Effect of Porphyromonas gingivalis LPS on Kidney in Senescence-accelerated Mice

Objectives: Although a clinical association between periodontitis and chronic kidney disease (CKD) has been suggested, the mechanism is still unclear. We have previously shown that systemic administration of lipopolysaccharides derived from Porphylomonas gingivalis(PG-LPS) for a month induced upregulated expression of several mRNAs involved in CKD of mice. We hypothesized that senescence might affect mRNA and protein expression in the kidneys. In the present study, we examined the effect of PG-LPS on the kidneys in senescence-accelerated mice.
Methods: The mice, c57BL/6J (normal) and the Senescence-accelerated mice prone (SAMP), were injected with PG-LPS at a concentration of 5 mg/kg intraperitoneally, every 3 days, for three months. DDW administered group served as controls. We stained kidney tissue with H&E, PAS and Silver staining. Obtained samples were evaluated with a pathological score. We confirmed mRNA expression of Saa3, Ticam2, Reg3b, Oxct2a and Xcr1 by pPCR method. The data was compared by Mann-Whitney’s U test, with *p< 0.05 accepted as statistically significant.
Results: The expression levels of Saa3, Ticam2, Reg3b, Oxct2a and Xcr1 were significantly higher in both normal and SAMP administered with PG-LPS than in the controls (p<0.05). The expression levels of these five genes in SAMP administered with PG-LPS were higher than in the normal administered with PG-LPS. Histologically, hypercellularity of mesangial cell in glomeruli was clearly observed in SAMP administered with PG-LPS. The histological scores of the kidneys were significantly higher in the PG-LPS administered group than in the controls (p<0.05).
Conclusions: The present study indicated that both PG-LPS and senescence may be involved in the pathogenesis of CKD.