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Aagaard Nolting L, Holling T, Nishimura G, Ek J, Bak M, Ljungberg M, Kutsche K, Hove H. Novel biallelic PISD missense variants cause spondyloepimetaphyseal dysplasia with disproportionate short stature and fragmented mitochondrial morphology. Clin Genet 2024; 106:360-366. [PMID: 38801004 DOI: 10.1111/cge.14549] [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: 03/05/2024] [Revised: 04/24/2024] [Accepted: 05/10/2024] [Indexed: 05/29/2024]
Abstract
Biallelic variants in PISD cause a phenotypic spectrum ranging from short stature with spondyloepimetaphyseal dysplasia (SEMD) to a multisystem disorder affecting eyes, ears, bones, and brain. PISD encodes the mitochondrial-localized enzyme phosphatidylserine decarboxylase. The PISD precursor is self-cleaved to generate a heteromeric mature enzyme that converts phosphatidylserine to the phospholipid phosphatidylethanolamine. We describe a 17-year-old male patient, born to unrelated healthy parents, with disproportionate short stature and SEMD, featuring platyspondyly, prominent epiphyses, and metaphyseal dysplasia. Trio genome sequencing revealed compound heterozygous PISD variants c.569C>T; p.(Ser190Leu) and c.799C>T; p.(His267Tyr) in the patient. Investigation of fibroblasts showed similar levels of the PISD precursor protein in both patient and control cells. However, patient cells had a significantly higher proportion of fragmented mitochondria compared to control cells cultured under basal condition and after treatment with 2-deoxyglucose that represses glycolysis and stimulates respiration. Structural data from the PISD orthologue in Escherichia coli suggest that the amino acid substitutions Ser190Leu and His267Tyr likely impair PISD's autoprocessing activity and/or phosphatidylethanolamine biosynthesis. Based on the data, we propose that the novel PISD p.(Ser190Leu) and p.(His267Tyr) variants likely act as hypomorphs and underlie the pure skeletal phenotype in the patient.
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Affiliation(s)
- Line Aagaard Nolting
- Department of Pediatrics, Center for Rare Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Tess Holling
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gen Nishimura
- Center for Intractable Diseases, Saitama Medical University Hospital, Saitama, Japan
| | - Jakob Ek
- Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Mads Bak
- Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Merete Ljungberg
- Department of Pediatrics, Center for Rare Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hanne Hove
- Department of Pediatrics, Center for Rare Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
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2
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Messina M, Vaz FM, Rahman S. Mitochondrial membrane synthesis, remodelling and cellular trafficking. J Inherit Metab Dis 2024. [PMID: 38872485 DOI: 10.1002/jimd.12766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/14/2024] [Accepted: 05/21/2024] [Indexed: 06/15/2024]
Abstract
Mitochondria are dynamic cellular organelles with complex roles in metabolism and signalling. Primary mitochondrial disorders are a group of approximately 400 monogenic disorders arising from pathogenic genetic variants impacting mitochondrial structure, ultrastructure and/or function. Amongst these disorders, defects of complex lipid biosynthesis, especially of the unique mitochondrial membrane lipid cardiolipin, and membrane biology are an emerging group characterised by clinical heterogeneity, but with recurrent features including cardiomyopathy, encephalopathy, neurodegeneration, neuropathy and 3-methylglutaconic aciduria. This review discusses lipid synthesis in the mitochondrial membrane, the mitochondrial contact site and cristae organising system (MICOS), mitochondrial dynamics and trafficking, and the disorders associated with defects of each of these processes. We highlight overlapping functions of proteins involved in lipid biosynthesis and protein import into the mitochondria, pointing to an overarching coordination and synchronisation of mitochondrial functions. This review also focuses on membrane interactions between mitochondria and other organelles, namely the endoplasmic reticulum, peroxisomes, lysosomes and lipid droplets. We signpost disorders of these membrane interactions that may explain the observation of secondary mitochondrial dysfunction in heterogeneous pathological processes. Disruption of these organellar interactions ultimately impairs cellular homeostasis and organismal health, highlighting the central role of mitochondria in human health and disease.
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Affiliation(s)
- Martina Messina
- Mitochondrial Research Group, Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Metabolic Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Frédéric M Vaz
- Department of Laboratory Medicine and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam Gastroenterology Endocrinology Metabolism, Inborn Errors of Metabolism, Amsterdam, The Netherlands
| | - Shamima Rahman
- Mitochondrial Research Group, Genetics and Genomic Medicine Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Metabolic Unit, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
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3
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Gaertner Z, Oram C, Schneeweis A, Schonfeld E, Bolduc C, Chen C, Dombeck D, Parisiadou L, Poulin JF, Awatramani R. Molecular and spatial transcriptomic classification of midbrain dopamine neurons and their alterations in a LRRK2 G2019S model of Parkinson's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.06.597807. [PMID: 38895448 PMCID: PMC11185743 DOI: 10.1101/2024.06.06.597807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Several studies have revealed that midbrain dopamine (DA) neurons, even within a single neuroanatomical area, display heterogeneous properties. In parallel, studies using single cell profiling techniques have begun to cluster DA neurons into subtypes based on their molecular signatures. Recent work has shown that molecularly defined DA subtypes within the substantia nigra (SNc) display distinctive anatomic and functional properties, and differential vulnerability in Parkinson's disease (PD). Based on these provocative results, a granular understanding of these putative subtypes and their alterations in PD models, is imperative. We developed an optimized pipeline for single-nuclear RNA sequencing (snRNA-seq) and generated a high-resolution hierarchically organized map revealing 20 molecularly distinct DA neuron subtypes belonging to three main families. We integrated this data with spatial MERFISH technology to map, with high definition, the location of these subtypes in the mouse midbrain, revealing heterogeneity even within neuroanatomical sub-structures. Finally, we demonstrate that in the preclinical LRRK2G2019S knock-in mouse model of PD, subtype organization and proportions are preserved. Transcriptional alterations occur in many subtypes including those localized to the ventral tier SNc, where differential expression is observed in synaptic pathways, which might account for previously described DA release deficits in this model. Our work provides an advancement of current taxonomic schemes of the mouse midbrain DA neuron subtypes, a high-resolution view of their spatial locations, and their alterations in a prodromal mouse model of PD.
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Affiliation(s)
- Zachary Gaertner
- Northwestern University Feinberg School of Medicine, Dept of Neurology, Chicago, IL 60611
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Cameron Oram
- McGill University (Montreal Neurological Institute), Faculty of Medicine and Health Sciences, Dept of Neurology and Neurosurgery, Montreal (QC), Canada
| | - Amanda Schneeweis
- Northwestern University Feinberg School of Medicine, Dept of Neurology, Chicago, IL 60611
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Elan Schonfeld
- Northwestern University Feinberg School of Medicine, Dept of Neurology, Chicago, IL 60611
| | - Cyril Bolduc
- McGill University (Montreal Neurological Institute), Faculty of Medicine and Health Sciences, Dept of Neurology and Neurosurgery, Montreal (QC), Canada
| | - Chuyu Chen
- Northwestern University Feinberg School of Medicine, Dept of Pharmacology, Chicago, IL 60611
| | - Daniel Dombeck
- Northwestern University, Dept of Neurobiology, Evanston, IL 60201
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Loukia Parisiadou
- Northwestern University Feinberg School of Medicine, Dept of Pharmacology, Chicago, IL 60611
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Jean Francois Poulin
- McGill University (Montreal Neurological Institute), Faculty of Medicine and Health Sciences, Dept of Neurology and Neurosurgery, Montreal (QC), Canada
| | - Rajeshwar Awatramani
- Northwestern University Feinberg School of Medicine, Dept of Neurology, Chicago, IL 60611
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
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4
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Saukko-Paavola AJ, Klemm RW. Remodelling of mitochondrial function by import of specific lipids at multiple membrane-contact sites. FEBS Lett 2024; 598:1274-1291. [PMID: 38311340 DOI: 10.1002/1873-3468.14813] [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: 11/29/2023] [Revised: 12/14/2023] [Accepted: 12/28/2023] [Indexed: 02/08/2024]
Abstract
Organelles form physical and functional contact between each other to exchange information, metabolic intermediates, and signaling molecules. Tethering factors and contact site complexes bring partnering organelles into close spatial proximity to establish membrane contact sites (MCSs), which specialize in unique functions like lipid transport or Ca2+ signaling. Here, we discuss how MCSs form dynamic platforms that are important for lipid metabolism. We provide a perspective on how import of specific lipids from the ER and other organelles may contribute to remodeling of mitochondria during nutrient starvation. We speculate that mitochondrial adaptation is achieved by connecting several compartments into a highly dynamic organelle network. The lipid droplet appears to be a central hub in coordinating the function of these organelle neighborhoods.
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Affiliation(s)
| | - Robin W Klemm
- Department of Physiology, Anatomy and Genetics, University of Oxford, UK
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5
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Siripoksup P, Cao G, Cluntun AA, Maschek JA, Pearce Q, Brothwell MJ, Jeong MY, Eshima H, Ferrara PJ, Opurum PC, Mahmassani ZS, Peterlin AD, Watanabe S, Walsh MA, Taylor EB, Cox JE, Drummond MJ, Rutter J, Funai K. Sedentary behavior in mice induces metabolic inflexibility by suppressing skeletal muscle pyruvate metabolism. J Clin Invest 2024; 134:e167371. [PMID: 38652544 PMCID: PMC11142742 DOI: 10.1172/jci167371] [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: 11/21/2022] [Accepted: 04/16/2024] [Indexed: 04/25/2024] Open
Abstract
Carbohydrates and lipids provide the majority of substrates to fuel mitochondrial oxidative phosphorylation. Metabolic inflexibility, defined as an impaired ability to switch between these fuels, is implicated in a number of metabolic diseases. Here, we explore the mechanism by which physical inactivity promotes metabolic inflexibility in skeletal muscle. We developed a mouse model of sedentariness, small mouse cage (SMC), that, unlike other classic models of disuse in mice, faithfully recapitulated metabolic responses that occur in humans. Bioenergetic phenotyping of skeletal muscle mitochondria displayed metabolic inflexibility induced by physical inactivity, demonstrated by a reduction in pyruvate-stimulated respiration (JO2) in the absence of a change in palmitate-stimulated JO2. Pyruvate resistance in these mitochondria was likely driven by a decrease in phosphatidylethanolamine (PE) abundance in the mitochondrial membrane. Reduction in mitochondrial PE by heterozygous deletion of phosphatidylserine decarboxylase (PSD) was sufficient to induce metabolic inflexibility measured at the whole-body level, as well as at the level of skeletal muscle mitochondria. Low mitochondrial PE in C2C12 myotubes was sufficient to increase glucose flux toward lactate. We further implicate that resistance to pyruvate metabolism is due to attenuated mitochondrial entry via mitochondrial pyruvate carrier (MPC). These findings suggest a mechanism by which mitochondrial PE directly regulates MPC activity to modulate metabolic flexibility in mice.
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Affiliation(s)
- Piyarat Siripoksup
- Diabetes & Metabolism Research Center
- Department of Physical Therapy and Athletic Training
| | - Guoshen Cao
- Diabetes & Metabolism Research Center
- Department of Biochemistry
| | | | - J. Alan Maschek
- Metabolomics Core Research Facility
- Department of Nutrition & Integrative Physiology, and
| | | | - Marisa J. Brothwell
- Diabetes & Metabolism Research Center
- Department of Nutrition & Integrative Physiology, and
| | - Mi-Young Jeong
- Diabetes & Metabolism Research Center
- Department of Biochemistry
| | - Hiroaki Eshima
- Diabetes & Metabolism Research Center
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA
| | - Patrick J. Ferrara
- Diabetes & Metabolism Research Center
- Department of Nutrition & Integrative Physiology, and
| | - Precious C. Opurum
- Diabetes & Metabolism Research Center
- Department of Nutrition & Integrative Physiology, and
| | - Ziad S. Mahmassani
- Diabetes & Metabolism Research Center
- Department of Physical Therapy and Athletic Training
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA
| | - Alek D. Peterlin
- Diabetes & Metabolism Research Center
- Department of Nutrition & Integrative Physiology, and
| | - Shinya Watanabe
- Diabetes & Metabolism Research Center
- Department of Nutrition & Integrative Physiology, and
| | - Maureen A. Walsh
- Diabetes & Metabolism Research Center
- Department of Physical Therapy and Athletic Training
| | - Eric B. Taylor
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa, USA
| | - James E. Cox
- Diabetes & Metabolism Research Center
- Department of Biochemistry
- Metabolomics Core Research Facility
| | - Micah J. Drummond
- Diabetes & Metabolism Research Center
- Department of Physical Therapy and Athletic Training
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA
| | - Jared Rutter
- Diabetes & Metabolism Research Center
- Department of Biochemistry
- Howard Hughes Medical Institute, University of Utah, Salt Lake City, Utah, USA
| | - Katsuhiko Funai
- Diabetes & Metabolism Research Center
- Department of Physical Therapy and Athletic Training
- Department of Biochemistry
- Department of Nutrition & Integrative Physiology, and
- Molecular Medicine Program, University of Utah, Salt Lake City, Utah, USA
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Makio T, Simmen T. Not So Rare: Diseases Based on Mutant Proteins Controlling Endoplasmic Reticulum-Mitochondria Contact (MERC) Tethering. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2024; 7:25152564241261228. [PMID: 39070058 PMCID: PMC11273598 DOI: 10.1177/25152564241261228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/12/2024] [Accepted: 05/27/2024] [Indexed: 07/30/2024]
Abstract
Mitochondria-endoplasmic reticulum contacts (MERCs), also called endoplasmic reticulum (ER)-mitochondria contact sites (ERMCS), are the membrane domains, where these two organelles exchange lipids, Ca2+ ions, and reactive oxygen species. This crosstalk is a major determinant of cell metabolism, since it allows the ER to control mitochondrial oxidative phosphorylation and the Krebs cycle, while conversely, it allows the mitochondria to provide sufficient ATP to control ER proteostasis. MERC metabolic signaling is under the control of tethers and a multitude of regulatory proteins. Many of these proteins have recently been discovered to give rise to rare diseases if their genes are mutated. Surprisingly, these diseases share important hallmarks and cause neurological defects, sometimes paired with, or replaced by skeletal muscle deficiency. Typical symptoms include developmental delay, intellectual disability, facial dysmorphism and ophthalmologic defects. Seizures, epilepsy, deafness, ataxia, or peripheral neuropathy can also occur upon mutation of a MERC protein. Given that most MERC tethers and regulatory proteins have secondary functions, some MERC protein-based diseases do not fit into this categorization. Typically, however, the proteins affected in those diseases have dominant functions unrelated to their roles in MERCs tethering or their regulation. We are discussing avenues to pharmacologically target genetic diseases leading to MERC defects, based on our novel insight that MERC defects lead to common characteristics in rare diseases. These shared characteristics of MERCs disorders raise the hope that they may allow for similar treatment options.
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Affiliation(s)
- Tadashi Makio
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Thomas Simmen
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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Eshima H, Johnson JM, Funai K. Lipid peroxidation does not mediate muscle atrophy induced by PSD deficiency. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.22.573082. [PMID: 38187526 PMCID: PMC10769360 DOI: 10.1101/2023.12.22.573082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Mechanisms by which disuse promotes skeletal muscle atrophy is not well understood. We previously demonstrated that disuse reduces the abundance of mitochondrial phosphatidylethanolamine (PE) in skeletal muscle. Deletion of phosphatidylserine decarboxylase (PSD), an enzyme that generates mitochondrial PE, was sufficient to promote muscle atrophy. In this study, we tested the hypothesis that muscle atrophy induced by PSD deletion is driven by an accumulation of lipid hydroperoxides (LOOH). Mice with muscle-specific knockout of PSD (PSD-MKO) were crossed with glutathione peroxidase 4 (GPx4) transgenic mice (GPx4Tg) to suppress the accumulation of LOOH. However, PSD-MKO × GPx4Tg mice and PSD-MKO mice demonstrated equally robust loss of muscle mass. These results suggest that muscle atrophy induced by PSD deficiency is not driven by the accumulation of LOOH.
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Affiliation(s)
- Hiroaki Eshima
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
- Department of International Tourism, Nagasaki International University
| | - Jordan M. Johnson
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
| | - Katsuhiko Funai
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
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Li Y, Zhang J, Zhang Y, Zhang B, Wang Z, Wu C, Zhou Z, Chang X. Integrated metabolomic and transcriptomic analysis reveals perturbed glycerophospholipid metabolism in mouse neural stem cells exposed to cadmium. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 264:115411. [PMID: 37660531 DOI: 10.1016/j.ecoenv.2023.115411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 07/29/2023] [Accepted: 08/24/2023] [Indexed: 09/05/2023]
Abstract
Cadmium (Cd) is a ubiquitous heavy metal with neurotoxicity. Our previous study reported that Cd could inhibit the proliferation of mouse neural stem cells (mNSCs). However, the underlying mechanisms are obscure. In recent years, the rapid growth of multi-omics techniques enables us to explore the cellular responses that occurred after toxicant exposure at the molecular level. In this study, we used a combination of metabolomics and transcriptomics approaches to investigate the effects of exposure to Cd on mNSCs. After treatment with Cd, the metabolites and transcripts in mNSCs changed significantly with 110 differentially expressed metabolites and 2135 differentially expressed genes identified, respectively. The altered metabolites were mainly involved in glycerophospholipid metabolism, arginine and proline metabolism, arginine biosynthesis, glyoxylate and dicarboxylate metabolism. Meanwhile, the transcriptomic data demonstrated perturbed membrane function and signal transduction. Furthermore, integrated analysis of metabolomic and transcriptomic data suggested that glycerophospholipid metabolism might be the major metabolic pathway affected by Cd in mNSCs. More interestingly, the supplementation of lysophosphatidylethanolamine (LPE) attenuated Cd-induced mitochondrial impairment and the inhibition of cell proliferation and differentiation in mNSCs, further supporting our analysis. Overall, the study provides new insights into the mechanisms of Cd-induced neurotoxicity.
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Affiliation(s)
- Yixi Li
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Jiming Zhang
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yuwei Zhang
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Bing Zhang
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zheng Wang
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Chunhua Wu
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zhijun Zhou
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xiuli Chang
- Department of Toxicology, School of Public Health, Shanghai Medical College of Fudan University, Shanghai 200032, China.
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Yin S, Li Z, Yang F, Guo H, Zhao Q, Zhang Y, Yin Y, Wu X, He J. A Comprehensive Genomic Analysis of Chinese Indigenous Ningxiang Pigs: Genomic Breed Compositions, Runs of Homozygosity, and Beyond. Int J Mol Sci 2023; 24:14550. [PMID: 37833998 PMCID: PMC10572203 DOI: 10.3390/ijms241914550] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/15/2023] Open
Abstract
Ningxiang pigs are a renowned indigenous pig breed in China, known for their meat quality, disease resistance, and environmental adaptability. In recent decades, consumer demand for meats from indigenous breeds has grown significantly, fueling the selection and crossbreeding of Ningxiang pigs (NXP). The latter has raised concerns about the conservation and sustainable use of Ningxiang pigs as an important genetic resource. To address these concerns, we conducted a comprehensive genomic study using 2242 geographically identified Ningxiang pigs. The estimated genomic breed composition (GBC) suggested 2077 pigs as purebred Ningxiang pigs based on a ≥94% NXP-GBC cut-off. The remaining 165 pigs were claimed to be crosses, including those between Duroc and Ningxiang pigs and between Ningxiang and Shaziling pigs, and non-Ningxiang pigs. Runs of homozygosity (ROH) were identified in the 2077 purebred Ningxiang pigs. The number and length of ROH varied between individuals, with an average of 32.14 ROH per animal and an average total length of 202.4 Mb per animal. Short ROH (1-5 Mb) was the most abundant, representing 66.5% of all ROH and 32.6% of total ROH coverage. The genomic inbreeding estimate was low (0.089) in purebred Ningxiang pigs compared to imported western pig breeds. Nine ROH islands were identified, pinpointing candidate genes and QTLs associated with economic traits of interest, such as reproduction, carcass and growth traits, lipid metabolism, and fat deposition. Further investigation of these ROH islands and candidate genes is anticipated to better understand the genomics of Ningxiang pigs.
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Affiliation(s)
- Shishu Yin
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China; (S.Y.); (Z.L.); (F.Y.); (H.G.); (Q.Z.); (Y.Z.)
| | - Zhi Li
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China; (S.Y.); (Z.L.); (F.Y.); (H.G.); (Q.Z.); (Y.Z.)
| | - Fang Yang
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China; (S.Y.); (Z.L.); (F.Y.); (H.G.); (Q.Z.); (Y.Z.)
| | - Haimin Guo
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China; (S.Y.); (Z.L.); (F.Y.); (H.G.); (Q.Z.); (Y.Z.)
| | - Qinghua Zhao
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China; (S.Y.); (Z.L.); (F.Y.); (H.G.); (Q.Z.); (Y.Z.)
| | - Yuebo Zhang
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China; (S.Y.); (Z.L.); (F.Y.); (H.G.); (Q.Z.); (Y.Z.)
- Key Laboratory for Evaluation and Utilization of Livestock and Poultry Resources (Pigs) of the Ministry of Agriculture and Rural Affairs, Changsha 410128, China;
| | - Yulong Yin
- Key Laboratory for Evaluation and Utilization of Livestock and Poultry Resources (Pigs) of the Ministry of Agriculture and Rural Affairs, Changsha 410128, China;
- Animal Nutrition Genome and Germplasm Innovation Research Center, Hunan Provincial Key Laboratory for Genetic Improvement of Domestic Animal, College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China
- Laboratory of Animal Nutrition Physiology and Metabolism, The Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha 410125, China
| | - Xiaolin Wu
- Council on Dairy Cattle Breeding, Bowie, MD 20716, USA
- Department of Animal and Dairy Sciences, University of Wisconsin, Madison, WI 53706, USA
| | - Jun He
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China; (S.Y.); (Z.L.); (F.Y.); (H.G.); (Q.Z.); (Y.Z.)
- Key Laboratory for Evaluation and Utilization of Livestock and Poultry Resources (Pigs) of the Ministry of Agriculture and Rural Affairs, Changsha 410128, China;
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10
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Joshi A, Richard TH, Gohil VM. Mitochondrial phospholipid metabolism in health and disease. J Cell Sci 2023; 136:jcs260857. [PMID: 37655851 PMCID: PMC10482392 DOI: 10.1242/jcs.260857] [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: 09/02/2023] Open
Abstract
Studies of rare human genetic disorders of mitochondrial phospholipid metabolism have highlighted the crucial role that membrane phospholipids play in mitochondrial bioenergetics and human health. The phospholipid composition of mitochondrial membranes is highly conserved from yeast to humans, with each class of phospholipid performing a specific function in the assembly and activity of various mitochondrial membrane proteins, including the oxidative phosphorylation complexes. Recent studies have uncovered novel roles of cardiolipin and phosphatidylethanolamine, two crucial mitochondrial phospholipids, in organismal physiology. Studies on inter-organellar and intramitochondrial phospholipid transport have significantly advanced our understanding of the mechanisms that maintain mitochondrial phospholipid homeostasis. Here, we discuss these recent advances in the function and transport of mitochondrial phospholipids while describing their biochemical and biophysical properties and biosynthetic pathways. Additionally, we highlight the roles of mitochondrial phospholipids in human health by describing the various genetic diseases caused by disruptions in their biosynthesis and discuss advances in therapeutic strategies for Barth syndrome, the best-studied disorder of mitochondrial phospholipid metabolism.
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Affiliation(s)
- Alaumy Joshi
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Travis H. Richard
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Vishal M. Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
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11
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Murari A, Rhooms SK, Vimal D, Hossain KFB, Saini S, Villanueva M, Schlame M, Owusu-Ansah E. Phospholipids can regulate complex I assembly independent of their role in maintaining mitochondrial membrane integrity. Cell Rep 2023; 42:112846. [PMID: 37516961 DOI: 10.1016/j.celrep.2023.112846] [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: 09/02/2022] [Revised: 05/22/2023] [Accepted: 07/06/2023] [Indexed: 08/01/2023] Open
Abstract
Several phospholipid (PL) molecules are intertwined with some mitochondrial complex I (CI) subunits in the membrane domain of CI, but their function is unclear. We report that when the Drosophila melanogaster ortholog of the intramitochondrial PL transporter, STARD7, is severely disrupted, assembly of the oxidative phosphorylation (OXPHOS) system is impaired, and the biogenesis of several CI subcomplexes is hampered. However, intriguingly, a restrained knockdown of STARD7 impairs the incorporation of NDUFS5 and NDUFA1 into the proximal part of the CI membrane domain without directly affecting the incorporation of subunits in the distal part of the membrane domain, OXPHOS complexes already assembled, or mitochondrial cristae integrity. Importantly, the restrained knockdown of STARD7 appears to induce a modest amount of cardiolipin remodeling, indicating that there could be some alteration in the composition of the mitochondrial phospholipidome. We conclude that PLs can regulate CI biogenesis independent of their role in maintaining mitochondrial membrane integrity.
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Affiliation(s)
- Anjaneyulu Murari
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Shauna-Kay Rhooms
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Divya Vimal
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Kaniz Fatima Binte Hossain
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Sanjay Saini
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Maximino Villanueva
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Michael Schlame
- Departments of Anesthesiology and Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Edward Owusu-Ansah
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA.
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12
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Jin K, Yao Z, van Velthoven CTJ, Kaplan ES, Glattfelder K, Barlow ST, Boyer G, Carey D, Casper T, Chakka AB, Chakrabarty R, Clark M, Departee M, Desierto M, Gary A, Gloe J, Goldy J, Guilford N, Guzman J, Hirschstein D, Lee C, Liang E, Pham T, Reding M, Ronellenfitch K, Ruiz A, Sevigny J, Shapovalova N, Shulga L, Sulc J, Torkelson A, Tung H, Levi B, Sunkin SM, Dee N, Esposito L, Smith K, Tasic B, Zeng H. Cell-type specific molecular signatures of aging revealed in a brain-wide transcriptomic cell-type atlas. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.26.550355. [PMID: 38168182 PMCID: PMC10760145 DOI: 10.1101/2023.07.26.550355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Biological aging can be defined as a gradual loss of homeostasis across various aspects of molecular and cellular function. Aging is a complex and dynamic process which influences distinct cell types in a myriad of ways. The cellular architecture of the mammalian brain is heterogeneous and diverse, making it challenging to identify precise areas and cell types of the brain that are more susceptible to aging than others. Here, we present a high-resolution single-cell RNA sequencing dataset containing ~1.2 million high-quality single-cell transcriptomic profiles of brain cells from young adult and aged mice across both sexes, including areas spanning the forebrain, midbrain, and hindbrain. We find age-associated gene expression signatures across nearly all 130+ neuronal and non-neuronal cell subclasses we identified. We detect the greatest gene expression changes in non-neuronal cell types, suggesting that different cell types in the brain vary in their susceptibility to aging. We identify specific, age-enriched clusters within specific glial, vascular, and immune cell types from both cortical and subcortical regions of the brain, and specific gene expression changes associated with cell senescence, inflammation, decrease in new myelination, and decreased vasculature integrity. We also identify genes with expression changes across multiple cell subclasses, pointing to certain mechanisms of aging that may occur across wide regions or broad cell types of the brain. Finally, we discover the greatest gene expression changes in cell types localized to the third ventricle of the hypothalamus, including tanycytes, ependymal cells, and Tbx3+ neurons found in the arcuate nucleus that are part of the neuronal circuits regulating food intake and energy homeostasis. These findings suggest that the area surrounding the third ventricle in the hypothalamus may be a hub for aging in the mouse brain. Overall, we reveal a dynamic landscape of cell-type-specific transcriptomic changes in the brain associated with normal aging that will serve as a foundation for the investigation of functional changes in the aging process and the interaction of aging and diseases.
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Affiliation(s)
- Kelly Jin
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Zizhen Yao
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | | | | | - Daniel Carey
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | | | - Max Departee
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Amanda Gary
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Jessica Gloe
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Jeff Goldy
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | - Changkyu Lee
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | | | | | - Josh Sevigny
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | - Josef Sulc
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Herman Tung
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Boaz Levi
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Nick Dee
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | | | | | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA, USA
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13
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Pinto E, Pinto C, Ramos C, Alves JE. Brain imaging findings in Liberfarb syndrome: hypomyelination and optic nerve and cerebellar atrophy. Pediatr Radiol 2023; 53:561-563. [PMID: 36136119 DOI: 10.1007/s00247-022-05503-7] [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: 06/14/2022] [Revised: 08/07/2022] [Accepted: 09/01/2022] [Indexed: 11/29/2022]
Abstract
Liberfarb syndrome is an extremely rare mitochondrial multisystem disorder, recently described and characterized by early-onset retinal degeneration and sensorineural hearing loss, spondyloepimetaphyseal dysplasia, joint laxity, short stature, microcephaly, developmental delay and intellectual disability, but clinical variability has been observed. We report a case that presented to the hospital with a flare-up of the disease. We describe the brain magnetic resonance imaging findings, which are still not well characterized, to raise awareness of this diagnosis.
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Affiliation(s)
- Eduarda Pinto
- Neuroradiology Department, Centro Hospitalar Universitário Do Porto, Porto, Portugal. .,Rua do Cruzeiro, n. 340, 4650-069, Airães, Felgueiras, Portugal.
| | - Catarina Pinto
- Neuroradiology Department, Centro Hospitalar Universitário Do Porto, Porto, Portugal
| | - Cristina Ramos
- Neuroradiology Department, Centro Hospitalar Universitário Do Porto, Porto, Portugal
| | - José E Alves
- Neuroradiology Department, Centro Hospitalar Universitário Do Porto, Porto, Portugal
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14
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Johnson JM, Peterlin AD, Balderas E, Sustarsic EG, Maschek JA, Lang MJ, Jara-Ramos A, Panic V, Morgan JT, Villanueva CJ, Sanchez A, Rutter J, Lodhi IJ, Cox JE, Fisher-Wellman KH, Chaudhuri D, Gerhart-Hines Z, Funai K. Mitochondrial phosphatidylethanolamine modulates UCP1 to promote brown adipose thermogenesis. SCIENCE ADVANCES 2023; 9:eade7864. [PMID: 36827367 PMCID: PMC9956115 DOI: 10.1126/sciadv.ade7864] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 01/24/2023] [Indexed: 05/08/2023]
Abstract
Thermogenesis by uncoupling protein 1 (UCP1) is one of the primary mechanisms by which brown adipose tissue (BAT) increases energy expenditure. UCP1 resides in the inner mitochondrial membrane (IMM), where it dissipates membrane potential independent of adenosine triphosphate (ATP) synthase. Here, we provide evidence that phosphatidylethanolamine (PE) modulates UCP1-dependent proton conductance across the IMM to modulate thermogenesis. Mitochondrial lipidomic analyses revealed PE as a signature molecule whose abundance bidirectionally responds to changes in thermogenic burden. Reduction in mitochondrial PE by deletion of phosphatidylserine decarboxylase (PSD) made mice cold intolerant and insensitive to β3 adrenergic receptor agonist-induced increase in whole-body oxygen consumption. High-resolution respirometry and fluorometry of BAT mitochondria showed that loss of mitochondrial PE specifically lowers UCP1-dependent respiration without compromising electron transfer efficiency or ATP synthesis. These findings were confirmed by a reduction in UCP1 proton current in PE-deficient mitoplasts. Thus, PE performs a previously unknown role as a temperature-responsive rheostat that regulates UCP1-dependent thermogenesis.
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Affiliation(s)
- Jordan M. Johnson
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - Alek D. Peterlin
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- Utah Center for Clinical and Translational Research, University of Utah, Salt Lake City, UT, USA
| | - Enrique Balderas
- Nora Eccles Harrison Cardiovascular Research and Training Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - Elahu G. Sustarsic
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - J. Alan Maschek
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- Metabolomics Core Research Facility, University of Utah, Salt Lake City, UT, USA
| | - Marisa J. Lang
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - Alejandro Jara-Ramos
- Nora Eccles Harrison Cardiovascular Research and Training Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | - Vanja Panic
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Jeffrey T. Morgan
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
- Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Claudio J. Villanueva
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Alejandro Sanchez
- Division of Urology, Department of Surgery, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA
| | - Jared Rutter
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
- Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Irfan J. Lodhi
- Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, St. Louis, MO, USA
| | - James E. Cox
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Metabolomics Core Research Facility, University of Utah, Salt Lake City, UT, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | | | - Dipayan Chaudhuri
- Nora Eccles Harrison Cardiovascular Research and Training Institute, Division of Cardiovascular Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Zachary Gerhart-Hines
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Katsuhiko Funai
- Diabetes and Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
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15
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St Germain M, Iraji R, Bakovic M. Phosphatidylethanolamine homeostasis under conditions of impaired CDP-ethanolamine pathway or phosphatidylserine decarboxylation. Front Nutr 2023; 9:1094273. [PMID: 36687696 PMCID: PMC9849821 DOI: 10.3389/fnut.2022.1094273] [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: 11/09/2022] [Accepted: 12/14/2022] [Indexed: 01/07/2023] Open
Abstract
Phosphatidylethanolamine is the major inner-membrane lipid in the plasma and mitochondrial membranes. It is synthesized in the endoplasmic reticulum from ethanolamine and diacylglycerol (DAG) by the CDP-ethanolamine pathway and from phosphatidylserine by decarboxylation in the mitochondria. Recently, multiple genetic disorders that impact these pathways have been identified, including hereditary spastic paraplegia 81 and 82, Liberfarb syndrome, and a new type of childhood-onset neurodegeneration-CONATOC. Individuals with these diseases suffer from multisystem disorders mainly affecting neuronal function. This indicates the importance of maintaining proper phospholipid homeostasis when major biosynthetic pathways are impaired. This study summarizes the current knowledge of phosphatidylethanolamine metabolism in order to identify areas of future research that might lead to the development of treatment options.
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16
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Buckley MT, Sun ED, George BM, Liu L, Schaum N, Xu L, Reyes JM, Goodell MA, Weissman IL, Wyss-Coray T, Rando TA, Brunet A. Cell-type-specific aging clocks to quantify aging and rejuvenation in neurogenic regions of the brain. NATURE AGING 2023; 3:121-137. [PMID: 37118510 PMCID: PMC10154228 DOI: 10.1038/s43587-022-00335-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 11/14/2022] [Indexed: 12/24/2022]
Abstract
The diversity of cell types is a challenge for quantifying aging and its reversal. Here we develop 'aging clocks' based on single-cell transcriptomics to characterize cell-type-specific aging and rejuvenation. We generated single-cell transcriptomes from the subventricular zone neurogenic region of 28 mice, tiling ages from young to old. We trained single-cell-based regression models to predict chronological age and biological age (neural stem cell proliferation capacity). These aging clocks are generalizable to independent cohorts of mice, other regions of the brains, and other species. To determine if these aging clocks could quantify transcriptomic rejuvenation, we generated single-cell transcriptomic datasets of neurogenic regions for two interventions-heterochronic parabiosis and exercise. Aging clocks revealed that heterochronic parabiosis and exercise reverse transcriptomic aging in neurogenic regions, but in different ways. This study represents the first development of high-resolution aging clocks from single-cell transcriptomic data and demonstrates their application to quantify transcriptomic rejuvenation.
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Affiliation(s)
- Matthew T Buckley
- Department of Genetics, Stanford University, Stanford, CA, USA
- Genetics Graduate Program, Stanford University, Stanford, CA, USA
| | - Eric D Sun
- Department of Genetics, Stanford University, Stanford, CA, USA
- Biomedical Informatics Graduate Program, Stanford University, Stanford, CA, USA
| | - Benson M George
- Stanford Medical Scientist Training Program, Stanford University, Stanford, CA, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA, USA
| | - Ling Liu
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Department of Neurology, UCLA, Los Angeles, CA, USA
| | - Nicholas Schaum
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Lucy Xu
- Department of Genetics, Stanford University, Stanford, CA, USA
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Jaime M Reyes
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Margaret A Goodell
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Irving L Weissman
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA, USA
- Ludwig Center for Cancer Stem Cell Research and Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
- Glenn Center for the Biology of Aging, Stanford University, Stanford, CA, USA
| | - Thomas A Rando
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, USA
- Glenn Center for the Biology of Aging, Stanford University, Stanford, CA, USA
- Neurology Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
- Department of Neurology, UCLA, Los Angeles, CA, USA
- Broad Stem Cell Research Center, UCLA, Los Angeles, CA, USA
| | - Anne Brunet
- Department of Genetics, Stanford University, Stanford, CA, USA.
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA.
- Glenn Center for the Biology of Aging, Stanford University, Stanford, CA, USA.
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17
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Young C, Batkovskyte D, Kitamura M, Shvedova M, Mihara Y, Akiba J, Zhou W, Hammarsjö A, Nishimura G, Yatsuga S, Grigelioniene G, Kobayashi T. A hypomorphic variant in the translocase of the outer mitochondrial membrane complex subunit TOMM7 causes short stature and developmental delay. HGG ADVANCES 2022; 4:100148. [PMID: 36299998 PMCID: PMC9589026 DOI: 10.1016/j.xhgg.2022.100148] [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: 05/23/2022] [Accepted: 09/29/2022] [Indexed: 11/26/2022] Open
Abstract
Mitochondrial diseases are a heterogeneous group of genetic disorders caused by pathogenic variants in genes encoding gene products that regulate mitochondrial function. These genes are located either in the mitochondrial or in the nuclear genome. The TOMM7 gene encodes a regulatory subunit of the translocase of outer mitochondrial membrane (TOM) complex that plays an essential role in translocation of nuclear-encoded mitochondrial proteins into mitochondria. We report an individual with a homozygous variant in TOMM7 (c.73T>C, p.Trp25Arg) that presented with a syndromic short stature, skeletal abnormalities, muscle hypotonia, microvesicular liver steatosis, and developmental delay. Analysis of mouse models strongly suggested that the identified variant is hypomorphic because mice homozygous for this variant showed a milder phenotype than those with homozygous Tomm7 deletion. These Tomm7 mutant mice show pathological changes consistent with mitochondrial dysfunction, including growth defects, severe lipoatrophy, and lipid accumulation in the liver. These mice die prematurely following a rapidly progressive weight loss during the last week of their lives. Tomm7 deficiency causes a unique alteration in mitochondrial function; despite the bioenergetic deficiency, mutant cells show increased oxygen consumption with normal responses to electron transport chain (ETC) inhibitors, suggesting that Tomm7 deficiency leads to an uncoupling between oxidation and ATP synthesis without impairing the function of the tricarboxylic cycle metabolism or ETC. This study presents evidence that a hypomorphic variant in one of the genes encoding a subunit of the TOM complex causes mitochondrial disease.
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Affiliation(s)
- Cameron Young
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Dominyka Batkovskyte
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm 17177, Sweden
| | - Miyuki Kitamura
- Department of Pediatrics and Child Health, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Maria Shvedova
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Yutaro Mihara
- Department of Pathology, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Jun Akiba
- Department of Diagnostic Pathology, Kurume University Hospital, Kurume, Fukuoka 830-0011, Japan
| | - Wen Zhou
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Anna Hammarsjö
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm 17177, Sweden,Department of Clinical Genetics, Karolinska University Laboratory, Karolinska University Hospital, Stockholm 17176, Sweden
| | - Gen Nishimura
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm 17177, Sweden,Center for Intractable Disease, Saitama Medical University Hospital, Saitama, Japan
| | - Shuichi Yatsuga
- Department of Pediatrics and Child Health, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan,Department of Pediatrics, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Giedre Grigelioniene
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm 17177, Sweden,Department of Clinical Genetics, Karolinska University Laboratory, Karolinska University Hospital, Stockholm 17176, Sweden,Department of Clinical Genetics, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping 58183, Sweden,Corresponding author
| | - Tatsuya Kobayashi
- Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA,Corresponding author
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18
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Zaman M, Shutt TE. The Role of Impaired Mitochondrial Dynamics in MFN2-Mediated Pathology. Front Cell Dev Biol 2022; 10:858286. [PMID: 35399520 PMCID: PMC8989266 DOI: 10.3389/fcell.2022.858286] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 03/07/2022] [Indexed: 12/17/2022] Open
Abstract
The Mitofusin 2 protein (MFN2), encoded by the MFN2 gene, was first described for its role in mediating mitochondrial fusion. However, MFN2 is now recognized to play additional roles in mitochondrial autophagy (mitophagy), mitochondrial motility, lipid transfer, and as a tether to other organelles including the endoplasmic reticulum (ER) and lipid droplets. The tethering role of MFN2 is an important mediator of mitochondrial-ER contact sites (MERCs), which themselves have many important functions that regulate mitochondria, including calcium homeostasis and lipid metabolism. Exemplifying the importance of MFN2, pathogenic variants in MFN2 are established to cause the peripheral neuropathy Charcot-Marie-Tooth Disease Subtype 2A (CMT2A). However, the mechanistic basis for disease is not clear. Moreover, additional pathogenic phenotypes such as lipomatosis, distal myopathy, optic atrophy, and hearing loss, can also sometimes be present in patients with CMT2A. Given these variable patient phenotypes, and the many cellular roles played by MFN2, the mechanistic underpinnings of the cellular impairments by which MFN2 dysfunction leads to disease are likely to be complex. Here, we will review what is known about the various functions of MFN2 that are impaired by pathogenic variants causing CMT2A, with a specific emphasis on the ties between MFN2 variants and MERCs.
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Affiliation(s)
- Mashiat Zaman
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
- Alberta Children’s Hospital Research Institute (ACHRI), Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Timothy E. Shutt
- Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
- Alberta Children’s Hospital Research Institute (ACHRI), Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Department of Medical Genetics, University of Calgary, Calgary, AB, Canada
- *Correspondence: Timothy E. Shutt,
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19
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Wang F, Tan P, Zhang P, Ren Y, Zhou J, Li Y, Hou S, Li S, Zhang L, Ma Y, Wang C, Tang W, Wang X, Huo Y, Hu Y, Cui T, Niu C, Wang D, Liu B, Lan Y, Yu J. Single-cell architecture and functional requirement of alternative splicing during hematopoietic stem cell formation. SCIENCE ADVANCES 2022; 8:eabg5369. [PMID: 34995116 PMCID: PMC8741192 DOI: 10.1126/sciadv.abg5369] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Single-cell transcriptional profiling has rapidly advanced our understanding of the embryonic hematopoiesis; however, whether and what role RNA alternative splicing (AS) plays remains an enigma. This is important for understanding the mechanisms underlying splicing-associated hematopoietic diseases and for the derivation of therapeutic stem cells. Here, we used single-cell full-length transcriptome data to construct an isoform-based transcriptional atlas of the murine endothelial-to-hematopoietic stem cell (HSC) transition, which enables the identification of hemogenic signature isoforms and stage-specific AS events. We showed that the inclusion of these hemogenic-specific AS events was essential for hemogenic function in vitro. Expression data and knockout mouse studies highlighted the critical role of Srsf2: Early Srsf2 deficiency from endothelial cells affected the splicing pattern of several master hematopoietic regulators and significantly impaired HSC generation. These results redefine our understanding of the dynamic HSC developmental transcriptome and demonstrate that elaborately controlled RNA splicing governs cell fate in HSC formation.
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Affiliation(s)
- Fang Wang
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China
- The Key Laboratory of RNA and Hematopoietic Regulation, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Puwen Tan
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Pengcheng Zhang
- State Key Laboratory of Experimental Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing 100071, China
- Department of Environmental Medicine, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China
| | - Yue Ren
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China
- The Key Laboratory of RNA and Hematopoietic Regulation, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Jie Zhou
- State Key Laboratory of Experimental Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing 100071, China
| | - Yunqiao Li
- State Key Laboratory of Experimental Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing 100071, China
| | - Siyuan Hou
- Key Laboratory for Regenerative Medicine of Ministry of Education, Institute of Hematology, School of Medicine, Jinan University, Guangzhou 510632, China
- Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou 510632, China
| | - Shuaili Li
- State Key Laboratory of Experimental Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing 100071, China
| | - Linlin Zhang
- State Key Laboratory of Experimental Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing 100071, China
| | - Yanni Ma
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China
- The Key Laboratory of RNA and Hematopoietic Regulation, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Chaojie Wang
- Key Laboratory for Regenerative Medicine of Ministry of Education, Institute of Hematology, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Wanbo Tang
- State Key Laboratory of Experimental Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing 100071, China
| | - Xiaoshuang Wang
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China
- The Key Laboratory of RNA and Hematopoietic Regulation, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Yue Huo
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China
- The Key Laboratory of RNA and Hematopoietic Regulation, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Yongfei Hu
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Tianyu Cui
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Chao Niu
- Department of Environmental Medicine, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300050, China
| | - Dong Wang
- Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
- Corresponding author. (D.W.); (B.L.); (Y.Lan); (J.Y.)
| | - Bing Liu
- State Key Laboratory of Experimental Hematology, Fifth Medical Center of Chinese PLA General Hospital, Beijing 100071, China
- Corresponding author. (D.W.); (B.L.); (Y.Lan); (J.Y.)
| | - Yu Lan
- Key Laboratory for Regenerative Medicine of Ministry of Education, Institute of Hematology, School of Medicine, Jinan University, Guangzhou 510632, China
- Corresponding author. (D.W.); (B.L.); (Y.Lan); (J.Y.)
| | - Jia Yu
- State Key Laboratory of Medical Molecular Biology, Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing 100005, China
- The Key Laboratory of RNA and Hematopoietic Regulation, Chinese Academy of Medical Sciences, Beijing 100005, China
- Corresponding author. (D.W.); (B.L.); (Y.Lan); (J.Y.)
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20
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Tamura Y, Kawano S, Endo T. Lipid homeostasis in mitochondria. Biol Chem 2021; 401:821-833. [PMID: 32229651 DOI: 10.1515/hsz-2020-0121] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/10/2020] [Indexed: 12/13/2022]
Abstract
Mitochondria are surrounded by the two membranes, the outer and inner membranes, whose lipid compositions are optimized for proper functions and structural organizations of mitochondria. Although a part of mitochondrial lipids including their characteristic lipids, phosphatidylethanolamine and cardiolipin, are synthesized within mitochondria, their precursor lipids and other lipids are transported from other organelles, mainly the ER. Mitochondrially synthesized lipids are re-distributed within mitochondria and to other organelles, as well. Recent studies pointed to the important roles of inter-organelle contact sites in lipid trafficking between different organelle membranes. Identification of Ups/PRELI proteins as lipid transfer proteins shuttling between the mitochondrial outer and inner membranes established a part of the molecular and structural basis of the still elusive intra-mitochondrial lipid trafficking.
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Affiliation(s)
- Yasushi Tamura
- Faculty of Science, Yamagata University, 1-4-12, Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Shin Kawano
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Toshiya Endo
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan
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21
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Sam PN, Calzada E, Acoba MG, Zhao T, Watanabe Y, Nejatfard A, Trinidad JC, Shutt TE, Neal SE, Claypool SM. Impaired phosphatidylethanolamine metabolism activates a reversible stress response that detects and resolves mutant mitochondrial precursors. iScience 2021; 24:102196. [PMID: 33718843 PMCID: PMC7921845 DOI: 10.1016/j.isci.2021.102196] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/27/2021] [Accepted: 02/10/2021] [Indexed: 02/06/2023] Open
Abstract
Phosphatidylethanolamine (PE) made in mitochondria has long been recognized as an important precursor for phosphatidylcholine production that occurs in the endoplasmic reticulum (ER). Recently, the strict mitochondrial localization of the enzyme that makes PE in the mitochondrion, phosphatidylserine decarboxylase 1 (Psd1), was questioned. Since a dual localization of Psd1 to the ER would have far-reaching implications, we initiated our study to independently re-assess the subcellular distribution of Psd1. Our results support the unavoidable conclusion that the vast majority, if not all, of functional Psd1 resides in the mitochondrion. Through our efforts, we discovered that mutant forms of Psd1 that impair a self-processing step needed for it to become functional are dually localized to the ER when expressed in a PE-limiting environment. We conclude that severely impaired cellular PE metabolism provokes an ER-assisted adaptive response that is capable of identifying and resolving nonfunctional mitochondrial precursors.
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Affiliation(s)
- Pingdewinde N. Sam
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Elizabeth Calzada
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michelle Grace Acoba
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Tian Zhao
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Yasunori Watanabe
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Anahita Nejatfard
- Division of Biological Sciences, The Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | | | - Timothy E. Shutt
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Sonya E. Neal
- Division of Biological Sciences, The Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Steven M. Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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22
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Iadarola DM, Joshi A, Caldwell CB, Gohil VM. Choline restores respiration in Psd1-deficient yeast by replenishing mitochondrial phosphatidylethanolamine. J Biol Chem 2021; 296:100539. [PMID: 33722607 PMCID: PMC8054189 DOI: 10.1016/j.jbc.2021.100539] [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: 12/01/2020] [Revised: 03/02/2021] [Accepted: 03/10/2021] [Indexed: 11/23/2022] Open
Abstract
Phosphatidylethanolamine (PE) is essential for mitochondrial respiration in yeast, Saccharomyces cerevisiae, whereas the most abundant mitochondrial phospholipid, phosphatidylcholine (PC), is largely dispensable. Surprisingly, choline (Cho), which is a biosynthetic precursor of PC, has been shown to rescue the respiratory growth of mitochondrial PE-deficient yeast; however, the mechanism underlying this rescue has remained unknown. Using a combination of yeast genetics, lipid biochemistry, and cell biological approaches, we uncover the mechanism by showing that Cho rescues mitochondrial respiration by partially replenishing mitochondrial PE levels in yeast cells lacking the mitochondrial PE-biosynthetic enzyme Psd1. This rescue is dependent on the conversion of Cho to PC via the Kennedy pathway as well as on Psd2, an enzyme catalyzing PE biosynthesis in the endosome. Metabolic labeling experiments reveal that in the absence of exogenously supplied Cho, PE biosynthesized via Psd2 is mostly directed to the methylation pathway for PC biosynthesis and is unavailable for replenishing mitochondrial PE in Psd1-deleted cells. In this setting, stimulating the Kennedy pathway for PC biosynthesis by Cho spares Psd2-synthesized PE from the methylation pathway and redirects it to the mitochondria. Cho-mediated elevation in mitochondrial PE is dependent on Vps39, which has been recently implicated in PE trafficking to the mitochondria. Accordingly, epistasis experiments placed Vps39 downstream of Psd2 in Cho-based rescue. Our work, thus, provides a mechanism of Cho-based rescue of mitochondrial PE deficiency and uncovers an intricate interorganelle phospholipid regulatory network that maintains mitochondrial PE homeostasis.
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Affiliation(s)
- Donna M Iadarola
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, Texas, USA
| | - Alaumy Joshi
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, Texas, USA
| | - Cameron B Caldwell
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, Texas, USA
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, MS 3474, Texas A&M University, College Station, Texas, USA.
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23
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Skeletal Phenotypes Due to Abnormalities in Mitochondrial Protein Homeostasis and Import. Int J Mol Sci 2020; 21:ijms21218327. [PMID: 33171986 PMCID: PMC7664180 DOI: 10.3390/ijms21218327] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/28/2020] [Accepted: 11/03/2020] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial disease represents a collection of rare genetic disorders caused by mitochondrial dysfunction. These disorders can be quite complex and heterogeneous, and it is recognized that mitochondrial disease can affect any tissue at any age. The reasons for this variability are not well understood. In this review, we develop and expand a subset of mitochondrial diseases including predominantly skeletal phenotypes. Understanding how impairment ofdiverse mitochondrial functions leads to a skeletal phenotype will help diagnose and treat patients with mitochondrial disease and provide additional insight into the growing list of human pathologies associated with mitochondrial dysfunction. The underlying disease genes encode factors involved in various aspects of mitochondrial protein homeostasis, including proteases and chaperones, mitochondrial protein import machinery, mediators of inner mitochondrial membrane lipid homeostasis, and aminoacylation of mitochondrial tRNAs required for translation. We further discuss a complex of frequently associated phenotypes (short stature, cataracts, and cardiomyopathy) potentially explained by alterations to steroidogenesis, a process regulated by mitochondria. Together, these observations provide novel insight into the consequences of impaired mitochondrial protein homeostasis.
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24
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Zhao H, Wang T. PE homeostasis rebalanced through mitochondria-ER lipid exchange prevents retinal degeneration in Drosophila. PLoS Genet 2020; 16:e1009070. [PMID: 33064773 PMCID: PMC7592913 DOI: 10.1371/journal.pgen.1009070] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/28/2020] [Accepted: 08/21/2020] [Indexed: 02/06/2023] Open
Abstract
The major glycerophospholipid phosphatidylethanolamine (PE) in the nervous system is essential for neural development and function. There are two major PE synthesis pathways, the CDP-ethanolamine pathway in the endoplasmic reticulum (ER) and the phosphatidylserine decarboxylase (PSD) pathway in mitochondria. However, the role played by mitochondrial PE synthesis in maintaining cellular PE homeostasis is unknown. Here, we show that Drosophila pect (phosphoethanolamine cytidylyltransferase) mutants lacking the CDP-ethanolamine pathway, exhibited alterations in phospholipid composition, defective phototransduction, and retinal degeneration. Induction of the PSD pathway fully restored levels and composition of cellular PE, thus rescued the retinal degeneration and defective visual responses in pect mutants. Disrupting lipid exchange between mitochondria and ER blocked the ability of PSD to rescue pect mutant phenotypes. These findings provide direct evidence that the synthesis of PE in mitochondria contributes to cellular PE homeostasis, and suggest the induction of mitochondrial PE synthesis as a promising therapeutic approach for disorders associated with PE deficiency.
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Affiliation(s)
- Haifang Zhao
- National Institute of Biological Sciences, Beijing, China
| | - Tao Wang
- National Institute of Biological Sciences, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
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25
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Sabouny R, Shutt TE. Reciprocal Regulation of Mitochondrial Fission and Fusion. Trends Biochem Sci 2020; 45:564-577. [DOI: 10.1016/j.tibs.2020.03.009] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 03/03/2020] [Accepted: 03/16/2020] [Indexed: 12/24/2022]
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26
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Watanabe Y, Watanabe Y, Watanabe S. Structural Basis for Phosphatidylethanolamine Biosynthesis by Bacterial Phosphatidylserine Decarboxylase. Structure 2020; 28:799-809.e5. [PMID: 32402247 DOI: 10.1016/j.str.2020.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 03/12/2020] [Accepted: 04/08/2020] [Indexed: 02/06/2023]
Abstract
In both prokaryotes and eukaryotes, phosphatidylethanolamine (PE), one of the most abundant membrane phospholipids, plays important roles in various membrane functions and is synthesized through the decarboxylation of phosphatidylserine (PS) by PS decarboxylases (PSDs). However, the catalysis and substrate recognition mechanisms of PSDs remain unclear. In this study, we focused on the PSD from Escherichia coli (EcPsd) and determined the crystal structures of EcPsd in the apo form and PE-bound form at resolutions of 2.6 and 3.6 Å, respectively. EcPsd forms a homodimer, and each protomer has a positively charged substrate binding pocket at the active site. Structure-based mutational analyses revealed that conserved residues in the pocket are involved in PS decarboxylation. EcPsd has an N-terminal hydrophobic helical region that is important for membrane binding, thereby achieving efficient PS recognition. These results provide a structural basis for understanding the mechanism of PE biosynthesis by PSDs.
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Affiliation(s)
- Yasunori Watanabe
- Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan.
| | - Yasuo Watanabe
- Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Seiya Watanabe
- Department of Bioscience, Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan; Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
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27
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Sugawara S, Kanamaru Y, Sekine S, Maekawa L, Takahashi A, Yamamoto T, Watanabe K, Fujisawa T, Hattori K, Ichijo H. The mitochondrial protein PGAM5 suppresses energy consumption in brown adipocytes by repressing expression of uncoupling protein 1. J Biol Chem 2020; 295:5588-5601. [PMID: 32144202 PMCID: PMC7186182 DOI: 10.1074/jbc.ra119.011508] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 03/04/2020] [Indexed: 01/06/2023] Open
Abstract
Accumulating evidence suggests that brown adipose tissue (BAT) is a potential therapeutic target for managing obesity and related diseases. PGAM family member 5, mitochondrial serine/threonine protein phosphatase (PGAM5), is a protein phosphatase that resides in the mitochondria and regulates many biological processes, including cell death, mitophagy, and immune responses. Because BAT is a mitochondria-rich tissue, we have hypothesized that PGAM5 has a physiological function in BAT. We previously reported that PGAM5-knockout (KO) mice are resistant to severe metabolic stress. Importantly, lipid accumulation is suppressed in PGAM5-KO BAT, even under unstressed conditions, raising the possibility that PGAM5 deficiency stimulates lipid consumption. However, the mechanism underlying this observation is undetermined. Here, using an array of biochemical approaches, including quantitative RT-PCR, immunoblotting, and oxygen consumption assays, we show that PGAM5 negatively regulates energy expenditure in brown adipocytes. We found that PGAM5-KO brown adipocytes have an enhanced oxygen consumption rate and increased expression of uncoupling protein 1 (UCP1), a protein that increases energy consumption in the mitochondria. Mechanistically, we found that PGAM5 phosphatase activity and intramembrane cleavage are required for suppression of UCP1 activity. Furthermore, utilizing a genome-wide siRNA screen in HeLa cells to search for regulators of PGAM5 cleavage, we identified a set of candidate genes, including phosphatidylserine decarboxylase (PISD), which catalyzes the formation of phosphatidylethanolamine at the mitochondrial membrane. Taken together, these results indicate that PGAM5 suppresses mitochondrial energy expenditure by down-regulating UCP1 expression in brown adipocytes and that its phosphatase activity and intramembrane cleavage are required for UCP1 suppression.
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Affiliation(s)
- Sho Sugawara
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yusuke Kanamaru
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shiori Sekine
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Lila Maekawa
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Akinori Takahashi
- Cell Signal Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Okinawa 904-0495, Japan
| | - Tadashi Yamamoto
- Cell Signal Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Okinawa 904-0495, Japan; Laboratory for Immunogenetics, Center for Integrative Medical Sciences, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama City, Kanagawa 230-0045, Japan
| | - Kengo Watanabe
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takao Fujisawa
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kazuki Hattori
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Hidenori Ichijo
- Laboratory of Cell Signaling, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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28
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Funai K, Summers SA, Rutter J. Reign in the membrane: How common lipids govern mitochondrial function. Curr Opin Cell Biol 2020; 63:162-173. [PMID: 32106003 DOI: 10.1016/j.ceb.2020.01.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 12/09/2019] [Accepted: 01/07/2020] [Indexed: 12/12/2022]
Abstract
The lipids that make up biological membranes tend to be the forgotten molecules of cell biology. The paucity of data on these important entities likely reflects the difficulties of studying and understanding their biological roles, rather than revealing a lack of importance. Indeed, the lipid composition of biological membranes has a profound impact on a diverse array of cellular processes. The focus of this review is on the effects of different lipid classes on the function of mitochondria, particularly bioenergetics, in health and disease.
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Affiliation(s)
- Katsuhiko Funai
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA; Department of Physical Therapy & Athletic Training, University of Utah, Salt Lake City, UT, USA; Department of Nutrition & Integrative Physiology, University of Utah, Salt Lake City, UT, USA.
| | - Scott A Summers
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA; Department of Nutrition & Integrative Physiology, University of Utah, Salt Lake City, UT, USA; Department of Biochemistry, University of Utah, Salt Lake City, UT, USA.
| | - Jared Rutter
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA; Department of Nutrition & Integrative Physiology, University of Utah, Salt Lake City, UT, USA; Department of Biochemistry, University of Utah, Salt Lake City, UT, USA; Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA.
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29
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Deshwal S, Fiedler KU, Langer T. Mitochondrial Proteases: Multifaceted Regulators of Mitochondrial Plasticity. Annu Rev Biochem 2020; 89:501-528. [PMID: 32075415 DOI: 10.1146/annurev-biochem-062917-012739] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mitochondria are essential metabolic hubs that dynamically adapt to physiological demands. More than 40 proteases residing in different compartments of mitochondria, termed mitoproteases, preserve mitochondrial proteostasis and are emerging as central regulators of mitochondrial plasticity. These multifaceted enzymes limit the accumulation of short-lived, regulatory proteins within mitochondria, modulate the activity of mitochondrial proteins by protein processing, and mediate the degradation of damaged proteins. Various signaling cascades coordinate the activity of mitoproteases to preserve mitochondrial homeostasis and ensure cell survival. Loss of mitoproteases severely impairs the functional integrity of mitochondria, is associated with aging, and causes pleiotropic diseases. Understanding the dual function of mitoproteases as regulatory and quality control enzymes will help unravel the role of mitochondrial plasticity in aging and disease.
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Affiliation(s)
- Soni Deshwal
- Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany;
| | - Kai Uwe Fiedler
- Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany;
| | - Thomas Langer
- Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany; .,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
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30
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Somerharju P, Virtanen JA, Hermansson M. Hypothesis: Chemical activity regulates and coordinates the processes maintaining glycerophospholipid homeostasis in mammalian cells. FASEB Bioadv 2020; 2:182-187. [PMID: 32161907 PMCID: PMC7059623 DOI: 10.1096/fba.2019-00058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 07/19/2019] [Accepted: 12/31/2019] [Indexed: 02/06/2023] Open
Abstract
Mammalian cells maintain the complex glycerophospholipid (GPL) class compositions of their various membranes within close limits because this is essential to their well‐being or viability. Surprisingly, however, it is still not understood how those compositions are maintained except that GPL synthesis and degradation are closely coordinated. Here, we hypothesize that abrupt changes in the chemical activity of the individual GPL classes coordinate synthesis and degradation as well other the homeostatic processes. We have previously proposed that only a limited number of “allowed” or “optimal” GPL class compositions exist in cellular membranes because those compositions are energetically more favorable than others, that is, they represent local free energy minima (Somerharju et al 2009, Biochim. Biophys. Acta 1788, 12‐23). This model, however, could not satisfactorily explain how the “optimal” compositions are sensed by the key homeostatic enzymes, that is, rate‐limiting synthetizing enzymes and homeostatic phospholipases. We now hypothesize that when the mole fraction of a GPL class exceeds an optimal value, its chemical activity abruptly increases which (a) increases its propensity to efflux from the membrane thus making it susceptible for hydrolysis by homeostatic phospholipases; (b) increases its potency to inhibit its own biosynthesis via a feedback mechanism; (c) enhances its conversion to another glycerophospholipid class via a novel process termed “head group remodeling” or (d) enhances its translocation to other subcellular membranes. In summary, abrupt change in the chemical activity of the individual GPL classes is proposed to regulate and coordinate those four processes maintaining GPL class homeostasis in mammalian cells.
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Affiliation(s)
| | - Jorma A Virtanen
- Medicum Faculty of Medicine University of Helsinki Helsinki Finland
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31
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Loganovsky KN, Fedirko PA, Kuts KV, Marazziti D, Antypchuk KY, Perchuk IV, Babenko TF, Loganovska TK, Kolosynska OO, Kreinis GY, Gresko MV, Masiuk SV, Zdorenko LL, Zdanevich NA, Garkava NA, Dorichevska RY, Vasilenko ZL, Kravchenko VI, Drosdova NV, Yefimova YV. BRAIN AND EYE AS POTENTIAL TARGETS FOR IONIZING RADIATION IMPACT. Part І. THE CONSEQUENCES OF IRRADIATION OF THE PARTICIPANTS OF THE LIQUIDATION OF THE CHORNOBYL ACCIDENT. PROBLEMY RADIAT︠S︡IĬNOÏ MEDYT︠S︡YNY TA RADIOBIOLOHIÏ 2020; 25:90-129. [PMID: 33361831 DOI: 10.33145/2304-8336-2020-25-90-129] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Exposure to ionizing radiation could affect the brain and eyes leading to cognitive and vision impairment, behavior disorders and performance decrement during professional irradiation at medical radiology, includinginterventional radiological procedures, long-term space flights, and radiation accidents. OBJECTIVE The objective was to analyze the current experimental, epidemiological, and clinical data on the radiation cerebro-ophthalmic effects. MATERIALS AND METHODS In our analytical review peer-reviewed publications via the bibliographic and scientometric bases PubMed / MEDLINE, Scopus, Web of Science, and selected papers from the library catalog of NRCRM - theleading institution in the field of studying the medical effects of ionizing radiation - were used. RESULTS The probable radiation-induced cerebro-ophthalmic effects in human adults comprise radiation cataracts,radiation glaucoma, radiation-induced optic neuropathy, retinopathies, angiopathies as well as specific neurocognitive deficit in the various neuropsychiatric pathology including cerebrovascular pathology and neurodegenerativediseases. Specific attention is paid to the likely stochastic nature of many of those effects. Those prenatally and inchildhood exposed are a particular target group with a higher risk for possible radiation effects and neurodegenerative diseases. CONCLUSIONS The experimental, clinical, epidemiological, anatomical and pathophysiological rationale for visualsystem and central nervous system (CNS) radiosensitivity is given. The necessity for further international studieswith adequate dosimetric support and the follow-up medical and biophysical monitoring of high radiation riskcohorts is justified. The first part of the study currently being published presents the results of the study of theeffects of irradiation in the participants of emergency works at the Chornobyl Nuclear Power Plant (ChNPP).
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Affiliation(s)
- K N Loganovsky
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - P A Fedirko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - K V Kuts
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - D Marazziti
- Dipartimento di Medicina Clinica e Sperimentale Section of Psychiatry, University of Pisa, Via Roma, 67, I 56100, Pisa, Italy
| | - K Yu Antypchuk
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - I V Perchuk
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - T F Babenko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - T K Loganovska
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - O O Kolosynska
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - G Yu Kreinis
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - M V Gresko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - S V Masiuk
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - L L Zdorenko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - N A Zdanevich
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - N A Garkava
- State Institution «Dnipropetrovsk Medical Academy of the Ministry of Health of Ukraine», 9 Vernadsky Street, Dnipro, 49044, Ukraine
| | - R Yu Dorichevska
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - Z L Vasilenko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - V I Kravchenko
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - N V Drosdova
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
| | - Yu V Yefimova
- State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Illyenko Street, Kyiv, 04050, Ukraine
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Abstract
Synthesis and regulation of lipid levels and identities is critical for a wide variety of cellular functions, including structural and morphological properties of organelles, energy storage, signaling, and stability and function of membrane proteins. Proteolytic cleavage events regulate and/or influence some of these lipid metabolic processes and as a result help modulate their pleiotropic cellular functions. Proteins involved in lipid regulation are proteolytically cleaved for the purpose of their relocalization, processing, turnover, and quality control, among others. The scope of this review includes proteolytic events governing cellular lipid dynamics. After an initial discussion of the classic example of sterol regulatory element-binding proteins, our focus will shift to the mitochondrion, where a range of proteolytic events are critical for normal mitochondrial phospholipid metabolism and enforcing quality control therein. Recently, mitochondrial phospholipid metabolic pathways have been implicated as important for the proliferative capacity of cancers. Thus, the assorted proteases that regulate, monitor, or influence the activity of proteins that are important for phospholipid metabolism represent attractive targets to be manipulated for research purposes and clinical applications.
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Affiliation(s)
- Pingdewinde N. Sam
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Erica Avery
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Steven M. Claypool
- Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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Heden TD, Johnson JM, Ferrara PJ, Eshima H, Verkerke ARP, Wentzler EJ, Siripoksup P, Narowski TM, Coleman CB, Lin CT, Ryan TE, Reidy PT, de Castro Brás LE, Karner CM, Burant CF, Maschek JA, Cox JE, Mashek DG, Kardon G, Boudina S, Zeczycki TN, Rutter J, Shaikh SR, Vance JE, Drummond MJ, Neufer PD, Funai K. Mitochondrial PE potentiates respiratory enzymes to amplify skeletal muscle aerobic capacity. SCIENCE ADVANCES 2019; 5:eaax8352. [PMID: 31535029 PMCID: PMC6739096 DOI: 10.1126/sciadv.aax8352] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/15/2019] [Indexed: 05/08/2023]
Abstract
Exercise capacity is a strong predictor of all-cause mortality. Skeletal muscle mitochondrial respiratory capacity, its biggest contributor, adapts robustly to changes in energy demands induced by contractile activity. While transcriptional regulation of mitochondrial enzymes has been extensively studied, there is limited information on how mitochondrial membrane lipids are regulated. Here, we show that exercise training or muscle disuse alters mitochondrial membrane phospholipids including phosphatidylethanolamine (PE). Addition of PE promoted, whereas removal of PE diminished, mitochondrial respiratory capacity. Unexpectedly, skeletal muscle-specific inhibition of mitochondria-autonomous synthesis of PE caused respiratory failure because of metabolic insults in the diaphragm muscle. While mitochondrial PE deficiency coincided with increased oxidative stress, neutralization of the latter did not rescue lethality. These findings highlight the previously underappreciated role of mitochondrial membrane phospholipids in dynamically controlling skeletal muscle energetics and function.
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Affiliation(s)
- Timothy D. Heden
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Kinesiology, East Carolina University, Greenville, NC, USA
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Jordan M. Johnson
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Kinesiology, East Carolina University, Greenville, NC, USA
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, UT, USA
| | - Patrick J. Ferrara
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Kinesiology, East Carolina University, Greenville, NC, USA
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, UT, USA
| | - Hiroaki Eshima
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
| | - Anthony R. P. Verkerke
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Kinesiology, East Carolina University, Greenville, NC, USA
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, UT, USA
| | - Edward J. Wentzler
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Kinesiology, East Carolina University, Greenville, NC, USA
| | - Piyarat Siripoksup
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, UT, USA
| | - Tara M. Narowski
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Kinesiology, East Carolina University, Greenville, NC, USA
| | - Chanel B. Coleman
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Kinesiology, East Carolina University, Greenville, NC, USA
| | - Chien-Te Lin
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Physiology, East Carolina University, Greenville, NC, USA
| | - Terence E. Ryan
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Physiology, East Carolina University, Greenville, NC, USA
- Department of Applied Physiology & Kinesiology, University of Florida, Gainesville, FL, USA
| | - Paul T. Reidy
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, UT, USA
| | | | - Courtney M. Karner
- Department of Orthopedic Surgery & Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA
| | - Charles F. Burant
- Michigan Regional Comprehensive Metabolomics Resource Core, University of Michigan, Ann Arbor, MI, USA
| | - J. Alan Maschek
- Metabolomics Core Research Facility, University of Utah, Salt Lake City, UT, USA
| | - James E. Cox
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Metabolomics Core Research Facility, University of Utah, Salt Lake City, UT, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Douglas G. Mashek
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Gabrielle Kardon
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA
| | - Sihem Boudina
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
| | - Tonya N. Zeczycki
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Biochemistry and Molecular Biology, East Carolina University, Greenville, NC, USA
| | - Jared Rutter
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Saame Raza Shaikh
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Biochemistry and Molecular Biology, East Carolina University, Greenville, NC, USA
- Department of Nutrition, University of North Carolina, Chapel Hill, NC, USA
| | - Jean E. Vance
- Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Micah J. Drummond
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, UT, USA
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
| | - P. Darrell Neufer
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Kinesiology, East Carolina University, Greenville, NC, USA
- Department of Physiology, East Carolina University, Greenville, NC, USA
| | - Katsuhiko Funai
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA
- Department of Kinesiology, East Carolina University, Greenville, NC, USA
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, UT, USA
- Department of Physiology, East Carolina University, Greenville, NC, USA
- Molecular Medicine Program, University of Utah, Salt Lake City, UT, USA
- Corresponding author.
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The Liberfarb syndrome, a multisystem disorder affecting eye, ear, bone, and brain development, is caused by a founder pathogenic variant in thePISD gene. Genet Med 2019; 21:2734-2743. [PMID: 31263216 PMCID: PMC6892740 DOI: 10.1038/s41436-019-0595-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/17/2019] [Indexed: 01/24/2023] Open
Abstract
Purpose We observed four individuals in two unrelated but consanguineous
families from Portugal and Brazil affected by early-onset retinal degeneration,
sensorineural hearing loss, microcephaly, intellectual disability, and skeletal
dysplasia with scoliosis and short stature. The phenotype precisely matched that
of an individual of Azorean descent published in 1986 by Liberfarb and
coworkers. Methods Patients underwent specialized clinical examinations (including
ophthalmological, audiological, orthopedic, radiological, and developmental
assessment). Exome and targeted sequencing was performed on selected
individuals. Minigene constructs were assessed by quantitative polymerase chain
reaction (qPCR) and Sanger sequencing. Results Affected individuals shared a 3.36-Mb region of autozygosity on
chromosome 22q12.2, including a 10-bp deletion
(NM_014338.3:c.904-12_904-3delCTATCACCAC), immediately upstream of the last exon
of the PISD (phosphatidylserine
decarboxylase) gene. Sequencing of PISD from
paraffin-embedded tissue from the 1986 case revealed the identical homozygous
variant. In HEK293T cells, this variant led to aberrant splicing of PISD transcripts. Conclusion We have identified the genetic etiology of the Liberfarb syndrome,
affecting brain, eye, ear, bone, and connective tissue. Our work documents the
migration of a rare Portuguese founder variant to two continents and highlights
the link between phospholipid metabolism and bone formation, sensory defects,
and cerebral development, while raising the possibility of therapeutic
phospholipid replacement.
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Almutawa W, Smith C, Sabouny R, Smit RB, Zhao T, Wong R, Lee-Glover L, Desrochers-Goyette J, Ilamathi HS, Suchowersky O, Germain M, Mains PE, Parboosingh JS, Pfeffer G, Innes AM, Shutt TE. The R941L mutation in MYH14 disrupts mitochondrial fission and associates with peripheral neuropathy. EBioMedicine 2019; 45:379-392. [PMID: 31231018 PMCID: PMC6642256 DOI: 10.1016/j.ebiom.2019.06.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 06/06/2019] [Accepted: 06/12/2019] [Indexed: 11/25/2022] Open
Abstract
Background Peripheral neuropathies are often caused by disruption of genes responsible for myelination or axonal transport. In particular, impairment in mitochondrial fission and fusion are known causes of peripheral neuropathies. However, the causal mechanisms for peripheral neuropathy gene mutations are not always known. While loss of function mutations in MYH14 typically cause non-syndromic hearing loss, the recently described R941L mutation in MYH14, encoding the non-muscle myosin protein isoform NMIIC, leads to a complex clinical presentation with an unexplained peripheral neuropathy phenotype. Methods Confocal microscopy was used to examine mitochondrial dynamics in MYH14 patient fibroblast cells, as well as U2OS and M17 cells overexpressing NMIIC. The consequence of the R941L mutation on myosin activity was modeled in C. elegans. Findings We describe the third family carrying the R941L mutation in MYH14, and demonstrate that the R941L mutation impairs non-muscle myosin protein function. To better understand the molecular basis of the peripheral neuropathy phenotype associated with the R941L mutation, which has been hindered by the fact that NMIIC is largely uncharacterized, we have established a previously unrecognized biological role for NMIIC in mediating mitochondrial fission in human cells. Notably, the R941L mutation acts in a dominant-negative fashion to inhibit mitochondrial fission, especially in the cell periphery. In addition, we observed alterations to the organization of the mitochondrial genome. Interpretation As impairments in mitochondrial fission cause peripheral neuropathy, this insight into the function of NMIIC likely explains the peripheral neuropathy phenotype associated with the R941L mutation. Fund This study was supported by the Alberta Children's Hospital Research Institute, the Canadian Institutes of Health Research and the Care4Rare Canada Consortium.
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Affiliation(s)
- Walaa Almutawa
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Christopher Smith
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Rasha Sabouny
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Ryan B Smit
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Tian Zhao
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Rachel Wong
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Laurie Lee-Glover
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Justine Desrochers-Goyette
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada; Centre de Recherche Biomed, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Hema Saranya Ilamathi
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada; Centre de Recherche Biomed, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Oksana Suchowersky
- Departments of Medicine (Neurology), Medical Genetics and Pediatrics, University of Alberta, Edmonton, AB, Canada
| | - Marc Germain
- Groupe de Recherche en Signalisation Cellulaire and Département de Biologie Médicale, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada; Centre de Recherche Biomed, Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
| | - Paul E Mains
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jillian S Parboosingh
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Gerald Pfeffer
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - A Micheil Innes
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
| | - Timothy E Shutt
- Alberta Children's Hospital Research Institute, Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Department of Biochemistry & Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Hotchkiss Brain Institute, Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
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