Kidney infection pathogen/P. gingivalis lipopolysaccharides modulate pro-inflammatory response in hRPTEpiCs

Abstract

Objectives: Renal tubular epithelial cells play a crucial role in kidney function, and it could be markedly affected by kidney infection and increased systemic inflammation. Escherichia coli is one of the most common pathogens for urinary tract infection, while Salmonella species often involve in hematogenous renal infection. Emerging evidence shows that periodontal disease is associated with kidney disease. This pilot study explored the effects of kidney infection-associated bacteria and Porphyromonas gingivalis lipopolysaccharides (LPS) on immuno-inflammatory response in human renal proximal tubular epithelial cells (hRPTEpiCs). Methods: Primary hRPTEpiCs were obtained from ScienCell (#4100). The cells were treated with LPS respectively from E. coli (ATCC 12014), Salmonella Minnesota (mutant R595) and P. gingivalis (ATCC 33277) at various concentrations (0.1, 1 and 10 µg/ml) as well as IL-1β (0.01, 0.1 and 1 ng/ml) for 24 h. The expression of IL-6 and IL-8 in the culture media was assessed using ELISA kits. Results: E. coli and S. Minnesota LPS at all concentrations could significantly upregulate the levels of IL-6 and IL-8 in hRPTEpiCs, with reference to the controls (p<0.001). Moreover, IL-1β strongly induced the expression of these inflammatory cytokines as well (p<0.001). However, P. gingivalis LPS did not stimulate notable inflammatory response of these cells. Conclusions: This preliminary study suggests that E. coli, S. Minnesota and P. gingivalis LPS differentially modulate pro-inflammatory response in hRPTEpiCs. The relevant biological and clinical implications need further investigations.