Redox Regulation of Canine Embryonic Stem Cells

干细胞的特征在于它们延长细胞分裂的能力和它们分化成多种细胞类型的能力。因此，干细胞有助于在整个生命过程中保持组织功能。有氧代谢，同时使有效的能源生产，也产生活性氧（ROS）。干细胞生物学主要关注ROS的有害影响，包括细胞/组织老化，癌症发展和抗应激修复机制的激活。相比之下，令人兴奋的新数据表明，干细胞的特征实际上是由ROS调节的。 我的NSERC资助的研究计划（自2001年以来一直持续）导致了几种犬胚胎干细胞（cESC）系的新发展。 有趣的是，我们的cESC似乎需要白血病抑制因子（LIF）和碱性成纤维细胞生长因子（bFGF）在其培养基中生存，增殖和维持其干细胞特性-不像小鼠或人类ESC，它们分别只需要LIF或bFGF。表征这些新型犬干细胞的下一个关键步骤是了解ROS如何管理它们的干细胞属性。使用犬胚胎干细胞培养模型，模拟生理低和高氧化条件下，我们将表征氧化还原状态和信号通路，控制犬胚胎干细胞分裂在未分化状态。使用一种新的蛋白质分离技术，我们将确定受ROS水平增加影响的二硫键连接蛋白质的谱，并通过调节ROS水平来提高从犬成纤维细胞生产诱导多能干细胞的效率。 活性氧传感蛋白的鉴定和分析将提供深入了解氧化细胞条件如何影响干细胞功能。对这些研究的支持将使加拿大处于这些新兴生物技术的最前沿，为众多高素质人员（HQP）提供高科技培训，同时增强在犬中实施干细胞疗法的生物医学和商业潜力。

Stem cells are characterized by their capacity for prolong cell division and their ability to differentiate into multiple cell types. As such, stem cells help preserve tissue functions throughout life. Aerobic metabolism, while enabling efficient energy production, also generates reactive oxygen species (ROS). Stem cell biology has primarily focused on the harmful effects of ROS, which include cell/tissue aging, cancer development and activation of anti-stress repair mechanisms. In contrast, exciting new data that we have contributed to generating, indicates that the characteristic traits of stem cells are in fact regulated by ROS. My NSERC funded research program (continuously since 2001) has resulted in the novel development of several canine embryonic stem cell (cESC) lines. Interestingly, our cESCs appear to require both leukemia inhibitory factor (LIF) and basic fibroblast growth factor (bFGF) in their culture medium to survive, proliferate and maintain their stem cell characteristics - unlike mouse or human ESCs, which solely require LIF or bFGF, respectively. The next critical step in characterizing these novel canine stem cells is to understand how ROS govern their stem cell attributes. Using canine embryonic stem cell culture models that mimic physiological low and high oxidative conditions, we will characterize the redox status and signaling pathways that control canine embryonic stem cell division in the undifferentiated state. Using a novel protein separation technique, we will determine the spectrum of disulfide-linked proteins that are affected by increased ROS levels and by modulating the levels of ROS aim to increase the efficiency of producing induced pluripotent stem cells from canine fibroblasts. Identification and analysis of ROS sensing proteins will provide insight into how oxidative cellular conditions influence stem cell functions. Support for these studies will place Canada in the forefront of these emerging biotechnologies, providing high-tech training for numerous highly qualified personnel (HQP) while enhancing the biomedical and commercial potential for implementing stem cell therapies in the dog.**