Substrate elasticity induces quiescence and promotes neurogenesis of primary neural stem cells-A biophysical in vitro model of the physiological cerebral milieu
Substrate elasticity induces quiescence and promotes neurogenesis of primary neural stem cells-A biophysical in vitro model of the physiological cerebral milieu
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DOI：
10.1002/term.2838
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发表时间：
2019-06-01
影响因子：
3.3
通讯作者：
Rueger, Maria Adele
中科院分区：
文献类型：
--
作者：
Blaschke, Stefan;Vay, Sabine Ulrike;Rueger, Maria Adele
在大脑中，神经干细胞(NSC)受到外部信号和生物物理信号的严格调控，这些信号和生物物理信号是由局部微环境或“生态位”介导的。特别是，已知的从根本上影响体内各种细胞类型的功能的组织弹性对NSC的影响仍然知之甚少。因此，我们的目标是表征弹性底物对临界NSC功能的影响。原代培养的大鼠神经干细胞在聚二甲基硅氧烷(PDMS)凝胶上单层生长。模拟活脑生理微环境的PDMS涂层细胞培养板以不同程度的弹性产生，范围从1到50kpa；此外，还将结果与细胞培养工作中通常使用的常规玻璃板进行了比较。神经干细胞在PDMS基底物上的存活未受影响。与50kPaPMDS相比，1kPaPDMS的增殖率降低了45%(p<；0.05)，而细胞周期蛋白依赖的激酶抑制物1B/p27Kip1的表达增加了一倍以上(p<；0.01)，提示NSC处于静止状态。在较软的基质上，神经干细胞的分化速度加快，并有利于神经元的产生(1kPaPDMS上42%的神经元，50kPaPDMS上25%的神经元；p<；0.05)。在1kPaPDMS上产生的神经元与那些在更硬的PDMS上培养的神经元相比，突起长29%(p<；0.05)，这表明神经元的成熟得到了优化，神经元网络的生成加快了。数据表明，原始NSC受其微环境的力学性质影响很大。将神经干细胞培养在类似大脑的弹性底物上，使其保持在生理、静止状态，并增加其神经生成潜力。
In the brain, neural stem cells (NSC) are tightly regulated by external signals and biophysical cues mediated by the local microenvironment or "niche." In particular, the influence of tissue elasticity, known to fundamentally affect the function of various cell types in the body, on NSC remains poorly understood. We, accordingly, aimed to characterize the effects of elastic substrates on critical NSC functions. Primary rat NSC were grown as monolayers on polydimethylsiloxane- (PDMS-) based gels. PDMS-coated cell culture plates, simulating the physiological microenvironment of the living brain, were generated in various degrees of elasticity, ranging from 1 to 50 kPa; additionally, results were compared with regular glass plates as usually used in cell culture work. Survival of NSC on the PDMS-based substrates was unimpaired. The proliferation rate on 1 kPa PDMS decreased by 45% compared with stiffer PMDS substrates of 50 kPa (p < 0.05) whereas expression of cyclin-dependent kinase inhibitor 1B/p27Kip1 increased more than two fold (p < 0.01), suggesting NSC quiescence. NSC differentiation was accelerated on softer substrates and favored the generation of neurons (42% neurons on 1 kPa PDMS vs. 25% on 50 kPa PDMS; p < 0.05). Neurons generated on 1 kPa PDMS showed 29% longer neurites compared with those on stiffer PDMS substrates (p < 0.05), suggesting optimized neuronal maturation and an accelerated generation of neuronal networks. Data show that primary NSC are significantly affected by the mechanical properties of their microenvironment. Culturing NSC on a substrate of brain-like elasticity keeps them in their physiological, quiescent state and increases their neurogenic potential.