Influence Of Active-smoking On The Expression Of NOD1 Signal Pathway Of Oral Mucosal Epithelial Cells

Chapter 1Establishment of an animal model of via mouth active moking[Objective] Smoking can impair various systems of body, such as respiratory system, digestive system, cardiovascular system, reproductive system, and so on. Recent studies on smoking-related disease models mainly focus on in vitro cell model, animal model and clinical specimen model. However, studies about the animal model of active smoking is little. So far, the animal model of via mouth active- smoking hasn’t been reported in the literature. The purpose of this study was to establish an animal model of via mouth active- smoking.[Methods] There were 10 Wistar rats in both the experimental group and control group each. An active- smoking device was used to establish the animal model of via mouth active smoking in the experimental group. Each experimental rat smoked actively for 3 months, twice per day, half an hour every time. The control rats sucked air through the mouth; and the time and frequency is the same as the experimental group. In the experimental group, we observed smoking addiction, neurobehavioral alteration, appearance change of oral mucosa, loss of body weight, and so on. We detected histopathological changes of oral mucosa by HE staining.[Results] The experimental rats were addict to smoking after 2 weeks. At the end of the study, the oral mucosa of the experimental rats changed into gray, rough, less elastic. The body weight in the experimental group was significantly lower than that of the control group. The results of histopathologic examination confirmed the occurrence of oral leukoplakia in experimental group with the incidence rate of 75%.[Conclusions] The animal model of via mouth active smoking was established. Active smoking could result in general and histopathological changes of oral mucosa and occurrence of oral leukoplakia in rats.Chapter 2Influence of active smoking on NOD1 signal pathway of oral mucosal epithelial cells in rats[Objective] Oral mucosal epithelial cells is the first line of defense between oral tissue and external environment. NOD1 signal pathway is an important component of innate immunity of oral mucosa. After a series of investigations, we have found that smoking can reduce the expression of NOD1, suggesting that smoking may inhibit NOD1 pathway and impair local immunity of oral mucosa. Based on the previous results, we conducted to study the influence of active smoking on NOD1 signal pathway of oral mucosal epithelial cells in rats.[Methods] The buccal mucosal tissues of rats were harvested from the active smoking group and the control group. The protein expression levels of NOD1, RIP2, NF-κB, and P-NF-κB were assayed by using western blotting and immunohistochemistry.[Results] Compared with the control group, the expression levels of NOD1 and NF-κB were reduced and the expression levels of RIP2 and P-NF-κB were elevated in the active smoking group.[Conclusions] Active smoking could influence NOD1 signal pathway of oral mucosal epithelial cells.