title: Activation of NFκB dependent apoptotic pathway in pancreatic islet cells by hypoxia.
abstract: Insulin producing β-cells are exposed to hypoxic stress in the early period after islet transplantation. Although it has been suggested that hypoxia leads to islet loss, the underlying mechanisms are unclear. In this study, the early transcriptional profiles of b cell response to hypoxia were determined by using the Affymetrix Murine Genome Array U74Av2 GeneChip (about 12,422 genes). In addition to the upregulation of genes associated with glycolysis, genes related to apoptosis and stress response were also upregulated. The downregulated genes on hypoxia are classified as transcription and inflammatory response. These findings were confirmed by TUNEL assay and real-time reverse transcription-PCR for mRNA of genes related to apoptosis. On the other hand, we have found that the transcription factor NFκB was activated by hypoxia in islet cells. The affected genes involved in the activated NFκB pathway were mainly categorized as apoptosis-related genes by quantitative real-time PCR array (84 genes). Our comprehensive analysis of transcriptional changes of islets by hypoxia may assist the development of strategies that protect islet grafts from early loss.
authors.affiliation: The Third Medical Clinic, Justus Liebig University, Germany.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lai
authors.forename: Heide
authors.initials: H
authors.lastname: Brandhorst
authors.forename: Hamid
authors.initials: H
authors.lastname: Hossain
authors.forename: Angelika
authors.initials: A
authors.lastname: Bierhaus
authors.forename: Chunguang
authors.initials: C
authors.lastname: Chen
authors.forename: Reinhard G
authors.initials: RG
authors.lastname: Bretzel
authors.forename: Thomas
authors.initials: T
authors.lastname: Linn
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015687:Cell Hypoxia / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007515:Islets of Langerhans / Q000166:cytology / Q000378:metabolism* / Q000502:physiology*; D051379:Mice; D046228:Microarray Analysis; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010100:Oxygen / Q000494:pharmacology; D016133:Polymerase Chain Reaction / Q000379:methods; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D013997:Time Factors
chemical_list: D016328:NF-kappa B; D010100:Oxygen