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Ge WD, Du TT, Wang CY, Sun LN, Wang YQ. Calcium signaling crosstalk between the endoplasmic reticulum and mitochondria, a new drug development strategies of kidney diseases. Biochem Pharmacol 2024; 225:116278. [PMID: 38740223 DOI: 10.1016/j.bcp.2024.116278] [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: 01/12/2024] [Revised: 04/25/2024] [Accepted: 05/10/2024] [Indexed: 05/16/2024]
Abstract
Calcium (Ca2+) acts as a second messenger and constitutes a complex and large information exchange system between the endoplasmic reticulum (ER) and mitochondria; this process is involved in various life activities, such as energy metabolism, cell proliferation and apoptosis. Increasing evidence has suggested that alterations in Ca2+ crosstalk between the ER and mitochondria, including alterations in ER and mitochondrial Ca2+ channels and related Ca2+ regulatory proteins, such as sarco/endoplasmic reticulum Ca2+-ATPase (SERCA), inositol 1,4,5-trisphosphate receptor (IP3R), and calnexin (CNX), are closely associated with the development of kidney disease. Therapies targeting intracellular Ca2+ signaling have emerged as an emerging field in the treatment of renal diseases. In this review, we focused on recent advances in Ca2+ signaling, ER and mitochondrial Ca2+ monitoring methods and Ca2+ homeostasis in the development of renal diseases and sought to identify new targets and insights for the treatment of renal diseases by targeting Ca2+ channels or related Ca2+ regulatory proteins.
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Affiliation(s)
- Wen-Di Ge
- Research Division of Clinical Pharmacology, the First Affiliated Hospital of Nanjing Medical University & Jiangsu Province Hospital, Nanjing, China; Department of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Tian-Tian Du
- Research Division of Clinical Pharmacology, the First Affiliated Hospital of Nanjing Medical University & Jiangsu Province Hospital, Nanjing, China; Department of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Cao-Yang Wang
- Research Division of Clinical Pharmacology, the First Affiliated Hospital of Nanjing Medical University & Jiangsu Province Hospital, Nanjing, China; Department of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Lu-Ning Sun
- Research Division of Clinical Pharmacology, the First Affiliated Hospital of Nanjing Medical University & Jiangsu Province Hospital, Nanjing, China; Department of Pharmacy, Nanjing Medical University, Nanjing, China.
| | - Yong-Qing Wang
- Research Division of Clinical Pharmacology, the First Affiliated Hospital of Nanjing Medical University & Jiangsu Province Hospital, Nanjing, China; Department of Pharmacy, Nanjing Medical University, Nanjing, China.
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2
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Cheng D, Lei ZG, Chu K, Lam OJH, Chiang CY, Zhang ZJ. N, N-Dimethyltryptamine, a natural hallucinogen, ameliorates Alzheimer's disease by restoring neuronal Sigma-1 receptor-mediated endoplasmic reticulum-mitochondria crosstalk. Alzheimers Res Ther 2024; 16:95. [PMID: 38693554 PMCID: PMC11061967 DOI: 10.1186/s13195-024-01462-3] [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: 02/14/2024] [Accepted: 04/17/2024] [Indexed: 05/03/2024]
Abstract
BACKGROUND Aberrant neuronal Sigma-1 receptor (Sig-1r)-mediated endoplasmic reticulum (ER)- mitochondria signaling plays a key role in the neuronal cytopathology of Alzheimer's disease (AD). The natural psychedelic N, N-dimethyltryptamine (DMT) is a Sig-1r agonist that may have the anti-AD potential through protecting neuronal ER-mitochondrial interplay. METHODS 3×TG-AD transgenic mice were administered with chronic DMT (2 mg/kg) for 3 weeks and then performed water maze test. The Aβ accumulation in the mice brain were determined. The Sig-1r level upon DMT treatment was tested. The effect of DMT on the ER-mitochondrial contacts site and multiple mitochondria-associated membrane (MAM)-associated proteins were examined. The effect of DMT on calcium transport between ER and mitochondria and the mitochondrial function were also evaluated. RESULTS chronic DMT (2 mg/kg) markedly alleviated cognitive impairment of 3×TG-AD mice. In parallel, it largely diminished Aβ accumulation in the hippocampus and prefrontal cortex. DMT restored the decreased Sig-1r levels of 3×TG-AD transgenic mice. The hallucinogen reinstated the expression of multiple MAM-associated proteins in the brain of 3×TG-AD mice. DMT also prevented physical contact and calcium dynamic between the two organelles in in vitro and in vivo pathological circumstances. DMT modulated oxidative phosphorylation (OXPHOS) and ATP synthase in the in vitro model of AD. CONCLUSION The anti-AD effects of DMT are associated with its protection of neuronal ER-mitochondria crosstalk via the activation of Sig-1r. DMT has the potential to serve as a novel preventive and therapeutic agent against AD.
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Affiliation(s)
- Dan Cheng
- Department of Chinese Medicine, The University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen, China
- School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Zhuo-Gui Lei
- Department of Neuroscience, City University of Hong Kong, Hong Kong, China
| | - Kin Chu
- Department of Psychology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Oi Jin Honey Lam
- School of Biomedical Sciences, Faculty of Science, The University of Hong Kong, Hong Kong, China
| | - Chun Yuan Chiang
- Digital Centre of State Key Laboratory of Quality Research in Chinese Medicine, Macau, China
| | - Zhang-Jin Zhang
- Department of Chinese Medicine, The University of Hong Kong-Shenzhen Hospital (HKU-SZH), Shenzhen, China.
- School of Chinese Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
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3
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Aryal SP, Xia M, Ortinski PI, Richards CI. Study of Calcium Signaling in Astrocytes with a Novel Endoplasmic Reticulum-Targeted GCaMP Sensor. Curr Protoc 2022; 2:e491. [PMID: 35938843 PMCID: PMC9373517 DOI: 10.1002/cpz1.491] [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] [Indexed: 06/15/2023]
Abstract
The endoplasmic reticulum (ER), the major organelle for the storage of Ca2+ , maintains a concentration of Ca2+ much higher than in the cytosol or other subcellular organelles, such as the mitochondria. A variety of tools have been developed for measuring Ca2+ activity in neuronal and glial cells, but most of these sensors target either the plasma membrane (PM) or the cytosol. Though these sensors are important for measuring Ca2+ transients, they lack the capability to measure activity in the periphery of the ER or to measure low-amplitude events resulting from Ca2+ exchange between the ER and other organelles, such as the mitochondria. We recently developed an ER-targeted GCaMP6f anchored to the cytosolic side of the ER that can measure minute calcium exchange occurring in this region. In this article, we discuss detailed methods to characterize the ER-GCaMP6f sensor, utilize it for calcium imaging in cultured astrocytes, and assess its expression and calcium imaging in astrocytes in rodent brains. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Expression and characterization of ER-GCaMP6f Support Protocol 1: ER-GCaMP6f-expressing stable cell line generation Basic Protocol 2: In vitro calcium imaging with ER-GCaMP6f Support Protocol 2: Imaging of drug-induced calcium activity Alternate Protocol 1: Transduction of astrocytes with ER-GCaMP6f AAV Alternate Protocol 2: Calcium imaging of astrocytes with Fluo-4 AM Basic Protocol 3: In vivo ER-GCaMP6f expression and slice calcium imaging Support Protocol 3: Pharmacological studies with 2-APB in brain slices.
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Affiliation(s)
- Surya P Aryal
- Department of Chemistry, University of Kentucky, Lexington, Kentucky
| | - Mengfan Xia
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
| | - Pavel I Ortinski
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky
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Kempmann A, Gensch T, Offenhäusser A, Tihaa I, Maybeck V, Balfanz S, Baumann A. The Functional Characterization of GCaMP3.0 Variants Specifically Targeted to Subcellular Domains. Int J Mol Sci 2022; 23:ijms23126593. [PMID: 35743038 PMCID: PMC9223625 DOI: 10.3390/ijms23126593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 05/31/2022] [Accepted: 06/06/2022] [Indexed: 11/16/2022] Open
Abstract
Calcium (Ca2+) ions play a pivotal role in physiology and cellular signaling. The intracellular Ca2+ concentration ([Ca2+]i) is about three orders of magnitude lower than the extracellular concentration, resulting in a steep transmembrane concentration gradient. Thus, the spatial and the temporal dynamics of [Ca2+]i are ideally suited to modulate Ca2+-mediated cellular responses to external signals. A variety of highly sophisticated methods have been developed to gain insight into cellular Ca2+ dynamics. In addition to electrophysiological measurements and the application of synthetic dyes that change their fluorescent properties upon interaction with Ca2+, the introduction and the ongoing development of genetically encoded Ca2+ indicators (GECI) opened a new era to study Ca2+-driven processes in living cells and organisms. Here, we have focused on one well-established GECI, i.e., GCaMP3.0. We have systematically modified the protein with sequence motifs, allowing localization of the sensor in the nucleus, in the mitochondrial matrix, at the mitochondrial outer membrane, and at the plasma membrane. The individual variants and a cytosolic version of GCaMP3.0 were overexpressed and purified from E. coli cells to study their biophysical properties in solution. All versions were examined to monitor Ca2+ signaling in stably transfected cell lines and in primary cortical neurons transduced with recombinant Adeno-associated viruses (rAAV). In this comparative study, we provide evidence for a robust approach to reliably trace Ca2+ signals at the (sub)-cellular level with pronounced temporal resolution.
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Affiliation(s)
- Annika Kempmann
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
| | - Thomas Gensch
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
| | - Andreas Offenhäusser
- Institute of Biological Information Processing, IBI-3, Research Center Jülich, 52428 Jülich, Germany; (A.O.); (I.T.); (V.M.)
| | - Irina Tihaa
- Institute of Biological Information Processing, IBI-3, Research Center Jülich, 52428 Jülich, Germany; (A.O.); (I.T.); (V.M.)
| | - Vanessa Maybeck
- Institute of Biological Information Processing, IBI-3, Research Center Jülich, 52428 Jülich, Germany; (A.O.); (I.T.); (V.M.)
| | - Sabine Balfanz
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
| | - Arnd Baumann
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
- Correspondence: ; Tel.: +49-2461-614014
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Brondi M, Bruzzone M, Lodovichi C, dal Maschio M. Optogenetic Methods to Investigate Brain Alterations in Preclinical Models. Cells 2022; 11:cells11111848. [PMID: 35681542 PMCID: PMC9180859 DOI: 10.3390/cells11111848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/27/2022] [Accepted: 05/31/2022] [Indexed: 02/05/2023] Open
Abstract
Investigating the neuronal dynamics supporting brain functions and understanding how the alterations in these mechanisms result in pathological conditions represents a fundamental challenge. Preclinical research on model organisms allows for a multiscale and multiparametric analysis in vivo of the neuronal mechanisms and holds the potential for better linking the symptoms of a neurological disorder to the underlying cellular and circuit alterations, eventually leading to the identification of therapeutic/rescue strategies. In recent years, brain research in model organisms has taken advantage, along with other techniques, of the development and continuous refinement of methods that use light and optical approaches to reconstruct the activity of brain circuits at the cellular and system levels, and to probe the impact of the different neuronal components in the observed dynamics. These tools, combining low-invasiveness of optical approaches with the power of genetic engineering, are currently revolutionizing the way, the scale and the perspective of investigating brain diseases. The aim of this review is to describe how brain functions can be investigated with optical approaches currently available and to illustrate how these techniques have been adopted to study pathological alterations of brain physiology.
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Affiliation(s)
- Marco Brondi
- Institute of Neuroscience, National Research Council-CNR, Viale G. Colombo 3, 35121 Padova, Italy; (M.B.); (C.L.)
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy
| | - Matteo Bruzzone
- Department of Biomedical Sciences, Università degli Studi di Padova, Via U. Bassi 58B, 35121 Padova, Italy;
- Padova Neuroscience Center (PNC), Università degli Studi di Padova, Via Orus 2, 35129 Padova, Italy
| | - Claudia Lodovichi
- Institute of Neuroscience, National Research Council-CNR, Viale G. Colombo 3, 35121 Padova, Italy; (M.B.); (C.L.)
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy
- Department of Biomedical Sciences, Università degli Studi di Padova, Via U. Bassi 58B, 35121 Padova, Italy;
- Padova Neuroscience Center (PNC), Università degli Studi di Padova, Via Orus 2, 35129 Padova, Italy
| | - Marco dal Maschio
- Department of Biomedical Sciences, Università degli Studi di Padova, Via U. Bassi 58B, 35121 Padova, Italy;
- Padova Neuroscience Center (PNC), Università degli Studi di Padova, Via Orus 2, 35129 Padova, Italy
- Correspondence:
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Serrat R, Oliveira-Pinto A, Marsicano G, Pouvreau S. Imaging mitochondrial calcium dynamics in the central nervous system. J Neurosci Methods 2022; 373:109560. [PMID: 35320763 DOI: 10.1016/j.jneumeth.2022.109560] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 03/04/2022] [Accepted: 03/06/2022] [Indexed: 12/28/2022]
Abstract
Mitochondrial calcium handling is a particularly active research area in the neuroscience field, as it plays key roles in the regulation of several functions of the central nervous system, such as synaptic transmission and plasticity, astrocyte calcium signaling, neuronal activity… In the last few decades, a panel of techniques have been developed to measure mitochondrial calcium dynamics, relying mostly on photonic microscopy, and including synthetic sensors, hybrid sensors and genetically encoded calcium sensors. The goal of this review is to endow the reader with a deep knowledge of the historical and latest tools to monitor mitochondrial calcium events in the brain, as well as a comprehensive overview of the current state of the art in brain mitochondrial calcium signaling. We will discuss the main calcium probes used in the field, their mitochondrial targeting strategies, their key properties and major drawbacks. In addition, we will detail the main roles of mitochondrial calcium handling in neuronal tissues through an extended report of the recent studies using mitochondrial targeted calcium sensors in neuronal and astroglial cells, in vitro and in vivo.
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Affiliation(s)
- Roman Serrat
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France
| | - Alexandre Oliveira-Pinto
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France
| | - Giovanni Marsicano
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France
| | - Sandrine Pouvreau
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215 NeuroCentre Magendie, France; University of Bordeaux, Bordeaux 33077, France.
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7
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Bourque K, Hawey C, Jiang A, Mazarura GR, Hébert TE. Biosensor-based profiling to track cellular signalling in patient-derived models of dilated cardiomyopathy. Cell Signal 2022; 91:110239. [PMID: 34990783 DOI: 10.1016/j.cellsig.2021.110239] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/06/2021] [Accepted: 12/29/2021] [Indexed: 12/18/2022]
Abstract
Dilated cardiomyopathies (DCM) represent a diverse group of cardiovascular diseases impacting the structure and function of the myocardium. To better treat these diseases, we need to understand the impact of such cardiomyopathies on critical signalling pathways that drive disease progression downstream of receptors we often target therapeutically. Our understanding of cellular signalling events has progressed substantially in the last few years, in large part due to the design, validation and use of biosensor-based approaches to studying such events in cells, tissues and in some cases, living animals. Another transformative development has been the use of human induced pluripotent stem cells (hiPSCs) to generate disease-relevant models from individual patients. We highlight the importance of going beyond monocellular cultures to incorporate the influence of paracrine signalling mediators. Finally, we discuss the recent coalition of these approaches in the context of DCM. We discuss recent work in generating patient-derived models of cardiomyopathies and the utility of using signalling biosensors to track disease progression and test potential therapeutic strategies that can be later used to inform treatment options in patients.
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Affiliation(s)
- Kyla Bourque
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Cara Hawey
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Alyson Jiang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Grace R Mazarura
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
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Redolfi N, García-Casas P, Fornetto C, Sonda S, Pizzo P, Pendin D. Lighting Up Ca 2+ Dynamics in Animal Models. Cells 2021; 10:2133. [PMID: 34440902 PMCID: PMC8392631 DOI: 10.3390/cells10082133] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/08/2021] [Accepted: 08/16/2021] [Indexed: 12/11/2022] Open
Abstract
Calcium (Ca2+) signaling coordinates are crucial processes in brain physiology. Particularly, fundamental aspects of neuronal function such as synaptic transmission and neuronal plasticity are regulated by Ca2+, and neuronal survival itself relies on Ca2+-dependent cascades. Indeed, impaired Ca2+ homeostasis has been reported in aging as well as in the onset and progression of neurodegeneration. Understanding the physiology of brain function and the key processes leading to its derangement is a core challenge for neuroscience. In this context, Ca2+ imaging represents a powerful tool, effectively fostered by the continuous amelioration of Ca2+ sensors in parallel with the improvement of imaging instrumentation. In this review, we explore the potentiality of the most used animal models employed for Ca2+ imaging, highlighting their application in brain research to explore the pathogenesis of neurodegenerative diseases.
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Affiliation(s)
- Nelly Redolfi
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (N.R.); (P.G.-C.); (C.F.); (S.S.); (P.P.)
| | - Paloma García-Casas
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (N.R.); (P.G.-C.); (C.F.); (S.S.); (P.P.)
| | - Chiara Fornetto
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (N.R.); (P.G.-C.); (C.F.); (S.S.); (P.P.)
| | - Sonia Sonda
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (N.R.); (P.G.-C.); (C.F.); (S.S.); (P.P.)
| | - Paola Pizzo
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (N.R.); (P.G.-C.); (C.F.); (S.S.); (P.P.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
| | - Diana Pendin
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy; (N.R.); (P.G.-C.); (C.F.); (S.S.); (P.P.)
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy
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9
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Endoplasmic reticulum-mitochondria coupling increases during doxycycline-induced mitochondrial stress in HeLa cells. Cell Death Dis 2021; 12:657. [PMID: 34183648 PMCID: PMC8238934 DOI: 10.1038/s41419-021-03945-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 06/16/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023]
Abstract
Subcellular organelles communicate with each other to regulate function and coordinate responses to changing cellular conditions. The physical-functional coupling of the endoplasmic reticulum (ER) with mitochondria allows for the direct transfer of Ca2+ between organelles and is an important avenue for rapidly increasing mitochondrial metabolic activity. As such, increasing ER-mitochondrial coupling can boost the generation of ATP that is needed to restore homeostasis in the face of cellular stress. The mitochondrial unfolded protein response (mtUPR) is activated by the accumulation of unfolded proteins in mitochondria. Retrograde signaling from mitochondria to the nucleus promotes mtUPR transcriptional responses aimed at restoring protein homeostasis. It is currently unknown whether the changes in mitochondrial-ER coupling also play a role during mtUPR stress. We hypothesized that mitochondrial stress favors an expansion of functional contacts between mitochondria and ER, thereby increasing mitochondrial metabolism as part of a protective response. Hela cells were treated with doxycycline, an antibiotic that inhibits the translation of mitochondrial-encoded proteins to create protein disequilibrium. Treatment with doxycycline decreased the abundance of mitochondrial encoded proteins while increasing expression of CHOP, C/EBPβ, ClpP, and mtHsp60, markers of the mtUPR. There was no change in either mitophagic activity or cell viability. Furthermore, ER UPR was not activated, suggesting focused activation of the mtUPR. Within 2 h of doxycycline treatment, there was a significant increase in physical contacts between mitochondria and ER that was distributed throughout the cell, along with an increase in the kinetics of mitochondrial Ca2+ uptake. This was followed by the rise in the rate of oxygen consumption at 4 h, indicating a boost in mitochondrial metabolic activity. In conclusion, an early phase of the response to doxycycline-induced mitochondrial stress is an increase in mitochondrial-ER coupling that potentiates mitochondrial metabolic activity as a means to support subsequent steps in the mtUPR pathway and sustain cellular adaptation.
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Wang H, Fang B, Peng B, Wang L, Xue Y, Bai H, Lu S, Voelcker NH, Li L, Fu L, Huang W. Recent Advances in Chemical Biology of Mitochondria Targeting. Front Chem 2021; 9:683220. [PMID: 34012953 PMCID: PMC8126688 DOI: 10.3389/fchem.2021.683220] [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: 03/20/2021] [Accepted: 04/19/2021] [Indexed: 12/14/2022] Open
Abstract
Mitochondria are vital subcellular organelles that generate most cellular chemical energy, regulate cell metabolism and maintain cell function. Mitochondrial dysfunction is directly linked to numerous diseases including neurodegenerative disorders, diabetes, thyroid squamous disease, cancer and septicemia. Thus, the design of specific mitochondria-targeting molecules and the realization of real-time acquisition of mitochondrial activity are powerful tools in the study and treatment of mitochondria dysfunction in related diseases. Recent advances in mitochondria-targeting agents have led to several important mitochondria chemical probes that offer the opportunity for selective targeting molecules, novel biological applications and therapeutic strategies. This review details the structural and physiological functional characteristics of mitochondria, and comprehensively summarizes and classifies mitochondria-targeting agents. In addition, their pros and cons and their related chemical biological applications are discussed. Finally, the potential biomedical applications of these agents are briefly prospected.
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Affiliation(s)
- Haiwei Wang
- Frontiers Science Center for Flexible Electronics, Xi’an Institute of Flexible Electronics (IFE) and Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an, China
| | - Bin Fang
- Frontiers Science Center for Flexible Electronics, Xi’an Institute of Flexible Electronics (IFE) and Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an, China
- School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, China
| | - Bo Peng
- Frontiers Science Center for Flexible Electronics, Xi’an Institute of Flexible Electronics (IFE) and Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an, China
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, VIC, Australia
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Limin Wang
- Frontiers Science Center for Flexible Electronics, Xi’an Institute of Flexible Electronics (IFE) and Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an, China
| | - Yufei Xue
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, VIC, Australia
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Hua Bai
- Frontiers Science Center for Flexible Electronics, Xi’an Institute of Flexible Electronics (IFE) and Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an, China
| | - Shenci Lu
- Frontiers Science Center for Flexible Electronics, Xi’an Institute of Flexible Electronics (IFE) and Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an, China
| | - Nicolas H. Voelcker
- Frontiers Science Center for Flexible Electronics, Xi’an Institute of Flexible Electronics (IFE) and Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an, China
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, VIC, Australia
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, VIC, Australia
- Department of Materials Science & Engineering, Monash University, Clayton, VIC, Australia
| | - Lin Li
- Frontiers Science Center for Flexible Electronics, Xi’an Institute of Flexible Electronics (IFE) and Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an, China
| | - Li Fu
- School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, China
| | - Wei Huang
- Frontiers Science Center for Flexible Electronics, Xi’an Institute of Flexible Electronics (IFE) and Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an, China
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing, China
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11
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Calvo-Rodriguez M, Kharitonova EK, Bacskai BJ. In vivo brain imaging of mitochondrial Ca 2+ in neurodegenerative diseases with multiphoton microscopy. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:118998. [PMID: 33684410 DOI: 10.1016/j.bbamcr.2021.118998] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/22/2021] [Indexed: 10/22/2022]
Abstract
Mitochondria are involved in a large number of essential roles related to neuronal function. Ca2+ handling by mitochondria is critical for many of these functions, including energy production and cellular fate. Conversely, mitochondrial Ca2+ mishandling has been related to a variety of neurodegenerative diseases. Investigating mitochondrial Ca2+ dynamics is essential for advancing our understanding of the role of intracellular mitochondrial Ca2+ signals in physiology and pathology. Improved Ca2+ indicators, and the ability to target them to different cells and compartments, have emerged as useful tools for analysis of Ca2+ signals in living organisms. Combined with state-of-the-art techniques such as multiphoton microscopy, they allow for the study of mitochondrial Ca2+ dynamics in vivo in mouse models of the disease. Here, we provide an overview of the Ca2+ transporters/ion channels in mitochondrial membranes, and the involvement of mitochondrial Ca2+ in neurodegenerative diseases followed by a summary of the main tools available to evaluate mitochondrial Ca2+ dynamics in vivo using the aforementioned technique.
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Affiliation(s)
- Maria Calvo-Rodriguez
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St, Charlestown, MA, 02129, USA.
| | - Elizabeth K Kharitonova
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St, Charlestown, MA, 02129, USA
| | - Brian J Bacskai
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 114, 16th St, Charlestown, MA, 02129, USA
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12
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Redolfi N, Greotti E, Zanetti G, Hochepied T, Fasolato C, Pendin D, Pozzan T. A New Transgenic Mouse Line for Imaging Mitochondrial Calcium Signals. FUNCTION 2021; 2:zqab012. [PMID: 35330679 PMCID: PMC8788866 DOI: 10.1093/function/zqab012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/19/2021] [Accepted: 02/24/2021] [Indexed: 01/06/2023] Open
Abstract
Mitochondria play a key role in cellular calcium (Ca2+) homeostasis. Dysfunction in the organelle Ca2+ handling appears to be involved in several pathological conditions, ranging from neurodegenerative diseases, cardiac failure and malignant transformation. In the past years, several targeted green fluorescent protein (GFP)-based genetically encoded Ca2+ indicators (GECIs) have been developed to study Ca2+ dynamics inside mitochondria of living cells. Surprisingly, while there is a number of transgenic mice expressing different types of cytosolic GECIs, few examples are available expressing mitochondria-localized GECIs, and none of them exhibits adequate spatial resolution. Here we report the generation and characterization of a transgenic mouse line (hereafter called mt-Cam) for the controlled expression of a mitochondria-targeted, Förster resonance energy transfer (FRET)-based Cameleon, 4mtD3cpv. To achieve this goal, we engineered the mouse ROSA26 genomic locus by inserting the optimized sequence of 4mtD3cpv, preceded by a loxP-STOP-loxP sequence. The probe can be readily expressed in a tissue-specific manner upon Cre recombinase-mediated excision, obtainable with a single cross. Upon ubiquitous Cre expression, the Cameleon is specifically localized in the mitochondrial matrix of cells in all the organs and tissues analyzed, from embryos to aged animals. Ca2+ imaging experiments performed in vitro and ex vivo in brain slices confirmed the functionality of the probe in isolated cells and live tissues. This new transgenic mouse line allows the study of mitochondrial Ca2+ dynamics in different tissues with no invasive intervention (such as viral infection or electroporation), potentially allowing simple calibration of the fluorescent signals in terms of mitochondrial Ca2+ concentration ([Ca2+]).
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Affiliation(s)
- Nelly Redolfi
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
| | - Elisa Greotti
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), Via U. Bassi 58/B, 35131 Padua, Italy
| | - Giulia Zanetti
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
| | - Tino Hochepied
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Cristina Fasolato
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
| | - Diana Pendin
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), Via U. Bassi 58/B, 35131 Padua, Italy
| | - Tullio Pozzan
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), Via U. Bassi 58/B, 35131 Padua, Italy
- Veneto Institute of Molecular Medicine (VIMM), Via G. Orus 2, 35129 Padua, Italy
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13
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Díaz-García CM, Meyer DJ, Nathwani N, Rahman M, Martínez-François JR, Yellen G. The distinct roles of calcium in rapid control of neuronal glycolysis and the tricarboxylic acid cycle. eLife 2021; 10:e64821. [PMID: 33555254 PMCID: PMC7870136 DOI: 10.7554/elife.64821] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 01/26/2021] [Indexed: 12/31/2022] Open
Abstract
When neurons engage in intense periods of activity, the consequent increase in energy demand can be met by the coordinated activation of glycolysis, the tricarboxylic acid (TCA) cycle, and oxidative phosphorylation. However, the trigger for glycolytic activation is unknown and the role for Ca2+ in the mitochondrial responses has been debated. Using genetically encoded fluorescent biosensors and NAD(P)H autofluorescence imaging in acute hippocampal slices, here we find that Ca2+ uptake into the mitochondria is responsible for the buildup of mitochondrial NADH, probably through Ca2+ activation of dehydrogenases in the TCA cycle. In the cytosol, we do not observe a role for the Ca2+/calmodulin signaling pathway, or AMPK, in mediating the rise in glycolytic NADH in response to acute stimulation. Aerobic glycolysis in neurons is triggered mainly by the energy demand resulting from either Na+ or Ca2+ extrusion, and in mouse dentate granule cells, Ca2+ creates the majority of this demand.
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Affiliation(s)
| | - Dylan J Meyer
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Nidhi Nathwani
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Mahia Rahman
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | | | - Gary Yellen
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
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14
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Nguyen H, Zerimech S, Baltan S. Astrocyte Mitochondria in White-Matter Injury. Neurochem Res 2021; 46:2696-2714. [PMID: 33527218 DOI: 10.1007/s11064-021-03239-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 12/11/2022]
Abstract
This review summarizes the diverse structure and function of astrocytes to describe the bioenergetic versatility required of astrocytes that are situated at different locations. The intercellular domain of astrocyte mitochondria defines their roles in supporting and regulating astrocyte-neuron coupling and survival against ischemia. The heterogeneity of astrocyte mitochondria, and how subpopulations of astrocyte mitochondria adapt to interact with other glia and regulate axon function, require further investigation. It has become clear that mitochondrial permeability transition pores play a key role in a wide variety of human diseases, whose common pathology may be based on mitochondrial dysfunction triggered by Ca2+ and potentiated by oxidative stress. Reactive oxygen species cause axonal degeneration and a reduction in axonal transport, leading to axonal dystrophies and neurodegeneration including Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, and Huntington's disease. Developing new tools to allow better investigation of mitochondrial structure and function in astrocytes, and techniques to specifically target astrocyte mitochondria, can help to unravel the role of mitochondrial health and dysfunction in a more inclusive context outside of neuronal cells. Overall, this review will assess the value of astrocyte mitochondria as a therapeutic target to mitigate acute and chronic injury in the CNS.
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Affiliation(s)
- Hung Nguyen
- Anesthesiology and Peri-Operative Medicine (APOM), Oregon Health and Science University, Portland, OR, 97239, USA
| | - Sarah Zerimech
- Anesthesiology and Peri-Operative Medicine (APOM), Oregon Health and Science University, Portland, OR, 97239, USA
| | - Selva Baltan
- Anesthesiology and Peri-Operative Medicine (APOM), Oregon Health and Science University, Portland, OR, 97239, USA.
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15
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Filadi R, Greotti E. The yin and yang of mitochondrial Ca 2+ signaling in cell physiology and pathology. Cell Calcium 2020; 93:102321. [PMID: 33310302 DOI: 10.1016/j.ceca.2020.102321] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/16/2020] [Accepted: 11/16/2020] [Indexed: 12/26/2022]
Abstract
Mitochondria are autonomous and dynamic cellular organelles orchestrating a diverse range of cellular activities. Numerous cell-signaling pathways target these organelles and Ca2+ is one of the most significant. Mitochondria are able to rapidly and transiently take up Ca2+, thanks to the mitochondrial Ca2+ uniporter complex, as well as to extrude it through the Na+/Ca2+ and H+/Ca2+ exchangers. The transient accumulation of Ca2+ in the mitochondrial matrix impacts on mitochondrial functions and cell pathophysiology. Here we summarize the role of mitochondrial Ca2+ signaling in both physiological (yang) and pathological (yin) processes and the methods that can be used to investigate mitochondrial Ca2+ homeostasis. As an example of the pivotal role of mitochondria in pathology, we described the state of the art of mitochondrial Ca2+ alterations in different pathological conditions, with a special focus on Alzheimer's disease.
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Affiliation(s)
- Riccardo Filadi
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy; Department of Biomedical Sciences, University of Padua, 35131, Padua, Italy.
| | - Elisa Greotti
- Neuroscience Institute, National Research Council (CNR), 35131 Padua, Italy; Department of Biomedical Sciences, University of Padua, 35131, Padua, Italy.
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16
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Cisneros IE, Ghorpade A, Borgmann K. Methamphetamine Activates Trace Amine Associated Receptor 1 to Regulate Astrocyte Excitatory Amino Acid Transporter-2 via Differential CREB Phosphorylation During HIV-Associated Neurocognitive Disorders. Front Neurol 2020; 11:593146. [PMID: 33324330 PMCID: PMC7724046 DOI: 10.3389/fneur.2020.593146] [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: 08/09/2020] [Accepted: 10/28/2020] [Indexed: 12/23/2022] Open
Abstract
Methamphetamine (METH) use, referred to as methamphetamine use disorder (MUD), results in neurocognitive decline, a characteristic shared with HIV-associated neurocognitive disorders (HAND). MUD exacerbates HAND partly through glutamate dysregulation. Astrocyte excitatory amino acid transporter (EAAT)-2 is responsible for >90% of glutamate uptake from the synaptic environment and is significantly decreased with METH and HIV-1. Our previous work demonstrated astrocyte trace amine associated receptor (TAAR) 1 to be involved in EAAT-2 regulation. Astrocyte EAAT-2 is regulated at the transcriptional level by cAMP responsive element binding (CREB) protein and NF-κB, transcription factors activated by cAMP, calcium and IL-1β. Second messengers, cAMP and calcium, are triggered by TAAR1 activation, which is upregulated by IL-1β METH-mediated increases in these second messengers and signal transduction pathways have not been shown to directly decrease astrocyte EAAT-2. We propose CREB activation serves as a master regulator of EAAT-2 transcription, downstream of METH-induced TAAR1 activation. To investigate the temporal order of events culminating in CREB activation, genetically encoded calcium indicators, GCaMP6s, were used to visualize METH-induced calcium signaling in primary human astrocytes. RNA interference and pharmacological inhibitors targeting or blocking cAMP-dependent protein kinase A and calcium/calmodulin kinase II confirmed METH-induced regulation of EAAT-2 and resultant glutamate clearance. Furthermore, we investigated METH-mediated CREB phosphorylation at both serine 133 and 142, the co-activator and co-repressor forms, respectively. Overall, this work revealed METH-induced differential CREB phosphorylation is a critical regulator for EAAT-2 function and may thus serve as a mechanistic target for the attenuation of METH-induced excitotoxicity in the context of HAND.
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Affiliation(s)
- Irma E Cisneros
- Department of Microbiology, Immunology, and Genetics, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Anuja Ghorpade
- Department of Microbiology, Immunology, and Genetics, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Kathleen Borgmann
- Department of Microbiology, Immunology, and Genetics, University of North Texas Health Science Center, Fort Worth, TX, United States
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17
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Wang X, Zhang Z, Zhang N, Li H, Zhang L, Baines CP, Ding S. Subcellular NAMPT-mediated NAD + salvage pathways and their roles in bioenergetics and neuronal protection after ischemic injury. J Neurochem 2019; 151:732-748. [PMID: 31553812 DOI: 10.1111/jnc.14878] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/12/2019] [Accepted: 09/16/2019] [Indexed: 12/21/2022]
Abstract
NAD+ is a cofactor required for glycolysis, tricarboxylic acid cycle, and complex I enzymatic reaction. In mammalian cells, NAD+ is predominantly synthesized through the salvage pathway, where nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme. Previously, we demonstrated that NAMPT exerts a neuroprotective effect in ischemia through the suppression of mitochondrial dysfunction. Mammalian cells maintain distinct NAD+ pools in the cytosol, mitochondria, and nuclei. However, it is unknown whether mitochondria have an intact machinery for NAD+ salvage, and if so, whether it plays a dominant role in bioenergetics, mitochondrial function, and neuronal protection after ischemia. Here, using mouse primary cortical neuron and cortical tissue preparations, and multiple technologies including cytosolic and mitochondrial subfractionation, viral over-expression of transgenes, molecular biology, and confocal microscopy, we provided compelling evidence that neuronal mitochondria possess an intact machinery of NAMPT-mediated NAD+ salvage pathway, and that NAMPT and nicotinamide mononucleotide adenylyltransferase 3 (NMNAT3) are localized in the mitochondrial matrix. By knocking down NMNAT1-3 and NAMPT with siRNA, we found that NMNAT3 has a larger effect on basal and ATP production-related mitochondrial respiration than NMNAT1-2 in primary cultured neurons, while NMNAT1-2 have a larger effect on glycolytic flux than NMNAT3. Using an oxygen glucose deprivation model, we found that mitochondrial, cytoplasmic, and non-subcellular compartmental over-expressions of NAMPT have a comparable effect on neuronal protection and suppression of apoptosis-inducing factor translocation. The current study provides novel insights into the roles of subcellular compartmental NAD+ salvage pathways in NAD+ homeostasis, bioenergetics, and neuronal protection in ischemic conditions.
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Affiliation(s)
- Xiaowan Wang
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, Missouri, USA
| | - Zhe Zhang
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, Missouri, USA
| | - Nannan Zhang
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
| | - Hailong Li
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, Missouri, USA.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
| | - Li Zhang
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, Missouri, USA
| | - Christopher P Baines
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA.,Department of Biomedical Science, University of Missouri, Columbia, Missouri, USA
| | - Shinghua Ding
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, Missouri, USA.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
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18
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Okubo Y, Iino M. Visualization of astrocytic intracellular Ca 2+ mobilization. J Physiol 2019; 598:1671-1681. [PMID: 30825213 DOI: 10.1113/jp277609] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 02/06/2019] [Indexed: 11/08/2022] Open
Abstract
Astrocytes generate robust intracellular Ca2+ concentration changes (Ca2+ signals), which are assumed to regulate astrocytic functions that play crucial roles in the regulation of brain functions. One frequently used strategy for exploring the role of astrocytic Ca2+ signalling is the use of mice deficient in the type 2 inositol 1,4,5-trisphosphate receptor (IP3 R2). These IP3 R2-knockout (KO) mice are reportedly devoid of Ca2+ mobilization from the endoplasmic reticulum (ER) in astrocytes. However, they have shown no functional deficits in several studies, causing a heated debate as to the functional relevance of ER-mediated Ca2+ signalling in astrocytes. Recently, the assumption that Ca2+ mobilization from the ER is absent in IP3 R2-KO astrocytes has been re-evaluated using intraorganellar Ca2+ imaging techniques. The new results indicated that IP3 R2-independent Ca2+ release may generate Ca2+ nanodomains around the ER, which may help explain the absence of functional deficits in IP3 R2-KO mice.
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Affiliation(s)
- Yohei Okubo
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, 133-0033, Japan
| | - Masamitsu Iino
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, 173-8610, Japan
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19
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Baeza-Lehnert F, Saab AS, Gutiérrez R, Larenas V, Díaz E, Horn M, Vargas M, Hösli L, Stobart J, Hirrlinger J, Weber B, Barros LF. Non-Canonical Control of Neuronal Energy Status by the Na + Pump. Cell Metab 2019; 29:668-680.e4. [PMID: 30527744 DOI: 10.1016/j.cmet.2018.11.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 08/01/2018] [Accepted: 11/12/2018] [Indexed: 12/31/2022]
Abstract
Neurons have limited intracellular energy stores but experience acute and unpredictable increases in energy demand. To better understand how these cells repeatedly transit from a resting to active state without undergoing metabolic stress, we monitored their early metabolic response to neurotransmission using ion-sensitive probes and FRET sensors in vitro and in vivo. A short theta burst triggered immediate Na+ entry, followed by a delayed stimulation of the Na+/K+ ATPase pump. Unexpectedly, cytosolic ATP and ADP levels were unperturbed across a wide range of physiological workloads, revealing strict flux coupling between the Na+ pump and mitochondria. Metabolic flux measurements revealed a "priming" phase of mitochondrial energization by pyruvate, whereas glucose consumption coincided with delayed Na+ pump stimulation. Experiments revealed that the Na+ pump plays a permissive role for mitochondrial ATP production and glycolysis. We conclude that neuronal energy homeostasis is not mediated by adenine nucleotides or by Ca2+, but by a mechanism commanded by the Na+ pump.
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Affiliation(s)
- Felipe Baeza-Lehnert
- Centro de Estudios Científicos (CECs), Casilla 1469, 5110466 Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - Aiman S Saab
- Institute of Pharmacology and Toxicology, University and ETH Zurich, Switzerland; Neuroscience Center Zurich, Zurich, Switzerland
| | - Robin Gutiérrez
- Centro de Estudios Científicos (CECs), Casilla 1469, 5110466 Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - Valeria Larenas
- Centro de Estudios Científicos (CECs), Casilla 1469, 5110466 Valdivia, Chile
| | - Esteban Díaz
- Centro de Estudios Científicos (CECs), Casilla 1469, 5110466 Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - Melanie Horn
- Centro de Estudios Científicos (CECs), Casilla 1469, 5110466 Valdivia, Chile
| | - Miriam Vargas
- Centro de Estudios Científicos (CECs), Casilla 1469, 5110466 Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - Ladina Hösli
- Institute of Pharmacology and Toxicology, University and ETH Zurich, Switzerland; Neuroscience Center Zurich, Zurich, Switzerland
| | - Jillian Stobart
- Institute of Pharmacology and Toxicology, University and ETH Zurich, Switzerland; Neuroscience Center Zurich, Zurich, Switzerland
| | - Johannes Hirrlinger
- Carl-Ludwig-Institute for Physiology, Faculty of Medicine, University of Leipzig, 04103 Leipzig, Germany; Department of Neurogenetics, Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University and ETH Zurich, Switzerland; Neuroscience Center Zurich, Zurich, Switzerland
| | - L Felipe Barros
- Centro de Estudios Científicos (CECs), Casilla 1469, 5110466 Valdivia, Chile.
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20
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Montagna E, Crux S, Luckner M, Herber J, Colombo AV, Marinković P, Tahirovic S, Lichtenthaler SF, Wanner G, Müller UC, Sgobio C, Herms J. In vivo
Ca
2+
imaging of astrocytic microdomains reveals a critical role of the amyloid precursor protein for mitochondria. Glia 2019; 67:985-998. [DOI: 10.1002/glia.23584] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 12/17/2018] [Accepted: 12/20/2018] [Indexed: 01/04/2023]
Affiliation(s)
- Elena Montagna
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Division of Translational Brain Research, Center for Neuropathology and Prion ResearchLudwig–Maximilians University Munich Germany
- Munich Cluster of Systems Neurology (SyNergy)Ludwig‐Maximilians University Munich Germany
| | - Sophie Crux
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Division of Translational Brain Research, Center for Neuropathology and Prion ResearchLudwig–Maximilians University Munich Germany
- Munich Cluster of Systems Neurology (SyNergy)Ludwig‐Maximilians University Munich Germany
| | - Manja Luckner
- Department Biology I, BiocenterLudwig‐Maximilians University Munich Martinsried Germany
| | - Julia Herber
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar and Institute for Advanced StudyTechnische Universität München Munich Germany
| | - Alessio V. Colombo
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
| | - Petar Marinković
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
| | - Sabina Tahirovic
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
| | - Stefan F. Lichtenthaler
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Munich Cluster of Systems Neurology (SyNergy)Ludwig‐Maximilians University Munich Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar and Institute for Advanced StudyTechnische Universität München Munich Germany
| | - Gerhard Wanner
- Department Biology I, BiocenterLudwig‐Maximilians University Munich Martinsried Germany
| | - Ulrike C. Müller
- Department of Functional Genomics, Institute of Pharmacy and Molecular BiotechnologyHeidelberg University Heidelberg Germany
| | - Carmelo Sgobio
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
| | - Jochen Herms
- Division of Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE) Munich Germany
- Division of Translational Brain Research, Center for Neuropathology and Prion ResearchLudwig–Maximilians University Munich Germany
- Munich Cluster of Systems Neurology (SyNergy)Ludwig‐Maximilians University Munich Germany
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21
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Li H, Wei X, Yang J, Dong D, Huang Y, Lan X, Plath M, Lei C, Qi X, Bai Y, Chen H. Developmental transcriptome profiling of bovine muscle tissue reveals an abundant GosB that regulates myoblast proliferation and apoptosis. Oncotarget 2018; 8:32083-32100. [PMID: 28404879 PMCID: PMC5458270 DOI: 10.18632/oncotarget.16644] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/28/2017] [Indexed: 01/20/2023] Open
Abstract
The formation of bovine skeletal muscle involves complex developmental and physiological processes that play a vital role in determining the quality of beef; however, the regulatory mechanisms underlying differences in meat quality are largely unknown. We conducted transcriptome analysis of bovine muscle tissues to compare gene expression profiles between embryonic and adult stages. Total RNAs from skeletal muscle of Qinchuan cattle at fetal and adult stages were used to construct libraries for Illumina next-generation sequencing using the Ribo-Zero RNA sequencing (RNA-Seq) method. We found a total of 19,695 genes to be expressed in fetal and adult stages, whereby 3,299 were expressed only in fetal, and 433 only in adult tissues. We characterized the role of a candidate gene (GosB), which was highly (but differentially) expressed in embryonic and adult skeletal muscle tissue. GosB increased the number of myoblasts in the S-phase of the cell cycle, and decreased the proportion of cells in the G0/G1 phase. GosB promoted the proliferation of myoblasts and protected them from apoptosis via regulating Bcl-2 expression and controlling the intracellular calcium concentration. Modulation of GosB expression in muscle tissue may emerge as a potential target in breeding strategies attempting to alter myoblast numbers in cattle.
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Affiliation(s)
- Hui Li
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Xuefeng Wei
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Jiameng Yang
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Dong Dong
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yongzhen Huang
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Xianyong Lan
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Martin Plath
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Chuzhao Lei
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Xinglei Qi
- Bureau of Animal Husbandry of Biyang County, Biyang, Henan 463700, China
| | - Yueyu Bai
- Animal Health Supervision of Henan Province, Bureau of Animal Husbandry of Henan province, Zhengzhou, Henan 450008, China
| | - Hong Chen
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China
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22
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Zhang N, Ding S. Imaging of Mitochondrial and Cytosolic Ca 2+ Signals in Cultured Astrocytes. ACTA ACUST UNITED AC 2018; 82:2.29.1-2.29.11. [PMID: 29357111 DOI: 10.1002/cpns.42] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This unit provides a step-by-step protocol for constructing cell type- and mitochondria-targeted GCaMP genetically encoded Ca2+ indicators (GECIs) for mitochondrial Ca2+ imaging in astrocytes. Mitochondrial Ca2+ plays a critical role in controlling cytosolic Ca2+ buffering, energy metabolism, and cellular signal transduction. Mitochondrial Ca2+ overload contributes to various pathological conditions, including neurodegeneration and apoptotic cell death in neurological diseases. Live-cell mitochondrial Ca2+ imaging is an important approach to understand mitochondrial Ca2+ dynamics and thus cell physiology and pathology. We implement astrocyte-specific mitochondrial targeting of GCaMP5G/6s (mito-GCaMP5G/6s). By loading X-Rhod-1 into astrocytes, we can simultaneously image mitochondrial and cytosolic Ca2+ signals. This protocol provides a novel approach to image mitochondrial Ca2+ dynamics as well as Ca2+ interplay between the endoplasmic reticulum and mitochondria. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Nannan Zhang
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Shinghua Ding
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri.,Department of Bioengineering, University of Missouri, Columbia, Missouri
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23
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GosB Inhibits Triacylglycerol Synthesis and Promotes Cell Survival in Mouse Mammary Epithelial Cells. BIOMED RESEARCH INTERNATIONAL 2017; 2017:7394869. [PMID: 29181403 PMCID: PMC5664265 DOI: 10.1155/2017/7394869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 08/26/2017] [Accepted: 09/07/2017] [Indexed: 11/18/2022]
Abstract
It has been demonstrated that the activator protein related transcription factor Finkel-Biskis-Jinkins murine osteosarcoma B (GosB) is involved in preadipocyte differentiation and triacylglycerol synthesis. However, the role of GosB in regulating the synthesis of milk fatty acid in mouse mammary glands remains unclear. This research uncovered potentially new roles of GosB in suppressing milk fatty acid synthesis. Results revealed that GosB had the highest expression in lung tissue and showed a higher expression level during nonlactation than during lactation. GosB inhibited the expression of fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD), fatty acid binding protein 4 (FABP4), diacylglycerol acyltransferase 1 (DGAT1), perilipin 2 (PLIN2), perilipin 3 (PLIN3), and C/EBPα in mouse mammary gland epithelial cells (MEC). In addition, GosB reduced cellular triglyceride content and the accumulation of lipid droplets; in particular, GosB enhanced saturated fatty acid concentration (C16:0 and C18:0). The PPARγ agonist, rosiglitazone (ROSI), promoted apoptosis and inhibited cell proliferation. GosB increased the expression of Bcl-2 and protected MEC from ROSI-induced apoptosis. Furthermore, MECs were protected from apoptosis through the GosB regulation of intracellular calcium concentrations. These findings suggest that GosB may regulate mammary epithelial cells milk fat synthesis and apoptosis via PPARγ in mouse mammary glands.
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Wei X, Li H, Zhao G, Yang J, Li L, Huang Y, Lan X, Ma Y, Hu L, Zheng H, Chen H. ΔFosB regulates rosiglitazone-induced milk fat synthesis and cell survival. J Cell Physiol 2017; 233:9284-9298. [PMID: 29154466 DOI: 10.1002/jcp.26218] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 10/09/2017] [Indexed: 02/06/2023]
Abstract
Rosiglitazone induces adipogenesis in adipocyte and regulates cell survival and differentiation in number of cell types. However, whether PPARγ regulates the synthesis of milk fat and cell survival in goat mammary gland remains unknown. Rosiglitazone strongly enhanced cellular triacylglycerol content and accumulation of lipid droplet in goat mammary epithelial cells (GMEC). Furthermore, ΔFosB decreased the expression of PPARγ at both mRNA and protein levels, and rosiglitazone-induced milk fat synthesis was abolished by ΔFosB overexpression. ΔFosB reduced milk fat synthesis and enhanced saturated fatty acid concentration. Rosiglitazone increased the number of GMEC in G0/G1 phase and inhibited cell proliferation, and these effects were improved by overexpression of ΔFosB. ΔFosB was found to promote the expression of Bcl-2 and suppress the expression of Bax, and protected GMEC from apoptosis induced by rosiglitazone. Intracellular calcium trafficking assay revealed that rosiglitazone markedly increased intracellular calcium concentration. ΔFosB protected GMEC from apoptosis induced by intracellular Ca2+ overload. ΔFosB increased MMP-9 gelatinolytic activity. SB-3CT, an MMP-9 inhibitor, suppressed the expression of Bcl-2, and increased intracellular calcium levels, and this effect was abolished by ΔFosB overexpression. SB-3CT induced GMEC apoptosis and this effect was inhibited by ΔFosB overexpression. These findings suggest that ΔFosB regulates rosiglitazone-induced milk fat synthesis and cell survival. Therefore, ΔFosB may be an important checkpoint to control milk fat synthesis and cell apoptosis.
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Affiliation(s)
- Xuefeng Wei
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.,College of Life Sciences, Xinyang Normal University, Institute for Conservation and Utilization of Agro-Bioresources in Dabie Mountains, Xinyang, Henan, China
| | - Hui Li
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.,College of Life Sciences, Xinyang Normal University, Institute for Conservation and Utilization of Agro-Bioresources in Dabie Mountains, Xinyang, Henan, China
| | - Guangwei Zhao
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Jiameng Yang
- College of Life Sciences, Xinyang Normal University, Institute for Conservation and Utilization of Agro-Bioresources in Dabie Mountains, Xinyang, Henan, China
| | - Lihui Li
- College of Life Sciences, Xinyang Normal University, Institute for Conservation and Utilization of Agro-Bioresources in Dabie Mountains, Xinyang, Henan, China
| | - Yongzhen Huang
- College of Life Sciences, Xinyang Normal University, Institute for Conservation and Utilization of Agro-Bioresources in Dabie Mountains, Xinyang, Henan, China
| | - Xianyong Lan
- College of Life Sciences, Xinyang Normal University, Institute for Conservation and Utilization of Agro-Bioresources in Dabie Mountains, Xinyang, Henan, China
| | - Yun Ma
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Linyong Hu
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, Qinghai, China
| | - Huiling Zheng
- College of Life Sciences, Xinyang Normal University, Institute for Conservation and Utilization of Agro-Bioresources in Dabie Mountains, Xinyang, Henan, China
| | - Hong Chen
- Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.,College of Life Sciences, Xinyang Normal University, Institute for Conservation and Utilization of Agro-Bioresources in Dabie Mountains, Xinyang, Henan, China
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25
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Comparison of GCaMP3 and GCaMP6f for studying astrocyte Ca2+ dynamics in the awake mouse brain. PLoS One 2017; 12:e0181113. [PMID: 28742117 PMCID: PMC5524333 DOI: 10.1371/journal.pone.0181113] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 06/25/2017] [Indexed: 12/16/2022] Open
Abstract
In recent years it has become increasingly clear that astrocytes play a much more active role in neural processes than the traditional view of them as supporting cells suggests. Although not electrically excitable, astrocytes exhibit diverse Ca2+ dynamics across spatial and temporal scales, more or less dependent on the animal's behavioral state. Ca2+ dynamics range from global elevations lasting multiple seconds encompassing the soma up to the finest processes, to short elevations restricted to so-called microdomains within fine processes. Investigations of astrocyte Ca2+ dynamics have particularly benefitted from the development of Genetically-Encoded Calcium Indicators (GECIs). GECI expression can be achieved non-invasively in a cell type-specific manner and it can be genetically targeted to subcellular domains. The GCaMP family, a group of GECIs derived from the green fluorescent protein, has experienced some of the fastest advancements during the past decade. As a consequence we are now facing the challenge of needing to compare published data obtained with different versions of GECIs. With the intention to provide some guidance, here we compared Ca2+ dynamics across scales in awake transgenic mice expressing either the well-established GCaMP3, or the increasingly popular GCaMP6f, specifically in astrocytes. We found that locomotion-induced global Ca2+ elevations in cortical astrocytes displayed only minor kinetic differences and their apparent dynamic ranges for Ca2+ sensing were not different. In contrast, Ca2+ waves in processes and microdomain Ca2+ transients were much more readily detectable with GCaMP6f. Our findings suggest that behavioral state-dependent global astrocyte Ca2+ responses can be studied with either GCaMP3 or GCaMP6f whereas the latter is more appropriate for studies of spatially restricted weak and fast Ca2+ dynamics.
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Spatiotemporal control of mitochondrial network dynamics in astroglial cells. Biochem Biophys Res Commun 2017; 500:17-25. [PMID: 28676398 DOI: 10.1016/j.bbrc.2017.06.191] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/30/2017] [Indexed: 12/17/2022]
Abstract
Mitochondria are increasingly recognized for playing important roles in regulating the evolving metabolic state of mammalian cells. This is particularly true for nerve cells, as dysregulation of mitochondrial dynamics is invariably associated with a number of neuropathies. Accumulating evidence now reveals that changes in mitochondrial dynamics and structure may play equally important roles also in the cell biology of astroglial cells. Astroglial cells display significant heterogeneity in their morphology and specialized functions across different brain regions, however besides fundamental differences they seem to share a surprisingly complex meshwork of mitochondria, which is highly suggestive of tightly regulated mechanisms that contribute to maintain this unique architecture. Here, we summarize recent work performed in astrocytes in situ indicating that this may indeed be the case, with astrocytic mitochondrial networks shown to experience rapid dynamic changes in response to defined external cues. Although the mechanisms underlying this degree of mitochondrial re-shaping are far from being understood, recent data suggest that they may contribute to demarcate astrocyte territories undergoing key signalling and metabolic functions.
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27
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Dong Z, Zhao P, Xu M, Zhang C, Guo W, Chen H, Tian J, Wei H, Lu R, Cao T. Astragaloside IV alleviates heart failure via activating PPARα to switch glycolysis to fatty acid β-oxidation. Sci Rep 2017; 7:2691. [PMID: 28578382 PMCID: PMC5457407 DOI: 10.1038/s41598-017-02360-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 04/10/2017] [Indexed: 01/01/2023] Open
Abstract
In heart failure (HF), energy metabolism pathway in cardiac muscle changes from fatty acid β-oxidation to glycolysis. However, the exact mechanism is unknown. Sarcoendoplasmic reticulum Ca2+α ATPase (SERCA) expression is downregulated and mitochondrial function is reduced in HF, perhaps partly due to a substantially reduced energy supply for excitation–contraction coupling resulting from a lower fatty acid β-oxidation rate. We investigated whether Astragaloside IV can activate peroxisome proliferator-activated receptor alpha (PPARα) to stimulate fatty acid β-oxidation and increase cardiac energy production, improving mitochondrial function and the efficiency of SERCA in HF. In pressure overload-induced HF mice and isolated hypertrophic myocardial cells, fatty acid β-oxidation and heart function were substantially strengthened following Astragaloside IV treatment, as demonstrated by the increased expression of PPARα and SERCA2a. In vitro, Astragaloside IV regulated energy metabolism by increasing ATP production and enhancing mitochondrial function, attributable to increased oxygen consumption and slightly increased mitochondrial Ca2+ uptake. In HF, Astragaloside IV switched glycolysis to fatty acid β-oxidation, as confirmed by reduced anaerobic glycolysis and an increased oxygen consumption ratio. These results suggest that Astragaloside IV can stimulate fatty acid β-oxidation and improve mitochondrial function, which may present a novel cardioprotective treatment that inhibits the progress of HF.
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Affiliation(s)
- Zhiwei Dong
- Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University, Chongqing, 400038, China
| | - Pei Zhao
- Department of Pathology, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Ming Xu
- Department of Pathology, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Chen Zhang
- Division of Cardiothoracic Surgery, Baylor college of medicine, Houston, Texas, USA
| | - Wei Guo
- Department of Pathology, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Huihua Chen
- Department of Pathology, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Jing Tian
- Department of Pathology, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Hongchang Wei
- Department of Pathology, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Rong Lu
- Department of Pathology, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China.
| | - Tongtong Cao
- Department of Pathology, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China.
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28
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Bassett JJ, Monteith GR. Genetically Encoded Calcium Indicators as Probes to Assess the Role of Calcium Channels in Disease and for High-Throughput Drug Discovery. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 79:141-171. [PMID: 28528667 DOI: 10.1016/bs.apha.2017.01.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The calcium ion (Ca2+) is an important signaling molecule implicated in many cellular processes, and the remodeling of Ca2+ homeostasis is a feature of a variety of pathologies. Typical methods to assess Ca2+ signaling in cells often employ small molecule fluorescent dyes, which are sometimes poorly suited to certain applications such as assessment of cellular processes, which occur over long periods (hours or days) or in vivo experiments. Genetically encoded calcium indicators are a set of tools available for the measurement of Ca2+ changes in the cytosol and subcellular compartments, which circumvent some of the inherent limitations of small molecule Ca2+ probes. Recent advances in genetically encoded calcium sensors have greatly increased their ability to provide reliable monitoring of Ca2+ changes in mammalian cells. New genetically encoded calcium indicators have diverse options in terms of targeting, Ca2+ affinity and fluorescence spectra, and this will further enhance their potential use in high-throughput drug discovery and other assays. This review will outline the methods available for Ca2+ measurement in cells, with a focus on genetically encoded calcium sensors. How these sensors will improve our understanding of the deregulation of Ca2+ handling in disease and their application to high-throughput identification of drug leads will also be discussed.
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Affiliation(s)
- John J Bassett
- School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia
| | - Gregory R Monteith
- School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia; Mater Research, The University of Queensland, Brisbane, QLD, Australia.
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29
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Eraso-Pichot A, Larramona-Arcas R, Vicario-Orri E, Villalonga R, Pardo L, Galea E, Masgrau R. CREB decreases astrocytic excitability by modifying subcellular calcium fluxes via the sigma-1 receptor. Cell Mol Life Sci 2017; 74:937-950. [PMID: 27761593 PMCID: PMC11107612 DOI: 10.1007/s00018-016-2397-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/04/2016] [Accepted: 10/10/2016] [Indexed: 12/15/2022]
Abstract
Astrocytic excitability relies on cytosolic calcium increases as a key mechanism, whereby astrocytes contribute to synaptic transmission and hence learning and memory. While it is a cornerstone of neurosciences that experiences are remembered, because transmitters activate gene expression in neurons, long-term adaptive astrocyte plasticity has not been described. Here, we investigated whether the transcription factor CREB mediates adaptive plasticity-like phenomena in astrocytes. We found that activation of CREB-dependent transcription reduced the calcium responses induced by ATP, noradrenaline, or endothelin-1. As to the mechanism, expression of VP16-CREB, a constitutively active CREB mutant, had no effect on basal cytosolic calcium levels, extracellular calcium entry, or calcium mobilization from lysosomal-related acidic stores. Rather, VP16-CREB upregulated sigma-1 receptor expression thereby increasing the release of calcium from the endoplasmic reticulum and its uptake by mitochondria. Sigma-1 receptor was also upregulated in vivo upon VP16-CREB expression in astrocytes. We conclude that CREB decreases astrocyte responsiveness by increasing calcium signalling at the endoplasmic reticulum-mitochondria interface, which might be an astrocyte-based form of long-term depression.
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Affiliation(s)
- A Eraso-Pichot
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Edifici M, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Catalonia, Spain
| | - R Larramona-Arcas
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Edifici M, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Catalonia, Spain
| | - E Vicario-Orri
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Edifici M, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Catalonia, Spain
- Department of Neurosciences, School of Medicine, University of California, 9500 Gilman Dr, La Jolla, CA, 92093, USA
| | - R Villalonga
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Edifici M, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Catalonia, Spain
| | - L Pardo
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Edifici M, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Catalonia, Spain
| | - E Galea
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Edifici M, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Catalonia, Spain.
- Institució Catalana De Recerca I Estudis Avançats (ICREA), Passeig Lluís Companys 23, 08010, Barcelona, Catalonia, Spain.
| | - R Masgrau
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Edifici M, Universitat Autònoma de Barcelona, Bellaterra, 08193, Barcelona, Catalonia, Spain.
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30
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Diercks BP, Fliegert R, Guse AH. Mag-Fluo4 in T cells: Imaging of intra-organelle free Ca 2+ concentrations. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:977-986. [PMID: 27913206 DOI: 10.1016/j.bbamcr.2016.11.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/21/2016] [Accepted: 11/22/2016] [Indexed: 01/22/2023]
Abstract
Ca2+ signaling is a major signal transduction pathway involved in T cell activation, but also in apoptosis of T cells. Since T cells make use of several Ca2+-mobilizing second messengers, such as nicotinic acid adenine dinucleotide phosphate, d-myo-inositol 1,4,5-trisphosphate, and cyclic ADP-ribose, we intended to analyze luminal Ca2+ concentration upon cell activation. Mag-Fluo4/AM, a low-affinity Ca2+ dye known to localize to the endoplasmic reticular lumen in many cell types, showed superior brightness and bleaching stability, but, surprisingly, co-localized with mito-tracker, but not with ER-tracker in Jurkat T cells. Thus, we used Mag-Fluo4/AM to monitor the free luminal mitochondrial Ca2+ concentration ([Ca2+]mito) in these cells. Simultaneous analysis of the free cytosolic Ca2+ concentration ([Ca2+]i) and [Ca2+]mito upon cell stimulation revealed that Ca2+ signals in the majority of mitochondria were initiated at [Ca2+ ]i≥approx. 400 to 550nM. In primary murine CD4+ T cells, Mag-Fluo4 showed two different localization patterns: either co-localization with mito-tracker, as in Jurkat T cells, or with ER-tracker. Thus, in single primary murine CD4+ T cells, either decreases of [Ca2+ ]ER or increases of [Ca2+ ]mito were observed upon cell stimulation. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.
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Affiliation(s)
- Björn-Philipp Diercks
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Ralf Fliegert
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Andreas H Guse
- The Calcium Signalling Group, Department of Biochemistry and Molecular Cell Biology, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
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31
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Zorec R, Parpura V, Verkhratsky A. Astroglial Vesicular Trafficking in Neurodegenerative Diseases. Neurochem Res 2016; 42:905-917. [DOI: 10.1007/s11064-016-2055-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/30/2016] [Accepted: 08/31/2016] [Indexed: 12/20/2022]
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32
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Wang X, Li H, Ding S. Pre-B-cell colony-enhancing factor protects against apoptotic neuronal death and mitochondrial damage in ischemia. Sci Rep 2016; 6:32416. [PMID: 27576732 PMCID: PMC5006239 DOI: 10.1038/srep32416] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 08/09/2016] [Indexed: 01/08/2023] Open
Abstract
We previously demonstrated that Pre-B-cell colony-enhancing factor (PBEF), also known as nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in mammalian NAD+ biosynthesis pathway, plays a brain and neuronal protective role in ischemic stroke. In this study, we further investigated the mechanism of its neuroprotective effect after ischemia in the primary cultured mouse cortical neurons. Using apoptotic cell death assay, fluorescent imaging, molecular biology, mitochondrial biogenesis measurements and Western blotting analysis, our results show that the overexpression of PBEF in neurons can significantly promote neuronal survival, reduce the translocation of apoptosis inducing factor (AIF) from mitochondria to nuclei and inhibit the activation of capase-3 after glutamate-induced excitotoxicity. We further found that the overexpression of PBEF can suppress glutamate-induced mitochondrial fragmentation, the loss of mitochondrial DNA (mtDNA) content and the reduction of PGC-1 and NRF-1 expressions. Furthermore, these beneficial effects by PBEF are dependent on its enzymatic activity of NAD+ synthesis. In summary, our study demonstrated that PBEF ameliorates ischemia-induced neuronal death through inhibiting caspase-dependent and independent apoptotic signaling pathways and suppressing mitochondrial damage and dysfunction. Our study provides novel insights into the mechanisms underlying the neuroprotective effect of PBEF, and helps to identify potential targets for ischemic stroke therapy.
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Affiliation(s)
- Xiaowan Wang
- Dept. of Bioengineering, University of Missouri, Columbia, MO 65211
| | - Hailong Li
- Dept. of Bioengineering, University of Missouri, Columbia, MO 65211.,Dalton Cardiovascular Research Center University of Missouri, Columbia, MO 65211
| | - Shinghua Ding
- Dept. of Bioengineering, University of Missouri, Columbia, MO 65211.,Dalton Cardiovascular Research Center University of Missouri, Columbia, MO 65211
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Suzuki J, Kanemaru K, Iino M. Genetically Encoded Fluorescent Indicators for Organellar Calcium Imaging. Biophys J 2016; 111:1119-1131. [PMID: 27477268 DOI: 10.1016/j.bpj.2016.04.054] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/30/2016] [Accepted: 04/01/2016] [Indexed: 12/14/2022] Open
Abstract
Optical Ca(2+) indicators are powerful tools for investigating intracellular Ca(2+) signals in living cells. Although a variety of Ca(2+) indicators have been developed, deciphering the physiological functions and spatiotemporal dynamics of Ca(2+) in intracellular organelles remains challenging. Genetically encoded Ca(2+) indicators (GECIs) using fluorescent proteins are promising tools for organellar Ca(2+) imaging, and much effort has been devoted to their development. In this review, we first discuss the key points of organellar Ca(2+) imaging and summarize the requirements for optimal organellar Ca(2+) indicators. Then, we highlight some of the recent advances in the engineering of fluorescent GECIs targeted to specific organelles. Finally, we discuss the limitations of currently available GECIs and the requirements for advancing the research on intraorganellar Ca(2+) signaling.
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Affiliation(s)
- Junji Suzuki
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Physiology, University of California San Francisco, San Francisco, California
| | - Kazunori Kanemaru
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masamitsu Iino
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, Japan.
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34
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Shigetomi E, Patel S, Khakh BS. Probing the Complexities of Astrocyte Calcium Signaling. Trends Cell Biol 2016; 26:300-312. [PMID: 26896246 PMCID: PMC4946798 DOI: 10.1016/j.tcb.2016.01.003] [Citation(s) in RCA: 168] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 01/08/2023]
Abstract
Astrocytes are abundant glial cells that tile the entire central nervous system and mediate well-established functions for neurons, blood vessels, and other glia. These ubiquitous cells display intracellular Ca(2+) signals, which have been intensely studied for 25 years. Recently, the use of improved methods has unearthed the panoply of astrocyte Ca(2+) signals and a variable landscape of basal Ca(2+) levels. In vivo studies have started to reveal the settings under which astrocytes display behaviorally relevant Ca(2+) signaling. Studies in mice have emphasized how astrocyte Ca(2+) signaling is altered in distinct neurodegenerative diseases. Progress in the past few years, fueled by methodological advances, has thus reignited interest in astrocyte Ca(2+) signaling for brain function and dysfunction.
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Affiliation(s)
- Eiji Shigetomi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
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35
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Xia N, Zhang Q, Wang ST, Gu L, Yang HM, Liu L, Bakshi R, Yang H, Zhang H. Blockade of metabotropic glutamate receptor 5 protects against DNA damage in a rotenone-induced Parkinson's disease model. Free Radic Biol Med 2015; 89:567-80. [PMID: 26454081 DOI: 10.1016/j.freeradbiomed.2015.09.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 09/14/2015] [Accepted: 09/15/2015] [Indexed: 12/11/2022]
Abstract
Glutamate excitotoxicity contributes to the development of Parkinson's disease (PD) and pharmacological blockade of metabotropic glutamate receptor 5 (mGluR5) has beneficial anti-akinetic effects in animal models of PD; however, the mechanism by which these antagonists alleviate PD symptoms is largely unknown. In our study, the effects of mGluR5 inhibition on DNA damage were investigated in a rotenone-induced model of PD. We first found that the selective mGluR5 antagonist, 2-methyl-6- (phenylethynyl) pyridine, prevented rotenone-induced DNA damage in MN9D dopaminergic neurons through a mechanism involving the downregulation of intracellular calcium release which was associated with a reduction in endoplasmic reticulum stress and reactive oxygen species (ROS)-related mitochondrial dysfunction. Interestingly, the ROS-related mitochondrial dysfunction was accompanied by an increase in expression of the antioxidant protein, Trx2. Treatment of cells with the calcium chelating agent 1,2-bis-(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid or the ROS scavenger N-acetyl-L-cysteine, also reduced rotenone-induced DNA damage, while transfection of a dominant-negative form of Trx2 increased it. In addition, mGluR5 inhibition altered the expression profiles of proteins involved in DNA repair activity. Specifically, the expression of phosphorylated ERK (p-ERK) and CREB, as well as APE1 and Rad51 were elevated after rotenone stimulation and were subsequently downregulated following blockade of mGluR5. These findings were confirmed in vivo in a rotenone-induced rat model of PD. Inhibition of mGluR5 protected against neurotoxicity by mitigating oxidative stress-related DNA damage associated with 8-hydroxy-2'-deoxyguanosine production and also reduced p-ERK activity and Trx2 expression. These findings provide a novel link between mGluR5 and DNA damage in a model of PD, and reveal a potential mechanism by which mGluR5 mediates DNA damage in neurodegenerative diseases.
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Affiliation(s)
- Ning Xia
- Department of Neurobiology, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Qian Zhang
- Department of Neurobiology, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Shu Ting Wang
- Department of Neurobiology, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Li Gu
- Department of Neurobiology, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Hui Min Yang
- Department of Neurobiology, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Li Liu
- Department of Neurobiology, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Rachit Bakshi
- Department of Neurology, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Boston, MA 02129
| | - Hui Yang
- Department of Neurobiology, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Hong Zhang
- Department of Neurobiology, Beijing Institute for Brain Disorders and Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Capital Medical University, Beijing 100069, China.
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Partridge JG. Utilizing GCaMP transgenic mice to monitor endogenous Gq/11-coupled receptors. Front Pharmacol 2015; 6:42. [PMID: 25805995 PMCID: PMC4353298 DOI: 10.3389/fphar.2015.00042] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 02/17/2015] [Indexed: 01/12/2023] Open
Abstract
The family of GCaMPs are engineered proteins that contain Ca2+ binding motifs within a circularly permutated variant of the Aequorea Victoria green fluorescent protein (cp-GFP). The rapidly advancing field of utilizing GCaMP reporter constructs represents a major step forward in our ability to monitor intracellular Ca2+ dynamics. With the use of these genetically encoded Ca2+ sensors, investigators have studied activation of endogenous Gq types of G protein-coupled receptors (GPCRs) and subsequent rises in intracellular calcium. Escalations in intracellular Ca2+ from GPCR activation can be faithfully monitored in space and time as an increase in fluorescent emission from these proteins. Further, transgenic mice are now commercially available that express GCaMPs in a Cre recombinase dependent fashion. These GCaMP reporter mice can be bred to distinct Cre recombinase driver mice to direct expression of this sensor in unique populations of cells. Concerning the central nervous system (CNS), sources of calcium influx, including those arising from Gq activation can be observed in targeted cell types like neurons or astrocytes. This powerful genetic method allows simultaneous monitoring of the activity of dozens of cells upon activation of endogenous Gq-coupled GPCRs. Therefore, in combination with pharmacological tools, this strategy of monitoring GPCR activation is amenable to analysis of orthosteric and allosteric ligands of Gq-coupled receptors in their endogenous environments.
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Affiliation(s)
- John G Partridge
- Department of Pharmacology and Physiology, Georgetown University School of Medicine , Washington, DC, USA ; Interdisciplinary Program in Neuroscience, Georgetown University School of Medicine , Washington, DC, USA
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