scholarly journals Deletion or inhibition of astrocytic transglutaminase 2 promotes functional recovery after spinal cord injury

2021 ◽  
Author(s):  
Anissa Elahi ◽  
Jacen Emerson ◽  
Jacob Rudlong ◽  
Jeffrey W. Keillor ◽  
Garrick Salois ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Functional Recovery ◽  
Molecular Mechanisms ◽  
Genetic Model ◽  
Transglutaminase 2 ◽  
Cns Injury ◽  
Metabolic Coupling ◽  
Cord Injury ◽  
Spinal Cord Contusion ◽  
Novel Strategy

AbstractFollowing CNS injury astrocytes become “reactive” and exhibit pro-regenerative or harmful properties. However, the molecular mechanisms that cause astrocytes to adopt either phenotype are not well understood. Transglutaminase 2 (TG2) plays a key role in regulating the response of astrocytes to insults. Here we used mice in which TG2 was specifically deleted in astrocytes (Gfap-Cre+/-TG2fl/fl, referred to here as TG2-A-cKO) in a spinal cord contusion injury (SCI) model. Deletion of TG2 from astrocytes resulted in a significant improvement in motor function following SCI. GFAP and NG2 immunoreactivity, as well as number of SOX9 positive cells, were significantly reduced in TG2-A-cKO_mice. RNA-seq analysis of spinal cords from TG2-A-cKO and control mice 3 days postinjury identified thirty-seven differentially expressed genes, all of which were increased in TG2-A-cKO mice. Pathway analysis reveals a prevalence for fatty acid metabolism, lipid storage and energy pathways, which play essential roles in neuron-astrocyte metabolic coupling. Excitingly, treatment of wild type mice with the selective TG2 inhibitor VA4 significantly improved functional recovery after SCI, similar to what was observed using the genetic model. These findings indicate the use of TG2 inhibitors as a novel strategy for the treatment of SCI and other CNS injuries.

scholarly journals Deletion or Inhibition of Astrocytic Transglutaminase 2 Promotes Functional Recovery after Spinal Cord Injury

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2942
Author(s):  
Anissa Elahi ◽  
Jacen Emerson ◽  
Jacob Rudlong ◽  
Jeffrey W. Keillor ◽  
Garrick Salois ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Functional Recovery ◽  
Molecular Mechanisms ◽  
Genetic Model ◽  
Transglutaminase 2 ◽  
Cns Injury ◽  
Post Injury ◽  
Metabolic Coupling ◽  
Cord Injury ◽  
Spinal Cord Contusion

Following CNS injury, astrocytes become “reactive” and exhibit pro-regenerative or harmful properties. However, the molecular mechanisms that cause astrocytes to adopt either phenotype are not well understood. Transglutaminase 2 (TG2) plays a key role in regulating the response of astrocytes to insults. Here, we used mice in which TG2 was specifically deleted in astrocytes (Gfap-Cre+/− TG2fl/fl, referred to here as TG2-A-cKO) in a spinal cord contusion injury (SCI) model. Deletion of TG2 from astrocytes resulted in a significant improvement in motor function following SCI. GFAP and NG2 immunoreactivity, as well as number of SOX9 positive cells, were significantly reduced in TG2-A-cKO mice. RNA-seq analysis of spinal cords from TG2-A-cKO and control mice 3 days post-injury identified thirty-seven differentially expressed genes, all of which were increased in TG2-A-cKO mice. Pathway analysis revealed a prevalence for fatty acid metabolism, lipid storage and energy pathways, which play essential roles in neuron–astrocyte metabolic coupling. Excitingly, treatment of wild type mice with the selective TG2 inhibitor VA4 significantly improved functional recovery after SCI, similar to what was observed using the genetic model. These findings indicate the use of TG2 inhibitors as a novel strategy for the treatment of SCI and other CNS injuries.

scholarly journals Transcriptome analyses reveal molecular mechanisms underlying functional recovery after spinal cord injury

2015 ◽  
Vol 112 (43) ◽  
pp. 13360-13365 ◽  
Author(s):  
Hongmei Duan ◽  
Weihong Ge ◽  
Aifeng Zhang ◽  
Yue Xi ◽  
Zhihua Chen ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Functional Recovery ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Cns Injury ◽  
Neurotrophin 3 ◽  
Cord Injury ◽  
Transcriptome Analyses ◽  
Regeneration Capability

Spinal cord injury (SCI) is considered incurable because axonal regeneration in the central nervous system (CNS) is extremely challenging, due to harsh CNS injury environment and weak intrinsic regeneration capability of CNS neurons. We discovered that neurotrophin-3 (NT3)-loaded chitosan provided an excellent microenvironment to facilitate nerve growth, new neurogenesis, and functional recovery of completely transected spinal cord in rats. To acquire mechanistic insight, we conducted a series of comprehensive transcriptome analyses of spinal cord segments at the lesion site, as well as regions immediately rostral and caudal to the lesion, over a period of 90 days after SCI. Using weighted gene coexpression network analysis (WGCNA), we established gene modules/programs corresponding to various pathological events at different times after SCI. These objective measures of gene module expression also revealed that enhanced new neurogenesis and angiogenesis, and reduced inflammatory responses were keys to conferring the effect of NT3-chitosan on regeneration.

scholarly journals EGCG modulates PKD1 and ferroptosis to promote recovery in ST rats

2020 ◽  
Vol 11 (1) ◽  
pp. 173-181 ◽  
Author(s):  
Jianjun Wang ◽  
Ying Chen ◽  
Long Chen ◽  
Yanzhi Duan ◽  
Xuejun Kuang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Functional Recovery ◽  
Antioxidant Properties ◽  
Underlying Mechanism ◽  
Maximal Effect ◽  
Loss Of Function ◽  
Protein Kinase D1 ◽  
Erk Phosphorylation ◽  
Cord Injury ◽  
Novel Strategy

AbstractBackgroundSpinal cord injury (SCI) causes devastating loss of function and neuronal death without effective treatment. (−)-Epigallocatechin-3-gallate (EGCG) has antioxidant properties and plays an essential role in the nervous system. However, the underlying mechanism by which EGCG promotes neuronal survival and functional recovery in complete spinal cord transection (ST) remains unclear.MethodsIn the present study, we established primary cerebellar granule neurons (CGNs) and a T10 ST rat model to investigate the antioxidant effects of EGCG via its modulation of protein kinase D1 (PKD1) phosphorylation and inhibition of ferroptosis.ResultsWe revealed that EGCG significantly increased the cell survival rate of CGNs and PKD1 phosphorylation levels in comparison to the vehicle control, with a maximal effect observed at 50 µM. EGCG upregulated PKD1 phosphorylation levels and inhibited ferroptosis to reduce the cell death of CGNs under oxidative stress and to promote functional recovery and ERK phosphorylation in rats following complete ST.ConclusionTogether, these results lay the foundation for EGCG as a novel strategy for the treatment of SCI related to PKD1 phosphorylation and ferroptosis.

scholarly journals Molecular mechanisms underlying functional recovery after spinal cord injury

IBRO Reports ◽  
2019 ◽  
Vol 6 ◽  
pp. S532-S533
Author(s):  
Nadezda Lukacova ◽  
Katarina Bimbova ◽  
Andrea Stropkovska ◽  
Alexandra Kisucka ◽  
Maria Bacova ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Functional Recovery ◽  
Molecular Mechanisms ◽  
Cord Injury

scholarly journals NT3-chitosan elicits robust endogenous neurogenesis to enable functional recovery after spinal cord injury

2015 ◽  
Vol 112 (43) ◽  
pp. 13354-13359 ◽  
Author(s):  
Zhaoyang Yang ◽  
Aifeng Zhang ◽  
Hongmei Duan ◽  
Sa Zhang ◽  
Peng Hao ◽  
...  
Keyword(s):  
Neural Networks ◽  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Neural Regeneration ◽  
Cns Injury ◽  
Behavioral Recovery ◽  
Thoracic Spinal Cord ◽  
Thoracic Spinal ◽  
Cord Injury ◽  
Novel Strategy

Neural stem cells (NSCs) in the adult mammalian central nervous system (CNS) hold the key to neural regeneration through proper activation, differentiation, and maturation, to establish nascent neural networks, which can be integrated into damaged neural circuits to repair function. However, the CNS injury microenvironment is often inhibitory and inflammatory, limiting the ability of activated NSCs to differentiate into neurons and form nascent circuits. Here we report that neurotrophin-3 (NT3)-coupled chitosan biomaterial, when inserted into a 5-mm gap of completely transected and excised rat thoracic spinal cord, elicited robust activation of endogenous NSCs in the injured spinal cord. Through slow release of NT3, the biomaterial attracted NSCs to migrate into the lesion area, differentiate into neurons, and form functional neural networks, which interconnected severed ascending and descending axons, resulting in sensory and motor behavioral recovery. Our study suggests that enhancing endogenous neurogenesis could be a novel strategy for treatment of spinal cord injury.

scholarly journals The Biology of Regeneration Failure and Success After Spinal Cord Injury

2018 ◽  
Vol 98 (2) ◽  
pp. 881-917 ◽  
Author(s):  
Amanda Phuong Tran ◽  
Philippa Mary Warren ◽  
Jerry Silver
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Functional Recovery ◽  
Axonal Regeneration ◽  
Molecular Mechanisms ◽  
Glial Scar ◽  
Perineuronal Net ◽  
Physical Trauma ◽  
Axonal Regrowth ◽  
Cord Injury

Since no approved therapies to restore mobility and sensation following spinal cord injury (SCI) currently exist, a better understanding of the cellular and molecular mechanisms following SCI that compromise regeneration or neuroplasticity is needed to develop new strategies to promote axonal regrowth and restore function. Physical trauma to the spinal cord results in vascular disruption that, in turn, causes blood-spinal cord barrier rupture leading to hemorrhage and ischemia, followed by rampant local cell death. As subsequent edema and inflammation occur, neuronal and glial necrosis and apoptosis spread well beyond the initial site of impact, ultimately resolving into a cavity surrounded by glial/fibrotic scarring. The glial scar, which stabilizes the spread of secondary injury, also acts as a chronic, physical, and chemo-entrapping barrier that prevents axonal regeneration. Understanding the formative events in glial scarring helps guide strategies towards the development of potential therapies to enhance axon regeneration and functional recovery at both acute and chronic stages following SCI. This review will also discuss the perineuronal net and how chondroitin sulfate proteoglycans (CSPGs) deposited in both the glial scar and net impede axonal outgrowth at the level of the growth cone. We will end the review with a summary of current CSPG-targeting strategies that help to foster axonal regeneration, neuroplasticity/sprouting, and functional recovery following SCI.

scholarly journals Grafted human induced pluripotent stem cells improve the outcome of spinal cord injury: modulation of the lesion microenvironment

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tamás Bellák ◽  
Zoltán Fekécs ◽  
Dénes Török ◽  
Zsuzsanna Táncos ◽  
Csilla Nemes ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Stem Cells ◽  
Spinal Cord Injury ◽  
Functional Recovery ◽  
Pluripotent Stem Cells ◽  
Functional Improvement ◽  
Cord Injury ◽  
Contusion Injury ◽  
Spinal Cord Contusion ◽  
Induced Pluripotent

AbstractSpinal cord injury results in irreversible tissue damage followed by a very limited recovery of function. In this study we investigated whether transplantation of undifferentiated human induced pluripotent stem cells (hiPSCs) into the injured rat spinal cord is able to induce morphological and functional improvement. hiPSCs were grafted intraspinally or intravenously one week after a thoracic (T11) spinal cord contusion injury performed in Fischer 344 rats. Grafted animals showed significantly better functional recovery than the control rats which received only contusion injury. Morphologically, the contusion cavity was significantly smaller, and the amount of spared tissue was significantly greater in grafted animals than in controls. Retrograde tracing studies showed a statistically significant increase in the number of FB-labeled neurons in different segments of the spinal cord, the brainstem and the sensorimotor cortex. The extent of functional improvement was inversely related to the amount of chondroitin-sulphate around the cavity and the astrocytic and microglial reactions in the injured segment. The grafts produced GDNF, IL-10 and MIP1-alpha for at least one week. These data suggest that grafted undifferentiated hiPSCs are able to induce morphological and functional recovery after spinal cord contusion injury.

scholarly journals New insights into glial scar formation after spinal cord injury

2021 ◽  
Author(s):  
Amanda Phuong Tran ◽  
Philippa Mary Warren ◽  
Jerry Silver
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Molecular Mechanisms ◽  
Complex Structure ◽  
Traumatic Injury ◽  
Treatment Strategies ◽  
The Body ◽  
Cns Injury ◽  
Loss Of Function ◽  
Cord Injury

AbstractSevere spinal cord injury causes permanent loss of function and sensation throughout the body. The trauma causes a multifaceted torrent of pathophysiological processes which ultimately act to form a complex structure, permanently remodeling the cellular architecture and extracellular matrix. This structure is traditionally termed the glial/fibrotic scar. Similar cellular formations occur following stroke, infection, and neurodegenerative diseases of the central nervous system (CNS) signifying their fundamental importance to preservation of function. It is increasingly recognized that the scar performs multiple roles affecting recovery following traumatic injury. Innovative research into the properties of this structure is imperative to the development of treatment strategies to recover motor function and sensation following CNS trauma. In this review, we summarize how the regeneration potential of the CNS alters across phyla and age through formation of scar-like structures. We describe how new insights from next-generation sequencing technologies have yielded a more complex portrait of the molecular mechanisms governing the astrocyte, microglial, and neuronal responses to injury and development, especially of the glial component of the scar. Finally, we discuss possible combinatorial therapeutic approaches centering on scar modulation to restore function after severe CNS injury.

scholarly journals Dopamine Reduced Pyroptosis and Improved Functional Recovery After Spinal Cord Injury 

2020 ◽  
Author(s):  
Liulong Zhu ◽  
Guoming Ding ◽  
Fan He ◽  
Maoqiang Li ◽  
Wu Jiang
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Inflammatory Response ◽  
Functional Recovery ◽  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Neuronal Loss ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation ◽  
Cord Injury

Abstract Background: Neuronal loss, demyelination, and an excessive inflammatory response accompany the pathogenesis of spinal cord injury (SCI). The inflammatory response is promoted by inflammasomes in variety diseases. Dopamine is a neurotransmitter that also functions as a regulator in NLRP3 (nucleotide-binding oligomerization domain-like receptor 3) inflammasome-dependent neuroinflammation. However, the effects and molecular mechanisms underlying the role of dopamine in SCI are little known. Methods:Functional recovery was assessed using Basso Mouse Scale (BMS) and BMS subscore. Histopathologic damage was evaluated by H&E staining. Demyelination was evaluated using immunofluorescence staining of myelin basic protein. Neuronal loss was evaluated by immunochemistry staining of NeuN. Pyroptosis was assessed by flow cytometry, western blot, and cell viability and cytotoxicity assays.Results: This study using mice showed that dopamine was significantly associated with enhanced locomotor recovery after SCI; with a reduction in NLRP3 inflammasome activation, pyroptosis, neuron and myelin loss, and histological changes. In vitro data suggested an association between dopamine and suppressed NLRP3 inflammasome activation and neuronal pyroptosis, and greater survival of neurons. Conclusion: Thus, dopamine may be a novel and effective approach for improving recovery after SCI.

scholarly journals Targeted Inhibition of STAT3 in Neural Stem Cells Promotes Neuronal Differentiation and Functional Recovery in Rats with Spinal Cord Injury

2020 ◽  
Author(s):  
Tingting Li ◽  
xiaoyang zhao ◽  
Jing Duan ◽  
Shangbin Cui ◽  
Kai Zhu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Stem Cells ◽  
Spinal Cord Injury ◽  
Neural Stem Cells ◽  
Neuronal Differentiation ◽  
Functional Recovery ◽  
Tissue Repair ◽  
Molecular Mechanisms ◽  
Control Shrna ◽  
Cord Injury

Abstract BackgroundSignal transducer and activator of transcription protein 3 (STAT3) is expressed in neural stem cells (NSCs), and some studies have shown that STAT3 is involved in regulating NSC differentiation. However, the possible molecular mechanism and the role of STAT3 in spinal cord injury (SCI) are unknown. Thus, in the present study, we identified possible molecular mechanisms by which STAT3 regulates NSC differentiation in vitro and investigated the potential therapeutic effect of transplanting STAT3-silenced NSCs in rat SCI models in vivo.MethodsIn vitro, NSCs were divided into the following three groups: control, control shRNA, and STAT3-shRNA lentivirus groups. NSCs in each treatment group were examined for neuronal differentiation via immunofluorescence, and Western blot analysis was used to investigate the possible molecular mechanisms. In vivo, the rats were divided into four groups that underwent laminectomy and complete spinal cord transection accompanied by transplantation of control-shRNA-treated or STAT3-shRNA-treated NSCs at the injured site. Spinal cord-evoked potentials and the Basso-Beattie-Bresnahan score were used to examine functional recovery after SCI. Axonal regeneration and tissue repair were assessed via retrograde tracing using Fluorogold, hematoxylin-eosin staining and immunofluorescence.ResultsKnockdown of STAT3 promoted neuronal differentiation in NSCs and mechanistic target of mammal rapamycin (mTOR) activation in vitro, and transplantation of STAT3-RNAi-treated NSCs enhanced rat functional recovery and tissue repair, as well as neuronal differentiation of the transplanted NSCs in vivo.ConclusionsWe have provided in vitro and in vivo evidence that STAT3 is a negative regulator of NSC neuronal differentiation. Transplantation of STAT3-inhibited NSCs appears to be a promising potential strategy for enhancing the benefit of NSC-mediated regenerative cell therapy for SCI.

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