1
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Nekanti U, Sakthivel PS, Zahedi A, Creasman DA, Nishi RA, Dumont CM, Piltti KM, Guardamondo GL, Hernandez N, Chen X, Song H, Lin X, Martinez J, On L, Lakatos A, Pawar K, David BT, Guo Z, Seidlits SK, Xu X, Shea LD, Cummings BJ, Anderson AJ. Multichannel bridges and NSC synergize to enhance axon regeneration, myelination, synaptic reconnection, and recovery after SCI. NPJ Regen Med 2024; 9:12. [PMID: 38499577 PMCID: PMC10948859 DOI: 10.1038/s41536-024-00356-0] [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: 06/09/2023] [Accepted: 02/15/2024] [Indexed: 03/20/2024] Open
Abstract
Regeneration in the injured spinal cord is limited by physical and chemical barriers. Acute implantation of a multichannel poly(lactide-co-glycolide) (PLG) bridge mechanically stabilizes the injury, modulates inflammation, and provides a permissive environment for rapid cellularization and robust axonal regrowth through this otherwise inhibitory milieu. However, without additional intervention, regenerated axons remain largely unmyelinated (<10%), limiting functional repair. While transplanted human neural stem cells (hNSC) myelinate axons after spinal cord injury (SCI), hNSC fate is highly influenced by the SCI inflammatory microenvironment, also limiting functional repair. Accordingly, we investigated the combination of PLG scaffold bridges with hNSC to improve histological and functional outcome after SCI. In vitro, hNSC culture on a PLG scaffold increased oligodendroglial lineage selection after inflammatory challenge. In vivo, acute PLG bridge implantation followed by chronic hNSC transplantation demonstrated a robust capacity of donor human cells to migrate into PLG bridge channels along regenerating axons and integrate into the host spinal cord as myelinating oligodendrocytes and synaptically integrated neurons. Axons that regenerated through the PLG bridge formed synaptic circuits that connected the ipsilateral forelimb muscle to contralateral motor cortex. hNSC transplantation significantly enhanced the total number of regenerating and myelinated axons identified within the PLG bridge. Finally, the combination of acute bridge implantation and hNSC transplantation exhibited robust improvement in locomotor recovery. These data identify a successful strategy to enhance neurorepair through a temporally layered approach using acute bridge implantation and chronic cell transplantation to spare tissue, promote regeneration, and maximize the function of new axonal connections.
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Affiliation(s)
- Usha Nekanti
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA.
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA.
| | - Pooja S Sakthivel
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA
| | - Atena Zahedi
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
| | - Dana A Creasman
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA
| | - Rebecca A Nishi
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
| | - Courtney M Dumont
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Katja M Piltti
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
| | - Glenn L Guardamondo
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
| | - Norbert Hernandez
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
| | - Xingyuan Chen
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
| | - Hui Song
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
| | - Xiaoxiao Lin
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA
| | - Joshua Martinez
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
| | - Lillian On
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
| | - Anita Lakatos
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
| | - Kiran Pawar
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Brian T David
- Department of Neurosurgery, Rush University Medical Center, Chicago, IL, USA
| | - Zhiling Guo
- Department of Medicine & Susan Samueli Integrative Health Institute, University of California, Irvine, CA, USA
| | - Stephanie K Seidlits
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA
- Center for Neural Circuit Mapping, University of California Irvine, Irvine, CA, USA
| | - Lonnie D Shea
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Brian J Cummings
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA
- Department of Physical Medicine and Rehabilitation, University of California, Irvine, CA, USA
- Institute for Memory Impairments & Neurological Disorder, University of California Irvine, Irvine, CA, USA
| | - Aileen J Anderson
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, CA, USA.
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA.
- Department of Physical Medicine and Rehabilitation, University of California, Irvine, CA, USA.
- Institute for Memory Impairments & Neurological Disorder, University of California Irvine, Irvine, CA, USA.
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2
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Jagrit V, Koffler J, Dulin JN. Combinatorial strategies for cell transplantation in traumatic spinal cord injury. Front Neurosci 2024; 18:1349446. [PMID: 38510468 PMCID: PMC10951004 DOI: 10.3389/fnins.2024.1349446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 02/20/2024] [Indexed: 03/22/2024] Open
Abstract
Spinal cord injury (SCI) substantially reduces the quality of life of affected individuals. Recovery of function is therefore a primary concern of the patient population and a primary goal for therapeutic interventions. Currently, even with growing numbers of clinical trials, there are still no effective treatments that can improve neurological outcomes after SCI. A large body of work has demonstrated that transplantation of neural stem/progenitor cells (NSPCs) can promote regeneration of the injured spinal cord by providing new neurons that can integrate into injured host neural circuitry. Despite these promising findings, the degree of functional recovery observed after NSPC transplantation remains modest. It is evident that treatment of such a complex injury cannot be addressed with a single therapeutic approach. In this mini-review, we discuss combinatorial strategies that can be used along with NSPC transplantation to promote spinal cord regeneration. We begin by introducing bioengineering and neuromodulatory approaches, and highlight promising work using these strategies in integration with NSPCs transplantation. The future of NSPC transplantation will likely include a multi-factorial approach, combining stem cells with biomaterials and/or neuromodulation as a promising treatment for SCI.
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Affiliation(s)
- Vipin Jagrit
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Jacob Koffler
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, United States
- Veterans Affairs Medical Center, San Diego, CA, United States
| | - Jennifer N. Dulin
- Department of Biology, Texas A&M University, College Station, TX, United States
- Texas A&M Institute for Neuroscience, Texas A&M University, College Station, TX, United States
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3
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Ghosh M, Pearse DD. Schwann Cell-Derived Exosomal Vesicles: A Promising Therapy for the Injured Spinal Cord. Int J Mol Sci 2023; 24:17317. [PMID: 38139147 PMCID: PMC10743801 DOI: 10.3390/ijms242417317] [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: 11/10/2023] [Revised: 12/02/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Exosomes are nanoscale-sized membrane vesicles released by cells into their extracellular milieu. Within these nanovesicles reside a multitude of bioactive molecules, which orchestrate essential biological processes, including cell differentiation, proliferation, and survival, in the recipient cells. These bioactive properties of exosomes render them a promising choice for therapeutic use in the realm of tissue regeneration and repair. Exosomes possess notable positive attributes, including a high bioavailability, inherent safety, and stability, as well as the capacity to be functionalized so that drugs or biological agents can be encapsulated within them or to have their surface modified with ligands and receptors to imbue them with selective cell or tissue targeting. Remarkably, their small size and capacity for receptor-mediated transcytosis enable exosomes to cross the blood-brain barrier (BBB) and access the central nervous system (CNS). Unlike cell-based therapies, exosomes present fewer ethical constraints in their collection and direct use as a therapeutic approach in the human body. These advantageous qualities underscore the vast potential of exosomes as a treatment option for neurological injuries and diseases, setting them apart from other cell-based biological agents. Considering the therapeutic potential of exosomes, the current review seeks to specifically examine an area of investigation that encompasses the development of Schwann cell (SC)-derived exosomal vesicles (SCEVs) as an approach to spinal cord injury (SCI) protection and repair. SCs, the myelinating glia of the peripheral nervous system, have a long history of demonstrated benefit in repair of the injured spinal cord and peripheral nerves when transplanted, including their recent advancement to clinical investigations for feasibility and safety in humans. This review delves into the potential of utilizing SCEVs as a therapy for SCI, explores promising engineering strategies to customize SCEVs for specific actions, and examines how SCEVs may offer unique clinical advantages over SC transplantation for repair of the injured spinal cord.
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Affiliation(s)
- Mousumi Ghosh
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
- The Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Veterans Affairs, Veterans Affairs Medical Center, Miami, FL 33136, USA
| | - Damien D. Pearse
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
- The Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- Department of Veterans Affairs, Veterans Affairs Medical Center, Miami, FL 33136, USA
- The Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
- The Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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4
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Georgelou K, Saridaki EA, Karali K, Papagiannaki A, Charalampopoulos I, Gravanis A, Tzeranis DS. Microneurotrophin BNN27 Reduces Astrogliosis and Increases Density of Neurons and Implanted Neural Stem Cell-Derived Cells after Spinal Cord Injury. Biomedicines 2023; 11:biomedicines11041170. [PMID: 37189788 DOI: 10.3390/biomedicines11041170] [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: 03/04/2023] [Revised: 04/02/2023] [Accepted: 04/12/2023] [Indexed: 05/17/2023] Open
Abstract
Microneurotrophins, small-molecule mimetics of endogenous neurotrophins, have demonstrated significant therapeutic effects on various animal models of neurological diseases. Nevertheless, their effects on central nervous system injuries remain unknown. Herein, we evaluate the effects of microneurotrophin BNN27, an NGF analog, in the mouse dorsal column crush spinal cord injury (SCI) model. BNN27 was delivered systemically either by itself or combined with neural stem cell (NSC)-seeded collagen-based scaffold grafts, demonstrated recently to improve locomotion performance in the same SCI model. Data validate the ability of NSC-seeded grafts to enhance locomotion recovery, neuronal cell integration with surrounding tissues, axonal elongation and angiogenesis. Our findings also show that systemic administration of BNN27 significantly reduced astrogliosis and increased neuron density in mice SCI lesion sites at 12 weeks post injury. Furthermore, when BNN27 administration was combined with NSC-seeded PCS grafts, BNN27 increased the density of survived implanted NSC-derived cells, possibly addressing a major challenge of NSC-based SCI treatments. In conclusion, this study provides evidence that small-molecule mimetics of endogenous neurotrophins can contribute to effective combinatorial treatments for SCI, by simultaneously regulating key events of SCI and supporting grafted cell therapies in the lesion site.
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Affiliation(s)
- Konstantina Georgelou
- Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 71003 Heraklion, Greece
| | | | - Kanelina Karali
- Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 71003 Heraklion, Greece
| | - Argyri Papagiannaki
- Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Greece
| | - Ioannis Charalampopoulos
- Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 71003 Heraklion, Greece
| | - Achille Gravanis
- Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Greece
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 71003 Heraklion, Greece
| | - Dimitrios S Tzeranis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 71003 Heraklion, Greece
- Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 2109, Cyprus
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5
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Lima R, Monteiro A, Salgado AJ, Monteiro S, Silva NA. Pathophysiology and Therapeutic Approaches for Spinal Cord Injury. Int J Mol Sci 2022; 23:ijms232213833. [PMID: 36430308 PMCID: PMC9698625 DOI: 10.3390/ijms232213833] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 11/07/2022] [Indexed: 11/12/2022] Open
Abstract
Spinal cord injury (SCI) is a disabling condition that disrupts motor, sensory, and autonomic functions. Despite extensive research in the last decades, SCI continues to be a global health priority affecting thousands of individuals every year. The lack of effective therapeutic strategies for patients with SCI reflects its complex pathophysiology that leads to the point of no return in its function repair and regeneration capacity. Recently, however, several studies started to uncover the intricate network of mechanisms involved in SCI leading to the development of new therapeutic approaches. In this work, we present a detailed description of the physiology and anatomy of the spinal cord and the pathophysiology of SCI. Additionally, we provide an overview of different molecular strategies that demonstrate promising potential in the modulation of the secondary injury events that promote neuroprotection or neuroregeneration. We also briefly discuss other emerging therapies, including cell-based therapies, biomaterials, and epidural electric stimulation. A successful therapy might target different pathologic events to control the progression of secondary damage of SCI and promote regeneration leading to functional recovery.
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Affiliation(s)
- Rui Lima
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s Associate Laboratory, PT Government Associated Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - Andreia Monteiro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s Associate Laboratory, PT Government Associated Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - António J. Salgado
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s Associate Laboratory, PT Government Associated Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - Susana Monteiro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s Associate Laboratory, PT Government Associated Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - Nuno A. Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s Associate Laboratory, PT Government Associated Laboratory, 4806-909 Braga/Guimarães, Portugal
- Correspondence:
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6
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Hawkins KA, DeMark LA, Vistamehr A, Snyder HJ, Conroy C, Wauneka C, Tonuzi G, Fuller DD, Clark DJ, Fox EJ. Feasibility of transcutaneous spinal direct current stimulation combined with locomotor training after spinal cord injury. Spinal Cord 2022; 60:971-977. [PMID: 35477745 PMCID: PMC9606142 DOI: 10.1038/s41393-022-00801-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 03/30/2022] [Accepted: 04/01/2022] [Indexed: 11/16/2022]
Abstract
Study Design: Feasibility study, consisting of random-order, cross-over study of a single intervention session, followed by a parallel-arm study of 16 sessions Objectives: To investigate the feasibility of a novel combinatorial approach with simultaneous delivery of transcutaneous spinal direct current stimulation (tsDCS) and locomotor training (tsDCS+LT) after spinal cord injury, compared to sham stimulation and locomotor training (sham+LT), and examine preliminary effects on walking function. Setting: Clinical research center in the southeastern United States Methods: Eight individuals with chronic incomplete spinal cord injury (ISCI) completed the two-part protocol. Feasibility was assessed based on safety (adverse responses), tolerability (pain, spasticity, skin integrity), and protocol achievement (session duration, intensity). Walking function was assessed with the 10-meter and 6-minute walk tests. Results: There were no major adverse responses. Minimal reports of skin irritation and musculoskeletal pain were consistent between groups. Average training peak heart rate as percent of maximum (mean(SD); tsDCS+LT: 66(4)%, sham+LT: 69(10)%) and Borg ratings of perceived exertion (tsDCS+LT: 17.5(1.2), sham+LT: 14.4(1.8)) indicate both groups trained at high intensities. Walking speed gains exceeded the minimal clinically important difference (MCID) in three of four who received tsDCS+LT (0.18(0.29) m/s) and one of four in sham+LT (−0.05(0.23) m/s). Gains in walking endurance exceeded the MCID in one of four in each group (tsDCS+LT: 36.4(69.0) m, sham+LT: 4.9(56.9) m). Conclusions: Combinatorial tsDCS and locomotor training is safe and feasible for individuals with chronic ISCI, even those with considerable walking impairment. Study outcomes support the need to investigate the efficacy of this approach.
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Affiliation(s)
- Kelly A Hawkins
- Department of Physical Therapy, University of Florida, Gainesville, FL, USA
| | | | | | | | | | | | | | - David D Fuller
- Department of Physical Therapy, University of Florida, Gainesville, FL, USA
| | - David J Clark
- Brain Rehabilitation Research Center of Excellence, North Florida/South Georgia Veterans Health System, Gainesville, FL, USA.,Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, USA
| | - Emily J Fox
- Department of Physical Therapy, University of Florida, Gainesville, FL, USA. .,Brooks Rehabilitation, Jacksonville, FL, USA.
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7
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Transplantation of Wnt5a-modified NSCs promotes tissue repair and locomotor functional recovery after spinal cord injury. Exp Mol Med 2020; 52:2020-2033. [PMID: 33311637 PMCID: PMC8080632 DOI: 10.1038/s12276-020-00536-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 09/15/2020] [Accepted: 10/14/2020] [Indexed: 01/15/2023] Open
Abstract
Traditional therapeutic strategies for spinal cord injury (SCI) are insufficient to repair locomotor function because of the failure of axonal reconnection and neuronal regeneration in the injured central nervous system (CNS). Neural stem cell (NSC) transplantation has been considered a potential strategy and is generally feasible for repairing the neural circuit after SCI; however, the most formidable problem is that the neuronal differentiation rate of NSCs is quite limited. Therefore, it is essential to induce the neuronal differentiation of NSCs and improve the differentiation rate of NSCs in spinal cord repair. Our results demonstrate that both Wnt5a and miRNA200b-3p could promote NSC differentiation into neurons and that Wnt5a upregulated miRNA200b-3p expression through MAPK/JNK signaling to promote NSC differentiation into neurons. Wnt5a could reduce RhoA expression by upregulating miRNA200b-3p expression to inhibit activation of the RhoA/Rock signaling pathway, which has been reported to suppress neuronal differentiation. Overexpression of RhoA abolished the neurogenic capacity of Wnt5a and miRNA200b-3p. In vivo, miRNA200b-3p was critical for Wnt5a-induced NSC differentiation into neurons to promote motor functional and histological recovery after SCI by suppressing RhoA/Rock signaling. These findings provide more insight into SCI and help with the identification of novel treatment strategies. Incorporating key molecules into neural stem cells enhances their ability to differentiate correctly and promote repair following spinal cord injury. Spinal cord injuries can have a debilitating effect on patients’ lives, yet there are no therapies that fully restore movement and sensation. Therapies based on neural stem cells (NSCs) show promise, but initial studies show many NSCs differentiate into astrocytes, supportive cells that do not conduct nerve impulses, instead of neurons, leading to treatment failure. Yong Wan and Le Wang at Sun Yat-sen University in Guangzhou, China, and co-workers demonstrated that adding a protein called Wnt5a and a specific microRNA molecule to NSCs significantly increases differentiation into neurons. Wnt5a suppresses a signalling pathway that otherwise interferes with NSC differentiation. Experiments on rat models showed that the therapy improved locomotor function and tissue repair after injury.
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8
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Wiseman TM, Baron-Heeris D, Houwers IGJ, Keenan R, Williams RJ, Nisbet DR, Harvey AR, Hodgetts SI. Peptide Hydrogel Scaffold for Mesenchymal Precursor Cells Implanted to Injured Adult Rat Spinal Cord. Tissue Eng Part A 2020; 27:993-1007. [PMID: 33040713 DOI: 10.1089/ten.tea.2020.0115] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A unique, biomimetic self-assembling peptide (SAP) hydrogel, Fmoc-DIKVAV, has been shown to be a suitable cell and drug delivery system in the injured brain. In this study, we assessed its utility in adult Fischer 344 (F344) rats as a stabilizing scaffold and vehicle for grafted cells after mild thoracic (thoracic level 10 [T10]) contusion spinal cord injury (SCI). Treatments were as follows: Fmoc-DIKVAV alone, Fmoc-DIKVAV containing viable or nonviable rat mesenchymal precursor cells (rMPCs), and rMPCs alone. The majority of post-SCI treatments were administered at 11-15 days (mean 13.5 days) and the results then compared to SCI-only control (no treatment) rats. Postinjury behavior was quantified using open field locomotion (BBB) and LadderWalk analysis. After perfusion at 8 weeks, longitudinal spinal cord sections were immunostained with a panel of antibodies. Qualitatively, in the SAP-only treatment group, implanted gels contained regenerate axons as well as astrocytic, immune cell, and extracellular matrix (ECM) component profiles. Grafts of Fmoc-DIKVAV plus viable or nonviable rMPCs also contained numerous macrophages/microglia and ECM components, but astrocytes were generally confined to implant margins, and axons were rare. Quantitative analysis showed that, while average cyst size was reduced in all experimental groups, the decrease compared to SCI-only controls was only significant in the SAP and rMPC treatment groups. There was gradual improvement in functionality after SCI, but a consistent trend was only seen between the rMPC treatment group and SCI-only controls. In summary, after contusion SCI, implantation of Fmoc-DIKVAV hydrogel provided a favorable microenvironment for cellular infiltration and axonal regrowth, a supportive role that unexpectedly appeared to be compromised by prior inclusion of rMPCs into the gel matrix. Impact statement The self-assembling peptide hydrogel, Fmoc-DIKVAV, is a biomimetic scaffold that is an effective cell and drug delivery system in the injured brain. We examined whether this hydrogel, alone or combined with mesenchymal precursor cells, was also able to stabilise spinal cord tissue after thoracic contusion injury and improve morphological and behavioral outcomes. While improved functionality was not consistently seen, there was reduced cyst size and increased tissue sparing in some groups. There was regenerative axonal growth into hydrogels, but only in initially cell-free implants. This type of polymer is a suitable candidate for further testing in spinal cord injury models.
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Affiliation(s)
- Tylie M Wiseman
- School of Human Sciences, The University of Western Australia (UWA), Perth, Australia
| | - Danii Baron-Heeris
- School of Human Sciences, The University of Western Australia (UWA), Perth, Australia
| | - Imke G J Houwers
- School of Human Sciences, The University of Western Australia (UWA), Perth, Australia
| | - Rory Keenan
- School of Human Sciences, The University of Western Australia (UWA), Perth, Australia
| | - Richard J Williams
- Centre for Molecular and Medical Research, School of Medicine, Deakin University, Burwood, Australia.,Biofab3D, St. Vincent's Hospital, Melbourne, Australia
| | - David R Nisbet
- Biofab3D, St. Vincent's Hospital, Melbourne, Australia.,Laboratory of Advanced Biomaterials, College of Engineering and Computer Science, The Australian National University, Canberra, Australia
| | - Alan R Harvey
- School of Human Sciences, The University of Western Australia (UWA), Perth, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, Australia
| | - Stuart I Hodgetts
- School of Human Sciences, The University of Western Australia (UWA), Perth, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, Australia
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9
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Li X, Peng Z, Long L, Tuo Y, Wang L, Zhao X, Le W, Wan Y. Wnt4-modified NSC transplantation promotes functional recovery after spinal cord injury. FASEB J 2020; 34:82-94. [PMID: 31914702 DOI: 10.1096/fj.201901478rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/27/2019] [Accepted: 10/08/2019] [Indexed: 01/26/2023]
Abstract
Spinal cord injury (SCI) can lead to severe motor and sensory dysfunction, yet there are no effective therapies currently due to the failure of reconstructing the interruption of the neuroanatomical circuit. While neural stem cell (NSC) transplantation has been considered a potential strategy to repair the neural circuit after SCI, the efficacy of this strategy remains unproven. The main reason is that most of the transplanted NSC differentiates into astrocyte rather than neuron in the microenvironment of SCI. Our results demonstrated that Wnt4 significantly promotes the differentiation of NSC into neuron by activating both β-catenin and MAPK/JNK pathways and suppressing the activation of Notch signaling, which is acknowledged as prevention of NSC differentiation into neuron, through downregulating NICD expression, translocating and preventing the combination of NICD and RbpJ in nucleus. In addition, Wnt4 rescues the negative effect of Jagged, the ligand of Notch signaling, to promote neuronal differentiation. Moreover, in vivo study, transplantation of Wnt4-modified NSC efficaciously repairs the injured spinal cord and recovers the motor function of hind limbs after SCI. This study sheds new light into mechanisms that Wnt4-modified NSC transplantation is sufficient to repair the injured spinal cord and recover the motor dysfunction after SCI.
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Affiliation(s)
- Xiang Li
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhiming Peng
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Lingli Long
- Research Center of Translational Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Ying Tuo
- Department of Pathology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Liqin Wang
- Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiaoyang Zhao
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Wang Le
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- The First Affiliated Hospital of Sun Yat-sen University, Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
| | - Yong Wan
- Department of Spine Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- The First Affiliated Hospital of Sun Yat-sen University, Guangdong Provincial Key Laboratory of Orthopaedics and Traumatology, Guangzhou, China
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10
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Morgado PI, Palacios M, Larrain J. In situ injectable hydrogels for spinal cord regeneration: advances from the last 10 years. Biomed Phys Eng Express 2019; 6:012002. [PMID: 33438588 DOI: 10.1088/2057-1976/ab52e8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Spinal cord injury (SCI) is a tremendously devastating disorder with no effective therapy. Neuroprotective strategies have been applied aiming to prevent secondary cell death but no successful and robust effects have been observed. Recently, combinatorial approaches using biomaterials with cells and/or growth factors have demonstrated promising therapeutic effects because of the improvement of axonal growth and in vivo functional recovery in model organisms. In situ injectable hydrogels are a particularly attractive neuroregenerative approach to improve spinal cord repair and regeneration since they can be precisely injected into the lesion site filling the space prior to gelification, decrease scarring and promote axon growth due to the hydrogel's soft structure. Important advances regarding the use of hydrogels as potential therapeutic approaches has been reported during the last 10 years. Injectable alginate hydrogel loaded with GDNF, thermoresponsives heparin-poloxamer loaded with NGF and imidazole-poly(organophosphazenes) hydrogels are just three examples of biomaterials that can promote neurite, axon growth and improve functional recovery in hemisected and resected rats. Here we will review the status of in situ injectable hydrogels for spinal cord regeneration with special focus in the advantages of using hydrogel scaffolds, the ideal polymers to be used, the gelification process and the cells or growth factors combined. The in vitro and in vivo results reported for those biomaterials will be presented, compared and discussed.
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