Figure 7.

Role of miR193a in HIV-, interferon (IFN)-γ–, and vitamin D receptor (VDR) agonist–mediated APOL1 induction in parietal epithelial cells (PECs). A: To examine the role of miR193a in the induction of APOL1 by IFN-γ, PECs were incubated in media that contained a different concentration of IFN-γ (0, 1, 5, and 10 ng/mL) for 48 hours and assayed for miR193a. cDNAs were amplified with a primer specific for APOL1. Cumulative data on the expression of miR193a and APOL1 mRNA are shown in the top row and bottom row, respectively. IFN-γ down-regulates miR193a expression and enhances the transcription of APOL1 in a dose-dependent manner. B: To assess the role of miR193a in the induction of APOL1 by HIV, PECs were transduced with different concentrations of HIV [NL4-3; 10⁴, 10³, or 10² green fluorescent protein–expressing units (GEU)/mL]. After 48 hours, RNAs were assayed for miR193a. cDNAs were amplified for APOL1. Levels of miR193a and APOL1 mRNA are shown in the top row and bottom row, respectively. HIV decreases the expression of miR193a and enhances the transcription of APOL1 in a dose-dependent manner. C: To evaluate the role of miR193a in the induction of APOL1 by VDR agonist, PECs were incubated in media that contained different concentrations of VDR agonist (EB1089, 0, 1, 10, and 100 nmol/L; 0 containing the vehicle only) for 48 hours. RNAs were assayed for miR193a. cDNAs were amplified for APOL1. Cumulative data on the expression of miR193a and APOL1 mRNA are shown in the bottom row and top row, respectively. VDR agonist attenuated miR193a levels but enhances the expression of APOL1 mRNA in a dose-dependent manner. D: To validate the effect of miR193a inhibition on the expression of PECs and PEC transition markers, PECs (undifferentiated) grown on coverslip were transfected with an empty vector (EV) or inhibitor of miR93a (50 nmol/L). Subsequently (after 48 hours), cells were labeled for PECs and PEC transition markers. Cells were examined under a confocal microscope. Representative fluoromicrographs are displayed. Inhibition of miR193a down-regulates PEC markers but enhances the expression of transition markers in PECs. n = 3. ^∗P < 0.05, ^∗∗∗P < 0.001 versus respective 0 ng/mL of IFN-γ; ^∗∗P < 0.01 versus respective 1.0 ng/mL of IFN-γ; ^†P < 0.05 versus 0, 10⁴ and 10² HIV; ^††P < 0.01, ^†††P < 0.001 versus respective 0 HIV; ^‡P < 0.05 versus 0 and 100 nmol/L VDR agonist; ^‡‡P < 0.01 versus respective 0, 1.0, and 100 nmol/L VDR agonist; ^‡‡‡P < 0.001 versus respective 0. Scale bar = 50 µm (D, all panels). VDA, VDR agonist.