Serrano Nathan, Buras Matthew R, Roust Lori R, De Filippis Eleanna, Katsanos Christos S
School of Life Sciences, Arizona State University, Tempe, AZ, 85281, USA.
Department of Quantitative Health Sciences, Mayo Clinic Arizona, 85259, Scottsdale, AZ, USA.
Sci Rep. 2025 Aug 16;15(1):30006. doi: 10.1038/s41598-025-15163-w.
Isolating individual muscle fibers and characterizing their myosin heavy chain (MHC) content using SDS-PAGE has become an increasingly common method for describing skeletal muscle fiber type proportions. In this study, we aimed to assess how the number of muscle fibers analyzed, and whether they are characterized in the order of isolation or randomly selected from a larger pool of muscle fibers, affects the precision of fiber type proportion estimates. A total of 170 individual muscle fibers were isolated from vastus lateralis biopsies from each of eight human subjects, and their MHC isoform content was analyzed using SDS-PAGE. To evaluate the precision of fiber type proportion estimates, we employed a resampling approach, varying both the muscle fiber sample size (25, 50, or 100 fibers) and the selection method (ordered vs. random selection). Our results indicate that when analyzing a small number of muscle fibers, precision improves if the fibers are randomly selected from a larger pool rather than characterized in the order they were isolated. These findings have important implications for designing experiments to assess skeletal muscle fiber heterogeneity and its role in health and disease.
使用十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS - PAGE）分离单个肌纤维并表征其肌球蛋白重链（MHC）含量，已成为描述骨骼肌纤维类型比例的一种越来越常见的方法。在本研究中，我们旨在评估所分析的肌纤维数量，以及这些肌纤维是按照分离顺序进行表征还是从更大的肌纤维库中随机选择，如何影响纤维类型比例估计的精度。从八名人类受试者的每一个的股外侧肌活检样本中总共分离出170条单个肌纤维，并使用SDS - PAGE分析其MHC同工型含量。为了评估纤维类型比例估计的精度，我们采用了重采样方法，改变肌纤维样本大小（25、50或100条纤维）和选择方法（有序选择与随机选择）。我们的结果表明，当分析少量肌纤维时，如果从更大的库中随机选择纤维而不是按照分离顺序进行表征，精度会提高。这些发现对于设计评估骨骼肌纤维异质性及其在健康和疾病中的作用的实验具有重要意义。
