FIG. 8.

Effect of exogenous TGF-β on NHE3 and aquaporin-1 (AQP1) expression in cultured primary renal proximal tubule cells on soft and stiff substrates. Expression levels of SLC9A3 (NHE3) (A) and AQP1 (B) were determined by qPCR in primary HREC cultured on soft (0.5 kPa) and stiff (50 kPa) hydrogels for 4 weeks. Confluent cells in duplicate wells were cultured for 10 days on soft (0.5 kPa) and stiff (50 kPa) hydrogels, then treated with TGF-β (10 ng/mL) or treated with the TGF-β inhibitor SB431542 (10 μM) for 2.5 weeks before harvest. Fold change differences were normalized relative to GAPDH levels, and results from replicate wells were pooled for analysis.