Upregulation of ubiquitinated proteins and their degradation pathway in muscle atrophy induced by cisplatin in mice
Upregulation of ubiquitinated proteins and their degradation pathway in muscle atrophy induced by cisplatin in mice
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顺铂诱导小鼠肌肉萎缩中泛素化蛋白的上调及其降解途径
DOI：
10.1016/j.taap.2020.115165
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Junzo Kamei
中科院分区：
文献类型：
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作者：
Hiroyasu Sakai;Yohei Ikeno;Yuka Tsukimura;Maya Inomata;Yuta Suzuki;Risako Kon;Nobutomo Ikarashi;Yoshihiko Chiba;Takeshi Yamada;Junzo Kamei
我们以前证明，顺铂给药在小鼠诱导肌肉萎缩和两个肌肉特异性泛素E3连接酶基因，肌肉环指蛋白1（MuRF 1），和萎缩基因-1（atrogin-1），在骨骼肌的表达增加。泛素化在泛素-蛋白酶体途径和选择性自噬途径中都是降解信号。在本研究中，我们研究了泛素和泛素化蛋白的表达及其降解途径的变化。与溶媒组和饮食限制（DR）组相比，顺铂增加了泛素和泛素化蛋白水平。为了定量泛素和泛素化蛋白的水平，我们使用抗泛素抗体进行了斑点印迹分析。与溶媒组和DR组相比，顺铂组泛素的表达也显著增加。由于泛素蛋白被顺铂上调，我们测量了泛素基因Ubb、Ubc、Rps 27 a和Uba 52的mRNA水平。与溶媒组和DR组相比，顺铂组四头肌组织中所有这四种基因均增加。当用顺铂处理C2 C12肌管时，抗泛素抗体敏感条带增加。此外，MG-132（26 s蛋白酶体抑制剂），而不是巴弗洛霉素A1（自噬抑制剂），引起表达的进一步增加。总之，泛素和泛素化蛋白在顺铂诱导的肌肉萎缩中上调。顺铂诱导的泛素化蛋白通过26 s蛋白酶体途径降解。
We previously demonstrated that cisplatin administration in mice induces muscle atrophy and an increase in the expression of two muscle-specific ubiquitin E3 ligase genes, muscle ring finger protein 1 (MuRF1), and atrophy gene-1 (atrogin-1), in skeletal muscle. Ubiquitination serves as a degradation signal in both the ubiquitin-proteasome and selective autophagy pathways. In the present study, we investigated changes in the expression of ubiquitin and ubiquitinated proteins and their degradation pathways. Ubiquitin and ubiquitinated protein levels were increased by cisplatin compared with those in the vehicle and dietary restriction (DR) groups. To quantify the levels of ubiquitin and ubiquitinated proteins, we conducted a dot blot assay using an anti-ubiquitin antibody. The expression of ubiquitin was also significantly increased by cisplatin compared with that in the vehicle and DR groups. Since the ubiquitin proteins were upregulated by cisplatin, we measured the mRNA levels of the ubiquitin genes: Ubb, Ubc, Rps27a, and Uba52. All these four genes were increased by cisplatin administration compared with those in both the vehicle-treated and DR groups in quadriceps muscle tissue. The anti-ubiquitin antibody-sensitive bands increased when C2C12 myotubes were treated with cisplatin. Furthermore, MG-132 (26 s proteasome inhibitor), but not bafilomycin A1 (autophagy inhibitor), caused a further increase in expression. In conclusion, ubiquitin and ubiquitinated proteins are upregulated in cisplatin-induced muscle atrophy. Cisplatin-induced ubiquitinated proteins are degraded by the 26 s proteasome pathway.