Figure 3. Post-transcriptional regulation alters the expression of Nephrin, Podocin, and Synpo in Tjp1△pod mice.
(A and B) The glomerular lysates from the control and Tjp1△pod mice at 1 week and 2 weeks of age were analyzed by Western blotting with the antibodies against podocyte components (A). The results were quantified (B). Nephrin and podocin were significantly downregulated in the Tjp1△pod mice both at 1 week and 2 weeks of age. The considerable increase in the Synpo protein was observed in 2-week-old Tjp1△pod mice. The expression level of CD2AP, Fyn, and α-actinin4 (ACTN4) did not exhibit differences between the control and Tjp1△pod mice. (C) mRNA expression of podocyte components was determined by qPCR. The difference in the neprhin and podocin mRNA levels between the control and Tjp1△pod mice at 1 week and 2 weeks of age did not correlate with the reduction in the protein levels of those molecules. The mRNA level of most other molecules did not show these alterations, although some of them did exhibit upregulation without an increase in protein levels except for Synpo at 2 weeks of age. (D and E) The protein expression of the podocyte components in the developing glomerulus was examined by Western blotting. The kidney lysates from the control and Tjp1△pod mice at P0 and P3 were probed with antibodies against podocyte components (D). The quantification data indicated that podocin was downregulated at P0 and P3, while the reduction of nephrin protein was detected at P3. All data are represented as mean ± SEM of n = 3. *p<0.01, **p<0.001