Localized gene expression of axon guidance molecules in neuronal co-cultures

Heron, Paula; Sutton, Brandon; Curinga, Gabrielle; Smith, George M.; Snow, Diane

doi:10.1016/j.jneumeth.2006.07.013

Cited by 14 publications

(16 citation statements)

References 56 publications

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“…Neurons do not attach well to surfaces coated with brevican and do not extend axons toward a surface containing this chondroitin sulfate proteoglycan (53,54). In vivo, brevican is expressed around the boundaries of the rostral migratory stream (55) and is a major up-regulated component of the glial scar after neural injury (56,57), limiting axonal extension and probably limiting neuroblast and astrocyte motility (53,55).…”

Section: Discussionmentioning

confidence: 99%

The Proteoglycan Brevican Binds to Fibronectin after Proteolytic Cleavage and Promotes Glioma Cell Motility

Kong

Matthews

et al. 2008

Journal of Biological Chemistry

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The adult neural parenchyma contains a distinctive extracellular matrix that acts as a barrier to cell and neurite motility. Nonneural tumors that metastasize to the central nervous system almost never infiltrate it and instead displace the neural tissue as they grow. In contrast, invasive gliomas disrupt the extracellular matrix and disperse within the neural tissue. A major inhibitory component of the neural matrix is the lectican family of chondroitin sulfate proteoglycans, of which brevican is the most abundant member in the adult brain. Interestingly, brevican is also highly up-regulated in gliomas and promotes glioma dispersion by unknown mechanisms. Here we show that brevican secreted by glioma cells enhances cell adhesion and motility only after proteolytic cleavage. At the molecular level, brevican promotes epidermal growth factor receptor activation, increases the expression of cell adhesion molecules, and promotes the secretion of fibronectin and accumulation of fibronectin microfibrils on the cell surface. Moreover, the N-terminal cleavage product of brevican, but not the full-length protein, associates with fibronectin in cultured cells and in surgical samples of glioma. Taken together, our results provide the first evidence of the cellular and molecular mechanisms that may underlie the motility-promoting role of brevican in primary brain tumors. In addition, these results underscore the important functional implications of brevican processing in glioma progression.Malignant gliomas are primary tumors of the central nervous system with an almost invariably rapid and lethal outcome. Current treatments for gliomas fail to remove the invasive cells that remain diffusely embedded within normal tissue even after aggressive surgical and postsurgical treatment (1). The dispersion of glioma cells is the major cause of disease progression after initial treatment and, therefore, of therapeutic failure.The ability of glioma cells to disperse within the mature central nervous system is unusual, because adult neural tissue is predominantly inhibitory to process extension and cell movement (2, 3). One of the major barriers to cellular movement in the central nervous system is the neural extracellular matrix (ECM).2 This matrix is primarily composed of a scaffold of hyaluronic acid (HA) and associated glycoproteins, with a remarkable absence of fibrillar proteins that support cell motility (2, 4). The inhibitory nature of the neural ECM has been largely attributed to a family of chondroitin sulfate proteoglycans that bind and organize HA within the ECM: aggrecan, neurocan, versican, and brevican, collectively known as lecticans (5-7). It is thought that, to overcome this barrier to movement, glioma cells degrade the normal ECM (8, 9) and secrete mesenchymal matrix components that promote cell adhesion and motility, such as fibronectin and collagens (10 -13). However, surprisingly, gliomas also express large amounts of the inhibitory lecticans versican (14) and brevican (15, 16).Brevican, also known as brain-enrich...

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Section: Discussionmentioning

confidence: 99%

The Proteoglycan Brevican Binds to Fibronectin after Proteolytic Cleavage and Promotes Glioma Cell Motility

Kong

Matthews

et al. 2008

Journal of Biological Chemistry

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“…As an alternative to manipulating cell adhesion, the deposition of the vector can be controlled. The spatially controlled deposition of gene therapy vectors can be achieved by several methods, such as spotting, printing, microfluidics, or pinning (i.e., the aqueous vector solution wets the hydrophilic but not hydrophobic region) [151][152][153][154][155][156]. The deposition procedure must retain vector activity, while the vector-material interactions must maintain the vector locally.…”

Section: Spatially Patterned Gene Deliverymentioning

confidence: 99%

“…Spatially controlled binding of gene vectors and transgene expression was achieved, resulting in directed neurite outgrowth [155,156]. Patterned stripes of vectors in widths as small as 100 $m were achieved using microfluidic deposition [156], resulting in transfection of cells only within the pattern, with different pattern widths requiring varying amounts of DNA to achieve maximal transfection.…”

Section: Spatially Patterned Gene Deliverymentioning

confidence: 99%

“…Neuron survival was observed primarily within the pattern, and the extending neurites remained within the pattern. Adenovirus has been similarly been patterned onto surfaces, with patterned expression of brevican inducing neurite extension between, and not within, the brevican-rich regions [155].…”

Section: Spatially Patterned Gene Deliverymentioning

confidence: 99%

“…NGF, brainderived neurotrophic factor (BDNF), and netrins have all been implicated as chemoattractants that direct neurite extension in different neuronal networks for the central and peripheral nervous systems [168][169][170][171]. Manipulating the location of transfected cells secreting diffusible factors and their level of transgene expression, or creating gradients of transfected cells [155] can be employed to create and control concentration gradients [155,156]. The ability to effectively create, control, and maintain concentration gradients in vitro and in vivo is still under development, and could provide a valuable tool to guide progenitor cell differentiation and organize tissue formation.…”

Section: Concentration Gradientsmentioning

confidence: 99%

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Matrices and scaffolds for DNA delivery in tissue engineering

Laporte¹,

Shea²

2007

Advanced Drug Delivery Reviews

240

208

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Regenerative medicine aims to create functional tissue replacements, typically through creating a controlled environment that promotes and directs the differentiation of stem or progenitor cells, either endogenous or transplanted. Scaffolds serve a central role in many strategies by providing the means to control the local environment. Gene delivery from the scaffold represents a versatile approach to manipulating the local environment for directing cell function. Research at the interface of biomaterials, gene therapy, and drug delivery has identified several design parameters for the vector and the biomaterial scaffold that must be satisfied. Progress has been made towards achieving gene delivery within a tissue engineering scaffold, though the design principles for the materials and vectors that produce efficient delivery require further development. Nevertheless, these advances in obtaining transgene expression with the scaffold have created opportunities to develop greater control of either delivery or expression and to identify the best practices for promoting tissue formation. Strategies to achieve controlled localized expression within the tissue engineering scaffold will have broad application to the regeneration of many tissues, with great promise for clinical therapies.

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Spatially patterned gene expression for guided neurite extension

Houchin-Ray

Huang

West

et al. 2008

J of Neuroscience Research

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Axon pathfinding by localized expression of guidance molecules is critical for the proper development of the nervous system. In this report, we present a well-defined spatially patterned gene expression system to investigate neurite guidance in vitro. Nonviral gene delivery was patterned by combining substrate-mediated gene delivery with soft lithography techniques, and the amount of protein produced at the region of localized expression was varied by altering the vector concentration and the width of the pattern, highlighting the flexibility of the system. A neuronal coculture model was used to investigate responses to spatial patterns of nerve growth factor (NGF) expression. The soluble NGF gradient elicited a guidance cue, and the degree of guidance was governed by the distance a neuron was cultured from the pattern and the time between accessory cell and neuron seedings. A portion of the diffusible NGF bound to the culture surface in the extracellular space, and the surface-associated NGF supported neuron survival and neurite outgrowth. However, the surfacebound NGF gradient alone did not elicit a guidance signal, and in fact masked the guidance cue by soluble NGF gradients. Mathematical modeling of NGF diffusion was used to predict the concentration gradients, and both the absolute and fractional gradients capable of guiding neurites produced by patterned gene expression differed substantially from the values obtained with existing engineered protein gradients. Spatially patterned gene expression provides a versatile tool to investigate the factors that may promote neurite guidance.

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Localized gene expression of axon guidance molecules in neuronal co-cultures

Cited by 14 publications

References 56 publications

The Proteoglycan Brevican Binds to Fibronectin after Proteolytic Cleavage and Promotes Glioma Cell Motility

The Proteoglycan Brevican Binds to Fibronectin after Proteolytic Cleavage and Promotes Glioma Cell Motility

Matrices and scaffolds for DNA delivery in tissue engineering

Spatially patterned gene expression for guided neurite extension

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