1
|
Tohda C. Pharmacological intervention for chronic phase of spinal cord injury. Neural Regen Res 2025; 20:1377-1389. [PMID: 38934397 DOI: 10.4103/nrr.nrr-d-24-00176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 05/30/2024] [Indexed: 06/28/2024] Open
Abstract
Spinal cord injury is an intractable traumatic injury. The most common hurdles faced during spinal cord injury are failure of axonal regrowth and reconnection to target sites. These also tend to be the most challenging issues in spinal cord injury. As spinal cord injury progresses to the chronic phase, lost motor and sensory functions are not recovered. Several reasons may be attributed to the failure of recovery from chronic spinal cord injury. These include factors that inhibit axonal growth such as activated astrocytes, chondroitin sulfate proteoglycan, myelin-associated proteins, inflammatory microglia, and fibroblasts that accumulate at lesion sites. Skeletal muscle atrophy due to denervation is another chronic and detrimental spinal cord injury-specific condition. Although several intervention strategies based on multiple outlooks have been attempted for treating spinal cord injury, few approaches have been successful. To treat chronic spinal cord injury, neural cells or tissue substitutes may need to be supplied in the cavity area to enable possible axonal growth. Additionally, stimulating axonal growth activity by extrinsic factors is extremely important and essential for maintaining the remaining host neurons and transplanted neurons. This review focuses on pharmacotherapeutic approaches using small compounds and proteins to enable axonal growth in chronic spinal cord injury. This review presents some of these candidates that have shown promising outcomes in basic research ( in vivo animal studies) and clinical trials: AA-NgR(310)ecto-Fc (AXER-204), fasudil, phosphatase and tensin homolog protein antagonist peptide 4, chondroitinase ABC, intracellular sigma peptide, (-)-epigallocatechin gallate, matrine, acteoside, pyrvate kinase M2, diosgenin, granulocyte-colony stimulating factor, and fampridine-sustained release. Although the current situation suggests that drug-based therapies to recover function in chronic spinal cord injury are limited, potential candidates have been identified through basic research, and these candidates may be subjects of clinical studies in the future. Moreover, cocktail therapy comprising drugs with varied underlying mechanisms may be effective in treating the refractory status of chronic spinal cord injury.
Collapse
Affiliation(s)
- Chihiro Tohda
- Section of Neuromedical Science, Institute of Natural Medicine, University of Toyama, Toyama, Japan
| |
Collapse
|
2
|
Michel-Flutot P, Cheng L, Thomas SJ, Lisi B, Schwartz H, Lam S, Lyttle M, Jaffe DA, Smith G, Li S, Wright MC, Lepore AC. PTEN inhibition promotes robust growth of bulbospinal respiratory axons and partial recovery of diaphragm function in a chronic model of cervical contusion spinal cord injury. Exp Neurol 2024; 378:114816. [PMID: 38789023 PMCID: PMC11200215 DOI: 10.1016/j.expneurol.2024.114816] [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: 01/10/2024] [Revised: 03/25/2024] [Accepted: 05/16/2024] [Indexed: 05/26/2024]
Abstract
High spinal cord injury (SCI) leads to persistent and debilitating compromise in respiratory function. Cervical SCI not only causes the death of phrenic motor neurons (PhMNs) that innervate the diaphragm, but also damages descending respiratory pathways originating in the rostral ventral respiratory group (rVRG) located in the brainstem, resulting in denervation and consequent silencing of spared PhMNs located caudal to injury. It is imperative to determine whether interventions targeting rVRG axon growth and respiratory neural circuit reconnection are efficacious in chronic cervical contusion SCI, given that the vast majority of individuals are chronically-injured and most cases of SCI involve contusion-type damage to the cervical region. We therefore employed a rat model of chronic cervical hemicontusion to test therapeutic manipulations aimed at reconstructing damaged rVRG-PhMN-diaphragm circuitry to achieve recovery of respiratory function. At a chronic time point post-injury, we systemically administered: an antagonist peptide directed against phosphatase and tensin homolog (PTEN), a central inhibitor of neuron-intrinsic axon growth potential; an antagonist peptide directed against receptor-type protein tyrosine phosphatase sigma (PTPσ), another important negative regulator of axon growth capacity; or a combination of these two peptides. PTEN antagonist peptide (PAP4) promoted partial recovery of diaphragm motor activity out to nine months post-injury (though this effect depended on the anesthetic regimen used during recording), while PTPσ peptide did not impact diaphragm function after cervical SCI. Furthermore, PAP4 promoted robust growth of descending bulbospinal rVRG axons caudal to the injury within the denervated portion of the PhMN pool, while PTPσ peptide did not affect rVRG axon growth at this location that is critical to control of diaphragmatic respiratory function. In conclusion, we find that, when PTEN inhibition is targeted at a chronic time point following cervical contusion, our non-invasive PAP4 strategy can successfully promote significant regrowth of damaged respiratory neural circuitry and also partial recovery of diaphragm motor function.
Collapse
Affiliation(s)
- Pauline Michel-Flutot
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Lan Cheng
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Samantha J Thomas
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Brianna Lisi
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Harrison Schwartz
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Sandy Lam
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Megan Lyttle
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - David A Jaffe
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - George Smith
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 191405104, USA
| | - Shuxin Li
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 191405104, USA
| | - Megan C Wright
- Department of Biology, Arcadia University, Glenside, PA 19038, USA
| | - Angelo C Lepore
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| |
Collapse
|
3
|
Sahoo PK, Hanovice N, Ward P, Agrawal M, Smith TP, SiMa H, Dulin JN, Vaughn LS, Tuszynski M, Welshhans K, Benowitz L, English A, Houle JD, Twiss JL. Disruption of Core Stress Granule Protein Aggregates Promotes CNS Axon Regeneration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.597743. [PMID: 38895344 PMCID: PMC11185597 DOI: 10.1101/2024.06.07.597743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Depletion or inhibition of core stress granule proteins, G3BP1 in mammals and TIAR-2 in C. elegans , increases axon regeneration in injured neurons that show spontaneous regeneration. Inhibition of G3BP1 by expression of its acidic or 'B-domain' accelerates axon regeneration after nerve injury bringing a potential therapeutic intervention to promote neural repair in the peripheral nervous system. Here, we asked if G3BP1 inhibition is a viable strategy to promote regeneration in the injured mammalian central nervous system where axons do not regenerate spontaneously. G3BP1 B-domain expression was found to promote axon regeneration in both the mammalian spinal cord and optic nerve. Moreover, a cell permeable peptide to a subregion of G3BP1's B-domain (rodent G3BP1 amino acids 190-208) accelerated axon regeneration after peripheral nerve injury and promoted the regrowth of reticulospinal axons into the distal transected spinal cord through a bridging peripheral nerve graft. The rodent and human G3BP1 peptides promoted axon growth from rodent and human neurons cultured on permissive substrates, and this function required alternating Glu/Asp-Pro repeats that impart a unique predicted tertiary structure. These studies point to G3BP1 granules as a critical impediment to CNS axon regeneration and indicate that G3BP1 granule disassembly represents a novel therapeutic strategy for promoting neural repair after CNS injury.
Collapse
|
4
|
Saikia BB, Bhowmick S, Malat A, Preetha Rani MR, Thaha A, Abdul-Muneer PM. ICAM-1 Deletion Using CRISPR/Cas9 Protects the Brain from Traumatic Brain Injury-Induced Inflammatory Leukocyte Adhesion and Transmigration Cascades by Attenuating the Paxillin/FAK-Dependent Rho GTPase Pathway. J Neurosci 2024; 44:e1742232024. [PMID: 38326036 PMCID: PMC10941244 DOI: 10.1523/jneurosci.1742-23.2024] [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: 09/15/2023] [Revised: 01/09/2024] [Accepted: 01/27/2024] [Indexed: 02/09/2024] Open
Abstract
Intercellular adhesion molecule-1 (ICAM-1) is identified as an initiator of neuroinflammatory responses that lead to neurodegeneration and cognitive and sensory-motor deficits in several pathophysiological conditions including traumatic brain injury (TBI). However, the underlying mechanisms of ICAM-1-mediated leukocyte adhesion and transmigration and its link with neuroinflammation and functional deficits following TBI remain elusive. Here, we hypothesize that blocking of ICAM-1 attenuates the transmigration of leukocytes to the brain and promotes functional recovery after TBI. The experimental TBI was induced in vivo by fluid percussion injury (25 psi) in male and female wild-type and ICAM-1-/- mice and in vitro by stretch injury (3 psi) in human brain microvascular endothelial cells (hBMVECs). We treated hBMVECs and animals with ICAM-1 CRISPR/Cas9 and conducted several biochemical analyses and demonstrated that CRISPR/Cas9-mediated ICAM-1 deletion mitigates blood-brain barrier (BBB) damage and leukocyte transmigration to the brain by attenuating the paxillin/focal adhesion kinase (FAK)-dependent Rho GTPase pathway. For analyzing functional outcomes, we used a cohort of behavioral tests that included sensorimotor functions, psychological stress analyses, and spatial memory and learning following TBI. In conclusion, this study could establish the significance of deletion or blocking of ICAM-1 in transforming into a novel preventive approach against the pathophysiology of TBI.
Collapse
Affiliation(s)
- Bibhuti Ballav Saikia
- Laboratory of CNS injury and Molecular Therapy, JFK Neuroscience Institute, Hackensack Meridian Health JFK University Medical Center, Edison, New Jersey 08820
| | - Saurav Bhowmick
- Laboratory of CNS injury and Molecular Therapy, JFK Neuroscience Institute, Hackensack Meridian Health JFK University Medical Center, Edison, New Jersey 08820
| | - Anitha Malat
- Laboratory of CNS injury and Molecular Therapy, JFK Neuroscience Institute, Hackensack Meridian Health JFK University Medical Center, Edison, New Jersey 08820
| | - M R Preetha Rani
- Laboratory of CNS injury and Molecular Therapy, JFK Neuroscience Institute, Hackensack Meridian Health JFK University Medical Center, Edison, New Jersey 08820
| | - Almas Thaha
- Laboratory of CNS injury and Molecular Therapy, JFK Neuroscience Institute, Hackensack Meridian Health JFK University Medical Center, Edison, New Jersey 08820
| | - P M Abdul-Muneer
- Laboratory of CNS injury and Molecular Therapy, JFK Neuroscience Institute, Hackensack Meridian Health JFK University Medical Center, Edison, New Jersey 08820
- Department of Neurology, Hackensack Meridian School of Medicine, Nutley, New Jersey 07110
| |
Collapse
|
5
|
Michel-Flutot P, Cheng L, Thomas SJ, Lisi B, Schwartz H, Lam S, Lyttle M, Jaffe DA, Smith G, Li S, Wright MC, Lepore AC. PTEN inhibition promotes robust growth of bulbospinal respiratory axons and partial recovery of diaphragm function in a chronic model of cervical contusion spinal cord injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.10.575021. [PMID: 38260313 PMCID: PMC10802567 DOI: 10.1101/2024.01.10.575021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
High spinal cord injury (SCI) leads to persistent and debilitating compromise in respiratory function. Cervical SCI not only causes the death of phrenic motor neurons (PhMNs) that innervate the diaphragm, but also damages descending respiratory pathways originating in the rostral ventral respiratory group (rVRG) located in the brainstem, resulting in denervation and consequent silencing of spared PhMNs located caudal to injury. It is imperative to determine whether interventions targeting rVRG axon growth and respiratory neural circuit reconnection are efficacious in chronic cervical contusion SCI, given that the vast majority of individuals are chronically-injured and most cases of SCI involve contusion-type damage to the cervical region. We therefore employed a clinically-relevant rat model of chronic cervical hemicontusion to test therapeutic manipulations aimed at reconstructing damaged rVRG-PhMN-diaphragm circuitry to achieve recovery of respiratory function. At a chronic time point post-injury, we systemically administered: an antagonist peptide directed against phosphatase and tensin homolog (PTEN), a central inhibitor of neuron-intrinsic axon growth potential; an antagonist peptide directed against receptor-type protein tyrosine phosphatase sigma (PTPσ), another important negative regulator of axon growth capacity; or a combination of these two peptides. PTEN antagonist peptide (PAP4) promoted partial recovery of diaphragm motor activity out to nine months post-injury, while PTPσ peptide did not impact diaphragm function after cervical SCI. Furthermore, PAP4 promoted robust growth of descending bulbospinal rVRG axons caudal to the injury within the denervated portion of the PhMN pool, while PTPσ peptide did not affect rVRG axon growth at this location that is critical to control of diaphragmatic respiratory function. In conclusion, we find that, when PTEN inhibition is targeted at a chronic time point following cervical contusion that is most relevant to the SCI clinical population, our non-invasive PAP4 strategy can successfully promote significant regrowth of damaged respiratory neural circuitry and also partial recovery of diaphragm motor function. HIGHLIGHTS PTEN antagonist peptide promotes partial diaphragm function recovery in chronic cervical contusion SCI.PTPσ inhibitory peptide does not impact diaphragm function recovery in chronic cervical contusion SCI.PTEN antagonist peptide promotes growth of bulbospinal rVRG axons in chronic cervical contusion SCI.PTPσ peptide does not affect rVRG axon growth in chronic cervical contusion SCI.
Collapse
|
6
|
Kim HJ, Saikia JM, Monte KMA, Ha E, Romaus-Sanjurjo D, Sanchez JJ, Moore AX, Hernaiz-Llorens M, Chavez-Martinez CL, Agba CK, Li H, Zhang J, Lusk DT, Cervantes KM, Zheng B. Deep scRNA sequencing reveals a broadly applicable Regeneration Classifier and implicates antioxidant response in corticospinal axon regeneration. Neuron 2023; 111:3953-3969.e5. [PMID: 37848024 PMCID: PMC10843387 DOI: 10.1016/j.neuron.2023.09.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/26/2023] [Accepted: 09/15/2023] [Indexed: 10/19/2023]
Abstract
Despite substantial progress in understanding the biology of axon regeneration in the CNS, our ability to promote regeneration of the clinically important corticospinal tract (CST) after spinal cord injury remains limited. To understand regenerative heterogeneity, we conducted patch-based single-cell RNA sequencing on rare regenerating CST neurons at high depth following PTEN and SOCS3 deletion. Supervised classification with Garnett gave rise to a Regeneration Classifier, which can be broadly applied to predict the regenerative potential of diverse neuronal types across developmental stages or after injury. Network analyses highlighted the importance of antioxidant response and mitochondrial biogenesis. Conditional gene deletion validated a role for NFE2L2 (or NRF2), a master regulator of antioxidant response, in CST regeneration. Our data demonstrate a universal transcriptomic signature underlying the regenerative potential of vastly different neuronal populations and illustrate that deep sequencing of only hundreds of phenotypically identified neurons has the power to advance regenerative biology.
Collapse
Affiliation(s)
- Hugo J Kim
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Junmi M Saikia
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA; Neurosciences Graduate Program, University of California San Diego, La Jolla, CA, USA USA
| | - Katlyn Marie A Monte
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Eunmi Ha
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Daniel Romaus-Sanjurjo
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Joshua J Sanchez
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Andrea X Moore
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Marc Hernaiz-Llorens
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Carmine L Chavez-Martinez
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA; Graduate program in Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Chimuanya K Agba
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA; Neurosciences Graduate Program, University of California San Diego, La Jolla, CA, USA USA
| | - Haoyue Li
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Joseph Zhang
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Daniel T Lusk
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Kayla M Cervantes
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA; VA San Diego Research Service, San Diego, CA, USA.
| |
Collapse
|
7
|
Stewart AN, Kumari R, Bailey WM, Glaser EP, Bosse-Joseph CC, Park KA, Hammers GV, Wireman OH, Gensel JC. PTEN knockout using retrogradely transported AAVs transiently restores locomotor abilities in both acute and chronic spinal cord injury. Exp Neurol 2023; 368:114502. [PMID: 37558155 PMCID: PMC10498341 DOI: 10.1016/j.expneurol.2023.114502] [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: 04/25/2023] [Revised: 07/07/2023] [Accepted: 08/07/2023] [Indexed: 08/11/2023]
Abstract
Restoring function in chronic stages of spinal cord injury (SCI) has often been met with failure or reduced efficacy when regenerative strategies are delayed past the acute or sub-acute stages of injury. Restoring function in the chronically injured spinal cord remains a critical challenge. We found that a single injection of retrogradely transported adeno-associated viruses (AAVrg) to knockout the phosphatase and tensin homolog protein (PTEN) in chronic SCI can effectively target both damaged and spared axons and transiently restore locomotor functions in near-complete injury models. AAVrg's were injected to deliver cre recombinase and/or a red fluorescent protein (RFP) under the human Synapsin 1 promoter (hSyn1) into the spinal cords of C57BL/6 PTENFloxΔ/Δ mice to knockout PTEN (PTEN-KO) in a severe thoracic SCI crush model at both acute and chronic time points. PTEN-KO improved locomotor abilities in both acute and chronic SCI conditions over a 9-week period. Regardless of whether treatment was initiated at the time of injury (acute), or three months after SCI (chronic), mice with limited hindlimb joint movement gained hindlimb weight support after treatment. Interestingly, functional improvements were not sustained beyond 9 weeks coincident with a loss of RFP reporter-gene expression and a near-complete loss of treatment-associated functional recovery by 6 months post-treatment. Treatment effects were also specific to severely injured mice; animals with weight support at the time of treatment lost function over a 6-month period. Retrograde tracing with Fluorogold revealed viable neurons throughout the motor cortex despite a loss of RFP expression at 9 weeks post-PTEN-KO. However, few Fluorogold labeled neurons were detected within the motor cortex at 6 months post-treatment. BDA labeling from the motor cortex revealed a dense corticospinal tract (CST) bundle in all groups except chronically treated PTEN-KO mice, indicating a potential long-term toxic effect of PTEN-KO to neurons in the motor cortex which was corroborated by a loss of β-tubulin III labeling above the lesion within spinal cords after PTEN-KO. PTEN-KO mice had significantly more β-tubulin III labeled axons within the lesion when treatment was delivered acutely, but not chronically post-SCI. In conclusion, we have found that using AAVrg's to knockout PTEN is an effective manipulation capable of restoring motor functions in chronic SCI and can enhance axon growth of currently unidentified axon populations when delivered acutely after injury. However, the long-term consequences of PTEN-KO on neuronal health and viability should be further explored.
Collapse
Affiliation(s)
- Andrew N Stewart
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA.
| | - Reena Kumari
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - William M Bailey
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Ethan P Glaser
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Christopher C Bosse-Joseph
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Kennedy A Park
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Gabrielle V Hammers
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Olivia H Wireman
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - John C Gensel
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA; College of Medicine, University of Kentucky, Lexington, KY 40536, USA.
| |
Collapse
|
8
|
Lear BP, Moore DL. Moving CNS axon growth and regeneration research into human model systems. Front Neurosci 2023; 17:1198041. [PMID: 37425013 PMCID: PMC10324669 DOI: 10.3389/fnins.2023.1198041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/25/2023] [Indexed: 07/11/2023] Open
Abstract
Axon regeneration is limited in the adult mammalian central nervous system (CNS) due to both intrinsic and extrinsic factors. Rodent studies have shown that developmental age can drive differences in intrinsic axon growth ability, such that embryonic rodent CNS neurons extend long axons while postnatal and adult CNS neurons do not. In recent decades, scientists have identified several intrinsic developmental regulators in rodents that modulate growth. However, whether this developmentally programmed decline in CNS axon growth is conserved in humans is not yet known. Until recently, there have been limited human neuronal model systems, and even fewer age-specific human models. Human in vitro models range from pluripotent stem cell-derived neurons to directly reprogrammed (transdifferentiated) neurons derived from human somatic cells. In this review, we discuss the advantages and disadvantages of each system, and how studying axon growth in human neurons can provide species-specific knowledge in the field of CNS axon regeneration with the goal of bridging basic science studies to clinical trials. Additionally, with the increased availability and quality of 'omics datasets of human cortical tissue across development and lifespan, scientists can mine these datasets for developmentally regulated pathways and genes. As there has been little research performed in human neurons to study modulators of axon growth, here we provide a summary of approaches to begin to shift the field of CNS axon growth and regeneration into human model systems to uncover novel drivers of axon growth.
Collapse
Affiliation(s)
| | - Darcie L. Moore
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, United States
| |
Collapse
|
9
|
Pearson A, Ortiz C, Eisenbaum M, Arrate C, Browning M, Mullan M, Bachmeier C, Crawford F, Ojo JO. Deletion of PTEN in microglia ameliorates chronic neuroinflammation following repetitive mTBI. Mol Cell Neurosci 2023; 125:103855. [PMID: 37084991 DOI: 10.1016/j.mcn.2023.103855] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 03/25/2023] [Accepted: 04/17/2023] [Indexed: 04/23/2023] Open
Abstract
Traumatic brain injury is a leading cause of morbidity and mortality in adults and children in developed nations. Following the primary injury, microglia, the resident innate immune cells of the CNS, initiate several inflammatory signaling cascades and pathophysiological responses that may persist chronically; chronic neuroinflammation following TBI has been closely linked to the development of neurodegeneration and neurological dysfunction. Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that have been shown to regulate several key mechanisms in the inflammatory response to TBI. Increasing evidence has shown that the modulation of the PI3K/AKT signaling pathway has the potential to influence the cellular response to inflammatory stimuli. However, directly targeting PI3K signaling poses several challenges due to its regulatory role in several cell survival pathways. We have previously identified that the phosphatase and tensin homolog deleted on chromosome 10 (PTEN), the major negative regulator of PI3K/AKT signaling, is dysregulated following exposure to repetitive mild traumatic brain injury (r-mTBI). Moreover, this dysregulated PI3K/AKT signaling was correlated with chronic microglial-mediated neuroinflammation. Therefore, we interrogated microglial-specific PTEN as a therapeutic target in TBI by generating a microglial-specific, Tamoxifen inducible conditional PTEN knockout model using a CX3CR1 Cre recombinase mouse line PTENfl/fl/CX3CR1+/CreERT2 (mcg-PTENcKO), and exposed them to our 20-hit r-mTBI paradigm. Animals were treated with tamoxifen at 76 days post-last injury, and the effects of microglia PTEN deletion on immune-inflammatory responses were assessed at 90-days post last injury. We observed that the deletion of microglial PTEN ameliorated the proinflammatory response to repetitive brain trauma, not only reducing chronic microglial activation and proinflammatory cytokine production but also rescuing TBI-induced reactive astrogliosis, demonstrating that these effects extended beyond microglia alone. Additionally, we observed that the pharmacological inhibition of PTEN with BpV(HOpic) ameliorated the LPS-induced activation of microglial NFκB signaling in vitro. Together, these data provide support for the role of PTEN as a regulator of chronic neuroinflammation following repetitive mild TBI.
Collapse
Affiliation(s)
- Andrew Pearson
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom.
| | - Camila Ortiz
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom
| | - Max Eisenbaum
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom
| | - Clara Arrate
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
| | | | - Michael Mullan
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom
| | - Corbin Bachmeier
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom
| | - Fiona Crawford
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom; James A. Haley Veterans' Hospital, 13000 Bruce B Downs Blvd, Tampa, FL 33612, USA
| | - Joseph O Ojo
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA; The Open University, Walton Hall, Kents Hill, Milton Keynes MK7 6AA, United Kingdom
| |
Collapse
|
10
|
Stewart AN, Kumari R, Bailey WM, Glaser EP, Hammers GV, Wireman OH, Gensel JC. PTEN knockout using retrogradely transported AAVs restores locomotor abilities in both acute and chronic spinal cord injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.17.537179. [PMID: 37131840 PMCID: PMC10153160 DOI: 10.1101/2023.04.17.537179] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Restoring function in chronic stages of spinal cord injury (SCI) has often been met with failure or reduced efficacy when regenerative strategies are delayed past the acute or sub-acute stages of injury. Restoring function in the chronically injured spinal cord remains a critical challenge. We found that a single injection of retrogradely transported adeno-associated viruses (AAVrg) to knockout the phosphatase and tensin homolog protein (PTEN) in chronic SCI can effectively target both damaged and spared axons and restore locomotor functions in near-complete injury models. AAVrg's were injected to deliver cre recombinase and/or a red fluorescent protein (RFP) under the human Synapsin 1 promoter (hSyn1) into the spinal cords of C57BL/6 PTEN FloxΔ / Δ mice to knockout PTEN (PTEN-KO) in a severe thoracic SCI crush model at both acute and chronic time points. PTEN-KO improved locomotor abilities in both acute and chronic SCI conditions over a 9-week period. Regardless of whether treatment was initiated at the time of injury (acute), or three months after SCI (chronic), mice with limited hindlimb joint movement gained hindlimb weight support after treatment. Interestingly, functional improvements were not sustained beyond 9 weeks coincident with a loss of RFP reporter-gene expression and a near-complete loss of treatment-associated functional recovery by 6 months post-treatment. Treatment effects were also specific to severely injured mice; animals with weight support at the time of treatment lost function over a 6-month period. Retrograde tracing with Fluorogold revealed viable neurons throughout the motor cortex despite a loss of RFP expression at 9 weeks post-PTEN-KO. However, few Fluorogold labeled neurons were detected within the motor cortex at 6 months post-treatment. BDA labeling from the motor cortex revealed a dense corticospinal tract (CST) bundle in all groups except chronically treated PTEN-KO mice indicating a potential long-term toxic effect of PTEN-KO to neurons in the motor cortex. PTEN-KO mice had significantly more β - tubulin III labeled axons within the lesion when treatment was delivered acutely, but not chronically post-SCI. In conclusion, we have found that using AAVrg's to knockout PTEN is an effective manipulation capable of restoring motor functions in chronic SCI and can enhance axon growth of currently unidentified axon populations when delivered acutely after injury. However, the long-term consequences of PTEN-KO may exert neurotoxic effects.
Collapse
Affiliation(s)
- Andrew N. Stewart
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, USA
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Reena Kumari
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, USA
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky 40536, USA
| | - William M. Bailey
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, USA
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Ethan P. Glaser
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, USA
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Gabrielle V. Hammers
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, USA
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Olivia H. Wireman
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, USA
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky 40536, USA
| | - John C. Gensel
- Department of Physiology, University of Kentucky, Lexington, Kentucky 40536, USA
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky 40536, USA
- College of Medicine, University of Kentucky, Lexington, Kentucky 40536, USA
| |
Collapse
|
11
|
Kim HN, McCrea MR, Li S. Advances in molecular therapies for targeting pathophysiology in spinal cord injury. Expert Opin Ther Targets 2023; 27:171-187. [PMID: 37017093 PMCID: PMC10148912 DOI: 10.1080/14728222.2023.2194532] [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: 01/23/2023] [Revised: 03/20/2023] [Accepted: 03/20/2023] [Indexed: 04/06/2023]
Abstract
INTRODUCTION Spinal cord injury (SCI) affects 25,000-50,000 people around the world each year and there is no cure for SCI patients currently. The primary injury damages spinal cord tissues and secondary injury mechanisms, including ischemia, apoptosis, inflammation, and astrogliosis, further exacerbate the lesions to the spinal cord. Recently, researchers have designed various therapeutic approaches for SCI by targeting its major cellular or molecular pathophysiology. AREAS COVERED Some strategies have shown promise in repairing injured spinal cord for functional recoveries, such as administering neuroprotective reagents, targeting specific genes to promote robust axon regeneration of disconnected spinal fiber tracts, targeting epigenetic factors to enhance cell survival and neural repair, and facilitating neuronal relay pathways and neuroplasticity for restoration of function after SCI. This review focuses on the major advances in preclinical molecular therapies for SCI reported in recent years. EXPERT OPINION Recent progress in developing novel and effective repairing strategies for SCI is encouraging, but many challenges remain for future design of effective treatments, including developing highly effective neuroprotectants for early interventions, stimulating robust neuronal regeneration with functional synaptic reconnections among disconnected neurons, maximizing the recovery of lost neural functions with combination strategies, and translating the most promising therapies into human use.
Collapse
Affiliation(s)
- Ha Neui Kim
- Shriners Hospitals Pediatric Research Center, Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Madeline R. McCrea
- Shriners Hospitals Pediatric Research Center, Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center, Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| |
Collapse
|
12
|
Almeida F, Marques S, Santos A, Prins C, Cardoso F, Heringer L, Mendonça H, Martinez A. Molecular approaches for spinal cord injury treatment. Neural Regen Res 2023; 18:23-30. [PMID: 35799504 PMCID: PMC9241396 DOI: 10.4103/1673-5374.344830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Injuries to the spinal cord result in permanent disabilities that limit daily life activities. The main reasons for these poor outcomes are the limited regenerative capacity of central neurons and the inhibitory milieu that is established upon traumatic injuries. Despite decades of research, there is still no efficient treatment for spinal cord injury. Many strategies are tested in preclinical studies that focus on ameliorating the functional outcomes after spinal cord injury. Among these, molecular compounds are currently being used for neurological recovery, with promising results. These molecules target the axon collapsed growth cone, the inhibitory microenvironment, the survival of neurons and glial cells, and the re-establishment of lost connections. In this review we focused on molecules that are being used, either in preclinical or clinical studies, to treat spinal cord injuries, such as drugs, growth and neurotrophic factors, enzymes, and purines. The mechanisms of action of these molecules are discussed, considering traumatic spinal cord injury in rodents and humans.
Collapse
|
13
|
Stem Cell Strategies in Promoting Neuronal Regeneration after Spinal Cord Injury: A Systematic Review. Int J Mol Sci 2022; 23:ijms232112996. [PMID: 36361786 PMCID: PMC9657320 DOI: 10.3390/ijms232112996] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 10/09/2022] [Accepted: 10/25/2022] [Indexed: 11/25/2022] Open
Abstract
Spinal cord injury (SCI) is a devastating condition with a significant medical and socioeconomic impact. To date, no effective treatment is available that can enable neuronal regeneration and recovery of function at the damaged level. This is thought to be due to scar formation, axonal degeneration and a strong inflammatory response inducing a loss of neurons followed by a cascade of events that leads to further spinal cord damage. Many experimental studies demonstrate the therapeutic effect of stem cells in SCI due to their ability to differentiate into neuronal cells and release neurotrophic factors. Therefore, it appears to be a valid strategy to use in the field of regenerative medicine. This review aims to provide an up-to-date summary of the current research status, challenges, and future directions for stem cell therapy in SCI models, providing an overview of this constantly evolving and promising field.
Collapse
|
14
|
Liu W, Tao JC, Zhu SZ, Dai CL, Wang YX, Yu B, Yao C, Sun YY. Expression and regulatory network of long noncoding RNA in rats after spinal cord hemisection injury. Neural Regen Res 2022; 17:2300-2304. [PMID: 35259853 PMCID: PMC9083175 DOI: 10.4103/1673-5374.337052] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/27/2021] [Accepted: 12/14/2021] [Indexed: 11/05/2022] Open
Abstract
Long noncoding RNAs (lncRNAs) participate in a variety of biological processes and diseases. However, the expression and function of lncRNAs after spinal cord injury has not been extensively analyzed. In this study of right side hemisection of the spinal cord at T10, we detected the expression of lncRNAs in the proximal tissue of T10 lamina at different time points and found 445 lncRNAs and 6522 mRNA were differentially expressed. We divided the differentially expressed lncRNAs into 26 expression trends and analyzed Profile 25 and Profile 2, the two expression trends with the most significant difference. Our results showed that the expression of 68 lncRNAs in Profile 25 rose first and remained high 3 days post-injury. There were 387 mRNAs co-expressed with the 68 lncRNAs in Profile 25. The co-expression network showed that the co-expressed genes were mainly enriched in cell division, inflammatory response, FcγR-mediated cell phagocytosis signaling pathway, cell cycle and apoptosis. The expression of 56 lncRNAs in Profile2 first declined and remained low after 3 days post-injury. There were 387 mRNAs co-expressed with the 56 lncRNAs in Profile 2. The co-expression network showed that the co-expressed genes were mainly enriched in the chemical synaptic transmission process and in the signaling pathway of neuroactive ligand-receptor interaction. The results provided the expression and regulatory network of the main lncRNAs after spinal cord injury and clarified their co-expressed gene enriched biological processes and signaling pathways. These findings provide a new direction for the clinical treatment of spinal cord injury.
Collapse
Affiliation(s)
- Wei Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Jin-Cheng Tao
- Medical College, Nantong University, Nantong, Jiangsu Province, China
| | - Sheng-Ze Zhu
- Medical College, Nantong University, Nantong, Jiangsu Province, China
| | - Chao-Lun Dai
- Medical College, Nantong University, Nantong, Jiangsu Province, China
| | - Ya-Xian Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Bin Yu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Chun Yao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Yu-Yu Sun
- Department of Orthopedics, Nantong Third People’s Hospital, Nantong University, Nantong, Jiangsu Province, China
| |
Collapse
|
15
|
Noristani HN. Intrinsic regulation of axon regeneration after spinal cord injury: Recent advances and remaining challenges. Exp Neurol 2022; 357:114198. [DOI: 10.1016/j.expneurol.2022.114198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/20/2022] [Accepted: 08/02/2022] [Indexed: 11/16/2022]
|
16
|
Self-delivering RNAi compounds as therapeutic agents in the central nervous system to enhance axonal regeneration after injury. iScience 2022; 25:104379. [PMID: 35620420 PMCID: PMC9127586 DOI: 10.1016/j.isci.2022.104379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 12/10/2021] [Accepted: 05/04/2022] [Indexed: 12/01/2022] Open
Abstract
The therapeutic use of RNAi has grown but often faces several hurdles related to delivery systems, compound stability, immune activation, and on-target/off-tissue effects. Self-delivering RNAi (sdRNA) molecules do not require delivery agents or excipients. Here we demonstrate the ability of sdRNA to reduce the expression of PTEN (phosphatase and tensin homolog) to stimulate regenerative axon regrowth in the injured adult CNS. PTEN-targeting sdRNA compounds were tested for efficacy in vivo by intravitreal injection after adult rat optic nerve injury. We describe critical steps in lead compound generation through the optimization of nucleotide modifications, enhancements for stability in biological matrices, and screening for off-target immunostimulatory activity. The data show that PTEN expression in vivo can be reduced using sdRNA and this enhances regeneration in adult CNS neurons after injury, raising the possibility that this method could be utilized for other clinically relevant nervous system indications. self-delivering siRNA (sdRNA) can decrease neuronal gene expression in vivo sdRNA can be successfully delivered in vivo without using vectors or excipients Phosphatase and tensin homolog (PTEN)-targeting sdRNA can enhance CNS neuronal regeneration after injury
Collapse
|
17
|
Inositol Polyphosphate-5-Phosphatase K ( Inpp5k) Enhances Sprouting of Corticospinal Tract Axons after CNS Trauma. J Neurosci 2022; 42:2190-2204. [PMID: 35135857 PMCID: PMC8936595 DOI: 10.1523/jneurosci.0897-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 01/13/2022] [Accepted: 01/14/2022] [Indexed: 11/21/2022] Open
Abstract
Failure of CNS neurons to mount a significant growth response after trauma contributes to chronic functional deficits after spinal cord injury. Activator and repressor screening of embryonic cortical neurons and retinal ganglion cells in vitro and transcriptional profiling of developing CNS neurons harvested in vivo have identified several candidates that stimulate robust axon growth in vitro and in vivo Building on these studies, we sought to identify novel axon growth activators induced in the complex adult CNS environment in vivo We transcriptionally profiled intact sprouting adult corticospinal neurons (CSNs) after contralateral pyramidotomy (PyX) in nogo receptor-1 knock-out mice and found that intact CSNs were enriched in genes in the 3-phosphoinositide degradation pathway, including six 5-phosphatases. We explored whether inositol polyphosphate-5-phosphatase K (Inpp5k) could enhance corticospinal tract (CST) axon growth in preclinical models of acute and chronic CNS trauma. Overexpression of Inpp5k in intact adult CSNs in male and female mice enhanced the sprouting of intact CST terminals after PyX and cortical stroke and sprouting of CST axons after acute and chronic severe thoracic spinal contusion. We show that Inpp5k stimulates axon growth in part by elevating the density of active cofilin in labile growth cones, thus stimulating actin polymerization and enhancing microtubule protrusion into distal filopodia. We identify Inpp5k as a novel CST growth activator capable of driving compensatory axon growth in multiple complex CNS injury environments and underscores the veracity of using in vivo transcriptional screening to identify the next generation of cell-autonomous factors capable of repairing the damaged CNS.SIGNIFICANCE STATEMENT Neurologic recovery is limited after spinal cord injury as CNS neurons are incapable of self-repair post-trauma. In vitro screening strategies exploit the intrinsically high growth capacity of embryonic CNS neurons to identify novel axon growth activators. While promising candidates have been shown to stimulate axon growth in vivo, concomitant functional recovery remains incomplete. We identified Inpp5k as a novel axon growth activator using transcriptional profiling of intact adult corticospinal tract (CST) neurons that had initiated a growth response after pyramidotomy in plasticity sensitized nogo receptor-1-null mice. Here, we show that Inpp5k overexpression can stimulate CST axon growth after pyramidotomy, stroke, and acute and chronic contusion injuries. These data support in vivo screening approaches to identify novel axon growth activators.
Collapse
|
18
|
Campion TJ, Sheikh IS, Smit RD, Iffland PH, Chen J, Junker IP, Krynska B, Crino PB, Smith GM. Viral expression of constitutively active AKT3 induces CST axonal sprouting and regeneration, but also promotes seizures. Exp Neurol 2021; 349:113961. [PMID: 34953897 DOI: 10.1016/j.expneurol.2021.113961] [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: 06/03/2021] [Revised: 12/17/2021] [Accepted: 12/18/2021] [Indexed: 12/01/2022]
Abstract
Increasing the intrinsic growth potential of neurons after injury has repeatedly been shown to promote some level of axonal regeneration in rodent models. One of the most studied pathways involves the activation of the PI3K/AKT/mTOR pathways, primarily by reducing the levels of PTEN, a negative regulator of PI3K. Likewise, activation of signal transducer and activator of transcription 3 (STAT3) has previously been shown to boost axonal regeneration and sprouting within the injured nervous system. Here, we examined the regeneration of the corticospinal tract (CST) after cortical expression of constitutively active (ca) Akt3 and STAT3, both separately and in combination. Overexpression of caAkt3 induced regeneration of CST axons past the injury site independent of caSTAT3 overexpression. STAT3 demonstrated improved axon sprouting compared to controls and contributed to a synergistic improvement in effects when combined with Akt3 but failed to promote axonal regeneration as an individual therapy. Despite showing impressive axonal regeneration, animals expressing Akt3 failed to show any functional improvement and deteriorated with time. During this period, we observed progressive Akt3 dose-dependent increase in behavioral seizures. Histology revealed increased phosphorylation of ribosomal S6 protein within the unilateral cortex, increased neuronal size, microglia activation and hemispheric enlargement (hemimegalencephaly).
Collapse
Affiliation(s)
- Thomas J Campion
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Imran S Sheikh
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Rupert D Smit
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Philip H Iffland
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jie Chen
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Ian P Junker
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Barbara Krynska
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - George M Smith
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America.
| |
Collapse
|
19
|
Nieuwenhuis B, Eva R. Promoting axon regeneration in the central nervous system by increasing PI3-kinase signaling. Neural Regen Res 2021; 17:1172-1182. [PMID: 34782551 PMCID: PMC8643051 DOI: 10.4103/1673-5374.327324] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Much research has focused on the PI3-kinase and PTEN signaling pathway with the aim to stimulate repair of the injured central nervous system. Axons in the central nervous system fail to regenerate, meaning that injuries or diseases that cause loss of axonal connectivity have life-changing consequences. In 2008, genetic deletion of PTEN was identified as a means of stimulating robust regeneration in the optic nerve. PTEN is a phosphatase that opposes the actions of PI3-kinase, a family of enzymes that function to generate the membrane phospholipid PIP3 from PIP2 (phosphatidylinositol (3,4,5)-trisphosphate from phosphatidylinositol (4,5)-bisphosphate). Deletion of PTEN therefore allows elevated signaling downstream of PI3-kinase, and was initially demonstrated to promote axon regeneration by signaling through mTOR. More recently, additional mechanisms have been identified that contribute to the neuron-intrinsic control of regenerative ability. This review describes neuronal signaling pathways downstream of PI3-kinase and PIP3, and considers them in relation to both developmental and regenerative axon growth. We briefly discuss the key neuron-intrinsic mechanisms that govern regenerative ability, and describe how these are affected by signaling through PI3-kinase. We highlight the recent finding of a developmental decline in the generation of PIP3 as a key reason for regenerative failure, and summarize the studies that target an increase in signaling downstream of PI3-kinase to facilitate regeneration in the adult central nervous system. Finally, we discuss obstacles that remain to be overcome in order to generate a robust strategy for repairing the injured central nervous system through manipulation of PI3-kinase signaling.
Collapse
Affiliation(s)
- Bart Nieuwenhuis
- John van Geest Center for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Richard Eva
- John van Geest Center for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| |
Collapse
|
20
|
MicroRNAs 21 and 199a-3p Regulate Axon Growth Potential through Modulation of Pten and mTor mRNAs. eNeuro 2021; 8:ENEURO.0155-21.2021. [PMID: 34326064 PMCID: PMC8362682 DOI: 10.1523/eneuro.0155-21.2021] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 07/11/2021] [Accepted: 07/15/2021] [Indexed: 12/14/2022] Open
Abstract
Increased mTOR activity has been shown to enhance regeneration of injured axons by increasing neuronal protein synthesis, while PTEN signaling can block mTOR activity to attenuate protein synthesis. MicroRNAs (miRs) have been implicated in regulation of PTEN and mTOR expression, and previous work in spinal cord showed an increase in miR-199a-3p after spinal cord injury (SCI) and increase in miR-21 in SCI animals that had undergone exercise. Pten mRNA is a target for miR-21 and miR-199a-3p is predicted to target mTor mRNA. Here, we show that miR-21 and miR-199a-3p are expressed in adult dorsal root ganglion (DRG) neurons, and we used culture preparations to test functions of the rat miRs in adult DRG and embryonic cortical neurons. miR-21 increases and miR-199a-3p decreases in DRG neurons after in vivo axotomy. In both the adult DRG and embryonic cortical neurons, miR-21 promotes and miR-199a-3p attenuates neurite growth. miR-21 directly bound to Pten mRNA and miR-21 overexpression decreased Pten mRNA levels. Conversely, miR-199a-3p directly bound to mTor mRNA and miR-199a-3p overexpression decreased mTor mRNA levels. Overexpressing miR-21 increased both overall and intra-axonal protein synthesis in cultured DRGs, while miR-199a-3p overexpression decreased this protein synthesis. The axon growth phenotypes seen with miR-21 and miR-199a-3p overexpression were reversed by co-transfecting PTEN and mTOR cDNA expression constructs with the predicted 3′ untranslated region (UTR) miR target sequences deleted. Taken together, these studies indicate that injury-induced alterations in miR-21 and miR-199a-3p expression can alter axon growth capacity by changing overall and intra-axonal protein synthesis through regulation of the PTEN/mTOR pathway.
Collapse
|
21
|
Chen Y, Wei Z, Liu J, Xie H, Wang B, Wu J, Zhu Z, Fan Y. Long noncoding RNA ZFAS1 aggravates spinal cord injury by binding with miR-1953 and regulating the PTEN/PI3K/AKT pathway. Neurochem Int 2021; 147:104977. [PMID: 33524472 DOI: 10.1016/j.neuint.2021.104977] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/21/2021] [Accepted: 01/24/2021] [Indexed: 01/22/2023]
Abstract
Multiple evidence has shown that long non-coding RNAs (lncRNAs) are novel modulators in the development of many neurological diseases, including spinal cord injury (SCI). Recently, a novel lncRNA zinc finger antisense 1 (ZFAS1) has been found to facilitate the development of many human diseases. However, the effect of ZFAS1 in SCI has not been explored. In the present study, we used the SCI mouse models and LPS-treated BV-2 cellular models to explore the role of ZFAS1 in SCI. Basso Mouse Scale score was applied to reveal locomotor function. Cresyl violet staining was used to reveal volume of spared myelin around the lesion in the injured cord. RIP and luciferase reporter assay were applied to detect binding capacity among RNAs. Next, ZFAS1 was identified to be upregulated in spinal cord tissues of SCI mice. ZFAS1 knockdown promoted functional recovery and inhibited cell apoptosis and the inflammatory response in SCI mice. ZFAS1 bound with microRNA 1953 (miR-1953), and miR-1953 was downregulated in spinal cord tissues of SCI mice. Furthermore, we confirmed that ZFAS1 promoted SCI progression via binding with miR-1953. In addition, phosphatase and tensin homolog (PTEN) was verified to be a downstream target for miR-1953 in vitro, and PTEN was upregulated in spinal cord tissues of SCI mice. Finally, we illustrated that ZFAS1 inactivated the PI3K/AKT pathway through upregulation of PTEN. In conclusion, our study revealed that ZFAS1 facilitated SCI by binding with miR-1953 and regulating the PTEN/PI3K/AKT pathway, which may provide a potential novel insight for treatment of SCI.
Collapse
Affiliation(s)
- Yunxiang Chen
- Department of Neurosurgery, Affiliated Jinhua Hospital, Zhejiang University School of Medicine (Jinhua Municipal Central Hospital), Jinhua, 321000, Zhejiang, China
| | - Zijian Wei
- Department of Orthopaedics, Sir Run Run Hospital, Nanjing Medical University, Nanjing, 211100, Jiangsu, China; Department of Spine Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, 210008, Jiangsu, China
| | - Jun Liu
- Department of Orthopaedics, Sir Run Run Hospital, Nanjing Medical University, Nanjing, 211100, Jiangsu, China; Department of Orthopaedics, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, 210011, Jiangsu, China
| | - Hao Xie
- Department of Orthopaedics, Sir Run Run Hospital, Nanjing Medical University, Nanjing, 211100, Jiangsu, China
| | - Binbin Wang
- Department of Orthopaedics, Sir Run Run Hospital, Nanjing Medical University, Nanjing, 211100, Jiangsu, China
| | - Ji Wu
- Department of Orthopaedics, Sir Run Run Hospital, Nanjing Medical University, Nanjing, 211100, Jiangsu, China
| | - Zezhang Zhu
- Department of Spine Surgery, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, 210008, Jiangsu, China; Department of Spine Surgery, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, 210008, Jiangsu, China
| | - Yuejun Fan
- Department of Neurosurgery, Affiliated Jinhua Hospital, Zhejiang University School of Medicine (Jinhua Municipal Central Hospital), Jinhua, 321000, Zhejiang, China.
| |
Collapse
|
22
|
Bhowmick S, Abdul-Muneer PM. PTEN Blocking Stimulates Corticospinal and Raphespinal Axonal Regeneration and Promotes Functional Recovery After Spinal Cord Injury. J Neuropathol Exp Neurol 2021; 80:169-181. [PMID: 33367790 DOI: 10.1093/jnen/nlaa147] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The long-term disabilities associated with spinal cord injury (SCI) are primarily due to the absence of robust neuronal regeneration and functional plasticity. The inability of the axon to regenerate after SCI is contributed by several intrinsic factors that trigger a cascade of molecular growth program and modulates axonal sprouting. Phosphatase and tensin homolog (PTEN) is one of the intrinsic factors contributing to growth failure after SCI, however, the underlying mechanism is not well known. Here, we developed a novel therapeutic approach for treating SCI by suppressing the action of PTEN in a mouse model of hemisection SCI. We have used a novel peptide, PTEN antagonistic peptide (PAP) to block the critical domains of PTEN to demonstrate its ability to potentially promote axon growth. PAP treatment not only enhanced regeneration of corticospinal axons into the caudal spinal cord but also promoted the regrowth of descending serotonergic axons in SCI mice. Furthermore, expression levels of p-mTOR, p-S6, p-Akt, p-Erk, p-GSK, p-PI3K downstream of PTEN signaling pathway were increased significantly in the spinal cord of SCI mice systemically treated with PAP than control TAT peptide-treated mice. Our novel strategy of administering deliverable compounds postinjury may facilitate translational feasibility for central nervous system injury.
Collapse
Affiliation(s)
- Saurav Bhowmick
- From the Laboratory of CNS Injury and Molecular Therapy, JFK Neuroscience Institute, Hackensack Meridian Health JFK University Medical Center, Edison, New Jersey
| | - P M Abdul-Muneer
- Department of Neurology, Hackensack Meridian School of Medicine, Nutley, New Jersey
| |
Collapse
|
23
|
Cheng L, Sami A, Ghosh B, Goudsward HJ, Smith GM, Wright MC, Li S, Lepore AC. Respiratory axon regeneration in the chronically injured spinal cord. Neurobiol Dis 2021; 155:105389. [PMID: 33975016 DOI: 10.1016/j.nbd.2021.105389] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/19/2021] [Accepted: 05/05/2021] [Indexed: 02/01/2023] Open
Abstract
Promoting the combination of robust regeneration of damaged axons and synaptic reconnection of these growing axon populations with appropriate neuronal targets represents a major therapeutic goal following spinal cord injury (SCI). A key impediment to achieving this important aim includes an intrinsic inability of neurons to extend axons in adult CNS, particularly in the context of the chronically-injured spinal cord. We tested whether an inhibitory peptide directed against phosphatase and tensin homolog (PTEN: a central inhibitor of neuron-intrinsic axon growth potential) could restore inspiratory diaphragm function by reconnecting critical respiratory neural circuitry in a rat model of chronic cervical level 2 (C2) hemisection SCI. We found that systemic delivery of PTEN antagonist peptide 4 (PAP4) starting at 8 weeks after C2 hemisection promoted substantial, long-distance regeneration of injured bulbospinal rostral Ventral Respiratory Group (rVRG) axons into and through the lesion and back toward phrenic motor neurons (PhMNs) located in intact caudal C3-C5 spinal cord. Despite this robust rVRG axon regeneration, PAP4 stimulated only minimal recovery of diaphragm function. Furthermore, re-lesion through the hemisection site completely removed PAP4-induced functional improvement, demonstrating that axon regeneration through the lesion was responsible for this partial functional recovery. Interestingly, there was minimal formation of putative excitatory monosynaptic connections between regrowing rVRG axons and PhMN targets, suggesting that (1) limited rVRG-PhMN synaptic reconnectivity was responsible at least in part for the lack of a significant functional effect, (2) chronically-injured spinal cord presents an obstacle to achieving synaptogenesis between regenerating axons and post-synaptic targets, and (3) addressing this challenge is a potentially-powerful strategy to enhance therapeutic efficacy in the chronic SCI setting. In conclusion, our study demonstrates a non-invasive and transient pharmacological approach in chronic SCI to repair the critically-important neural circuitry controlling diaphragmatic respiratory function, but also sheds light on obstacles to circuit plasticity presented by the chronically-injured spinal cord.
Collapse
Affiliation(s)
- Lan Cheng
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Armin Sami
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Biswarup Ghosh
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Hannah J Goudsward
- Department of Biology, Arcadia University, 450 S. Easton Rd., 220 Boyer Hall, Glenside, PA 19038, USA
| | - George M Smith
- Department of Neuroscience, Shriners Hospitals for Pediatric Research Center, Temple University School of Medicine, 3500 North Broad Street, Philadelphia, PA 19140-5104, USA
| | - Megan C Wright
- Department of Biology, Arcadia University, 450 S. Easton Rd., 220 Boyer Hall, Glenside, PA 19038, USA
| | - Shuxin Li
- Department of Neuroscience, Shriners Hospitals for Pediatric Research Center, Temple University School of Medicine, 3500 North Broad Street, Philadelphia, PA 19140-5104, USA
| | - Angelo C Lepore
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| |
Collapse
|
24
|
Chen Y, Tian Z, He L, Liu C, Wang N, Rong L, Liu B. Exosomes derived from miR-26a-modified MSCs promote axonal regeneration via the PTEN/AKT/mTOR pathway following spinal cord injury. Stem Cell Res Ther 2021; 12:224. [PMID: 33820561 PMCID: PMC8022427 DOI: 10.1186/s13287-021-02282-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 03/11/2021] [Indexed: 12/16/2022] Open
Abstract
Background Exosomes derived from the bone marrow mesenchymal stem cell (MSC) have shown great potential in spinal cord injury (SCI) treatment. This research was designed to investigate the therapeutic effects of miR-26a-modified MSC-derived exosomes (Exos-26a) following SCI. Methods Bioinformatics and data mining were performed to explore the role of miR-26a in SCI. Exosomes were isolated from miR-26a-modified MSC culture medium by ultracentrifugation. A series of experiments, including assessment of Basso, Beattie and Bresnahan scale, histological evaluation, motor-evoked potential recording, diffusion tensor imaging, and western blotting, were performed to determine the therapeutic influence and the underlying molecular mechanisms of Exos-26a in SCI rats. Results Exos-26a was shown to promote axonal regeneration. Furthermore, we found that exosomes derived from miR-26a-modified MSC could improve neurogenesis and attenuate glial scarring through PTEN/AKT/mTOR signaling cascades. Conclusions Exosomes derived from miR-26a-modified MSC could activate the PTEN-AKT-mTOR pathway to promote axonal regeneration and neurogenesis and attenuate glia scarring in SCI and thus present great potential for SCI treatment. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02282-0.
Collapse
Affiliation(s)
- Yuyong Chen
- Department of Spine Surgery, The 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, Guangdong, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China
| | - Zhenming Tian
- Department of Spine Surgery, The 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, Guangdong, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China
| | - Lei He
- Department of Spine Surgery, The 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, Guangdong, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China
| | - Can Liu
- Department of Spine Surgery, The 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, Guangdong, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China
| | - Nangxiang Wang
- Department of Spine Surgery, The 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, Guangdong, China.,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China.,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China
| | - Limin Rong
- Department of Spine Surgery, The 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, Guangdong, China. .,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China. .,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China.
| | - Bin Liu
- Department of Spine Surgery, The 3rd Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, Guangdong, China. .,Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China. .,Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, Guangzhou, 510630, Guangdong, China.
| |
Collapse
|
25
|
MicroRNA-92a-3p enhances functional recovery and suppresses apoptosis after spinal cord injury via targeting phosphatase and tensin homolog. Biosci Rep 2021; 40:222664. [PMID: 32297644 PMCID: PMC7199448 DOI: 10.1042/bsr20192743] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 03/17/2020] [Accepted: 03/23/2020] [Indexed: 02/08/2023] Open
Abstract
Spinal cord injury (SCI) is a neurological disease commonly caused by traumatic events on spinal cords. MiRNA-92a-3p is reported to be down-regulated after SCI. Our study investigated the effects of up-regulated miR-92a-3p on SCI and the underlying mechanisms. SCI mice model was established to evaluate the functional recovery of hindlimbs of mice through open-field locomotion and scored by Basso, Beattie, and Bresnahan (BBB) locomotion scale. Apoptosis of spinal cord cells was determined by flow cytometry. The effects of miR-92a-3p on SCI were detected by intrathecally injecting miR-92a-3p agomiR (agomiR-92) into the mice prior to the establishment of SCI. Phosphatase and tensin homolog (PTEN) was predicted as a target of miR-29a-3p by TargetScan. We further assessed the effects of agomiR-92 or/and overexpressed PTEN on apoptosis rates and apoptotic protein expressions in SCI mice. Moreover, the activation of protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling was determined by Western blot. The results showed that compared with the sham-operated mice, SCI mice had much lower BBB scores, and theapoptosis rate of spinal cord cells was significantly increased. After SCI, the expression of miR-92a-3p was down-regulated, and increased expression of miR-92a-3p induced by agomiR-92 further significantly increased the BBB score and decreased apoptosis. PTEN was specifically targeted by miR-92a-3p. In addition, the phosphorylation levels of Akt and mTOR were up-regulated under the treatment of agomiR-92. Our data demonstrated that the neuroprotective effects of miR-92a-3p on spinal cord safter SCI were highly associated with the activation of the PTEN/AKT/mTOR pathway.
Collapse
|
26
|
Transneuronal delivery of hyper-interleukin-6 enables functional recovery after severe spinal cord injury in mice. Nat Commun 2021; 12:391. [PMID: 33452250 PMCID: PMC7810685 DOI: 10.1038/s41467-020-20112-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 11/13/2020] [Indexed: 12/27/2022] Open
Abstract
Spinal cord injury (SCI) often causes severe and permanent disabilities due to the regenerative failure of severed axons. Here we report significant locomotor recovery of both hindlimbs after a complete spinal cord crush. This is achieved by the unilateral transduction of cortical motoneurons with an AAV expressing hyper-IL-6 (hIL-6), a potent designer cytokine stimulating JAK/STAT3 signaling and axon regeneration. We find collaterals of these AAV-transduced motoneurons projecting to serotonergic neurons in both sides of the raphe nuclei. Hence, the transduction of cortical neurons facilitates the axonal transport and release of hIL-6 at innervated neurons in the brain stem. Therefore, this transneuronal delivery of hIL-6 promotes the regeneration of corticospinal and raphespinal fibers after injury, with the latter being essential for hIL-6-induced functional recovery. Thus, transneuronal delivery enables regenerative stimulation of neurons in the deep brain stem that are otherwise challenging to access, yet highly relevant for functional recovery after SCI.
Collapse
|
27
|
Lv SQ, Wu W. ISP and PAP4 peptides promote motor functional recovery after peripheral nerve injury. Neural Regen Res 2021; 16:1598-1605. [PMID: 33433490 PMCID: PMC8323685 DOI: 10.4103/1673-5374.294565] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Both intracellular sigma peptide (ISP) and phosphatase and tensin homolog agonist protein (PAP4) promote nerve regeneration and motor functional recovery after spinal cord injury. However, the role of these two small peptides in peripheral nerve injury remains unclear. A rat model of brachial plexus injury was established by crush of the C6 ventral root. The rats were then treated with subcutaneous injection of PAP4 (497 µg/d, twice per day) or ISP (11 µg/d, once per day) near the injury site for 21 successive days. After ISP and PAP treatment, the survival of motoneurons was increased, the number of regenerated axons and neuromuscular junctions was increased, muscle atrophy was reduced, the electrical response of the motor units was enhanced and the motor function of the injured upper limbs was greatly improved in rats with brachial plexus injury. These findings suggest that ISP and PAP4 promote the recovery of motor function after peripheral nerve injury in rats. The animal care and experimental procedures were approved by the Laboratory Animal Ethics Committee of Jinan University of China (approval No. 20111008001) in 2011.
Collapse
Affiliation(s)
- Shi-Qin Lv
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, Guangdong Province, China
| | - Wutian Wu
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, Guangdong Province; Re-Stem Biotechnology Co., Ltd., Suzhou, Jiangsu Province, China
| |
Collapse
|
28
|
Kang J, Zhang C, Zhi Z, Wang Y, Liu J, Wu F, Xu G. Stem-like cells of various origins showed therapeutic effect to improve the recovery of spinal cord injury. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2020; 48:627-638. [PMID: 32054316 DOI: 10.1080/21691401.2020.1725031] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We aimed to evaluate the therapeutic effects of exosomes, which were collected from human neuroepithelial stem cells (HNESCs) treated by miR-29b mimics, on the treatment of spinal cord injury (SCI). Computational analysis, real-time PCR, Western blot analysis and TUNEL assay, a BBB score system, the Nissl staining and IHC assay were conducted to explore the molecular signalling pathway underlying the function of exosomes in SCI. Exosomes isolated from cells treated with HNESC exhibited the strongest inhibitory effect on cell apoptosis while exhibiting the highest level of miR-29b expression and the lowest levels of PTEN and caspase-3 expression. Moreover, PTEN and caspase-3 were identified as the direct target genes of miR-29b. The exosomes isolated from the groups of HNESC and HNESC + miR-29b mimics exhibited in vivo therapeutic effects by restoring the BBB score and apoptosis index of post-SCI neuron cells to those of normal neuron cells, with the exosomes collected from the group of HNESC + miR-29b mimics showing the strongest effect. We suggested that the exosomes derived from the group of HNESC + miR-29b mimics exerted therapeutic effects on SCI by down-regulating the expression of PTEN/caspase-3 and subsequently suppressing the apoptosis of neuron cells.
Collapse
Affiliation(s)
- Jian Kang
- Department of Orthopedics, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Chenglin Zhang
- Department of Orthopedics, School of Medicine, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Zhongzheng Zhi
- Department of Orthopedics, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Yingjie Wang
- Department of Orthopedics, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Jingdong Liu
- Department of Orthopedics, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| | - Furong Wu
- Shanghai Clinical Research Center for Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China
| | - Guanghui Xu
- Department of Orthopedics, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, China
| |
Collapse
|
29
|
Cheng RD, Ren W, Sun P, Tian L, Zhang L, Zhang J, Li JB, Ye XM. Spinal cord injury causes insulin resistance associated with PI3K signaling pathway in hypothalamus. Neurochem Int 2020; 140:104839. [PMID: 32853751 DOI: 10.1016/j.neuint.2020.104839] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 07/12/2020] [Accepted: 08/16/2020] [Indexed: 11/19/2022]
Abstract
Spinal cord injury (SCI) is an independent risk factor for type 2 diabetes, and may induce insulin resistance that leads to this disease. Studies have shown that greater phosphoinositide 3-kinase (PI3K) activation in the hypothalamus leads to activation of the anti-inflammatory pathway, and the anti-inflammatory reflex may protect against insulin resistance and type 2 diabetes. However, the importance of this phenomenon in type 2 diabetes pathogenesis after SCI remains elusive. In the present study, the expression of c-Fos in the hypothalamus of rats with SCI was elevated, and the hypothalamus injury was observer following SCI. Then we showed that SCI could induce increased levels of blood glucose and glucose tolerance in rats. Also, we found that SCI could damage the liver, adipocyte and pancreas, and led to lipid position in liver. Western blots were used to detect the level of PI3K and p-Akt in the hypothalamus, and the results showed a significant downregulation of PI3K and p-Akt after SCI. Furthermore, to verify the activity of the PI3K signaling pathway, immunofluorescence was used to examine the expression of neurons positive for p-S6 (a marker of PI3K activation) after SCI. The results showed that the expression of p-S6-positive neurons decreased after SCI. In addition, the effect of SCI on peripheral inflammation was also investigated. Following SCI, the serum levels of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 increased. Collectively, our results suggest abnormality in glucose metabolism after SCI, and demonstrate that SCI may impair activation of the PI3K signaling pathway in the hypothalamus. The reduced activity of the PI3K signaling pathway in the hypothalamus may lead to peripheral inflammation, which might be the mechanism underlying the development of insulin resistance and type 2 diabetes following SCI.
Collapse
Affiliation(s)
- Rui-Dong Cheng
- Department of Rehabilitation Medicine, Zhejiang Provincial Peoples' Hospital/People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Wen Ren
- Department of Family Medicine, The First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang, China
| | - Peng Sun
- Department of Rehabilitation Medicine, Zhejiang Provincial Peoples' Hospital/People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Liang Tian
- Department of Rehabilitation Medicine, Zhejiang Provincial Peoples' Hospital/People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Li Zhang
- Department of Rehabilitation Medicine, Zhejiang Provincial Peoples' Hospital/People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Jie Zhang
- Department of Rehabilitation Medicine, Zhejiang Provincial Peoples' Hospital/People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Jue-Bao Li
- Department of Rehabilitation Medicine, Zhejiang Provincial Peoples' Hospital/People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Xiang-Ming Ye
- Department of Rehabilitation Medicine, Zhejiang Provincial Peoples' Hospital/People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang, China.
| |
Collapse
|
30
|
Moses C, Hodgetts SI, Nugent F, Ben-Ary G, Park KK, Blancafort P, Harvey AR. Transcriptional repression of PTEN in neural cells using CRISPR/dCas9 epigenetic editing. Sci Rep 2020; 10:11393. [PMID: 32647121 PMCID: PMC7347541 DOI: 10.1038/s41598-020-68257-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 06/19/2020] [Indexed: 12/11/2022] Open
Abstract
After damage to the adult mammalian central nervous system (CNS), surviving neurons have limited capacity to regenerate and restore functional connectivity. Conditional genetic deletion of PTEN results in robust CNS axon regrowth, while PTEN repression with short hairpin RNA (shRNA) improves regeneration but to a lesser extent, likely due to suboptimal PTEN mRNA knockdown using this approach. Here we employed the CRISPR/dCas9 system to repress PTEN transcription in neural cells. We targeted the PTEN proximal promoter and 5' untranslated region with dCas9 fused to the repressor protein Krüppel-associated box (KRAB). dCas9-KRAB delivered in a lentiviral vector with one CRISPR guide RNA (gRNA) achieved potent and specific PTEN repression in human cell line models and neural cells derived from human iPSCs, and induced histone (H)3 methylation and deacetylation at the PTEN promoter. The dCas9-KRAB system outperformed a combination of four shRNAs targeting the PTEN transcript, a construct previously used in CNS injury models. The CRISPR system also worked more effectively than shRNAs for Pten repression in rat neural crest-derived PC-12 cells, and enhanced neurite outgrowth after nerve growth factor stimulation. PTEN silencing with CRISPR/dCas9 epigenetic editing may provide a new option for promoting axon regeneration and functional recovery after CNS trauma.
Collapse
Affiliation(s)
- C Moses
- School of Human Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
- Cancer Epigenetics Laboratory, The Harry Perkins Institute of Medical Research, 6 Verdun Street, Nedlands, WA, 6009, Australia
| | - S I Hodgetts
- School of Human Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
- Perron Institute for Neurological and Translational Science, 8 Verdun Street, Nedlands, WA, 6009, Australia
| | - F Nugent
- Cancer Epigenetics Laboratory, The Harry Perkins Institute of Medical Research, 6 Verdun Street, Nedlands, WA, 6009, Australia
- School of Molecular Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - G Ben-Ary
- School of Human Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - K K Park
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - P Blancafort
- School of Human Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia.
- Cancer Epigenetics Laboratory, The Harry Perkins Institute of Medical Research, 6 Verdun Street, Nedlands, WA, 6009, Australia.
- Greehey Children's Cancer Research Institute, UT Health San Antonio, 8403 Floyd Curl Drive, San Antonio, TX, 78229, USA.
| | - A R Harvey
- School of Human Sciences, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Perth, WA, 6009, Australia.
- Perron Institute for Neurological and Translational Science, 8 Verdun Street, Nedlands, WA, 6009, Australia.
| |
Collapse
|
31
|
Liu J, Li K, Huang K, Yang C, Huang Z, Zhao X, Song S, Pang T, Zhou J, Wang Y, Wang C, Tang Y. Acellularized spinal cord scaffolds incorporating bpV(pic)/PLGA microspheres promote axonal regeneration and functional recovery after spinal cord injury. RSC Adv 2020; 10:18677-18686. [PMID: 35518337 PMCID: PMC9053942 DOI: 10.1039/d0ra02661a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/07/2020] [Indexed: 01/20/2023] Open
Abstract
Spinal cord injury (SCI) is a traumatic injury to the central nervous system (CNS) with a high rate of disability and a low capability of self-recovery. Phosphatase and tensin homolog (PTEN) inhibition by pharmacological blockade with bisperoxovanadium (pic) (bpV(pic)) has been reported to increase AKT/mTOR activity and induce robust axonal elongation and regeneration. However, the therapeutic effect of bpV(pic) in treating SCI is limited due to the lack of efficient delivery approaches. In this study, a composite scaffold consisting of an acellular spinal cord (ASC) scaffold and incorporated bpV(pic) loaded poly (lactic-co-glycolic acid) (PLGA) microspheres was developed, in order to improve the therapeutic effect of bpV(pic) on SCI. The inhibition of PTEN activity and activation of the mTORC1/AKT pathway, the axonal regeneration and the markers of apoptosis were analyzed via western blot and immunofluorescence in vitro. The bpV(pic)/PLGA/ASC scaffolds showed excellent biocompatibility and promoted the viability of neural stem cells and axonal growth in vitro. Implantation of the composite scaffold into rats with hemi-sectioned SCI resulted in increased axonal regeneration and functional recovery in vivo. Besides, bpV(pic) inhibited the phosphorylation of PTEN and activated the PI3K/mTOR signaling pathway. The successful construction of the composite scaffold improves the therapeutic effect of bpV(pic) on SCI.
Collapse
Affiliation(s)
- Jia Liu
- Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities18 Zhongshan II RoadBaiseGuangxi533000China+86-0776-2833076
| | - Kai Li
- Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital of Southern Medical UniversityGuangzhouGuangdong510000China
| | - Ke Huang
- Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities18 Zhongshan II RoadBaiseGuangxi533000China+86-0776-2833076
| | - Chengliang Yang
- Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities18 Zhongshan II RoadBaiseGuangxi533000China+86-0776-2833076
| | - Zhipeng Huang
- Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities18 Zhongshan II RoadBaiseGuangxi533000China+86-0776-2833076
| | - Xingchang Zhao
- Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities18 Zhongshan II RoadBaiseGuangxi533000China+86-0776-2833076
| | - Shiqiang Song
- Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities18 Zhongshan II RoadBaiseGuangxi533000China+86-0776-2833076
| | - Taisen Pang
- Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities18 Zhongshan II RoadBaiseGuangxi533000China+86-0776-2833076
| | - Jing Zhou
- Department of Anatomy, Youjiang Medical College for NationalitiesBaiseGuangxi533000China
| | - Yuhai Wang
- Academy of Orthopedics, People's Hospital of Ningxia Hui Autonomous RegionNingxia502213China
| | - Chong Wang
- School of Mechanical Engineering, Dongguan University of TechnologyNo. 1 University Road, Songshan LakeDongguanGuangdong523808P. R. China+86-1341-6885162
| | - Yujin Tang
- Department of Orthopedics, Affiliated Hospital of Youjiang Medical University for Nationalities18 Zhongshan II RoadBaiseGuangxi533000China+86-0776-2833076
| |
Collapse
|
32
|
Nathan FM, Ohtake Y, Wang S, Jiang X, Sami A, Guo H, Zhou FQ, Li S. Upregulating Lin28a Promotes Axon Regeneration in Adult Mice with Optic Nerve and Spinal Cord Injury. Mol Ther 2020; 28:1902-1917. [PMID: 32353321 DOI: 10.1016/j.ymthe.2020.04.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 03/16/2020] [Accepted: 04/09/2020] [Indexed: 12/22/2022] Open
Abstract
Severed CNS axons fail to regenerate in adult mammals and there are no effective regenerative strategies to treat patients with CNS injuries. Several genes, including phosphatase and tensin homolog (PTEN) and Krüppel-like factors, regulate intrinsic growth capacity of mature neurons. The Lin28 gene is essential for cell development and pluripotency in worms and mammals. In this study, we evaluated the role of Lin28a in regulating regenerative capacity of diverse populations of CNS neurons in adult mammals. Using a neuron-specific Thy1 promoter, we generated transgenic mice that overexpress Lin28a protein in multiple populations of projection neurons, including corticospinal tracts and retinal ganglion cells. We demonstrate that upregulation of Lin28a in transgenic mice induces significant long distance regeneration of both corticospinal axons and the optic nerve in adult mice. Importantly, overexpression of Lin28a by post-injury treatment with adeno-associated virus type 2 (AAV2) vector stimulates dramatic regeneration of descending spinal tracts and optic nerve axons after lesions. Upregulation of Lin28a also enhances activity of the Akt signaling pathway in mature CNS neurons. Therefore, Lin28a is critical for regulating growth capacity of multiple CNS neurons and may become an important molecular target for treating CNS injuries.
Collapse
Affiliation(s)
- Fatima M Nathan
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Yosuke Ohtake
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Shuo Wang
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Xinpei Jiang
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Armin Sami
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Hua Guo
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Feng-Quan Zhou
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
| |
Collapse
|
33
|
CRISPR, Prime Editing, Optogenetics, and DREADDs: New Therapeutic Approaches Provided by Emerging Technologies in the Treatment of Spinal Cord Injury. Mol Neurobiol 2020; 57:2085-2100. [DOI: 10.1007/s12035-019-01861-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 12/15/2019] [Indexed: 02/07/2023]
|
34
|
Sabirzhanov B, Matyas J, Coll-Miro M, Yu LL, Faden AI, Stoica BA, Wu J. Inhibition of microRNA-711 limits angiopoietin-1 and Akt changes, tissue damage, and motor dysfunction after contusive spinal cord injury in mice. Cell Death Dis 2019; 10:839. [PMID: 31685802 PMCID: PMC6828685 DOI: 10.1038/s41419-019-2079-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 10/09/2019] [Accepted: 10/18/2019] [Indexed: 02/06/2023]
Abstract
Spinal cord injury (SCI) causes neuronal cell death and vascular damage, which contribute to neurological dysfunction. Given that many biochemical changes contribute to such secondary injury, treatment approaches have increasingly focused on combined therapies or use of multi-functional drugs. MicroRNAs (miRs) are small (20-23 nucleotide), non-protein-coding RNAs and can negatively regulate target gene expression at the post-transcriptional level. As individual miRs can potentially modulate expression of multiple relevant proteins after injury, they are attractive candidates as upstream regulators of the secondary SCI progression. In the present study we examined the role of miR-711 modulation after SCI. Levels of miR-711 were increased in injured spinal cord early after SCI, accompanied by rapid downregulation of its target angiopoietin-1 (Ang-1), an endothelial growth factor. Changes of miR-711 were also associated with downregulation of the pro-survival protein Akt (protein kinase B), another target of miR-711, with sequential activation of glycogen synthase kinase 3 and the pro-apoptotic BH3-only molecule PUMA. Central administration of a miR-711 hairpin inhibitor after SCI limited decreases of Ang-1/Akt expression and attenuated apoptotic pathways. Such treatment also reduced neuronal/axonal damage, protected microvasculature and improved motor dysfunction following SCI. In vitro, miR-711 levels were rapidly elevated by neuronal insults, but not by activated microglia and astrocytes. Together, our data suggest that post-traumatic miR-711 elevation contributes to neuronal cell death after SCI, in part by inhibiting Ang-1 and Akt pathways, and may serve as a novel therapeutic target.
Collapse
Affiliation(s)
- Boris Sabirzhanov
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA
| | - Jessica Matyas
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA
| | - Marina Coll-Miro
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA
| | - Laina Lijia Yu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA
| | - Alan I Faden
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA.,University of Maryland Center to Advance Chronic Pain Research, University of Maryland Baltimore, Baltimore, MD, 21201, USA
| | - Bogdan A Stoica
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA
| | - Junfang Wu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), School of Medicine, Baltimore, MD, USA. .,University of Maryland Center to Advance Chronic Pain Research, University of Maryland Baltimore, Baltimore, MD, 21201, USA.
| |
Collapse
|
35
|
Wang Z, Song Y, Han X, Qu P, Wang W. Long noncoding RNA PTENP1 affects the recovery of spinal cord injury by regulating the expression of miR‐19b and miR‐21. J Cell Physiol 2019; 235:3634-3645. [PMID: 31583718 DOI: 10.1002/jcp.29253] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 09/03/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Zhan Wang
- Department of Orthopedics Gansu Provincial Hospital Lanzhou Gansu China
- Department of Orthopedics People's Clinical Medical College of Lanzhou University Lanzhou Gansu China
| | - Yuxin Song
- Department of Orthopedics Gansu Provincial Hospital Lanzhou Gansu China
- Department of Orthopedics People's Clinical Medical College of Lanzhou University Lanzhou Gansu China
| | - Xingwen Han
- Department of Orthopedics The First Hospital of Lanzhou University Lanzhou Gansu China
- Department of Orthopedics The First Clinical Medicine College of Lanzhou University Lanzhou Gansu China
| | - Peng Qu
- Department of Orthopedics The First Hospital of Lanzhou University Lanzhou Gansu China
| | - Wenji Wang
- Department of Orthopedics The First Hospital of Lanzhou University Lanzhou Gansu China
- Department of Orthopedics The First Clinical Medicine College of Lanzhou University Lanzhou Gansu China
| |
Collapse
|
36
|
Kang J, Li Z, Zhi Z, Wang S, Xu G. MiR-21 derived from the exosomes of MSCs regulates the death and differentiation of neurons in patients with spinal cord injury. Gene Ther 2019; 26:491-503. [PMID: 31570818 DOI: 10.1038/s41434-019-0101-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/25/2018] [Accepted: 03/27/2019] [Indexed: 12/19/2022]
Abstract
In this study, we aimed to investigate the therapeutic effect of miR-21 in the treatment of spinal cord injury (SCI) as well as its underlying molecular mechanisms. Real-time PCR and western blot were performed to measure the expression of miR-21, PTEN, and PDCD4 in SCI rats. Locomotion recovery assessment, Nissl staining, IHC assay, and TUNEL assay were utilized to observe the therapeutic effect of miR-21 in the treatment of SCI. Bioinformatics analysis and luciferase assay were conducted to establish the signaling pathway of miR-21, PTEN, and PDCD4. The regulatory relationships between miR-21 and PTEN/PDCD4 were further validated by real-time PCR, western blot, MTT assay, and flow cytometry. Compared with sham-operated rats, SCI rats showed decreased expression of miR-21 along with increased expression of PTEN/PDCD4. Exosomes were equally distributed in MSCs transfected with miR-21, PTEN siRNA, or scramble controls. The exosomes isolated from the supernatant of cultured MSCs could improve the functional recovery of SCI rats by reducing SCI-induced neuron loss. In addition, miR-21 was shown to inhibit the expression of PTEN/PDCD4 and suppress neuron cell death. Moreover, PTEN and PDCD4 were validated as virtual targets of miR-21. In addition, the miR-21/PTEN/PDCD4 signaling pathway was shown to enhance cell viability and suppress cell death in vivo. The exosomes collected from the supernatant of transfected MSCs contained miR-21, which could improve the functional recovery of SCI rats and suppress cell death both in vivo and in vitro via the miR-21/PTEN/PDCD4 signaling pathway.
Collapse
Affiliation(s)
- Jian Kang
- Department of Orthopedics, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, 200081, China
| | - Zhenhuan Li
- Department of Orthopedics, ZhaBei Central Hospital of JingaAn District, Shanghai, 200070, China
| | - Zhongzheng Zhi
- Department of Orthopedics, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, 200081, China
| | - Shiqiang Wang
- Department of Orthopedics, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, 200081, China
| | - Guanghui Xu
- Department of Orthopedics, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, Shanghai, 200081, China.
| |
Collapse
|
37
|
Barros Ribeiro da Silva V, Porcionatto M, Toledo Ribas V. The Rise of Molecules Able To Regenerate the Central Nervous System. J Med Chem 2019; 63:490-511. [PMID: 31518122 DOI: 10.1021/acs.jmedchem.9b00863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Injury to the adult central nervous system (CNS) usually leads to permanent deficits of cognitive, sensory, and/or motor functions. The failure of axonal regeneration in the damaged CNS limits functional recovery. The lack of information concerning the biological mechanism of axonal regeneration and its complexity has delayed the process of drug discovery for many years compared to other drug classes. Starting in the early 2000s, the ability of many molecules to stimulate axonal regrowth was evaluated through automated screening techniques; many hits and some new mechanisms involved in axonal regeneration were identified. In this Perspective, we discuss the rise of the CNS regenerative drugs, the main biological techniques used to test these drug candidates, some of the most important screens performed so far, and the main challenges following the identification of a drug that is able to induce axonal regeneration in vivo.
Collapse
Affiliation(s)
| | - Marimélia Porcionatto
- Universidade Federal de São Paulo , Escola Paulista de Medicina, Laboratório de Neurobiologia Molecular, Departmento de Bioquímica , Rua Pedro de Toledo, 669 - third floor, 04039-032 São Paulo , São Paolo , Brazil
| | - Vinicius Toledo Ribas
- Universidade Federal de Minas Gerais , Instituto de Ciências Biológicas, Departamento de Morfologia, Laboratório de Neurobiologia Av. Antônio Carlos, 6627, room O3-245 , - Campus Pampulha, 31270-901 , Belo Horizonte , Minas Gerais , Brazil
| |
Collapse
|
38
|
Long-Distance Axon Regeneration Promotes Recovery of Diaphragmatic Respiratory Function after Spinal Cord Injury. eNeuro 2019; 6:ENEURO.0096-19.2019. [PMID: 31427403 PMCID: PMC6794082 DOI: 10.1523/eneuro.0096-19.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/11/2019] [Accepted: 06/14/2019] [Indexed: 12/14/2022] Open
Abstract
Compromise in inspiratory breathing following cervical spinal cord injury (SCI) is caused by damage to descending bulbospinal axons originating in the rostral ventral respiratory group (rVRG) and consequent denervation and silencing of phrenic motor neurons (PhMNs) that directly control diaphragm activation. In a rat model of high-cervical hemisection SCI, we performed systemic administration of an antagonist peptide directed against phosphatase and tensin homolog (PTEN), a central inhibitor of neuron-intrinsic axon growth potential. PTEN antagonist peptide (PAP4) robustly restored diaphragm function, as determined with electromyography (EMG) recordings in living SCI animals. PAP4 promoted substantial, long-distance regeneration of injured rVRG axons through the lesion and back toward PhMNs located throughout the C3–C5 spinal cord. These regrowing rVRG axons also formed putative excitatory synaptic connections with PhMNs, demonstrating reconnection of rVRG-PhMN-diaphragm circuitry. Lastly, re-lesion through the hemisection site completely ablated functional recovery induced by PAP4. Collectively, our findings demonstrate that axon regeneration in response to systemic PAP4 administration promoted recovery of diaphragmatic respiratory function after cervical SCI.
Collapse
|
39
|
Guo S, Perets N, Betzer O, Ben-Shaul S, Sheinin A, Michaelevski I, Popovtzer R, Offen D, Levenberg S. Intranasal Delivery of Mesenchymal Stem Cell Derived Exosomes Loaded with Phosphatase and Tensin Homolog siRNA Repairs Complete Spinal Cord Injury. ACS NANO 2019; 13:10015-10028. [PMID: 31454225 DOI: 10.1021/acsnano.9b01892] [Citation(s) in RCA: 229] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Individuals with spinal cord injury (SCI) usually suffer from permanent neurological deficits, while spontaneous recovery and therapeutic efficacy are limited. Here, we demonstrate that when given intranasally, exosomes derived from mesenchymal stem cells (MSC-Exo) could pass the blood brain barrier and migrate to the injured spinal cord area. Furthermore, MSC-Exo loaded with phosphatase and tensin homolog small interfering RNA (ExoPTEN) could attenuate the expression of PTEN in the injured spinal cord region following intranasal administrations. In addition, the loaded MSC-Exo considerably enhanced axonal growth and neovascularization, while reducing microgliosis and astrogliosis. The intranasal ExoPTEN therapy could also partly improve structural and electrophysiological function and, most importantly, significantly elicited functional recovery in rats with complete SCI. The results imply that intranasal ExoPTEN may be used clinically to promote recovery for SCI individuals.
Collapse
Affiliation(s)
- Shaowei Guo
- Department of Biomedical Engineering , Technion-Israel Institute of Technology , Haifa 3200003 , Israel
- The First Affiliated Hospital , Shantou University Medical College , Shantou 515041 , China
| | | | - Oshra Betzer
- Faculty of Engineering and the Institute of Nanotechnology & Advanced Materials , Bar-Ilan University , Ramat Gan 5290002 , Israel
| | - Shahar Ben-Shaul
- Department of Biomedical Engineering , Technion-Israel Institute of Technology , Haifa 3200003 , Israel
| | | | - Izhak Michaelevski
- Department of Molecular Biology , Ariel University , Ariel 40700 , Israel
| | - Rachela Popovtzer
- Faculty of Engineering and the Institute of Nanotechnology & Advanced Materials , Bar-Ilan University , Ramat Gan 5290002 , Israel
| | | | - Shulamit Levenberg
- Department of Biomedical Engineering , Technion-Israel Institute of Technology , Haifa 3200003 , Israel
| |
Collapse
|
40
|
Wang S, Smith GM, Selzer ME, Li S. Emerging molecular therapeutic targets for spinal cord injury. Expert Opin Ther Targets 2019; 23:787-803. [PMID: 31460807 DOI: 10.1080/14728222.2019.1661381] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Introduction: Spinal cord injury (SCI) is a complicated and devastating neurological disorder. Patients with SCI usually have dramatically reduced quality of life. In recent years, numerous studies have reported advances in understanding the pathophysiology of SCI and developing preclinical therapeutic strategies for SCI, including various molecular therapies, and yet there is still no cure. Areas covered: After SCI, tissue damage, responses and repair involve interactions among many cellular components, including neurons, axons, glia, leukocytes, and other cells. Accordingly, numerous cellular genes and molecules have become therapeutic targets for neural tissue repair, circuit reconstruction, and behavioral restoration. Here, we review the major recent advances in biological and molecular strategies to enhance neuroprotection, axon regeneration, remyelination, neuroplasticity and functional recovery in preclinical studies of SCI. Expert opinion: Researchers have made tremendous progress in identifying individual and combined molecular therapies in animal studies. It is very important to identify additional highly effective treatments for early neuroprotective intervention and for functionally meaningful axon regeneration and neuronal reconnections. Because multiple mechanisms contribute to the functional loss after SCI, combining the most promising approaches that target different pathophysiological and molecular mechanisms should exhibit synergistic actions for maximal functional restoration. [Databases searched: PubMed; inclusive dates: 6/27/2019].
Collapse
Affiliation(s)
- Shuo Wang
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Anatomy and Cell Biology, Temple University School of Medicine , Philadelphia , PA , USA
| | - George M Smith
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Neuroscience, Temple University School of Medicine , Philadelphia , PA , USA
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Neurology, Temple University School of Medicine , Philadelphia , PA , USA
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Anatomy and Cell Biology, Temple University School of Medicine , Philadelphia , PA , USA
| |
Collapse
|
41
|
Akhmetzyanova E, Kletenkov K, Mukhamedshina Y, Rizvanov A. Different Approaches to Modulation of Microglia Phenotypes After Spinal Cord Injury. Front Syst Neurosci 2019; 13:37. [PMID: 31507384 PMCID: PMC6718713 DOI: 10.3389/fnsys.2019.00037] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 07/29/2019] [Indexed: 01/04/2023] Open
Abstract
Microglial cells, which are highly plastic, immediately respond to any change in the microenvironment by becoming activated and shifting the phenotype toward neurotoxicity or neuroprotection. The polarization of microglia/macrophages after spinal cord injury (SCI) seems to be a dynamic process and can change depending on the microenvironment, stage, course, and severity of the posttraumatic process. Effective methods to modulate microglia toward a neuroprotective phenotype in order to stimulate neuroregeneration are actively sought for. In this context, available approaches that can selectively impact the polarization of microglia/macrophages regulate synthesis of trophic factors and cytokines/chemokines in them, and their phagocytic function and effects on the course and outcome of SCI are discussed in this review.
Collapse
Affiliation(s)
- Elvira Akhmetzyanova
- OpenLab Gene and Cell Technologies, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Konstantin Kletenkov
- OpenLab Gene and Cell Technologies, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Yana Mukhamedshina
- OpenLab Gene and Cell Technologies, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia.,Department of Histology, Cytology and Embryology, Kazan State Medical University, Kazan, Russia
| | - Albert Rizvanov
- OpenLab Gene and Cell Technologies, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| |
Collapse
|
42
|
Perrin FE, Noristani HN. Serotonergic mechanisms in spinal cord injury. Exp Neurol 2019; 318:174-191. [PMID: 31085200 DOI: 10.1016/j.expneurol.2019.05.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 12/12/2022]
Abstract
Spinal cord injury (SCI) is a tragic event causing irreversible losses of sensory, motor, and autonomic functions, that may also be associated with chronic neuropathic pain. Serotonin (5-HT) neurotransmission in the spinal cord is critical for modulating sensory, motor, and autonomic functions. Following SCI, 5-HT axons caudal to the lesion site degenerate, and the degree of axonal degeneration positively correlates with lesion severity. Rostral to the lesion, 5-HT axons sprout, irrespective of the severity of the injury. Unlike callosal fibers and cholinergic projections, 5-HT axons are more resistant to an inhibitory milieu and undergo active sprouting and regeneration after central nervous system (CNS) traumatism. Numerous studies suggest that a chronic increase in serotonergic neurotransmission promotes 5-HT axon sprouting in the intact CNS. Moreover, recent studies in invertebrates suggest that 5-HT has a pro-regenerative role in injured axons. Here we present a brief description of 5-HT discovery, 5-HT innervation of the CNS, and physiological functions of 5-HT in the spinal cord, including its role in controlling bladder function. We then present a comprehensive overview of changes in serotonergic axons after CNS damage, and discuss their plasticity upon altered 5-HT neurotransmitter levels. Subsequently, we provide an in-depth review of therapeutic approaches targeting 5-HT neurotransmission, as well as other pre-clinical strategies to promote an increase in re-growth of 5-HT axons, and their functional consequences in SCI animal models. Finally, we highlight recent findings signifying the direct role of 5-HT in axon regeneration and suggest strategies to further promote robust long-distance re-growth of 5-HT axons across the lesion site and eventually achieve functional recovery following SCI.
Collapse
Affiliation(s)
- Florence Evelyne Perrin
- University of Montpellier, Montpellier, F-34095 France; INSERM, U1198, Montpellier, F-34095 France; EPHE, Paris, F-75014 France
| | - Harun Najib Noristani
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
| |
Collapse
|
43
|
Walker CL, Wu X, Liu NK, Xu XM. Bisperoxovanadium Mediates Neuronal Protection through Inhibition of PTEN and Activation of PI3K/AKT-mTOR Signaling after Traumatic Spinal Injuries. J Neurotrauma 2019; 36:2676-2687. [PMID: 30672370 DOI: 10.1089/neu.2018.6294] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although mechanisms involved in progression of cell death in spinal cord injury (SCI) have been studied extensively, few are clear targets for translation to clinical application. One of the best-understood mechanisms of cell survival in SCI is phosphatidylinositol-3-kinase (PI3K)/Akt and associated downstream signaling. Clear therapeutic efficacy of a phosphatase and tensin homologue (PTEN) inhibitor called bisperoxovanadium (bpV) has been shown in SCI, traumatic brain injury, stroke, and other neurological disease models in both neuroprotection and functional recovery. The present study aimed to elucidate mechanistic influences of bpV activity in neuronal survival in in vitro and in vivo models of SCI. Treatment with 100 nM bpV(pic) reduced cell death in a primary spinal neuron injury model (p < 0.05) in vitro, and upregulated both Akt and ribosomal protein S6 (pS6) activity (p < 0.05) compared with non-treated injured neurons. Pre-treatment of spinal neurons with a PI3K inhibitor, LY294002 or mammalian target of rapamycin (mTOR) inhibitor, rapamycin blocked bpV activation of Akt and ribosomal protein S6 activity, respectively. Treatment with bpV increased extracellular signal-related kinase (Erk) activity after scratch injury in vitro, and rapamycin reduced influence by bpV on Erk phosphorylation. After a cervical hemicontusive SCI, Akt phosphorylation decreased in total tissue via Western blot analysis (p < 0.01) as well as in penumbral ventral horn motor neurons throughout the first week post-injury (p < 0.05). Conversely, PTEN activity appeared to increase over this period. As observed in vitro, bpV also increased Erk activity post-SCI (p < 0.05). Our results suggest that PI3K/Akt signaling is the likely primary mechanism of bpV action in mediating neuroprotection in injured spinal neurons.
Collapse
Affiliation(s)
- Chandler L Walker
- Department of Biomedical and Applied Sciences, Indiana University School of Dentistry, Indianapolis, Indiana.,Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery and Goodman Campbell Brain and Spine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Xiangbing Wu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery and Goodman Campbell Brain and Spine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Nai-Kui Liu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery and Goodman Campbell Brain and Spine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Xiao-Ming Xu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Department of Neurological Surgery and Goodman Campbell Brain and Spine, Indiana University School of Medicine, Indianapolis, Indiana
| |
Collapse
|
44
|
Tang YJ, Li K, Yang CL, Huang K, Zhou J, Shi Y, Xie KG, Liu J. Bisperoxovanadium protects against spinal cord injury by regulating autophagy via activation of ERK1/2 signaling. DRUG DESIGN DEVELOPMENT AND THERAPY 2019; 13:513-521. [PMID: 30774313 PMCID: PMC6362923 DOI: 10.2147/dddt.s187878] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Background Spinal cord injury (SCI) is a disease of the central nervous system with few restorative treatments. Autophagy has been regarded as a promising therapeutic target for SCI. The inhibitor of phosphatase and tensin homolog deleted on chromosome ten (PTEN) bisperoxovanadium (bpV[pic]) had been claimed to provide a neuroprotective effect on SCI; but the underlying mechanism is still not fully understood. Materials and methods Acute SCI model were generated with SD Rats and were treated with control, acellular spinal cord scaffolds (ASC) obtained from normal rats, bpV(pic), and combined material of ASC and bpV(pic). We used BBB score to assess the motor function of the rats and the motor neurons were stained with Nissl staining. The expressions of the main autophagy markers LC3B, Beclin1 and P62, expressions of apoptosis makers Bax, Bcl2, PARP and Caspase 3 were detected with IF or Western Blot analysis. Results The bpV(pic) showed significant improvement in functional recovery by activating autophagy and accompanied by decreased neuronal apoptosis; combined ASC with bpV(pic) enhanced these effects. In addition, after treatment with ERK1/2 inhibitor SCH772984, we revealed that bpV(pic) promotes autophagy and inhibits apoptosis through activating ERK1/2 signaling after SCI. Conclusion These results illustrated that the bpV(pic) protects against SCI by regulating autophagy via activation of ERK1/2 signaling.
Collapse
Affiliation(s)
- Yu-Jin Tang
- Department of Orthopaedics, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China,
| | - Kai Li
- Academy of Orthopedics, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong, China
| | - Cheng-Liang Yang
- Department of Orthopaedics, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China,
| | - Ke Huang
- Department of Orthopaedics, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China,
| | - Jing Zhou
- Department of Anatomy, Youjiang Medical University for Nationalities, Baise, Guangxi, China
| | - Yu Shi
- Department of Orthopaedics, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China,
| | - Ke-Gong Xie
- Department of Orthopaedics, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China,
| | - Jia Liu
- Department of Orthopaedics, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, China,
| |
Collapse
|
45
|
Romeo-Guitart D, Casas C. Network-centric medicine for peripheral nerve injury: Treating the whole to boost endogenous mechanisms of neuroprotection and regeneration. Neural Regen Res 2019; 14:1122-1128. [PMID: 30804234 PMCID: PMC6425822 DOI: 10.4103/1673-5374.251187] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Peripheral nerve injuries caused by accidents may lead to paralysis, sensory disturbances, anaesthesia, and lack of autonomic functions. Functional recovery after disconnection of the motoneuronal soma from target tissue with proximal rupture of axons is determined by several factors: motoneuronal soma viability, proper axonal sprouting across inhibitory zones and elongation toward specific muscle, effective synapse contact rebuilding, and prevention of muscle atrophy. Therapies, such as adjuvant drugs with pleiotropic effects, that promote functional recovery after peripheral nerve injury are needed. Toward this aim, we designed a drug discovery workflow based on a network-centric molecular vision using unbiased proteomic data and neural artificial computational tools. Our focus is on boosting intrinsic capabilities of neurons for neuroprotection; this is in contrast to the common approach based on suppression of a pathobiological pathway known to be associated with disease condition. Using our workflow, we discovered neuroheal, a combination of two repurposed drugs that promotes motoneuronal soma neuroprotection, is anti-inflammatory, enhances axonal regeneration after axotomy, and reduces muscle atrophy. This drug discovery workflow has thus yielded a therapy that is close to its clinical application.
Collapse
Affiliation(s)
- David Romeo-Guitart
- Institut de Neurociències (INc) and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona (UAB) & Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Barcelona, Spain
| | - Caty Casas
- Institut de Neurociències (INc) and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona (UAB) & Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Barcelona, Spain
| |
Collapse
|
46
|
Goulão M, Ghosh B, Urban MW, Sahu M, Mercogliano C, Charsar BA, Komaravolu S, Block CG, Smith GM, Wright MC, Lepore AC. Astrocyte progenitor transplantation promotes regeneration of bulbospinal respiratory axons, recovery of diaphragm function, and a reduced macrophage response following cervical spinal cord injury. Glia 2018; 67:452-466. [PMID: 30548313 DOI: 10.1002/glia.23555] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 09/10/2018] [Accepted: 10/11/2018] [Indexed: 02/06/2023]
Abstract
Stem/progenitor cell transplantation delivery of astrocytes is a potentially powerful strategy for spinal cord injury (SCI). Axon extension into SCI lesions that occur spontaneously or in response to experimental manipulations is often observed along endogenous astrocyte "bridges," suggesting that augmenting this response via astrocyte lineage transplantation can enhance axon regrowth. Given the importance of respiratory dysfunction post-SCI, we transplanted glial-restricted precursors (GRPs)-a class of lineage-restricted astrocyte progenitors-into the C2 hemisection model and evaluated effects on diaphragm function and the growth response of descending rostral ventral respiratory group (rVRG) axons that innervate phrenic motor neurons (PhMNs). GRPs survived long term and efficiently differentiated into astrocytes in injured spinal cord. GRPs promoted significant recovery of diaphragm electromyography amplitudes and stimulated robust regeneration of injured rVRG axons. Although rVRG fibers extended across the lesion, no regrowing axons re-entered caudal spinal cord to reinnervate PhMNs, suggesting that this regeneration response-although impressive-was not responsible for recovery. Within ipsilateral C3-5 ventral horn (PhMN location), GRPs induced substantial sprouting of spared fibers originating in contralateral rVRG and 5-HT axons that are important for regulating PhMN excitability; this sprouting was likely involved in functional effects of GRPs. Finally, GRPs reduced the macrophage response (which plays a key role in inducing axon retraction and limiting regrowth) both within the hemisection and at intact caudal spinal cord surrounding PhMNs. These findings demonstrate that astrocyte progenitor transplantation promotes significant plasticity of rVRG-PhMN circuitry and restoration of diaphragm function and suggest that these effects may be in part through immunomodulation.
Collapse
Affiliation(s)
- Miguel Goulão
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania.,Life and Health Sciences Research Institute (ICVS), School of Medicine, ICVS/3B's - PT Government Associate Laborator, University of Minho, Braga, Portugal
| | - Biswarup Ghosh
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Mark W Urban
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Malya Sahu
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Christina Mercogliano
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Brittany A Charsar
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Sreeya Komaravolu
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Cole G Block
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania
| | - George M Smith
- Department of Neuroscience, Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Megan C Wright
- Department of Biology, Arcadia University, Glenside, Pennsylvania
| | - Angelo C Lepore
- Department of Neuroscience, Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania
| |
Collapse
|
47
|
Ohtake Y, Sami A, Jiang X, Horiuchi M, Slattery K, Ma L, Smith GM, Selzer ME, Muramatsu SI, Li S. Promoting Axon Regeneration in Adult CNS by Targeting Liver Kinase B1. Mol Ther 2018; 27:102-117. [PMID: 30509565 DOI: 10.1016/j.ymthe.2018.10.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 10/24/2018] [Accepted: 10/26/2018] [Indexed: 12/21/2022] Open
Abstract
Liver kinase B1 (LKB1), a downstream effector of cyclic AMP (cAMP)/PKA and phosphatidylinositol 3-kinase (PI3K) pathways, is a determinant for migration and differentiation of many cells, but its role in CNS axon regeneration is unknown. Therefore, LKB1 was overexpressed in sensorimotor cortex of adult mice five days after mid-thoracic spinal cord injury, using an AAV2 vector. Regeneration of corticospinal axons was dramatically enhanced. Next, systemic injection of a mutant-AAV9 vector was used to upregulate LKB1 specifically in neurons. This promoted long-distance regeneration of injured corticospinal fibers into caudal spinal cord in adult mice and regrowth of descending serotonergic and tyrosine hydroxylase immunoreactive axons. Either intracortical or systemic viral delivery of LKB1 significantly improved recovery of locomotor functions in adult mice with spinal cord injury. Moreover, we demonstrated that LKB1 used AMPKα, NUAK1, and ERK as the downstream effectors in the cortex of adult mice. Thus, LKB1 may be a critical factor for enhancing the growth capacity of mature neurons and may be an important molecular target in the treatment of CNS injuries.
Collapse
Affiliation(s)
- Yosuke Ohtake
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Armin Sami
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Xinpei Jiang
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Makoto Horiuchi
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Kieran Slattery
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Lena Ma
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - George M Smith
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Neuroscience, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Neurology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Shin-Ichi Muramatsu
- Division of Neurology, Jichi Medical University, Shimotsuke, Tochigi 329-0498, Japan
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
| |
Collapse
|
48
|
Eriksen AZ, Eliasen R, Oswald J, Kempen PJ, Melander F, Andresen TL, Young M, Baranov P, Urquhart AJ. Multifarious Biologic Loaded Liposomes that Stimulate the Mammalian Target of Rapamycin Signaling Pathway Show Retina Neuroprotection after Retina Damage. ACS NANO 2018; 12:7497-7508. [PMID: 30004669 PMCID: PMC6117751 DOI: 10.1021/acsnano.8b00596] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 07/13/2018] [Indexed: 05/08/2023]
Abstract
A common event in optic neuropathies is the loss of axons and death of retinal ganglion cells (RGCs) resulting in irreversible blindness. Mammalian target of rapamycin (mTOR) signaling pathway agonists have been shown to foster axon regeneration and RGC survival in animal models of optic nerve damage. However, many challenges remain in developing therapies that exploit cell growth and tissue remodeling including (i) activating/inhibiting cell pathways synergistically, (ii) avoiding tumorigenesis, and (iii) ensuring appropriate physiological tissue function. These challenges are further exacerbated by the need to overcome ocular physiological barriers and clearance mechanisms. Here we present liposomes loaded with multiple mTOR pathway stimulating biologics designed to enhance neuroprotection after retina damage. Liposomes were loaded with ciliary neurotrophic factor, insulin-like growth factor 1, a lipopeptide N-fragment osteopontin mimic, and lipopeptide phosphatase tension homologue inhibitors for either the ATP domain or the c-terminal tail. In a mouse model of N-methyl-d-aspartic acid induced RGC death, a single intravitreal administration of liposomes reduced both RGC death and loss of retina electrophysiological function. Furthermore, combining liposomes with transplantation of induced pluripotent stem cell derived RGCs led to an improved electrophysiological outcome in mice. The results presented here show that liposomes carrying multiple signaling pathway modulators can facilitate neuroprotection and transplant electrophysiological outcome.
Collapse
Affiliation(s)
- Anne Z. Eriksen
- DTU
Nanotech, Department of Micro- and Nanotechnology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Rasmus Eliasen
- DTU
Nanotech, Department of Micro- and Nanotechnology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Julia Oswald
- Schepens
Eye Research Institute, Massachusetts Eye and Ear, 20 Staniford Street, Boston, Massachusetts 02114, United States
| | - Paul J. Kempen
- DTU
Nanotech, Department of Micro- and Nanotechnology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Fredrik Melander
- DTU
Nanotech, Department of Micro- and Nanotechnology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Thomas L. Andresen
- DTU
Nanotech, Department of Micro- and Nanotechnology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Michael Young
- Schepens
Eye Research Institute, Massachusetts Eye and Ear, 20 Staniford Street, Boston, Massachusetts 02114, United States
| | - Petr Baranov
- Schepens
Eye Research Institute, Massachusetts Eye and Ear, 20 Staniford Street, Boston, Massachusetts 02114, United States
| | - Andrew J. Urquhart
- DTU
Nanotech, Department of Micro- and Nanotechnology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| |
Collapse
|
49
|
Lu X, Perera TH, Aria AB, Callahan LAS. Polyethylene glycol in spinal cord injury repair: a critical review. J Exp Pharmacol 2018; 10:37-49. [PMID: 30100766 PMCID: PMC6067622 DOI: 10.2147/jep.s148944] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Polyethylene glycol (PEG) is a synthetic biocompatible polymer with many useful properties for developing therapeutics to treat spinal cord injury. Direct application of PEG as a fusogen to the injury site can repair cell membranes, mitigate oxidative stress, and promote axonal regeneration to restore motor function. PEG can be covalently or noncovalently conjugated to proteins, peptides, and nanoparticles to limit their clearance by the reticuloendothelial system, reduce their immunogenicity, and facilitate crossing the blood-brain barrier. Cross-linking PEG produces hydrogels that can act as delivery vehicles for bioactive molecules including growth factors and cells such as bone marrow stromal cells, which can modulate the inflammatory response and support neural tissue regeneration. PEG hydrogels can be cross-linked in vitro or delivered as an injectable formulation that can gel in situ at the site of injury. Chemical and mechanical properties of PEG hydrogels are tunable and must be optimized for creating the most favorable delivery environment. Peptides mimicking extracellular matrix protein such as laminin and n-cadherin can be incorporated into PEG hydrogels to promote neural differentiation and axonal extensions. Different hydrogel cross-linking densities and stiffness will also affect the differentiation process. PEG hydrogels with a gradient of peptide concentrations or Young's modulus have been developed to systematically study these factors. This review will describe these and other recent advancements of PEG in the field of spinal cord injury in greater detail.
Collapse
Affiliation(s)
- Xi Lu
- Department of Neurosurgery, Center for Stem Cells and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA,
| | - T Hiran Perera
- Department of Neurosurgery, Center for Stem Cells and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA,
| | - Alexander B Aria
- Department of Neurosurgery, Center for Stem Cells and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA,
| | - Laura A Smith Callahan
- Department of Neurosurgery, Center for Stem Cells and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA,
| |
Collapse
|
50
|
Chen H, Xiang J, Wu J, He B, Lin T, Zhu Q, Liu X, Zheng C. Expression patterns and role of PTEN in rat peripheral nerve development and injury. Neurosci Lett 2018; 676:78-84. [DOI: 10.1016/j.neulet.2018.04.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 03/29/2018] [Accepted: 04/07/2018] [Indexed: 12/13/2022]
|