title: Pancreatic β-cell death in response to pro-inflammatory cytokines is distinct from genuine apoptosis.
abstract: A reduction in functional β-cell mass leads to both major forms of diabetes; pro-inflammatory cytokines, such as interleukin-1beta (IL-1β) and gamma-interferon (γ-IFN), activate signaling pathways that direct pancreatic β-cell death and dysfunction. However, the molecular mechanism of β-cell death in this context is not well understood. In this report, we tested the hypothesis that individual cellular death pathways display characteristic phenotypes that allow them to be distinguished by the precise biochemical and metabolic responses that occur during stimulus-specific initiation. Using 832/13 and INS-1E rat insulinoma cells and isolated rat islets, we provide evidence that apoptosis is unlikely to be the primary pathway underlying β-cell death in response to IL-1β+γ-IFN. This conclusion was reached via the experimental results of several different interdisciplinary strategies, which included: 1) tandem mass spectrometry to delineate the metabolic differences between IL-1β+γ-IFN exposure versus apoptotic induction by camptothecin and 2) pharmacological and molecular interference with either NF-κB activity or apoptosome formation. These approaches provided clear distinctions in cell death pathways initiated by pro-inflammatory cytokines and bona fide inducers of apoptosis. Collectively, the results reported herein demonstrate that pancreatic β-cells undergo apoptosis in response to camptothecin or staurosporine, but not pro-inflammatory cytokines.
authors.affiliation: Department of Nutrition, University of Tennessee, Knoxville, Tennessee, United States of America. Jason.Collier@utk.edu
authors.forename: J Jason
authors.initials: JJ
authors.lastname: Collier
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Burke
authors.forename: Mary E
authors.initials: ME
authors.lastname: Eisenhauer
authors.forename: Danhong
authors.initials: D
authors.lastname: Lu
authors.forename: Renee C
authors.initials: RC
authors.lastname: Sapp
authors.forename: Carlie J
authors.initials: CJ
authors.lastname: Frydman
authors.forename: Shawn R
authors.initials: SR
authors.lastname: Campagna
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D002166:Camptothecin / Q000494:pharmacology; D020169:Caspases / Q000378:metabolism; D016923:Cell Death; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007249:Inflammation; D007328:Insulin / Q000494:pharmacology; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D007340:Insulinoma / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D007371:Interferon-gamma / Q000494:pharmacology; D053583:Interleukin-1beta / Q000494:pharmacology; D055432:Metabolomics; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D015398:Signal Transduction; D019311:Staurosporine / Q000494:pharmacology; D053719:Tandem Mass Spectrometry
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D016207:Cytokines; D004791:Enzyme Inhibitors; D007328:Insulin; D053583:Interleukin-1beta; D016328:NF-kappa B; D007371:Interferon-gamma; D020169:Caspases; D019311:Staurosporine; D002166:Camptothecin