Quercetin 3-Glucoside Protects Neuroblastoma (SH-SY5Y) Cells in Vitro against Oxidative Damage by Inducing Sterol Regulatory Element-binding Protein-2-mediated Cholesterol Biosynthesis*

  1. Ramani Soundararajan ‡ 1 ,
  2. Alexander D. Wishart ‡ 2 ,
  3. H. P. Vasantha Rupasinghe § ,
  4. Mayi Arcellana-Panlilio ,
  5. Carolanne M. Nelson ∥ ,
  6. Michael Mayne ** and
  7. George S. Robertson ‡‡ 3
  1. ‡Department of Pharmacology and ‡‡Departments of Psychiatry and Pharmacology, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada, the §Department of Environmental Sciences, Nova Scotia Agricultural College, Truro, Nova Scotia B2N 5E3, Canada, the Department of Biochemistry and Molecular Biology, University of Calgary, HM 393b-3330 Hospital Drive, N.W., Calgary, Alberta T2N 4N1, Canada, the ∥Department of Family and Nutritional Sciences, University of Prince Edward Island, Charlottetown, Prince Edward Island C1A 4P3, Canada and the **Institute for Nutrisciences and Health, National Research Council of Canada, Charlottetown, Prince Edward Island C1A 5T1, Canada
  1. 3 To whom correspondence should be addressed: Dept. of Psychiatry and Pharmacology, Sir Charles Tupper Medical Bldg., Dalhousie University, 5850 College St., Halifax, Nova Scotia B3H 1X5, Canada. Tel.: 902-494-1528; Fax: 902-494-1388; E-mail: George.Robertson{at}dal.ca.

Abstract

The flavonoid quercetin 3-glucoside (Q3G) protected SH-SY5Y, HEK293, and MCF-7 cells against hydrogen peroxide-induced oxidative stress. cDNA microarray studies suggested that Q3G-pretreated cells subjected to oxidative stress up-regulate the expression of genes associated with lipid and cholesterol biosynthesis. Q3G pretreatment elevated both the expression and activation of sterol regulatory element-binding protein-2 (SREBP-2) only in SH-SY5Y cells subjected to oxidative stress. Inhibition of SREBP-2 expression by small interfering RNA or small molecule inhibitors of 2,3-oxidosqualene:lanosterol cyclase or HMG-CoA reductase blocked Q3G-mediated cytoprotection in SH-SY5Y cells. By contrast, Q3G did not protect either HEK293 or MCF-7 cells via this signaling pathway. Moreover, the addition of isopentenyl pyrophosphate rescued SH-SY5Y cells from the inhibitory effect of HMG-CoA reductase inhibition. Last, Q3G pretreatment enhanced the incorporation of [14C]acetate into [14C]cholesterol in SH-SY5Y cells under oxidative stress. Taken together, these studies suggest a novel mechanism for flavonoid-induced cytoprotection in SH-SY5Y cells involving SREBP-2-mediated sterol synthesis that decreases lipid peroxidation by maintaining membrane integrity in the presence of oxidative stress.

Footnotes

  • ↵4 The abbreviations used are: LDL, low density lipoprotein; Q3G, quercetin 3-glucoside; Q dihydrate, quercetin dihydrate; MTT, (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide); SCD1, stearoyl-CoA-desaturase 1; HMG-CoA reductase, 3-hydroxy-3-methylglutaryl-coenzyme A reductase; SREBP, sterol regulatory element-binding protein; SCAP, SREBP cleavage-activating protein; ROS, reactive oxygen species; siRNA, small interfering RNA; OSCi, oxidosqualene:lanosterol cyclase inhibitor; LDLr, LDL receptor; PBS, phosphate-buffered saline; ELISA, enzyme-linked immunosorbent assay; LDH, lactate dehydrogenase; TUNEL, terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick end in situ labeling; SAMF, Southern Alberta Microarray Facility; RT, reverse transcription; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; tBHQ, tert-butylhydroquinone; SAM, Significance Analysis of Microarray; qRT, quantitative RT; IPP, isopentenyl pyrophosphate.

  • The microarray data has been deposited to the NCBI gene expression and hybridization array repository (GEO; http://www.ncbi.nlm.nih.gov/geo), and GEO accession numbers are GSE6199, GSE6200, GSM143163, GSM143243, GSM143247, GSM143248, GSM143249, GSM143250, GSM143251, GSM143252, GSM143253, GSM143254, GSM143255, GSM143256, GSM143257, GSM143258, GSM143259, and GSM143260.

  • ↵* This work was supported in part by grants from Atlantic Canada Opportunities Agency-Atlantic Innovation Funds (to C. M. N. and G. S. R.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

  • ↵Graphic The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. 1–5.

  • ↵1 Supported by a Postdoctoral fellowship from the Department of Family and Nutritional Sciences, University of Prince Edward Island.

  • ↵2 Supported by a studentship from Vaccinium Technologies Inc.

    • Received April 30, 2007.
    • Revision received November 20, 2007.
View this article with LENS
Table of Contents

This Article

  1. First Published on November 20, 2007 doi: 10.1074/jbc.M703583200 The Journal of Biological Chemistry 283, 2231-2245.
  1. » Abstract(Free)
  2. Full Text(Free)
  3. PDF(Free)
  4. PDF + Supp Info
  5. Supplemental Data
  6. All Versions of this Article:
    1. M703583200v1
    2. 283/4/2231 (most recent)

Article Usage Stats

  1. Article Usage Statistics

Submit your work to JBC.

You'll be in good company.