Fig. 4

Indirect co-culture with human MSC results in potent inhibition of high glucose-induced secretion of inflammatory cytokines by RPTEC/TERT1 cell stable monolayers. a Schematic diagram of the experimental protocol. b Graphs depicting the concentrations of IL-8, IL-6, MCP-1 and NGAL in the supernatants from RPTEC/TERT1 cell monolayers cultured without (control) and with (cells) various transwell co-cultures during the final 2 days of 5-day cultures under high glucose (D-glucose, blue) and mannitol (D-mannitol, purple) conditions. Results are shown for co-cultures carried out with human bone marrow MSC from two different donors (BM-MSC-1 and BM-MSC-2) and with a non-MSC control cell line (HCEC, grey). All results are expressed as mean ± SD of n = 6 technical replicates for each condition. Statistical analyses performed by one-way ANOVA (for BM-MSC versus control) and unpaired Student’s t test (for HCEC versus control). ****p < 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05, ns = not significant