1
|
Jacovetti C, Donnelly C, Menoud V, Suleiman M, Cosentino C, Sobel J, Wu K, Bouzakri K, Marchetti P, Guay C, Kayser B, Regazzi R. The mitochondrial tRNA-derived fragment, mt-tRF-Leu TAA, couples mitochondrial metabolism to insulin secretion. Mol Metab 2024; 84:101955. [PMID: 38704026 PMCID: PMC11112368 DOI: 10.1016/j.molmet.2024.101955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/29/2024] [Accepted: 04/29/2024] [Indexed: 05/06/2024] Open
Abstract
OBJECTIVE The contribution of the mitochondrial electron transfer system to insulin secretion involves more than just energy provision. We identified a small RNA fragment (mt-tRF-LeuTAA) derived from the cleavage of a mitochondrially-encoded tRNA that is conserved between mice and humans. The role of mitochondrially-encoded tRNA-derived fragments remains unknown. This study aimed to characterize the impact of mt-tRF-LeuTAA, on mitochondrial metabolism and pancreatic islet functions. METHODS We used antisense oligonucleotides to reduce mt-tRF-LeuTAA levels in primary rat and human islet cells, as well as in insulin-secreting cell lines. We performed a joint transcriptome and proteome analysis upon mt-tRF-LeuTAA inhibition. Additionally, we employed pull-down assays followed by mass spectrometry to identify direct interactors of the fragment. Finally, we characterized the impact of mt-tRF-LeuTAA silencing on the coupling between mitochondrial metabolism and insulin secretion using high-resolution respirometry and insulin secretion assays. RESULTS Our study unveils a modulation of mt-tRF-LeuTAA levels in pancreatic islets in different Type 2 diabetes models and in response to changes in nutritional status. The level of the fragment is finely tuned by the mechanistic target of rapamycin complex 1. Located within mitochondria, mt-tRF-LeuTAA interacts with core subunits and assembly factors of respiratory complexes of the electron transfer system. Silencing of mt-tRF-LeuTAA in islet cells limits the inner mitochondrial membrane potential and impairs mitochondrial oxidative phosphorylation, predominantly by affecting the Succinate (via Complex II)-linked electron transfer pathway. Lowering mt-tRF-LeuTAA impairs insulin secretion of rat and human pancreatic β-cells. CONCLUSIONS Our findings indicate that mt-tRF-LeuTAA interacts with electron transfer system complexes and is a pivotal regulator of mitochondrial oxidative phosphorylation and its coupling to insulin secretion.
Collapse
Affiliation(s)
- Cecile Jacovetti
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland.
| | - Chris Donnelly
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Véronique Menoud
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Mara Suleiman
- Department of Clinical and Experimental Medicine, Diabetes Unit, University of Pisa, Pisa, Italy
| | - Cristina Cosentino
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Jonathan Sobel
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Kejing Wu
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Karim Bouzakri
- UMR DIATHEC, EA 7294, Centre Européen d'Etude du Diabète, Université de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, Strasbourg, France
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, Diabetes Unit, University of Pisa, Pisa, Italy
| | - Claudiane Guay
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Bengt Kayser
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Romano Regazzi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
2
|
Coluccino G, Muraca VP, Corazza A, Lippe G. Cyclophilin D in Mitochondrial Dysfunction: A Key Player in Neurodegeneration? Biomolecules 2023; 13:1265. [PMID: 37627330 PMCID: PMC10452829 DOI: 10.3390/biom13081265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/11/2023] [Accepted: 08/15/2023] [Indexed: 08/27/2023] Open
Abstract
Mitochondrial dysfunction plays a pivotal role in numerous complex diseases. Understanding the molecular mechanisms by which the "powerhouse of the cell" turns into the "factory of death" is an exciting yet challenging task that can unveil new therapeutic targets. The mitochondrial matrix protein CyPD is a peptidylprolyl cis-trans isomerase involved in the regulation of the permeability transition pore (mPTP). The mPTP is a multi-conductance channel in the inner mitochondrial membrane whose dysregulated opening can ultimately lead to cell death and whose involvement in pathology has been extensively documented over the past few decades. Moreover, several mPTP-independent CyPD interactions have been identified, indicating that CyPD could be involved in the fine regulation of several biochemical pathways. To further enrich the picture, CyPD undergoes several post-translational modifications that regulate both its activity and interaction with its clients. Here, we will dissect what is currently known about CyPD and critically review the most recent literature about its involvement in neurodegenerative disorders, focusing on Alzheimer's Disease and Parkinson's Disease, supporting the notion that CyPD could serve as a promising therapeutic target for the treatment of such conditions. Notably, significant efforts have been made to develop CyPD-specific inhibitors, which hold promise for the treatment of such complex disorders.
Collapse
Affiliation(s)
- Gabriele Coluccino
- Department of Medicine (DAME), University of Udine, 33100 Udine, Italy; (V.P.M.); (A.C.)
| | | | | | - Giovanna Lippe
- Department of Medicine (DAME), University of Udine, 33100 Udine, Italy; (V.P.M.); (A.C.)
| |
Collapse
|
3
|
Belyaeva EA. Modulators of mitochondrial ATP-sensitive potassium channel affect cytotoxicity of heavy metals: Action on isolated rat liver mitochondria and AS-30D ascites hepatoma cells. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 256:114829. [PMID: 36989557 DOI: 10.1016/j.ecoenv.2023.114829] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 03/06/2023] [Accepted: 03/22/2023] [Indexed: 06/19/2023]
Abstract
Heavy metals are ubiquitous environmental pollutants that are extremely dangerous for public health, but the molecular mechanisms of their cytotoxic action are still not fully understood. In the present work, the possible contribution of the mitochondrial ATP-sensitive potassium channel (mK(ATP)), which is usually considered protective for the cell, to hepatotoxicity caused by heavy metals was investigated using polarography and swelling techniques as well as flow cytometry. Using isolated liver mitochondria from adult male Wistar rats and various potassium media containing or not containing penetrating anions (KNO3, KSCN, KAcet, KCl), we studied the effect of mK(ATP) modulators, namely its blockers (5-hydroxydecanoate, glibenclamide, ATP, ADP) and activators (diazoxide, malonate), on respiration and/or membrane permeability in the presence of hepatotoxins such as Cd2+, Hg2+, and Cu2+. It has been shown for the first time that, contrary to Hg2+ and depending on media used, the mK(ATP) modulators affect Cd2+- and/or Cu2+-induced alterations in mitochondrial swelling and respiration rates, although differently, nevertheless, in the ways compatible with mK(ATP) participation in both these cases. On rat AS-30D ascites hepatoma cells, it was found that, unlike Cd2+, an increase in the production of reactive oxygen species was observed with the simultaneous use of Cu2+ and diazoxide; in addition, there was no protective effect of diazoxide against cell death, which also occurred in the presence of Cu2+. In conclusion, the relationships (functional, structural and/or regulatory) between mK(ATP), components of the mitochondrial electron transport chain (CI, CII-CIII and/or ATP synthase, CV) and mitochondrial permeability transition pores were discussed, as well as the role of these molecular structures in the mechanisms of the cytotoxic action of heavy metals.
Collapse
Affiliation(s)
- Elena A Belyaeva
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, Thorez av. 44, 194223, St.-Petersburg, Russia.
| |
Collapse
|
4
|
Bernardi P, Carraro M, Lippe G. The mitochondrial permeability transition: Recent progress and open questions. FEBS J 2022; 289:7051-7074. [PMID: 34710270 PMCID: PMC9787756 DOI: 10.1111/febs.16254] [Citation(s) in RCA: 71] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 10/27/2021] [Indexed: 01/13/2023]
Abstract
Major progress has been made in defining the basis of the mitochondrial permeability transition, a Ca2+ -dependent permeability increase of the inner membrane that has puzzled mitochondrial research for almost 70 years. Initially considered an artefact of limited biological interest by most, over the years the permeability transition has raised to the status of regulator of mitochondrial ion homeostasis and of druggable effector mechanism of cell death. The permeability transition is mediated by opening of channel(s) modulated by matrix cyclophilin D, the permeability transition pore(s) (PTP). The field has received new impulse (a) from the hypothesis that the PTP may originate from a Ca2+ -dependent conformational change of F-ATP synthase and (b) from the reevaluation of the long-standing hypothesis that it originates from the adenine nucleotide translocator (ANT). Here, we provide a synthetic account of the structure of ANT and F-ATP synthase to discuss potential and controversial mechanisms through which they may form high-conductance channels; and review some intriguing findings from the wealth of early studies of PTP modulation that still await an explanation. We hope that this review will stimulate new experiments addressing the many outstanding problems, and thus contribute to the eventual solution of the puzzle of the permeability transition.
Collapse
Affiliation(s)
- Paolo Bernardi
- Department of Biomedical Sciences and CNR Neuroscience InstituteUniversity of PadovaItaly
| | - Michela Carraro
- Department of Biomedical Sciences and CNR Neuroscience InstituteUniversity of PadovaItaly
| | | |
Collapse
|
5
|
Bai Y, Carrillo JA, Li Y, He Y, Song J. Diet induced the change of mtDNA copy number and metabolism in Angus cattle. J Anim Sci Biotechnol 2020; 11:84. [PMID: 32699629 PMCID: PMC7372754 DOI: 10.1186/s40104-020-00482-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/09/2020] [Indexed: 12/16/2022] Open
Abstract
Background Grass-fed and grain-fed Angus cattle differ in the diet regimes. However, the intricate mechanisms of different beef quality and other phenotypes induced by diet differences are still unclear. Diet affects mitochondrial function and dynamic behavior in response to changes in energy demand and supply. In this study, we examined the mtDNA copy number, mitochondria-related genes expression, and metabolic biomarkers in grass-fed and grain-fed Angus cattle. Results We found that the grass-fed group had a higher mtDNA copy number than the grain-fed group. Among different tissues, the mtDNA copy number was the highest in the liver than muscle, rumen, and spleen. Based on the transcriptome of the four tissues, a lower expression of mtDNA-encoded genes in the grass-fed group compared to the grain-fed group was discovered. For the mitochondria-related nuclear genes, however, most of them were significantly down-regulated in the muscle of the grass-fed group and up-regulated in the other three tissues. In which, COX6A2, POLG2, PPIF, DCN, and NDUFA12, involving in ATP synthesis, mitochondrial replication, transcription, and maintenance, might contribute to the alterations of mtDNA copy number and gene expression. Meanwhile, 40 and 23 metabolic biomarkers were identified in the blood and muscle of the grain-fed group compared to a grass-fed group, respectively. Integrated analysis of the altered metabolites and gene expression revealed the high expression level of MDH1 in the grain-fed group might contribute to the mitochondrial NADH oxidation and spermidine metabolism for adapting the deletion mtDNA copy number. Conclusions Overall, the study may provide further deep insight into the adaptive and regulatory modulations of the mitochondrial function in response to different feeding systems in Angus cattle.
Collapse
Affiliation(s)
- Ying Bai
- College of Life Sciences and Food Engineering, Hebei University of Engineering, Handan, 056038 China.,Department of Animal & Avian Sciences, University of Maryland, College Park, MD 20742 USA
| | - José A Carrillo
- Department of Animal & Avian Sciences, University of Maryland, College Park, MD 20742 USA.,Council on Dairy Cattle Breeding, Bowie, MD 20716 USA
| | - Yaokun Li
- Department of Animal & Avian Sciences, University of Maryland, College Park, MD 20742 USA
| | - Yanghua He
- Department of Animal & Avian Sciences, University of Maryland, College Park, MD 20742 USA.,Human Nutrition, Food and Animal Sciences, University of Hawaii at Manoa, Honolulu, HI 96822 USA
| | - Jiuzhou Song
- Department of Animal & Avian Sciences, University of Maryland, College Park, MD 20742 USA
| |
Collapse
|
6
|
Ure DR, Trepanier DJ, Mayo PR, Foster RT. Cyclophilin inhibition as a potential treatment for nonalcoholic steatohepatitis (NASH). Expert Opin Investig Drugs 2019; 29:163-178. [DOI: 10.1080/13543784.2020.1703948] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Daren R. Ure
- Hepion Pharmaceuticals Inc, Edmonton, AB, Canada
| | | | | | | |
Collapse
|
7
|
Novel insights into molecular mechanisms of Pseudourostyla cristata encystment using comparative transcriptomics. Sci Rep 2019; 9:19109. [PMID: 31836801 PMCID: PMC6911008 DOI: 10.1038/s41598-019-55608-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 11/20/2019] [Indexed: 12/17/2022] Open
Abstract
The encystment of many ciliates is an advanced survival strategy against adversity and the most important reason for ciliates existence worldwide. However, the molecular mechanism for the encystment of free-living ciliates is poorly understood. Here, we performed comparative transcriptomic analysis of dormant cysts and trophonts from Pseudourostyla cristata using transcriptomics, qRT-PCR and bioinformatic techniques. We identified 2565 differentially expressed unigenes between the dormant cysts and the trophonts. The total number of differentially expressed genes in GO database was 1752. The differential unigenes noted to the GO terms were 1993. These differential categories were mainly related to polyamine transport, pectin decomposition, cytoplasmic translation, ribosome, respiratory chain, ribosome structure, ion channel activity, and RNA ligation. A total of 224 different pathways were mapped. Among them, 184 pathways were upregulated, while 162 were downregulated. Further investigation showed that the calcium and AMPK signaling pathway had important induction effects on the encystment. In addition, FOXO and ubiquitin-mediated proteolysis signaling pathway jointly regulated the encystment. Based on these findings, we propose a hypothetical signaling network that regulates Pseudourostyla cristata encystment. Overall, these results provide deeper insights into the molecular mechanisms of ciliates encystment and adaptation to adverse environments.
Collapse
|
8
|
Su H, Tang X, Zhang X, Liu L, Jing L, Pan D, Sun W, He H, Yang C, Zhao D, Zhang H, Qi B. Comparative proteomics analysis reveals the difference during antler regeneration stage between red deer and sika deer. PeerJ 2019; 7:e7299. [PMID: 31346498 PMCID: PMC6642628 DOI: 10.7717/peerj.7299] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 06/14/2019] [Indexed: 12/21/2022] Open
Abstract
Deer antler, as the only mammalian regenerative appendage, provides an optimal model to study regenerative medicine. Antler harvested from red deer or sika deer were mainly study objects used to disclose the mechanism underlying antler regeneration over past decades. A previous study used proteomic technology to reveal the signaling pathways of antler stem cell derived from red deer. Moreover, transcriptome of antler tip from sika deer provide us with the essential genes, which regulated antler development and regeneration. However, antler comparison between red deer and sika deer has not been well studied. In our current study, proteomics were employed to analyze the biological difference of antler regeneration between sika deer and red deer. The proteomics profile was completed by searching the UniProt database, and differentially expressed proteins were identified by bioinformatic software. Thirty-six proteins were highly expressed in red deer antler, while 144 proteins were abundant in sika deer. GO and KEGG analysis revealed that differentially expressed proteins participated in the regulation of several pathways including oxidative phosphorylation, ribosome, extracellular matrix interaction, and PI3K-Akt pathway.
Collapse
Affiliation(s)
- Hang Su
- Practice Innovations Center, Changchun University of Chinese Medicine, Changchun, China
| | - Xiaolei Tang
- College of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Xiaocui Zhang
- College of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Li Liu
- College of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| | - Li Jing
- Practice Innovations Center, Changchun University of Chinese Medicine, Changchun, China
| | - Daian Pan
- School of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Weijie Sun
- Jilin Ginseng Academy, Changchun University of Chinese Medicine, Changchun, China
| | - Huinan He
- Jilin Ginseng Academy, Changchun University of Chinese Medicine, Changchun, China
| | - Chonghui Yang
- Jilin Ginseng Academy, Changchun University of Chinese Medicine, Changchun, China
| | - Daqing Zhao
- Jilin Ginseng Academy, Changchun University of Chinese Medicine, Changchun, China
| | - He Zhang
- School of Clinical Medicine, Changchun University of Chinese Medicine, Changchun, China
| | - Bin Qi
- College of Pharmacy, Changchun University of Chinese Medicine, Changchun, China
| |
Collapse
|
9
|
Young D, Pedre B, Ezeriņa D, De Smet B, Lewandowska A, Tossounian MA, Bodra N, Huang J, Astolfi Rosado L, Van Breusegem F, Messens J. Protein Promiscuity in H 2O 2 Signaling. Antioxid Redox Signal 2019; 30:1285-1324. [PMID: 29635930 DOI: 10.1089/ars.2017.7013] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
SIGNIFICANCE Decrypting the cellular response to oxidative stress relies on a comprehensive understanding of the redox signaling pathways stimulated under oxidizing conditions. Redox signaling events can be divided into upstream sensing of oxidants, midstream redox signaling of protein function, and downstream transcriptional redox regulation. Recent Advances: A more and more accepted theory of hydrogen peroxide (H2O2) signaling is that of a thiol peroxidase redox relay, whereby protein thiols with low reactivity toward H2O2 are instead oxidized through an oxidative relay with thiol peroxidases. CRITICAL ISSUES These ultrareactive thiol peroxidases are the upstream redox sensors, which form the first cellular port of call for H2O2. Not all redox-regulated interactions between thiol peroxidases and cellular proteins involve a transfer of oxidative equivalents, and the nature of redox signaling is further complicated through promiscuous functions of redox-regulated "moonlighting" proteins, of which the precise cellular role under oxidative stress can frequently be obscured by "polygamous" interactions. An ultimate goal of redox signaling is to initiate a rapid response, and in contrast to prokaryotic oxidant-responsive transcription factors, mammalian systems have developed redox signaling pathways, which intersect both with kinase-dependent activation of transcription factors, as well as direct oxidative regulation of transcription factors through peroxiredoxin (Prx) redox relays. FUTURE DIRECTIONS We highlight that both transcriptional regulation and cell fate can be modulated either through oxidative regulation of kinase pathways, or through distinct redox-dependent associations involving either Prxs or redox-responsive moonlighting proteins with functional promiscuity. These protein associations form systems of crossregulatory networks with multiple nodes of potential oxidative regulation for H2O2-mediated signaling.
Collapse
Affiliation(s)
- David Young
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Brandan Pedre
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Daria Ezeriņa
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Barbara De Smet
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.,4 Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,5 Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Aleksandra Lewandowska
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.,4 Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,5 Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Maria-Armineh Tossounian
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Nandita Bodra
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.,4 Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,5 Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Jingjing Huang
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.,4 Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,5 Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Leonardo Astolfi Rosado
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Frank Van Breusegem
- 2 Brussels Center for Redox Biology, Brussels, Belgium.,4 Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,5 Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Joris Messens
- 1 Center for Structural Biology, VIB, Brussels, Belgium.,2 Brussels Center for Redox Biology, Brussels, Belgium.,3 Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| |
Collapse
|
10
|
Porter GA, Beutner G. Cyclophilin D, Somehow a Master Regulator of Mitochondrial Function. Biomolecules 2018; 8:E176. [PMID: 30558250 PMCID: PMC6316178 DOI: 10.3390/biom8040176] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 12/10/2018] [Accepted: 12/12/2018] [Indexed: 12/14/2022] Open
Abstract
Cyclophilin D (CyPD) is an important mitochondrial chaperone protein whose mechanism of action remains a mystery. It is well known for regulating mitochondrial function and coupling of the electron transport chain and ATP synthesis by controlling the mitochondrial permeability transition pore (PTP), but more recent evidence suggests that it may regulate electron transport chain activity. Given its identification as a peptidyl-prolyl, cis-trans isomerase (PPIase), CyPD, is thought to be involved in mitochondrial protein folding, but very few reports demonstrate the presence of this activity. By contrast, CyPD may also perform a scaffolding function, as it binds to a number of important proteins in the mitochondrial matrix and inner mitochondrial membrane. From a clinical perspective, inhibiting CyPD to inhibit PTP opening protects against ischemia⁻reperfusion injury, making modulation of CyPD activity a potentially important therapeutic goal, but the lack of knowledge about the mechanisms of CyPD's actions remains problematic for such therapies. Thus, the important yet enigmatic nature of CyPD somehow makes it a master regulator, yet a troublemaker, for mitochondrial function.
Collapse
Affiliation(s)
- George A Porter
- Department of Pediatrics, Division of Cardiology, University of Rochester School of Medicine, Rochester, NY 14642, USA.
| | - Gisela Beutner
- Department of Pediatrics, Division of Cardiology, University of Rochester School of Medicine, Rochester, NY 14642, USA.
| |
Collapse
|
11
|
Michaletti A, Gioia M, Tarantino U, Zolla L. Effects of microgravity on osteoblast mitochondria: a proteomic and metabolomics profile. Sci Rep 2017; 7:15376. [PMID: 29133864 PMCID: PMC5684136 DOI: 10.1038/s41598-017-15612-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/30/2017] [Indexed: 01/21/2023] Open
Abstract
The response of human primary osteoblasts exposed to simulated microgravity has been investigated and analysis of metabolomic and proteomic profiles demonstrated a prominent dysregulation of mitochondrion homeostasis. Gravitational unloading treatment induced a decrease in mitochondrial proteins, mainly affecting efficiency of the respiratory chain. Metabolomic analysis revealed that microgravity influenced several metabolic pathways; stimulating glycolysis and the pentose phosphate pathways, while the Krebs cycle was interrupted at succinate-fumarate transformation. Interestingly, proteomic analysis revealed that Complex II of the mitochondrial respiratory chain, which catalyses the biotransformation of this step, was under-represented by 50%. Accordingly, down-regulation of quinones 9 and 10 was measured. Complex III resulted in up-regulation by 60%, while Complex IV was down-regulated by 14%, accompanied by a reduction in proton transport synthesis of ATP. Finally, microgravity treatment induced an oxidative stress response, indicated by significant decreases in oxidised glutathione and antioxidant enzymes. Decrease in malate dehydrogenase induced a reverse in the malate-aspartate shuttle, contributing to dysregulation of ATP synthesis. Beta-oxidation of fatty acids was inhibited, promoting triglyceride production along with a reduction in the glycerol shuttle. Taken together, our findings suggest that microgravity may suppress bone cell functions, impairing mitochondrial energy potential and the energy state of the cell.
Collapse
Affiliation(s)
- Anna Michaletti
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Magda Gioia
- Department of Clinical Medicine and Translational Science, University of Rome Tor Vergata, Rome, Italy
| | - Umberto Tarantino
- Department of Clinical Medicine and Translational Science, University of Rome Tor Vergata, Rome, Italy
| | - Lello Zolla
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy.
| |
Collapse
|
12
|
An innovative strategy to clone positive modifier genes of defects caused by mtDNA mutations: MRPS18C as suppressor gene of m.3946G>A mutation in MT-ND1 gene. Hum Genet 2017; 136:885-896. [PMID: 28526948 DOI: 10.1007/s00439-017-1812-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 05/13/2017] [Indexed: 12/31/2022]
Abstract
We have developed a new functional complementation approach to clone modifier genes which overexpression is able to suppress the biochemical defects caused by mtDNA mutations (suppressor genes). This strategy consists in transferring human genes into respiratory chain-deficient fibroblasts, followed by a metabolic selection in a highly selective medium. We used a normalized expression cDNA library in an episomal vector (pREP4) to transfect the fibroblasts, and a medium with glutamine and devoid of any carbohydrate source to select metabolically. Growing the patient's fibroblasts in this selective medium, the deficient cells rapidly disappear unless they are rescued by the cDNA of a suppressor gene. The use of an episomal vector allows us to carry out several rounds of transfection/selection (cyclical phenotypic rescue) to enrich the rescue with true clones of suppressor genes. Using fibroblasts from a patient with epileptic encephalopathy with the m.3946G>A (p.E214K) mutation in the MT-ND1 gene, several candidate genes were identified and one of them was characterized functionally. Thus, overexpression of MRPS18C gene (that encode for bS18m protein) suppressed the molecular defects produced by this mtDNA mutation, recovering the complex I activity and reducing the ROS produced by this complex to normal levels. We suggest that modulation of bS18m expression may be an effective therapeutic strategy for the patients with this mutation.
Collapse
|