Photobiomodulation Inhibits the Activation of Neurotoxic Microglia and Astrocytes Through Inhibiting the Crosstalk of Lcn2/JAK2-STAT3 after Spinal Cord Injury in Rats

2021 ◽  
Author(s):  
Xuankang Wang ◽  
Xin Li ◽  
Xiaoshuang Zuo ◽  
Zhuowen Liang ◽  
Zhe Wang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Function ◽  
Janus Kinase ◽  
Vehicle Group ◽  
Lipocalin 2 ◽  
Stat3 Pathway ◽  
Cord Injury ◽  
Recovery Of Motor Function

Abstract BackgroundIn situ microglia and astrocytes begin to activate and participate in neuroinflammation after spinal cord injury (SCI), and the high expression of lipocalin 2 (Lcn2) and the activation of the Janus kinase-2 (JAK2)-signal transducer and activator of transcription-3 (STAT3) pathway promote the polarization of activated microglia and astrocytes towards the neurotoxic phenotype (M1 microglia and A1 astrocytes). We previously reported that photobiomodulation (PBM) can promote functional recovery by reducing neuroinflammation after SCI, but the mechanism of PBM on the microglia and astrocytes involved is still unclear. Therefore, the purpose of this study was to explore the role of the Lcn2 and JAK2-STAT3 pathways in the activation of M1 and A1 and the mechanism by which PBM may play a therapeutic role.MethodsPBM intervention was performed every day after the SCI model was established, and the activation of microglia and astrocytes was observed at different time points post injury (1, 3, 7, 14, 28 dpi). The level of tissue apoptosis, the number of surviving neurons, the recovery of motor function, the level of Lcn2 and the activation of JAK2-STAT3 were evaluated in the PBM group and the vehicle group. M1 and A1 cells were irradiated with PBM in vitro, and the JAK2-STAT3 pathway inhibitor cucurbitacin I, adenovirus transfection and recombinant Lcn2 protein were cotreated with PBM to explore the mechanism of the activation of M1 and A1 and the underlying effect of PBM.ResultsPBM inhibited the activation of neurotoxic microglia and astrocytes, decreased secondary inflammation and tissue apoptosis, increased the number of neurons retained, and promoted the recovery of motor function after SCI. The upregulation of Lcn2 and the activation of the JAK2-STAT3 pathway after SCI were suppressed by PBM. In vitro experiments also proved that PBM can inhibit the activation of M1 microglia and A1 astrocytes, and the effect is related to the level of Lcn2 and the activation of the JAK2-STAT3 pathway.ConclusionThe crosstalk of Lcn2/JAK2-STAT3 is involved in the activation of neurotoxic microglia and astrocytes after SCI, and this process can be alleviated by PBM.

scholarly journals Photobiomodulation inhibits the activation of neurotoxic microglia and astrocytes by inhibiting Lcn2/JAK2-STAT3 crosstalk after spinal cord injury in male rats

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Xuankang Wang ◽  
Xin Li ◽  
Xiaoshuang Zuo ◽  
Zhuowen Liang ◽  
Tan Ding ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Function ◽  
Male Rats ◽  
In Vitro Experiments ◽  
Post Injury ◽  
Stat3 Pathway ◽  
Cord Injury ◽  
Recovery Of Motor Function

Abstract Background Neurotoxic microglia and astrocytes begin to activate and participate in pathological processes after spinal cord injury (SCI), subsequently causing severe secondary damage and affecting tissue repair. We have previously reported that photobiomodulation (PBM) can promote functional recovery by reducing neuroinflammation after SCI, but little is known about the underlying mechanism. Therefore, we aimed to investigate whether PBM ameliorates neuroinflammation by modulating the activation of microglia and astrocytes after SCI. Methods Male Sprague–Dawley rats were randomly divided into three groups: a sham control group, an SCI + vehicle group and an SCI + PBM group. PBM was performed for two consecutive weeks after clip-compression SCI models were established. The activation of neurotoxic microglia and astrocytes, the level of tissue apoptosis, the number of motor neurons and the recovery of motor function were evaluated at different days post-injury (1, 3, 7, 14, and 28 days post-injury, dpi). Lipocalin 2 (Lcn2) and Janus kinase-2 (JAK2)-signal transducer and activator of transcription-3 (STAT3) signaling were regarded as potential targets by which PBM affected neurotoxic microglia and astrocytes. In in vitro experiments, primary microglia and astrocytes were irradiated with PBM and cotreated with cucurbitacin I (a JAK2-STAT3 pathway inhibitor), an adenovirus (shRNA-Lcn2) and recombinant Lcn2 protein. Results PBM promoted the recovery of motor function, inhibited the activation of neurotoxic microglia and astrocytes, alleviated neuroinflammation and tissue apoptosis, and increased the number of neurons retained after SCI. The upregulation of Lcn2 and the activation of the JAK2-STAT3 pathway after SCI were suppressed by PBM. In vitro experiments also showed that Lcn2 and JAK2-STAT3 were mutually promoted and that PBM interfered with this interaction, inhibiting the activation of microglia and astrocytes. Conclusion Lcn2/JAK2-STAT3 crosstalk is involved in the activation of neurotoxic microglia and astrocytes after SCI, and this process can be suppressed by PBM.

4:40104. Experimental Distraction Spinal Cord Injury and Recovery of Motor Function

2006 ◽  
Vol 6 (5) ◽  
pp. 51S ◽  
Author(s):  
Mary K. Nagai ◽  
Kirk Dabney ◽  
Marina Ehrenshteyn ◽  
Dianna Willis ◽  
Jeffery Twiss
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Function ◽  
Cord Injury ◽  
Recovery Of Motor Function

scholarly journals Rapamycin Preserves Neural Tissue, Promotes Schwann Cell Myelination and Reduces Glial Scar Formation After Hemi-Contusion Spinal Cord Injury in Mice

2021 ◽  
Vol 13 ◽  
Author(s):  
Junhao Liu ◽  
Ruoyao Li ◽  
Zucheng Huang ◽  
Junyu Lin ◽  
Wei Ji ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
White Matter ◽  
Schwann Cell ◽  
Motor Function ◽  
Neural Tissue ◽  
Glial Scar ◽  
Vehicle Group ◽  
Spinal Cord Tissue ◽  
Cord Injury

Protecting white matter is one of the key treatment strategies for spinal cord injury (SCI), including alleviation of myelin loss and promotion of remyelination. Rapamycin has been shown neuroprotective effects against SCI and cardiotoxic effects while enhancing autophagy. However, specific neuroprotection of rapamycin for the white matter after cervical SCI has not been reported. Therefore, we aim to evaluate the role of rapamycin in neuroprotection after hemi-contusion SCI in mice. Forty-six 8-week-old mice were randomly assigned into the rapamycin group (n = 16), vehicle group (n = 16), and sham group (n = 10). All mice of the rapamycin and vehicle groups received a unilateral contusion with 1.2-mm displacement at C5 followed by daily intraperitoneal injection of rapamycin or dimethyl sulfoxide solution (1.5 mg⋅kg–1⋅day–1). The behavioral assessment was conducted before the injury, 3 days and every 2 weeks post-injury (WPI). The autophagy-related proteins, the area of spared white matter, the number of oligodendrocytes (OLs) and axons were evaluated at 12 WPI, as well as the glial scar and the myelin sheaths formed by Schwann cells at the epicenter. The 1.2 mm contusion led to a consistent moderate–severe SCI in terms of motor function and tissue damage. Rapamycin administration promoted autophagy in spinal cord tissue after injury and reduced the glial scar at the epicenter. Additionally, rapamycin increased the number of OLs and improved motor function significantly than in the vehicle group. Furthermore, the rapamycin injection resulted in an increase of Schwann cell-mediated remyelination and weight loss. Our results suggest that rapamycin can enhance autophagy, promote Schwann cell myelination and motor function recovery by preserved neural tissue, and reduce glial scar after hemi-contusive cervical SCI, indicating a potential strategy for SCI treatment.

scholarly journals TRIM32 affects the recovery of motor function following spinal cord injury through regulating proliferation of glia

Oncotarget ◽  
2017 ◽  
Vol 8 (28) ◽  
pp. 45380-45390 ◽  
Author(s):  
Qiang Fu ◽  
Ming-Ming Zou ◽  
Jian-Wei Zhu ◽  
Yan Zhang ◽  
Wen-Jin Chen ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Function ◽  
Cord Injury ◽  
Recovery Of Motor Function

Mechanisms of Behavioral Changes After Spinal Cord Injury

2019 ◽  
Author(s):  
Karim Fouad ◽  
Abel Torres-Espín ◽  
Keith K. Fenrich
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Function ◽  
Lesion Size ◽  
Behavioral Changes ◽  
Sensory Function ◽  
Wide Range ◽  
Cord Injury ◽  
New Treatment ◽  
Recovery Of Motor Function

Spinal cord injury results in a wide range of behavioral changes including impaired motor and sensory function, autonomic dysfunction, spasticity, and depression. Currently, restoring lost motor function is the most actively studied and sought-after goal of spinal cord injury research. This research is rooted in the fact that although self-repair following spinal cord injury in adult mammals is very limited, there can be some recovery of motor function. This recovery is strongly dependent on the lesion size and location as well as on neural activity of denervated networks activated mainly through physical activity (i.e., rehabilitative training). Recovery of motor function is largely due to neuroplasticity, which includes adaptive changes in spared and injured neural circuitry. Neuroplasticity after spinal cord injury is extensive and includes mechanisms such as moderate axonal sprouting, the formation of new synaptic connections, network remapping, and changes to neuron cell properties. Neuroplasticity after spinal cord injury has been described at various physiological and anatomical levels of the central nervous system including the brain, brainstem, and spinal cord, both above and below injury sites. The growing number of mechanisms underlying postinjury plasticity indicate the vast complexity of injury-induced plasticity. This poses important opportunities to further enhance and harness plasticity in order to promote recovery. However, the diversity of neuroplasticity also creates challenges for research, which is frequently based on mechanistically driven approaches. The appreciation of the complexity of neuronal plasticity and the findings that recovery is based on a multitude and interlinked adaptations will be essential in developing meaningful new treatment avenues.

Effect of vitamins C and E on recovery of motor function after spinal cord injury: systematic review and meta-analysis of animal studies

2019 ◽  
Vol 78 (6) ◽  
pp. 465-473 ◽  
Author(s):  
Mostafa Hosseini ◽  
Arash Sarveazad ◽  
Asrin Babahajian ◽  
Masoud Baikpour ◽  
Alexander R Vaccaro ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Vitamin E ◽  
Animal Models ◽  
Vitamin C ◽  
Motor Function ◽  
Animal Studies ◽  
Meta Analysis ◽  
Cord Injury ◽  
Recovery Of Motor Function

Abstract Context Many animal studies have evaluated the role of vitamins in the recovery of motor function after spinal cord injury, but their results have been contradictory and no consensus has been reached. Objective This meta-analysis aimed to investigate the effects of vitamin C and vitamin E on recovery of motor function after spinal cord injury in animal models. Data Sources Two authors independently collected the records of relevant articles published in MEDLINE, Embase, Scopus, and Web of Science through November 2018. Study Selection All studies conducted in animal models to evaluate the therapeutic effects of vitamin C or vitamin E or both on recovery of motor function after spinal cord injury were included. Studies that lacked a control group or a standard treatment, lacked an assessment of motor function, included genetically modified/engineered animals, included animals pretreated with vitamin C or vitamin E, or combined vitamin treatment with other methods, such as cell therapies, were excluded. Data Extraction Data from 10 articles met the inclusion criteria for meta-analysis, conducted in accordance with PRISMA guidelines. Results Daily supplementation with vitamin C (P < 0.0001) and vitamin E (P < 0.0001) significantly improved the recovery of motor function in animals affected by spinal cord injury. Vitamin C supplementation is effective only when administered intraperitoneally (P < 0.0001). Concurrent supplementation with both vitamins does not show better efficacy than treatment with either one alone. Conclusion Administration of vitamin C and vitamin E in animal models of spinal cord injury significantly improves the recovery of motor function.

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