title: Mechanism Governing Human Kappa-Opioid Receptor Expression under Desferrioxamine-Induced Hypoxic Mimic Condition in Neuronal NMB Cells.
abstract: Cellular adaptation to hypoxia is a protective mechanism for neurons and relevant to cancer. Treatment with desferrioxamine (DFO) to induce hypoxia reduced the viability of human neuronal NMB cells. Surviving/attached cells exhibited profound increases of expression of the human kappa-opioid receptor (hKOR) and hypoxia inducible factor-1α (HIF-1α). The functional relationship between hKOR and HIF-1α was investigated using RT-PCR, Western blot, luciferase reporter, mutagenesis, siRNA and receptor-ligand binding assays. In surviving neurons, DFO increased HIF-1α expression and its amount in the nucleus. DFO also dramatically increased hKOR expression. Two (designated as HIFC and D) out of four potential HIF response elements of thehKORgene (HIFA-D) synergistically mediated the DFO response. Mutation of both elements completely abolished the DFO-induced effect. The CD11 plasmid (containing HIFC and D with an 11 bp spacing) produced greater augmentation than that of the CD17 plasmid (HIFC and D with a 17 bp-spacing), suggesting that a proper topological interaction of these elements synergistically enhanced the promoter activity. HIF-1α siRNA knocked down the increase of endogenous HIF-1α messages and diminished the DFO-induced increase of hKOR expression. Increased hKOR expression resulted in the up-regulation of hKOR protein. In conclusion, the adaptation of neuronal hKOR under hypoxia was governed by HIF-1, revealing a new mechanism of hKOR regulation.
authors.affiliation: Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA. jennifer.candelora@student.shu.edu.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Babcock
authors.affiliation: Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA. alberto.herrera@student.shu.edu.
authors.forename: Alberto
authors.initials: A
authors.lastname: Herrera
authors.affiliation: Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA. gc0506@gmail.com.
authors.forename: George
authors.initials: G
authors.lastname: Coricor
authors.affiliation: Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA. chris.karch@LIVE.COM.
authors.forename: Christopher
authors.initials: C
authors.lastname: Karch
authors.affiliation: Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA. alcolumbia@gmail.com.
authors.forename: Alexander H
authors.initials: AH
authors.lastname: Liu
authors.affiliation: Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA. aida139@gmail.com.
authors.forename: Aida
authors.initials: A
authors.lastname: Rivera-Gines
authors.affiliation: Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA. jane.ko@shu.edu.
authors.forename: Jane L
authors.initials: JL
authors.lastname: Ko
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002448:Cell Adhesion / Q000235:genetics; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics; D003676:Deferoxamine / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D009447:Neuroblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D034622:RNA Interference; D017473:Receptors, Opioid, kappa / Q000235:genetics* / Q000378:metabolism; D020218:Response Elements / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017262:Siderophores / Q000494:pharmacology; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D003676:Deferoxamine; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D017473:Receptors, Opioid, kappa; D017262:Siderophores; D000099162:Endothelial PAS Domain-Containing Protein 1
keywords: HIF response elements; desferrioxamine; human NMB neuronal cells; human kappa-opioid receptor; hypoxia; hypoxia inducible factor-1α