1
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Palandt N, Resch C, Unterlechner P, Voshagen L, Winhart VR, Kunz L. Metabolic response of auditory brainstem neurons to their broad physiological activity range. J Neurochem 2024; 168:663-676. [PMID: 38439211 DOI: 10.1111/jnc.16091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 02/19/2024] [Accepted: 02/20/2024] [Indexed: 03/06/2024]
Abstract
Neurons exhibit a high energetic need, and the question arises as how they metabolically adapt to changing activity states. This is relevant for interpreting functional neuroimaging in different brain areas. Particularly, neurons with a broad firing range might exhibit metabolic adaptations. Therefore, we studied MNTB (medial nucleus of the trapezoid body) principal neurons, which generate action potentials (APs) at frequencies up to several hundred hertz. We performed the experiments in acute brainstem slices of the Mongolian gerbil (Meriones unguiculatus) at 22.5-24.5°C. Upon electrical stimulation of afferent MNTB fibres with 400 stimuli at varying frequencies, we monitored autofluorescence levels of NAD(P)H and FAD and determined the extremum amplitudes of their biphasic response. Additionally, we compared these data with alterations in O2 concentrations measured with an electrochemical sensor. These O2 changes are prominent since MNTB neurons rely on oxidative phosphorylation as shown by our pharmacological experiments. We calculated the O2 consumption rate as change in O2 concentration divided by stimulus durations, because these periods varied inversely with stimulus frequency as a result of the constant number of 400 stimuli applied. The O2 consumption rate increased with stimulation frequency up to a constant value at 600 Hz; that is, energy demand depends on temporal characteristics of activity despite the same number of stimuli. The rates showed no correlation with peak amplitudes of NAD(P)H or FAD, whilst the values of the two molecules were linearly correlated. This points at the complexity of analysing autofluorescence imaging for quantitative metabolic studies, because these values report only relative net changes of many superimposed oxidative and reductive processes. Monitoring O2 concentration rates is, thus, an important tool to improve the interpretation of NAD(P)H/FAD autofluorescence data, as they do not under all conditions and in all systems appropriately reflect the metabolic activity or energy demand.
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Affiliation(s)
- Nicola Palandt
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximillians-Universität (LMU), Munich, Germany
- Graduate School of Systemic Neurosciences (GSN), Ludwig-Maximillians-Universität (LMU), Munich, Germany
| | - Cibell Resch
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximillians-Universität (LMU), Munich, Germany
| | - Patricia Unterlechner
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximillians-Universität (LMU), Munich, Germany
| | - Lukas Voshagen
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximillians-Universität (LMU), Munich, Germany
| | - Valentin R Winhart
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximillians-Universität (LMU), Munich, Germany
- Graduate School of Systemic Neurosciences (GSN), Ludwig-Maximillians-Universität (LMU), Munich, Germany
| | - Lars Kunz
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximillians-Universität (LMU), Munich, Germany
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2
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Huo C, Zhang X, Gu Y, Wang D, Zhang S, Liu T, Li Y, He W. Organoids: Construction and Application in Gastric Cancer. Biomolecules 2023; 13:biom13050875. [PMID: 37238742 DOI: 10.3390/biom13050875] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/11/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023] Open
Abstract
Gastric organoids are biological models constructed in vitro using stem cell culture and 3D cell culture techniques, which are the latest research hotspots. The proliferation of stem cells in vitro is the key to gastric organoid models, making the cell subsets within the models more similar to in vivo tissues. Meanwhile, the 3D culture technology also provides a more suitable microenvironment for the cells. Therefore, the gastric organoid models can largely restore the growth condition of cells in terms of morphology and function in vivo. As the most classic organoid models, patient-derived organoids use the patient's own tissues for in vitro culture. This kind of model is responsive to the 'disease information' of a specific patient and has great effect on evaluating the strategies of individualized treatment. Herein, we review the current literature on the establishment of organoid cultures, and also explore organoid translational applications.
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Affiliation(s)
- Chengdong Huo
- Department of the Second Clinical Medical College, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Digestive System Tumors of Gansu Province, Lanzhou 730030, China
- Department of Ophthalmology, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - Xiaoxia Zhang
- Department of the Second Clinical Medical College, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Digestive System Tumors of Gansu Province, Lanzhou 730030, China
- Department of Ophthalmology, Lanzhou University Second Hospital, Lanzhou 730030, China
| | - Yanmei Gu
- Department of the Second Clinical Medical College, Lanzhou University, Lanzhou 730030, China
| | - Daijun Wang
- Department of the Second Clinical Medical College, Lanzhou University, Lanzhou 730030, China
| | - Shining Zhang
- Key Laboratory of Digestive System Tumors of Gansu Province, Lanzhou 730030, China
| | - Tao Liu
- Department of the Second Clinical Medical College, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Digestive System Tumors of Gansu Province, Lanzhou 730030, China
| | - Yumin Li
- Department of the Second Clinical Medical College, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Digestive System Tumors of Gansu Province, Lanzhou 730030, China
| | - Wenting He
- Department of the Second Clinical Medical College, Lanzhou University, Lanzhou 730030, China
- Key Laboratory of Digestive System Tumors of Gansu Province, Lanzhou 730030, China
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3
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Singh A, Chen R. The Duration of Oxygen and Glucose Deprivation (OGD) Determines the Effects of Subsequent Reperfusion on Rat Pheochromocytoma (PC12) Cells and Primary Cortical Neurons. Int J Mol Sci 2023; 24:7106. [PMID: 37108268 PMCID: PMC10138834 DOI: 10.3390/ijms24087106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/06/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
Reperfusion is the fundamental treatment for ischaemic stroke; however, many ischaemic stroke patients cannot undergo reperfusion treatment. Furthermore, reperfusion can cause ischaemic reperfusion injuries. This study aimed to determine the effects of reperfusion in an in vitro ischaemic stroke model-oxygen and glucose deprivation (OGD) (0.3% O2)-with rat pheochromocytoma (PC12) cells and cortical neurons. In PC12 cells, OGD resulted in a time-dependent increase in cytotoxicity and apoptosis, and reduction in MTT activity from 2 h onwards. Reperfusion following shorter periods (4 and 6 h) of OGD recovered apoptotic PC12 cells, whereas after 12 h, OGD increased LDH release. In primary neurons, 6 h OGD led to significant increase in cytotoxicity, reduction in MTT activity and dendritic MAP2 staining. Reperfusion following 6 h OGD increased the cytotoxicity. HIF-1a was stabilised by 4 and 6 h OGD in PC12 cells and 2 h OGD onwards in primary neurons. A panel of hypoxic genes were upregulated by the OGD treatments depending on the duration. In conclusion, the duration of OGD determines the mitochondrial activity, cell viability, HIF-1a stabilization, and hypoxic gene expression in both cell types. Reperfusion following OGD of short duration is neuroprotective, whereas OGD of long duration is cytotoxic.
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Affiliation(s)
| | - Ruoli Chen
- School of Pharmacy and Bioengineering, Keele University, Staffordshire ST5 5BG, UK;
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4
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Dong R, Zhang B, Zhang X. Liver organoids: an in vitro 3D model for liver cancer study. Cell Biosci 2022; 12:152. [PMID: 36085085 PMCID: PMC9463833 DOI: 10.1186/s13578-022-00890-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/28/2022] [Indexed: 11/21/2022] Open
Abstract
Primary liver cancer (PLC) is the second leading cause of cancer mortality worldwide, and its morbidity unceasingly increases these years. Hepatitis B virus (HBV) infection accounted for approximately 50% of hepatocellular carcinoma (HCC) cases globally in 2015. Due to the lack of an effective model to study HBV-associated liver carcinogenesis, research has made slow progress. Organoid, an in vitro 3D model which maintains self-organization, has recently emerged as a powerful tool to investigate human diseases. In this review, we first summarize the categories and development of liver organoids. Then, we mainly focus on the functions of culture medium components and applications of organoids for HBV infection and HBV-associated liver cancer studies. Finally, we provide insights into a potential patient-derived organoid model from those infected with HBV based on our study, as well as the limitations and future applications of organoids in liver cancer research.
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5
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Schröter M, Wang C, Terrigno M, Hornauer P, Huang Z, Jagasia R, Hierlemann A. Functional imaging of brain organoids using high-density microelectrode arrays. MRS BULLETIN 2022; 47:530-544. [PMID: 36120104 PMCID: PMC9474390 DOI: 10.1557/s43577-022-00282-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/02/2022] [Indexed: 05/31/2023]
Abstract
ABSTRACT Studies have provided evidence that human cerebral organoids (hCOs) recapitulate fundamental milestones of early brain development, but many important questions regarding their functionality and electrophysiological properties persist. High-density microelectrode arrays (HD-MEAs) represent an attractive analysis platform to perform functional studies of neuronal networks at the cellular and network scale. Here, we use HD-MEAs to derive large-scale electrophysiological recordings from sliced hCOs. We record the activity of hCO slices over several weeks and probe observed neuronal dynamics pharmacologically. Moreover, we present results on how the obtained recordings can be spike-sorted and subsequently studied across scales. For example, we show how to track single neurons across several days on the HD-MEA and how to infer axonal action potential velocities. We also infer putative functional connectivity from hCO recordings. The introduced methodology will contribute to a better understanding of developing neuronal networks in brain organoids and provide new means for their functional characterization. IMPACT STATEMENT Human cerebral organoids (hCOs) represent an attractive in vitro model system to study key physiological mechanisms underlying early neuronal network formation in tissue with healthy or disease-related genetic backgrounds. Despite remarkable advances in the generation of brain organoids, knowledge on the functionality of their neuronal circuits is still scarce. Here, we used complementary metal-oxide-semiconductor (CMOS)-based high-density microelectrode arrays (HD-MEAs) to perform large-scale recordings from sliced hCOs over several weeks and quantified their activity across scales. Using single-cell and network metrics, we were able to probe aspects of hCO neurophysiology that are more difficult to obtain with other techniques, such as patch clamping (lower yield) and calcium imaging (lower temporal resolution). These metrics included, for example, extracellular action potential (AP) waveform features and axonal AP velocity at the cellular level, as well as functional connectivity at the network level. Analysis was enabled by the large sensing area and the high spatiotemporal resolution provided by HD-MEAs, which allowed recordings from hundreds of neurons and spike sorting of their activity. Our results demonstrate that HD-MEAs provide a multi-purpose platform for the functional characterization of hCOs, which will be key in improving our understanding of this model system and assessing its relevance for translational research. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1557/s43577-022-00282-w.
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Affiliation(s)
- Manuel Schröter
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Congwei Wang
- NRD, F. Hoffmann-La Roche Ltd., Roche Innovation Center Basel, Basel, Switzerland
| | - Marco Terrigno
- NRD, F. Hoffmann-La Roche Ltd., Roche Innovation Center Basel, Basel, Switzerland
| | - Philipp Hornauer
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Ziqiang Huang
- EMBL Imaging Centre, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Ravi Jagasia
- NRD, F. Hoffmann-La Roche Ltd., Roche Innovation Center Basel, Basel, Switzerland
| | - Andreas Hierlemann
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
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6
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Galanin and Neuropeptide Y Interaction Enhances Proliferation of Granule Precursor Cells and Expression of Neuroprotective Factors in the Rat Hippocampus with Consequent Augmented Spatial Memory. Biomedicines 2022; 10:biomedicines10061297. [PMID: 35740319 PMCID: PMC9219743 DOI: 10.3390/biomedicines10061297] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 05/27/2022] [Accepted: 05/28/2022] [Indexed: 02/04/2023] Open
Abstract
Dysregulation of hippocampal neurogenesis is linked to several neurodegenereative diseases, where boosting hippocampal neurogenesis in these patients emerges as a potential therapeutic approach. Accumulating evidence for a neuropeptide Y (NPY) and galanin (GAL) interaction was shown in various limbic system regions at molecular-, cellular-, and behavioral-specific levels. The purpose of the current work was to evaluate the role of the NPY and GAL interaction in the neurogenic actions on the dorsal hippocampus. We studied the Y1R agonist and GAL effects on: hippocampal cell proliferation through the proliferating cell nuclear antigen (PCNA), the expression of neuroprotective and anti-apoptotic factors, and the survival of neurons and neurite outgrowth on hippocampal neuronal cells. The functional outcome was evaluated in the object-in-place task. We demonstrated that the Y1R agonist and GAL promote cell proliferation and the induction of neuroprotective factors. These effects were mediated by the interaction of NPYY1 (Y1R) and GAL2 (GALR2) receptors, which mediate the increased survival and neurites’ outgrowth observed on neuronal hippocampal cells. These cellular effects are linked to the improved spatial-memory effects after the Y1R agonist and GAL co-injection at 24 h in the object-in-place task. Our results suggest the development of heterobivalent agonist pharmacophores, targeting Y1R–GALR2 heterocomplexes, therefore acting on the neuronal precursor cells of the DG in the dorsal hippocampus for the novel therapy of neurodegenerative cognitive-affecting diseases.
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Santangelo R, Giuffrida ML, Satriano C, Tomasello MF, Zimbone S, Copani A. β-amyloid monomers drive up neuronal aerobic glycolysis in response to energy stressors. Aging (Albany NY) 2021; 13:18033-18050. [PMID: 34290150 PMCID: PMC8351713 DOI: 10.18632/aging.203330] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 07/09/2021] [Indexed: 12/15/2022]
Abstract
Research on cerebral glucose metabolism has shown that the aging brain experiences a fall of aerobic glycolysis, and that the age-related loss of aerobic glycolysis may accelerate Alzheimer’s disease pathology. In the healthy brain, aerobic glycolysis, namely the use of glucose outside oxidative phosphorylation, may cover energy demand and increase neuronal resilience to stressors at once. Currently, the drivers of aerobic glycolysis in neurons are unknown. We previously demonstrated that synthetic monomers of β-amyloid protein (Aβ) enhance glucose uptake in neurons, and that endogenous Aβ is required for depolarization-induced glucose uptake in cultured neurons. In this work, we show that cultured cortical neurons increased aerobic glycolysis in response to the inhibition of oxidative phosphorylation by oligomycin or to a kainate pulse. Such an increase was prevented by blocking the endogenous Aβ tone and re-established by the exogenous addition of synthetic Aβ monomers. The activity of mitochondria-bound hexokinase-1 appeared to be necessary for monomers-stimulated aerobic glycolysis during oxidative phosphorylation blockade or kainate excitation. Our data suggest that, through Aβ release, neurons coordinate glucose uptake with aerobic glycolysis in response to metabolic stressors. The implications of this new finding are that the age-related drop in aerobic glycolysis and the susceptibility to Alzheimer’s disease could be linked to factors interfering with release and functions of Aβ monomers.
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Affiliation(s)
- Rosa Santangelo
- Department of Drug and Health Sciences, University of Catania, Catania 95125, Italy
| | - Maria Laura Giuffrida
- Institute of Crystallography, National Council of Research, Catania Unit, Catania 95126, Italy
| | - Cristina Satriano
- Department of Chemical Sciences, University of Catania, Catania 95125, Italy
| | | | - Stefania Zimbone
- Institute of Crystallography, National Council of Research, Catania Unit, Catania 95126, Italy
| | - Agata Copani
- Department of Drug and Health Sciences, University of Catania, Catania 95125, Italy.,Institute of Crystallography, National Council of Research, Catania Unit, Catania 95126, Italy
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8
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Santo SD, Seiler S, Guzman R, Widmer HR. Endothelial Progenitor Cell-Derived Factors Exert Neuroprotection in Cultured Cortical Neuronal Progenitor Cells. Cell Transplant 2021; 29:963689720912689. [PMID: 32193955 PMCID: PMC7444205 DOI: 10.1177/0963689720912689] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
There is substantial evidence that stem and progenitor cells secrete
trophic factors that have potential for repairing injured tissues. We
have previously reported that the conditioned medium (CM) obtained
from endothelial progenitor cells (EPC) cultures protects striatal
neurons against 3-nitropropionic acid-induced toxicity. In the present
study we tested the hypothesis that EPC-CM may support cortical
neuronal cell function and/or survival. EPC were isolated from the
peripheral blood of healthy human donors and cultured in hypoxic
conditions (1.5% O2) to stimulate the secretion of growth
factors. The supernatant or conditioned medium (EPC-CM) was then
collected and used for the various experiments. Primary cultures of
cerebral cortex from fetal rat embryonic day 14 were treated with
EPC-CM and challenged by glucose and serum deprivation. We observed
that EPC-CM treatment significantly increased total cell number and
cell viability in the cultures. Similarly, the number of
lba1-expressing cells was significantly upregulated by EPC-CM, while
western blot analyses for the astroglial marker glial fibrillary
acidic protein did not show a marked difference. Importantly, the
number of beta-lll-tubulin-positive neurons in the cultures was
significantly augmented after EPC-CM treatment. Similarly, western
blot analyses for beta-III-tubulin showed significant higher signal
intensities. Furthermore, EPC-CM administration protected neurons
against glucose- and serum deprivation-induced cell loss. In sum, our findings identified EPC-CM as a means to promote viability
and/or differentiation of cortical neurons and suggest that EPC-CM
might be useful for neurorestorative approaches.
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Affiliation(s)
- Stefano Di Santo
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, Bern University Hospital, University of Bern, Bern, Switzerland.,Departments of Neurosurgery and Biomedicine, Basel University Hospital, University of Basel, Basel, Switzerland
| | - Stefanie Seiler
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Raphael Guzman
- Departments of Neurosurgery and Biomedicine, Basel University Hospital, University of Basel, Basel, Switzerland.,Both the authors share senior authorship
| | - Hans Rudolf Widmer
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, Bern University Hospital, University of Bern, Bern, Switzerland.,Both the authors share senior authorship
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9
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Lourbopoulos A, Mourouzis I, Xinaris C, Zerva N, Filippakis K, Pavlopoulos A, Pantos C. Translational Block in Stroke: A Constructive and "Out-of-the-Box" Reappraisal. Front Neurosci 2021; 15:652403. [PMID: 34054413 PMCID: PMC8160233 DOI: 10.3389/fnins.2021.652403] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/06/2021] [Indexed: 12/13/2022] Open
Abstract
Why can we still not translate preclinical research to clinical treatments for acute strokes? Despite > 1000 successful preclinical studies, drugs, and concepts for acute stroke, only two have reached clinical translation. This is the translational block. Yet, we continue to routinely model strokes using almost the same concepts we have used for over 30 years. Methodological improvements and criteria from the last decade have shed some light but have not solved the problem. In this conceptual analysis, we review the current status and reappraise it by thinking "out-of-the-box" and over the edges. As such, we query why other scientific fields have also faced the same translational failures, to find common denominators. In parallel, we query how migraine, multiple sclerosis, and hypothermia in hypoxic encephalopathy have achieved significant translation successes. Should we view ischemic stroke as a "chronic, relapsing, vascular" disease, then secondary prevention strategies are also a successful translation. Finally, based on the lessons learned, we propose how stroke should be modeled, and how preclinical and clinical scientists, editors, grant reviewers, and industry should reconsider their routine way of conducting research. Translational success for stroke treatments may eventually require a bold change with solutions that are outside of the box.
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Affiliation(s)
- Athanasios Lourbopoulos
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- Department of Neurointensive Care Unit, Schoen Klinik Bad Aibling, Bad Aibling, Germany
- Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig Maximilian University, Munich, Germany
| | - Iordanis Mourouzis
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Christodoulos Xinaris
- IRCCS – Istituto di Ricerche Farmacologiche ‘Mario Negri’, Centro Anna Maria Astori, Bergamo, Italy
- University of Nicosia Medical School, Nicosia, Cyprus
| | - Nefeli Zerva
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Konstantinos Filippakis
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Angelos Pavlopoulos
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Constantinos Pantos
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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10
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Gordon A, Yoon SJ, Tran SS, Makinson CD, Park JY, Andersen J, Valencia AM, Horvath S, Xiao X, Huguenard JR, Pașca SP, Geschwind DH. Long-term maturation of human cortical organoids matches key early postnatal transitions. Nat Neurosci 2021; 24:331-342. [PMID: 33619405 PMCID: PMC8109149 DOI: 10.1038/s41593-021-00802-y] [Citation(s) in RCA: 157] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 01/12/2021] [Indexed: 01/31/2023]
Abstract
Human stem-cell-derived models provide the promise of accelerating our understanding of brain disorders, but not knowing whether they possess the ability to mature beyond mid- to late-fetal stages potentially limits their utility. We leveraged a directed differentiation protocol to comprehensively assess maturation in vitro. Based on genome-wide analysis of the epigenetic clock and transcriptomics, as well as RNA editing, we observe that three-dimensional human cortical organoids reach postnatal stages between 250 and 300 days, a timeline paralleling in vivo development. We demonstrate the presence of several known developmental milestones, including switches in the histone deacetylase complex and NMDA receptor subunits, which we confirm at the protein and physiological levels. These results suggest that important components of an intrinsic in vivo developmental program persist in vitro. We further map neurodevelopmental and neurodegenerative disease risk genes onto in vitro gene expression trajectories to provide a resource and webtool (Gene Expression in Cortical Organoids, GECO) to guide disease modeling.
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Affiliation(s)
- Aaron Gordon
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Se-Jin Yoon
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis, Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
| | - Stephen S Tran
- Department of Psychiatry, University of California San Diego, San Diego, CA, USA
- Department of Integrative Biology, University of California Los Angeles, Angeles, CA, USA
| | - Christopher D Makinson
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Jin Young Park
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis, Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
| | - Jimena Andersen
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis, Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
| | - Alfredo M Valencia
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Stanford Brain Organogenesis, Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
| | - Steve Horvath
- Department of Biostatistics, Fielding School of Public Health, University of California Los Angeles, Los Angeles, CA, USA
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Xinshu Xiao
- Department of Integrative Biology, University of California Los Angeles, Angeles, CA, USA
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, USA
- Institute for Quantitative and Computational Biology, University of California Los Angeles, Los Angeles, CA, USA
| | - John R Huguenard
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Sergiu P Pașca
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA.
- Stanford Brain Organogenesis, Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA.
| | - Daniel H Geschwind
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
- Program in Neurobehavioral Genetics, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
- Center for Autism Research and Treatment, Semel Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
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11
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Chouaib B, Collart-Dutilleul PY, Blanc-Sylvestre N, Younes R, Gergely C, Raoul C, Scamps F, Cuisinier F, Romieu O. Identification of secreted factors in dental pulp cell-conditioned medium optimized for neuronal growth. Neurochem Int 2021; 144:104961. [PMID: 33465470 DOI: 10.1016/j.neuint.2021.104961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 01/04/2021] [Accepted: 01/11/2021] [Indexed: 02/05/2023]
Abstract
With their potent regenerative and protective capacities, stem cell-derived conditioned media emerged as an effective alternative to cell therapy, and have a prospect to be manufactured as pharmaceutical products for tissue regeneration applications. Our study investigates the neuroregenerative potential of human dental pulp cells (DPCs) conditioned medium (CM) and defines an optimization strategy of DPC-CM for enhanced neuronal outgrowth. Primary sensory neurons from mouse dorsal root ganglia were cultured with or without DPC-CM, and the lengths of βIII-tubulin positive neurites were measured. The impacts of several manufacturing features as the duration of cell conditioning, CM storage, and preconditioning of DPCs with some factors on CM functional activity were assessed on neurite length. We observed that DPC-CM significantly enhanced neurites outgrowth of sensory neurons in a concentration-dependent manner. The frozen storage of DPC-CM had no impact on experimental outcomes and 48 h of DPC conditioning is optimal for an effective activity of CM. To further understand the regenerative feature of DPC-CM, we studied DPC secretome by human growth factor antibody array analysis and revealed the presence of several factors involved in either neurogenesis, neuroprotection, angiogenesis, and osteogenesis. The conditioning of DPCs with the B-27 supplement enhanced significantly the neuroregenerative effect of their secretome by changing its composition in growth factors. Here, we show that DPC-CM significantly stimulate neurite outgrowth in primary sensory neurons. Moreover, we identified secreted protein candidates that can potentially promote this promising regenerative feature of DPC-CM.
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Affiliation(s)
| | | | | | - Richard Younes
- LBN, Univ Montpellier, Montpellier, France; The Neuroscience Institute of Montpellier, Inserm UMR1051, Univ Montpellier, Saint Eloi Hospital, Montpellier, France
| | | | - Cédric Raoul
- The Neuroscience Institute of Montpellier, Inserm UMR1051, Univ Montpellier, Saint Eloi Hospital, Montpellier, France
| | - Frédérique Scamps
- The Neuroscience Institute of Montpellier, Inserm UMR1051, Univ Montpellier, Saint Eloi Hospital, Montpellier, France
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12
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Schaeffer J, Delpech C, Albert F, Belin S, Nawabi H. Adult Mouse Retina Explants: From ex vivo to in vivo Model of Central Nervous System Injuries. Front Mol Neurosci 2020; 13:599948. [PMID: 33324161 PMCID: PMC7723849 DOI: 10.3389/fnmol.2020.599948] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 10/16/2020] [Indexed: 12/14/2022] Open
Abstract
In mammals, adult neurons fail to regenerate following any insult to adult central nervous system (CNS), which leads to a permanent and irreversible loss of motor and cognitive functions. For a long time, much effort has been deployed to uncover mechanisms of axon regeneration in the CNS. Even if some cases of functional recovery have been reported, there is still a discrepancy regarding the functionality of a neuronal circuit upon lesion. Today, there is a need not only to identify new molecules implicated in adult CNS axon regeneration, but also to decipher the fine molecular mechanisms associated with regeneration failure. Here, we propose to use cultures of adult retina explants to study all molecular and cellular mechanisms that occur during CNS regeneration. We show that adult retinal explant cultures have the advantages to (i) recapitulate all the features observed in vivo, including axon regeneration induced by intrinsic factors, and (ii) be an ex vivo set-up with high accessibility and many downstream applications. Thanks to several examples, we demonstrate that adult explants can be used to address many questions, such as axon guidance, growth cone formation and cytoskeleton dynamics. Using laser guided ablation of a single axon, axonal injury can be performed at a single axon level, which allows to record early and late molecular events that occur after the lesion. Our model is the ideal tool to study all molecular and cellular events that occur during CNS regeneration at a single-axon level, which is currently not doable in vivo. It is extremely valuable to address unanswered questions of neuroprotection and neuroregeneration in the context of CNS lesion and neurodegenerative diseases.
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13
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Singh A, Chow O, Jenkins S, Zhu L, Rose E, Astbury K, Chen R. Characterizing Ischaemic Tolerance in Rat Pheochromocytoma (PC12) Cells and Primary Rat Neurons. Neuroscience 2020; 453:17-31. [PMID: 33246056 DOI: 10.1016/j.neuroscience.2020.11.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 11/05/2020] [Accepted: 11/06/2020] [Indexed: 12/16/2022]
Abstract
Preconditioning tissue with sublethal ischaemia or hypoxia can confer tolerance (protection) against subsequent ischaemic challenge. In vitro ischaemic preconditioning (IPC) is typically achieved through oxygen glucose deprivation (OGD), whereas hypoxic preconditioning (HPC) involves oxygen deprivation (OD) alone. Here, we report the effects of preconditioning of OGD, OD or glucose deprivation (GD) in ischaemic tolerance models with PC12 cells and primary rat neurons. PC12 cells preconditioned (4 h) with GD or OGD, but not OD, prior to reperfusion (24 h) then ischaemic challenge (OGD 6 h), showed greater mitochondrial activity, reduced cytotoxicity and decreased apoptosis, compared to sham preconditioned PC12 cells. Furthermore, 4 h preconditioning with reduced glucose (0.565 g/L, reduced from 4.5 g/L) conferred protective effects, but not for higher concentrations (1.125 or 2.25 g/L). Preconditioning (4 h) with OGD, but not OD or GD, induced stabilization of hypoxia inducible factor 1α (HIF1α) and upregulation of HIF1 downstream genes (Vegf, Glut1, Pfkfb3 and Ldha). In primary rat neurons, only OGD preconditioning (4 h) conferred neuroprotection. OGD preconditioning (4 h) induced stabilization of HIF1α and upregulation of HIF1 downstream genes (Vegf, Phd2 and Bnip3). In conclusion, OGD preconditioning (4 h) followed by 24 h reperfusion induced ischaemic tolerance (against OGD, 6 h) in both PC12 cells and primary rat neurons. The OGD preconditioning protection is associated with HIF1α stabilization and upregulation of HIF1 downstream gene expression. GD preconditioning (4 h) leads to protection in PC12 cells, but not in neurons. This GD preconditioning-induced protection was not associated with HIF1α stabilization.
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Affiliation(s)
- Ayesha Singh
- School of Pharmacy and Bioengineering, Keele University, Staffordshire ST5 5BG, UK.
| | - Oliver Chow
- Department of Molecular, Cellular, Developmental Biology, University of Colorado, Boulder, CO 80302, USA
| | - Stuart Jenkins
- School of Medicine, Keele University, Staffordshire ST5 5BG, UK.
| | - Lingling Zhu
- Department of Brain Protection and Plasticity, Institute of Basic Medical Sciences, Beijing, China
| | - Emily Rose
- School of Pharmacy and Bioengineering, Keele University, Staffordshire ST5 5BG, UK.
| | - Katherine Astbury
- School of Pharmacy and Bioengineering, Keele University, Staffordshire ST5 5BG, UK
| | - Ruoli Chen
- School of Pharmacy and Bioengineering, Keele University, Staffordshire ST5 5BG, UK.
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14
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Ceder MM, Lekholm E, Klaesson A, Tripathi R, Schweizer N, Weldai L, Patil S, Fredriksson R. Glucose Availability Alters Gene and Protein Expression of Several Newly Classified and Putative Solute Carriers in Mice Cortex Cell Culture and D. melanogaster. Front Cell Dev Biol 2020; 8:579. [PMID: 32733888 PMCID: PMC7358622 DOI: 10.3389/fcell.2020.00579] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/15/2020] [Indexed: 12/16/2022] Open
Abstract
Many newly identified solute carriers (SLCs) and putative transporters have the possibility to be intricately involved in glucose metabolism. Here we show that many transporters of this type display a high degree of regulation at both mRNA and protein level following no or low glucose availability in mouse cortex cultures. We show that this is also the case in Drosophila melanogaster subjected to starvation or diets with different sugar content. Interestingly, re-introduction of glucose to media, or refeeding flies, normalized the gene expression of a number of the targets, indicating a fast and highly dynamic control. Our findings demonstrate high conservation of these transporters and how dependent both cell cultures and organisms are on gene and protein regulation during metabolic fluctuations. Several transporter genes were regulated simultaneously maybe to initiate alternative metabolic pathways as a response to low glucose levels, both in the cell cultures and in D. melanogaster. Our results display that newly identified SLCs of Major Facilitator Superfamily type, as well as the putative transporters included in our study, are regulated by glucose availability and could be involved in several cellular aspects dependent of glucose and/or its metabolites. Recently, a correlation between dysregulation of glucose in the central nervous system and numerous diseases such as obesity, type 2 diabetes mellitus as well as neurological disease such as Alzheimer’s and Parkinson’s diseases indicate a complex regulation and fine tuning of glucose levels in the brain. The fact that almost one third of transporters and transporter-related proteins remain orphans with unknown or contradictive substrate profile, location and function, pinpoint the need for further research about them to fully understand their mechanistic role and their impact on cellular metabolism.
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Affiliation(s)
- Mikaela M Ceder
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Emilia Lekholm
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Axel Klaesson
- Pharmaceutical Cell Biology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Rekha Tripathi
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Nadine Schweizer
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Lydia Weldai
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Sourabh Patil
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | - Robert Fredriksson
- Molecular Neuropharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
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15
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Pouraghaei S, Moztarzadeh F, Chen C, Ansari S, Moshaverinia A. Microenvironment Can Induce Development of Auditory Progenitor Cells from Human Gingival Mesenchymal Stem Cells. ACS Biomater Sci Eng 2020; 6:2263-2273. [PMID: 33455314 DOI: 10.1021/acsbiomaterials.9b01795] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Sensorineural hearing loss in mammals occurs due to irreversible damage to the sensory epithelia of the inner ear and has very limited treatment options. The ability to regenerate the auditory progenitor cells is a promising approach for the treatment of sensorineural hearing loss; therefore, finding an appropriate and easily accessible stem cell source for restoring the sense of hearing would be of great interest. Here, we proposed a novel easy-to-access source of cells with the ability to recover auditory progenitor cells. In this study, gingival mesenchymal stem cells (GMSCs) were utilized, as these cells have high self-renewal and multipotent differentiation capacity and can be obtained easily from the oral cavity or discarded tissue samples at dental clinics. To manipulate the biophysical properties of the cellular microenvironment for promoting GMSC differentiation toward the target cells, we also tried to propose a candidate biomaterial. GMSCs in combination with an appropriate scaffold material can, therefore, present advantageous therapeutic options for a number of conditions. Here, we report the potential of GMSCs to differentiate into auditory progenitor cells while supporting them with an optimized three-dimensional scaffold and certain growth factors. A hybrid hydrogel scaffold based on peptide modified alginate and Matrigel was used here in addition to the presence of fibroblast growth factor-basic (bFGF), insulin-like growth factor (IGF), and epidermal growth factor (EGF). Our in vitro and in vivo studies confirmed the auditory differentiation potential of GMSCs within the engineered microenvironment.
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Affiliation(s)
- Sevda Pouraghaei
- Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
- Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, School of Dentistry, University of California, Los Angeles, California, United States
| | - Fathollah Moztarzadeh
- Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Chider Chen
- Department of Oral and Maxillofacial Surgery and Pharmacology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Sahar Ansari
- Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Alireza Moshaverinia
- Weintraub Center for Reconstructive Biotechnology, Division of Advanced Prosthodontics, School of Dentistry, University of California, Los Angeles, California, United States
- California NanoSystems Institute, University of California, Los Angeles, California, United States
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16
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In vitro modeling of dendritic atrophy in Rett syndrome: determinants for phenotypic drug screening in neurodevelopmental disorders. Sci Rep 2020; 10:2491. [PMID: 32051524 PMCID: PMC7016139 DOI: 10.1038/s41598-020-59268-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 01/21/2020] [Indexed: 01/16/2023] Open
Abstract
Dendritic atrophy, defined as the reduction in complexity of the neuronal arborization, is a hallmark of several neurodevelopmental disorders, including Rett Syndrome (RTT). RTT, affecting 1:10,000 girls worldwide, is mainly caused by mutations in the MECP2 gene and has no cure. We describe here an in vitro model of dendritic atrophy in Mecp2−/y mouse hippocampal primary cultures, suitable for phenotypic drug-screening. Using High-Content Imaging techniques, we systematically investigated the impact of culturing determinants on several parameters such as neuronal survival, total dendritic length, dendritic endpoints, soma size, cell clusterization, spontaneous activity. Determinants included cell-seeding density, glass or polystyrene substrates, coating with poly-Ornithine with/without Matrigel and miniaturization from 24 to 96-half surface multiwell plates. We show that in all plate-sizes at densities below 320 cells/mm2, morphological parameters remained constant while spontaneous network activity decreased according to the cell-density. Mecp2−/y neurons cultured at 160 cells/mm2 density in 96 multiwell plates, displayed significant dendritic atrophy and showed a marked increase in dendritic length following treatment with Brain-derived neurotrophic factor (BDNF) or Mirtazapine. In conclusion, we have established a phenotypic assay suitable for fast screening of hundreds of compounds, which may be extended to other neurodevelopmental diseases with dendritic atrophy.
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17
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Tourigny DS, Karim MKA, Echeveste R, Kotter MRN, O’Neill JS. Energetic substrate availability regulates synchronous activity in an excitatory neural network. PLoS One 2019; 14:e0220937. [PMID: 31408504 PMCID: PMC6692003 DOI: 10.1371/journal.pone.0220937] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 07/26/2019] [Indexed: 12/16/2022] Open
Abstract
Neural networks are required to meet significant metabolic demands associated with performing sophisticated computational tasks in the brain. The necessity for efficient transmission of information imposes stringent constraints on the metabolic pathways that can be used for energy generation at the synapse, and thus low availability of energetic substrates can reduce the efficacy of synaptic function. Here we study the effects of energetic substrate availability on global neural network behavior and find that glucose alone can sustain excitatory neurotransmission required to generate high-frequency synchronous bursting that emerges in culture. In contrast, obligatory oxidative energetic substrates such as lactate and pyruvate are unable to substitute for glucose, indicating that processes involving glucose metabolism form the primary energy-generating pathways supporting coordinated network activity. Our experimental results are discussed in the context of the role that metabolism plays in supporting the performance of individual synapses, including the relative contributions from postsynaptic responses, astrocytes, and presynaptic vesicle cycling. We propose a simple computational model for our excitatory cultures that accurately captures the inability of metabolically compromised synapses to sustain synchronous bursting when extracellular glucose is depleted.
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Affiliation(s)
- David S. Tourigny
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Columbia University Irving Medical Center, New York, New York, United States of America
- * E-mail: (DST); (MRNK); (JSO)
| | - Muhammad Kaiser Abdul Karim
- Department of Clinical Neurosciences and Wellcome Trust- MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Rodrigo Echeveste
- Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Mark R. N. Kotter
- Department of Clinical Neurosciences and Wellcome Trust- MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- * E-mail: (DST); (MRNK); (JSO)
| | - John S. O’Neill
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
- * E-mail: (DST); (MRNK); (JSO)
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18
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Abstract
Glucose is the long-established, obligatory fuel for brain that fulfills many critical functions, including ATP production, oxidative stress management, and synthesis of neurotransmitters, neuromodulators, and structural components. Neuronal glucose oxidation exceeds that in astrocytes, but both rates increase in direct proportion to excitatory neurotransmission; signaling and metabolism are closely coupled at the local level. Exact details of neuron-astrocyte glutamate-glutamine cycling remain to be established, and the specific roles of glucose and lactate in the cellular energetics of these processes are debated. Glycolysis is preferentially upregulated during brain activation even though oxygen availability is sufficient (aerobic glycolysis). Three major pathways, glycolysis, pentose phosphate shunt, and glycogen turnover, contribute to utilization of glucose in excess of oxygen, and adrenergic regulation of aerobic glycolysis draws attention to astrocytic metabolism, particularly glycogen turnover, which has a high impact on the oxygen-carbohydrate mismatch. Aerobic glycolysis is proposed to be predominant in young children and specific brain regions, but re-evaluation of data is necessary. Shuttling of glucose- and glycogen-derived lactate from astrocytes to neurons during activation, neurotransmission, and memory consolidation are controversial topics for which alternative mechanisms are proposed. Nutritional therapy and vagus nerve stimulation are translational bridges from metabolism to clinical treatment of diverse brain disorders.
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Affiliation(s)
- Gerald A Dienel
- Department of Neurology, University of Arkansas for Medical Sciences , Little Rock, Arkansas ; and Department of Cell Biology and Physiology, University of New Mexico , Albuquerque, New Mexico
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19
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Díaz-García CM, Yellen G. Neurons rely on glucose rather than astrocytic lactate during stimulation. J Neurosci Res 2018; 97:883-889. [PMID: 30575090 DOI: 10.1002/jnr.24374] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/29/2018] [Accepted: 12/03/2018] [Indexed: 12/31/2022]
Abstract
Brain metabolism increases during stimulation, but this increase does not affect all energy metabolism equally. Briefly after stimulation, there is a local increase in cerebral blood flow and in glucose uptake, but a smaller increase in oxygen uptake. This indicates that temporarily the rate of glycolysis is faster than the rate of oxidative metabolism, with a corresponding temporary increase in lactate production. This minireview discusses the long-standing controversy about which cell type, neurons or astrocytes, are involved in this increased aerobic glycolysis. Recent biosensor studies measuring metabolic changes in neurons, in acute brain slices or in vivo, are placed in the context of other data bearing on this question. The most direct measurements indicate that, although both neurons and astrocytes may increase glycolysis after stimulation, neurons do not rely on import of astrocytic-produced lactate, and instead they increase their own glycolytic rate and become net exporters of lactate. This temporary increase in neuronal glycolysis may provide rapid energy to meet the acute energy demands of neurons.
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Affiliation(s)
| | - Gary Yellen
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts
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20
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Wendland K, Meisel A, Mergenthaler P. Investigating Gene Function for Neuronal Survival After Metabolic Stress Using Semi-Automated Fluorescence Microscopy and Automated Image Analysis. Front Mol Neurosci 2018; 11:393. [PMID: 30450034 PMCID: PMC6224347 DOI: 10.3389/fnmol.2018.00393] [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: 03/28/2018] [Accepted: 10/09/2018] [Indexed: 11/13/2022] Open
Abstract
Overexpression approaches and fluorescence microscopy techniques allow investigating important spatiotemporal aspects of gene regulation as well as quantifying gene function. Consequently, fluorescence microscopy techniques help answer important questions on gene regulation such as addressing the role of a specific gene product for neuronal survival under different treatments. Here, we describe a versatile tool to measure effects of a transfected gene of interest on neuronal survival upon metabolic stress. We focus on nutrient starvation of cultured rodent primary neurons as a model of metabolic stress but our approach can easily be generalized and adapted to other cell types or to investigate single gene function in regulating neuronal survival under various conditions.
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Affiliation(s)
- Kristin Wendland
- Charité-Universitätsmedizin Berlin, Department of Experimental Neurology, Berlin, Germany.,Charité-Universitätsmedizin Berlin, NeuroCure Clinical Research Center, Berlin, Germany
| | - Andreas Meisel
- Charité-Universitätsmedizin Berlin, Department of Experimental Neurology, Berlin, Germany.,Charité-Universitätsmedizin Berlin, NeuroCure Clinical Research Center, Berlin, Germany.,Charité-Universitätsmedizin Berlin, Center for Stroke Research Berlin, Berlin, Germany.,Charité-Universitätsmedizin Berlin, Department of Neurology, Berlin, Germany
| | - Philipp Mergenthaler
- Charité-Universitätsmedizin Berlin, Department of Experimental Neurology, Berlin, Germany.,Charité-Universitätsmedizin Berlin, NeuroCure Clinical Research Center, Berlin, Germany.,Charité-Universitätsmedizin Berlin, Center for Stroke Research Berlin, Berlin, Germany.,Charité-Universitätsmedizin Berlin, Department of Neurology, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
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21
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Yellen G. Fueling thought: Management of glycolysis and oxidative phosphorylation in neuronal metabolism. J Cell Biol 2018; 217:2235-2246. [PMID: 29752396 PMCID: PMC6028533 DOI: 10.1083/jcb.201803152] [Citation(s) in RCA: 208] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 04/30/2018] [Accepted: 05/02/2018] [Indexed: 01/02/2023] Open
Abstract
Yellen reviews how cellular metabolism responds acutely to the intense energy requirements of neurons when they are stimulated. The brain’s energy demands are remarkable both in their intensity and in their moment-to-moment dynamic range. This perspective considers the evidence for Warburg-like aerobic glycolysis during the transient metabolic response of the brain to acute activation, and it particularly addresses the cellular mechanisms that underlie this metabolic response. The temporary uncoupling between glycolysis and oxidative phosphorylation led to the proposal of an astrocyte-to-neuron lactate shuttle whereby during stimulation, lactate produced by increased glycolysis in astrocytes is taken up by neurons as their primary energy source. However, direct evidence for this idea is lacking, and evidence rather supports that neurons have the capacity to increase their own glycolysis in response to stimulation; furthermore, neurons may export rather than import lactate in response to stimulation. The possible cellular mechanisms for invoking metabolic resupply of energy in neurons are also discussed, in particular the roles of feedback signaling via adenosine diphosphate and feedforward signaling by calcium ions.
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Affiliation(s)
- Gary Yellen
- Department of Neurobiology, Harvard Medical School, Boston, MA
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22
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Kimura K, Matsumoto K, Ohtake H, Oka JI, Fujiwara H. Endogenous acetylcholine regulates neuronal and astrocytic vascular endothelial growth factor expression levels via different acetylcholine receptor mechanisms. Neurochem Int 2018; 118:42-51. [PMID: 29705288 DOI: 10.1016/j.neuint.2018.04.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 04/20/2018] [Accepted: 04/22/2018] [Indexed: 12/22/2022]
Abstract
Vascular endothelial growth factor (VEGF), a signaling molecule involved in angiogenesis, plays an important role in neuroprotection and neurogenesis. In the present study, we aimed to elucidate the mechanisms underlying endogenous acetylcholine (ACh)-induced VEGF expression in neurons and astrocytes, and identify the neuronal cells contributing to its expression in the medial septal area, a nuclear origin of cholinergic neurons mainly projecting to the hippocampus. The mRNA expression and secretion of VEGF were measured by RT-PCR and ELISA using mouse primary cultured cortical neurons and astrocytes. VEGF expression in the medial septal area was assessed by RT-PCR and immunostaining using mice treated with tacrine [9-amino-1,2,3,4-tetrahydro-acridine HCl (THA); 2.5 mg/kg, i.p.] once daily for 7 days. The THA treatment increased VEGF mRNA expression in neurons in a manner that was reversed by mecamylamine, a nicotinic ACh receptor (AChR) antagonist, whereas in mouse primary cultured astrocytes, carbachol, but not THA dose-dependently increased VEGF mRNA expression and secretion in a manner that was inhibited by scopolamine, a muscarinic AChR inhibitor. In in vivo studies, the administration of THA significantly increased the expression of VEGF in medial septal cholinergic neurons and the effects of THA were significantly blocked by mecamylamine. THA also significantly increased the expression levels of a phosphorylated form of VEGF receptor 2 (p-VEGFR2), an activated form of VEGFR2. The present results suggest that endogenous ACh plays an up-regulatory role for VEGF expression in neurons and astrocytes via different mechanisms. Moreover, endogenous ACh-induced increases in VEGF levels appear to activate VEGFR2 on medial septal cholinergic neurons via an autocrine mechanism.
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Affiliation(s)
- Kyoko Kimura
- Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Kinzo Matsumoto
- Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Hironori Ohtake
- Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Jun-Ichiro Oka
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Hironori Fujiwara
- Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
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