Abstract: FR-PO632

Human Mesenchymal Stem Cells Suppress Glucose-Induced Inflammatory Responses of Stable Renal Proximal Tubular Epithelial Cell Monolayers

Session Information

Category: Diabetes

  • 501 Diabetes Mellitus and Obesity: Basic - Experimental

Authors

  • Islam, Md nahidul, Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland, Galway, Ireland
  • Griffin, Tomas P., Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland, Galway, Ireland
  • Rocks, Stephanie, Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland, Galway, Ireland
  • Cabral, Joana, Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland, Galway, Ireland
  • Ritter, Thomas, Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland, Galway, Ireland
  • McMorrow, Tara, School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin, Ireland
  • O'Brien, Timothy, Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland, Galway, Ireland
  • Griffin, Matthew D., Regenerative Medicine Institute, School of Medicine, National University of Ireland Galway, Galway, Ireland, Galway, Ireland
Background

Renal proximal tubular epithelial cells (RPTEC) are dysfunctional in diabetic kidney disease (DKD). Mesenchymal stem cells (MSCs) may modulate DKD pathogenesis. We aimed to investigate the pro-inflammatory effects of prolonged exposure to high-glucose concentration on RPTECs and to determine whether MSC-derived factors modulate this response.

Methods

Human RPTEC/TERT1 cells were cultured for 12 days to generate stable confluent monolayers. Media containing “Normal” (5mM) and “High” (25mM) D-Glucose or D-Mannitol (25mM) were added for a further 5 days. Supernatants/cells were collected for ELISA (IL-6, IL-8, MCP-1, NGAL) and flow-cytometry (cell death by Annexin-V/PI staining). 10X-concentrated “full” and “extracellular vesicle (EV) depleted” conditioned media (CM) from human bone marrow-derived MSCs were added for the final 2 days at 20:80v/v. Additionally, MSCs were co-cultured 1:10 with RPTEC for 2 days in a trans-well system. Results were statistically analysed with Graphpad Prism 6.0®.

Results

Five day exposure to high-glucose caused significant increases in RPTEC/TERT1 secretion of IL-6, IL-8, MCP-1 and NGAL compared to normal-glucose and mannitol without increasing cell death. The increases in cytokine secretion were only evident after 80-hours (IL-6, MCP-1, NGAL) or 96-hours (IL-8) of culture. Addition of either full- or EV-depleted-CM was associated with significantly reduced high glucose-induced RPTEC/TERT1 secretion of IL-6, IL-8 and MCP-1 (40%-125%), but not NGAL. Indirect contact of MSCs with RPTEC/TERT1 cells in trans-well cultures resulted in even more potent reduction in the secretion of IL-8, IL-6 and MCP-1 (90%-250%).

Conclusion

Prolonged high-glucose exposure induced secretion of pro-inflammatory mediators by RPTEC stable monolayers. Soluble factors released by MSC suppressed high-glucose-induced RPTEC secretion of inflammatory cytokines. EV depletion did not prevent this suppressive effect. Indirect contact of MSCs with RPTEC/TERT1 cells resulted in more potent anti-inflammatory effects.

Funding

  • Government Support - Non-U.S.