Ceci Roberta, Duranti Guglielmo, Leonetti Alessia, Pietropaoli Stefano, Spinozzi Federico, Marcocci Lucia, Amendola Roberto, Cecconi Francesco, Sabatini Stefania, Mariottini Paolo, Cervelli Manuela
Unit of Biology, Genetics and Biochemistry, University of Rome "Foro Italico", Piazza Lauro De Bosis 15, 00135, Rome, Italy.
Department of Sciences, Roma Tre Università, 00146, Rome, Italy.
Free Radic Biol Med. 2017 Feb;103:216-225. doi: 10.1016/j.freeradbiomed.2016.12.040. Epub 2016 Dec 30.
Spermine oxidase oxidizes spermine to produce HO, spermidine, and 3-aminopropanal. It is involved in cell drug response, apoptosis, and in the etiology of several pathologies, including cancer. Spermine oxidase is an important positive regulator of muscle gene expression and fiber size and, when repressed, leads to muscle atrophy. We have generated a transgenic mouse line overexpressing Smox gene in all organs, named Total-Smox. The spermine oxidase overexpression was revealed by β-Gal staining and reverse-transcriptase/PCR analysis, in all tissues analysed. Spermine oxidase activity resulted higher in Total-Smox than controls. Considering the important role of this enzyme in muscle physiology, we have focused our study on skeletal muscle and heart of Total-Smox mice by measuring redox status and oxidative damage. We assessed the redox homeostasis through the analysis of the reduced/oxidized glutathione ratio. Chronic HO production induced by spermine oxidase overexpression leads to a cellular redox state imbalance in both tissues, although they show different redox adaptation. In skeletal muscle, catalase and glutathione S-transferase activities were significantly increased in Total-Smox mice compared to controls. In the heart, no differences were found in CAT activity level, while GST activity decreased compared to controls. The skeletal muscle showed a lower oxidative damage than in the heart, evaluated by lipid peroxidation and protein carbonylation. Altogether, our findings illustrate that skeletal muscle adapts more efficiently than heart to oxidative stress HO-induced. The Total-Smox line is a new genetic model useful to deepen our knowledge on the role of spermine oxidase in muscle atrophy and muscular pathological conditions like dystrophy.
精胺氧化酶将精胺氧化生成过氧化氢、亚精胺和3-氨基丙醛。它参与细胞对药物的反应、细胞凋亡以及包括癌症在内的多种病理状况的病因学过程。精胺氧化酶是肌肉基因表达和纤维大小的重要正向调节因子，当其受到抑制时会导致肌肉萎缩。我们构建了一个在所有器官中过表达Smox基因的转基因小鼠品系，命名为Total-Smox。通过β-半乳糖苷酶染色和逆转录/聚合酶链反应分析，在所有分析的组织中均显示出精胺氧化酶的过表达。Total-Smox小鼠的精胺氧化酶活性高于对照组。鉴于该酶在肌肉生理学中的重要作用，我们通过测量氧化还原状态和氧化损伤，将研究重点放在了Total-Smox小鼠的骨骼肌和心脏上。我们通过分析还原型/氧化型谷胱甘肽比率来评估氧化还原稳态。尽管骨骼肌和心脏表现出不同的氧化还原适应性，但精胺氧化酶过表达诱导的慢性过氧化氢产生会导致这两种组织的细胞氧化还原状态失衡。与对照组相比，Total-Smox小鼠骨骼肌中的过氧化氢酶和谷胱甘肽S-转移酶活性显著增加。在心脏中，过氧化氢酶活性水平未发现差异，而谷胱甘肽S-转移酶活性与对照组相比有所下降。通过脂质过氧化和蛋白质羰基化评估，骨骼肌的氧化损伤低于心脏。总之，我们的研究结果表明，骨骼肌比心脏更能有效地适应由过氧化氢诱导的氧化应激。Total-Smox品系是一种新的遗传模型，有助于加深我们对精胺氧化酶在肌肉萎缩和营养不良等肌肉病理状况中作用的认识。
