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Misprogramming of glucose metabolism impairs recovery of hippocampal slices from neuronal GLT-1 knockout mice and contributes to excitotoxic injury through mitochondrial superoxide production. 葡萄糖代谢的错误编程会损害神经元GLT-1基因敲除小鼠海马切片的恢复,并通过线粒体超氧化物的产生导致兴奋性毒性损伤。
IF 4.2 3区 医学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY Pub Date : 2024-08-28 DOI: 10.1111/jnc.16205
S Li, J Wang, J V Andersen, B I Aldana, B Zhang, E V Prochownik, P A Rosenberg

We have previously reported a failure of recovery of synaptic function in the CA1 region of acute hippocampal slices from mice with a conditional neuronal knockout (KO) of GLT-1 (EAAT2, Slc1A2) driven by synapsin-Cre (synGLT-1 KO). The failure of recovery of synaptic function is due to excitotoxic injury. We hypothesized that changes in mitochondrial metabolism contribute to the heightened vulnerability to excitotoxicity in the synGLT-1 KO mice. We found impaired flux of carbon from 13C-glucose into the tricarboxylic acid cycle in synGLT-1 KO cortical and hippocampal slices compared with wild-type (WT) slices. In addition, we found downregulation of the neuronal glucose transporter GLUT3 in both genotypes. Flux of carbon from [1,2-13C]acetate, thought to be astrocyte-specific, was increased in the synGLT-KO hippocampal slices but not cortical slices. Glycogen stores, predominantly localized to astrocytes, are rapidly depleted in slices after cutting, and are replenished during ex vivo incubation. In the synGLT-1 KO, replenishment of glycogen stores during ex vivo incubation was compromised. These results suggest both neuronal and astrocytic metabolic perturbations in the synGLT-1 KO slices. Supplementing incubation medium during recovery with 20 mM D-glucose normalized glycogen replenishment but had no effect on recovery of synaptic function. In contrast, 20 mM non-metabolizable L-glucose substantially improved recovery of synaptic function, suggesting that D-glucose metabolism contributes to the excitotoxic injury in the synGLT-1 KO slices. L-lactate substitution for D-glucose did not promote recovery of synaptic function, implicating mitochondrial metabolism. Consistent with this hypothesis, phosphorylation of pyruvate dehydrogenase, which decreases enzyme activity, was increased in WT slices during the recovery period, but not in synGLT-1 KO slices. Since metabolism of glucose by the mitochondrial electron transport chain is associated with superoxide production, we tested the effect of drugs that scavenge and prevent superoxide production. The superoxide dismutase/catalase mimic EUK-134 conferred complete protection and full recovery of synaptic function. A site-specific inhibitor of complex III superoxide production, S3QEL-2, was also protective, but inhibitors of NADPH oxidase were not. In summary, we find that the failure of recovery of synaptic function in hippocampal slices from the synGLT-1 KO mouse, previously shown to be due to excitotoxic injury, is caused by production of superoxide by mitochondrial metabolism.

我们以前曾报道过,在突触素-Cre(synapsin-Cre,synGLT-1 KO)驱动的条件性神经元敲除(KO)GLT-1(EAAT2,Slc1A2)的小鼠急性海马切片的CA1区,突触功能未能恢复。突触功能无法恢复的原因是兴奋毒性损伤。我们推测,线粒体代谢的变化是导致 synGLT-1 KO 小鼠更易受兴奋毒性伤害的原因。与野生型(WT)切片相比,我们发现在 synGLT-1 KO 小鼠的皮质和海马切片中,13C-葡萄糖进入三羧酸循环的碳通量受损。此外,我们还发现两种基因型的神经元葡萄糖转运体 GLUT3 均出现下调。在 synGLT-KO 海马切片中,被认为是星形胶质细胞特异性的 [1,2-13C] 乙酸的碳通量增加了,但在大脑皮层切片中却没有增加。糖原储存主要定位于星形胶质细胞,切片后会迅速耗尽,并在体外培养过程中得到补充。在 synGLT-1 KO 中,体内外培养期间糖原储存的补充受到影响。这些结果表明,在 synGLT-1 KO 切片中,神经元和星形胶质细胞的代谢都受到了干扰。在恢复期间用 20 mM D-葡萄糖补充培养基可使糖原补充正常化,但对突触功能的恢复没有影响。与此相反,20 mM 不可代谢的 L-葡萄糖大大改善了突触功能的恢复,这表明 D-葡萄糖代谢是 synGLT-1 KO 切片兴奋毒性损伤的原因之一。用 L-乳酸替代 D-葡萄糖并不能促进突触功能的恢复,这与线粒体代谢有关。与这一假设相一致的是,丙酮酸脱氢酶的磷酸化会降低酶的活性,而在恢复期间,WT 切片的丙酮酸脱氢酶的磷酸化会增加,但在 synGLT-1 KO 切片中则不会。由于线粒体电子传递链的葡萄糖代谢与超氧化物的产生有关,我们测试了清除和防止超氧化物产生的药物的效果。超氧化物歧化酶/催化酶模拟物 EUK-134 能提供完全保护并完全恢复突触功能。复合体 III 超氧化物产生的位点特异性抑制剂 S3QEL-2 也具有保护作用,但 NADPH 氧化酶抑制剂则没有保护作用。总之,我们发现,之前被证明是兴奋毒性损伤导致的 synGLT-1 KO 小鼠海马切片突触功能恢复失败,是由线粒体代谢产生的超氧化物引起的。
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引用次数: 0
A tribute to Arne Schousboe's contributions to neurochemistry and his innovative and enduring research in GABA, glutamate, and brain energy metabolism. 向 Arne Schousboe 对神经化学的贡献以及他在 GABA、谷氨酸和脑能量代谢方面的创新和持久研究致敬。
IF 4.2 3区 医学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY Pub Date : 2024-08-26 DOI: 10.1111/jnc.16207
Mary C McKenna, Ursula Sonnewald, Helle S Waageptersen, H Steve White

This is a tribute to Arne Schousboe, Professor Emeritus at the University of Copenhagen, an eminent neurochemist and neuroscientist who was a leader in the fields of GABA, glutamate, and brain energy metabolism. Arne was known for his keen intellect, his wide-ranging expertise in neurochemistry and neuropharmacology of GABA and glutamate and brain energy metabolism. Arne was also known for his strong leadership, his warm and engaging personality and his enjoyment of fine wine and great food shared with friends, family, and colleagues. Sadly, Arne passed away on February 27, 2024, after a short illness. He is survived by his wife Inger Schousboe, his two children, and three wonderful grandchildren. His death is a tremendous loss to the neuroscience community. He will be greatly missed by his friends, family, and colleagues. Some of the highlights of Arne's career are described in this tribute.

这是对哥本哈根大学名誉教授、著名神经化学家和神经科学家阿尔纳-舒斯博(Arne Schousboe)的悼念,他是 GABA、谷氨酸和脑能量代谢领域的领军人物。阿恩以其敏锐的智慧、在 GABA 和谷氨酸的神经化学和神经药理学以及脑能量代谢方面的广泛专业知识而闻名。阿恩还以其强大的领导力、热情和富有感染力的个性以及喜欢与朋友、家人和同事分享美酒佳肴而闻名。不幸的是,阿恩于 2024 年 2 月 27 日因病去世。他的妻子英格-舒斯博(Inger Schousboe)、两个孩子和三个可爱的孙子孙女都健在。他的去世是神经科学界的巨大损失。他的朋友、家人和同事都会深深地怀念他。本悼文介绍了阿恩职业生涯中的一些亮点。
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引用次数: 0
Poly (I:C)-induced maternal immune activation generates impairment of reversal learning performance in offspring. 多聚(I:C)诱导的母体免疫激活会损害后代的逆转学习能力。
IF 4.2 3区 医学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY Pub Date : 2024-08-25 DOI: 10.1111/jnc.16212
Eva Munarriz-Cuezva, Jose Javier Meana

Maternal immune activation (MIA) induces a variety of behavioral and brain abnormalities in offspring of rodent models, compatible with neurodevelopmental disorders, such as schizophrenia or autism. However, it remains controversial whether MIA impairs reversal learning, a basic expression of cognitive flexibility that seems to be altered in schizophrenia. In the present study, MIA was induced by administration of a single dose of polyriboinosinic-polyribocytidylic acid (Poly (I:C) (5 mg/kg i.p.)) or saline to mouse pregnant dams in gestational day (GD) 9.5. Immune activation was monitored through changes in weight and temperature. The offspring were evaluated when they reached adulthood (8 weeks) using a touchscreen-based system to investigate the effects of Poly (I:C) on discrimination and reversal learning performance. After an initial pre-training, mice were trained to discriminate between two different stimuli, of which only one was rewarded (acquisition phase). When the correct response reached above 80% values for two consecutive days, the images were reversed (reversal phase) to assess the adaptation capacity to a changing environment. Maternal Poly (I:C) treatment did not interfere with the learning process but induced deficits in reversal learning compared to control saline animals. Thus, the accuracy in the reversal phase was lower, and Poly (I:C) animals required more sessions to complete it, suggesting impairments in cognitive flexibility. This study advances the knowledge of how MIA affects behavior, especially cognitive domains that are impaired in schizophrenia. The findings support the validity of the Poly (I:C)-based MIA model as a tool to develop pharmacological treatments targeting cognitive deficits associated with neurodevelopmental disorders.

母体免疫激活(MIA)会诱发啮齿类动物模型后代的各种行为和大脑异常,这与神经发育障碍(如精神分裂症或自闭症)是一致的。然而,MIA 是否会损害反向学习能力仍存在争议,反向学习能力是认知灵活性的基本表现形式,在精神分裂症中似乎会发生改变。在本研究中,通过给妊娠日(GD)为9.5的小鼠妊娠母体注射单剂量的多核苷酸-多核苷酸(Poly (I:C)(5 mg/kg i.p.))或生理盐水来诱导MIA。通过体重和体温的变化来监测免疫激活。后代成年后(8 周),使用触摸屏系统对其进行评估,以研究 Poly (I:C) 对辨别和逆转学习能力的影响。经过初步的预训练后,小鼠被训练辨别两种不同的刺激,其中只有一种刺激是有奖励的(习得阶段)。当小鼠连续两天的正确率达到 80% 以上时,就会将图像反转(反转阶段),以评估小鼠对不断变化的环境的适应能力。与盐水对照组相比,母体多聚物(I:C)处理不会干扰学习过程,但会导致逆转学习的缺陷。因此,逆转阶段的准确率较低,而且Poly (I:C)动物需要更多的训练才能完成,这表明它们的认知灵活性受到了影响。这项研究加深了人们对 MIA 如何影响行为的认识,尤其是精神分裂症患者认知领域的障碍。研究结果支持将基于Poly (I:C)的MIA模型作为开发针对神经发育障碍相关认知缺陷的药物治疗工具的有效性。
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引用次数: 0
Function of a complex of p-Y42 RhoA GTPase and pyruvate kinase M2 in EGF signaling pathway in glioma cells. 胶质瘤细胞中 p-Y42 RhoA GTPase 和丙酮酸激酶 M2 复合物在 EGF 信号通路中的功能。
IF 4.2 3区 医学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY Pub Date : 2024-08-25 DOI: 10.1111/jnc.16210
Yoon-Beom Lee, Yohan Park, Amir Hamza, Jung Ki Min, Oyungerel Dogsom, Sung-Chan Kim, Jae-Bong Park

Epidermal growth factor (EGF) is known to be a critical stimulant for inducing the proliferation of glioma cancer cells. In our study, we observed that GST-RhoA binds to pyruvate kinase M2 (PKM2) in vitro. While EGF reduced the levels of RhoA protein, it significantly increased p-Y42 RhoA, as well as PKM1 and PKM2 in LN18 glioma cell line. We determined that RhoA undergoes degradation through ubiquitination involving SCF1 and Smurf1. Interestingly, we observed that p-Y42 RhoA binds to PKM2, while the dephosphomimetic form, RhoA Y42F, did not. Additionally, our observation revealed that PKM2 stabilized both RhoA and p-Y42 RhoA. Importantly, RhoA, p-Y42 RhoA, and PKM2, but not RhoA-GTP, were localized in the nucleus upon EGF stimulation. Knockdown of RhoA with siRNA resulted in the reduced levels of phosphoglycerate kinase1 (PGK1) and microtubule affinity-regulating kinase 4 (MARK). Furthermore, we found that the promoter of PGK1 was associated with β-catenin and YAP. Notably, p-Y42 RhoA and PKM2 co-immunoprecipitated with β-catenin and YAP. Based on these findings, we proposed a novel mechanism by which p-Y42 RhoA and PKM2, in conjunction with β-catenin and YAP, regulate PGK1 expression, contributing to the progression of glioma upon EGF.

众所周知,表皮生长因子(EGF)是诱导胶质瘤癌细胞增殖的重要刺激物。在我们的研究中,我们观察到 GST-RhoA 在体外与丙酮酸激酶 M2(PKM2)结合。虽然 EGF 降低了 RhoA 蛋白的水平,但却显著增加了 LN18 脑胶质瘤细胞系中的 p-Y42 RhoA 以及 PKM1 和 PKM2。有趣的是,我们观察到 p-Y42 RhoA 能与 PKM2 结合,而去磷酸化形式的 RhoA Y42F 却不能。此外,我们的观察还发现,PKM2 能稳定 RhoA 和 p-Y42 RhoA。重要的是,在 EGF 刺激下,RhoA、p-Y42 RhoA 和 PKM2(而不是 RhoA-GTP)定位于细胞核中。用 siRNA 敲除 RhoA 会导致磷酸甘油酸激酶 1(PGK1)和微管亲和调节激酶 4(MARK)的水平降低。此外,我们还发现 PGK1 的启动子与 β-catenin 和 YAP 相关。值得注意的是,p-Y42 RhoA和PKM2与β-catenin和YAP共免疫沉淀。基于这些发现,我们提出了一种新的机制,即p-Y42 RhoA和PKM2与β-catenin和YAP共同调控PGK1的表达,从而在EGF作用下促进胶质瘤的进展。
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引用次数: 0
HSP110 is a modulator of amyloid beta (Aβ) aggregation and proteotoxicity. HSP110是淀粉样蛋白β(Aβ)聚集和蛋白毒性的调节剂。
IF 4.2 3区 医学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY Pub Date : 2024-08-23 DOI: 10.1111/jnc.16214
Sabrina Montresor, Maria Lucia Pigazzini, Sudarson Baskaran, Mira Sleiman, Govinda Adhikari, Lukas Basilicata, Luca Secker, Natascha Jacob, Yara Ehlert, Anushree Kelkar, Gurleen Kaur Kalsi, Niraj Kulkarni, Paul Spellerberg, Janine Kirstein

Chaperones safeguard protein homeostasis by promoting folding and preventing aggregation. HSP110 is a cytosolic chaperone that functions as a nucleotide exchange factor for the HSP70 cycle. Together with HSP70 and a J-domain protein (JDP), HSP110 maintains protein folding and resolubilizes aggregates. Interestingly, HSP110 is vital for the HSP70/110/JDP-mediated disaggregation of amyloidogenic proteins implicated in neurodegenerative diseases (i.e., α-synuclein, HTT, and tau). However, despite its abundance, HSP110 remains still an enigmatic chaperone, and its functional spectrum is not very well understood. Of note, the disaggregation activity of neurodegenerative disease-associated amyloid fibrils showed both beneficial and detrimental outcomes in vivo. To gain a more comprehensive understanding of the chaperone HSP110 in vivo, we analyzed its role in neuronal proteostasis and neurodegeneration in C. elegans. Specifically, we investigated the role of HSP110 in the regulation of amyloid beta peptide (Aβ) aggregation using an established Aβ-C. elegans model that mimics Alzheimer's disease pathology. We generated a novel C. elegans model that over-expresses hsp-110 pan-neuronally, and we also depleted hsp-110 by RNAi-mediated knockdown. We assessed Aβ aggregation in vivo and in situ by fluorescence lifetime imaging. We found that hsp-110 over-expression exacerbated Aβ aggregation and appeared to reduce the conformational variability of the Aβ aggregates, whereas hsp-110 depletion reduced aggregation more significantly in the IL2 neurons, which marked the onset of Aβ aggregation. HSP-110 also plays a central role in growth and fertility as its over-expression compromises nematode physiology. In addition, we found that HSP-110 modulation affects the autophagy pathway. While hsp-110 over-expression impairs the autophagic flux, a depletion enhances it. Thus, HSP-110 regulates multiple nodes of the proteostasis network to control amyloid protein aggregation, disaggregation, and autophagic clearance.

伴侣蛋白通过促进折叠和防止聚集来保护蛋白质的平衡。HSP110 是一种细胞膜伴侣蛋白,是 HSP70 循环的核苷酸交换因子。HSP110 与 HSP70 和一种 J-结构域蛋白(JDP)共同维持蛋白质折叠并分解聚集体。有趣的是,HSP110 对于 HSP70/110/JDP 介导的与神经退行性疾病有关的淀粉样蛋白(即 α-突触核蛋白、HTT 和 tau)的分解至关重要。然而,尽管 HSP110 数量巨大,但它仍然是一种神秘的伴侣蛋白,其功能谱系也不甚明了。值得注意的是,神经退行性疾病相关淀粉样蛋白纤维的分解活性在体内既显示出有益的结果,也显示出有害的结果。为了更全面地了解体内伴侣蛋白 HSP110,我们分析了它在秀丽隐杆线虫神经元蛋白稳态和神经退行性变中的作用。具体来说,我们利用已建立的模拟阿尔茨海默病病理的 Aβ - elegans 模型,研究了 HSP110 在调节淀粉样 beta 肽(Aβ)聚集中的作用。我们生成了一种在泛神经元中过度表达 hsp-110 的新型 elegans 模型,并通过 RNAi- 介导的基因敲除技术耗尽了 hsp-110。我们通过荧光寿命成像评估了体内和原位的Aβ聚集。我们发现,hsp-110 的过度表达会加剧 Aβ 的聚集,并似乎会降低 Aβ 聚集的构象变异性,而 hsp-110 的耗竭则会更显著地降低 IL2 神经元的聚集,这标志着 Aβ 聚集的开始。HSP-110 在生长和繁殖中也起着核心作用,因为它的过度表达会损害线虫的生理机能。此外,我们还发现 HSP-110 的调节会影响自噬途径。HSP-110过度表达会损害自噬通量,而HSP-110缺乏则会增强自噬通量。因此,HSP-110调节蛋白稳态网络的多个节点,控制淀粉样蛋白的聚集、分解和自噬清除。
{"title":"HSP110 is a modulator of amyloid beta (Aβ) aggregation and proteotoxicity.","authors":"Sabrina Montresor, Maria Lucia Pigazzini, Sudarson Baskaran, Mira Sleiman, Govinda Adhikari, Lukas Basilicata, Luca Secker, Natascha Jacob, Yara Ehlert, Anushree Kelkar, Gurleen Kaur Kalsi, Niraj Kulkarni, Paul Spellerberg, Janine Kirstein","doi":"10.1111/jnc.16214","DOIUrl":"https://doi.org/10.1111/jnc.16214","url":null,"abstract":"<p><p>Chaperones safeguard protein homeostasis by promoting folding and preventing aggregation. HSP110 is a cytosolic chaperone that functions as a nucleotide exchange factor for the HSP70 cycle. Together with HSP70 and a J-domain protein (JDP), HSP110 maintains protein folding and resolubilizes aggregates. Interestingly, HSP110 is vital for the HSP70/110/JDP-mediated disaggregation of amyloidogenic proteins implicated in neurodegenerative diseases (i.e., α-synuclein, HTT, and tau). However, despite its abundance, HSP110 remains still an enigmatic chaperone, and its functional spectrum is not very well understood. Of note, the disaggregation activity of neurodegenerative disease-associated amyloid fibrils showed both beneficial and detrimental outcomes in vivo. To gain a more comprehensive understanding of the chaperone HSP110 in vivo, we analyzed its role in neuronal proteostasis and neurodegeneration in C. elegans. Specifically, we investigated the role of HSP110 in the regulation of amyloid beta peptide (Aβ) aggregation using an established Aβ-C. elegans model that mimics Alzheimer's disease pathology. We generated a novel C. elegans model that over-expresses hsp-110 pan-neuronally, and we also depleted hsp-110 by RNAi-mediated knockdown. We assessed Aβ aggregation in vivo and in situ by fluorescence lifetime imaging. We found that hsp-110 over-expression exacerbated Aβ aggregation and appeared to reduce the conformational variability of the Aβ aggregates, whereas hsp-110 depletion reduced aggregation more significantly in the IL2 neurons, which marked the onset of Aβ aggregation. HSP-110 also plays a central role in growth and fertility as its over-expression compromises nematode physiology. In addition, we found that HSP-110 modulation affects the autophagy pathway. While hsp-110 over-expression impairs the autophagic flux, a depletion enhances it. Thus, HSP-110 regulates multiple nodes of the proteostasis network to control amyloid protein aggregation, disaggregation, and autophagic clearance.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142046826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Insulin and leptin acutely modulate the energy metabolism of primary hypothalamic and cortical astrocytes. 胰岛素和瘦素可急性调节原发性下丘脑和皮层星形胶质细胞的能量代谢。
IF 4.2 3区 医学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY Pub Date : 2024-08-22 DOI: 10.1111/jnc.16211
Christopher Wolff, Dorit John, Ulrike Winkler, Luise Hochmuth, Johannes Hirrlinger, Susanne Köhler

Astrocytes constitute a heterogeneous cell population within the brain, contributing crucially to brain homeostasis and playing an important role in overall brain function. Their function and metabolism are not only regulated by local signals, for example, from nearby neurons, but also by long-range signals such as hormones. Thus, two prominent hormones primarily known for regulating the energy balance of the whole organism, insulin, and leptin, have been reported to also impact astrocytes within the brain. In this study, we investigated the acute regulation of astrocytic metabolism by these hormones in cultured astrocytes prepared from the mouse cortex and hypothalamus, a pivotal region in the context of nutritional regulation. Utilizing genetically encoded, fluorescent nanosensors, the cytosolic concentrations of glucose, lactate, and ATP, along with glycolytic rate and the NADH/NAD+ redox state were measured. Under basal conditions, differences between the two populations of astrocytes were observed for glucose and lactate concentrations as well as the glycolytic rate. Additionally, astrocytic metabolism responded to insulin and leptin in both brain regions, with some unique characteristics for each cell population. Finally, both hormones influenced how cells responded to elevated extracellular levels of potassium ions, a common indicator of neuronal activity. In summary, our study provides evidence that insulin and leptin acutely regulate astrocytic metabolism within minutes. Additionally, while astrocytes from the hypothalamus and cortex share similarities in their metabolism, they also exhibit distinct properties, further underscoring the growing recognition of astrocyte heterogeneity.

星形胶质细胞是大脑中的一个异质性细胞群,对大脑的平衡起着至关重要的作用,并在大脑的整体功能中扮演着重要角色。星形胶质细胞的功能和新陈代谢不仅受附近神经元等局部信号的调节,还受激素等远距离信号的调节。因此,两种主要调节整个机体能量平衡的重要激素--胰岛素和瘦素,据报道也会影响脑内的星形胶质细胞。在这项研究中,我们研究了这些激素对小鼠大脑皮层和下丘脑(营养调节的关键区域)中培养的星形胶质细胞新陈代谢的急性调节。利用基因编码的荧光纳米传感器,测量了细胞膜中葡萄糖、乳酸和 ATP 的浓度,以及糖酵解率和 NADH/NAD+ 氧化还原状态。在基础条件下,观察到两组星形胶质细胞的葡萄糖和乳酸浓度以及糖酵解率存在差异。此外,两个脑区的星形胶质细胞代谢对胰岛素和瘦素都有反应,每个细胞群都有一些独特的特征。最后,这两种激素都会影响细胞对细胞外钾离子水平升高的反应,而钾离子是神经元活动的常见指标。总之,我们的研究提供了证据,证明胰岛素和瘦素可在几分钟内调节星形胶质细胞的新陈代谢。此外,虽然下丘脑和大脑皮层的星形胶质细胞在新陈代谢方面有相似之处,但它们也表现出不同的特性,这进一步强调了人们对星形胶质细胞异质性的日益认识。
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引用次数: 0
Unraveling the role of oligodendrocytes and myelin in pain. 揭示少突胶质细胞和髓鞘在疼痛中的作用。
IF 4.2 3区 医学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY Pub Date : 2024-08-20 DOI: 10.1111/jnc.16206
Woojin Kim, María Cecilia Angulo

Oligodendrocytes, the myelin-producing cells in the central nervous system (CNS), are crucial for rapid action potential conduction and neuronal communication. While extensively studied for their roles in neuronal support and axonal insulation, their involvement in pain modulation is an emerging research area. This review explores the interplay between oligodendrocytes, myelination, and pain, focusing on neuropathic pain following peripheral nerve injury, spinal cord injury (SCI), chemotherapy, and HIV infection. Studies indicate that a decrease in oligodendrocytes and increased cytokine production by oligodendroglia in response to injury can induce or exacerbate pain. An increase in endogenous oligodendrocyte precursor cells (OPCs) may be a compensatory response to repair damaged oligodendrocytes. Exogenous OPC transplantation shows promise in alleviating SCI-induced neuropathic pain and enhancing remyelination. Additionally, oligodendrocyte apoptosis in brain regions such as the medial prefrontal cortex is linked to opioid-induced hyperalgesia, highlighting their role in central pain mechanisms. Chemotherapeutic agents disrupt oligodendrocyte differentiation, leading to persistent pain, while HIV-associated neuropathy involves up-regulation of oligodendrocyte lineage cell markers. These findings underscore the multifaceted roles of oligodendrocytes in pain pathways, suggesting that targeting myelination processes could offer new therapeutic strategies for chronic pain management. Further research should elucidate the underlying molecular mechanisms to develop effective pain treatments.

少突胶质细胞是中枢神经系统(CNS)中产生髓鞘的细胞,对动作电位的快速传导和神经元的交流至关重要。人们对少突胶质细胞在神经元支持和轴突绝缘中的作用进行了广泛的研究,而它们在疼痛调节中的参与则是一个新兴的研究领域。这篇综述探讨了少突胶质细胞、髓鞘化和疼痛之间的相互作用,重点是周围神经损伤、脊髓损伤(SCI)、化疗和艾滋病病毒感染后的神经性疼痛。研究表明,少突胶质细胞因损伤而减少,细胞因子分泌增加,可诱发或加剧疼痛。内源性少突胶质前体细胞(OPC)的增加可能是修复受损少突胶质细胞的一种代偿反应。外源性少突胶质细胞前体细胞移植有望减轻 SCI 引起的神经性疼痛并促进髓鞘再形成。此外,内侧前额叶皮层等脑区的少突胶质细胞凋亡与阿片类药物诱发的痛觉减退有关,这突显了它们在中枢疼痛机制中的作用。化疗药物会破坏少突胶质细胞的分化,从而导致持续性疼痛,而艾滋病毒相关神经病则涉及少突胶质细胞系细胞标记的上调。这些发现强调了少突胶质细胞在疼痛通路中的多方面作用,表明针对髓鞘化过程可为慢性疼痛治疗提供新的治疗策略。进一步的研究应阐明潜在的分子机制,以开发有效的疼痛治疗方法。
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引用次数: 0
Transcription factor 7-like 2 (TCF7l2) regulates CNS myelination separating from its role in upstream oligodendrocyte differentiation. 转录因子 7-like 2(TCF7l2)调节中枢神经系统髓鞘化的作用与其在上游少突胶质细胞分化中的作用相分离。
IF 4.2 3区 医学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY Pub Date : 2024-08-20 DOI: 10.1111/jnc.16208
Sheng Zhang, Meina Zhu, Zhaohui Lan, Fuzheng Guo

Oligodendrocyte progenitor cells (OPCs) differentiation into oligodendrocytes (OLs) and subsequent myelination are two closely coordinated yet differentially regulated steps for myelin formation and repair in the CNS. Previously thought as an inhibitory factor by activating Wnt/beta-catenin signaling, we and others have demonstrated that the Transcription factor 7-like 2 (TCF7l2) promotes OL differentiation independent of Wnt/beta-catenin signaling activation. However, it remains elusive if TCF7l2 directly controls CNS myelination separating from its role in upstream oligodendrocyte differentiation. This is partially because of the lack of genetic animal models that could tease out CNS myelination from upstream OL differentiation. Here, we report that constitutively depleting TCF7l2 transiently inhibited oligodendrocyte differentiation during early postnatal development, but it impaired CNS myelination in the long term in adult mice. Using time-conditional and developmental-stage-specific genetic approaches, we further showed that depleting TCF7l2 in already differentiated OLs did not impact myelin protein gene expression nor oligodendroglial populations, instead, it perturbed CNS myelination in the adult. Therefore, our data convincingly demonstrate the crucial role of TCF7l2 in regulating CNS myelination independent of its role in upstream oligodendrocyte differentiation.

少突胶质祖细胞(OPCs)分化成少突胶质细胞(OLs)以及随后的髓鞘化是中枢神经系统中髓鞘形成和修复的两个密切配合但又受不同调控的步骤。我们和其他人已经证明,转录因子 7-like 2(TCF7l2)能促进少突胶质细胞的分化,而不依赖于 Wnt/beta-catenin 信号的激活。然而,除了在上游少突胶质细胞分化中的作用外,TCF7l2 是否能直接控制中枢神经系统的髓鞘化仍是一个未知数。部分原因是缺乏能将中枢神经系统髓鞘化与上游少突胶质细胞分化区分开来的遗传动物模型。在这里,我们报告了组成性消耗 TCF7l2 在小鼠出生后早期发育过程中短暂抑制少突胶质细胞分化,但在成年小鼠中却长期损害中枢神经系统的髓鞘化。通过使用时间条件和发育阶段特异性遗传方法,我们进一步发现,在已经分化的少突胶质细胞中消耗 TCF7l2 不会影响髓鞘蛋白基因的表达或少突胶质细胞的数量,相反,它会扰乱成年小鼠的中枢神经系统髓鞘化。因此,我们的数据令人信服地证明了 TCF7l2 在调节中枢神经系统髓鞘化过程中的关键作用,而非其在上游少突胶质细胞分化过程中的作用。
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引用次数: 0
Evaluation of mechanisms involved in regulation of intrinsic excitability by extracellular calcium in CA1 pyramidal neurons of rat. 评估大鼠 CA1 锥体神经元细胞外钙调节固有兴奋性的机制
IF 4.2 3区 医学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY Pub Date : 2024-08-20 DOI: 10.1111/jnc.16209
My Forsberg, Dinna Zhou, Shadi Jalali, Giorgia Faravelli, Henrik Seth, Andreas Björefeldt, Eric Hanse

It is well recognized that changes in the extracellular concentration of calcium ions influence the excitability of neurons, yet what mechanism(s) mediate these effects is still a matter of debate. Using patch-clamp recordings from rat hippocampal CA1 pyramidal neurons, we examined the contribution of G-proteins and intracellular calcium-dependent signaling mechanisms to changes in intrinsic excitability evoked by altering the extracellular calcium concentration from physiological (1.2 mM) to a commonly used experimental (2 mM) level. We find that the inhibitory effect on intrinsic excitability of calcium ions is mainly expressed as an increased threshold for action potential firing (with no significant effect on resting membrane potential) that is not blocked by either the G-protein inhibitor GDPβS or the calcium chelator BAPTA. Our results therefore argue that in the concentration range studied, G-protein coupled calcium-sensing receptors, non-selective cation conductances, and intracellular calcium signaling pathways are not involved in mediating the effect of extracellular calcium ions on intrinsic excitability. Analysis of the derivative of the action potential, dV/dt versus membrane potential, indicates a current shift towards more depolarized membrane potentials at the higher calcium concentration. Our results are thus consistent with a mechanism in which extracellular calcium ions act directly on the voltage-gated sodium channels by neutralizing negative charges on the extracellular surface of these channels to modulate the threshold for action potential activation.

众所周知,细胞外钙离子浓度的变化会影响神经元的兴奋性,但这些影响是由什么机制介导的仍是一个争论不休的问题。利用大鼠海马 CA1 锥体神经元的贴片钳记录,我们研究了 G 蛋白和细胞内钙离子依赖性信号机制对改变细胞外钙离子浓度(从生理水平(1.2 mM)到常用的实验水平(2 mM))所诱发的内在兴奋性变化的贡献。我们发现,钙离子对内在兴奋性的抑制作用主要表现为动作电位发射阈值的升高(对静息膜电位无明显影响),这种作用不会被 G 蛋白抑制剂 GDPβS 或钙螯合剂 BAPTA 所阻断。因此,我们的研究结果表明,在所研究的浓度范围内,G 蛋白偶联钙传感受体、非选择性阳离子传导和细胞内钙信号途径并未参与介导细胞外钙离子对内在兴奋性的影响。对动作电位的导数 dV/dt 与膜电位的分析表明,在钙离子浓度较高时,电流转向更多的去极化膜电位。因此,我们的结果与细胞外钙离子通过中和这些通道细胞外表面的负电荷直接作用于电压门控钠通道以调节动作电位激活阈值的机制是一致的。
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引用次数: 0
A biallelic mutation in CACNA2D2 associated with developmental and epileptic encephalopathy affects calcium channel-dependent as well as synaptic functions of α2δ-2. 与发育和癫痫性脑病相关的 CACNA2D2 双重突变会影响α2δ-2 的钙通道依赖性和突触功能。
IF 4.2 3区 医学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY Pub Date : 2024-08-19 DOI: 10.1111/jnc.16197
Sabrin Haddad, Cornelia Ablinger, Ruslan Stanika, Manuel Hessenberger, Marta Campiglio, Nadine J Ortner, Petronel Tuluc, Gerald J Obermair

α2δ proteins serve as auxiliary subunits of voltage-gated calcium channels and regulate channel membrane expression and current properties. Besides their channel function, α2δ proteins regulate synapse formation, differentiation, and synaptic wiring. Considering these important functions, it is not surprising that CACNA2D1-4, the genes encoding for α2δ-1 to -4 isoforms, have been implicated in neurological, neurodevelopmental, and neuropsychiatric disorders. Mutations in CACNA2D2 have been associated with developmental and epileptic encephalopathy (DEE) and cerebellar atrophy. In our present study, we performed a detailed functional characterization of the p.R593P mutation in α2δ-2, a homozygous mutation previously identified in two siblings with DEE. Importantly, we analyzed both calcium channel-dependent as well as synaptic functions of α2δ-2. Our data show that the corresponding p.R596P mutation in mouse α2δ-2 drastically decreases membrane expression and synaptic targeting of α2δ-2. This defect correlates with altered biophysical properties of postsynaptic CaV1.3 channel but has no effect on presynaptic CaV2.1 channels upon heterologous expression in tsA201 cells. However, homologous expression of α2δ-2_R596P in primary cultures of hippocampal neurons affects the ability of α2δ-2 to induce a statistically significant increase in the presynaptic abundance of endogenous CaV2.1 channels and presynaptic calcium transients. Moreover, our data demonstrate that in addition to lowering membrane expression, the p.R596P mutation reduces the trans-synaptic recruitment of GABAA receptors and presynaptic synapsin clustering in glutamatergic synapses. Lastly, the α2δ-2_R596P reduces the amplitudes of glutamatergic miniature postsynaptic currents in transduced hippocampal neurons. Taken together, our data strongly link the human biallelic p.R593P mutation to the underlying severe neurodevelopmental disorder and highlight the importance of studying α2δ mutations not only in the context of channelopathies but also synaptopathies.

α2δ蛋白是电压门控钙通道的辅助亚基,调节通道膜的表达和电流特性。除了通道功能外,α2δ 蛋白还能调节突触的形成、分化和突触接线。考虑到这些重要功能,CACNA2D1-4(α2δ-1 至 -4异构体的编码基因)与神经系统、神经发育和神经精神疾病有关就不足为奇了。CACNA2D2 基因突变与发育性癫痫性脑病(DEE)和小脑萎缩有关。在本研究中,我们对α2δ-2中的p.R593P突变进行了详细的功能表征,这一同源突变先前在两个患有DEE的兄弟姐妹中被发现。重要的是,我们分析了α2δ-2的钙通道依赖功能和突触功能。我们的数据显示,小鼠α2δ-2中相应的p.R596P突变大大降低了α2δ-2的膜表达和突触靶向性。这种缺陷与突触后 CaV1.3 通道生物物理特性的改变有关,但在 tsA201 细胞中异源表达时对突触前 CaV2.1 通道没有影响。然而,α2δ-2_R596P 在海马神经元原代培养物中的同源表达会影响 α2δ-2诱导内源性 CaV2.1 通道突触前丰度和突触前钙离子瞬态显著增加的能力。此外,我们的数据表明,除了降低膜表达外,p.R596P 突变还减少了谷氨酸能突触中 GABAA 受体的跨突触招募和突触前突触素聚集。最后,α2δ-2_R596P 会降低转导海马神经元中谷氨酸能微型突触后电流的振幅。总之,我们的数据将人类双倍p.R593P突变与潜在的严重神经发育障碍紧密地联系在一起,并强调了研究α2δ突变不仅在通道病变中而且在突触病变中的重要性。
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引用次数: 0
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Journal of Neurochemistry
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