Yokoyama N, Ohta H, Yamazaki J, Kagawa Y, Ichii O, Khoirun N, Morita T, Osuga T, Lim S Y, Sasaki N, Morishita K, Nakamura K, Takiguchi M
Laboratory of Veterinary Internal Medicine, Department of Veterinary Clinical Sciences, Sapporo, Japan.
Laboratory of Molecular Medicine, Department of Veterinary Clinical Sciences, Sapporo, Japan.
J Comp Pathol. 2017 Feb-Apr;156(2-3):183-190. doi: 10.1016/j.jcpa.2016.10.010. Epub 2017 Jan 12.
Inflammatory colorectal polyps (ICRPs) are characterized by the formation of multiple or solitary polyps with marked neutrophil infiltration in the colorectal area, and are speculated to be a novel form of breed-specific canine idiopathic inflammatory bowel disease (IBD). In human IBD, toll-like receptor (TLR) 2 and TLR4 have been reported to be involved in the pathogenesis of the disease. The aim of this study was to evaluate the expression of TLR2 and TLR4 mRNA in the colorectal mucosa of dogs with ICRPs by in-situ hybridization using an RNAscope assay. Samples of inflamed colorectal mucosa (n = 5) and non-inflamed mucosa (n = 5) from miniature dachshunds (MDs) with ICRPs and colonic mucosa from healthy beagles (n = 5) were examined. TLR2 and TLR4 hybridization signals were localized to the colorectal epithelium, inflammatory cells and fibroblasts in the inflamed colorectal mucosa of affected dogs. The signals were significantly greater in inflamed colorectal epithelium compared with non-inflamed epithelium of MDs with ICRPs and healthy beagles (P <0.05). These results suggest that increased expression of TLR2 and TLR4 mRNA in the inflamed colorectal mucosa results from not only inflammatory cell infiltration, but also the upregulation of TLR2 and TLR4 mRNA in the colonic epithelium.
炎症性大肠息肉（ICRPs）的特征是在大肠区域形成多个或单个息肉，并伴有明显的中性粒细胞浸润，据推测这是一种特定品种犬特发性炎症性肠病（IBD）的新形式。在人类IBD中，据报道Toll样受体（TLR）2和TLR4参与了该病的发病机制。本研究的目的是通过使用RNAscope检测法进行原位杂交，评估ICRPs犬大肠黏膜中TLR2和TLR4 mRNA的表达。对患有ICRPs的迷你腊肠犬（MDs）的发炎大肠黏膜样本（n = 5）、非发炎黏膜样本（n = 5）以及健康比格犬的结肠黏膜样本（n = 5）进行了检测。在患病犬发炎的大肠黏膜中，TLR2和TLR4杂交信号定位于大肠上皮、炎症细胞和成纤维细胞。与患有ICRPs的MDs和健康比格犬的非发炎上皮相比，发炎的大肠上皮中的信号明显更强（P <0.05）。这些结果表明，发炎的大肠黏膜中TLR2和TLR4 mRNA表达的增加不仅是由于炎症细胞浸润，还源于结肠上皮中TLR2和TLR4 mRNA的上调。
