线粒体蛋白酪氨酸磷酸酶对骨髓间充质干细胞代谢调控机制的研究

发布时间：2018-06-25 08:37

本文选题：PTPMT1 + 骨髓间充质干细胞　；参考：《兰州大学》2017年博士论文

【摘要】：【背景与目的】线粒体是高动力学细胞器,在细胞多种生命活动中起重要作用。线粒体蛋白酪氨酸磷酸酶1(PTPMT1)是一种新发现的仅存在于线粒体内的PTEN样蛋白酪氨酸磷酸酶,广泛表达于多种组织中,破坏PTPMT1的表达会严重干扰线粒体功能,并引起一系列疾病。骨髓间充质干细胞(MSC)是具有自我更新和多向分化潜能的干细胞,由于MSC具有促进造血及组织修复的能力,使得MSC广泛应用于多种疾病的细胞治疗。然而,我们对于MSC增殖与分化过程中能量代谢及细胞氧化还原状态的变化却知之甚少。因此,本研究旨在明确PTPMT1如何通过影响线粒体的生物生成和底物利用,从而进一步调控MSC的自我更新及分化。【方法】通过基因打靶技术构建PTPMT1完全性敲除或在造血系统中特异性敲除的小鼠,并从小鼠体内纯化培养MSC,检测野生型MSC(WT MSC)和PTPMT1敲除MSC的细胞增殖、凋亡、分化、细胞周期、能量代谢以及细胞内信号转导通路的改变等。【结果】小鼠体内PTPMT1基因完全性敲除导致胚胎发育停滞及着床后死亡。将造血系统中PTPMT1敲除后,小鼠体内干细胞池显著增加。相比于WT MSC,PTPTM1敲除MSC的细胞增殖减慢且向脂肪细胞的分化完全受阻,同时,细胞内周期蛋白依赖性蛋白激酶抑制剂上调以及细胞周期阻滞。进一步的研究表明,PTPMT1敲除MSC的有氧代谢降低,而细胞的糖酵解增加。此外,在应激状态下,PTPMT1敲除的MSC对于丙酮酸的有氧代谢下降,对于氨基酸和脂肪酸的代谢则高于WT MSC。【结论】本研究证实了PTPMT1对于小鼠早期胚胎发育及干细胞的代谢调控具有至关重要的作用。作为线粒体压力介导的检查点,PTPMT1通过调控细胞代谢影响MSC的自我更新与分化。
[Abstract]:Background & objective mitochondria are highly dynamic organelles and play an important role in many cell life activities. Mitochondrial protein tyrosine phosphatase 1 (PTPMT1) is a newly discovered PTEN-like protein tyrosine phosphatase (PTPMT1) which exists only in mitochondria. It is widely expressed in a variety of tissues. Destroying the expression of PTPMT1 will seriously interfere with mitochondrial function and cause a series of diseases. Bone marrow mesenchymal stem cells (MSC) are stem cells with self-renewal and multi-differentiation potential. Because MSC has the ability to promote hematopoiesis and tissue repair, MSC has been widely used in the cell therapy of many diseases. However, little is known about the changes of energy metabolism and cell redox state during MSC proliferation and differentiation. Therefore, the aim of this study was to clarify how PTPMT1 affects mitochondrial biogeneration and substrate utilization. In order to further regulate the self-renewal and differentiation of MSC. [methods] the PTPMT1 knockout or specific knockout mice were constructed by gene targeting technique. MSCs were purified from mice to detect the proliferation, apoptosis, differentiation and cell cycle of wild type MSC (WT MSC) and PTPMT1 knockout MSC. [results] complete knockout of PTPMT1 gene in mice resulted in embryo development stagnation and postimplantation death. After knockout of PTPMT1 in hematopoietic system, the stem cell pool in mice increased significantly. Compared with WT MSCT PTM1 knockout MSC, the proliferation of MSCs was slowed down and the differentiation into adipocytes was completely blocked. At the same time, intracellular cyclin dependent protein kinase inhibitor up-regulated and cell cycle arrest. Further studies showed that the aerobic metabolism of PTPMT1 knockout MSC decreased, while the glycolysis of cells increased. In addition, the aerobic metabolism of pyruvate was decreased by PTPMT1 knockout MSC under stress. The metabolism of amino acids and fatty acids is higher than that of WT MSC.Conclusion PTPMT1 plays an important role in early embryonic development and metabolic regulation of stem cells in mice. PTPMT1, a mitochondrial stress-mediated checkpoint, affects the self-renewal and differentiation of MSC by regulating cell metabolism.
【学位授予单位】：兰州大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R329.2

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