Aix-Marseille Univ, CNRS, CRMBM, Marseille, France.
Aix Marseille Univ, Université de Toulon, CNRS, LIS, Marseille, France.
Muscle Nerve. 2020 Mar;61(3):416-424. doi: 10.1002/mus.26798. Epub 2020 Jan 21.
The conditional nebulin knockout mouse is a new model mimicking nemaline myopathy, a rare disease characterized by muscle weakness and rods within muscle fibers. We investigated the impact of nebulin (NEB) deficiency on muscle function in vivo.
Conditional nebulin knockout mice and control littermates were studied at 10 to 12 months. Muscle function (force and fatigue) and anatomy (muscles volume and fat content) were measured in vivo. Myosin heavy chain (MHC) composition and nebulin (NEB) protein expression were assessed by protein electrophoresis.
Conditional nebulin knockout mice displayed a lower NEB level (-90%) leading to a 40% and 45% reduction in specific maximal force production and muscles volume, respectively. Nebulin deficiency was also associated with higher resistance to fatigue and increased MHC I content.
Adult nebulin-deficient mice displayed severe muscle atrophy and weakness in vivo related to a low NEB content but an improved fatigue resistance due to a slower contractile phenotype.
条件性纽蛋白敲除小鼠是一种新的模拟杆状体肌病的模型，杆状体肌病是一种以肌肉无力和肌纤维内出现杆状体为特征的罕见疾病。我们研究了纽蛋白（NEB）缺乏对体内肌肉功能的影响。
在 10 至 12 个月时研究了条件性纽蛋白敲除小鼠和对照同窝仔鼠。通过体内测量肌肉功能（力量和疲劳）和解剖结构（肌肉体积和脂肪含量）来评估。通过蛋白质电泳评估肌球蛋白重链（MHC）组成和纽蛋白（NEB）蛋白表达。
条件性纽蛋白敲除小鼠的 NEB 水平降低了 90%，导致特定最大力产生和肌肉体积分别减少了 40%和 45%。纽蛋白缺乏还与更高的抗疲劳能力和 MHC I 含量增加有关。
成年纽蛋白缺乏型小鼠表现出严重的肌肉萎缩和体内无力，这与 NEB 含量低有关，但由于收缩表型较慢，疲劳抵抗力提高。
