Ruixuan (Sunnie) Yang’s bio
Experimental Medicine Graduate Student with over 5 years of renal research experience. Her study centres around the urinary microbiome and its implications on renal transplant patients, with results arguing for the microbiome’s function as early health indicator.
Gram-Positive and Gram-Negative Bacterial Surface Constituents Hinder Kidney Cell Viability In Vitro
Dirk Lange, Caigan Du, David Harriman
Introduction and Objectives: There is a paucity of research on the urinary microbiome in transplant patients, although increasing evidence have argued for the influence of bacterial species on patient health. Our goal is to better understand the nature of this interaction from a cellular standpoint, assessing the effects of bacterial components on kidney cell lines. Lipopolysaccharide (LPS) are gram-negative bacterial surface membrane components that trigger inflammation, while lipoteichoic acid (LTA) act as the functional equivalent in gram-positive bacteria. This project aims to assess the effects of LPS and LTA on kidney cell viability as an initial study of the urinary microbiome and renal allograft health.
Methods: In vitro models using kidney cell lines: Human Mesangial Cells (T-HMC) and Human Kidney Proximal Tubular Cells (HKC-8), were designed to assess the cellular impact of LPS and LTA. Cells were cultured in vitro with LPS from Escherichia coli and LTA from Staphylococcus aureus in varying concentrations for 48 hours. FACS and MTT tests were performed to assess cell apoptosis and metabolic activity, respectively.
Results: Increased LTA and LPS concentration both resulted in a steady decline of kidney cell metabolic rates. Contrastingly, cell apoptosis was independent of changing concentration.Tubular cells showed higher sensitivity to treatment groups when compared to mesangial cells, while combining LPS and LTA appear to have a modulating effect which reduces their overall toxicity.
Conclusions: LPS and LTA both act as stressors to kidney cells which may hinder renal allograft health. When combined, they seem to have a modulating effect which decreases their joint toxicity, further supporting the potential protective functions of a diverse microbiome on patient health. Our next steps will be to assess the cytokine inflammatory signals produced from these interactions in addition to analyzing the urinary microbiome of renal transplant recipients in a shotgun sequencing format.