Fig. 3: Osteoblastic-derived RegIIIγ assists mice in resisting STZ-induced T1DM.

a Representative images of IF staining of RegIIIγ in bone tissue from the RegIIIγ cKO mice and their littermates. b Serum RegIIIγ levels in the RegIIIγ cKO mice and their littermate controls (n = 6). c Random blood glucose levels in the RegIIIγ cKO mice and their littermate controls after STZ induction (n = 5). d Fasting blood glucose levels in the RegIIIγ cKO mice and their littermate controls after STZ induction (n = 6). e Serum insulin levels in the RegIIIγ cKO mice and their littermate controls after STZ induction (n = 5). f GTTs of the RegIIIγ cKO mice and their littermate controls subjected to STZ induction (n = 6). g Compared with the control mice, the RegIIIγ cKO mice exhibited a decreased ability to increase GSIS under STZ conditions. h Representative images of HE-stained pancreatic islets from the RegIIIγ cKO mice and their littermate controls subjected to STZ induction. i, j Representative images of insulin IHC and IF staining of the RegIIIγ cKO mice and their littermate controls subjected to STZ induction. k Insulin mRNA expression in the pancreatic islets of the RegIIIγ cKO mice and their littermate controls after STZ induction (n = 3). l, n Pancreatic islet BAX IHC staining of the RegIIIγ cKO mice and their littermate controls after STZ induction. m, o PCNA IHC staining of pancreatic islets from the RegIIIγ cKO mice and their littermate controls after STZ induction. p The islet equivalent (IEQ) of the RegIIIγ cKO mice was lower than that of their control littermates after STZ treatment (n = 5). q Body weight changes in the RegIIIγ cKO mice and their littermate controls after STZ injection. All data are presented as the mean ± SEM, and p values were analyzed by two-tailed t-tests in (b–e, k, n–p) and two-way ANOVA in (f, g, q). **p < 0.01, ***p < 0.001. All the data are representative of two to three independent experiments. The data were obtained from male mice.