Multi-molecular gradients of permissive and inhibitory cues direct neurite outgrowth
Multi-molecular gradients of permissive and inhibitory cues direct neurite outgrowth
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DOI：
10.1007/s10439-008-9486-z
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发表时间：
2008-06-01
影响因子：
3.8
通讯作者：
Hoffman-Kim, Diane
中科院分区：
文献类型：
--
作者：
Li, Grace N.;Liu, Jeffrey;Hoffman-Kim, Diane
神经束的正确发育需要多种允许和抑制信号的协调。通过使用软光刻和微流体技术生成体外微环境，可以以空间限定的方式呈现多个引导线索。在这里，我们评估了背根神经节神经元的神经突如何响应底物结合的分子梯度所提出的允许和抑制线索。含有抑制性硫酸软骨素蛋白聚糖（CSPG）和/或允许性层粘连蛋白-1（LN）的线性梯度被生成为单线索梯度、平行双线索梯度和具有不同斜率的相反双线索梯度。使用循环统计方法分析神经突生长，并且对于检查的所有梯度，神经元向较低CSPG和较高LN浓度的区域延伸神经突。单一线索梯度引起类似的定向神经突生长反应，在较高的浓度测试LN和CSPG，梯度斜率和分数浓度变化影响神经突生长。当这两种截然不同的分子线索同时出现时，神经突的反应会因梯度方向的不同而不同。相反方向的LN-CSPG双梯度上的神经突生长方向性强，而平行方向的LN-CSPG双梯度上的神经突生长均匀。这些结果代表了理解神经突生长如何被包含多种分子线索的复杂微环境引导的重要一步。
Correct development of neuronal tracts requires the coordination of multiple permissive and inhibitory signals. By generating an in vitro microenvironment using soft lithography and microfluidic techniques, multiple guidance cues can be presented in a spatially defined way. Here we evaluated how neurites of dorsal root ganglia neurons responded to permissive and inhibitory cues presented by substrate-bound molecular gradients. Linear gradients containing inhibitory chondroitin sulfate proteoglycan (CSPG) and/or permissive laminin-1 (LN) were generated as single-cue gradients, parallel double-cue gradients, and opposing double-cue gradients with varying slopes. Neurite growth was analyzed using circular statistical methods, and for all gradients examined, neurons extended neurites toward regions of lower CSPG and higher LN concentrations. Single-cue gradients elicited similarly directed neurite growth responses at the higher concentrations tested for both LN and CSPG, and both gradient slope and fractional concentration change affected neurite growth. When the two contrasting molecular cues were presented together, neurites responded differently depending on the directions of the gradients. Neurite growth on LN-CSPG double gradients of opposite direction was strongly directed, while neurite growth on LN-CSPG double gradients of parallel direction was uniform. These results represent an important step toward understanding how neurite growth is guided by complex microenvironments containing multiple molecular cues.