Protective effect of ilomastat on trinitrobenzenesulfonic acid-induced ulcerative colitis in rats

Digestive Inflammation: Role of Proteolytic Dysregulation

Dysregulation of the proteolytic balance is often associated with diseases. Serine proteases and matrix metalloproteases are involved in a multitude of biological processes and notably in the inflammatory response. Within the framework of digestive inflammation, several studies have stressed the role of serine proteases and matrix metalloproteases (MMPs) as key actors in its pathogenesis and pointed to the unbalance between these proteases and their respective inhibitors. Substantial efforts have been made in developing new inhibitors, some of which have reached clinical trial phases, notwithstanding that unwanted side effects remain a major issue. However, studies on the proteolytic imbalance and inhibitors conception are directed toward host serine/MMPs proteases revealing a hitherto overlooked factor, the potential contribution of their bacterial counterpart. In this review, we highlight the role of proteolytic imbalance in human digestive inflammation focusing on serine proteases and MMPs and their respective inhibitors considering both host and bacterial origin.

Novel Barbiturate-Nitrate Compounds Inhibit the Upregulation of Matrix Metalloproteinase-9 Gene Expression in Intestinal Inflammation through a cGMP-Mediated Pathway

Matrix metalloproteinase-9 is upregulated in inflammatory bowel disease. Barbiturate nitrate hybrid compounds have been designed to inhibit MMP secretion and enzyme activity. In this study, we investigated the mechanism of action of barbiturate-nitrate hybrid compounds and their component parts using models of intestinal inflammation in vitro. Cytokine-stimulated Caco-2 cells were used in all in vitro experiments. The NO donors SNAP and DETA-NONOate were used to study the effect of NO on MMP-9 mRNA. Mechanistic elucidation was carried out using the soluble guanylate cyclase (sGC) inhibitor, ODQ, and the cGMP analogue, 8-Bromo-cGMP. Further experiments were carried out to elucidate the role of NF-κB. NO donors exerted an inhibitory effect on MMP-9 mRNA in cytokine-stimulated cells. While the non-nitrate barbiturates had a limited effect on MMP-9 expression, the hybrid compounds inhibited MMP-9 expression through its NO-mimetic properties. No effect could be observed on mRNA for MMP-1 or MMP-2. The sGC inhibitior, ODQ, abolished the nitrate-barbiturate inhibition of MMP-9 gene expression, an effect which was reversed by 8-Br-cGMP. This study shows that the barbiturate scaffold is suitable for hybrid design as an MMP-9 inhibitor in cytokine-stimulated Caco-2 cells. The inhibition of MMP-9 levels was largely mediated through a reduction in its mRNA by a sGC/cGMP pathway mediated mechanism.

Ilomastat, a synthetic inhibitor of MMPs, prevents lung injury induced by γ-ray irradiation in mice

Lung injury is one of the pathological features in human or animal after radiation and the main side effect for patient after lung cancer radiotherapy. The efficient protective strategy still needs to exploit and the underlying mechanisms remain to be investigated. We found that the expression and activity of matrix metalloproteinases (MMPs) significantly increased at the early stage of radiation-induced lung injury (RILI). Pretreatment with Ilomastat, a synthetic inhibitor of MMPs, decreased the expression and activity of MMPs and significantly alleviated the lung inflammation and fibrosis in the irradiated mice, as well as enhanced the survival of irradiated mice. In addition, the levels of TGF-β, IL-6, TNF-α and IL-1β in the tissues dramatically reduced in the irradiated mice pretreated with Ilomastat. Furthermore, our experiments in vitro also showed that radiation significantly increased the MMPs activity, and Ilomastat pretreatment inhibited the activity of MMPs activated by irradiation and increased the cell survival. It is the first report, to our knowledge, to demonstrate that Ilomastat is a potential effective reliever for RILI and MMPs may play important roles in the process of RILI.

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.

Protective role of metalloproteinase inhibitor (AE-941) on ulcerative colitis in rats

AIM: To evaluate the protective role of AE-941, a matrix metalloproteinase (MMP) inhibitor, on ulcerative colitis (UC) in rats.

METHODS: Sprague Dawley (SD) rats were randomly divided into three groups: a control group, an AE-941 treatment group, and an UC model group. Rats were sacrificed on days 7, 21, or 56 following administration of treatment by enema and the disease activity index (DAI), colonic mucosa damage index (CMDI) and colonic expression of MMP-2 and MMP-9 were assessed.

RESULTS: DAI and CDMI scores in the UC model group increased significantly compared to the control group at all timepoints (P < 0.001), and also increased significantly at the 21- and 56-d timepoints compared to the AE-941-treated group (DAI: 21- and 56-d = 2.09 ± 0.25, 1.52 ± 0.30 vs 1.55 ± 0.28, 0.59 ± 0.19, respectively, P = 0.040 and 0.007, CMDI: 21- and 56-d = 3.03 ± 0.42, 1.60 ± 0.35 vs 2.08 ± 0.46, 0.86 ± 0.37, respectively, P = 0.040 and 0.005). Furthermore, the colonic expression of MMP-2 and MMP-9 in the UC model group increased significantly compared to the control group (P < 0.001), and also increased compared to the AE-941-treated group on the 21- and 56-d timepoints (MMP-2: 21- and 56-d = 0.6048 ± 0.0522, 0.4163 ± 0.0330 vs 0.3983 ± 0.0218, 0.1093 ± 0.0072, respectively, P = 0.010; MMP-9: 21- and 56-d = 0.6873 ± 0.0472, 0.4328 ± 0.0257 vs 0.5179 ± 0.0305, 0.2673 ± 0.0210, respectively, P = 0.010 and 0.040).

CONCLUSION: Expression of MMP-2 and MMP-9 increased significantly in rats with UC. AE-941 can reduce colonic mucosal damage by downregulating the expression of MMP-2 and MMP-9.

Results of the 2nd scientific workshop of the ECCO (III): basic mechanisms of intestinal healing

The second scientific workshop of the European Crohn's and Colitis Organization (ECCO) focused on the relevance of intestinal healing for the disease course of inflammatory bowel disease (IBD). The objective was to better understand basic mechanisms, markers for disease prediction, detection and monitoring of intestinal healing, impact of intestinal healing on the disease course of IBD as well as therapeutic strategies. The results of this workshop are presented in four separate manuscripts. This section describes basic mechanisms of intestinal healing, identifies open questions in the field and provides a framework for future studies.