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1.
Cereb Cortex ; 33(7): 3866-3881, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-35989311

RESUMO

Protein quality control (PQC) is essential for maintaining protein homeostasis and guarding the accuracy of neurodevelopment. Previously, we found that a conserved EBAX-type CRL regulates the protein quality of SAX-3/ROBO guidance receptors in Caenorhabditis elegans. Here, we report that ZSWIM8, the mammalian homolog of EBAX-1, is essential for developmental stability of mammalian brains. Conditional deletion of Zswim8 in the embryonic nervous system causes global cellular stress, partial perinatal lethality and defective migration of neural progenitor cells. CRISPR-mediated knockout of ZSWIM8 impairs spine formation and synaptogenesis in hippocampal neurons. Mechanistic studies reveal that ZSWIM8 controls protein quality of Disabled 1 (Dab1), a key signal molecule for brain development, thus protecting the signaling strength of Dab1. As a ubiquitin ligase enriched with intrinsically disordered regions (IDRs), ZSWIM8 specifically recognizes IDRs of Dab1 through a "disorder targets misorder" mechanism and eliminates misfolded Dab1 that cannot be properly phosphorylated. Adult survivors of ZSWIM8 CKO show permanent hippocampal abnormality and display severely impaired learning and memory behaviors. Altogether, our results demonstrate that ZSWIM8-mediated PQC is critical for the stability of mammalian brain development.


Assuntos
Proteína Reelina , Ubiquitina , Animais , Feminino , Gravidez , Moléculas de Adesão Celular Neuronais/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Ligases , Mamíferos/metabolismo , Serina Endopeptidases/metabolismo , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas do Tecido Nervoso/metabolismo
2.
Proc Natl Acad Sci U S A ; 118(7)2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33563763

RESUMO

Sociability is fundamental for our daily life and is compromised in major neuropsychiatric disorders. However, the neuronal circuit mechanisms underlying prosocial behavior are still elusive. Here we identify a causal role of the basal forebrain (BF) in the control of prosocial behavior via inhibitory projections that disinhibit the midbrain ventral tegmental area (VTA) dopamine (DA) neurons. Specifically, BF somatostatin-positive (SST) inhibitory neurons were robustly activated during social interaction. Optogenetic inhibition of these neurons in BF or their axon terminals in the VTA largely abolished social preference. Electrophysiological examinations further revealed that SST neurons predominantly targeted VTA GABA neurons rather than DA neurons. Consistently, optical inhibition of SST neuron axon terminals in the VTA decreased DA release in the nucleus accumbens during social interaction, confirming a disinhibitory action. These data reveal a previously unappreciated function of the BF in prosocial behavior through a disinhibitory circuitry connected to the brain's reward system.


Assuntos
Neurônios Dopaminérgicos/fisiologia , Prosencéfalo/fisiologia , Comportamento Social , Área Tegmentar Ventral/fisiologia , Animais , Neurônios Dopaminérgicos/metabolismo , Neurônios GABAérgicos/metabolismo , Neurônios GABAérgicos/fisiologia , Masculino , Camundongos , Inibição Neural , Prosencéfalo/citologia , Recompensa , Somatostatina/genética , Somatostatina/metabolismo , Área Tegmentar Ventral/citologia
3.
Sensors (Basel) ; 24(6)2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38544055

RESUMO

Aiming at the traditional single sensor vibration signal cannot fully express the bearing running state, and in the high noise background, the traditional algorithm is insufficient for fault feature extraction. This paper proposes a fault diagnosis algorithm based on multi-sensor and hybrid multimodal feature fusion to achieve high-precision fault diagnosis by leveraging the operating state information of bearings in a high-noise environment to the fullest extent possible. First, the horizontal and vertical vibration signals from two sensors are fused using principal component analysis, aiming to provide a more comprehensive description of the bearing's operating condition, followed by data set segmentation. Following fusion, time-frequency feature maps are generated using a continuous wavelet transform for global time-frequency feature extraction. A first diagnostic model is then developed utilizing a residual neural network. Meanwhile, the feature data is normalized, and 28 time-frequency feature indexes are extracted. Subsequently, a second diagnostic model is constructed using a support vector machine. Lastly, the two diagnosis models are integrated to derive the final model through an ensemble learning algorithm fused at the decision level and complemented by a genetic algorithm solution to improve the diagnosis accuracy. Experimental results demonstrate the effectiveness of the proposed algorithm in achieving superior diagnostic performance with a 97.54% accuracy rate.

4.
Brain ; 144(11): 3405-3420, 2021 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-34244727

RESUMO

Neuropathic pain is a major health problem that affects up to 7-10% of the population worldwide. Currently, neuropathic pain is difficult to treat because of its elusive mechanisms. Here we report that orphan G protein-coupled receptor 151 (GPR151) in nociceptive sensory neurons controls neuropathic pain induced by nerve injury. GPR151 was mainly expressed in non-peptidergic C-fibre dorsal root ganglion neurons and highly upregulated after nerve injury. Importantly, conditional knockout of Gpr151 in adult nociceptive sensory neurons significantly alleviated chronic constriction injury-induced neuropathic pain-like behaviour but did not affect basal nociception. Moreover, GPR151 in DRG neurons was required for chronic constriction injury-induced neuronal hyperexcitability and upregulation of colony-stimulating factor 1 (CSF1), which is necessary for microglial activation in the spinal cord after nerve injury. Mechanistically, GPR151 coupled with P2X3 ion channels and promoted their functional activities in neuropathic pain-like hypersensitivity. Knockout of Gpr151 suppressed P2X3-mediated calcium elevation and spontaneous pain behaviour in chronic constriction injury mice. Conversely, overexpression of Gpr151 significantly enhanced P2X3-mediated calcium elevation and dorsal root ganglion neuronal excitability. Furthermore, knockdown of P2X3 in dorsal root ganglia reversed chronic constriction injury-induced CSF1 upregulation, spinal microglial activation and neuropathic pain-like behaviour. Finally, the coexpression of GPR151 and P2X3 was confirmed in small-diameter human dorsal root ganglion neurons, indicating the clinical relevance of our findings. Together, our results indicate that GPR151 in nociceptive dorsal root ganglion neurons plays a key role in the pathogenesis of neuropathic pain and could be a potential target for treating neuropathic pain.


Assuntos
Microglia/metabolismo , Neuralgia/metabolismo , Nociceptores/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores Purinérgicos P2X3/metabolismo , Animais , Gânglios Espinais/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
5.
J Neurosci ; 39(31): 6202-6215, 2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31152125

RESUMO

Mechanical allodynia is a cardinal feature of pathological pain. Recent work has demonstrated the necessity of Aß-low-threshold mechanoreceptors (Aß-LTMRs) for mechanical allodynia-like behaviors in mice, but it remains unclear whether these neurons are sufficient to produce pain under pathological conditions. We generated a transgenic mouse in which channelrhodopsin-2 (ChR2) is conditionally expressed in vesicular glutamate transporter 1 (Vglut1) sensory neurons (Vglut1-ChR2), which is a heterogeneous population of large-sized sensory neurons with features consistent with Aß-LTMRs. In naive male Vglut1-ChR2 mice, transdermal hindpaw photostimulation evoked withdrawal behaviors in an intensity- and frequency-dependent manner, which were abolished by local anesthetic and selective A-fiber blockade. Surprisingly, male Vglut1-ChR2 mice did not show significant differences in light-evoked behaviors or real-time aversion after nerve injury despite marked hypersensitivity to punctate mechanical stimuli. We conclude that optogenetic activation of cutaneous Vglut1-ChR2 neurons alone is not sufficient to produce pain-like behaviors in neuropathic mice.SIGNIFICANCE STATEMENT Mechanical allodynia, in which innocuous touch is perceived as pain, is a common feature of pathological pain. To test the contribution of low-threshold mechanoreceptors (LTMRs) to nerve-injury-induced mechanical allodynia, we generated and characterized a new transgenic mouse (Vglut1-ChR2) to optogenetically activate cutaneous vesicular glutamate transporter 1 (Vglut1)-positive LTMRs. Using this mouse, we found that light-evoked behaviors were unchanged by nerve injury, which suggests that activation of Vglut1-positive LTMRs alone is not sufficient to produce pain. The Vglut1-ChR2 mouse will be broadly useful for the study of touch, pain, and itch.


Assuntos
Hiperalgesia/fisiopatologia , Mecanorreceptores/fisiologia , Neuralgia/fisiopatologia , Células Receptoras Sensoriais/fisiologia , Proteína Vesicular 1 de Transporte de Glutamato/metabolismo , Animais , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Optogenética/métodos , Traumatismos dos Nervos Periféricos
6.
Entropy (Basel) ; 20(12)2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-33266647

RESUMO

The purpose of this paper is to predict failures based on textual sequence data. The current failure prediction is mainly based on structured data. However, there are many unstructured data in aircraft maintenance. The failure mentioned here refers to failure types, such as transmitter failure and signal failure, which are classified by the clustering algorithm based on the failure text. For the failure text, this paper uses the natural language processing technology. Firstly, segmentation and the removal of stop words for Chinese failure text data is performed. The study applies the word2vec moving distance model to obtain the failure occurrence sequence for failure texts collected in a fixed period of time. According to the distance, a clustering algorithm is used to obtain a typical number of fault types. Secondly, the failure occurrence sequence is mined using sequence mining algorithms, such as-PrefixSpan. Finally, the above failure sequence is used to train the Bayesian failure network model. The final experimental results show that the Bayesian failure network has higher accuracy for failure prediction.

7.
J Biol Chem ; 289(19): 13385-96, 2014 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-24659779

RESUMO

The chemerin receptor (CMKLR1) is a G protein-coupled receptor found on select immune, epithelial, and dorsal root ganglion/spinal cord neuronal cells. CMKLR1 is primarily coupled to the inhibitory G protein, Gαi, and has been shown to modulate the resolution of inflammation and neuropathic pain. CMKLR1 is activated by both lipid and peptide agonists, resolvin E1 and chemerin, respectively. Notably, these ligands have short half-lives. To expedite the development of long acting, stable chemerin analogs as candidate therapeutics, we used membrane-tethered ligand technology. Membrane-tethered ligands are recombinant proteins comprised of an extracellular peptide ligand, a linker sequence, and an anchoring transmembrane domain. Using this technology, we established that a 9-amino acid-tethered chemerin fragment (amino acids 149-157) activates both mouse and human CMKLR1 with efficacy exceeding that of the full-length peptide (amino acids 21-157). To enable in vivo delivery of a corresponding soluble membrane anchored ligand, we generated lipidated analogs of the 9-amino acid fragment. Pharmacological assessment revealed high potency and wash resistance (an index of membrane anchoring). When tested in vivo, a chemerin SMAL decreased allergic airway inflammation and attenuated neuropathic pain in mice. This compound provides a prototype membrane-anchored peptide for the treatment of inflammatory disease. A parallel approach may be applied to developing therapeutics targeting other peptide hormone G protein-coupled receptors.


Assuntos
Asma/tratamento farmacológico , Quimiocinas/farmacologia , Fatores Quimiotáticos/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Neuralgia/tratamento farmacológico , Peptídeos/farmacologia , Receptores de Quimiocinas/agonistas , Receptores Acoplados a Proteínas G/agonistas , Animais , Asma/genética , Asma/metabolismo , Quimiocinas/química , Quimiocinas/genética , Fatores Quimiotáticos/química , Fatores Quimiotáticos/genética , Células HEK293 , Humanos , Inflamação/tratamento farmacológico , Inflamação/genética , Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/química , Peptídeos e Proteínas de Sinalização Intercelular/genética , Masculino , Camundongos , Neuralgia/genética , Neuralgia/metabolismo , Peptídeos/química , Peptídeos/genética , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo
8.
Ann Neurol ; 74(3): 490-5, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23686636

RESUMO

Prevalence of neuropathic pain is high after major surgery. However, effective treatment for preventing neuropathic pain is lacking. Here we report that perisurgical treatment of neuroprotectin D1/protectin D1 (NPD1/PD1), derived from docosahexaenoic acid, prevents nerve injury-induced mechanical allodynia and ongoing pain in mice. Intrathecal post-treatment of NPD1/PD1 also effectively reduces established neuropathic pain and produces no apparent signs of analgesic tolerance. Mechanistically, NPD1/PD1 treatment blocks nerve injury-induced long-term potentiation, glial reaction, and inflammatory responses, and reverses synaptic plasticity in the spinal cord. Thus, NPD1/PD1 and related mimetics might serve as a new class of analgesics for preventing and treating neuropathic pain.


Assuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Neuralgia/prevenção & controle , Traumatismos dos Nervos Periféricos/complicações , Nervo Isquiático/lesões , Animais , Ácidos Docosa-Hexaenoicos/uso terapêutico , Camundongos , Neuralgia/tratamento farmacológico , Neuralgia/etiologia , Medição da Dor , Traumatismos dos Nervos Periféricos/fisiopatologia , Nervo Isquiático/fisiopatologia , Medula Espinal/efeitos dos fármacos
9.
Pak J Pharm Sci ; 27(4 Suppl): 1001-4, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25016258

RESUMO

Most viruses have RNA genomes, their biological functions are expressed more by folded architecture than by sequence. Among the various RNA structures, pseudoknots are the most typical. In general, RNA secondary structures prediction doesn't contain pseudoknots because of its difficulty in modeling. Here we present an algorithm of dynamic matching to predict RNA secondary structures with pseudoknots by combining the merits of comparative and thermodynamic approaches. We have tested and verified our algorithm on some viral RNA. Comparisons show that our algorithm and loop matching method has similar accuracy and time complexity, and are more sensitive than the maximum weighted matching method and Rivas algorithm. Among the four methods, our algorithm has the best prediction specificity. The results show that our algorithm is more reliable and efficient than the other methods.


Assuntos
Algoritmos , RNA Viral/química , Sequência de Bases , Conformação de Ácido Nucleico , Estruturas Virais
10.
Cell Discov ; 10(1): 66, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38886367

RESUMO

Thermosensation is vital for the survival, propagation, and adaption of all organisms, but its mechanism is not fully understood yet. Here, we find that TMC6, a membrane protein of unknown function, is highly expressed in dorsal root ganglion (DRG) neurons and functions as a Gαq-coupled G protein-coupled receptor (GPCR)-like receptor to sense noxious heat. TMC6-deficient mice display a substantial impairment in noxious heat sensation while maintaining normal perception of cold, warmth, touch, and mechanical pain. Further studies show that TMC6 interacts with Gαq via its intracellular C-terminal region spanning Ser780 to Pro810. Specifically disrupting such interaction using polypeptide in DRG neurons, genetically ablating Gαq, or pharmacologically blocking Gαq-coupled GPCR signaling can replicate the phenotype of TMC6 deficient mice regarding noxious heat sensation. Noxious heat stimulation triggers intracellular calcium release from the endoplasmic reticulum (ER) of TMC6- but not control vector-transfected HEK293T cell, which can be significantly inhibited by blocking PLC or IP3R. Consistently, noxious heat-induced intracellular Ca2+ release from ER and action potentials of DRG neurons largely reduced when ablating TMC6 or blocking Gαq/PLC/IP3R signaling pathway as well. In summary, our findings indicate that TMC6 can directly function as a Gαq-coupled GPCR-like receptor sensing noxious heat.

11.
J Neurosci ; 32(18): 6364-72, 2012 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-22553041

RESUMO

Epoxyeicosatrienoic acids (EETs) are cytochrome P450-epoxygenase-derived metabolites of arachidonic acid that act as endogenous signaling molecules in multiple biological systems. Here we have investigated the specific contribution of 5,6-EET to transient receptor potential (TRP) channel activation in nociceptor neurons and its consequence for nociceptive processing. We found that, during capsaicin-induced nociception, 5,6-EET levels increased in dorsal root ganglia (DRGs) and the dorsal spinal cord, and 5,6-EET is released from activated sensory neurons in vitro. 5,6-EET potently induced a calcium flux (100 nm) in cultured DRG neurons that was completely abolished when TRPA1 was deleted or inhibited. In spinal cord slices, 5,6-EET dose dependently enhanced the frequency, but not the amplitude, of spontaneous EPSCs (sEPSCs) in lamina II neurons that also responded to mustard oil (allyl isothiocyanate), indicating a presynaptic action. Furthermore, 5,6-EET-induced enhancement of sEPSC frequency was abolished in TRPA1-null mice, suggesting that 5,6-EET presynaptically facilitated spinal cord synaptic transmission by TRPA1. Finally, in vivo intrathecal injection of 5,6-EET caused mechanical allodynia in wild-type but not TRPA1-null mice. We conclude that 5,6-EET is synthesized on the acute activation of nociceptors and can produce mechanical hypersensitivity via TRPA1 at central afferent terminals in the spinal cord.


Assuntos
Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Potenciais de Ação/fisiologia , Vias Aferentes/fisiopatologia , Hiperalgesia/fisiopatologia , Células Receptoras Sensoriais/metabolismo , Ácido 8,11,14-Eicosatrienoico/metabolismo , Animais , Células Cultivadas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
12.
FASEB J ; 26(4): 1755-65, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22253477

RESUMO

Self-resolving inflammatory exudates and lipid mediator metabolomics recently uncovered a new family of potent anti-inflammatory and proresolving mediators biosynthesized by macrophages (MΦs), denoted maresins. Here we determined that maresin 1 (MaR1) produced by human MΦs from endogenous docosahexaenoic acid (DHA) matched synthetic 7R,14S-dihydroxydocosa-4Z,8E,10E,12Z,16Z,19Z-hexaenoic acid. The MaR1 alcohol groups and Z/E geometry of conjugated double bonds were matched using isomers prepared by total organic synthesis. MaR1's potent defining actions were confirmed with synthetic MaR1, i.e., limiting polymorphonuclear neutrophil (PMN) infiltration in murine peritonitis (ng/mouse range) as well as enhancing human macrophage uptake of apoptotic PMNs. At 1 nM, MaR1 was slightly more potent than resolvin D1 in stimulating human MΦ efferocytosis, an action not shared by leukotriene B(4). MaR1 also accelerated surgical regeneration in planaria, increasing the rate of head reappearance. On injury of planaria, MaR1 was biosynthesized from deuterium-labeled (d(5))-DHA that was blocked with lipoxygenase (LOX) inhibitor. MaR1 dose-dependently inhibited TRPV1 currents in neurons, blocked capsaicin (100 nM)-induced inward currents (IC(50) 0.49±0.02 nM), and reduced both inflammation- and chemotherapy-induced neuropathic pain in mice. These results demonstrate the potent actions of MaR1 in regulating inflammation resolution, tissue regeneration, and pain resolution. These findings suggest that chemical signals are shared in resolution cellular trafficking, a key process in tissue regeneration. Moreover, immunoresolvents of the innate immune response, such as MaR1, offer new opportunities for assessing MΦs and their local DHA metabolome in the return to tissue homeostasis.


Assuntos
Ácidos Docosa-Hexaenoicos/farmacologia , Ácidos Docosa-Hexaenoicos/uso terapêutico , Macrófagos/metabolismo , Dor/tratamento farmacológico , Regeneração/efeitos dos fármacos , Animais , Comportamento Animal/fisiologia , Cromatografia Líquida/métodos , Ácidos Docosa-Hexaenoicos/química , Ácidos Docosa-Hexaenoicos/metabolismo , Gânglios Espinais/citologia , Humanos , Masculino , Metabolômica/métodos , Camundongos , Estrutura Molecular , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Medição da Dor , Técnicas de Patch-Clamp , Planárias/anatomia & histologia , Planárias/efeitos dos fármacos , Planárias/fisiologia , Regeneração/fisiologia , Canais de Cátion TRPV/metabolismo , Espectrometria de Massas em Tandem/métodos
13.
Cell Rep ; 42(2): 112133, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36800288

RESUMO

Expansion of the hexanucleotide repeat GGGGCC in the C9orf72 gene is the most common genetic factor in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Poly-Gly-Ala (poly-GA), one form of dipeptide repeat proteins (DPRs) produced from GGGGCC repeats, tends to form neurotoxic protein aggregates. The C9orf72 GGGGCC repeats and microglial receptor TREM2 are both associated with risk for ALS/FTD. The role and regulation of TREM2 in C9orf72-ALS/FTD remain unclear. Here, we found that poly-GA proteins activate the microglial NLRP3 inflammasome to produce interleukin-1ß (IL-1ß), which promotes ADAM10-mediated TREM2 cleavage and inhibits phagocytosis of poly-GA. The inhibitor of the NLRP3 inflammasome, MCC950, reduces the TREM2 cleavage and poly-GA aggregates, resulting in the alleviation of motor deficits in poly-GA mice. Our study identifies a crosstalk between NLRP3 and TREM2 signaling, suggesting that targeting the NLRP3 inflammasome to sustain TREM2 is an approach to treat C9orf72-ALS/FTD.


Assuntos
Esclerose Lateral Amiotrófica , Demência Frontotemporal , Animais , Camundongos , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Dipeptídeos/metabolismo , Expansão das Repetições de DNA , Demência Frontotemporal/genética , Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteínas/genética
14.
Nat Commun ; 14(1): 4, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36596769

RESUMO

Transient receptor potential vanilloid 1 (TRPV1) ion channel is a classic analgesic target, but antagonists of TRPV1 failed in clinical trials due to their side effects like hyperthermia. Here we rationally engineer a peptide s-RhTx as a positive allosteric modulator (PAM) of TRPV1. Patch-clamp recordings demonstrate s-RhTx selectively potentiated TRPV1 activation. s-RhTx also slows down capsaicin-induced desensitization of TRPV1 in the presence of calcium to cause more calcium influx in TRPV1-expressing cells. In addition, our thermodynamic mutant cycle analysis shows that E652 in TRPV1 outer pore specifically interacts with R12 and K22 in s-RhTx. Furthermore, we demonstrate in vivo that s-RhTx exhibits long-lasting analgesic effects in noxious heat hyperalgesia and CFA-induced chronic inflammatory pain by promoting the reversible degeneration of intra-epidermal nerve fiber (IENF) expressing TRPV1 channels in mice, while their body temperature remains unaffected. Our results suggest s-RhTx is an analgesic agent as a PAM of TRPV1.


Assuntos
Analgesia , Canais de Potencial de Receptor Transitório , Camundongos , Animais , Cálcio , Canais de Cátion TRPV/genética , Dor/tratamento farmacológico , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Capsaicina/farmacologia , Peptídeos/farmacologia , Peptídeos/uso terapêutico
15.
Neurosci Bull ; 39(5): 745-758, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36587114

RESUMO

Diabetic neuropathic pain (DNP) is the most common disabling complication of diabetes. Emerging evidence has linked the pathogenesis of DNP to the aberrant sprouting of sensory axons into the epidermal area; however, the underlying molecular events remain poorly understood. Here we found that an axon guidance molecule, Netrin-3 (Ntn-3), was expressed in the sensory neurons of mouse dorsal root ganglia (DRGs), and downregulation of Ntn-3 expression was highly correlated with the severity of DNP in a diabetic mouse model. Genetic ablation of Ntn-3 increased the intra-epidermal sprouting of sensory axons and worsened the DNP in diabetic mice. In contrast, the elevation of Ntn-3 levels in DRGs significantly inhibited the intra-epidermal axon sprouting and alleviated DNP in diabetic mice. In conclusion, our studies identified Ntn-3 as an important regulator of DNP pathogenesis by gating the aberrant sprouting of sensory axons, indicating that Ntn-3 is a potential druggable target for DNP treatment.


Assuntos
Diabetes Mellitus Experimental , Neuropatias Diabéticas , Neuralgia , Camundongos , Animais , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/metabolismo , Axônios/fisiologia , Células Receptoras Sensoriais/metabolismo , Neuralgia/metabolismo
16.
J Neurosci ; 31(42): 15072-85, 2011 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-22016541

RESUMO

Mechanisms of inflammatory pain are not fully understood. We investigated the role of TRPV1 (transient receptor potential subtype V1) and TNF-α, two critical mediators for inflammatory pain, in regulating spinal cord synaptic transmission. We found in mice lacking Trpv1 the frequency but not the amplitude of spontaneous EPSCs (sEPSCs) in lamina II neurons of spinal cord slices is reduced. Further, C-fiber-induced spinal long-term potentiation (LTP) in vivo is abolished in Trpv1 knock-out mice. TNF-α also increases sEPSC frequency but not amplitude in spinal outer lamina II (lamina IIo) neurons, and this increase is abolished in Trpv1 knock-out mice. Single-cell PCR analysis revealed that TNF-α-responding neurons in lamina IIo are exclusively excitatory (vGluT2(+)) neurons. Notably, neuroprotectin-1 (NPD1), an anti-inflammatory lipid mediator derived from ω-3 polyunsaturated fatty acid (docosahexaenoic acid), blocks TNF-α- and capsaicin-evoked sEPSC frequency increases but has no effect on basal synaptic transmission. Strikingly, NPD1 potently inhibits capsaicin-induced TRPV1 current (IC(50) = 0.4 nm) in dissociated dorsal root ganglion neurons, and this IC(50) is ≈ 500 times lower than that of AMG9810, a commonly used TRPV1 antagonist. NPD1 inhibition of TRPV1 is mediated by GPCRs, since the effects were blocked by pertussis toxin. In contrast, NPD1 had no effect on mustard oil-induced TRPA1 currents. Spinal injection of NPD1, at very low doses (0.1-10 ng), blocks spinal LTP and reduces TRPV1-dependent inflammatory pain, without affecting baseline pain. NPD1 also reduces TRPV1-independent but TNF-α-dependent pain hypersensitivity. Our findings demonstrate a novel role of NPD1 in regulating TRPV1/TNF-α-mediated spinal synaptic plasticity and identify NPD1 as a novel analgesic for treating inflammatory pain.


Assuntos
Ácidos Docosa-Hexaenoicos/uso terapêutico , Potenciação de Longa Duração/efeitos dos fármacos , Potenciação de Longa Duração/genética , Neurônios/efeitos dos fármacos , Dor/tratamento farmacológico , Medula Espinal/patologia , Canais de Cátion TRPV/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , 6-Ciano-7-nitroquinoxalina-2,3-diona/farmacologia , Acrilamidas , Análise de Variância , Animais , Compostos Bicíclicos Heterocíclicos com Pontes , Células Cultivadas , Modelos Animais de Doenças , Inibidores Enzimáticos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Adjuvante de Freund/efeitos adversos , Gânglios Espinais/citologia , Técnicas In Vitro , Inflamação/induzido quimicamente , Inflamação/complicações , Inflamação/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/fisiologia , Dor/etiologia , Dor/patologia , Medição da Dor , Técnicas de Patch-Clamp , Receptores do Fator de Necrose Tumoral/deficiência , Receptores Tipo I de Fatores de Necrose Tumoral/deficiência , Canais de Cátion TRPV/antagonistas & inibidores , Canais de Cátion TRPV/deficiência
17.
J Neurosci ; 31(50): 18433-8, 2011 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-22171045

RESUMO

Inflammatory pain such as arthritic pain is typically treated with opioids and cyclo-oxygenase-2 inhibitors with well known side effects. Transient receptor potential subtype vanilloid 1 (TRPV1) and TRP ankyryn 1 (TRPA1) contribute importantly to the genesis of inflammatory pain via both peripheral mechanisms (peripheral sensitization) and spinal cord mechanisms (central sensitization). Although these TRP channels have been intensively studied, little is known about their endogenous inhibitors. Recent studies have demonstrated that the endogenous lipid mediators resolvins (RvE1 and RvD1), derived from ω-3 unsaturated fatty acids, are potent inhibitors for inflammatory pain, without noticeable side effects. However, the molecular mechanisms underlying resolvins' distinct analgesic actions in mice are unclear. RvD2 is a novel family member of resolvins. Here we report that RvD2 is a remarkably potent inhibitor of TRPV1 (IC(50) = 0.1 nm) and TRPA1 (IC(50) = 2 nm) in primary sensory neurons, whereas RvE1 and RvD1 selectively inhibited TRPV1 (IC(50) = 1 nm) and TRPA1 (IC(50) = 9 nm), respectively. Accordingly, RvD2, RvE1, and RvD1 differentially regulated TRPV1 and TRPA1 agonist-elicited acute pain and spinal cord synaptic plasticity [spontaneous EPSC (sEPSC) frequency increase]. RvD2 also abolished inflammation-induced sEPSC increases (frequency and amplitude), without affecting basal synaptic transmission. Intrathecal administration of RvD2 at very low doses (0.01-1 ng) prevented formalin-induced spontaneous pain. Intrathecal RvD2 also reversed adjuvant-induced inflammatory pain without altering baseline pain and motor function. Finally, intrathecal RvD2 reversed C-fiber stimulation-evoked long-term potentiation in the spinal cord. Our findings suggest distinct roles of resolvins in regulating TRP channels and identify RvD2 as a potent endogenous inhibitor for TRPV1/TRPA1 and inflammatory pain.


Assuntos
Ácidos Docosa-Hexaenoicos/metabolismo , Ácido Eicosapentaenoico/análogos & derivados , Inflamação/metabolismo , Plasticidade Neuronal/fisiologia , Dor/metabolismo , Medula Espinal/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/metabolismo , Ácido Eicosapentaenoico/farmacologia , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Masculino , Camundongos , Plasticidade Neuronal/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Medula Espinal/efeitos dos fármacos
18.
Mol Pain ; 8: 18, 2012 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-22439811

RESUMO

BACKGROUND: Activation of spinal cord glial cells such as microglia and astrocytes has been shown to regulate chronic opioid-induced antinociceptive tolerance and hyperalgesia, due to spinal up-regulation of the proinflammatory cytokines such as interleukin-1 beta (IL-1ß). Matrix metalloprotease-9 (MMP-9) has been implicated in IL-1ß activation in neuropathic pain. However, it is unclear whether acute opioid treatment can activate glial cells in the peripheral nervous system. We examined acute morphine-induced activation of satellite glial cells (SGCs) and up-regulation of IL-1ß in dorsal root ganglia (DRGs), and further investigated the involvement of MMP-9 in these opioid-induced peripheral changes. RESULTS: Subcutaneous morphine injection (10 mg/kg) induced robust peripheral glial responses, as evidenced by increased GFAP expression in DRGs but not in spinal cords. The acute morphine-induced GFAP expression is transient, peaking at 2 h and declining after 3 h. Acute morphine treatment also increased IL-1ß immunoreactivity in SGCs and IL-1ß activation in DRGs. MMP-9 and GFAP are expressed in DRG neurons and SGCs, respectively. Confocal analysis revealed a close proximity of MMP-9 and GFAP immunostaining. Importantly, morphine-induced DRG up-regulation of GFAP expression and IL-1ß activation was abolished after Mmp9 deletion or naloxone pre-treatment. Finally, intrathecal injections of IL-1ß-selective siRNA not only reduced DRG IL-1ß expression but also prolonged acute morphine-induced analgesia. CONCLUSIONS: Acute morphine induces opioid receptors- and MMP-9-dependent up-regulation of GFAP expression and IL-1ß activation in SGCs of DRGs. MMP-9 could mask and shorten morphine analgesia via peripheral neuron-glial interactions. Targeting peripheral glial activation might prolong acute opioid analgesia.


Assuntos
Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Interleucina-1beta/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Morfina/farmacologia , Neuroglia/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Western Blotting , Imuno-Histoquímica , Masculino , Metaloproteinase 9 da Matriz/genética , Camundongos , Camundongos Knockout , Neuroglia/efeitos dos fármacos , Reação em Cadeia da Polimerase em Tempo Real
19.
Environ Sci Pollut Res Int ; 29(55): 82729-82739, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36224464

RESUMO

To promote the development of the green and low-carbon wood industry and explore the current status and trend of China's used-furniture recycling, this paper summarizes the research status of used-furniture recycling and interprets governmental strategies, such as the development of used-furniture recycling system, the way of handling used-furniture by manufacturers, and the attitudes of customers towards used-furniture, through extensive literature reviews and market research. From such three respects as government, furniture manufacturers, and consumers, the problems of national used-furniture recycling are analyzed, for example, imperfect system, high cost, and weak awareness. Therefore, to solve the above issues, it is necessary to construct national used-furniture recycling system and methods. The government should pay attention to the construction of recycling network, the supervision and support of entrepreneurial responsibilities, and the formulation of recycling standards. For furniture manufacturers, the improvement of the durability and recyclability of furniture and the development of new models and new technologies for furniture recycling and transportation are their primary assignment. And for consumers, the improvements of their concepts of consuming and the environmental protection are in focus. In sum, it aims to provide both suggestions for the amelioration of the measures and methods, and support for the understanding of the change, of used-furniture recycling in China.


Assuntos
Indústria da Construção , Reciclagem , China , Decoração de Interiores e Mobiliário , Gerenciamento de Resíduos/métodos , Madeira
20.
JCI Insight ; 7(22)2022 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-36194480

RESUMO

Neuropathic pain is a refractory condition that involves de novo protein synthesis in the nociceptive pathway. The mTOR is a master regulator of protein translation; however, mechanisms underlying its role in neuropathic pain remain elusive. Using the spared nerve injury-induced neuropathic pain model, we found that mTOR was preferentially activated in large-diameter dorsal root ganglion (DRG) neurons and spinal microglia. However, selective ablation of mTOR in DRG neurons, rather than microglia, alleviated acute neuropathic pain in mice. We show that injury-induced mTOR activation promoted the transcriptional induction of neuropeptide Y (Npy), likely via signal transducer and activator of transcription 3 phosphorylation. NPY further acted primarily on Y2 receptors (Y2R) to enhance neuronal excitability. Peripheral replenishment of NPY reversed pain alleviation upon mTOR removal, whereas Y2R antagonists prevented pain restoration. Our findings reveal an unexpected link between mTOR and NPY/Y2R in promoting nociceptor sensitization and neuropathic pain.


Assuntos
Neuralgia , Neuropeptídeo Y , Animais , Camundongos , Gânglios Espinais/metabolismo , Neuralgia/tratamento farmacológico , Neuralgia/metabolismo , Neuropeptídeo Y/metabolismo , Nociceptores/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Serina-Treonina Quinases TOR/metabolismo
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