In Vitro Formation of Neuroclusters in Microfluidic Devices and Cell Migration as a Function of Stromal-Derived Growth Factor 1 Gradients (original) (raw)
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Integrative Biology
Harnessing neural stem cells to repair neuronal damage is a promising potential treatment for neuronal diseases. To enable future therapeutic efficacy, the survival, proliferation, migration and differentiation of neural stem/progenitor cells (NPCs) should be accurately studied and optimized in in vitro platforms before transplanting these cells into the body for treatment purposes. Such studies can determine the appropriate quantities of the biochemical and biomechanical factors needed to control and optimize NPC behavior in vivo. In this study, NPCs were cultured within a microfluidic device while being encapsulated within the collagen matrix. The migration and differentiation of NPCs were studied in response to varying concentrations of nerve growth factor (NGF) and within varying densities of collagen matrices. It was shown that the migration and differentiation of NPCs can be significantly improved by providing the appropriate range of NGF concentrations while encapsulating the cells within the collagen matrix of optimal density. In particular, it was observed that within collagen matrices of intermediate density (0.9 mg ml À1), NPCs have a higher ability to migrate farther and in a collective manner while their differentiation into neurons is significantly higher and the cells can form protrusions and connections with their neighboring cells. Within collagen matrices with higher densities (1.8 mg ml À1), the cells did not migrate significantly as compared to the ones within lower matrix densities; within the matrices with lower collagen densities (0.45 mg ml À1) most of the cells migrated in an individual manner. However, no significant differentiation into neurons was observed for these two cases. It was also found that depending on the collagen matrix density, a minimum concentration of NGF caused a collective migration of NPCs, and a minimum concentration gradient of this factor stimulated the directional navigation of the cells. The results of this study can be implemented in designing platforms appropriate for regeneration of damaged neuronal systems. Insight, innovation, integration A quantitative study of neural stem cell (NPC) migration and differentiation within 3D collagen matrices of varying densities is presented. Different patterns and mechanisms of cell migration were observed as a function of matrix density. NPC differentiation was also observed to happen within a specific range of collagen matrix density. A microfluidic platform was designed specifically to culture the shear sensitive NPCs in a static chamber and allow them to migrate in a 3D microenvironment and in response to quantified concentrations of biochemical factors. Using this novel platform, we could determine the mechanism of neural stem cell migration and differentiation in response to a complex interplay of biochemical and biophysical factors.
Developmental dynamics : an official publication of the American Association of Anatomists, 2016
To send meaningful information to the brain, an inner ear cochlear implant (CI) must become closely coupled to as large and healthy a population of remaining Spiral Ganglion Neurons (SGN) as possible. Inner ear gangliogenesis depends on macrophage migration inhibitory factor (MIF), a directionally attractant neurotrophic cytokine made by both Schwann and supporting cells (Bank et al., 2012). MIF-induced mouse embryonic stem cell (mESC)-derived "neurons" could potentially substitute for lost or damaged SGN. mESC-derived "Schwann cells" produce MIF as do all Schwann cells (Huang et al., 2002; Roth et al., 2007, 2008) and could attract SGN to "cell coated" implant. Neuron- and Schwann cell-like cells were produced from a common population of mESC in an ultra-slow flow microfluidic device. As the populations interacted; "neurons" grew over the "Schwann cell" lawn and early events in myelination were documented. Blocking MIF on the Schwan...
Low Concentration Microenvironments Enhance the Migration of Neonatal Cells of Glial Lineage
Cellular and molecular bioengineering, 2012
Glial tumors have demonstrated abilities to sustain growth via recruitment of glial progenitor cells (GPCs), which is believed to be driven by chemotactic cues. Previous studies have illustrated that mouse GPCs of different genetic backgrounds are able to replicate the dispersion pattern seen in the human disease. How GPCs with genetic backgrounds transformed by tumor paracrine signaling respond to extracellular cues via migration is largely unexplored, and remains a limiting factor in utilizing GPCs as therapeutic targets. In this study, we utilized a microfluidic device to examine the chemotaxis of three genetically-altered mouse GPC populations towards tumor conditioned media, as well as towards three growth factors known to initiate the chemotaxis of cells excised from glial tumors: Hepatocyte Growth Factor (HGF), Platelet-Derived Growth Factor-BB (PDGF-BB), and Transforming Growth Factor-α (TGF-α). Our results illustrate that GPC types studied exhibited chemoattraction and chem...
Journal of neuroscience methods, 2015
The developing visual system in Drosophila Melanogaster provides an excellent model with which to examine the effects of changing microenvironments on neural cell migration via microfluidics, because the combined experimental system enables direct genetic manipulation, in vivo observation, and in vitro imaging of cells, post-embryo. Exogenous signaling from ligands such as Fibroblast Growth Factor (FGF) are well-known to control glia differentiation, cell migration, and axonal wrapping central to vision. The current study employs a microfluidic device to examine how controlled concentration gradient fields of FGF are able to regulate the migration of vision-critical glia cells with and without cellular contact with neuronal progenitors. Our findings quantitatively illustrate a concentration-gradient dependent chemotaxis toward FGF, and further demonstrate that glia require collective and coordinated neuronal locomotion to achieve directionality, sustain motility, and propagate long ...
Journal of Neuroscience Research, 2000
Vascular endothelial growth factor (VEGF) is an endothelial and neuronal survival factor and a mitogen for endothelial cells and astrocytes in both explant and in vivo injury models. In the CNS, interplay between the vasculature and neural stem progenitor (NSP) cells is required for the maintenance of angiogenic/neurogenic coordination in the germinal niche in the subventricular zone (SVZ) of the lateral ventricle. Using an in vitro SVZ neurosphere (NS) model, this study aimed to understand the direct effects of VEGF and its receptor signaling on neonatal NSP cell growth and migration. Our data indicate that VEGF administration, compared with untreated or brain-derived neurotrophic factor-treated NS, significantly increased growth and migratory capacity of glial fibrillary acidic protein (GFAP) 1 and nestin 1 NSP cells and in secondary cultures induced a stellate astrocyte morphology. Blockade of both VEGF, which is normally expressed in some NS cells, and its flt-1 receptor signaling by neutralizing antibodies caused morphological changes specifically in GFAP 1 cells and disrupted sphere formation and outward migration. These cells did not appear as conventional polygonal astrocytes; their process growth was severely restricted, and overall migration was reduced by up to 76% of control cultures. Blockade of VEGF's flk-1 receptor reduced VEGF expression and caused a lesser, though significant, decrease (29%) in NSP (GFAP 1 ) cell migration. The results show that both VEGF and, in particular, flt-1 receptor signaling are critical to the proper configuration of the NS and its subsequent development. VEGF is also an important growth and migratory factor particularly for GFAP 1 cells developing in SVZ-derived NS in culture. V V C 2009 Wiley-Liss, Inc.
Application of microfluidic systems for neural differentiation of cells
Precision Nanomedicine
Neural differentiation of stem cells is an important issue in development of central nervous system. Different methods such as chemical stimulation with small molecules, scaffolds, and microRNA can be used for inducing the differentiation of neural stem cells. However, microfluidic systems with the potential to induce neuronal differentiation have established their reputation in the field of regenerative medicine. Organization of microfluidic system represents a novel model that mimic the physiologic microenvironment of cells among other two and three dimensional cell culture systems. Microfluidic system has patterned and well-organized structure that can be combined with other differentiation techniques to provide optimal conditions for neuronal differentiation of stem cells. In this review, different methods for effective differentiation of stem cells to neuronal cells are summarized. The efficacy of microfluidic systems in promoting neuronal differentiation is also addressed.
Experimental Cell Research, 2011
The directed migration of cells towards chemical stimuli incorporates simultaneous changes in both the concentration of a chemotactic agent and its concentration gradient, each of which may influence cell migratory response. In this study, we utilized a microfluidic system to examine the interactions between Epidermal Growth Factor (EGF) concentration and EGF gradient in stimulating the chemotaxis of connective-tissue derived fibroblast cells. Cells seeded within microfluidic devices were exposed to concentration gradients established by EGF concentrations that matched or exceeded those required for maximum chemotactic responses seen in transfilter migration assays. The migration of individual cells within the device was measured optically after steady-state gradients had been experimentally established. Results illustrate that motility was maximal at EGF concentration gradients between .01-and 0.1-ng/(mL.mm) for all concentrations used. In contrast, the numbers of motile cells continually increased with increasing gradient steepness for all concentrations examined. Microfluidics-based experiments exposed cells to minute changes in EGF concentration and gradient that were in line with the acute EGFR phosphorylation measured. Correlation of experimental data with established mathematical models illustrated that the fibroblasts studied exhibit an unreported chemosensitivity to minute changes in EGF concentration, similar to that reported for highly motile cells, such as macrophages. Our results demonstrate that shallow chemotactic gradients, while previously unexplored, are necessary to induce the rate of directed cellular migration and the number of motile cells in the connective tissue-derived cells examined.