Expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in ulcerative colitis

AIM: To examine the expression of metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the colonic mucosa of patients with ulcer- ative colitis (UC). METHODS: Reverse transcription-polymerase chain re- action (RT-PCR) and immunohistochemistry were used to study the expression of MMP-1 and TIMP-1 at both mRNA and protein levels in patients with UC and con- trols. The relationship between MMP-1 mRNA, TIMP-1 mRNA, MMP-1 mRNA/TIMP-1 mRNA ratio and the sever- ity of clinical symptoms of the patients with UC were also analyzed. RESULTS: The expression of MMP-1 mRNA and TIMP-1 mRNA in the ulcerated and inflamed colonic mucosa was signifi cantly higher than that in the non-inflamed colonic mucosa (P < 0.001), but there was no statistically signif i- cant difference in the non-inflamed colonic mucosa of UC patients and normal controls (P > 0.05). The mRNA ex- pression of MMP-1 and TIMP-1 in ulcerated colonic mu- cosa of UC patients was increased by 80-fold and 2.2-fold, respectively when compared with the normal controls. In the inflamed colonic mucosa, the increase was 30-fold and 1.6-fold, respectively. Immunohistochemical analy- sis showed that among the ulcerated, inflamed, and non-inflamed colonic mucosae of UC patients and the normal controls, the positive rate of MMP-1 expression was 87%, 87%, 40% and 35% respectively, and the positive rate of TIMP-1 expression was 89%, 89%, 80% and 75%, respectively. Furthermore, the expression of MMP-1 mRNA, TIMP-1 mRNA and the MMP-1 mRNA/ TIMP-1 mRNA ratio were correlated with the severity of clinical symptoms (P <0.05).CONCLUSION: Excessive expression of MMP-1 in the diseased colonic mucosa causes excessive hydrolysis of the extracellular matrix (ECM) and ulceration in UC pa-tients. MMP-1 mRNA, TIMP-1 mRNA and MMP-1 mRNA/ TIMP-1 mRNA ratio can be used as biomarkers to judge the severity of clinical symptoms in patients with UC. Exogenous TIMP-1 or MMP-1 inhibitor therapy is a novel treatment for patients with UC.

Expression of matrix metalloproteinase-1 and tumor necrosis factor-α in ulcerative colitis

AIM： To examine the expression of matrix metalloproteinase-1 （MMP-1） and tumor necrosis factor-α （TNF-~~） in the colon mucosa of patients with ulcerative colitis （UC）.METHODS： Reverse transcription-polymerase chain reaction （RT-PCR） and immunohistochemistry were used to examine the expression of MMP-1 and TNF-α at both mRNA and protein levels in the colon mucosa of patients with UC. Correlation between MMP-1 and TNF-α and their correlation with the severity of the disease were also analyzed statistically.RESULTS： The expression of MMP-1 and TNF-α in the ulcerated and inflamed colon mucosa of patients with UC was significantly higher than that in the non-inflamed mucosa of normal controls at both mRNA and protein levels. Furthermore, the expression of MMP-1 and TNF-α in the ulcerated area was significantly higher than that in the inflamed area of patients with UC （0.9797 ± 0.1433 vs 0.6746 ± 0.0373, 0.8669 ± 0.0746 vs 0.5227 ± 0.0435, P 〈 0.05）. There was no statistically significant difference in the non-inflamed area of normal controls. There was a significant correlation between MMP-1 and TNF-c~ expression （0.9797 ± 0.1433 vs 0.8669 ± 0.0746, P 〈 0.05）, the correlating factor was 0.877. MMP-1 and TNF-α showed a significant correlation with the severity of the disease （0.0915 ：e 0.0044 vs 0.0749 vs 0.0032, 0.0932 ± 0.0019 vs 0.0724 ± 0.0043, P 〈 0.05）, their correlating factors were 0.942 and 0.890, respectively.CONCLUSION： Excessively expressed MMP-1 directly damages the colon mucosa by degrading extracellular matrix （ECM） in patients with UC. While damaging colon mucosa, excessively expressed TNF-α stimulates MMPs secreting cells to produce more MMP-1 and aggravates the mucosa damage. MMP-1 promotes secretion of TNF-α in a positive feedback manner to cause further injury in the colon mucosa. MMP-1 and TNF-α correlate well with the severity of the disease, and therefore, can be used clinically as biological markers to judge the severity of UC.