Furthermore, all diabetic mice gradually became normoglycemic following transplantation of 50 islets into the SP (Fig 1A). SP was 200, 100, and 50, respectively. Some plasma inflammatory cytokine levels in the SP group were significantly lower than those of the PV group after receiving a marginal number of islets, indicating reduced inflammation in the SP group. Insulin contents were increased 280 days after islet transplantation compared with those immediately following transplantation (p 0.05). Proflavine Additionally, Tlx1-related genes, including and test. The statistical significance among three or more groups was determined by one-way analysis of variance and the Tukey-Kramer post hoc test. Differences were considered significant when p-values were less than 0.05. Results Marginal number of islets required to ameliorate hyperglycemia in STZ-induced diabetic recipient mice by syngeneic islet transplantation into three different transplant sites First, we performed syngeneic islet transplantation at three different sites, including intra-PV, beneath the KC, and intra-SP. To ameliorate hyperglycemia in STZ-induced diabetic recipient mice Mouse monoclonal to GFP by islet transplantation into the PV (n = 7) and beneath the KC (n = 6), 200 and 100 islets were required, respectively (Fig 1A). Surprisingly, only 50 islets were required to ameliorate hyperglycemia in STZ-induced diabetic recipient mice by islet transplantation into the SP (n = 10) (Fig 1A). A splenectomy was performed 60 or 160 days after the 50 islets were transplanted into the SP. All recipient mice became hyperglycemic soon after splenectomy, indicating that the intra-splenic islet Proflavine grafts had maintained normoglycemia (Fig 1A). After 200 islets (n = 3) or 100 islets (n = 7) were transplanted into the SP, all diabetic recipient mice suddenly became normoglycemic. Furthermore, all diabetic mice gradually became normoglycemic following transplantation of 50 islets into the SP (Fig 1A). None of the diabetic recipient mice (n = 5) became normoglycemic after receiving 25 islets into the SP (Fig 1A). Insulin- and vWF-stained islets were observed in the spleen from day 0 to day 120 after transplantation (Fig 1B). Open in a separate windows Fig 1 Marginal number of islets required to ameliorate hyperglycemia in STZ-induced diabetic recipient mice by islet transplantation into the liver, beneath the kidney capsules, or into the spleen.(A) Non-fasting blood glucose levels in STZ-induced diabetic mice (C57BL/6) transplanted with 200, 100, 50, or 25 syngeneic islets into the liver (PV), kidney capsule (KC), or spleen (SP). Individual lines represent glucose levels for each animal. The arrowhead indicates the time of graftectomy. (B) Photomicrographs of islet cells after transplantation in the spleen. Sections were stained with Haematoxylin & Eosin (H&E), anti-insulin antibody, or anti-vWF antibody. vWF+ cells are indicated by arrowheads. Scale bars: 100 m (H&E and insulin staining); 200 m (vWF and insulin staining). (C) The response to intraperitoneal glucose tolerance assessments (IPGTT; 1 g/kg body weight) in na?ve (circles), STZ-DM (triangles), and SP50 (squares) mice. Blood glucose levels were measured at the indicated time points. (D) Area under the curve following an IPGTT for each individual mouse. Values are meansSD. *p 0.05. Glucose tolerance was improved following transplantation of 50 islets into the SP To evaluate glucose tolerance, IPGTTs were performed 50 days after transplantation. The blood glucose levels of na?ve mice (n = 8) at 0, 30, and 120 minutes after intraperitoneal glucose injection (1 g/kg body weight) were 59.93.3, 257.59.8, and 133.54.8 mg/dL (meanstandard deviation [sd]), respectively. The blood glucose levels of STZ-DM mice (n = 7) at 0, 30, and 120 minutes after intraperitoneal glucose injection (1 g/kg body weight) were 482.659.9, 686.034.7, and 597.465.8 mg/dL (meansd), respectively. Proflavine The blood glucose levels of diabetic recipient mice that received 50 islets into the spleen (SP50; n = 10) at 0, 30, and 120 minutes after intraperitoneal glucose injection (1 g/kg body) were 81.712.4, 316.748.9, and 103.729.8 mg/dL (meansd), respectively. The SP50 group displayed a similar glucose tolerance pattern to the na?ve mice (Fig 1C). Next, we calculated Proflavine the area under the curve for each Proflavine mouse and compared the na?ve, STZ-DM, and SP50 mice. The areas under the curve for na?ve, STZ-DM, and SP50 mice were 22,355.6723.9, 75,2825,503.3, and 24,8944,179.1 (meansd), respectively (Fig 1D). Significant differences were observed between na?ve and STZ-DM (p 0.05) and between STZ-DM and SP50 (p 0.05) mice. These results exhibited that glucose tolerance after receiving SP50 was comparable to that of na?ve control mice. Early inflammatory reactions after receiving a marginal number of islets into the PV, beneath the KC, or into the SP Next, we compared the severity of early inflammatory reactions after receiving a marginal number of islets into each transplant site. As displayed in Fig 1A, 200, 100, or 50 islets were transplanted into the PV, beneath the.