Locomotor Function Recovery In Rats Research Articles

Shenqisherong pill ameliorates neuronal apoptosis by inhibiting the JNK/caspase-3 signaling pathway in a rat model of cervical cord compression

Ethnopharmacological relevanceThe Shenqisherong (SQSR) pill is an empirical prescription of traditional Chinese medicine (TCM), which originated from the National Chinese Medical Science Master, Shi Qi. It has been widely used in the treatment of cervical spondylotic myelopathy (CSM) and promote the recovery of spinal cord function, but underlying molecular mechanism remains unclear. Aim of the studyThe objective of this study was to confirm the neuroprotective effects of the SQSR pill. Materials and methodsA rat model of chronic compression at double-level cervical cord was used in vivo. The protective role of SQSR pill on CSM rats was measured by Basso, Beattie, and Bresnahan (BBB) locomotor scale, inclined plane test, forelimb grip strength assessment, hindlimb pain threshold assessment, and gait analysis. The levels of reactive oxygen species (ROS) were examined by Dihydroethidium (DHE) staining and 2′,7′-Dichlorofluorescein (DCF) assay, and apoptosis was detected by TdT-mediated dUTP nick-end labeling (TUNEL) assay. The expression of apoptosis proteins was evaluated by immunofluorescence staining and Western blot. ResultsSQSR pill could facilitate locomotor function recovery in rats with chronic cervical cord compression, reduce local ROS in the spinal cord and downregulate the c-Jun-N-terminal kinase (JNK)/caspase-3 signaling pathway. In addition, the SQSR pill could protect primary rat cortical neurons from glutamate-treated toxicity in vitro by reducing the ROS and downregulating the phosphorylation of JNK and its downstream factors related to neuronal apoptosis meditated by the caspase cascade. Then, the neuroprotective effect was counteracted by a JNK activator. ConclusionsTogether, SQSR pill could ameliorate neuronal apoptosis by restraining ROS accumulation and inhibiting the JNK/caspase-3 signaling pathway, indicating that SQSR pill could be a candidate drug for CSM.

The mechanisms through which auricular vagus nerve stimulation protects against cerebral ischemia/reperfusion injury.

Previous studies have shown that vagus nerve stimulation can improve patients' locomotor function. The stimulation of the auricular vagus nerve, which is the only superficial branch of the vagus nerve, may have similar effects to vagus nerve stimulation. However, the precise mechanisms remain poorly understood. In this study, rat models of cerebral ischemia/reperfusion injury were established by modified Longa ligation. Twenty-four hours later, 7-day auricular vagus nerve stimulation was performed. The results showed that auricular vagus nerve stimulation promoted the secretion of acetylcholine, inhibited the secretion of interleukin-1β, interleukin-6, and tumor necrosis factor-α, and reduced connexin 43 phosphorylation in the ischemic penumbra and motor cortex, promoting locomotor function recovery in rats with cerebral ischemia/reperfusion injury. These findings suggested that auricular vagus nerve stimulation promotes the recovery of locomotor function in rats with cerebral ischemia/reperfusion injury by altering the secretion of acetylcholine and inflammatory factors and the phosphorylation of connexin 43. This study was approved by the Animal Use and Management Committee of Shanghai University of Traditional Chinese Medicine on November 8, 2019 (approval No. PZSHUTCM191108014).

Erythropoietin-Induced Autophagy Protects Against Spinal Cord Injury and Improves Neurological Function via the Extracellular-Regulated Protein Kinase Signaling Pathway.

The objective of this study was to explore the neuroprotective molecular mechanisms of erythropoietin (EPO) in rats following spinal cord injury (SCI). First, a standard SCI model was established. After drug or saline treatment was administered, locomotor function was evaluated in rats using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale. H&E, Nissl, and TUNEL staining were performed to assess the ratio of cavities, number of motor neurons, and apoptotic cells in the damaged area. The relative protein and mRNA expressions were examined using western blot and qRT-PCR analyses, and the inflammatory markers, axon special protein, and neuromuscular junctions (NMJs) were detected by immunofluorescence. Both doses of EPO notably improved locomotor function, but high-dose EPO was more effective than low-dose EPO. Moreover, EPO reduced the cavity ratio, cell apoptosis, and motor neuron loss in the damaged area, but enhanced the autophagy level and extracellular-regulated protein kinase (ERK) activity. Treatment with an ERK inhibitor significantly prevented the effect of EPO on SCI, and an activator mimicked the benefits of EPO. Further investigation revealed that EPO promoted SCI-induced autophagy via the ERK signaling pathway. EPO activates autophagy to promote locomotor function recovery in rats with SCI via the ERK signaling pathway.

MiR-384-5p promotes spinal cord injury recovery in rats through suppressing of autophagy and endoplasmic reticulum stress

BackgroundSpinal cord injury (SCI) is one of the most serious neurological disorders and is characterized by high morbidity and disability. Unfortunately, there is a lack of effective treatment. Recently, the micro RNA, miR-384-5p, was reported to play a significant role in cell survival in response to different insults. MethodsIn vitro model of traumatic neuronal injury was induced by application of a sharp sterile blade to generate cuts in PC12 cells, and in vivo SCI was produced by applying vascular clips (force of 15 g) to the dura via T9–T10 laminectomy, and then, the role of miR-384-5p in the development of SCI was investigated. ResultsDual-luciferase reporter assays confirmed that miR-384-5p regulates the gene expression of Beclin-1, an important promoter of autophagy. Quantitative polymerase chain reaction and western blot analyses revealed that treatment with miR-384-5p decreased mRNA and protein expression of Beclin-1 in the mechanically injured PC12 cells. In rats with spinal cord compression injuries, miR-384-5p expression was significantly decreased. Treatment with miR-384-5p increased spinal cord neuron survival and promoted locomotor function recovery in rats. Further study revealed that miR-384-5p administration decreased immunofluorescent labeling of Beclin-1 in spinal cord tissues and reduced autophagosome formation in neurons, as shown by transmission electron microscopy. These results indicated that miR-384-5p promotes recovery of rats with SCI by suppressing autophagy via direct targeting of Beclin-1. Moreover, miR-384-5p also inhibited the activation of endoplasmic reticulum (ER) stress by decreasing GRP78 expression in both in vitro and in vivo models. ConclusionsThis study for the first time demonstrates that the protective role of miR-384-5p in the process of SCI is associated with simultaneous suppression of autophagy and ER stress and miR-384-5p could be a promising candidate for SCI therapeutics.

MiR-325-3p promotes locomotor function recovery in rats with spinal cord injury via inhibiting the expression of neutrophil elastase.

This study aims to investigate the potential function of miR-325-3p in vascular integrity and inflammatory response following spinal cord injury (SCI). The protein levels of ANG-1, ANG-2, and caspase-3 in HUVECs incubated with 0, 100, 200, 400, and 800 ng/ml NE for 24 h were determined. The regulatory effect of overexpressed miR-325-3p on the protein levels of ANG-1 and ANG-2 was determined by Western blot. The SCI model in SD rats was established by spinal injury at T10. Subsequently, the relative levels of miR-325-3p, ANG-1, and ANG-2 were determined in SCI rats and controls. Furthermore, SCI rats were administrated with miR-325-3p mimics or negative control and the relative levels of miR-325-3p, ANG-1, and ANG-2 were examined as well. At day 14, the protein levels of iNOS and GFAP in SCI rats and those overexpressing miR-325-3p were detected. BBB (Basso, Beattie, and Bresnahan) locomotor rating scale was applied for evaluating the locomotor function recovery at day 1, 3, 7, 14, 21, and 28 following SCI. NE treatment in HUVECs downregulated ANG-1 and upregulated ANG-2 and caspase-3 in a dose-dependent manner. The overexpression of miR-325-3p upregulated NE-induced decreased the level of ANG-1 and downregulated NE-induced increased level of ANG-2. After the establishment of the SCI model in rats, the miR-325-3p level gradually decreased in SCI rats relative to controls in a time-dependent manner. ANG-1 level in SCI rats decreased to the lowest on the first day following SCI, and gradually increased at day 3, 5, and 7. ANG-2 level was firstly upregulated and achieved the peak on day 3, and then decreased at day 5 and 7. Moreover, SCI rats overexpressing miR-325-3p showed a higher level of ANG-1 and lower level of ANG-2 than those of SCI rats. Overexpression of miR-325-3p downregulated the protein levels of iNOS and GFAP in SCI rats. BBB scale showed elevated locomotor function recovery in SCI rats overexpressing miR-325-3p compared with SCI rats. MiR-325-3p protects the integrity of the vascular wall, reduces infiltration of inflammation, and improves locomotor function recovery at post-SCI.

MiR-379-5p improved locomotor function recovery after spinal cord injury in rats by reducing endothelin 1 and inhibiting astrocytes expression.

The aim of this study was to investigate the effect of microRNA-214-5p (miR-214-5p) on spinal cord injury (SCI) and to explore the mechanism of action in pathophysiological relevance. The model of SCI was successfully established in rats aged 6-8 weeks. The levels of the locomotor function recovery in rats of the miR-379-5p group and SCI group were detected one month later by Basso-Beattie-Bresnahan (BBB) locomotor rating scale. Biochemical indexes were measured by Western blotting and real time-PCR, respectively. In addition, rat astrocytes were cultured to verify the effect of miR-379-5p on activated astrocytes in vitro. Compared with the SCI group, the rats in the miR-379-5p group showed prominent improvement in the locomotor function in vivo. MiR-379-5p attenuated the activation of astrocytes and significantly suppressed the expressions of the nerve growth inhibitors. Furthermore, the down-regulation of endothelin-1 (ET-1) ameliorated the spinal cord ischemia, thereby reducing apoptosis and oxidative stress. Compared with the pentylenetetrazol (PTZ) group, ET-1 and chondroitin sulfate poly-glycoprotein (CSPG) in miR-379-5p group decreased significantly in the astrocytes transfected with miR-214-5p in vitro. MiR-379-5p retarded the neurofilament regeneration block effect by inhibiting endothelin 1 and the expression of the astrocytes after SCI. Furthermore, it might relieve nerve structure destruction, resist oxidative stress, and inhibit apoptosis, eventually promoting functional recovery.

Inhibition of miR-214-5p attenuates inflammatory chemotaxis and nerve regeneration obstruction after spinal cord injury in rats.

To investigate the effect of miR-214-5p on spinal cord injury (SCI) and the possible mechanism in pathophysiological relevance, and to evaluate the therapeutic efficacy of the corresponding inhibitor. The SCI model was successfully established in 6-week-old rats. The levels of locomotor function recovery in rats of miR-214-5p inhibitor group and SCI group were detected one month later by Basso-Beattie-Bresnahan (BBB) locomotor rating scale, Western blotting, quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Rat microglia cells were cultured in vitro. Furthermore, the effect of miR-214-5p and its inhibitor on inflammatory microglia was explored. Compared with SCI group, rats in miR-214-5p inhibitor group showed a significant retardation of inflammatory diffusion in terms of reduced production of inflammatory factors and chemokines in vivo. MiR-214-5p inhibitor markedly attenuated antioxidant stress, inhibited apoptosis, and increased nerve fibers repair. Compared with lipopolysaccharide (LPS) group, tumor necrosis factor alpha (TNF-α) and interleukin 1 (IL-1) decreased significantly in microglia treated with miR-214-5p inhibitor in vitro. Furthermore, inhibition of miR-214-5p remarkably promoted locomotor function recovery in rats. MiR-214-5p inhibitor retarded inflammatory diffusion by inhibiting inflammatory factors and chemokines after SCI. In addition, this might relieve nerve structure destruction, resist oxidative stress and inhibit apoptosis, eventually promoting function recovery.

Retraction Note to: Triptolide (TPL) improves locomotor function recovery in rats and reduces inflammation after spinal cord injury.

In this study, we studied the effect of triptolide (TPL) on locomotor function in rats with spinal cord injury. A total of 40 rats were studied after dividing them in two major groups, one was experimental group denoted as TPL group while other was control group denoted as PBS group. Each group was subdivided in four subgroups having five rats each (n = 5). TPL was given intraperitonially at the rate of 5 mg/kg/day in TPL group while PBS was given at the same time interval in the same manner in control group for comparison. A reduction in the cavity area of tissue sections was observed by bright field microscopy from 0.22 ± 0.05 to 0.12 ± 0.05 mm2 in experimental group after 28 days of treatment while BBB score also improved from 1 to 5 after 14 days of treatment. SPSS software, one way ANOVA, was used for recording statistical analysis and values were expressed as mean ± SEM where P value of <0.01 was considered significant. The expression of I-kBα and NF-kB p65 was also studied using western blotting and after recording optical density (OD) values of western blots. It was observed that treatment with TPL significantly reduced the expression of these factors after 28 days of treatment compared with controls.

Triptolide (TPL) improves locomotor function recovery in rats and reduces inflammation after spinal cord injury.

In this study, we studied the effect of triptolide (TPL) on locomotor function in rats with spinal cord injury. A total of 40 rats were studied after dividing them in two major groups, one was experimental group denoted as TPL group while other was control group denoted as PBS group. Each group was subdivided in four subgroups having five rats each (n = 5). TPL was given intraperitonially at the rate of 5 mg/kg/day in TPL group while PBS was given at the same time interval in the same manner in control group for comparison. A reduction in the cavity area of tissue sections was observed by bright field microscopy from 0.22 ± 0.05 to 0.12 ± 0.05 mm(2) in experimental group after 28 days of treatment while BBB score also improved from 1 to 5 after 14 days of treatment. SPSS software, one way ANOVA, was used for recording statistical analysis and values were expressed as mean ± SEM where P value of <0.01 was considered significant. The expression of I-kBα and NF-kB p65 was also studied using western blotting and after recording optical density (OD) values of western blots. It was observed that treatment with TPL significantly reduced the expression of these factors after 28 days of treatment compared with controls.

Spinal cord injury models: neurophysiology.

Spinal cord injury models: neurophysiology.