Expression Of Transforming Growth Factor-β And Its Isoforms In Colonic Mucosa Of Patients With Ulcerative Colitis

Ulcerative colitis (UC) is a chronic nonspecific inflammatory disease of colon and rectum of unknown cause. The pathogenesis of UC has not been fully clarified. It is generally considered that it may have relationship with environmental factors, genetics, infection, abnormal immune response, smoking, psychology factors and so on. Now abnormal immune response especial focus on immune disorders of local colonic mucosa played an important role in the pathogenesis of UC. The increase of pro-inflammatory cytokine and decrease of anti-inflammatory cytokine are the primary causes of abnormal immune reaction and chronic inflammatory in intestinal mucosa with UC. Transforming growth factor-β(TGF-β) is a cytokine which regulates the growth and differentiation of cell and the process of physiology and pathology. It is the member of transforming growth factor-βsuperfamily. TGF-βis a very important anti-inflammatory cytokine. It can inhibit the effluence and development of inflammatory by down regulating the excessive immune reaction. Now about TGF-βthe scientists had discovered five isoforms (TGF-β1～5) in vertebrates. However, it exist TGF-β1～3 in mammals.Objective:In our experiment we apply method of immunohistochemistry to detect the expression of TGF-βand its isoforms in the colonic mucosa of patients with UC and irritable bowel syndrome (IBS). The aims are to investigate the relationship between TGF-βand its isoforms and UC and to explain its role in the pathogenesis of UC.Methods:The lineage of 50 UC and 30 IBS colon tissue paraffin block was detected under colonoscopy. The expression of TGF-βand its isoforms was detected using immunohistochemical enhance labeled polymer system method in colonic mucosa of these two diseases. Then the expression of TGF-βand its isoforms was observed in UC of different stage of pathogenetic condition, different degree of severity, different clinic type, and different extent of disease. And the correlation of the expression between TGF-βand its isoforms in colonic mucosa was analyzed. Results:1. The expression of TGF-βin UC group was significant higher than that in IBS group (P<0.01), and the expression in active stage was significantly higher than that in remission stage (P<0.01). In UC of active stage, the expression of TGF-βhad statistic difference in different degree of severity (P<0.05), but it had no statistic difference in different clinic type and different extent of disease (P>0.05).2. The expression of TGF-β1 in UC group was significant higher than that in IBS group (P<0.01), and the expression in active stage was significantly higher than that in remission stage (P<0.01). In UC of active stage, the expression of TGF-β1 had statistic difference in different degree of severity (P<0.05), but it had no statistic difference in different clinic type and different extent of disease (P>0.05). There was positive correlation of the expression of TGF-β1 with the expression of TGF-β(rs=0.749, P<0.05).3. The expression of TGF-β2 in UC group was significant higher than that in IBS group (P<0.01), and the expression in active stage was significantly higher than that in remission stage (P<0.01). In UC of active stage, the expression of TGF-β2 had statistic difference in different degree of severity (P<0.05), but it had no statistic difference in different clinic type and different extent of disease (P>0.05). There was positive correlation of the expression of TGF-β2 with the expression of TGF-β(rs=0.690, P<0.05).4. The expression of TGF-β3 was no significant difference between UC group and IBS group (P>0.05), and the expression was no significant difference between active stage and remission stage (P>0.05). In UC of active stage, the expression of TGF-β3 had no statistic difference in different degree of severity, different clinic type and different extent of disease (P>0.05). There was no correlation of the expression of TGF-β1 with the expression of TGF-p (rs=0.068, P>0.05).Conclusions:1. In colonic mucosa of UC, the positive expression of TGF-βhas obvious increase along with aggravation of pathogenetic condition, and is correlated with the pathogenesis of UC. Therefore, the monitoring of TGF-βin the colonic mucosa can comprehend the stage of pathogenetic condition and degree of severity.2. In UC, TGF-β1 and TGF-β2 play an important role in regulatory mechanism of inflammatory through the secretion of TGF-β.3. In UC, TGF-β3 may not play a significant role in regulatory mechanism of inflammatory through the secretion of TGF-β.