The effect of MSCs in vivo. (A) PCNA immunohistochemical staining was performed on the sections of MSC- and PBS-injected mice, and the percentage of PCNA-positive cells in the growth plate was determined. 3,3′-diaminobenzidine signals were pseudocolored red. A representative picture of each group is shown. Original magnification, ×200 (P < .001, n = 12). (B left panel) Representative photographs of lumbar vertebrae of 8-week-old oim/oim mice, 4 weeks after PBS or MSC infusion, or PBS-injected oim/oim mice at 8 weeks old. (Right panel) Lumbar vertebral length of each group (P < .001, n = 4). (C left panel) Photographs of representative 8-week-old oim/oim mice 4 weeks after PBS or MSC infusion. (Right panel) The 8-week-old: 4-week-old body-weight ratio of oim/oim after PBS or MSC infusion (P = .003, PBS group, n = 7; MSC group, n = 10). All data are mean ± SEM.