Fig. 2
P131R-SLC26A3 weakens the epithelial barrier and augments TNF-α-induced damage. a Representative GFP for overexpressing SLC26A3. b Representative images of SLC26A3 mRNA levels in Caco-2 cells transfected with pCS6 (empty vector) and SLC26A3-pCS6 (SLC26A3OE) measured by RT-PCR. GAPDH expression was presented as control. c Relative RT-PCR quantification of SLC26A3 mRNA levels in Caco-2 cells transfected with pCS6(empty vector) and SLC26A3OE. d Caco-2 cells onto array chambers containing 40 gold electrodes per well (8W10E+) pretreated with 10 mM cysteine and coated with fibronectin (20 µg). The experiments were initiated when the cells reached confluence, as determined by a capacitance of 10 nF at 32,000 Hz, the monolayers were starved from serum for 2 h, then treated with 100 ng/ml of TNF-α. Representative figure of transepithelial electric resistance (TEER) data from ECIS analysis at 500HZ of wild-type Caco-2 cells, Caco-2 cells containing the rs386833481(c.392C>G; p.P131R) SNP generated by CRISPR/Cas9 knock-in, SLC26A3 overexpressing Caco-2 cells (SLC26A3OE) and Caco-2 cells transfected with empty vector pCS6 (Control) are shown. e P131R SLC26A3 in Caco-2 cells significantly decreased the maximum TNF-α-induced decrease in TEER value compared with WT Caco-2 cells, but SLC26A3 over expression prevented the TNF-α-induced decrease in TEER value compared with the empty vector pCS6(Control) cells. TNF-α treatment resulted in similar decrease of TEER values between WT and control cells. *P < 0.05, **P < 0.01, ***P < 0.001