To induce diabetes, mice were given serial intraperitoneal injections of streptozotocin (STZ, 180 mg/kg, Sigma Chemical Co., St. recipients displayed a slight decrease in serum MCP-1 concentration, Torcetrapib (CP-529414) as compared to controls. After 15 days, recipients of nicotinamide-pretreated islets showed higher levels of graft function (as measured by IPGTT) than controls. The pretreatment also prolonged graft survival ( 100 days) and function; these were confirmed by partial hepatectomy, which led to the recurrence of diabetes. Pretreatment PLA2G4F/Z of islet grafts with nicotinamide may prevent their deterioration on the early period following IPIT in a syngeneic mouse model. = 3). NIC, nicotinamide. Histological evaluation Following intraportal infusion with 300 untreated or nicotinamide-pretreated syngeneic islets, recipient Torcetrapib (CP-529414) livers were examined for pathology at 3 h and 24 h (Physique 4). The percentage of granulated islets was calculated by counting the total number of insulin-positive cells and then grouping them into granulated or de-granulated islets according to morphology (Physique 4C). Open in a separate window Physique 4 Morphological changes in the engrafted liver. Liver tissues were collected 3 h (A) and 24 h post-transplantation (B, C), and stained with H&E (A, B) and monoclonal antibody to insulin (C). Insulin-positive cells were morphologically granulated or de-granulated (C, left or right, respectively). The percentage of granulation was based on the number of granulated islets out of the total number of insulin staining cells at 0, 3, and 24 h post-transplantation. The percentage of granulation at 0 h was calculated with islets before transplantation, and no de-granulated islets were observed. The morphology was comparable in both groups at 3 h after IPIT (Physique 4A and 4D). Most insulin-positive cells were well-granulated, and these healthy islets were located in blood vessels. The condition of the liver was normal or slightly abnormal. After 24 h, however, serious necrosis was observed in the islet recipients’ livers. In the control group, more islets were de-granulated (68% granulated) as compared with those after 3 h (96% granulated) (= 0.004) (Physique 4B and 4D). In contrast, islets pretreated with nicotinamide were consistently well-granulated (94% and 92% granulation at 3 h and 24 h after transplantation) and significantly different from untreated islets (= 0.01) (Physique 4D). Expression of inflammatory mediators in the liver For RT-PCR and western blot, total RNA and protein were extracted from the recipient livers (lateral right and caudal lobe) at 3 h (Physique 5A and 5C) and 24 h (Physique 5B and 5D) after transplantation of 300 islets cultured with or without nicotinamide. At 3 h after IPIT, RNA expression of both TF and TNF- had increased markedly in both groups; but by 24 h, it had declined (Physique 5A and 5B). IL-1 and MCP-1 were, however, weakly expressed in the liver after both 3 h and 24 h of IPTX. In addition, nicotinamide-pretreatment showed Torcetrapib (CP-529414) comparable expression patterns to non-treatment. And also C3 was detected strongly in all recipient livers of both groups after 3 h in western blot (Physique 5C and 5D). Interestingly, C3 protein was found only a third in the nicotinamide pretreatment mice, whereas it was detected Torcetrapib (CP-529414) in all control recipients whole experimental period. Open in a separate window Physique 5 Expression of inflammatory mediators in the liver after IPTX. Islet cells pretreated without (control; lanes 1-3) or with nicotinamide (nicotinamide; lanes 4-6 and/or 7) were intraportally transplanted in the diabetic mouse. After 3 h or 24 h of transplantation, liver of recipient was sacrificed. RNA expressions for IL-1, TNF-, TF, MCP-1, insulin, and GAPDH were detected by RT-PCR analysis in the liver 3 h (A) or 24 h (B) after IPTX. C3 and -actin were detected by Western blot analysis in the liver sample at both occasions (C, D). Cell line RAW 264.7 activated by LPS was used as a positive control (Po.) of IL-1, TNF-, TF, MCP-1, and GAPDH. Cell line MIN 6 was used as a positive control of insulin. NIC, nicotinamide. Decreased serum MCP-1 concentration The concentration of serum MCP-1 was decided in recipients of untreated or nicotinamide- pretreated grafts on day one after intraportal infusion of 300 islets (Physique 6). Serum MCP-1 levels increased in all recipients after IPIT, but were lower in the nicotinamide-pretreatment group (although the difference did not reach statistical significance). Open in a separate windows Physique 6 MCP-1 concentrations after Torcetrapib (CP-529414) intraportal transplantation of nicotinamide-pretreated and untreated islets. Diabetic mice receiving 300 IEQ with or without nicotinamide pretreatment were divided with two groups (CON, control;.