title: Cholesterol biosynthesis and the pro-apoptotic effects of the p75 nerve growth factor receptor in PC12 pheochromocytoma cells.
abstract: Neocarzinostatin (NCS), an enediyne antimitotic agent, induces cell death in both p75NTR neurotrophin receptor (NTR)-positive and p75NTR-negative PC12 cells in a concentration-dependent fashion. However, p75NTR-positive cells demonstrate a higher susceptibility to NCS-induced cell damage. Furthermore, treatment of p75NTR-positive cells with the p75NTR-specific ligand, MC192, resulted in apoptosis, while treatment of these cells with the TrkA-specific ligand, NGF-mAbNGF30, protected them from NCS-induced death, implying that both the naked and liganded p75NTR receptors have a pro-apoptotic effect on PC12 cells. Microarray studies aimed at examining differential gene expression between p75NTR-positive and p75NTR-negative cells suggested that enzymes of the cholesterol biosynthetic pathway are differentially expressed. We therefore tested the hypothesis that altered cholesterol biosynthesis contributes directly to the pro-apoptotic effects of p75NTR in this PC12 cell-NCS model. Subsequent Northern blotting studies confirmed that the expression of p75NTR is associated with the upregulation of cholesterol biosynthetic enzymes including 3-hydroxy-3-methylglutaryl CoA reductase (HMG CoA reductase), farnesyl-diphosphate synthase, and 7-dehydro-cholesterol reductase. Mevastatin, an HMG CoA reductase inhibitor, converts the apoptosis susceptibility of p75NTR-positive cells to that of p75NTR-negative cells. It does so at concentrations that do not themselves alter cell survival. These studies provide evidence that the pro-apoptotic effects of p75NTR in PC12 cells are related to the upregulation of cholesterol biosynthetic enzymes and consequent increased cholesterol biosynthesis.
authors.affiliation: Division of Child Neurology, The Pediatric Center for Neuroscience, Children's Hospital of Pittsburgh, 3705 Fifth Avenue, Pittsburgh, PA 15213, USA.
authors.forename: Chaohua
authors.initials: C
authors.lastname: Yan
authors.forename: Zeljka Korade
authors.initials: ZK
authors.lastname: Mirnics
authors.forename: Carmel F
authors.initials: CF
authors.lastname: Portugal
authors.forename: Ye
authors.initials: Y
authors.lastname: Liang
authors.forename: Karen D
authors.initials: KD
authors.lastname: Nylander
authors.forename: Marcelo
authors.initials: M
authors.lastname: Rudzinski
authors.forename: Clara
authors.initials: C
authors.lastname: Zaccaro
authors.forename: H Uri
authors.initials: HU
authors.lastname: Saragovi
authors.forename: Nina Felice
authors.initials: NF
authors.lastname: Schor
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D015152:Blotting, Northern / Q000379:methods; D015153:Blotting, Western / Q000379:methods; D002452:Cell Count / Q000379:methods; D002784:Cholesterol / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D051228:Geranyltranstransferase / Q000378:metabolism; D008148:Lovastatin / Q000031:analogs & derivatives / Q000494:pharmacology; D046228:Microarray Analysis / Q000379:methods; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000378:metabolism; D016716:PC12 Cells; D010766:Phosphorylation / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D020800:Receptor, Nerve Growth Factor / Q000276:immunology / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D009353:Zinostatin / Q000494:pharmacology
chemical_list: D000214:Acyl Coenzyme A; D000911:Antibodies, Monoclonal; D004791:Enzyme Inhibitors; D019384:Nucleic Acid Synthesis Inhibitors; D012333:RNA, Messenger; D020800:Receptor, Nerve Growth Factor; C008047:3-hydroxy-3-methylglutaryl-coenzyme A; C012258:mevastatin; D009353:Zinostatin; D002784:Cholesterol; D008148:Lovastatin; D044925:Oxidoreductases Acting on CH-CH Group Donors; C019995:7-dehydrocholesterol reductase; D051228:Geranyltranstransferase