Fig. 3.

L5 suppresses STRA6 cascades and increases cell injury in HK-2 cells. A: Western blots show LOX1, STRA6, CRBP1, RARα, RARγ, RXRα, pJNK, pSmad2, and collagen 1 (Col1) in control siRNA (siC)-transfected or LOX1 siRNA (siLOX1)-transfected HK-2 cells (n = 3) after PBS (Ctl), L1, or L5 treatment for 24 h. In L5-treated HK-2 cells, quantitative analysis showed that LOX1 (B) protein levels significantly increased; STRA6 (C), CRBP1 (D), RARα (E), RARγ (F), and RXRα (G) protein levels decreased; pJNK/JNK (H) and pSmad2/Smad2 (I) ratios increased; and collagen 1 (J) increased. These changes were reversed in LOX1 siRNA-transfected L5-injected HK-2 cells, as compared with L5-injected siC mice. K: Representative images (400×) show immunoreactive staining for STRA6 (red fluorescence) emerged to cell membrane staining (green fluorescence) on chamber slides of Ctl-, L1-, and L5-treated cells, and L5-treated LOX1 siRNA-transfected cells. L: ELISA showed an increase of TGFβ₁ concentration in L5-treated siC cells, but not in L5-treated siLOX1 cells. M: Cytochemistry images show the nucleus of apoptotic cells (green fluorescence) emerged to staining of nucleus (blue fluorescence) in Ctl-, L1-, and L5-treated cells, and in L5-treated LOX1 siRNA-transfected cells. N: Number of apoptotic cells significantly increased in L5-treated siC cells, but not in L5-treated siLOX1 cells. O: Real-time PCR analysis showed that LOX1 siRNA significantly increased mRNA levels of STRA6, CRBP1, RARα, and RXRα in L5-treated HK-2 cells. All results are represented as mean ± SE. *P < 0.05 versus Ctl- and L1-siC; ^#P < 0.05 versus L5-siC group.