Spinal cord injury is one of the leading causes of morbidity and mortality among young adults in many countries including the United States.Difficulty in the regeneration of neurons is one of the main obstacles that l...Spinal cord injury is one of the leading causes of morbidity and mortality among young adults in many countries including the United States.Difficulty in the regeneration of neurons is one of the main obstacles that leave spinal cord injury patients with permanent paralysis in most instances.Recent research has found that preventing acute and subacute secondary cellular damages to the neurons and supporting glial cells can help slow the progression of spinal cord injury pathogenesis,in part by reactivating endogenous regenerative proteins including Noggin that are normally present during spinal cord development.Noggin is a complex protein and natural inhibitor of the multifunctional bone morphogenetic proteins,and its expression is high during spinal cord development and after induction of spinal cord injury.In this review article,we first discuss the change in expression of Noggin during pathogenesis in spinal cord injury.Second,we discuss the current research knowledge about the neuroprotective role of Noggin in preclinical models of spinal cord injury.Lastly,we explain the gap in the knowledge for the use of Noggin in the treatment of spinal cord injury.The results from extensive in vitro and in vivo research have revealed that the therapeutic efficacy of Noggin treatment remains debatable due to its neuroprotective effects observed only in early phases of spinal cord injury but little to no effect on altering pathogenesis and functional recovery observed in the chronic phase of spinal cord injury.Furthermore,clinical information regarding the role of Noggin in the alleviation of progression of pathogenesis,its therapeutic efficacy,bioavailability,and safety in human spinal cord injury is still lacking and therefore needs further investigation.展开更多
Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibi...Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.展开更多
Emerging evidence has suggested global histone H4 acetylation status plays an important role in neural plasticity. For instance, the imbalance of this epigenetic marker has been hypothesized as a key factor for the de...Emerging evidence has suggested global histone H4 acetylation status plays an important role in neural plasticity. For instance, the imbalance of this epigenetic marker has been hypothesized as a key factor for the development and progression of several neurological diseases. Likewise, astrocytic reactivity-a wellknown process that markedly influences the tissue remodeling after a central nervous system injury-is crucial for tissue remodeling after spinal cord injury（SCI）. However, the linkage between the above-mentioned mechanisms after SCI remains poorly understood. We sought to investigate the relation between both glial fibrillary acidic protein（GFAP） and S100 calcium-binding protein B（S100B）（astrocytic reactivity classical markers） and global histone H4 acetylation levels. Sixty-one male Wistar rats（aged ~3 months） were divided into the following groups： sham; 6 hours post-SCI; 24 hours post-SCI; 48 hours post-SCI; 72 hours post-SCI; and 7 days post-SCI. The results suggested that GFAP, but not S100B was associated with global histone H4 acetylation levels. Moreover, global histone H4 acetylation levels exhibited a complex pattern after SCI, encompassing at least three clearly defined phases（first phase： no changes in the 6, 24 and 48 hours post-SCI groups; second phase： increased levels in the 72 hours post-SCI group; and a third phase： return to levels similar to control in the 7 days post-SCI group）. Overall, these findings suggest global H4 acetylation levels exhibit distinct patterns of expression during the first week post-SCI, which may be associated with GFAP levels in the perilesional tissue. Current data encourage studies using H4 acetylation as a possible biomarker for tissue remodeling after spinal cord injury.展开更多
目的分析脊髓压迫性损伤(compressed spinal cord injury,CSCI)后脱髓鞘病变与髓鞘碱性蛋白(myelinbasic protein,MBP)、DNA结合抑制物2(inhibitor of DNA binding2,Id2)的表达变化之间的关系,以探讨CSCI脱髓鞘病变机制。方法采用自行...目的分析脊髓压迫性损伤(compressed spinal cord injury,CSCI)后脱髓鞘病变与髓鞘碱性蛋白(myelinbasic protein,MBP)、DNA结合抑制物2(inhibitor of DNA binding2,Id2)的表达变化之间的关系,以探讨CSCI脱髓鞘病变机制。方法采用自行设计的方法制作SD大鼠CSCI模型,通过锇酸染色检测CSCI后1、3、7 d有髓神经纤维变化;运用免疫荧光双标和免疫印迹(Western blot)检测MBP及Id2的表达变化。结果 CSCI后出现脱髓鞘病变,并随着压迫时间延长,髓鞘逐渐发生水肿、变性、崩解;脊髓损伤后MBP表达下调,其表达趋势与脱髓鞘溃变的严重程度一致;CSCI后,Id2广泛分布于白质,随着压迫时间延长,其表达逐渐上调。结论 Id2表达上调,并负向调控MBP基因启动子的活性,使MBP的表达下降,是CSCI后神经纤维脱髓鞘病变的机制之一。展开更多
目的探讨血清髓鞘碱性蛋白含量对脊髓损伤程度早期诊断的价值。方法54只家兔随机分为轻、中、重度脊髓损伤组,每组动物通过大脑皮层体感诱发电位、损伤脊髓病理组织学和损伤后动物改良Tarlov评分评定损伤程度;应用酶联免疫吸附试验检测...目的探讨血清髓鞘碱性蛋白含量对脊髓损伤程度早期诊断的价值。方法54只家兔随机分为轻、中、重度脊髓损伤组,每组动物通过大脑皮层体感诱发电位、损伤脊髓病理组织学和损伤后动物改良Tarlov评分评定损伤程度;应用酶联免疫吸附试验检测损伤前后血清髓鞘碱性蛋白含量。结果3组实验动物血清髓鞘碱性蛋白含量损伤后均升高,在损伤后24 h、48 h和72 h时3组间有显著性差异( P <0.05),而第7天时已无显著性差异( P >0.05)。结论血清髓鞘碱性蛋白含量可作为脊髓损伤程度早期判断指标之一,但有一定的时限性。展开更多
基金supported by SCIRF-2020 PD-01 from the South Carolina Spinal Cord Injury Research Fund(Columbia,SC,USA)(to SKR).
文摘Spinal cord injury is one of the leading causes of morbidity and mortality among young adults in many countries including the United States.Difficulty in the regeneration of neurons is one of the main obstacles that leave spinal cord injury patients with permanent paralysis in most instances.Recent research has found that preventing acute and subacute secondary cellular damages to the neurons and supporting glial cells can help slow the progression of spinal cord injury pathogenesis,in part by reactivating endogenous regenerative proteins including Noggin that are normally present during spinal cord development.Noggin is a complex protein and natural inhibitor of the multifunctional bone morphogenetic proteins,and its expression is high during spinal cord development and after induction of spinal cord injury.In this review article,we first discuss the change in expression of Noggin during pathogenesis in spinal cord injury.Second,we discuss the current research knowledge about the neuroprotective role of Noggin in preclinical models of spinal cord injury.Lastly,we explain the gap in the knowledge for the use of Noggin in the treatment of spinal cord injury.The results from extensive in vitro and in vivo research have revealed that the therapeutic efficacy of Noggin treatment remains debatable due to its neuroprotective effects observed only in early phases of spinal cord injury but little to no effect on altering pathogenesis and functional recovery observed in the chronic phase of spinal cord injury.Furthermore,clinical information regarding the role of Noggin in the alleviation of progression of pathogenesis,its therapeutic efficacy,bioavailability,and safety in human spinal cord injury is still lacking and therefore needs further investigation.
基金a Ph D fellowship by FCT-Fundacao para a Ciência Tecnologia (SFRH/BD/135868/2018)(to SSC)。
文摘Axonal growth inhibitors are released during traumatic injuries to the adult mammalian central nervous system, including after spinal cord injury. These molecules accumulate at the injury site and form a highly inhibitory environment for axonal regeneration. Among these inhibitory molecules, myelinassociated inhibitors, including neurite outgrowth inhibitor A, oligodendrocyte myelin glycoprotein, myelin-associated glycoprotein, chondroitin sulfate proteoglycans and repulsive guidance molecule A are of particular importance. Due to their inhibitory nature, they represent exciting molecular targets to study axonal inhibition and regeneration after central injuries. These molecules are mainly produced by neurons, oligodendrocytes, and astrocytes within the scar and in its immediate vicinity. They exert their effects by binding to specific receptors, localized in the membranes of neurons. Receptors for these inhibitory cues include Nogo receptor 1, leucine-rich repeat, and Ig domain containing 1 and p75 neurotrophin receptor/tumor necrosis factor receptor superfamily member 19(that form a receptor complex that binds all myelin-associated inhibitors), and also paired immunoglobulin-like receptor B. Chondroitin sulfate proteoglycans and repulsive guidance molecule A bind to Nogo receptor 1, Nogo receptor 3, receptor protein tyrosine phosphatase σ and leucocyte common antigen related phosphatase, and neogenin, respectively. Once activated, these receptors initiate downstream signaling pathways, the most common amongst them being the Rho A/ROCK signaling pathway. These signaling cascades result in actin depolymerization, neurite outgrowth inhibition, and failure to regenerate after spinal cord injury. Currently, there are no approved pharmacological treatments to overcome spinal cord injuries other than physical rehabilitation and management of the array of symptoms brought on by spinal cord injuries. However, several novel therapies aiming to modulate these inhibitory proteins and/or their receptors are under investigation in ongoing clinical trials. Investigation has also been demonstrating that combinatorial therapies of growth inhibitors with other therapies, such as growth factors or stem-cell therapies, produce stronger results and their potential application in the clinics opens new venues in spinal cord injury treatment.
基金supported by Brazilian funding agencies CNPq,CAPES and FAPERGS
文摘Emerging evidence has suggested global histone H4 acetylation status plays an important role in neural plasticity. For instance, the imbalance of this epigenetic marker has been hypothesized as a key factor for the development and progression of several neurological diseases. Likewise, astrocytic reactivity-a wellknown process that markedly influences the tissue remodeling after a central nervous system injury-is crucial for tissue remodeling after spinal cord injury（SCI）. However, the linkage between the above-mentioned mechanisms after SCI remains poorly understood. We sought to investigate the relation between both glial fibrillary acidic protein（GFAP） and S100 calcium-binding protein B（S100B）（astrocytic reactivity classical markers） and global histone H4 acetylation levels. Sixty-one male Wistar rats（aged ~3 months） were divided into the following groups： sham; 6 hours post-SCI; 24 hours post-SCI; 48 hours post-SCI; 72 hours post-SCI; and 7 days post-SCI. The results suggested that GFAP, but not S100B was associated with global histone H4 acetylation levels. Moreover, global histone H4 acetylation levels exhibited a complex pattern after SCI, encompassing at least three clearly defined phases（first phase： no changes in the 6, 24 and 48 hours post-SCI groups; second phase： increased levels in the 72 hours post-SCI group; and a third phase： return to levels similar to control in the 7 days post-SCI group）. Overall, these findings suggest global H4 acetylation levels exhibit distinct patterns of expression during the first week post-SCI, which may be associated with GFAP levels in the perilesional tissue. Current data encourage studies using H4 acetylation as a possible biomarker for tissue remodeling after spinal cord injury.
文摘目的探讨血清髓鞘碱性蛋白含量对脊髓损伤程度早期诊断的价值。方法54只家兔随机分为轻、中、重度脊髓损伤组,每组动物通过大脑皮层体感诱发电位、损伤脊髓病理组织学和损伤后动物改良Tarlov评分评定损伤程度;应用酶联免疫吸附试验检测损伤前后血清髓鞘碱性蛋白含量。结果3组实验动物血清髓鞘碱性蛋白含量损伤后均升高,在损伤后24 h、48 h和72 h时3组间有显著性差异( P <0.05),而第7天时已无显著性差异( P >0.05)。结论血清髓鞘碱性蛋白含量可作为脊髓损伤程度早期判断指标之一,但有一定的时限性。
