Differential expression and processing of matrix metalloproteinase 19 marks progression of gastrointestinal diseases.

Matrix metalloproteinases (MMPs), responsible for extracellular matrix remodelling and processing of numerous soluble and cell-surface proteins, appear to play important roles in pathogenesis of gastrointestinal diseases. MMPs influence migration of inflammatory cells, mucosal destruction, matrix deposition and degradation. In this study, we analysed the expression of MMP-19 in the main forms of gastrointestinal diseases including inflammatory bowel diseases (IBD) such as ulcerative coliReceived November 26, 2013. Accepted January 10, 2014. Financial support was given to RS by GACR (P302/11/2048 and P303/10/2044), the project BIOCEV – Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (CZ.1.05/1.1.00/02.0109; European Regional Development Fund), GAUK (project 64212) and OPVK (CZ.1.07/2.3.00/ 20.0102). The work was institutionally supported by RVO: 68378050. Corresponding author: Radislav Sedlacek, Laboratory of Transgenic Models of Diseases, Institute of Molecular Genetics of the ASCR, v. v. i., Videňska 1083, 142 20 Prague 4, Czech Republic. Phone: (+420) 24106 3137; Fax: (+420) 22431 0955; e-mail: radislav.sedlacek@img.cas.cz. Abbreviations: CD – cluster of differentiation, CRC – colorectal cancer, DAB – diaminobenzidine, ECM – extracellular matrix, EGFP – enhanced green fluorescent protein, GAPDH – glyceraldehyde-3-phosphate dehydrogenase, HUVEC – human umbilical vein endothelial cells, IBD – inflammatory bowel disease, IGF – insulin-like growth factor, IGFBP – insulin-like growth factorbinding protein, MMP – matrix metalloproteinase, PFA – paraformaldehyde, qRT-PCR – quantitative reverse transcriptase polymerase chain reaction, RT – room temperature. tis and Crohn’s disease, and colorectal carcinoma. We identified prominent MMP-19 expression in unaffected areas of intestinal epithelia and macrophages but not in other cells or tissues. Abundant expression of MMP-19 was also found in the endothelium of blood and lymphatic vessels of inflamed intestinal tissue. High MMP-19 immunoreactivity was also associated with macrophages in inflamed areas and myenteric plexuses. In comparison to the intestinal epithelium, all these cell types and compartments appeared to express MMP-19 irrespective of the disease pathogenesis and progression. Intestinal epithelia exhibited striking differential immunoreactivity for MMP-19. While immunoreactivity of monoclonal antibody recognizing the propeptide domain declined in virtually all IBD and colorectal carcinoma samples, other polyclonal antibodies against the hinge region and propetide domain did not show such an obvious decrease. Additional Western blotting analysis revealed that the antibodies against MMP-19 recognize differently processed forms of this MMP. The disappearance of immunoreactivity of the monoclonal anti-propeptide domain antibody does not mean down-regulation of MMP-19, but processing of the immature form. As this processing likely leads to the activation of this MMP, the differential staining pattern may be an important sign of disease progression.