TY - JOUR
T1 - Superoxide dismutase gene expression in skeletal muscle
T2 - Fiber-specific effect of age
AU - Hollander, J.
AU - Bejma, J.
AU - Ookawara, T.
AU - Ohno, H.
AU - Ji, L. L.
PY - 2000/7/10
Y1 - 2000/7/10
N2 - The influence of ageing on the expression of two superoxide dismutase (SOD) isozymes was examined in three different skeletal muscle fiber types of young (Y, 8 mo) and old (O, 25 mo) rats. Total SOD activity was increased with age in the gastrocnemius (Gas, type II(mix)) and superficial vastus lateralis (SVL, type IIb) but unchanged in the soleus (Sol, type I). The increased SOD activity in SVL was due to increased cytosolic SOD (CuZn SOD), whereas both mitochondrial (Mn SOD) and CuZn SOD activities were increased in Gas. In Sol, Mn SOD activity was significantly increased in aged rats. Mn SOD mRNA level was significantly decreased with age in all three muscles examined, while Mn SOD protein content was not altered. Ageing did not affect CuZn SOD mRNA abundance in any of the muscles, but significantly increased CuZn SOD protein content in aged Gas and Sol. Binding of two redox-sensitive transcription factors, nuclear factor-κB (NFκB) and activator protein-1 (AP-1) was significantly decreased with age in all three muscle types. These results indicate that increased SOD activity in aged skeletal muscle is not associated with higher levels of gene transcription. Increases in Mn SOD activity seen in aged Gas and Sol are the result of post-translational modification of the enzyme, whereas increases in CuZn SOD activity during ageing may be due to both translational and post-translational control. Copyright (C) 2000 Elsevier Science Ireland Ltd.
AB - The influence of ageing on the expression of two superoxide dismutase (SOD) isozymes was examined in three different skeletal muscle fiber types of young (Y, 8 mo) and old (O, 25 mo) rats. Total SOD activity was increased with age in the gastrocnemius (Gas, type II(mix)) and superficial vastus lateralis (SVL, type IIb) but unchanged in the soleus (Sol, type I). The increased SOD activity in SVL was due to increased cytosolic SOD (CuZn SOD), whereas both mitochondrial (Mn SOD) and CuZn SOD activities were increased in Gas. In Sol, Mn SOD activity was significantly increased in aged rats. Mn SOD mRNA level was significantly decreased with age in all three muscles examined, while Mn SOD protein content was not altered. Ageing did not affect CuZn SOD mRNA abundance in any of the muscles, but significantly increased CuZn SOD protein content in aged Gas and Sol. Binding of two redox-sensitive transcription factors, nuclear factor-κB (NFκB) and activator protein-1 (AP-1) was significantly decreased with age in all three muscle types. These results indicate that increased SOD activity in aged skeletal muscle is not associated with higher levels of gene transcription. Increases in Mn SOD activity seen in aged Gas and Sol are the result of post-translational modification of the enzyme, whereas increases in CuZn SOD activity during ageing may be due to both translational and post-translational control. Copyright (C) 2000 Elsevier Science Ireland Ltd.
KW - Activator protein-1 (AP-1)
KW - Ageing
KW - Gene expression
KW - Nuclear factor-κB (NFκB)
KW - Skeletal muscle
KW - Superoxide dismutase
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U2 - 10.1016/S0047-6374(00)00130-5
DO - 10.1016/S0047-6374(00)00130-5
M3 - Article
C2 - 10936506
AN - SCOPUS:0034631756
VL - 116
SP - 33
EP - 45
JO - Mechanisms of Ageing and Development
JF - Mechanisms of Ageing and Development
SN - 0047-6374
IS - 1
ER -