Mitochondrial fragmentation and superoxide anion production in coronary endothelial cells from a mouse model of type 1 diabetes.
OBJECTIVE
Mitochondria frequently change their shapes by fusion and fission and these morphological dynamics play important roles in mitochondrial function and development as well as programmed cell death. The goal of this study is to investigate whether: (1) mitochondria in mouse coronary endothelial cells (MCECs) isolated from diabetic mice exhibit increased fragmentation; and (2) chronic treatment with a superoxide anion (O(2)(-)) scavenger has a beneficial effect on mitochondrial fragmentation in MCECs.


METHODS
MCECs were freshly isolated and lysed for protein measurement, or cultured to determine mitochondrial morphology and O(2)(-) production. For the ex vivo hyperglycaemia experiments, human coronary endothelial cells were used.


RESULTS
Elongated mitochondrial tubules were observed in MCECs isolated from control mice, whereas mitochondria in MCECs from diabetic mice exhibited augmented fragmentation. The level of optic atrophy 1 (OPA1) protein, which leads to mitochondrial fusion, was significantly decreased, while dynamin-related protein 1 (DRP1), which leads to mitochondrial fission, was significantly increased in MCECs from diabetic mice. Diabetic MCECs exhibited significantly higher O(2)(-) concentrations in cytosol and mitochondria than control MCECs. Administration of the O(2)(-) scavenger TEMPOL to diabetic mice for 4 weeks led to a significant decrease in mitochondrial fragmentation without altering the levels of OPA1 and DRP1 proteins in MCECs. High-glucose treatment for 24 h significantly induced mitochondrial fragmentation, which was restored by TEMPOL treatment. In addition, excess O(2)(-) production, either in cytosol or in mitochondria, significantly increased mitochondrial fragmentation.


CONCLUSIONS
These data suggest that lowering the O(2)(-) concentration can restore the morphological change in mitochondria and may help improve mitochondrial function in diabetic MCECs.
Makino
A
A
Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, 9500 Gilman Drive, MC0618, La Jolla, CA 92093-0618, USA.
Scott
B T
BT
Dillmann
W H
WH
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D015153:Blotting, Western; D002478:Cells, Cultured; D003497:Cyclic N-Oxides / Q000494:pharmacology; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism / Q000473:pathology*; D015232:Dinoprostone / Q000031:analogs & derivatives / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D005947:Glucose / Q000494:pharmacology; D028421:Isoprostanes / Q000378:metabolism; D008561:Membrane Fusion / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D013113:Spin Labels; D013481:Superoxides / Q000378:metabolism*
D000975:Antioxidants; D003497:Cyclic N-Oxides; D028421:Isoprostanes; D013113:Spin Labels; D013481:Superoxides; D005947:Glucose; D015232:Dinoprostone; C001803:tempol; C011987:8-isoprostaglandin E2
FEBS Lett. 2002 Jul 17;523(1-3):171-6
12123827
J Cell Biol. 2000 Oct 16;151(2):367-80
11038183
Circ Res. 2003 Sep 19;93(6):507-14
12933701
Nat Genet. 2000 Oct;26(2):211-5
11017080
Nat Genet. 2000 Oct;26(2):207-10
11017079
Am J Physiol Cell Physiol. 2008 Jul;295(1):C221-30
18463230
Adv Drug Deliv Rev. 2008 Oct-Nov;60(13-14):1512-26
18692534
Neurobiol Dis. 2006 Jul;23(1):11-22
16684605
J Biol Chem. 2003 May 9;278(19):17190-7
12598526
Nat Genet. 2004 May;36(5):449-51
15064763
Biochim Biophys Acta. 2006 May-Jun;1757(5-6):518-24
16829229
Am J Physiol Lung Cell Mol Physiol. 2006 Jul;291(1):L38-45
16510472
Nature. 2000 Apr 13;404(6779):787-90
10783895
Diabetes. 1991 Apr;40(4):405-12
2010041
Circulation. 2005 Apr 26;111(16):2073-85
15851615
Biol Chem. 2006 Dec;387(12):1551-8
17132100
Biochim Biophys Acta. 2006 May-Jun;1763(5-6):549-60
16574258
Proc Natl Acad Sci U S A. 2006 Feb 21;103(8):2653-8
16477035
Am J Physiol Heart Circ Physiol. 2005 Aug;289(2):H701-7
15821039
Nat Genet. 2001 Jul;28(3):272-5
11431699
J Clin Invest. 2003 Sep;112(5):725-35
12952921
J Cell Biol. 2003 Jan 20;160(2):189-200
12527753
J Cell Sci. 2002 Apr 15;115(Pt 8):1663-74
11950885
Exp Biol Med (Maywood). 2002 Oct;227(9):671-82
12324649
Nat Cell Biol. 2004 Sep;6(9):872-83
15322553
Biochem Biophys Res Commun. 2007 Jun 22;358(1):203-8
17475217
Mol Cell Biol. 2003 Aug;23(15):5409-20
12861026
Mol Biol Cell. 2001 Aug;12(8):2245-56
11514614
Annu Rev Genet. 2005;39:359-407
16285865
Diabetes. 2002 Jan;51(1):198-203
11756341
Diabetes Care. 1996 Mar;19(3):257-67
8742574
Neurology. 2005 Mar 22;64(6):966-72
15781809
Free Radic Biol Med. 2005 Aug 1;39(3):381-91
15993337
Nat Rev Neurosci. 2008 Jul;9(7):505-18
18568013
Am J Pathol. 2006 Feb;168(2):629-38
16436676
Curr Opin Cell Biol. 2003 Aug;15(4):482-8
12892790
Circ Res. 2001 Feb 2;88(2):E14-22
11157681
Proc Natl Acad Sci U S A. 2004 Nov 9;101(45):15927-32
15509649
Diabetologia. 2003 Oct;46(10):1438-45
12928773
Mitochondrion. 2008 Sep;8(4):293-304
18602028
Cardiovasc Res. 2000 Jan 14;45(2):513-21
10728373
Microsc Res Tech. 1994 Feb 15;27(3):198-219
8204911
Hum Mol Genet. 2005 Oct 15;14 Spec No. 2:R283-9
16244327
Nat Med. 2001 Aug;7(8):934-40
11479626
Diabetes Metab Res Rev. 2006 May-Jun;22(3):198-203
16453381
Annu Rev Cell Dev Biol. 2006;22:79-99
16704336
Ann Neurol. 2004 Nov;56(5):719-23
15505825
Diabetes. 2005 Sep;54(9):2685-93
16123358
Cell. 2008 Apr 18;133(2):265-79
18423198
Endocrinology. 2004 Nov;145(11):5305-12
15308612