Effects of Administration of LPS Derived From P. gingivalis on Kidney Gene-expression in Mice

Objectives: Periodontal disease has been reported to be a risk factor associated with systemic diseases such as diabetes, infectious endocarditis and autoimmune diseases. There are also reports suggesting an association with kidney disease, but the mechanism is not clear. In the present study, we observe the effect on the kidneys of periodontal pathogens, P. gingivalis LPS from attempts to establish a model system of a mouse that does not cause acute inflammation in various organs, and was exhaustively analyzed the gene expression of the kidney in this model.
Methods: 8-10 week-old C57BL / 6J mice were used .The mice were administered intraperitoneally PG-LPS (P. gingivalis, WAKO, Japan) at 5 mg/kg every 84 hours for 1 month. Saline treated samples were used as controls. The kidney tissue was fixed with formaldehyde, and was observed with HE and PAS staining. Total RNA was extracted from the remaining kidney was performed microarray analysis. A quantitative polymerase chain reaction was carried out to confirm the reproducibility of the microarray data. The expression levels of mRNA of the selected genes from the data were analyzed by quantitative RT− PCR. As a result were performed using pathway analysis by Ingenuity Pathway Analysis (IPA).
Results: Overall, 1020 probes were expressed at higher level at more than 2-fold in the kidney cell treated with LPS over the controls. We confirmed the mRNA expression of SAA3, TICAM2 and REGA3A by quantified real-time PCR, and the expression level of these mRNAs in the experimental group were significantly higher than in the control (p<0.05). Result of IPA, it was shown that the changes in gene expression by stimulation of LPS is involved lipid metabolism suppression and insulin resistance, the risk of carcinogenesis.
Conclusions: These results indicate that may become periodontal disease model mice that do not cause acute inflammation in the kidneys treated intraperitoneally with LPS, furthermore, expression of genes involved in lipid metabolism, organ damage, cardiac disease, and carcinogenesis has been suggested that increased by LPS stimulation.