion of IL-16 and sICAM-1 by T cells resulting in an increased production of MMP-9 and IL-8 by monocytes. IL-8, in turn, may support MMP-9 and its own expression in a positive autocrine feedback loop.

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.

Surrogate Fecal Biomarkers in Inflammatory Bowel Disease: Rivals or Complementary Tools of Fecal Calprotectin?

BACKGROUND

Current noninvasive methods for assessing intestinal inflammation in inflammatory bowel disease (IBD) remain unsatisfactory. Along with C-reactive protein and erythrocyte sedimentation rate, fecal calprotectin (FC) is the standard test for assessing IBD activity, even though its specificity and accuracy are not optimal and it lacks a validated cutoff. Over the past few decades, several fecal markers released from intestinal inflammatory cells have been investigated in IBD; they are the subject of this systematic review.

METHODS

A systematic electronic search of the English literature up to April 2017 was performed using Medline and the Cochrane Library. Only papers written in English that analyzed fecal biomarkers in IBD were included. In vitro studies, animal studies, studies on blood/serum samples, and studies analyzing FC or fecal lactoferrin alone were excluded.

RESULTS

Out of 1023 citations, 125 eligible studies were identified. Data were grouped according to each fecal marker including S100A12, high-mobility group box 1, neopterin, polymorphonuclear neutrophil elastase, fecal hemoglobin, alpha1-antitrypsin, human neutrophil peptides, neutrophil gelatinase-associated lipocalin, chitinase 3-like-1, matrix metalloproteinase 9, lysozyme, M2-pyruvate kinase, myeloperoxidase, fecal eosinophil proteins, human beta-defensin-2, and beta-glucuronidase. Some of these markers showed a high sensitivity and specificity and correlated with disease activity, response to therapy, and mucosal healing. Furthermore, they showed a potential utility in the prediction of clinical relapse.

CONCLUSIONS

Several fecal biomarkers have the potential to become useful tools complementing FC in IBD diagnosis and monitoring. However, wide variability in their accuracy in assessment of intestinal inflammation suggests the need for further studies.

Pathobiology of neutrophil-epithelial interactions

Polymorphonuclear neutrophils (PMNs) are innate immune system cells that play an essential role in eradicating invading pathogens. PMN migration to sites of infection/inflammation requires exiting the microcirculation and subsequent crossing of epithelial barriers in mucosa-lined organs such as the lungs and intestines. Although these processes usually occur without significant damage to surrounding host tissues, dysregulated/excessive PMN transmigration and resultant bystander-tissue damage are characteristic of numerous mucosal inflammatory disorders. Mechanisms controlling PMN extravasation have been well characterized, but the molecular details regarding regulation of PMN migration across mucosal epithelia are poorly understood. Given that PMN migration across mucosal epithelia is strongly correlated with disease symptoms in many inflammatory mucosal disorders, enhanced understanding of the mechanisms regulating PMN transepithelial migration should provide insights into clinically relevant tissue-targeted therapies aimed at ameliorating PMN-mediated bystander-tissue damage. This review will highlight current understanding of the molecular interactions between PMNs and mucosal epithelia and the associated functional consequences.

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.

Role of biomarkers in diagnosis and evaluation of disease activity of Crohn's disease

Crohn's disease (CD) is a group of chronic, relapsing inflammatory gastrointestinal diseases with unknown etiology. The goals of treatment are to induce the transition from active stage into inactive stage and to maintain remission. Therefore, it is important to diagnose and assess disease activity in patients with CD. Recently, noninvasive markers for intestinal inflammation have been wildly adopted in clinical practice in order to differentiate CD from other diseases, to grade inflammation, to assess the response to therapy, and to demonstrate recurrent inflammation after medical or surgically-induced remission. Fecal and serum calprotectins are among the best-studied noninvasive biomarkers of inflammation in CD which have attracted clinicians' attention. This paper gives an overview of the clinical implications of biomarkers for diagnosing and monitoring disease activity of CD.

Biomarkers for colitis-associated colorectal cancer

Patients with extensive ulcerative colitis (UC) of more than eight years duration have an increased risk of colorectal cancer. Molecular biomarkers for dysplasia and cancer could have a great clinical value in managing cancer risk in these UC patients. Using a wide range of molecular techniques - including cutting-edge OMICS technologies - recent studies have identified clinically relevant biomarker candidates from a variety of biosamples, including colonic biopsies, blood, stool, and urine. While the challenge remains to validate these candidate biomarkers in multi-center studies and with larger patient cohorts, it is certain that accurate biomarkers of colitis-associated neoplasia would improve clinical management of neoplastic risk in UC patients. This review highlights the ongoing avenues of research in biomarker development for colitis-associated colorectal cancer.

Anti-MMP-9 Antibody: A Promising Therapeutic Strategy for Treatment of Inflammatory Bowel Disease Complications with Fibrosis

BACKGROUND

Despite medical treatments or surgical options, more than one-third of patients with Crohn's disease suffer from recurring fistulae. Matrix metalloprotease 9 (MMP-9), a type IV collagenase that cleaves components of the extracellular matrix leading to tissue remodeling, is upregulated in crypt abscesses and around fistulae suggesting an important role for this enzyme in fistula formation. Our aims were (1) to correlate serum levels of MMP-9 degradation products in patients with CD with the presence of fistulae and (2) to investigate the impact of selective MMP-9 inhibition in a mouse model of intestinal fibrosis.

METHODS

Serum MMP-9 degradation products were quantified in subjects affected with nonstricturing and nonpenetrating CD (n = 50), stricturing CD (n = 41), penetrating CD (n = 22), CD with perianal fistula (n = 29), and healthy controls (n = 10). Therapeutic efficacy of anti-MMP-9 monoclonal antibodies was assessed in a heterotopic xenograft model of intestinal fibrosis.

RESULTS

C3M, an MMP-9 degradation product of collagen III, demonstrated the highest serum levels in patients with penetrating CD and differentiated penetrating CD from other CD subgroups and healthy controls, P = 0.0005. Anti-MMP-9 treatments reduced collagen deposition and hydroxyproline content in day-14 intestinal grafts indicating reduced fibrosis.

CONCLUSIONS

The serologic biomarker C3M can discriminate penetrating CD from other CD subgroups and could serve as marker for the development of penetrating CD. Anti-MMP-9 antibody has therapeutic potential to prevent intestinal fibrosis in CD complications.

Matrix metalloproteinase 9-induced increase in intestinal epithelial tight junction permeability contributes to the severity of experimental DSS colitis

Recent studies have implicated a pathogenic role for matrix metalloproteinases 9 (MMP-9) in inflammatory bowel disease. Although loss of epithelial barrier function has been shown to be a key pathogenic factor for the development of intestinal inflammation, the role of MMP-9 in intestinal barrier function remains unclear. The aim of this study was to investigate the role of MMP-9 in intestinal barrier function and intestinal inflammation. Wild-type (WT) and MMP-9(-/-) mice were subjected to experimental dextran sodium sulfate (DSS) colitis by administration of 3% DSS in drinking water for 7 days. The mouse colonic permeability was measured in vivo by recycling perfusion of the entire colon using fluorescently labeled dextran. The DSS-induced increase in the colonic permeability was accompanied by an increase in intestinal epithelial cell MMP-9 expression in WT mice. The DSS-induced increase in intestinal permeability and the severity of DSS colitis was found to be attenuated in MMP-9(-/-) mice. The colonic protein expression of myosin light chain kinase (MLCK) and phospho-MLC was found to be significantly increased after DSS administration in WT mice but not in MMP-9(-/-) mice. The DSS-induced increase in colonic permeability and colonic inflammation was attenuated in MLCK(-/-) mice and MLCK inhibitor ML-7-treated WT mice. The DSS-induced increase in colonic surface epithelial cell MLCK mRNA was abolished in MMP-9(-/-) mice. Lastly, increased MMP-9 protein expression was detected within the colonic surface epithelial cells in ulcerative colitis cases. These data suggest a role of MMP-9 in modulation of colonic epithelial permeability and inflammation via MLCK.

Serum Neutrophil Gelatinase B-associated Lipocalin and Matrix Metalloproteinase-9 Complex as a Surrogate Marker for Mucosal Healing in Patients with Crohn's Disease

BACKGROUND AND AIMS

Although costly and uncomfortable for the patient, the current standard to assess mucosal healing in Crohn's disease [CD] patients is endoscopy. The aim of this study was to evaluate NGAL-MMP-9 as surrogate marker for mucosal healing in CD patients.

METHODS

Serum NGAL-MMP-9 levels were determined with sandwich enzyme-linked immunosorbent assay before and up to 5 years after first infliximab infusion in 108 active CD patients [median age at first infliximab 36 years, 57% female] and 43 healthy controls [HC, median age 27 years, 60% female]. Serum samples were matched to the time of endoscopy and complete endoscopic healing was defined as absence of ulcerations. Histological healing was defined as absence of epithelial damage [D'Haens score].

RESULTS

At baseline, median [interquartile range] NGAL-MMP-9 levels were significantly higher in active CD patients vs HC (77.6 [36.9-141.0] vs 25.5 [17.8-42.8] ng/ml; p < 0.001). After treatment, NGAL-MMP-9 levels significantly decreased in completely healed CD patients [n = 38] (84.5 [36.7-138.4] to 23.4 [7.4-42.5] ng/ml; p < 0.001) and--to a lesser extent--in non-healed CD patients [n = 36] (100.9 [43.4-152.6] to 43.8 [27.0-96.8] ng/ml; p = 0.001). Receiver operating characteristic analysis defined a NGAL-MMP-9 cut-off level of 45 ng/ml corresponding to complete endoscopic healing (area under the curve [AUC] = 0.79, 82% sensitivity, 65% specificity) and histological healing [AUC = 0.72, 79% sensitivity, 53% specificity]. At baseline, C-reactive protein [CRP] was not elevated in 33% of active CD patients, whereas 53% of these patients did have elevated NGAL-MMP-9 levels.

CONCLUSIONS

In the search for surrogate markers to assess mucosal healing in inflammatory bowel disease, NGAL-MMP-9 supplements and outperforms CRP in both ulcerative colitis and CD patients.

Matrix metalloproteinases in inflammatory bowel disease: an update

Matrix metalloproteinases (MMPs) are known to be upregulated in inflammatory bowel disease (IBD) and other inflammatory conditions, but while their involvement is clear, their role in many settings has yet to be determined. Studies of the involvement of MMPs in IBD since 2006 have revealed an array of immune and stromal cells which release the proteases in response to inflammatory cytokines and growth factors. Through digestion of the extracellular matrix and cleavage of bioactive proteins, a huge diversity of roles have been revealed for the MMPs in IBD, where they have been shown to regulate epithelial barrier function, immune response, angiogenesis, fibrosis, and wound healing. For this reason, MMPs have been recognised as potential biomarkers for disease activity in IBD and inhibition remains a huge area of interest. This review describes new roles of MMPs in the pathophysiology of IBD and suggests future directions for the development of treatment strategies in this condition.

Neutrophil gelatinase-associated lipocalin in blood in children with inflammatory bowel disease

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is a 25 kDa glycoprotein present in the bodily fluids and tissues. It is secreted by neutrophils, epithelial cells, hepatocytes and adipocytes, and its expression is highly increased in response to cellular stress. The role of NGAL in the pathophysiology of inflammatory bowel disease including Crohn's disease and ulcerative colitis in children has thus far not been studied.

METHODS

The following groups of children were included: (i) inflammatory bowel disease group, n = 36, aged from 1 to 18 years with Crohn's disease (n = 19) and ulcerative colitis (n = 17); (ii) control group, n = 126; and (iii) disease control group, n = 27, without inflammatory bowel disease, with a food and/or inhalant allergy.

RESULTS

Healthy children aged from 1 to 8 years exhibited lower NGAL level than those of 9 to 18 years old (39.0; 18.1-83.7 ng/mL vs 57.6; 28.7-107 ng/mL, P = 0.001). In the younger, but not in the older children, the serum NGAL level correlated with their age, r = 0.334, P = 0.001. In children with inflammatory bowel disease, serum NGAL level was higher (108; 37.3-245 ng/mL) than in healthy (42.0; 18.1-107 ng/mL) and allergic, noninflammatory bowel disease children (49.3; 19.3-107 ng/mL), P = 0.001. Serum NGAL levels in Crohn's disease and ulcerative colitis children did not correlate with age, gender, disease activity, and indices of the inflammation.

CONCLUSION

Serum NAGL levels are highly elevated in Crohn's disease and ulcerative colitis in children compared to the healthy control group. Systematic studies are needed to explain the role of this protein in the inflammatory bowel disease.

Role of neutrophil gelatinase-associated lipocalin for early detection of acute kidney injury

Acute kidney injury (AKI) is characterized by abrupt or rapid decline of renal function and is usually associated with the development of serious complications as well as an independent risk of mortality in hospitalized patients. Emergency physicians play a critical role in recognizing early AKI, preventing iatrogenic injury, and reversing the course of AKI. Among the various available biomarkers for AKI, reliable and automated assay methods are commercially available for only cystatin-C and neutrophil gelatinase-associated lipocalin (NGAL). NGAL appears to be a promising marker for early detection of AKI and is likely to be adapted for wide-scale clinical use in patient management as a point-of-care test. Use of NGAL along with panel of other renal biomarkers can improve the rate of early detection of AKI. Large, multicenter studies demonstrate the association between biomarkers and hard end points such as need for renal replacement therapy (RRT), cardiovascular events, hospital stay, and death, independent of serum creatinine concentrations.

Neutrophil gelatinase B-associated lipocalin and matrix metalloproteinase-9 complex as a surrogate serum marker of mucosal healing in ulcerative colitis

BACKGROUND

The current standard for the assessment of mucosal healing after therapy in inflammatory bowel diseases is endoscopy. However, a high need exists for noninvasive, accurate surrogate markers.

METHODS

In 2 independent cohorts, levels of serum neutrophil gelatinase B-associated lipocalin and matrix metalloproteinase-9 complex (NGAL-MMP-9) from patients with active ulcerative colitis (UC) before and after first treatment with infliximab and from healthy controls (HC) were determined with zymography and sandwich enzyme-linked immunosorbent assay. The response to infliximab was defined as complete mucosal healing (Mayo endoscopic subscore 0-1) at control endoscopy. Data were analyzed with SPSS, and P values <0.05 were considered significant.

RESULTS

In cohort 1 (n = 66; median age, 30 yr; 38% female), serum NGAL-MMP-9 levels significantly increased at baseline in UC patients versus HC (103.8 versus 42.4 ng/mL; P < 0.0001), whereas 55% of the patients had normal C-reactive protein levels. NGAL-MMP-9 levels significantly decreased after therapy in UC responders (from 116.3 ng/mL to 32.0 ng/mL; P < 0.0001) and in nonresponders (from 94.7 ng/mL to 54.1 ng/mL; P = 0.047). In cohort 2 (n = 132; median age, 39 yr; 53% female), NGAL-MMP-9 levels increased at baseline in active UC patients versus HC (86.5 versus 60.4 ng/mL; P = 0.10), whereas 45% of the patients had normal C-reactive protein levels. NGAL-MMP-9 levels significantly decreased after therapy in responders (from 87.5 ng/mL to 16.3 ng/mL; P < 0.0001) but not in nonresponders (from 82.7 ng/mL to 57.8 ng/mL; P = 0.19). After pooling the data, a cutoff value of 97.7 ng/mL for NGAL-MMP-9 complex was determined to predict complete mucosal healing with high specificity (91%).

CONCLUSIONS

Serum NGAL-MMP-9 is suggested as a new surrogate marker for the assessment of mucosal healing in UC patients treated with infliximab.

Matrix metalloproteinase-9: its interplay with angiogenic factors in inflammatory bowel diseases

Matrix metalloproteinase- (MMP-) 9 is one of the main metalloproteinases reported to be involved in extracellular matrix degradation and recently also in triggering of angiogenic switch in the course of inflammatory bowel diseases (IBD). The goal of our studies was to estimate in one experimental setting the levels of MMP-9 in sera of Crohn's Disease (CD) and ulcerative colitis (UC) patients and to evaluate its possible diagnostic potential in comparison with other biochemical markers and selected proinflammatory and angiogenic factors. The study group included 176 subjects (CD = 64, UC = 85, control = 27). Concentrations of serum MMP-9 were significantly higher in active than inactive forms of IBD, being higher in active UC than in active CD. Both in the case of CD and UC serum MMP-9 positively correlated with disease activity, IL-6 levels, platelet and leukocyte count, midkine, and PDGF-BB, as well as in UC with ESR and in CD with CRP, IL-1, and VEGF-A. Diagnostic accuracy of MMP-9 in distinguishing active UC from active CD was 66%, and displayed higher specificity than CRP (79.0% versus 61.6%, resp.). Evaluation of serum MMP-9 concentrations could aid in differentiation of active UC from active CD. MMP-9 correlated better with inflammatory and angiogenic parameters in CD than in UC.

MicroRNA-124 regulates STAT3 expression and is down-regulated in colon tissues of pediatric patients with ulcerative colitis

BACKGROUND & AIMS

Altered levels and functions of microRNAs (miRs) have been associated with inflammatory bowel diseases (IBDs), although little is known about their roles in pediatric IBD. We investigated whether colonic mucosal miRs are altered in children with ulcerative colitis (UC).

METHODS

We used a library of 316 miRs to identify those that regulate phosphorylation of signal transducer and activator of transcription 3 (STAT3) in NCM460 human colonocytes incubated with interleukin-6. Levels of miR-124 were measured by real-time polymerase chain reaction analysis of colon biopsies from pediatric and adult patients with UC and patients without IBD (controls), and of HCT-116 colonocytes incubated with 5-aza-2'-deoxycytidine (5-AZA). Methylation of the MIR124 promoter was measured by quantitative methylation-specific polymerase chain reaction.

RESULTS

Levels of phosphorylated STAT3 and the genes it regulates (encoding vascular endothelial growth factor (VEGF), BCL2, BCLXL, and matrix metallopeptidase 9 [MMP9]) were increased in pediatric patients with UC compared with control tissues. Overexpression of miR-124, let-7, miR-125, miR-26, or miR-101 reduced STAT3 phosphorylation by ≥ 75% in NCM460 cells; miR-124 had the greatest effect. miR-124 was down-regulated specifically in colon tissues from pediatric patients with UC and directly targeted STAT3 messenger RNA (mRNA). Levels of miR-124 were decreased, whereas levels of STAT3 phosphorylation increased in colon tissues from pediatric patients with active UC compared with those with inactive disease. In addition, levels of miR-124 and STAT3 were inversely correlated in mice with experimental colitis. Down-regulation of miR-124 in tissues from children with UC was attributed to hypermethylation of its promoter region. Incubation of HCT-116 colonocytes with 5-AZA up-regulated miR-124 and reduced levels of STAT3 mRNA.

CONCLUSIONS

miR-124 appears to regulate the expression of STAT3. Reduced levels of miR-124 in colon tissues of children with active UC appear to increase expression and activity of STAT3, which could promote inflammation and the pathogenesis of UC in children.

Relationship between neutrophil gelatinase-associated lipocalin (NGAL) levels and inflammatory bowel disease type and activity

BACKGROUND AND AIM

Neutrophil gelatinase associated lipocalin (NGAL) is a recently identified molecule, which is bacteriostatic, has tissue destructive effects and is pro-inflammatory with chemoattractant molecule binding properties. Our aim was to investigate the relationship between serum NGAL levels and the type and level of disease activity of IBD.

METHODS

A total of 92 patients [43 with Crohn's disease (CD) and 49 with ulcerative colitis (UC)], and 30 age- and sex-matched healthy controls (HC) were included in this study. Serum NGAL levels were measured using ELISA.

RESULTS

Serum NGAL levels were elevated in the IBD group [median 171, range (57-312) ng/mL] compared to the HC group [107 (45-234) ng/mL] (p<0.0001) and were elevated in UC patients [188 (74-312) ng/mL] compared to CD patients [168 (57-279) ng/mL] (p=0.006). When NGAL levels were further analysed based on localization of the CD and UC, the levels in ulcerative pancolitis [233 (144-312) ng/mL] were significantly higher (p=0.004) than the left-sided colitis [156 (103-309) ng/mL]. Similarly, NGAL levels were significantly higher in colonic CD [207 (125-249) ng/mL] than ileal CD [114 (78-210) ng/mL], and also in ileocolonic CD [198 (57-279) ng/mL] than ileal CD (p=0.033). When CD and UC groups were further categorized as active and inactive according to clinical and endoscopic activity indices, serum NGAL concentrations did not differ between inquiescent versus active stages. When a cut-off level of 129 ng/mL was used to distinguish IBD from HC, a sensitivity of 76.1% and a specificity of 60.9% was reached.

CONCLUSIONS

The serum NGAL levels in the IBD group was significantly higher than the HC group. Serum NGAL levels were higher in more extensive colonic involvement.

Fecal MMP-9: a new noninvasive differential diagnostic and activity marker in ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is characterized by frequent relapses, with the presence of colorectal inflammation and mucosal lesions. Matrix-metalloprotease 9 (MMP-9) is elevated in colonic biopsies, urine, and blood plasma of UC patients. MMP-9 has been suggested as a predictor of UC in the urine of children; however, 20% of the controls tested positive. So far, fecal MMP-9 levels have never been measured. Our aims were: 1) to compare fecal MMP-9 levels in UC patients to control subjects and a functional gastrointestinal disorder characterized by diarrhea (IBS-D); 2) to test the correlation between UC disease activity and fecal levels of MMP-9; and 3) to correlate fecal MMP-9 levels with a known fecal marker of UC activity, calprotectin.

METHODS

UC (n = 47), IBS-D (n = 23) patients, and control subjects (n = 24) provided fecal samples for MMP-9 analysis. In UC patients, disease severity was evaluated by the Mayo score. Fecal MMP-9 and calprotectin levels were measured by enzyme-linked immunosorbent assay and lateral flow assay, respectively.

RESULTS

MMP-9 was undetectable or ≤0.22 ng/mL in the feces of all controls and IBS-D patients. In UC patients, fecal MMP-9 levels significantly correlated with the overall Mayo score (P < 0.001), the endoscopic score (P < 0.001), and the serum C-reactive protein levels (P = 0.002). Additionally, in UC patients fecal MMP-9 levels showed a significant correlation with a known disease activity marker, fecal calprotectin (P = 0.014).

CONCLUSIONS

These results highlight fecal MMP-9 as a useful tool in the differential diagnosis of diarrheic disorders and in the noninvasive evaluation of disease activity and mucosal healing in UC.

Urinary proteome analysis of irritable bowel syndrome (IBS) symptom subgroups

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder characterized by chronic abdominal pain associated with alterations in bowel function. Given the heterogeneity of the symptoms, multiple pathophysiologic factors are suspected to play a role. We classified women with IBS into four subgroups based on distinct symptom profiles. In-depth shotgun proteomic analysis was carried out to profile the urinary proteomes to identify possible proteins associated with these subgroups. First void urine samples with urine creatinine level≥100 mg/dL were used after excluding samples that tested positive for blood. Urine from 10 subjects representing each symptom subgroup was pooled for proteomic analysis. The urine proteome was analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using a data-independent method known as Precursor Acquisition Independent From Ion Count (PAcIFIC) that allowed extended detectable dynamic range. Differences in protein quantities were determined by peptide spectral counting followed by validation of select proteins with ELISA or a targeted single reaction monitoring (LC-SRM/MS) approach. Four IBS symptom subgroups were selected: (1) Constipation, (2) Diarrhea+Low Pain, (3) Diarrhea+High Pain, and (4) High Pain+High Psychological Distress. A fifth group consisted of Healthy Control subjects. From comparisons of quantitative spectral counting data among the symptom subgroups and controls, a total of 18 proteins that showed quantitative differences in relative abundance and possible physiological relevance to IBS were selected for further investigation. Three of the 18 proteins were chosen for validation by either ELISA or SRM. An elevated expression of gelsolin (GSN) was associated with the high pain groups. Trefoil Factor 3 (TFF3) levels were higher in IBS groups compared to controls. In this study, the IBS patients subclassified by predominant symptoms showed differences in urine proteome levels. Proteins showing distinctive changes are involved in homeostasis of intestinal function and inflammatory response. These findings warrant future studies with larger, independent cohorts to enable more extensive assessment and validation of urinary protein markers as a diagnostic tool in adults with IBS.

Hyperhomocysteinemia decreases intestinal motility leading to constipation

Elevated levels of plasma homocysteine (Hcy) called hyperhomocysteinemia (HHcy) have been implicated in inflammation and remodeling in intestinal vasculature, and HHcy is also known to aggravate the pathogenesis of inflammatory bowel disease (IBD). Interestingly, colon is the pivotal site that regulates Hcy levels in the plasma. We hypothesize that HHcy decreases intestinal motility through matrix metalloproteinase-9 (MMP-9)-induced intestinal remodeling leading to constipation. To verify this hypothesis, we used C57BL/6J or wild-type (WT), cystathionine β-synthase (CBS(+/-)), MMP-9(-/-), and MMP-9(-/-) + Hcy mice. Intestinal motility was assessed by barium meal studies and daily feces output. Plasma Hcy levels were measured by HPLC. Expression of ICAM-1, inducible nitric oxide synthase, MMP-9, and tissue inhibitors of MMPs was studied by Western blot and immunohistochemistry. Reactive oxygen species (ROS) including super oxide were measured by the Invitrogen molecular probe method. Tissue nitric oxide levels were assessed by a commercially available kit. Plasma Hcy levels in the treated MMP-9 group mice were comparable to CBS(+/-) mice. Barium meal studies suggest that intestinal motility is significantly decreased in CBS(+/-) mice compared with other groups. Fecal output-to-body weight ratio was significantly reduced in CBS(+/-) mice compared with other groups. There was significant upregulation of MMP-9, iNOS, and ICAM-1 expression in the colon from CBS(+/-) mice compared with WT mice. Levels of ROS, superoxide, and inducible nitric oxide were elevated in the CBS(+/-) mice compared with other groups. Results suggest that HHcy decreases intestinal motility due to MMP-9-induced intestinal remodeling leading to constipation.

Neutrophil gelatinase-associated lipocalin (NGAL) in inflammatory bowel disease: association with pathophysiology of inflammation, established markers, and disease activity

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is a multi-potent 25-kDa protein mainly secreted by neutrophils. In inflammatory bowel disease (IBD), overexpression of NGAL in colon epithelium has been previously shown. This is the first study analyzing serum and urinary NGAL levels in IBD patients, with regard to specific characteristics of patients and disease.

METHODS

Serum and urinary NGAL levels were determined in 181 patients with IBD, 93 with ulcerative colitis (UC), and 88 with Crohn's disease (CD), 82 healthy controls (HC), and 41 patients with irritable bowel syndrome (IBS).

RESULTS

Serum NGAL levels were elevated in IBD patients (88.19 ± 40.75 ng/mL) compared with either HC (60.06 ± 24.18 ng/mL) or IBS patients (60.80 ± 20.30 ng/mL), P < 0.0001. No significant difference was shown between UC (86.62 ± 35.40 ng/mL) and CD (89.92 ± 46.05 ng/mL). Significantly higher levels of serum NGAL were observed in patients with active (120.1 ± 38.46) versus inactive IBD (61.58 ± 15.98), P < 0.0001. Serum NGAL displayed a strong ability to distinguish active IBD from inactive disease, healthy controls, or IBS patients with a sensitivity of 100, 95, and 95% and a specificity of 68, 83, and 79%, respectively, performing better than erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in the assessment of disease activity in both UC and CD. Urinary NGAL levels showed neither significant difference among patients and controls nor correlation with disease activity.

CONCLUSIONS

Serum NGAL is elevated particularly in active IBD and correlates with established markers of inflammation and disease activity, implicating its role in the pathophysiology of IBD.

Local and systemic expressions of MMP-9, TIMP-1 and PAI-1 in patients undergoing surgery for clinically suspected appendicitis

BACKGROUND/AIMS

To examine, compare and correlate the expressions of matrix metalloproteinase 9 (MMP-9), tissue inhibitor of metalloproteinase 1 (TIMP-1) and plasminogen activator inhibitor type 1 (PAI-1) in appendiceal tissue and pre- and postoperative blood samples in patients undergoing surgery for clinically suspected appendicitis.

METHODS

Fifty-seven patients with complete tissue and blood samples were included and divided into groups of noninflamed appendix/lymphadenitis (n = 7), phlegmonous appendicitis (n = 30), gangrenous appendicitis (n = 11) and perforated appendicitis (n = 9). The protein expressions were assessed with ELISAs. The local expressions of MMP-9, TIMP-1 and PAI-1 were correlated with the systemic expressions at the time of surgery while the systemic individual differences between surgery and recovery were compared.

RESULTS

There was a positive correlation between tissue and plasma PAI-1 (p < 0.05). The individual differences for plasma MMP-9 and PAI-1 were statistically nonsignificant, while they were higher for TIMP-1 in patients with perforated appendicitis compared with phlegmonous (p < 0.0001) and gangrenous appendicitis (p < 0.01).

CONCLUSIONS

Plasma PAI-1 reflected the levels in appendiceal tissue at the time of surgery. Systemic TIMP-1 could have the potential of distinguishing perforated from nonperforated appendicitis.

Insights on urinary NGAL obtained in a primary care setting

BACKGROUND

A majority of patients developing acute kidney injury (AKI) receive medical care from their primary care physicians prior to the occurrence of conditions that predispose them to this complication.

METHODS

To characterize the uNGAL concentrations in primary care patients and to assess these concentrations with regard to different reference intervals, we conducted a multicenter, cross-sectional study with random selection of general practitioners (GP) from all GP offices in seven Swiss cantons. 1000 adults (566 females; mean age 57±17 years) were included.

RESULTS

The median absolute uNGAL was 21 ng/L. Elevated uNGAL (>100 ng/L) together with normal kidney test results (eGFR and albuminuria) were found in 6.5% of all patients. Females had a significantly higher uNGAL than did males. Among a multitude of different clinical and laboratory variables, only age, gender, liver function parameters, WBC and CRP were significantly associated with uNGAL levels in a multivariate analysis. When examining the proposed KDIGO classification of chronic kidney disease, the uNGAL levels at the given eGFR stages changed with increasing albuminuria stages and vice versa.

CONCLUSIONS

Age, gender, markers of inflammation and liver function, exert influences on uNGAL concentrations. A substantial proportion of patients exhibited normal kidney testing together with elevated uNGAL, potentially identifying patients with increased renal stress and at increased risk for the development of AKI.

The behavior of matrix metalloproteinase-9 in lymphocytic colitis, collagenous colitis and ulcerative colitis

Matrix metalloproteinases play an important role in extracellular matrix remodelling. It has been proposed that matrix metalloproteinase-9 (MMP-9) is involved in epithelial damage in ulcerative colitis (UC). However, to our knowledge, no data are available in terms of MMP-9 expression in microscopic colitis. Determination of mucosal protein expression levels of MMP-9 in lymphocytic colitis (LC), collagenous colitis (CC) and UC. MMP-9 immunohistochemical expressions were analyzed in paraffin-embedded tissue samples by immunohistochemistry including patients with LC, CC, UC, active diverticulitis, inactive diverticular disease and healthy control subjects. UC was also subgrouped according to the severity of inflammation. Immunostaining was determined semiquantitatively. Independent colonic biopsies from healthy and severe UC cases were used for gene expression analyses. For further comparison MMP-9 serum antigen levels were also determined in patients with UC and control patients without macroscopic or microscopic changes during colonoscopy. MMP-9 mucosal expression was significantly higher in UC (26.7 ± 19.5%) compared to LC (6.6 ± 9.3%), CC (6.4 ± 7.6%), active diverticulitis (5.33 ± 2.4%), inactive diverticular disease (5.0 ± 2.2%) and controls (6.3 ± 2.6%) (P < 0.001). The immunohistochemical expression of MMP-9 in LC and CC was similar as compared to controls. MMP-9 expression was significantly higher in each inflammatory group of UC compared to controls (mild: 11.0 ± 2.8%, moderate: 23.9 ± 3.7%, severe UC: 52.6 ± 3.9% and 6.3 ± 2.6%, respectively, P < 0.005). The gene expression microarray data and RT-PCR results demonstrated a significantly higher expression of MMP-9 in severely active UC compared to healthy controls (P < 0.001). Significantly higher MMP-9 serum antigen concentrations were observed in UC patients compared with the control group (P < 0.05). MMP-9 seems to play no role in the inflammatory process of LC and CC. In contrast, the mucosal up-regulation of MMP-9 correlated with the severity of inflammation in UC. The increased MMP-9 expression could contribute to the severity of mucosal damage in active UC.

Correlation of MMP-3 and MMP-9 with Crohn's disease activity in children

BACKGROUND

Recently published data indicate that the inflammation in Crohn's disease (CD) may be accompanied by elevated levels of matrix metalloproteinases.

AIMS

The goals of the present study were the estimation of MMP-3 and -9 concentrations in sera of children with Crohn's disease, the examination of correlation between the concentrations of MMP-3 and -9 and clinical activity of the disease in the relation to the control group and the evaluation of the utility of MMP-3 and -9 concentration measurements as markers of disease activity.

METHODS

Serum concentrations of MMP-3 and -9 were estimated in 82 children (45 CD patients divided into severe, moderate and mild subgroups; 37 controls) and correlated with disease activity estimated by the Pediatric Crohn's Disease Activity Index (PCDAI), CRP, seromucoid and ESR.

RESULTS

Mean MMP-3 concentrations were: 2.49 ng/ml (95% CI: 1.76-3.52) for mild, 16.44 ng/ml (95% CI: 10.34-26.15) for moderate, 5.25 ng/ml (95% CI: 2.73-10.11) for severe CD and 1.95 ng/ml (95% CI: 1.53-2.48) for the control group (differences between all three groups were statistically significant; P < 0.001). Median MMP-9 concentrations were: 2.14 ng/ml (95% CI: 0-8.9) for mild, 14.21 ng/ml (95% CI: 4.53-21.48) for moderate, 42.2 ng/ml (95% CI: 5.74-61.27) for severe CD and 1.3 ng/ml (95% CI: 0.7-2.18) for the control group. MMP-9 concentrations in moderate and severe CD differed from the concentrations in mild CD (P = 0.002) and control group (P = 0.0001). MMP-3 concentration significantly correlated with MMP-9, PCDAI and ESR, while MMP-9 concentration significantly positively correlated with MMP-3, PCDAI, and CRP. Diagnostic utilities of the tests were: MMP-3 accuracy 75%, positive likelihood ratio (LR+) = 4.11 and negative likelihood ratio (LR-) = 0.51, sensitivity 56%, specificity 87%, Youden index 0.43; for MMP-9, accuracy 73%, LR+ = 5.14 and LR- = 0.50, sensitivity 56%, specificity 89%, Youden index 0.45; and for CRP, accuracy 74%, LR+ = 8.56 and LR- = 0.54, sensitivity 49%, specificity 94%, Youden index 0.43.

CONCLUSIONS

MMP-9 serum concentration increasing along with the activity of the disease, exhibiting high specificity and correlating well with the indices of inflammation might be of better usefulness in the prediction of CD activity status in children than MMP-3.

Candidate mucosal and surrogate biomarkers of inflammatory bowel disease in the era of new technology

OBJECTIVE

There is increasing knowledge of the pathophysiology behind inflammatory bowel disease (IBD) although the exact mechanism is far from fully understood. In the era of new technology, over the last years molecular approaches have shed light on the inflammatory mechanisms and their metabolic end products. This opens for a molecular fingerprinting that can be used in the biomarker field of IBD. There is a great need of biomarkers for prediction of clinical outcome and prognostic biomarker for prediction of therapeutic effects in IBD. Although the biomarker concept is old, so far very few really useful biomarkers exist in IBD.

MATERIAL AND METHODS

Here, we review the predictive and prognostic biomarkers in IBD in the era of new technologies with emphasis on the potential of molecular fingerprinting.

RESULTS

Very few candidate biomarkers have been documented. The most promising candidate predictor is tumor necrosis factor-α, but there is a lack of validation.

CONCLUSION

So far, there are few biomarkers documented in IBD, but we are at the start of a new scientific field that will be of great value for the handling of the disease.

Matrix metalloproteinase-9 inhibition reduces inflammation and improves motility in murine models of postoperative ileus

BACKGROUND & AIMS

Matrix metalloproteinase (MMP)-9, a member of the gelatinase family of MMPs, mediates leukocyte migration during inflammation. Inflammation contributes to development of postoperative ileus (POI), which is caused by physical disturbances to the bowel during abdominal surgery. We evaluated the role of MMP-9 in POI and investigated whether disruption of MMP-9 or administration of an inhibitor of MMP-9 activity reduced cellular inflammation and bowel dysmotility in rat and mouse models of POI.

METHODS

Mice and rats underwent laparotomy and bowel manipulation; bowel tissues were collected 3 to 24 hours later and analyzed by real-time reverse-transcriptase polymerase chain reaction, immunoblot, in situ zymography, and functional analyses.

RESULTS

Bowel manipulation resulted in a time-dependent increase in MMP-9 expression within the intestinal muscularis; increases in MMP-9 messenger RNA were inducible nitric oxide synthase dependent. Immunoblot analyses confirmed the presence of the proenzyme and the catalytically active form of MMP-9. Administration of MMP-2/MMP-9 II, a dual active-site inhibitor, reduced the number of myeloperoxidase-positive immune cells that infiltrated the muscularis and prevented the surgically induced reduction in bowel smooth muscle contractility. Zymography analysis, performed in muscularis whole mounts in situ, indicated that MMP-9 and not MMP-2 mediated the gelatinase activity observed in infiltrating cells. MMP-9 knockout mice were protected from the inflammation and dysmotility associated with POI.

CONCLUSIONS

MMP-9 mediates cellular inflammatory responses within the intestinal muscularis in mouse and rat models of POI. Inhibition of MMP-9 activity reduced recruitment of immune cells to the intestinal muscularis, preventing loss of smooth muscle contractility. Induction of MMP-9 expression requires inducible nitric oxide synthase.

Results of the 2nd part Scientific Workshop of the ECCO. II: Measures and markers of prediction to achieve, detect, and monitor intestinal healing in inflammatory bowel disease

The healing of the intestine is becoming an important objective in the management of inflammatory bowel diseases. It is associated with improved disease outcome. Therefore the assessment of this healing both in clinical studies and routine practice is a key issue. Endoscopy for the colon and terminal ileum and computerized tomography or magnetic resonance imaging for the small bowel are the most direct ways to evaluate intestinal healing. However, there are many unsolved questions about the definition and the precise assessment of intestinal healing using these endoscopic and imaging techniques. Furthermore, these are relatively invasive and expensive procedures that may be inadequate for regular patients' monitoring. Therefore, biomarkers such as C-reactive protein and fecal calprotectin have been proposed as surrogate markers for intestinal healing. Nevertheless, the sensitivity and specificity of these markers for the prediction of healing may be insufficient for routine practice. New stool, blood or intestinal biomarkers are currently studied and may improve our ability to monitor intestinal healing in the future.

Urinary matrix metalloproteinase activities: biomarkers for plaque angiogenesis and nephropathy in diabetes

Diabetic complications of nephropathy and accelerated atherosclerosis are associated with vascular remodeling and dysregulated angiogenesis. Matrix metalloproteinases (MMP) modify extracellular matrix during vascular remodeling and are excreted in urine of patients with vascular malformation or tumor angiogenesis. We hypothesized that urinary MMP activities would be sensitive biomarkers for vascular remodeling in diabetic complications. Activities of MMP-2, MMP-9, and its complex with neutrophil gelatinase-associated lipocalin (NGAL/MMP-9) were measured by substrate gel zymography in urine from nondiabetic (ND) and type 1 diabetic (T1D) rodents that were susceptible to both T1D-induced plaque angiogenesis and nephropathy, or nephropathy alone. Additionally, these urine activities were measured in ND and T1D adolescents. Urinary MMP-9, MMP-2, and NGAL/MMP-9 activities were increased and more prevalent in T1D compared with ND controls. Urinary MMP-2 activity was detected in mice with T1D-induced plaque neovascularization. In nephropathy models, urinary NGAL/MMP-9 and MMP-9 activities appeared before onset of albuminuria, whereas MMP-2 was absent or delayed. Finally, urinary MMP activities were increased in adolescents with early stages of T1D. Urinary MMP activities may be sensitive, noninvasive, and clinically useful biomarkers for predicting vascular remodeling in diabetic renal and vascular complications.

New biomarkers of acute kidney injury and the cardio-renal syndrome

Changes in renal function are one of the most common manifestations of severe illness. There is a clinical need to intervene early with proven treatments in patients with potentially deleterious changes in renal function. Unfortunately progress has been hindered by poor definitions of renal dysfunction and a lack of early biomarkers of renal injury. In recent years, the definitional problem has been addressed with the establishment of a new well-defined diagnostic entity, acute kidney injury (AKI), which encompasses the wide spectrum of kidney dysfunction, together with clearer definition and sub-classification of the cardio-renal syndromes. From the laboratory have emerged new biomarkers which allow early detection of AKI, including neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C. This review describes the new concepts of AKI and the cardio-renal syndromes as well as novel biomarkers which allow early detection of AKI. Panels of AKI biomarker tests are likely to revolutionise the diagnosis and management of critically ill patients in the coming years. Earlier diagnosis and intervention should significantly reduce the morbidity and mortality associated with acute kidney damage.

Normal quantity and distribution of mast cells and eosinophils in the pediatric colon

The normal number and distribution of mast cells (MCs) and eosinophils in colonic mucosa are largely unknown. Accordingly, we examined colonic biopsies obtained during endoscopic examinations of pediatric patients. The study included 41 patients (21 males and 20 females). The mean age was 11.72 years (range 3.3-19.7 years). Patients were followed for a mean time of 23.4 months (range 12-50 months). Our results showed a gradual decrease in the number of eosinophils in the lamina propria from the cecum to the descending colon (14.2 ± 6.1 and 10.7 ± 5.6 eosinophils//high-power field [hpf], respectively), with another peak in the rectosigmoid (12.4 ± 6.1 eosinophils/hpf). Eosinophils within the surface and crypt epithelium were more commonly encountered in the cecum and the rectosigmoid. Eosinophils clusters were rare but were more frequently found in the cecum and rectosigmoid. The largest number of MCs was observed in the descending colon and the lowest in the rectosigmoid (17.56 ± 7.28 and 14.5 ± 6.35 MCs/hpf, respectively). No MCs were identified within the surface epithelium. Very rare MCs were observed within the crypt epithelium, with the highest number observed in the cecum (0.34 ± 0.53 MCs/hpf) and the lowest number observed in the descending colon (0.02 ± 0.16 MCs/hpf). More MCs were present in the cecum and descending colon of females vs males (P  =  0.02 and 0.04, respectively). Our results establish baseline gastrointestinal eosinophils and MC counts in various parts of the pediatric colon.

The behavior of matrix metalloproteinase-9 in lymphocytic colitis, collagenous colitis and ulcerative colitis

Matrix metalloproteinases play an important role in extracellular matrix remodelling. It has been proposed that matrix metalloproteinase-9 (MMP-9) is involved in epithelial damage in ulcerative colitis (UC). However, to our knowledge, no data are available in terms of MMP-9 expression in microscopic colitis. Determination of mucosal protein expression levels of MMP-9 in lymphocytic colitis (LC), collagenous colitis (CC) and UC. MMP-9 immunohistochemical expressions were analyzed in paraffin-embedded tissue samples by immunohistochemistry including patients with LC, CC, UC, active diverticulitis, inactive diverticular disease and healthy control subjects. UC was also subgrouped according to the severity of inflammation. Immunostaining was determined semiquantitatively. Independent colonic biopsies from healthy and severe UC cases were used for gene expression analyses. For further comparison MMP-9 serum antigen levels were also determined in patients with UC and control patients without macroscopic or microscopic changes during colonoscopy. MMP-9 mucosal expression was significantly higher in UC (26.7 ± 19.5%) compared to LC (6.6 ± 9.3%), CC (6.4 ± 7.6%), active diverticulitis (5.33 ± 2.4%), inactive diverticular disease (5.0 ± 2.2%) and controls (6.3 ± 2.6%) (P < 0.001). The immunohistochemical expression of MMP-9 in LC and CC was similar as compared to controls. MMP-9 expression was significantly higher in each inflammatory group of UC compared to controls (mild: 11.0 ± 2.8%, moderate: 23.9 ± 3.7%, severe UC: 52.6 ± 3.9% and 6.3 ± 2.6%, respectively, P < 0.005). The gene expression microarray data and RT-PCR results demonstrated a significantly higher expression of MMP-9 in severely active UC compared to healthy controls (P < 0.001). Significantly higher MMP-9 serum antigen concentrations were observed in UC patients compared with the control group (P < 0.05). MMP-9 seems to play no role in the inflammatory process of LC and CC. In contrast, the mucosal up-regulation of MMP-9 correlated with the severity of inflammation in UC. The increased MMP-9 expression could contribute to the severity of mucosal damage in active UC.