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Halstuk O, Dayan R, Silverstein S, Fellig Y, Saada A, Harel T, Arkadir D. Low prevalence of SCA27B in adult-onset cerebellar ataxia cohort of Jewish ancestry. Parkinsonism Relat Disord 2024; 126:107067. [PMID: 39003951 DOI: 10.1016/j.parkreldis.2024.107067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 07/04/2024] [Accepted: 07/10/2024] [Indexed: 07/16/2024]
Affiliation(s)
- Orli Halstuk
- Department of Genetics, Hadassah Medical Center and the Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - Roy Dayan
- Department of Neurology, Hadassah Medical Center and the Faculty of Medicine, The Hebrew University, Jerusalem, Israel.
| | - Shira Silverstein
- Department of Genetics, Hadassah Medical Center and the Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - Yakov Fellig
- Department of Pathology, Hadassah Medical Center and the Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - Ann Saada
- Department of Genetics, Hadassah Medical Center and the Faculty of Medicine, The Hebrew University, Jerusalem, Israel; Hadassah Academic College Jerusalem, Jerusalem, Israel
| | - Tamar Harel
- Department of Genetics, Hadassah Medical Center and the Faculty of Medicine, The Hebrew University, Jerusalem, Israel
| | - David Arkadir
- Department of Neurology, Hadassah Medical Center and the Faculty of Medicine, The Hebrew University, Jerusalem, Israel
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Kamranian H, Asoudeh H, Sharif RK, Taheri F, Hayes AW, Gholami M, Alavi A, Motaghinejad M. Neuroprotective potential of trimetazidine against tramadol-induced neurotoxicity: role of PI3K/Akt/mTOR signaling pathways. Toxicol Mech Methods 2023; 33:607-623. [PMID: 37051630 DOI: 10.1080/15376516.2023.2202785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 04/10/2023] [Accepted: 04/10/2023] [Indexed: 04/14/2023]
Abstract
Tramadol (TRA) causes neurotoxicity whereas trimetazidine (TMZ) is neuroprotective. The potential involvement of the PI3K/Akt/mTOR signaling pathway in the neuroprotection of TMZ against TRA-induced neurotoxicity was evaluated. Seventy male Wistar rats were divided into groups. Groups 1 and 2 received saline or TRA (50 mg/kg). Groups 3, 4, and 5 received TRA (50 mg/kg) and TMZ (40, 80, or 160 mg/kg) for 14 days. Group 6 received TMZ (160 mg/kg). Hippocampal neurodegenerative, mitochondrial quadruple complex enzymes, phosphatidylinositol-3-kinases (PI3Ks)/protein kinase B levels, oxidative stress, inflammatory, apoptosis, autophagy, and histopathology were evaluated. TMZ decreased anxiety and depressive-like behavior induced by TRA. TMZ in tramadol-treated animals inhibited lipid peroxidation, GSSG, TNF-α, and IL-1β while increasing GSH, SOD, GPx, GR, and mitochondrial quadruple complex enzymes in the hippocampus. TRA inhibited Glial fibrillary acidic protein expression and increased pyruvate dehydrogenase levels. TMZ reduced these changes. TRA decreased the level of JNK and increased Beclin-1 and Bax. TMZ decreased phosphorylated Bcl-2 while increasing the unphosphorylated form in tramadol-treated rats. TMZ activated phosphorylated PI3Ks, Akt, and mTOR proteins. TMZ inhibited tramadol-induced neurotoxicity by modulating the PI3K/Akt/mTOR signaling pathways and its downstream inflammatory, apoptosis, and autophagy-related cascades.
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Affiliation(s)
- Houman Kamranian
- Department of Psychiatry, Faculty of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | - Hadi Asoudeh
- Faculty of Pharmacy, Central Branch of Islamic Azad University, Tehran, Iran
| | | | - Fereshteh Taheri
- Department of Medicine, Islamic Azad University, Qom Branch, Iran
| | - A Wallace Hayes
- University of South Florida College of Public Health, Tampa, FL, USA and Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
| | - Mina Gholami
- Chronic Respiratory Disease Research Center (CRDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ahmad Alavi
- Department of Medicine, Islamic Azad University, Qom Branch, Iran
| | - Majid Motaghinejad
- Chronic Respiratory Disease Research Center (CRDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Hu Y, Kang Y, Huang F, Su Y, Zhou X, Wang AJ, Gao SH. Distinct responses of Pseudomonas aeruginosa PAO1 exposed to different levels of polystyrene nanoplastics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 852:158214. [PMID: 36028032 DOI: 10.1016/j.scitotenv.2022.158214] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/18/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Large amounts of discarded plastics in the environment can be aged into microplastics and nanoplastics, which are not easily removed, posing potential nonnegligible risks to the ecosystem and human health. Although previous studies have revealed that nanoplastics have detrimental impacts on microorganisms, the potential molecular mechanisms of nanoplastic particles' effect on microbial growth and metabolism are still lacking. Here, multiple responses of Pseudomonas aeruginosa PAO1 (PAO1) to different levels of polystyrene nanoplastics (PS NPs) exposure were investigated by physiological experiments, live/dead staining, redox status, and genome-wide RNA sequencing. The results showed that PS NPs had dual effects on PAO1, and different concentrations of PS NPs demonstrated different effects on the growth and metabolism of PAO1. All levels of PS NPs had no obvious biocidal effect on PAO1. The production and consumption of ROS were in dynamic equilibrium and could be regulated genetically to ensure that the ROS level was in the biotolerable range. 20 and 50 mg/L of PS NPs severely inhibited the nitrate reduction, while 0.1 mg/L of PS NPs promoted the denitrification and TCA cycle. Meanwhile, 20 and 50 mg/L of PS NPs resulted in intense down-regulation of genes involved in denitrification. In contrast, the expression of genes involved in respiration is promoted with generated energy to withstand stress from high-level PS NPs, coinciding with the physiological results. In addition, our results showed that PS NPs concentrations of 20 and 50 mg/L exposure substantially up-regulated the expression of genes encoding for flagellar biosynthesis and biofilm formation to tackle the stress. Our findings would provide new insights into the interactions between environmental bacteria and PS NPs at the transcriptional level, thereby enhancing our understanding of the potential risks of PS NPs to microbial ecosystems and public health.
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Affiliation(s)
- Yuxin Hu
- State Key Laboratory of Urban Water Resource and Environment, School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Yuanyuan Kang
- State Key Laboratory of Urban Water Resource and Environment, School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Fang Huang
- State Key Laboratory of Urban Water Resource and Environment, School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China; State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Yiyi Su
- State Key Laboratory of Urban Water Resource and Environment, School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Xu Zhou
- State Key Laboratory of Urban Water Resource and Environment, School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Ai-Jie Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Shu-Hong Gao
- State Key Laboratory of Urban Water Resource and Environment, School of Civil & Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
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Sobhani S, Tehrani AA, Sobhani G, Fatima S, Ulloa L, Motaghinejad M, Atif A. Melatonin Protects Against Titanium Oxide-Induced Neurotoxicity: Neurochemical, Neurobehavioral, and Histopathological Evidences. Biol Trace Elem Res 2022:10.1007/s12011-022-03464-4. [PMID: 36378265 DOI: 10.1007/s12011-022-03464-4] [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: 04/01/2022] [Accepted: 10/25/2022] [Indexed: 11/16/2022]
Abstract
titania (titanium dioxide, TiO2) is known to induce neurotoxicity and CNS dysfunctions. Numerous studies have explored the neuroprotective effects of melatonin against neurotoxicity. This study evaluates the potential of melatonin to protect against titania-induced neurotoxicity and the role of the Keap1/Nrf2/ARE signaling pathway. One group of animals were treated with Titania (0.045 and 0.075 g/rat) alone while the other with added melatonin (1 mg/kg and 3 mg/kg) and behavioral alterations were assessed using OFT (open field test). Neurochemical and histopathological changes were also studied in the hippocampus by analyzing kelch ECH associating protein 1 (Keap1), nuclear factor erythroid 2-related factor 2 (Nrf2), and antioxidant response element (ARE). It was seen that the animals with added Melatonin had improved behavioral scores in the OFT, like anxiety and motor dysfunction triggered by TiO2. Melatonin also reduced lipid peroxidation, ROS, GSSG, IL1β, TNFα, Bax, and Keap1 levels, but boosted GSH, GPx, GR, SOD,IL10,IL4, Bcl2, Nrf2, and ARE levels and improved quadruple mitochondrial enzyme complex activity in titania-treated animals. Histopathological examination showed melatonin induced cytoprotection against vacuolization and necrosis in granular cells of DG and pyramidal cells of CA1 area of the hippocampus. In our study, pretreatment with melatonin reduced titania-induced neurotoxicity in the hippocampus through a mechanism potentially mediated by the Keap-1/Nrf2/ARE pathway.
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Affiliation(s)
- Sarvenaz Sobhani
- Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
| | - Ali-Asghar Tehrani
- Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
| | - Golnar Sobhani
- Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
| | - Sulail Fatima
- Department of Physiology, Jinnah Medical & Dental College, Sohail University, Karachi, Pakistan
| | - Luis Ulloa
- Center for Perioperative Organ Protection, Department of Anesthesiology, Duke University, Durham, NC, USA
| | - Majid Motaghinejad
- Chronic Respiratory Disease Research Center (CRDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Masih Daneshvari Hospital, Darabad Avenue, Shahid Bahonar roundabout, Tehran, Iran.
| | - Alina Atif
- Department of Physiology, Jinnah Medical & Dental College, Sohail University, Karachi, Pakistan
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Wu S, Yun J, Wang R, Zhang W, Hao L, Pei P. Analysis of the effects of antifungal peptide P-1 from Bacillus pumilus HN-10 on energy metabolism of Trichothecium roseum. FOOD BIOSCI 2022. [DOI: 10.1016/j.fbio.2022.101668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Aharon-Hananel G, Romero-Afrima L, Saada A, Mantzur C, Raz I, Weksler-Zangen S. Cytochrome c Oxidase Activity as a Metabolic Regulator in Pancreatic Beta-Cells. Cells 2022; 11:cells11060929. [PMID: 35326380 PMCID: PMC8946064 DOI: 10.3390/cells11060929] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 02/06/2023] Open
Abstract
Pancreatic β-cells couple glucose-stimulated insulin secretion (GSIS) with oxidative phosphorylation via cytochrome c oxidase (COX), a mitochondrial respiratory-chain enzyme. The Cohen diabetic-sensitive (CDs) rats exhibit hyperglycemia when fed a diabetogenic diet but maintain normoglycemia on a regular diet. We have previously reported a decreased COX activity in CDs rats and explored its relevance for type 2 diabetes (T2D). In this study, we investigated the relation between COX activity in islets, peripheral-blood mononuclear cells (PBMCs), and GSIS during diabetes development in CDs rats fed a diabetogenic diet for 4, 11, 20, and 30 days and during reversion to normoglycemia in hyperglycemic CDs rats fed a reversion diet for 7, 11, and 20 days. An oral glucose-tolerance test was performed at different periods of the diets measuring blood glucose and insulin concentrations. COX activity was determined in islets and PBMCs isolated from rats at the different periods of the diets. We demonstrated a progressive reduction in COX activity in CDs-islets that correlated positively with the decreasing GSIS (R2 = 0.9691, p < 0.001) and inversely with the elevation in blood glucose levels (R2 = 0.8396, p < 0.001). Hyperglycemia was initiated when islet COX activity decreased below 46%. The reversion diet restored >46% of the islet COX activity and GSIS while re-establishing normoglycemia. Interestingly, COX activity in PBMCs correlated significantly with islet COX activity (R2 = 0.8944, p < 0.001). Our data support islet COX activity as a major metabolic regulator of β-cells function. The correlation between COX activity in PBMCs and islets may serve as a noninvasive biomarker to monitor β-cell dysfunction in diabetes.
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Affiliation(s)
- Genya Aharon-Hananel
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Division of Endocrinology, Diabetes and Metabolism, The Chaim Sheba Medical Center, Tel Hashomer, Ramat-Gan 5266202, Israel
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
| | - Leonor Romero-Afrima
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
| | - Ann Saada
- The Department of Genetics, Hadassah Medical Center, Jerusalem 9112102, Israel;
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
| | - Carmit Mantzur
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
| | - Itamar Raz
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
| | - Sarah Weksler-Zangen
- The Hadassah Diabetes Center, Hadassah Medical Center, Jerusalem 9112102, Israel; (G.A.-H.); (L.R.-A.); (C.M.); (I.R.)
- Faculty of Medicine Hebrew, University of Jerusalem, Jerusalem 9112102, Israel
- The Liver Research Laboratory, Hadassah Medical Center, Jerusalem 9112102, Israel
- Correspondence: ; Tel.: +972-50-5172008
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7
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Eldad S, Hertz R, Vainer G, Saada A, Bar-Tana J. Treatment of ErbB2 breast cancer by mitochondrial targeting. Cancer Metab 2020; 8:17. [PMID: 32695336 PMCID: PMC7362624 DOI: 10.1186/s40170-020-00223-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 07/01/2020] [Indexed: 12/14/2022] Open
Abstract
Background ErbB2 breast cancer still remains an unmet need due to primary and/or acquired resistance to current treatment strategies. MEDICA compounds consist of synthetic long-chain α,ω-dicarboxylic acids previously reported to suppress breast cancer in PyMT transgenic mice. Methods MEDICA efficacy and mode of action in the ErbB2 context was studied in ErbB2 transgenic mice and human breast cancer cells. Results MEDICA treatment is shown here to suppress ErbB2 breast tumors and lung metastasis in ErbB2/neu MMTV transgenic mice, to suppress ErbB2/neu xenografts in nod/scid mice, and to suppress survival of AU565 and BT474 human ErbB2 breast cancer cells. Suppression of ErbB2 breast tumors by MEDICA is due to lipid raft disruption with loss of ErbB family members, including EGFR, ErbB2, and ErbB3. In addition, MEDICA inhibits mTORC1 activity, independently of abrogating the ErbB receptors and their signaling cascades. The double hit of MEDICA in abrogating ErbB and mTORC1 is partly accounted for by targeting mitochondria complex I. Conclusions Mitochondrial targeting by MEDICA suppresses ErbB2 breast tumors and metastasis due to lipid raft disruption and inhibition of mTORC1 activity. Inhibition of mTORC1 activity by MEDICA avoids the resistance acquired by canonical mTORC1 inhibitors like rapalogs or mTOR kinase inhibitors.
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Affiliation(s)
- Sophia Eldad
- Dept of Human Nutrition and Metabolism, Hebrew University Medical School, 91120 Jerusalem, Israel
| | - Rachel Hertz
- Dept of Human Nutrition and Metabolism, Hebrew University Medical School, 91120 Jerusalem, Israel
| | - Gilad Vainer
- Dept of Pathology, Hadassah-Hebrew University Medical Center, 91120 Jerusalem, Israel
| | - Ann Saada
- Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, 91120 Jerusalem, Israel
| | - Jacob Bar-Tana
- Dept of Human Nutrition and Metabolism, Hebrew University Medical School, 91120 Jerusalem, Israel
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8
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Copper mediates mitochondrial biogenesis in retinal pigment epithelial cells. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165843. [PMID: 32454166 DOI: 10.1016/j.bbadis.2020.165843] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 02/29/2020] [Accepted: 05/19/2020] [Indexed: 11/22/2022]
Abstract
Age related macular degeneration (AMD) is a multifactorial disease with genetic, biochemical and environmental risk factors. We observed a significant increase in copper levels in choroid-RPE from donor eyeballs with AMD. Adult retinal pigment epithelial cells (ARPE19 cells) exposed to copper in-vitro showed a 2-fold increase in copper influx transporter CTR1 and copper uptake at 50 μM concentration. Further there was 2-fold increase in cytochrome C oxidase activity and a 2-fold increase in the mRNA expression of NRF 2 with copper treatment. There was a significant increase in mitochondrial biogenesis markers PGC1β and TFAM which was confirmed by mitochondrial mass and copy number. On the contrary, in AMD choroid-RPE, the CTR1 mRNA was found to be significantly down-regulated compared to its respective controls. SCO1 and PGC1β mRNA showed an increase in choroid-RPE. Our study proposes copper to play an important role in mitochondrial biogenesis in RPE cells.
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Zehavi Y, Mandel H, Eran A, Ravid S, Abu Rashid M, Jansen EEW, Wamelink MMC, Saada A, Shaag A, Elpeleg O, Spiegel R. Severe infantile epileptic encephalopathy associated with D-glyceric aciduria: report of a novel case and review. Metab Brain Dis 2019; 34:557-563. [PMID: 30637540 DOI: 10.1007/s11011-019-0384-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Accepted: 01/07/2019] [Indexed: 10/27/2022]
Abstract
D-glycerate 2 kinase (DGK) is an enzyme that mediates the conversion of D-glycerate, an intermediate metabolite of serine and fructose metabolism, to 2-phosphoglycerate. Deficiency of DGK leads to accumulation of D-glycerate in various tissues and its massive excretion in urine. D-glyceric aciduria (DGA) is an autosomal recessive metabolic disorder caused by mutations in the GLYCTK gene. The clinical spectrum of DGA is highly variable, ranging from severe progressive infantile encephalopathy to a practically asymptomatic condition. We describe a male patient from a consanguineous Arab family with infantile onset of DGA, characterized by profound psychomotor retardation, progressive microcephaly, intractable seizures, cortical blindness and deafness. Consecutive brain MR imaging showed an evolving brain atrophy, thinning of the corpus callosum and diffuse abnormal white matter signals. Whole exome sequencing identified the homozygous missense variant in the GLYCTK gene [c.455 T > C, NM_145262.3], which affected a highly conserved leucine residue located at a domain of yet unknown function of the enzyme [p.Leu152Pro, NP_660305]. In silico analysis of the variant supported its pathogenicity. A review of the 15 previously reported patients, together with the current one, confirms a clear association between DGA and severe neurological impairment. Yet, future studies of additional patients with DGA are required to better understand the clinical phenotype and pathogenesis.
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Affiliation(s)
- Yoav Zehavi
- Department of Pediatrics B, Emek Medical Center, Afula, Israel
| | - Hanna Mandel
- Institute of Human Genetics and Metabolic Diseases, Galilee Medical Center, Nahariya, Israel
| | - Ayelet Eran
- Neuroradiology Unit Department of Radiology, Rambam Health Care Campus, Haifa, Israel
- Rappaport School of Medicine, Technion, Haifa, Israel
| | - Sarit Ravid
- Rappaport School of Medicine, Technion, Haifa, Israel
- Pediatric Neurology Unit, Ruth Rappaport Children's Hospital, Rambam Health Care Campus, Haifa, Israel
| | | | - Erwin E W Jansen
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Mirjam M C Wamelink
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
- Metabolic Laboratory, Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Avraham Shaag
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Orly Elpeleg
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ronen Spiegel
- Department of Pediatrics B, Emek Medical Center, Afula, Israel.
- Rappaport School of Medicine, Technion, Haifa, Israel.
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10
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Keller G, Binyamin O, Frid K, Saada A, Gabizon R. Mitochondrial dysfunction in preclinical genetic prion disease: A target for preventive treatment? Neurobiol Dis 2018; 124:57-66. [PMID: 30423473 DOI: 10.1016/j.nbd.2018.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 11/09/2018] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial malfunction is a common feature in advanced stages of neurodegenerative conditions, as is the case for the accumulation of aberrantly folded proteins, such as PrP in prion diseases. In this work, we investigated mitochondrial activity and expression of related factors vis a vis PrP accumulation at the subclinical stages of TgMHu2ME199K mice, modeling for genetic prion diseases. While these mice remain healthy until 5-6 months of age, they succumb to fatal disease at 12-14 months. We found that mitochondrial respiratory chain enzymatic activates and ATP/ROS production, were abnormally elevated in asymptomatic mice, concomitant with initial accumulation of disease related PrP. In parallel, the expression of Cytochrome c oxidase (COX) subunit IV isoform 1(Cox IV-1) was reduced and replaced by the activity of Cox IV isoform 2, which operates in oxidative neuronal conditions. At all stages of disease, Cox IV-1 was absent from cells accumulating disease related PrP, suggesting that PrP aggregates may directly compromise normal mitochondrial function. Administration of Nano-PSO, a brain targeted antioxidant, to TgMHu2ME199K mice, reversed functional and biochemical mitochondrial functions to normal conditions regardless of the presence of misfolded PrP. Our results therefore indicate that in genetic prion disease, oxidative damage initiates long before clinical manifestations. These manifest only when aggregated PrP levels are too high for the compensatory mechanisms to sustain mitochondrial activity.
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Affiliation(s)
- Guy Keller
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Israel; Medical School, The Hebrew University, Jerusalem, Israel
| | - Orli Binyamin
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Israel; Medical School, The Hebrew University, Jerusalem, Israel
| | - Kati Frid
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Israel; Medical School, The Hebrew University, Jerusalem, Israel
| | - Ann Saada
- Department of Genetics and Metabolic Diseases, The Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Israel; Medical School, The Hebrew University, Jerusalem, Israel
| | - Ruth Gabizon
- Department of Neurology, The Agnes Ginges Center for Human Neurogenetics, Israel; Medical School, The Hebrew University, Jerusalem, Israel.
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Friederich MW, Timal S, Powell CA, Dallabona C, Kurolap A, Palacios-Zambrano S, Bratkovic D, Derks TGJ, Bick D, Bouman K, Chatfield KC, Damouny-Naoum N, Dishop MK, Falik-Zaccai TC, Fares F, Fedida A, Ferrero I, Gallagher RC, Garesse R, Gilberti M, González C, Gowan K, Habib C, Halligan RK, Kalfon L, Knight K, Lefeber D, Mamblona L, Mandel H, Mory A, Ottoson J, Paperna T, Pruijn GJM, Rebelo-Guiomar PF, Saada A, Sainz B, Salvemini H, Schoots MH, Smeitink JA, Szukszto MJ, Ter Horst HJ, van den Brandt F, van Spronsen FJ, Veltman JA, Wartchow E, Wintjes LT, Zohar Y, Fernández-Moreno MA, Baris HN, Donnini C, Minczuk M, Rodenburg RJ, Van Hove JLK. Pathogenic variants in glutamyl-tRNA Gln amidotransferase subunits cause a lethal mitochondrial cardiomyopathy disorder. Nat Commun 2018; 9:4065. [PMID: 30283131 PMCID: PMC6170436 DOI: 10.1038/s41467-018-06250-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 08/23/2018] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial protein synthesis requires charging a mitochondrial tRNA with its amino acid. Here, the authors describe pathogenic variants in the GatCAB protein complex genes required for the generation of glutaminyl-mt-tRNAGln, that impairs mitochondrial translation and presents with cardiomyopathy. Mitochondrial protein synthesis requires charging mt-tRNAs with their cognate amino acids by mitochondrial aminoacyl-tRNA synthetases, with the exception of glutaminyl mt-tRNA (mt-tRNAGln). mt-tRNAGln is indirectly charged by a transamidation reaction involving the GatCAB aminoacyl-tRNA amidotransferase complex. Defects involving the mitochondrial protein synthesis machinery cause a broad spectrum of disorders, with often fatal outcome. Here, we describe nine patients from five families with genetic defects in a GatCAB complex subunit, including QRSL1, GATB, and GATC, each showing a lethal metabolic cardiomyopathy syndrome. Functional studies reveal combined respiratory chain enzyme deficiencies and mitochondrial dysfunction. Aminoacylation of mt-tRNAGln and mitochondrial protein translation are deficient in patients’ fibroblasts cultured in the absence of glutamine but restore in high glutamine. Lentiviral rescue experiments and modeling in S. cerevisiae homologs confirm pathogenicity. Our study completes a decade of investigations on mitochondrial aminoacylation disorders, starting with DARS2 and ending with the GatCAB complex.
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Affiliation(s)
- Marisa W Friederich
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Sharita Timal
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands.,Department of Human Genetics, Radboud Institute for Molecular Life Sciences and Donders Centre for Neuroscience, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Christopher A Powell
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom
| | - Cristina Dallabona
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Alina Kurolap
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3109601, Israel
| | - Sara Palacios-Zambrano
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Drago Bratkovic
- SA Pathology, Women and Children's Hospital Adelaide, Adelaide, 5006, Australia
| | - Terry G J Derks
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - David Bick
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
| | - Katelijne Bouman
- Department of Genetics, University Medical Center of Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - Kathryn C Chatfield
- Department of Pediatrics, Section of Pediatric Cardiology, Children's Hospital Colorado, University of Colorado, Aurora, CO, 80045, USA
| | - Nadine Damouny-Naoum
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel.,Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Megan K Dishop
- Department of Pathology, Children's Hospital Colorado, University of Colorado, Aurora, 80045, CO, USA
| | - Tzipora C Falik-Zaccai
- Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel.,The Azrieli Faculty of Medicine in the Galilee, Bar Ilan University, Safed, 1311502, Israel
| | - Fuad Fares
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Ayalla Fedida
- Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel.,The Azrieli Faculty of Medicine in the Galilee, Bar Ilan University, Safed, 1311502, Israel
| | - Ileana Ferrero
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Renata C Gallagher
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Rafael Garesse
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Micol Gilberti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Cristina González
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Katherine Gowan
- Department of Biochemistry and Molecular Genetics, University of Colorado, Aurora, CO, 80045, USA
| | - Clair Habib
- Department of Pediatrics, Bnai Zion Medical Center, Haifa, 3339419, Israel
| | - Rebecca K Halligan
- SA Pathology, Women and Children's Hospital Adelaide, Adelaide, 5006, Australia
| | - Limor Kalfon
- Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel
| | - Kaz Knight
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Dirk Lefeber
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences and Donders Centre for Neuroscience, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Laura Mamblona
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Hanna Mandel
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3109601, Israel.,Institute of Human Genetics, Galilee Medical Center, Nahariya, 22100, Israel.,Metabolic Unit, Rambam Health Care Campus, Haifa, 3109601, Israel
| | - Adi Mory
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel
| | - John Ottoson
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA
| | - Tamar Paperna
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel
| | - Ger J M Pruijn
- Department of Biomolecular Chemistry, Institute for Molecules and Materials, Radboud University, Nijmegen, 6500 HB, The Netherlands
| | - Pedro F Rebelo-Guiomar
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom.,Graduate Program in Areas of Basic and Applied Biology (GABBA), University of Porto, Porto, 4200-135, Portugal
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research and the Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Bruno Sainz
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Enfermedades Crónicas y Cáncer Area, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, 28034, Spain
| | - Hayley Salvemini
- SA Pathology, Women and Children's Hospital Adelaide, Adelaide, 5006, Australia
| | - Mirthe H Schoots
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, 9700 RB, Groningen, The Netherlands
| | - Jan A Smeitink
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Maciej J Szukszto
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom
| | - Hendrik J Ter Horst
- Division of Neonatology, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - Frans van den Brandt
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Francjan J van Spronsen
- Division of Metabolic Diseases, Beatrix Children's Hospital, University Medical Center Groningen, University of Groningen, Groningen, 9700 RB, The Netherlands
| | - Joris A Veltman
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences and Donders Centre for Neuroscience, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands.,Institute of Genetic Medicine, Newcastle University, Newcastle, NE1 3BZ, United Kingdom
| | - Eric Wartchow
- Department of Pathology, Children's Hospital Colorado, University of Colorado, Aurora, 80045, CO, USA
| | - Liesbeth T Wintjes
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Yaniv Zohar
- Institute of Pathology, Rambam Health Care Campus, 3109601, Haifa, Israel
| | - Miguel A Fernández-Moreno
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas "Alberto Sols" UAM-CSIC and Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER). Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, 28029, Spain.,Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12), Madrid, 28041, Spain
| | - Hagit N Baris
- The Genetics Institute, Rambam Health Care Campus, Haifa, 3109601, Israel.,The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 3109601, Israel
| | - Claudia Donnini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, 43124, Italy
| | - Michal Minczuk
- Medical Research Council, Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 OXY, United Kingdom
| | - Richard J Rodenburg
- Radboud Center for Mitochondrial Medicine, Translational Metabolic Laboratory, Department of Pediatrics, Radboud University Medical Center, Nijmegen, 6500 HB, The Netherlands
| | - Johan L K Van Hove
- Section of Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Aurora, 80045, CO, USA.
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12
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Shufaro Y, Saada A, Simeonov M, Tsuberi BZ, Alban C, Kogot-Levin A, Shochat T, Fisch B, Abir R. The influence of in vivo exposure to nonylphenol ethoxylate 10 (NP-10) on the ovarian reserve in a mouse model. Reprod Toxicol 2018; 81:246-252. [PMID: 30176375 DOI: 10.1016/j.reprotox.2018.08.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/27/2018] [Accepted: 08/29/2018] [Indexed: 12/18/2022]
Abstract
AIM To determine the effect of nonylphenol-ethoxylate-10 (NP-10) on the ovarian reserve in a mouse model. DESIGN Female mice were maintained on purified water or exposed to NP-10 from 3-7-weeks of age. At 7-weeks they were stimulated, mated and the zygotes were cultured in-vitro. Three and 7-weeks old mice were untreated controls. Identical groups were sacrificed without stimulation. Ovaries were analysed for follicular composition. Respiratory-chain (RC) activity and reactive-oxygen-species (ROS) production were measured in brains and livers. RESULTS Seven-weeks-old mice produced fewer oocytes/embryos than 3-week-old mice. At 7-weeks, mice exposed to NP-10 produced more oocytes/embryos the controls. Their ovaries contained more primordial/primary follicles, with a lower rate of proliferation and fewer antral follicles. There were no differences in follicular apoptosis, RC-activity or ROS production. CONCLUSIONS In this model, exposure to NP-10 inhibited the spontaneous follicular recruitment, the first report of successful inhibition of physiologic ovarian aging, to the best of our knowledge.
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Affiliation(s)
- Yoel Shufaro
- Infertility and IVF Unit, Helen Schneider Hospital for Women, Rabin Medical Center - Beilinson Hospital, and Felsenstein Medical Research Center, Petach Tikva 4941492; the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel.
| | - Ann Saada
- Monique and Jaques Roboh Department of Genetic Research, Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Monica Simeonov
- Infertility and IVF Unit, Helen Schneider Hospital for Women, Rabin Medical Center - Beilinson Hospital, and Felsenstein Medical Research Center, Petach Tikva 4941492; the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ben-Zion Tsuberi
- Transgenic Mice Unit, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Corinne Alban
- Monique and Jaques Roboh Department of Genetic Research, Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Aviram Kogot-Levin
- Monique and Jaques Roboh Department of Genetic Research, Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, 91120, Israel
| | - Tzippy Shochat
- Infertility and IVF Unit, Helen Schneider Hospital for Women, Rabin Medical Center - Beilinson Hospital, and Felsenstein Medical Research Center, Petach Tikva 4941492; the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Benjamin Fisch
- Infertility and IVF Unit, Helen Schneider Hospital for Women, Rabin Medical Center - Beilinson Hospital, and Felsenstein Medical Research Center, Petach Tikva 4941492; the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ronit Abir
- Infertility and IVF Unit, Helen Schneider Hospital for Women, Rabin Medical Center - Beilinson Hospital, and Felsenstein Medical Research Center, Petach Tikva 4941492; the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
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13
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Bigelman E, Cohen L, Aharon-Hananel G, Levy R, Rozenbaum Z, Saada A, Keren G, Entin-Meer M. Pathological presentation of cardiac mitochondria in a rat model for chronic kidney disease. PLoS One 2018; 13:e0198196. [PMID: 29889834 PMCID: PMC5995391 DOI: 10.1371/journal.pone.0198196] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/15/2018] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Mitochondria hold crucial importance in organs with high energy demand especially the heart. We investigated whether chronic kidney disease (CKD), which eventually culminates in cardiorenal syndrome, could affect cardiac mitochondria and assessed the potential involvement of angiotensin II (AngII) in the process. METHODS Male Lewis rats underwent 5/6 nephrectomy allowing CKD development for eight months or for eleven weeks. Short-term CKD rats were administered with AngII receptor blocker (ARB). Cardiac function was assessed by echocardiography and cardiac sections were evaluated for interstitial fibrosis and cardiomyocytes' hypertrophy. Electron microscopy was used to explore the spatial organization of the cardiomyocytes. Expression levels of mitochondrial content and activity markers were tested in order to delineate the underlying mechanisms for mitochondrial pathology in the CKD setting with or without ARB administration. RESULTS CKD per-se resulted in induced cardiac interstitial fibrosis and cardiomyocytes' hypertrophy combined with a marked disruption of the mitochondrial structure. Moreover, CKD led to enhanced cytochrome C leakage to the cytosol and to enhanced PARP-1 cleavage which are associated with cellular apoptosis. ARB treatment did not improve kidney function but markedly reduced left ventricular mass, cardiomyocytes' hypertrophy and interstitial fibrosis. Interestingly, ARB administration improved the spatial organization of cardiac mitochondria and reduced their increased volume compared to untreated CKD animals. Nevertheless, ARB did not improve mitochondrial content, mitochondrial biogenesis or the respiratory enzyme activity. ARB mildly upregulated protein levels of mitochondrial fusion-related proteins. CONCLUSIONS CKD results in cardiac pathological changes combined with mitochondrial damage and elevated apoptotic markers. We anticipate that the increased mitochondrial volume mainly represents mitochondrial swelling that occurs during the pathological process of cardiac hypertrophy. Chronic administration of ARB may improve the pathological appearance of the heart. Further recognition of the molecular pathways leading to mitochondrial insult and appropriate intervention is of crucial importance.
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Affiliation(s)
- Einat Bigelman
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- The Laboratory of Cardiovascular Research, Department of Cardiology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel
| | - Lena Cohen
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- The Laboratory of Cardiovascular Research, Department of Cardiology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel
| | | | - Ran Levy
- The Laboratory of Cardiovascular Research, Department of Cardiology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel
| | - Zach Rozenbaum
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- The Laboratory of Cardiovascular Research, Department of Cardiology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel
| | - Ann Saada
- Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Gad Keren
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- The Laboratory of Cardiovascular Research, Department of Cardiology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel
| | - Michal Entin-Meer
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- The Laboratory of Cardiovascular Research, Department of Cardiology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel
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14
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Cohen I, Staretz-Chacham O, Wormser O, Perez Y, Saada A, Kadir R, Birk OS. A novel homozygous SLC25A1 mutation with impaired mitochondrial complex V: Possible phenotypic expansion. Am J Med Genet A 2017; 176:330-336. [PMID: 29226520 DOI: 10.1002/ajmg.a.38574] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 11/13/2017] [Accepted: 11/16/2017] [Indexed: 11/08/2022]
Abstract
SLC25A1 mutations are associated with combined D,L-2-hydroxyglutaric aciduria (DL- 2HGA; OMIM #615182), characterized by muscular hypotonia, severe neurodevelopmental dysfunction and intractable seizures. SLC25A1 encodes the mitochondrial citrate carrier (CIC), which mediates efflux of the mitochondrial tricarboxylic acid (TCA) cycle intermediates citrate and isocitrate in exchange for cytosolic malate. Only a single family with an SLC25A1 mutation has been described in which mitochondrial respiratory chain dysfunction was documented, specifically in complex IV. Five infants of two consanguineous Bedouin families of the same tribe presented with small head circumference and neonatal-onset encephalopathy with severe muscular weakness, intractable seizures, respiratory distress, and lack of psychomotor development culminating in early death. Ventricular septal defects (VSD) were demonstrated in three patients. Blood and CSF lactate were elevated with normal levels of plasma amino acids and free carnitine and increased 2-OH-glutaric acid urinary exertion. EEG was compatible with white matter disorder. Brain MRI revealed ventriculomegaly, thin corpus callosum with increased lactate peak on spectroscopy. Mitochondrial complex V deficiency was demonstrated in skeletal muscle biopsy of one infant. Homozygosity mapping and sequencing ruled out homozygosity of affected individuals in all known complex V-associated genes. Whole exome sequencing identified a novel homozygous SLC25A1 c.713A>G (p.Asn238Ser) mutation, segregating as expected in the affected kindred and not found in 220 control alleles. Thus, SLC25A1 mutations might be associated with mitochondrial complex V deficiency and should be considered in the differential diagnosis of mitochondrial respiratory chain defects.
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Affiliation(s)
- Idan Cohen
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Orna Staretz-Chacham
- Metabolic unit, Division of Pediatrics, Soroka Medical Center, Ben Gurion University, Beer Sheva, Israel
| | - Ohad Wormser
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Yonatan Perez
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research and The Department of Genetic Metabolic Diseases, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Rotem Kadir
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel
| | - Ohad S Birk
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben Gurion University of the Negev, Beer-Sheva, Israel.,Genetics Institute, Soroka Medical Center, Beer-Sheva, Israel
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15
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Abu-Libdeh B, Douiev L, Amro S, Shahrour M, Ta-Shma A, Miller C, Elpeleg O, Saada A. Mutation in the COX4I1 gene is associated with short stature, poor weight gain and increased chromosomal breaks, simulating Fanconi anemia. Eur J Hum Genet 2017; 25:1142-1146. [PMID: 28766551 DOI: 10.1038/ejhg.2017.112] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 06/15/2017] [Accepted: 06/20/2017] [Indexed: 11/09/2022] Open
Abstract
We describe a novel autosomal recessive form of mitochondrial disease in a child with short stature, poor weight gain, and mild dysmorphic features with highly suspected Fanconi anemia due to a mutation in COX4I1 gene. Whole Exome Sequencing was performed then followed by Sanger confirmation, identified a K101N mutation in COX4I1, segregating with the disease. This nuclear gene encodes the common isoform of cytochrome c oxidase (COX) subunit 4 (COX 4-1), an integral regulatory part of COX (respiratory chain complex IV) the terminal electron acceptor of the mitochondrial respiratory chain. The patient's fibroblasts disclosed decreased COX activity, impaired ATP production, elevated ROS production, decreased expression of COX4I1 mRNA and undetectable (COX4) protein. COX activity and ATP production were restored by lentiviral transfection with the wild-type gene. Our results demonstrate the first human mutation in the COX4I1 gene linked to diseases and confirm its role in the pathogenesis. Thus COX4I1 mutations should be considered in any patient with features suggestive of this diagnosis.
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Affiliation(s)
- Bassam Abu-Libdeh
- Department of Pediatrics, Makassed Hospital and Al-Quds University, Jerusalem, Palestinian Authority
| | - Liza Douiev
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, Jerusalem, Israel.,Department of Genetic and Metabolic Diseases, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Sarah Amro
- Department of Pediatrics, Makassed Hospital and Al-Quds University, Jerusalem, Palestinian Authority
| | - Maher Shahrour
- Department of Pediatrics, Makassed Hospital and Al-Quds University, Jerusalem, Palestinian Authority
| | - Asaf Ta-Shma
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Chaya Miller
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, Jerusalem, Israel.,Department of Genetic and Metabolic Diseases, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Orly Elpeleg
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, Jerusalem, Israel.,Department of Genetic and Metabolic Diseases, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
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16
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The Relationship between Mitochondrial Respiratory Chain Activities in Muscle and Metabolites in Plasma and Urine: A Retrospective Study. J Clin Med 2017; 6:jcm6030031. [PMID: 28287425 PMCID: PMC5373000 DOI: 10.3390/jcm6030031] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 03/06/2017] [Accepted: 03/09/2017] [Indexed: 11/17/2022] Open
Abstract
The relationship between 114 cases with decreased enzymatic activities of mitochondrial respiratory chain (MRC) complexes I-V (C I-V) in muscle and metabolites in urine and plasma was retrospectively examined. Less than 35% disclosed abnormal plasma amino acids and acylcarnitines, with elevated alanine and low free carnitine or elevated C4-OH-carnitine as the most common findings, respectively. Abnormal urine organic acids (OA) were detected in 82% of all cases. In CI and CII defects, lactic acid (LA) in combination with other metabolites was the most common finding. 3-Methylglutaconic (3MGA) acid was more frequent in CIV and CV, while Tyrosine metabolites, mainly 4-hydroxyphenyllactate, were common in CI and IV defects. Ketones were present in all groups but more prominent in combined deficiencies. There was a significant strong correlation between elevated urinary LA and plasma lactate but none between urine Tyrosine metabolites and plasma Tyrosine or urinary LA and plasma Alanine. All except one of 14 cases showed elevated FGF21, but correlation with urine OA was weak. Although this study is limited, we conclude that urine organic acid test in combination with plasma FGF21 determination are valuable tools in the diagnosis of mitochondrial diseases.
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17
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Volpert G, Ben-Dor S, Tarcic O, Duan J, Saada A, Merrill AH, Pewzner-Jung Y, Futerman AH. Oxidative stress elicited by modifying the ceramide acyl chain length reduces the rate of clathrin-mediated endocytosis. J Cell Sci 2017; 130:1486-1493. [PMID: 28280117 DOI: 10.1242/jcs.199968] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 02/28/2017] [Indexed: 12/11/2022] Open
Abstract
Sphingolipids modulate clathrin-mediated endocytosis (CME) by altering the biophysical properties of membranes. We now examine CME in astrocytes cultured from ceramide synthase 2 (CerS2) null mice, which have an altered sphingolipid acyl chain composition. The rate of endocytosis of low-density lipoprotein and transferrin, which are internalized via CME, was reduced in CerS2 null astrocytes, although the rate of caveolin-mediated endocytosis was unaltered. Levels of clathrin heavy chain were increased, which was due to decreased levels of Hsc70 (also known as HSPA8), a protein involved in clathrin uncoating. Hsc70 levels were decreased because of lower levels of binding of Sp1 to position -68 in the Hsc70 promoter. Levels of Sp1 were downregulated due to oxidative stress, which was elevated fourfold in CerS2 null astrocytes. Furthermore, induction of oxidative stress in wild-type astrocytes decreased the rate of CME, whereas amelioration of oxidative stress in CerS2 null astrocytes reversed the decrease. Our data are consistent with the notion that sphingolipids not only change membrane biophysical properties but also that changes in their composition can result in downstream effects that indirectly impinge upon a number of cellular pathways, such as CME.
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Affiliation(s)
- Giora Volpert
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Shifra Ben-Dor
- Department of Biological Services, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ohad Tarcic
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Jingjing Duan
- School of Biology and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0230, USA
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Hospital, Jerusalem 91120, Israel.,The Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Hospital, Jerusalem 91120, Israel
| | - Alfred H Merrill
- School of Biology and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332-0230, USA
| | - Yael Pewzner-Jung
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Anthony H Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
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18
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The Effects of Ascorbate, N-Acetylcysteine, and Resveratrol on Fibroblasts from Patients with Mitochondrial Disorders. J Clin Med 2016; 6:jcm6010001. [PMID: 28025489 PMCID: PMC5294954 DOI: 10.3390/jcm6010001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/11/2016] [Accepted: 12/14/2016] [Indexed: 12/15/2022] Open
Abstract
Reactive oxygen species (ROS) are assumed to be implicated in the pathogenesis of inborn mitochondrial diseases affecting oxidative phosphorylation (OXPHOS). In the current study, we characterized the effects of three small molecules with antioxidant properties (N-acetylcysteine, ascorbate, and resveratrol) on ROS production and several OXPHOS parameters (growth in glucose free medium, ATP production, mitochondrial content and membrane potential (MMP)), in primary fibroblasts derived from seven patients with different molecularly defined and undefined mitochondrial diseases. N-acetylcysteine appeared to be the most beneficial compound, reducing ROS while increasing growth and ATP production in some patients' cells. Ascorbate showed a variable positive or negative effect on ROS, ATP production, and mitochondrial content, while incubation with resveratrol disclosed either no effect or detrimental effect on ATP production and MMP in some cells. The individual responses highlight the importance of investigating multiple parameters in addition to ROS to obtain a more balanced view of the overall effect on OXPHOS when evaluating antioxidant treatment options for mitochondrial diseases.
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Kogot-Levin A, Saada A, Leibowitz G, Soiferman D, Douiev L, Raz I, Weksler-Zangen S. Upregulation of Mitochondrial Content in Cytochrome c Oxidase Deficient Fibroblasts. PLoS One 2016; 11:e0165417. [PMID: 27780242 PMCID: PMC5079646 DOI: 10.1371/journal.pone.0165417] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 10/11/2016] [Indexed: 12/20/2022] Open
Abstract
Cytochrome-c-oxidase (COX) deficiency is a frequent cause of mitochondrial disease and is associated with a wide spectrum of clinical phenotypes. We studied mitochondrial function and biogenesis in fibroblasts derived from the Cohen (CDs) rat, an animal model of COX deficiency. COX activity in CDs-fibroblasts was 50% reduced compared to control rat fibroblasts (P<0.01). ROS-production in CDs fibroblasts increased, along with marked mitochondrial fragmentation and decreased mitochondrial membrane-potential, indicating mitochondrial dysfunction. Surprisingly, cellular ATP content, oxygen consumption rate (OCR) and the extracellular acidification rate (ECAR) were unchanged. To clarify the discrepancy between mitochondrial dysfunction and ATP production, we studied mitochondrial biogenesis and turnover. The content of mitochondria was higher in CDs-fibroblasts. Consistently, AMPK activity and the expression of NRF1-target genes, NRF2 and PGC1-α that mediate mitochondrial biogenesis were increased (P<0.01 vs control fibroblast). In CDs-fibrobalsts, the number of autophagosomes (LC3+ puncta) containing mitochondria in CDs fibroblasts was similar to that in control fibroblasts, suggesting that mitophagy was intact. Altogether, our findings demonstrate that mitochondrial dysfunction and oxidative stress are associated with an increase in mitochondrial biogenesis, resulting in preservation of ATP generation.
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Affiliation(s)
- Aviram Kogot-Levin
- The Diabetes Unit, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research and Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Gil Leibowitz
- The Diabetes Unit, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Devorah Soiferman
- Monique and Jacques Roboh Department of Genetic Research and Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Liza Douiev
- Monique and Jacques Roboh Department of Genetic Research and Department of Genetic and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Itamar Raz
- The Diabetes Unit, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Sarah Weksler-Zangen
- The Diabetes Unit, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
- * E-mail:
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Novel Homozygous Missense Mutation in SPG20 Gene Results in Troyer Syndrome Associated with Mitochondrial Cytochrome c Oxidase Deficiency. JIMD Rep 2016; 33:55-60. [PMID: 27539578 DOI: 10.1007/8904_2016_580] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 07/14/2016] [Accepted: 07/18/2016] [Indexed: 12/13/2022] Open
Abstract
Troyer syndrome is an autosomal recessive form of hereditary spastic paraplegia (HSP) caused by deleterious mutations in the SPG20 gene. Although the disease is associated with a loss of function mechanism of spartin, the protein encoded by SPG20, the precise pathogenesis is yet to be elucidated. Recent data indicated an important role for spartin in both mitochondrial maintenance and function. Here we report a child presenting with progressive spastic paraparesis, generalized muscle weakness, dysarthria, impaired growth, and severe isolated decrease in muscle cytochrome c oxidase (COX) activity. Whole exome sequencing identified the homozygous c.988A>G variant in SPG20 gene (p.Met330Val) resulting in almost complete loss of spartin in skeletal muscle. Further analyses demonstrated significant tissue specific reduction of COX 4, a nuclear encoded subunit of COX, in muscle suggesting a role for spartin in proper mitochondrial respiratory chain function mediated by COX activity. Our findings need to be verified in other Troyer syndrome patients in order to classify it as a form of HSP caused by mitochondrial dysfunction.
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Two transgenic mouse models for β-subunit components of succinate-CoA ligase yielding pleiotropic metabolic alterations. Biochem J 2016; 473:3463-3485. [PMID: 27496549 PMCID: PMC5126846 DOI: 10.1042/bcj20160594] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/05/2016] [Indexed: 12/14/2022]
Abstract
Succinate-CoA ligase (SUCL) is a heterodimer enzyme composed of Suclg1 α-subunit and a substrate-specific Sucla2 or Suclg2 β-subunit yielding ATP or GTP, respectively. In humans, the deficiency of this enzyme leads to encephalomyopathy with or without methylmalonyl aciduria, in addition to resulting in mitochondrial DNA depletion. We generated mice lacking either one Sucla2 or Suclg2 allele. Sucla2 heterozygote mice exhibited tissue- and age-dependent decreases in Sucla2 expression associated with decreases in ATP-forming activity, but rebound increases in cardiac Suclg2 expression and GTP-forming activity. Bioenergetic parameters including substrate-level phosphorylation (SLP) were not different between wild-type and Sucla2 heterozygote mice unless a submaximal pharmacological inhibition of SUCL was concomitantly present. mtDNA contents were moderately decreased, but blood carnitine esters were significantly elevated. Suclg2 heterozygote mice exhibited decreases in Suclg2 expression but no rebound increases in Sucla2 expression or changes in bioenergetic parameters. Surprisingly, deletion of one Suclg2 allele in Sucla2 heterozygote mice still led to a rebound but protracted increase in Suclg2 expression, yielding double heterozygote mice with no alterations in GTP-forming activity or SLP, but more pronounced changes in mtDNA content and blood carnitine esters, and an increase in succinate dehydrogenase activity. We conclude that a partial reduction in Sucla2 elicits rebound increases in Suclg2 expression, which is sufficiently dominant to overcome even a concomitant deletion of one Suclg2 allele, pleiotropically affecting metabolic pathways associated with SUCL. These results as well as the availability of the transgenic mouse colonies will be of value in understanding SUCL deficiency.
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Vainer GW, Saada A, Kania-Almog J, Amartely A, Bar-Tana J, Hertz R. PF-4708671 activates AMPK independently of p70S6K1 inhibition. PLoS One 2014; 9:e107364. [PMID: 25202971 PMCID: PMC4159345 DOI: 10.1371/journal.pone.0107364] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 08/15/2014] [Indexed: 12/31/2022] Open
Abstract
The P70 ribosomal protein S6 kinase 1 (P70S6K1) is activated by the mammalian target of rapamycin (mTORC1) and regulates proliferation, growth, and metabolism. PF-4708671 is a novel, cell-permeable, has been proposed to be a highly specific inhibitor of p70S6K1. It is used in micromolar concentration range to dissect signaling pathways downstream of mTORC1 and to study the function of p70S6K1. Here we show that PF-4708671 induces AMP-activated protein kinase (AMPK) phosphorylation and activation in immortalized mouse embryonic fibroblasts (MEF) independently of p70S6K1, due to specific inhibition of mitochondrial respiratory chain Complex I.
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Affiliation(s)
- Gilad W. Vainer
- Department of Pathology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel
- * E-mail:
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research, and Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | | | - Adir Amartely
- Department of Pathology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Jacob Bar-Tana
- Human Nutrition and Metabolism, Hebrew University Medical School, Jerusalem, Israel
| | - Rachel Hertz
- Human Nutrition and Metabolism, Hebrew University Medical School, Jerusalem, Israel
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Mitochondrial complex IV deficiency, caused by mutated COX6B1, is associated with encephalomyopathy, hydrocephalus and cardiomyopathy. Eur J Hum Genet 2014; 23:159-64. [PMID: 24781756 DOI: 10.1038/ejhg.2014.85] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 03/19/2014] [Accepted: 04/04/2014] [Indexed: 11/08/2022] Open
Abstract
Isolated cytochrome c oxidase (COX) deficiency is a prevalent cause of mitochondrial disease and is mostly caused by nuclear-encoded mutations in assembly factors while rarely by mutations in structural subunits. We hereby report a case of isolated COX deficiency manifesting with encephalomyopathy, hydrocephalus and hypertropic cardiomyopathy due to a missense p.R20C mutation in the COX6B1 gene, which encodes an integral, nuclear-encoded COX subunit. This novel mutation was predicted to be severe in silico. In accord, enzymatic activity was undetectable in muscle and fibroblasts, was severely decreased in lymphocytes and the COX6B1 protein was barely detectable in patient's muscle mitochondria. Complementation with the wild-type cDNA by a lentiviral construct restored COX activity, and mitochondrial function was improved by 5-aminoimidazole-4-carboxamide ribonucleotide, resveratrol and ascorbate in the patient's fibroblasts. We suggest that genetic analysis of COX6B1should be included in the investigation of isolated COX deficiency, including patients with cardiac defects. Initial measurement of COX activity in lymphocytes may be useful as it might circumvent the need for invasive muscle biopsy. The evaluation of ascorbate supplementation to patients with mutated COX6B1 is warranted.
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Weksler-Zangen S, Aharon-Hananel G, Mantzur C, Aouizerat T, Gurgul-Convey E, Raz I, Saada A. IL-1β hampers glucose-stimulated insulin secretion in Cohen diabetic rat islets through mitochondrial cytochrome c oxidase inhibition by nitric oxide. Am J Physiol Endocrinol Metab 2014; 306:E648-57. [PMID: 24425765 DOI: 10.1152/ajpendo.00451.2013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A high-sucrose, low-copper-diet (HSD) induces inhibition of glucose-sensitive rats (CDs) but not Cohen diabetes-resistant rats (CDr). Copper-supplemented HSD increased activity of the copper-dependent mitochondrial respiratory chain enzyme cytochrome c oxidase (COX) and reversed hyperglycemia. This study examined the mechanism by which interleukin-1β modulates GSIS and the role of COX in this process. We measured COX activity, ATP content, GSIS, iNOS expression, and nitrite production with and without IL-1β, N(ω)-nitro-l-arginine, copper, or potassium cyanide in isolated islets of CDs and CDr fed different diets. We found reduced COX activity, ATP content, and GSIS in isolated islets of CDs rats fed a regular diet. These were severely reduced following HSD and were restored to regular diet levels on copper-supplemented HSD (P < 0.01 vs. CDr islets). Potassium cyanide chemically reduced COX activity, decreasing GSIS and thus reinforcing the link between islet COX activity and GSIS. Interleukin-1β (2.5 U/ml) reduced GSIS and COX activity in CDs islets. Exposure to 10 U/ml interleukin-1β decreased GSIS and COX activity in both CDs and CDr islets, inducing a similar nitrite production. Nevertheless, the effect on GSIS was more marked in CDs islets. A significant iNOS expression was detected in CDs on the HSD diet, which was reduced by copper supplementation. N(ω)-nitro-l-arginine and copper prevented the deleterious effect of interleukin-1β on COX activity and GSIS. We conclude that reduced islet COX activity renders vulnerability to GSIS inhibition on low-copper HSD through two interrelated pathways: 1) by further reducing the activity of COX that is essential for β-cell ATP-production and insulin secretion and 2) by inducing the expression of iNOS and nitric oxide-mediated COX inhibition. We suggest that islet COX activity must be maintained above a critical threshold to sustain adequate GSIS with exposure to low-copper HSD.
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Affiliation(s)
- Sarah Weksler-Zangen
- Diabetes Unit, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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25
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Delineation of C12orf65-related phenotypes: a genotype-phenotype relationship. Eur J Hum Genet 2014; 22:1019-25. [PMID: 24424123 DOI: 10.1038/ejhg.2013.284] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 10/13/2013] [Accepted: 11/09/2013] [Indexed: 11/08/2022] Open
Abstract
C12orf65 participates in the process of mitochondrial translation and has been shown to be associated with a spectrum of phenotypes, including early onset optic atrophy, progressive encephalomyopathy, peripheral neuropathy, and spastic paraparesis.We used whole-genome homozygosity mapping as well as exome sequencing and targeted gene sequencing to identify novel C12orf65 disease-causing mutations in seven affected individuals originating from two consanguineous families. In four family members affected with childhood-onset optic atrophy accompanied by slowly progressive peripheral neuropathy and spastic paraparesis, we identified a homozygous frame shift mutation c.413_417 delAACAA, which predicts a truncated protein lacking the C-terminal portion. In the second family, we studied three affected individuals who presented with early onset optic atrophy, peripheral neuropathy, and spastic gait in addition to moderate intellectual disability. Muscle biopsy in two of the patients revealed decreased activities of the mitochondrial respiratory chain complexes I and IV. In these patients, we identified a homozygous splice mutation, g.21043 T>A (c.282+2 T>A) which leads to skipping of exon 2. Our study broadens the phenotypic spectrum of C12orf65 defects and highlights the triad of optic atrophy, axonal neuropathy and spastic paraparesis as its key clinical features. In addition, a clear genotype-phenotype correlation is anticipated in which deleterious mutations which disrupt the GGQ-containing domain in the first coding exon are expected to result in a more severe phenotype, whereas down-stream C-terminal mutations may result in a more favorable phenotype, typically lacking cognitive impairment.
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26
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Spiegel R, Saada A, Halvardson J, Soiferman D, Shaag A, Edvardson S, Horovitz Y, Khayat M, Shalev SA, Feuk L, Elpeleg O. Deleterious mutation in FDX1L gene is associated with a novel mitochondrial muscle myopathy. Eur J Hum Genet 2013; 22:902-6. [PMID: 24281368 DOI: 10.1038/ejhg.2013.269] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 10/04/2013] [Accepted: 10/25/2013] [Indexed: 11/09/2022] Open
Abstract
Isolated metabolic myopathies encompass a heterogeneous group of disorders, with mitochondrial myopathies being a subgroup, with depleted skeletal muscle energy production manifesting either by recurrent episodes of myoglobinuria or progressive muscle weakness. In this study, we investigated the genetic cause of a patient from a consanguineous family who presented with adolescent onset autosomal recessive mitochondrial myopathy. Analysis of enzyme activities of the five respiratory chain complexes in our patients' skeletal muscle showed severely impaired activities of iron sulfur (Fe-S)-dependent complexes I, II and III and mitochondrial aconitase. We employed exome sequencing combined with homozygosity mapping to identify a homozygous mutation, c.1A>T, in the FDX1L gene, which encodes the mitochondrial ferredoxin 2 (Fdx2) protein. The mutation disrupts the ATG initiation translation site resulting in severe reduction of Fdx2 content in the patient muscle and fibroblasts mitochondria. Fdx2 is the second component of the Fe-S cluster biogenesis machinery, the first being IscU that is associated with isolated mitochondrial myopathy. We suggest adding genetic analysis of FDX1L in cases of mitochondrial myopathy especially when associated with reduced activity of the respiratory chain complexes I, II and III.
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Affiliation(s)
- Ronen Spiegel
- 1] Department of Pediatric A', Emek Medical Center, Afula, Rappaport School of Medicine, Technion, Haifa, Israel [2] Genetic Institute, Emek Medical Center, Afula, Rappaport School of Medicine, Technion, Haifa, Israel
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Jonatan Halvardson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory Uppsala, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Devorah Soiferman
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Avraham Shaag
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Simon Edvardson
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
| | - Yoseph Horovitz
- Department of Pediatric A', Emek Medical Center, Afula, Rappaport School of Medicine, Technion, Haifa, Israel
| | - Morad Khayat
- Genetic Institute, Emek Medical Center, Afula, Rappaport School of Medicine, Technion, Haifa, Israel
| | - Stavit A Shalev
- Genetic Institute, Emek Medical Center, Afula, Rappaport School of Medicine, Technion, Haifa, Israel
| | - Lars Feuk
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory Uppsala, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Orly Elpeleg
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, Jerusalem, Israel
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Soiferman D, Ayalon O, Weissman S, Saada A. The effect of small molecules on nuclear-encoded translation diseases. Biochimie 2013; 100:184-91. [PMID: 24012549 DOI: 10.1016/j.biochi.2013.08.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 08/25/2013] [Indexed: 01/18/2023]
Abstract
The five complexes of the mitochondrial respiratory chain (MRC) supply most organs and tissues with ATP produced by oxidative phosphorylation (OXPHOS). Inherited mitochondrial diseases affecting OXPHOS dysfunction are heterogeneous; symptoms may present at any age and may affect a wide range of tissues, with many diseases giving rise to devastating multisystemic disorders resulting in neonatal death. Combined respiratory chain deficiency with normal complex II accounts for a third of all respiratory deficiencies; mutations in nuclear-encoded components of the mitochondrial translation machinery account for many cases. Although mutations have been identified in over 20 such genes and our understanding of the mitochondrial translation apparatus is increasing, to date no definitive cure for these disorders exists. We evaluated the effect of seven small molecules with reported therapeutic potential in fibroblasts of four patients with combined respiratory complex disorders, each harboring a known mutation in a different nuclear-encoded component of the mitochondrial translation machinery: EFTs, GFM1, MRPS22 and TRMU. Six mitochondrial parameters were screened as follows; growth in glucose-free medium, reactive oxygen species (ROS) production, ATP content, mitochondrial content, mitochondrial membrane potential and complex IV activity. It was clearly evident that each patient displayed an individual response and there was no universally beneficial compound. AICAR increased complex IV activity in GFM1 cells and increased ATP content in MRPS22 fibroblasts but was detrimental to TRMU, who benefitted from bezafibrate. Two antioxidants, ascorbate and N-acetylcysteine (NAC), significantly improved cell growth, ATP content and mitochondrial membrane potential and decreased levels of intracellular reactive oxygen species (ROS) in EFTs fibroblasts. This study presents an expanded repertoire of assays that can be performed using the microtiter screening system with a small number of patients' fibroblasts and highlights some therapeutic options while providing additional evidence for the importance of personalized medicine in mitochondrial disorders.
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Affiliation(s)
- Devorah Soiferman
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel; Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Oshrat Ayalon
- Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Sarah Weissman
- Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ann Saada
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel; Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
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Weksler-Zangen S, Jörns A, Tarsi-Chen L, Vernea F, Aharon-Hananel G, Saada A, Lenzen S, Raz I. Dietary copper supplementation restores β-cell function of Cohen diabetic rats: a link between mitochondrial function and glucose-stimulated insulin secretion. Am J Physiol Endocrinol Metab 2013; 304:E1023-34. [PMID: 23512809 DOI: 10.1152/ajpendo.00036.2013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
β-Cell mitochondrial dysfunction as well as proinflammatory cytokines have been suggested to contribute to reduced glucose-stimulated insulin secretion (GSIS) in type 2 diabetes. We recently demonstrated that Cohen diabetic sensitive (CDs) rats fed a high-sucrose, low-copper diet (HSD) developed hyperglycemia and reduced GSIS in association with peri-islet infiltration of fat and interleukin (IL)-1β-expressing macrophages, whereas CD resistant (CDr) rats remained normoglycemic on HSD. We examined: 1) the correlation between copper concentration in the HSD and progression, prevention, and reversion of hyperglycemia in CDs rats, 2) the relationship between activity of the copper-dependent, respiratory-chain enzyme cytochrome c oxidase (COX), infiltration of fat, IL-1β-expressing macrophages, and defective GSIS in hyperglycemic CDs rats. CDs and CDr rats were fed HSD or copper-supplemented HSD before and during hyperglycemia development. Blood glucose and insulin concentrations were measured during glucose tolerance tests. Macrophage infiltration and IL-1β expression were evaluated in pancreatic sections by electron-microscopy and immunostaining. COX activity was measured in pancreatic sections and isolated islets. In CDs rats fed HSD, GSIS and islet COX activity decreased, while blood glucose and infiltration of fat and IL-1β-expressing macrophages increased with time on HSD (P < 0.01 vs. CDr-HSD rats, all parameters, respectively). CDs rats maintained on copper-supplemented HSD did not develop hyperglycemia, and in hyperglycemic CDs rats, copper supplementation restored GSIS and COX activity, reversed hyperglycemia and infiltration of fat and IL-1β-expressing macrophages (P < 0.01 vs. hyperglycemic CDs-HSD rats, all parameters, respectively). We provide novel evidence for a critical role of low dietary copper in diminished GSIS of susceptible CDs rats involving the combined consequence of reduced islet COX activity and pancreatic low-grade inflammation.
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Affiliation(s)
- Sarah Weksler-Zangen
- Diabetes Unit, Hadassah-Hebrew Univ. Medical Center, Jerusalem 12000, Israel 91120.
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29
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Negari SBH, Aouizerat T, Tenenbaum A, Cohen-Cymberknoh M, Shoseyov D, Kerem E, Saada A. Mitochondrial OXPHOS function is unaffected by chronic azithromycin treatment. J Cyst Fibros 2013; 12:682-7. [PMID: 23680642 DOI: 10.1016/j.jcf.2013.04.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 03/11/2013] [Accepted: 04/17/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND Certain antibiotics may cause unwanted side effects due to the similarity of the mitochondrial translation system to the prokaryotic one. Children with cystic fibrosis (CF) are vulnerable to recurrent respiratory tract infections and azithromycin, a translation targeted antibiotic, is often used chronically to treat CF patients. No major clinical side effects were found with chronic treatment. However, mitochondrial function was not previously assessed. We evaluated oxidative phosphorylation (OXPHOS) in lymphocytes from children with CF receiving chronic azithromycin treatment using an improved ATP production assay. METHOD Enzymatic activities of respiratory chain complexes II-IV and ATP production were measured in lymphocytes. RESULTS Relative to controls and to CF patients without azithromycin treatment, no significant difference in mitochondrial respiratory chain complexes II-IV was detected, and ATP production with pyruvate, glutamate and succinate, did not disclose any differences between the groups. CONCLUSION We suggest that chronic treatment with azithromycin does not significantly affect OXPHOS function.
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Affiliation(s)
- Shelly Ben-Harush Negari
- Monique and Jacques Roboh Department of Genetic Research Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem 91120, Israel; Department of Pediatrics Hadassah-Hebrew University Medical Center, Jerusalem Israel; Division of Adolescent Medicine Cincinnati Children's Hospital Medical Center, OH, USA
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30
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Zigdon H, Kogot-Levin A, Park JW, Goldschmidt R, Kelly S, Merrill AH, Scherz A, Pewzner-Jung Y, Saada A, Futerman AH. Ablation of ceramide synthase 2 causes chronic oxidative stress due to disruption of the mitochondrial respiratory chain. J Biol Chem 2013; 288:4947-56. [PMID: 23283968 DOI: 10.1074/jbc.m112.402719] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Ceramide is a key intermediate in the pathway of sphingolipid biosynthesis and is an important intracellular messenger. We recently generated a ceramide synthase 2 (CerS2) null mouse that cannot synthesize very long acyl chain (C22-C24) ceramides. This mouse displays severe and progressive hepatopathy. Significant changes were observed in the sphingolipid profile of CerS2 null mouse liver, including elevated C16-ceramide and sphinganine levels in liver and in isolated mitochondrial fractions. Because ceramide may be involved in reactive oxygen species (ROS) formation, we examined whether ROS generation was affected in CerS2 null mice. Levels of a number of anti-oxidant enzymes were elevated, as were lipid peroxidation, protein nitrosylation, and ROS. ROS were generated from mitochondria due to impaired complex IV activity. C16-ceramide, sphingosine, and sphinganine directly inhibited complex IV activity in isolated mitochondria and in mitoplasts, whereas other ceramide species, sphingomyelin, and diacylglycerol were without effect. A fluorescent analog of sphinganine accumulated in mitochondria. Heart mitochondria did not display a substantial alteration in the sphingolipid profile or in complex IV activity. We suggest that C16-ceramide and/or sphinganine induce ROS formation through the modulation of mitochondrial complex IV activity, resulting in chronic oxidative stress. These results are of relevance for understanding modulation of ROS signaling by sphingolipids.
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Affiliation(s)
- Hila Zigdon
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
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31
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Assayag M, Saada A, Gerstenblith G, Canaana H, Shlomai R, Horowitz M. Mitochondrial performance in heat acclimation--a lesson from ischemia/reperfusion and calcium overload insults in the heart. Am J Physiol Regul Integr Comp Physiol 2012; 303:R870-81. [PMID: 22895744 DOI: 10.1152/ajpregu.00155.2012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Long-term heat acclimation (LTHA; 30 days, 34°C) causes phenotypic adaptations that render protection against ischemic/reperfusion insult (I/R, 30 min global ischemia and 40 min reperfusion) via heat acclimation-mediated cross-tolerance (HACT) mechanisms. Short-term acclimation (STHA, 2 days, 34 °C), in contrast, is characterized by cellular perturbations, leading to increased susceptibility to insults. Here, we tested the hypothesis that enhanced mitochondrial respiratory function is part of the acclimatory repertoire and that the 30-day regimen is required for protection via HACT. We subjected isolated hearts and mitochondria from controls (C), STHA, or LTHA rats to I/R, hypoxia/reoxygenation, or Ca2+ overload insults. Mitochondrial function was assessed by measuring O2 consumption, membrane potential (ΔΨm), mitochondrial Ca2+ ([Ca2+]m), ATP production, respiratory chain complex activities, and molecular markers of mitochondrial biogenesis. Our results, combining physiological and biochemical parameters, confirmed that mitochondria from LTHA rats subjected to insults, in contrast to C, preserve respiratory functions (e.g., upon I/R, C mitochondria fueled by glutamate-malate, demonstrated decreases of 81%, 13%, 25%, and 50% in O2/P ratio, ATP production, ΔΨm, and complex I activity, respectively, whereas the corresponding LTHA parameters remained unchanged). STHA mitochondria maintained ΔΨm but did not preserve ATP production. LTHA [Ca2+]m was significantly higher than that of C and STHA and was not affected by the hypoxia/reoxygenation protocol compared with C. Enhanced mitochondrial biogenesis markers, switched-on during STHA coincidentally with enhanced membrane integrity (ΔΨm), were insufficient to confer intact respiratory function upon insult. LTHA was required for respiratory complex I adaptation and HACT. Stabilized higher basal [Ca2+]m and attenuated Ca2+ overload are likely connected to this adaptation.
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Affiliation(s)
- Miri Assayag
- Laboratory of Environmental Physiology, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
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Fang G, Gao W, Deng Q, Qian K, Han H, Wang S. Highly selective capture of phosphopeptides using a nano titanium dioxide–multiwalled carbon nanotube nanocomposite. Anal Biochem 2012; 423:210-7. [DOI: 10.1016/j.ab.2012.01.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Revised: 01/11/2012] [Accepted: 01/27/2012] [Indexed: 10/14/2022]
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Saada A, Edvardson S, Shaag A, Chung WK, Segel R, Miller C, Jalas C, Elpeleg O. Combined OXPHOS complex I and IV defect, due to mutated complex I assembly factor C20ORF7. J Inherit Metab Dis 2012; 35:125-31. [PMID: 21607760 DOI: 10.1007/s10545-011-9348-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 04/13/2011] [Accepted: 05/04/2011] [Indexed: 12/25/2022]
Abstract
Defects of the mitochondrial oxidative phosphorylation (OXPHOS) system are frequent causes of neurological disorders in children. Linkage analysis and DNA sequencing identified a new founder p.G250V substitution in the C20ORF7 complex I chaperone in five Ashkenazi Jewish patients from two families with a combined OXPHOS complex I and IV defect presenting with Leigh's syndrome in infancy. Complementation with the wild type gene restored complex I, but only partially complex IV activity. Although the pathogenic mechanism remains elusive, a C20ORF7 defect should be considered not only in isolated complex I deficiency, but also in combination with decreased complex IV. Given the significant 1:290 carrier rate for the p.G250V mutation among Ashkenazi Jews, this mutation should be screened in all Ashkenazi patients with Leigh's syndrome prior to muscle biopsy.
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Affiliation(s)
- Ann Saada
- Monique and Jacques Roboh Department of Genetic Research, Hadassah, Hebrew University Medical Center, POB 1200, 91120 Jerusalem, Israel.
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Golubitzky A, Dan P, Weissman S, Link G, Wikstrom JD, Saada A. Screening for active small molecules in mitochondrial complex I deficient patient's fibroblasts, reveals AICAR as the most beneficial compound. PLoS One 2011; 6:e26883. [PMID: 22046392 PMCID: PMC3202581 DOI: 10.1371/journal.pone.0026883] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 10/05/2011] [Indexed: 01/13/2023] Open
Abstract
Congenital deficiency of the mitochondrial respiratory chain complex I (CI) is a common defect of oxidative phosphorylation (OXPHOS). Despite major advances in the biochemical and molecular diagnostics and the deciphering of CI structure, function assembly and pathomechanism, there is currently no satisfactory cure for patients with mitochondrial complex I defects. Small molecules provide one feasible therapeutic option, however their use has not been systematically evaluated using a standardized experimental system. In order to evaluate potentially therapeutic compounds, we set up a relatively simple system measuring different parameters using only a small amount of patient's fibroblasts, in glucose free medium, where growth is highly OXPOS dependent. Ten different compounds were screened using fibroblasts derived from seven CI patients, harboring different mutations. 5-Aminoimidazole-4-carboxamide ribotide (AICAR) was found to be the most beneficial compound improving growth and ATP content while decreasing ROS production. AICAR also increased mitochondrial biogenesis without altering mitochondrial membrane potential (Δψ). Fluorescence microscopy data supported increased mitochondrial biogenesis and activation of the AMP activated protein kinase (AMPK). Other compounds such as; bezafibrate and oltipraz were rated as favorable while polyphenolic phytochemicals (resverastrol, grape seed extract, genistein and epigallocatechin gallate) were found not significant or detrimental. Although the results have to be verified by more thorough investigation of additional OXPHOS parameters, preliminary rapid screening of potential therapeutic compounds in individual patient's fibroblasts could direct and advance personalized medical treatment.
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Affiliation(s)
- Anna Golubitzky
- Monique and Jacques Roboh Department of Genetic Research, Department of Genetics and Metabolic Diseases, Hadassah, Hebrew University Medical Center, Jerusalem, Israel.
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35
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Saada A. The use of individual patient's fibroblasts in the search for personalized treatment of nuclear encoded OXPHOS diseases. Mol Genet Metab 2011; 104:39-47. [PMID: 21835663 DOI: 10.1016/j.ymgme.2011.07.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 07/12/2011] [Accepted: 07/12/2011] [Indexed: 11/19/2022]
Abstract
Mitochondrial diseases, are a prevalent but diverse group of inherited disorders affecting the oxidative phosphorylation (OXPHOS) system. Vast amount of information with respect to pathomechanism and the assembly of the various OXPHOS complexes has been accumulated by studying the different variants of these diseases. Conversely, the investigation of therapeutic strategies has been hampered by this extreme variability. Individual patient's fibroblast may therefore provide a suitable platform in the search for personalized treatments, of nuclear encoded defects, when the phenotype is expressed in multiple tissues. Examples and different approaches in the search for treatment options, while using fibroblasts from patients with nuclear encoded OXPHOS defects as model systems, are summarized and discussed.
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Affiliation(s)
- Ann Saada
- Department of Genetics and Metabolic Diseases and the Monique and Jacques Roboh, Hadassah-Hebrew University Medical Center, POB 1200, 91120 Jerusalem, Israel.
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36
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The effects of antidepressants on mitochondrial function in a model cell system and isolated mitochondria. Neurochem Res 2010; 36:327-38. [PMID: 21120605 DOI: 10.1007/s11064-010-0331-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2010] [Indexed: 12/16/2022]
Abstract
The in vitro effects of antidepressant drugs on mitochondrial function were investigated in a CHOβ(2)SPAP cell line used previously to determine the effects of antidepressants on gene transcription (Abdel-Razaq et al., Biochem Pharmacol 73:1995-2003, 2007) and in rat heart isolated mitochondria. Apoptotic effects of clomipramine (CLOM), desipramine (DMI) and of norfluoxetine (NORF, the active metabolite of fluoxetine), on cellular viability were indicated by morphological changes and concentration-dependent increases in caspase-3 activity in CHO cells after 18 h exposure to CLOM, DMI and NORF. However, tianeptine (TIAN) was without effect. CLOM and NORF both reduced integrated mitochondrial function as shown by marked reductions in membrane potential (MMP) in mitochondria isolated from rat hearts. DMI also showed a similar but smaller effect, whereas, TIAN did not elicit any significant change in MMP. Moreover, micromolar concentrations of CLOM, DMI and NORF caused significant inhibitions of the activities of mitochondrial complexes (I, II/III and IV). The inhibitory effects on complex IV activity were most marked. TIAN inhibited only complex I activity at concentrations in excess of 20 μM. The observed inhibitory effects of antidepressants on the mitochondrial complexes were accompanied by a significant decrease in the mitochondrial state-3 respiration at concentrations above 10 μM. The results demonstrate that the apoptotic cell death observed in antidepressant-treated cells could be due to disruption of mitochondrial function resulting from multiple inhibition of mitochondrial enzyme complexes. The possibility that antimitochondrial actions of antidepressants could provide a potentially protective pre-conditioning effect is discussed.
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Edvardson S, Korman SH, Livne A, Shaag A, Saada A, Nalbandian R, Allouche-Arnon H, Gomori JM, Katz-Brull R. l-arginine:glycine amidinotransferase (AGAT) deficiency: clinical presentation and response to treatment in two patients with a novel mutation. Mol Genet Metab 2010; 101:228-32. [PMID: 20682460 DOI: 10.1016/j.ymgme.2010.06.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 06/29/2010] [Accepted: 06/29/2010] [Indexed: 11/30/2022]
Abstract
Creatine and creatine phosphate provide storage and transmission of phosphate-bound energy in muscle and brain. Of the three inborn errors of creatine metabolism causing brain creatine depletion, l-arginine:glycine amidinotransferase (AGAT) deficiency has been described in only two families. We describe clinical and biochemical features, magnetic resonance spectroscopy (MRS) findings and response to creatine supplementation in two siblings with a novel mutation in the AGAT-encoding GATM gene. The sister and brother were evaluated at age 12 and 18years, respectively, because of mild mental retardation, muscle weakness and low weight. Extensive work-up had previously yielded negative results. Electron microscopy of the muscle revealed tubular aggregates and the activity of respiratory chain complexes was decreased in the muscle. Urine organic acid concentrations normalized to urine creatinine concentration were all increased, suggesting a creatine metabolism disorder. Brain MRS was remarkable for absence of creatine. Urine guanidinoacetate levels by tandem mass spectrometry were low, suggesting AGAT deficiency. GATM sequencing revealed a homozygous single nucleotide insertion 1111_1112insA, producing a frame-shift at Met-371 and premature termination at codon 376. Eleven months after commencing treatment with oral creatine monohydrate 100mg/kg/day, repeat MRI/MRS showed significantly increased brain creatine in the sister and a slight increase in the older brother. The parents' impression of improved strength and stamina was substantiated by increased post-treatment versus pre-treatment scores in the Vineland Adaptive Behavior Scale, straight-arm raising and timed up-and-go tests. Similarly, there was an apparent improvement in cognitive function, with significantly increased IQ-scores in the sister and marginal improvement in the brother.
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Affiliation(s)
- Simon Edvardson
- Pediatric Neurology Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
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38
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Levitas A, Muhammad E, Harel G, Saada A, Caspi VC, Manor E, Beck JC, Sheffield V, Parvari R. Familial neonatal isolated cardiomyopathy caused by a mutation in the flavoprotein subunit of succinate dehydrogenase. Eur J Hum Genet 2010; 18:1160-5. [PMID: 20551992 DOI: 10.1038/ejhg.2010.83] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Cardiomyopathies are common disorders resulting in heart failure; the most frequent form is dilated cardiomyopathy (DCM), which is characterized by dilatation of the left or both ventricles and impaired systolic function. DCM causes considerable morbidity and mortality, and is one of the major causes of sudden cardiac death. Although about one-third of patients are reported to have a genetic form of DCM, reported mutations explain only a minority of familial DCM. Moreover, the recessive neonatal isolated form of DCM has rarely been associated with a mutation. In this study, we present the association of a mutation in the SDHA gene with recessive neonatal isolated DCM in 15 patients of two large consanguineous Bedouin families. The cardiomyopathy is presumably caused by the significant tissue-specific reduction in SDH enzymatic activity in the heart muscle, whereas substantial activity is retained in the skeletal muscle and lymphoblastoid cells. Notably, the same mutation was previously reported to cause a multisystemic failure leading to neonatal death and Leigh's syndrome. This study contributes to the molecular characterization of a severe form of neonatal cardiomyopathy and highlights extreme phenotypic variability resulting from a specific missense mutation in a nuclear gene encoding a protein of the mitochondrial respiratory chain.
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Affiliation(s)
- Aviva Levitas
- Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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39
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Yakunin E, Moser A, Loeb V, Saada A, Faust P, Crane DI, Baes M, Sharon R. alpha-Synuclein abnormalities in mouse models of peroxisome biogenesis disorders. J Neurosci Res 2010; 88:866-76. [PMID: 19830841 DOI: 10.1002/jnr.22246] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
alpha-Synuclein (alphaS) is a presynaptic protein implicated in Parkinson's disease (PD). Growing evidence implicates mitochondrial dysfunction, oxidative stress, and alphaS-lipid interactions in the gradual accumulation of alphaS in pathogenic forms and its deposition in Lewy bodies, the pathological hallmark of PD and related synucleinopathies. The peroxisomal biogenesis disorders (PBD), with Zellweger syndrome serving as the prototype of this group, are characterized by malformed and functionally impaired peroxisomes. Here we utilized the PBD mouse models Pex2-/-, Pex5-/-, and Pex13-/- to study the potential effects of peroxisomal dysfunction on alphaS-related pathogenesis. We found increased alphaS oligomerization and phosphorylation and its increased deposition in cytoplasmic inclusions in these PBD mouse models. Furthermore, we show that alphaS abnormalities correlate with the altered lipid metabolism and, specifically, with accumulation of long chain, n-6 polyunsaturated fatty acids that occurs in the PBD models.
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Affiliation(s)
- Eugenia Yakunin
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research-Israel Canada, Hebrew University, Jerusalem, Israel
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Loeb V, Yakunin E, Saada A, Sharon R. The transgenic overexpression of alpha-synuclein and not its related pathology associates with complex I inhibition. J Biol Chem 2010; 285:7334-43. [PMID: 20053987 DOI: 10.1074/jbc.m109.061051] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Alpha-synuclein (alphaS) is a protein involved in the cytopathology and genetics of Parkinson disease and is thought to affect mitochondrial complex I activity. Previous studies have shown that mitochondrial toxins and specifically inhibitors of complex I activity enhance alphaS pathogenesis. Here we show that alphaS overexpression specifically inhibits complex I activity in dopaminergic cells and in A53T alphaS transgenic mouse brains. Importantly, our results indicate that the inhibitory effect on complex I activity is not associated with alphaS-related pathology. Specifically, complex I activity measured in purified mitochondria from A53T alphaS transgenic mouse brains was not affected by mouse age; Parkinson disease-like symptoms; levels of alphaS soluble oligomers; levels of insoluble, lipid-associated alphaS; or alphaS intraneuronal depositions in vivo. Likewise, no correlation was found between complex I activity and polyunsaturated fatty acid-induced alphaS depositions in Lewy body-like inclusions in cultured dopaminergic cells. We further show that the effect of alphaS on complex I activity is not due to altered mitochondrial protein levels or affected complex I assembly. Based on the results herein, we suggest that alphaS expression negatively regulates complex I activity as part of its normal, physiological role.
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Affiliation(s)
- Virginie Loeb
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research, Israel-Canada, Hebrew University, Jerusalem 91120, Israel
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41
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Belaiche C, Holt A, Saada A. Nonylphenol Ethoxylate Plastic Additives Inhibit Mitochondrial Respiratory Chain Complex I. Clin Chem 2009; 55:1883-4. [DOI: 10.1373/clinchem.2009.130054] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Corinne Belaiche
- Metabolic Disease Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Andrew Holt
- Department of Pharmacology, University of Alberta, Edmonton, Canada
| | - Ann Saada
- Metabolic Disease Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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de Wit LEA, Sluiter W. Chapter 9 Reliable assay for measuring complex I activity in human blood lymphocytes and skin fibroblasts. Methods Enzymol 2009; 456:169-81. [PMID: 19348888 DOI: 10.1016/s0076-6879(08)04409-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
Complex I deficiency is probably the most common enzyme defect among the group of OXPHOS disorders. To evaluate a deficiency of complex I activity, biochemical measurements based on estimation of the mitochondrial rotenone-sensitive NADH: ubiquinone oxidoreductase activity are an important tool. Skeletal muscle is the most widely used tissue to examine complex I deficiency. However, obtaining a muscle biopsy requires an invasive surgical operation. It is much easier to obtain blood lymphocytes or skin fibroblasts, and, moreover, these cells can be expanded in number by standard techniques for extensive research on complex I. On the other hand, each of these cell types has disadvantages that hinder its measurement, such as the apparent low enzyme activity of lymphocytes and the highly contaminating nonmitochondrial NADH-quinone oxidoreductase activity of fibroblasts. This chapter describes a method to assay complex I activity reliably in a minute amount of either cell type.
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Affiliation(s)
- L Elly A de Wit
- Department of Biochemistry, Mitochondrial Research Unit, Erasmus MC, Dr. Molewaterplein 50-60, Rotterdam, The Netherlands
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43
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Saada A, Vogel RO, Hoefs SJ, van den Brand MA, Wessels HJ, Willems PH, Venselaar H, Shaag A, Barghuti F, Reish O, Shohat M, Huynen MA, Smeitink JAM, van den Heuvel LP, Nijtmans LG. Mutations in NDUFAF3 (C3ORF60), encoding an NDUFAF4 (C6ORF66)-interacting complex I assembly protein, cause fatal neonatal mitochondrial disease. Am J Hum Genet 2009; 84:718-27. [PMID: 19463981 DOI: 10.1016/j.ajhg.2009.04.020] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 03/24/2009] [Accepted: 04/27/2009] [Indexed: 11/28/2022] Open
Abstract
Mitochondrial complex I deficiency is the most prevalent and least understood disorder of the oxidative phosphorylation system. The genetic cause of many cases of isolated complex I deficiency is unknown because of insufficient understanding of the complex I assembly process and the factors involved. We performed homozygosity mapping and gene sequencing to identify the genetic defect in five complex I-deficient patients from three different families. All patients harbored mutations in the NDUFAF3 (C3ORF60) gene, of which the pathogenic nature was assessed by NDUFAF3-GFP baculovirus complementation in fibroblasts. We found that NDUFAF3 is a genuine mitochondrial complex I assembly protein that interacts with complex I subunits. Furthermore, we show that NDUFAF3 tightly interacts with NDUFAF4 (C6ORF66), a protein previously implicated in complex I deficiency. Additional gene conservation analysis links NDUFAF3 to bacterial-membrane-insertion gene cluster SecF/SecD/YajC and to C8ORF38, also implicated in complex I deficiency. These data not only show that NDUFAF3 mutations cause complex I deficiency but also relate different complex I disease genes by the close cooperation of their encoded proteins during the assembly process.
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Affiliation(s)
- Ann Saada
- Metabolic Disease Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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Mutated NDUFS6 is the cause of fatal neonatal lactic acidemia in Caucasus Jews. Eur J Hum Genet 2009; 17:1200-3. [PMID: 19259137 DOI: 10.1038/ejhg.2009.24] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
NADH:ubiquinone oxidoreductase (complex I; EC 1.6.5.3), the largest respiratory chain complex is composed of 45 proteins and is located at the mitochondrial inner membrane. Defects in complex I are associated with energy generation disorders, of which the most severe is congenital lactic acidosis. We report on four infants from two unrelated families of Jewish Caucasus origin with fatal neonatal lactic acidemia due to isolated complex I deficiency. Whole genome homozygosity mapping, identified a 2.6 Mb region of identical haplotype in the affected babies. Sequence analysis of the nuclear gene encoding for the NDUFS6 mitochondrial complex I subunit located within this region identified the c.344G>A homozygous mutation resulting in substitution of a highly evolutionary conserved cysteine residue by tyrosine. This is the second report of NDUFS6 mutation in humans. Both reports describe three diverse homozygous mutations with variable consequential NDUFS6 protein defects that result in similar phenotype. Our study further emphasizes that NDUFS6 sequence should be analyzed in patients presenting with lethal neonatal lactic acidemia due to isolated complex I deficiency.
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Barghuti F, Elian K, Gomori JM, Shaag A, Edvardson S, Saada A, Elpeleg O. The unique neuroradiology of complex I deficiency due to NDUFA12L defect. Mol Genet Metab 2008; 94:78-82. [PMID: 18180188 DOI: 10.1016/j.ymgme.2007.11.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Revised: 11/25/2007] [Accepted: 11/25/2007] [Indexed: 11/29/2022]
Abstract
In two patients who presented at late infancy with hypotonia, nystagmus and ataxia, interspersed with acute episodes of encephalopathy, we identified a mutation in a complex I assembly factor, NDUFA12L, which resulted in a marked reduction of the NDUFA12L protein and of complex I activity. The involvement of the mamillothalamic tracts, substantia nigra/medial lemniscus, medial longitudinal fasciculus, the corpus medullare and the cerebellum, with relative sparing of the cortex and subcortical white matter was distinctive and resembled the findings in the first and only known patient with mutation in the NDUFA12L gene.
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Mitochondrial complex III deficiency associated with a homozygous mutation in UQCRQ. Am J Hum Genet 2008; 82:1211-6. [PMID: 18439546 DOI: 10.1016/j.ajhg.2008.03.020] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2007] [Revised: 03/17/2008] [Accepted: 03/31/2008] [Indexed: 11/20/2022] Open
Abstract
A consanguineous Israeli Bedouin kindred presented with an autosomal-recessive nonlethal phenotype of severe psychomotor retardation and extrapyramidal signs, dystonia, athetosis and ataxia, mild axial hypotonia, and marked global dementia with defects in verbal and expressive communication skills. Metabolic workup was normal except for mildly elevated blood lactate levels. Brain magnetic resonance imaging (MRI) showed increased density in the putamen, with decreased density and size of the caudate and lentiform nuclei. Reduced activity specifically of mitochondrial complex III and variable decrease in complex I activity were evident in muscle biopsies. Homozygosity of affected individuals to UQCRB and to BCSIL, previously associated with isolated complex III deficiency, was ruled out. Genome-wide linkage analysis identified a homozygosity locus of approximately 9 cM on chromosome 5q31 that was further narrowed down to 2.14 cM, harboring 30 genes (logarithm of the odds [LOD] score 8.82 at theta = 0). All 30 genes were sequenced, revealing a single missense (p.Ser45Phe) mutation in UQCRQ (encoding ubiquinol-cytochrome c reductase, complex III subunit VII, 9.5 kDa), one of the ten nuclear genes encoding proteins of mitochondrial complex III.
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Berger I, Hershkovitz E, Shaag A, Edvardson S, Saada A, Elpeleg O. Mitochondrial complex I deficiency caused by a deleterious NDUFA11 mutation. Ann Neurol 2008; 63:405-8. [DOI: 10.1002/ana.21332] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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48
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Saada A, Edvardson S, Rapoport M, Shaag A, Amry K, Miller C, Lorberboum-Galski H, Elpeleg O. C6ORF66 is an assembly factor of mitochondrial complex I. Am J Hum Genet 2008; 82:32-8. [PMID: 18179882 DOI: 10.1016/j.ajhg.2007.08.003] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2007] [Revised: 08/15/2007] [Accepted: 08/16/2007] [Indexed: 01/01/2023] Open
Abstract
Homozygosity mapping was performed in five patients from a consanguineous family who presented with infantile mitochondrial encephalomyopathy attributed to isolated NADH:ubiquinone oxidoreductase (complex I) deficiency. This resulted in the identification of a missense mutation in a conserved residue of the C6ORF66 gene, which encodes a 20.2 kDa mitochondrial protein. The mutation was also detected in a patient who presented with antenatal cardiomyopathy. In muscle of two patients, the levels of the C6ORF66 protein and of the fully assembled complex I were markedly reduced. Transfection of the patients' fibroblasts with wild-type C6ORF66 cDNA restored complex I activity. These data suggest that C6ORF66 is an assembly factor of complex I. Interestingly, the C6ORF66 gene product was previously shown to promote breast cancer cell invasiveness.
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Affiliation(s)
- Ann Saada
- Metabolic Disease Unit and, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
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de Wit LEA, Spruijt L, Schoonderwoerd GC, de Coo IFM, Smeets HJM, Scholte HR, Sluiter W. A simplified and reliable assay for complex I in human blood lymphocytes. J Immunol Methods 2007; 326:76-82. [PMID: 17706244 DOI: 10.1016/j.jim.2007.07.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 04/10/2007] [Accepted: 07/11/2007] [Indexed: 11/22/2022]
Abstract
Complex I activity of the mitochondrial respiratory chain is difficult to measure in blood lymphocytes because of the limited access of substrates to the enzyme complex in these cells. The results of the present study show that permeabilization of human blood lymphocytes in the presence of protease inhibitors by three cycles of freeze-thawing enables reproducible detection of the rotenone-sensitive complex I activity. To that end, the water-soluble coenzyme Q(10) analogue CoQ(1) and a relatively high concentration of blood lymphocytes were combined in small quartz cuvettes so that the amount of blood needed for this assay remained low. The relationship between the initial rate of NADH oxidation by complex I and the protein concentration was quasi-linear. The fractional inhibition of the total NADH:CoQ(1) oxidoreductase by a saturating concentration of rotenone decreased sharply at CoQ(1) concentrations higher than 20 muM, which is indicative, but does not prove the involvement of a second CoQ(1) binding site at complex I. Since the present complex I assay requires only a small amount of blood, the functionality of this important respiratory chain complex can be assessed in an easy and reliable manner not only in adult patients but also in children suspected to have a mitochondrial disease.
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Affiliation(s)
- L E A de Wit
- Department of Biochemistry, Mitochondrial Research Unit, Erasmus MC, Rotterdam, The Netherlands
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50
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Mythili Y, Sudharsan PT, Amudha G, Varalakshmi P. Effect of dl-α-lipoic acid on cyclophosphamide induced lysosomal changes in oxidative cardiotoxicity. Life Sci 2007; 80:1993-8. [PMID: 17418239 DOI: 10.1016/j.lfs.2007.02.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 01/31/2007] [Accepted: 02/28/2007] [Indexed: 10/23/2022]
Abstract
Cyclophosphamide (CP), one of the widely prescribed antineoplastic drugs can cause fatal cardiotoxicity. The present study is aimed at evaluating the cardioprotective role of lipoic acid in CP induced toxicity. Male albino rats of Wistar strain were divided into four groups and treated as follows: Group I served as control, Group II received a single dose of CP (200 mg/kg b.wt., i.p.), Group III received lipoic acid (25 mg/kg b.wt., orally) for 10 days, and Group IV received CP immediately followed by lipoic acid for 10 days. In CP administered rats, the levels of protein carbonyl and 8-hydroxy-2-deoxyguanosine were increased significantly (P<0.001) indicating oxidative changes in the heart tissue. The activities of lysosomal acid hydrolases, beta-Glu, beta-Gal, NAG, Cat-D and ACP increased significantly (P<0.001) in the serum as well as in the heart tissue after CP administration. An increase in hydroxyproline was observed in CP induced rats. Lipoic acid effectively reverted these abnormal biochemical changes to near normalcy. These observations highlight the protective role of lipoic acid in CP induced cardiotoxicity.
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Affiliation(s)
- Y Mythili
- Department of Medical Biochemistry, Dr. ALM. Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai - 600 113, India
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