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.

Presence and significance of CD-95 (Fas/APO1) expression after spinal cord injury

2001 ◽  
Vol 94 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Mercedes Zurita ◽  
Jesús Vaquero ◽  
Isabel Zurita
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
White Matter ◽  
Gray Matter ◽  
Spinal Cord Tissue ◽  
Injured Spinal Cord ◽  
Content Type ◽  
Cord Injury ◽  
Positive Immunostaining ◽  
Fine Print

Object. A glycoprotein, CD95 (Fas/APO1) is widely considered to be implicated in the development of apoptosis in a number of tissues. Based on the hypothesis that apoptosis is related to cell death after spinal cord injury (SCI), the authors studied the presence and distribution of CD95 (Fas/APO1)-positive cells in injured spinal cord tissue for the purpose of determining the significance of this protein during the early phases of SCI. Methods. The presence and distribution of cells showing positive immunostaining for CD95 (Fas/APO1) were studied 1, 4, 8, 24, 48, and 72 hours and 1, 2, and 4 weeks after induction of experimental SCI in rats. Studies were conducted using a monoclonal antibody to the CD95 (Fas/APO1) protein. Positivity for CD95 (Fas/APO1) was observed in apoptotic cells, mainly in the gray matter, 1 hour after trauma, and the number of immunostained cells increased for the first 8 hours, at which time the protein was expressed in both gray and white matter. From 24 to 72 hours postinjury, the number of immunostained cells decreased in the gray matter, but increased in the white matter. From then on, there were fewer CD95 (Fas/APO1)-positive cells, but some cells in the white matter still exhibited positive immunostaining 1 and 2 weeks after injury. At 4 weeks, there remained no CD95 (Fas/APO1)-positive cells in injured spinal cord. Conclusions. These findings indicate that CD95 (Fas/APO1) is expressed after SCI, suggesting a role for this protein in the development of apoptosis after trauma and the possibility of a new therapeutic approach to SCI based on blocking the CD95 (Fas/APO1) system.

scholarly journals Mmu-miR-27a-5p Promotes the Polarization of Macrophages to the M2 Phenotype at the Site of Spinal Cord Injury in Mice

2021 ◽  
Author(s):  
Mingkun Yang ◽  
Xiaoqian Dang ◽  
Xu Zhang ◽  
Chuan Liu ◽  
Min He
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Function ◽  
Macrophage Polarization ◽  
Spinal Cord Tissue ◽  
Injured Spinal Cord ◽  
Arginase 1 ◽  
Tnf Α ◽  
Cord Injury ◽  
M2 Phenotype

Abstract BackgroundTo investigate the effect of mmu-miR-27a-5p on macrophage polarization in the injured spinal cord and the recovery of motor function after spinal cord injury (SCI) in mice.MethodsA total of 160 specific-pathogen-free male mice were randomly divided into sham, model, mmu-miR-27a-5p, mmu-miR-27a-5p-negative control (NC) groups, with 40 mice in each group. Hindlimb motor function was assessed using the Basso Mouse scale (BMS) before injury and at 1, 3, 7, and 14 days after surgery. Spinal cord tissue samples were obtained at 1, 3, 7, and 14 days after surgery, and macrophage polarization types were detected by using western blot analysis, immunofluorescence, flow cytometry and RT-qPCR.ResultsThe BMS score in the mmu-miR-27a-5p group was significantly higher than that in the model and mmu-miR-27a-5p-NC groups at 7 and 14 days after SCI (X2=26.45-57.62, P<0.05). No significant changes in the expression of M1 markers IL-1β, TNF-α and M2 markers IL-10, Arginase-1 at each time point in the sham group (P=0.96). The expression of IL-1β and TNF-α was significantly lower, while the expression of IL-10 and Arginase-1 were significantly higher in the mmu-miR-27a-5p group as compared to the model and mmu-miR-27a-5p-NC groups at 7 and 14 days after SCI (P<0.05).ConclusionAdministration of mmu-miR-27a-5p can promote the polarization of macrophages to the M2 phenotype in the injured spinal cord, and improve motor function recovery within 14 days after SCI in mice.

scholarly journals Investigation of Cerebral White Matter Changes After Spinal Cord Injury With a Measure of Fiber Density

2021 ◽  
Vol 12 ◽  
Author(s):  
Vincent Huynh ◽  
Philipp Staempfli ◽  
Robin Luetolf ◽  
Roger Luechinger ◽  
Armin Curt ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
White Matter ◽  
Motor Function ◽  
Roc Analysis ◽  
Diffusion Tensor ◽  
Tensor Model ◽  
Fiber Density ◽  
Microstructural Changes ◽  
Cord Injury

Remote neurodegenerative changes in supraspinal white matter (WM) can manifest after central lesions such as spinal cord injury (SCI). The majority of diffusion tensor imaging (DTI) studies use traditional metrics such as fractional anisotropy (FA) and mean diffusivity (MD) to investigate microstructural changes in cerebral WM after SCI. However, interpretation of FA readouts is often challenged by inherent limitations of the tensor model. Recent developments in novel diffusion markers, such as fiber density (FD), allows more accurate depictions of WM pathways and has shown more reliable quantification of WM alterations compared to FA in recent studies of neurological diseases. This study investigated if FD provides useful characterization of supraspinal WM integrity after SCI in addition to the traditional DTI readouts. FA, MD, and FD maps were derived from diffusion datasets of 20 patients with chronic SCI and compared with 19 healthy controls (HC). Group differences were investigated across whole brain WM using tract-based spatial statistics and averaged diffusion values of the corticospinal tract (CST) and thalamic radiation (TR) were extracted for comparisons between HC and SCI subgroups. We also related diffusion readouts of the CST and TR with clinical scores of sensorimotor function. To investigate which diffusion markers of the CST and TR delineate HC and patients with SCI a receiver operating characteristic (ROC) analysis was performed. Overall, patients with an SCI showed decreased FA of the TR and CST. ROC analysis differentiated HC and SCI based on diffusion markers of large WM tracts including FD of the TR. Furthermore, patients' motor function was positively correlated with greater microstructural integrity of the CST. While FD showed the strongest correlation, motor function was also associated with FA and MD of the CST. In summary, microstructural changes of supraspinal WM in patients with SCI can be detected using FD as a complementary marker to traditional DTI readouts and correlates with their clinical characteristics. Future DTI studies may benefit from utilizing this novel marker to investigate complex large WM tracts in patient cohorts with varying presentations of SCI or neurodegenerative diseases.

scholarly journals Transplantation of rat cranial bone-derived mesenchymal stem cells promotes functional recovery in rats with spinal cord injury

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuyo Maeda ◽  
Takashi Otsuka ◽  
Masaaki Takeda ◽  
Takahito Okazaki ◽  
Kiyoharu Shimizu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Stem Cells ◽  
Spinal Cord Injury ◽  
Mesenchymal Stem Cells ◽  
Motor Function ◽  
Cranial Bone ◽  
Transcranial Electrical Stimulation ◽  
Spinal Cord Tissue ◽  
Cell Based Therapy ◽  
Cord Injury

AbstractCell-based therapy using mesenchymal stem cells (MSCs) is a novel treatment strategy for spinal cord injury (SCI). MSCs can be isolated from various tissues, and their characteristics vary based on the source. However, reports demonstrating the effect of transplanted rat cranial bone-derived MSCs (rcMSCs) on rat SCI models are lacking. In this study, we determined the effect of transplanting rcMSCs in rat SCI models. MSCs were established from collected bone marrow and cranial bones. SCI rats were established using the weight-drop method and transplanted intravenously with MSCs at 24 h post SCI. The recovery of motor function and hindlimb electrophysiology was evaluated 4 weeks post transplantation. Electrophysiological recovery was evaluated by recording the transcranial electrical stimulation motor-evoked potentials. Tissue repair after SCI was assessed by calculating the cavity ratio. The expression of genes involved in the inflammatory response and cell death in the spinal cord tissue was assessed by real-time polymerase chain reaction. The transplantation of rcMSCs improved motor function and electrophysiology recovery, and reduced cavity ratio. The expression of proinflammatory cytokines was suppressed in the spinal cord tissues of the rats that received rcMSCs. These results demonstrate the efficacy of rcMSCs as cell-based therapy for SCI.

scholarly journals Testing Pathological Variation of White Matter Tract in Adult Rats after Severe Spinal Cord Injury with MRI

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Wei Song ◽  
Guiyun Song ◽  
Can Zhao ◽  
Xiaoguang Li ◽  
Xiaojiao Pei ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
White Matter ◽  
Motor Function ◽  
Critical Role ◽  
White Matter Tract ◽  
Noninvasive Technique ◽  
Function Recovery ◽  
Cord Injury

The purpose of this study was to assess the pathological variation in white matter tracts in the adult severe thoracic contusion spinal cord injury (SCI) rat models combined with in vivo magnetic resonance imaging (MRI), as well as the effect of spared white matter (WM) quantity on hindlimb motor function recovery. 7.0T MRI was conducted for all experimental animals before SCI and 1, 3, 7, and 14 days after SCI. The variation in the white matter tract in different regions of the spinal cord after SCI was examined by luxol fast blue (LFB) staining, NF200 immunochemistry, and diffusion tensor imaging (DTI) parameters, including fraction anisotropy, mean diffusivity, axial diffusion, and radial diffusivity. Meanwhile, Basso-Beattie-Bresnahan (BBB) open-field scoring was performed to evaluate the behavior of the paraplegic hind limbs. The quantitative analysis showed that spared white matter measures assessed by LFB and MRI had a close correlation (R2 = 0.8508). The percentage of spared white matter area was closely correlated with BBB score (R2 = 0.8460). After SCI, spared white matter in the spinal cord, especially the ventral column WM, played a critical role in motor function restoration. The results suggest that the first three days provides a key time window for SCI protection and treatment; spared white matter, especially in the ventral column, plays a key role in motor function recovery in rats. Additionally, DTI may be an important noninvasive technique to diagnose acute SCI degree as well as a tool to evaluate functional prognosis. During the transition from nerve protection toward clinical treatment after SCI, in vivo DTI may serve as an emerging noninvasive technique to diagnose acute SCI degree and predict the degree of spontaneous functional recovery after SCI.

scholarly journals Jia-Ji Electro-Acupuncture Improves Locomotor Function With Spinal Cord Injury by Regulation of Autophagy Flux and Inhibition of Necroptosis

2021 ◽  
Vol 14 ◽  
Author(s):  
Yin Hongna ◽  
Tian Hongzhao ◽  
Li Quan ◽  
Feng Delin ◽  
Liu Guijun ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Function ◽  
Acupuncture Treatment ◽  
Spinal Cord Tissue ◽  
Autophagy Flux ◽  
Nissl Staining ◽  
Microscopy Imaging ◽  
Locomotor Function ◽  
Cord Injury

Jia-Ji electro-acupuncture (EA) has been widely applied in clinic to exhibit curative effects on spinal cord injury (SCI). However, its underlying mechanisms leading to improvement of motor function after SCI remain unclear. Allen’s method was made by NYU Impactor M-III equipment to create the SCI rats model. Rats were randomly divided into four groups: Sham (only laminectomy), Model (SCI group), EA (SCI + Jia-Ji EA treatment), EA + CQ (SCI + Jia-Ji EA treatment + inhibitor chloroquine). Basso-Beattie-Bresnahan assessment showed improvement of hind limb motor function after Jia-Ji electro-acupuncture treatment. Histological change of injured spinal cord tissue was alleviated after treatment, observed by hematoxylin-eosin and Nissl staining. The mRNA and protein expression levels of RIPK1, RIPK3 and MLKL were decreased in EA group. Besides, the increased expression of LC3 and reduced expression of P62 after treatment compared with Model group, confirmed that Jia-Ji electro-acupuncture could enhance the autophagy flux. Electron microscopy imaging showed increasing the number of lysosomes, autophagosomes, and autolysosomes after Jia-Ji electro-acupuncture treatment. Furthermore, inhibition of lysosome function with CQ led to partly eliminate the effect of EA on reducing necroptosis. These data make the case that Jia-Ji electro-acupuncture treatment may improve locomotor function by promoting autophagy flux and inhibiting necroptosis.

scholarly journals Mettl14-mediated m6A modification modulates neuron apoptosis during the repair of spinal cord injury by regulating the transformation from pri‐mir‐375 to miR-375

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haoyu Wang ◽  
Jing Yuan ◽  
Xiaoqian Dang ◽  
Zhibin Shi ◽  
Wenrui Ban ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Function ◽  
Critical Region ◽  
Cell Model ◽  
Spinal Cord Tissue ◽  
Spinal Cord Neurons ◽  
Cord Injury ◽  
Neuron Apoptosis

Abstract Background Spinal cord injury (SCI) is a disabling disorder, resulting in neurological impairments. This study investigated the mechanism of methyltransferase-like 14 (Mettl14) on apoptosis of spinal cord neurons during SCI repair by mediating pri-microRNA (miR) dependent N6-methyladenosine (m6A) methylation. Methods The m6A content in total RNA and Mettl14 levels in spinal cord tissues of SCI rats were detected. Mettl14 expression was intervened in SCI rats to examine motor function, neuron apoptosis, and recovery of neurites. The cell model of SCI was established and intervened with Mettl14. miR-375, related to SCI and positively related to Mettl14, was screened out. The expression of miR-375 and pri-miR-375 after Mettl14 intervention was detected. The expression of pri-miR-375 combined with DiGeorge critical region 8 (DGCR8) and that modified by m6A was detected. Furthermore, the possible downstream gene and pathway of miR-375 were analysed. SCI cell model with Mettl14 intervention was combined with Ras-related dexamethasone-induced 1 (RASD1)/miR-375 intervention to observe the apoptosis. Results Mettl14 level and m6A content in spinal cord tissue were significantly increased. After Mettl14 knockdown, the injured motor function was restored and neuron apoptosis was reduced. In vitro, Mettl14 silencing reduced the apoptosis of SCI cells; miR-375 was reduced and pri-miR-375 was increased; miR-375 targeted RASD1. Silencing Mettl14 inactivated the mTOR pathway. The apoptosis in cells treated with silencing Mettl14 + RASD1/miR-375 was inhibited. Conclusions Mettl14-mediated m6A modification inhibited RASD1 and induced the apoptosis of spinal cord neurons in SCI by promoting the transformation of pri-miR-375 to mature miR-375.

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