Proliferative response in wild-type and Gas6–/– mice with NTN. (a) Immunostaining for PCNA in wild-type and Gas6–/– mice sacrificed on day 7. Magnification, ×200. (b) Number of PCNA-positive cells per glomerulus in wild-type and Gas6–/– mice. Solid bars represent Gas6–/– mice, while open bars represent wild-type mice. Each group contained eight mice, and 40 glomeruli per mouse were evaluated in a blinded fashion. Data are expressed as mean ± SD. ***P < 0.001. (c) Immunostaining for phospho-STAT3 in wild-type and Gas6–/– mice sacrificed on day 7. Magnification, ×200. (d) Immunoblotting of kidney protein from wild-type and Gas6–/– mice with anti-STAT3 and anti–phospho-STAT3 antibodies. Mice were sacrificed on the day indicated, and kidney proteins were subjected to immunoblotting with anti-STAT3 and anti–phospho-STAT3 (pSTAT3) antibodies. Representative immunoblotting is shown from four independent experiments.