Proteomic analysis of mitochondrial proteins in a mouse model of type 2 diabetes.
OBJECTIVE
Impaired mitochondrial function may contribute to the onset of contractile dysfunction with insulin resistance/type 2 diabetes. Our aim was therefore to determine alterations in the mitochondrial proteome of a mouse model of obesity/type 2 diabetes.


METHODS
Mitochondrial proteins were isolated from hearts collected from 18- to 20-week-old female db/db mice and compared to matched controls. We performed two-dimensional polyacrylamide gel electrophoresis to determine differentially expressed proteins. Peptides of interest were further analysed by mass spectrometry and Mascot software was employed to identify protein matches.


RESULTS
Our data showed that ATP synthase D chain, ubiquinol cytochrome-C reductase core protein 1 and electron transfer flavoprotein subunit alpha peptide levels were altered with obesity. Moreover, we found coordinate downregulation of contractile proteins in the obese heart, i.e. α-smooth muscle actin, α-cardiac actin, myosin heavy-chain α and myosin-binding protein C.


CONCLUSIONS
We propose that decreased contractile protein levels may contribute to contractile dysfunction of hearts from diabetic mice.
Essop
M F
MF
Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa. mfessop@sun.ac.za
Chan
W A
WA
Hattingh
S
S
D000818:Animals; D003285:Contractile Proteins / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D004195:Disease Models, Animal; D015180:Electrophoresis, Gel, Two-Dimensional; D004734:Energy Metabolism; D005260:Female; D051379:Mice; D018345:Mice, Knockout; D008929:Mitochondria, Heart / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D009200:Myocardial Contraction; D009206:Myocardium / Q000378:metabolism*; D009765:Obesity / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D054411:Receptors, Leptin / Q000172:deficiency / Q000235:genetics; D012984:Software; D021241:Spectrometry, Mass, Electrospray Ionization
D003285:Contractile Proteins; D024101:Mitochondrial Proteins; D054411:Receptors, Leptin; C515447:leptin receptor, mouse