Biological Behavior of Human Nucleus Pulposus Mesenchymal Stem Cells in Response to Changes in the Acidic Environment During Intervertebral Disc Degeneration
Biological Behavior of Human Nucleus Pulposus Mesenchymal Stem Cells in Response to Changes in the Acidic Environment During Intervertebral Disc Degeneration
复制标题
椎间盘退变过程中人髓核间充质干细胞响应酸性环境变化的生物学行为
DOI：
10.1089/scd.2016.0314
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发表时间：
2017-06-15
影响因子：
4
通讯作者：
Shen, Cailiang
中科院分区：
文献类型：
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作者：
Liu, Jianjun;Tao, Hui;Shen, Cailiang
酸性环境对于维持细胞活动至关重要，但在椎间盘退变（IVDD）期间会受到巨大影响。然而，环境酸度变化对人髓核间充质干细胞（NP-MSCs）的影响尚不清楚。因此，本研究旨在观察模拟退变椎间盘的酸性条件对体外NP-MSCs的生物学效应。从腰椎间盘突出症患者中分离NP-MSCs，并通过其免疫表型和多向分化进行进一步鉴定。然后，将细胞在酸性pH水平（pH 6.2、pH 6.5、pH 6.8、pH 7.1和pH 7.4）下在有/没有阿米洛利（酸敏感离子通道（ASIC）阻断剂）的情况下培养。评价NP-MSCs的增殖和凋亡以及NP-MSCs中干细胞相关基因（Oct 4、Nanog、Jagged、Notch 1）、ASIC和功能基因（Aggrecan、SOX-9、Collagen-I和Collagen-II）的表达。我们的工作表明，从人退化NP中获得的细胞符合国际细胞治疗学会的标准。因此，从退变的髓核中获得的细胞被明确鉴定为NP-MSC。我们的研究结果还表明，酸性条件下可以显着抑制细胞增殖和增加细胞凋亡。基因表达结果表明，酸性条件可降低干细胞相关基因的表达，抑制细胞外基质的合成，但可增加ASICs的表达。本研究进一步验证了阿米洛利能显著提高NP-MSCs的上述生物学活性。因此，本研究结果提示酸性环境可抑制NP-MSCs在体外培养过程中的生物学行为，阿米洛利可能通过提高NP-MSCs的活性来改善体外培养过程。
An acidic environment is vital for the maintenance of cellular activities but can be affected tremendously during intervertebral disc degeneration (IVDD). The effect of changes in the acidity of the environment on human nucleus pulposus mesenchymal stem cells (NP-MSCs) is, however, unknown. Thus, this study aimed to observe the biological effects of acidic conditions mimicking a degenerated intervertebral disc on NP-MSCs in vitro. NP-MSCs were isolated from patients with lumbar disc herniation and were further identified by their immunophenotypes and multilineage differentiation. Then, cells were cultured at acidic pH levels (pH 6.2, pH 6.5, pH 6.8, pH 7.1, and pH 7.4) with/without amiloride, an acid-sensing ion channel (ASIC) blocker. The proliferation and apoptosis of NP-MSCs and the expression of stem cell-related genes (Oct4, Nanog, Jagged, Notch1), ASICs, and functional genes (Aggrecan, SOX-9, Collagen-I, and Collagen-II) in NP-MSCs were evaluated. Our work showed that cells obtained from human degenerated NP met the criteria of International Society for Cellular Therapy. Therefore, cells obtained from a degenerated nucleus pulposus were definitively identified as NP-MSCs. Our results also indicated that acidic conditions could significantly inhibit cell proliferation and increase cell apoptosis. Gene expression results demonstrated that acidic conditions could decrease the expression of stem cell-related genes and inhibit extracellular matrix synthesis, whereas it could increase the expression of ASICs. Our study further verified that the above-mentioned biological activities of NP-MSCs could be significantly improved by amiloride. Therefore, the results of the study indicated that the biological behavior of NP-MSCs could be inhibited by acidic conditions during IVDD, and amiloride may meliorate IVDD by improving the activities of NP-MSCs.