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Yu W, Lin M, Peng M, Yan H, Wang J, Zhou J, Lu G, Wang Z, Shim WB. Fusarium verticillioides FvPex8 Is a Key Component of the Peroxisomal Docking/Translocation Module That Serves Important Roles in Fumonisin Biosynthesis but Not in Virulence. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:803-814. [PMID: 33749306 DOI: 10.1094/mpmi-10-20-0273-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Peroxisomes are ubiquitous organelles in eukaryotes that fulfill various important metabolic functions. In this study, we investigated the role of docking/translocation module (DTM) peroxins, mainly FvPex8, FvPex13, FvPex14, and FvPex33, in Fusarium verticillioides development, virulence, and fumonisin B1 (FB1) biosynthesis. Protein interaction experiments suggested that FvPex13 serves as the central DTM subunit in F. verticillioides. Notably, FvPex8 and FvPex14 did not show direct interaction in our experiments. We generated gene-deletion mutants (ΔFvpex8, ΔFvpex13, ΔFvpex14, ΔFvpex33, ΔFvpex33/14) and further examined the functional role of these peroxins. Deletion mutants exhibited disparity in carbon nutrient utilization and defect in cell-wall integrity when stress agents were applied. Under nutrient starvation, mutants also showed higher levels of lipid droplet accumulation. Particularly, ΔFvpex8 mutant showed significant FB1 reduction and altered expression of key FB1 biosynthesis genes. However, FvPex13 was primarily responsible for asexual conidia reproduction and virulence, while the ΔFvpex33/14 double mutant also showed a virulence defect. In summary, our study suggests that FvPex13 is the central component of DTM, with direct physical interaction with other DTM peroxins, and regulates peroxisome membrane biogenesis as well as PTS1- and PTS2-mediated transmembrane cargo transportation. Importantly, we also characterized FvPex8 as a key component in F. verticillioides DTM that affects peroxisome function and FB1 biosynthesis.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Wenying Yu
- Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Mei Lin
- Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Minghui Peng
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Huijuan Yan
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843-2132, U.S.A
| | - Jiajia Wang
- Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jie Zhou
- Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Fujian Universities Key Laboratory for Plant-Microbe Interaction, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Guodong Lu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zonghua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Won Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843-2132, U.S.A
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Okechukwu PN, Ekeuku SO, Chan HK, Eluri K, Froemming GRA. Palmatine Inhibits Up-Regulation of GRP78 and CALR Protein in an STZ-Induced Diabetic Rat Model. Curr Pharm Biotechnol 2021; 22:288-298. [PMID: 32744968 DOI: 10.2174/1389201021666200730124208] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/22/2020] [Accepted: 06/19/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Diabetes Mellitus (DM) is characterized by hyperglycemia (high blood glucose levels) which is due to the destruction of insulin-producing β-cells in the islets of Langerhans in the pancreas. It is associated with oxidative and endoplasmic reticulum stress. The plant alkaloid Palmatine has been previously reported to possess antidiabetic and antioxidant properties as well as other protective properties against kidney and liver tissue damage. OBJECTIVE Here, we investigated the ability of Palmatine to reduce the up-regulation of chaperone proteins Glucose Regulatory Protein 78 (GRP78), and Calreticulin (CALR) protein in a Streptozotocin (STZ)-induced diabetic rat model. METHODS Streptozotocin (STZ) induced diabetes in Sprague Dawley rats treated with 2mg/kg of Palmatine for 12 weeks after the elevation of plasma glucose levels above 11mmol/L post-STZ administration. Proteins were extracted from the pancreas after treatment and Two-Dimensional gel electrophoresis (2-DE), PDQuest 2-D analysis software genomic solutions and mass spectrometer were used to analyze differentially expressed protein. Mass Spectrometry (MS/MS), Multidimensional Protein Identification Technology (MudPIT) was used for protein identification. RESULTS There was an up-regulation of the expression of chaperone proteins CALR and GRP78 and down-regulation of the expression of antioxidant and protection proteins peroxidoxin 4 (Prdx4), protein disulfide isomerase (PDIA2/3), Glutathione-S-Transferase (GSTs), and Serum Albumin (ALB) in non-diabetic rats. Palmatine treatment down-regulated the expression of chaperone proteins CALR and GRP78 and up-regulated the expression of Prdx4, PDIA2/3, GST, and ALB. CONCLUSION Palmatine may have activated antioxidant proteins, which protected the cells against reactive oxygen species and endoplasmic stress. The result is in consonance with our previous report on Palmatine.
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Affiliation(s)
- Patrick N Okechukwu
- Department of Biotechnology, Faculty of Applied Science UCSI University No. 1, Jalan Menara Gading, UCSI Heights, (Taman Connaught) Cheras 56000 Kuala Lumpur, Malaysia
| | - Sophia O Ekeuku
- Department of Biotechnology, Faculty of Applied Science UCSI University No. 1, Jalan Menara Gading, UCSI Heights, (Taman Connaught) Cheras 56000 Kuala Lumpur, Malaysia
| | - Hor K Chan
- Department of Biotechnology, Faculty of Applied Science UCSI University No. 1, Jalan Menara Gading, UCSI Heights, (Taman Connaught) Cheras 56000 Kuala Lumpur, Malaysia
| | - Kalpana Eluri
- Department of Medicine, Faculty of Medicine and Health Sciences, UCSI University Kuala Lumpur Campus, No. 1, Jalan Meara Gading, UCSI Heights, Cheras, 56000 Kuala Lumpur, Malaysia
| | - Gabriele R A Froemming
- Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak, Jalan Datuk Mohammad Musa, 94300 Kota Samarahan, Sarawak, Malaysia
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3
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Stradomska TJ, Syczewska M, Jamroz E, Pleskaczyńska A, Kruczek P, Ciara E, Tylki-Szymanska A. Serum very long-chain fatty acids (VLCFA) levels as predictive biomarkers of diseases severity and probability of survival in peroxisomal disorders. PLoS One 2020; 15:e0238796. [PMID: 32946460 PMCID: PMC7500652 DOI: 10.1371/journal.pone.0238796] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 08/24/2020] [Indexed: 12/03/2022] Open
Abstract
Peroxisomal disorders (PD) are a heterogeneous group of rare diseases caused by a defect in peroxisome biogenesis or a disruption of a peroxisomal function at a single enzyme or at transporter level. The main biochemical markers for PD are very long-chain fatty acids (VLCFA). The aim of the study was to investigate the correlation of basic diagnostic parameter, i.e. VLCFA, with disease severity, determined through the survival time. We performed a retrospective study in patients with PD (n = 31; aged 1 week—21 years). Evaluation of VLCFA results from patients were as follows: 15 patients with classical Zellweger syndrome (ZS), 3 patients with mild outcome of ZS, 9 individuals with D-Bifunctional Protein Deficiency (DBP), and no specified results in the case of 4 patients. Patients with classical ZS had higher VLCFA levels, compared to individuals with mild form of ZS and also to patients with DBP; for C26:0/C22:0: 0.65±0.18; 0.11±0.09; 0.30±0.13 (P < 0.001) and for C26:0: 5.20±1.78; 0.76±0.46; 2.61±0.97[mg/mL] (P < 0.001) respectively. The only variable parameter, i.e. the one that determines the survival time of patients, was C26:0 (Chi2 = 19,311, P < 0.0001). Correlation coefficient between survival time and C26:0 level was statistically significant (r = -0.762), and the results showed that high levels of C26:0 were associated with short survival time.
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Affiliation(s)
- Teresa Joanna Stradomska
- Department of Biochemistry, Radioimmunology & Experimental Medicine, Children’s Memorial Health Institute, Warsaw, Poland
- * E-mail:
| | - Małgorzata Syczewska
- Department of Pediatrics Rehabilitation, Children’s Memorial Health Institute, Warsaw, Poland
| | - Ewa Jamroz
- Department of Pediatric and Neurology of Developmental Age, Clinical Hospital No. 6 of Medical University of Silesia, Katowice, Poland
| | - Agata Pleskaczyńska
- Department of Neonatology, Pathology and Neonatal Intensive Care Unit, Children’s Memorial Health Institute, Warsaw, Poland
| | - Piotr Kruczek
- Department of Neonatal Pathology and Intensive Care Unit, University Children’s Hospital of Cracow, Cracow, Poland
| | - Elżbieta Ciara
- Department of Medical Genetics, Children’s Memorial Health Institute, Warsaw, Poland
| | - Anna Tylki-Szymanska
- Department of Pediatrics, Nutrition and Metabolic Disease, Children’s Memorial Health Institute, Warsaw, Poland
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4
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Peruzzo R, Costa R, Bachmann M, Leanza L, Szabò I. Mitochondrial Metabolism, Contact Sites and Cellular Calcium Signaling: Implications for Tumorigenesis. Cancers (Basel) 2020; 12:E2574. [PMID: 32927611 PMCID: PMC7564994 DOI: 10.3390/cancers12092574] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 09/01/2020] [Accepted: 09/07/2020] [Indexed: 12/11/2022] Open
Abstract
Mitochondria are organelles that are mainly involved in the generation of ATP by cellular respiration. In addition, they modulate several intracellular functions, ranging from cell proliferation and differentiation to cell death. Importantly, mitochondria are social and can interact with other organelles, such as the Endoplasmic Reticulum, lysosomes and peroxisomes. This symbiotic relationship gives advantages to both partners in regulating some of their functions related to several aspects of cell survival, metabolism, sensitivity to cell death and metastasis, which can all finally contribute to tumorigenesis. Moreover, growing evidence indicates that modulation of the length and/or numbers of these contacts, as well as of the distance between the two engaged organelles, impacts both on their function as well as on cellular signaling. In this review, we discuss recent advances in the field of contacts and communication between mitochondria and other intracellular organelles, focusing on how the tuning of mitochondrial function might impact on both the interaction with other organelles as well as on intracellular signaling in cancer development and progression, with a special focus on calcium signaling.
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Affiliation(s)
| | | | | | - Luigi Leanza
- Department of Biology, University of Padova, 35131 Padova, Italy; (R.P.); (R.C.); (M.B.); (I.S.)
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5
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Staying in Healthy Contact: How Peroxisomes Interact with Other Cell Organelles. Trends Mol Med 2019; 26:201-214. [PMID: 31727543 DOI: 10.1016/j.molmed.2019.09.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/24/2019] [Accepted: 09/24/2019] [Indexed: 11/24/2022]
Abstract
Peroxisomes share extensive metabolic connections with other cell organelles. Membrane contact sites (MCSs) establish and maintain such interactions, and they are vital for organelle positioning and motility. In the past few years peroxisome interactions and MCSs with other cellular organelles have been explored extensively, resulting in the identification of new MCSs, the tethering molecules involved, and their functional characterization. Defective tethering and compartmental communication can lead to pathological conditions that can be termed 'organelle interaction diseases'. We review peroxisome-organelle interactions in mammals and summarize the most recent knowledge of mammalian peroxisomal organelle contacts in health and disease.
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6
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Xia M, Zhang Y, Jin K, Lu Z, Zeng Z, Xiong W. Communication between mitochondria and other organelles: a brand-new perspective on mitochondria in cancer. Cell Biosci 2019; 9:27. [PMID: 30931098 PMCID: PMC6425566 DOI: 10.1186/s13578-019-0289-8] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/09/2019] [Indexed: 12/24/2022] Open
Abstract
Mitochondria are energy factories of cells and are important pivots for intracellular interactions with other organelles. They interact with the endoplasmic reticulum, peroxisomes, and nucleus through signal transduction, vesicle transport, and membrane contact sites to regulate energy metabolism, biosynthesis, immune response, and cell turnover. However, when the communication between organelles fails and the mitochondria are dysfunctional, it may induce tumorigenesis. In this review, we elaborate on how mitochondria interact with the endoplasmic reticulum, peroxisomes, and cell nuclei, as well as the relation between organelle communication and tumor development .
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Affiliation(s)
- MengFang Xia
- 1NHC Key Laboratory of Carcinogenesis, Xiangya Hospital, Central South University, Changsha, Hunan China.,2The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan China.,3Hunan Key Laboratory of Non Resolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan China
| | - YaZhuo Zhang
- 1NHC Key Laboratory of Carcinogenesis, Xiangya Hospital, Central South University, Changsha, Hunan China.,2The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan China.,3Hunan Key Laboratory of Non Resolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan China
| | - Ke Jin
- 2The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan China
| | - ZiTong Lu
- 2The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan China
| | - Zhaoyang Zeng
- 1NHC Key Laboratory of Carcinogenesis, Xiangya Hospital, Central South University, Changsha, Hunan China.,2The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan China.,3Hunan Key Laboratory of Non Resolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan China
| | - Wei Xiong
- 1NHC Key Laboratory of Carcinogenesis, Xiangya Hospital, Central South University, Changsha, Hunan China.,2The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan China.,3Hunan Key Laboratory of Non Resolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan China
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7
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Diogo CV, Yambire KF, Fernández Mosquera L, Branco F T, Raimundo N. Mitochondrial adventures at the organelle society. Biochem Biophys Res Commun 2018; 500:87-93. [PMID: 28456629 PMCID: PMC5930832 DOI: 10.1016/j.bbrc.2017.04.124] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Accepted: 04/23/2017] [Indexed: 01/16/2023]
Abstract
Mitochondria are constantly communicating with the rest of the cell. Defects in mitochondria underlie severe pathologies, whose mechanisms remain poorly understood. It is becoming increasingly evident that mitochondrial malfunction resonates in other organelles, perturbing their function and their biogenesis. In this manuscript, we review the current knowledge on the cross-talk between mitochondria and other organelles, particularly lysosomes, peroxisomes and the endoplasmic reticulum. Several organelle interactions are mediated by transcriptional programs, and other signaling mechanisms are likely mediating organelle dysfunction downstream of mitochondrial impairments. Many of these organelle crosstalk pathways are likely to have a role in pathological processes.
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Affiliation(s)
- Cátia V Diogo
- Universitätsmedizin Göttingen, Institute fur Zellbiochemie, Humboldtallee 23, room 01.423, 37073 Göttingen, Germany
| | - King Faisal Yambire
- Universitätsmedizin Göttingen, Institute fur Zellbiochemie, Humboldtallee 23, room 01.423, 37073 Göttingen, Germany; International Max-Planck Research School in Neuroscience, Göttingen, Germany
| | - Lorena Fernández Mosquera
- Universitätsmedizin Göttingen, Institute fur Zellbiochemie, Humboldtallee 23, room 01.423, 37073 Göttingen, Germany
| | - Tiago Branco F
- Universitätsmedizin Göttingen, Institute fur Zellbiochemie, Humboldtallee 23, room 01.423, 37073 Göttingen, Germany
| | - Nuno Raimundo
- Universitätsmedizin Göttingen, Institute fur Zellbiochemie, Humboldtallee 23, room 01.423, 37073 Göttingen, Germany.
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8
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Soliman K, Göttfert F, Rosewich H, Thoms S, Gärtner J. Super-resolution imaging reveals the sub-diffraction phenotype of Zellweger Syndrome ghosts and wild-type peroxisomes. Sci Rep 2018; 8:7809. [PMID: 29773809 PMCID: PMC5958128 DOI: 10.1038/s41598-018-24119-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 03/22/2018] [Indexed: 11/12/2022] Open
Abstract
Peroxisomes are ubiquitous cell organelles involved in many metabolic and signaling functions. Their assembly requires peroxins, encoded by PEX genes. Mutations in PEX genes are the cause of Zellweger Syndrome spectrum (ZSS), a heterogeneous group of peroxisomal biogenesis disorders (PBD). The size and morphological features of peroxisomes are below the diffraction limit of light, which makes them attractive for super-resolution imaging. We applied Stimulated Emission Depletion (STED) microscopy to study the morphology of human peroxisomes and peroxisomal protein localization in human controls and ZSS patients. We defined the peroxisome morphology in healthy skin fibroblasts and the sub-diffraction phenotype of residual peroxisomal structures (‘ghosts’) in ZSS patients that revealed a relation between mutation severity and clinical phenotype. Further, we investigated the 70 kDa peroxisomal membrane protein (PMP70) abundance in relationship to the ZSS sub-diffraction phenotype. This work improves the morphological definition of peroxisomes. It expands current knowledge about peroxisome biogenesis and ZSS pathoethiology to the sub-diffraction phenotype including key peroxins and the characteristics of ghost peroxisomes.
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Affiliation(s)
- Kareem Soliman
- Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Georg August University Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany.,Optical Nanoscopy, Laser-Laboratorium Göttingen e.V., 37077, Göttingen, Germany
| | - Fabian Göttfert
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany
| | - Hendrik Rosewich
- Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Georg August University Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany
| | - Sven Thoms
- Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Georg August University Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany.
| | - Jutta Gärtner
- Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, Georg August University Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany
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9
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Bülow MH, Wingen C, Senyilmaz D, Gosejacob D, Sociale M, Bauer R, Schulze H, Sandhoff K, Teleman AA, Hoch M, Sellin J. Unbalanced lipolysis results in lipotoxicity and mitochondrial damage in peroxisome-deficient Pex19 mutants. Mol Biol Cell 2017; 29:396-407. [PMID: 29282281 PMCID: PMC6014165 DOI: 10.1091/mbc.e17-08-0535] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/11/2017] [Accepted: 12/13/2017] [Indexed: 01/01/2023] Open
Abstract
Peroxisomal dysfunction is often associated with mitochondrial abnormalities for unknown reasons. We found that peroxisomal loss upon Pex19 mutation in Drosophila results in Hnf4 hyperactivation with free fatty acid accumulation and mitochondrial damage as a consequence. Genetic reduction of Hnf4 in Pex19 mutants improves all phenotypes, including lethality. Inherited peroxisomal biogenesis disorders (PBDs) are characterized by the absence of functional peroxisomes. They are caused by mutations of peroxisomal biogenesis factors encoded by Pex genes, and result in childhood lethality. Owing to the many metabolic functions fulfilled by peroxisomes, PBD pathology is complex and incompletely understood. Besides accumulation of peroxisomal educts (like very-long-chain fatty acids [VLCFAs] or branched-chain fatty acids) and lack of products (like bile acids or plasmalogens), many peroxisomal defects lead to detrimental mitochondrial abnormalities for unknown reasons. We generated Pex19 Drosophila mutants, which recapitulate the hallmarks of PBDs, like absence of peroxisomes, reduced viability, neurodegeneration, mitochondrial abnormalities, and accumulation of VLCFAs. We present a model of hepatocyte nuclear factor 4 (Hnf4)-induced lipotoxicity and accumulation of free fatty acids as the cause for mitochondrial damage in consequence of peroxisome loss in Pex19 mutants. Hyperactive Hnf4 signaling leads to up-regulation of lipase 3 and enzymes for mitochondrial β-oxidation. This results in enhanced lipolysis, elevated concentrations of free fatty acids, maximal β-oxidation, and mitochondrial abnormalities. Increased acid lipase expression and accumulation of free fatty acids are also present in a Pex19-deficient patient skin fibroblast line, suggesting the conservation of key aspects of our findings.
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Affiliation(s)
- Margret H Bülow
- Department of Molecular Developmental Biology, Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany
| | - Christian Wingen
- Department of Molecular Developmental Biology, Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany
| | - Deniz Senyilmaz
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Dominic Gosejacob
- Department of Molecular Developmental Biology, Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany
| | - Mariangela Sociale
- Department of Molecular Developmental Biology, Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany
| | - Reinhard Bauer
- Department of Molecular Developmental Biology, Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany
| | - Heike Schulze
- Department of Membrane Biology & Lipid Biochemistry, Life & Medical Sciences Institute (LIMES), Kekulé Institute of Organic Chemistry and Biochemistry, University of Bonn, 53121 Bonn, Germany
| | - Konrad Sandhoff
- Department of Membrane Biology & Lipid Biochemistry, Life & Medical Sciences Institute (LIMES), Kekulé Institute of Organic Chemistry and Biochemistry, University of Bonn, 53121 Bonn, Germany
| | - Aurelio A Teleman
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Michael Hoch
- Department of Molecular Developmental Biology, Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany
| | - Julia Sellin
- Department of Molecular Developmental Biology, Life & Medical Sciences Institute (LIMES), University of Bonn, 53115 Bonn, Germany
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10
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Abstract
Recently, the group of McBride reported a stunning observation regarding peroxisome biogenesis: newly born peroxisomes are hybrids of mitochondrial and ER-derived pre-peroxisomes. What was stunning? Studies performed with the yeast Saccharomyces cerevisiae had convincingly shown that peroxisomes are ER-derived, without indications for mitochondrial involvement. However, the recent finding using fibroblasts dovetails nicely with a mechanism inferred to be driving the eukaryotic invention of peroxisomes: reduction of mitochondrial reactive oxygen species (ROS) generation associated with fatty acid (FA) oxidation. This not only explains the mitochondrial involvement, but also its apparent absence in yeast. The latest results allow a reconstruction of the evolution of the yeast's highly derived metabolism and its limitations as a model organism in this instance. As I review here, peroxisomes are eukaryotic inventions reflecting mutual host endosymbiont adaptations: this is predicted by symbiogenetic theory, which states that the defining eukaryotic characteristics evolved as a result of mutual adaptations of two merging prokaryotes.
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Affiliation(s)
- Dave Speijer
- Medical Biochemistry, Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands
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11
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Being right on Q: shaping eukaryotic evolution. Biochem J 2017; 473:4103-4127. [PMID: 27834740 PMCID: PMC5103874 DOI: 10.1042/bcj20160647] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 08/18/2016] [Accepted: 08/31/2016] [Indexed: 12/11/2022]
Abstract
Reactive oxygen species (ROS) formation by mitochondria is an incompletely understood eukaryotic process. I proposed a kinetic model [BioEssays (2011) 33, 88–94] in which the ratio between electrons entering the respiratory chain via FADH2 or NADH (the F/N ratio) is a crucial determinant of ROS formation. During glucose breakdown, the ratio is low, while during fatty acid breakdown, the ratio is high (the longer the fatty acid, the higher is the ratio), leading to higher ROS levels. Thus, breakdown of (very-long-chain) fatty acids should occur without generating extra FADH2 in mitochondria. This explains peroxisome evolution. A potential ROS increase could also explain the absence of fatty acid oxidation in long-lived cells (neurons) as well as other eukaryotic adaptations, such as dynamic supercomplex formation. Effective combinations of metabolic pathways from the host and the endosymbiont (mitochondrion) allowed larger varieties of substrates (with different F/N ratios) to be oxidized, but high F/N ratios increase ROS formation. This might have led to carnitine shuttles, uncoupling proteins, and multiple antioxidant mechanisms, especially linked to fatty acid oxidation [BioEssays (2014) 36, 634–643]. Recent data regarding peroxisome evolution and their relationships with mitochondria, ROS formation by Complex I during ischaemia/reperfusion injury, and supercomplex formation adjustment to F/N ratios strongly support the model. I will further discuss the model in the light of experimental findings regarding mitochondrial ROS formation.
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12
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Hung V, Lam SS, Udeshi ND, Svinkina T, Guzman G, Mootha VK, Carr SA, Ting AY. Proteomic mapping of cytosol-facing outer mitochondrial and ER membranes in living human cells by proximity biotinylation. eLife 2017; 6:24463. [PMID: 28441135 PMCID: PMC5404927 DOI: 10.7554/elife.24463] [Citation(s) in RCA: 240] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/14/2017] [Indexed: 12/24/2022] Open
Abstract
The cytosol-facing membranes of cellular organelles contain proteins that enable signal transduction, regulation of morphology and trafficking, protein import and export, and other specialized processes. Discovery of these proteins by traditional biochemical fractionation can be plagued with contaminants and loss of key components. Using peroxidase-mediated proximity biotinylation, we captured and identified endogenous proteins on the outer mitochondrial membrane (OMM) and endoplasmic reticulum membrane (ERM) of living human fibroblasts. The proteomes of 137 and 634 proteins, respectively, are highly specific and highlight 94 potentially novel mitochondrial or ER proteins. Dataset intersection identified protein candidates potentially localized to mitochondria-ER contact sites. We found that one candidate, the tail-anchored, PDZ-domain-containing OMM protein SYNJ2BP, dramatically increases mitochondrial contacts with rough ER when overexpressed. Immunoprecipitation-mass spectrometry identified ribosome-binding protein 1 (RRBP1) as SYNJ2BP's ERM binding partner. Our results highlight the power of proximity biotinylation to yield insights into the molecular composition and function of intracellular membranes.
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Affiliation(s)
- Victoria Hung
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, United States
| | - Stephanie S Lam
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, United States
| | | | - Tanya Svinkina
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Gaelen Guzman
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Vamsi K Mootha
- Broad Institute of MIT and Harvard, Cambridge, United States.,Department of Molecular Biology, Howard Hughes Medical Institute, Massachusetts General Hospital, Harvard Medical School, Boston, United States
| | - Steven A Carr
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Alice Y Ting
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
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Yofe I, Soliman K, Chuartzman SG, Morgan B, Weill U, Yifrach E, Dick TP, Cooper SJ, Ejsing CS, Schuldiner M, Zalckvar E, Thoms S. Pex35 is a regulator of peroxisome abundance. J Cell Sci 2017; 130:791-804. [PMID: 28049721 DOI: 10.1242/jcs.187914] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 11/24/2016] [Indexed: 12/12/2022] Open
Abstract
Peroxisomes are cellular organelles with vital functions in lipid, amino acid and redox metabolism. The cellular formation and dynamics of peroxisomes are governed by PEX genes; however, the regulation of peroxisome abundance is still poorly understood. Here, we use a high-content microscopy screen in Saccharomyces cerevisiae to identify new regulators of peroxisome size and abundance. Our screen led to the identification of a previously uncharacterized gene, which we term PEX35, which affects peroxisome abundance. PEX35 encodes a peroxisomal membrane protein, a remote homolog to several curvature-generating human proteins. We systematically characterized the genetic and physical interactome as well as the metabolome of mutants in PEX35, and we found that Pex35 functionally interacts with the vesicle-budding-inducer Arf1. Our results highlight the functional interaction between peroxisomes and the secretory pathway.
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Affiliation(s)
- Ido Yofe
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Kareem Soliman
- Department of Child and Adolescent Health, University Medical Center, Göttingen 37075, Germany
| | - Silvia G Chuartzman
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Bruce Morgan
- Department of Cellular Biochemistry, University of Kaiserslautern, Kaiserslautern 67653, Germany.,Division of Redox Regulation, ZMBH-DKFZ Alliance, German Cancer Research Center (DKFZ), Heidelberg 69121, Germany
| | - Uri Weill
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Eden Yifrach
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Tobias P Dick
- Division of Redox Regulation, ZMBH-DKFZ Alliance, German Cancer Research Center (DKFZ), Heidelberg 69121, Germany
| | - Sara J Cooper
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Christer S Ejsing
- Department of Biochemistry and Molecular Biology, VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Odense 5230, Denmark
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Einat Zalckvar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sven Thoms
- Department of Child and Adolescent Health, University Medical Center, Göttingen 37075, Germany
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14
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Costa A, Frezza C. Metabolic Reprogramming and Oncogenesis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 332:213-231. [DOI: 10.1016/bs.ircmb.2017.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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15
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Targeting and insertion of peroxisomal membrane proteins: ER trafficking versus direct delivery to peroxisomes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:870-80. [PMID: 26392202 DOI: 10.1016/j.bbamcr.2015.09.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 09/11/2015] [Accepted: 09/16/2015] [Indexed: 12/11/2022]
Abstract
The importance of peroxisomes is highlighted by severe inherited human disorders linked to impaired peroxisomal biogenesis. Besides the simple architecture of these ubiquitous and dynamic organelles, their biogenesis is surprisingly complex and involves specialized proteins, termed peroxins, which mediate targeting and insertion of peroxisomal membrane proteins (PMPs) into the peroxisomal bilayer, and the import of soluble proteins into the protein-dense matrix of the organelle. The long-standing paradigm that all peroxisomal proteins are imported directly into preexisting peroxisomes has been challenged by the detection of PMPs inside the endoplasmic reticulum (ER). New models propose that the ER originates peroxisomal biogenesis by mediating PMP trafficking to the peroxisomes via budding vesicles. However, the relative contribution of this ER-derived pathway to the total peroxisome population in vivo, and the detailed mechanisms of ER entry and exit of PMPs are controversially discussed. This review aims to summarize present knowledge about how PMPs are targeted to the ER, instead of being inserted directly into preexisting peroxisomes. Moreover, molecular mechanisms that facilitate bilayer insertion of PMPs among different species are discussed.
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16
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Kasote DM, Katyare SS, Hegde MV, Bae H. Significance of antioxidant potential of plants and its relevance to therapeutic applications. Int J Biol Sci 2015; 11:982-91. [PMID: 26157352 PMCID: PMC4495415 DOI: 10.7150/ijbs.12096] [Citation(s) in RCA: 388] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/17/2015] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress has been identified as the root cause of the development and progression of several diseases. Supplementation of exogenous antioxidants or boosting endogenous antioxidant defenses of the body is a promising way of combating the undesirable effects of reactive oxygen species (ROS) induced oxidative damage. Plants have an innate ability to biosynthesize a wide range of non-enzymatic antioxidants capable of attenuating ROS- induced oxidative damage. Several in vitro methods have been used to screen plants for their antioxidant potential, and in most of these assays they revealed potent antioxidant activity. However, prior to confirming their in vivo therapeutic efficacy, plant antioxidants have to pass through several physiopharmacological processes. Consequently, the findings of in vitro and in vivo antioxidant potential assessment studies are not always the same. Nevertheless, the results of in vitro assays have been irrelevantly extrapolated to the therapeutic application of plant antioxidants without undertaking sufficient in vivo studies. Therefore, we have briefly reviewed the physiology and redox biology of both plants and humans to improve our understanding of plant antioxidants as therapeutic entities. The applications and limitations of antioxidant activity measurement assays were also highlighted to identify the precise path to be followed for future research in the area of plant antioxidants.
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Affiliation(s)
- Deepak M. Kasote
- 1. School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 712-749, Republic of Korea
| | - Surendra S. Katyare
- 2. Center for Innovation in Nutrition Health Diseases, IRSHA, Medical College Campus, Pune, Maharashtra, India
| | - Mahabaleshwar V. Hegde
- 2. Center for Innovation in Nutrition Health Diseases, IRSHA, Medical College Campus, Pune, Maharashtra, India
| | - Hanhong Bae
- 1. School of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 712-749, Republic of Korea
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17
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Oxidative Stress during the Progression of β-Amyloid Pathology in the Neocortex of the Tg2576 Mouse Model of Alzheimer's Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:967203. [PMID: 25973140 PMCID: PMC4418010 DOI: 10.1155/2015/967203] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/26/2015] [Accepted: 03/27/2015] [Indexed: 12/05/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia, characterized by progressive neurodegeneration. Pathogenetic mechanisms, triggered by β-amyloid (Aβ) accumulation, include oxidative stress, derived from energy homeostasis deregulation and involving mitochondria and peroxisomes. We here addressed the oxidative stress status and the elicited cellular response at the onset and during the progression of Aβ pathology, studying the neocortex of Tg2576 model of AD. Age-dependent changes of oxidative damage markers, antioxidant enzymes, and related transcription factors were analysed in relation to the distribution of Aβ peptide and oligomers, by a combined molecular/morphological approach. Nucleic acid oxidative damage, accompanied by defective antioxidant defences, and decreased PGC1α expression are already detected in 3-month-old Tg2576 neurons. Conversely, PPARα is increased in these cells, with its cytoplasmic localization suggesting nongenomic, anti-inflammatory actions. At 6 months, when intracellular Aβ accumulates, PMP70 is downregulated, indicating impairment of fatty acids peroxisomal translocation and their consequent harmful accumulation. In 9-month-old Tg2576 neocortex, Aβ oligomers and acrolein deposition correlate with GFAP, GPX1, and PMP70 increases, supporting a compensatory response, involving astroglial peroxisomes. At severe pathological stages, when senile plaques disrupt cortical cytoarchitecture, antioxidant capacity is gradually lost. Overall, our data suggest early therapeutic intervention in AD, also targeting peroxisomes.
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18
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Schuldiner M, Zalckvar E. Peroxisystem: Harnessing systems cell biology to study peroxisomes. Biol Cell 2015; 107:89-97. [DOI: 10.1111/boc.201400091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/05/2015] [Indexed: 12/14/2022]
Affiliation(s)
- Maya Schuldiner
- Department of Molecular Genetics; Weizmann Institute of Science; Rehovot 7610001 Israel
| | - Einat Zalckvar
- Department of Molecular Genetics; Weizmann Institute of Science; Rehovot 7610001 Israel
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19
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Cohen Y, Klug YA, Dimitrov L, Erez Z, Chuartzman SG, Elinger D, Yofe I, Soliman K, Gärtner J, Thoms S, Schekman R, Elbaz-Alon Y, Zalckvar E, Schuldiner M. Peroxisomes are juxtaposed to strategic sites on mitochondria. MOLECULAR BIOSYSTEMS 2014; 10:1742-8. [PMID: 24722918 DOI: 10.1039/c4mb00001c] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Peroxisomes are ubiquitous and dynamic organelles that house many important pathways of cellular metabolism. In recent years it has been demonstrated that mitochondria are tightly connected with peroxisomes and are defective in several peroxisomal diseases. Indeed, these two organelles share metabolic routes as well as resident proteins and, at least in mammals, are connected via a vesicular transport pathway. However the exact extent of cross-talk between peroxisomes and mitochondria remains unclear. Here we used a combination of high throughput genetic manipulations of yeast libraries alongside high content screens to systematically unravel proteins that affect the transport of peroxisomal proteins and peroxisome biogenesis. Follow up work on the effector proteins that were identified revealed that peroxisomes are not randomly distributed in cells but are rather localized to specific mitochondrial subdomains such as mitochondria-ER junctions and sites of acetyl-CoA synthesis. Our approach highlights the intricate geography of the cell and suggests an additional layer of organization as a possible way to enable efficient metabolism. Our findings pave the way for further studying the machinery aligning mitochondria and peroxisomes, the role of the juxtaposition, as well as its regulation during various metabolic conditions. More broadly, the approaches used here can be easily applied to study any organelle of choice, facilitating the discovery of new aspects in cell biology.
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Affiliation(s)
- Yifat Cohen
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel.
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20
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Raimundo N. Mitochondrial pathology: stress signals from the energy factory. Trends Mol Med 2014; 20:282-92. [PMID: 24508276 DOI: 10.1016/j.molmed.2014.01.005] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 01/06/2014] [Accepted: 01/08/2014] [Indexed: 12/16/2022]
Abstract
Mitochondria are undergoing a renaissance. The cellular power plant is now recognized as a key cellular signaling platform. The signals released by mitochondria are currently an area of intense research. A complex network is emerging involving metabolic intermediates, the roles of the mitochondrial unfolded protein response, and the interaction of mitochondria with other organelles and with the cellular autophagic system. Despite the diversity of the perturbations leading to mitochondrial diseases, some emerging trends are apparent. The long-held notion that mitochondrial diseases result from decreased mitochondrial energy output has been challenged by new data showing that mitochondrial pathological signaling can cause disease irrespective of the energy output. This review proposes a novel integrative view of mitochondrial signaling in physiology and disease.
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Affiliation(s)
- Nuno Raimundo
- University Medical Center Goettingen, Institute for Cellular Biochemistry, Humboldtallee 23, Room 01.423, 37073 Goettingen, Germany.
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21
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Kim YI, Bhandari S, Lee JN, Yoo KW, Kim SJ, Oh GS, Kim HJ, Cho M, Kwak JY, So HS, Park R, Choe SK. Developmental roles of D-bifunctional protein-A zebrafish model of peroxisome dysfunction. Mol Cells 2014; 37:74-80. [PMID: 24552713 PMCID: PMC3907007 DOI: 10.14348/molcells.2014.2300] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 11/08/2013] [Accepted: 11/08/2013] [Indexed: 12/17/2022] Open
Abstract
The peroxisome is an intracellular organelle that responds dynamically to environmental changes. Various model organisms have been used to study the roles of peroxisomal proteins in maintaining cellular homeostasis. By taking advantage of the zebrafish model whose early stage of embryogenesis is dependent on yolk components, we examined the developmental roles of the D-bifunctional protein (Dbp), an essential enzyme in the peroxisomal β-oxidation. The knockdown of dbp in zebrafish phenocopied clinical manifestations of its deficiency in human, including defective craniofacial morphogenesis, growth retardation, and abnormal neuronal development. Overexpression of murine Dbp rescued the morphological phenotypes induced by dbp knockdown, indicative of conserved roles of Dbp during zebrafish and mammalian development. Knockdown of dbp impaired normal development of blood, blood vessels, and most strikingly, endoderm-derived organs including the liver and pancreas - a phenotype not reported elsewhere in connection with peroxisome dysfunction. Taken together, our results demonstrate for the first time that zebrafish might be a useful model animal to study the role of peroxisomes during vertebrate development.
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Affiliation(s)
- Yong-Il Kim
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Sushil Bhandari
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Joon No Lee
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Kyeong-Won Yoo
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
- Immune-network Pioneer Research Center, Department of Biochemistry, College of Medicine, Dong-A University, Busan 602-714,
Korea
| | - Se-Jin Kim
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Gi-Su Oh
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Hyung-Jin Kim
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Meyoung Cho
- Department of Internal Medicine, Gunsan Medical Center, Gunsan 573-713
Korea
| | - Jong-Young Kwak
- Immune-network Pioneer Research Center, Department of Biochemistry, College of Medicine, Dong-A University, Busan 602-714,
Korea
| | - Hong-Seob So
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Raekil Park
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Seong-Kyu Choe
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
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22
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Witkiewicz H, Oh P, Schnitzer JE. III. Cellular ultrastructures in situ as key to understanding tumor energy metabolism: biological significance of the Warburg effect. F1000Res 2013; 2:10. [PMID: 24358890 PMCID: PMC3829121 DOI: 10.12688/f1000research.2-10.v1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/02/2013] [Indexed: 12/14/2022] Open
Abstract
Despite the universality of metabolic pathways, malignant cells were found to have their metabolism reprogrammed to generate energy by glycolysis even under normal oxygen concentrations (the Warburg effect). Therefore, the pathway energetically 18 times less efficient than oxidative phosphorylation was implicated to match increased energy requirements of growing tumors. The paradox was explained by an abnormally high rate of glucose uptake, assuming unlimited availability of substrates for tumor growth
in vivo. However, ultrastructural analysis of tumor vasculature morphogenesis showed that the growing tissue regions did not have continuous blood supply and intermittently depended on autophagy for survival. Erythrogenic autophagy, and resulting ATP generation by glycolysis, appeared critical to initiating vasculature formation where it was missing. This study focused on ultrastructural features that reflected metabolic switch from aerobic to anaerobic. Morphological differences between and within different types of cells were evident in tissue sections. In cells undergoing nucleo-cytoplasmic conversion into erythrosomes (erythrogenesis), gradual changes led to replacing mitochondria with peroxisomes, through an intermediate form connected to endoplasmic reticulum. Those findings related to the issue of peroxisome biogenesis and to the phenomenon of hemogenic endothelium. Mitochondria were compacted also during mitosis.
In vivo, cells that lost and others that retained capability to use oxygen coexisted side-by-side; both types were important for vasculature morphogenesis and tissue growth. Once passable, the new vasculature segment could deliver external oxygen and nutrients. Nutritional and redox status of microenvironment had similar effect on metabolism of malignant and non-malignant cells demonstrating the necessity to maintain structure-energy equivalence in all living cells. The role of glycolysis in initiating vasculature formation, and in progression of cell cycle through mitosis, indicated that Warburg effect had a fundamental biological significance extending to non-malignant tissues. The approach used here could facilitate integration of accumulated cyber knowledge on cancer metabolism into predictive science.
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Affiliation(s)
- Halina Witkiewicz
- Proteogenomics Research Institute for Systems Medicine, San Diego, California, 92121, USA
| | - Phil Oh
- Proteogenomics Research Institute for Systems Medicine, San Diego, California, 92121, USA
| | - Jan E Schnitzer
- Proteogenomics Research Institute for Systems Medicine, San Diego, California, 92121, USA
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Essential roles of peroxisomally produced and metabolized biomolecules in regulating yeast longevity. Subcell Biochem 2013; 69:153-67. [PMID: 23821148 DOI: 10.1007/978-94-007-6889-5_9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The essential role of the peroxisome in oxidizing fatty acids, maintaining reactive oxygen species homeostasis and replenishing tricarboxylic acid cycle intermediates is well known. Recent findings have broadened a spectrum of biomolecules that are synthesized and metabolized in peroxisomes. Emergent evidence supports the view that, by releasing various biomolecules known to modulate essential cellular processes, the peroxisome not only operates as an organizing platform for several developmental and differentiation programs but is also actively involved in defining the replicative and chronological age of a eukaryotic cell. The scope of this chapter is to summarize the evidence that the peroxisome defines yeast longevity by operating as a system controller that: (1) modulates levels of non-esterified fatty acids and diacylglycerol; (2) replenishes tricarboxylic acid cycle intermediates destined for mitochondria; and (3) contributes to the synthesis of polyamines. We critically evaluate molecular mechanisms underlying the essential role of peroxisomally produced and metabolized biomolecules in governing cellular aging in yeast.
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Abstract
Peroxisomes are remarkably versatile cell organelles whose size, shape, number, and protein content can vary greatly depending on the organism, the developmental stage of the organism’s life cycle, and the environment in which the organism lives. The main functions usually associated with peroxisomes include the metabolism of lipids and reactive oxygen species. However, in recent years, it has become clear that these organelles may also act as intracellular signaling platforms that mediate developmental decisions by modulating extraperoxisomal concentrations of several second messengers. To fulfill their functions, peroxisomes physically and functionally interact with other cell organelles, including mitochondria and the endoplasmic reticulum. Defects in peroxisome dynamics can lead to organelle dysfunction and have been associated with various human disorders. The purpose of this paper is to thoroughly summarize and discuss the current concepts underlying peroxisome formation, multiplication, and degradation. In addition, this paper will briefly highlight what is known about the interplay between peroxisomes and other cell organelles and explore the physiological and pathological implications of this interorganellar crosstalk.
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Affiliation(s)
- Marc Fransen
- Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, P.O. Box 601, 3000 Leuven, Belgium
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25
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Beach A, Burstein MT, Richard VR, Leonov A, Levy S, Titorenko VI. Integration of peroxisomes into an endomembrane system that governs cellular aging. Front Physiol 2012; 3:283. [PMID: 22936916 PMCID: PMC3424522 DOI: 10.3389/fphys.2012.00283] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 06/28/2012] [Indexed: 01/01/2023] Open
Abstract
The peroxisome is an organelle that has long been known for its essential roles in oxidation of fatty acids, maintenance of reactive oxygen species (ROS) homeostasis and anaplerotic replenishment of tricarboxylic acid (TCA) cycle intermediates destined for mitochondria. Growing evidence supports the view that these peroxisome-confined metabolic processes play an essential role in defining the replicative and chronological age of a eukaryotic cell. Much progress has recently been made in defining molecular mechanisms that link cellular aging to fatty acid oxidation, ROS turnover, and anaplerotic metabolism in peroxisomes. Emergent studies have revealed that these organelles not only house longevity-defining metabolic reactions but can also regulate cellular aging via their dynamic communication with other cellular compartments. Peroxisomes communicate with other organelles by establishing extensive physical contact with lipid bodies, maintaining an endoplasmic reticulum (ER) to peroxisome connectivity system, exchanging certain metabolites, and being involved in the bidirectional flow of some of their protein and lipid constituents. The scope of this review is to summarize the evidence that peroxisomes are dynamically integrated into an endomembrane system that governs cellular aging. We discuss recent progress in understanding how communications between peroxisomes and other cellular compartments within this system influence the development of a pro- or anti-aging cellular pattern. We also propose a model for the integration of peroxisomes into the endomembrane system governing cellular aging and critically evaluate several molecular mechanisms underlying such integration.
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Affiliation(s)
- Adam Beach
- Department of Biology, Concordia University, Montreal PQ, Canada
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26
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From networks of protein interactions to networks of functional dependencies. BMC SYSTEMS BIOLOGY 2012; 6:44. [PMID: 22607727 PMCID: PMC3434018 DOI: 10.1186/1752-0509-6-44] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 05/20/2012] [Indexed: 11/23/2022]
Abstract
Background As protein-protein interactions connect proteins that participate in either the same or different functions, networks of interacting and functionally annotated proteins can be converted into process graphs of inter-dependent function nodes (each node corresponding to interacting proteins with the same functional annotation). However, as proteins have multiple annotations, the process graph is non-redundant, if only proteins participating directly in a given function are included in the related function node. Results Reasoning that topological features (e.g., clusters of highly inter-connected proteins) might help approaching structured and non-redundant understanding of molecular function, an algorithm was developed that prioritizes inclusion of proteins into the function nodes that best overlap protein clusters. Specifically, the algorithm identifies function nodes (and their mutual relations), based on the topological analysis of a protein interaction network, which can be related to various biological domains, such as cellular components (e.g., peroxisome and cellular bud) or biological processes (e.g., cell budding) of the model organism S. cerevisiae. Conclusions The method we have described allows converting a protein interaction network into a non-redundant process graph of inter-dependent function nodes. The examples we have described show that the resulting graph allows researchers to formulate testable hypotheses about dependencies among functions and the underlying mechanisms.
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Poretti A, Blaser SI, Lequin MH, Fatemi A, Meoded A, Northington FJ, Boltshauser E, Huisman TAGM. Neonatal neuroimaging findings in inborn errors of metabolism. J Magn Reson Imaging 2012; 37:294-312. [PMID: 22566357 DOI: 10.1002/jmri.23693] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 04/03/2012] [Indexed: 12/22/2022] Open
Abstract
Individually, metabolic disorders are rare, but overall they account for a significant number of neonatal disorders affecting the central nervous system. The neonatal clinical manifestations of inborn errors of metabolism (IEMs) are characterized by nonspecific systemic symptoms that may mimic more common acute neonatal disorders like sepsis, severe heart insufficiency, or neonatal hypoxic-ischemic encephalopathy. Certain IEMs presenting in the neonatal period may also be complicated by sepsis and cardiomyopathy. Early diagnosis is mandatory to prevent death and permanent long-term neurological impairments. Although neuroimaging findings are rarely specific, they play a key role in suggesting the correct diagnosis, limiting the differential diagnosis, and may consequently allow early initiation of targeted metabolic and genetic laboratory investigations and treatment. Neuroimaging may be especially helpful to distinguish metabolic disorders from other more common causes of neonatal encephalopathy, as a newborn may present with an IEM prior to the availability of the newborn screening results. It is therefore important that neonatologists, pediatric neurologists, and pediatric neuroradiologists are familiar with the neuroimaging findings of metabolic disorders presenting in the neonatal time period.
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Affiliation(s)
- Andrea Poretti
- Division of Pediatric Radiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
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Hwang I, Lee J, Huh JY, Park J, Lee HB, Ho YS, Ha H. Catalase deficiency accelerates diabetic renal injury through peroxisomal dysfunction. Diabetes 2012; 61:728-38. [PMID: 22315314 PMCID: PMC3282807 DOI: 10.2337/db11-0584] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Mitochondrial reactive oxygen species (ROS) play an important role in diabetes complications, including diabetic nephropathy (DN). Plasma free fatty acids (FFAs) as well as glucose are increased in diabetes, and peroxisomes and mitochondria participate in FFA oxidation in an interconnected fashion. Therefore, we investigated whether deficiency of catalase, a major peroxisomal antioxidant, accelerates DN through peroxisomal dysfunction and abnormal renal FFA metabolism. Diabetes was induced by multiple injections of low-dose streptozotocin into catalase knock-out (CKO) and wild-type (WT) C57BL/6 mice. Murine mesangial cells (MMCs) transfected with catalase small interfering RNA followed by catalase overexpression were used to further elucidate the role of endogenous catalase. Despite equivalent hyperglycemia, parameters of DN, along with markers of oxidative stress, were more accelerated in diabetic CKO mice than in diabetic WT mice up to 10 weeks of diabetes. CKO mice and MMCs showed impaired peroxisomal/mitochondrial biogenesis and FFA oxidation. Catalase deficiency increased mitochondrial ROS and fibronectin expression in response to FFAs, which were effectively restored by catalase overexpression or N-acetylcysteine. These data provide unprecedented evidence that FFA-induced peroxisomal dysfunction exacerbates DN and that endogenous catalase plays an important role in protecting the kidney from diabetic stress through maintaining peroxisomal and mitochondrial fitness.
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Affiliation(s)
- Inah Hwang
- Department of Bioinspired Science, Division of Life and Pharmaceutical Sciences, Center for Cell Signaling and Drug Discovery Research, College of Pharmacy, Ewha Womans University, Seoul, Korea
| | - Jiyoun Lee
- Department of Bioinspired Science, Division of Life and Pharmaceutical Sciences, Center for Cell Signaling and Drug Discovery Research, College of Pharmacy, Ewha Womans University, Seoul, Korea
| | - Joo Young Huh
- Department of Bioinspired Science, Division of Life and Pharmaceutical Sciences, Center for Cell Signaling and Drug Discovery Research, College of Pharmacy, Ewha Womans University, Seoul, Korea
| | - Jehyun Park
- Department of Bioinspired Science, Division of Life and Pharmaceutical Sciences, Center for Cell Signaling and Drug Discovery Research, College of Pharmacy, Ewha Womans University, Seoul, Korea
| | - Hi Bahl Lee
- Kim’s Clinic and Dialysis Unit, Myrang, Korea
| | - Ye-Shih Ho
- Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan
| | - Hunjoo Ha
- Department of Bioinspired Science, Division of Life and Pharmaceutical Sciences, Center for Cell Signaling and Drug Discovery Research, College of Pharmacy, Ewha Womans University, Seoul, Korea
- Corresponding author: Hunjoo Ha,
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Abstract
Despite a lack of consistent diagnostic criteria, the metabolic syndrome (MetS) is increasingly evident in children and adolescents, portending a tsunami of chronic disease and mortality as this generation ages. The diagnostic criteria for MetS apply absolute cutoffs to continuous variables and fail to take into account aging, pubertal changes, and race/ethnicity. We attempt to define MetS mechanistically to determine its specific etiologies and to identify targets for therapy. Whereas the majority of studies document a relationship of visceral fat to insulin resistance, ectopic liver fat correlates better with dysfunctional insulin dynamics from which the rest of MetS derives. In contrast to the systemic metabolism of glucose, the liver is the primary metabolic clearinghouse for 4 specific foodstuffs that have been associated with the development of MetS: trans-fats, branched-chain amino acids, ethanol, and fructose. These 4 substrates (1) are not insulin regulated and (2) deliver metabolic intermediates to hepatic mitochondria without an appropriate "pop-off" mechanism for excess substrate, enhancing lipogenesis and ectopic adipose storage. Excessive fatty acid derivatives interfere with hepatic insulin signal transduction. Reactive oxygen species accumulate, which cannot be quenched by adjacent peroxisomes; these reactive oxygen species reach the endoplasmic reticulum, leading to a compensatory process termed the "unfolded protein response," driving further insulin resistance and eventually insulin deficiency. No obvious drug target exists in this pathway; thus, the only rational therapeutic approaches remain (1) altering hepatic substrate availability (dietary modification), (2) reducing hepatic substrate flux (high fiber), or (3) increasing mitochondrial efficiency (exercise).
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Affiliation(s)
- Andrew A. Bremer
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Michele Mietus-Snyder
- Department of Pediatrics and Children’s National Obesity Institute, Children’s National Medical Center, Washington, District of Columbia; and
| | - Robert H. Lustig
- Department of Pediatrics, University of California, San Francisco, San Francisco, California
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Thoms S, Harms I, Kalies KU, Gärtner J. Peroxisome formation requires the endoplasmic reticulum channel protein Sec61. Traffic 2012; 13:599-609. [PMID: 22212716 DOI: 10.1111/j.1600-0854.2011.01324.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 12/21/2011] [Accepted: 12/23/2011] [Indexed: 12/21/2022]
Abstract
In peroxisome formation, models of near-autonomous peroxisome biogenesis with membrane protein integration directly from the cytosol into the peroxisomal membrane are in direct conflict with models whereby peroxisomes bud from the endoplasmic reticulum and receive their membrane proteins through a branch of the secretory pathway. We therefore reinvestigated the role of the Sec61 complex, the protein-conducting channel of the endoplasmic reticulum (ER) in peroxisome formation. We found that depletion or partial inactivation of Sec61 in yeast disables peroxisome formation. The ER entry of the early peroxisomal membrane protein Pex3 engineered with a glycosylation tag is reduced in sec61 mutant cells. Moreover, we were able to reconstitute Pex3 import into ER membranes in vitro, and we identified a variant of a signal anchor sequence for ER translocation at the Pex3 N-terminus. Our findings are consistent with a Sec61 requirement for peroxisome formation and a fundamental role of the ER in peroxisome biogenesis.
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Affiliation(s)
- Sven Thoms
- Department of Pediatrics and Pediatric Neurology, University Medical Center, Georg August University of Göttingen, 37075, Göttingen, Germany.
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Quentin T, Steinmetz M, Poppe A, Thoms S. Metformin differentially activates ER stress signaling pathways without inducing apoptosis. Dis Model Mech 2011; 5:259-69. [PMID: 22107872 PMCID: PMC3291647 DOI: 10.1242/dmm.008110] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Endoplasmic reticulum stress signaling (ERSS) plays an important role in the pathogenesis of diabetes and heart disease. The latter is a common comorbidity of diabetes and worsens patient outcome. Results from clinical studies suggest beneficial effects of metformin – a widely used oral drug for the treatment of type 2 diabetes – on the heart of diabetic patients with heart failure. We therefore analyzed the effect of metformin on ERSS in primary rat cardiomyocytes. We found that metformin activates the PERK-ATF4 but not the ATF6 or IRE1-XBP1 branch in ERSS and leads to a strong upregulation of CHOP mRNA and protein. Surprisingly, long-term induction of CHOP by metformin is not accompanied by apoptosis even though CHOP is regarded to be a mediator of ER-stress-induced apoptosis. In conclusion, metformin induces distinct ER stress pathways in cardiomyocytes and our results indicate that CHOP is not necessarily a mediator of apoptosis. Metformin might exert its cardioprotective effect through selective activation of ERSS pathways in the cardiomyocyte.
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Affiliation(s)
- Thomas Quentin
- Department of Pediatric Cardiology and Pediatric Intensive Care Medicine, University of Göttingen, Göttingen, Germany.
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Wood PL, Khan MA, Smith T, Ehrmantraut G, Jin W, Cui W, Braverman NE, Goodenowe DB. In vitro and in vivo plasmalogen replacement evaluations in rhizomelic chrondrodysplasia punctata and Pelizaeus-Merzbacher disease using PPI-1011, an ether lipid plasmalogen precursor. Lipids Health Dis 2011; 10:182. [PMID: 22008564 PMCID: PMC3238230 DOI: 10.1186/1476-511x-10-182] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 10/18/2011] [Indexed: 01/21/2023] Open
Abstract
Background Childhood peroxisomal disorders and leukodystrophies are devastating diseases characterized by dysfunctional lipid metabolism. Plasmalogens (ether glycerophosphoethanolamine lipids) are decreased in these genetic disorders. The biosynthesis of plasmalogens is initiated in peroxisomes but completed in the endoplasmic reticulum. We therefore undertook a study to evaluate the ability of a 3-substituted, 1-alkyl, 2-acyl glyceryl ether lipid (PPI-1011) to replace plasmalogens in rhizomelic chrondrodysplasia punctata type 1 (RCDP1) and rhizomelic chrondrodysplasia punctata type 2 (RCDP2) lymphocytes which possess peroxisomal mutations culminating in deficient plasmalogen synthesis. We also examined plasmalogen synthesis in Pelizaeus-Merzbacher disease (PMD) lymphocytes which possess a proteolipid protein-1 (PLP1) missense mutation that results in abnormal PLP1 folding and it's accumulation in the endoplasmic reticulum (ER), the cellular site of the last steps in plasmalogen synthesis. In vivo incorporation of plasmalogen precursor into tissue plasmalogens was also evaluated in the Pex7 mouse model of plasmalogen deficiency. Results In both RCDP1 and RCDP2 lymphocytes, PPI-1011 repleted the target ethanolamine plasmalogen (PlsEtn16:0/22:6) in a concentration dependent manner. In addition, deacylation/reacylation reactions resulted in repletion of PlsEtn 16:0/20:4 in both RCDP1 and RCDP2 lymphocytes, repletion of PlsEtn 16:0/18:1 and PlsEtn 16:0/18:2 in RCDP2 lymphocytes, and partial repletion of PlsEtn 16:0/18:1 and PlsEtn 16:0/18:2 in RCDP1 lymphocytes. In the Pex7 mouse, oral dosing of labeled PPI-1011 demonstrated repletion of tissue levels of the target plasmalogen PlsEtn 16:0/22:6 with phospholipid remodeling also resulting in significant repletion of PlsEtn 16:0/20:4 and PlsEtn 16:0/18:1. Metabolic conversion of PPI-1011 to the target plasmalogen was most active in the liver. Conclusions Our data demonstrate that PPI-1011 is activated (removal of 3-substitution) and converted to PlsEtn in vitro in both RCDP1 and RCDP2 lymphocytes and in vivo in the Pex7 mouse model of RCPD1 effectively bypassing the peroxisomal dysfunction present in these disorders. While PPI-1011 was shown to replete PlsEtns 16:0/x, ether lipid precursors of PlsEtn 18:0/x and PlsEtn 18:1/x may also be needed to achieve optimal clinical benefits of plasmalogen replacement in these complex patient populations. In contrast, only limited plasmalogen replacement was observed in PMD lymphocytes suggesting that the effects of protein misfolding and accumulation in the ER negatively affect processing of plasmalogen precursors in this cellular compartment.
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Affiliation(s)
- Paul L Wood
- Dept, of Pharmacology, DeBusk College of Osteopathic Medicine, Lincoln Memorial University, 6965 Cumberland Gap Parkway, Harrogate, TN 37752, USA.
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The unusual extended C-terminal helix of the peroxisomal α/β-hydrolase Lpx1 is involved in dimer contacts but dispensable for dimerization. J Struct Biol 2011; 175:362-71. [DOI: 10.1016/j.jsb.2011.06.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 06/20/2011] [Accepted: 06/22/2011] [Indexed: 11/24/2022]
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Speijer D. Oxygen radicals shaping evolution: why fatty acid catabolism leads to peroxisomes while neurons do without it: FADH₂/NADH flux ratios determining mitochondrial radical formation were crucial for the eukaryotic invention of peroxisomes and catabolic tissue differentiation. Bioessays 2011; 33:88-94. [PMID: 21137096 DOI: 10.1002/bies.201000097] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Oxygen radical formation in mitochondria is a highly important, but incompletely understood, attribute of eukaryotic cells. I propose a kinetic model in which the ratio between electrons entering the respiratory chain via FADH₂ or NADH is a major determinant in radical formation. During the breakdown of glucose, this ratio is low; during fatty acid breakdown, this ratio is much higher. The longer the fatty acid, the higher the ratio and the higher the level of radical formation. This means that very long chain fatty acids should be broken down without generation of FADH₂ for mitochondria. This is accomplished in peroxisomes, thus explaining their role and evolution. The model explains many recent observations regarding radical formation by the respiratory chain. It also sheds light on the reasons for the lack of neuronal fatty acid (beta-) oxidation and for beneficial aspects of unsaturated fatty acids. Last but not least, it has very important implications for all models describing eukaryotic origins.
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Affiliation(s)
- Dave Speijer
- Academic Medical Centre, Department of Medical Biochemistry, University of Amsterdam, Amsterdam, The Netherlands
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35
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Plasmalogens the neglected regulatory and scavenging lipid species. Chem Phys Lipids 2011; 164:573-89. [PMID: 21723266 DOI: 10.1016/j.chemphyslip.2011.06.008] [Citation(s) in RCA: 230] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 06/08/2011] [Accepted: 06/14/2011] [Indexed: 12/17/2022]
Abstract
Plasmalogens are a class of phospholipids carrying a vinyl ether bond in sn-1 and an ester bond in sn-2 position of the glycerol backbone. Although they are widespread in all tissues and represent up to 18% of the total phospholipid mass in humans, their physiological function is still poorly understood. The aim of this review is to give an overview over the current knowledge in plasmalogen biology and pathology with an emphasis on neglected aspects of their involvement in neurological and metabolic diseases. Furthermore a better understanding of plasmalogen biology in health and disease could also lead to the development of better diagnostic and prognostic biomarkers for vascular and metabolic diseases such as obesity and diabetes mellitus, inflammation, neuro-degeneration and cancer.
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Wood PL, Smith T, Pelzer L, Goodenowe DB. Targeted metabolomic analyses of cellular models of pelizaeus-merzbacher disease reveal plasmalogen and myo-inositol solute carrier dysfunction. Lipids Health Dis 2011; 10:102. [PMID: 21682894 PMCID: PMC3141545 DOI: 10.1186/1476-511x-10-102] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 06/17/2011] [Indexed: 11/17/2022] Open
Abstract
Background Leukodystrophies are devastating diseases characterized by dys- and hypo-myelination. While there are a number of histological and imaging studies of these disorders, there are limited biochemical data available. We undertook targeted lipidomic analyses of Pelizaeus-Merzbacher disease (PMD) fibroblasts, PMD lymphocytes, and 158JP oligodendrocytes, a murine model of PMD, to define the lipid changes in these cell models. Further targeted metabolomics analyses were conducted to obtain a preliminary evaluation of the metabolic consequences of lipid changes and gene mutations in these cell models. Results In both PMD fibroblasts and lymphocytes, and 158JP oligodendrocytes, ethanolamine plasmalogens were significantly decreased. Labeling studies with 158JP oligodendrocytes further demonstrated a decreased rate of lipid remodeling at sn-2. Targeted metabolomics analyses of these cells revealed dramatic increases in cellular levels of myo-inositol. Further uptake studies demonstrated increased rates of myo-inositol uptake by PMD lymphocytes. Conclusions Our data demonstrating PlsEtn decrements, support previous studies indicating leukodystrophy cells possess significant peroxisomal deficits. Our data for the first time also demonstrate that decrements in peroxisomal function coupled with the PLP1 gene defects of PMD, result in changes in the function of membrane myo-inositol solute carriers resulting in dramatic increases in cellular myo-inositol levels.
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Affiliation(s)
- Paul L Wood
- Phenomenome Discoveries Inc, 204-407 Downey Road, Saskatoon, SK S7N4L8, Canada.
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37
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Bartoszewska M, Opaliński L, Veenhuis M, van der Klei IJ. The significance of peroxisomes in secondary metabolite biosynthesis in filamentous fungi. Biotechnol Lett 2011; 33:1921-31. [PMID: 21660569 PMCID: PMC3173629 DOI: 10.1007/s10529-011-0664-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Accepted: 05/24/2011] [Indexed: 01/08/2023]
Abstract
Peroxisomes are ubiquitous organelles characterized by a protein-rich matrix surrounded by a single membrane. In filamentous fungi, peroxisomes are crucial for the primary metabolism of several unusual carbon sources used for growth (e.g. fatty acids), but increasing evidence is presented that emphasize the crucial role of these organelles in the formation of a variety of secondary metabolites. In filamentous fungi, peroxisomes also play a role in development and differentiation whereas specialized peroxisomes, the Woronin bodies, play a structural role in plugging septal pores. The biogenesis of peroxisomes in filamentous fungi involves the function of conserved PEX genes, as well as genes that are unique for these organisms. Peroxisomes are also subject to autophagic degradation, a process that involves ATG genes. The interplay between organelle biogenesis and degradation may serve a quality control function, thereby allowing a continuous rejuvenation of the organelle population in the cells.
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Affiliation(s)
- Magdalena Bartoszewska
- Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Kluyver Centre for Genomics of Industrial Fermentation, P.O. Box 11103, 9700 CC Groningen, The Netherlands
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38
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Faust PL, Kaye EM, Powers JM. Myelin lesions associated with lysosomal and peroxisomal disorders. Expert Rev Neurother 2010; 10:1449-66. [PMID: 20819015 DOI: 10.1586/ern.10.127] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Abnormalities of myelin are common in lysosomal and peroxisomal disorders. Most display a primary loss of myelin in which the myelin sheath and/or oligodendrocytes are selectively targeted by diverse pathogenetic processes. The most severe and, hence, clinically relevant are heritable diseases predominantly of infants and children, the leukodystrophies: metachromatic, globoid cell (Krabbe disease) and adreno-leukodystrophy. Our still limited understanding of these diseases has derived from multiple sources: originally, neurological-neuropathologic-neurochemical correlative studies of the natural disease in humans or other mammals, which has been enhanced by more sophisticated and contemporary techniques of cell and molecular biology. Transgenic mouse models seem to be the most promising methodology, allowing the examination of the cellular role of lysosomes and peroxisomes for formation and maintenance of both myelin and axons, and providing initial platforms to evaluate therapies. Treatment options are woefully inadequate and in their nascent stages, but still inspire some hope for the future.
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Affiliation(s)
- Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University, 630 West 168th Street, New York, NY 10032, USA.
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Abstract
The essential role of peroxisomes in fatty acid oxidation, anaplerotic metabolism, and hydrogen peroxide turnover is well established. Recent findings suggest that these and other related biochemical processes governed by the organelle may also play a critical role in regulating cellular aging. The goal of this review is to summarize and integrate into a model the evidence that peroxisome metabolism actually helps define the replicative and chronological age of a eukaryotic cell. In this model, peroxisomal reactive oxygen species (ROS) are seen as altering organelle biogenesis and function, and eliciting changes in the dynamic communication networks that exist between peroxisomes and other cellular compartments. At low levels, peroxisomal ROS activate an anti-aging program in the cell; at concentrations beyond a specific threshold, a pro-aging course is triggered.
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Affiliation(s)
- Vladimir I Titorenko
- Department of Biology, Concordia University, 7141 Sherbrooke Street, West, SP Building, Office SP-501-9, Montreal, Quebec H4B1R6, Canada.
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Abstract
PURPOSE OF REVIEW Knowledge of the metabolic and genetic basis of known and previously unknown leukodystrophies is constantly increasing, opening new treatment options such as enzyme replacement or cell-based therapies. This brief review highlights some recent work, particularly emphasizing results from studies in adulthood leukodystrophies. RECENT FINDINGS Evidence from recent studies suggests increasing importance of metabolic dysfunctions, for example, in peroxisomal lipid metabolism or energy homeostasis, influencing axonal integrity and oligodendrocyte function and leading to white matter demyelination. In addition, diagnostic and therapeutic progress in metachromatic leukodystrophy, X-linked adrenoleukodystrophy, Krabbe diseases and other rare leukodystrophies with late onset are summarized. SUMMARY Better understanding of leukodystrophies in neurological routine practice is of crucial importance for differentiating between other white matter diseases such as toxic, inflammatory or vascular leukoencephalopathies. Many leukodystrophies are particularly important to recognize because specific treatments already exist or are currently under investigation. The article also provides an overview of currently known leukodystrophies in adulthood.
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Mariman ECM, Wang P. Adipocyte extracellular matrix composition, dynamics and role in obesity. Cell Mol Life Sci 2010; 67:1277-92. [PMID: 20107860 PMCID: PMC2839497 DOI: 10.1007/s00018-010-0263-4] [Citation(s) in RCA: 359] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 01/05/2010] [Accepted: 01/07/2010] [Indexed: 01/08/2023]
Abstract
The central role of the adipose tissue in lipid metabolism places specific demands on the cell structure of adipocytes. The protein composition and dynamics of the extracellular matrix (ECM) is of crucial importance for the functioning of those cells. Adipogenesis is a bi-phasic process in which the ECM develops from a fibrillar to a laminar structure as cells move from the commitment phase to the growth phase characterized by storage of vast amounts of triglycerides. Mature adipocytes appear to spend a lot of energy on the maintenance of the ECM. ECM remodeling is mediated by a balanced complement of constructive and destructive enzymes together with their enhancers and inhibitors. ECM remodeling is an energy costing process regulated by insulin, by the energy metabolism, and by mechanical forces. In the obese, overgrowth of adipocytes may lead to instability of the ECM, possibly mediated by hypoxia.
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Affiliation(s)
- Edwin C M Mariman
- Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University, Maastricht, The Netherlands.
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