OGT2115 prevented loss of intra-islet HS level and reduced infiltration of immunocytes in STZ mice
To investigate whether the protective effect of OGT2115 on STZ-induced pancreatic beta cell damage was directly due to restoration of intra-islet HS levels, HS was stained with Alcian blue dye or HS antibody. As shown in Fig. 5A and 5B, the intra-islet HS was clearly lost in the STZ mice. By contrast, the STZ mice treated with either 3 mg/kg or 10 mg/kg OGT2115 showed a significant increase in intra-islet HS (Fig. 5A and Fig. 5B). Multiple low-dose injections of STZ caused beta cell death and could induce subsequent infiltration of F4/80-positive monocytes (Fig. 5A and 5C), CD8 or CD4-positive T cells (Fig. 5A and 5D). Quantitative analysis of F4/80, CD8, and CD4 positive cell numbers demonstrated a notable decrease in the infiltration of immunocytes in the islets of 10 mg/kg OGT2115-treated STZ mice when compared with vehicle-treated STZ mice (Fig. 5C and Fig. 5D).