Few studies have investigated alterations in the immune cell microenvironment of the dorsal root ganglia following spinal cord injury and whether these modifications facilitate axonal regeneration.In this study,we use...Few studies have investigated alterations in the immune cell microenvironment of the dorsal root ganglia following spinal cord injury and whether these modifications facilitate axonal regeneration.In this study,we used a single-cell RNA sequencing dataset to create a comprehensive profile of the diverse cell types in the dorsal root ganglia and spinal cord of a mid-thoracic contusion injury model in cynomolgus monkeys.Cell communication analysis indicated that specific signaling events among various dorsal root ganglia cell types occur in response to spinal cord injury.Single-cell analysis using dimensionality reduction clustering identified distinct molecular signatures for nine cell types,including macrophage subpopulations,and differential gene expression profiles between dorsal root ganglia cells and spinal cord cells following spinal cord injury.The macrophage subpopulations were categorized into 11 clusters(MC0-MC10)based on differentially expressed genes,with the top 10 genes being ABCA6,RBMS3,EBF1,LAMA4,ANTXR2,LAMA2,SOX5,FOXP2,GHR,and APOD.MC0,MC1,and MC2 constituted the predominant macrophage populations.MC4,MC6,and MC9 were nearly absent in the spinal cord,but exhibited significant increases in the dorsal root ganglia post-spinal cord injury.Notably,these subpopulations possess a strong capacity for regulating axonal regeneration.The developmental progression of dorsal root ganglia macrophages after spinal cord injury was elucidated using cell trajectory and pseudo-time analyses.Genes such as EBF1(MC6 and MC9 marker),RBMS3(MC6 and MC9 marker),and ABCA6(MC6 marker)showed high expression levels in the critical pathways of macrophage function.Through ligand-receptor pair analysis,we determined that the effects of macrophages on microglia are predominantly mediated through interaction pairs(e.g.,SPP1-CD44,LAMC1-CD44,and FN1-CD44),potentially facilitating specific cellular communications within the immune microenvironment.The single-cell RNA sequencing dataset used in this study represents the first comprehensive transcriptional analysis of the dorsal root ganglia after spinal cord injury in cynomolgus monkeys,encompassing nearly all cell types within the dorsal root ganglia region.Using this dataset,we evaluated diverse subtypes of macrophages in the post-spinal cord injury dorsal root ganglia area and examined the signaling pathways that facilitate interactions among immune response-related macrophages in the dorsal root ganglia.Findings from this study provide a theoretical basis for understanding how the immune microenvironment influences the regenerative capacity of dorsal root ganglia neurons after spinal cord injury and offer novel insights into the complex processes underlying the pathobiology of spinal cord injury.展开更多
AIM: To investigate proteomic changes in spinal cord and dorsal root ganglia (DRG) of rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. METHODS: The colonic myeloperoxidase (MPO) activity and tumor necro...AIM: To investigate proteomic changes in spinal cord and dorsal root ganglia (DRG) of rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. METHODS: The colonic myeloperoxidase (MPO) activity and tumor necrosis factor-(TNF- ) level were determined. A two-dimensional electrophoresis (2-DE)-based proteomic technique was used to profile the global protein expression changes in the DRG and spinal cord of the rats with acute colitis induced by intracolonic injection of TNBS. RESULTS: TNBS group showed significantly elevated colonic MPO activity and increased TNF-level. The proteins derived from lumbosacral enlargement of the spinal cord and DRG were resolved by 2-DE; and 26 and 19 proteins that displayed significantly different expression levels in the DRG and spinal cord were identified respectively. Altered proteins were found to be involved in a number of biological functions, such as inflammation/immunity, cell signaling, redox regulation, sulfate transport and cellular metabolism. The over-expression of the protein similar to potassium channel tetramerisation domain containing protein 12 (Kctd 12) and low expression of proteasome subunit type-1 (psma) were validated by Western blotting analysis. CONCLUSION: TNBS-induced colitis has a profound impact on protein profiling in the nervous system. This result helps understand the neurological pathogenesis of inflammatory bowel disease.展开更多
OBJECTIVE: To demonstrate the analgesic effect of Tuina mainly from mechanically sensitive ion channels in peripheral myelinated nerve fibers.METHODS: A total of 40 healthy and pathogen-free adult male Sprague-Dawley ...OBJECTIVE: To demonstrate the analgesic effect of Tuina mainly from mechanically sensitive ion channels in peripheral myelinated nerve fibers.METHODS: A total of 40 healthy and pathogen-free adult male Sprague-Dawley rats were used in the study [weight:(220.0 ± 1.4) g, Shanghai Slac Laboratory Animal Co., Ltd., Shanghai, China; license No. Shanghai ICP 05033115]. The rats were housed in cages with free access to water and food in a temperature-controlled room [(22 ± 1) ℃] and12-h/12-h light-dark cycle. Thirty-two rats were randomly divided into five groups: naive, sham, chronic compression of dorsal root ganglion(CCD), Tuina(7 d) and Tuina(21 d). CCD rat model was established via unilateral DRG compression by"L"liked steel bar. Chinese Tuina treatment was accepted once per day. Behavior monitoring of paw withdrawal threshold(PWT) and paw withdrawal latency(PWL) were tested. The expression of Piezo1 and Piezo2 in myelinated nerve fiber were analyzed by immunohistochemistry and Western-blotting.RESULTS: There was a high expression of Piezo2 and a low expression of Piezo1 in the naive and CCD groups. In contrast, the expression of Piezo2 was down regulated and Piezo1 was increased after a period of Tuina. There was significant difference(P ≤ 0.05) between the groups.CONCLUSION: Our findings suggest that Tuina therapy can increase the expression of Piezo2 and decrease the expression of Piezo1 in the test rats.The different changes in the expressions of Piezo1 and Piezo2 may play an important role in alleviating CCD-induced allodynia and hyperalgesia.展开更多
Objective To investigate whether chronic constriction injury(CCI)of the sciatic nerve of rats could produce alterations in the phosphorylation of cyclic AMP response element binding(CREB)protein in dorsal root ganglia...Objective To investigate whether chronic constriction injury(CCI)of the sciatic nerve of rats could produce alterations in the phosphorylation of cyclic AMP response element binding(CREB)protein in dorsal root ganglia(DRG)and superficial dorsal horn neurons of the spinal cord.Methods Chronic constriction injury(CCI)of the sciatic nerve was employed as a model of neuropathic pain.Thirty-two Sprague-Dawley rats were randomly divided into Na⒍ve,Sham,CCI2w(received CCI for2weeks)and CCI4w(received CCI for4weeks)groups.Hind pawwithdrawal threshold to mechanical stimuli and withdrawal latency to thermal stimuli were used to determine the mechanical and thermal hyperalgesia.Then all the rats were deeply anesthetized and perfused intracardially with paraformaldehyde.The fixed L 4-5 spinal cord and the L 5 DRG ipsilateral to CCI were harvested for fixation.The pCREB-immunoreactive(pCREB-IR)cells in both DRG and superficial dorsal horn neurons were quantified for analysis using immunohistochemistry methods.Results On the14th day after sciatic nerve injury,all the rats exhibited significant mechanical and thermal hyperalgesia.The mechanical withdrawal thresholds to von Frey filament from CCI2w group decreased significantly compared to both baseline values and those of Sham group(P<0.01);Thermal withdwal latencies from CCI2w group decreased significantly compared to both baseline values and those of Sham group(P<0.01).Some rats from Sham group also showed mechanical hyperalgesia compared to both baseline values and those of Na⒍ve group(P<0.01).28days after CCI,both mechanical and thermal hypersensitivity were significantly alleviated,with no statistical significance compared to those of Sham group.On the14th day after CCI,the number of pCREB-IR cells significantly increased in ipsilateral L 5 DRGs and superficial dorsal horns(P<0.01)compared to Sham group.The number of phosphorylated CREB-IR cells in the ipsilateral DRGs from Sham group also increased compared to that of Naive rats(P<0.05).There were no significant statistical differences of numbers of CREB-IR neuron between Sham group and CCI4wgroup.Conclusion CCI increases CREB phosphorylation both in DRG and superficial dorsal horn neurons of the lumbar spinal cord,and may be one of the key molecular mechanisms of central and peripheral sensitization following peripheral nerve injury.展开更多
To investigate the effects of continuous spinal anesthesia with different concentrations and doses of ropivacaine on the ultrastructure of the spinal cord and nerve roots.Methods Twenty-four male SD rats weighing 220...To investigate the effects of continuous spinal anesthesia with different concentrations and doses of ropivacaine on the ultrastructure of the spinal cord and nerve roots.Methods Twenty-four male SD rats weighing 220～280 g were anesthetized with intraperitoneal 10% chloral hydrate 300～350 mg/kg.A polyurethane microcatheter was inserted into the lumbar subarachnoid space according to the technique described by Yaksh.An 8 cm catheter segment was left in the subarachnoid space.The animals were randomized to receive normal saline,0.5%,0.75% or 1.0% ropivacaine 40 μl intrathecally 3 times at 1.5 h interval.Six hours after the first intrathecal administration the animals were decaptiated and L 1,2 segment of the spinal cord and nerve roots were immediately removed for electron microscopic examination.Results Electron microscopic examination revealed that in animals which received intrathecal (i.t.) normal saline,0.5% or 0.75% ropivacaine the neurolemma of the nerve roots and the mitochondria and endoplasmic reticulum of the neurons in the spinal cord were intact,while in animals which received i.t. 10.% ropivacaine the neurolemma was stratified and partly disrupted and there were swelling of endoplasmic reticulum and vacuole degeneration.Conclusion Six hours continuous spinal anesthesia with 10.% ropivacaine may be injurious to the spinal cord and nerve roots.12 refs,8 figs,1 tab.展开更多
Objective: To investigate the expression and pattern of vascular endothelial growth factor (VEGF) and its fetal liver kinase-1 (Flk-1) receptor in spinal cord and dorsal root ganglia after neurotomy of sciatic nerve i...Objective: To investigate the expression and pattern of vascular endothelial growth factor (VEGF) and its fetal liver kinase-1 (Flk-1) receptor in spinal cord and dorsal root ganglia after neurotomy of sciatic nerve in rats. Methods: Forty-five adult male Wistar rats were divided randomly into a control group (n=5) and an experimental group (n=40). The bilateral sciatic nerves of the rats in the experimental group underwent neurotomy and the L 4-L 6 spinal cord and the corresponding dorsal root ganglia were harvested respectively at 8 hours, and 1, 3, 5, 7, 10, 14 and 21 days (8 subgroups with 5 rats each) after operation. The rats in the control group only underwent an exposure of sciatic nerve without neurotomy. Immunohistochemistry and image analysis were used to study the expression of VEGF and its Flk-1 receptor. Results: Both VEGF and Flk-1 receptor expressed in the normal rat spinal cord and dorsal root ganglia. In response to neurotomy, their expression reached a higher level and persisted for a short time then declined to the normal level rapidly. Besides, positive staining of Flk-1 was observed in both glial cells and nerve fibers, which located in the white matter of the spinal cord.Conclusions: VEGF can promote the regeneration of peripheral nerves from the angle of central neurons, which establishes the experimental and theoretical foundation for VEGF treating peripheral nerve injuries.展开更多
Objective: To observe the ultrastructural change of the route of gut bacterial translocation in a rat with spinal cord injury(SCI).Methods: Forty Wistar rats were divided into the following groups: control group and 3...Objective: To observe the ultrastructural change of the route of gut bacterial translocation in a rat with spinal cord injury(SCI).Methods: Forty Wistar rats were divided into the following groups: control group and 3 SCI groups(10 in each group). The rats in the SCI groups were established SCI model at 24 h, 48 h, and 72 h after SCI. Small intestine mucous membrane tissue was identified and assayed by transmission electron microscope, scanning electron microscope and immunofluorescence microscopy. Results: Small intestine mucous membrane tissue in control group was not damaged significantly, but those in SCI groups were damaged significantly. Proliferation bacteria in gut lumen attached on microvilli. The extracellular bacteria torn the intestinal barrier and perforated into the small intestinal mucosal epithelial cell. The bacteria and a lot of particles of the seriously damaged region penetrated into the lymphatic system and the blood system directly. Some bacteria were internalized into the goblet cell through the apical granule. Some bacteria and particles perforated into the submucosa of the M cell running the long axis of M cells through the tight junctions. In the microcirculation of mucosa, the bacteria that had already broken through the microvilli into blood circulation swim accompanying with erythrocytes. Conclusion: The routes of bacterial translocation interact and format a vicious circle. At early step, the transcellular pathway of bacterial translocation is major. Following with the destroyed small intestine mucous, the routes of bacterial translocation through the lymphatic system and the blood system become direct pathways. The goblet cell-dendritic cell and M cell pathway also play an important role in the bacterial translocation.展开更多
Nociceptive signals conveyed to the dorsal horn of the spinal cord by primary nociceptors are subject to extensive modulation by local neurons and by supraspinal descending pathways to the spinal cord before being rel...Nociceptive signals conveyed to the dorsal horn of the spinal cord by primary nociceptors are subject to extensive modulation by local neurons and by supraspinal descending pathways to the spinal cord before being relayed to higher brain centers. Descending modulatory pathways to the spinal cord comprise,among others, noradrenergic, serotonergic, γ-aminobutyric acid(GABA)ergic, and dopaminergic fibers.The contributions of noradrenaline, serotonin, and GABA to pain modulation have been extensively investigated. In contrast, the contributions of dopamine to pain modulation remain poorly understood.The focus of this review is to summarize the current knowledge of the contributions of dopamine to pain modulation. Hypothalamic A11 dopaminergic neurons project to all levels of the spinal cord and provide the main source of spinal dopamine. Dopamine receptors are expressed in primary nociceptors as well as in spinal neurons located in different laminae in the dorsal horn of the spinal cord, suggesting that dopamine can modulate pain signals by acting at both presynaptic and postsynaptic targets. Here, I will review the literature on the effects of dopamine and dopamine receptor agonists/antagonists on the excitability of primary nociceptors, the effects of dopamine on the synaptic transmission between primary nociceptors and dorsal horn neurons, and the effects of dopamine on pain in rodents. Published data support both anti-nociceptive effects of dopamine mediated by D2-like receptors and pro-nociceptive effects mediated by D1-like receptors.展开更多
Very little is known about the role of melatonin in the trigeminal system, including the function of melatonin receptor 1. In the present study, adult rats were injected with formaldehyde into the right vibrissae pad ...Very little is known about the role of melatonin in the trigeminal system, including the function of melatonin receptor 1. In the present study, adult rats were injected with formaldehyde into the right vibrissae pad to establish a model of orofacial inflammatory pain. The distribution of melatonin re- ceptor 1 and nicotinamide adenine dinucleotide phosphate diaphorase in the caudal spinal trigeminal nucleus and trigeminal ganglion was determined with immunohistochemistry and histo- chemistry. The results show that there are significant differences in melatonin receptor 1 expression and nicotinamide adenine dinucleotide phosphate diaphorase expression in the trigeminal ganglia and caudal spinal nucleus during the early stage of orofacial inflammatory pain. Our findings sug- gest that when melatonin receptor 1 expression in the caudal spinal nucleus is significantly reduced, melatonin＇s regulatory effect on pain is attenuated.展开更多
OBJECTIVE:To explore the mechanisms of dorsal root ganglia and spinal microglia cascade cross in electroacupuncture(EA)analgesia in the treatment of lumbar disc herniation.METHODS:A rat model of lumbar disc herniation...OBJECTIVE:To explore the mechanisms of dorsal root ganglia and spinal microglia cascade cross in electroacupuncture(EA)analgesia in the treatment of lumbar disc herniation.METHODS:A rat model of lumbar disc herniation(LDH)was established,EA was administered at Huantiao(GB30)acupoint 30 min once a day,for 3 d.Before and after modeling,and after EA,mechanical allodynia thresholds were detected.Hyperpolarization-activated cyclic nucleotide-gated 2(HCN2)in dorsal root ganglia was detected by quantitative polymerase chain reaction(qPCR)and Western blot.C-X3-C motif chemokine ligand 1(CX3CL1)and activity of microglia in spinal cord was observed separately via qPCR and immunofluorescence staining.RESULTS:The mechanical allodynia threshold of the right planta of model rats was significantly reduced(P<0.01),EA increased the mechanical pain threshold of rats(P<0.01),and decreased HCN2 mRNA,and protein expression,reduced the expression of CX3CL1 and the activation of microglia.ZD7288(a blocker of HCN channel)reduced the analgesic effect of EA from 1.83±0.84 to 0.74±0.20(P<0.05),and the expression of CX3CL1 in the spinal cord decreased from 0.52±0.11 to 0.15±0.05(P<0.01).CONCLUSION:EA analgesia on the radicular pain of LDH is definite.EA reduced the expression of HCN2 channel in the dorsal root ganglion,thereby decreasing the noxious stimulation entered to microglia in spinal dorsal horn.Our work supports EA is an effective treatment for radicular pain of LDH.展开更多
Spinal cord injury is a severe and devastating disease,and spasticity is a common and severe complication that is notoriously refractory to treatment.However,the pathophysiological mechanisms underlying spasticity and...Spinal cord injury is a severe and devastating disease,and spasticity is a common and severe complication that is notoriously refractory to treatment.However,the pathophysiological mechanisms underlying spasticity and its development remain largely unknown.The goal of the present study was to find differences,if any,in metabolites of the left precentral gyrus and basal ganglia of patients who have spinal cord injury with or without spasticity,and to explore the relationship between the brain metabolite concentrations and clinical status.Thirty-six participants were recruited for magnetic resonance spectroscopic examination:23 with spinal cord injury(12 with spasticity and 11 without spasticity)and 13 healthy controls.We acquired localized proton spectra from the precentral gyrus and basal ganglia via 10 mm^(3) voxels.Notably,univariate linear regression analysis demonstrated that the lower that the N-acetylaspartate concentration(a marker for neuronal loss)was in the precentral gyrus of the patients,the lower their ASIA(American Spinal Injury Association)light-touch scores,pinprick scores,and motor scores.Additionally,longer durations of injury were associated with higher N-acetylaspartate levels in the precentral gyrus.Compared with the healthy participants and patients without spasticity,N-acetylaspartate levels in the patients with spasticity were significantly lower in both the precentral gyrus and basal ganglia.Lower N-acetylaspartate levels also correlated with greater sensory and motor dysfunction in the patients who had spinal cord injury with spasticity.展开更多
基金supported by the Tianjin Key Medical Discipline(Specialty)Construct Project,No.TJYXZDXK-027A(to SF)the National Key Research andDevelopment Project of Stem Cell and Transformation Research,No.2019YFA0112100(to SF)+2 种基金Tianjin Natural Science Foundation’s Youth Project for DiverseInvestments,No.21JCQNJC01300(to BF)the National Natural Science Foundation of China(Youth Program),No.82102563(to BF)Tianjin Major Science andTechnology Special Projects and Engineering Projects,No.21ZXJBSY00080(to YR).
文摘Few studies have investigated alterations in the immune cell microenvironment of the dorsal root ganglia following spinal cord injury and whether these modifications facilitate axonal regeneration.In this study,we used a single-cell RNA sequencing dataset to create a comprehensive profile of the diverse cell types in the dorsal root ganglia and spinal cord of a mid-thoracic contusion injury model in cynomolgus monkeys.Cell communication analysis indicated that specific signaling events among various dorsal root ganglia cell types occur in response to spinal cord injury.Single-cell analysis using dimensionality reduction clustering identified distinct molecular signatures for nine cell types,including macrophage subpopulations,and differential gene expression profiles between dorsal root ganglia cells and spinal cord cells following spinal cord injury.The macrophage subpopulations were categorized into 11 clusters(MC0-MC10)based on differentially expressed genes,with the top 10 genes being ABCA6,RBMS3,EBF1,LAMA4,ANTXR2,LAMA2,SOX5,FOXP2,GHR,and APOD.MC0,MC1,and MC2 constituted the predominant macrophage populations.MC4,MC6,and MC9 were nearly absent in the spinal cord,but exhibited significant increases in the dorsal root ganglia post-spinal cord injury.Notably,these subpopulations possess a strong capacity for regulating axonal regeneration.The developmental progression of dorsal root ganglia macrophages after spinal cord injury was elucidated using cell trajectory and pseudo-time analyses.Genes such as EBF1(MC6 and MC9 marker),RBMS3(MC6 and MC9 marker),and ABCA6(MC6 marker)showed high expression levels in the critical pathways of macrophage function.Through ligand-receptor pair analysis,we determined that the effects of macrophages on microglia are predominantly mediated through interaction pairs(e.g.,SPP1-CD44,LAMC1-CD44,and FN1-CD44),potentially facilitating specific cellular communications within the immune microenvironment.The single-cell RNA sequencing dataset used in this study represents the first comprehensive transcriptional analysis of the dorsal root ganglia after spinal cord injury in cynomolgus monkeys,encompassing nearly all cell types within the dorsal root ganglia region.Using this dataset,we evaluated diverse subtypes of macrophages in the post-spinal cord injury dorsal root ganglia area and examined the signaling pathways that facilitate interactions among immune response-related macrophages in the dorsal root ganglia.Findings from this study provide a theoretical basis for understanding how the immune microenvironment influences the regenerative capacity of dorsal root ganglia neurons after spinal cord injury and offer novel insights into the complex processes underlying the pathobiology of spinal cord injury.
基金Supported by The Research Grants Council of Hong Kong,RGC-HKBU2/07CThe Hong Kong Jockey Club Institute of Chinese Medicine, JCICM4-07
文摘AIM: To investigate proteomic changes in spinal cord and dorsal root ganglia (DRG) of rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. METHODS: The colonic myeloperoxidase (MPO) activity and tumor necrosis factor-(TNF- ) level were determined. A two-dimensional electrophoresis (2-DE)-based proteomic technique was used to profile the global protein expression changes in the DRG and spinal cord of the rats with acute colitis induced by intracolonic injection of TNBS. RESULTS: TNBS group showed significantly elevated colonic MPO activity and increased TNF-level. The proteins derived from lumbosacral enlargement of the spinal cord and DRG were resolved by 2-DE; and 26 and 19 proteins that displayed significantly different expression levels in the DRG and spinal cord were identified respectively. Altered proteins were found to be involved in a number of biological functions, such as inflammation/immunity, cell signaling, redox regulation, sulfate transport and cellular metabolism. The over-expression of the protein similar to potassium channel tetramerisation domain containing protein 12 (Kctd 12) and low expression of proteasome subunit type-1 (psma) were validated by Western blotting analysis. CONCLUSION: TNBS-induced colitis has a profound impact on protein profiling in the nervous system. This result helps understand the neurological pathogenesis of inflammatory bowel disease.
基金Supported by High Level Innovation Team of Traditional Chinese Medicine Peak Plateau Subject(No.30304114316)Study on the Core Technical Specifications and Clinical Evaluation of Guided Exercise Therapy Combined with Acupoints Application in the Prevention of Chronic Fatigue Syndrome(No.2015468003-1)+3 种基金the National Natural Science Foundation of China(No.81603710)the National Natural Science Foundation of China(No.8150151117)Natural Science Foundation of Fujian Province(No.2017J01828)Major Disease Clinical Skills Upgrading Project of Shanghai Shen-kang Hospital Development Center(No.16CR1023A)
文摘OBJECTIVE: To demonstrate the analgesic effect of Tuina mainly from mechanically sensitive ion channels in peripheral myelinated nerve fibers.METHODS: A total of 40 healthy and pathogen-free adult male Sprague-Dawley rats were used in the study [weight:(220.0 ± 1.4) g, Shanghai Slac Laboratory Animal Co., Ltd., Shanghai, China; license No. Shanghai ICP 05033115]. The rats were housed in cages with free access to water and food in a temperature-controlled room [(22 ± 1) ℃] and12-h/12-h light-dark cycle. Thirty-two rats were randomly divided into five groups: naive, sham, chronic compression of dorsal root ganglion(CCD), Tuina(7 d) and Tuina(21 d). CCD rat model was established via unilateral DRG compression by"L"liked steel bar. Chinese Tuina treatment was accepted once per day. Behavior monitoring of paw withdrawal threshold(PWT) and paw withdrawal latency(PWL) were tested. The expression of Piezo1 and Piezo2 in myelinated nerve fiber were analyzed by immunohistochemistry and Western-blotting.RESULTS: There was a high expression of Piezo2 and a low expression of Piezo1 in the naive and CCD groups. In contrast, the expression of Piezo2 was down regulated and Piezo1 was increased after a period of Tuina. There was significant difference(P ≤ 0.05) between the groups.CONCLUSION: Our findings suggest that Tuina therapy can increase the expression of Piezo2 and decrease the expression of Piezo1 in the test rats.The different changes in the expressions of Piezo1 and Piezo2 may play an important role in alleviating CCD-induced allodynia and hyperalgesia.
文摘Objective To investigate whether chronic constriction injury(CCI)of the sciatic nerve of rats could produce alterations in the phosphorylation of cyclic AMP response element binding(CREB)protein in dorsal root ganglia(DRG)and superficial dorsal horn neurons of the spinal cord.Methods Chronic constriction injury(CCI)of the sciatic nerve was employed as a model of neuropathic pain.Thirty-two Sprague-Dawley rats were randomly divided into Na⒍ve,Sham,CCI2w(received CCI for2weeks)and CCI4w(received CCI for4weeks)groups.Hind pawwithdrawal threshold to mechanical stimuli and withdrawal latency to thermal stimuli were used to determine the mechanical and thermal hyperalgesia.Then all the rats were deeply anesthetized and perfused intracardially with paraformaldehyde.The fixed L 4-5 spinal cord and the L 5 DRG ipsilateral to CCI were harvested for fixation.The pCREB-immunoreactive(pCREB-IR)cells in both DRG and superficial dorsal horn neurons were quantified for analysis using immunohistochemistry methods.Results On the14th day after sciatic nerve injury,all the rats exhibited significant mechanical and thermal hyperalgesia.The mechanical withdrawal thresholds to von Frey filament from CCI2w group decreased significantly compared to both baseline values and those of Sham group(P<0.01);Thermal withdwal latencies from CCI2w group decreased significantly compared to both baseline values and those of Sham group(P<0.01).Some rats from Sham group also showed mechanical hyperalgesia compared to both baseline values and those of Na⒍ve group(P<0.01).28days after CCI,both mechanical and thermal hypersensitivity were significantly alleviated,with no statistical significance compared to those of Sham group.On the14th day after CCI,the number of pCREB-IR cells significantly increased in ipsilateral L 5 DRGs and superficial dorsal horns(P<0.01)compared to Sham group.The number of phosphorylated CREB-IR cells in the ipsilateral DRGs from Sham group also increased compared to that of Naive rats(P<0.05).There were no significant statistical differences of numbers of CREB-IR neuron between Sham group and CCI4wgroup.Conclusion CCI increases CREB phosphorylation both in DRG and superficial dorsal horn neurons of the lumbar spinal cord,and may be one of the key molecular mechanisms of central and peripheral sensitization following peripheral nerve injury.
文摘To investigate the effects of continuous spinal anesthesia with different concentrations and doses of ropivacaine on the ultrastructure of the spinal cord and nerve roots.Methods Twenty-four male SD rats weighing 220～280 g were anesthetized with intraperitoneal 10% chloral hydrate 300～350 mg/kg.A polyurethane microcatheter was inserted into the lumbar subarachnoid space according to the technique described by Yaksh.An 8 cm catheter segment was left in the subarachnoid space.The animals were randomized to receive normal saline,0.5%,0.75% or 1.0% ropivacaine 40 μl intrathecally 3 times at 1.5 h interval.Six hours after the first intrathecal administration the animals were decaptiated and L 1,2 segment of the spinal cord and nerve roots were immediately removed for electron microscopic examination.Results Electron microscopic examination revealed that in animals which received intrathecal (i.t.) normal saline,0.5% or 0.75% ropivacaine the neurolemma of the nerve roots and the mitochondria and endoplasmic reticulum of the neurons in the spinal cord were intact,while in animals which received i.t. 10.% ropivacaine the neurolemma was stratified and partly disrupted and there were swelling of endoplasmic reticulum and vacuole degeneration.Conclusion Six hours continuous spinal anesthesia with 10.% ropivacaine may be injurious to the spinal cord and nerve roots.12 refs,8 figs,1 tab.
文摘Objective: To investigate the expression and pattern of vascular endothelial growth factor (VEGF) and its fetal liver kinase-1 (Flk-1) receptor in spinal cord and dorsal root ganglia after neurotomy of sciatic nerve in rats. Methods: Forty-five adult male Wistar rats were divided randomly into a control group (n=5) and an experimental group (n=40). The bilateral sciatic nerves of the rats in the experimental group underwent neurotomy and the L 4-L 6 spinal cord and the corresponding dorsal root ganglia were harvested respectively at 8 hours, and 1, 3, 5, 7, 10, 14 and 21 days (8 subgroups with 5 rats each) after operation. The rats in the control group only underwent an exposure of sciatic nerve without neurotomy. Immunohistochemistry and image analysis were used to study the expression of VEGF and its Flk-1 receptor. Results: Both VEGF and Flk-1 receptor expressed in the normal rat spinal cord and dorsal root ganglia. In response to neurotomy, their expression reached a higher level and persisted for a short time then declined to the normal level rapidly. Besides, positive staining of Flk-1 was observed in both glial cells and nerve fibers, which located in the white matter of the spinal cord.Conclusions: VEGF can promote the regeneration of peripheral nerves from the angle of central neurons, which establishes the experimental and theoretical foundation for VEGF treating peripheral nerve injuries.
基金Supported by National Natural Science Foundation of China(NSFC)program(81101441)Tianjin city enterprise postdoctoral innovation projects merit aid(First rate)
文摘Objective: To observe the ultrastructural change of the route of gut bacterial translocation in a rat with spinal cord injury(SCI).Methods: Forty Wistar rats were divided into the following groups: control group and 3 SCI groups(10 in each group). The rats in the SCI groups were established SCI model at 24 h, 48 h, and 72 h after SCI. Small intestine mucous membrane tissue was identified and assayed by transmission electron microscope, scanning electron microscope and immunofluorescence microscopy. Results: Small intestine mucous membrane tissue in control group was not damaged significantly, but those in SCI groups were damaged significantly. Proliferation bacteria in gut lumen attached on microvilli. The extracellular bacteria torn the intestinal barrier and perforated into the small intestinal mucosal epithelial cell. The bacteria and a lot of particles of the seriously damaged region penetrated into the lymphatic system and the blood system directly. Some bacteria were internalized into the goblet cell through the apical granule. Some bacteria and particles perforated into the submucosa of the M cell running the long axis of M cells through the tight junctions. In the microcirculation of mucosa, the bacteria that had already broken through the microvilli into blood circulation swim accompanying with erythrocytes. Conclusion: The routes of bacterial translocation interact and format a vicious circle. At early step, the transcellular pathway of bacterial translocation is major. Following with the destroyed small intestine mucous, the routes of bacterial translocation through the lymphatic system and the blood system become direct pathways. The goblet cell-dendritic cell and M cell pathway also play an important role in the bacterial translocation.
基金supported by internal funds to MP from the Department of Anesthesiology,Stony Brook Medicine,USA
文摘Nociceptive signals conveyed to the dorsal horn of the spinal cord by primary nociceptors are subject to extensive modulation by local neurons and by supraspinal descending pathways to the spinal cord before being relayed to higher brain centers. Descending modulatory pathways to the spinal cord comprise,among others, noradrenergic, serotonergic, γ-aminobutyric acid(GABA)ergic, and dopaminergic fibers.The contributions of noradrenaline, serotonin, and GABA to pain modulation have been extensively investigated. In contrast, the contributions of dopamine to pain modulation remain poorly understood.The focus of this review is to summarize the current knowledge of the contributions of dopamine to pain modulation. Hypothalamic A11 dopaminergic neurons project to all levels of the spinal cord and provide the main source of spinal dopamine. Dopamine receptors are expressed in primary nociceptors as well as in spinal neurons located in different laminae in the dorsal horn of the spinal cord, suggesting that dopamine can modulate pain signals by acting at both presynaptic and postsynaptic targets. Here, I will review the literature on the effects of dopamine and dopamine receptor agonists/antagonists on the excitability of primary nociceptors, the effects of dopamine on the synaptic transmission between primary nociceptors and dorsal horn neurons, and the effects of dopamine on pain in rodents. Published data support both anti-nociceptive effects of dopamine mediated by D2-like receptors and pro-nociceptive effects mediated by D1-like receptors.
基金supported by the National Natural Science Foundation of China,No.81271166,81371107the Natural Science Foundation of Guangdong Province in China,No.10451008901006145
文摘Very little is known about the role of melatonin in the trigeminal system, including the function of melatonin receptor 1. In the present study, adult rats were injected with formaldehyde into the right vibrissae pad to establish a model of orofacial inflammatory pain. The distribution of melatonin re- ceptor 1 and nicotinamide adenine dinucleotide phosphate diaphorase in the caudal spinal trigeminal nucleus and trigeminal ganglion was determined with immunohistochemistry and histo- chemistry. The results show that there are significant differences in melatonin receptor 1 expression and nicotinamide adenine dinucleotide phosphate diaphorase expression in the trigeminal ganglia and caudal spinal nucleus during the early stage of orofacial inflammatory pain. Our findings sug- gest that when melatonin receptor 1 expression in the caudal spinal nucleus is significantly reduced, melatonin＇s regulatory effect on pain is attenuated.
基金Supported by Inheritance and Innovation in TCM“Hundred-Thousand-Ten Thousand”Talent Project(Qinhuang Project)(No.F119090038)the National Natural Science Foundation of China(Based on the Cascade Reaction of Microglia-Astrocyte research exosomal mi RNA mechanisms of the inhibitory transition from acute to chronic pain of LDH by electroacupuncture,No.82074529)Scientific Research Projects of Traditional Chinese Medicine Bureau of Guangdong Province(Based on the cAMP-PKA-HCN2 pathway the mechanism of electro-acupuncture to prevent the development of pain in lumbar disc herniation,No.20211254)
文摘OBJECTIVE:To explore the mechanisms of dorsal root ganglia and spinal microglia cascade cross in electroacupuncture(EA)analgesia in the treatment of lumbar disc herniation.METHODS:A rat model of lumbar disc herniation(LDH)was established,EA was administered at Huantiao(GB30)acupoint 30 min once a day,for 3 d.Before and after modeling,and after EA,mechanical allodynia thresholds were detected.Hyperpolarization-activated cyclic nucleotide-gated 2(HCN2)in dorsal root ganglia was detected by quantitative polymerase chain reaction(qPCR)and Western blot.C-X3-C motif chemokine ligand 1(CX3CL1)and activity of microglia in spinal cord was observed separately via qPCR and immunofluorescence staining.RESULTS:The mechanical allodynia threshold of the right planta of model rats was significantly reduced(P<0.01),EA increased the mechanical pain threshold of rats(P<0.01),and decreased HCN2 mRNA,and protein expression,reduced the expression of CX3CL1 and the activation of microglia.ZD7288(a blocker of HCN channel)reduced the analgesic effect of EA from 1.83±0.84 to 0.74±0.20(P<0.05),and the expression of CX3CL1 in the spinal cord decreased from 0.52±0.11 to 0.15±0.05(P<0.01).CONCLUSION:EA analgesia on the radicular pain of LDH is definite.EA reduced the expression of HCN2 channel in the dorsal root ganglion,thereby decreasing the noxious stimulation entered to microglia in spinal dorsal horn.Our work supports EA is an effective treatment for radicular pain of LDH.
基金supported by the National Natural Science Foundation of China,Nos.82071400,81870979the Scientific Research Foundation of China Rehabilitation Research Center,No.2020cz-01the Special Capital Health Research and Development of China,No.2018-1-6011(all to JJL)。
文摘Spinal cord injury is a severe and devastating disease,and spasticity is a common and severe complication that is notoriously refractory to treatment.However,the pathophysiological mechanisms underlying spasticity and its development remain largely unknown.The goal of the present study was to find differences,if any,in metabolites of the left precentral gyrus and basal ganglia of patients who have spinal cord injury with or without spasticity,and to explore the relationship between the brain metabolite concentrations and clinical status.Thirty-six participants were recruited for magnetic resonance spectroscopic examination:23 with spinal cord injury(12 with spasticity and 11 without spasticity)and 13 healthy controls.We acquired localized proton spectra from the precentral gyrus and basal ganglia via 10 mm^(3) voxels.Notably,univariate linear regression analysis demonstrated that the lower that the N-acetylaspartate concentration(a marker for neuronal loss)was in the precentral gyrus of the patients,the lower their ASIA(American Spinal Injury Association)light-touch scores,pinprick scores,and motor scores.Additionally,longer durations of injury were associated with higher N-acetylaspartate levels in the precentral gyrus.Compared with the healthy participants and patients without spasticity,N-acetylaspartate levels in the patients with spasticity were significantly lower in both the precentral gyrus and basal ganglia.Lower N-acetylaspartate levels also correlated with greater sensory and motor dysfunction in the patients who had spinal cord injury with spasticity.
