Mitochondria was long thought to be an “end function” organelle that regulated the metabolic flux and apoptosis in the cell. However, with the discovery of the mitochondrial peptide (MDP) humanin (HN/MTRNR2), the cytoprotective and pro-survival applications of MDPs have taken the forefront of therapeutic and diagnostic research. However, the regulation of humanin-like MDPs in natural model systems that can tolerate lethal environmental and cytotoxic insults remains to be investigated. Red-eared sliders are champion anaerobes that can withstand three continuous months of anoxia followed by rapid bouts of oxygen reperfusion without incurring cellular damage. Freshwater turtles employ extensive physiological and biochemical strategies to combat anoxia, with metabolic rate depression and a global enhancement of antioxidant and cytoprotective pathways being the two most important contributors. The main aim of this study was to uncover and characterize the humanin-homologue in freshwater turtles as well as investigate the differential regulation of humanin in response to short and long-term oxygen deprivation. In this study we have used de novo and homology-based protein modelling to elucidate the putative structure of humanin in red-eared sliders as well as an ELISA and western immunoblotting to confirm the protein abundance in the turtle brain and six peripheral tissues during control, 5 h, and 20 h anoxia (n = 4/group). We found that a humanin-homologue (TSE-humanin) is present in red-eared sliders and it may play a cytoprotective role against oxidative damage.

长期以来，线粒体被认为是调节细胞代谢通量和细胞凋亡的“最终功能”细胞器。然而，随着线粒体肽（MDP）人体蛋白（HN / MTRNR2）的发现，MDP的细胞保护和促存活应用已成为治疗和诊断研究的前沿。然而，在自然模型系统中可以耐受致死性环境和细胞毒性损害的类人源蛋白样MDP的调控仍有待研究。红耳滑鼠是最佳的厌氧菌，可以承受连续三个月的缺氧，然后迅速反弹氧气再灌注而不会引起细胞损伤。淡水龟采用广泛的生理和生化策略来对抗缺氧症，代谢率下降，抗氧化剂和细胞保护途径的整体增强是最重要的两个因素。这项研究的主要目的是发现和表征淡水龟中的人源同源物，并研究人源于短期和长期缺氧的人源性激素的差异调节。在这项研究中，我们使用了从头和基于同源性的蛋白质建模方法，阐明了红耳滑子中的人类素的假定结构，并通过ELISA和Western免疫印迹法确认了对照过程中the脑和六个周围组织中的蛋白质丰度， 5小时和20小时缺氧（n = 4 /组）。我们发现在红耳滑子中存在一种人源性同源物（TSE-人源性），它可能对氧化损伤起细胞保护作用。