Retraction: G. Marwarha, T. Rhen, T. Schommer, and O. Ghribi, "The Oxysterol 27-Hydroxycholesterol Regulates α-Synuclein and Tyrosine Hydroxylase Expression Levels in Human Neuroblastoma Cells Through Modulation of Liver X Receptors and Estrogen Receptors-Relevance to Parkinson's Disease," Journal of Neurochemistry 119, no. 5 (2011): 1119-1136, https://doi.org/10.1111/j.1471-4159.2011.07497.x. The above article, published online on 23 September 2011 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor-in-Chief, Andrew Lawrence; the International Society for Neurochemistry; and John Wiley & Sons Ltd. The retraction has been agreed upon following an investigation by the authors' institution, the University of North Dakota, which determined that Figure 2E was falsified by the corresponding author Othman Ghribi. Source data were not available for the article. The other authors were unaware of Ghribi's actions and not in any way involved. All authors were notified of the retraction decision, but did not respond.
撤回:G. Marwarha, T. Rhen, T. Schommer, and O. Ghribi, "The Oxysterol 27-Hydroxycholesterol Regulates α-Synuclein and Tyrosine Hydroxylase Expression Levels in Human Neuroblastoma Cells Through Modulation of Liver X Receptors and Estrogen Receptors-Relevance to Parkinson's Disease," Journal of Neurochemistry 119, no.5 (2011):1119-1136, https://doi.org/10.1111/j.1471-4159.2011.07497.x。上述文章于 2011 年 9 月 23 日在线发表于 Wiley Online Library (wileyonlinelibrary.com),经期刊主编 Andrew Lawrence、国际神经化学学会和 John Wiley & Sons Ltd.协商,该文章已被撤回。作者所在的北达科他大学经过调查,认定图 2E 是通讯作者 Othman Ghribi 捏造的,因此同意撤稿。这篇文章没有原始数据。其他作者不知道格里比的行为,也没有以任何方式参与其中。所有作者都收到了撤稿决定的通知,但没有做出回应。
{"title":"RETRACTION: The oxysterol 27-hydroxycholesterol regulates α-synuclein and tyrosine hydroxylase expression levels in human neuroblastoma cells through modulation of liver X receptors and estrogen receptors-relevance to Parkinson's disease.","authors":"","doi":"10.1111/jnc.16240","DOIUrl":"https://doi.org/10.1111/jnc.16240","url":null,"abstract":"<p><p>Retraction: G. Marwarha, T. Rhen, T. Schommer, and O. Ghribi, \"The Oxysterol 27-Hydroxycholesterol Regulates α-Synuclein and Tyrosine Hydroxylase Expression Levels in Human Neuroblastoma Cells Through Modulation of Liver X Receptors and Estrogen Receptors-Relevance to Parkinson's Disease,\" Journal of Neurochemistry 119, no. 5 (2011): 1119-1136, https://doi.org/10.1111/j.1471-4159.2011.07497.x. The above article, published online on 23 September 2011 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor-in-Chief, Andrew Lawrence; the International Society for Neurochemistry; and John Wiley & Sons Ltd. The retraction has been agreed upon following an investigation by the authors' institution, the University of North Dakota, which determined that Figure 2E was falsified by the corresponding author Othman Ghribi. Source data were not available for the article. The other authors were unaware of Ghribi's actions and not in any way involved. All authors were notified of the retraction decision, but did not respond.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142467935","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}
Christopher R Brown, Madhur Shetty, James D Foster
Postural orthostatic tachycardia syndrome (POTS) is an adrenergic signaling disorder characterized by excessive plasma norepinephrine, postural tachycardia, and syncope. The norepinephrine transporter (NET) modulates adrenergic homeostasis via the reuptake of extracellular catecholamines and is implicated in the pathogenesis of adrenergic and neurological disorders. In this study, we reveal NET is palmitoylated in male Sprague-Dawley rats and Lilly Laboratory Cell Porcine Kidney (LLC-PK1) cells. S-palmitoylation, or the addition of a 16-carbon saturated fatty acid, is a reversible post-translational modification responsible for the regulation of numerous biological mechanisms. We found that LLC-PK1 NET is dynamically palmitoylated, and that inhibition with the palmitoyl acyltransferase (DHHC) inhibitor, 2-bromopalmitate (2BP) results in decreased NET palmitoylation within 90 min of treatment. This result was followed closely by a reduction in transport capacity, cell surface, and total cellular NET expression after 120 min of treatment. Increasing 2BP concentrations and treatment time revealed a nearly complete loss of total NET protein. Co-expression with individual DHHCs revealed a single DHHC enzyme, DHHC1, promoted wild-type (WT) hNET palmitoylation and elevated NET protein levels. The POTS-associated NET mutant, A457P, exhibits dramatically decreased transport capacity and cell surface levels which we have confirmed in the current study. In an attempt to recover A457P NET expression, we co-expressed the A457P variant with DHHC1 to drive expression as seen with the WT protein but instead saw an increase in NET N-terminal immuno-detectable forms and fragments. Elimination of a potential palmitoylation site at cysteine 44 in the N-terminal tail of hNET resulted in a low expression phenotype mimicking the A457P hNET variant. Further investigation of A457P NET palmitoylation and surface expression is necessary, but our preliminary novel findings reveal palmitoylation as a mechanism of NET regulation and suggest that dysregulation of this process may contribute to the pathogenesis of adrenergic disorders like POTS.
体位性正位性心动过速综合征(POTS)是一种肾上腺素能信号紊乱,其特征是血浆去甲肾上腺素过多、体位性心动过速和晕厥。去甲肾上腺素转运体(NET)通过对细胞外儿茶酚胺的再摄取调节肾上腺素能平衡,并与肾上腺素能和神经系统疾病的发病机制有关。在这项研究中,我们发现在雄性 Sprague-Dawley 大鼠和 Lilly 实验室细胞猪肾(LLC-PK1)细胞中,NET 存在棕榈酰化。S-棕榈酰化或添加 16 碳饱和脂肪酸是一种可逆的翻译后修饰,负责调节多种生物机制。我们发现,LLC-PK1 NET 是动态棕榈酰化的,使用棕榈酰酰基酰基转移酶(DHHC)抑制剂 2-溴棕榈酸酯(2BP)进行抑制,可在 90 分钟内减少 NET 的棕榈酰化。紧接着,在处理 120 分钟后,转运能力、细胞表面和细胞 NET 总表达量也随之降低。随着 2BP 浓度和处理时间的增加,NET 蛋白总量几乎完全丧失。与单个 DHHC 的共表达显示,单个 DHHC 酶(DHHC1)促进了野生型(WT)hNET 棕榈酰化和 NET 蛋白水平的升高。POTS相关的NET突变体A457P的转运能力和细胞表面水平显著下降,我们在本研究中证实了这一点。为了恢复 A457P NET 的表达,我们将 A457P 变体与 DHHC1 共同表达,以驱动 WT 蛋白的表达,但结果却发现 NET N 端可免疫检测的形式和片段增加了。消除 hNET N 端尾部半胱氨酸 44 处的潜在棕榈酰化位点会导致模仿 A457P hNET 变体的低表达表型。有必要对 A457P NET 的棕榈酰化和表面表达进行进一步研究,但我们的初步新发现揭示了棕榈酰化是 NET 的一种调控机制,并表明这一过程的失调可能会导致肾上腺素能紊乱(如 POTS)的发病机制。
{"title":"Palmitoylation regulates norepinephrine transporter uptake, surface localization, and total expression with pathogenic implications in postural orthostatic tachycardia syndrome.","authors":"Christopher R Brown, Madhur Shetty, James D Foster","doi":"10.1111/jnc.16241","DOIUrl":"https://doi.org/10.1111/jnc.16241","url":null,"abstract":"<p><p>Postural orthostatic tachycardia syndrome (POTS) is an adrenergic signaling disorder characterized by excessive plasma norepinephrine, postural tachycardia, and syncope. The norepinephrine transporter (NET) modulates adrenergic homeostasis via the reuptake of extracellular catecholamines and is implicated in the pathogenesis of adrenergic and neurological disorders. In this study, we reveal NET is palmitoylated in male Sprague-Dawley rats and Lilly Laboratory Cell Porcine Kidney (LLC-PK<sub>1</sub>) cells. S-palmitoylation, or the addition of a 16-carbon saturated fatty acid, is a reversible post-translational modification responsible for the regulation of numerous biological mechanisms. We found that LLC-PK<sub>1</sub> NET is dynamically palmitoylated, and that inhibition with the palmitoyl acyltransferase (DHHC) inhibitor, 2-bromopalmitate (2BP) results in decreased NET palmitoylation within 90 min of treatment. This result was followed closely by a reduction in transport capacity, cell surface, and total cellular NET expression after 120 min of treatment. Increasing 2BP concentrations and treatment time revealed a nearly complete loss of total NET protein. Co-expression with individual DHHCs revealed a single DHHC enzyme, DHHC1, promoted wild-type (WT) hNET palmitoylation and elevated NET protein levels. The POTS-associated NET mutant, A457P, exhibits dramatically decreased transport capacity and cell surface levels which we have confirmed in the current study. In an attempt to recover A457P NET expression, we co-expressed the A457P variant with DHHC1 to drive expression as seen with the WT protein but instead saw an increase in NET N-terminal immuno-detectable forms and fragments. Elimination of a potential palmitoylation site at cysteine 44 in the N-terminal tail of hNET resulted in a low expression phenotype mimicking the A457P hNET variant. Further investigation of A457P NET palmitoylation and surface expression is necessary, but our preliminary novel findings reveal palmitoylation as a mechanism of NET regulation and suggest that dysregulation of this process may contribute to the pathogenesis of adrenergic disorders like POTS.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142467933","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}
Interplanetary travel poses serious risks because of Galactic cosmic radiations (GCRs). A recent study by Sanghee et al. revealed long-term cognitive impairments in female mice exposed to a 33-beam GCR simulator, highlighting persistent risks for astronauts. The study's use of touchscreen tasks, similar to human cognitive tests, enhances its relevance for space missions. Additionally, the antioxidant/anti-inflammatory compound CDDO-EA showed potential in mitigating these cognitive deficits. While offering critical insights into GCR effects, the study emphasizes the need for further research into protective strategies, including dietary interventions, to ensure astronaut safety on extended missions beyond Earth's protective shield.
{"title":"Beyond Earth's shield: The surprising way antioxidants could pave the road to Mars.","authors":"Miguel Skirzewski, Aureliano Skirzewski","doi":"10.1111/jnc.16233","DOIUrl":"https://doi.org/10.1111/jnc.16233","url":null,"abstract":"<p><p>Interplanetary travel poses serious risks because of Galactic cosmic radiations (GCRs). A recent study by Sanghee et al. revealed long-term cognitive impairments in female mice exposed to a 33-beam GCR simulator, highlighting persistent risks for astronauts. The study's use of touchscreen tasks, similar to human cognitive tests, enhances its relevance for space missions. Additionally, the antioxidant/anti-inflammatory compound CDDO-EA showed potential in mitigating these cognitive deficits. While offering critical insights into GCR effects, the study emphasizes the need for further research into protective strategies, including dietary interventions, to ensure astronaut safety on extended missions beyond Earth's protective shield.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142467931","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}
Diego R Hernandez-Espinosa, Gabriela I Medina-Ruiz, Mia G Scrabis, Amantha Thathiah, Elias Aizenman
Infection and subsequent inflammatory processes negatively impact prognosis in individuals with traumatic brain injury (TBI). Tissue repair following TBI is tightly regulated by microglia, promoting or, importantly, preventing astrocyte-mediated repair processes, depending on the activation state of the neuroimmune cells. This study investigated the poorly understood mechanism linking proinflammatory microglia activation and astrocyte-mediated tissue repair using an in vitro mechanical injury model in mixed cortical cultures of rat neurons and glia. We hypothesized that proinflammatory activation disrupts the microglial response to colony-stimulating factor 1 (CSF-1), which stimulates microglia migration and proliferation, both essential for astrocyte-mediated tissue repair. Following mechanical damage, cultures were treated with lipopolysaccharide (LPS) and interferon-gamma (IFNγ) to induce a proinflammatory state. Immunocytochemical and biochemical analyses were used to evaluate glial repair. Proinflammatory activation dramatically impeded wound closure, reducing microglial levels via upregulation of the zinc-dependent disintegrin and metalloprotease 17 (ADAM17), leading to the cleavage of the CSF-1 receptor (CSF-1R). Indeed, pharmacological inhibition of ADAM17 effectively promoted wound closure during inflammation. Moreover, zinc chelation prevented ADAM17-mediated cleavage of CSF-1R and induced the release of trophic factors, dramatically improving tissue recovery. Our findings strongly identify ADAM17 as a primary regulator of CSF-1R-mediated signaling and establish a mechanism defining the association between pro-inflammatory microglial activation and tissue repair following injury.
{"title":"Proinflammatory microglial activation impairs in vitro cortical tissue repair via zinc-dependent ADAM17 cleavage of the CSF-1 receptor.","authors":"Diego R Hernandez-Espinosa, Gabriela I Medina-Ruiz, Mia G Scrabis, Amantha Thathiah, Elias Aizenman","doi":"10.1111/jnc.16239","DOIUrl":"https://doi.org/10.1111/jnc.16239","url":null,"abstract":"<p><p>Infection and subsequent inflammatory processes negatively impact prognosis in individuals with traumatic brain injury (TBI). Tissue repair following TBI is tightly regulated by microglia, promoting or, importantly, preventing astrocyte-mediated repair processes, depending on the activation state of the neuroimmune cells. This study investigated the poorly understood mechanism linking proinflammatory microglia activation and astrocyte-mediated tissue repair using an in vitro mechanical injury model in mixed cortical cultures of rat neurons and glia. We hypothesized that proinflammatory activation disrupts the microglial response to colony-stimulating factor 1 (CSF-1), which stimulates microglia migration and proliferation, both essential for astrocyte-mediated tissue repair. Following mechanical damage, cultures were treated with lipopolysaccharide (LPS) and interferon-gamma (IFNγ) to induce a proinflammatory state. Immunocytochemical and biochemical analyses were used to evaluate glial repair. Proinflammatory activation dramatically impeded wound closure, reducing microglial levels via upregulation of the zinc-dependent disintegrin and metalloprotease 17 (ADAM17), leading to the cleavage of the CSF-1 receptor (CSF-1R). Indeed, pharmacological inhibition of ADAM17 effectively promoted wound closure during inflammation. Moreover, zinc chelation prevented ADAM17-mediated cleavage of CSF-1R and induced the release of trophic factors, dramatically improving tissue recovery. Our findings strongly identify ADAM17 as a primary regulator of CSF-1R-mediated signaling and establish a mechanism defining the association between pro-inflammatory microglial activation and tissue repair following injury.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142467934","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}
Michael Kalyn, Rose Garvey, Hyojin Lee, Herman Aishi Mbesha, Jory Curry, Vishal Saxena, Jan A Mennigen, Marc Ekker
Dopaminergic (DAnergic) dysfunction and imbalanced dopamine (DA) levels are known contributors to the pathogenesis of numerous psychiatric and neurodegenerative disorders. Of the many identified risk factors for DA-associated disorders, nuclear receptor subfamily 4 group A2 (NR4A2; or nuclear receptor related-1 protein (NURR1)), a transcription factor involved in DAnergic differentiation, has been associated with Parkinson's disease and attention deficit hyperactive disorder (ADHD). In zebrafish, transient loss of nr4a2 was previously shown to decrease tyrosine hydroxylase (TH) expression and impair locomotion. To further characterize the roles of the two zebrafish nr4a2 paralogs, nr4a2a, and nr4a2b, we produced targeted loss-of-function mutants and examined DAnergic neuron regeneration, oxidative respiration, and behavioral traits. The loss of nr4a2a function more closely recapitulated Parkinsonian phenotypes and affected neurotrophic factor gene expression. Conversely, nr4a2b mutants displayed behavioral symptoms reminiscent of mice deficient in Nr4a2 with increased neurotrophic output. In contrast, nr4a2b mutants also displayed increased metabolic input from non-mitochondrial sources indicative of high cytosolic reactive oxygen species and perturbed mitochondrial function. The nr4a2a mutants also showed increased maximal respiration, which may suggest a compensatory mechanism to meet the metabolic requirements of DAnergic neuron health. Overall, the zebrafish mutants generated in this study helped uncover molecular mechanisms involved in DA-related disease pathologies, and in the regeneration of DAnergic neurons.
{"title":"Differential roles of NR4A2 (NURR1) paralogs in the brain and behavior of zebrafish.","authors":"Michael Kalyn, Rose Garvey, Hyojin Lee, Herman Aishi Mbesha, Jory Curry, Vishal Saxena, Jan A Mennigen, Marc Ekker","doi":"10.1111/jnc.16234","DOIUrl":"https://doi.org/10.1111/jnc.16234","url":null,"abstract":"<p><p>Dopaminergic (DAnergic) dysfunction and imbalanced dopamine (DA) levels are known contributors to the pathogenesis of numerous psychiatric and neurodegenerative disorders. Of the many identified risk factors for DA-associated disorders, nuclear receptor subfamily 4 group A2 (NR4A2; or nuclear receptor related-1 protein (NURR1)), a transcription factor involved in DAnergic differentiation, has been associated with Parkinson's disease and attention deficit hyperactive disorder (ADHD). In zebrafish, transient loss of nr4a2 was previously shown to decrease tyrosine hydroxylase (TH) expression and impair locomotion. To further characterize the roles of the two zebrafish nr4a2 paralogs, nr4a2a, and nr4a2b, we produced targeted loss-of-function mutants and examined DAnergic neuron regeneration, oxidative respiration, and behavioral traits. The loss of nr4a2a function more closely recapitulated Parkinsonian phenotypes and affected neurotrophic factor gene expression. Conversely, nr4a2b mutants displayed behavioral symptoms reminiscent of mice deficient in Nr4a2 with increased neurotrophic output. In contrast, nr4a2b mutants also displayed increased metabolic input from non-mitochondrial sources indicative of high cytosolic reactive oxygen species and perturbed mitochondrial function. The nr4a2a mutants also showed increased maximal respiration, which may suggest a compensatory mechanism to meet the metabolic requirements of DAnergic neuron health. Overall, the zebrafish mutants generated in this study helped uncover molecular mechanisms involved in DA-related disease pathologies, and in the regeneration of DAnergic neurons.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142467932","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}
Joseph M Holden, Olivia L Bossardet, Ghazi Bou Ghanem, David J Calkins, Lauren K Wareham
Astrocytes are the principle glial cells of the central nervous system and play an active role in maintaining proper metabolism in surrounding neurons. Because of their involvement in metabolic control, it is likely that their physiology changes in response to metabolic diseases such as diabetes and associated diabetic retinopathy. Here, we investigated whether microstructural changes in astrocyte morphology occur during the early stages of chronic hyperglycemia that may be indicative of early pathogenic programs. We used MORF3 mice in conjunction with streptozotocin-induced hyperglycemia to investigate the morphology of single retinal astrocytes at an early timepoint in diabetic disease. We report that astrocytes initiate a morphological remodeling program, which depends on both the glycemic background and the presence of intravitreal injury, to alter the amount of the neuronal-associated pad and bristle microstructural motifs. Additionally, hyperglycemia increases astrocyte uptake of cholera toxin B, possibly reflecting changes in glycolipid and glycoprotein biosynthesis. Chronic hyperglycemia coupled with intravitreal injection of cholera toxin B also causes extensive leukocyte infiltration into the retina. Our results have important clinical relevance as current therapies for diabetic retinopathy involve intravitreal injection of pharmaceuticals in individuals with often poorly controlled blood glucose levels.
星形胶质细胞是中枢神经系统的主要胶质细胞,在维持周围神经元的正常新陈代谢方面发挥着积极作用。由于星形胶质细胞参与代谢控制,它们的生理机能很可能会随着代谢性疾病(如糖尿病和相关的糖尿病视网膜病变)的发生而发生变化。在此,我们研究了星形胶质细胞形态的微观结构变化是否发生在慢性高血糖的早期阶段,而这种变化可能是早期致病程序的标志。我们利用 MORF3 小鼠和链脲佐菌素诱导的高血糖,研究了糖尿病病变早期单个视网膜星形胶质细胞的形态。我们报告说,星形胶质细胞启动了一个形态重塑程序,该程序取决于血糖背景和是否存在玻璃体内损伤,从而改变与神经元相关的垫和鬃毛微结构图案的数量。此外,高血糖会增加星形胶质细胞对霍乱毒素 B 的吸收,这可能反映了糖脂和糖蛋白生物合成的变化。长期高血糖加上静脉注射霍乱毒素 B 还会导致大量白细胞浸润视网膜。我们的研究结果具有重要的临床意义,因为目前治疗糖尿病视网膜病变的方法包括向血糖水平通常控制不佳的患者进行玻璃体内注射药物。
{"title":"Chronic hyperglycemia alters retinal astrocyte microstructure and uptake of cholera toxin B in a murine model of diabetes.","authors":"Joseph M Holden, Olivia L Bossardet, Ghazi Bou Ghanem, David J Calkins, Lauren K Wareham","doi":"10.1111/jnc.16237","DOIUrl":"https://doi.org/10.1111/jnc.16237","url":null,"abstract":"<p><p>Astrocytes are the principle glial cells of the central nervous system and play an active role in maintaining proper metabolism in surrounding neurons. Because of their involvement in metabolic control, it is likely that their physiology changes in response to metabolic diseases such as diabetes and associated diabetic retinopathy. Here, we investigated whether microstructural changes in astrocyte morphology occur during the early stages of chronic hyperglycemia that may be indicative of early pathogenic programs. We used MORF3 mice in conjunction with streptozotocin-induced hyperglycemia to investigate the morphology of single retinal astrocytes at an early timepoint in diabetic disease. We report that astrocytes initiate a morphological remodeling program, which depends on both the glycemic background and the presence of intravitreal injury, to alter the amount of the neuronal-associated pad and bristle microstructural motifs. Additionally, hyperglycemia increases astrocyte uptake of cholera toxin B, possibly reflecting changes in glycolipid and glycoprotein biosynthesis. Chronic hyperglycemia coupled with intravitreal injection of cholera toxin B also causes extensive leukocyte infiltration into the retina. Our results have important clinical relevance as current therapies for diabetic retinopathy involve intravitreal injection of pharmaceuticals in individuals with often poorly controlled blood glucose levels.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391207","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}
High-fat diet (HFD)-induced obesity induces peripheral inflammation and hypothalamic pathogenesis linking the activation of astrocytes and microglia. Clinical evidence indicates a positive correlation between obesity and psychiatric disorders, such as depression. The connectivity of the frontal-striatal (FS) circuit, involving the caudate putamen (CPu) and anterior cingulate cortex (ACC) within the prefrontal cortex (PFC), is known for its role in stress-induced depression. Thus, there is a need for a thorough investigation into whether chronic obesity-induced gliosis, characterized by the activation of astrocytes and microglia, in these brain regions of individuals with chronic obesity. The results revealed increased S100β+ astrocytes and Iba1+ microglia in the CPu and ACC of male obese mice, along with immune cell accumulation in meningeal lymphatic drainage. Activated GFAP+ astrocytes and Iba1+ microglia were observed in the corpus callosum of obese mice. Gliosis in the CPu and ACC was linked to elevated cleaved caspase-3 levels, indicating potential neural cell death by chronic HFD feeding. There was a loss of myelin and adenomatous polyposis coli (APC)+ oligodendrocytes (OLs) in the corpus callosum, an area known to be linked with injury to the CPu. Additionally, reduced levels of aquaporin-4 (AQP4), a protein associated within the glymphatic systems, were noted in the CPu and ACC, while ciliary neurotrophic factor (CNTF) gene expression was upregulated in these brain regions of obese mice. The in vitro study revealed that high-dose CNTF causing a trend of reduced astrocytic AQP4 expression, but it significantly impaired OL maturation. This pathological evidence highlights that prolonged HFD consumption induces persistent FS gliosis and demyelination in the corpus callosum. An elevated level of CNTF appears to act as a potential regulator, leading to AQP4 downregulation in the FS areas and demyelination in the corpus callosum. This cascade of events might contribute to neural cell damage within these regions and disrupt the glymphatic flow.
高脂饮食(HFD)引起的肥胖会诱发外周炎症和下丘脑发病机制,并与星形胶质细胞和小胶质细胞的活化有关。临床证据表明,肥胖与抑郁症等精神疾病之间存在正相关。额叶-纹状体(FS)回路的连接涉及前额叶皮层(PFC)内的尾状丘脑(CPu)和前扣带回皮层(ACC)。因此,有必要深入研究慢性肥胖患者的这些脑区是否存在以星形胶质细胞和小胶质细胞活化为特征的慢性肥胖诱导的神经胶质病变。结果发现,雄性肥胖小鼠 CPu 和 ACC 中的 S100β+ 星形胶质细胞和 Iba1+ 小胶质细胞增多,同时脑膜淋巴引流中的免疫细胞聚集。在肥胖小鼠的胼胝体中观察到活化的 GFAP+星形胶质细胞和 Iba1+小胶质细胞。CPu和ACC的神经胶质增生与裂解的caspase-3水平升高有关,表明长期摄入高脂低糖可能导致神经细胞死亡。胼胝体中出现了髓鞘和腺瘤性息肉病大肠杆菌(APC)+少突胶质细胞(OLs)的缺失,而这一区域已知与CPu的损伤有关。此外,在肥胖小鼠的 CPu 和 ACC 中还发现了与甘液系统相关的蛋白 Aquaporin-4 (AQP4)水平降低,而睫状神经营养因子 (CNTF) 基因表达在肥胖小鼠的这些脑区上调。体外研究显示,大剂量 CNTF 会导致星形胶质细胞 AQP4 表达减少,但会显著影响 OL 的成熟。这些病理证据突出表明,长期摄入高纤维食物会诱发胼胝体持续性FS胶质增生和脱髓鞘。CNTF 水平的升高似乎是一个潜在的调节因子,导致 FS 区域的 AQP4 下调和胼胝体的脱髓鞘。这一系列事件可能会导致这些区域的神经细胞受损,并破坏血流。
{"title":"Exploring the reduction in aquaporin-4 and increased expression of ciliary neurotrophic factor with the frontal-striatal gliosis induced by chronic high-fat dietary stress.","authors":"Jing-Ting Fu, Hui-Ting Huang, Pei-Chun Chen, Yu-Min Kuo, Po-See Chen, Shun-Fen Tzeng","doi":"10.1111/jnc.16236","DOIUrl":"https://doi.org/10.1111/jnc.16236","url":null,"abstract":"<p><p>High-fat diet (HFD)-induced obesity induces peripheral inflammation and hypothalamic pathogenesis linking the activation of astrocytes and microglia. Clinical evidence indicates a positive correlation between obesity and psychiatric disorders, such as depression. The connectivity of the frontal-striatal (FS) circuit, involving the caudate putamen (CPu) and anterior cingulate cortex (ACC) within the prefrontal cortex (PFC), is known for its role in stress-induced depression. Thus, there is a need for a thorough investigation into whether chronic obesity-induced gliosis, characterized by the activation of astrocytes and microglia, in these brain regions of individuals with chronic obesity. The results revealed increased S100β<sup>+</sup> astrocytes and Iba1<sup>+</sup> microglia in the CPu and ACC of male obese mice, along with immune cell accumulation in meningeal lymphatic drainage. Activated GFAP<sup>+</sup> astrocytes and Iba1<sup>+</sup> microglia were observed in the corpus callosum of obese mice. Gliosis in the CPu and ACC was linked to elevated cleaved caspase-3 levels, indicating potential neural cell death by chronic HFD feeding. There was a loss of myelin and adenomatous polyposis coli (APC)<sup>+</sup> oligodendrocytes (OLs) in the corpus callosum, an area known to be linked with injury to the CPu. Additionally, reduced levels of aquaporin-4 (AQP4), a protein associated within the glymphatic systems, were noted in the CPu and ACC, while ciliary neurotrophic factor (CNTF) gene expression was upregulated in these brain regions of obese mice. The in vitro study revealed that high-dose CNTF causing a trend of reduced astrocytic AQP4 expression, but it significantly impaired OL maturation. This pathological evidence highlights that prolonged HFD consumption induces persistent FS gliosis and demyelination in the corpus callosum. An elevated level of CNTF appears to act as a potential regulator, leading to AQP4 downregulation in the FS areas and demyelination in the corpus callosum. This cascade of events might contribute to neural cell damage within these regions and disrupt the glymphatic flow.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391209","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}
Oligodendrocytes, a type of glial cell in the central nervous system, have a critical role in the formation of myelin around axons, facilitating saltatory conduction, and maintaining the integrity of nerve axons. The dysregulation of oligodendrocyte differentiation and homeostasis have been implicated in a wide range of neurological diseases, including dysmyelinating disorders (e.g., Pelizaeus-Merzbacher disease), demyelinating diseases (e.g., multiple sclerosis), Alzheimer's disease, and psychiatric disorders. Therefore, unraveling the mechanisms of oligodendrocyte development, differentiation, and homeostasis is essential for understanding the pathogenesis of these diseases and the development of therapeutic interventions. Numerous studies have identified and analyzed the functions of transcription factors, RNA metabolic factors, translation control factors, and intracellular and extracellular signals involved in the series of processes from oligodendrocyte fate determination to terminal differentiation. DEAD-box proteins, multifunctional RNA helicases that regulate various intracellular processes, including transcription, RNA processing, and translation, are increasingly recognized for their diverse roles in various aspects of oligodendrocyte development, differentiation, and maintenance of homeostasis. This review introduces the latest insights into the regulatory networks of oligodendrocyte biology mediated by DEAD-box proteins.
{"title":"Diverse functions of DEAD-box proteins in oligodendrocyte development, differentiation, and homeostasis.","authors":"Norihisa Bizen, Hirohide Takebayashi","doi":"10.1111/jnc.16238","DOIUrl":"https://doi.org/10.1111/jnc.16238","url":null,"abstract":"<p><p>Oligodendrocytes, a type of glial cell in the central nervous system, have a critical role in the formation of myelin around axons, facilitating saltatory conduction, and maintaining the integrity of nerve axons. The dysregulation of oligodendrocyte differentiation and homeostasis have been implicated in a wide range of neurological diseases, including dysmyelinating disorders (e.g., Pelizaeus-Merzbacher disease), demyelinating diseases (e.g., multiple sclerosis), Alzheimer's disease, and psychiatric disorders. Therefore, unraveling the mechanisms of oligodendrocyte development, differentiation, and homeostasis is essential for understanding the pathogenesis of these diseases and the development of therapeutic interventions. Numerous studies have identified and analyzed the functions of transcription factors, RNA metabolic factors, translation control factors, and intracellular and extracellular signals involved in the series of processes from oligodendrocyte fate determination to terminal differentiation. DEAD-box proteins, multifunctional RNA helicases that regulate various intracellular processes, including transcription, RNA processing, and translation, are increasingly recognized for their diverse roles in various aspects of oligodendrocyte development, differentiation, and maintenance of homeostasis. This review introduces the latest insights into the regulatory networks of oligodendrocyte biology mediated by DEAD-box proteins.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391208","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}
R Gutiérrez Fuster, A León, G I Aparicio, F Brizuela Sotelo, C Scorticati
The mechanisms underlying neuronal development and synaptic formation in the brain depend on intricate cellular and molecular processes. The neuronal membrane glycoprotein GPM6a promotes neurite elongation, filopodia/spine formation, and synapse development, yet its molecular mechanisms remain unknown. Since the extracellular domains of GPM6a (ECs) command its function, we investigated the interaction between ICAM5, the neuronal member of the intercellular adhesion molecule (ICAM) family, and GPM6a's ECs. Our study aimed to explore the functional relationship between GPM6a and ICAM5 in hippocampal culture neurons and cell lines. Immunostaining of 15 days in vitro (DIV) neurons revealed significant co-localization between endogenous GPM6a clusters and ICAM5 clusters in the dendritic shaft. These results were further corroborated by overexpressing GPM6a and ICAM5 in N2a cells and hippocampal neurons at 5 DIV. Moreover, results from the co-immunoprecipitations and cell aggregation assays prove the cis and trans interaction between both proteins in GPM6a/ICAM5 overexpressing HEK293 cells. Additionally, GPM6a and ICAM5 overexpression additively enhanced neurite length, the number of neurites in N2a cells, and filopodia formation in 5 DIV neurons, indicating their cooperative role. These findings highlight the dynamic association between GPM6a and ICAM5 during neuronal development, offering insights into their contributions to neurite outgrowth, filopodia formation, and cell-cell interactions.
{"title":"Combined additive effects of neuronal membrane glycoprotein GPM6a and the intercellular cell adhesion molecule ICAM5 on neuronal morphogenesis.","authors":"R Gutiérrez Fuster, A León, G I Aparicio, F Brizuela Sotelo, C Scorticati","doi":"10.1111/jnc.16231","DOIUrl":"https://doi.org/10.1111/jnc.16231","url":null,"abstract":"<p><p>The mechanisms underlying neuronal development and synaptic formation in the brain depend on intricate cellular and molecular processes. The neuronal membrane glycoprotein GPM6a promotes neurite elongation, filopodia/spine formation, and synapse development, yet its molecular mechanisms remain unknown. Since the extracellular domains of GPM6a (ECs) command its function, we investigated the interaction between ICAM5, the neuronal member of the intercellular adhesion molecule (ICAM) family, and GPM6a's ECs. Our study aimed to explore the functional relationship between GPM6a and ICAM5 in hippocampal culture neurons and cell lines. Immunostaining of 15 days in vitro (DIV) neurons revealed significant co-localization between endogenous GPM6a clusters and ICAM5 clusters in the dendritic shaft. These results were further corroborated by overexpressing GPM6a and ICAM5 in N2a cells and hippocampal neurons at 5 DIV. Moreover, results from the co-immunoprecipitations and cell aggregation assays prove the cis and trans interaction between both proteins in GPM6a/ICAM5 overexpressing HEK293 cells. Additionally, GPM6a and ICAM5 overexpression additively enhanced neurite length, the number of neurites in N2a cells, and filopodia formation in 5 DIV neurons, indicating their cooperative role. These findings highlight the dynamic association between GPM6a and ICAM5 during neuronal development, offering insights into their contributions to neurite outgrowth, filopodia formation, and cell-cell interactions.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142348454","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}
The five-choice serial reaction time task (5CSRTT) is a test of attention that provides a well-validated ancillary measure of impulsive action, measured by premature responses. The task has been adapted for mice in touchscreen operant boxes, which is thought to offer improved test-retest reliability. Few studies have assessed the long-term stability of performance, including premature responding in this version of the task. We used the touchscreen 5CSRTT to conduct longitudinal testing of stability of premature responding following repeated behavioral and pharmacological manipulations. Male C57BL/6J mice were trained on a baseline version of the 5CSRTT. They were then tested on versions of the task in which the stimulus duration was reduced, and inter-trial intervals were elongated or varied within-session. Premature responding was subsequently tested following administration of pharmacological agents known to bi-directionally affect attention and impulsive action-cocaine, atomoxetine, and yohimbine. Mice were lastly re-tested 6 months later using the 5CSRTT with elongated inter-trial intervals. A reduced stimulus duration impacted attention, with reduced accuracy and increased omissions, but had no effect on premature responding. Both elongating and varying the inter-trial interval within-session increased premature responses. Mice showed similar and stable levels of increased premature responding 6 months later. Cocaine increased premature responding, though less than previously reported in rats. Atomoxetine reduced premature responding. Yohimbine had no effect on premature responding in the baseline task but decreased premature responding when tested using an elongated inter-trial interval. Overall, these results highlight that the touch screen adaptation of the 5CSRTT is an effective method for longitudinal testing of attention and impulsive action and remains sensitive to performance changes arising from repeated pharmacological and behavioral challenges.
{"title":"Assessing the stability of responding of male mice in the touchscreen 5 choice serial reaction time task: Focus on premature responding.","authors":"Arya Rahbarnia, Andrew R Abela, Paul J Fletcher","doi":"10.1111/jnc.16232","DOIUrl":"https://doi.org/10.1111/jnc.16232","url":null,"abstract":"<p><p>The five-choice serial reaction time task (5CSRTT) is a test of attention that provides a well-validated ancillary measure of impulsive action, measured by premature responses. The task has been adapted for mice in touchscreen operant boxes, which is thought to offer improved test-retest reliability. Few studies have assessed the long-term stability of performance, including premature responding in this version of the task. We used the touchscreen 5CSRTT to conduct longitudinal testing of stability of premature responding following repeated behavioral and pharmacological manipulations. Male C57BL/6J mice were trained on a baseline version of the 5CSRTT. They were then tested on versions of the task in which the stimulus duration was reduced, and inter-trial intervals were elongated or varied within-session. Premature responding was subsequently tested following administration of pharmacological agents known to bi-directionally affect attention and impulsive action-cocaine, atomoxetine, and yohimbine. Mice were lastly re-tested 6 months later using the 5CSRTT with elongated inter-trial intervals. A reduced stimulus duration impacted attention, with reduced accuracy and increased omissions, but had no effect on premature responding. Both elongating and varying the inter-trial interval within-session increased premature responses. Mice showed similar and stable levels of increased premature responding 6 months later. Cocaine increased premature responding, though less than previously reported in rats. Atomoxetine reduced premature responding. Yohimbine had no effect on premature responding in the baseline task but decreased premature responding when tested using an elongated inter-trial interval. Overall, these results highlight that the touch screen adaptation of the 5CSRTT is an effective method for longitudinal testing of attention and impulsive action and remains sensitive to performance changes arising from repeated pharmacological and behavioral challenges.</p>","PeriodicalId":16527,"journal":{"name":"Journal of Neurochemistry","volume":" ","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142348453","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}