TY - JOUR
T1 - Oxidative stress and mitochondrial impairment can be separated from lipofuscin accumulation in aged human skeletal muscle
AU - Hütter, Eveline
AU - Skovbro, Mette
AU - Lener, Barbara
AU - Prats, Clara
AU - Rabøl, Rasmus
AU - Dela, Flemming
AU - Jansen-Dürr, Pidder
N1 - Keywords: Adult; Aged; Aging; Biopsy; Cell Respiration; Female; Humans; Lipofuscin; Male; Mitochondria; Muscle, Skeletal; Oxidative Stress; Oxygen Consumption; Reactive Oxygen Species
PY - 2007
Y1 - 2007
N2 - According to the free radical theory of aging, reactive oxygen species (ROS) act as a driving force of the aging process, and it is generally believed that mitochondrial dysfunction is a major source of increased oxidative stress in tissues with high content of mitochondria, such as muscle or brain. However, recent experiments in mouse models of premature aging have questioned the role of mitochondrial ROS production in premature aging. To address the role of mitochondrial impairment and ROS production for aging in human muscles, we have analyzed mitochondrial properties in muscle fibres isolated from the vastus lateralis of young and elderly donors. Mitochondrial respiratory functions were addressed by high-resolution respirometry, and ROS production was analyzed by in situ staining with the redox-sensitive dye dihydroethidium. We found that aged human skeletal muscles contain fully functional mitochondria and that the level of ROS production is higher in young compared to aged muscle. Accordingly, we could not find any increase in oxidative modification of proteins in muscle from elderly donors. However, the accumulation of lipofuscin was identified as a robust marker of human muscle aging. The data support a model, where ROS-induced molecular damage is continuously removed, preventing the accumulation of dysfunctional mitochondria despite ongoing ROS production.
AB - According to the free radical theory of aging, reactive oxygen species (ROS) act as a driving force of the aging process, and it is generally believed that mitochondrial dysfunction is a major source of increased oxidative stress in tissues with high content of mitochondria, such as muscle or brain. However, recent experiments in mouse models of premature aging have questioned the role of mitochondrial ROS production in premature aging. To address the role of mitochondrial impairment and ROS production for aging in human muscles, we have analyzed mitochondrial properties in muscle fibres isolated from the vastus lateralis of young and elderly donors. Mitochondrial respiratory functions were addressed by high-resolution respirometry, and ROS production was analyzed by in situ staining with the redox-sensitive dye dihydroethidium. We found that aged human skeletal muscles contain fully functional mitochondria and that the level of ROS production is higher in young compared to aged muscle. Accordingly, we could not find any increase in oxidative modification of proteins in muscle from elderly donors. However, the accumulation of lipofuscin was identified as a robust marker of human muscle aging. The data support a model, where ROS-induced molecular damage is continuously removed, preventing the accumulation of dysfunctional mitochondria despite ongoing ROS production.
U2 - 10.1111/j.1474-9726.2007.00282.x
DO - 10.1111/j.1474-9726.2007.00282.x
M3 - Journal article
C2 - 17376148
SN - 1474-9718
VL - 6
SP - 245
EP - 256
JO - Aging Cell
JF - Aging Cell
IS - 2
ER -