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Venkatraman K, Budin I. Cardiolipin remodeling maintains the inner mitochondrial membrane in cells with saturated lipidomes. J Lipid Res 2024:100601. [PMID: 39038656 DOI: 10.1016/j.jlr.2024.100601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/14/2024] [Accepted: 07/16/2024] [Indexed: 07/24/2024] Open
Abstract
Cardiolipin (CL) is a unique, four-chain phospholipid synthesized in the inner mitochondrial membrane (IMM). The acyl chain composition of CL is regulated through a remodeling pathway, whose loss causes mitochondrial dysfunction in Barth syndrome (BTHS). Yeast has been used extensively as a model system to characterize CL metabolism, but mutants lacking its two remodeling enzymes, Cld1p and Taz1p, exhibit mild structural and respiratory phenotypes compared to mammalian cells. Here we show the essential role of CL remodeling in the structure and function of the IMM in yeast grown under reduced oxygenation. Microaerobic fermentation, which mimics natural yeast environments, caused the accumulation of saturated fatty acids and, under these conditions, remodeling mutants showed a loss of IMM ultrastructure. We extended this observation to HEK293 cells, where iPLA2 inhibition by Bromoenol lactone resulted in respiratory dysfunction and cristae loss upon mild treatment with exogenous saturated fatty acids. In microaerobic yeast, remodeling mutants accumulated unremodeled, saturated CL, but also displayed reduced total CL levels, highlighting the interplay between saturation and CL biosynthesis and breakdown. We identified the mitochondrial phospholipase A1 Ddl1p as a regulator of CL levels, and those of its precursors phosphatidylglycerol and phosphatidic acid, under these conditions. Loss of DDL1 partially rescued IMM structure in cells unable to initiate CL remodeling and had differing lipidomic effects depending on oxygenation. These results introduce a revised yeast model for investigating CL remodeling and suggest that its structural functions are dependent on the overall lipid environment in the mitochondrion.
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Affiliation(s)
- Kailash Venkatraman
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - Itay Budin
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA.
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Hachmann M, Gülcan G, Rajendran R, Höring M, Liebisch G, Bachhuka A, Kohlhaas M, Maack C, Ergün S, Dudek J, Karnati S. Tafazzin deficiency causes substantial remodeling in the lipidome of a mouse model of Barth Syndrome cardiomyopathy. FRONTIERS IN MOLECULAR MEDICINE 2024; 4:1389456. [PMID: 39086433 PMCID: PMC11285559 DOI: 10.3389/fmmed.2024.1389456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 04/09/2024] [Indexed: 08/02/2024]
Abstract
Barth Syndrome (BTHS) is a rare X-linked disease, characterized clinically by cardiomyopathy, skeletal myopathy, neutropenia, and growth retardation. BTHS is caused by mutations in the phospholipid acyltransferase tafazzin (Gene: TAFAZZIN, TAZ). Tafazzin catalyzes the final step in the remodeling of cardiolipin (CL), a glycerophospholipid located in the inner mitochondrial membrane. As the phospholipid composition strongly determines membrane properties, correct biosynthesis of CL and other membrane lipids is essential for mitochondrial function. Mitochondria provide 95% of the energy demand in the heart, particularly due to their role in fatty acid oxidation. Alterations in lipid homeostasis in BTHS have an impact on mitochondrial membrane proteins and thereby contribute to cardiomyopathy. We analyzed a transgenic TAFAZZIN-knockdown (TAZ-KD) BTHS mouse model and determined the distribution of 193 individual lipid species in TAZ-KD and WT hearts at 10 and 50 weeks of age, using electrospray ionization tandem mass spectrometry (ESI-MS/MS). Our results revealed significant lipid composition differences between the TAZ-KD and WT groups, indicating genotype-dependent alterations in most analyzed lipid species. Significant changes in the myocardial lipidome were identified in both young animals without cardiomyopathy and older animals with heart failure. Notable alterations were found in phosphatidylcholine (PC), phosphatidylethanolamine (PE), lysophosphatidylethanolamine (LPE), lysophosphatidylcholine (LPC) and plasmalogen species. PC species with 2-4 double bonds were significantly increased, while polyunsaturated PC species showed a significant decrease in TAZ-KD mice. Furthermore, Linoleic acid (LA, 18:2) containing PC and PE species, as well as arachidonic acid (AA, 20:4) containing PE 38:4 species are increased in TAZ-KD. We found higher levels of AA containing LPE and PE-based plasmalogens (PE P-). Furthermore, we are the first to show significant changes in sphingomyelin (SM) and ceramide (Cer) lipid species Very long-chained SM species are accumulating in TAZ-KD hearts, whereas long-chained Cer and several hexosyl ceramides (HexCer) species accumulate only in 50-week-old TAZ-KD hearts These findings offer potential avenues for the diagnosis and treatment of BTHS, presenting new possibilities for therapeutic approaches.
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Affiliation(s)
- Malte Hachmann
- Institute of Anatomy and Cell Biology, University of Würzburg, Würzburg, Germany
| | - Güntas Gülcan
- Department of Medical Biochemistry, Faculty of Medicine, Atlas University, Istanbul, Turkey
| | - Ranjithkumar Rajendran
- Experimental Neurology, Department of Neurology, Justus Liebig University, Giessen, Germany
| | - Marcus Höring
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital of Regensburg, Regensburg, Germany
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital of Regensburg, Regensburg, Germany
| | - Akash Bachhuka
- Department of Electronics, Electric, and Automatic Engineering, Rovira I Virgili University, Tarragona, Spain
| | - Michael Kohlhaas
- Department of Translational Research, Comprehensive Heart Failure Center, University Hospital Würzburg, Würzburg, Germany
| | - Christoph Maack
- Department of Translational Research, Comprehensive Heart Failure Center, University Hospital Würzburg, Würzburg, Germany
- Medical Clinic 1, University Hospital Würzburg, Würzburg, Germany
| | - Süleyman Ergün
- Institute of Anatomy and Cell Biology, University of Würzburg, Würzburg, Germany
| | - Jan Dudek
- Department of Translational Research, Comprehensive Heart Failure Center, University Hospital Würzburg, Würzburg, Germany
| | - Srikanth Karnati
- Institute of Anatomy and Cell Biology, University of Würzburg, Würzburg, Germany
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Muylle E, Jiang H, Johnsen C, Byeon SK, Ranatunga W, Garapati K, Zenka RM, Preston G, Pandey A, Kozicz T, Fang F, Morava E. TRIT1 defect leads to a recognizable phenotype of myoclonic epilepsy, speech delay, strabismus, progressive spasticity, and normal lactate levels. J Inherit Metab Dis 2022; 45:1039-1047. [PMID: 36047296 PMCID: PMC9826177 DOI: 10.1002/jimd.12550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 01/11/2023]
Abstract
TRIT1 defect is a rare, autosomal-recessive disorder of transcription, initially described as a condition with developmental delay, myoclonic seizures, and abnormal mitochondrial function. Currently, only 13 patients have been reported. We reviewed the genetic, clinical, and metabolic aspects of the disease in all known patients, including two novel, unrelated TRIT1 cases with abnormalities in oxidative phosphorylation complexes I and IV in fibroblasts. Taken together the features of all 15 patients, TRIT1 defect could be identified as a potentially recognizable syndrome including myoclonic epilepsy, speech delay, strabismus, progressive spasticity, and variable microcephaly, with normal lactate levels. Half of the patients had oxidative phosphorylation complex measurements and had multiple complex abnormalities.
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Affiliation(s)
- Ewout Muylle
- Department of Clinical GenomicsMayo ClinicRochesterMinnesotaUSA
| | - Huafang Jiang
- Department of NeurologyBeijing Children's Hospital, Capital Medical University, National Center for Children's HealthBeijingChina
| | | | - Seul Kee Byeon
- Department of Laboratory Medicine and PathologyMayo ClinicRochesterMinnesotaUSA
| | | | - Kishore Garapati
- Department of Laboratory Medicine and PathologyMayo ClinicRochesterMinnesotaUSA
- Institute of Bioinformatics, International Technology ParkBangaloreKarnatakaIndia
- Manipal Academy of Higher EducationManipalKarnatakaIndia
| | - Roman M. Zenka
- Department of Laboratory Medicine and PathologyMayo ClinicRochesterMinnesotaUSA
| | - Graeme Preston
- Department of Clinical GenomicsMayo ClinicRochesterMinnesotaUSA
| | - Akhilesh Pandey
- Department of Laboratory Medicine and PathologyMayo ClinicRochesterMinnesotaUSA
| | - Tamas Kozicz
- Department of Clinical GenomicsMayo ClinicRochesterMinnesotaUSA
- Department of Laboratory Medicine and PathologyMayo ClinicRochesterMinnesotaUSA
| | - Fang Fang
- Department of NeurologyBeijing Children's Hospital, Capital Medical University, National Center for Children's HealthBeijingChina
| | - Eva Morava
- Department of Clinical GenomicsMayo ClinicRochesterMinnesotaUSA
- Department of Laboratory Medicine and PathologyMayo ClinicRochesterMinnesotaUSA
- Department of Medical GeneticsUniversity of Pecs Medical SchoolPecsHungary
- Department of BiophysicsUniversity of Pecs Medical SchoolPecsHungary
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