International Science Community Association Research Journal of Recent Sciences 2277-2502 7 10 2018 10 2 Comparison of the osteopontin gene expression in gingival tissue related to chronic and acute periodontitis mRNA expression of osteopontin in gingival tissue of the chronic and acute periodontitis 1 5 EN Satary M. 1 Department of Immunology, Shahidbeheshti University, Tehran, Iran Yousefi Babadi V. 2 Department of Biology, Payamenoor University, Tehran, Iran Mohammadbeygi A. 3 Department of Immunology, Shahidbeheshti University, Tehran, Iran Yeganeh F. 4 Department of Immunology, Shahidbeheshti University, Tehran, Iran and Department of Biology, Payamenoor University, Tehran, Iran Kosary B. 5 Department of Immunology, Shahidbeheshti University, Tehran, Iran > Research Paper 2018 4 28 2018 10 2 Bacterial infection of periodontal tissue refers to periodontal disease which can lead to bone resorption and tooth loss in severe cases. During the disease procedure, both innate and adaptive immune responses involve that trigger inflammation. Osteopontin (OPN) is an extracellular glycosylated phosphoprotein which increases in inflammation status such as periodontitis. Correlation of the OPN expression and severity of periodontal tissue infection does not investigated yet. Therefore this study assessed OPN expression level in chronic and acute periodontitis to introducing a new correlation between them. For this purpose, gingival tissue samples were collected from 20 patients with chronic periodontitis and 10 persons without obvious sign of periodontitis. Total RNA related to each tissue sample was extracted after homogenizing. The expression of OPNgen (amount of corresponding mRAN) was evaluated by real-time PCR method. Expression of the OPNgene decreased in both types of examined periodontitis and reduced more significantly in acute cases (P<0.05). Statistical analysis revealed presence of significant correlation between negative fold change of gene expression and severity of infectious in periodontal tissue (P<0.05). Results suggest OPN has a possible important role in protection against periodontopathic bacteria and bone lesion, but disease progression accompanied by reduced expression may be due toOPN producer cell death. Copyright@ International Science Community Association