Regulation of TNFalpha and TNFbeta gene expression in inflammatory bowel disease

肿瘤坏死因子α (TNFalpha)和TNF β是具有相似免疫调节作用的细胞因子，通过TNF受体与靶细胞结合。为了阐明TNFalpha和tnf - β在IBD患者粘膜病变中的调节作用，我们检测了粘膜中TNFalpha和tnf - β mRNA转录物的水平和这些肽的产生。方法：1)内镜下或手术中取肠标本，采用GTP法提取总RNA。用M-MLV-RT将RNA逆转录为cDNA。采用线性PCR法定量tnffalpha和TNFbeta mRNA。作为内对照，用β -肌动蛋白、t细胞受体α、铁蛋白重链引物PCR扩增cDNA。2)患者其他粘膜用LPS （10mug/ml）培养1、2小时，提取粘膜中的tRNA。结果与结论：IBD患者炎症黏膜中tnfβ mRNA水平较对照组升高32-64倍，tnfβ mRNA水平升高4-16倍。LPS诱导的IBD黏膜中，tnfβ mRNA升高4-8倍，而tnfβ mRNA未升高。TNFalpha是IBD对内毒素反应的重要介质。

Tumor necrosis factor alpha (TNFalpha) and TNFbeta are cytokines with similar immunoregulatory effects binding to their target cells via TNF receptors. To clarify the regulation of TNFalpha and TNFbeta in the mucosal lesions of IBD patients, we examined levels of TNFalpha and TNFbeta mRNA transcripts and these peptide production in the mucosa.METHODS : 1)Intestinal specimens were obtained through an endoscopy or at operation, and total RNA was extracted by a GTP method. RNA was reverse transcribed with M-MLV-RT into cDNA. TNFalpha and TNFbeta mRNA were quantitated using linear PCR methods. As internal controls, cDNA was amplified by PCR with primers for beta-actin, T-cell receptor alpha, ferritin heavy chain. 2)Other mucosa from patients were cultured for 1,2 hours with LPS (10mug/ml) and tRNA in the mucosa was extracted.RESULTS & CONCLUSIONS : The level of TNFalpha mRN was 32-64 fold increased and TNFbeta mRNA was 4-16 fold increased in inflamed mucosa of IBD patients compared to mucosa of control donors. TNFalpha mRNA was 4-8 fold increased and TNFbeta mRNA was not increased in LPS primed IBD mucosa. TNFalpha is an important mediator in response to endotoxin in IBD.