NADH dehydrogenase activity and expression of mRNA of complex I (ND1, 51kDa, and 75kDa) in heart mitochondria of klotho mouse.
Mitochondrial enzyme activities and ultrastructure of mitochondria prepared from klotho mutant mice were compared with those in wild-type mice. We also measured the levels of expression of ND1, 51kDa, and 75kDa mRNA associated with the genes encoding NADH dehydrogenase and complex I and that of alpha cardiac myosin heavy chain mRNA in both groups. Mitochondrial NADH oxidoreductase activity was higher in klotho mutant mice during aging than that in wild-type mice. The area of mitochondria per unit area (300 microm2) of cell was almost constant from 4 to 7 weeks of age in both groups. A few large mitochondria were scattered between numerous small mitochondria with compact cristae and myofibrils in klotho mice from 5 weeks of age. The levels of ND1 and 75kDa mRNA were slightly high from 7 weeks of age in klotho mutant mice, whereas they were almost constant in wild-type mice, in spite of reduced expression of alpha cardiac myosin heavy chain mRNA. Our results indicate that klotho protein indirectly plays a role in diminished functional adaptability of enzymes in aged heart muscle, and is required for hypertrophy of cardiac mitochondria.
Sato
Iwao
I
Department of Anatomy, Nippon Dental University School of Dentistry, Fujimi 1-9-20, Chiyoda-ku, Tokyo, Japan.
Miyado
Mami
M
Sunohara
Masataka
M
D000375:Aging; D000818:Animals; D042967:Electron Transport Complex I / Q000096:biosynthesis*; D005966:Glucuronidase; D049670:History, 17th Century; D000090265:Klotho Proteins; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008928:Mitochondria / Q000502:physiology*; D009206:Myocardium / Q000201:enzymology*; D009245:NADH Dehydrogenase / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis
D008565:Membrane Proteins; D012333:RNA, Messenger; D009245:NADH Dehydrogenase; D005966:Glucuronidase; D000090265:Klotho Proteins; D042967:Electron Transport Complex I