Fig. 7.

IR-induced extensive and chronic activation of STAT3, which was suppressed in netrin-1 transgenic animals. A: phospho STAT3 immunostaining was carried out as described in materials and methods. No immunostaining for phospho STAT3 was seen in sham-operated kidney of both WT and netrin-1 transgenic animals. A larger increase in the number of STAT3-positive tubular epithelial cells, interstitial cells, and glomerular mesangial cells after IR was seen in WT mice. However, netrin-1 overexpression suppressed STAT3 activation. B: Western blot analysis of phospho STAT3 and phospho JNK in sham and IR-operated kidney. IR caused a large increase in phospho STAT3 and JNK phosphorylation, which was suppressed by netrin-1 overexpression. Protein loading was normalized to GAPDH. Magnification ×660. Scale bar = 100 μM. C: densitometric quantification of p-STAT3 and p-JNK. *P < 0.001 vs. N1 transgenic mice with corresponding reperfusion time and sham. #P < 0.05 vs. sham operated; n = 6.