Induction of glomerular injury by rGas6 but not by GlaΔGas6 in Gas6^–/– mice. (a) Urinary albumin level of Gas6^–/– mice injected with Gas6 and GlaΔGas6. Urinary albumin was collected 7 days after the injection of NTS. Each group consisted of seven mice, and data are expressed as mean ± SD. Data from wild-type mice and Gas6^–/– mice without treatment are consistent with the results shown in Figure 4b. (b) Number of PCNA-positive cells per glomerulus in Gas6^–/– mice injected with Gas6 and GlaΔGas6. Mice were sacrificed on day 7, and kidney sections were subjected to immunostaining with anti-PCNA antibody. Each group contained eight mice, and 40 glomeruli per mouse were evaluated in a blinded fashion. Data are expressed as mean ± SD. Data from wild-type mice and Gas6^–/– mice without (c). Quantitative assessment of glomerular injury in Gas6^–/– mice injected with Gas6 and GlaΔGas6. Mice were sacrificed on day 21. Kidney sections were subjected to PAS staining. Data from wild-type mice and untreated Gas6^–/– mice are comparable to the results shown in Figure 5b. Each group contained seven mice, and 40 glomeruli per mouse were evaluated in a blinded fashion. Data are expressed as mean ± SD. White bars, wild-type mice; black bars, Gas6^–/– mice without treatment; light gray bars, Gas6^–/– mice injected with Gas6; dark gray bars, Gas6^–/– injected with GlaΔGas6. *P < 0.05; **P < 0.01; ***P < 0.001.