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Rike WA, Stern S. Proteins and Transcriptional Dysregulation of the Brain Extracellular Matrix in Parkinson's Disease: A Systematic Review. Int J Mol Sci 2023; 24:ijms24087435. [PMID: 37108598 PMCID: PMC10138539 DOI: 10.3390/ijms24087435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/06/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023] Open
Abstract
The extracellular matrix (ECM) of the brain is a dynamic structure made up of a vast network of bioactive macromolecules that modulate cellular events. Structural, organizational, and functional changes in these macromolecules due to genetic variation or environmental stressors are thought to affect cellular functions and may result in disease. However, most mechanistic studies to date usually focus on the cellular aspects of diseases and pay less attention to the relevance of the processes governing the dynamic nature of the extracellular matrix in disease pathogenesis. Thus, due to the ECM's diversified biological roles, increasing interest in its involvement in disease, and the lack of sufficient compiled evidence regarding its relationship with Parkinson's disease (PD) pathology, we aimed to compile the existing evidence to boost the current knowledge on the area and provide refined guidance for the future research. Here, in this review, we gathered postmortem brain tissue and induced pluripotent stem cell (iPSC)-related studies from PubMed and Google Scholar to identify, summarize and describe common macromolecular alterations in the expression of brain ECM components in Parkinson's disease (PD). A literature search was conducted up until 10 February 2023. The overall hits from the database and manual search for proteomic and transcriptome studies were 1243 and 1041 articles, respectively. Following a full-text review, 10 articles from proteomic and 24 from transcriptomic studies were found to be eligible for inclusion. According to proteomic studies, proteins such as collagens, fibronectin, annexins, and tenascins were recognized to be differentially expressed in Parkinson's disease. Transcriptomic studies displayed dysregulated pathways including ECM-receptor interaction, focal adhesion, and cell adhesion molecules in Parkinson's disease. A limited number of relevant studies were accessed from our search, indicating that much work remains to be carried out to better understand the roles of the ECM in neurodegeneration and Parkinson's disease. However, we believe that our review will elicit focused primary studies and thus support the ongoing efforts of the discovery and development of diagnostic biomarkers as well as therapeutic agents for Parkinson's disease.
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Affiliation(s)
- Wote Amelo Rike
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel
| | - Shani Stern
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel
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2
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Yu X, Wang L, He W. Cytophilic Agarose-Epoxide-Amine Cryogels Engineered with Granulated Microstructures. ACS APPLIED BIO MATERIALS 2023; 6:694-702. [PMID: 36695539 DOI: 10.1021/acsabm.2c00938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Inherent cytophobicity of agarose limits its direct use for the growth of anchorage-dependent cells. Here, we report a simple strategy allowing the development of agarose-based hydrogels entailed with both cytophilicity and microstructured morphology. Through the reaction of water-soluble 1,4-butanediol diglycidyl ether (BDDE) with trifunctional polyetheramine Jeffamine T403 in agarose solution followed by cryogelation of the mixtures, a series of macroporous agarose-epoxide-amine cryogels were prepared readily. Results from fluorescent labeling and energy-dispersive X-ray elemental mapping showed the formation of granulated microstructures in the cryogels. Such features closely correlated to the phase separation of BDDE-T403 polymers within the agarose matrix. Cytophilicity of the microstructured cryogels due to the integrated amine moieties was demonstrated through the adhesion of fibroblasts. Functional enrichment of the cryogels was further highlighted by leveraging the granulates as micro-reservoirs for polyphenol proanthocyanidin to enable antioxidation and protection of fibroblasts from H2O2-induced cytotoxic effect in vitro.
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Affiliation(s)
- Xueying Yu
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, Liaoning116024, China.,School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning116024, China
| | - Liwei Wang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, Liaoning116024, China.,School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning116024, China
| | - Wei He
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, Liaoning116024, China.,School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning116024, China
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3
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Samanipour R, Tahmooressi H, Rezaei Nejad H, Hirano M, Shin SR, Hoorfar M. A review on 3D printing functional brain model. BIOMICROFLUIDICS 2022; 16:011501. [PMID: 35145569 PMCID: PMC8816519 DOI: 10.1063/5.0074631] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 12/31/2021] [Indexed: 05/08/2023]
Abstract
Modern neuroscience increasingly relies on 3D models to study neural circuitry, nerve regeneration, and neural disease. Several different biofabrication approaches have been explored to create 3D neural tissue model structures. Among them, 3D bioprinting has shown to have great potential to emerge as a high-throughput/high precision biofabrication strategy that can address the growing need for 3D neural models. Here, we have reviewed the design principles for neural tissue engineering. The main challenge to adapt printing technologies for biofabrication of neural tissue models is the development of neural bioink, i.e., a biomaterial with printability and gelation properties and also suitable for neural tissue culture. This review shines light on a vast range of biomaterials as well as the fundamentals of 3D neural tissue printing. Also, advances in 3D bioprinting technologies are reviewed especially for bioprinted neural models. Finally, the techniques used to evaluate the fabricated 2D and 3D neural models are discussed and compared in terms of feasibility and functionality.
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Affiliation(s)
| | - Hamed Tahmooressi
- Department of Mechanical Engineering, University of British Columbia, Kelowna, British Columbia V1V 1V7, Canada
| | - Hojatollah Rezaei Nejad
- Department of Electrical and Computer Engineering, Tufts University, 161 College Avenue, Medford, Massachusetts 02155, USA
| | | | - Su-Royn Shin
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02139, USA
- Authors to whom correspondence should be addressed: and
| | - Mina Hoorfar
- Faculty of Engineering, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
- Authors to whom correspondence should be addressed: and
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4
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Middendorf JM, Ita ME, Winkelstein BA, H Barocas V. Local tissue heterogeneity may modulate neuronal responses via altered axon strain fields: insights about innervated joint capsules from a computational model. Biomech Model Mechanobiol 2021; 20:2269-2285. [PMID: 34514531 PMCID: PMC9289994 DOI: 10.1007/s10237-021-01506-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/12/2021] [Indexed: 02/08/2023]
Abstract
In innervated collagenous tissues, tissue scale loading may contribute to joint pain by transmitting force through collagen fibers to the embedded mechanosensitive axons. However, the highly heterogeneous collagen structures of native tissues make understanding this relationship challenging. Recently, collagen gels with embedded axons were stretched and the resulting axon signals were measured, but these experiments were unable to measure the local axon strain fields. Computational discrete fiber network models can directly determine axon strain fields due to tissue scale loading. Therefore, this study used a discrete fiber network model to identify how heterogeneous collagen networks (networks with multiple collagen fiber densities) change axon strain due to tissue scale loading. In this model, a composite cylinder (axon) was embedded in a Delaunay network (collagen). Homogeneous networks with a single collagen volume fraction and two types of heterogeneous networks with either a sparse center or dense center were created. Measurements of fiber forces show higher magnitude forces in sparse regions of heterogeneous networks and uniform force distributions in homogeneous networks. The average axon strain in the sparse center networks decreases when compared to homogeneous networks with similar collagen volume fractions. In dense center networks, the average axon strain increases compared to homogeneous networks. The top 1% of axon strains are unaffected by network heterogeneity. Based on these results, the interaction of tissue scale loading, collagen network heterogeneity, and axon strains in native musculoskeletal tissues should be considered when investigating the source of joint pain.
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Affiliation(s)
- Jill M Middendorf
- Department of Biomedical Engineering, College of Science and Engineering, University of Minnesota, Nils Hasselmo Hall, 312 Church St SE, Minneapolis, MN, USA
| | - Meagan E Ita
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Beth A Winkelstein
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Victor H Barocas
- Department of Biomedical Engineering, College of Science and Engineering, University of Minnesota, Nils Hasselmo Hall, 312 Church St SE, Minneapolis, MN, USA.
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5
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Keating CE, Browne KD, Cullen DK. Dietary manipulation of vulnerability to traumatic brain injury-induced neuronal plasma membrane permeability. Exp Neurol 2021; 340:113649. [PMID: 33600812 DOI: 10.1016/j.expneurol.2021.113649] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/22/2021] [Accepted: 02/12/2021] [Indexed: 01/22/2023]
Abstract
Traumatic brain injury (TBI) can produce physical disruptions in the plasma membranes of neurons, referred to as mechanoporation, which lead to increased cell permeability. We suspect that such trauma-induced membrane disruptions may be influenced by the physical properties of the plasma membrane, such as elasticity or rigidity. These membrane properties are influenced by lipid composition, which can be modulated via diet, leading to the intriguing possibility of prophylactically altering diet to confer resiliency to this mechanism of acute neuronal damage in TBI. In this proof-of-concept study, we used three different diets-one high in polyunsaturated fatty acids suggested to increase elasticity (Fish Oil), one high in saturated fatty acids and cholesterol suggested to increase rigidity (High Fat), and one standard rat chow (Control)-to alter brain plasma membrane lipid composition before subjecting rats to lateral fluid percussion injury (FPI). Lipid analysis (n = 12 rats) confirmed that diets altered brain fatty acid composition after 4 weeks of feeding, with the Fish Oil diet increasing unsaturated fatty acids, and interestingly, the High Fat diet increasing omega-6 docosapentaenoic acid. One cohort of animals (n = 34 rats) was assessed immediately after FPI or sham injury for acute changes in neuronal membrane permeability in the injury-adjacent cortex. Surprisingly, sham animals fed Fish Oil had increased membrane permeability, suggesting altered passive membrane properties. In contrast, injured animals fed the High Fat diet displayed less intense uptake of permeability marker, suggesting a reduced extent of injury-induced plasma membrane disruption, although the density of affected cells matched the other diet groups. In a separate cohort survived for 7 days after FPI (n = 48 rats), animals fed the High Fat diet exhibited a reduced lesion area. At both time points there were no statistically significant differences in inflammation. Unexpectedly, these results indicate that the High Fat diet, as opposed to the Fish Oil diet, beneficially modulated acute plasma membrane permeability and resulted in a smaller lesion size at 7 days post-injury. Additional studies are necessary to determine the impact of these various diets on behavioral outcomes post-TBI. Further investigation is also needed to understand the physical properties in neuronal plasma membranes that may underlie increased resiliency to trauma-induced disruptions and, importantly, to understand how these properties may be influenced by targeted dietary modifications for vulnerable populations.
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Affiliation(s)
- Carolyn E Keating
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, 19104, USA.
| | - Kevin D Browne
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, 19104, USA.
| | - D Kacy Cullen
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, 19104, USA.
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6
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Keating CE, Cullen DK. Mechanosensation in traumatic brain injury. Neurobiol Dis 2020; 148:105210. [PMID: 33259894 DOI: 10.1016/j.nbd.2020.105210] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/10/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) is distinct from other neurological disorders because it is induced by a discrete event that applies extreme mechanical forces to the brain. This review describes how the brain senses, integrates, and responds to forces under both normal conditions and during injury. The response to forces is influenced by the unique mechanical properties of brain tissue, which differ by region, cell type, and sub-cellular structure. Elements such as the extracellular matrix, plasma membrane, transmembrane receptors, and cytoskeleton influence its properties. These same components also act as force-sensors, allowing neurons and glia to respond to their physical environment and maintain homeostasis. However, when applied forces become too large, as in TBI, these components may respond in an aberrant manner or structurally fail, resulting in unique pathological sequelae. This so-called "pathological mechanosensation" represents a spectrum of cellular responses, which vary depending on the overall biomechanical parameters of the injury and may be compounded by repetitive injuries. Such aberrant physical responses and/or damage to cells along with the resulting secondary injury cascades can ultimately lead to long-term cellular dysfunction and degeneration, often resulting in persistent deficits. Indeed, pathological mechanosensation not only directly initiates secondary injury cascades, but this post-physical damage environment provides the context in which these cascades unfold. Collectively, these points underscore the need to use experimental models that accurately replicate the biomechanics of TBI in humans. Understanding cellular responses in context with injury biomechanics may uncover therapeutic targets addressing various facets of trauma-specific sequelae.
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Affiliation(s)
- Carolyn E Keating
- Department of Neurosurgery, Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, USA
| | - D Kacy Cullen
- Department of Neurosurgery, Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, USA.
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7
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Bobo J, Garg A, Venkatraman P, Puthenveedu M, LeDuc PR. 3D In Vitro Neuron on a Chip for Probing Calcium Mechanostimulation. ACTA ACUST UNITED AC 2020; 4:e2000080. [PMID: 32875741 DOI: 10.1002/adbi.202000080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 08/05/2020] [Indexed: 12/13/2022]
Abstract
The evolution of tissue on a chip systems holds promise for mimicking the response of biological functionality of physiological systems. One important direction for tissue on a chip approaches are neuron-based systems that could mimic neurological responses and lessen the need for in vivo experimentation. For neural research, more attention has been devoted recently to understanding mechanics due to issues in areas such as traumatic brain injury (TBI) and pain, among others. To begin to address these areas, a 3D Nerve Integrated Tissue on a Chip (NITC) approach combined with a Mechanical Excitation Testbed (MET) System is developed to impose external mechanical stimulation toward more realistic physiological environments. PC12 cells differentiated with nerve growth factor, which were cultured in a controlled 3D scaffolds, are used. The cells are labeled in a 3D NITC system with Fluo-4-AM to examine their calcium response under mechanical stimulation synchronized with image capture. Understanding the neural responses to mechanical stimulation beyond 2D systems is very important for neurological studies and future personalized strategies. This work will have implications in a diversity of areas including tissue-on-a-chip systems, biomaterials, and neuromechanics.
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Affiliation(s)
- Justin Bobo
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA
| | - Akash Garg
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA
| | - Prahatha Venkatraman
- Department of Pharmacology, University of Michigan, 1150 W Medical Center Dr, Ann Arbor, MI, 48109, USA
| | - Manoj Puthenveedu
- Department of Pharmacology, University of Michigan, 1150 W Medical Center Dr, Ann Arbor, MI, 48109, USA
| | - Philip R LeDuc
- Department of Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA.,Department of Biological Sciences, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA, 15213, USA
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8
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Rouleau N, Murugan NJ, Rusk W, Koester C, Kaplan DL. Matrix Deformation with Ectopic Cells Induced by Rotational Motion in Bioengineered Neural Tissues. Ann Biomed Eng 2020; 48:2192-2203. [PMID: 32671625 PMCID: PMC7405955 DOI: 10.1007/s10439-020-02561-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 06/29/2020] [Indexed: 11/30/2022]
Abstract
The brain's extracellular matrix (ECM) is a dynamic protein-based scaffold within which neural networks can form, self-maintain, and re-model. When the brain incurs injuries, microscopic tissue tears and active ECM re-modelling give way to abnormal brain structure and function including the presence of ectopic cells. Post-mortem and neuroimaging data suggest that the brains of jet pilots and astronauts, who are exposed to rotational forces, accelerations, and microgravity, display brain anomalies which could be indicative of a mechanodisruptive pathology. Here we present a model of non-impact-based brain injury induced by matrix deformation following mechanical shaking. Using a bioengineered 3D neural tissue platform, we designed a repetitive shaking paradigm to simulate subtle rotational acceleration. Our results indicate shaking induced ectopic cell clustering that could be inhibited by physically restraining tissue movement. Imaging revealed that the collagen substrate surrounding cells was deformed following shaking. Applied to neonatal rat brains, shaking induced deformation of extracellular spaces within the cerebral cortices and reduced the number of cell bodies at higher accelerations. We hypothesize that ECM deformation may represent a more significant role in brain injury progression than previously assumed and that the present model system contributes to its understanding as a phenomenon.
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Affiliation(s)
- Nicolas Rouleau
- Department of Biomedical Engineering, Science & Technology Center, Tufts University, Medford, MA, USA
- Initiative for Neural Science, Disease, and Engineering (INSciDE), Tufts University, Medford, USA
- The Allen Discovery Center, Tufts University, Medford, USA
| | - Nirosha J Murugan
- Department of Biomedical Engineering, Science & Technology Center, Tufts University, Medford, MA, USA
- The Allen Discovery Center, Tufts University, Medford, USA
- Department of Biology, Tufts University, Medford, USA
| | - William Rusk
- Department of Biomedical Engineering, Science & Technology Center, Tufts University, Medford, MA, USA
| | - Cole Koester
- Department of Biomedical Engineering, Science & Technology Center, Tufts University, Medford, MA, USA
| | - David L Kaplan
- Department of Biomedical Engineering, Science & Technology Center, Tufts University, Medford, MA, USA.
- Initiative for Neural Science, Disease, and Engineering (INSciDE), Tufts University, Medford, USA.
- The Allen Discovery Center, Tufts University, Medford, USA.
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Belousov A, Titov S, Shved N, Malykin G, Kovalev V, Suprunova I, Khotimchenko Y, Kumeiko V. Hydrogels based on modified pectins capable of modulating neural cell behavior as prospective biomaterials in glioblastoma treatment. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2020; 151:111-138. [PMID: 32448603 DOI: 10.1016/bs.irn.2020.03.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Glioblastoma is the most common malignant tumor of the brain, but its treatment outcomes can be improved by new therapeutic techniques using biocompatible materials. Utilizing controllable alkaline de-esterification we obtained pectin preparation with 27.4% esterification degree and used it for bio-artificial matrix production. We discovered optimal gelation conditions in the presence of Ca2+ by the analysis of visco-elastic properties of the gels and produced a series of biomaterials in hydrogel forms. Hydrogels based on low-esterified pectin significantly slow down the metabolism of C6 glioma cells and neural stem cells (NSCs) and slightly decrease the viability of the C6 glioma, but not of NSCs. This happens due to a decrease in cell proliferation rate, while apoptosis degrees remain stable or negligibly decrease. We created a set of pectin hydrogels supplemented with different ratios of two ECM proteins-collagens I and IV. We have shown that the formation of cell processes in glioma C6 can be regulated by varying the ratio of two ECM proteins in gels used for 3D cell cultivation. Thus, composite matrix materials obtained can be used for modeling brain tumor invasion. The results presented suggest that modified pectins supplemented with two collagen types may serve as prospective biomaterials for glioblastoma treatment due to their ability to regulate glioma cell dynamics.
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Affiliation(s)
- Andrei Belousov
- School of Biomedicine, Far Eastern Federal University, Vladivostok, Russia
| | - Sergei Titov
- School of Biomedicine, Far Eastern Federal University, Vladivostok, Russia
| | - Nikita Shved
- School of Biomedicine, Far Eastern Federal University, Vladivostok, Russia; A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russia
| | - Grigorii Malykin
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russia
| | - Valeri Kovalev
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russia
| | - Irina Suprunova
- School of Biomedicine, Far Eastern Federal University, Vladivostok, Russia
| | - Yuri Khotimchenko
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russia; Department of Fundamental Medicine, School of Biomedicine, Far Eastern Federal University, Vladivostok, Russia
| | - Vadim Kumeiko
- School of Biomedicine, Far Eastern Federal University, Vladivostok, Russia; A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russia.
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10
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Cambria E, Brunner S, Heusser S, Fisch P, Hitzl W, Ferguson SJ, Wuertz-Kozak K. Cell-Laden Agarose-Collagen Composite Hydrogels for Mechanotransduction Studies. Front Bioeng Biotechnol 2020; 8:346. [PMID: 32373605 PMCID: PMC7186378 DOI: 10.3389/fbioe.2020.00346] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/30/2020] [Indexed: 12/12/2022] Open
Abstract
The increasing investigation of cellular mechanotransduction mechanisms requires biomaterials combining biofunctionality and suitable mechanical properties. Agarose is a standard biomaterial for cartilage and intervertebral disc mechanobiology studies, but lacks adhesion motifs and the necessary cell-matrix interaction for mechanotransduction. Here, collagen type I was blended at two concentrations (2 and 4.5 mg/mL) with agarose 2% wt/vol. The composite hydrogels were characterized in terms of structural homogeneity, rheological properties and size stability. Nucleus pulposus (NP) cell viability, proliferation, morphology, gene expression, GAG production, adhesion and mechanotransduction ability were further tested. Blended hydrogels presented a homogenous network of the two polymers. While the addition of 4.5 mg/mL collagen significantly decreased the storage modulus and increased the loss modulus of the gels, blended gels containing 2 mg/mL collagen displayed similar mechanical properties to agarose. Hydrogel size was conserved over 21 days for all agarose-based gels. Embedded cells were viable (>80%) and presented reduced proliferation and a round morphology typical of NP cells in vivo. Gene expression of collagen types I and II and aggrecan significantly increased in blended hydrogels from day 1 to 7, further resulting in a significantly superior GAG/DNA ratio compared to agarose gels at day 7. Agarose-collagen hydrogels not only promoted cell adhesion, contrary to agarose gels, but also showed a 5.36-fold higher focal adhesion kinase phosphorylation (pFAK/β-tubulin) when not compressed, and increased pFAK/FAK values 10 min after compression. Agarose-collagen thus outperforms agarose, mimics native tissues constituted of non-fibrillar matrix and collagens, and allows exploring complex loading in a highly reproducible system.
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Affiliation(s)
- Elena Cambria
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Silvio Brunner
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Sally Heusser
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Philipp Fisch
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Wolfgang Hitzl
- Research Office (Biostatistics), Paracelsus Medical University, Salzburg, Austria.,Department of Ophthalmology and Optometry, Paracelsus Medical University, Salzburg, Austria.,Research Program Experimental Ophthalmology and Glaucoma Research, Paracelsus Medical University, Salzburg, Austria
| | | | - Karin Wuertz-Kozak
- Institute for Biomechanics, ETH Zurich, Zurich, Switzerland.,Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, United States.,Spine Center, Schön Klinik München Harlaching, Academic Teaching Hospital and Spine Research Institute of the Paracelsus Private Medical University Salzburg (Austria), Munich, Germany
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11
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Dravid A, Raos B, Aqrawe Z, Parittotokkaporn S, O'Carroll SJ, Svirskis D. A Macroscopic Diffusion-Based Gradient Generator to Establish Concentration Gradients of Soluble Molecules Within Hydrogel Scaffolds for Cell Culture. Front Chem 2019; 7:638. [PMID: 31620430 PMCID: PMC6759698 DOI: 10.3389/fchem.2019.00638] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/04/2019] [Indexed: 01/28/2023] Open
Abstract
Concentration gradients of soluble molecules are ubiquitous within the living body and known to govern a number of key biological processes. This has motivated the development of numerous in vitro gradient-generators allowing researchers to study cellular response in a precise, controlled environment. Despite this, there remains a current paucity of simplistic, convenient devices capable of generating biologically relevant concentration gradients for cell culture assays. Here, we present the design and fabrication of a compartmentalized polydimethylsiloxane diffusion-based gradient generator capable of sustaining concentration gradients of soluble molecules within thick (5 mm) and thin (2 mm) agarose and agarose-collagen co-gel matrices. The presence of collagen within the agarose-collagen co-gel increased the mechanical properties of the gel. Our model molecules sodium fluorescein (376 Da) and FITC-Dextran (10 kDa) quickly established a concentration gradient that was maintained out to 96 h, with 24 hourly replenishment of the source and sink reservoirs. FITC-Dextran (40 kDa) took longer to establish in all hydrogel setups. The steepness of gradients generated are within appropriate range to elicit response in certain cell types. The compatibility of our platform with cell culture was demonstrated using a LIVE/DEAD® assay on terminally differentiated SH-SY5Y neurons. We believe this device presents as a convenient and useful tool that can be easily adopted for study of cellular response in gradient-based assays.
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Affiliation(s)
- Anusha Dravid
- Faculty of Medical and Health Sciences, School of Pharmacy, University of Auckland, Auckland, New Zealand
| | - Brad Raos
- Faculty of Medical and Health Sciences, School of Pharmacy, University of Auckland, Auckland, New Zealand
| | - Zaid Aqrawe
- Faculty of Medical and Health Sciences, School of Pharmacy, University of Auckland, Auckland, New Zealand
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Sam Parittotokkaporn
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Simon J. O'Carroll
- Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Darren Svirskis
- Faculty of Medical and Health Sciences, School of Pharmacy, University of Auckland, Auckland, New Zealand
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12
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Ita ME, Winkelstein BA. Concentration-Dependent Effects of Fibroblast-Like Synoviocytes on Collagen Gel Multiscale Biomechanics and Neuronal Signaling: Implications for Modeling Human Ligamentous Tissues. J Biomech Eng 2019; 141:091013. [PMID: 31209465 PMCID: PMC6808009 DOI: 10.1115/1.4044051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 06/12/2019] [Indexed: 12/13/2022]
Abstract
Abnormal loading of a joint's ligamentous capsule causes pain by activating the capsule's nociceptive afferent fibers, which reside in the capsule's collagenous matrix alongside fibroblast-like synoviocytes (FLS) and transmit pain to the dorsal root ganglia (DRG). This study integrated FLS into a DRG-collagen gel model to better mimic the anatomy and physiology of human joint capsules; using this new model, the effect of FLS on multiscale biomechanics and cell physiology under load was investigated. Primary FLS cells were co-cultured with DRGs at low or high concentrations, to simulate variable anatomical FLS densities, and failed in tension. Given their roles in collagen degradation and nociception, matrix-metalloproteinase (MMP-1) and neuronal expression of the neurotransmitter substance P were probed after gel failure. The amount of FLS did not alter (p > 0.3) the gel failure force, displacement, or stiffness. FLS doubled regional strains at both low (p < 0.01) and high (p = 0.01) concentrations. For high FLS, the collagen network showed more reorganization at failure (p < 0.01). Although total MMP-1 and neuronal substance P were the same regardless of FLS concentration before loading, protein expression of both increased after failure, but only in low FLS gels (p ≤ 0.02). The concentration-dependent effect of FLS on microstructure and cellular responses implies that capsule regions with different FLS densities experience variable microenvironments. This study presents a novel DRG-FLS co-culture collagen gel system that provides a platform for investigating the complex biomechanics and physiology of human joint capsules, and is the first relating DRG and FLS interactions between each other and their surrounding collagen network.
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Affiliation(s)
- Meagan E Ita
- Department of Bioengineering,University of Pennsylvania,240 Skirkanich Hall, 210 South 33rd Street,Philadelphia, PA 19104e-mail:
| | - Beth A Winkelstein
- Mem. ASMEDepartment of Bioengineering,University of Pennsylvania, 240 Skirkanich Hall, 210 South 33rd Street,Philadelphia, PA 19104
- Department of Neurosurgery,University of Pennsylvania,240 Skirkanich Hall, 210 South 33rd Street,Philadelphia, PA 19104e-mail:
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13
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Mobini S, Song YH, McCrary MW, Schmidt CE. Advances in ex vivo models and lab-on-a-chip devices for neural tissue engineering. Biomaterials 2019; 198:146-166. [PMID: 29880219 PMCID: PMC6957334 DOI: 10.1016/j.biomaterials.2018.05.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/25/2018] [Accepted: 05/07/2018] [Indexed: 02/08/2023]
Abstract
The technologies related to ex vivo models and lab-on-a-chip devices for studying the regeneration of brain, spinal cord, and peripheral nerve tissues are essential tools for neural tissue engineering and regenerative medicine research. The need for ex vivo systems, lab-on-a-chip technologies and disease models for neural tissue engineering applications are emerging to overcome the shortages and drawbacks of traditional in vitro systems and animal models. Ex vivo models have evolved from traditional 2D cell culture models to 3D tissue-engineered scaffold systems, bioreactors, and recently organoid test beds. In addition to ex vivo model systems, we discuss lab-on-a-chip devices and technologies specifically for neural tissue engineering applications. Finally, we review current commercial products that mimic diseased and normal neural tissues, and discuss the future directions in this field.
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Affiliation(s)
- Sahba Mobini
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Young Hye Song
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Michaela W McCrary
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Christine E Schmidt
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
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14
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Khoshakhlagh P, Bowser DA, Brown JQ, Moore MJ. Comparison of visible and UVA phototoxicity in neural culture systems micropatterned with digital projection photolithography. J Biomed Mater Res A 2018; 107:134-144. [PMID: 30358101 DOI: 10.1002/jbm.a.36540] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/02/2018] [Accepted: 08/16/2018] [Indexed: 01/12/2023]
Abstract
Photopolymerization provides a favorable method for hydrogel formation due to its simplicity, convenience, and versatility. However, the light exposure required to initiate photopolymerization is known to have a cytotoxic effect on encapsulated cells. Here, a 3D in vitro model of the nervous system microenvironment, micropatterned through the use of digital projection photolithography using a single hydrogel formulation that cross-links similarly under ultraviolet A (UVA, 315-400 nm) and visible light (400-700 nm) exposure, is presented. This setup allowed for the investigation of neuronal responses to different light wavelengths and exposure times during photoencapsulation, while ruling out effects due to the hydrogel formulation or photoinitiators used. Cellular studies-including neurite viability, DNA fragmentation, and neurite outgrowth for both UVA and visible light irradiation, the most common spectra used in biological photomicropatterning applications-were performed to assess the effect of light source on neuronal cultures. These studies indicated that while cell death occurs after exposure to either spectrum, visible light was less phototoxic than UVA, when using comparable levels of irradiation, and interestingly, glial cells were more susceptible to phototoxicity than neuronal cells. Thus, while utilizing visible light for micropatterning and cell encapsulation for nervous system applications is beneficial, it is helpful to keep the light exposure low to ensure optimal neuronal survival and growth. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 134-144, 2019.
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Affiliation(s)
| | - Devon A Bowser
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana.,Bioinnovation Program, Tulane University, New Orleans, Louisiana
| | - J Quincy Brown
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana
| | - Michael J Moore
- Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana.,Tulane Brain Institute, Tulane University, New Orleans, Louisiana.,AxoSim Inc., New Orleans, Louisiana
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15
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Regional variations in stiffness in live mouse brain tissue determined by depth-controlled indentation mapping. Sci Rep 2018; 8:12517. [PMID: 30131608 PMCID: PMC6104037 DOI: 10.1038/s41598-018-31035-y] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 08/10/2018] [Indexed: 11/08/2022] Open
Abstract
The mechanical properties of brain tissue play a pivotal role in neurodevelopment and neurological disorders. Yet, at present, there is no consensus on how the different structural parts of the tissue contribute to its stiffness variations. Here, we have gathered depth-controlled indentation viscoelasticity maps of the hippocampus of acute horizontal live mouse brain slices. Our results confirm the highly viscoelestic nature of brain tissue. We further show that the mechanical properties are non-uniform and at least related to differences in morphological composition. Interestingly, areas with higher nuclear density appear to be softer than areas with lower nuclear density.
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16
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Paiva I, Jain G, Lázaro DF, Jerčić KG, Hentrich T, Kerimoglu C, Pinho R, Szegő ÈM, Burkhardt S, Capece V, Halder R, Islam R, Xylaki M, Caldi Gomes LA, Roser AE, Lingor P, Schulze-Hentrich JM, Borovečki F, Fischer A, Outeiro TF. Alpha-synuclein deregulates the expression of COL4A2 and impairs ER-Golgi function. Neurobiol Dis 2018; 119:121-135. [PMID: 30092270 DOI: 10.1016/j.nbd.2018.08.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/12/2018] [Accepted: 08/03/2018] [Indexed: 12/21/2022] Open
Abstract
Alpha-synuclein (aSyn) is the major protein component of Lewy bodies and Lewy neurites, the typical pathological hallmarks in Parkinson's disease (PD) and Dementia with Lewy bodies. aSyn is capable of inducing transcriptional deregulation, but the precise effect of specific aSyn mutants associated with familial forms of PD, remains unclear. Here, we used transgenic mice overexpressing human wild-type (WT) or A30P aSyn to compare the transcriptional profiles of the two animal models. We found that A30P aSyn promotes strong transcriptional deregulation and increases DNA binding. Interestingly, COL4A2, a major component of basement membranes, was found to be upregulated in both A30P aSyn transgenic mice and in dopaminergic neurons expressing A30P aSyn, suggesting a crucial role for collagen related genes in aSyn-induced toxicity. Finally, we observed that A30P aSyn alters Golgi morphology and increases the susceptibility to endoplasmic reticulum (ER) stress in dopaminergic cells. In total, our findings provide novel insight into the putative role of aSyn on transcription and on the molecular mechanisms involved, thereby opening novel avenues for future therapeutic interventions in PD and other synucleinopathies.
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Affiliation(s)
- Isabel Paiva
- Department of Experimental Neurodegeneration, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen 37073, Germany
| | - Gaurav Jain
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Diana F Lázaro
- Department of Experimental Neurodegeneration, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen 37073, Germany
| | - Kristina Gotovac Jerčić
- Department for Functional Genomics, Center for Translational and Clinical Research, University Hospital Center Zagreb, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Thomas Hentrich
- Institute of Medical Genetics and Applied Genomics, Faculty of Medicine, University of Tübingen, Tübingen 72076, Germany
| | - Cemil Kerimoglu
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany; Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Raquel Pinho
- Department of Experimental Neurodegeneration, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen 37073, Germany
| | - Èva M Szegő
- Department of Experimental Neurodegeneration, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen 37073, Germany
| | - Susanne Burkhardt
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Vincenzo Capece
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Rashi Halder
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Rezaul Islam
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany
| | - Mary Xylaki
- Department of Experimental Neurodegeneration, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen 37073, Germany
| | - Lucas A Caldi Gomes
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Anna-Elisa Roser
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Paul Lingor
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Julia M Schulze-Hentrich
- Institute of Medical Genetics and Applied Genomics, Faculty of Medicine, University of Tübingen, Tübingen 72076, Germany
| | - Fran Borovečki
- Department for Functional Genomics, Center for Translational and Clinical Research, University Hospital Center Zagreb, University of Zagreb School of Medicine, Zagreb, Croatia
| | - André Fischer
- Department for Epigenetics and Systems Medicine in Neurodegenerative Diseases, German Center for Neurodegenerative Diseases (DZNE) Göttingen, Göttingen, Germany; Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Tiago F Outeiro
- Department of Experimental Neurodegeneration, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen 37073, Germany; CEDOC - Chronic Diseases Research Center, Faculdade de Ciencias Medicas, Universidade Nova de Lisboa, Lisboa, Portugal; Max Planck Institute for Experimental Medicine, Göttingen 37075, Germany; Institute of Neuroscience, The Medical School, Newcastle University, Framlington Place, Newcastle NE2 4HH, UK.
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17
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Zarei V, Zhang S, Winkelstein BA, Barocas VH. Tissue loading and microstructure regulate the deformation of embedded nerve fibres: predictions from single-scale and multiscale simulations. J R Soc Interface 2018; 14:rsif.2017.0326. [PMID: 28978743 DOI: 10.1098/rsif.2017.0326] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 09/11/2017] [Indexed: 12/16/2022] Open
Abstract
Excessive deformation of nerve fibres (axons) in the spinal facet capsular ligaments (FCLs) can be a cause of pain. The axons are embedded in the fibrous extracellular matrix (ECM) of FCLs, so understanding how local fibre organization and micromechanics modulate their mechanical behaviour is essential. We constructed a computational discrete-fibre model of an axon embedded in a collagen fibre network attached to the axon by distinct fibre-axon connections. This model was used to relate the axonal deformation to the fibre alignment and collagen volume concentration of the surrounding network during transverse, axial and shear deformations. Our results showed that fibre alignment affects axonal deformation only during transverse and axial loading, but higher collagen volume concentration results in larger overall axonal strains for all loading cases. Furthermore, axial loading leads to the largest stretch of axonal microtubules and induces the largest forces on axon's surface in most cases. Comparison between this model and a multiscale continuum model for a representative case showed that although both models predicted similar averaged axonal strains, strain was more heterogeneous in the discrete-fibre model.
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Affiliation(s)
- Vahhab Zarei
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sijia Zhang
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104-6321, USA
| | - Beth A Winkelstein
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104-6321, USA
| | - Victor H Barocas
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
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18
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Serruya MD, Harris JP, Adewole DO, Struzyna LA, Burrell JC, Nemes A, Petrov D, Kraft RH, Chen HI, Wolf JA, Cullen DK. Engineered Axonal Tracts as "Living Electrodes" for Synaptic-Based Modulation of Neural Circuitry. ADVANCED FUNCTIONAL MATERIALS 2018; 28:1701183. [PMID: 34045935 PMCID: PMC8152180 DOI: 10.1002/adfm.201701183] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Brain-computer interface and neuromodulation strategies relying on penetrating non-organic electrodes/optrodes are limited by an inflammatory foreign body response that ultimately diminishes performance. A novel "biohybrid" strategy is advanced, whereby living neurons, biomaterials, and microelectrode/optical technology are used together to provide a biologically-based vehicle to probe and modulate nervous-system activity. Microtissue engineering techniques are employed to create axon-based "living electrodes", which are columnar microstructures comprised of neuronal population(s) projecting long axonal tracts within the lumen of a hydrogel designed to chaperone delivery into the brain. Upon microinjection, the axonal segment penetrates to prescribed depth for synaptic integration with local host neurons, with the perikaryal segment remaining externalized below conforming electrical-optical arrays. In this paradigm, only the biological component ultimately remains in the brain, potentially attenuating a chronic foreign-body response. Axon-based living electrodes are constructed using multiple neuronal subtypes, each with differential capacity to stimulate, inhibit, and/or modulate neural circuitry based on specificity uniquely afforded by synaptic integration, yet ultimately computer controlled by optical/electrical components on the brain surface. Current efforts are assessing the efficacy of this biohybrid interface for targeted, synaptic-based neuromodulation, and the specificity, spatial density and long-term fidelity versus conventional microelectronic or optical substrates alone.
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Affiliation(s)
- Mijail D Serruya
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - James P Harris
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - Dayo O Adewole
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA; Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Laura A Struzyna
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA; Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Justin C Burrell
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - Ashley Nemes
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - Dmitriy Petrov
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - Reuben H Kraft
- Computational Biomechanics Group, Department of Mechanical & Nuclear Engineering, Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16801, USA
| | - H Isaac Chen
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - John A Wolf
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
| | - D Kacy Cullen
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA 19104, USA
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19
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Zhang S, Zarei V, Winkelstein BA, Barocas VH. Multiscale mechanics of the cervical facet capsular ligament, with particular emphasis on anomalous fiber realignment prior to tissue failure. Biomech Model Mechanobiol 2018; 17:133-145. [PMID: 28821971 PMCID: PMC5809183 DOI: 10.1007/s10237-017-0949-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 08/04/2017] [Indexed: 12/11/2022]
Abstract
The facet capsular ligaments encapsulate the bilateral spinal facet joints and are common sources of painful injury due to afferent innervation. These ligaments exhibit architectural complexity, which is suspected to contribute to the experimentally observed lack of co-localization between macroscopic strain and microstructural tissue damage. The heterogeneous and multiscale nature of this ligament, combined with challenges in experimentally measuring its microscale mechanics, hinders the ability to understand sensory mechanisms under normal or injurious loading. Therefore, image-based, subject-specific, multiscale finite-element models were constructed to predict the mechanical responses of the human cervical facet capsular ligament under uniaxial tensile stretch. The models precisely simulated the force-displacement responses for all samples ([Formula: see text]) and showed promise in predicting the magnitude and location of peak regional strains at two different displacements. Yet, there was a loss of agreement between the model and experiment in terms of fiber organization at large tissue stretch, possibly due to a lack of accounting for tissue failure. The mean fiber stretch ratio predicted by the models was found to be significantly higher in regions that exhibited anomalous fiber realignment experimentally than in regions with normal realignment ([Formula: see text]). The development of microstructural abnormalities was associated with the predicted fiber-level stretch ([Formula: see text]), but not with the elemental maximum principal stress or maximum principal strain by logistic regression. The multiscale models elucidate a potential mechanical basis for predicting injury-prone tissue domains and for defining the relationships between macroscopic ligament stretch and microscale pathophysiology in the subfailure regime.
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Affiliation(s)
- Sijia Zhang
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Vahhab Zarei
- Department of Mechanical Engineering, University of Minnesota - Twin Cities, Minneapolis, MN, 55455, USA
| | - Beth A Winkelstein
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Victor H Barocas
- Department of Biomedical Engineering, University of Minnesota - Twin Cities, Minneapolis, MN, 55455, USA.
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20
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Katiyar KS, Winter CC, Gordián-Vélez WJ, O'Donnell JC, Song YJ, Hernandez NS, Struzyna LA, Cullen DK. Three-dimensional Tissue Engineered Aligned Astrocyte Networks to Recapitulate Developmental Mechanisms and Facilitate Nervous System Regeneration. J Vis Exp 2018. [PMID: 29364269 DOI: 10.3791/55848] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to replace lost neurons and regenerate axonal pathways. However, during nervous system development, neuronal migration and axonal extension often occur along pathways formed by other cells, referred to as "living scaffolds". Seeking to emulate these mechanisms and to design a strategy that circumvents the inhibitory environment of the CNS, this manuscript presents a protocol to fabricate tissue engineered astrocyte-based "living scaffolds". To create these constructs, we employed a novel biomaterial encasement scheme to induce astrocytes to self-assemble into dense three-dimensional bundles of bipolar longitudinally-aligned somata and processes. First, hollow hydrogel micro-columns were assembled, and the inner lumen was coated with collagen extracellular-matrix. Dissociated cerebral cortical astrocytes were then delivered into the lumen of the cylindrical micro-column and, at a critical inner diameter of <350 µm, spontaneously self-aligned and contracted to produce long fiber-like cables consisting of dense bundles of astrocyte processes and collagen fibrils measuring <150 µm in diameter yet extending several cm in length. These engineered living scaffolds exhibited >97% cell viability and were virtually exclusively comprised of astrocytes expressing a combination of the intermediate filament proteins glial-fibrillary acidic protein (GFAP), vimentin, and nestin. These aligned astrocyte networks were found to provide a permissive substrate for neuronal attachment and aligned neurite extension. Moreover, these constructs maintain integrity and alignment when extracted from the hydrogel encasement, making them suitable for CNS implantation. These preformed constructs structurally emulate key cytoarchitectural elements of naturally occurring glial-based "living scaffolds" in vivo. As such, these engineered living scaffolds may serve as test-beds to study neurodevelopmental mechanisms in vitro or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding following CNS degeneration in vivo.
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Affiliation(s)
- Kritika S Katiyar
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center; School of Biomedical Engineering, Drexel University
| | - Carla C Winter
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center; Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania
| | - Wisberty J Gordián-Vélez
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center; Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania
| | - John C O'Donnell
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center
| | - Yeri J Song
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Neuroscience Graduate Group, Perelman School of Medicine, University of Pennsylvania
| | - Nicole S Hernandez
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Neuroscience Graduate Group, Perelman School of Medicine, University of Pennsylvania
| | - Laura A Struzyna
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center; Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania
| | - D Kacy Cullen
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center; Neuroscience Graduate Group, Perelman School of Medicine, University of Pennsylvania;
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21
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Wan Q, TruongVo T, Steele HE, Ozcelikkale A, Han B, Wang Y, Oh J, Yokota H, Na S. Subcellular domain-dependent molecular hierarchy of SFK and FAK in mechanotransduction and cytokine signaling. Sci Rep 2017; 7:9033. [PMID: 28831165 PMCID: PMC5567257 DOI: 10.1038/s41598-017-09495-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/26/2017] [Indexed: 01/23/2023] Open
Abstract
Focal adhesion kinase (FAK) and Src family kinases (SFK) are known to play critical roles in mechanotransduction and other crucial cell functions. Recent reports indicate that they reside in different microdomains of the plasma membrane. However, little is known about their subcellular domain-dependent roles and responses to extracellular stimuli. Here, we employed fluorescence resonance energy transfer (FRET)-based biosensors in conjunction with collagen-coupled agarose gels to detect subcellular activities of SFK and FAK in three-dimensional (3D) settings. We observed that SFK and FAK in the lipid rafts and nonrafts are differently regulated by fluid flow and pro-inflammatory cytokines. Inhibition of FAK in the lipid rafts blocked SFK response to fluid flow, while inhibition of SFK in the non-rafts blocked FAK activation by the cytokines. Ex-vivo FRET imaging of mouse cartilage explants showed that intermediate level of interstitial fluid flow selectively decreased cytokine-induced SFK/FAK activation. These findings suggest that SFK and FAK exert distinctive molecular hierarchy depending on their subcellular location and extracellular stimuli.
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Affiliation(s)
- Qiaoqiao Wan
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, 46202, USA
- School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, 47907, USA
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - ThucNhi TruongVo
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, 46202, USA
| | - Hannah E Steele
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, 46202, USA
| | - Altug Ozcelikkale
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, 47907, USA
| | - Bumsoo Han
- School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, 47907, USA
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, 47907, USA
| | - Yingxiao Wang
- Department of Bioengineering, University of California San Diego, La Jolla, California, 92093, USA
| | - Junghwan Oh
- Department of Biomedical Engineering, Pukyong National University, Busan, 48513, Republic of Korea
| | - Hiroki Yokota
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, 46202, USA
- School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, 47907, USA
| | - Sungsoo Na
- Department of Biomedical Engineering, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, 46202, USA.
- School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, 47907, USA.
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Struzyna LA, Adewole DO, Gordián-Vélez WJ, Grovola MR, Burrell JC, Katiyar KS, Petrov D, Harris JP, Cullen DK. Anatomically Inspired Three-dimensional Micro-tissue Engineered Neural Networks for Nervous System Reconstruction, Modulation, and Modeling. J Vis Exp 2017. [PMID: 28605376 DOI: 10.3791/55609] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Functional recovery rarely occurs following injury or disease-induced degeneration within the central nervous system (CNS) due to the inhibitory environment and the limited capacity for neurogenesis. We are developing a strategy to simultaneously address neuronal and axonal pathway loss within the damaged CNS. This manuscript presents the fabrication protocol for micro-tissue engineered neural networks (micro-TENNs), implantable constructs consisting of neurons and aligned axonal tracts spanning the extracellular matrix (ECM) lumen of a preformed hydrogel cylinder hundreds of microns in diameter that may extend centimeters in length. Neuronal aggregates are delimited to the extremes of the three-dimensional encasement and are spanned by axonal projections. Micro-TENNs are uniquely poised as a strategy for CNS reconstruction, emulating aspects of brain connectome cytoarchitecture and potentially providing means for network replacement. The neuronal aggregates may synapse with host tissue to form new functional relays to restore and/or modulate missing or damaged circuitry. These constructs may also act as pro-regenerative "living scaffolds" capable of exploiting developmental mechanisms for cell migration and axonal pathfinding, providing synergistic structural and soluble cues based on the state of regeneration. Micro-TENNs are fabricated by pouring liquid hydrogel into a cylindrical mold containing a longitudinally centered needle. Once the hydrogel has gelled, the needle is removed, leaving a hollow micro-column. An ECM solution is added to the lumen to provide an environment suitable for neuronal adhesion and axonal outgrowth. Dissociated neurons are mechanically aggregated for precise seeding within one or both ends of the micro-column. This methodology reliably produces self-contained miniature constructs with long-projecting axonal tracts that may recapitulate features of brain neuroanatomy. Synaptic immunolabeling and genetically encoded calcium indicators suggest that micro-TENNs possess extensive synaptic distribution and intrinsic electrical activity. Consequently, micro-TENNs represent a promising strategy for targeted neurosurgical reconstruction of brain pathways and may also be applied as biofidelic models to study neurobiological phenomena in vitro.
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Affiliation(s)
- Laura A Struzyna
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania; Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center
| | - Dayo O Adewole
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania; Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center
| | - Wisberty J Gordián-Vélez
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania; Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center
| | - Michael R Grovola
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center
| | - Justin C Burrell
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center
| | - Kritika S Katiyar
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center; School of Biomedical Engineering, Drexel University
| | - Dmitriy Petrov
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center
| | - James P Harris
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center
| | - D Kacy Cullen
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania; Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center;
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Lee HC, Ejserholm F, Gaire J, Currlin S, Schouenborg J, Wallman L, Bengtsson M, Park K, Otto KJ. Histological evaluation of flexible neural implants; flexibility limit for reducing the tissue response? J Neural Eng 2017; 14:036026. [PMID: 28470152 DOI: 10.1088/1741-2552/aa68f0] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Flexible neural probes are hypothesized to reduce the chronic foreign body response (FBR) mainly by reducing the strain-stress caused by an interplay between the tethered probe and the brain's micromotion. However, a large discrepancy of Young's modulus still exists (3-6 orders of magnitude) between the flexible probes and the brain tissue. This raises the question of whether we need to bridge this gap; would increasing the probe flexibility proportionally reduce the FBR? APPROACH Using novel off-stoichiometry thiol-enes-epoxy (OSTE+) polymer probes developed in our previous work, we quantitatively evaluated the FBR to four types of probes with different softness: silicon (~150 GPa), polyimide (1.5 GPa), OSTE+Hard (300 MPa), and OSTE+Soft (6 MPa). MAIN RESULTS We observed a significant reduction in the fluorescence intensity of biomarkers for activated microglia/macrophages and blood-brain barrier (BBB) leakiness around the three soft polymer probes compared to the silicon probe, both at 4 weeks and 8 weeks post-implantation. However, we did not observe any consistent differences in the biomarkers among the polymer probes. SIGNIFICANCE The results suggest that the mechanical compliance of neural probes can mediate the degree of FBR, but its impact diminishes after a hypothetical threshold level. This infers that resolving the mechanical mismatch alone has a limited effect on improving the lifetime of neural implants.
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Affiliation(s)
- Heui Chang Lee
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States of America. J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States of America
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Zhang S, Cao X, Stablow AM, Shenoy VB, Winkelstein BA. Tissue Strain Reorganizes Collagen With a Switchlike Response That Regulates Neuronal Extracellular Signal-Regulated Kinase Phosphorylation In Vitro: Implications for Ligamentous Injury and Mechanotransduction. J Biomech Eng 2016; 138:021013. [PMID: 26549105 DOI: 10.1115/1.4031975] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Indexed: 12/26/2022]
Abstract
Excessive loading of ligaments can activate the neural afferents that innervate the collagenous tissue, leading to a host of pathologies including pain. An integrated experimental and modeling approach was used to define the responses of neurons and the surrounding collagen fibers to the ligamentous matrix loading and to begin to understand how macroscopic deformation is translated to neuronal loading and signaling. A neuron-collagen construct (NCC) developed to mimic innervation of collagenous tissue underwent tension to strains simulating nonpainful (8%) or painful ligament loading (16%). Both neuronal phosphorylation of extracellular signal-regulated kinase (ERK), which is related to neuroplasticity (R2 ≥ 0.041; p ≤ 0.0171) and neuronal aspect ratio (AR) (R2 ≥ 0.250; p < 0.0001), were significantly correlated with tissue-level strains. As NCC strains increased during a slowly applied loading (1%/s), a "switchlike" fiber realignment response was detected with collagen reorganization occurring only above a transition point of 11.3% strain. A finite-element based discrete fiber network (DFN) model predicted that at bulk strains above the transition point, heterogeneous fiber strains were both tensile and compressive and increased, with strains in some fibers along the loading direction exceeding the applied bulk strain. The transition point identified for changes in collagen fiber realignment was consistent with the measured strain threshold (11.7% with a 95% confidence interval of 10.2-13.4%) for elevating ERK phosphorylation after loading. As with collagen fiber realignment, the greatest degree of neuronal reorientation toward the loading direction was observed at the NCC distraction corresponding to painful loading. Because activation of neuronal ERK occurred only at strains that produced evident collagen fiber realignment, findings suggest that tissue strain-induced changes in the micromechanical environment, especially altered local collagen fiber kinematics, may be associated with mechanotransduction signaling in neurons.
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Strain and rate-dependent neuronal injury in a 3D in vitro compression model of traumatic brain injury. Sci Rep 2016; 6:30550. [PMID: 27480807 PMCID: PMC4969749 DOI: 10.1038/srep30550] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/06/2016] [Indexed: 12/11/2022] Open
Abstract
In the United States over 1.7 million cases of traumatic brain injury are reported yearly, but predictive correlation of cellular injury to impact tissue strain is still lacking, particularly for neuronal injury resulting from compression. Given the prevalence of compressive deformations in most blunt head trauma, this information is critically important for the development of future mitigation and diagnosis strategies. Using a 3D in vitro neuronal compression model, we investigated the role of impact strain and strain rate on neuronal lifetime, viability, and pathomorphology. We find that strain magnitude and rate have profound, yet distinctively different effects on the injury pathology. While strain magnitude affects the time of neuronal death, strain rate influences the pathomorphology and extent of population injury. Cellular injury is not initiated through localized deformation of the cytoskeleton but rather driven by excess strain on the entire cell. Furthermore we find that, mechanoporation, one of the key pathological trigger mechanisms in stretch and shear neuronal injuries, was not observed under compression.
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26
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Lu C, Xia J, Bin W, Wu Y, Liu X, Zhang Y. Advances in diagnosis, treatments, and molecular mechanistic studies of traumatic brain injury. Biosci Trends 2016; 9:138-48. [PMID: 26166367 DOI: 10.5582/bst.2015.01066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Traumatic brain injury (TBI) is a main cause of death and disability around the world especially in soldiers, children, and young men. Since its clinical diagnosis and treatment cannot predict its prognosis, novel diagnostic techniques need to be developed, insight into its molecular mechanisms needs to be gleaned, and alternative and complementary medicine (ACM) approaches to its treatment need to be developed. This review summarizes the new diagnostic methods used in clinical practice, such as imaging of structural abnormalities after TBI and measurement of prognosis-related biomarkers. This review also describes the cellular mechanisms of traditional Chinese medicine in terms of intracellular signaling pathways, the extracellular microenvironment, and stem cells. This review concludes by describing experimental and clinical studies of the use of traditional Chinese medicine as a form of ACM to treat TBI. This review helps to understand advances in the field of TBI diagnosis and treatment.
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Affiliation(s)
- Chunyu Lu
- Department of Neurosurgery, The People's Hospital of Huaibei
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Gilmour AD, Woolley AJ, Poole-Warren LA, Thomson CE, Green RA. A critical review of cell culture strategies for modelling intracortical brain implant material reactions. Biomaterials 2016; 91:23-43. [PMID: 26994876 DOI: 10.1016/j.biomaterials.2016.03.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 02/29/2016] [Accepted: 03/06/2016] [Indexed: 02/07/2023]
Abstract
The capacity to predict in vivo responses to medical devices in humans currently relies greatly on implantation in animal models. Researchers have been striving to develop in vitro techniques that can overcome the limitations associated with in vivo approaches. This review focuses on a critical analysis of the major in vitro strategies being utilized in laboratories around the world to improve understanding of the biological performance of intracortical, brain-implanted microdevices. Of particular interest to the current review are in vitro models for studying cell responses to penetrating intracortical devices and their materials, such as electrode arrays used for brain computer interface (BCI) and deep brain stimulation electrode probes implanted through the cortex. A background on the neural interface challenge is presented, followed by discussion of relevant in vitro culture strategies and their advantages and disadvantages. Future development of 2D culture models that exhibit developmental changes capable of mimicking normal, postnatal development will form the basis for more complex accurate predictive models in the future. Although not within the scope of this review, innovations in 3D scaffold technologies and microfluidic constructs will further improve the utility of in vitro approaches.
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Affiliation(s)
- A D Gilmour
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.
| | - A J Woolley
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia; Western Sydney University, Sydney, NSW, Australia
| | - L A Poole-Warren
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - C E Thomson
- Department of Veterinary Medicine, University of Alaska, Fairbanks, AK 99775, USA
| | - R A Green
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
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28
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Harris JP, Struzyna LA, Murphy PL, Adewole DO, Kuo E, Cullen DK. Advanced biomaterial strategies to transplant preformed micro-tissue engineered neural networks into the brain. J Neural Eng 2016; 13:016019. [PMID: 26760138 DOI: 10.1088/1741-2560/13/1/016019] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Connectome disruption is a hallmark of many neurological diseases and trauma with no current strategies to restore lost long-distance axonal pathways in the brain. We are creating transplantable micro-tissue engineered neural networks (micro-TENNs), which are preformed constructs consisting of embedded neurons and long axonal tracts to integrate with the nervous system to physically reconstitute lost axonal pathways. APPROACH We advanced micro-tissue engineering techniques to generate micro-TENNs consisting of discrete populations of mature primary cerebral cortical neurons spanned by long axonal fascicles encased in miniature hydrogel micro-columns. Further, we improved the biomaterial encasement scheme by adding a thin layer of low viscosity carboxymethylcellulose (CMC) to enable needle-less insertion and rapid softening for mechanical similarity with brain tissue. MAIN RESULTS The engineered architecture of cortical micro-TENNs facilitated robust neuronal viability and axonal cytoarchitecture to at least 22 days in vitro. Micro-TENNs displayed discrete neuronal populations spanned by long axonal fasciculation throughout the core, thus mimicking the general systems-level anatomy of gray matter-white matter in the brain. Additionally, micro-columns with thin CMC-coating upon mild dehydration were able to withstand a force of 893 ± 457 mN before buckling, whereas a solid agarose cylinder of similar dimensions was predicted to withstand less than 150 μN of force. This thin CMC coating increased the stiffness by three orders of magnitude, enabling needle-less insertion into brain while significantly reducing the footprint of previous needle-based delivery methods to minimize insertion trauma. SIGNIFICANCE Our novel micro-TENNs are the first strategy designed for minimally invasive implantation to facilitate nervous system repair by simultaneously providing neuronal replacement and physical reconstruction of long-distance axon pathways in the brain. The micro-TENN approach may offer the ability to treat several disorders that disrupt the connectome, including Parkinson's disease, traumatic brain injury, stroke, and brain tumor excision.
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Affiliation(s)
- J P Harris
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA
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29
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Struzyna LA, Wolf JA, Mietus CJ, Adewole DO, Chen HI, Smith DH, Cullen DK. Rebuilding Brain Circuitry with Living Micro-Tissue Engineered Neural Networks. Tissue Eng Part A 2015; 21:2744-56. [PMID: 26414439 DOI: 10.1089/ten.tea.2014.0557] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Prominent neuropathology following trauma, stroke, and various neurodegenerative diseases includes neuronal degeneration as well as loss of long-distance axonal connections. While cell replacement and axonal pathfinding strategies are often explored independently, there is no strategy capable of simultaneously replacing lost neurons and re-establishing long-distance axonal connections in the central nervous system. Accordingly, we have created micro-tissue engineered neural networks (micro-TENNs), which are preformed constructs consisting of long integrated axonal tracts spanning discrete neuronal populations. These living micro-TENNs reconstitute the architecture of long-distance axonal tracts, and thus may serve as an effective substrate for targeted neurosurgical reconstruction of damaged pathways in the brain. Cerebral cortical neurons or dorsal root ganglia neurons were precisely delivered into the tubular constructs, and properties of the hydrogel exterior and extracellular matrix internal column (180-500 μm diameter) were optimized for robust neuronal survival and to promote axonal extensions across the 2.0 cm tube length. The very small diameter permits minimally invasive delivery into the brain. In this study, preformed micro-TENNs were stereotaxically injected into naive rats to bridge deep thalamic structures with the cerebral cortex to assess construct survival and integration. We found that micro-TENN neurons survived at least 1 month and maintained their long axonal architecture along the cortical-thalamic axis. Notably, we also found neurite penetration from micro-TENN neurons into the host cortex, with evidence of synapse formation. These micro-TENNs represent a new strategy to facilitate nervous system repair by recapitulating features of neural pathways to restore or modulate damaged brain circuitry.
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Affiliation(s)
- Laura A Struzyna
- 1 Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.,2 Philadelphia Veterans Affairs Medical Center , Philadelphia, Pennsylvania.,3 Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania , Philadelphia, Pennsylvania
| | - John A Wolf
- 1 Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.,2 Philadelphia Veterans Affairs Medical Center , Philadelphia, Pennsylvania
| | - Constance J Mietus
- 1 Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Dayo O Adewole
- 1 Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.,2 Philadelphia Veterans Affairs Medical Center , Philadelphia, Pennsylvania.,3 Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania , Philadelphia, Pennsylvania
| | - H Isaac Chen
- 1 Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.,2 Philadelphia Veterans Affairs Medical Center , Philadelphia, Pennsylvania
| | - Douglas H Smith
- 1 Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - D Kacy Cullen
- 1 Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania.,2 Philadelphia Veterans Affairs Medical Center , Philadelphia, Pennsylvania
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Ross JD, Cullen DK, Harris JP, LaPlaca MC, DeWeerth SP. A three-dimensional image processing program for accurate, rapid, and semi-automated segmentation of neuronal somata with dense neurite outgrowth. Front Neuroanat 2015; 9:87. [PMID: 26257609 PMCID: PMC4507056 DOI: 10.3389/fnana.2015.00087] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 06/18/2015] [Indexed: 12/02/2022] Open
Abstract
Three-dimensional (3-D) image analysis techniques provide a powerful means to rapidly and accurately assess complex morphological and functional interactions between neural cells. Current software-based identification methods of neural cells generally fall into two applications: (1) segmentation of cell nuclei in high-density constructs or (2) tracing of cell neurites in single cell investigations. We have developed novel methodologies to permit the systematic identification of populations of neuronal somata possessing rich morphological detail and dense neurite arborization throughout thick tissue or 3-D in vitro constructs. The image analysis incorporates several novel automated features for the discrimination of neurites and somata by initially classifying features in 2-D and merging these classifications into 3-D objects; the 3-D reconstructions automatically identify and adjust for over and under segmentation errors. Additionally, the platform provides for software-assisted error corrections to further minimize error. These features attain very accurate cell boundary identifications to handle a wide range of morphological complexities. We validated these tools using confocal z-stacks from thick 3-D neural constructs where neuronal somata had varying degrees of neurite arborization and complexity, achieving an accuracy of ≥95%. We demonstrated the robustness of these algorithms in a more complex arena through the automated segmentation of neural cells in ex vivo brain slices. These novel methods surpass previous techniques by improving the robustness and accuracy by: (1) the ability to process neurites and somata, (2) bidirectional segmentation correction, and (3) validation via software-assisted user input. This 3-D image analysis platform provides valuable tools for the unbiased analysis of neural tissue or tissue surrogates within a 3-D context, appropriate for the study of multi-dimensional cell-cell and cell-extracellular matrix interactions.
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Affiliation(s)
- James D Ross
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory Atlanta, GA, USA ; School of Electrical and Computer Engineering, Georgia Institute of Technology Atlanta, GA, USA
| | - D Kacy Cullen
- Department of Neurosurgery, University of Pennsylvania Philadelphia, PA, USA ; Philadelphia Veterans Affairs Medical Center Philadelphia, PA, USA
| | - James P Harris
- Department of Neurosurgery, University of Pennsylvania Philadelphia, PA, USA ; Philadelphia Veterans Affairs Medical Center Philadelphia, PA, USA
| | - Michelle C LaPlaca
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory Atlanta, GA, USA
| | - Stephen P DeWeerth
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory Atlanta, GA, USA ; School of Electrical and Computer Engineering, Georgia Institute of Technology Atlanta, GA, USA
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31
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Struzyna LA, Harris JP, Katiyar KS, Chen HI, Cullen DK. Restoring nervous system structure and function using tissue engineered living scaffolds. Neural Regen Res 2015; 10:679-85. [PMID: 26109930 PMCID: PMC4468747 DOI: 10.4103/1673-5374.156943] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2015] [Indexed: 12/23/2022] Open
Abstract
Neural tissue engineering is premised on the integration of engineered living tissue with the host nervous system to directly restore lost function or to augment regenerative capacity following nervous system injury or neurodegenerative disease. Disconnection of axon pathways – the long-distance fibers connecting specialized regions of the central nervous system or relaying peripheral signals – is a common feature of many neurological disorders and injury. However, functional axonal regeneration rarely occurs due to extreme distances to targets, absence of directed guidance, and the presence of inhibitory factors in the central nervous system, resulting in devastating effects on cognitive and sensorimotor function. To address this need, we are pursuing multiple strategies using tissue engineered “living scaffolds”, which are preformed three-dimensional constructs consisting of living neural cells in a defined, often anisotropic architecture. Living scaffolds are designed to restore function by serving as a living labeled pathway for targeted axonal regeneration – mimicking key developmental mechanisms– or by restoring lost neural circuitry via direct replacement of neurons and axonal tracts. We are currently utilizing preformed living scaffolds consisting of neuronal clusters spanned by long axonal tracts as regenerative bridges to facilitate long-distance axonal regeneration and for targeted neurosurgical reconstruction of local circuits in the brain. Although there are formidable challenges in preclinical and clinical advancement, these living tissue engineered constructs represent a promising strategy to facilitate nervous system repair and functional recovery.
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Affiliation(s)
- Laura A Struzyna
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA ; Center for Neurotrauma, Neurodegeneration, and Restoration, Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA
| | - James P Harris
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA ; Center for Neurotrauma, Neurodegeneration, and Restoration, Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA
| | - Kritika S Katiyar
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA ; School of Biomedical Engineering, Drexel University, Philadelphia, PA, USA
| | - H Isaac Chen
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA ; Center for Neurotrauma, Neurodegeneration, and Restoration, Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA
| | - D Kacy Cullen
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA ; Center for Neurotrauma, Neurodegeneration, and Restoration, Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA
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32
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Traumatic Brain Injury and the Neuronal Microenvironment: A Potential Role for Neuropathological Mechanotransduction. Neuron 2015; 85:1177-92. [DOI: 10.1016/j.neuron.2015.02.041] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Hopkins AM, DeSimone E, Chwalek K, Kaplan DL. 3D in vitro modeling of the central nervous system. Prog Neurobiol 2015; 125:1-25. [PMID: 25461688 PMCID: PMC4324093 DOI: 10.1016/j.pneurobio.2014.11.003] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 10/12/2014] [Accepted: 11/15/2014] [Indexed: 12/15/2022]
Abstract
There are currently more than 600 diseases characterized as affecting the central nervous system (CNS) which inflict neural damage. Unfortunately, few of these conditions have effective treatments available. Although significant efforts have been put into developing new therapeutics, drugs which were promising in the developmental phase have high attrition rates in late stage clinical trials. These failures could be circumvented if current 2D in vitro and in vivo models were improved. 3D, tissue-engineered in vitro systems can address this need and enhance clinical translation through two approaches: (1) bottom-up, and (2) top-down (developmental/regenerative) strategies to reproduce the structure and function of human tissues. Critical challenges remain including biomaterials capable of matching the mechanical properties and extracellular matrix (ECM) composition of neural tissues, compartmentalized scaffolds that support heterogeneous tissue architectures reflective of brain organization and structure, and robust functional assays for in vitro tissue validation. The unique design parameters defined by the complex physiology of the CNS for construction and validation of 3D in vitro neural systems are reviewed here.
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Affiliation(s)
- Amy M Hopkins
- Department of Biomedical Engineering, Tufts University, Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA
| | - Elise DeSimone
- Department of Biomedical Engineering, Tufts University, Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA
| | - Karolina Chwalek
- Department of Biomedical Engineering, Tufts University, Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA.
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Shamloo A, Heibatollahi M, Mofrad MRK. Directional migration and differentiation of neural stem cells within three-dimensional microenvironments. Integr Biol (Camb) 2015; 7:335-44. [PMID: 25633746 DOI: 10.1039/c4ib00144c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
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(-1)), 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(-1)), 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(-1)) 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.
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Affiliation(s)
- Amir Shamloo
- Molecular Cell Biomechanics Laboratory, Departments of Bioengineering and Mechanical Engineering, University of California, Berkeley, CA 94720, USA.
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Sommakia S, Lee HC, Gaire J, Otto KJ. Materials approaches for modulating neural tissue responses to implanted microelectrodes through mechanical and biochemical means. CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE 2014; 18:319-328. [PMID: 25530703 PMCID: PMC4267064 DOI: 10.1016/j.cossms.2014.07.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Implantable intracortical microelectrodes face an uphill struggle for widespread clinical use. Their potential for treating a wide range of traumatic and degenerative neural disease is hampered by their unreliability in chronic settings. A major factor in this decline in chronic performance is a reactive response of brain tissue, which aims to isolate the implanted device from the rest of the healthy tissue. In this review we present a discussion of materials approaches aimed at modulating the reactive tissue response through mechanical and biochemical means. Benefits and challenges associated with these approaches are analyzed, and the importance of multimodal solutions tested in emerging animal models are presented.
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Affiliation(s)
- Salah Sommakia
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907-1791
| | - Heui C. Lee
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907-1791
| | - Janak Gaire
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-1791
| | - Kevin J. Otto
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907-1791
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-1791
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Struzyna LA, Katiyar K, Cullen DK. Living scaffolds for neuroregeneration. CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE 2014; 18:308-318. [PMID: 28736499 PMCID: PMC5520662 DOI: 10.1016/j.cossms.2014.07.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Neural tissue engineers are exploiting key mechanisms responsible for neural cell migration and axonal path finding during embryonic development to create living scaffolds for neuroregeneration following injury and disease. These mechanisms involve the combined use of haptotactic, chemotactic, and mechanical cues to direct cell movement and re-growth. Living scaffolds provide these cues through the use of cells engineered in a predefined architecture, generally in combination with biomaterial strategies. Although several hurdles exist in the implementation of living regenerative scaffolds, there are considerable therapeutic advantages to using living cells in conjunction with biomaterials. The leading contemporary living scaffolds for neurorepair are utilizing aligned glial cells and neuronal/axonal tracts to direct regenerating axons across damaged tissue to appropriate targets, and in some cases to directly replace the function of lost cells. Future advances in technology, including the use of exogenous stimulation and genetically engineered stem cells, will further the potential of living scaffolds and drive a new era of personalized medicine for neuroregeneration.
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Affiliation(s)
- Laura A Struzyna
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, United States
| | - Kritika Katiyar
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- School of Biomedical Engineering, Drexel University, Philadelphia, PA, United States
| | - D Kacy Cullen
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, United States
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Lien TL, Ban J, Tormen M, Migliorini E, Grenci G, Pozzato A, Torre V. Can hippocampal neurites and growth cones climb over obstacles? PLoS One 2013; 8:e73966. [PMID: 24040128 PMCID: PMC3765352 DOI: 10.1371/journal.pone.0073966] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 07/25/2013] [Indexed: 11/19/2022] Open
Abstract
Guidance molecules, such as Sema3A or Netrin-1, can induce growth cone (GC) repulsion or attraction in the presence of a flat surface, but very little is known of the action of guidance molecules in the presence of obstacles. Therefore we combined chemical and mechanical cues by applying a steady Netrin-1 stream to the GCs of dissociated hippocampal neurons plated on polydimethylsiloxane (PDMS) surfaces patterned with lines 2 µm wide, with 4 µm period and with a height varying from 100 to 600 nm. GC turning experiments performed 24 hours after plating showed that filopodia crawl over these lines within minutes. These filopodia do not show staining for the adhesion marker Paxillin. GCs and neurites crawl over lines 100 nm high, but less frequently and on a longer time scale over lines higher than 300 nm; neurites never crawl over lines 600 nm high. When neurons are grown for 3 days over patterned surfaces, also neurites can cross lines 300 nm and 600 nm high, grow parallel to and on top of these lines and express Paxillin. Axons - selectively stained with SMI 312 - do not differ from dendrites in their ability to cross these lines. Our results show that highly motile structures such as filopodia climb over high obstacle in response to chemical cues, but larger neuronal structures are less prompt and require hours or days to climb similar obstacles.
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Affiliation(s)
- Thuy Linh Lien
- Neurobiology Sector, International School for Advanced Studies (SISSA), Trieste, Italy
| | - Jelena Ban
- Neurobiology Sector, International School for Advanced Studies (SISSA), Trieste, Italy
| | - Massimo Tormen
- Istituto Officina dei Materiali (IOM-CNR), Basovizza, Trieste, Italy
| | - Elisa Migliorini
- Istituto Officina dei Materiali (IOM-CNR), Basovizza, Trieste, Italy
| | - Gianluca Grenci
- Istituto Officina dei Materiali (IOM-CNR), Basovizza, Trieste, Italy
| | | | - Vincent Torre
- Neurobiology Sector, International School for Advanced Studies (SISSA), Trieste, Italy
- * E-mail:
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Ribeiro A, Balasubramanian S, Hughes D, Vargo S, Powell EM, Leach JB. β1-Integrin cytoskeletal signaling regulates sensory neuron response to matrix dimensionality. Neuroscience 2013; 248:67-78. [PMID: 23764511 DOI: 10.1016/j.neuroscience.2013.05.057] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 05/30/2013] [Indexed: 10/26/2022]
Abstract
Neuronal differentiation, pathfinding and morphology are directed by biochemical cues that in vivo are presented in a complex scaffold of extracellular matrix. This microenvironment is three-dimensional (3D) and heterogeneous. Therefore, it is not surprising that more physiologically-relevant cellular responses are found in 3D culture environments rather than on two-dimensional (2D) flat substrates. One key difference between 2D and 3D environments is the spatial arrangement of cell-matrix interactions. Integrins and other receptor proteins link the various molecules presented in the extracellular environment to intracellular signaling cascades and thus influence a number of neuronal responses including the availability and activation of integrins themselves. We have previously reported that a 3D substrate induces an important morphological transformation of embryonic mouse dorsal root ganglion (DRG) neurons. Here, we investigate the hypothesis that β1-integrin signaling via focal adhesion kinase (FAK) and the RhoGTPases Rac and Rho influences neuronal morphology in 2D vs 3D environments. We report that β1-integrin activity and FAK phosphorylation at tyrosine 397 (FAKpY397) are linked to neuronal polarization as well as neurite outgrowth and branching. Rac and Rho expression are decreased in 3D vs 2D culture but not correlated with β1-integrin function. These results suggest that proper β1-integrin activity is required for the elaboration of physiologic DRG morphology and that 3D culture provides a more appropriate milieu to the mimic in vivo scenario. We propose that neuronal morphology may be directed during development and regeneration by factors that influence how β1-integrin, FAK and RhoGTPase molecules integrate substrate signals in the 3D microenvironment.
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Affiliation(s)
- A Ribeiro
- Department of Chemical, Biochemical & Environmental Engineering, UMBC, Eng 314, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - S Balasubramanian
- Department of Chemical, Biochemical & Environmental Engineering, UMBC, Eng 314, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - D Hughes
- Department of Chemical, Biochemical & Environmental Engineering, UMBC, Eng 314, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - S Vargo
- Department of Chemical, Biochemical & Environmental Engineering, UMBC, Eng 314, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - E M Powell
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, HSF II S251, 20 Penn Street, Baltimore, MD 21201, USA; Department of Psychiatry, University of Maryland School of Medicine, HSF II S251, 20 Penn Street, Baltimore, MD 21201, USA; Department of Bioengineering, University of Maryland School of Medicine, HSF II S251, 20 Penn Street, Baltimore, MD 21201, USA
| | - J B Leach
- Department of Chemical, Biochemical & Environmental Engineering, UMBC, Eng 314, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
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Pineda ET, Nerem RM, Ahsan T. Differentiation patterns of embryonic stem cells in two- versus three-dimensional culture. Cells Tissues Organs 2013; 197:399-410. [PMID: 23406658 DOI: 10.1159/000346166] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2012] [Indexed: 11/19/2022] Open
Abstract
Pluripotent stem cells are attractive candidates as a cell source for regenerative medicine and tissue engineering therapies. Current methods of differentiation result in low yields and impure populations of target phenotypes, with attempts for improved efficiency often comparing protocols that vary multiple parameters. This basic science study focused on a single variable to understand the effects of two-dimensional (2D) versus three-dimensional (3D) culture on directed differentiation. We compared mouse embryonic stem cells (ESCs) differentiated on collagen type I-coated surfaces (SLIDEs), embedded in collagen type I gels (GELs), and in suspension as embryoid bodies (EBs). For a systematic analysis in these studies, key parameters were kept identical to allow for direct comparison across culture configurations. We determined that all three configurations supported differentiation of ESCs and that the kinetics of differentiation differed greatly for cells cultured in 2D versus 3D. SLIDE cultures induced overall differentiation more quickly than 3D configurations, with earlier expression of cytoskeletal and extracellular matrix proteins. For 3D culture as GELs or EBs, cells clustered similarly, formed complex structures and promoted differentiation towards cardiovascular phenotypes. GEL culture, however, also allowed for contraction of the collagen matrix. For differentiation towards fibroblasts and smooth muscle cells which actively remodel their environment, GEL culture may be particularly beneficial. Overall, this study determined the effects of dimensionality on differentiation and helps in the rational design of protocols to generate phenotypes needed for tissue engineering and regenerative medicine.
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Affiliation(s)
- Emma T Pineda
- Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118, USA
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Cullen DK, Tang-Schomer MD, Struzyna LA, Patel AR, Johnson VE, Wolf JA, Smith DH. Microtissue engineered constructs with living axons for targeted nervous system reconstruction. Tissue Eng Part A 2012; 18:2280-9. [PMID: 22702955 DOI: 10.1089/ten.tea.2011.0534] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
As a common feature of many neurological diseases and injury, the loss of axon pathways can have devastating effects on function. Here, we demonstrate a new strategy to restore damaged axon pathways using transplantable miniature constructs consisting of living neurons and axonal tracts internalized within hydrogel tubes. These hydrogel microconduits were developed through an iterative process to support neuronal survival and directed axon growth. The design included hollow agarose tubes providing a relatively stiff outer casing to direct constrained unidirectional outgrowth of axons through a central soft collagen matrix, with overall dimensions of 250 μm inner diameter ×500 μm outer diameter and extending up to several centimeters. The outer casing was also designed to provide structural support of neuronal/axonal cultures during transplantation of the construct. Using neuron culture conditions optimized for the microconduits, dissociated dorsal root ganglia neurons were seeded in the collagen at one end of the conduits. Over the following week, high-resolution confocal microscopy demonstrated that the neurons survived and the somata remained in a tight cluster at the original seeding site. In addition, robust outgrowth of axons from the neurons was found, with axon fascicles constrained in a longitudinal projection along the internal collagen canal and extending over 5 mm in length. Notably, this general geometry recapitulates the anatomy of axon tracts. As such, these constructs may be useful to repair damaged axon projections by providing a transplantable bridge of living axons. Moreover, the small size of the construct permits follow-on studies of minimally invasive transplantation into potentially sensitive regions of the nervous system.
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Affiliation(s)
- D Kacy Cullen
- Department of Neurosurgery, School of Medicine, Center for Brain Injury and Repair, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Cullen DK, Vernekar VN, LaPlaca MC. Trauma-induced plasmalemma disruptions in three-dimensional neural cultures are dependent on strain modality and rate. J Neurotrauma 2012; 28:2219-33. [PMID: 22023556 DOI: 10.1089/neu.2011.1841] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Traumatic brain injury (TBI) results from cell dysfunction or death following supra-threshold physical loading. Neural plasmalemma compromise has been observed following traumatic neural insults; however, the biomechanical thresholds and time-course of such disruptions remain poorly understood. In order to investigate trauma-induced membrane disruptions, we induced dynamic strain fields (0.50 shear or compressive strain at 1, 10, or 30?sec(?1) strain rate) in 3-D neuronal-astrocytic co-cultures (>500??m thick). Impermeant dyes were present during mechanical loading and entered cells in a strain rate-dependent manner for both shear and compression. Real-time imaging revealed increased membrane permeability in a sub-population of cells immediately upon deformation. Alterations in cell membrane permeability, however, were transient and biphasic over the ensuing hour post-insult, suggesting initial membrane damage and rapid repair, followed by a phase of secondary membrane degradation. At 48?h post-insult, cell death increased significantly in the high-strain-rate group, but not after quasi-static loading, suggesting that cell survival relates to the initial extent of transient structural compromise. Cells were more sensitive to bulk shear deformation than compression with respect to acute permeability changes and subsequent cell survival. These results provide insight into the temporally varying alterations in membrane stability following traumatic loading and provide a basis for elucidating physical cellular tolerances.
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Affiliation(s)
- D Kacy Cullen
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Li X, Katsanevakis E, Liu X, Zhang N, Wen X. Engineering neural stem cell fates with hydrogel design for central nervous system regeneration. Prog Polym Sci 2012. [DOI: 10.1016/j.progpolymsci.2012.02.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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43
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Swindle-Reilly KE, Papke JB, Kutosky HP, Throm A, Hammer JA, Harkins AB, Willits RK. The impact of laminin on 3D neurite extension in collagen gels. J Neural Eng 2012; 9:046007. [DOI: 10.1088/1741-2560/9/4/046007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Valmikinathan CM, Mukhatyar VJ, Jain A, Karumbaiah L, Dasari M, Bellamkonda RV. Photocrosslinkable chitosan based hydrogels for neural tissue engineering. SOFT MATTER 2012; 8:1964-1976. [PMID: 29805470 PMCID: PMC5969809 DOI: 10.1039/c1sm06629c] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Hydrogel based scaffolds for neural tissue engineering can provide appropriate physico-chemical and mechanical properties to support neurite extension and facilitate transplantation of cells by acting as 'cell delivery vehicles'. Specifically, in situ gelling systems such as photocrosslinkable hydrogels can potentially conformally fill irregular neural tissue defects and serve as stem cell delivery systems. Here, we report the development of a novel chitosan based photocrosslinkable hydrogel system with tunable mechanical properties and degradation rates. A two-step synthesis of amino-ethyl methacrylate derivitized, degradable, photocrosslinkable chitosan hydrogels is described. When human mesenchymal stem cells were cultured in photocrosslinkable chitosan hydrogels, negligible cytotoxicity was observed. Photocrosslinkable chitosan hydrogels facilitated enhanced neurite differentiation from primary cortical neurons and enhanced neurite extension from dorsal root ganglia (DRG) as compared to agarose based hydrogels with similar storage moduli. Neural stem cells (NSCs) cultured within photocrosslinkable chitosan hydrogels facilitated differentiation into tubulin positive neurons and astrocytes. These data demonstrate the potential of photocrosslinked chitosan hydrogels, and contribute to an increasing repertoire of hydrogels designed for neural tissue engineering.
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Affiliation(s)
- Chandra M. Valmikinathan
- Neurological Biomaterials and Cancer Therapeutics Laboratory, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
| | - Vivek J. Mukhatyar
- Neurological Biomaterials and Cancer Therapeutics Laboratory, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
| | - Anjana Jain
- Neurological Biomaterials and Cancer Therapeutics Laboratory, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
| | - Lohitash Karumbaiah
- Neurological Biomaterials and Cancer Therapeutics Laboratory, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
| | - Madhuri Dasari
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
| | - Ravi V. Bellamkonda
- Neurological Biomaterials and Cancer Therapeutics Laboratory, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 3108, UA Whitaker Building, 313 Ferst Drive, Atlanta, Georgia, 30332-0535, USA
- ; Fax: +1 404 385 5044; Tel: +1 404 385 5038
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Olivero D, LaPlaca M, Kottke PA. Ambient nanoelectrospray ionization with in-line microdialysis for spatially resolved transient biochemical monitoring within cell culture environments. Anal Chem 2012; 84:2072-5. [PMID: 22263997 DOI: 10.1021/ac203009s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have developed a new mass spectrometry (MS) based approach for continuous, spatially resolved in vitro biochemical detection and demonstrated its utility in a 3-D cell culture system. Extracellular liquid is passively extracted at a low flow rate (~10 nL/s) through a small bore silica capillary (ID 50 μm); inline microdialysis (MD) removes ions that would interfere with mass spectrometric analysis, and the sample is ionized by nanoelectrospray ionization (nano-ESI) and mass analyzed in a time-of-flight mass spectrometer. The system successfully detects low-volume, low-concentration releases of a small protein (8 μL of 5 μM cytochrome-c, molecular mass ~12 kDa) and exhibits ~1 min temporal resolution. The system also displays sensitivity to probe proximity to the sample release point. Due to the sensitivity of ESI-MS and its ability to simultaneously detect and identify multiple unanticipated biochemicals, this approach shows considerable potential as a biomarker discovery tool.
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Affiliation(s)
- Daniel Olivero
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
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Stabenfeldt SE, LaPlaca MC. Variations in rigidity and ligand density influence neuronal response in methylcellulose-laminin hydrogels. Acta Biomater 2011; 7:4102-8. [PMID: 21839862 DOI: 10.1016/j.actbio.2011.07.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 07/15/2011] [Accepted: 07/25/2011] [Indexed: 11/15/2022]
Abstract
Cells are continuously sensing their physical and chemical environment, generating dynamic interactions with the surrounding microenvironment and neighboring cells. Specific to neurons, neurite outgrowth is influenced by many factors, including the mechanical properties and adhesive signals of the growth substrata. In designing biomaterials for neural regeneration, it is important to understand the influence of substrate material, rigidity and bioadhesion on neurite outgrowth. To this end, we developed and characterized a tunable 3-D methylcellulose (MC) hydrogel polymeric system tethered to laminin-1 (MC-x-LN) across a range of substrate rigidities (G* range = 50-565 Pa) and laminin densities. Viability and neurite outgrowth of primary cortical neurons plated within 3-D MC hydrogels were used as cell outcome measures. After 4 days in culture, neuronal viability was significantly augmented with increasing rigidity for MC-x-LN as compared to control non-bioactive MC; however, neurite outgrowth was only observed in MC hydrogels with complex moduli of 565 Pa. Varying LN while maintaining a constant MC formulation (G* = 565 Pa) revealed a threshold response for neuronal viability, whereas a direct dose-dependent response to LN density was observed for neurite outgrowth. Collectively, these data demonstrate the synergistic play between material compliance and bioactive ligand concentrations within MC hydrogels. Such results can be used to better understand the adhesive and mechanical factors that mediate neuronal response to MC-based, tissue-engineered materials.
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Affiliation(s)
- Sarah E Stabenfeldt
- Petit Institute for Bioengineering and Bioscience, Laboratory for Neuroengineering, W.H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Emory University, Atlanta, GA, USA
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Patel TP, Ventre SC, Meaney DF. Dynamic changes in neural circuit topology following mild mechanical injury in vitro. Ann Biomed Eng 2011; 40:23-36. [PMID: 21994056 DOI: 10.1007/s10439-011-0390-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Accepted: 08/24/2011] [Indexed: 11/26/2022]
Abstract
Despite its enormous incidence, mild traumatic brain injury is not well understood. One aspect that needs more definition is how the mechanical energy during injury affects neural circuit function. Recent developments in cellular imaging probes provide an opportunity to assess the dynamic state of neural networks with single-cell resolution. In this article, we developed imaging methods to assess the state of dissociated cortical networks exposed to mild injury. We estimated the imaging conditions needed to achieve accurate measures of network properties, and applied these methodologies to evaluate if mild mechanical injury to cortical neurons produces graded changes to either spontaneous network activity or altered network topology. We found that modest injury produced a transient increase in calcium activity that dissipated within 1 h after injury. Alternatively, moderate mechanical injury produced immediate disruption in network synchrony, loss in excitatory tone, and increased modular topology. A calcium-activated neutral protease (calpain) was a key intermediary in these changes; blocking calpain activation restored the network nearly completely to its pre-injury state. Together, these findings show a more complex change in neural circuit behavior than previously reported for mild mechanical injury, and highlight at least one important early mechanism responsible for these changes.
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Affiliation(s)
- Tapan P Patel
- Department of Bioengineering, University of Pennsylvania, 220 S 33rd St, Philadelphia, PA 19104, USA
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Nakamura Y, Nakamichi N, Takarada T, Ogita K, Yoneda Y. Transferrin receptor-1 suppresses neurite outgrowth in neuroblastoma Neuro2A cells. Neurochem Int 2011; 60:448-57. [PMID: 22019713 DOI: 10.1016/j.neuint.2011.08.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 08/24/2011] [Accepted: 08/25/2011] [Indexed: 10/16/2022]
Abstract
Transferrin receptor-1 (TfR1) is a cell membrane-associated glycoprotein responsible for incorporation of the iron bound to transferrin through an endocytotic process from the circulating blood. Iron is believed to play a dual role as an active center of the electron transfer system in mitochondria and as an endogenous cytotoxin through promoted generation of reactive oxygen species in different eukaryotic cells. In this study, we evaluated expression profiles of different genes related to iron mobilization across plasma membranes in neuronal cells. Marked mRNA expression was seen for various iron-related genes such as TfR1 in cultured mouse neocortical neurons, while TfR1 mRNA levels were more than doubled during culture from 3 to 6days. In mouse embryonal carcinoma P19 cells endowed to differentiate into neuronal and astroglial lineages, a transient increase was seen in both mRNA and corresponding protein for TfR1 in association with neuronal marker expression during culture with all-trans retinoic acid (ATRA). In neuronal Neuro2A cells cultured with ATRA, moreover, neurite was elongated together with increased expression of both mRNA and protein for TfR1. Overexpression of TfR1 significantly decreased the length of neurite elongated, however, while significant promotion was invariably seen in the neurite elongation in Neuro2A cells transfected with TfR1 siRNA as well as in Neuro2A cells cultured with an iron chelator. These results suggest that TfR1 would be highly expressed by neurons rather than astroglia to play a negative role in the neurite outgrowth after the incorporation of circulating transferrin in the brain.
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Affiliation(s)
- Yukary Nakamura
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School of Natural Science and Technology, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
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Hemphill MA, Dabiri BE, Gabriele S, Kerscher L, Franck C, Goss JA, Alford PW, Parker KK. A possible role for integrin signaling in diffuse axonal injury. PLoS One 2011; 6:e22899. [PMID: 21799943 PMCID: PMC3142195 DOI: 10.1371/journal.pone.0022899] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 07/05/2011] [Indexed: 01/16/2023] Open
Abstract
Over the past decade, investigators have attempted to establish the pathophysiological mechanisms by which non-penetrating injuries damage the brain. Several studies have implicated either membrane poration or ion channel dysfunction pursuant to neuronal cell death as the primary mechanism of injury. We hypothesized that traumatic stimulation of integrins may be an important etiological contributor to mild Traumatic Brain Injury. In order to study the effects of forces at the cellular level, we utilized two hierarchical, in vitro systems to mimic traumatic injury to rat cortical neurons: a high velocity stretcher and a magnetic tweezer system. In one system, we controlled focal adhesion formation in neurons cultured on a stretchable substrate loaded with an abrupt, one dimensional strain. With the second system, we used magnetic tweezers to directly simulate the abrupt injury forces endured by a focal adhesion on the neurite. Both systems revealed variations in the rate and nature of neuronal injury as a function of focal adhesion density and direct integrin stimulation without membrane poration. Pharmacological inhibition of calpains did not mitigate the injury yet the inhibition of Rho-kinase immediately after injury reduced axonal injury. These data suggest that integrin-mediated activation of Rho may be a contributor to the diffuse axonal injury reported in mild Traumatic Brain Injury.
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Affiliation(s)
- Matthew A. Hemphill
- Disease Biophysics Group, School of Engineering and Applied Sciences, Wyss Institute of Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
| | - Borna E. Dabiri
- Disease Biophysics Group, School of Engineering and Applied Sciences, Wyss Institute of Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
| | - Sylvain Gabriele
- Disease Biophysics Group, School of Engineering and Applied Sciences, Wyss Institute of Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
| | - Lucas Kerscher
- Disease Biophysics Group, School of Engineering and Applied Sciences, Wyss Institute of Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
| | - Christian Franck
- Disease Biophysics Group, School of Engineering and Applied Sciences, Wyss Institute of Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
| | - Josue A. Goss
- Disease Biophysics Group, School of Engineering and Applied Sciences, Wyss Institute of Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
| | - Patrick W. Alford
- Disease Biophysics Group, School of Engineering and Applied Sciences, Wyss Institute of Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
| | - Kevin Kit Parker
- Disease Biophysics Group, School of Engineering and Applied Sciences, Wyss Institute of Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, United States of America
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Localized bimodal response of neurite extensions and structural proteins in dorsal-root ganglion neurons with controlled polydimethylsiloxane substrate stiffness. J Biomech 2011; 44:856-62. [DOI: 10.1016/j.jbiomech.2010.12.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 12/08/2010] [Accepted: 12/08/2010] [Indexed: 12/17/2022]
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