title: Conditional and specific inhibition of NF-κB in mouse pancreatic β cells prevents cytokine-induced deleterious effects and improves islet survival posttransplant.
abstract: BACKGROUND
  Islets are susceptible to damage by proinflammatory cytokines via activation of transcription factor NF-κB. We hypothesized that inhibition of NF-κB activity will decrease cytokine-mediated β-cell injury and improve islet transplant functional outcome.
  
  
  METHODS
  We created a transgenic mouse expressing a degradation resistant N-terminally deleted IκBα (ΔNIκBα) under the control of a commercially available tetracycline-controlled transcriptional activation system using a rat insulin promoter. Isolated islets from transgenic and control mouse strains were exposed to cytokines in vitro and assayed or transplanted.
  
  
  RESULTS
  Western blot analysis showed that ΔNIκBα was significantly increased with doxycycline treatment. Cytokine-induced NF-κB activation was significantly decreased in transgenic (0.065 ± 0.013 absorbance value/μg protein) vs control islets (0.128 ± 0.006; P < .05). Suppression of cytokine-mediated NF-κB activity decreased expression of inducible nitric oxide synthase, monocyte chemoattractant protein-1, and interferon-γ inducible protein-10 RNA transcripts, and significantly decreased nitric oxide production in transgenic islets (0.084 ± 0.043 μM/μg protein) vs. controls (0.594 ± 0.174; P < .01). The insulin stimulation index in islets exposed to cytokines was higher in transgenic vs controls (1.500 ± 0.106 vs 0.800 ± 0.098; P < .01). Syngeneic transplants of a marginal mass of intraportally infused transgenic islets resulted in a reversion to euglycemia in 69.2% of diabetic recipients at a mean of 7.8 ± 1.1 days vs. 35.7% of control islet recipients reverting at a mean of 15.8 ± 2.9 days (P < .05).
  
  
  CONCLUSIONS
  Conditional and specific suppression of NF-κB activity in β cells protected islets from cytokine-induced dysfunction in vitro and in vivo. These results provide a proof of principle that inhibition of NF-κB activity in donor islets enhances function and improves the outcome of islet transplantation.
authors: Department of Surgery and Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors: Jonathan S
authors: JS
authors: Rink
authors: Xiaojuan
authors: X
authors: Chen
authors: Xiaomin
authors: X
authors: Zhang
authors: Dixon B
authors: DB
authors: Kaufman
mesh_terms: D000818:Animals; D016207:Cytokines / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000601:surgery; D004195:Disease Models, Animal; D005947:Glucose / Q000494:pharmacology; D006085:Graft Survival / Q000502:physiology*; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects* / Q000378:metabolism*; D016381:Islets of Langerhans Transplantation / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D013311:Streptozocin / Q000009:adverse effects
chemical_list: D016207:Cytokines; D007328:Insulin; D016328:NF-kappa B; D009569:Nitric Oxide; D013311:Streptozocin; D005947:Glucose