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BACKGROUND@#Repair of long-distance peripheral nerve defects remains an important clinical problem. Nerve grafts incorporated with extracellular vesicles (EVs) from various cell types have been developed to bridge peripheral nerve defects. In our previous research, EVs obtained from skin-derived precursor Schwann cells (SKP-SC-EVs) were demonstrated to promote neurite outgrowth in cultured cells and facilitate nerve regeneration in animal studies. @*METHODS@#To further assess the functions of SKP-SC-EVs in nerve repair, we incorporated SKP-SC-EVs and Matrigel into chitosan nerve conduits (EV-NG) for repairing a 15-mm long-distance sciatic nerve defect in a rat model. Behavioral analysis, electrophysiological recording, histological investigation, molecular analysis, and morphometric assessment were carried out. @*RESULTS@#The results revealed EV-NG significantly improved motor and sensory function recovery compared with nerve conduits (NG) without EVs incorporation. The outgrowth and myelination of regenerated axons were improved, while the atrophy of target muscles induced by denervation was alleviated after EVs addition. @*CONCLUSION@#Our data indicated SKP-SC-EVs incorporation into nerve grafts represents a promising method for extended peripheral nerve damage repair.
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Nerve regeneration in adult mammalian spinal cord is poor because of the lack of intrinsic regeneration of neurons and extrinsic factors - the glial scar is triggered by injury and inhibits or promotes regeneration. Recent technological advances in spatial transcriptomics (ST) provide a unique opportunity to decipher most genes systematically throughout scar formation, which remains poorly understood. Here, we first constructed the tissue-wide gene expression patterns of mouse spinal cords over the course of scar formation using ST after spinal cord injury from 32 samples. Locally, we profiled gene expression gradients from the leading edge to the core of the scar areas to further understand the scar microenvironment, such as neurotransmitter disorders, activation of the pro-inflammatory response, neurotoxic saturated lipids, angiogenesis, obstructed axon extension, and extracellular structure re-organization. In addition, we described 21 cell transcriptional states during scar formation and delineated the origins, functional diversity, and possible trajectories of subpopulations of fibroblasts, glia, and immune cells. Specifically, we found some regulators in special cell types, such as Thbs1 and Col1a2 in macrophages, CD36 and Postn in fibroblasts, Plxnb2 and Nxpe3 in microglia, Clu in astrocytes, and CD74 in oligodendrocytes. Furthermore, salvianolic acid B, a blood-brain barrier permeation and CD36 inhibitor, was administered after surgery and found to remedy fibrosis. Subsequently, we described the extent of the scar boundary and profiled the bidirectional ligand-receptor interactions at the neighboring cluster boundary, contributing to maintain scar architecture during gliosis and fibrosis, and found that GPR37L1_PSAP, and GPR37_PSAP were the most significant gene-pairs among microglia, fibroblasts, and astrocytes. Last, we quantified the fraction of scar-resident cells and proposed four possible phases of scar formation: macrophage infiltration, proliferation and differentiation of scar-resident cells, scar emergence, and scar stationary. Together, these profiles delineated the spatial heterogeneity of the scar, confirmed the previous concepts about scar architecture, provided some new clues for scar formation, and served as a valuable resource for the treatment of central nervous system injury.
Subject(s)
Mice , Animals , Gliosis/pathology , Cicatrix/pathology , Spinal Cord Injuries , Astrocytes/metabolism , Spinal Cord/pathology , Fibrosis , Mammals , Receptors, G-Protein-CoupledABSTRACT
The inhibitory environment that surrounds the lesion site and the lack of intrinsic regenerative capacity of the adult mammalian central nervous system (CNS) impede the regrowth of injured axons and thereby the reestablishment of neural circuits required for functional recovery after spinal cord injuries (SCI). To circumvent these barriers, biomaterial scaffolds are applied to bridge the lesion gaps for the regrowing axons to follow, and, often by combining stem cell transplantation, to enable the local environment in the growth-supportive direction. Manipulations, such as the modulation of PTEN/mTOR pathways, can also enhance intrinsic CNS axon regrowth after injury. Given the complex pathophysiology of SCI, combining biomaterial scaffolds and genetic manipulation may provide synergistic effects and promote maximal axonal regrowth. Future directions will primarily focus on the translatability of these approaches and promote therapeutic avenues toward the functional rehabilitation of patients with SCIs.
Subject(s)
Animals , Humans , Axons , Physiology , Biocompatible Materials , Genetic Enhancement , Methods , Nerve Regeneration , PTEN Phosphohydrolase , Metabolism , Recovery of Function , Spinal Cord Injuries , Tissue Engineering , Methods , Tissue ScaffoldsABSTRACT
Brain-computer interface (BCI) provides a direct communicating and controlling approach between the brain and surrounding environment, which attracts a wide range of interest in the fields of brain science and artificial intelligence. It is a core to decode the electroencephalogram (EEG) feature in the BCI system. The decoding efficiency highly depends on the feature extraction and feature classification algorithms. In this paper, we first introduce the commonly-used EEG features in the BCI system. Then we introduce the basic classical algorithms and their advanced versions used in the BCI system. Finally, we present some new BCI algorithms proposed in recent years. We hope this paper can spark fresh thinking for the research and development of high-performance BCI system.
Subject(s)
Humans , Algorithms , Brain , Physiology , Brain-Computer Interfaces , Electroencephalography , Pattern Recognition, AutomatedABSTRACT
Objective To evaluate the improvement effect of Nerve Growth Decoction ( NGD) on symptoms in senile Parkinson's disease (PD) patients with multi-scales.Methods Totally 100 PD patients who have previously taken Madopa therapy were divided into NGD treatment group(70 cases) and control group( 30 cases) .The NGD treatment group took a package of NGD oral solution twice a day for 30 days,and went on next period of 30 days after an interval of 1~2 weeks.The Unified Parkinson disease Rating Scale (UPDRSⅡ,UPDRSⅢ),the PD NMS Questionnaire (NMSQuest),Activity of Daily Living Scale (ADL), the 39-item Parkinson's Disease Questionnaire ( PDQ-39 ) and Schwab & England Daily Living Scale ( Schwab) were used to evaluate both NGD treatment and control group,and within NGD treatment group be-fore and after NGD treatment.Results ( 1) There were significant differences comparing NGD treatment group with control group in ADL,Schwab,PDQ-39 and NMSQuest ( P<0.05) ((27.78±10.54)points,(0.87 ±0.14)points,(26.07±19.18)points,(9.95±4.70)points vs ((34.15±13.88)points,(0.77±0.21)points, (37.47±24.05)points,(13.46±4.01)points,respectively).(2)There were significant differences in UPDRSⅡ,UPDRSⅢ,NMSQuest,ADL,PDQ-39 and Schwab (10.68±7.15)points,(23.79±16.64)points,(33.96± 14.06)points,(0.77±0.21)points,(36.96±24.26)points,(11.96±5.17)points vs ((8.50±6.40)points, (16.79±13.48)points,(27.78±10.54)points,(0.87±0.14)points,(26.07±19.18)points,(9.95±4.70) points,respectively) between before and after treatment in NGD treatment group (P<0.05, P<0.01) .Con-clusion Based on Madopa therapy,the NGD may obviously improves the symptoms,the patient's quality of life and ability of daily life in senile PD patients.Multi-scale evaluations can be used systematically to evalu-ate PD patients,and as assessment indicators for effects of Traditional Chinese drugs.
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Objective To investigate the biocompatibility of bone marrow stromal cells(BMSCs) of mice in vitro with silk fibroin materials and to explore a novel scaffold material to fabricate tissue-engineered nerve with introduction of BMSCs.Methods BMSCs were typically isolated from other cells by adherence to plastic.The mice-derived bone marrow stromal cells were cultured on the substrate of silk fibroin fibers and the cell attachment and growth during culture was observed by using light and electron microscopy.Mice-derived BMSCs were also cultured in the silk fibroin extract fluid.The cell ultrastructure was observed by transmission electron microscopy.MTT test was used to detect cell viability in different media for 12,24,48,72 hours and 7 days respectively(the test was repeated 12 times for each group).Flow cytometry was employed to detect BMSCs cell cycle and phenotypes(the test was repeated 3 times).Results BMSCs cells were tightly attached to the silk fibroin fibers and grew along the silk fibroin fibers;some of them enwrapped the silk fibroin fibers and they exhibited either a spherical or spindle shape.The results of transmission electron microscopy,MTT test and flow cytometry analysis showed that there was no significant difference between BMSCs cultured in the silk fibroin extract fluid and those in plain IMDM medium in their morphology,cell viability,proliferation and phenotypes.Conclusion These data indicate that silk fibroin has good biocompatibility with BMSCs and is also beneficial to the survival of BMSCs without exerting any significant cytotoxic effects on their phenotype;thus it's a potential scaffold material to fabricate tissue-engineered nerve with introduction of BMSCs.
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AIM To Detect the varying of gene expression in cultured dorsal root ganglion cells treated by Nerve Regeneration Factor and explore its molecular mechanism promoting to nerve growth. METHODS By RT-PCR, the change of gene expression in GAP-43 and NF-L on the cultured DRG cells with Nerve Regeneration Factor were studied during 4 h, 12 h, 24 h. RESULTS The expression of GAP-43 and NF-L were increased by Nerve Regeneration Factor on DRG′s culture. CONCLUSION This study indicated Nerve Regeneration Factor may up-regulate the gene expression associated nerve growth on cultured nervous cells.
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Objective To explore the relationship of plasma salusin-? level with the stability,severity,and other risks of coronary atherosclerosis.Methods The patient group included 122 hospitalized patients with coronary artery disease(CAD),whose diagnoses were confirmed by coronary angiography(CAG).The CAD group was further divided into subgroups according to the clinical types,the number of diseased coronary branches,and Gensini's scores.Control group inlcuded 60 healthy subjects who underwent physical examination in our hospital.Salusin-? level and other general biochemical indicators were determined,and the general clinical data were obtained before CAG in all subjects.Results The peripheral blood salusin-? level in CAD patients was significantly lower than that in the controls([0.50?0.18]ng/ml vs [0.69?0.23 ng/ml],P
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The special trichrome stain and immunocytochemical stain were used to show neurites, Schwann's cells in cultured pe-ripheral nerve tissue. The dorsal root ganglia(DRG) of rat were cultured on polypyrrole membrane for 2 weeks. Then, the cul-tured speciments were stained by special stain, which was composed of hematoxylin, fast green FCF. ehromotrope 2R and phos-photungstic acid; or by immunocytochemical stain with anti-S-100 protein and anti-neurofilament antibodies. In the specialtrichrome stained specimen the long processes from DRG were stained aquamarine blue; part of the cell nuclei on the processes orpolypyrrole membrane were stained red or purplish red, and the cytoplasm ashen. We testified that the long processes from DRGwere neurites and the cells which were purplish red nuclei and ashen cytoplasm were Schwann's cells in immunocytochemicalstain. The special staining could differentiate neurites and Schwann's cells in cultured peripheral nerve tissue.
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Objective To observe expression of neuronal nitric oxide synthase (nNOS) and inducible NOS (iNOS) in nerve and dominated muscle of rat after injury of sciatic nerve.Methods 12 female SD rats were divided into 4 groups, right sciatic nerve was squeezed by using forceps for 0.5hr, 1hr, 2hr and 5hr respectively. Then right sciatic nerve and gastrocnemius was isolated and RNA was extracted by using Trizol reagent and meanwhile, the left sciatic nerve and gastrocnemius was used as a normal control. NOS expression was detected by using RT PCR and RNAase protection assay (RPA), and GAPDH was used as an internal standard. The density of PCR and RPA bands was determined by using NIH image software.Results 2 NOSs did not vary in nerve tissue in 4 groups, but in muscle, nNOS increased in 1h group, decreased in 2h group and increased in 5h group; iNOS decreased in 1h and 2h groups but increased in 5h group when compared to normal control.Conclusion Injuring of nerve does not effect NOS expression itself within short period, but effects the dominated muscle via the transmission of non NOS nerve signal.
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Objective To evaluate the expressive variety of NGF gene in injured sciatic nerves of rat. Methods For hemi-quanti- tative analysis, RT-PCR method was used in the detection of the levels of NGF mRNA in the distal stumps at 1 day and 1, 2, 4 weeks following transection of sciatic nerve. Results The 1evel of NGF mRNA was low in the normal sciatic nerve. But it was increased in the distal stump after sciatic nerve transection. The biphasic increase in NGF mRNA was characterized by a first very rapid and transient increase peaking at ist day after lesion, than a second prolonged and slow elevation starting around ist weed after lesion. Conclusion The process in NGF gene expression after sciatic nerve lesion was biphasicly increased.
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Objective To establish a method of neurons and glial cell culture from embryonic Gekko japonicus cerebral cortex. Methods Embryonic(E15) pallium was dissociated and digesting by trypsin.After counting,cells were seeded in culture flask.The glial cells were obtained by using differential adhesion potential combined with successive passage purified methods,and neurons were obtained by using neurobasal medium supplemented with B27.The cells were fixed and analyzed with immunohistochemic assay. Results After tetra-generation,GFAP positive cells were more than 95% in glial cells cultured condition;Neurons grew well in neurobasal medium,and NF and MAP-2 positive signals co-localized on neurons.After cultured for 10 days,the percentage of neurons was more than 95%.Conclusion The methods of isolation,culture and purification for embryonic Gekko japonicus cortical neurons and glial cells were established and it might be a valuable cell model to further investigate the central nerve system in Gekko japonicus.
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Objective To observe CNTF gene expression and expressive variety during postnatal development in rat spinal cord. Methods The spatial expression of CNTF mRNA in spinal cord was examined by in situ hybridization with dig\|CNTF cDNA probe.Reverse transcription\|polymerse chain reaction(RT\|PCR),as hemi\|quantitative method was used to investigate the expressive variety of CNTF mRNA levels in spinal cord during postnatal development. Results Hybridized signals of CNTF mRNA was found only in part of glial cells on the peripheral region of the ventral and lateral white funiculi of spinal cord,but could not be detected in the gray matter of spinal cord.The expression of CNTF mRNA in spinal cord appeared with a lower level on the first postnatal day.It increased significantly at postnatal 15th days,the expression of CNTF mRNA reached the peak at 30th days,and it began to decrease on the 60th days. Conclusion This study indicated that CNTF mRNA might be expressed in part of glial cells in the white matter.There was expression in spinal cord on the 1st day after birth and the expression levels of CNTF mRNA possessed the changeable character during spinal cord development.
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Objective In order to study the effect of ? 1,4 GalT Ⅰ on proliferation of Schwann cells, The changes in cell proliferation were checked after Schwann cells transfected with sense or antisense ? 1,4 GalT Ⅰ plasmids. Methods Methods of counting numbers of proliferating cell and measuring [ 3H] thymidine incorporation by liquid scintillation were used to study the proliferation of purified Schwann cells which transfected with ? 1,4 GalT Ⅰ plasmids. Cell cycles of those transfected cells were determined by fluorescence activated cell sorting. Results After Schwann cells transfected with sense ? 1,4 GalT Ⅰ plasmids, the proliferation of those cells was restrained, and the number at G 1/G 0 phase of those cells increased while the number at S phase decreased. Schwann cells transfected with antisense ? 1,4 GalT Ⅰ plasmid showed opposite changes.Conclusion ? 1,4 GalT Ⅰ may play an important role in regulating the proliferation of Schwann cells in peripheral nerve.\;[
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Objective To observe the protective effects of salidroside on glutamate-induced injury in cultured hippocampal neurons.Methods Primarily cultured hippocampal neurons from fetal Wistar rat were incubated with salidroside(10,20 and 40mg/L) for 24 hours,then glutamate(125?mol/L) was added for 15 minutes to induce injury.Cell viability was detected by MTT assay,the vigor of LDH was determined by biochemistry method,the apoptosis rates were anallyzed using Annexin V-FITC and PI labelling and Hoechst 33342 staining and flow cylometric assay.Fluorescent intensity of intracellular free calcium was observed with laser scanning confocal microscopy(LSCM).Results After the pretreatment with salidroside for 24 hours,the increases of LDH vigor and apoptosis rates and the decrease of cell viability caused by glutamate were resisted obviously.Salidroside inhibited the increase of Ca~2+ in cytoplasm significantly.Conclusion Salidroside can significantly resist the injury induced by glutamate.The neuroprotective activities of salidroside can be related to its ability to reduce Ca~2+ overload in cytoplasm.
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Objective\ Clone and sequence choriocarcinoma related gene T26. Method\ Choriocarcinoma related gene T26 was ligated into PGEM\|T vector using T\|A clone method.PGEM\|T\|T26 was digested with EcoRⅠ and sequenced,comparing the T26 sequence with GenBank. Results\ The sequence of choriocarcinoma related gene band T26 showed more than 99% identity with the 3' end of human scar,rps4 and ccg2 genes. Conclusion\ The gene T26 besides scar,rps4 and ccg2 genes were related with the oncogenesis of choriocarcinoma. [