HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Rachek, L. I. Articles by Wilson, G. L. Search for Related Content PubMed PubMed Citation Articles by Rachek, L. I. Articles by Wilson, G. L. Social Bookmarking                What's this?

Protection of INS-1 Cells From Free Fatty Acid–Induced Apoptosis by Targeting hOGG1 to Mitochondria

¹ Department of Cell Biology and Neuroscience, College of Medicine, University of South Alabama, Mobile, Alabama
² Department of Orthopedics, College of Medicine, University of South Alabama, Mobile, Alabama

Address correspondence and reprint requests to Lyudmila I. Rachek, Department of Cell BiologyNeuroscience, University of South Alabama, Mobile, AL 36688. E-mail: lrachek{at}jaguar1.usouthal.edu

Abbreviations: ELISA, enzyme-linked immunosorbent assay; FFA, free fatty acid; hOGG1, human 8-oxoguanine DNA glycosylase/apurinic lyase; iNOS, inducible nitric oxide synthase; MTS, mitochondrial targeting sequence

Chronic exposure to elevated levels of free fatty acids (FFAs) impairs pancreatic ß-cell function and contributes to the decline of insulin secretion in type 2 diabetes. Previously, we reported that FFAs caused increased nitric oxide (NO) production, which damaged mitochondrial DNA (mtDNA) and ultimately led to apoptosis in INS-1 cells. To firmly establish the link between FFA-generated mtDNA damage and apoptosis, we stably transfected INS-1 cells with an expression vector containing the gene for the DNA repair enzyme human 8-oxoguanine DNA glycosylase/apurinic lyase (hOGG1) downstream of the mitochondrial targeting sequence (MTS) from manganese superoxide dismutase. Successful integration of MTS-OGG1 into the INS-1 cellular genome was confirmed by Southern blot analysis. Western blots and enzyme activity assays revealed that hOGG1 was targeted to mitochondria and the recombinant enzyme was active. MTS-OGG1 cells showed a significant decrease in FFA-induced mtDNA damage compared with vector-only transfectants. Additionally, hOGG1 overexpression in mitochondria decreased FFA-induced inhibition of ATP production and protected INS-1 cells from apoptosis. These results indicate that mtDNA damage plays a pivotal role in FFA-induced ß-cell dysfunction and apoptosis. Therefore, targeting DNA repair enzymes into ß-cell mitochondria could be a potential therapeutic strategy for preventing or delaying the onset of type 2 diabetes symptoms.

CiteULike    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				P. Newsholme, E. P. Haber, S. M. Hirabara, E. L. O. Rebelato, J. Procopio, D. Morgan, H. C. Oliveira-Emilio, A. R. Carpinelli, and R. Curi Diabetes associated cell stress and dysfunction: role of mitochondrial and non-mitochondrial ROS production and activity J. Physiol., August 15, 2007; 583(1): 9 - 24. [Abstract] [Full Text] [PDF]

				L. I. Rachek, S. I. Musiyenko, S. P. LeDoux, and G. L. Wilson Palmitate Induced Mitochondrial Deoxyribonucleic Acid Damage and Apoptosis in L6 Rat Skeletal Muscle Cells Endocrinology, January 1, 2007; 148(1): 293 - 299. [Abstract] [Full Text] [PDF]