Adaptive changes in structure of skeletal muscles from adult Sod1 homozygous knockout mice
Adaptive changes in structure of skeletal muscles from adult Sod1 homozygous knockout mice
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DOI：
10.1007/s00441-006-0297-y
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发表时间：
2007-03-01
影响因子：
3.6
通讯作者：
Faulkner, John A.
中科院分区：
文献类型：
--
作者：
Kostrominova, Tatiana Y.;Pasyk, Krystyna A.;Faulkner, John A.
Cu/Zn超氧化物歧化酶（SOD 1）定位于细胞质和线粒体膜间隙中，是对超氧化物自由基清除至关重要的酶。与年龄匹配的野生型同窝小鼠（Sod 1（+/+））相比，SOD 1纯合敲除小鼠（Sod 1（-/-））的体重、心脏和骨骼肌质量以及肌肉横截面积较小。在光学显微镜水平上，Sod 1（-/-）小鼠骨骼肌的横截面未显示出大体结构异常。对Sod 1（-/-）小鼠肌肉进行琥珀酸脱氢酶（SDH）酶活性染色后，观察到一组SDH阳性纤维。Sod 1（-/-）小鼠腓肠肌神经细胞粘附标记物的免疫染色显示了少量萎缩的失神经支配肌纤维。在趾长伸肌（EDL）、胫骨前肌或跖肌中未观察到失神经纤维。在Sod 1（-/-）小鼠的肌肉中检测到肌细胞生成素和乙酰胆碱受体α的mRNA表达水平增加，但MyoD表达没有变化。与Sod 1（+/+）小鼠的EDL肌肉中的快速氧化纤维相比，Sod 1（-/-）小鼠的EDL肌肉中显示肌膜下线粒体的积累增加。我们的结论是，缺乏SOD 1在成年Sod 1（-/-）小鼠不会导致广泛的骨骼肌纤维去神经支配，虽然纤维类型的分布被修改，快速氧化纤维的数量和空间分布的肌膜下线粒体的发展变化。
Cu/Zn superoxide dismutase (SOD1), which is localized cytoplasmically and in the mitochondrial intermembrane space, is an enzyme that is critically important for superoxide free-radical elimination. Compared with age-matched wild-type littermates (Sod1(+/+)), SOD1 homozygous knockout (Sod1(-/-)) mice have smaller body masses, heart and skeletal muscle masses, and muscle cross-sectional areas. At the light-microscopic level, cross sections of skeletal muscles from Sod1(-/-) mice show no gross structural abnormalities. Following the staining of muscles of Sod1(-/-) mice for succinate dehydrogenase (SDH) enzymatic activity, a grouping of SDH-positive fibers has been observed. Immunostaining for neural cell adhesion marker in the gastrocnemius muscle of Sod1(-/-) mice has revealed a small number of atrophic denervated muscle fibers. No denervated fibers are observed in extensor digitorum longus (EDL), tibialis anterior, or plantaris muscles. An increase in mRNA expression levels of myogenin and acetylcholine receptor alpha has been detected in muscles in Sod1(-/-) mice, but no changes in MyoD expression occur. Compared with fast oxidative fibers in EDL muscles of Sod1(+/+) mice, those of Sod1(-/-) mice show increased accumulations of sub-sarcolemmal mitochondria. We conclude that the lack of SOD1 in adult Sod1(-/-) mice does not result in extensive denervation of skeletal muscle fibers, although the distribution of fiber types is modified, and that fast oxidative fibers develop alterations in the amount and spatial distribution of sub-sarcolemmal mitochondria.