Predicting myosin heavy chain isoform from postdissection fiber length in human skeletal muscle fibers.
Predicting myosin heavy chain isoform from postdissection fiber length in human skeletal muscle fibers.
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根据人体骨骼肌纤维的解剖后纤维长度预测肌球蛋白重链亚型。
DOI：
10.1152/ajpcell.00700.2023
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发表时间：
2024
期刊：
影响因子：
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通讯作者：
Callahan,DamienM
中科院分区：
文献类型：
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作者：
Privett,GraceE;Ricci,AustinW;Ortiz-Delatorre,Julissa;Callahan,DamienM
在单个人骨骼肌细胞中的实验技术需要手动解剖。与其他哺乳动物物种不同，人类骨骼肌的特征在于肌球蛋白重链（MHC）亚型的异质混合物，通常用于定义“纤维类型”，这深刻影响细胞功能。因此，在解剖时预测MHC亚型是有益的，有助于从潜在不平衡的样品中获得更平衡的纤维型分布。尽管进行单纤维解剖的研究人员报告了基于解剖时纤维的机械性能预测纤维类型，但尚未对这种方法进行严格的检查。因此，我们在解剖后立即测量了单根纤维的归一化纤维长度（表示为纤维被解剖的纤维束长度的%）。从健康的年轻成年人的肌肉组织样本中解剖出668个单独的纤维，以评估这种特征是否可以区分含有MHC I的纤维（“慢”纤维类型）或不含MHC I的纤维（“快”纤维类型）。使用受试者操作特征（ROC）曲线，我们发现标准化纤维长度的差异（114 ± 13%，MHC I; 124 ± 17%，MHC IIA，P< 0.01）可用于预测纤维类型，具有良好的可靠性（曲线下面积= 0.72）。我们将这些分析扩展到包括老年人（2名女性，1名男性），以证明这种方法在可能具有不同形态和机械特性的纤维中的耐久性。我们报告说，MHC亚型表达在人类骨骼肌纤维可以预测在解剖时，无论origin.NEW & NOTEWORTHYA先验估计肌球蛋白重链（MHC）亚型在个别肌纤维可能会偏向相对丰富的纤维类型在随后的评估。到目前为止，还没有提出标准化的评估方法来表征纤维在解剖时。我们展示了一种基于归一化纤维长度的方法，该方法可能会显着地使样品偏向慢收缩（MHC I）或快收缩（非MHC I）纤维群体。
Experimental techniques in single human skeletal muscle cells require manual dissection. Unlike other mammalian species, human skeletal muscle is characterized by a heterogeneous mixture of myosin heavy chain (MHC) isoforms, typically used to define “fiber type,” which profoundly influences cellular function. Therefore, it is beneficial to predict MHC isoform at the time of dissection, facilitating a more balanced fiber-type distribution from a potentially imbalanced sample. Although researchers performing single fiber dissection report predicting fiber-type based on mechanical properties of fibers upon dissection, a rigorous examination of this approach has not been performed. Therefore, we measured normalized fiber length (expressed as a % of the length of the bundle from which the fiber was dissected) in single fibers immediately following dissection. Six hundred sixty-eight individual fibers were dissected from muscle tissue samples from healthy, young adults to assess whether this characteristic could differentiate fibers containing MHC I (“slow” fiber type) or not (“fast” fiber type). Using receiver operator characteristic (ROC) curves, we found that differences in normalized fiber length (114 ± 13%, MHC I; 124 ± 17%, MHC IIA,P< 0.01) could be used to predict fiber type with excellent reliability (area under the curve = 0.72). We extended these analyses to include older adults (2 females, 1 male) to demonstrate the durability of this approach in fibers with likely different morphology and mechanical characteristics. We report that MHC isoform expression in human skeletal muscle fibers can be predicted at the time of dissection, regardless of origin.NEW & NOTEWORTHYA priori estimation of myosin heavy chain (MHC) isoform in individual muscle fibers may bias the relative abundance of fiber types in subsequent assessment. Until now, no standardized assessment approach has been proposed to characterize fibers at the time of dissection. We demonstrate an approach based on normalized fiber length that may dramatically bias a sample toward slow twitch (MHC I) or fast twitch (not MHC I) fiber populations.