1
|
Kim YD, Park HG, Song S, Kim J, Lee BJ, Broadie K, Lee S. Presynaptic structural and functional plasticity are coupled by convergent Rap1 signaling. J Cell Biol 2024; 223:e202309095. [PMID: 38748250 PMCID: PMC11096849 DOI: 10.1083/jcb.202309095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 02/07/2024] [Accepted: 03/27/2024] [Indexed: 05/18/2024] Open
Abstract
Dynamic presynaptic actin remodeling drives structural and functional plasticity at synapses, but the underlying mechanisms remain largely unknown. Previous work has shown that actin regulation via Rac1 guanine exchange factor (GEF) Vav signaling restrains synaptic growth via bone morphogenetic protein (BMP)-induced receptor macropinocytosis and mediates synaptic potentiation via mobilization of reserve pool vesicles in presynaptic boutons. Here, we find that Gef26/PDZ-GEF and small GTPase Rap1 signaling couples the BMP-induced activation of Abelson kinase to this Vav-mediated macropinocytosis. Moreover, we find that adenylate cyclase Rutabaga (Rut) signaling via exchange protein activated by cAMP (Epac) drives the mobilization of reserve pool vesicles during post-tetanic potentiation (PTP). We discover that Rap1 couples activation of Rut-cAMP-Epac signaling to Vav-mediated synaptic potentiation. These findings indicate that Rap1 acts as an essential, convergent node for Abelson kinase and cAMP signaling to mediate BMP-induced structural plasticity and activity-induced functional plasticity via Vav-dependent regulation of the presynaptic actin cytoskeleton.
Collapse
Affiliation(s)
- Yeongjin David Kim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
| | - Hyun Gwan Park
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
| | - Seunghwan Song
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea
| | - Joohyung Kim
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Byoung Ju Lee
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Kendal Broadie
- Departments of Cell and Developmental Biology, Pharmacology, and Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN, USA
| | - Seungbok Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Korea
- Department of Cell and Developmental Biology and Dental Research Institute, Seoul National University, Seoul, Korea
| |
Collapse
|
2
|
Wai T. Is mitochondrial morphology important for cellular physiology? Trends Endocrinol Metab 2024:S1043-2760(24)00123-1. [PMID: 38866638 DOI: 10.1016/j.tem.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/07/2024] [Accepted: 05/13/2024] [Indexed: 06/14/2024]
Abstract
Mitochondria are double membrane-bound organelles the network morphology of which in cells is shaped by opposing events of fusion and fission executed by dynamin-like GTPases. Mutations in these genes can perturb the form and functions of mitochondria in cell and animal models of mitochondrial diseases. An expanding array of chemical, mechanical, and genetic stressors can converge on mitochondrial-shaping proteins and disrupt mitochondrial morphology. In recent years, studies aimed at disentangling the multiple roles of mitochondrial-shaping proteins beyond fission or fusion have provided insights into the homeostatic relevance of mitochondrial morphology. Here, I review the pleiotropy of mitochondrial fusion and fission proteins with the aim of understanding whether mitochondrial morphology is important for cell and tissue physiology.
Collapse
Affiliation(s)
- Timothy Wai
- Institut Pasteur, Mitochondrial Biology, CNRS UMR 3691, Université Paris Cité, Paris, France.
| |
Collapse
|
3
|
Myeong J, Stunault MI, Klyachko VA, Ashrafi G. Metabolic regulation of single synaptic vesicle exo- and endocytosis in hippocampal synapses. Cell Rep 2024; 43:114218. [PMID: 38758651 DOI: 10.1016/j.celrep.2024.114218] [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: 11/13/2023] [Revised: 02/26/2024] [Accepted: 04/25/2024] [Indexed: 05/19/2024] Open
Abstract
Glucose has long been considered a primary energy source for synaptic function. However, it remains unclear to what extent alternative fuels, such as lactate/pyruvate, contribute to powering synaptic transmission. By detecting individual release events in hippocampal synapses, we find that mitochondrial ATP production regulates basal vesicle release probability and release location within the active zone (AZ), evoked by single action potentials. Mitochondrial inhibition shifts vesicle release closer to the AZ center and alters the efficiency of vesicle retrieval by increasing the occurrence of ultrafast endocytosis. Furthermore, we uncover that terminals can use oxidative fuels to maintain the vesicle cycle during trains of activity. Mitochondria are sparsely distributed along hippocampal axons, and we find that terminals containing mitochondria display enhanced vesicle release and reuptake during high-frequency trains. Our findings suggest that mitochondria not only regulate several fundamental features of synaptic transmission but may also contribute to modulation of short-term synaptic plasticity.
Collapse
Affiliation(s)
- Jongyun Myeong
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Marion I Stunault
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Vitaly A Klyachko
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Ghazaleh Ashrafi
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine, St. Louis, MO 63110, USA.
| |
Collapse
|
4
|
Pavlowsky A, Comyn T, Minatchy J, Geny D, Bun P, Danglot L, Preat T, Plaçais PY. Spaced training activates Miro/Milton-dependent mitochondrial dynamics in neuronal axons to sustain long-term memory. Curr Biol 2024; 34:1904-1917.e6. [PMID: 38642548 DOI: 10.1016/j.cub.2024.03.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 12/21/2023] [Accepted: 03/25/2024] [Indexed: 04/22/2024]
Abstract
Neurons have differential and fluctuating energy needs across distinct cellular compartments, shaped by brain electrochemical activity associated with cognition. In vitro studies show that mitochondria transport from soma to axons is key to maintaining neuronal energy homeostasis. Nevertheless, whether the spatial distribution of neuronal mitochondria is dynamically adjusted in vivo in an experience-dependent manner remains unknown. In Drosophila, associative long-term memory (LTM) formation is initiated by an early and persistent upregulation of mitochondrial pyruvate flux in the axonal compartment of neurons in the mushroom body (MB). Through behavior experiments, super-resolution analysis of mitochondria morphology in the neuronal soma and in vivo mitochondrial fluorescence recovery after photobleaching (FRAP) measurements in the axons, we show that LTM induction, contrary to shorter-lived memories, is sustained by the departure of some mitochondria from MB neuronal soma and increased mitochondrial dynamics in the axonal compartment. Accordingly, impairing mitochondrial dynamics abolished the increased pyruvate consumption, specifically after spaced training and in the MB axonal compartment, thereby preventing LTM formation. Our results thus promote reorganization of the mitochondrial network in neurons as an integral step in elaborating high-order cognitive processes.
Collapse
Affiliation(s)
- Alice Pavlowsky
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Typhaine Comyn
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Julia Minatchy
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - David Geny
- Université de Paris, NeurImag Imaging Facility, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, 75014 Paris, France
| | - Philippe Bun
- Université de Paris, NeurImag Imaging Facility, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, 75014 Paris, France
| | - Lydia Danglot
- Université de Paris, NeurImag Imaging Facility, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, 75014 Paris, France
| | - Thomas Preat
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France.
| | - Pierre-Yves Plaçais
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France.
| |
Collapse
|
5
|
Wu Y, Ding C, Sharif B, Weinreb A, Swaim G, Hao H, Yogev S, Watanabe S, Hammarlund M. Polarized localization of kinesin-1 and RIC-7 drives axonal mitochondria anterograde transport. J Cell Biol 2024; 223:e202305105. [PMID: 38470363 PMCID: PMC10932739 DOI: 10.1083/jcb.202305105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 12/17/2023] [Accepted: 02/26/2024] [Indexed: 03/13/2024] Open
Abstract
Mitochondria transport is crucial for axonal mitochondria distribution and is mediated by kinesin-1-based anterograde and dynein-based retrograde motor complexes. While Miro and Milton/TRAK were identified as key adaptors between mitochondria and kinesin-1, recent studies suggest the presence of additional mechanisms. In C. elegans, ric-7 is the only single gene described so far, other than kinesin-1, that is absolutely required for axonal mitochondria localization. Using CRISPR engineering in C. elegans, we find that Miro is important but is not essential for anterograde traffic, whereas it is required for retrograde traffic. Both the endogenous RIC-7 and kinesin-1 act at the leading end to transport mitochondria anterogradely. RIC-7 binding to mitochondria requires its N-terminal domain and partially relies on MIRO-1, whereas RIC-7 accumulation at the leading end depends on its disordered region, kinesin-1, and metaxin2. We conclude that transport complexes containing kinesin-1 and RIC-7 polarize at the leading edge of mitochondria and are required for anterograde axonal transport in C. elegans.
Collapse
Affiliation(s)
- Youjun Wu
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Chen Ding
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Behrang Sharif
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Alexis Weinreb
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Grace Swaim
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Hongyan Hao
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Shaul Yogev
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Shigeki Watanabe
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Marc Hammarlund
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| |
Collapse
|
6
|
Stahl A, Tomchik SM. Modeling neurodegenerative and neurodevelopmental disorders in the Drosophila mushroom body. Learn Mem 2024; 31:a053816. [PMID: 38876485 DOI: 10.1101/lm.053816.123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 05/01/2024] [Indexed: 06/16/2024]
Abstract
The common fruit fly Drosophila melanogaster provides a powerful platform to investigate the genetic, molecular, cellular, and neural circuit mechanisms of behavior. Research in this model system has shed light on multiple aspects of brain physiology and behavior, from fundamental neuronal function to complex behaviors. A major anatomical region that modulates complex behaviors is the mushroom body (MB). The MB integrates multimodal sensory information and is involved in behaviors ranging from sensory processing/responses to learning and memory. Many genes that underlie brain disorders are conserved, from flies to humans, and studies in Drosophila have contributed significantly to our understanding of the mechanisms of brain disorders. Genetic mutations that mimic human diseases-such as Fragile X syndrome, neurofibromatosis type 1, Parkinson's disease, and Alzheimer's disease-affect MB structure and function, altering behavior. Studies dissecting the effects of disease-causing mutations in the MB have identified key pathological mechanisms, and the development of a complete connectome promises to add a comprehensive anatomical framework for disease modeling. Here, we review Drosophila models of human neurodevelopmental and neurodegenerative disorders via the effects of their underlying mutations on MB structure, function, and the resulting behavioral alterations.
Collapse
Affiliation(s)
- Aaron Stahl
- Neuroscience and Pharmacology, University of Iowa, Iowa City, Iowa 52242, USA
| | - Seth M Tomchik
- Neuroscience and Pharmacology, University of Iowa, Iowa City, Iowa 52242, USA
- Stead Family Department of Pediatrics, University of Iowa, Iowa City, Iowa 52242, USA
- Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242, USA
- Hawk-IDDRC, University of Iowa, Iowa City, Iowa 52242, USA
| |
Collapse
|
7
|
Liao JZ, Chung HL, Shih C, Wong KKL, Dutta D, Nil Z, Burns CG, Kanca O, Park YJ, Zuo Z, Marcogliese PC, Sew K, Bellen HJ, Verheyen EM. Cdk8/CDK19 promotes mitochondrial fission through Drp1 phosphorylation and can phenotypically suppress pink1 deficiency in Drosophila. Nat Commun 2024; 15:3326. [PMID: 38637532 PMCID: PMC11026413 DOI: 10.1038/s41467-024-47623-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 04/08/2024] [Indexed: 04/20/2024] Open
Abstract
Cdk8 in Drosophila is the orthologue of vertebrate CDK8 and CDK19. These proteins have been shown to modulate transcriptional control by RNA polymerase II. We found that neuronal loss of Cdk8 severely reduces fly lifespan and causes bang sensitivity. Remarkably, these defects can be rescued by expression of human CDK19, found in the cytoplasm of neurons, suggesting a non-nuclear function of CDK19/Cdk8. Here we show that Cdk8 plays a critical role in the cytoplasm, with its loss causing elongated mitochondria in both muscles and neurons. We find that endogenous GFP-tagged Cdk8 can be found in both the cytoplasm and nucleus. We show that Cdk8 promotes the phosphorylation of Drp1 at S616, a protein required for mitochondrial fission. Interestingly, Pink1, a mitochondrial kinase implicated in Parkinson's disease, also phosphorylates Drp1 at the same residue. Indeed, overexpression of Cdk8 significantly suppresses the phenotypes observed in flies with low levels of Pink1, including elevated levels of ROS, mitochondrial dysmorphology, and behavioral defects. In summary, we propose that Pink1 and Cdk8 perform similar functions to promote Drp1-mediated fission.
Collapse
Affiliation(s)
- Jenny Zhe Liao
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
- Center for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
| | - Hyung-Lok Chung
- Department of Neurology, Houston Methodist Research Institute, Houston, TX, USA
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Claire Shih
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
- Center for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
| | - Kenneth Kin Lam Wong
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Debdeep Dutta
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Zelha Nil
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Catherine Grace Burns
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Ye-Jin Park
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Paul C Marcogliese
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, R3E0J9, MB, Canada
- Children's Hospital Research Institute of Manitoba, Winnipeg, R3E3P4, MB, Canada
| | - Katherine Sew
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
- Center for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, V5A1S6, BC, Canada
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Jan and Dan Duncan Neurological Institute, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA.
| | - Esther M Verheyen
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, V5A1S6, BC, Canada.
- Center for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, V5A1S6, BC, Canada.
| |
Collapse
|
8
|
Pan K, Jinnah HA, Hess EJ, Smith Y, Villalba RM. Ultrastructural analysis of nigrostriatal dopaminergic terminals in a knockin mouse model of DYT1 dystonia. Eur J Neurosci 2024; 59:1407-1427. [PMID: 38123503 DOI: 10.1111/ejn.16197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 11/02/2023] [Accepted: 11/05/2023] [Indexed: 12/23/2023]
Abstract
DYT1 dystonia is associated with decreased striatal dopamine release. In this study, we examined the possibility that ultrastructural changes of nigrostriatal dopamine terminals could contribute to this neurochemical imbalance using a serial block face/scanning electron microscope (SBF/SEM) and three-dimensional reconstruction to analyse striatal tyrosine hydroxylase-immunoreactive (TH-IR) terminals and their synapses in a DYT1(ΔE) knockin (DYT1-KI) mouse model of DYT1 dystonia. Furthermore, to study possible changes in vesicle packaging capacity of dopamine, we used transmission electron microscopy to assess the synaptic vesicle size in striatal dopamine terminals. Quantitative comparative analysis of 80 fully reconstructed TH-IR terminals in the WT and DYT1-KI mice indicate (1) no significant difference in the volume of TH-IR terminals; (2) no major change in the proportion of axo-spinous versus axo-dendritic synapses; (3) no significant change in the post-synaptic density (PSD) area of axo-dendritic synapses, while the PSDs of axo-spinous synapses were significantly smaller in DYT1-KI mice; (4) no significant change in the contact area between TH-IR terminals and dendritic shafts or spines, while the ratio of PSD area/contact area decreased significantly for both axo-dendritic and axo-spinous synapses in DYT1-KI mice; (5) no significant difference in the mitochondria volume; and (6) no significant difference in the synaptic vesicle area between the two groups. Altogether, these findings suggest that abnormal morphometric changes of nigrostriatal dopamine terminals and their post-synaptic targets are unlikely to be a major source of reduced striatal dopamine release in DYT1 dystonia.
Collapse
Affiliation(s)
- Ke Pan
- Emory National Primate Research Center, Emory University, Atlanta, Georgia, USA
- Department of Physical Therapy & Human Movement Sciences, Northwestern University, Chicago, Illinois, USA
| | - Hyder A Jinnah
- Department of Neurology, Emory University, Atlanta, Georgia, USA
- Department of Human Genetics and Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Ellen J Hess
- Department of Neurology, Emory University, Atlanta, Georgia, USA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, Georgia, USA
| | - Yoland Smith
- Emory National Primate Research Center, Emory University, Atlanta, Georgia, USA
- Department of Neurology, Emory University, Atlanta, Georgia, USA
| | - Rosa M Villalba
- Emory National Primate Research Center, Emory University, Atlanta, Georgia, USA
| |
Collapse
|
9
|
Dithmar S, Zare A, Salehi S, Briese M, Sendtner M. hnRNP R regulates mitochondrial movement and membrane potential in axons of motoneurons. Neurobiol Dis 2024; 193:106454. [PMID: 38408684 DOI: 10.1016/j.nbd.2024.106454] [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: 12/12/2023] [Revised: 02/12/2024] [Accepted: 02/23/2024] [Indexed: 02/28/2024] Open
Abstract
Axonal mitochondria defects are early events in the pathogenesis of motoneuron disorders such as spinal muscular atrophy and amyotrophic lateral sclerosis. The RNA-binding protein hnRNP R interacts with different motoneuron disease-related proteins such as SMN and TDP-43 and has important roles in axons of motoneurons, including axonal mRNA transport. However, whether hnRNP R also modulates axonal mitochondria is currently unknown. Here, we show that axonal mitochondria exhibit altered function and motility in hnRNP R-deficient motoneurons. Motoneurons lacking hnRNP R show decreased anterograde and increased retrograde transport of mitochondria in axons. Furthermore, hnRNP R-deficiency leads to mitochondrial hyperpolarization, caused by decreased complex I and reversed complex V activity within the respiratory chain. Taken together, our data indicate a role for hnRNP R in regulating transport and maintaining functionality of axonal mitochondria in motoneurons.
Collapse
Affiliation(s)
- Sophia Dithmar
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Abdolhossein Zare
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Saeede Salehi
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Michael Briese
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany.
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany.
| |
Collapse
|
10
|
Haynes PR, Pyfrom ES, Li Y, Stein C, Cuddapah VA, Jacobs JA, Yue Z, Sehgal A. A neuron-glia lipid metabolic cycle couples daily sleep to mitochondrial homeostasis. Nat Neurosci 2024; 27:666-678. [PMID: 38360946 PMCID: PMC11001586 DOI: 10.1038/s41593-023-01568-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 12/29/2023] [Indexed: 02/17/2024]
Abstract
Sleep is thought to be restorative to brain energy homeostasis, but it is not clear how this is achieved. We show here that Drosophila glia exhibit a daily cycle of glial mitochondrial oxidation and lipid accumulation that is dependent on prior wake and requires the Drosophila APOE orthologs NLaz and GLaz, which mediate neuron-glia lipid transfer. In turn, a full night of sleep is required for glial lipid clearance, mitochondrial oxidative recovery and maximal neuronal mitophagy. Knockdown of neuronal NLaz causes oxidative stress to accumulate in neurons, and the neuronal mitochondrial integrity protein, Drp1, is required for daily glial lipid accumulation. These data suggest that neurons avoid accumulation of oxidative mitochondrial damage during wake by using mitophagy and passing damage to glia in the form of lipids. We propose that a mitochondrial lipid metabolic cycle between neurons and glia reflects a fundamental function of sleep relevant for brain energy homeostasis.
Collapse
Affiliation(s)
- Paula R Haynes
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, USA
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Elana S Pyfrom
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Yongjun Li
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Carly Stein
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Vishnu Anand Cuddapah
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, USA
| | - Jack A Jacobs
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Zhifeng Yue
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Amita Sehgal
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, USA.
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
- Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
11
|
Findinier J, Joubert LM, Schmid MF, Malkovskiy A, Chiu W, Burlacot A, Grossman AR. Dramatic Changes in Mitochondrial Subcellular Location and Morphology Accompany Activation of the CO 2 Concentrating Mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.25.586705. [PMID: 38585955 PMCID: PMC10996633 DOI: 10.1101/2024.03.25.586705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Dynamic changes in intracellular ultrastructure can be critical for the ability of organisms to acclimate to environmental conditions. Microalgae, which are responsible for ~50% of global photosynthesis, compartmentalize their Rubisco into a specialized structure known as the pyrenoid when the cells experience limiting CO2 conditions; this compartmentalization appears to be a component of the CO2 Concentrating Mechanism (CCM), which facilitates photosynthetic CO2 fixation as environmental levels of inorganic carbon (Ci) decline. Changes in the spatial distribution of mitochondria in green algae have also been observed under CO2 limiting conditions, although a role for this reorganization in CCM function remains unclear. We used the green microalgae Chlamydomonas reinhardtii to monitor changes in the position and ultrastructure of mitochondrial membranes as cells transition between high CO2 (HC) and Low/Very Low CO2 (LC/VLC). Upon transferring cells to VLC, the mitochondria move from a central to a peripheral location, become wedged between the plasma membrane and chloroplast envelope, and mitochondrial membranes orient in parallel tubular arrays that extend from the cell's apex to its base. We show that these ultrastructural changes require protein and RNA synthesis, occur within 90 min of shifting cells to VLC conditions, correlate with CCM induction and are regulated by the CCM master regulator CIA5. The apico-basal orientation of the mitochondrial membrane, but not the movement of the mitochondrion to the cell periphery, is dependent on microtubules and the MIRO1 protein, which is involved in membrane-microtubule interactions. Furthermore, blocking mitochondrial electron transport in VLC acclimated cells reduces the cell's affinity for inorganic carbon. Overall, our results suggest that CIA5-dependent mitochondrial repositioning/reorientation functions in integrating cellular architecture and energetics with CCM activities and invite further exploration of how intracellular architecture can impact fitness under dynamic environmental conditions.
Collapse
Affiliation(s)
- Justin Findinier
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
| | - Michael F. Schmid
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
| | - Andrey Malkovskiy
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
| | - Wah Chiu
- SLAC National Accelerator Laboratory, Division of CryoEM and Bioimaging, Menlo Park, CA 94025, USA
- Stanford University, Department of Bioengineering, Stanford, CA 94305, USA
| | - Adrien Burlacot
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
- Stanford University, Biology Department, Stanford, CA 94305, USA
| | - Arthur R. Grossman
- The Carnegie Institution for Science, Biosphere Sciences & Engineering, Stanford, CA 94305, USA
- Stanford University, Biology Department, Stanford, CA 94305, USA
| |
Collapse
|
12
|
Rathor L, Curry S, Park Y, McElroy T, Robles B, Sheng Y, Chen WW, Min K, Xiao R, Lee MH, Han SM. Mitochondrial stress in GABAergic neurons non-cell autonomously regulates organismal health and aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.20.585932. [PMID: 38585797 PMCID: PMC10996468 DOI: 10.1101/2024.03.20.585932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Mitochondrial stress within the nervous system can trigger non-cell autonomous responses in peripheral tissues. However, the specific neurons involved and their impact on organismal aging and health have remained incompletely understood. Here, we demonstrate that mitochondrial stress in γ-aminobutyric acid-producing (GABAergic) neurons in Caenorhabditis elegans ( C. elegans ) is sufficient to significantly alter organismal lifespan, stress tolerance, and reproductive capabilities. This mitochondrial stress also leads to significant changes in mitochondrial mass, energy production, and levels of reactive oxygen species (ROS). DAF-16/FoxO activity is enhanced by GABAergic neuronal mitochondrial stress and mediates the induction of these non-cell-autonomous effects. Moreover, our findings indicate that GABA signaling operates within the same pathway as mitochondrial stress in GABAergic neurons, resulting in non-cell-autonomous alterations in organismal stress tolerance and longevity. In summary, these data suggest the crucial role of GABAergic neurons in detecting mitochondrial stress and orchestrating non-cell-autonomous changes throughout the organism.
Collapse
|
13
|
Masilamoni GJ, Kelly H, Swain AJ, Pare JF, Villalba RM, Smith Y. Structural Plasticity of GABAergic Pallidothalamic Terminals in MPTP-Treated Parkinsonian Monkeys: A 3D Electron Microscopic Analysis. eNeuro 2024; 11:ENEURO.0241-23.2024. [PMID: 38514185 PMCID: PMC10957232 DOI: 10.1523/eneuro.0241-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 02/22/2024] [Accepted: 02/26/2024] [Indexed: 03/23/2024] Open
Abstract
The internal globus pallidus (GPi) is a major source of tonic GABAergic inhibition to the motor thalamus. In parkinsonism, the firing rate of GPi neurons is increased, and their pattern switches from a tonic to a burst mode, two pathophysiological changes associated with increased GABAergic pallidothalamic activity. In this study, we used high-resolution 3D electron microscopy to demonstrate that GPi terminals in the parvocellular ventral anterior nucleus (VApc) and the centromedian nucleus (CM), the two main GPi-recipient motor thalamic nuclei in monkeys, undergo significant morphometric changes in parkinsonian monkeys including (1) increased terminal volume in both nuclei; (2) increased surface area of synapses in both nuclei; (3) increased number of synapses/GPi terminals in the CM, but not VApc; and (4) increased total volume, but not number, of mitochondria/terminals in both nuclei. In contrast to GPi terminals, the ultrastructure of putative GABAergic nonpallidal terminals was not affected. Our results also revealed striking morphological differences in terminal volume, number/area of synapses, and volume/number of mitochondria between GPi terminals in VApc and CM of control monkeys. In conclusion, GABAergic pallidothalamic terminals are endowed with a high level of structural plasticity that may contribute to the development and maintenance of the abnormal increase in pallidal GABAergic outflow to the thalamus in the parkinsonian state. Furthermore, the evidence for ultrastructural differences between GPi terminals in VApc and CM suggests that morphologically distinct pallidothalamic terminals from single pallidal neurons may underlie specific physiological properties of pallidal inputs to VApc and CM in normal and diseased states.
Collapse
Affiliation(s)
- G J Masilamoni
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
| | - H Kelly
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
| | - A J Swain
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
| | - J F Pare
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
| | - R M Villalba
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
| | - Y Smith
- Emory National Primate Research Center, Atlanta, Georgia 30322
- Udall Center of Excellence for Parkinson's Disease, Emory University, Atlanta, Georgia 30322
- Department of Neurology, Emory University, Atlanta, Georgia 30322
| |
Collapse
|
14
|
Liu J, Bao X, Huang J, Chen R, Tan Y, Zhang Z, Xiao B, Kong F, Gu C, Du J, Wang H, Qi J, Tan J, Ma D, Shi C, Xu G. TMEM135 maintains the equilibrium of osteogenesis and adipogenesis by regulating mitochondrial dynamics. Metabolism 2024; 152:155767. [PMID: 38154611 DOI: 10.1016/j.metabol.2023.155767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/10/2023] [Accepted: 12/20/2023] [Indexed: 12/30/2023]
Abstract
BACKGROUND Disturbance in the differentiation process of bone marrow mesenchymal stem cells (BMSCs) leads to osteoporosis. Mitochondrial dynamics plays a pivotal role in the metabolism and differentiation of BMSCs. However, the mechanisms underlying mitochondrial dynamics and their impact on the differentiation equilibrium of BMSCs remain unclear. METHODS We investigated the mitochondrial morphology and markers related to mitochondrial dynamics during BMSCs osteogenic and adipogenic differentiation. Bioinformatics was used to screen potential genes regulating BMSCs differentiation through mitochondrial dynamics. Subsequently, we evaluated the impact of Transmembrane protein 135 (TMEM135) deficiency on bone homeostasis by comparing Tmem135 knockout mice with their littermates. The mechanism of TMEM135 in mitochondrial dynamics and BMSCs differentiation was also investigated in vivo and in vitro. RESULTS Distinct changes in mitochondrial morphology were observed between osteogenic and adipogenic differentiation of BMSCs, manifesting as fission in the late stage of osteogenesis and fusion in adipogenesis. Additionally, we revealed that TMEM135, a modulator of mitochondrial dynamics, played a functional role in regulating the equilibrium between adipogenesis and osteogenesis. The TMEM135 deficiency impaired mitochondrial fission and disrupted crucial mitochondrial energy metabolism during osteogenesis. Tmem135 knockout mice showed osteoporotic phenotype, characterized by reduced osteogenesis and increased adipogenesis. Mechanistically, TMEM135 maintained intracellular calcium ion homeostasis and facilitated the dephosphorylation of dynamic-related protein 1 at Serine 637 in BMSCs. CONCLUSIONS Our findings underscore the significant role of TMEM135 as a modulator in orchestrating the differentiation trajectory of BMSCs and promoting a shift in mitochondrial dynamics toward fission. This ultimately contributes to the osteogenesis process. This work has provided promising biological targets for the treatment of osteoporosis.
Collapse
Affiliation(s)
- Jia Liu
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Xiaogang Bao
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Jian Huang
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Rukun Chen
- Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Yixuan Tan
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Zheng Zhang
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Bing Xiao
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Fanqi Kong
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Changjiang Gu
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Jianhang Du
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Haotian Wang
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Junqiang Qi
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China
| | - Junming Tan
- Department of Orthopedics, The 72nd Army Hospital of the People's Liberation Army, Huzhou 313099, PR China
| | - Duan Ma
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, PR China.
| | - Changgui Shi
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China.
| | - Guohua Xu
- Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai 200003, PR China.
| |
Collapse
|
15
|
Glausier JR, Bouchet-Marquis C, Maier M, Banks-Tibbs T, Wu K, Ning J, Melchitzky D, Lewis DA, Freyberg Z. Characterization of the three-dimensional synaptic and mitochondrial nanoarchitecture within glutamatergic synaptic complexes in postmortem human brain via focused ion beam-scanning electron microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.26.582174. [PMID: 38463986 PMCID: PMC10925168 DOI: 10.1101/2024.02.26.582174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Glutamatergic synapses are the primary site of excitatory synaptic signaling and neural communication in the cerebral cortex. Electron microscopy (EM) studies in non-human model organisms have demonstrated that glutamate synaptic activity and functioning are directly reflected in quantifiable ultrastructural features. Thus, quantitative EM analysis of glutamate synapses in ex vivo preserved human brain tissue has the potential to provide novel insight into in vivo synaptic functioning. However, factors associated with the acquisition and preservation of human brain tissue have resulted in persistent concerns regarding the potential confounding effects of antemortem and postmortem biological processes on synaptic and sub-synaptic ultrastructural features. Thus, we sought to determine how well glutamate synaptic relationships and nanoarchitecture are preserved in postmortem human dorsolateral prefrontal cortex (DLPFC), a region that substantially differs in size and architecture from model systems. Focused ion beam-scanning electron microscopy (FIB-SEM), a powerful volume EM (VEM) approach, was employed to generate high-fidelity, fine-resolution, three-dimensional (3D) micrographic datasets appropriate for quantitative analyses. Using postmortem human DLPFC with a 6-hour postmortem interval, we optimized a tissue preservation and staining workflow that generated samples of excellent ultrastructural preservation and the high-contrast staining intensity required for FIB-SEM imaging. Quantitative analysis of sub-cellular, sub-synaptic and organelle components within glutamate axo-spinous synapses revealed that ultrastructural features of synaptic function and activity were well-preserved within and across individual synapses in postmortem human brain tissue. The synaptic, sub-synaptic and organelle measures were highly consistent with findings from experimental models that are free from antemortem or postmortem effects. Further, dense reconstruction of neuropil revealed a unique, ultrastructurally-complex, spiny dendritic shaft that exhibited features characteristic of neuronal processes with heightened synaptic communication, integration and plasticity. Altogether, our findings provide a critical proof-of-concept that ex vivo VEM analysis provides a valuable and informative means to infer in vivo functioning of human brain.
Collapse
Affiliation(s)
| | | | | | - Tabitha Banks-Tibbs
- Department of Psychiatry, University of Pittsburgh
- Department of Human Genetics, University of Pittsburgh
- College of Medicine, The Ohio State University
| | - Ken Wu
- Materials and Structural Analysis, Thermo Fisher Scientific
| | - Jiying Ning
- Department of Psychiatry, University of Pittsburgh
| | | | | | - Zachary Freyberg
- Department of Psychiatry, University of Pittsburgh
- Department of Cell Biology, University of Pittsburgh
| |
Collapse
|
16
|
Vaglio-Garro A, Kozlov AV, Smirnova YD, Weidinger A. Pathological Interplay between Inflammation and Mitochondria Aggravates Glutamate Toxicity. Int J Mol Sci 2024; 25:2276. [PMID: 38396952 PMCID: PMC10889519 DOI: 10.3390/ijms25042276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 02/25/2024] Open
Abstract
Mitochondrial dysfunction and glutamate toxicity are associated with neural disorders, including brain trauma. A review of the literature suggests that toxic and transmission actions of neuronal glutamate are spatially and functionally separated. The transmission pathway utilizes synaptic GluN2A receptors, rapidly released pool of glutamate, evoked release of glutamate mediated by Synaptotagmin 1 and the amount of extracellular glutamate regulated by astrocytes. The toxic pathway utilizes extrasynaptic GluN2B receptors and a cytoplasmic pool of glutamate, which results from the spontaneous release of glutamate mediated by Synaptotagmin 7 and the neuronal 2-oxoglutarate dehydrogenase complex (OGDHC), a tricarboxylic acid (TCA) cycle enzyme. Additionally, the inhibition of OGDHC observed upon neuro-inflammation is due to an excessive release of reactive oxygen/nitrogen species by immune cells. The loss of OGDHC inhibits uptake of glutamate by mitochondria, thus facilitating its extracellular accumulation and stimulating toxic glutamate pathway without affecting transmission. High levels of extracellular glutamate lead to dysregulation of intracellular redox homeostasis and cause ferroptosis, excitotoxicity, and mitochondrial dysfunction. The latter affects the transmission pathway demanding high-energy supply and leading to cell death. Mitochondria aggravate glutamate toxicity due to impairments in the TCA cycle and become a victim of glutamate toxicity, which disrupts oxidative phosphorylation. Thus, therapies targeting the TCA cycle in neurological disorders may be more efficient than attempting to preserve mitochondrial oxidative phosphorylation.
Collapse
Affiliation(s)
- Annette Vaglio-Garro
- Ludwig Boltzmann Institute for Traumatology, The Research Center in Cooperation with AUVA, 1200 Vienna, Austria; (A.V.-G.); (Y.D.S.); (A.W.)
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
| | - Andrey V. Kozlov
- Ludwig Boltzmann Institute for Traumatology, The Research Center in Cooperation with AUVA, 1200 Vienna, Austria; (A.V.-G.); (Y.D.S.); (A.W.)
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
| | - Yuliya D. Smirnova
- Ludwig Boltzmann Institute for Traumatology, The Research Center in Cooperation with AUVA, 1200 Vienna, Austria; (A.V.-G.); (Y.D.S.); (A.W.)
- Laboratory of Metagenomics and Food Biotechnology, Voronezh State University of Engineering Technologies, 394036 Voronezh, Russia
| | - Adelheid Weidinger
- Ludwig Boltzmann Institute for Traumatology, The Research Center in Cooperation with AUVA, 1200 Vienna, Austria; (A.V.-G.); (Y.D.S.); (A.W.)
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
| |
Collapse
|
17
|
Hirabayashi Y, Lewis TL, Du Y, Virga DM, Decker AM, Coceano G, Alvelid J, Paul MA, Hamilton S, Kneis P, Takahashi Y, Gaublomme JT, Testa I, Polleux F. Most axonal mitochondria in cortical pyramidal neurons lack mitochondrial DNA and consume ATP. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.12.579972. [PMID: 38405915 PMCID: PMC10888904 DOI: 10.1101/2024.02.12.579972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
In neurons of the mammalian central nervous system (CNS), axonal mitochondria are thought to be indispensable for supplying ATP during energy-consuming processes such as neurotransmitter release. Here, we demonstrate using multiple, independent, in vitro and in vivo approaches that the majority (~80-90%) of axonal mitochondria in cortical pyramidal neurons (CPNs), lack mitochondrial DNA (mtDNA). Using dynamic, optical imaging analysis of genetically encoded sensors for mitochondrial matrix ATP and pH, we demonstrate that in axons of CPNs, but not in their dendrites, mitochondrial complex V (ATP synthase) functions in a reverse way, consuming ATP and protruding H+ out of the matrix to maintain mitochondrial membrane potential. Our results demonstrate that in mammalian CPNs, axonal mitochondria do not play a major role in ATP supply, despite playing other functions critical to regulating neurotransmission such as Ca2+ buffering.
Collapse
Affiliation(s)
- Yusuke Hirabayashi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo; Tokyo, 113-8656, Japan
| | - Tommy L. Lewis
- Aging & Metabolism Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Yudan Du
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo; Tokyo, 113-8656, Japan
| | - Daniel M. Virga
- Department of Biological Sciences, Columbia University; New York, NY, 10027, USA
- Department of Neuroscience, Columbia University; New York, NY, 10027, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, USA
| | - Aubrianna M. Decker
- Department of Biological Sciences, Columbia University; New York, NY, 10027, USA
| | - Giovanna Coceano
- Department of Applied Physics and SciLifeLab, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Jonatan Alvelid
- Department of Applied Physics and SciLifeLab, KTH Royal Institute of Technology, Stockholm, Sweden
- Department of Biophysical Imaging, Leibniz Institute of Photonic Technology, Jena, Germany
| | - Maëla A. Paul
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, USA
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL; Paris, France
| | - Stevie Hamilton
- Department of Neuroscience, Columbia University; New York, NY, 10027, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, USA
| | - Parker Kneis
- Aging & Metabolism Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Yasufumi Takahashi
- Department of Electronics, Graduate School of Engineering, Nagoya University, 464-8603, Nagoya, Japan
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, 920–1192 Japan
| | - Jellert T. Gaublomme
- Department of Biological Sciences, Columbia University; New York, NY, 10027, USA
| | - Ilaria Testa
- Department of Applied Physics and SciLifeLab, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Franck Polleux
- Department of Neuroscience, Columbia University; New York, NY, 10027, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University; New York, NY, 10027, USA
| |
Collapse
|
18
|
Hintze A, Lange F, Steyer AM, Anstatt J, Möbius W, Jakobs S, Wichmann C. Developmental changes of the mitochondria in the murine anteroventral cochlear nucleus. iScience 2024; 27:108700. [PMID: 38213623 PMCID: PMC10783593 DOI: 10.1016/j.isci.2023.108700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 10/22/2023] [Accepted: 12/06/2023] [Indexed: 01/13/2024] Open
Abstract
Mitochondria are key organelles to provide ATP for synaptic transmission. This study aims to unravel the structural adaptation of mitochondria to an increase in presynaptic energy demand and upon the functional impairment of the auditory system. We use the anteroventral cochlear nucleus (AVCN) of wild-type and congenital deaf mice before and after hearing onset as a model system for presynaptic states of lower and higher energy demands. We combine focused ion beam scanning electron microscopy and electron tomography to investigate mitochondrial morphology. We found a larger volume of synaptic boutons and mitochondria after hearing onset with a higher crista membrane density. In deaf animals lacking otoferlin, we observed a shallow increase of mitochondrial volumes toward adulthood in endbulbs, while in wild-type animals mitochondria further enlarged. We propose that in the AVCN, presynaptic mitochondria undergo major structural changes likely to serve higher energy demands upon the onset of hearing and further maturation.
Collapse
Affiliation(s)
- Anika Hintze
- Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience, InnerEarLab and Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Felix Lange
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
- Clinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Anna M. Steyer
- Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Electron Microscopy-City Campus, Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, 37075 Göttingen, Germany
| | - Jannis Anstatt
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
- Clinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Wiebke Möbius
- Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Electron Microscopy-City Campus, Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, 37075 Göttingen, Germany
| | - Stefan Jakobs
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, 37077 Göttingen, Germany
- Clinic of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany
- Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany
- Translational Neuroinflammation and Automated Microscopy, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Göttingen, Germany
| | - Carolin Wichmann
- Molecular Architecture of Synapses Group, Institute for Auditory Neuroscience, InnerEarLab and Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, 37075 Göttingen, Germany
- Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, 37075 Göttingen, Germany
| |
Collapse
|
19
|
Miao Y, Xie L, Song J, Cai X, Yang J, Ma X, Chen S, Xie P. Unraveling the causes of sarcopenia: Roles of neuromuscular junction impairment and mitochondrial dysfunction. Physiol Rep 2024; 12:e15917. [PMID: 38225199 PMCID: PMC10789655 DOI: 10.14814/phy2.15917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/11/2023] [Accepted: 12/22/2023] [Indexed: 01/17/2024] Open
Abstract
Sarcopenia is a systemic skeletal muscle disease characterized by a decline in skeletal muscle mass and function. Originally defined as an age-associated condition, sarcopenia presently also encompasses muscular atrophy due to various pathological factors, such as intensive care unit-acquired weakness, inactivity, and malnutrition. The exact pathogenesis of sarcopenia is still unknown; herein, we review the pathological roles of the neuromuscular junction and mitochondria in this condition. Sarcopenia is caused by complex and interdependent pathophysiological mechanisms, including aging, neuromuscular junction impairment, mitochondrial dysfunction, insulin resistance, lipotoxicity, endocrine factors, oxidative stress, and inflammation. Among these, neuromuscular junction instability and mitochondrial dysfunction are particularly significant. Dysfunction in neuromuscular junction can lead to muscle weakness or paralysis. Mitochondria, which are plentiful in neurons and muscle fibers, play an important role in neuromuscular junction transmission. Therefore, impairments in both mitochondria and neuromuscular junction may be one of the key pathophysiological mechanisms leading to sarcopenia. Moreover, this article explores the structural and functional alterations in the neuromuscular junction and mitochondria in sarcopenia, suggesting that a deeper understanding of these changes could provide valuable insights for the prevention or treatment of sarcopenia.
Collapse
Affiliation(s)
- Yanmei Miao
- Department of Critical Care Medicine of the Third Affiliated Hospital (The First People's Hospital of Zunyi)Zunyi Medical UniversityZunyiChina
| | - Leiyu Xie
- Department of Critical Care Medicine of the Third Affiliated Hospital (The First People's Hospital of Zunyi)Zunyi Medical UniversityZunyiChina
| | - Jiamei Song
- Department of Nursing of Affiliated HospitalZunyi Medical UniversityZunyiChina
| | - Xing Cai
- Department of Critical Care Medicine of the Third Affiliated Hospital (The First People's Hospital of Zunyi)Zunyi Medical UniversityZunyiChina
| | - Jinghe Yang
- Department of Critical Care Medicine of the Third Affiliated Hospital (The First People's Hospital of Zunyi)Zunyi Medical UniversityZunyiChina
- Department of The First Clinical CollegeZunyi Medical UniversityZunyiChina
| | - Xinglong Ma
- Department of Critical Care Medicine of the Third Affiliated Hospital (The First People's Hospital of Zunyi)Zunyi Medical UniversityZunyiChina
| | - Shaolin Chen
- Department of Nursing of Affiliated HospitalZunyi Medical UniversityZunyiChina
| | - Peng Xie
- Department of Critical Care Medicine of the Third Affiliated Hospital (The First People's Hospital of Zunyi)Zunyi Medical UniversityZunyiChina
| |
Collapse
|
20
|
Soustelle L, Aimond F, López-Andrés C, Brugioti V, Raoul C, Layalle S. ALS-Associated KIF5A Mutation Causes Locomotor Deficits Associated with Cytoplasmic Inclusions, Alterations of Neuromuscular Junctions, and Motor Neuron Loss. J Neurosci 2023; 43:8058-8072. [PMID: 37748861 PMCID: PMC10669773 DOI: 10.1523/jneurosci.0562-23.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 09/12/2023] [Accepted: 09/13/2023] [Indexed: 09/27/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting motor neurons. Recently, genome-wide association studies identified KIF5A as a new ALS-causing gene. KIF5A encodes a protein of the kinesin-1 family, allowing the anterograde transport of cargos along the microtubule rails in neurons. In ALS patients, mutations in the KIF5A gene induce exon 27 skipping, resulting in a mutated protein with a new C-terminal region (KIF5A Δ27). To understand how KIF5A Δ27 underpins the disease, we developed an ALS-associated KIF5A Drosophila model. When selectively expressed in motor neurons, KIF5A Δ27 alters larval locomotion as well as morphology and synaptic transmission at neuromuscular junctions in both males and females. We show that the distribution of mitochondria and synaptic vesicles is profoundly disturbed by KIF5A Δ27 expression. That is consistent with the numerous KIF5A Δ27-containing inclusions observed in motor neuron soma and axons. Moreover, KIF5A Δ27 expression leads to motor neuron death and reduces life expectancy. Our in vivo model reveals that a toxic gain of function underlies the pathogenicity of ALS-linked KIF5A mutant.SIGNIFICANCE STATEMENT Understanding how a mutation identified in patients with amyotrophic lateral sclerosis (ALS) causes the disease and the loss of motor neurons is crucial to fight against this disease. To this end, we have created a Drosophila model based on the motor neuron expression of the KIF5A mutant gene, recently identified in ALS patients. KIF5A encodes a kinesin that allows the anterograde transport of cargos. This model recapitulates the main features of ALS, including alterations of locomotion, synaptic neurotransmission, and morphology at neuromuscular junctions, as well as motor neuron death. KIF5A mutant is found in cytoplasmic inclusions, and its pathogenicity is because of a toxic gain of function.
Collapse
Affiliation(s)
- Laurent Soustelle
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| | - Franck Aimond
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| | - Cristina López-Andrés
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| | - Véronique Brugioti
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| | - Cédric Raoul
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| | - Sophie Layalle
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| |
Collapse
|
21
|
Myeong J, Stunault MI, Klyachko VA, Ashrafi G. Metabolic Regulation of Single Synaptic Vesicle Exo- and Endocytosis in Hippocampal Synapses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.08.566236. [PMID: 37986894 PMCID: PMC10659320 DOI: 10.1101/2023.11.08.566236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Glucose has long been considered a primary source of energy for synaptic function. However, it remains unclear under what conditions alternative fuels, such as lactate/pyruvate, contribute to powering synaptic transmission. By detecting individual release events in cultured hippocampal synapses, we found that mitochondrial ATP production from oxidation of lactate/pyruvate regulates basal vesicle release probability and release location within the active zone (AZ) evoked by single action potentials (APs). Mitochondrial inhibition shifted vesicle release closer to the AZ center, suggesting that the energetic barrier for vesicle release is lower in the AZ center that the periphery. Mitochondrial inhibition also altered the efficiency of single AP evoked vesicle retrieval by increasing occurrence of ultrafast endocytosis, while inhibition of glycolysis had no effect. Mitochondria are sparsely distributed along hippocampal axons and we found that nerve terminals containing mitochondria displayed enhanced vesicle release and reuptake during high-frequency trains, irrespective of whether neurons were supplied with glucose or lactate. Thus, synaptic terminals can entirely bypass glycolysis to robustly maintain the vesicle cycle using oxidative fuels in the absence of glucose. These observations further suggest that mitochondrial metabolic function not only regulates several fundamental features of synaptic transmission but may also contribute to modulation of short-term synaptic plasticity.
Collapse
Affiliation(s)
- Jongyun Myeong
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, 63132, United States
| | - Marion I Stunault
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, 63132, United States
| | - Vitaly A Klyachko
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, 63132, United States
| | - Ghazaleh Ashrafi
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, 63132, United States
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, 63132, United States
| |
Collapse
|
22
|
Wali G, Li Y, Liyanage E, Kumar KR, Day ML, Sue CM. Pharmacological rescue of mitochondrial and neuronal defects in SPG7 hereditary spastic paraplegia patient neurons using high throughput assays. Front Neurosci 2023; 17:1231584. [PMID: 37766787 PMCID: PMC10520970 DOI: 10.3389/fnins.2023.1231584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 08/21/2023] [Indexed: 09/29/2023] Open
Abstract
SPG7 is the most common form of autosomal recessive hereditary spastic paraplegia (HSP). There is a lack of HSP-SPG7 human neuronal models to understand the disease mechanism and identify new drug treatments. We generated a human neuronal model of HSP-SPG7 using induced pluripotent stem (iPS) cell technology. We first generated iPS cells from three HSP-SPG7 patients carrying different disease-causing variants and three healthy controls. The iPS cells were differentiated to form neural progenitor cells (NPCs) and then from NPCs to mature cortical neurons. Mitochondrial and neuronal defects were measured using a high throughout imaging and analysis-based assay in live cells. Our results show that compared to control NPCs, patient NPCs had aberrant mitochondrial morphology with increased mitochondrial size and reduced membrane potential. Patient NPCs develop to form mature cortical neurons with amplified mitochondrial morphology and functional defects along with defects in neuron morphology - reduced neurite complexity and length, reduced synaptic gene, protein expression and activity, reduced viability and increased axonal degeneration. Treatment of patient neurons with Bz-423, a mitochondria permeability pore regulator, restored the mitochondrial and neurite morphological defects and mitochondrial membrane potential back to control neuron levels and rescued the low viability and increased degeneration in patient neurons. This study establishes a direct link between mitochondrial and neuronal defects in HSP-SPG7 patient neurons. We present a strategy for testing mitochondrial targeting drugs to rescue neuronal defects in HSP-SPG7 patient neurons.
Collapse
Affiliation(s)
- Gautam Wali
- Neuroscience Research Australia, Sydney, NSW, Australia
- Kolling Institute for Medical Research, University of Sydney, NSW, Australia
| | - Yan Li
- Neuroscience Research Australia, Sydney, NSW, Australia
- Kolling Institute for Medical Research, University of Sydney, NSW, Australia
- University of New South Wales, Sydney, NSW, Australia
| | - Erandhi Liyanage
- Neuroscience Research Australia, Sydney, NSW, Australia
- Kolling Institute for Medical Research, University of Sydney, NSW, Australia
- University of New South Wales, Sydney, NSW, Australia
| | - Kishore R. Kumar
- University of New South Wales, Sydney, NSW, Australia
- Translational Neurogenomics Group, Molecular Medicine Laboratory and Department of Neurology, Concord Repatriation General Hospital, Concord Clinical School, University of Sydney, Concord, NSW, Australia
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Margot L. Day
- School of Medical Science, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Carolyn M. Sue
- Neuroscience Research Australia, Sydney, NSW, Australia
- Kolling Institute for Medical Research, University of Sydney, NSW, Australia
- University of New South Wales, Sydney, NSW, Australia
| |
Collapse
|
23
|
Chen W, Zhao H, Li Y. Mitochondrial dynamics in health and disease: mechanisms and potential targets. Signal Transduct Target Ther 2023; 8:333. [PMID: 37669960 PMCID: PMC10480456 DOI: 10.1038/s41392-023-01547-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 05/29/2023] [Accepted: 06/24/2023] [Indexed: 09/07/2023] Open
Abstract
Mitochondria are organelles that are able to adjust and respond to different stressors and metabolic needs within a cell, showcasing their plasticity and dynamic nature. These abilities allow them to effectively coordinate various cellular functions. Mitochondrial dynamics refers to the changing process of fission, fusion, mitophagy and transport, which is crucial for optimal function in signal transduction and metabolism. An imbalance in mitochondrial dynamics can disrupt mitochondrial function, leading to abnormal cellular fate, and a range of diseases, including neurodegenerative disorders, metabolic diseases, cardiovascular diseases and cancers. Herein, we review the mechanism of mitochondrial dynamics, and its impacts on cellular function. We also delve into the changes that occur in mitochondrial dynamics during health and disease, and offer novel perspectives on how to target the modulation of mitochondrial dynamics.
Collapse
Affiliation(s)
- Wen Chen
- Department of Medical Oncology, Chongqing University Cancer Hospital, Chongqing, 400030, China
| | - Huakan Zhao
- Department of Medical Oncology, Chongqing University Cancer Hospital, Chongqing, 400030, China.
| | - Yongsheng Li
- Department of Medical Oncology, Chongqing University Cancer Hospital, Chongqing, 400030, China.
| |
Collapse
|
24
|
Underwood EL, Redell JB, Hood KN, Maynard ME, Hylin M, Waxham MN, Zhao J, Moore AN, Dash PK. Enhanced presynaptic mitochondrial energy production is required for memory formation. Sci Rep 2023; 13:14431. [PMID: 37660191 PMCID: PMC10475119 DOI: 10.1038/s41598-023-40877-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 08/17/2023] [Indexed: 09/04/2023] Open
Abstract
Some of the prominent features of long-term memory formation include protein synthesis, gene expression, enhanced neurotransmitter release, increased excitability, and formation of new synapses. As these processes are critically dependent on mitochondrial function, we hypothesized that increased mitochondrial respiration and dynamics would play a prominent role in memory formation. To address this possibility, we measured mitochondrial oxygen consumption (OCR) in hippocampal tissue punches from trained and untrained animals. Our results show that context fear training significantly increased basal, ATP synthesis-linked, and maximal OCR in the Shaffer collateral-CA1 synaptic region, but not in the CA1 cell body layer. These changes were recapitulated in synaptosomes isolated from the hippocampi of fear-trained animals. As dynamin-related protein 1 (Drp1) plays an important role in mitochondrial fission, we examined its role in the increased mitochondrial respiration observed after fear training. Drp1 inhibitors decreased the training-associated enhancement of OCR and impaired contextual fear memory, but did not alter the number of synaptosomes containing mitochondria. Taken together, our results show context fear training increases presynaptic mitochondria respiration, and that Drp-1 mediated enhanced energy production in CA1 pre-synaptic terminals is necessary for context fear memory that does not result from an increase in the number of synaptosomes containing mitochondria or an increase in mitochondrial mass within the synaptic layer.
Collapse
Affiliation(s)
- Erica L Underwood
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| | - John B Redell
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA.
| | - Kimberly N Hood
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| | - Mark E Maynard
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
- Department of Electrical and Computer Engineering, University of Houston, Houston, TX, USA
| | - Michael Hylin
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
- Department of Psychology, Southern Illinois University, Carbondale, IL, USA
| | - M Neal Waxham
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| | - Jing Zhao
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| | - Anthony N Moore
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| | - Pramod K Dash
- Department of Neurobiology and Anatomy, The University of Texas McGovern Medical School, P.O. Box 20708, Houston, TX, 77225, USA
| |
Collapse
|
25
|
Aquilani R, Cotta Ramusino M, Maestri R, Iadarola P, Boselli M, Perini G, Boschi F, Dossena M, Bellini A, Buonocore D, Doria E, Costa A, Verri M. Several dementia subtypes and mild cognitive impairment share brain reduction of neurotransmitter precursor amino acids, impaired energy metabolism, and lipid hyperoxidation. Front Aging Neurosci 2023; 15:1237469. [PMID: 37655338 PMCID: PMC10466813 DOI: 10.3389/fnagi.2023.1237469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 08/03/2023] [Indexed: 09/02/2023] Open
Abstract
Objective Dementias and mild cognitive impairment (MCI) are associated with variously combined changes in the neurotransmitter system and signaling, from neurotransmitter synthesis to synaptic binding. The study tested the hypothesis that different dementia subtypes and MCI may share similar reductions of brain availability in amino acid precursors (AAPs) of neurotransmitter synthesis and concomitant similar impairment in energy production and increase of oxidative stress, i.e., two important metabolic alterations that impact neurotransmission. Materials and methods Sixty-five demented patients (Alzheimer's disease, AD, n = 44; frontotemporal disease, FTD, n = 13; vascular disease, VaD, n = 8), 10 subjects with MCI and 15 control subjects (CTRL) were recruited for this study. Cerebrospinal fluid (CSF) and plasma levels of AAPs, energy substrates (lactate, pyruvate), and an oxidative stress marker (malondialdehyde, MDA) were measured in all participants. Results Demented patients and subjects with MCI were similar for age, anthropometric parameters, biohumoral variables, insulin resistance (HOMA index model), and CSF neuropathology markers. Compared to age-matched CTRL, both demented patients and MCI subjects showed low CSF AAP tyrosine (precursor of dopamine and catecholamines), tryptophan (precursor of serotonin), methionine (precursor of acetylcholine) limited to AD and FTD, and phenylalanine (an essential amino acid largely used for protein synthesis) (p = 0.03 to <0.0001). No significant differences were found among dementia subtypes or between each dementia subtype and MCI subjects. In addition, demented patients and MCI subjects, compared to CTRL, had similar increases in CSF and plasma levels of pyruvate (CSF: p = 0.023 to <0.0001; plasma: p < 0.002 to <0.0001) and MDA (CSF: p < 0.035 to 0.002; plasma: p < 0.0001). Only in AD patients was the CSF level of lactate higher than in CTRL (p = 0.003). Lactate/pyruvate ratios were lower in all experimental groups than in CTRL. Conclusion AD, FTD, and VaD dementia patients and MCI subjects may share similar deficits in AAPs, partly in energy substrates, and similar increases in oxidative stress. These metabolic alterations may be due to AAP overconsumption following high brain protein turnover (leading to phenylalanine reductions), altered mitochondrial structure and function, and an excess of free radical production. All these metabolic alterations may have a negative impact on synaptic plasticity and activity.
Collapse
Affiliation(s)
- Roberto Aquilani
- Department of Biology and Biotechnology, “Lazzaro Spallanzani,” University of Pavia, Pavia, Italy
| | - Matteo Cotta Ramusino
- Unit of Behavioral Neurology and Center for Cognitive Disorders and Dementia, IRCCS C. Mondino Foundation, Pavia, Italy
- Dementia Research Center, IRCCS Mondino Foundation, Pavia, Italy
| | - Roberto Maestri
- Department of Biomedical Engineering of the Montescano Institute, Istituti Clinici Scientifici Maugeri IRCCS, Montescano, Italy
| | - Paolo Iadarola
- Department of Biology and Biotechnology, “Lazzaro Spallanzani,” University of Pavia, Pavia, Italy
| | - Mirella Boselli
- Neurorehabilitation Unit of the Montescano Institute, Istituti Clinici Scientifici Maugeri IRCCS, Montescano, Italy
| | - Giulia Perini
- Unit of Behavioral Neurology and Center for Cognitive Disorders and Dementia, IRCCS C. Mondino Foundation, Pavia, Italy
- Dementia Research Center, IRCCS Mondino Foundation, Pavia, Italy
| | - Federica Boschi
- Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Maurizia Dossena
- Department of Biology and Biotechnology, “Lazzaro Spallanzani,” University of Pavia, Pavia, Italy
| | - Anna Bellini
- Department of Biology and Biotechnology, “Lazzaro Spallanzani,” University of Pavia, Pavia, Italy
| | - Daniela Buonocore
- Department of Biology and Biotechnology, “Lazzaro Spallanzani,” University of Pavia, Pavia, Italy
| | - Enrico Doria
- Department of Biology and Biotechnology, “Lazzaro Spallanzani,” University of Pavia, Pavia, Italy
| | - Alfredo Costa
- Unit of Behavioral Neurology and Center for Cognitive Disorders and Dementia, IRCCS C. Mondino Foundation, Pavia, Italy
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Manuela Verri
- Department of Biology and Biotechnology, “Lazzaro Spallanzani,” University of Pavia, Pavia, Italy
| |
Collapse
|
26
|
Mondal R, Banerjee C, Nandy S, Roy M, Chakraborty J. Calcineurin inhibition protects against dopamine toxicity and attenuates behavioral decline in a Parkinson's disease model. Cell Biosci 2023; 13:140. [PMID: 37528492 PMCID: PMC10394860 DOI: 10.1186/s13578-023-01068-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/12/2023] [Indexed: 08/03/2023] Open
Abstract
BACKGROUND Parkinson's disease (PD), a highly prevalent neuro-motor disorder is caused due to progressive loss of dopaminergic (DAergic) neurons at substantia nigra region of brain. This leads to depleted dopamine (DA) content at striatum, thus affecting the fine tuning of basal ganglia. In patients, this imbalance is manifested by akinesia, catalepsy and tremor. PD associated behavioral dysfunctions are frequently mitigated by l-DOPA (LD) therapy, a precursor for DA synthesis. Due to progressive neurodegeneration, LD eventually loses applicability in PD. Although DA is cytotoxic, it is unclear whether LD therapy can accelerate PD progression or not. LD itself does not lead to neurodegeneration in vivo, but previous reports demonstrate that LD treatment mediated excess DA can potentiate neurotoxicity when PD associated genetic or epigenetic aberrations are involved. So, minimizing DA toxicity during the therapy is an absolute necessity to halt or slowdown PD progression. The two major contributing factors associated with DA toxicity are: degradation by Monoamine oxidase and DAquinone (DAQ) formation. RESULTS Here, we report that apoptotic mitochondrial fragmentation via Calcineurin (CaN)-DRP1 axis is a common downstream event for both these initial cues, inhibiting which can protect cells from DA toxicity comprehensively. No protective effect is observed, in terms of cell survival when only PxIxIT domain of CaN is obstructed, demonstrating the importance to block DRP1-CaN axis specifically. Further, evaluation of the impact of DA exposure on PD progression in a mice model reveal that LD mediated behavioral recovery diminishes with time, mostly because of continued DAergic cell death and dendritic spine loss at striatum. CaN inhibition, alone or in combination with LD, offer long term behavioral protection. This protective effect is mediated specifically by hindering CaN-DRP1 axis, whereas inhibiting interaction between CaN and other substrates, including proteins involved in neuro-inflammation, remained ineffective when LD is co-administered. CONCLUSIONS In this study, we conclude that DA toxicity can be circumvented by CaN inhibition and it can mitigate PD related behavioral aberrations by protecting neuronal architecture at striatum. We propose that CaN inhibitors might extend the therapeutic efficacy of LD treatment.
Collapse
Affiliation(s)
- Rupsha Mondal
- CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Chayan Banerjee
- CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sumangal Nandy
- CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India
| | - Moumita Roy
- CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Joy Chakraborty
- CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| |
Collapse
|
27
|
Calligaro H, Shoghi A, Chen X, Kim KY, Yu HL, Khov B, Finander B, Le H, Ellisman MH, Panda S. Ultrastructure of Synaptic Connectivity within Subregions of the Suprachiasmatic Nucleus Revealed by a Genetically Encoded Tag and Serial Blockface Electron Microscopy. eNeuro 2023; 10:ENEURO.0227-23.2023. [PMID: 37500494 PMCID: PMC10449486 DOI: 10.1523/eneuro.0227-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 07/01/2023] [Indexed: 07/29/2023] Open
Abstract
The hypothalamic suprachiasmatic nucleus (SCN) is the central circadian pacemaker in vertebrates. The SCN receives photic information exclusively through melanopsin-expressing retinal ganglion cells (mRGCs) to synchronize circadian rhythms with the environmental light cycles. The SCN is composed of two major peptidergic neuron types in the core and shell regions of the SCN. Determining how mRGCs interact with the network of synaptic connections onto and between SCN neurons is key to understand how light regulates the circadian clock and to elucidate the relevant local circuits within the SCN. To map these connections, we used a newly developed Cre-dependent electron microscopy (EM) reporter, APEX2, to label the mitochondria of mRGC axons. Serial blockface scanning electron microscopy was then used to resolve the fine 3D structure of mRGC axons and synaptic boutons in the SCN of a male mouse. The resulting maps reveal patterns of connectomic organization in the core and shell of the SCN. We show that these regions are composed of different neuronal subtypes and differ with regard to the pattern of mRGC input, as the shell receives denser mRGC synaptic input compared with the core. This finding challenges the present view that photic information coming directly from the retina is received primarily by the core region of the SCN.
Collapse
Affiliation(s)
- Hugo Calligaro
- Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Azarin Shoghi
- Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Xinyue Chen
- Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Keun-Young Kim
- Department of Neurosciences, University of California at San Diego School of Medicine, La Jolla, CA 92161
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92161
| | - Hsin Liu Yu
- Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Brian Khov
- Salk Institute for Biological Studies, La Jolla, CA 92037
| | | | - Hiep Le
- Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Mark H. Ellisman
- Department of Neurosciences, University of California at San Diego School of Medicine, La Jolla, CA 92161
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92161
| | | |
Collapse
|
28
|
Smith G, Sweeney ST, O’Kane CJ, Prokop A. How neurons maintain their axons long-term: an integrated view of axon biology and pathology. Front Neurosci 2023; 17:1236815. [PMID: 37564364 PMCID: PMC10410161 DOI: 10.3389/fnins.2023.1236815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/06/2023] [Indexed: 08/12/2023] Open
Abstract
Axons are processes of neurons, up to a metre long, that form the essential biological cables wiring nervous systems. They must survive, often far away from their cell bodies and up to a century in humans. This requires self-sufficient cell biology including structural proteins, organelles, and membrane trafficking, metabolic, signalling, translational, chaperone, and degradation machinery-all maintaining the homeostasis of energy, lipids, proteins, and signalling networks including reactive oxygen species and calcium. Axon maintenance also involves specialised cytoskeleton including the cortical actin-spectrin corset, and bundles of microtubules that provide the highways for motor-driven transport of components and organelles for virtually all the above-mentioned processes. Here, we aim to provide a conceptual overview of key aspects of axon biology and physiology, and the homeostatic networks they form. This homeostasis can be derailed, causing axonopathies through processes of ageing, trauma, poisoning, inflammation or genetic mutations. To illustrate which malfunctions of organelles or cell biological processes can lead to axonopathies, we focus on axonopathy-linked subcellular defects caused by genetic mutations. Based on these descriptions and backed up by our comprehensive data mining of genes linked to neural disorders, we describe the 'dependency cycle of local axon homeostasis' as an integrative model to explain why very different causes can trigger very similar axonopathies, providing new ideas that can drive the quest for strategies able to battle these devastating diseases.
Collapse
Affiliation(s)
- Gaynor Smith
- Cardiff University, School of Medicine, College of Biomedical and Life Sciences, Cardiff, United Kingdom
| | - Sean T. Sweeney
- Department of Biology, University of York and York Biomedical Research Institute, York, United Kingdom
| | - Cahir J. O’Kane
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Andreas Prokop
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biology, The University of Manchester, Manchester, United Kingdom
| |
Collapse
|
29
|
Lu D, Wang Y, Liu G, Wang S, Duan A, Wang Z, Wang J, Sun X, Wu Y, Wang Z. Armcx1 attenuates secondary brain injury in an experimental traumatic brain injury model in male mice by alleviating mitochondrial dysfunction and neuronal cell death. Neurobiol Dis 2023:106228. [PMID: 37454781 DOI: 10.1016/j.nbd.2023.106228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/20/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023] Open
Abstract
Armcx1 is highly expressed in the brain and is located in the mitochondrial outer membrane of neurons, where it mediates mitochondrial transport. Mitochondrial transport promotes the removal of damaged mitochondria and the replenishment of healthy mitochondria, which is essential for neuronal survival after traumatic brain injury (TBI). This study investigated the role of Armcx1 and its potential regulator(s) in secondary brain injury (SBI) after TBI. An in vivo TBI model was established in male C57BL/6 mice via controlled cortical impact (CCI). Adeno-associated viruses (AAVs) with Armcx1 overexpression and knockdown were constructed and administered to mice via stereotactic cortical injection. Exogenous miR-223-3p mimic or inhibitor was transfected into cultured cortical neurons, which were then scratched to simulate TBI in vitro. It was found that Armcx1 expression decreased significantly, while miR-223-3p levels increased markedly in peri-lesion tissues after TBI. The overexpression of Armcx1 significantly reduced TBI-induced neurological dysfunction, neuronal cell death, mitochondrial dysfunction, and axonal injury, while the knockdown of Armcx1 had the opposite effect. Armcx1 was potentially a direct target of miR-223-3p. The miR-223-3p mimic obviously reduced the Armcx1 protein level, while the miR-223-3p inhibitor had the opposite effect. Finally, the miR-223-3p inhibitor dramatically improved mitochondrial membrane potential (MMP) and increased the total length of the neurites without affecting branching numbers. In summary, our results suggest that the decreased expression of Armcx1 protein in neurons after experimental TBI aggravates secondary brain injury, which may be regulated by miR-223-3p. Therefore, this study provides a potential therapeutic approach for treating TBI.
Collapse
Affiliation(s)
- Dengfeng Lu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Yi Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Guangjie Liu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Shixin Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Aojie Duan
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Zongqi Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Jing Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Xiaoou Sun
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
| | - Yu Wu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
| | - Zhong Wang
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| |
Collapse
|
30
|
Xu X, Li H, Lu S, Shen Y. Roles of syntaphilin and armadillo repeat-containing X-linked protein 1 in brain injury after experimental intracerebral hemorrhage. Neurosci Lett 2023; 809:137300. [PMID: 37187340 DOI: 10.1016/j.neulet.2023.137300] [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: 01/27/2023] [Revised: 04/15/2023] [Accepted: 05/12/2023] [Indexed: 05/17/2023]
Abstract
Studies have indicated that neuronal mitochondrial injury may be involved in the brain injury caused by intracerebral hemorrhage (ICH). Syntaphilin (SNPH) is associated with mitochondrial anchoring and Armadillo repeat-containing X-linked protein 1 (Armcx1) is linked to mitochondrial transport. This study aimed to analyze the contribution of SNPH and Armcx1 to the neuronal damage resulting from ICH. Primary cultured neuron cells were exposed to oxygenated hemoglobin to replicate the effects of ICH stimulation, while a mouse model of ICH was established by injecting autoblood into the basal ganglia. Specific SNPH knockout or Armcx1 overexpression in neurons is achieved by stereolocalization injection of adeno-associated virus vectors carrying hsyn specific promoters. First, it was confirmed that there is a correlation between SNPH/Armcx1 and ICH pathology, as evidenced by the rise of SNPH and the decrease of Armcx1 in neurons exposed to ICH both in vitro and in vivo. Second, our research revealed the protective effects of SNPH knockdown and Armcx1 overexpression on brain cell death around the hematoma in mice. In addition, the efficacy of SNPH knockdown and Armcx1 overexpression in improving neurobehavioral deficits was also demonstrated in mouse ICH model. Thus, moderate adjusting the levels of SNPH and Armcx1 may be an effective way to improve the outcome of ICH.
Collapse
Affiliation(s)
- Xiaowen Xu
- Department of Intensive Care Unit, The First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China
| | - Haiying Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou 215100, Jiangsu Province, China
| | - Shiqi Lu
- Department of Intensive Care Unit, The First Affiliated Hospital of Soochow University, Suzhou 215006, Jiangsu Province, China.
| | - Yi Shen
- Department of Intensive Care Unit, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Suzhou 215002, Jiangsu Province, China.
| |
Collapse
|
31
|
Wu Y, Ding C, Weinreb A, Manning L, Swaim G, Yogev S, Colón-Ramos DA, Hammarlund M. Polarized localization of kinesin-1 and RIC-7 drives axonal mitochondria anterograde transport. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.12.548706. [PMID: 37502914 PMCID: PMC10369933 DOI: 10.1101/2023.07.12.548706] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Mitochondria transport is crucial for mitochondria distribution in axons and is mediated by kinesin-1-based anterograde and dynein-based retrograde motor complexes. While Miro and Milton/TRAK were identified as key adaptors between mitochondria and kinesin-1, recent studies suggest the presence of additional mechanisms. In C. elegans, ric-7 is the only single gene described so far, other than kinesin-1, that is absolutely required for axonal mitochondria localization. Using CRISPR engineering in C. elegans, we find that Miro is important but is not essential for anterograde traffic, whereas it is required for retrograde traffic. Both the endogenous RIC-7 and kinesin-1 act at the leading end to transport mitochondria anterogradely. RIC-7 recruitment to mitochondria requires its N-terminal domain and partially relies on MIRO-1, whereas RIC-7 accumulation at the leading end depends on its disordered region, kinesin-1 and metaxin2. We conclude that polarized transport complexes containing kinesin-1 and RIC-7 form at the leading edge of mitochondria, and that these complexes are required for anterograde axonal transport.
Collapse
Affiliation(s)
- Youjun Wu
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06536, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Chen Ding
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Alexis Weinreb
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06536, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Laura Manning
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Grace Swaim
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Shaul Yogev
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Daniel A Colón-Ramos
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Marc Hammarlund
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06536, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| |
Collapse
|
32
|
Mohylyak I, Bengochea M, Pascual-Caro C, Asfogo N, Fonseca-Topp S, Danda N, Atak ZK, De Waegeneer M, Plaçais PY, Preat T, Aerts S, Corti O, de Juan-Sanz J, Hassan BA. Developmental transcriptional control of mitochondrial homeostasis is required for activity-dependent synaptic connectivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.11.544500. [PMID: 37333418 PMCID: PMC10274921 DOI: 10.1101/2023.06.11.544500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
During neuronal circuit formation, local control of axonal organelles ensures proper synaptic connectivity. Whether this process is genetically encoded is unclear and if so, its developmental regulatory mechanisms remain to be identified. We hypothesized that developmental transcription factors regulate critical parameters of organelle homeostasis that contribute to circuit wiring. We combined cell type-specific transcriptomics with a genetic screen to discover such factors. We identified Telomeric Zinc finger-Associated Protein (TZAP) as a temporal developmental regulator of neuronal mitochondrial homeostasis genes, including Pink1 . In Drosophila , loss of dTzap function during visual circuit development leads to loss of activity-dependent synaptic connectivity, that can be rescued by Pink1 expression. At the cellular level, loss of dTzap/TZAP leads to defects in mitochondrial morphology, attenuated calcium uptake and reduced synaptic vesicle release in fly and mammalian neurons. Our findings highlight developmental transcriptional regulation of mitochondrial homeostasis as a key factor in activity-dependent synaptic connectivity.
Collapse
|
33
|
Pérez-Moreno JJ, Smith RC, Oliva MK, Gallo F, Ojha S, Müller KH, O’Kane CJ. Drosophila SPG12 ortholog, reticulon-like 1, governs presynaptic ER organization and Ca2+ dynamics. J Cell Biol 2023; 222:e202112101. [PMID: 36952540 PMCID: PMC10072275 DOI: 10.1083/jcb.202112101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/01/2023] [Accepted: 02/24/2023] [Indexed: 03/25/2023] Open
Abstract
Neuronal endoplasmic reticulum (ER) appears continuous throughout the cell. Its shape and continuity are influenced by ER-shaping proteins, mutations in which can cause distal axon degeneration in Hereditary Spastic Paraplegia (HSP). We therefore asked how loss of Rtnl1, a Drosophila ortholog of the human HSP gene RTN2 (SPG12), which encodes an ER-shaping protein, affects ER organization and the function of presynaptic terminals. Loss of Rtnl1 depleted ER membrane markers at Drosophila presynaptic motor terminals and appeared to deplete narrow tubular ER while leaving cisternae largely unaffected, thus suggesting little change in resting Ca2+ storage capacity. Nevertheless, these changes were accompanied by major reductions in activity-evoked Ca2+ fluxes in the cytosol, ER lumen, and mitochondria, as well as reduced evoked and spontaneous neurotransmission. We found that reduced STIM-mediated ER-plasma membrane contacts underlie presynaptic Ca2+ defects in Rtnl1 mutants. Our results show the importance of ER architecture in presynaptic physiology and function, which are therefore potential factors in the pathology of HSP.
Collapse
Affiliation(s)
| | | | - Megan K. Oliva
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Filomena Gallo
- Development and Neuroscience, Cambridge Advanced Imaging Centre, Cambridge, UK
| | - Shainy Ojha
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - Karin H. Müller
- Development and Neuroscience, Cambridge Advanced Imaging Centre, Cambridge, UK
| | - Cahir J. O’Kane
- Department of Genetics, University of Cambridge, Cambridge, UK
| |
Collapse
|
34
|
O'Connor K, Spendiff S, Lochmüller H, Horvath R. Mitochondrial Mutations Can Alter Neuromuscular Transmission in Congenital Myasthenic Syndrome and Mitochondrial Disease. Int J Mol Sci 2023; 24:ijms24108505. [PMID: 37239850 DOI: 10.3390/ijms24108505] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 05/28/2023] Open
Abstract
Congenital myasthenic syndromes (CMS) are a group of rare, neuromuscular disorders that usually present in childhood or infancy. While the phenotypic presentation of these disorders is diverse, the unifying feature is a pathomechanism that disrupts neuromuscular transmission. Recently, two mitochondrial genes-SLC25A1 and TEFM-have been reported in patients with suspected CMS, prompting a discussion about the role of mitochondria at the neuromuscular junction (NMJ). Mitochondrial disease and CMS can present with similar symptoms, and potentially one in four patients with mitochondrial myopathy exhibit NMJ defects. This review highlights research indicating the prominent roles of mitochondria at both the pre- and postsynapse, demonstrating the potential for mitochondrial involvement in neuromuscular transmission defects. We propose the establishment of a novel subcategorization for CMS-mitochondrial CMS, due to unifying clinical features and the potential for mitochondrial defects to impede transmission at the pre- and postsynapse. Finally, we highlight the potential of targeting the neuromuscular transmission in mitochondrial disease to improve patient outcomes.
Collapse
Affiliation(s)
- Kaela O'Connor
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Centre for Neuromuscular Disease, University of Ottawa Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada
| | - Sally Spendiff
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada
| | - Hanns Lochmüller
- Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada
- Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada
- Brain and Mind Research Institute, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Department of Neuropediatrics and Muscle Disorders, Faculty of Medicine, Medical Center-University of Freiburg, 79104 Freiburg, Germany
- Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), 08028 Barcelona, Catalonia, Spain
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge, Cambridge CB3 0FD, UK
| |
Collapse
|
35
|
Varte V, Munkelwitz JW, Rincon-Limas DE. Insights from Drosophila on Aβ- and tau-induced mitochondrial dysfunction: mechanisms and tools. Front Neurosci 2023; 17:1184080. [PMID: 37139514 PMCID: PMC10150963 DOI: 10.3389/fnins.2023.1184080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 03/31/2023] [Indexed: 05/05/2023] Open
Abstract
Alzheimer's disease (AD) is the most prevalent neurodegenerative dementia in older adults worldwide. Sadly, there are no disease-modifying therapies available for treatment due to the multifactorial complexity of the disease. AD is pathologically characterized by extracellular deposition of amyloid beta (Aβ) and intracellular neurofibrillary tangles composed of hyperphosphorylated tau. Increasing evidence suggest that Aβ also accumulates intracellularly, which may contribute to the pathological mitochondrial dysfunction observed in AD. According with the mitochondrial cascade hypothesis, mitochondrial dysfunction precedes clinical decline and thus targeting mitochondria may result in new therapeutic strategies. Unfortunately, the precise mechanisms connecting mitochondrial dysfunction with AD are largely unknown. In this review, we will discuss how the fruit fly Drosophila melanogaster is contributing to answer mechanistic questions in the field, from mitochondrial oxidative stress and calcium dysregulation to mitophagy and mitochondrial fusion and fission. In particular, we will highlight specific mitochondrial insults caused by Aβ and tau in transgenic flies and will also discuss a variety of genetic tools and sensors available to study mitochondrial biology in this flexible organism. Areas of opportunity and future directions will be also considered.
Collapse
Affiliation(s)
- Vanlalrinchhani Varte
- Department of Neurology, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States
| | - Jeremy W. Munkelwitz
- Department of Neurology, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States
| | - Diego E. Rincon-Limas
- Department of Neurology, McKnight Brain Institute, Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
- Genetics Institute, University of Florida, Gainesville, FL, United States
| |
Collapse
|
36
|
Cheramangalam RN, Anand T, Pandey P, Balasubramanian D, Varghese R, Singhal N, Jaiswal SN, Jaiswal M. Bendless is essential for PINK1-Park mediated Mitofusin degradation under mitochondrial stress caused by loss of LRPPRC. PLoS Genet 2023; 19:e1010493. [PMID: 37098042 PMCID: PMC10162545 DOI: 10.1371/journal.pgen.1010493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 05/05/2023] [Accepted: 04/03/2023] [Indexed: 04/26/2023] Open
Abstract
Cells under mitochondrial stress often co-opt mechanisms to maintain energy homeostasis, mitochondrial quality control and cell survival. A mechanistic understanding of such responses is crucial for further insight into mitochondrial biology and diseases. Through an unbiased genetic screen in Drosophila, we identify that mutations in lrpprc2, a homolog of the human LRPPRC gene that is linked to the French-Canadian Leigh syndrome, result in PINK1-Park activation. While the PINK1-Park pathway is well known to induce mitophagy, we show that PINK1-Park regulates mitochondrial dynamics by inducing the degradation of the mitochondrial fusion protein Mitofusin/Marf in lrpprc2 mutants. In our genetic screen, we also discover that Bendless, a K63-linked E2 conjugase, is a regulator of Marf, as loss of bendless results in increased Marf levels. We show that Bendless is required for PINK1 stability, and subsequently for PINK1-Park mediated Marf degradation under physiological conditions, and in response to mitochondrial stress as seen in lrpprc2. Additionally, we show that loss of bendless in lrpprc2 mutant eyes results in photoreceptor degeneration, indicating a neuroprotective role for Bendless-PINK1-Park mediated Marf degradation. Based on our observations, we propose that certain forms of mitochondrial stress activate Bendless-PINK1-Park to limit mitochondrial fusion, which is a cell-protective response.
Collapse
Affiliation(s)
| | - Tarana Anand
- Tata Institute of Fundamental Research, Hyderabad, India
| | - Priyanka Pandey
- CSIR–Centre For Cellular and Molecular Biology, Hyderabad, India
| | | | - Reshmi Varghese
- CSIR–Centre For Cellular and Molecular Biology, Hyderabad, India
| | - Neha Singhal
- Tata Institute of Fundamental Research, Hyderabad, India
| | | | - Manish Jaiswal
- Tata Institute of Fundamental Research, Hyderabad, India
| |
Collapse
|
37
|
Wang W, Zhao F, Lu Y, Siedlak SL, Fujioka H, Feng H, Perry G, Zhu X. Damaged mitochondria coincide with presynaptic vesicle loss and abnormalities in alzheimer's disease brain. Acta Neuropathol Commun 2023; 11:54. [PMID: 37004141 PMCID: PMC10067183 DOI: 10.1186/s40478-023-01552-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 03/16/2023] [Indexed: 04/03/2023] Open
Abstract
Loss of synapses is the most robust pathological correlate of Alzheimer's disease (AD)-associated cognitive deficits, although the underlying mechanism remains incompletely understood. Synaptic terminals have abundant mitochondria which play an indispensable role in synaptic function through ATP provision and calcium buffering. Mitochondrial dysfunction is an early and prominent feature in AD which could contribute to synaptic deficits. Here, using electron microscopy, we examined synapses with a focus on mitochondrial deficits in presynaptic axonal terminals and dendritic spines in cortical biopsy samples from clinically diagnosed AD and age-matched non-AD control patients. Synaptic vesicle density within the presynaptic axon terminals was significantly decreased in AD cases which appeared largely due to significantly decreased reserve pool, but there were significantly more presynaptic axons containing enlarged synaptic vesicles or dense core vesicles in AD. Importantly, there was reduced number of mitochondria along with significantly increased damaged mitochondria in the presynapse of AD which correlated with changes in SV density. Mitochondria in the post-synaptic dendritic spines were also enlarged and damaged in the AD biopsy samples. This study provided evidence of presynaptic vesicle loss as synaptic deficits in AD and suggested that mitochondrial dysfunction in both pre- and post-synaptic compartments contribute to synaptic deficits in AD.
Collapse
Affiliation(s)
- Wenzhang Wang
- Department of Pathology, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH, 44106, USA
| | - Fanpeng Zhao
- Department of Pathology, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH, 44106, USA
| | - Yubing Lu
- Department of Pathology, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH, 44106, USA
| | - Sandra L Siedlak
- Department of Pathology, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH, 44106, USA
| | - Hisashi Fujioka
- Cryo-EM Core Facility, Case Western Reserve University, Cleveland, OH, USA
| | - Hao Feng
- Department of Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - George Perry
- Department of Neuroscience, Developmental and Regenerative Biology, University of Texas, San Antonio, TX, USA
| | - Xiongwei Zhu
- Department of Pathology, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH, 44106, USA.
| |
Collapse
|
38
|
Mitochondrial Neurodegeneration: Lessons from Drosophila melanogaster Models. Biomolecules 2023; 13:biom13020378. [PMID: 36830747 PMCID: PMC9953451 DOI: 10.3390/biom13020378] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/19/2023] Open
Abstract
The fruit fly-i.e., Drosophila melanogaster-has proven to be a very useful model for the understanding of basic physiological processes, such as development or ageing. The availability of straightforward genetic tools that can be used to produce engineered individuals makes this model extremely interesting for the understanding of the mechanisms underlying genetic diseases in physiological models. Mitochondrial diseases are a group of yet-incurable genetic disorders characterized by the malfunction of the oxidative phosphorylation system (OXPHOS), which is the highly conserved energy transformation system present in mitochondria. The generation of D. melanogaster models of mitochondrial disease started relatively recently but has already provided relevant information about the molecular mechanisms and pathological consequences of mitochondrial dysfunction. Here, we provide an overview of such models and highlight the relevance of D. melanogaster as a model to study mitochondrial disorders.
Collapse
|
39
|
Bademosi AT, Decet M, Kuenen S, Calatayud C, Swerts J, Gallego SF, Schoovaerts N, Karamanou S, Louros N, Martin E, Sibarita JB, Vints K, Gounko NV, Meunier FA, Economou A, Versées W, Rousseau F, Schymkowitz J, Soukup SF, Verstreken P. EndophilinA-dependent coupling between activity-induced calcium influx and synaptic autophagy is disrupted by a Parkinson-risk mutation. Neuron 2023; 111:1402-1422.e13. [PMID: 36827984 PMCID: PMC10166451 DOI: 10.1016/j.neuron.2023.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 11/09/2022] [Accepted: 01/31/2023] [Indexed: 02/26/2023]
Abstract
Neuronal activity causes use-dependent decline in protein function. However, it is unclear how this is coupled to local quality control mechanisms. We show in Drosophila that the endocytic protein Endophilin-A (EndoA) connects activity-induced calcium influx to synaptic autophagy and neuronal survival in a Parkinson disease-relevant fashion. Mutations in the disordered loop, including a Parkinson disease-risk mutation, render EndoA insensitive to neuronal stimulation and affect protein dynamics: when EndoA is more flexible, its mobility in membrane nanodomains increases, making it available for autophagosome formation. Conversely, when EndoA is more rigid, its mobility reduces, blocking stimulation-induced autophagy. Balanced stimulation-induced autophagy is required for dopagminergic neuron survival, and a variant in the human ENDOA1 disordered loop conferring risk to Parkinson disease also blocks nanodomain protein mobility and autophagy both in vivo and in human-induced dopaminergic neurons. Thus, we reveal a mechanism that neurons use to connect neuronal activity to local autophagy and that is critical for neuronal survival.
Collapse
Affiliation(s)
- Adekunle T Bademosi
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, Leuven 3000, Belgium; Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia Campus, Brisbane, QLD 4072, Australia
| | - Marianna Decet
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, Leuven 3000, Belgium
| | - Sabine Kuenen
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, Leuven 3000, Belgium
| | - Carles Calatayud
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, Leuven 3000, Belgium
| | - Jef Swerts
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, Leuven 3000, Belgium
| | - Sandra F Gallego
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, Leuven 3000, Belgium
| | - Nils Schoovaerts
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, Leuven 3000, Belgium
| | - Spyridoula Karamanou
- KU Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Leuven 3000, Belgium
| | - Nikolaos Louros
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium
| | - Ella Martin
- VIB-VUB Center for Structural Biology, Brussels 1050, Belgium; Department of Structural Biology Brussels, Vrije Universiteit Brussel, Brussels 1050, Belgium
| | - Jean-Baptiste Sibarita
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, F-33000 Bordeaux, France
| | - Katlijn Vints
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, Leuven 3000, Belgium; VIB Bio Core, KU Leuven, Leuven 3000, Belgium
| | - Natalia V Gounko
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, Leuven 3000, Belgium; VIB Bio Core, KU Leuven, Leuven 3000, Belgium
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St Lucia Campus, Brisbane, QLD 4072, Australia; School of Biomedical Sciences, The University of Queensland, St Lucia Campus, Brisbane, QLD 4072, Australia
| | - Anastassios Economou
- KU Leuven, Department of Microbiology and Immunology, Rega Institute for Medical Research, Leuven 3000, Belgium
| | - Wim Versées
- VIB-VUB Center for Structural Biology, Brussels 1050, Belgium; Department of Structural Biology Brussels, Vrije Universiteit Brussel, Brussels 1050, Belgium
| | - Frederic Rousseau
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium
| | - Joost Schymkowitz
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; Switch Laboratory, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium
| | | | - Patrik Verstreken
- VIB-KU Leuven Center for Brain & Disease Research, Leuven 3000, Belgium; KU Leuven, Department of Neurosciences, Leuven Brain Institute, Mission Lucidity, Leuven 3000, Belgium.
| |
Collapse
|
40
|
Venken KJ, Matinyan N, Gonzalez Y, Dierick HA. Serial Recombineering Cloning to Build Selectable and Tagged Genomic P[acman] BAC Clones for Selection Transgenesis and Functional Gene Analysis using Drosophila melanogaster. Curr Protoc 2023; 3:e675. [PMID: 36757632 PMCID: PMC9923880 DOI: 10.1002/cpz1.675] [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: 02/10/2023]
Abstract
Transgenes with genomic DNA fragments that encompass genes of interest are the gold standard for complementing null alleles in rescue experiments in the fruit fly Drosophila melanogaster. Of particular interest are genomic DNA clones available as bacterial artificial chromosomes (BACs) or fosmids from publicly available genomic DNA libraries. Genes contained within BAC and fosmid clones can be easily modified by recombineering cloning to insert peptide or protein tags to localize, visualize, or manipulate gene products, and to create point mutations or deletions for structure-function analysis of the inserted genes. However, since transgenesis efficiency is inversely correlated with transgene size, obtaining transgenic animals for increasingly larger BAC and fosmid clones requires increasingly laborious screening efforts using the transgenesis marker commonly used for these transgenes, the dominant eye color marker white+ . We recently described a drug-based selectable genetic platform for Drosophila melanogaster, which included four resistance markers that allow direct selection of transgenic animals, eliminating the need to identify transgenic progeny by laborious phenotypic screening. By integrating these resistance markers into BAC transgenes, we were able to isolate animals containing large transgenes by direct selection, avoiding laborious screening. Here we present procedures on how to upgrade BAC clones by serial recombineering cloning to build both selectable and tagged BAC transgenes, for selection transgenesis and functional gene analysis, respectively. We illustrate these procedures using a BAC clone encompassing the gene encoding the synaptic vesicle protein, cysteine string protein. We demonstrate that the modified BAC clone, serially recombineered with a selectable marker for selection transgenesis and an N-terminal green fluorescent protein tag for gene expression analysis, is functional by showing the expression pattern obtained after successful selection transgenesis. The protocols cover: (1) cloning and preparation of the recombineering templates needed for serial recombineering cloning to incorporate selectable markers and protein tags; (2) preparing electrocompetent cells needed to perform serial recombineering cloning; and (3) the serial recombineering workflow to generate both selectable and tagged genomic BAC reporter transgenes for selection transgenesis and functional gene analysis in Drosophila melanogaster. The protocols we describe can be easily adapted to incorporate any of four selectable markers, protein tags, or any other modification for structure-function analysis of the genes present within any of the BAC or fosmid clones. A protocol for generating transgenic animals using serially recombineered BAC clones is presented in an accompanying Current Protocols article (Venken, Matinyan, Gonzalez, & Dierick, 2023a). © 2023 Wiley Periodicals LLC. Basic Protocol 1: Cloning and preparation of recombineering templates used for serial recombineering cloning. Basic Protocol 2: Making electrocompetent cells of the bacterial strains used to perform serial recombineering cloning or induction of plasmid copy number. Basic Protocol 3: Serial recombineering cloning to generate both selectable and tagged genomic P[acman] BAC reporter transgenes for selection transgenesis and gene expression analysis in Drosophila melanogaster.
Collapse
Affiliation(s)
- Koen J.T. Venken
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Integrative Molecular Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
- McNair Medical Institute at The Robert and Janice McNair Foundation, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Nick Matinyan
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Integrative Molecular Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yezabel Gonzalez
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Herman A. Dierick
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| |
Collapse
|
41
|
Meta-analysis of brain samples of individuals with schizophrenia detects down-regulation of multiple ATP synthase encoding genes in both females and males. J Psychiatr Res 2023; 158:350-359. [PMID: 36640659 DOI: 10.1016/j.jpsychires.2023.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 10/05/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023]
Abstract
Schizophrenia is a chronic and debilitating mental disorder, with unknown pathophysiology. Converging lines of evidence suggest that mitochondrial functioning may be compromised in schizophrenia. Postmortem brain samples of individuals with schizophrenia showed dysregulated expression levels of genes encoding enzyme complexes comprising the mitochondrial electron transport chain (ETC), including ATP synthase, the fifth ETC complex. However, there are inconsistencies regarding the direction of change, i.e., up- or down-regulation, and differences between female and male patients were hardly examined. We have performed a systematic meta-analysis of the expression of 16 ATP synthase encoding genes in postmortem brain samples of individuals with schizophrenia vs. healthy controls of three regions: Brodmann Area 10 (BA10), BA22/Superior Temporal Gyrus (STG) and the cerebellum. Eight independent datasets were integrated (overall 294brain samples, 145 of individuals with schizophrenia and 149 controls). The meta-analysis was applied to all individuals with schizophrenia vs. the controls, and also to female and male patients vs. age-matched controls, separately. A significant down-regulation of two ATP synthase encoding genes was detected in schizophrenia, ATP5A1 and ATP5H, and a trend towards down-regulation of five further ATP synthase genes. The down-regulation tendency was shown for both females and males with schizophrenia. Our findings support the hypothesis that schizophrenia is associated with reduced ATP synthesis via the oxidative phosphorylation system, which is caused by reduced cellular demand of ATP. Abnormal cellular energy metabolism can lead to alterations in neural function and brain circuitry, and thereby to the cognitive and behavioral aberrations characteristic of schizophrenia.
Collapse
|
42
|
Guo Z, Wang Z, Gao Z, Feng T, Gao Y, Yin Z, Tian Z, Liu Y, Mao X, Xiang C. The status and trends of mitochondrial dynamics research: A global bibliometric and visualized analysis. J Bioenerg Biomembr 2023; 55:43-57. [PMID: 36807837 PMCID: PMC9942064 DOI: 10.1007/s10863-023-09959-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 02/06/2023] [Indexed: 02/23/2023]
Abstract
BACKGROUND Mitochondria are remarkably dynamic organelles encapsulated by bilayer membranes. The dynamic properties of mitochondria are critical for energy production. AIMS The aim of our study is to investigate the global status and trends of mitochondrial dynamics research and predict popular topics and directions in the field. METHODS Publications related to the studies of mitochondrial dynamics from 2002 to 2021 were retrieved from Web of Science database. A total of 4,576 publications were included. Bibliometric analysis was conducted by visualization of similarities viewer and GraphPadPrism 5 software. RESULTS There is an increasing trend of mitochondrial dynamics research during the last 20 years. The cumulative number of publications about mitochondrial dynamics research followed the logistic growth model [Formula: see text]. The USA made the highest contributions to the global research. The journal Biochimica et Biophysica Acta (BBA)-Molecular Cell Research had the largest publication numbers. Case Western Reserve University is the most contributive institution. The main research orientation and funding agency were cell biology and HHS. All keywords related studies could be divided into three clusters: "Related disease research", "Mechanism research" and "Cell metabolism research". CONCLUSIONS Attention should be drawn to the latest popular research and more efforts will be put into mechanistic research, which may inspire new clinical treatments for the associated diseases.
Collapse
Affiliation(s)
- Zijian Guo
- Department of Orthopedic, The Second Hospital of Shanxi Medical University, Taiyuan, China
| | - Zehua Wang
- Department of Orthopedic, The Second Hospital of Shanxi Medical University, Taiyuan, China
| | - Zhenzhong Gao
- Department of Orthopedic, The Second Hospital of Shanxi Medical University, Taiyuan, China
| | - Tengda Feng
- Department of Orthopedic, The Second Hospital of Shanxi Medical University, Taiyuan, China
| | - Yingjie Gao
- Department of Orthopedic, The Second Hospital of Shanxi Medical University, Taiyuan, China
| | - Zhiwen Yin
- Department of Orthopedic, The Second Hospital of Shanxi Medical University, Taiyuan, China
| | - Zui Tian
- Department of Orthopedic, The Second Hospital of Shanxi Medical University, Taiyuan, China
| | - Yang Liu
- Department of Orthopedic, The Second Hospital of Shanxi Medical University, Taiyuan, China
| | - Xingjia Mao
- Department of Basic Medicine Sciences, and Department of Orthopaedics of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058 China
| | - Chuan Xiang
- Department of Orthopedic, The Second Hospital of Shanxi Medical University, Taiyuan, China.
| |
Collapse
|
43
|
Yang C, Zhao X, An X, Zhang Y, Sun W, Zhang Y, Duan Y, Kang X, Sun Y, Jiang L, Lian F. Axonal transport deficits in the pathogenesis of diabetic peripheral neuropathy. Front Endocrinol (Lausanne) 2023; 14:1136796. [PMID: 37056668 PMCID: PMC10086245 DOI: 10.3389/fendo.2023.1136796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
Diabetic peripheral neuropathy (DPN) is a chronic and prevalent metabolic disease that gravely endangers human health and seriously affects the quality of life of hyperglycemic patients. More seriously, it can lead to amputation and neuropathic pain, imposing a severe financial burden on patients and the healthcare system. Even with strict glycemic control or pancreas transplantation, peripheral nerve damage is difficult to reverse. Most current treatment options for DPN can only treat the symptoms but not the underlying mechanism. Patients with long-term diabetes mellitus (DM) develop axonal transport dysfunction, which could be an important factor in causing or exacerbating DPN. This review explores the underlying mechanisms that may be related to axonal transport impairment and cytoskeletal changes caused by DM, and the relevance of the latter with the occurrence and progression of DPN, including nerve fiber loss, diminished nerve conduction velocity, and impaired nerve regeneration, and also predicts possible therapeutic strategies. Understanding the mechanisms of diabetic neuronal injury is essential to prevent the deterioration of DPN and to develop new therapeutic strategies. Timely and effective improvement of axonal transport impairment is particularly critical for the treatment of peripheral neuropathies.
Collapse
|
44
|
Chhimpa N, Singh N, Puri N, Kayath HP. The Novel Role of Mitochondrial Citrate Synthase and Citrate in the Pathophysiology of Alzheimer's Disease. J Alzheimers Dis 2023; 94:S453-S472. [PMID: 37393492 PMCID: PMC10473122 DOI: 10.3233/jad-220514] [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] [Accepted: 06/07/2023] [Indexed: 07/03/2023]
Abstract
Citrate synthase is a key mitochondrial enzyme that utilizes acetyl-CoA and oxaloacetate to form citrate in the mitochondrial membrane, which participates in energy production in the TCA cycle and linked to the electron transport chain. Citrate transports through a citrate malate pump and synthesizes acetyl-CoA and acetylcholine (ACh) in neuronal cytoplasm. In a mature brain, acetyl-CoA is mainly utilized for ACh synthesis and is responsible for memory and cognition. Studies have shown low citrate synthase in different regions of brain in Alzheimer's disease (AD) patients, which reduces mitochondrial citrate, cellular bioenergetics, neurocytoplasmic citrate, acetyl-CoA, and ACh synthesis. Reduced citrate mediated low energy favors amyloid-β (Aβ) aggregation. Citrate inhibits Aβ25-35 and Aβ1-40 aggregation in vitro. Hence, citrate can be a better therapeutic option for AD by improving cellular energy and ACh synthesis, and inhibiting Aβ aggregation, which prevents tau hyperphosphorylation and glycogen synthase kinase-3 beta. Therefore, we need clinical studies if citrate reverses Aβ deposition by balancing mitochondrial energy pathway and neurocytoplasmic ACh production. Furthermore, in AD's silent phase pathophysiology, when neuronal cells are highly active, they shift ATP utilization from oxidative phosphorylation to glycolysis and prevent excessive generation of hydrogen peroxide and reactive oxygen species (oxidative stress) as neuroprotective action, which upregulates glucose transporter-3 (GLUT3) and pyruvate dehydrogenase kinase-3 (PDK3). PDK3 inhibits pyruvate dehydrogenase, which decreases mitochondrial-acetyl-CoA, citrate, and cellular bioenergetics, and decreases neurocytoplasmic citrate, acetyl-CoA, and ACh formation, thus initiating AD pathophysiology. Therefore, GLUT3 and PDK3 can be biomarkers for silent phase of AD.
Collapse
Affiliation(s)
- Neeraj Chhimpa
- Department of Pharmacology, Post Graduate Institute of Medical Education & Research, Chandigarh, India
- Department of Pharmacology, Meharishi Markandeshwar College of Medical Science & Research, Ambala, India
| | - Neha Singh
- Department of Pharmacology, Post Graduate Institute of Medical Education & Research, Chandigarh, India
| | - Nikkita Puri
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, India
| | | |
Collapse
|
45
|
Lépine S, Castellanos-Montiel MJ, Durcan TM. TDP-43 dysregulation and neuromuscular junction disruption in amyotrophic lateral sclerosis. Transl Neurodegener 2022; 11:56. [PMID: 36575535 PMCID: PMC9793560 DOI: 10.1186/s40035-022-00331-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 11/29/2022] [Indexed: 12/28/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a disease characterized by upper and lower motor neuron (MN) loss with a signature feature of cytoplasmic aggregates containing TDP-43, which are detected in nearly all patients. Mutations in the gene that encodes TDP-43 (TARBDP) are known to result in both familial and sporadic ALS. In ALS, disruption of neuromuscular junctions (NMJs) constitutes a critical event in disease pathogenesis, leading to denervation atrophy, motor impairments and disability. Morphological defects and impaired synaptic transmission at NMJs have been reported in several TDP-43 animal models and in vitro, linking TDP-43 dysregulation to the loss of NMJ integrity in ALS. Through the lens of the dying-back and dying-forward hypotheses of ALS, this review discusses the roles of TDP-43 related to synaptic function, with a focus on the potential molecular mechanisms occurring within MNs, skeletal muscles and glial cells that may contribute to NMJ disruption in ALS.
Collapse
Affiliation(s)
- Sarah Lépine
- grid.14709.3b0000 0004 1936 8649The Neuro’s Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, 3801 University Street, Montreal, QC H3A 2B4 Canada ,grid.14709.3b0000 0004 1936 8649Faculty of Medicine and Health Sciences, McGill University, 3605 De La Montagne, Montreal, QC H3G 2M1 Canada
| | - Maria José Castellanos-Montiel
- grid.14709.3b0000 0004 1936 8649The Neuro’s Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, 3801 University Street, Montreal, QC H3A 2B4 Canada
| | - Thomas Martin Durcan
- grid.14709.3b0000 0004 1936 8649The Neuro’s Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, 3801 University Street, Montreal, QC H3A 2B4 Canada
| |
Collapse
|
46
|
Ren M, Yang Y, Heng KHY, Ng LY, Chong CYY, Ng YT, Gorur-Shandilya S, Lee RMQ, Lim KL, Zhang J, Koh TW. MED13 and glycolysis are conserved modifiers of α-synuclein-associated neurodegeneration. Cell Rep 2022; 41:111852. [PMID: 36543134 DOI: 10.1016/j.celrep.2022.111852] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 10/04/2022] [Accepted: 11/29/2022] [Indexed: 12/24/2022] Open
Abstract
α-Synuclein (α-syn) is important in synucleinopathies such as Parkinson's disease (PD). While genome-wide association studies (GWASs) of synucleinopathies have identified many risk loci, the underlying genes have not been shown for most loci. Using Drosophila, we screened 3,471 mutant chromosomes for genetic modifiers of α-synuclein and identified 12 genes. Eleven modifiers have human orthologs associated with diseases, including MED13 and CDC27, which lie within PD GWAS loci. Drosophila Skd/Med13 and glycolytic enzymes are co-upregulated by α-syn-associated neurodegeneration. While elevated α-syn compromises mitochondrial function, co-expressing skd/Med13 RNAi and α-syn synergistically increase the ratio of oxidized-to-reduced glutathione. The resulting neurodegeneration can be suppressed by overexpressing a glycolytic enzyme or treatment with deferoxamine, suggesting that compensatory glycolysis is neuroprotective. In addition, the functional relationship between α-synuclein, MED13, and glycolytic enzymes is conserved between flies and mice. We propose that hypoxia-inducible factor and MED13 are part of a druggable pathway for PD.
Collapse
Affiliation(s)
- Mengda Ren
- Temasek Life Sciences Laboratory, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308207, Singapore; National Neuroscience Institute, Singapore 308433, Singapore
| | - Ying Yang
- Department of Pathology, Zhejiang University First Affiliated Hospital and School of Medicine, Hangzhou, Zhejiang 310002, China
| | | | - Lu Yi Ng
- Temasek Life Sciences Laboratory, Singapore 117604, Singapore
| | | | - Yan Ting Ng
- Temasek Life Sciences Laboratory, Singapore 117604, Singapore
| | | | - Rachel Min Qi Lee
- Temasek Life Sciences Laboratory, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Kah Leong Lim
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308207, Singapore; National Neuroscience Institute, Singapore 308433, Singapore
| | - Jing Zhang
- Department of Pathology, Zhejiang University First Affiliated Hospital and School of Medicine, Hangzhou, Zhejiang 310002, China; China National Health and Disease Human Brain Tissue Resource Center, Hangzhou, Zhejiang 310002, China
| | - Tong-Wey Koh
- Temasek Life Sciences Laboratory, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore.
| |
Collapse
|
47
|
Mangosteen Pericarp Extract Supplementation Boosts Antioxidant Status via Rebuilding Gut Microbiota to Attenuate Motor Deficit in 6-OHDA-Induced Parkinson's Disease. Antioxidants (Basel) 2022; 11:antiox11122396. [PMID: 36552604 PMCID: PMC9774421 DOI: 10.3390/antiox11122396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/25/2022] [Accepted: 11/29/2022] [Indexed: 12/11/2022] Open
Abstract
Oxidative stress and gut dysbiosis have been known to precede Parkinson's disease (PD). An antioxidant-rich product, mangosteen pericarp (MP), has the ability to counterbalance excessive free radicals and the imbalanced gut microbiota composition, suggesting the MP's capacity to delay PD progression. In this study, we explored the effects of two doses of MP extract in a unilateral 6-hydroxydopamine (6-OHDA)-induced PD rat model. We revealed that the 8-week supplementation of a low dose (LMP) and a high dose of the MP extract (HMP) improved motor function, as observed in decreased contralateral rotation, improved time spent on rod, and higher dopamine binding transporter (DAT) in the substantia nigra pars compacta (SNc). The MP extract, especially the HMP, also increased antioxidant-related gene expressions, restored muscle mitochondrial function, and remodeled fecal microbiota composition, which were followed by reduced reactive oxygen species levels in brain and inflammation in plasma. Importantly, bacterial genera Sutterella, Rothia, and Aggregatibacter, which were negatively correlated with antioxidant gene expressions, decreased in the HMP group. It is imperative to note that in addition to directly acting as an antioxidant to reduce excessive free radicals, MP extract might also increase antioxidant state by rebuilding gut microbiota, thereby enhanced anti-inflammatory capacity and restored mitochondrial function to attenuate motor deficit in 6-OHDA-induced PD-like condition. All in all, MP extract is a potential candidate for auxiliary therapy for PD.
Collapse
|
48
|
Katti P, Ajayi PT, Aponte A, Bleck CKE, Glancy B. Identification of evolutionarily conserved regulators of muscle mitochondrial network organization. Nat Commun 2022; 13:6622. [PMID: 36333356 PMCID: PMC9636386 DOI: 10.1038/s41467-022-34445-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 10/25/2022] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial networks provide coordinated energy distribution throughout muscle cells. However, pathways specifying mitochondrial networks are incompletely understood and it is unclear how they might affect contractile fiber-type. Here, we show that natural energetic demands placed on Drosophila melanogaster muscles yield native cell-types among which contractile and mitochondrial network-types are regulated differentially. Proteomic analyses of indirect flight, jump, and leg muscles, together with muscles misexpressing known fiber-type specification factor salm, identified transcription factors H15 and cut as potential mitochondrial network regulators. We demonstrate H15 operates downstream of salm regulating flight muscle contractile and mitochondrial network-type. Conversely, H15 regulates mitochondrial network configuration but not contractile type in jump and leg muscles. Further, we find that cut regulates salm expression in flight muscles and mitochondrial network configuration in leg muscles. These data indicate cell type-specific regulation of muscle mitochondrial network organization through evolutionarily conserved transcription factors cut, salm, and H15.
Collapse
Affiliation(s)
- Prasanna Katti
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Peter T Ajayi
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Angel Aponte
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Christopher K E Bleck
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Brian Glancy
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
| |
Collapse
|
49
|
Sen A, Cox RT. Loss of Drosophila Clueless differentially affects the mitochondrial proteome compared to loss of Sod2 and Pink1. Front Physiol 2022; 13:1004099. [DOI: 10.3389/fphys.2022.1004099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
Mitochondria contain their own DNA, mitochondrial DNA, which encodes thirteen proteins. However, mitochondria require thousands of proteins encoded in the nucleus to carry out their many functions. Identifying the definitive mitochondrial proteome has been challenging as methods isolating mitochondrial proteins differ and different tissues and organisms may have specialized proteomes. Mitochondrial diseases arising from single gene mutations in nucleus encoded genes could affect the mitochondrial proteome, but deciphering which effects are due to loss of specific pathways or to accumulated general mitochondrial damage is difficult. To identify specific versus general effects, we have taken advantage of mutations in three Drosophila genes, clueless, Sod2, and Pink1, which are required for mitochondrial function through different pathways. We measured changes in each mutant’s mitochondrial proteome using quantitative tandem mass tag mass spectrometry. Our analysis identified protein classes that are unique to each mutant and those shared between them, suggesting that some changes in the mitochondrial proteome are due to general mitochondrial damage whereas others are gene specific. For example, clueless mutants had the greatest number of less and more abundant mitochondrial proteins whereas loss of all three genes increased stress and metabolism proteins. This study is the first to directly compare in vivo steady state levels of mitochondrial proteins by examining loss of three pathways critical for mitochondrial function. These data could be useful to understand disease etiology, and how mutations in genes critical for mitochondrial function cause specific mitochondrial proteomic changes as opposed to changes due to generalized mitochondrial damage.
Collapse
|
50
|
Karagas NE, Gupta R, Rastegari E, Tan KL, Leung HH, Bellen HJ, Venkatachalam K, Wong CO. Loss of Activity-Induced Mitochondrial ATP Production Underlies the Synaptic Defects in a Drosophila Model of ALS. J Neurosci 2022; 42:8019-8037. [PMID: 36261266 PMCID: PMC9617612 DOI: 10.1523/jneurosci.2456-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 08/23/2022] [Accepted: 08/27/2022] [Indexed: 11/21/2022] Open
Abstract
Mutations in the gene encoding vesicle-associated membrane protein B (VAPB) cause a familial form of amyotrophic lateral sclerosis (ALS). Expression of an ALS-related variant of vapb (vapbP58S ) in Drosophila motor neurons results in morphologic changes at the larval neuromuscular junction (NMJ) characterized by the appearance of fewer, but larger, presynaptic boutons. Although diminished microtubule stability is known to underlie these morphologic changes, a mechanism for the loss of presynaptic microtubules has been lacking. By studying flies of both sexes, we demonstrate the suppression of vapbP58S -induced changes in NMJ morphology by either a loss of endoplasmic reticulum (ER) Ca2+ release channels or the inhibition Ca2+/calmodulin (CaM)-activated kinase II (CaMKII). These data suggest that decreased stability of presynaptic microtubules at vapbP58S NMJs results from hyperactivation of CaMKII because of elevated cytosolic [Ca2+]. We attribute the Ca2+ dyshomeostasis to delayed extrusion of cytosolic Ca2+ Suggesting that this defect in Ca2+ extrusion arose from an insufficient response to the bioenergetic demand of neural activity, depolarization-induced mitochondrial ATP production was diminished in vapbP58S neurons. These findings point to bioenergetic dysfunction as a potential cause for the synaptic defects in vapbP58S -expressing motor neurons.SIGNIFICANCE STATEMENT Whether the synchrony between the rates of ATP production and demand is lost in degenerating neurons remains poorly understood. We report that expression of a gene equivalent to an amyotrophic lateral sclerosis (ALS)-causing variant of vesicle-associated membrane protein B (VAPB) in fly neurons decouples mitochondrial ATP production from neuronal activity. Consequently, levels of ATP in mutant neurons are unable to keep up with the bioenergetic burden of neuronal activity. Reduced rate of Ca2+ extrusion, which could result from insufficient energy to power Ca2+ ATPases, results in the accumulation of residual Ca2+ in mutant neurons and leads to alterations in synaptic vesicle (SV) release and synapse development. These findings suggest that synaptic defects in a model of ALS arise from the loss of activity-induced ATP production.
Collapse
Affiliation(s)
- Nicholas E Karagas
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, Texas 77030
- Graduate Program in Biochemistry and Cell Biology, MD Anderson Cancer Center and University of Texas Health Sciences Center Graduate School of Biomedical Sciences, Houston, TX, 77030
| | - Richa Gupta
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, Texas 77030
| | - Elham Rastegari
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, Texas 77030
| | - Kai Li Tan
- Departments of Molecular and Human Genetics and Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030
- Duncan Neurological Research Institute, Texas Children Hospital, Houston, Texas 77030
| | - Ho Hang Leung
- Department of Biological Sciences, Rutgers University, Newark, New Jersey 07102
| | - Hugo J Bellen
- Departments of Molecular and Human Genetics and Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030
- Duncan Neurological Research Institute, Texas Children Hospital, Houston, Texas 77030
| | - Kartik Venkatachalam
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center, Houston, Texas 77030
- Graduate Program in Biochemistry and Cell Biology, MD Anderson Cancer Center and University of Texas Health Sciences Center Graduate School of Biomedical Sciences, Houston, TX, 77030
- Graduate Program in Neuroscience, MD Anderson Cancer Center and University of Texas Health Sciences Center Graduate School of Biomedical Sciences, Houston, TX, 77030
| | - Ching-On Wong
- Department of Biological Sciences, Rutgers University, Newark, New Jersey 07102
| |
Collapse
|