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1.
PLoS One ; 15(1): e0221851, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31961897

RESUMO

BACKGROUND: There is currently no effective treatment for promoting regeneration of injured nerves in patients who have sustained injury to the central nervous system such as spinal cord injury. Chondroitinase ABC is an enzyme, which promotes neurite outgrowth and regeneration. It has shown considerable promise as a therapy for these conditions. The aim of the study is to determine if targeting chondroitinase ABC expression to the neuronal axon can further enhance its ability to promote axon outgrowth. Long-distance axon regeneration has not yet been achieved, and would be a significant step in attaining functional recovery following spinal cord injury. METHODOLOGY/PRINCIPAL FINDINGS: To investigate this, neuronal cultures were transfected with constructs encoding axon-targeted chondroitinase, non-targeted chondroitinase or GFP, and the effects on neuron outgrowth and sprouting determined on substrates either permissive or inhibitory to neuron regeneration. The mechanisms underlying the observed effects were also explored. Targeting chondroitinase to the neuronal axon markedly enhances its ability to promote neurite outgrowth. The increase in neurite length is associated with an upregulation of ß-integrin staining at the axonal cell surface. Staining for phosphofocal adhesion kinase, is also increased, indicating that the ß-integrins are in an activated state. Expression of chondroitinase within the neurons also resulted in a decrease in expression of PTEN and RhoA, molecules which present a block to neurite outgrowth, thus identifying two of the pathways by which ChABC promotes neurite outgrowth. CONCLUSIONS / SIGNIFICANCE: The novel finding that targeting ChABC to the axon significantly enhances its ability to promote neurite extension, suggests that this may be an effective way of promoting long-distance axon regeneration following spinal cord injury. It could also potentially improve its efficacy in the treatment of other pathologies, where it has been shown to promote recovery, such as myocardial infarction, stroke and Parkinson's disease.


Assuntos
Condroitina ABC Liase/genética , Regeneração Nervosa/genética , Crescimento Neuronal/genética , Traumatismos da Medula Espinal/genética , Animais , Axônios/metabolismo , Condroitina ABC Liase/antagonistas & inibidores , Regulação da Expressão Gênica/genética , Humanos , Neuritos/metabolismo , Neurônios/metabolismo , Neurônios/fisiologia , PTEN Fosfo-Hidrolase/genética , Recuperação de Função Fisiológica/genética , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/terapia , Proteína rhoA de Ligação ao GTP/genética
2.
Gene ; 726: 144171, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31669638

RESUMO

This study aims to investigate the genetic and epigenetic mechanisms involved in the pathogenesis of subacute stage of spinal cord injury (SCI). Gene-expression datasets associated with SCI were downloaded from the Gene Expression Omnibus (GEO) database, and differential expression analyses were performed in order to identify differentially expressed genes (DEGs). Multiple network types were constructed and analyzed, including protein-protein-interaction (PPI) network, miRNA-target network, lncRNA-associated competing endogenous RNA (ceRNA) network, and miRNA-transcription factor (TF)-target network. Cluster analyses were performed to identify significant modules. To verify the prediction accuracy of the in-silico identified molecules, qRT-PCR experiments were conducted. The results depicted the Ywhae gene as the hub gene with the highest degree in the PPI network. The ceRNA network identified specific genes (Flna, ID3, and HK2), miRNAs (miR-16-5p, miR-1958, and miR-185-5p), and lncRNAs (Neat1, Xist, and Malat1) as playing critical regulating roles in the pathological mechanisms of SCI. The miRNA-TF-gene interaction network identified four important TFs (Sp1, Trp53, Jun, and Rela). The miRNA-gene-TF interaction loops from the significant modules indicated that miR-325-3p can interact with the Asah1 gene and TF-Sp1 by forming a closed loop. The qRT-PCR experiments verified four selected genes (Flna, ID3, HK2, and Ywhae) and two selected TFs (Jun, and Sp1) as significantly up-regulated following SCI. The results indicated that four genes (Flna, ID3, HK2, and Ywhae), four transcription factors (Sp1, Trp53, Jun, and RelA), two miRNAs (miR-16-5p and miR-325-3p), and three lncRNAs (Neat1, Xist, and Malat1) are likely to be involved in the molecular mechanisms underlying the subacute stage of SCI. These findings uncover putative pathogenic mechanisms involved in SCI and might bear translation significance for future research towards therapeutic development.


Assuntos
Redes Reguladoras de Genes/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Traumatismos da Medula Espinal/genética , Animais , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/genética , Camundongos , Camundongos Endogâmicos C57BL , Mapas de Interação de Proteínas/genética , Fatores de Transcrição/genética , Regulação para Cima/genética
3.
Nat Rev Neurol ; 15(12): 732-745, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31728042

RESUMO

Over the past decade, we have witnessed a flourishing of novel strategies to enhance neuroplasticity and promote axon regeneration following spinal cord injury, and results from preclinical studies suggest that some of these strategies have the potential for clinical translation. Spinal cord injury leads to the disruption of neural circuitry and connectivity, resulting in permanent neurological disability. Recovery of function relies on augmenting neuroplasticity to potentiate sprouting and regeneration of spared and injured axons, to increase the strength of residual connections and to promote the formation of new connections and circuits. Neuroplasticity can be fostered by exploiting four main biological properties: neuronal intrinsic signalling, the neuronal extrinsic environment, the capacity to reconnect the severed spinal cord via neural stem cell grafts, and modulation of neuronal activity. In this Review, we discuss experimental evidence from rodents, nonhuman primates and patients regarding interventions that target each of these four properties. We then highlight the strengths and challenges of individual and combinatorial approaches with respect to clinical translation. We conclude by considering future developments and providing views on how to bridge the gap between preclinical studies and clinical translation.


Assuntos
Regeneração Nervosa/fisiologia , Plasticidade Neuronal/fisiologia , Recuperação de Função Fisiológica/fisiologia , Traumatismos da Medula Espinal/metabolismo , Pesquisa Médica Translacional/métodos , Animais , Axônios/fisiologia , Humanos , Traumatismos da Medula Espinal/diagnóstico , Traumatismos da Medula Espinal/genética
4.
Mol Med Rep ; 20(5): 4285-4292, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31545436

RESUMO

The aim of the present study was to investigate whether nuclear factor erythroid 2p45­related factor 2 (Nrf2) overexpression by gene transfer may protect neurons/glial cells and the association between neurons/glial cells and axons in spinal cord injury (SCI). In the present study, Nrf2 recombinant adenovirus (Ad) vectors were constructed. The protein levels of Nrf2 in the nucleus and of the Nrf2­regulated gene products heme oxygenase­1 (HO­1) and NAD (P)H­quinone oxidoreductase­1 (NQO1), were detected using western blot analysis in PC12 cells following 48 h of transfection. Furthermore, the expression of Nrf2 was localized using an immunofluorescence experiment, and the expression of Nrf2, HO­1 and NQO1 were detected using an immunohistochemical experiment in the grey matter of spinal cord in rats. Post­injury motor behavior was assessed via the Basso, Beattie and Bresnahan (BBB) locomotor scale method. In PC12 cells, subsequent to Ad­Nrf2 transfection, nuclear Nrf2, HO­1 and NQO1 levels were significantly increased compared with the control (P<0.01). There was statistically significant changes in the PC12­Ad­Nrf2 group [Nrf2 (1.146±0.095), HO­1 (1.816±0.095) and NQO1 (1.421±0.138)] compared with the PC12­control group [Nrf2 (0.717±0.055), HO­1 (1.264±0.081) and NQO1 (0.921±0.088)] and PC12­Ad­green fluorescent protein group [Nrf2 (0.714±0.111), HO­1 (1.238±0.053) and NQO1 (0.987±0.045); P<0.01]. The BBB scores of the rats indicated that they had improved functional recovery following the local injection of Ad­Nrf2. On the third day following the operation, BBB scores in the adenovirus groups (0.167±0.408) were significantly decreased compared with the SCI group (1±0.894; P<0.05). In the injured section of the spinal cord in the rats, the number of positive cells expressing Nrf2, HO­1 and NQO1 were raised compared with the control and SCI groups, indicating that the adenovirus vector­mediated gene transfer of Nrf2 promotes functional recovery following spinal cord contusion in rats.


Assuntos
Adenoviridae/genética , Expressão Gênica , Vetores Genéticos/genética , Fator 2 Relacionado a NF-E2/genética , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/reabilitação , Animais , Modelos Animais de Doenças , Feminino , Técnicas de Transferência de Genes , Genes Reporter , Terapia Genética , Vetores Genéticos/administração & dosagem , Imuno-Histoquímica , Masculino , Atividade Motora , Fator 2 Relacionado a NF-E2/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Ratos , Traumatismos da Medula Espinal/terapia , Transdução Genética
5.
Neurol Res ; 41(11): 991-1000, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31397222

RESUMO

Objectives: The aim of the study was to determine the relationships between microRNA-20a and microRNA-125b expression and apoptosis and inflammation in a rat model of spinal cord injury (SCI) using microscopy, immunohistochemistry, and molecular biology. Methods: Sixty-one rats were divided into three groups: a control group that was not subjected to any operation; a sham-operated group; and an experimental group that was subjected to spinal cord compression. The experimental group was further subdivided into two subgroups: the experimental control group, which did not receive any drug treatment; and the methylprednisolone treatment group, which received 30 mg/kg methylprednisolone on day 0 followed by 10 mg/kg/day methylprednisolone from days 1-14. Results: Tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 levels increased in the experimental control group on days 1 and 3, and decreased in the experimental control group and methylprednisolone treatment group on days 7 and 14. Caspase-3 levels increased in the experimental control group on day 1, and decreased in the experimental control group and methylprednisolone treatment group on days 3, 7, and 14. MicroRNA-20a expression was upregulated in the experimental control group on days 1 and 3, and microRNA-125b expression was downregulated on days 3 and 7. Conclusions: After SCI, upregulated microRNA-20a expression and increased proinflammatory cytokines may lead to an increase in inflammation. MicroRNA-125b may be associated with caspase-3, and microRNA-125b downregulation may inhibit apoptosis. Although the results of this study suggest potential relationships between microRNA-20a and microRNA-125b expression and apoptosis and inflammation in SCI, further studies are needed to confirm microRNA-20a and microRNA-125b as biomarkers in SCI and to develop new strategies for the treatment of SCI.


Assuntos
Apoptose/genética , MicroRNAs/genética , Traumatismos da Medula Espinal/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Citocinas/metabolismo , Regulação para Baixo/efeitos dos fármacos , Inflamação/metabolismo , Interleucina-6/metabolismo , Masculino , Metilprednisolona/uso terapêutico , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/metabolismo , Traumatismos da Medula Espinal/genética , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima/efeitos dos fármacos
6.
Mol Med Rep ; 20(4): 3011-3018, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31432119

RESUMO

Spinal cord injury (SCI) is a specific type of damage to the central nervous system causing temporary or permanent changes in its function. The present aimed to identify the genetic changes in neuroplasticity following SCI in rats. The GSE52763 microarray dataset, which included 15 samples [3 sham (1 week), 4 injury only (1 week), 4 injury only (3 weeks), 4 injury + treadmill (3 weeks)] was downloaded from the Gene Expression Omnibus database. An empirical Bayes linear regression model in limma package was used to identify the differentially expressed genes (DEGs) in injury vs. sham and treadmill vs. non­treadmill comparison groups. Subsequently, time series and enrichment analyses were performed using pheatmap and clusterProfile packages, respectively. Additionally, protein­protein interaction (PPI) and transcription factor (TF)­microRNA (miRNA)­target regulatory networks were constructed using Cytoscape software. In total, 159 and 105 DEGs were identified in injury vs. sham groups and treadmill vs. non­treadmill groups, respectively. There were 40 genes in cluster 1 that presented increased expression levels in the injury (1 week/3 weeks) groups compared with the sham group, and decreased expression levels in the injury + treadmill group compared with the injury only groups; conversely, 52 genes in cluster 2 exhibited decreased expression levels in the injury (1 week/3 weeks) groups compared with the sham group, and increased expression levels in the injury + treadmill group compared with the injury only groups. Enrichment analysis indicated that clusters 1 and 2 were associated with immune response and signal transduction, respectively. Furthermore, microtubule associated protein 1B, phosphofurin acidic cluster sorting protein 2 and adenosylhomocysteinase­like 1 exhibited the highest degrees in the regulatory network, and were regulated by miRNAs including miR­34A, miR­34B, miR­34C and miR­449. These miRNAs and their target genes may serve important roles in neuroplasticity following traumatic SCI in rats. Nevertheless, additional in­depth studies are required to confirm these data.


Assuntos
Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/biossíntese , MicroRNAs/biossíntese , Proteínas Associadas aos Microtúbulos/biossíntese , Plasticidade Neuronal , Análise de Sequência com Séries de Oligonucleotídeos , Traumatismos da Medula Espinal/metabolismo , Proteínas de Transporte Vesicular/biossíntese , Animais , Peptídeos e Proteínas de Sinalização Intracelular/genética , MicroRNAs/genética , Proteínas Associadas aos Microtúbulos/genética , Ratos , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/patologia , Proteínas de Transporte Vesicular/genética
7.
Mol Med Rep ; 20(3): 2763-2773, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31322240

RESUMO

Ectomesenchymal stem cells (EMSCs) represent a type of adult stem cells derived from the cranial neural crest. These cells are capable of self­renewal and have the potential for multidirectional differentiation. Tissue transglutaminase type 2 (TG2) is a ubiquitously expressed member of the transglutaminase family of Ca2+­dependent crosslinking enzymes. However, the effect of TG2 on neural differentiation and proliferation of EMSCs remains unknown. To determine whether TG2 improves EMSC proliferation and neurogenesis, a stable TG2­overexpressing EMSC cell line (TG2­EMSCs) was established by using an adenovirus system. Immunofluorescence staining and western blot analyses demonstrated that TG2 overexpression had beneficial effects on the rate of EMSC neurogenesis, and that the proliferative capacity of TG2­EMSCs was higher than that of controls. Furthermore, the results of western blotting revealed that extracellular matrix (ECM) and neurotrophic factors were upregulated during the differentiation of TG2­EMSCs. Notably, TG2­EMSC transplantation in an animal model of spinal cord injury (SCI), TG2­EMSCs differentiated into neuron­like cells and enhanced the repair of SCI. Taken together, these results demonstrated that TG2 gene transfection may offer a novel strategy to enhance EMSC proliferation and neurogenesis in vivo and in vitro, which may ultimately facilitate EMSC­based transplantation therapy in patients with SCI.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Neurogênese , Traumatismos da Medula Espinal/terapia , Transglutaminases/genética , Células-Tronco Adultas/citologia , Células-Tronco Adultas/metabolismo , Células-Tronco Adultas/transplante , Animais , Linhagem Celular , Feminino , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/transplante , Ratos , Ratos Sprague-Dawley , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/fisiopatologia , Regulação para Cima
8.
Neurochem Res ; 44(9): 2057-2067, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31325155

RESUMO

In the adult central nervous system (CNS), axon regeneration is a major hurdle for functional recovery after trauma. The intrinsic growth potential of an injured axon varies widely between neurons. The underlying molecular mechanisms of such heterogeneity are largely unclear. In the present study, the adult zebrafish dataset GSE56842 were downloaded. Differentially expressed genes (DEGs) were sorted and deeply analyzed by bioinformatics methods. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs were performed with the DAVID. A DEGs-associated protein-protein interaction network was constructed from the STRING database and visualized with Cytoscape software. In total, 621 DEGs were identified. GO analysis showed that the biological processes of DEGs focused mainly on the Notch signaling pathway, cell differentiation and positive regulation of neuron differentiation. The molecular functions mainly included calcium-transporting ATPase activity and calcium ion binding and structural constituents of the cytoskeleton. The cellular components included the plasma membrane, spectrin, and cytoplasmic and membrane-bound vesicles. KEGG pathway analysis showed that these DEGs were mainly involved in the metabolic pathway and Notch signaling pathway, and subnetworks revealed that genes within modules were involved in the metabolic pathway, Wnt signaling pathway, and calcium signaling pathway. This study identified DEG candidate genes and pathways involved in the heterogeneity of the intrinsic growth ability between neurons after spinal cord injury in adult zebrafish, which could facilitate our understanding of the molecular mechanisms underlying axon regeneration, and these candidate genes and pathways could be therapeutic targets for the treatment of CNS injury.


Assuntos
Axônios/metabolismo , Expressão Gênica , Regeneração Nervosa/genética , Traumatismos da Medula Espinal/metabolismo , Medula Espinal/metabolismo , Animais , Biologia Computacional , Bases de Dados Genéticas/estatística & dados numéricos , Perfilação da Expressão Gênica , Ontologia Genética , Mapas de Interação de Proteínas , Transdução de Sinais/genética , Traumatismos da Medula Espinal/genética , Peixe-Zebra
9.
Sci Data ; 6(1): 83, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31175296

RESUMO

Spinal cord injury (SCI) is a devastating clinical condition resulting in significant disabilities. Apart from local injury within the spinal cord, SCI patients develop a myriad of complications including multi-organ dysfunction. Some of the dysfunctions may be directly or indirectly related to the sensory neurons of the dorsal root ganglia (DRG), which signal to both the spinal cord and the peripheral organs. After SCI, some classes of DRG neurons exhibit sensitization and undergo axonal sprouting both peripherally and centrally. Such physiological and anatomical re-organization after SCI contributes to both adaptive and maladaptive plasticity processes, which may be modulated by activity and exercise. In this study, we collected comprehensive gene expression data in whole DRG below the levels of the injury to compare the effects of SCI with and without two different forms of exercise in rats.


Assuntos
Gânglios Espinais/metabolismo , Traumatismos da Medula Espinal , Transcriptoma , Animais , Comportamento Animal , Plasticidade Neuronal , Neurônios Aferentes/metabolismo , Condicionamento Físico Animal , Ratos , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/fisiopatologia
10.
Cell Mol Life Sci ; 76(21): 4355-4368, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31041455

RESUMO

Axons in the central nervous system (CNS) typically fail to regenerate after injury. This failure is multi-factorial and caused in part by disruption of the axonal cytoskeleton. The cytoskeleton, in particular microtubules (MT), plays a critical role in axonal transport and axon growth during development. In this regard, members of the kinesin superfamily of proteins (KIFs) regulate the extension of primary axons toward their targets and control the growth of collateral branches. KIF2A negatively regulates axon growth through MT depolymerization. Using three different injury models to induce SCI in adult rats, we examined the temporal and cellular expression of KIF2A in the injured spinal cord. We observed a progressive increase of KIF2A expression with maximal levels at 10 days to 8 weeks post-injury as determined by Western blot analysis. KIF2A immunoreactivity was present in axons, spinal neurons and mature oligodendrocytes adjacent to the injury site. Results from the present study suggest that KIF2A at the injured axonal tips may contribute to neurite outgrowth inhibition after injury, and that its increased expression in inhibitory spinal neurons adjacent to the injury site might contribute to an intrinsic wiring-control mechanism associated with neuropathic pain. Further studies will determine whether KIF2A may be a potential target for the development of regeneration-promoting or pain-preventing therapies.


Assuntos
Cinesina/análise , Cinesina/metabolismo , Traumatismos da Medula Espinal/metabolismo , Animais , Axônios/metabolismo , Axônios/patologia , Modelos Animais de Doenças , Cinesina/genética , Masculino , Regeneração Nervosa/genética , Neurônios/metabolismo , Neurônios/patologia , Ratos , Ratos Sprague-Dawley , Medula Espinal/metabolismo , Medula Espinal/patologia , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/patologia
11.
FEBS Open Bio ; 9(7): 1223-1231, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31050183

RESUMO

Neuronal apoptosis is the main pathological feature of spinal cord injury (SCI), while autophagy contributes to ameliorating neuronal damage via inhibition of apoptosis. Here, we investigated the role of tectonic family member 2 (TCTN2) long non-coding RNA on apoptosis and autophagy in SCI. TCTN2 was down-regulated in the spinal cord tissues of a rat model of SCI and in oxygen-glucose deprivation-induced hypoxic SY-SH-5Y cells, while microRNA-216b (miR-216b) was up-regulated. Overexpression of TCTN2 reduced neuron apoptosis by inducing autophagy, and TCTN2 was observed to negatively regulate miR-216b. Furthermore, TCTN2 promoted autophagy to repress apoptosis through the miR-216b-Beclin-1 pathway, and overexpression of TCTN2 improved neurological function in the SCI rat model. In summary, our data suggest that TCTN2 enhances autophagy by targeting the miR-216b-Beclin-1 pathway, thereby ameliorating neuronal apoptosis and relieving spinal cord injury.


Assuntos
Proteínas de Membrana/genética , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/patologia , Animais , Apoptose/genética , Autofagia/genética , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Linhagem Celular , Humanos , MicroRNAs/genética , Modelos Animais , Neurônios/metabolismo , Neurônios/patologia , RNA Longo não Codificante/genética , Ratos , Ratos Sprague-Dawley , Medula Espinal/metabolismo , Medula Espinal/patologia , Traumatismos da Medula Espinal/metabolismo
12.
Brain Dev ; 41(8): 649-661, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31036380

RESUMO

Apoptosis is a highly conservative energy demand program for non-inflammatory cell death, which is extremely significant in normal physiology and disease. There are many techniques used for studying apoptosis. MicroRNA (miRNA) is closely related to cell apoptosis, and especially microRNA-31 (miR-31) is involved in apoptosis by regulating a large number of target genes and signaling pathways. In many neurological diseases, cell apoptosis or programmed cell death plays an important role in the reduction of cell number, including the reduction of neurons in spinal cord injuries. In recent years, the phosphoinositol 3-kinase/AKT (PI3K/AKT) signal pathway, as a signal pathway involved in a variety of cell functions, has been studied in spinal cord injury diseases. The PI3K/AKT pathway directly or indirectly affects whether apoptosis occurs in a cell, thereby affecting a significant intracellular event sequence. This paper reviewed the interactions of miR-31 target sites in the PI3K/AKT signaling pathway, and explored new ways to prevent and treat spinal cord injury by regulating the effect of miR-31 on apoptosis.


Assuntos
MicroRNAs/genética , MicroRNAs/metabolismo , Traumatismos da Medula Espinal/genética , Apoptose/genética , Proliferação de Células , Neurônios/metabolismo , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/genética , Medula Espinal/metabolismo , Traumatismos da Medula Espinal/metabolismo
13.
Mol Med Rep ; 20(1): 41-48, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31115509

RESUMO

The present study was designed to investigate the effect of neuregulin­1 (NRG1) on the migration of rat bone marrow mesenchymal stem cells (BMSCs) and evaluate the role of NRG1 in the functional recovery following spinal cord injury (SCI). Firstly, the effect of NRG1 on the mRNA expression of Snail in the BMSCs was detected by reverse transcription­quantitative polymerase chain reaction (RT­qPCR) analysis; secondly, the BMSCs were transfected with a Snail­overexpression plasmid (pBabe­puro­Snail) and the expression levels of Snail and matrix metalloptoreinase­2 (MMP­2) were detected by RT­qPCR and western blot analyses; thirdly, the cell proliferation and migration of BMSCs modified with pBabe­puro­Snail were detected by methyl thiazolyl tetrazolium and migration assays, respectively; finally, functional recovery of SCI was assessed using the Basso, Beattie, and Bresnahan rating scales. The results showed that NRG1 concentration­dependently promoted the expression of Snail with a peak at 40 ng/ml and 48 h; NRG1 enhanced the promoting effect of Snail on the expression of MMP­2; the overexpression of Snail did not enhance the cell growth of the BMSCs. The NRG1­modified BMSCs promoted the functional recovery of SCI. These results suggested that NRG1 significantly promoted the expression of MMP­2 by upregulating the expression of Snail, and enhanced cell migration of the BMSCs conducive to the functional recovery of SCI.


Assuntos
Células-Tronco Mesenquimais/metabolismo , Neuregulina-1/genética , Traumatismos da Medula Espinal/genética , Medula Espinal/crescimento & desenvolvimento , Animais , Diferenciação Celular/genética , Movimento Celular/genética , Proliferação de Células/genética , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Humanos , Metaloproteinase 2 da Matriz/genética , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Plasmídeos/genética , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/genética , Fatores de Transcrição da Família Snail/genética , Medula Espinal/metabolismo , Medula Espinal/patologia , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/terapia , Transfecção
14.
J Mol Neurosci ; 68(2): 221-233, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30993646

RESUMO

Spinal cord injury (SCI) can be lethal; however, the precise mechanisms underlying healing are unclear, limiting the development of effective therapies. In this study, the molecular mechanisms involved in SCI were investigated. Clinical peripheral blood samples from normal individuals and patients with incomplete SCI (ISCI) and complete SCI (CSCI) were analyzed by RNA-Seq. The expression levels of EPHA4, CDK16, BAD, MAP2 Normal 2, EGR, and RHOB differed significantly between the SCI group and normal individuals, and these results were verified by q-PCR. A gene ontology (GO) enrichment analysis showed that differentially expressed genes were mostly enriched for the neurotrophin TRK receptor signaling pathway. We verified the expression of neurotrophic factors and found that they were all expressed most highly in the SCI group. The results of this study demonstrate that neurotrophic factors are highly expressed after SCI and the neurotrophin TRK receptor signaling pathway may be involved in the initiation of nerve system regeneration.


Assuntos
RNA Mensageiro/genética , Receptores de Fator de Crescimento Neural/genética , Traumatismos da Medula Espinal/genética , Transcriptoma , Biomarcadores/sangue , Estudos de Casos e Controles , Humanos , RNA Mensageiro/sangue , RNA Mensageiro/metabolismo , Receptores de Fator de Crescimento Neural/sangue , Receptores de Fator de Crescimento Neural/metabolismo , Transdução de Sinais , Traumatismos da Medula Espinal/sangue , Traumatismos da Medula Espinal/patologia
15.
J Mol Neurosci ; 68(2): 191-203, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30919247

RESUMO

Mitogen- and stress-activated kinase (MSK) 1 is a nuclear serine/threonine kinase. In the central nervous system, it plays an important role in regulating cell proliferation and neuronal survival; it is also involved in astrocyte inflammation and the inhibition of inflammatory cytokine production. However, its specific role in spinal cord injury is not clear. Here, we aimed to elucidate this role using an in vivo animal model. In this study, we found that MSK1 is gradually decreased, starting 1 day after spinal cord injury and to its lowest level 3 days post-injury, after which it gradually increased. To further investigate the possible function of MSK1 in spinal cord injury, we interfered with its expression by utilizing a small interfering RNA (siRNA)-encoding lentivirus, which was injected into the injured spinal cord to inhibit local expression. After MSK1 inhibition, we found that the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1ß were increased. Moreover, the expression of IL-10 was decreased. In addition, neuronal apoptotic cells were increased significantly and expression of the apoptosis-related protein caspase-3 was also increased. Ultrastructural analysis of nerve cells also revealed typical neuronal apoptosis and severe neuronal damage. Finally, we found that hindlimb motor function decreased significantly with MSK1 knockdown. Therefore, our findings suggest that the inhibition of this protein promotes inflammatory responses and apoptosis and suppresses functional recovery after spinal cord injury. MSK1 might thus play an important role in repair after spinal cord injury by regulating inflammation and apoptosis.


Assuntos
Apoptose , Citocinas/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Traumatismos da Medula Espinal/metabolismo , Animais , Citocinas/genética , Inativação Gênica , Masculino , Células PC12 , Ratos , Ratos Sprague-Dawley , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Traumatismos da Medula Espinal/genética
16.
Neurorehabil Neural Repair ; 33(5): 331-344, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30913975

RESUMO

BACKGROUND: The strong link between dopamine and motor learning has been well-established in the animal literature with similar findings reported in healthy adults and the elderly. OBJECTIVE: We aimed to conduct the first, to our knowledge, systematic review of the literature on the evidence for the effects of dopaminergic medications or genetic variations in dopamine transmission on motor recovery or learning after a nonprogressive neurological injury. METHODS: A PubMed search was conducted up until April 2018 for all English articles including participants with nonprogressive neurological injury such as cerebral palsy, stroke, spinal cord injury, and traumatic brain injury; quantitative motor outcomes; and assessments of the dopaminergic system or medications. RESULTS: The search yielded 237 articles, from which we identified 26 articles meeting all inclusion/exclusion criteria. The vast majority of articles were related to the use of levodopa poststroke; however, several studies assessed the effects of different medications and/or were on individuals with traumatic brain injury, spinal cord injury or cerebral palsy. CONCLUSIONS: The evidence suggests that a brain injury can decrease dopamine transmission and that levodopa may have a positive effect on motor outcomes poststroke, although evidence is not conclusive or consistent. Individual variations in genes related to dopamine transmission may also influence the response to motor skill training during neurorehabilitation and the extent to which dopaminergic medications or interventions can augment that response. More rigorous safety and efficacy studies of levodopa and dopaminergic medications in stroke and particularly other neurological injuries including genetic analyses are warranted.


Assuntos
Lesões Encefálicas Traumáticas/terapia , Paralisia Cerebral/terapia , Dopaminérgicos/farmacologia , Reabilitação Neurológica , Traumatismos da Medula Espinal/terapia , Acidente Vascular Cerebral/terapia , Adulto , Lesões Encefálicas Traumáticas/genética , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/fisiopatologia , Paralisia Cerebral/genética , Paralisia Cerebral/metabolismo , Paralisia Cerebral/fisiopatologia , Criança , Humanos , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/fisiopatologia , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/fisiopatologia
17.
World Neurosurg ; 126: e713-e722, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30849555

RESUMO

BACKGROUND: Spinal cord and neuron injury result in loss of muscle function, sensation, or autonomic function in the body. Tet1 produces 5-hydroxymethylcytosin. The conversion was proposed as the initial step of deoxyribonucleic acid demethylation in mammals. However, effects of Tet1 expression and hydroxymethylation status on neuron injury remain unclear. Therefore the current study was designed to explore effects of Tet1 expression and hydroxymethylation status on cell survival and gene expression after neuron injury. METHODS: Mouse models of spinal cord injury and cell model of neuron injury were created. Animals were sacrificed, and injured spinal cord tissue was harvested. Neuron-like cells were cultured after scratch injury. Hydroxymethylated deoxyribonucleic acid concentration was detected, and Tet1 expression was examined by qPCR. Neuron-like cells were divided into 3 groups: control, injury, and azacytidine + injury (before injury, cells were pretreated with azacytidine) groups. Culture supernatant was collected, and lactate dehydrogenase concentration was detected. Meanwhile, injured neuron-like cells were divided into 3 groups: negative control, Tet1 overexpression, and Tet1 interference. Relative expression of Tet1, BDNF, NTF3, A20, FLIP, HSP70, HSP90, HSP27, and Bcl2 in neuron-like cells was detected by qPCR. In addition, neuron-like cells were divided into 7 groups. RESULTS: Tet1 expression and deoxyribonucleic acid hydroxymethylation increased initially and decreased thereafter after neuron injury in both animal and cell models. Percentages of dead cells increased significantly in neuron-like cells after injury. The percentages of dead cells markedly decreased in injured neuron-like cells that were pretreated with azacytidine. The percentages of dead cells increased markedly in the Tet1 interference group and decreased significantly in the Tet1 overexpression group. Expression of Tet1, BDNF, A20, FLIP, HSP70, HSP90, and Bcl2 decreased significantly after injury. Azacytidine pretreatment in injured neuron-like cells markedly increased expression of Tet1, BDNF, NTF3, A20, FLIP, HSP70, HSP90, HSP27, and Bcl2. Moreover, Tet1 interference significantly decreased the expression of Tet1, BDNF, A20, FLIP, HSP70, and HSP90 in neuron-like cells, whereas Tet1 overexpression markedly increased the expression of Tet1, BDNF, NTF3, A20, FLIP, HSP70, HSP90, HSP27, and Bcl2. BDNF interference significantly increased percentages of dead cells after injury. BDNF interference also markedly decreased the protection of azacytidine and Tet1 overexpression against cell death. CONCLUSIONS: Tet1 overexpression and demethylation caused by azacytidine protect neurons against cell death after injury by increasing expression of genes involved in cell survival.


Assuntos
Morte Celular/genética , Sobrevivência Celular/genética , Metilação de DNA , Proteínas de Ligação a DNA/genética , Neurônios/metabolismo , Proteínas Proto-Oncogênicas/genética , Traumatismos da Medula Espinal/genética , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Camundongos , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Traumatismos da Medula Espinal/metabolismo
18.
J Mol Neurosci ; 68(2): 181-190, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30911940

RESUMO

Microglial activation and inflammatory response played an important role in the secondary injury of spinal cord injury (SCI). Several microRNAs were associated with this procedure, but the underlying molecular mechanism was poorly understood. Sprague-Dawley (SD) rats were divided into four groups: SCI group (n = 7), agomiR-325-3p group (n = 7), and their control groups. Expression of miR-325-3p and proteins in epidermal growth factor receptor (EGFR)/mitogen-activated protein kinase (MAPK) signaling pathway was evaluated in microglia from SCI rats and primary microglia/BV2 cells activated by lipopolysaccharide (LPS). Concentrations of interleukin-1ß (IL-1ß) and tumor necrosis factor α (TNF-α) in supernatants were measured by ELISA. Low expression of miR-325-3p and activation of EGFR/MAPK was observed in microglia of SCI and LPS-induced primary microglia. Overexpression of miR-325-3p in LPS-induced BV2 cells inhibited microglial activation and release of TNF-α and IL-1ß. Luciferase reporter assay confirmed that miR-325-3p negatively regulated EGFR by targeting its 3'-untranslated regions. Additionally, agomiR-325-3p inhibited the activation of microglia and EGFR/MAPK, alleviating the inflammatory response. These results indicated that miR-325-3p attenuated secondary injury after SCI through inhibition of EGFR/MAPK signaling pathway, the microglial activation, and the release of inflammatory cytokines, suggesting that miR-325-3p may be employed as a therapeutic target for SCI.


Assuntos
Receptores ErbB/metabolismo , Sistema de Sinalização das MAP Quinases , MicroRNAs/genética , Microglia/metabolismo , Traumatismos da Medula Espinal/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Receptores ErbB/genética , Interleucina-1beta/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , MicroRNAs/metabolismo , Microglia/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Traumatismos da Medula Espinal/genética
19.
Int J Neurosci ; 129(9): 856-863, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30821549

RESUMO

Purpose: As a neurodegenerative disease, spinal cord injury can lead to the loss of autonomic function, muscle function, or sensation. This study is designed to identify the key genes implicated in the excitability of motor neurons following spinal cord injury. Materials and methods: The GSE19701 dataset was obtained from Gene Expression Omnibus. It includes a total of 31 motor neurons after spinal cord injury (samples at day 0, 2, 7, 21 and 60 following injury). After the data were preprocessed by the Robust Multi-array Average method, soft clustering analysis was conducted by the Fuzzy C-Means method in the Mfuzz package to identify the differentially expressed genes. Afterward, the differentially expressed genes were analyzed with enrichment analysis using the DAVID online tool. Based on Cytoscape software, a protein-protein interaction network was constructed and then module analysis was carried out. Furthermore, miRNA-differentially expressed gene pairs were downloaded from the miRWalk2.0 database and the miRNA regulatory network was visualized by Cytoscape software. Results: We found 218 upregulated genes and 526 downregulated genes. In the protein-protein interaction network, Uba3, Sumo1, and Pik3ca had higher scores, and Uba3 interacted with Sumo1. Among the eight modules identified from the protein-protein interaction network, module 1 and 8 were significantly enriched in pathways related to degenerative diseases of the nervous system. Additionally, Pdcd4 was targeted by miR-21 in the miRNA regulatory network. Conclusion: Uba3, Sumo1, Pik3ca and miR-21 targeting Pdcd4 might be responsible for the excitability of motor neurons after spinal cord injury.


Assuntos
Bases de Dados Genéticas , Redes Reguladoras de Genes/genética , Neurônios Motores/fisiologia , Traumatismos da Medula Espinal/genética , Animais , Análise por Conglomerados , Vértebras Lombares , Masculino , Ratos , Ratos Wistar , Traumatismos da Medula Espinal/fisiopatologia
20.
Int J Mol Med ; 43(4): 1758-1768, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30816451

RESUMO

The aim of the present study was to investigate the function and mechanism of sirtuin 1 (SIRT1) in spinal cord injury (SCI). Reverse transcription­quantitative polymerase chain reaction was used to measure the expression levels of microRNA (miR)­494. MTT assay, lactate dehydrogenase activity assay and flow cytometry were used to analyze the effects of miR­494 on cell growth and apoptosis in a model of SCI. The present study demonstrated that SIRT1 expression was reduced; whereas miR­494 expression was increased in a rat model of SCI. Overexpression of miR­494 suppressed the protein expression levels of SIRT1, and induced p53 protein expression. Conversely, knockdown of miR­494 induced SIRT1 protein expression in an in vitro model of SCI. Furthermore, overexpression of miR­494 promoted cell apoptosis and decreased cell growth in an in vitro model of SCI; however, miR­494 knockdown enhanced cell growth and inhibited cell apoptosis. Administration of a SIRT1 agonist reduced the effects of miR­494 overexpression on cell apoptosis in an SCI model, whereas treatment with a p53 agonist reduced the effects of miR­494 knockdown on cell apoptosis in an SCI model. Together, these findings suggested that SIRT1 may inhibit apoptosis of SCI in vivo and in vitro through the p53 signaling pathway, whereas miR­494 suppressed SIRT1 and induced apoptosis.


Assuntos
Apoptose/genética , MicroRNAs/metabolismo , Sirtuína 1/metabolismo , Traumatismos da Medula Espinal/metabolismo , Animais , Sequência de Bases , Modelos Animais de Doenças , Lipopolissacarídeos/farmacologia , Masculino , MicroRNAs/genética , Modelos Biológicos , Células PC12 , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/patologia , Proteína Supressora de Tumor p53/agonistas , Proteína Supressora de Tumor p53/metabolismo
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