Oroxylin A inhibits inflammatory cytokines in periodontitis via HO­1.

Periodontal disease is a common infectious disease that can lead to the loss of teeth. Hower how to effectively suppress the inflammation with medication is unclear. The aim of the present study was to investigate the anti­inflammatory effect of Oroxylin A in periodontitis and its potential role through heme oxygenase­1 (HO­1). Primary rat gingival fibroblasts (RGFs) were cultured using the tissue block method and identified by immunofluorescence. Following lipopolysaccharide (LPS) stimulation of RGFs, Oroxylin A was administered at 50, 100, 200 or 400 µg/ml. Reverse transcription­quantitative PCR was used to assess mRNA expression of cyclooxygenase (COX)­2, TNF­α, RANKL and osteoprotegerin (OPG). Western blotting was used to detect protein expression levels of COX ­2, TNF­α, RANKL and OPG. Following HO­1 knockdown, the same treatment was performed. The expression of COX­2 in rat gingival tissue was observed by immunohistochemistry. One­way analysis of variance and Student's t test were used for statistical analysis. Oroxylin A downregulated mRNA expression of COX­2, TNF­α, RANKL and OPG in LPS­induced RGFs. With increase of Oroxylin A dose, the expression of HO­1 was gradually upregulated. When HO­1 was knocked down, Oroxylin A did not downregulate the expression of COX­2, TNF­α, RANKL and OPG in LPS­induced RGFs. Immunohistochemical results showed that expression of COX­2 was downregulated by Oroxylin A, and the expression of TNF­α, RANKL and OPG were also downregulated. Oroxylin A decreased expression of inflammatory cytokines in LPS­induced RGFs and had a good inhibitory effect on periodontitis in rats.

Expression of Matrix Metalloproteinases and Tissue Inhibitor of Matrix Metalloproteinases during Apical Periodontitis Development.

INTRODUCTION: Matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) are considered important mediators of the periapical immune response to infection. This study aimed to clarify the putative relationship between MMPs and TIMPs by elucidating the activity of MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1, and TIMP-2 in the temporal development of apical periodontitis (AP) in mice. METHODS: AP was induced in the lower first molars of 30 male Kunming mice. The animals were randomly killed at 0, 7, 14, 28, 60, and 90 days after pulp exposure. The jaws were removed and subjected to quantitative real-time reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemical analysis. RESULTS: The MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1, and TIMP-2 messenger RNA and protein expression levels increased with periapical inflammation progression (P < .05). The MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 messenger RNA and protein expression levels increased during the acute and chronic stages of periapical lesions, with less MMP-2 and MMP-9 expression levels at the chronic stage (P < .05). The MMP-8 expression increased at the chronic stage of inflammation (P < .05) but not at the acute stage. Immunostained MMP-2 and TIMP-1 were observed in all experimental periods. CONCLUSIONS: MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1, and TIMP-2 were expressed in all periapical samples with varying levels between them. MMP expression could be related to TIMP expression in the temporal development of AP.

The immune factors involved in the pathogenesis, diagnosis, and treatment of Sjogren's syndrome.

Sjogren's syndrome (SS) is a systemic, autoimmune disorder characterized by salivary insufficiency and lymphocytic infiltration of the exocrine glands. Even though the mechanism of its pathology and progression has been researched ever since its discovery, the roles of different parts of immune system remain inconclusive. There is no straightforward and simple theory for the pathogenesis and diagnosis of Sjogren's syndrome because of the multiple kinds and functions of autoantibodies, changing proportion of different T-lymphocyte subsets with the progression of disease, unsuspected abilities of B lymphocytes discovered recently, crosstalk between cytokines connecting the factors mentioned previously, and genetic predisposition that contributes to the initiation of this disease. On the other hand, the number of significant reports and open-label studies of B-cell depletion therapy showing clinical efficacy in sjogren's syndrome has continued to accumulate, which provides a promising future for the patients. In a word, further elucidation of the role of different components of the immune system will open avenues for better diagnosis and treatment of SS, whose current management is still mainly supportive.