Role of extracellular matrix in development of skeletal muscle and postmortem aging of meat
Role of extracellular matrix in development of skeletal muscle and postmortem aging of meat
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DOI：
10.1016/j.meatsci.2015.05.015
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发表时间：
2015-11-01
期刊：
影响因子：
7.1
通讯作者：
Nishimura, Takanori
中科院分区：
文献类型：
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作者：
Nishimura, Takanori
骨骼肌的完整性由肌内结缔组织（IMCT）维持，所述肌内结缔组织（IMCT）由细胞外基质（ECM）分子如胶原、蛋白聚糖和糖蛋白组成。ECM不仅在提供IMCT的生物力学强度方面起重要作用，而且在调节肌细胞行为方面起重要作用。一些ECM分子，如核心蛋白聚糖和层粘连蛋白，调节调节骨骼肌质量的肌生长抑制素的活性。此外，已显示核心蛋白聚糖激活胰岛素样生长因子-I受体（IGF-IR）下游的Akt并增强肌原细胞的分化，表明核心蛋白聚糖充当肌原细胞的信号分子。随着动物的生长，IMCT的结构完整性增加;肌内膜内的胶原纤维彼此更紧密地结合，肌束膜中的胶原纤维变得越来越厚，它们的波浪图案变得更规则。这些变化增加了IMCT的机械强度，有助于肉的增韧。然而，在高度大理石花纹的肉牛，如和牛，肌内脂肪沉积主要在肌纤维束之间的肌束膜在育肥期。脂肪组织的发育似乎打乱了IMCT的结构，并有助于和牛的嫩度。IMCT被认为是相当不变的相比，肌原纤维在宰后老化的肉。然而，一些研究表明，IMCT中的胶原网络被分解，蛋白多糖组分在死后老化过程中降解。ECM的这些变化似乎降低了IMCT的机械强度，并有助于低温下生肉或熟肉的嫩度。因此，ECM在骨骼肌发育和肉的死后老化中起多功能作用。(C)2015爱思唯尔有限公司版权所有。
The integrity of skeletal muscle is maintained by the intramuscular connective tissues (IMCTs) that are composed of extracellular matrix (ECM) molecules such as collagens, proteoglycans, and glycoproteins. The ECM plays an important role not only in providing biomechanical strength of the IMCT, but also in regulating muscle cell behavior. Some ECM molecules, such as decorin and laminin, modulate the activity of myostatin that regulates skeletal muscle mass. Furthermore, it has been shown that decorin activates Akt downstream of insulin-like growth factor-I receptor (IGF-IR) and enhances the differentiation of myogenic cells, suggesting that decorin acts as a signaling molecule to myogenic cells. With animal growth, the structural integrity of IMCT increases; collagen fibrils within the endomysium associate more closely with each other, and the collagen fibers in the perimysium become increasingly thick and their wavy pattern grows more regular. These changes increase the mechanical strength of IMCT, contributing to the toughening of meat. However, in highly marbled beef cattle like Wagyu, intramuscular fat deposits mainly in the perimysium between muscle fiber bundles during the fattening period. The development of adipose tissues appears to disorganize the structure of IMCT and contributes to the tenderness of Wagyu beef. The IMCT was considered to be rather immutable compared to myofibrils during postmortem aging of meat. However, several studies have shown that collagen networks in the IMCT are disintegrated and proteoglycan components are degraded during postmortem aging. These changes in ECM appear to reduce the mechanical strength of IMCT and contribute to the tenderness of uncooked meat or cooked meat at low temperature. Thus, the ECM plays a multifunctional role in skeletal muscle development and postmortem aging of meat. (C) 2015 Elsevier Ltd. All rights reserved.