b-cell function by NF-kB, transgenic mice expressing a dominant active IKKb to activate 12826236 NF-kB or a non-degradable form of IkBa to prevent NF-kB activation under control of the rat insulin promoter were generated. In addition to these genetic approaches, NF-kB activity was modulated both in vivo and in vitro using salicylates. Salicylate inhibits NF-kB, and forms of salicylate including salsalate are being investigated as a potential new therapeutic modality in patients with diabetes. Glucose tolerance tests with bIKK and bISR mice GTTs were performed on 812 wk old bIKK and bISR mice, as well as age and weight matched wild-type siblings. After an overnight fast, mice were injected i.p. with 2 g/kg glucose. Blood glucose levels were measured prior to the injection and at 15, 30, 60, 90 and 120 min using a glucose meter with blood obtained from a snipped tail. Mice receiving islet transplants Male C57BL/6AF1 mice age 6-10 weeks were used as donors and recipients of islet grafts. Transgenic bIKK or bISR mice were also used as transplant donors. Recipient animals were made diabetic with a single i.p. injection of streptozotocin 180 mg/kg body wt, freshly dissolved in citrate buffer. Only those mice with blood glucose levels greater than 20 mmol/l were used as recipients. Methods Ethics The Joslin Animal Care Committee approved all animal experiments. Establishing transgenic mice bIKK and bISR mice were created as described previously for both skeletal muscle and liver specific expression of dominant active IKKb and a non-degradable form of IkBa, respectively. To produce bIKK and bISR mice, IKKb and IkBa, respectively, were expressed selectively in b-cells using the rat insulin 2 promoter. N-terminal FLAG or His tag sequences were included in exon 2 of a b-globin splicing cassette. The DNA fragments were released by Pme1 enzyme digestion and microinjected into the pronuclei of C57BL/6 oocytes, which were then implanted into pseudopregnant female mice in the Joslin Transgenic Mouse Facility. Three founders for bIKK and two for bISR were identified by tail DNA genotyping. These mice were created using C57BL/6 mice, and are thus 100% C57BL/6 background. 11693460 Islet Isolation Islets were isolated using collagenase digestion followed by separation with a density gradient as previously described in detail. After isolation, islets were handpicked and transplanted immediately, or cultured for 72 h in RPMI 1640+10% FCS in the absence or presence of 2 mmol/l salicylate. Islet transplantation Animals were anaesthetised using 0.02 ml/g BW Avertin. The left kidney was exposed through a lumbar incision and the kidney capsule was incised. Using a Hamilton syringe and polyethylene tubing, islets were placed under the kidney capsule as previously described. A suboptimal number of 150 islets were used to assess the Chebulinic acid efficacy of the transplants. Visualization of NF-kB in dispersed cells NF-kB activation was assessed by immunocytochemistry. Cells in isolated islets from mice 812 weeks of age were dispersed using 1 mg/ml trypsin in Ca2+ and Mg2+ free Hanks’ solution at 37uC for 3 min as described previously washed in PBS and centrifuged onto glass slides. The cellular localization of NF-kB was examined by immunofluoresence as described previously using rabbit anti nuclear p50 and guinea-pig anti-human insulin. Secondary antibodies AlexaFluor 488 goat anti guinea-pig IgG and CY3 conjugated donkey anti-rabbit were used as a 1:200 dilution and nuclei were detected using DA
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