STUDIES ON PROTEOLYTIC SYSTEM-RELATED GENES IN THE PORCINE MUSCLE ATROPHY

猪肌肉萎缩蛋白水解系统相关基因的研究

• 批准号: 16580233
• 负责人: OHTSUKA Akira
• 金额: $ 1.73万
• 依托单位: Kagoshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16580233/
• 关键词: PORCINE MUSCLE; PROTEIN BERAKDOWN; GLUCOCORTICOID; MYOFIBRIL; ATROGIN-1; ストレスモデル; 遺伝子発現解析

Porcine Stress Syndrome (PSS) is caused by a combined genetic and environmental factor. In generally PSS pig exhibits the pale, soft and exudative meat in which cellular proteolytic systems are induced and activated resulting in accelerated proteolysis. The purpose of this study was to clarify the cellular and molecular mechanism of the muscle abnormality caused by stress hormone, glucocorticoid. [EXP 1] mRNA expression of atrogin-1, a muscle atrophy specific ubiquitin ligase, was investigated in the atrophying muscles from pigs treated with catabolic dose of cortisol (10 or 30 mg/kg/BW). The mRNA expressions of atrogin-1 and GAPDH as an internal marker gene were determined by the real-time quantitative PCR method. Unexpectedly, atrogin-1 mRNA expression was decreased in response to cortisol administration in a dose dependent manner. [EXP 2] Effects of dexamethasone (Dex), insulin-like growth factor 1 (IGF-1), and testosterone on mRNA expression of atrogin-1 in C2C12 myotubes were examined. Dex markedly increased the atrogin-1 expression (7-8-fold of control), on the other hand, IGF-1 and testosterone slightly reduced the increased expression. The rate of protein breakdown evaluated by the release of 3-methlyhisitidine as an index of myofibrillar degradation was significantly increased in the presence of Dex, but not changed in the presence of both of Dex and IGF-1. [EXP 3] Changes in cellular ultrastructure of the mouse muscle atrophies induced by Dex administration (1mg/kgBW/day) or 48h-fasting were investigated by using transmission electron microscope (TEM) and immune TEM with gold-conjugate secondary antibody. The myofibrillar structure was brittle, and the amount of desmin, a structural protein in the M-filament of myofibril, was reduced in the atrophying muscles. These results suggest that argoin-1 plays an important role in the initiation and progression of the muscle atrophies, and IGF-1 is could be used for the treatment of muscle atrophies.

猪应激综合症（PSS）是由遗传和环境因素共同引起的。一般来说，PSS 猪呈现出苍白、柔软和渗出的肉，其中细胞蛋白水解系统被诱导和激活，导致蛋白水解加速。本研究的目的是阐明应激激素、糖皮质激素引起肌肉异常的细胞和分子机制。 [实验 1] 在用分解代谢剂量的皮质醇（10 或 30 mg/kg/BW）处理的猪的萎缩肌肉中研究了 atrogin-1（一种肌肉萎缩特异性泛素连接酶）的 mRNA 表达。采用实时荧光定量PCR法测定内部标记基因atrogin-1和GAPDH mRNA的表达量。出乎意料的是，atrogin-1 mRNA 表达因皮质醇给药而以剂量依赖性方式降低。 [EXP 2] 检查了地塞米松 (Dex)、胰岛素样生长因子 1 (IGF-1) 和睾酮对 C2C12 肌管中 atrogin-1 mRNA 表达的影响。 Dex显着增加了atrogin-1的表达（对照的7-8倍），另一方面，IGF-1和睾酮略微减少了增加的表达。通过作为肌原纤维降解指标的 3-甲基组氨酸的释放来评估的蛋白质分解率在 Dex 存在下显着增加，但在 Dex 和 IGF-1 两者存在下没有变化。 [实验3]使用透射电子显微镜(TEM)和金偶联二抗免疫TEM研究了Dex给药(1mg/kgBW/天)或禁食48小时诱导的小鼠肌肉萎缩细胞超微结构的变化。肌原纤维结构脆弱，萎缩的肌肉中结蛋白（肌原纤维M丝中的一种结构蛋白）的量减少。这些结果表明argoin-1在肌肉萎缩的发生和进展中起重要作用，IGF-1可用于肌肉萎缩的治疗。

项目成果

Pectinase plays an important role in stimulating digestibility of a corn-soybean meal diet in broilers

果胶酶在刺激肉鸡玉米豆粕日粮消化率方面发挥着重要作用

• 发表时间: 2006
• 期刊: Journal of Poultry Science 43・4
• 作者: Tahir;M.;Saleh;F.;Ohtsuka;A.;Hayashi;K.
• 通讯作者: K.