Role of matrix metalloproteinase,tissue inhibitor of metalloproteinase and tumor necrosis factor-α single nucleotide gene polymorphisms in inflammatory bowel disease

AIM:To study the (functional) relevance of single nucleotide polymorphisms (SNPs) in genes encoding matrix metalloproteinases (MMP)-1,-2,-3,-9,tissue inhibitors of metalloproteinases (TIMP)-1,-2 and tumor necrosis factor (TNF)-α in the etiopathogenesis of inflammatory bowel diseases (IBD),that may enhance susceptibility and/or disease severity. METHODS:Genomic DNA from 134 Crohn's disease (CD),111 ulcerative colitis (UC) patients and 248 control subjects was isolated from resected intestinal tissue or blood. Allelic composition at SNP loci was determined by PCR-RFLP or tetra primer ARMS PCR. RESULTS:The TIMP-1 genotype TT in women and T in men at SNP +372 T/C was found to increase CD susceptibility (39% vs 23.8%,P=0.018 and 67.9% vs 51.6%,P=0.055,respectively),while women with this genotype were less prone to development of fistulae during follow-up (41.4% vs 68.3%,P=0.025). Male IBD or CD patients carrying the TIMP-1 +372 T-allele expressed lower levels of TIMP-1 in surgically resected macroscopically inflamed tissue (0.065 < P < 0.01). The 5T5T genotype at MMP-3 SNP -1613 5T/6T increased the chance of stenotic complications in CD during follow-up (91.2% vs 71.8%,P = 0.022) but seemed to protect against colonic involvement of this disease at first endoscopic/radiologic examination (35.3% vs 59.5%,P=0.017). CONCLUSION:Allelic composition at the examinedSNPs in genes coding for TIMP-1 and MMP-3 affect CD susceptibility and/or phenotype,i.e.,fistulizing disease,stricture pathogenesis and first disease localisation. These findings reinforce the important role of these proteins in IBD.

On tolerability and safety of a maintenance treatment with 6-thioguanine in azathioprineor 6-mercaptopurine intolerant IBD patients

AIM: To determine the tolerability and safety profile of a low-dose maintenance therapy with 6-TG in azathioprine (AZA) or 6-mercaptopurine (6-MP) intolerant inflammatory bowel disease (IBD) patients over a treatment period of at least 1 year.METHODS: Database analysis.RESULTS: Twenty out of ninety-five (21%) patients discontinued 6-TG (mean dose 24.6 mg; mean 6-TGN level 540 pmol/8×108 RBC) within 1 year. Reasons for discontinuation were GI complaints (31%), malaise (15%)and hepatotoxicity (15%). Hematological events occurred in three patients, one discontinued treatment. In the 6-TG-tolerant group, 9% (7/75) could be classified as hepatotoxicity. An abdominal ultrasound was performed in 54% of patients, one patient had splenomegaly.CONCLUSION: The majority of AZA or 6-MP-intolerant IBD patients (79%) is able to tolerate maintenance treatment with 6-TG (dosages between 0.3 and 0.4 mg/kg per d). 6-TG may still be considered as an escape maintenance immunosuppressant in this difficult to treat group of patients, taking into account potential toxicity and efficacy of other alternatives. The recently reported hepatotoxicity is worrisome and 6-TG should therefore be administered only in prospective trials.

Gene and cell therapy based treatment strategies for inflammatory bowel diseases

Inflammatory bowel diseases(IBD)are a group of chronic inflammatory disorders most commonly affecting young adults.Currently available therapies can result in induction and maintenance of remission,but are not curative and have sometimes important side effects.Advances in basic research in IBD have provided new therapeutic opportunities to target the inflammatory process involved.Gene and cell therapy approaches are suitable to prevent inflammation in the gastrointestinal tract and show therefore potential in the treatment of IBD.In this review,we present the current progress in the field of both gene and cell therapy and future prospects in the context of IBD.Regarding gene therapy,we focus on viral vectors and their applications in preclinical models.The focus for cell therapy is on regulatory T lymphocytes and mesenchymal stromal cells,their potential for the treatment of IBD and the progress made in both preclinical models and clinical trials.

Single-nucleotide polymorphisms of matrix metalloproteinases and their inhibitors in gastrointestinal cancer

Matrix metalloproteinases(MMPs) are implicated in cancer development and progression and are associated with prognosis.Single-nucleotide polymorphisms(SNPs) of MMPs,most frequently located in the promoter region of the genes,have been shown to influence cancer susceptibility and/or progression.SNPs of MMP-1,-2,-3,-7,-8,-9,-12,-13 and-21 and of the tissue inhibitor of metalloproteinases(TIMPs) TIMP-1 and TIMP-2 have been studied in digestive tract tumors.The contribution of these polymorphisms to the cancer risk and prognosis of gastrointestinal tumors are reviewed in this paper.

Adeno-associated virus mediated delivery of Tregitope 167 ameliorates experimental colitis

AIM:To explore the anti-inflammatory potential of adeno-associated virus-mediated delivery of Tregitope 167 in an experimental colitis model.METHODS:The trinitrobenzene sulfonate(TNBS) model of induced colitis was used in Balb/c mice.Subsequently after intravenous adeno-associated virusmediated regulatory T-cell epitopes(Tregitope) delivery,acute colitis was initiated by intra-rectal administration of 1.5 mg TNBS in 40% ethanol followed by a second treatment with TNBS(0.75 mg in 20% ethanol) 8 d later.Control groups included mice not treated with TNBS(healthy control group) and mice treated by TNBS only(diseased group).At the time of sacrifice colon weight,the disease activity index and histology damage score were determined.Immunohistochemical staining of the colonic tissues was performed to asses the cellular infiltrate and the presence of transcription factor forkhead Box-P3(Foxp3).Thymus,mesenteric lymph nodes,liver and spleen tissue were collected and the corresponding lymphocyte populations were further assessed by flow cytometry analysis for the expression of CD4+ T cell and regulatory T cell associated markers.RESULTS:The Tregitope 167 treated mice gained an average of 4% over their initial body weight at the time of sacrifice.In contrast,the mice treated with TNBS alone(no Tregitope) developed colitis,and lost 4% of their initial body weight at the time of sacrifice(P < 0.01).The body weight increase that had been observed in the mice pre-treated with Tregitope 167 was substantiated by a lower disease activity index and a decreased colon weight as compared to the diseased control group(P < 0.01 and P < 0.001,respectively).Immunohistochemical staining of the colonic tissues for CD4+ showed that inflammatory cell infiltrates were present in TNBS treated mice with or without administration with tregitope 167 and that these cellular infiltrates consisted mainly of CD4+ cells.For both TNBS treated groups CD4+ T cell infiltrates were observed in the sub-epithelial layer and the lamina propria.CD4+ T cell infiltrates were also present in the muscularis mucosa layer of the diseased control mice,but were absent in the Tregitope 167 treated group.Numerous Foxp3 positive cells were detected in the lamina propria and sub-epithelium of the colon sections from mice treated with Tregitope 167.Furthermore,the Foxp3 and glycoprotein A repetitions predominant markers were significantly increased in the CD4+ T lymphocyte population in the thymus of the mice pre-treated with adeno-associated virus serotype 5(cytomegalovirus promoter-Tregitope 167),as cytomegalovirus promoter compared to lymphocyte populations in the thymus of diseased and the healthy control mice(P < 0.05 and P < 0.001,respectively).CONCLUSION:This study identifies adeno-associated virus-mediated delivery of regulatory T-cell epitope 167 as a novel anti-inflammatory approach with the capacity to decrease intestinal inflammation and induce longterm remission in inflammatory bowel disease.