Floer Martin, Binion David G, Nelson Victoria M, Manley Sharon, Wellner Michael, Sadeghi Saba, Behmaram Behnaz, Sewell Chloe, Otterson Mary F, Kucharzik Torsten, Rafiee Parvaneh
Department of Medicine, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA.
Am J Physiol Gastrointest Liver Physiol. 2008 Sep;295(3):G581-90. doi: 10.1152/ajpgi.90311.2008. Epub 2008 Jul 17.
Tissue remodeling and mesenchymal cell accumulation accompanies chronic inflammatory disorders involving joints, lung, vasculature, and bowel. Chronic inflammation may alter DNA-mismatch repair (MMR) systems in mesenchymal cells, but is not defined in Crohn's disease (CD) and its associated intestinal remodeling and stricture formation. We determined whether DNA-MMR alteration plays a role in the pathogenesis of CD tissue remodeling. Control and CD bowel tissues were used to generate primary cultures of muscularis mucosa myofibroblasts, which were assessed directly or following stimulation with TNF-alpha/LPS or H2O2. MutS homolog (MSH)2, MSH3, and MSH6 expression in tissues and myofibroblasts was determined. Immunohistochemical staining revealed an increased expression of MSH2 in CD muscularis mucosa and submucosal tissues compared with controls or uninvolved CD tissue, and MSH2 expression was increased in CD myofibroblasts compared with control cells. TNF-alpha/LPS and H2O2 further enhanced MSH2 expression in both control and CD cells, which were decreased by simvastatin. There were no significant changes in MSH3 and MSH6 expression. Proliferating cell nuclear antigen and Ki67 staining of CD tissue revealed increased proliferation in the muscularis mucosa and submucosa of chronically inflamed tissues, and enhanced proliferation was seen in CD myofibroblasts compared with controls. Simvastatin reversed the effects of inflammatory stress on the DNA-MMR and inhibited proliferation of control and CD myofibroblasts. Gene silencing with MSH2 siRNA selectively decreased CD myofibroblast proliferation. These data demonstrate a potential role for MSH2 in the pathogenesis of nonneoplastic mesenchymal cell accumulation and intestinal remodeling in CD chronic inflammation.
组织重塑和间充质细胞积累伴随着涉及关节、肺、血管和肠道的慢性炎症性疾病。慢性炎症可能会改变间充质细胞中的DNA错配修复（MMR）系统，但在克罗恩病（CD）及其相关的肠道重塑和狭窄形成中尚未明确。我们确定DNA-MMR改变是否在CD组织重塑的发病机制中起作用。使用对照和CD肠道组织生成肌层黏膜肌成纤维细胞的原代培养物，直接评估或在用TNF-α/LPS或H2O2刺激后进行评估。测定组织和肌成纤维细胞中MutS同源物（MSH）2、MSH3和MSH6的表达。免疫组织化学染色显示，与对照或未受累的CD组织相比，CD肌层黏膜和黏膜下层组织中MSH2的表达增加，与对照细胞相比，CD肌成纤维细胞中MSH2的表达增加。TNF-α/LPS和H2O2进一步增强了对照和CD细胞中MSH2的表达，而辛伐他汀可降低其表达。MSH3和MSH6的表达没有显著变化。CD组织的增殖细胞核抗原和Ki67染色显示，慢性炎症组织的肌层黏膜和黏膜下层增殖增加，与对照相比，CD肌成纤维细胞的增殖增强。辛伐他汀逆转了炎症应激对DNA-MMR的影响，并抑制了对照和CD肌成纤维细胞的增殖。用MSH2 siRNA进行基因沉默可选择性降低CD肌成纤维细胞的增殖。这些数据表明MSH2在CD慢性炎症中非肿瘤性间充质细胞积累和肠道重塑的发病机制中具有潜在作用。
