Center of Translational Oral Research (TOR)-Tissue Engineering Group, Department of Clinical Dentistry, Faculty of Medicine, University of Bergen, 5009 Bergen, Norway.
Centre for International Health, University of Bergen, 5009 Bergen, Norway.
Int J Mol Sci. 2021 Dec 15;22(24):13458. doi: 10.3390/ijms222413458.
Oxidative stress from high levels of intracellular reactive oxygen species (ROS) has been linked to various bone diseases. Previous studies indicate that mesenchymal stem cells (MSC) secrete bioactive factors (conditioned medium (MSC-CM)) that have antioxidant effects. However, the antioxidant role of MSC-CM on osteogenesis has not been fully studied. We aimed to identify antioxidant proteins in MSC-CM using mass spectrometry-based proteomics and to explore their effects on osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSC) exposed to oxidative stress induced by hydrogen peroxide (HO). Our analysis revealed that MSC-CM is comprised of antioxidant proteins that are involved in several biological processes, including negative regulation of apoptosis and positive regulation of cell proliferation. Then, hBMSC exposed to HO were treated with MSC-CM, and the effects on their osteogenic differentiation were evaluated. MSC-CM restored HO-induced damage to hBMSC by increasing the antioxidant enzyme-SOD production and the mRNA expression level of the anti-apoptotic BCL-2. A decrease in ROS production and cellular apoptosis was also shown. MSC-CM also modulated mRNA expression levels of osteogenesis-related genes, runt-related transcription factor 2, collagen type I, bone morphogenic protein 2, and osteopontin. Furthermore, collagen type I protein secretion, alkaline phosphatase activity, and in vitro mineralization were increased. These results indicate that MSC-CM contains several proteins with antioxidant and anti-apoptotic properties that restored the impaired hBMSC osteogenic differentiation associated with oxidative stress.
高水平的细胞内活性氧（ROS）引起的氧化应激与各种骨疾病有关。先前的研究表明，间充质干细胞（MSC）分泌具有抗氧化作用的生物活性因子（条件培养基（MSC-CM））。然而，MSC-CM 对成骨作用的抗氧化作用尚未得到充分研究。我们旨在使用基于质谱的蛋白质组学鉴定 MSC-CM 中的抗氧化蛋白，并探讨其对过氧化氢（HO）诱导的氧化应激下人骨髓间充质干细胞（hBMSC）成骨分化的影响。我们的分析表明，MSC-CM 由参与多种生物学过程的抗氧化蛋白组成，包括负向调节细胞凋亡和正向调节细胞增殖。然后，用 MSC-CM 处理暴露于 HO 的 hBMSC，并评估其对成骨分化的影响。MSC-CM 通过增加抗氧化酶-SOD 的产生和抗凋亡 BCL-2 的 mRNA 表达水平，恢复了 HO 诱导的 hBMSC 损伤。还显示 ROS 产生和细胞凋亡减少。MSC-CM 还调节与成骨相关的基因 runt 相关转录因子 2、I 型胶原、骨形态发生蛋白 2 和骨桥蛋白的 mRNA 表达水平。此外，增加了 I 型胶原蛋白分泌、碱性磷酸酶活性和体外矿化。这些结果表明，MSC-CM 含有几种具有抗氧化和抗凋亡特性的蛋白质，可恢复与氧化应激相关的受损 hBMSC 成骨分化。
