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Nemati S, Kondiles BR, Wheeler S. The Contributions of the mTOR Complexes: How Does Regional and Temporal Heterogeneity Affect Myelination and Remyelination? J Neurosci 2023; 43:5590-5592. [PMID: 37532457 PMCID: PMC10401627 DOI: 10.1523/jneurosci.0545-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/18/2023] [Accepted: 06/21/2023] [Indexed: 08/04/2023] Open
Affiliation(s)
- Saina Nemati
- Undergraduate Student in the Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Bethany R Kondiles
- Postdoctoral Research Fellow in the Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Sarah Wheeler
- Graduate Student in the Department of Cell and Developmental Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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Jung H, Kim S, Ko J, Um JW. Intracellular signaling mechanisms that shape postsynaptic GABAergic synapses. Curr Opin Neurobiol 2023; 81:102728. [PMID: 37236068 DOI: 10.1016/j.conb.2023.102728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 04/21/2023] [Accepted: 04/23/2023] [Indexed: 05/28/2023]
Abstract
Postsynaptic GABAergic receptors interact with various membrane and intracellular proteins to mediate inhibitory synaptic transmission. They form structural and/or signaling synaptic protein complexes that perform a variety of postsynaptic functions. In particular, the key GABAergic synaptic scaffold, gephyrin, and its interacting partners govern downstream signaling pathways that are essential for GABAergic synapse development, transmission, and plasticity. In this review, we discuss recent researches on GABAergic synaptic signaling pathways. We also outline the main outstanding issues that need to be addressed in this field and highlight the association of dysregulated GABAergic synaptic signaling with the onset of various brain disorders.
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Affiliation(s)
- Hyeji Jung
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea
| | - Seungjoon Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea; Center for Synapse Diversity and Specificity, DGIST, 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea
| | - Jaewon Ko
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea; Center for Synapse Diversity and Specificity, DGIST, 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea
| | - Ji Won Um
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea; Center for Synapse Diversity and Specificity, DGIST, 333 Techno Jungangdae-Ro, Hyeonpoong-Eup, Dalseong-Gun, Daegu 42988, South Korea.
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Possible Involvement of DNA Methylation in TSC1 Gene Expression in Neuroprotection Induced by Hypoxic Preconditioning. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:9306097. [PMID: 36120601 PMCID: PMC9481362 DOI: 10.1155/2022/9306097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 07/19/2022] [Accepted: 08/13/2022] [Indexed: 11/18/2022]
Abstract
Background. It has been reported that ischemia and ischemic preconditioning (IPC) have different effects on the expression of tuberous sclerosis complex 1 (TSC1), which may contribute to the tolerance to ischemia/hypoxia with the increase of autophagy. The mechanisms of TSC1 differential expression are still unclear under ischemia/IPC conditions in hippocampal Cornu Ammon 1 (CA1) and Cornu Ammon 3 (CA3) area neuronal cells. While we have shown that 5-Aza-CdR, a DNA methyltransferase inhibitor, can upregulate TSC1 and increase hypoxic tolerance by autophagy in vivo and in vitro, in this study, we examined whether DNA methylation was involved in the differential expression of TSC1 in the CA1 and CA3 regions induced by hypoxic preconditioning (HPC). Methods. Level of rapamycin (mTOR) autophagy, a downstream molecular pathway of TSC1/TSC2 complex, was detected in HPC mouse hippocampal CA1 and CA3 areas as well as in the HPC model of mouse hippocampal HT22 cells. DNA methylation level of TSC1 promoter (-720 bp~ -360 bp) was determined in CA1 and CA3 areas by bisulfite-modified DNA sequencing (BMDS). At the same time, autophagy was detected in HT22 cells transfected with GFP-LC3 plasmid. The role of TSC1 in neuroprotection was measured by cell viability and apoptosis, and the role of TSC1 in metabolism was checked by ATP assay and ROS assay in HT22 cells that overexpressed/knocked down TSC1. Results. HPC upregulated the expression of TSC1, downregulated the level of P-mTOR (Ser2448) and P-p70S6K (Thr389), and enhanced the activity of autophagy in both in vivo and in vitro. The increased expression of TSC1 in HPC may depend on its DNA hypomethylation in the promoter region in vivo. HPC also could reduce energy consumption in HT22 cells. Overexpression and knockdown of TSC1 can affect cell viability, cell apoptosis, and metabolism in HT22 cells exposed to hypoxia. Conclusion. TSC1 expression induced by HPC may relate to the downregulation of its DNA methylation level with the increase of autophagy and the decrease of energy demand.
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Casas BS, Arancibia-Altamirano D, Acevedo-La Rosa F, Garrido-Jara D, Maksaev V, Pérez-Monje D, Palma V. It takes two to tango: Widening our understanding of the onset of schizophrenia from a neuro-angiogenic perspective. Front Cell Dev Biol 2022; 10:946706. [PMID: 36092733 PMCID: PMC9448889 DOI: 10.3389/fcell.2022.946706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/14/2022] [Indexed: 11/13/2022] Open
Abstract
Schizophrenia is a chronic debilitating mental disorder characterized by perturbations in thinking, perception, and behavior, along with brain connectivity deficiencies, neurotransmitter dysfunctions, and loss of gray brain matter. To date, schizophrenia has no cure and pharmacological treatments are only partially efficacious, with about 30% of patients describing little to no improvement after treatment. As in most neurological disorders, the main descriptions of schizophrenia physiopathology have been focused on neural network deficiencies. However, to sustain proper neural activity in the brain, another, no less important network is operating: the vast, complex and fascinating vascular network. Increasing research has characterized schizophrenia as a systemic disease where vascular involvement is important. Several neuro-angiogenic pathway disturbances have been related to schizophrenia. Alterations, ranging from genetic polymorphisms, mRNA, and protein alterations to microRNA and abnormal metabolite processing, have been evaluated in plasma, post-mortem brain, animal models, and patient-derived induced pluripotent stem cell (hiPSC) models. During embryonic brain development, the coordinated formation of blood vessels parallels neuro/gliogenesis and results in the structuration of the neurovascular niche, which brings together physical and molecular signals from both systems conforming to the Blood-Brain barrier. In this review, we offer an upfront perspective on distinctive angiogenic and neurogenic signaling pathways that might be involved in the biological causality of schizophrenia. We analyze the role of pivotal angiogenic-related pathways such as Vascular Endothelial Growth Factor and HIF signaling related to hypoxia and oxidative stress events; classic developmental pathways such as the NOTCH pathway, metabolic pathways such as the mTOR/AKT cascade; emerging neuroinflammation, and neurodegenerative processes such as UPR, and also discuss non-canonic angiogenic/axonal guidance factor signaling. Considering that all of the mentioned above pathways converge at the Blood-Brain barrier, reported neurovascular alterations could have deleterious repercussions on overall brain functioning in schizophrenia.
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Chen J, He W, Wang YY, Zhang MN, Lu Q, Wang QH, Luo XM, Wang B, Zou LP. Long-term administration of sirolimus does not affect the physical development of children with tuberous sclerosis complex. Childs Nerv Syst 2022; 38:947-952. [PMID: 35083513 DOI: 10.1007/s00381-022-05446-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 01/06/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE There was no evidence whether the mammalian/mechanistic target of rapamycin pathway hyperactivation and long-term use of mTOR inhibitors have any effects on the physical development of children. The aim was to evaluate these effects by comparing the physical development of children with TSC and normal children. METHODS A total of 120 eligible children were enrolled. They were administered sirolimus and followed for at least 12 months. Height, weight, BMI and lipid metabolism index were collected during treatment. Pearson's chi-square and Fisher's exact test were used for comparison of proportions of patients exhibiting normal and abnormal physical growth before and after 1 year of treatment. Logistic regression was used to evaluate the influence of age, sex and abnormal lipid metabolism on the increased BMIs of TSC patients after treatment. RESULTS Most of the enrolled TSC children were in the normal height, weight and BMI ranges at baseline (91.7%, 95.8% and 78.3%, respectively). Most remained in the normal height, weight and BMI ranges after 1 year of sirolimus treatment (94.2%, 95% and 76.7%, respectively). There was no significant difference in the proportion of physical development before and after treatment (p > 0.05). Thirty-eight (38/106, 35.8%) patients had increased BMIs after 1 year of treatment, but there was no significant correlation between age, sex and lipid metabolism and increased BMI. CONCLUSIONS Overactivation of the mTOR pathway and long-term administration of sirolimus does not affect the physical development of children with TSC.
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Affiliation(s)
- Jian Chen
- Faculty of Pediatrics, Department of Pediatrics, The First Medical Center of Chinese, Chinese PLA General Hospital, PLA General Hospital, 28 Fuxing road, Haidian district, Beijing, 100853, China
| | - Wen He
- Faculty of Pediatrics, Department of Pediatrics, The First Medical Center of Chinese, Chinese PLA General Hospital, PLA General Hospital, 28 Fuxing road, Haidian district, Beijing, 100853, China
| | - Yang-Yang Wang
- Faculty of Pediatrics, Department of Pediatrics, The First Medical Center of Chinese, Chinese PLA General Hospital, PLA General Hospital, 28 Fuxing road, Haidian district, Beijing, 100853, China
| | - Meng-Na Zhang
- Faculty of Pediatrics, Department of Pediatrics, The First Medical Center of Chinese, Chinese PLA General Hospital, PLA General Hospital, 28 Fuxing road, Haidian district, Beijing, 100853, China
| | - Qian Lu
- Faculty of Pediatrics, Department of Pediatrics, The First Medical Center of Chinese, Chinese PLA General Hospital, PLA General Hospital, 28 Fuxing road, Haidian district, Beijing, 100853, China
| | - Qiu-Hong Wang
- Faculty of Pediatrics, Department of Pediatrics, The First Medical Center of Chinese, Chinese PLA General Hospital, PLA General Hospital, 28 Fuxing road, Haidian district, Beijing, 100853, China
| | - Xiao-Mei Luo
- Center for Brain Disorders Research, Capital Medical University, Beijing Institute for Brain Disorders, Beijing, China
| | - Bin Wang
- Faculty of Pediatrics, Department of Pediatrics, The First Medical Center of Chinese, Chinese PLA General Hospital, PLA General Hospital, 28 Fuxing road, Haidian district, Beijing, 100853, China
| | - Li-Ping Zou
- Faculty of Pediatrics, Department of Pediatrics, The First Medical Center of Chinese, Chinese PLA General Hospital, PLA General Hospital, 28 Fuxing road, Haidian district, Beijing, 100853, China.
- Center for Brain Disorders Research, Capital Medical University, Beijing Institute for Brain Disorders, Beijing, China.
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Girodengo M, Ultanir SK, Bateman JM. Mechanistic target of rapamycin signaling in human nervous system development and disease. Front Mol Neurosci 2022; 15:1005631. [PMID: 36226315 PMCID: PMC9549271 DOI: 10.3389/fnmol.2022.1005631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 09/06/2022] [Indexed: 11/30/2022] Open
Abstract
Mechanistic target of rapamycin (mTOR) is a highly conserved serine/threonine kinase that regulates fundamental cellular processes including growth control, autophagy and metabolism. mTOR has key functions in nervous system development and mis-regulation of mTOR signaling causes aberrant neurodevelopment and neurological diseases, collectively called mTORopathies. In this mini review we discuss recent studies that have deepened our understanding of the key roles of the mTOR pathway in human nervous system development and disease. Recent advances in single-cell transcriptomics have been exploited to reveal specific roles for mTOR signaling in human cortical development that may have contributed to the evolutionary divergence from our primate ancestors. Cerebral organoid technology has been utilized to show that mTOR signaling is active in and regulates outer radial glial cells (RGCs), a population of neural stem cells that distinguish the human developing cortex. mTOR signaling has a well-established role in hamartoma syndromes such as tuberous sclerosis complex (TSC) and other mTORopathies. New ultra-sensitive techniques for identification of somatic mTOR pathway mutations have shed light on the neurodevelopmental origin and phenotypic heterogeneity seen in mTORopathy patients. These emerging studies suggest that mTOR signaling may facilitate developmental processes specific to human cortical development but also, when mis-regulated, cause cortical malformations and neurological disease.
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Affiliation(s)
- Marie Girodengo
- Kinases and Brain Development Lab, The Francis Crick Institute, London, United Kingdom.,King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
| | - Sila K Ultanir
- Kinases and Brain Development Lab, The Francis Crick Institute, London, United Kingdom
| | - Joseph M Bateman
- King's College London, Maurice Wohl Clinical Neuroscience Institute, London, United Kingdom
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Zhou X, Chen X, Hong T, Zhang M, Cai Y, Cui L. TTC3-Mediated Protein Quality Control, A Potential Mechanism for Cognitive Impairment. Cell Mol Neurobiol 2021; 42:1659-1669. [PMID: 33638766 PMCID: PMC9239942 DOI: 10.1007/s10571-021-01060-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 02/11/2021] [Indexed: 01/14/2023]
Abstract
The tetrapeptide repeat domain 3 (TTC3) gene falls within Down's syndrome (DS) critical region. Cognitive impairment is a common phenotype of DS and Alzheimer’s disease (AD), and overexpression of TTC3 can accelerate cognitive decline, but the specific mechanism is unknown. The TTC3-mediated protein quality control (PQC) mechanism, similar to the PQC system, is divided into three parts: it acts as a cochaperone to assist proteins in folding correctly; it acts as an E3 ubiquitin ligase (E3s) involved in protein degradation processes through the ubiquitin–proteasome system (UPS); and it may also eventually cause autophagy by affecting mitochondrial function. Thus, this article reviews the research progress on the structure, function, and metabolism of TTC3, including the recent research progress on TTC3 in DS and AD; the role of TTC3 in cognitive impairment through PQC in combination with the abovementioned attributes of TTC3; and the potential targets of TTC3 in the treatment of such diseases.
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Affiliation(s)
- Xu Zhou
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China
| | - Xiongjin Chen
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China
| | - Tingting Hong
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China
| | - Miaoping Zhang
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China
| | - Yujie Cai
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China
| | - Lili Cui
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical University, No.57, Renmindadaonan Road, Xiashan District, Zhanjiang, China.
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Castets P, Ham DJ, Rüegg MA. The TOR Pathway at the Neuromuscular Junction: More Than a Metabolic Player? Front Mol Neurosci 2020; 13:162. [PMID: 32982690 PMCID: PMC7485269 DOI: 10.3389/fnmol.2020.00162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/05/2020] [Indexed: 12/18/2022] Open
Abstract
The neuromuscular junction (NMJ) is the chemical synapse connecting motor neurons and skeletal muscle fibers. NMJs allow all voluntary movements, and ensure vital functions like breathing. Changes in the structure and function of NMJs are hallmarks of numerous pathological conditions that affect muscle function including sarcopenia, the age-related loss of muscle mass and function. However, the molecular mechanisms leading to the morphological and functional perturbations in the pre- and post-synaptic compartments of the NMJ remain poorly understood. Here, we discuss the role of the metabolic pathway associated to the kinase TOR (Target of Rapamycin) in the development, maintenance and alterations of the NMJ. This is of particular interest as the TOR pathway has been implicated in aging, but its role at the NMJ is still ill-defined. We highlight the respective functions of the two TOR-associated complexes, TORC1 and TORC2, and discuss the role of localized protein synthesis and autophagy regulation in motor neuron terminals and sub-synaptic regions of muscle fibers and their possible effects on NMJ maintenance.
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Affiliation(s)
- Perrine Castets
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Julian LM, Stanford WL. Organelle Cooperation in Stem Cell Fate: Lysosomes as Emerging Regulators of Cell Identity. Front Cell Dev Biol 2020; 8:591. [PMID: 32733892 PMCID: PMC7358313 DOI: 10.3389/fcell.2020.00591] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 06/17/2020] [Indexed: 12/26/2022] Open
Abstract
Regulation of stem cell fate is best understood at the level of gene and protein regulatory networks, though it is now clear that multiple cellular organelles also have critical impacts. A growing appreciation for the functional interconnectedness of organelles suggests that an orchestration of integrated biological networks functions to drive stem cell fate decisions and regulate metabolism. Metabolic signaling itself has emerged as an integral regulator of cell fate including the determination of identity, activation state, survival, and differentiation potential of many developmental, adult, disease, and cancer-associated stem cell populations and their progeny. As the primary adenosine triphosphate-generating organelles, mitochondria are well-known regulators of stem cell fate decisions, yet it is now becoming apparent that additional organelles such as the lysosome are important players in mediating these dynamic decisions. In this review, we will focus on the emerging role of organelles, in particular lysosomes, in the reprogramming of both metabolic networks and stem cell fate decisions, especially those that impact the determination of cell identity. We will discuss the inter-organelle interactions, cell signaling pathways, and transcriptional regulatory mechanisms with which lysosomes engage and how these activities impact metabolic signaling. We will further review recent data that position lysosomes as critical regulators of cell identity determination programs and discuss the known or putative biological mechanisms. Finally, we will briefly highlight the potential impact of elucidating mechanisms by which lysosomes regulate stem cell identity on our understanding of disease pathogenesis, as well as the development of refined regenerative medicine, biomarker, and therapeutic strategies.
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Affiliation(s)
- Lisa M. Julian
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - William L. Stanford
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
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Altered photoreceptor metabolism in mouse causes late stage age-related macular degeneration-like pathologies. Proc Natl Acad Sci U S A 2020; 117:13094-13104. [PMID: 32434914 PMCID: PMC7293639 DOI: 10.1073/pnas.2000339117] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The main cause for blindness in the elderly worldwide is age-related macular degeneration (AMD). What causes AMD remains unknown. The high metabolic demands of photoreceptors are thought to contribute to disease pathogenesis, yet whether photoreceptor metabolism differs in individuals with AMD has not been determined. Here, we show that photoreceptor metabolism does differ between diseased and nondiseased individuals. Mimicking the metabolic profile of diseased individuals in mouse resulted in the similar advanced pathologies as those that cause blindness in humans. A disease model with photoreceptors as a contributing factor explains also why AMD affects preferentially the macula; it is the region of highest photoreceptor density. The data might open new avenues to study the role of PRs in disease pathogenesis. Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. While the histopathology of the different disease stages is well characterized, the cause underlying the progression, from the early drusen stage to the advanced macular degeneration stage that leads to blindness, remains unknown. Here, we show that photoreceptors (PRs) of diseased individuals display increased expression of two key glycolytic genes, suggestive of a glucose shortage during disease. Mimicking aspects of this metabolic profile in PRs of wild-type mice by activation of the mammalian target of rapamycin complex 1 (mTORC1) caused early drusen-like pathologies, as well as advanced AMD-like pathologies. Mice with activated mTORC1 in PRs also displayed other early disease features, such as a delay in photoreceptor outer segment (POS) clearance and accumulation of lipofuscin in the retinal-pigmented epithelium (RPE) and of lipoproteins at the Bruch’s membrane (BrM), as well as changes in complement accumulation. Interestingly, formation of drusen-like deposits was dependent on activation of mTORC1 in cones. Both major types of advanced AMD pathologies, including geographic atrophy (GA) and neovascular pathologies, were also seen. Finally, activated mTORC1 in PRs resulted in a threefold reduction in di-docosahexaenoic acid (DHA)–containing phospholipid species. Feeding mice a DHA-enriched diet alleviated most pathologies. The data recapitulate many aspects of the human disease, suggesting that metabolic adaptations in photoreceptors could contribute to disease progression in AMD. Identifying the changes downstream of mTORC1 that lead to advanced pathologies in mouse might present new opportunities to study the role of PRs in AMD pathogenesis.
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Zhou X, Lv X, Zhang L, Yan J, Hu R, Sun Y, Xi S, Jiang H. Ketamine promotes the neural differentiation of mouse embryonic stem cells by activating mTOR. Mol Med Rep 2020; 21:2443-2451. [PMID: 32236601 PMCID: PMC7185302 DOI: 10.3892/mmr.2020.11043] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 08/31/2018] [Indexed: 12/23/2022] Open
Abstract
Ketamine is a widely used general anesthetic and has been reported to demonstrate neurotoxicity and neuroprotection. Investigation into the regulatory mechanism of ketamine on influencing neural development is of importance for a better and safer way of relieving pain. Reverse transcription‑quantitative polymerase chain reaction and western blotting were used to detect the critical neural associated gene expression, and flow cytometry to detect the neural differentiation effect. Hence, in the present study the underlying mechanism of ketamine (50 nM) on neural differentiation of the mouse embryonic stem cell (mESC) line 46C was investigated. The results demonstrated that a low dose of ketamine (50 nM) promoted the differentiation of mESCs to neural stem cells (NSCs) and activated mammalian target of rapamycin (mTOR) by upregulating the expression levels of phosphorylated (p)‑mTOR. Furthermore, inhibition of the mTOR signaling pathway by rapamycin or knockdown of mTOR suppressed neural differentiation. A rescue experiment further confirmed that downregulation of mTOR inhibited the promotion of neural differentiation induced by ketamine. Taken together, the present study indicated that a low level of ketamine upregulated p‑mTOR expression levels, promoting neural differentiation.
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Affiliation(s)
- Xuhui Zhou
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Center for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, P.R. China
| | - Xiang Lv
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Center for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, P.R. China
| | - Lei Zhang
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Center for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, P.R. China
| | - Jia Yan
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Center for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, P.R. China
| | - Rong Hu
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Center for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, P.R. China
| | - Yu Sun
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Center for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, P.R. China
| | - Siwei Xi
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Center for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, P.R. China
| | - Hong Jiang
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Center for Specialty Strategy Research of Shanghai Jiao Tong University China Hospital Development Institute, Shanghai 200011, P.R. China
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Kit OI, Gvaldin DY, Trifanov VS, Kolesnikov EN, Timoshkina NN. Molecular-Genetic Features of Pancreatic Neuroendocrine Tumors. RUSS J GENET+ 2020. [DOI: 10.1134/s1022795420020064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Liu Y, Yu M, Jiang D. Downregulation of STAT1 induces the differentiation of neural stem cells through JNK pathway. Tissue Cell 2019; 61:61-66. [PMID: 31759408 DOI: 10.1016/j.tice.2019.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/10/2019] [Accepted: 09/13/2019] [Indexed: 01/13/2023]
Abstract
Neural stem cells (NSCs) generated neurons and glial cells. Thus, it is a preferable candidate to the cell replacement-based therapy against neural disorders. The signaling pathways that regulate differentiation of NSCs are widely studied. In the current study, we used in vitro culture system to elucidate the role of signal transducer and activator of transcription 1 (STAT1) in NSCs' differentiation. Downregulation of STAT1 inhibited the proliferation of NSCs. Meanwhile, we also found STAT1 regulation could control the differentiation of NSCs. More neurons and glia cells were generated from NSCs with STAT1 silencing. This process was mediated by the JNK/STAT1 signaling. STAT1 inhibitor promoted differentiation of NSCs. After transplantation, we observed more neurons generated from NSCs with shRNA-STAT1 treatment. Collectively, this work showed an efficient way to regulate neuronal differentiation of NSCs through regulating the STAT1 expression. This is likely to provide source and theoretical support to cell replacement based theory.
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Affiliation(s)
- Yigang Liu
- Department of Neurology, Shanghai Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China
| | - Min Yu
- Department of Neurology, Seventh People's Hospital of Shanghai University of Traditional Chinese Medicine, Shanghai, 200137, China
| | - Dudu Jiang
- Department of Neurology, Seventh People's Hospital of Shanghai University of Traditional Chinese Medicine, Shanghai, 200137, China.
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Owens GC, Garcia AJ, Mochizuki AY, Chang JW, Reyes SD, Salamon N, Prins RM, Mathern GW, Fallah A. Evidence for Innate and Adaptive Immune Responses in a Cohort of Intractable Pediatric Epilepsy Surgery Patients. Front Immunol 2019; 10:121. [PMID: 30761153 PMCID: PMC6362260 DOI: 10.3389/fimmu.2019.00121] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 01/15/2019] [Indexed: 12/31/2022] Open
Abstract
Brain-infiltrating lymphocytes (BILs) were isolated from resected brain tissue from 10 pediatric epilepsy patients who had undergone surgery for Hemimegalencephaly (HME) (n = 1), Tuberous sclerosis complex (TSC) (n = 2), Focal cortical dysplasia (FCD) (n = 4), and Rasmussen encephalitis (RE) (n = 3). Peripheral blood mononuclear cells (PBMCs) were also isolated from blood collected at the time of the surgery. Cells were immunostained with a panel of 20 antibody markers, and analyzed by mass cytometry. To identify and quantify the immune cell types in the samples, an unbiased clustering method was applied to the entire data set. More than 85 percent of the CD45+ cells isolated from resected RE brain tissue comprised T cells; by contrast NK cells and myeloid cells constituted 80-95 percent of the CD45+ cells isolated from the TSC and the FCD brain specimens. Three populations of myeloid cells made up >50 percent of all of the myeloid cells in all of the samples of which a population of HLA-DR+ CD11b+ CD4- cells comprised the vast majority of myeloid cells in the BIL fractions from the FCD and TSC cases. CD45RA+ HLA-DR- CD11b+ CD16+ NK cells constituted the major population of NK cells in the blood from all of the cases. This subset also comprised the majority of NK cells in BILs from the resected RE and HME brain tissue, whereas NK cells defined as CD45RA- HLA-DR+ CD11b- CD16- cells comprised 86-96 percent of the NK cells isolated from the FCD and TSC brain tissue. Thirteen different subsets of CD4 and CD8 αβ T cells and γδ T cells accounted for over 80% of the CD3+ T cells in all of the BIL and PBMC samples. At least 90 percent of the T cells in the RE BILs, 80 percent of the T cells in the HME BILs and 40-66 percent in the TSC and FCD BILs comprised activated antigen-experienced (CD45RO+ HLA-DR+ CD69+) T cells. We conclude that even in cases where there is no evidence for an infection or an immune disorder, activated peripheral immune cells may be present in epileptogenic areas of the brain, possibly in response to seizure-driven brain inflammation.
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Affiliation(s)
- Geoffrey C. Owens
- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Alejandro J. Garcia
- Division of Hematology Oncology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Aaron Y. Mochizuki
- Division of Hematology Oncology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Julia W. Chang
- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Samuel D. Reyes
- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Noriko Salamon
- Department of Radiological Sciences, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, CA, United States
| | - Robert M. Prins
- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Parker Institute for Cancer Immunotherapy, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Gary W. Mathern
- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Mattel Children's Hospital, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Aria Fallah
- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Mattel Children's Hospital, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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