Effect of Etiasa on the Expression of MMP-2 and TNF-α in Rat Model of Ulcerative Colitis
|School||Dalian Medical University|
|Keywords||Ulcerative colitis Matrix metalloproteinase Cytokine Anaimal model|
Background and Objective: Ulcerative colitis(UC) is a non-specific inflammatory bowel disease. Its clinical manifestation is abdominal pain, diarrhea and blood stool with mucus and pus. Rectum and colon are the most frenquently affected sites. Its etiology and pathogenesis are still unknown. Ulcerative colitis mainly invades the intestinal mucosa and the submucosa. The degradation of extracellilar matrix(ECM) and the formation of mucosa ulcer are the main pathological characteristics. Nowadays, it is considered that matrix metalloproteinases (MMPs) play an important role in the precess of the degradation of mucosa, and many kinds of cytokines are also involved in the occurrence and development of UC. Currently, aminosalicylic acid(ASA) including Etiasa and SASP is the main and basic medication for the treatment of UC in human. In this study, trinitro-benzene-sulfonic acid (TNBS)-induced rat model of UC was treated by Etiasa and SASP in order to observe their effects on the general state of the UC model, disease activity index (DAI) score, expressions of MMP-2 and TNF-α, and to reveal the mechanism of Etiasa and SASP in the treatment of UC. Therefore, this study is to provide the basic therapeutic evidences for more effective treatment of UC in future.Method: 1. The rats were fasted but feed water only for 48 hours, and then given anesthesia by injection of chloral hydrate, and 100mg/kg TNBS and 50% ethanol 0.25ml mixture were given enema from anus.2. The male SD rats, six-week-old and with body weight of 180-220g were randomly devided into four groups. Control group: the rats were enemaed with normal saline and were treated with normal saline by intragastric administration.Etiasa group: the rats were enemaed with TNBS and were treated with Etiasa by intragastric administration.SASP group: the rats were enemaed with TNBS and were treated with SASP by intragastric administration. Model group:the rats were enemaed with TNBS and were treated with normal saline by intragastric administration.3. The general states were observed and the DAI scores were rocorded. The rats were killed at the day of 3, 7, 14, 21, 35, 56 after the emema. Six rats were killed in each group randomly at every time point. The colon tissues of rats were stored for the next step experiments. Parts of the samples were freezen-stored in liquid nitrogen for RT-PCR experiments,and other parts of the samples were stored in 10% formaldehyde for histopathological examinations and immunohistochemistry experiments.4. The protein expressions of MMP-2 and TNF-αin rat colonic mucosa were determined by immunohistochemistry.5. The mRNA expressions of MMP-2 and TNF-αin rat colonic mucosa were determined by RT-PCR.Results: 1. Changes in the general state of rats, disease activity index, and pathological examinations indicated that the establishment of TNBS-induced rat model of UC was successful.2. The immunohistochemical results showed that the expressions of MMP-2 and TNF-αin the model group were significantly higher than the control group, Etiasa group and SASP group(P<0.05).3. The RT-PCR result showed that the expressions of MMP-2 and TNF-αin the model group were significantly higher than the control group, Etiasa group , and SASP group(P<0.05).4. The results of RT- PCR and immunohistochemistry showed that there was no significant difference between Etiasa group and SASP group in expressions of MMP-2 and TNF-α(P>0.05).Conclusion:1. MMP-2 and TNF-αmay play an important role in the process of TNBS-induced rat model of ulcerative colitis.2. Etiasa and SASP are effective in the treatment of TNBS-induced rat model of ulcerative colitis, and Etiasa and SASP have inhibitory effects on the expressions of MMP-2 and TNF-αin the colonic mucosa. Etiasa and SASP have similar therapeutic effects on TNBS-induced rat model of ulcerative colitis.