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

Author(s):  
Mingkun Yang ◽  
Xiaoqian Dang ◽  
Xu Zhang ◽  
Chuan Liu ◽  
Min He

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.

2001 ◽  
Vol 94 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Mercedes Zurita ◽  
Jesús Vaquero ◽  
Isabel Zurita

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.


2021 ◽  
Vol 13 ◽  
Author(s):  
Junhao Liu ◽  
Ruoyao Li ◽  
Zucheng Huang ◽  
Junyu Lin ◽  
Wei Ji ◽  
...  

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.


Biomedicines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 96 ◽  
Author(s):  
Mohamed Ismail ◽  
Sara Ibrahim ◽  
Azza El-Amir ◽  
Amira EL-Rafei ◽  
Nageh Allam ◽  
...  

Innovative drug-delivery systems offer a unique approach to effectively provide therapeutic drug dose over the needed time to achieve better tissue protection and enhanced recovery. The hypothesis of the current study was to test the antioxidant and anti-inflammatory effects of genistein and nanofibers on the spinal cord tissue following experimental spinal cord injury (SCI). Rats were treated post SCI with genistein that is loaded on chitosan/polyvinyl alcohol (CS/PVA) nanofibers as an implantable drug-delivery system. SCI caused marked oxidative damage and inflammation, as is evident by the reduction in the super oxide dismutase (SOD) activity and the level of interleukin-10 (IL-10) in injured spinal cord tissue, as well as the significant increase in the levels of nitric oxide (NO), malondialdehyde (MDA), and tumor necrosis factor-alpha (TNF-α). Treatment of rats post SCI with genistein and CS/PVA nanofibers improved most of the above-mentioned biochemical parameters and shifted them toward the control group values. Genistein induced an increase in the activity of SOD and the level of IL-10, while causing a decrease in NO, MDA, and TNF-α in injured spinal cord tissue. Genistein and CS/PVA nanofibers provide a novel combination for treating inflammatory nervous tissue conditions, especially when combined as an implantable drug-delivery system.


Neurosurgery ◽  
2008 ◽  
Vol 63 (5) ◽  
pp. 981-988 ◽  
Author(s):  
Richard J. Zeman ◽  
Xialing Wen ◽  
Nengtai Ouyang ◽  
Ronald Rocchio ◽  
Lynn Shih ◽  
...  

Abstract OBJECTIVE Currently, because of the precision of stereotactic radiosurgery, radiation can now be delivered by techniques that shape the radiation beam to the tissue target for a variety of clinical applications. This avoids unnecessary and potentially damaging irradiation of surrounding tissues inherent in conventional irradiation, so that irradiation of the minimum volume of tissue necessary for optimal therapeutic benefit can be achieved. Although conventional x-irradiation has been shown to improve recovery from spinal cord injury in animals, the efficacy of targeted irradiation of the injured spinal cord has not been demonstrated previously. The purpose of these studies was to determine whether stereotactic x-irradiation of the injured spinal cord can enhance locomotor function and spare spinal cord tissue after contusion injury in a standard experimental model of spinal cord injury. METHODS Contusion injury was produced in rats at the level of T10 with a weight-drop device, and doses of x-irradiation were delivered 2 hours after injury via a Novalis, 6-MeV linear accelerator shaped beam radiosurgery system (BrainLAB USA, Westchester, IL) in 4 sequential fractions, with beam angles 60 to 70 degrees apart, at a rate of 6.4 Gy/minute. The target volume was a 4 × 15-mm cylinder along the axis of the spinal cord, with the isocenter positioned at the contusion epicenter. Locomotor function was determined for 6 weeks after injury with the 21-point Basso, Beattie, and Bresnahan (BBB) locomotor scale and tissue sparing in histological sections of the spinal cord. RESULTS Locomotor function recovered progressively during the 6-week postinjury observation period. BBB scores were significantly greater in the 10-Gy x-irradiated group compared with controls (9.4 versus 7.3; P &lt; 0.05), indicating hind limb weight support or dorsal stepping in contrast to hind limb joint mobility without weight bearing. Doses in the range of 2 to 10 Gy increased BBB scores progressively, whereas greater doses of 15 to 25 Gy were associated with lower BBB scores. The extent of locomotor recovery after treatment with x-irradiation correlated with measurements of spared spinal cord tissue at the contusion epicenter. CONCLUSION These results suggest a beneficial role for stereotactic radiosurgery in a rat model of acute spinal cord contusion injury and raise hopes for human treatment strategies. Additional animal studies are needed to further define potential benefits.


2020 ◽  
Author(s):  
Wu Wanjiang ◽  
Chen Xin ◽  
Chen Yaxing ◽  
Wang Jie ◽  
Zhang Hongyan ◽  
...  

Abstract Background Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) transplantation are assumed as a promising strategy in spinal cord injury (SCI). However, the complex pathological microenvironment after SCI induces the apoptosis of hUC-MSCs, which limits the clinical application for the cell replacement therapy. Methods In this study, in order to investigate whether combined with curcumin could strengthen the therapeutic effects of hUC-MSCs transplantation for SCI, we mediated the apoptosis of hUC-MSCs with TNF-α and transplanted hUC-MSCs into SCI rats, followed by assessed the anti- apoptosis effect and mechanism of curcumin. Results LDH release test and flow cytometry demonstrated that TNF-α led to the hUC-MSCs apoptosis and curcumin increased survival rate of hUC-MSCs with dose-dependent. In addition, we showed that the phosphorylation levels of ERK, JNK and P38 were up-regulated in the hUC-MSCs apoptosis, while curcumin strengthened the phosphorylation of ERK, but not activated the JNK and P38, which was reversed by p42/44 antagonist U0126. Furthermore, we exhibited that the motor function scores and surviving HNA-positive cells were significantly increased after curcumin combined with hUC-MSCs transplantation therapy 8 weeks post SCI, while U0126 markedly attenuated these phenomenons. Conclusions The aforementioned data confirmed that curcumin suppressed the apoptosis of hUC-MSCs through ERK signal pathway and combined curcumin with hUC-MSCs treatment improved motor function after SCI in rats. The current research provides a strong basis for hUC-MSCs replacement therapy in conjunction with curcumin in the treatment and management of SCI in human.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuyo Maeda ◽  
Takashi Otsuka ◽  
Masaaki Takeda ◽  
Takahito Okazaki ◽  
Kiyoharu Shimizu ◽  
...  

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.


Author(s):  
Ali Rismanbaf ◽  
Khashayar Afshari ◽  
Mehdi Ghasemi ◽  
Abolfazl Badripour ◽  
Arvin Haj-Mirzaian ◽  
...  

Abstract Background Inflammatory responses, including macrophages/microglia imbalance, are associated with spinal cord injury (SCI) complications. Accumulating evidence also suggests an anti-inflammatory property of azithromycin (AZM). Material and Methods Male Wistar rats were subjected to T9 vertebra laminectomy. SCI was induced by spinal cord compression at this level with an aneurysmal clip for 60 seconds. They were divided into three groups: the sham-operated group and two SCI treatment (normal saline as a vehicle control vs. AZM at 180 mg/kg/d intraperitoneally for 3 days postsurgery; first dose: 30 minutes after surgery) groups. Locomotor scaling and behavioral tests for neuropathic pain were evaluated and compared through a 28-day period. At the end of the study, tissue samples were taken to assess neuroinflammatory changes and neural demyelination using ELISA and histopathologic examinations, respectively. In addition, the proportion of M1/M2 macrophage polarization was assessed by using flow cytometry. Results Post-SCI AZM treatment (180 mg/kg/d for 3 days) significantly improved locomotion (p < 0.01) and decreased sensitivity to mechanical (p < 0.01) and thermal allodynia (p < 0.001). Moreover, there was a significant tumor necrosis factor-α (TNF-α) decline (p < 0.01) and interleukin-10 (IL-10) elevation (p < 0.01) in the spinal cord tissue of the AZM-treated group compared with the control groups 28 days post-SCI. AZM significantly improved neuroinflammation as evidenced by reduction of the M1 expression, elevation of M2 macrophages, and reduction of the M1/M2 ratio in both the dorsal root ganglion and the spinal cord tissue after SCI compared with controls (p < 0.01). Conclusion AZM treatment can be considered a therapeutic agent for SCI, as it could reduce neuroinflammation and SCI sensory/locomotor complications.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ke Li ◽  
Juntong Liu ◽  
Liangyu Song ◽  
Wei Lv ◽  
Xi Tian ◽  
...  

Electroacupuncture (EA) is widely recognized as clinical treatment of spinal cord injury (SCI). The purpose of this study is to elucidate whether and how the PI3K/AKT/mTOR signaling pathway plays any role in EA treating SCI. Rats were randomly divided into four equal groups: Control Group, Sham-operation Group, Model Group, and EA Group, then further randomly divided into the following subgroups: 1-day (n=12), 1-day rapamycin (n=6), 14-day (n=18), and 28-day (n=18). A rat model of SCI was established by a modified Allen’s weight-drop method. In the EA Group, rats were stimulated on Dazhui (GV14) and Mingmen (GV4) for 20 min by sterilized stainless steel needles. In the EA Group, the Basso, Beattie, and Bresnahan locomotor rating scale showed obvious improved locomotor function, and hematoxylin-eosin staining and magnetic resonance imaging showed that the histological morphology change of injured spinal cord tissue was obviously alleviated. Also, blocking spinal mTOR by injection of rapamycin showed that mTOR existed in the injured spinal cord, and EA could significantly activate mTOR in SCI rats. And immunohistochemistry and western blot analysis on the PI3K/AKT/mTOR signaling pathway showed that levels of PI3K, AKT, mTOR, and p70S6K in the injured spinal cord tissue were greatly increased in the EA Group, while the levels of PTEN and caspase 3 were decreased. The present study suggests that EA could affect cell growth, apoptosis, and autophagy through the PI3K/AKT/mTOR signaling pathway.


Physiology ◽  
2017 ◽  
Vol 32 (5) ◽  
pp. 391-398 ◽  
Author(s):  
Aiva Ievins ◽  
Chet T. Moritz

Paralysis due to spinal cord injury can severely limit motor function and independence. This review summarizes different approaches to electrical stimulation of the spinal cord designed to restore motor function, with a brief discussion of their origins and the current understanding of their mechanisms of action. Spinal stimulation leads to impressive improvements in motor function along with some benefits to autonomic functions such as bladder control. Nonetheless, the precise mechanisms underlying these improvements and the optimal spinal stimulation approaches for restoration of motor function are largely unknown. Finally, spinal stimulation may augment other therapies that address the molecular and cellular environment of the injured spinal cord. The fact that several stimulation approaches are now leading to substantial and durable improvements in function following spinal cord injury provides a new perspectives on the previously “incurable” condition of paralysis.


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