Differential degradation rate and underlying mechanism of a collagen/chitosan complex in subcutis, spinal cord and brain tissues of rat

AbstractBackgroundSpinal cord injury (SCI) causes devastating loss of function and neuronal death without effective treatment. (−)-Epigallocatechin-3-gallate (EGCG) has antioxidant properties and plays an essential role in the nervous system. However, the underlying mechanism by which EGCG promotes neuronal survival and functional recovery in complete spinal cord transection (ST) remains unclear.MethodsIn the present study, we established primary cerebellar granule neurons (CGNs) and a T10 ST rat model to investigate the antioxidant effects of EGCG via its modulation of protein kinase D1 (PKD1) phosphorylation and inhibition of ferroptosis.ResultsWe revealed that EGCG significantly increased the cell survival rate of CGNs and PKD1 phosphorylation levels in comparison to the vehicle control, with a maximal effect observed at 50 µM. EGCG upregulated PKD1 phosphorylation levels and inhibited ferroptosis to reduce the cell death of CGNs under oxidative stress and to promote functional recovery and ERK phosphorylation in rats following complete ST.ConclusionTogether, these results lay the foundation for EGCG as a novel strategy for the treatment of SCI related to PKD1 phosphorylation and ferroptosis.

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The Reorganization of Insular Subregions in Individuals with Below-Level Neuropathic Pain following Incomplete Spinal Cord Injury

Neural Plasticity ◽

10.1155/2020/2796571 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Xuejing Li ◽

Ling Wang ◽

Qian Chen ◽

Yongsheng Hu ◽

Jubao Du ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Neuropathic Pain ◽

Pearson Correlation ◽

Underlying Mechanism ◽

Anterior Insula ◽

Incomplete Spinal Cord Injury ◽

Cord Injury ◽

Vas Scores ◽

And Function

Objective. To investigate the reorganization of insular subregions in individuals suffering from neuropathic pain (NP) after incomplete spinal cord injury (ISCI) and further to disclose the underlying mechanism of NP. Method. The 3D high-resolution T1-weighted structural images and resting-state functional magnetic resonance imaging (rs-fMRI) of all individuals were obtained using a 3.0 Tesla MRI system. A comparative analysis of structure and function connectivity (FC) with insular subareas as seeds in 10 ISCI individuals with below-level NP (ISCI-P), 11 ISCI individuals without NP (ISCI-N), and 25 healthy controls (HCs) was conducted. Associations between the structural and functional alteration of insula subregions and visual analog scale (VAS) scores were analyzed using the Pearson correlation in SPSS 20. Results. Compared with ISCI-N patients, when the left posterior insula as the seed, ISCI-P showed increased FC in right cerebellum VIIb and cerebellum VIII, Brodmann 37 (BA 37). When the left ventral anterior insula as the seed, ISCI-P indicated enhanced FC in right BA18 compared with ISCI-N patients. These increased FCs positively correlated with VAS scores. Relative to HCs, ISCI-P presented increased FC in the left hippocampus when the left dorsal anterior insula was determined as the seed. There was no statistical difference in the volume of insula subregions among the three groups. Conclusion. Our study indicated that distinctive patterns of FC in each subregion of insula suggest that the insular subareas participate in the NP processing through different FC following ISCI. Further, insula subregions could serve as a therapeutic target for NP following ISCI.

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Longitudinal data in peripheral blood confirm that PM20D1 is a quantitative trait locus (QTL) for Alzheimer’s disease and implicate its dynamic role in disease progression

Clinical Epigenetics ◽

10.1186/s13148-020-00984-5 ◽

2020 ◽

Vol 12 (1) ◽

Author(s):

Qi Wang ◽

Yinghua Chen ◽

Benjamin Readhead ◽

Kewei Chen ◽

Yi Su ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Dna Methylation ◽

Longitudinal Data ◽

Disease Progression ◽

Peripheral Blood ◽

Early Stage ◽

Underlying Mechanism ◽

Methylation Data ◽

Brain Tissues

Abstract Background While Alzheimer’s disease (AD) remains one of the most challenging diseases to tackle, genome-wide genetic/epigenetic studies reveal many disease-associated risk loci, which sheds new light onto disease heritability, provides novel insights to understand its underlying mechanism and potentially offers easily measurable biomarkers for early diagnosis and intervention. Methods We analyzed whole-genome DNA methylation data collected from peripheral blood in a cohort (n = 649) from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) and compared the DNA methylation level at baseline among participants diagnosed with AD (n = 87), mild cognitive impairment (MCI, n = 175) and normal controls (n = 162), to identify differentially methylated regions (DMRs). We also leveraged up to 4 years of longitudinal DNA methylation data, sampled at approximately 1 year intervals to model alterations in methylation levels at DMRs to delineate methylation changes associated with aging and disease progression, by linear mixed-effects (LME) modeling for the unchanged diagnosis groups (AD, MCI and control, respectively) and U-shape testing for those with changed diagnosis (converters). Results When compared with controls, patients with MCI consistently displayed promoter hypomethylation at methylation QTL (mQTL) gene locus PM20D1. This promoter hypomethylation was even more prominent in patients with mild to moderate AD. This is in stark contrast with previously reported hypermethylation in hippocampal and frontal cortex brain tissues in patients with advanced-stage AD at this locus. From longitudinal data, we show that initial promoter hypomethylation of PM20D1 during MCI and early stage AD is reversed to eventual promoter hypermethylation in late stage AD, which helps to complete a fuller picture of methylation dynamics. We also confirm this observation in an independent cohort from the Religious Orders Study and Memory and Aging Project (ROSMAP) Study using DNA methylation and gene expression data from brain tissues as neuropathological staging (Braak score) advances. Conclusions Our results confirm that PM20D1 is an mQTL in AD and demonstrate that it plays a dynamic role at different stages of the disease. Further in-depth study is thus warranted to fully decipher its role in the evolution of AD and potentially explore its utility as a blood-based biomarker for AD.

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VGLUT2/Cdk5/p25 Signaling Pathway Contributed to Inflammatory Pain by Complete Freund’s Adjuvant

Pain Research and Management ◽

10.1155/2020/4807674 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Yuwen Tang ◽

Zhiyou Peng ◽

Shoujun Tao ◽

Jianliang Sun ◽

Wenyuan Wang ◽

...

Keyword(s):

Spinal Cord ◽

Signaling Pathway ◽

Inflammatory Pain ◽

Glutamate Transporter ◽

Underlying Mechanism ◽

Complete Freund’S Adjuvant ◽

Freund’S Adjuvant ◽

Complete Freund's Adjuvant ◽

Freund's Adjuvant ◽

Heat Hyperalgesia

Vesicular glutamate transporter type 2 (VGLUT2) is known to play an important role in mediating heat hyperalgesia induced by inflammation. However, the underlying mechanism for this activity is poorly understood. Cyclin-dependent kinase 5 (Cdk5), serving as a key regulator in modulating release of glutamate, acted a key player in the formation of heat hyperalgesia of inflammatory pain. However, it remains unknown whether there is a bridge between Cdk5 and VGLUT2 for mediating inflammatory pain. Therefore, we designed the experiment to determine whether VGLUT2 signaling pathway is involved in inflammatory pain mediated by Cdk5 in the inflammatory pain model induced by complete Freund’s adjuvant (CFA). Our results showed that the coexpression of Cdk5/VGLUT2 in small- and medium-sized neuronal cells of the dorsal root ganglion (DRG) and spinal cord between days 1 and 3 following subcutaneous injection of CFA was significantly increased. Moreover, our study revealed that the expression of VGLUT2 protein in the DRG and spinal cord was remarkably increased between days 1 and 3 following CFA injection and was significantly reduced by roscovitine, a selective antagonist of Cdk5. Additionally, p25 but not p35, an activator of Cdk5, protein was significantly increased by CFA and reduced by roscovitine. Our findings suggested that VGLUT2/Cdk5 signaling pathway contributes to inflammatory pain mediated by Cdk5/p25.

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Retained Medullary Cord in Humans: Late Arrest of Secondary Neurulation

Neurosurgery ◽

10.1227/neu.0b013e31820ee282 ◽

2011 ◽

Vol 68 (6) ◽

pp. 1500-1519 ◽

Cited By ~ 38

Author(s):

Dachling Pang ◽

John Zovickian ◽

Greg S. Moes

Keyword(s):

Spinal Cord ◽

Cell Mass ◽

Tethered Cord ◽

Underlying Mechanism ◽

Neurological Deficits ◽

Tail Bud ◽

Neural Structure ◽

Nerve Roots ◽

Secondary Neurulation ◽

Caudal Spinal Cord

Abstract BACKGROUND: Formation of the caudal spinal cord in vertebrates is by secondary neurulation, which begins with mesenchyme-epithelium transformation within a pluripotential blastema called the tail bud or caudal cell mass, from thence initiating an event sequence proceeding from the condensation of mesenchyme into a solid medullary cord, intrachordal lumen formation, to eventual partial degeneration of the cavitatory medullary cord until, in human and tailless mammals, only the conus and filum remain. OBJECTIVE: We describe a secondary neurulation malformation probably representing an undegenerated medullary cord that causes tethered cord symptoms. METHOD: We present 7 patients with a robust elongated neural structure continuous from the conus and extending to the dural cul-de-sac, complete with issuing nerve roots, which, except in 2 infants, produced neurological deficits by tethering. RESULTS: Intraoperative motor root and direct cord stimulation indicated that a large portion of this stout neural structure was “redundant” nonfunctional spinal cord below the true conus. Histopathology of the redundant cord resected at surgery showed a glioneuronal core with ependyma-lined lumen, nerve roots, and dorsal root ganglia, corroborating the picture of a blighted spinal cord. CONCLUSION: We propose that these redundant spinal cords are portions of the medullary cord normally destined to regress but are here retained because of late arrest of secondary neurulation before the degenerative phase. Because programmed cell death almost certainly plays a central role during degeneration, defective apoptosis may be the underlying mechanism.

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#75 IL-1β-induced reduction in spinal cord GRK2 as an underlying mechanism for chronic, inflammatory hyperalgesia

Brain Behavior and Immunity ◽

10.1016/j.bbi.2005.10.081 ◽

2005 ◽

Vol 19 (4) ◽

pp. e39

Author(s):

Wendy Kleibeuker ◽

Annemarie Ledeboer ◽

Jitske Zijlstra ◽

Steven F. Maier ◽

Linda R. Watkins ◽

...

Keyword(s):

Spinal Cord ◽

Underlying Mechanism ◽

Inflammatory Hyperalgesia

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Effect of Shikonin on Spinal Cord Injury in Rats Via Regulation of HMGB1/TLR4/NF-kB Signaling Pathway

Cellular Physiology and Biochemistry ◽

10.1159/000480474 ◽

2017 ◽

Vol 43 (2) ◽

pp. 481-491 ◽

Cited By ~ 13

Author(s):

Yihui Bi ◽

Yapeng Zhu ◽

Mingkai Zhang ◽

Keke Zhang ◽

Xingyi Hua ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Inflammatory Response ◽

Signaling Pathway ◽

Motor Function ◽

Tissue Repair ◽

Underlying Mechanism ◽

Molecular Signaling ◽

Cord Injury

Background/Aims: Shikonin, a compound extracted from Zicao, has been demonstrated to hold anti-bacterial, anti-inflammatory, and anti-tumor activities in various diseases and it has been shown to protect human organs from injuries. However, the effect of shikonin on the recovery of spinal cord injury (SCI) remains unknown. This study was designed to estimate the potential therapeutic effect and underlying mechanism of shikonin on SCI in vivo. Methods: In the study, we used HE staining, ELISA assay, transfection assay, TUNEL assay, real time PCR and Western blot to detect the effects of shikonin on spinal cord injury in rats. Results: we showed that shikonin could promote the recovery of motor function and tissue repair after SCI treatment in rats SCI model. Moreover, we demonstrated that shikonin inhibited the spinal cord edema in SCI model of rats. According to further investigation, shikonin induced the reduction of inflammatory response through decreasing the expression levels of HMGB1, TLR4 and NF-κB after SCI injury. In addition, we also found that shikonin could suppress the apoptosis and expression of caspase-3 protein in SCI model of rats. Conclusion: Our results demonstrated that shikonin induced the recovery of tissue repair and motor function via inactivation of HMGB1/TLR4/NF-κB signaling pathway in SCI model of rats. Meanwhile, shikonin regulated the inflammation response in SCI by suppressing the HMGB1/TLR4/NF-κB signaling pathway. The described mechanism sheds novel light on molecular signaling pathway in spinal cord injury and secondary injury including inflammatory response.

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Betulinic Acid Inhibits ROS-Mediated Pyroptosis in Spinal Cord Injury by Augmenting Autophagy via the AMPK-mTOR-TFEB Signaling Pathway

10.21203/rs.3.rs-100352/v1 ◽

2020 ◽

Author(s):

Chenyu Wu ◽

Huanwen Chen ◽

Rong Zhuang ◽

Yongli Wang ◽

Xinli Hu ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Signaling Pathway ◽

Betulinic Acid ◽

Neurological Diseases ◽

Underlying Mechanism ◽

Autophagy Flux ◽

Wide Range ◽

Cord Injury

Abstract Background：Spinal cord injury (SCI) results in a wide range of disabilities. Its complex pathophysiological process limits the effectiveness of many clinical treatments. Betulinic acid (BA) has been shown to be an effective treatment for some neurological diseases, but it has not been studied in SCI. In this study, we assessed the role of BA in SCI and investigated its underlying mechanism. Methods：Using a mouse model of SCI, survival and functional outcomes following injury were assessed. Western blotting, ELISA, and immunofluorescence techniques were employed to analyze levels of autophagy, mitophagy, and pyroptosis; ROS- and AMPK-related signaling pathways were also examined. Results：Our results showed that BA significantly improves functional recovery following SCI. Furthermore, autophagy, mitophagy, ROS-activity and pyroptosis were implicated in the mechanism of BA in the treatment of SCI. Specifically, our results suggest that BA restored autophagy flux following injury, which induces mitophagy to eliminate the accumulation of ROS and subsequently inhibits pyroptosis. Further mechanistic studies revealed that BA likely regulates autophagy and mitophagy via the AMPK-mTOR-TFEB signaling pathway. Conclusion: BA can significantly promote the recovery following SCI and that it may be a promising therapy for SCI.

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The effect of sonic hedgehog on motor neuron positioning in the spinal cord during chicken embryo development

10.1101/178491 ◽

2017 ◽

Author(s):

Ciqing Yang ◽

Xiaoying Li ◽

Qiuling Li ◽

Qiong Li ◽

Han Li ◽

...

Keyword(s):

Spinal Cord ◽

Motor Neuron ◽

Embryo Development ◽

Sonic Hedgehog ◽

Motor Neurons ◽

Chicken Embryo ◽

Positional Information ◽

Underlying Mechanism ◽

Correct Location ◽

Information Cell

ABSTRACTSonic hedgehog (Shh) is a vertebrate homologue of the secreted Drosophila protein hedgehog, and is expressed by the notochord and the floor plate in the developing spinal cord. Shh provides signals relevant for positional information, cell proliferation, and possibly cell survival depending on the time and location of the expression. Although the role of Shh in providing positional information in the neural tube has been experimentally proven, the exact underlying mechanism still remains unclear. In this study, we report that overexpression of Shh affects motor neuron positioning in the spinal cord during chicken embryo development by inducing abnormalities in the structure of the motor column and motor neuron integration. In addition, Shh overexpression inhibits the expression of dorsal transcription factors and commissural axon projections. Our results indicate that correct location of Shh expression is the key to the formation of the motor column. In conclusion, the overexpression of Shh in the spinal cord not only affects the positioning of motor neurons, but also induces abnormalities in the structure of the motor column.

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1,3,4-Oxadiazole Derivative Attenuates Chronic Constriction Injury Induced Neuropathic Pain: A Computational, Behavioral, and Molecular Approach

Brain Sciences ◽

10.3390/brainsci10100731 ◽

2020 ◽

Vol 10 (10) ◽

pp. 731

Author(s):

Muhammad Faheem ◽

Syed Hussain Ali ◽

Abdul Waheed Khan ◽

Mahboob Alam ◽

Umair Ilyas ◽

...

Keyword(s):

Spinal Cord ◽

Neuropathic Pain ◽

Sciatic Nerve ◽

Pain Perception ◽

Chronic Constriction Injury ◽

Neuroprotective Effect ◽

Underlying Mechanism ◽

Contributing Factors ◽

Neuroprotective Effects ◽

In Silico Studies

The production and up-regulation of inflammatory mediators are contributing factors for the development and maintenance of neuropathic pain. In the present study, the post-treatment of synthetic 1,3,4 oxadiazole derivative (B3) for its neuroprotective potential in chronic constriction injury-induced neuropathic pain was applied. In-silico studies were carried out through Auto Dock, PyRx, and DSV to obtain the possible binding and interactions of the ligands (B3) with COX-2, IL-6, and iNOS. The sciatic nerve of the anesthetized rat was constricted with sutures 3/0. Treatment with 1,3,4-oxadiazole derivative was started a day after surgery and continued until the 14th day. All behavioral studies were executed on day 0, 3rd, 7th, 10th, and 14th. The sciatic nerve and spinal cord were collected for further molecular analysis. The interactions in the form of hydrogen bonding stabilizes the ligand target complex. B3 showed three hydrogen bonds with IL-6. B3, in addition to correcting paw posture/deformation induced by CCI, attenuates hyperalgesia (p < 0.001) and allodynia (p < 0.001). B3 significantly raised the level of GST and GSH in both the sciatic nerve and spinal cord and reduced the LPO and iNOS (p < 0.001). B3 attenuates the pathological changes induced by nerve injury, which was confirmed by H&E staining and IHC examination. B3 down-regulates the over-expression of the inflammatory mediator IL-6 and hence provides neuroprotective effects in CCI-induced pain. The results demonstrate that B3 possess anti-nociceptive and anti-hyperalgesic effects and thus minimizes pain perception and inflammation. The possible underlying mechanism for the neuroprotective effect of B3 probably may be mediated through IL-6.

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