目的探讨癫痫失语疾病谱（epilepsy—aphasia spectrum，EAS）患JLGRIN2A基因的突变率及临床遗传学特点。方法以Landau—Kleffner综合征（Landau-Kleffner syndrome，LKs）、癫痫伴慢波睡眠期持续棘慢波（epilepsy with continuous spik...目的探讨癫痫失语疾病谱（epilepsy—aphasia spectrum，EAS）患JLGRIN2A基因的突变率及临床遗传学特点。方法以Landau—Kleffner综合征（Landau-Kleffner syndrome，LKs）、癫痫伴慢波睡眠期持续棘慢波（epilepsy with continuous spikes and waves during slow sleep，CSWS）、儿童良性癫痫伴中央颞区棘波（benign childhood epilepsy with centrotemporal spikes，BECT）及BECT变异型患儿为研究对象，采用Sanger测序法筛查GRIN2A基因的突变，并分析EAS患儿的临床遗传学特点。结果共收集到122例EAS患儿，包括9例LKS、26例CSWS、42例BECT变异型及45例BECT。该组患儿癫痫发作或失语的平均起病年龄为5岁（10个月至11岁）。GRIN2A突变筛查在4例无血缘关系的患儿中分别发现了1个可能致病的错义突变，包括c．2278G〉A（p．G760S）、C．4153G〉T（P．D1385Y）、C．1364G〉A（p．C455Y）和C．691T〉C（p．C231R），其中1例为LKS，其余3例为BECT变异型。GRIN2A在LKS和BECT变异型中的突变率分别为11．1％（1／9）和7．2％（3／42），而在26例CSWS及45例BECT患儿则均未发现突变。在122例患儿中，25例（20．5％）有热性惊厥或癫痫阳性家族史，但均未携带GRIN2A突变。结论EAS患儿可携带GRIN2A基因突变，但突变率相对较低。GRIN2A突变阴性的患儿中家族史为阳性者占一定的比例，提示EAS可能具有复杂的遗传学机制。展开更多
N-methyl-D-aspartate receptors（NMDARs）, a subtype of glutamate-gated ion channels, play a central role in epileptogenesis. Recent studies have identified an increasing number of GRIN2 A（a gene encoding the NMDAR Gl...N-methyl-D-aspartate receptors（NMDARs）, a subtype of glutamate-gated ion channels, play a central role in epileptogenesis. Recent studies have identified an increasing number of GRIN2 A（a gene encoding the NMDAR GluN2A subunit） mutations in patients with epilepsy. Phenotypes of GRIN2 A mutations include epilepsy-aphasia disorders and other epileptic encephalopathies, which pose challenges in clinical treatment. Here we identified a heterozygous GRIN2 A mutation（c.1341 T[A, p.N447 K） from a boy with Rolandic epilepsy by whole-exome sequencing. The patient became seizurefree with a combination of valproate and lamotrigine.Functional investigation was carried out using recombinant NMDARs containing a GluN2A-N447 K mutant that is located in the ligand-binding domain of the GluN2A subunit. Whole-cell current recordings in HEK 293 T cells revealed that the N447 K mutation increased the NMDAR current density by;.2-fold, enhanced the glutamate potency by 2-fold, and reduced the sensitivity to Mg;inhibition. These results indicated that N447 K is a gain-offunction mutation. Interestingly, alternative substitutions by alanine and glutamic acid at the same residue（N447 A and N447 E） did not change NMDAR function, suggesting a residual dependence of this mutation in altering NMDAR function. Taken together, this study identified human GluN2A N447 K as a novel mutation associated with epilepsy and validated its functional consequences in vitro.Identification of this mutation is also helpful for advancing our understanding of the role of NMDARs in epilepsy and provides new insights for precision therapeutics in epilepsy.展开更多
Expression of miR-137 is downregulated in brain tissue from patients with depression and suicidal behavior, and is also downregulated in peripheral blood from stroke patients. However, it is not yet known if miR-137 a...Expression of miR-137 is downregulated in brain tissue from patients with depression and suicidal behavior, and is also downregulated in peripheral blood from stroke patients. However, it is not yet known if miR-137 acts as a bridge between stroke and depression. To test this, we used middle cerebral artery occlusion and chronic mild stress to establish a post-stroke depression model in rats. Compared with controls, we found significantly lower miR-137 levels in the brain and peripheral blood from post-stroke depression rats. Injection of a miR-137 antagonist into the brain ventricles upregulated miR-137 levels, and improved behavioral changes in post-stroke depression rats. Luciferase assays showed miR-137 bound to the 3＇UTR of Grin2A, regulating Grin2A expression in a neuronal cell line. Grin2A gene overexpression in the brain of post-stroke depression rats, no- ticeably suppressed the inhibitory effect of miR-137 on post-stroke depression. Overall, our results show that miR-137 suppresses Grin2A protein expression through binding to Grin2A mRNA, thereby exerting an inhibitory effect on post-stroke depression. Our results offer a new therapeutic direction for post-stroke depression.展开更多
Objective The present study aimed to test whether exposure to benzo（a）pyrene [B（a）P] affects spatial learning and short-term memory by modulating the expression of the Gria1 and Grin2a glutamate receptor subunit g...Objective The present study aimed to test whether exposure to benzo（a）pyrene [B（a）P] affects spatial learning and short-term memory by modulating the expression of the Gria1 and Grin2a glutamate receptor subunit genes in the hippocampus.Methods Thirty-six 21-24-day-old,male rats were randomly assigned into high-,medium-,and low-dose toxin exposure groups （6.25,2.5,and 1 mg/kg,respectively） and a control group,each containing nine rats.The behavioral performance of adult rats exposed to sub-chronic administration of B（a）P was monitored by learning and memory tests （Morris water maze）.Real-time PCR assays were used to quantify Gria1 and Grin2a gene expression in the hippocampus.Results At medium and high doses,B（a）P impaired spatial learning performance.The crossing-platform-location frequency and the time spent swimming in the platform area,which both relate to short-term memory,were significantly decreased in B（a）P-treated rats compared with controls.The level of Gria1 mRNA increased 2.6-5.9-fold,and the level of Grin2a mRNA increased 10-14.5-fold,with a greater fold increase associated with higher doses of B（a）P.Conclusion We demonstrated that sub-chronic administration of B（a）P inhibits spatial learning and short-term memory,and increases Gria1 and Grin2a expression in the hippocampus.This suggests a relationship of B（a）P exposure levels with Gria1 and Grin2a expression and impairment of short-term and spatial memory.展开更多
The frequency of an extremely low frequency electromagnetic field (ELF-EMF) ranges from 3 to 3, 000 Hz. Workers who are exposed to ELF-EMF include electric power installers and repairers, power plant operators, electr...The frequency of an extremely low frequency electromagnetic field (ELF-EMF) ranges from 3 to 3, 000 Hz. Workers who are exposed to ELF-EMF include electric power installers and repairers, power plant operators, electricians, electrical fitters, other such professionals. The main work categories in an electrical company or for utility work can be defined according to the five main stages of electricity production and distribution. Studies on the central nervous system (CNS) reported depressed activity in the different neurotransmitter systems and decreased protein content in the brains of animals exposed to ELF-EMF. Some studies reported differences with respect to change in brain function after electromagnetic radiation among individuals[1].展开更多
Objective: To determine the mechanisms by which protein deficiency during pregnancy can lead to long-term alterations in learning and memory abilities of the offspring in rats. Study design: Fourty-two pregnant rats w...Objective: To determine the mechanisms by which protein deficiency during pregnancy can lead to long-term alterations in learning and memory abilities of the offspring in rats. Study design: Fourty-two pregnant rats were fed control (n = 23) or low protein (n = 19) diets ad libitum until parturition. On the 8th week of post-natal life which represented early adulthood, eighty-four offsprings (control group: n = 52, LP group: n = 32) were determined their learning & memory ability by using the Morris water maze test. Six offprings’ brain tissue (control group: n = 3, LP group: n = 3) was also analysed for DNA methylating profiles, the GO and KEGG pathways, methylation status and twelve for protein expression (control group: n = 6, LP group: n = 6). Results: The offsprings of the protein-deficient-diet fed rats learnt faster initially then lagged behind those of the control rats, especially in female rats (p = 0.035). There were a series of genes methylated in the CpG island and pormoter area. Quantitative Mass Array data showed methylation differences in Grin2b and Grin2b_3CpG 3, 4, & 5 might be the target sites as shown by dual-luciferase assay. A decreased level of protein expression of NMDAR2B was observed. Conclusion: Differential methylation status in Grin2b and changes in expression of NMDAR2B may partially explain the long-term impact of maternal protein deficiency on the cognitive and learning capabilities of offsprings.展开更多
Spinal cord injury(SCI)is one of the most devastating traumas,and the aberrant proliferation of astrocytes usually causes neurological deficits.However,the mechanism underlying astrocyte over-proliferation after SCI i...Spinal cord injury(SCI)is one of the most devastating traumas,and the aberrant proliferation of astrocytes usually causes neurological deficits.However,the mechanism underlying astrocyte over-proliferation after SCI is unclear.Grin2c(glutamate ionotropic receptor type 2c)plays an essential role in cell proliferation.Our bioinformatic analysis indicated that Grin2c and Ca^(2+)transport functions were inhibited in astrocytes after SCI.Suppression of Grin2c stimulated astrocyte proliferation by inhibiting the Ca^(2+)/calmodulin-dependent protein kinase 2b(CaMK2b)pathway in vitro.By screening different inflammatory factors,interleukin 1α(IL1α)was further found to inhibit Grin2c/Ca^(2+)/CaMK2b and enhance astrocyte proliferation in an oxidative damage model.Blockade of IL1αusing neutralizing antibody resulted in increased Grin2c expression and the inhibition of astrocyte proliferation post-SCI.Overall,this study suggests that IL1αpromotes astrocyte proliferation by suppressing the Grin2c/Ca^(2+)/CaMK2b pathway after SCI,revealing a novel pathological mechanism of astrocyte proliferation,and may provide potential targets for SCI repair.展开更多
文摘目的探讨癫痫失语疾病谱（epilepsy—aphasia spectrum，EAS）患JLGRIN2A基因的突变率及临床遗传学特点。方法以Landau—Kleffner综合征（Landau-Kleffner syndrome，LKs）、癫痫伴慢波睡眠期持续棘慢波（epilepsy with continuous spikes and waves during slow sleep，CSWS）、儿童良性癫痫伴中央颞区棘波（benign childhood epilepsy with centrotemporal spikes，BECT）及BECT变异型患儿为研究对象，采用Sanger测序法筛查GRIN2A基因的突变，并分析EAS患儿的临床遗传学特点。结果共收集到122例EAS患儿，包括9例LKS、26例CSWS、42例BECT变异型及45例BECT。该组患儿癫痫发作或失语的平均起病年龄为5岁（10个月至11岁）。GRIN2A突变筛查在4例无血缘关系的患儿中分别发现了1个可能致病的错义突变，包括c．2278G〉A（p．G760S）、C．4153G〉T（P．D1385Y）、C．1364G〉A（p．C455Y）和C．691T〉C（p．C231R），其中1例为LKS，其余3例为BECT变异型。GRIN2A在LKS和BECT变异型中的突变率分别为11．1％（1／9）和7．2％（3／42），而在26例CSWS及45例BECT患儿则均未发现突变。在122例患儿中，25例（20．5％）有热性惊厥或癫痫阳性家族史，但均未携带GRIN2A突变。结论EAS患儿可携带GRIN2A基因突变，但突变率相对较低。GRIN2A突变阴性的患儿中家族史为阳性者占一定的比例，提示EAS可能具有复杂的遗传学机制。
基金supported by the grants of the National Natural Science Foundation of China(81671162,81521062,81561168,and 81571273)the National Basic Research Development Program of China(2014CB910300 and 2013CB530904)Key Research Project of the Ministry of Science and Technology of China(2016YFC0904400)
文摘N-methyl-D-aspartate receptors（NMDARs）, a subtype of glutamate-gated ion channels, play a central role in epileptogenesis. Recent studies have identified an increasing number of GRIN2 A（a gene encoding the NMDAR GluN2A subunit） mutations in patients with epilepsy. Phenotypes of GRIN2 A mutations include epilepsy-aphasia disorders and other epileptic encephalopathies, which pose challenges in clinical treatment. Here we identified a heterozygous GRIN2 A mutation（c.1341 T[A, p.N447 K） from a boy with Rolandic epilepsy by whole-exome sequencing. The patient became seizurefree with a combination of valproate and lamotrigine.Functional investigation was carried out using recombinant NMDARs containing a GluN2A-N447 K mutant that is located in the ligand-binding domain of the GluN2A subunit. Whole-cell current recordings in HEK 293 T cells revealed that the N447 K mutation increased the NMDAR current density by;.2-fold, enhanced the glutamate potency by 2-fold, and reduced the sensitivity to Mg;inhibition. These results indicated that N447 K is a gain-offunction mutation. Interestingly, alternative substitutions by alanine and glutamic acid at the same residue（N447 A and N447 E） did not change NMDAR function, suggesting a residual dependence of this mutation in altering NMDAR function. Taken together, this study identified human GluN2A N447 K as a novel mutation associated with epilepsy and validated its functional consequences in vitro.Identification of this mutation is also helpful for advancing our understanding of the role of NMDARs in epilepsy and provides new insights for precision therapeutics in epilepsy.
文摘Expression of miR-137 is downregulated in brain tissue from patients with depression and suicidal behavior, and is also downregulated in peripheral blood from stroke patients. However, it is not yet known if miR-137 acts as a bridge between stroke and depression. To test this, we used middle cerebral artery occlusion and chronic mild stress to establish a post-stroke depression model in rats. Compared with controls, we found significantly lower miR-137 levels in the brain and peripheral blood from post-stroke depression rats. Injection of a miR-137 antagonist into the brain ventricles upregulated miR-137 levels, and improved behavioral changes in post-stroke depression rats. Luciferase assays showed miR-137 bound to the 3＇UTR of Grin2A, regulating Grin2A expression in a neuronal cell line. Grin2A gene overexpression in the brain of post-stroke depression rats, no- ticeably suppressed the inhibitory effect of miR-137 on post-stroke depression. Overall, our results show that miR-137 suppresses Grin2A protein expression through binding to Grin2A mRNA, thereby exerting an inhibitory effect on post-stroke depression. Our results offer a new therapeutic direction for post-stroke depression.
基金support by the National Science Foundation of China (NO.30671744)
文摘Objective The present study aimed to test whether exposure to benzo（a）pyrene [B（a）P] affects spatial learning and short-term memory by modulating the expression of the Gria1 and Grin2a glutamate receptor subunit genes in the hippocampus.Methods Thirty-six 21-24-day-old,male rats were randomly assigned into high-,medium-,and low-dose toxin exposure groups （6.25,2.5,and 1 mg/kg,respectively） and a control group,each containing nine rats.The behavioral performance of adult rats exposed to sub-chronic administration of B（a）P was monitored by learning and memory tests （Morris water maze）.Real-time PCR assays were used to quantify Gria1 and Grin2a gene expression in the hippocampus.Results At medium and high doses,B（a）P impaired spatial learning performance.The crossing-platform-location frequency and the time spent swimming in the platform area,which both relate to short-term memory,were significantly decreased in B（a）P-treated rats compared with controls.The level of Gria1 mRNA increased 2.6-5.9-fold,and the level of Grin2a mRNA increased 10-14.5-fold,with a greater fold increase associated with higher doses of B（a）P.Conclusion We demonstrated that sub-chronic administration of B（a）P inhibits spatial learning and short-term memory,and increases Gria1 and Grin2a expression in the hippocampus.This suggests a relationship of B（a）P exposure levels with Gria1 and Grin2a expression and impairment of short-term and spatial memory.
基金supported by the National Basic Research Program of China [2011CB503706]the National Natural Science Foundation of China [61571455]Innovation Foundation of Beijing Institute of Radiation Medicine [2015CXJJ004]
文摘The frequency of an extremely low frequency electromagnetic field (ELF-EMF) ranges from 3 to 3, 000 Hz. Workers who are exposed to ELF-EMF include electric power installers and repairers, power plant operators, electricians, electrical fitters, other such professionals. The main work categories in an electrical company or for utility work can be defined according to the five main stages of electricity production and distribution. Studies on the central nervous system (CNS) reported depressed activity in the different neurotransmitter systems and decreased protein content in the brains of animals exposed to ELF-EMF. Some studies reported differences with respect to change in brain function after electromagnetic radiation among individuals[1].
文摘Objective: To determine the mechanisms by which protein deficiency during pregnancy can lead to long-term alterations in learning and memory abilities of the offspring in rats. Study design: Fourty-two pregnant rats were fed control (n = 23) or low protein (n = 19) diets ad libitum until parturition. On the 8th week of post-natal life which represented early adulthood, eighty-four offsprings (control group: n = 52, LP group: n = 32) were determined their learning & memory ability by using the Morris water maze test. Six offprings’ brain tissue (control group: n = 3, LP group: n = 3) was also analysed for DNA methylating profiles, the GO and KEGG pathways, methylation status and twelve for protein expression (control group: n = 6, LP group: n = 6). Results: The offsprings of the protein-deficient-diet fed rats learnt faster initially then lagged behind those of the control rats, especially in female rats (p = 0.035). There were a series of genes methylated in the CpG island and pormoter area. Quantitative Mass Array data showed methylation differences in Grin2b and Grin2b_3CpG 3, 4, & 5 might be the target sites as shown by dual-luciferase assay. A decreased level of protein expression of NMDAR2B was observed. Conclusion: Differential methylation status in Grin2b and changes in expression of NMDAR2B may partially explain the long-term impact of maternal protein deficiency on the cognitive and learning capabilities of offsprings.
基金supported by the National Natural Science Foundation of China(82071362,82002899)the Basic Research Project of Shenzhen Science and Technology Innovation Commission(JCYJ202205303001577,JCYJ20190809165201646)Basic Research Projects of Shenzhen Science and Technology Program(JCYJ20180307150610733).
文摘Spinal cord injury(SCI)is one of the most devastating traumas,and the aberrant proliferation of astrocytes usually causes neurological deficits.However,the mechanism underlying astrocyte over-proliferation after SCI is unclear.Grin2c(glutamate ionotropic receptor type 2c)plays an essential role in cell proliferation.Our bioinformatic analysis indicated that Grin2c and Ca^(2+)transport functions were inhibited in astrocytes after SCI.Suppression of Grin2c stimulated astrocyte proliferation by inhibiting the Ca^(2+)/calmodulin-dependent protein kinase 2b(CaMK2b)pathway in vitro.By screening different inflammatory factors,interleukin 1α(IL1α)was further found to inhibit Grin2c/Ca^(2+)/CaMK2b and enhance astrocyte proliferation in an oxidative damage model.Blockade of IL1αusing neutralizing antibody resulted in increased Grin2c expression and the inhibition of astrocyte proliferation post-SCI.Overall,this study suggests that IL1αpromotes astrocyte proliferation by suppressing the Grin2c/Ca^(2+)/CaMK2b pathway after SCI,revealing a novel pathological mechanism of astrocyte proliferation,and may provide potential targets for SCI repair.
