Melatonin restores endoplasmic reticulum homeostasis to protect injured neurons in a rat model of chronic cervical cord compression.

Cervical spondylotic myelopathy (CSM) refers to a chronic injury of the cervical cord caused by cervical intervertebral disc degeneration. Endoplasmic reticulum (ER) homeostasis is essential to counteract neuronal apoptosis. ER stress, an integral part of ER homeostasis, was observed in a rat model of chronic cervical cord compression in our previous study. However, the correlation between ER homeostasis and CSM remains unknown. The antioxidant melatonin is known to exert therapeutic effects in acute spinal cord injury, but the specific effects and their potential mechanisms in the pathological processes of CSM require further exploration. The present study hypothesized that ER homeostasis is essential for neuronal apoptosis in the CSM and that melatonin maintains this homeostasis. The results showed that ER stress led to neuronal apoptosis in rats with chronic cervical cord compression. Conversely, melatonin attenuates protein kinase R-like ER kinase-eukaryotic initiation factor 2α-C/EBP-homologous protein, inositol-requiring enzyme 1, and transcription factor 6 signaling pathways to release ER stress and prevents Bax translocation to the mitochondrion, thereby promoting motor recovery and protecting neurons in vivo. It also rescued primary rat cortical neurons from ER stress-induced glutamate toxicity in vitro. Moreover, melatonin remodels the ER morphology and restores homeostasis via ER-phagy in injured neurons. FAM134B, CCPG1, RTN3, and Sec. 62 are four known ER-phagy receptors. In this study, Sec. 62 was identified as a key melatonin factor in promoting ER-phagy and restoring ER homeostasis in damaged neurons in vivo and in vitro. In conclusion, melatonin suppresses neuronal apoptosis by reducing ER stress and promoting ER-phagy to restore ER morphology and homeostasis. The current results suggested that melatonin is a promising treatment for CSM owing to its restorative effect on ER homeostasis; however, well-designed randomized controlled trials must be carried out to further investigate its clinical effects.

A systematic review and meta-analysis of chondroitinase ABC promotes functional recovery in rat models of spinal cord injury.

BACKGROUND: To comprehensively assess the neurologic recovery potential of chondroitinase ABC (ChABC) in rats after spinal cord injury (SCI). METHODS: The PubMed, Embase, ScienceDirect, Web of Science, and China National Knowledge Infrastructure databases were searched for animal experiments that evaluated the use of ChABC in the treatment of SCI up to November 2022. Studies reporting neurological function using the Basso, Beattie, and Bresnahan (BBB) scale, as well as assessments of cavity area, lesion area, and glial fibrillary acidic protein (GFAP) levels, were included in the analysis. RESULTS: A total of 46 studies were ultimately selected for inclusion. The results of the study showed that rats with SCI that received ChABC therapy exhibited a significant improvement in locomotor function after 7 days compared with controls (32 studies, weighted mean difference (WMD) = 0.58, [0.33, 0.83], p < 0.00001). Furthermore, the benefits of ChABC therapy were maintained for up to 28 days according to BBB scale. The lesion area was reduced by ChABC (5 studies, WMD = -20.94, [-28.42, -13.46], p < 0.00001). Meanwhile, GFAP levels were reduced in the ChABC treatment group (8 studies, WMD = -29.15, [-41.57, -16.72], p < 0.00001). Cavity area is not statistically significant. The subgroup analysis recommended that a single injection of 10 µL (8 studies, WMD = 2.82, [1.99, 3.65], p < 0.00001) or 20 U/mL (4 studies, WMD = 2.21, [0.73, 3.70], p = 0.003) had a better effect on improving the function. The funnel plot of the BBB scale was found to be essentially symmetrical, indicating a low risk of publication bias. CONCLUSIONS: This systematic review and meta-analysis has indicated that ChABC could improve functional recovery in rats after SCI.

A comprehensive and systematic review of the potential neuroprotective effect of quercetin in rat models of spinal cord injury.

CONTEXT: Spinal cord injury (SCI) is a potentially fatal neurological disease with severe complications and a high disability rate. An increasing number of animal experimental studies support the therapeutic effect of quercetin, which is a natural anti-inflammatory and antioxidant bioflavonoid. OBJECTIVE: This paper reviewed the therapeutic effect of quercetin on a rat SCI model and summarized the relevant mechanistic research. DATA SOURCES: PubMed, EMBASE, Web of Science, Science Direct, WanFang Data, SinoMed databases, the China National Knowledge Infrastructure, and the Vip Journal Integration Platform were searched from their inception to April 2023 for animal experiments applying quercetin to treat SCI. STUDY SELECTION: Based on the PICOS criteria, a total of 18 eligible studies were included, of which 14 were high quality. RESULTS: In this study, there was a gradual increase in effect based on the Basso, Beattie, and Bresnahan (BBB) score after three days (p < 0.0001). Furthermore, gender differences also appeared in the efficacy of quercetin; males performed better than females (p = 0.008). Quercetin was also associated with improved inclined plane test score (p = 0.008). In terms of biochemical indicators, meta-analysis showed that MDA (p < 0.0001) and MPO (p = 0.0002) were significantly reduced after quercetin administration compared with the control group, and SOD levels were increased (p = 0.004). Mechanistically, quercetin facilitates the inhibition of oxidative stress, inflammation, autophagy and apoptosis that occur after SCI. CONCLUSIONS: Generally, this systematic review suggests that quercetin has a neuroprotective effect on SCI.

Cross-cultural adaptation of The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire: A methodological systematic review.

BACKGROUND: The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) is a reliable and sensitive measure of disability to determine functional status and evaluate curative effects in low back pain, it has now been cross-cultural translated into many other languages and adapted for use in different countries. We aim to evaluate the translation procedures and measurement properties of cross-cultural adaptations of the JOABPEQ. METHODS: Studies related to cross-cultural adaptation of the JOABPEQ in a specific language/culture were searched in PubMed, Embase, CINAHL, SciELO, PsycINFO, SinoMed, and Web of Science from their inception to March 2022. The Guidelines for the Process of Cross-Cultural Adaptation of Self-Report Measures and the Consensus-based Standards for the Selection of Health Status Measurement Instruments guideline were used for evaluation. RESULTS: Nine different versions of cross-cultural JOABPEQ adaptations in 8 different languages/cultures were included. The adaptation process was not strictly performed, such as standard forward translation and expert committee review were rarely reported. Content validity (8/9), floor and ceiling effects (3/9), reliability (4/9), and interpretability (6/9) were assessed in most of the adaptations, while agreement (2/9), responsiveness (2/9), and the internal consistency (2/9) were not. JOABPEQ can replace functional and quality of life score to reduce the burden of scientific research. CONCLUSION: We recommend Persian-Iranian, simplified Chinese-Chinese Mandarin, Thai and Gunaydin G's Turkish adaptations for application. The numerical pain rating scale/visual analogue scale in low back pain and lower extremities, as well as numbness in lower extremities could not be neglected in JOABPEQ adaptations.

Network pharmacology analysis and animal experiment validation of neuroinflammation inhibition by total ginsenoside in treating CSM.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is a degenerative pathology that affects both upper and lower extremity mobility and sensory function, causing significant pressure on patients and society. Prior research has suggested that ginsenosides may have neuroprotective properties in central nervous system diseases. However, the efficacy and mechanism of ginsenosides for CSM have yet to be investigated. PURPOSE: This study aims to analyze the composition of ginsenosides using UPLC-MS, identify the underlying mechanism of ginsenosides in treating CSM using network pharmacology, and subsequently confirm the efficacy and mechanism of ginsenosides in rats with chronic spinal cord compression. METHODS: UPLC-Q-TOF-MS was utilized to obtain mass spectrum data of ginsenoside samples. The chemical constituents of the samples were analyzed by consulting literature reports and relevant databases. Ginsenoside and CSM targets were obtained from the TCMSP, OMIM, and GeneCards databases. GO and KEGG analyses were conducted, and a visualization network of ginsenosides-compounds-key targets-pathways-CSM was constructed, along with molecular docking of key bioactive compounds and targets, to identify the signaling pathways and proteins associated with the therapeutic effects of ginsenosides on CSM. Chronic spinal cord compression rats were intraperitoneally injected with ginsenosides (50 mg/kg and 150 mg/kg) and methylprednisolone for 28 days, and motor function was assessed to investigate the therapeutic efficacy of ginsenosides for CSM. The expression of proteins associated with TNF, IL-17, TLR4/MyD88/NF-κB, and NLRP3 signaling pathways was assessed by immunofluorescence staining and western blotting. RESULTS: Using UPLC-Q-TOF-MS, 37 compounds were identified from ginsenoside samples. Furthermore, ginsenosides-compounds-key targets-pathways-CSM visualization network indicated that ginsenosides may modulate the PI3K-Akt signaling pathway, TNF signaling pathway, MAPK signaling pathway, IL-17 signaling pathway, Toll-like receptor signaling pathway and Apoptosis by targeting AKT1, TNF, MAPK1, CASP3, IL6, and IL1B, exerting a therapeutic effect on CSM. By attenuating neuroinflammation through the TNF, IL-17, TLR4/MyD88/NF-κB, and MAPK signaling pathways, ginsenosides restored the motor function of rats with CSM, and ginsenosides 150 mg/kg showed better effect. This was achieved by reducing the phosphorylation of NF-κB and the activation of the NLRP3 inflammasome. CONCLUSIONS: The results of network pharmacology indicate that ginsenosides can inhibit neuroinflammation resulting from spinal cord compression through multiple pathways and targets. This finding was validated through in vivo tests, which demonstrated that ginsenosides can reduce neuroinflammation by inhibiting NLRP3 inflammasomes via multiple signaling pathways, additionally, it should be noted that 150 mg/kg was a relatively superior dose. This study is the first to verify the intrinsic molecular mechanism of ginsenosides in treating CSM by combining pharmacokinetics, network pharmacology, and animal experiments. The findings can provide evidence for subsequent clinical research and drug development.

Analysis of gene expression profiles and experimental validations of a rat chronic cervical cord compression model.

Cervical spondylotic myelopathy (CSM) is a severe non-traumatic spinal cord injury (SCI) wherein the spinal canal and cervical cord are compressed due to the degeneration of cervical tissues. To explore the mechanism of CSM, the ideal model of chronic cervical cord compression in rats was constructed by embedding a polyvinyl alcohol-polyacrylamide hydrogel in lamina space. Then, the RNA sequencing technology was used to screen the differentially expressed genes (DEGs) and enriched pathways among intact and compressed spinal cords. A total of 444 DEGs were filtered out based on the value of log2(Compression/Sham); these were associated with IL-17, PI3K-AKT, TGF-ß, and Hippo signaling pathways according to the GSEA, KEGG, and GO analyses. Transmission electron microscopy indicated the changes in mitochondrial morphology. Western blot and immunofluorescence staining revealed neuronal apoptosis, astrogliosis and microglial neuroinflammation in the lesion area. Specifically, the expression of apoptotic indicators, such as Bax and cleaved caspase-3, and inflammatory cytokines, such as IL-1ß, IL-6, and TNF-α, were upregulated. The activation of IL-17 signaling pathway was observed in microglia instead of neurons or astrocytes, the activation of TGF-ß and inhibition of Hippo signaling pathways were detected in astrocytes instead of neurons or microglia, and the inhibition of PI3K-AKT signaling pathway was discovered in neurons rather than microglia of astrocytes in the lesion area. In conclusion, this study indicated that neuronal apoptosis was accompanied by inhibiting of the PI3K-AKT pathway. Then, the activation of microglia IL-17 pathway and NLRP3 inflammasome effectuated the neuroinflammation, and astrogliosis was ascribed to the activation of TGF-ß and the inhibition of the Hippo pathway in the chronic cervical cord of compression. Therefore, therapeutic methods targeting these pathways in nerve cells could be promising CSM treatments.

Chronic spinal cord compression associated with intervertebral disc degeneration in SPARC-null mice.

Chronic spinal cord compression (CSCC) is induced by disc herniation and other reasons, leading to movement and sensation dysfunction, with a serious impact on quality of life. Spontaneous disc herniation rarely occurs in rodents, and therefore establishing a chronic spinal cord compression (CSCC) animal model is of crucial importance to explore the pathogenesis and treatment of CSCC. The absence of secreted protein, acidic, and rich in cysteine (SPARC) leads to spontaneous intervertebral disc degeneration in mice, which resembles human disc degeneration. In this study, we evaluated whether SPARC-null mice may serve as an animal model for CSCC. We performed rod rotation test, pain threshold test, gait analysis, and Basso Mouse Scale score. Our results showed that the motor function of SPARC-null mice was weakened, and magnetic resonance images revealed compression at different spinal cord levels, particularly in the lumbar segments. Immunofluorescence staining and western blot assay showed that the absence of SPARC induced apoptosis of neurons and oligodendrocytes, activation of microglia/macrophages with M1/M2 phenotype and astrocytes with A1/A2 phenotype; it also activated the expression of the NOD-like receptor protein 3 inflammasome and inhibited brain-derived neurotrophic factor/tyrosine kinase B signaling pathway. Notably, these findings are characteristics of CSCC. Therefore, we propose that SPARC-null mice may be an animal model for studying CSCC caused by disc herniation.

Neuroinflammation and apoptosis after surgery for a rat model of double-level cervical cord compression.

INTRODUCTION: Cervical spondylotic myelopathy (CSM) is the most prevalent type of non-traumatic spinal cord injury. The pathological process of CSM is relatively complicated. Most of the chronic cervical cord compression animal models established using hydrophilic expanding polymer are single-segment compression, which was deviated from clinical practice with double-segment or multi-segment compression. This study aims to better mimic the actual clinical compression by using a new type of hydrophilic expanding polymer to establish an animal model of double-level cervical cord compression. MATERIALS AND METHODS: Progressive cord compression was done with implantation of polyvinyl alcohol-polyacrylamide hydrogel in the spinal canal at the C3-4 and C5-6 levels. Sprague-Dawley rats (n = 32) were divided into three groups: sham (no compression, n = 12) and screw compression group (n = 8), and hydrogel compression group (n = 12). Functional deficits were characterized using motor function scores, forelimb grip strength, hindlimb pain threshold, and gait analysis, while compression was imaged with magnetic resonance imaging. The apoptosis, inflammation, and demyelination were assessed by hematoxylin and eosin staining, Luxol fast blue staining, TUNEL assay, immunofluorescence staining, and Western blot analysis. RESULTS: Motor function scores for rats with cervical cord hydrogel compression were significantly decline in motor function scores, an increase in allodynia, neurons and oligodendrocytes apoptosis related to B cell lymphoma-2 (Bcl-2)/Bcl-2 associated X (Bax)/cleaved caspase-3, and impaired axonal conduction, as well as neuroinflammation zone related to microglia or macrophages aggregation related to the nucleotide-binding domain, leucine-rich-repeat-containing family, pyrin domain-containing 3 (NLRP3) inflammasome activation, and activation of astrocytes, as well as oxidative stress were observed. CONCLUSION: We believe that this model utilizing compression on double-level cervical cord will allow researchers to investigate of translationally relevant therapeutic methods for CSM.

Neuroprotective Effect and Possible Mechanisms of Ginsenoside-Rd for Cerebral Ischemia/Reperfusion Damage in Experimental Animal: A Meta-Analysis and Systematic Review.

Ischemic stroke, the most common type of stroke, can lead to a long-term disability with the limitation of effective therapeutic approaches. Ginsenoside-Rd (G-Rd) has been found as a neuroprotective agent. In order to investigate and discuss the neuroprotective function and underlying mechanism of G-Rd in experimental animal models following cerebral ischemic/reperfusion (I/R) injury, PubMed, Embase, SinoMed, and China National Knowledge Infrastructure were searched from their inception dates to May 2022, with no language restriction. Studies that G-Rd was used to treat cerebral I/R damage in vivo were selected. A total of 18 articles were included in this paper, and it was showed that after cerebral I/R damage, G-Rd administration could significantly attenuate infarct volume (19 studies, SMD = -1.75 [-2.21 to - 1.30], P < 0.00001). Subgroup analysis concluded that G-Rd at the moderate doses of >10- <50 mg/kg reduced the infarct volume to the greatest extent, and increasing the dose beyond 50 mg/kg did not produce better results. The neuroprotective effect of G-Rd was not affected by other factors, such as the animal species, the order of administration, and the ischemia time. In comparison with the control group, G-Rd administration could improve neurological recovery (lower score means better recovery: 14 studies, SMD = -1.50 [-2.00 to - 1.00], P < 0.00001; higher score means better recovery: 8 studies, SMD = 1.57 [0.93 to 2.21], P < 0.00001). In addition, this review suggested that G-Rd in vivo can antagonize the reduced oxidative stress, regulate Ca2+, and inhibit inflammatory, resistance to apoptosis, and antipyroptosis on cerebral I/R damage. Collectively, G-Rd is a promising natural neuroprotective agent on cerebral I/R injury with unique advantages and a clear mechanism of action. More clinical randomized, blind-controlled trials are also needed to confirm the neuroprotective effect of G-Rd on cerebral I/R injury.