Fig. 7

WJMSC-apelin infusion leads to a pancreatic ß cell proliferation in T2D rats. a HE staining showed that the size of islets is normal and the islets are intact and full in sham rats. In T2D+saline rats, pathological display showed that pancreatic islets appeared moderate to severe atrophy, and the islet structure shrank. The islet cells were greatly reduced and distributed evenly. In WJMSC-apelin infusion rats, mild atrophy of whole islets was observed and the islet structure is not complete. Some islet cells distributed evenly, part of uneven density. b Representative images showing the colocalization of Ki67+ with insulin+ cell in the pancreatic islets of the WJMSC-apelin infusion T2D rats and saline infusion T2D rats. Nuclei were stained by DAPI (blue). Insulin (green) and Ki-67+ (red). WJMSC-apelin infusion strongly stimulates ß cell replication compared to the saline infusion control in T2D rats (each group n = 5). c, d Quantification of the insulin+ cells and the islet area from pancreatic islets (10 sections) by counting the numbers of positive cells per 100 nuclei per rat 42 days after WJMSC-apelin or saline infusion. Magnification × 40; bars indicate 95% confidence intervals (CIs). *P < 0.05, **P < 0.01. e, f ELISA analysis of insulin and C-peptide level in individual fasted rats 42 days after WJMSC-apelin or saline infusion. n = 10 rats per group. *P < 0.05 and **P < 0.01