Mutation of the IIB myosin heavy chain gene results in muscle fiber loss and compensatory hypertrophy
Mutation of the IIB myosin heavy chain gene results in muscle fiber loss and compensatory hypertrophy
复制标题
DOI：
10.1152/ajpcell.2001.280.3.c637
复制
发表时间：
2001-03-01
影响因子：
5.5
通讯作者：
Leinwand, LA
中科院分区：
文献类型：
--
作者：
Allen, DL;Harrison, BC;Leinwand, LA
快速骨骼肌IIb基因是成年小鼠骨骼肌肌球蛋白重链（MyHC）的主要来源。我们研究了IIb MyHC基因零突变对小鼠骨骼肌生长和形态的影响。在野生型中，一些头部和后肢肌肉的肌肉质量损失与该肌肉中IIb MyHC的表达量相关。细胞质量的减少伴随着平均纤维数量的减少，免疫和超微结构研究显示纤维病理。然而，所有纤维类型的平均横截面积都增加了，表明代偿性肥大。肌肉和体重的减少并不是由于咀嚼功能受损，而且由于软性饮食而减少的食物摄入量并不能阻止体重的减少。因此，主要MyHC异构体的缺失会导致纤维丢失和纤维病理，使人联想到肌肉疾病。
The fast skeletal IIb gene is the source of most myosin heavy chain (MyHC) in adult mouse skeletal muscle. We have examined the effects of a null mutation in the IIb MyHC gene on the growth and morphology of mouse skeletal muscle. Loss in muscle mass of several head and hindlimb muscles correlated with amounts of IIb MyHC expressed in that muscle in wild types. Decreased mass was accompanied by decreases in mean fiber number, and immunological and ultrastructural studies revealed fiber pathology. However, mean cross-sectional area was increased in all fiber types, suggesting compensatory hypertrophy. Loss of muscle and body mass was not attributable to impaired chewing, and decreased food intake as a softer diet did not prevent the decrease in body mass. Thus loss of the major MyHC isoform produces fiber loss and fiber pathology reminiscent of muscle disease.