Abstract:

Objective To investigate the changes of silencing information regulator 1 （SIRT1） in ligation-induced kidney injury in the chronic periodontitis rats， and to clarify the effect of SIRT1 on kidney injury in the chronic periodontitis rats. Methods Twenty rats were randomly divided into control group and periodontitis group，with 10 rats in each group.The periodontitis model was established by ligation of necks of bilateral maxillary first molars. The gingival color and shape of the rats in two groups were observed， and the gingival bleeding index （BI）， periodontal probing depth （PD） and tooth mobility （TM） were measured and recorded. Hematoxylin-eosin（HE） staining was used to observe the pathomorphology of periodontium of the rats in two groups； micro-computed tomography （Micro-CT） was used to evaluate the alveolar bone resorption of the rats in two groups. HE and PAS staining were used to observe the pathomorphology of kidney tissue of the rats in two groups. Biochemical kits were used to assess kidney function indicators and detect the oxidative stress levels of the rats in two groups； Western blotting method was used to detect the expression levels of tumor necrosis factor-α （TNF-α） and nuclear factor kappa B （NF-κB） p65 protein in kidney tissue of the rats in two groups； real-time fluorescence quantitative PCR（RT-qPCR） and immunohistochemical method were used to detect the expression levels of SIRT1 and peroxisome-proliferator-activated receptor γ coactivator 1α （PGC-1α） mRNA and proteins in kidney tissue of the rats in two groups. Results The clinical indicators of peridontium tissue detection results showed that compared with control group， swollen gums， soft texture， deep periodontal pocket， bleeding gums and loosening of tooth of the rats in periodontitis group were found.The HE staining and Micro-CT results of peridontium tissue showed that compared with control group， attachment loss and alveolar bone absorption of the rats occurred in periodontitis group.The HE and PAS staining results of kidney tissue showed that compared with control group， the renal cystic space was dilated， the basement membrane of the glomerular was slightly thickened， the epithelial cells of the renal tubules were exfoliated， and the brush edge was destroyed in periodontitis group.The biochemical detection results showed that there was no significant difference in renal function indexes of the rats in two groups （P>0.05）； compared with control group，the levels of total antioxidative status （TAS），managanse superoxide dismutase （Mn-SOD） and glutathione （GSH） in kidney tissue of the rats in periodontitis group were decreased（P<0.01）， while the level of malondialdehyde （MDA） was increased （P<0.01）.The Western blotting results showed that compared with control group， the expression levels of TNF-α and NF-κB p65 proteins in kidney tissue of the rats in periodontitis group were increased （P<0.05 or P<0.01）.The RT-qPCR and immunohistochemistry results showed that compared with control group， the expression levels of SIRT1 and PGC-1α mRNA and proteins in kidney tissue of the rats in periodontitis group were decreased （P<0.05 or P<0.01）. Conclusion In the rat model of chronic periodontitis， the expression of SIRT1 in kidney tissue is down-regulated and the level of oxidative stress is increased， which aggravats the kidney injury of chronic periodontitis rats.

Key words: Chronic periodontitis, Kidney injury, Sirtuin 1, Rats