1
|
Kritskaya KA, Fedotova EI, Berezhnov AV. Impaired Mitochondrial Network Morphology and Reactive Oxygen Species Production in Fibroblasts from Parkinson's Disease Patients. Biomedicines 2024; 12:282. [PMID: 38397882 PMCID: PMC10886641 DOI: 10.3390/biomedicines12020282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 02/25/2024] Open
Abstract
The mitochondrial network (MN) is a dynamic structure undergoing constant remodeling in the cell. It is assumed that perturbations to the MN may be associated with various pathologies, including Parkinson's disease (PD). Using automatic image analysis and super-resolution microscopy, we have assessed the MN parameters in fibroblasts from patients with established hereditary PD mutations (associated with PINK1, LRRK2, and α-synuclein, as well as PINK1 and Parkin proteins simultaneously) under normal conditions and after hydrogen peroxide-induced stress. Fibroblasts with the Pink1/Parkin mutation are most different in morphology to fibroblasts obtained from conditionally healthy donors: the MN is larger, and it contains longer mitochondria and accumulated individual mitochondria. In addition to MN, we evaluated other cellular parameters, such as cytosolic and mitochondrial ROS production and mitochondrial membrane potential. It has been shown that mitochondria of fibroblasts with mutations in genes encoding PINK1, α-synuclein, and Pink/Parkin tend towards hyperpolarization and cytosolic ROS overproduction, while mitochondrial ROS production was higher only in fibroblasts with PINK1 and α-synuclein mutations.
Collapse
Affiliation(s)
- Kristina A. Kritskaya
- Institute of Cell Biophysics, Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, 3 Institutskaya Street, 142290 Pushchino, Russia;
| | | | - Alexey V. Berezhnov
- Institute of Cell Biophysics, Russian Academy of Sciences, Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, 3 Institutskaya Street, 142290 Pushchino, Russia;
| |
Collapse
|
2
|
Espinosa A, Casas M, Jaimovich E. Energy (and Reactive Oxygen Species Generation) Saving Distribution of Mitochondria for the Activation of ATP Production in Skeletal Muscle. Antioxidants (Basel) 2023; 12:1624. [PMID: 37627619 PMCID: PMC10451830 DOI: 10.3390/antiox12081624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/27/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Exercise produces oxidants from a variety of intracellular sources, including NADPH oxidases (NOX) and mitochondria. Exercise-derived reactive oxygen species (ROS) are beneficial, and the amount and location of these ROS is important to avoid muscle damage associated with oxidative stress. We discuss here some of the evidence that involves ROS production associated with skeletal muscle contraction and the potential oxidative stress associated with muscle contraction. We also discuss the potential role of H2O2 produced after NOX activation in the regulation of glucose transport in skeletal muscle. Finally, we propose a model based on evidence for the role of different populations of mitochondria in skeletal muscle in the regulation of ATP production upon exercise. The subsarcolemmal population of mitochondria has the enzymatic and metabolic components to establish a high mitochondrial membrane potential when fissioned at rest but lacks the capacity to produce ATP. Calcium entry into the mitochondria will further increase the metabolic input. Upon exercise, subsarcolemmal mitochondria will fuse to intermyofibrillar mitochondria and will transfer the mitochondria membrane potential to them. These mitochondria are rich in ATP synthase and will subsequentially produce the ATP needed for muscle contraction in long-term exercise. These events will optimize energy use and minimize mitochondria ROS production.
Collapse
Affiliation(s)
- Alejandra Espinosa
- Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8320000, Chile; (A.E.)
- San Felipe Campus, School of Medicine, Faculty of Medicine, Universidad de Valparaiso, San Felipe 2172972, Chile
| | - Mariana Casas
- Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8320000, Chile; (A.E.)
| | - Enrique Jaimovich
- Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8320000, Chile; (A.E.)
| |
Collapse
|
3
|
Velmurugan GV, Hubbard WB, Prajapati P, Vekaria HJ, Patel SP, Rabchevsky AG, Sullivan PG. LRP1 Deficiency Promotes Mitostasis in Response to Oxidative Stress: Implications for Mitochondrial Targeting after Traumatic Brain Injury. Cells 2023; 12:1445. [PMID: 37408279 PMCID: PMC10217498 DOI: 10.3390/cells12101445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 05/16/2023] [Accepted: 05/18/2023] [Indexed: 07/07/2023] Open
Abstract
The brain undergoes oxidative stress and mitochondrial dysfunction following physiological insults such as Traumatic brain injury (TBI), ischemia-reperfusion, and stroke. Pharmacotherapeutics targeting mitochondria (mitoceuticals) against oxidative stress include antioxidants, mild uncouplers, and enhancers of mitochondrial biogenesis, which have been shown to improve pathophysiological outcomes after TBI. However, to date, there is no effective treatment for TBI. Studies have suggested that the deletion of LDL receptor-related protein 1 (LRP1) in adult neurons or glial cells could be beneficial and promote neuronal health. In this study, we used WT and LRP1 knockout (LKO) mouse embryonic fibroblast cells to examine mitochondrial outcomes following exogenous oxidative stress. Furthermore, we developed a novel technique to measure mitochondrial morphometric dynamics using transgenic mitochondrial reporter mice mtD2g (mitochondrial-specific Dendra2 green) in a TBI model. We found that oxidative stress increased the quantity of fragmented and spherical-shaped mitochondria in the injury core of the ipsilateral cortex following TBI, whereas rod-like elongated mitochondria were seen in the corresponding contralateral cortex. Critically, LRP1 deficiency significantly decreased mitochondrial fragmentation, preserving mitochondrial function and cell growth following exogenous oxidative stress. Collectively, our results show that targeting LRP1 to improve mitochondrial function is a potential pharmacotherapeutic strategy against oxidative damage in TBI and other neurodegenerative diseases.
Collapse
Affiliation(s)
- Gopal V. Velmurugan
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 405036, USA; (G.V.V.); (W.B.H.); (P.P.); (H.J.V.); (S.P.P.); (A.G.R.)
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
| | - W. Brad Hubbard
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 405036, USA; (G.V.V.); (W.B.H.); (P.P.); (H.J.V.); (S.P.P.); (A.G.R.)
- Lexington Veterans’ Affairs Healthcare System, Lexington, KY 40502, USA
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA
| | - Paresh Prajapati
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 405036, USA; (G.V.V.); (W.B.H.); (P.P.); (H.J.V.); (S.P.P.); (A.G.R.)
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
- Lexington Veterans’ Affairs Healthcare System, Lexington, KY 40502, USA
| | - Hemendra J. Vekaria
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 405036, USA; (G.V.V.); (W.B.H.); (P.P.); (H.J.V.); (S.P.P.); (A.G.R.)
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
- Lexington Veterans’ Affairs Healthcare System, Lexington, KY 40502, USA
| | - Samir P. Patel
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 405036, USA; (G.V.V.); (W.B.H.); (P.P.); (H.J.V.); (S.P.P.); (A.G.R.)
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA
| | - Alexander G. Rabchevsky
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 405036, USA; (G.V.V.); (W.B.H.); (P.P.); (H.J.V.); (S.P.P.); (A.G.R.)
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA
| | - Patrick G. Sullivan
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 405036, USA; (G.V.V.); (W.B.H.); (P.P.); (H.J.V.); (S.P.P.); (A.G.R.)
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
- Lexington Veterans’ Affairs Healthcare System, Lexington, KY 40502, USA
| |
Collapse
|
4
|
Wang Y, Li J, Zhang Z, Wang R, Bo H, Zhang Y. Exercise Improves the Coordination of the Mitochondrial Unfolded Protein Response and Mitophagy in Aging Skeletal Muscle. Life (Basel) 2023; 13:life13041006. [PMID: 37109535 PMCID: PMC10142204 DOI: 10.3390/life13041006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 04/09/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
The mitochondrial unfolded protein response (UPRmt) and mitophagy are two mitochondrial quality control (MQC) systems that work at the molecular and organelle levels, respectively, to maintain mitochondrial homeostasis. Under stress conditions, these two processes are simultaneously activated and compensate for each other when one process is insufficient, indicating mechanistic coordination between the UPRmt and mitophagy that is likely controlled by common upstream signals. This review focuses on the molecular signals regulating this coordination and presents evidence showing that this coordination mechanism is impaired during aging and promoted by exercise. Furthermore, the bidirectional regulation of reactive oxygen species (ROS) and AMPK in modulating this mechanism is discussed. The hierarchical surveillance network of MQC can be targeted by exercise-derived ROS to attenuate aging, which offers a molecular basis for potential therapeutic interventions for sarcopenia.
Collapse
Affiliation(s)
- Yan Wang
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, School of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China
- School of Physical Education, Guangdong Institute of Petrochemical Technology, Maoming 525000, China
| | - Jialin Li
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, School of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China
| | - Ziyi Zhang
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, School of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China
| | - Runzi Wang
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, School of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China
| | - Hai Bo
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, School of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China
- Department of Military Training Medicines, Logistics University of Chinese People's Armed Police Force, Tianjin 300162, China
| | - Yong Zhang
- Tianjin Key Laboratory of Exercise Physiology and Sports Medicine, School of Exercise and Health, Tianjin University of Sport, Tianjin 301617, China
| |
Collapse
|
5
|
Chatzinikita E, Maridaki M, Palikaras K, Koutsilieris M, Philippou A. The Role of Mitophagy in Skeletal Muscle Damage and Regeneration. Cells 2023; 12:716. [PMID: 36899852 PMCID: PMC10000750 DOI: 10.3390/cells12050716] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 02/26/2023] Open
Abstract
Mitochondria are cellular organelles that play an essential role in generating the chemical energy needed for the biochemical reactions in cells. Mitochondrial biogenesis, i.e., de novo mitochondria formation, results in enhanced cellular respiration, metabolic processes, and ATP generation, while autophagic clearance of mitochondria (mitophagy) is required to remove damaged or useless mitochondria. The balance between the opposing processes of mitochondrial biogenesis and mitophagy is highly regulated and crucial for the maintenance of the number and function of mitochondria as well as for the cellular homeostasis and adaptations to metabolic demands and extracellular stimuli. In skeletal muscle, mitochondria are essential for maintaining energy homeostasis, and the mitochondrial network exhibits complex behaviors and undergoes dynamic remodeling in response to various conditions and pathologies characterized by changes in muscle cell structure and metabolism, such as exercise, muscle damage, and myopathies. In particular, the involvement of mitochondrial remodeling in mediating skeletal muscle regeneration following damage has received increased attention, as modifications in mitophagy-related signals arise from exercise, while variations in mitochondrial restructuring pathways can lead to partial regeneration and impaired muscle function. Muscle regeneration (through myogenesis) following exercise-induced damage is characterized by a highly regulated, rapid turnover of poor-functioning mitochondria, permitting the synthesis of better-functioning mitochondria to occur. Nevertheless, essential aspects of mitochondrial remodeling during muscle regeneration remain poorly understood and warrant further characterization. In this review, we focus on the critical role of mitophagy for proper muscle cell regeneration following damage, highlighting the molecular mechanisms of the mitophagy-associated mitochondrial dynamics and network reformation.
Collapse
Affiliation(s)
- Eirini Chatzinikita
- Department of Physiology, Medical School, National and Kapodistrian University of Athens, 115 27 Athens, Greece
| | - Maria Maridaki
- Faculty of Physical Education and Sport Science, National and Kapodistrian University of Athens, 172 37 Athens, Greece
| | - Konstantinos Palikaras
- Department of Physiology, Medical School, National and Kapodistrian University of Athens, 115 27 Athens, Greece
| | - Michael Koutsilieris
- Department of Physiology, Medical School, National and Kapodistrian University of Athens, 115 27 Athens, Greece
| | - Anastassios Philippou
- Department of Physiology, Medical School, National and Kapodistrian University of Athens, 115 27 Athens, Greece
| |
Collapse
|
6
|
Vanisova M, Stufkova H, Kohoutova M, Rakosnikova T, Krizova J, Klempir J, Rysankova I, Roth J, Zeman J, Hansikova H. Mitochondrial organization and structure are compromised in fibroblasts from patients with Huntington's disease. Ultrastruct Pathol 2022; 46:462-475. [PMID: 35946926 DOI: 10.1080/01913123.2022.2100951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Huntington´s disease (HD) is a progressive neurodegenerative disease with onset in adulthood that leads to a complete disability and death in approximately 20 years after onset of symptoms. HD is caused by an expansion of a CAG triplet in the gene for huntingtin. Although the disease causes most damage to striatal neurons, other parts of the nervous system and many peripheral tissues are also markedly affected. Besides huntingtin malfunction, mitochondrial impairment has been previously described as an important player in HD. This study focuses on mitochondrial structure and function in cultivated skin fibroblasts from 10 HD patients to demonstrate mitochondrial impairment in extra-neuronal tissue. Mitochondrial structure, mitochondrial fission, and cristae organization were significantly disrupted and signs of elevated apoptosis were found. In accordance with structural changes, we also found indicators of functional alteration of mitochondria. Mitochondrial disturbances presented in fibroblasts from HD patients confirm that the energy metabolism damage in HD is not localized only to the central nervous system, but also may play role in the pathogenesis of HD in peripheral tissues. Skin fibroblasts can thus serve as a suitable cellular model to make insight into HD pathobiochemical processes and for the identification of possible targets for new therapies.
Collapse
Affiliation(s)
- Marie Vanisova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Hana Stufkova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Michaela Kohoutova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Tereza Rakosnikova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Jana Krizova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Jiri Klempir
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Irena Rysankova
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Jan Roth
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Jiri Zeman
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Hana Hansikova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| |
Collapse
|
7
|
Suzuki-Karasaki M, Ando T, Ochiai Y, Kawahara K, Suzuki-Karasaki M, Nakayama H, Suzuki-Karasaki Y. Air Plasma-Activated Medium Evokes a Death-Associated Perinuclear Mitochondrial Clustering. Int J Mol Sci 2022; 23:1124. [PMID: 35163042 DOI: 10.3390/ijms23031124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 12/01/2022] Open
Abstract
Intractable cancers such as osteosarcoma (OS) and oral cancer (OC) are highly refractory, recurrent, and metastatic once developed, and their prognosis is still disappointing. Tumor-targeted therapy, which eliminates cancers effectively and safely, is the current clinical choice. Since aggressive tumors are substantially resistant to multidisciplinary therapies that target apoptosis, tumor-specific activation of another cell death modality is a promising avenue for meeting this goal. Here, we report that a cold atmospheric air plasma-activated medium (APAM) can kill OS and OC by causing a unique mitochondrial clustering. This event was named monopolar perinuclear mitochondrial clustering (MPMC) based on its characteristic unipolar mitochondrial perinuclear accumulation. The APAM caused apoptotic and nonapoptotic cell death. The APAM increased mitochondrial ROS (mROS) and cell death, and the antioxidants such as N-acetylcysteine (NAC) prevented them. MPMC occurred following mitochondrial fragmentation, which coincided with nuclear damages. MPMC was accompanied by mitochondrial lipid peroxide (mLPO) accumulation and prevented by NAC, Ferrostatin-1, and Nocodazole. In contrast, the APAM induced minimal cell death, mROS generation, mLPO accumulation, and MPMC in fibroblasts. These results suggest that MPMC occurs in a tumor-specific manner via mitochondrial oxidative stress and microtubule-driven mitochondrial motility. MPMC induction might serve as a promising target for exerting tumor-specific cytotoxicity.
Collapse
|
8
|
García-Arroyo R, Gavaldà-Navarro A, Villarroya F, Marfany G, Mirra S. Overexpression of CERKL Protects Retinal Pigment Epithelium Mitochondria from Oxidative Stress Effects. Antioxidants (Basel) 2021; 10:2018. [PMID: 34943121 DOI: 10.3390/antiox10122018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/14/2021] [Accepted: 12/17/2021] [Indexed: 02/02/2023] Open
Abstract
The precise function of CERKL, a Retinitis Pigmentosa (RP) causative gene, is not yet fully understood. There is evidence that CERKL is involved in the regulation of autophagy, stress granules, and mitochondrial metabolism, and it is considered a gene that is resilient against oxidative stress in the retina. Mutations in most RP genes affect photoreceptors, but retinal pigment epithelium (RPE) cells may be also altered. Here, we aimed to analyze the effect of CERKL overexpression and depletion in vivo and in vitro, focusing on the state of the mitochondrial network under oxidative stress conditions. Our work indicates that the depletion of CERKL increases the vulnerability of RPE mitochondria, which show a shorter size and altered shape, particularly upon sodium arsenite treatment. CERKL-depleted cells have dysfunctional mitochondrial respiration particularly upon oxidative stress conditions. The overexpression of two human CERKL isoforms (558 aa and 419 aa), which display different protein domains, shows that a pool of CERKL localizes at mitochondria in RPE cells and that CERKL protects the mitochondrial network—both in size and shape—against oxidative stress. Our results support CERKL being a resilient gene that regulates the mitochondrial network in RPE as in retinal neurons and suggest that RPE cell alteration contributes to particular phenotypic traits in patients carrying CERKL mutations.
Collapse
|
9
|
Abstract
Mitochondria and lipid droplets in the insulin resistant skeletal muscle of type 2 diabetic individuals have both been heavily investigated independently and are characterized by more fragmented, dysfunctional mitochondrial networks and larger lipid droplets compared to skeletal muscle of healthy individuals. Specialized contacts between mitochondrial and lipid droplet membranes are known to decrease in diabetic muscle, though it remains unclear how energy transfer at the remaining mitochondria-lipid droplet contact sites may be altered by type 2 diabetes. The purpose of this review is to highlight recent data on mitochondrial structure and function and lipid droplet dynamics in type 2 diabetic skeletal muscle and to underscore the need for more detailed investigations into the functional nature of mitochondria-lipid droplet interactions in type 2 diabetes.
Collapse
|
10
|
Balvín O, Sasínková M, Martinů J, Nazarizadeh M, Bubová T, Booth W, Vargo EL, Štefka J. Early evidence of establishment of the tropical bedbug (Cimex hemipterus) in Central Europe. Med Vet Entomol 2021; 35:462-467. [PMID: 33948981 DOI: 10.1111/mve.12522] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/06/2021] [Accepted: 04/16/2021] [Indexed: 06/12/2023]
Abstract
In recent decades, the world has witnessed a remarkable resurgence of bedbugs (Hemiptera: Cimicidae). Although populations of the common bedbug, Cimex lectularius L., expanded in temperate regions of its original distribution, the tropical bedbug, C. hemipterus (F.), increased its abundance in warmer regions, where it also had been historically distributed. However, C. hemipterus has recently been observed to be expanding to other areas, e.g. North Australia, Middle East, the United States and Russia. In other parts of Europe, few sporadic and ephemeral introductions of C. hemipterus were recorded until recently. We conducted an extensive sampling of European bedbug populations starting in 2002 and found that C. hemipterus has recently become locally established. Among 566 examined infestations, nearly all of which involved C. lectularius, C. hemipterus occurred in six infestations collected since 2019. In at least three cases, the social background of inhabitants of the infested properties indicated that tropical bedbugs likely spread within local communities. Using cytochrome oxidase subunit I, we linked five of the infestations to the most common haplotype found globally, and one to an African haplotype. In all infestations, we observed two kdr-associated mutations in the sodium channel gene, which are also commonly found across the world.
Collapse
Affiliation(s)
- O Balvín
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences in Prague, Prague, Czech Republic
| | - M Sasínková
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences in Prague, Prague, Czech Republic
| | - J Martinů
- Institute of Parasitology, Biology Centre CAS, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - M Nazarizadeh
- Institute of Parasitology, Biology Centre CAS, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - T Bubová
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences in Prague, Prague, Czech Republic
- National Reference Laboratory for Vector Control, Centre for Epidemiology and Microbiology, National Institute of Public Health, Prague, Czech Republic
| | - W Booth
- Department of Biological Science, The University of Tulsa, Tulsa, OK, U.S.A
| | - E L Vargo
- Department of Entomology, Texas A&M University, College Station, TX, U.S.A
| | - J Štefka
- Institute of Parasitology, Biology Centre CAS, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| |
Collapse
|
11
|
Nasoni MG, Carloni S, Canonico B, Burattini S, Cesarini E, Papa S, Pagliarini M, Ambrogini P, Balduini W, Luchetti F. Melatonin reshapes the mitochondrial network and promotes intercellular mitochondrial transfer via tunneling nanotubes after ischemic-like injury in hippocampal HT22 cells. J Pineal Res 2021; 71:e12747. [PMID: 34085316 PMCID: PMC8365755 DOI: 10.1111/jpi.12747] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/21/2021] [Accepted: 05/31/2021] [Indexed: 12/17/2022]
Abstract
Mitochondrial dysfunction is considered one of the hallmarks of ischemia/reperfusion injury. Mitochondria are plastic organelles that undergo continuous biogenesis, fusion, and fission. They can be transferred between cells through tunneling nanotubes (TNTs), dynamic structures that allow the exchange of proteins, soluble molecules, and organelles. Maintaining mitochondrial dynamics is crucial to cell function and survival. The present study aimed to assess the effects of melatonin on mitochondrial dynamics, TNT formation, and mitochondria transfer in HT22 cells exposed to oxygen/glucose deprivation followed by reoxygenation (OGD/R). The results showed that melatonin treatment during the reoxygenation phase reduced mitochondrial reactive oxygen species (ROS) production, improved cell viability, and increased the expression of PGC1α and SIRT3. Melatonin also preserved the expression of the membrane translocase proteins TOM20 and TIM23, and of the matrix protein HSP60, which are involved in mitochondrial biogenesis. Moreover, it promoted mitochondrial fusion and enhanced the expression of MFN2 and OPA1. Remarkably, melatonin also fostered mitochondrial transfer between injured HT22 cells through TNT connections. These results provide new insights into the effect of melatonin on mitochondrial network reshaping and cell survival. Fostering TNTs formation represents a novel mechanism mediating the protective effect of melatonin in ischemia/reperfusion injury.
Collapse
Affiliation(s)
- Maria Gemma Nasoni
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| | - Silvia Carloni
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| | - Barbara Canonico
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| | - Sabrina Burattini
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| | - Erica Cesarini
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| | - Stefano Papa
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| | - Marica Pagliarini
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| | - Patrizia Ambrogini
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| | - Walter Balduini
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| | - Francesca Luchetti
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| |
Collapse
|
12
|
Comandatore F, Radaelli G, Montante S, Sacchi L, Clementi E, Epis S, Cafiso A, Serra V, Pajoro M, Di Carlo D, Floriano AM, Stavru F, Bandi C, Sassera D. Modeling the Life Cycle of the Intramitochondrial Bacterium " Candidatus Midichloria mitochondrii" Using Electron Microscopy Data. mBio 2021; 12:e0057421. [PMID: 34154402 DOI: 10.1128/mBio.00574-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
“Candidatus Midichloria mitochondrii” is a Gram-negative bacterium that lives in strict intracellular symbiosis with the hard tick Ixodes ricinus, forming one of the most intriguing endosymbiosis described to date. The bacterium is capable of durably colonizing the host mitochondria, a peculiar tropism that makes “Ca. Midichloria mitochondrii” a very interesting tool to study the physiology of these cellular organelles. The interaction between the symbiont and the organelle has, however, been difficult to characterize. A parallelism with the predatory bacterium Bdellovibrio bacteriovorus has been drawn, suggesting the hypothesis that “Ca. Midichloria mitochondrii” could prey on mitochondria and consume them to multiply. We studied the life cycle of the bacterium within the host oocytes using a multidisciplinary approach, including electron microscopy, molecular biology, statistics, and systems biology. Our results were not coherent with a predatory-like behavior by “Ca. Midichloria mitochondrii” leading us to propose a novel hypothesis for its life cycle. Based on our results, we here present a novel model called the “mitochondrion-to-mitochondrion hypothesis.” Under this model, the bacterium would be able to move from mitochondrion to mitochondrion, possibly within a mitochondrial network. We show that this model presents a good fit with quantitative electron microscopy data.
Collapse
|
13
|
Ando T, Suzuki-Karasaki M, Suzuki-Karasaki M, Ichikawa J, Ochiai T, Yoshida Y, Haro H, Suzuki-Karasaki Y. Combined Anticancer Effect of Plasma-Activated Infusion and Salinomycin by Targeting Autophagy and Mitochondrial Morphology. Front Oncol 2021; 11:593127. [PMID: 34150606 PMCID: PMC8212785 DOI: 10.3389/fonc.2021.593127] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 05/11/2021] [Indexed: 01/10/2023] Open
Abstract
Non-thermal atmospheric pressure plasma (NTAPP)-activated liquids have emerged as new promising anticancer agents because they preferentially injure malignant cells. Here, we report plasma-activated infusion (PAI) as a novel NTAPP-based anti-neoplastic agent. PAI was prepared by irradiating helium NTAP to form a clinically approved infusion fluid. PAI dose-dependently killed malignant melanoma and osteosarcoma cell lines while showing much lower cytotoxic effects on dermal and lung fibroblasts. We found that PAI and salinomycin (Sal), an emerging anticancer stem cell agent, mutually operated as adjuvants. The combined administration of PAI and Sal was much more effective than single-agent application in reducing the growth and lung metastasis of osteosarcoma allografts with minimal adverse effects. Mechanistically, PAI explicitly induced necroptosis and increased the phosphorylation of receptor-interacting protein 1/3 rapidly and transiently. PAI also suppressed the ambient autophagic flux by activating the mammalian target of the rapamycin pathway. PAI increased the phosphorylation of Raptor, Rictor, and p70-S6 kinase, along with decreased LC3-I/II expression. In contrast, Sal promoted autophagy. Moreover, Sal exacerbated the mitochondrial network collapse caused by PAI, resulting in aberrant clustering of fragmented mitochondrial in a tumor-specific manner. Our findings suggest that combined administration of PAI and Sal is a promising approach for treating these apoptosis-resistant cancers.
Collapse
Affiliation(s)
- Takashi Ando
- Department of Orthopaedic Surgery, Yamanashi University School of Medicine, Yamanashi, Japan
| | - Manami Suzuki-Karasaki
- Department of Research and Development, Plasma ChemiBio Laboratory, Plasma ChemiBio Laboratory, Nasushiobara, Tochigi, Japan
| | - Miki Suzuki-Karasaki
- Department of Research and Development, Plasma ChemiBio Laboratory, Plasma ChemiBio Laboratory, Nasushiobara, Tochigi, Japan
| | - Jiro Ichikawa
- Department of Orthopaedic Surgery, Yamanashi University School of Medicine, Yamanashi, Japan
| | - Toyoko Ochiai
- Department of Research and Development, Plasma ChemiBio Laboratory, Plasma ChemiBio Laboratory, Nasushiobara, Tochigi, Japan.,Department of Dermatology, Nihon University Hospital, Tokyo, Japan
| | - Yukihiro Yoshida
- Department of Orthopaedic Surgery, Nihon University School of Medicine, Nihon University Orthopaedic Surgery, Tokyo, Japan
| | - Hirotaka Haro
- Department of Orthopaedic Surgery, Yamanashi University School of Medicine, Yamanashi, Japan
| | - Yoshihiro Suzuki-Karasaki
- Department of Research and Development, Plasma ChemiBio Laboratory, Plasma ChemiBio Laboratory, Nasushiobara, Tochigi, Japan
| |
Collapse
|
14
|
Chidipi B, Shah SI, Reiser M, Kanithi M, Garces A, Cha BJ, Ullah G, Noujaim SF. All-Trans Retinoic Acid Increases DRP1 Levels and Promotes Mitochondrial Fission. Cells 2021; 10:1202. [PMID: 34068960 DOI: 10.3390/cells10051202] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 02/07/2023] Open
Abstract
In the heart, mitochondrial homeostasis is critical for sustaining normal function and optimal responses to metabolic and environmental stressors. Mitochondrial fusion and fission are thought to be necessary for maintaining a robust population of mitochondria, and disruptions in mitochondrial fission and/or fusion can lead to cellular dysfunction. The dynamin-related protein (DRP1) is an important mediator of mitochondrial fission. In this study, we investigated the direct effects of the micronutrient retinoid all-trans retinoic acid (ATRA) on the mitochondrial structure in vivo and in vitro using Western blot, confocal, and transmission electron microscopy, as well as mitochondrial network quantification using stochastic modeling. Our results showed that ATRA increases DRP1 protein levels, increases the localization of DRP1 to mitochondria in isolated mitochondrial preparations. Our results also suggested that ATRA remodels the mitochondrial ultrastructure where the mitochondrial area and perimeter were decreased and the circularity was increased. Microscopically, mitochondrial network remodeling is driven by an increased rate of fission over fusion events in ATRA, as suggested by our numerical modeling. In conclusion, ATRA results in a pharmacologically mediated increase in the DRP1 protein. It also results in the modulation of cardiac mitochondria by promoting fission events, altering the mitochondrial network, and modifying the ultrastructure of mitochondria in the heart.
Collapse
|
15
|
Fan W, Song Y, Ren Z, Cheng X, Li P, Song H, Jia L. Glioma cells are resistant to inflammation‑induced alterations of mitochondrial dynamics. Int J Oncol 2020; 57:1293-1306. [PMID: 33174046 PMCID: PMC7646598 DOI: 10.3892/ijo.2020.5134] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 09/24/2020] [Indexed: 12/18/2022] Open
Abstract
Accumulating evidence suggests that inflammation is present in solid tumors. However, it is poorly understood whether inflammation exists in glioma and how it affects the metabolic signature of glioma. By analyzing immunohistochemical data and gene expression data downloaded from bioinformatic datasets, the present study revealed an accumulation of inflammatory cells in glioma, activation of microglia, upregulation of proinflammatory factors (including IL-6, IL-8, hypoxia-inducible factor-1α, STAT3, NF-κB1 and NF-κB2), destruction of mitochondrial structure and altered expression levels of electron transfer chain complexes and metabolic enzymes. By monitoring glioma cells following proinflammatory stimulation, the current study observed a remodeling of their mitochondrial network via mitochondrial fission. More than half of the mitochondria presented ring-shaped or spherical morphologies. Transmission electron microscopic analyses revealed mitochondrial swelling with partial or total cristolysis. Furthermore, proinflammatory stimuli resulted in increased generation of reactive oxygen species, decreased mitochondrial membrane potential and reprogrammed metabolism. The defective mitochondria were not eliminated via mitophagy. However, cell viability was not affected, and apoptosis was decreased in glioma cells after proinflammatory stimuli. Overall, the present findings suggested that inflammation may be present in glioma and that glioma cells may be resistant to inflammation-induced mitochondrial dysfunction.
Collapse
Affiliation(s)
- Wange Fan
- Department of Medical Genetics and Cell Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Yanan Song
- Department of Medical Genetics and Cell Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Zongyao Ren
- Department of Medical Genetics and Cell Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Xiaoli Cheng
- Department of Medical Genetics and Cell Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Pu Li
- Department of Medical Genetics and Cell Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Huiling Song
- Department of Medical Genetics and Cell Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Liyun Jia
- Department of Medical Genetics and Cell Biology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| |
Collapse
|
16
|
Sekula M, Tworzydlo W, Bilinski SM. Morphogenesis of the Balbiani body in developing oocytes of an orthopteran, Metrioptera brachyptera, and multiplication of female germline mitochondria. J Morphol 2020; 281:1142-1151. [PMID: 32767591 DOI: 10.1002/jmor.21242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/19/2020] [Accepted: 07/17/2020] [Indexed: 12/23/2022]
Abstract
Balbiani body (Bb) is a female germline specific organelle complex. Although the morphology and morphogenesis of the Bb have been analyzed in numerous vertebrate and invertebrate species, the role and ultimate fate of this organelle assemblage are still under debate. As a result, various functions have been attributed to the Bb in given animal lineages or even species. Our analyses showed that in the bush cricket, Metrioptera brachyptera, the Bb is an elaborate and highly dynamic structure positioned at one side of the oocyte nucleus. It forms in early previtellogenic oocytes and consists of two compartments: perinuclear and cytoplasmic. In the cytoplasmic compartment, characteristic complexes of nuage and polymorphous mitochondria are present. Computer-aided 3D reconstructions revealed that mitochondria clustered around neighboring nuage accumulations remain in a physical contact and form an extensive, though dispersed network. As oogenesis progresses, nuage/mitochondria complexes are partitioned into progressively smaller entities that become separated from each other. Concurrently, the mitochondrial network splits into small individual mitochondria populating the whole ooplasm. Immunohistochemical analysis showed that the latter process involves dynamin-related protein 1 (Drp1). Collectively, our findings suggest that in basal insect species, the Bb might be responsible for the selection as well as multiplication of the oocyte mitochondria.
Collapse
Affiliation(s)
- Malgorzata Sekula
- Department of Developmental Biology and Invertebrate Morphology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University in Krakow, Krakow, Poland
| | - Waclaw Tworzydlo
- Department of Developmental Biology and Invertebrate Morphology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University in Krakow, Krakow, Poland
| | - Szczepan M Bilinski
- Department of Developmental Biology and Invertebrate Morphology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University in Krakow, Krakow, Poland
| |
Collapse
|
17
|
Mollo N, Cicatiello R, Aurilia M, Scognamiglio R, Genesio R, Charalambous M, Paladino S, Conti A, Nitsch L, Izzo A. Targeting Mitochondrial Network Architecture in Down Syndrome and Aging. Int J Mol Sci 2020; 21:E3134. [PMID: 32365535 PMCID: PMC7247689 DOI: 10.3390/ijms21093134] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 04/26/2020] [Accepted: 04/27/2020] [Indexed: 12/12/2022] Open
Abstract
Mitochondria are organelles that mainly control energy conversion in the cell. In addition, they also participate in many relevant activities, such as the regulation of apoptosis and calcium levels, and other metabolic tasks, all closely linked to cell viability. Functionality of mitochondria appears to depend upon their network architecture that may dynamically pass from an interconnected structure with long tubular units, to a fragmented one with short separate fragments. A decline in mitochondrial quality, which presents itself as an altered structural organization and a function of mitochondria, has been observed in Down syndrome (DS), as well as in aging and in age-related pathologies. This review provides a basic overview of mitochondrial dynamics, from fission/fusion mechanisms to mitochondrial homeostasis. Molecular mechanisms determining the disruption of the mitochondrial phenotype in DS and aging are discussed. The impaired activity of the transcriptional co-activator PGC-1α/PPARGC1A and the hyperactivation of the mammalian target of rapamycin (mTOR) kinase are emerging as molecular underlying causes of these mitochondrial alterations. It is, therefore, likely that either stimulating the PGC-1α activity or inhibiting mTOR signaling could reverse mitochondrial dysfunction. Evidence is summarized suggesting that drugs targeting either these pathways or other factors affecting the mitochondrial network may represent therapeutic approaches to improve and/or prevent the effects of altered mitochondrial function. Overall, from all these studies it emerges that the implementation of such strategies may exert protective effects in DS and age-related diseases.
Collapse
Affiliation(s)
- Nunzia Mollo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
| | - Rita Cicatiello
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
| | - Miriam Aurilia
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
| | - Roberta Scognamiglio
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
| | - Rita Genesio
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
| | - Maria Charalambous
- Institute of Experimental Endocrinology and Oncology “G. Salvatore”, National Research Council, 80131 Naples, Italy
| | - Simona Paladino
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
| | - Anna Conti
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
| | - Lucio Nitsch
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
- Institute of Experimental Endocrinology and Oncology “G. Salvatore”, National Research Council, 80131 Naples, Italy
| | - Antonella Izzo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
| |
Collapse
|
18
|
Kim S, Song J, Ernst P, Latimer MN, Ha CM, Goh KY, Ma W, Rajasekaran NS, Zhang J, Liu X, Prabhu SD, Qin G, Wende AR, Young ME, Zhou L. MitoQ regulates redox-related noncoding RNAs to preserve mitochondrial network integrity in pressure-overload heart failure. Am J Physiol Heart Circ Physiol 2020; 318:H682-H695. [PMID: 32004065 PMCID: PMC7099446 DOI: 10.1152/ajpheart.00617.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 01/29/2020] [Accepted: 01/29/2020] [Indexed: 01/04/2023]
Abstract
Evidence suggests that mitochondrial network integrity is impaired in cardiomyocytes from failing hearts. While oxidative stress has been implicated in heart failure (HF)-associated mitochondrial remodeling, the effect of mitochondrial-targeted antioxidants, such as mitoquinone (MitoQ), on the mitochondrial network in a model of HF (e.g., pressure overload) has not been demonstrated. Furthermore, the mechanism of this regulation is not completely understood with an emerging role for posttranscriptional regulation via long noncoding RNAs (lncRNAs). We hypothesized that MitoQ preserves mitochondrial fusion proteins (i.e., mitofusin), likely through redox-sensitive lncRNAs, leading to improved mitochondrial network integrity in failing hearts. To test this hypothesis, 8-wk-old C57BL/6J mice were subjected to ascending aortic constriction (AAC), which caused substantial left ventricular (LV) chamber remodeling and remarkable contractile dysfunction in 1 wk. Transmission electron microscopy and immunostaining revealed defective intermitochondrial and mitochondrial-sarcoplasmic reticulum ultrastructure in AAC mice compared with sham-operated animals, which was accompanied by elevated oxidative stress and suppressed mitofusin (i.e., Mfn1 and Mfn2) expression. MitoQ (1.36 mg·day-1·mouse-1, 7 consecutive days) significantly ameliorated LV dysfunction, attenuated Mfn2 downregulation, improved interorganellar contact, and increased metabolism-related gene expression. Moreover, our data revealed that MitoQ alleviated the dysregulation of an Mfn2-associated lncRNA (i.e., Plscr4). In summary, the present study supports a unique mechanism by which MitoQ improves myocardial intermitochondrial and mitochondrial-sarcoplasmic reticulum (SR) ultrastructural remodeling in HF by maintaining Mfn2 expression via regulation by an lncRNA. These findings underscore the important role of lncRNAs in the pathogenesis of HF and the potential of targeting them for effective HF treatment.NEW & NOTEWORTHY We have shown that MitoQ improves cardiac mitochondrial network integrity and mitochondrial-SR alignment in a pressure-overload mouse heart-failure model. This may be occurring partly through preventing the dysregulation of a redox-sensitive lncRNA-microRNA pair (i.e., Plscr4-miR-214) that results in an increase in mitofusin-2 expression.
Collapse
Affiliation(s)
- Seulhee Kim
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jiajia Song
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Patrick Ernst
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Mary N Latimer
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Chae-Myeong Ha
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kah Yong Goh
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Wenxia Ma
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | | | - Jianhua Zhang
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Xiaoguang Liu
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Sumanth D Prabhu
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Gangjian Qin
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| | - Adam R Wende
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Martin E Young
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Lufang Zhou
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, Alabama
| |
Collapse
|
19
|
Kingsbury C, Heyck M, Bonsack B, Lee JY, Borlongan CV. Stroke gets in your eyes: stroke-induced retinal ischemia and the potential of stem cell therapy. Neural Regen Res 2019; 15:1014-1018. [PMID: 31823871 PMCID: PMC7034271 DOI: 10.4103/1673-5374.270293] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Stroke persists as a global health and economic crisis, yet only two interventions to reduce stroke-induced brain injury exist. In the clinic, many patients who experience an ischemic stroke often further suffer from retinal ischemia, which can inhibit their ability to make a functional recovery and may diminish their overall quality of life. Despite this, no treatments for retinal ischemia have been developed. In both cases, ischemia-induced mitochondrial dysfunction initiates a cell loss cascade and inhibits endogenous brain repair. Stem cells have the ability to transfer healthy and functional mitochondria not only ischemic neurons, but also to similarly endangered retinal cells, replacing their defective mitochondria and thereby reducing cell death. In this review, we encapsulate and assess the relationship between cerebral and retinal ischemia, recent preclinical advancements made using in vitro and in vivo retinal ischemia models, the role of mitochondrial dysfunction in retinal ischemia pathology, and the therapeutic potential of stem cell-mediated mitochondrial transfer. Furthermore, we discuss the pitfalls in classic rodent functional assessments and the potential advantages of laser Doppler as a metric of stroke progression. The studies evaluated in this review highlight stem cell-derived mitochondrial transfer as a novel therapeutic approach to both retinal ischemia and stroke. Furthermore, we posit the immense correlation between cerebral and retinal ischemia as an underserved area of study, warranting exploration with the aim of these treating injuries together.
Collapse
Affiliation(s)
- Chase Kingsbury
- Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL, USA
| | - Matt Heyck
- Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL, USA
| | - Brooke Bonsack
- Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL, USA
| | - Jea-Young Lee
- Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL, USA
| | - Cesar V Borlongan
- Center of Excellence for Aging and Brain Repair, University of South Florida College of Medicine, Tampa, FL, USA
| |
Collapse
|
20
|
Yang M, Van Wijk E, Pang J, Yan Y, van der Greef J, Van Wijk R, Han J. A Bridge of Light: Toward Chinese and Western Medicine Perspectives Through Ultraweak Photon Emissions. Glob Adv Health Med 2019; 8:2164956119855930. [PMID: 31218117 PMCID: PMC6558537 DOI: 10.1177/2164956119855930] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 04/18/2019] [Accepted: 05/16/2019] [Indexed: 12/23/2022] Open
Abstract
The gap between Western medicine and traditional Chinese medicine (CM) is closely
related to the diversity in culture, philosophy, and scientific developments.
Although numerous studies have evaluated the efficacy of acupuncture, the gap in
explanatory disease models has not been bridged so far. Developments in research
of ultraweak photon emission (UPE) and organized dynamics of metabolism and its
relationship with technological advances in metabolomics have created the
conditions to bring the basics of the medicines of the West and East together
which might open the avenue for a scientific dialogue. The paper discusses (1)
the UPE in relation to Qi energy, meridians and acupuncture points in CM, (2)
the biochemical explanation of photon emission of living systems in Western
biomedicine, and (3) the progress in research on the large-scale organization
and dynamics of the metabolic network including photon metabolism.
Collapse
Affiliation(s)
- Meina Yang
- Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, China
| | - Eduard Van Wijk
- Sino-Dutch Centre for Preventive and Personalized Medicine, Tiel, The Netherlands.,Meluna Research, Geldermalsen, The Netherlands
| | - Jingxiang Pang
- Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, China
| | - Yu Yan
- Sino-Dutch Centre for Preventive and Personalized Medicine, Tiel, The Netherlands.,Meluna Research, Geldermalsen, The Netherlands
| | - Jan van der Greef
- Sino-Dutch Centre for Preventive and Personalized Medicine, Tiel, The Netherlands.,Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Roeland Van Wijk
- Sino-Dutch Centre for Preventive and Personalized Medicine, Tiel, The Netherlands.,Meluna Research, Geldermalsen, The Netherlands
| | - Jinxiang Han
- Shandong Medicinal Biotechnology Centre, Shandong Academy of Medical Sciences, Jinan, China
| |
Collapse
|
21
|
Papa L, Djedaini M, Hoffman R. Ex vivo HSC expansion challenges the paradigm of unidirectional human hematopoiesis. Ann N Y Acad Sci 2019; 1466:39-50. [PMID: 31199002 PMCID: PMC7216880 DOI: 10.1111/nyas.14133] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/30/2019] [Accepted: 05/10/2019] [Indexed: 12/21/2022]
Abstract
Understanding mechanisms that determine the behavior of human hematopoietic stem cells (HSCs) is essential for developing novel strategies to expand ex vivo the number of fully functional HSCs. In this review, we focus on the complex interplay between intrinsic mechanisms regulated by transcriptional and mitochondrial networks and extrinsic signals imposed by the bone marrow microenvironment, which in concert regulate the balance between HSC self‐renewal and differentiation. Such integrated signaling mechanisms that dictate the fate of HSCs in vivo must be recapitulated ex vivo to achieve successful expansion of clinically relevant HSCs. We also highlight some of the most recent ex vivo HSC expansion strategies that have currently entered clinical development. Finally, based on the evidence reviewed here and lessons learned from ex vivo HSC expansion, we raise some critical questions regarding HSC fate and the cellular plasticity of hematopoietic cells that challenge the unidirectional model of human hematopoiesis.
Collapse
Affiliation(s)
- Luena Papa
- Division of Hematology/Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Mansour Djedaini
- Division of Hematology/Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Ronald Hoffman
- Division of Hematology/Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| |
Collapse
|
22
|
Engelhart EA, Hoppins S. A catalytic domain variant of mitofusin requiring a wildtype paralog for function uncouples mitochondrial outer-membrane tethering and fusion. J Biol Chem 2019; 294:8001-8014. [PMID: 30936207 DOI: 10.1074/jbc.ra118.006347] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 03/27/2019] [Indexed: 11/06/2022] Open
Abstract
Mitofusins (Mfns) are dynamin-related GTPases that mediate mitochondrial outer-membrane fusion, a process that is required for mitochondrial and cellular health. In Mfn1 and Mfn2 paralogs, a conserved phenylalanine (Phe-202 (Mfn1) and Phe-223 (Mfn2)) located in the GTPase domain on a conserved β strand is part of an aromatic network in the core of this domain. To gain insight into the poorly understood mechanism of Mfn-mediated membrane fusion, here we characterize a Mitofusin mutant variant etiologically linked to Charcot-Marie-Tooth syndrome. From analysis of mitochondrial structure in cells and mitochondrial fusion in vitro, we found that conversion of Phe-202 to leucine in either Mfn1 or Mfn2 diminishes the fusion activity of heterotypic complexes with both Mfn1 and Mfn2 and abolishes fusion activity of homotypic complexes. Using coimmunoprecipitation and native gel analysis, we further dissect the steps of mitochondrial fusion and demonstrate that the mutant variant has normal tethering activity but impaired higher-order nucleotide-dependent assembly. The defective coupling of tethering to membrane fusion observed here suggests that nucleotide-dependent self-assembly of Mitofusin is required after tethering to promote membrane fusion.
Collapse
Affiliation(s)
- Emily A Engelhart
- Department of Biochemistry, University of Washington School of Medicine, Seattle, Washington 98195
| | - Suzanne Hoppins
- Department of Biochemistry, University of Washington School of Medicine, Seattle, Washington 98195.
| |
Collapse
|
23
|
Zamponi E, Helguera PR. The Shape of Mitochondrial Dysfunction in Down Syndrome. Dev Neurobiol 2019; 79:613-621. [PMID: 30830726 DOI: 10.1002/dneu.22673] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/04/2019] [Accepted: 02/19/2019] [Indexed: 01/08/2023]
Abstract
Oxidative stress (OS) and mitochondrial dysfunction (MD) have been extensively studied and defined as therapeutic targets in Down syndrome (DS). Though originally associated to individual genes located in supernumerary chromosome 21, OS and MD metabolic compromises appear to be linked to whole genome functionally defined transcriptional fingerprints that further exacerbate the contribution of critical genes in DS-AD pathology. As the main ROS generator, mitochondrial complex double-membrane organization, tightly regulated fission/fusion dynamics, and involvement in critical pathways, makes it particularly vulnerable to functional alterations. Consequently, mitochondrial network morphology depends on its metabolic state and has been used as an indicator of cellular homeostasis. Initial qualitative categorization, suitable for sparse arranged fragments analysis, were proven to be ineffective to measure network connectivity and replaced by innovative tools that involve the transformation of raw images to linear skeletons. These manipulations allowed the development of a new generation of structural parameters, such as mean degree value (MDV). Alterations in DS mitochondrial networks include increased frequency of aberrant morphologies, shorter mitochondrial fragments, and significantly lower mitochondrial network connectivity. Similar structural and functional mitochondrial defects are common to other neurodegenerative diseases, such as Parkinson disease and Prion disease, and to a progeroid syndrome like HGPS. Therapeutic interventions aimed to either increase mitochondrial biogenesis or diminish OS using mitochondrial-targeted antioxidants, successfully restored mitochondrial activity and structural organization, confirming the strong correlation between network form and function.
Collapse
Affiliation(s)
- E Zamponi
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-UNC, Córdoba, Argentina
| | - P R Helguera
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-UNC, Córdoba, Argentina
| |
Collapse
|
24
|
Díaz-Vegas AR, Cordova A, Valladares D, Llanos P, Hidalgo C, Gherardi G, De Stefani D, Mammucari C, Rizzuto R, Contreras-Ferrat A, Jaimovich E. Mitochondrial Calcium Increase Induced by RyR1 and IP3R Channel Activation After Membrane Depolarization Regulates Skeletal Muscle Metabolism. Front Physiol 2018; 9:791. [PMID: 29988564 PMCID: PMC6026899 DOI: 10.3389/fphys.2018.00791] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 06/06/2018] [Indexed: 11/13/2022] Open
Abstract
Aim: We hypothesize that both type-1 ryanodine receptor (RyR1) and IP3-receptor (IP3R) calcium channels are necessary for the mitochondrial Ca2+ increase caused by membrane depolarization induced by potassium (or by electrical stimulation) of single skeletal muscle fibers; this calcium increase would couple muscle fiber excitation to an increase in metabolic output from mitochondria (excitation-metabolism coupling). Methods: Mitochondria matrix and cytoplasmic Ca2+ levels were evaluated in fibers isolated from flexor digitorium brevis muscle using plasmids for the expression of a mitochondrial Ca2+ sensor (CEPIA3mt) or a cytoplasmic Ca2+ sensor (RCaMP). The role of intracellular Ca2+ channels was evaluated using both specific pharmacological inhibitors (xestospongin B for IP3R and Dantrolene for RyR1) and a genetic approach (shIP3R1-RFP). O2 consumption was detected using Seahorse Extracellular Flux Analyzer. Results: In isolated muscle fibers cell membrane depolarization increased both cytoplasmic and mitochondrial Ca2+ levels. Mitochondrial Ca2+ uptake required functional inositol IP3R and RyR1 channels. Inhibition of either channel decreased basal O2 consumption rate but only RyR1 inhibition decreased ATP-linked O2 consumption. Cell membrane depolarization-induced Ca2+ signals in sub-sarcolemmal mitochondria were accompanied by a reduction in mitochondrial membrane potential; Ca2+ signals propagated toward intermyofibrillar mitochondria, which displayed increased membrane potential. These results are compatible with slow, Ca2+-dependent propagation of mitochondrial membrane potential from the surface toward the center of the fiber. Conclusion: Ca2+-dependent changes in mitochondrial membrane potential have different kinetics in the surface vs. the center of the fiber; these differences are likely to play a critical role in the control of mitochondrial metabolism, both at rest and after membrane depolarization as part of an “excitation-metabolism” coupling process in skeletal muscle fibers.
Collapse
Affiliation(s)
- Alexis R Díaz-Vegas
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Alex Cordova
- Biomedical Neuroscience Institute, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Denisse Valladares
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,Exercise and Movement Science Laboratory, Universidad Finis Terrae, Santiago, Chile
| | - Paola Llanos
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile.,Institute for Research in Dental Science, Universidad de Chile, Santiago, Chile
| | - Cecilia Hidalgo
- Biomedical Neuroscience Institute, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Gaia Gherardi
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ariel Contreras-Ferrat
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| | - Enrique Jaimovich
- Muscle Physiology Laboratory, Center of Studies in Exercise, Metabolism and Cancer, Institute of Biomedical Sciences, Universidad de Chile, Santiago, Chile
| |
Collapse
|
25
|
Gregorczyk KP, Wyżewski Z, Szczepanowska J, Toka FN, Mielcarska MB, Bossowska-Nowicka M, Gieryńska M, Boratyńska-Jasińska A, Struzik J, Niemiałtowski MG, Szulc-Dąbrowska L. Ectromelia Virus Affects Mitochondrial Network Morphology, Distribution, and Physiology in Murine Fibroblasts and Macrophage Cell Line. Viruses 2018; 10:E266. [PMID: 29772718 DOI: 10.3390/v10050266] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are multifunctional organelles that participate in numerous processes in response to viral infection, but they are also a target for viruses. The aim of this study was to define subcellular events leading to alterations in mitochondrial morphology and function during infection with ectromelia virus (ECTV). We used two different cell lines and a combination of immunofluorescence techniques, confocal and electron microscopy, and flow cytometry to address subcellular changes following infection. Early in infection of L929 fibroblasts and RAW 264.7 macrophages, mitochondria gathered around viral factories. Later, the mitochondrial network became fragmented, forming punctate mitochondria that co-localized with the progeny virions. ECTV-co-localized mitochondria associated with the cytoskeleton components. Mitochondrial membrane potential, mitochondrial fission–fusion, mitochondrial mass, and generation of reactive oxygen species (ROS) were severely altered later in ECTV infection leading to damage of mitochondria. These results suggest an important role of mitochondria in supplying energy for virus replication and morphogenesis. Presumably, mitochondria participate in transport of viral particles inside and outside of the cell and/or they are a source of membranes for viral envelope formation. We speculate that the observed changes in the mitochondrial network organization and physiology in ECTV-infected cells provide suitable conditions for viral replication and morphogenesis.
Collapse
|
26
|
Diquigiovanni C, Bergamini C, Evangelisti C, Isidori F, Vettori A, Tiso N, Argenton F, Costanzini A, Iommarini L, Anbunathan H, Pagotto U, Repaci A, Babbi G, Casadio R, Lenaz G, Rhoden KJ, Porcelli AM, Fato R, Bowcock A, Seri M, Romeo G, Bonora E. Mutant MYO1F alters the mitochondrial network and induces tumor proliferation in thyroid cancer. Int J Cancer 2018; 143:1706-1719. [PMID: 29672841 DOI: 10.1002/ijc.31548] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 03/21/2018] [Accepted: 04/11/2018] [Indexed: 12/26/2022]
Abstract
Familial aggregation is a significant risk factor for the development of thyroid cancer and familial non-medullary thyroid cancer (FNMTC) accounts for 5-7% of all NMTC. Whole exome sequencing analysis in the family affected by FNMTC with oncocytic features where our group previously identified a predisposing locus on chromosome 19p13.2, revealed a novel heterozygous mutation (c.400G > A, NM_012335; p.Gly134Ser) in exon 5 of MYO1F, mapping to the linkage locus. In the thyroid FRTL-5 cell model stably expressing the mutant MYO1F p.Gly134Ser protein, we observed an altered mitochondrial network, with increased mitochondrial mass and a significant increase in both intracellular and extracellular reactive oxygen species, compared to cells expressing the wild-type (wt) protein or carrying the empty vector. The mutation conferred a significant advantage in colony formation, invasion and anchorage-independent growth. These data were corroborated by in vivo studies in zebrafish, since we demonstrated that the mutant MYO1F p.Gly134Ser, when overexpressed, can induce proliferation in whole vertebrate embryos, compared to the wt one. MYO1F screening in additional 192 FNMTC families identified another variant in exon 7, which leads to exon skipping, and is predicted to alter the ATP-binding domain in MYO1F. Our study identified for the first time a role for MYO1F in NMTC.
Collapse
Affiliation(s)
- Chiara Diquigiovanni
- Department of Medical and Surgical Sciences, DIMEC, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Christian Bergamini
- Department of Pharmacy and Biotechnology, FABIT, University of Bologna, Bologna, Italy
| | - Cecilia Evangelisti
- Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna, Bologna, Italy
| | - Federica Isidori
- Department of Medical and Surgical Sciences, DIMEC, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Andrea Vettori
- Department of Biology, University of Padova, Padova, Italy
| | - Natascia Tiso
- Department of Biology, University of Padova, Padova, Italy
| | | | - Anna Costanzini
- Department of Medical and Surgical Sciences, DIMEC, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.,Department of Pharmacy and Biotechnology, FABIT, University of Bologna, Bologna, Italy
| | - Luisa Iommarini
- Department of Pharmacy and Biotechnology, FABIT, University of Bologna, Bologna, Italy
| | - Hima Anbunathan
- National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Uberto Pagotto
- Department of Medical and Surgical Sciences, DIMEC, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Andrea Repaci
- Endocrinology Unit, St. Orsola-Malpighi Hospital, Bologna, Italy
| | - Giulia Babbi
- Department of Pharmacy and Biotechnology, FABIT, University of Bologna, Bologna, Italy
| | - Rita Casadio
- Department of Pharmacy and Biotechnology, FABIT, University of Bologna, Bologna, Italy
| | - Giorgio Lenaz
- Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna, Bologna, Italy
| | - Kerry J Rhoden
- Department of Medical and Surgical Sciences, DIMEC, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Anna Maria Porcelli
- Department of Pharmacy and Biotechnology, FABIT, University of Bologna, Bologna, Italy
| | - Romana Fato
- Department of Pharmacy and Biotechnology, FABIT, University of Bologna, Bologna, Italy
| | - Anne Bowcock
- National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Marco Seri
- Department of Medical and Surgical Sciences, DIMEC, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Giovanni Romeo
- Department of Medical and Surgical Sciences, DIMEC, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| | - Elena Bonora
- Department of Medical and Surgical Sciences, DIMEC, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy
| |
Collapse
|
27
|
Jacquet A, Cottet-Rousselle C, Arnaud J, Julien Saint Amand K, Ben Messaoud R, Lénon M, Demeilliers C, Moulis JM. Mitochondrial Morphology and Function of the Pancreatic β-Cells INS-1 Model upon Chronic Exposure to Sub-Lethal Cadmium Doses. Toxics 2018; 6:E20. [PMID: 29565305 PMCID: PMC6027415 DOI: 10.3390/toxics6020020] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 03/12/2018] [Accepted: 03/20/2018] [Indexed: 11/29/2022]
Abstract
The impact of chronic cadmium exposure and slow accumulation on the occurrence and development of diabetes is controversial for human populations. Islets of Langerhans play a prominent role in the etiology of the disease, including by their ability to secrete insulin. Conversion of glucose increase into insulin secretion involves mitochondria. A rat model of pancreatic β-cells was exposed to largely sub-lethal levels of cadmium cations applied for the longest possible time. Cadmium entered cells at concentrations far below those inducing cell death and accumulated by factors reaching several hundred folds the basal level. The mitochondria reorganized in response to the challenge by favoring fission as measured by increased circularity at cadmium levels already ten-fold below the median lethal dose. However, the energy charge and respiratory flux devoted to adenosine triphosphate synthesis were only affected at the onset of cellular death. The present data indicate that mitochondria participate in the adaptation of β-cells to even a moderate cadmium burden without losing functionality, but their impairment in the long run may contribute to cellular dysfunction, when viability and β-cells mass are affected as observed in diabetes.
Collapse
Affiliation(s)
- Adeline Jacquet
- Laboratory of Fundamental and Applied Bioenergetics (LBFA), Inserm, Universite Grenoble Alpes, 38000 Grenoble, France.
| | - Cécile Cottet-Rousselle
- Laboratory of Fundamental and Applied Bioenergetics (LBFA), Inserm, Universite Grenoble Alpes, 38000 Grenoble, France.
| | - Josiane Arnaud
- Laboratory of Fundamental and Applied Bioenergetics (LBFA), Inserm, Universite Grenoble Alpes, 38000 Grenoble, France.
- Biochemistry, Molecular Biology and Environmental Toxicology (SB2TE), Grenoble University Hospital, CS 10217, 38043 Grenoble, France.
| | - Kevin Julien Saint Amand
- Laboratory of Fundamental and Applied Bioenergetics (LBFA), Inserm, Universite Grenoble Alpes, 38000 Grenoble, France.
| | - Raoua Ben Messaoud
- Laboratory of Fundamental and Applied Bioenergetics (LBFA), Inserm, Universite Grenoble Alpes, 38000 Grenoble, France.
| | - Marine Lénon
- Laboratory of Fundamental and Applied Bioenergetics (LBFA), Inserm, Universite Grenoble Alpes, 38000 Grenoble, France.
| | - Christine Demeilliers
- Laboratory of Fundamental and Applied Bioenergetics (LBFA), Inserm, Universite Grenoble Alpes, 38000 Grenoble, France.
| | - Jean-Marc Moulis
- Laboratory of Fundamental and Applied Bioenergetics (LBFA), Inserm, Universite Grenoble Alpes, 38000 Grenoble, France.
- CEA-Grenoble, Bioscience and Biotechnology Institute (BIG), 38054 Grenoble, France.
| |
Collapse
|
28
|
Saito K, Asai T, Fujiwara K, Sahara J, Koguchi H, Fukuda N, Suzuki-Karasaki M, Soma M, Suzuki-Karasaki Y. Tumor-selective mitochondrial network collapse induced by atmospheric gas plasma-activated medium. Oncotarget 2018; 7:19910-27. [PMID: 26942565 PMCID: PMC4991427 DOI: 10.18632/oncotarget.7889] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 02/09/2016] [Indexed: 12/03/2022] Open
Abstract
Non-thermal atmospheric gas plasma (AGP) exhibits cytotoxicity against malignant cells with minimal cytotoxicity toward normal cells. However, the mechanisms of its tumor-selective cytotoxicity remain unclear. Here we report that AGP-activated medium increases caspase-independent cell death and mitochondrial network collapse in a panel of human cancer cells, but not in non-transformed cells. AGP irradiation stimulated reactive oxygen species (ROS) generation in AGP-activated medium, and in turn the resulting stable ROS, most likely hydrogen peroxide (H2O2), activated intracellular ROS generation and mitochondrial ROS (mROS) accumulation. Culture in AGP-activated medium resulted in cell death and excessive mitochondrial fragmentation and clustering, and these responses were inhibited by ROS scavengers. AGP-activated medium also increased dynamin-related protein 1-dependent mitochondrial fission in a tumor-specific manner, and H2O2 administration showed similar effects. Moreover, the vulnerability of tumor cells to mitochondrial network collapse appeared to result from their higher sensitivity to mROS accumulation induced by AGP-activated medium or H2O2. The present findings expand our previous observations on death receptor-mediated tumor-selective cell killing and reinforce the importance of mitochondrial network remodeling as a powerful target for tumor-selective cancer treatment.
Collapse
Affiliation(s)
- Kosuke Saito
- Innovative Therapy Research Group, Nihon University Research Institute of Medical Science, Tokyo, Japan.,Division of General Medicine, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Tomohiko Asai
- Department of Physics, College of Science and Technology, Nihon University, Tokyo, Japan
| | - Kyoko Fujiwara
- Innovative Therapy Research Group, Nihon University Research Institute of Medical Science, Tokyo, Japan.,Division of General Medicine, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Junki Sahara
- Department of Physics, College of Science and Technology, Nihon University, Tokyo, Japan
| | - Haruhisa Koguchi
- The National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - Noboru Fukuda
- Division of Nephrology Hypertension and Endocrinology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
| | | | - Masayoshi Soma
- Innovative Therapy Research Group, Nihon University Research Institute of Medical Science, Tokyo, Japan.,Division of General Medicine, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Yoshihiro Suzuki-Karasaki
- Innovative Therapy Research Group, Nihon University Research Institute of Medical Science, Tokyo, Japan.,Division of Physiology, Department of Biomedical Sciences, Nihon University School of Medicine, Tokyo, Japan
| |
Collapse
|
29
|
Kawalec M, Beręsewicz M, Zabłocki K, Zabłocka B. [Mitofusin 2 and mitochondrial dynamics in norm and pathology]. Postepy Biochem 2016; 62:149-157. [PMID: 28132466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 05/19/2016] [Indexed: 06/06/2023]
Abstract
Results of an intensive research performed during last 25 years have revealed that an understanding of biochemical and molecular principles of oxidative phosphorylation has not finished the streak of ground-breaking discoveries of newly identified mitochondrial functions in numerous cellular processes. Among other things it has been shown that mitochondria undergo reversible fission and fusion processes, and may form a complex network which functionally and structurally interacts with the endoplasmic reticulum membranes and probably also other organelles. An organization of mitochondrial network is closely controlled and is of high importance for numerous intracellular processes to occur properly. In this review, mitofusin 2 - one of a few proteins involved in a maintenance of an appropriate mitochondrial architecture, and in the consequence in the regulation of mitochondrial metabolism and calcium signalling, the controlling of the mitochondrial DNA level, and the regulation of cell proliferation and differentiation is the focus. Mutations within mitofusin 2-encoding gene are a cause of Charcot-Marie-Tooh 2A - type neuropathies while an affected expression of this protein seems to be related to neoplasia, type 2 diabetes, or vascular hyperplasia. Numerous experimental data confirm pleiotropic effects of mitofisin 2 in animal cells.
Collapse
Affiliation(s)
- Maria Kawalec
- Molecular Biology Unit, Mossakowski Medical Research Centre, PAS, 5 A. Pawińskiego St., 02-106 Warsw, Poland
| | - Małgorzata Beręsewicz
- Molecular Biology Unit, Mossakowski Medical Research Centre, PAS, 5 A. Pawińskiego St., 02-106 Warsw, Poland
| | - Krzysztof Zabłocki
- Cell Metabolism Laboratory, Nencki Institute of Experimental Biology, PAS, 3 Pasteura St., 02-093 Warsaw, Poland
| | - Barbara Zabłocka
- Molecular Biology Unit, Mossakowski Medical Research Centre, PAS, 5 A. Pawińskiego St., 02-106 Warsw, Poland
| |
Collapse
|
30
|
Abstract
Mitochondrial dysfunction underlies many human disorders, including those that affect the visual system. The retinal ganglion cells, whose axons form the optic nerve, are often damaged by mitochondrial-related diseases which result in blindness. Both mitochondrial DNA (mtDNA) and nuclear gene mutations impacting many different mitochondrial processes can result in optic nerve disease. Of particular importance are mutations that impair mitochondrial network dynamics (fusion and fission), oxidative phosphorylation (OXPHOS), and formation of iron-sulfur complexes. Current genetic knowledge can inform genetic counseling and suggest strategies for novel gene-based therapies. Identifying new optic neuropathy-causing genes and defining the role of current and novel genes in disease will be important steps toward the development of effective and potentially neuroprotective therapies.
Collapse
Affiliation(s)
- Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School and Massachusetts Eye and Ear, Boston, Massachusetts 02114;
| |
Collapse
|
31
|
Bonifert T, Karle KN, Tonagel F, Batra M, Wilhelm C, Theurer Y, Schoenfeld C, Kluba T, Kamenisch Y, Carelli V, Wolf J, Gonzalez MA, Speziani F, Schüle R, Züchner S, Schöls L, Wissinger B, Synofzik M. Pure and syndromic optic atrophy explained by deep intronic OPA1 mutations and an intralocus modifier. Brain 2014; 137:2164-77. [PMID: 24970096 DOI: 10.1093/brain/awu165] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The genetic diagnosis in inherited optic neuropathies often remains challenging, and the emergence of complex neurological phenotypes that involve optic neuropathy is puzzling. Here we unravel two novel principles of genetic mechanisms in optic neuropathies: deep intronic OPA1 mutations, which explain the disease in several so far unsolved cases; and an intralocus OPA1 modifier, which explains the emergence of syndromic 'optic atrophy plus' phenotypes in several families. First, we unravelled a deep intronic mutation 364 base pairs 3' of exon 4b in OPA1 by in-depth investigation of a family with severe optic atrophy plus syndrome in which conventional OPA1 diagnostics including gene dosage analyses were normal. The mutation creates a new splice acceptor site resulting in aberrant OPA1 transcripts with retained intronic sequence and subsequent translational frameshift as shown by complementary DNA analysis. In patient fibroblasts we demonstrate nonsense mediated messenger RNA decay, reduced levels of OPA1 protein, and impairment of mitochondrial dynamics. Subsequent site-specific screening of >360 subjects with unexplained inherited optic neuropathy revealed three additional families carrying this deep intronic mutation and a base exchange four nucleotides upstream, respectively, thus confirming the clinical significance of this mutational mechanism. Second, in all severely affected patients of the index family, the deep intronic mutation occurred in compound heterozygous state with an exonic OPA1 missense variant (p.I382M; NM_015560.2). The variant alone did not cause a phenotype, even in homozygous state indicating that this long debated OPA1 variant is not pathogenic per se, but acts as a phenotypic modifier if it encounters in trans with an OPA1 mutation. Subsequent screening of whole exomes from >600 index patients identified a second family with severe optic atrophy plus syndrome due to compound heterozygous p.I382M, thus confirming this mechanism. In summary, we provide genetic and functional evidence that deep intronic mutations in OPA1 can cause optic atrophy and explain disease in a substantial share of families with unsolved inherited optic neuropathies. Moreover, we show that an OPA1 modifier variant explains the emergence of optic atrophy plus phenotypes if combined in trans with another OPA1 mutation. Both mutational mechanisms identified in this study-deep intronic mutations and intragenic modifiers-might represent more generalizable mechanisms that could be found also in a wide range of other neurodegenerative and optic neuropathy diseases.
Collapse
Affiliation(s)
- Tobias Bonifert
- 1 Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Röntgenweg 11, 72076 Tübingen, Germany2 Graduate School of Cellular and Molecular Neuroscience, University of Tübingen, Österbergstrasse 3, 72074 Tübingen, Germany
| | - Kathrin N Karle
- 3 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany4 Centre for Neurodegenerative Diseases (DZNE), Helmholtz Association of German Research Centers, Otfried-Müller-Straße 27, 72076 Tübingen, Germany
| | - Felix Tonagel
- 5 University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Schleichstrasse 12, 72076 Tübingen, Germany
| | - Marion Batra
- 6 Department of Neuroradiology, University of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany
| | - Christian Wilhelm
- 7 CeGaT GmbH, Centre for Genomics and Transcriptomics, Paul-Ehrlich-Str. 17, 72076 Tübingen, Germany
| | - Yvonne Theurer
- 3 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany4 Centre for Neurodegenerative Diseases (DZNE), Helmholtz Association of German Research Centers, Otfried-Müller-Straße 27, 72076 Tübingen, Germany
| | - Caroline Schoenfeld
- 3 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany4 Centre for Neurodegenerative Diseases (DZNE), Helmholtz Association of German Research Centers, Otfried-Müller-Straße 27, 72076 Tübingen, Germany
| | - Torsten Kluba
- 8 Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany
| | - York Kamenisch
- 9 Department of Dermatology, University Hospital Tübingen, Röntgenweg 13/1, 72076 Tübingen, Germany
| | - Valerio Carelli
- 10 IRCCS Istituto delle Scienze Neurologiche di Bologna, Bellaria Hospital, Via Altura 3, 40139 Bologna, Italy11 Neurology Unit, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via Altura 3, 40139 Bologna, Italy
| | - Julia Wolf
- 3 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany4 Centre for Neurodegenerative Diseases (DZNE), Helmholtz Association of German Research Centers, Otfried-Müller-Straße 27, 72076 Tübingen, Germany
| | - Michael A Gonzalez
- 12 Dr John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, 1501 NW 10 Ave, Miami, FL 33136, USA
| | - Fiorella Speziani
- 12 Dr John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, 1501 NW 10 Ave, Miami, FL 33136, USA
| | - Rebecca Schüle
- 3 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany4 Centre for Neurodegenerative Diseases (DZNE), Helmholtz Association of German Research Centers, Otfried-Müller-Straße 27, 72076 Tübingen, Germany12 Dr John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, 1501 NW 10 Ave, Miami, FL 33136, USA
| | - Stephan Züchner
- 12 Dr John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, 1501 NW 10 Ave, Miami, FL 33136, USA
| | - Ludger Schöls
- 3 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany4 Centre for Neurodegenerative Diseases (DZNE), Helmholtz Association of German Research Centers, Otfried-Müller-Straße 27, 72076 Tübingen, Germany
| | - Bernd Wissinger
- 1 Molecular Genetics Laboratory, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Röntgenweg 11, 72076 Tübingen, Germany
| | - Matthis Synofzik
- 3 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany4 Centre for Neurodegenerative Diseases (DZNE), Helmholtz Association of German Research Centers, Otfried-Müller-Straße 27, 72076 Tübingen, Germany
| |
Collapse
|
32
|
Sanmartín CD, Paula-Lima AC, García A, Barattini P, Hartel S, Núñez MT, Hidalgo C. Ryanodine receptor-mediated Ca(2+) release underlies iron-induced mitochondrial fission and stimulates mitochondrial Ca(2+) uptake in primary hippocampal neurons. Front Mol Neurosci 2014; 7:13. [PMID: 24653672 PMCID: PMC3949220 DOI: 10.3389/fnmol.2014.00013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 02/03/2014] [Indexed: 01/11/2023] Open
Abstract
Mounting evidence indicates that iron accumulation impairs brain function. We have reported previously that addition of sub-lethal concentrations of iron to primary hippocampal neurons produces Ca2+ signals and promotes cytoplasmic generation of reactive oxygen species. These Ca2+ signals, which emerge within seconds after iron addition, arise mostly from Ca2+ release through the redox-sensitive ryanodine receptor (RyR) channels present in the endoplasmic reticulum. We have reported also that addition of synaptotoxic amyloid-β oligomers to primary hippocampal neurons stimulates RyR-mediated Ca2+ release, generating long-lasting Ca2+ signals that activate Ca2+-sensitive cellular effectors and promote the disruption of the mitochondrial network. Here, we describe that 24 h incubation of primary hippocampal neurons with iron enhanced agonist-induced RyR-mediated Ca2+ release and promoted mitochondrial network fragmentation in 43% of neurons, a response significantly prevented by RyR inhibition and by the antioxidant agent N-acetyl-L-cysteine. Stimulation of RyR-mediated Ca2+ release by a RyR agonist promoted mitochondrial Ca2+ uptake in control neurons and in iron-treated neurons that displayed non-fragmented mitochondria, but not in neurons with fragmented mitochondria. Yet, the global cytoplasmic Ca2+ increase induced by the Ca2+ ionophore ionomycin prompted significant mitochondrial Ca2+ uptake in neurons with fragmented mitochondria, indicating that fragmentation did not prevent mitochondrial Ca2+ uptake but presumably decreased the functional coupling between RyR-mediated Ca2+ release and the mitochondrial Ca2+ uniporter. Taken together, our results indicate that stimulation of redox-sensitive RyR-mediated Ca2+ release by iron causes significant neuronal mitochondrial fragmentation, which presumably contributes to the impairment of neuronal function produced by iron accumulation.
Collapse
Affiliation(s)
- Carol D Sanmartín
- Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile Santiago, Chile ; Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile Santiago, Chile
| | - Andrea C Paula-Lima
- Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile Santiago, Chile ; Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile Santiago, Chile ; Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile Santiago, Chile
| | - Alejandra García
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile Santiago, Chile
| | - Pablo Barattini
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile Santiago, Chile
| | - Steffen Hartel
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile Santiago, Chile ; Laboratory of Scientific Image Processing, Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile Santiago, Chile
| | - Marco T Núñez
- Department of Biology, Faculty of Sciences and Research Ring on Oxidative Stress in the Nervous System, Universidad de Chile Santiago, Chile
| | - Cecilia Hidalgo
- Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile Santiago, Chile ; Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile Santiago, Chile ; Physiology and Biophysics Program, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile Santiago, Chile
| |
Collapse
|
33
|
Abstract
In skeletal muscle and many other cell types, mitochondria exist as an elaborate and dynamic network in which "individual" mitochondria exist only transiently even under nonstimulated conditions. The balance of continuous mitochondrial fission and fusion defines the morphology of the mitochondrial reticulum. Environmental stimuli, such as oxidative stress, can influence fusion and fission rates, resulting in a transformation of the network's connectivity. Using confocal laser scanning microscopy of C(2)C(12) mouse myocytes, we show that acute exposure to the reactive oxygen species (ROS) hydrogen peroxide (H(2)O(2)) induces a slow fragmentation of the mitochondrial reticulum that is reversible over 24h. Although H(2)O(2) decomposes rapidly in culture medium, the full extent of fragmentation occurs 5-6h posttreatment, suggesting that H(2)O(2) affects mitochondrial morphology by modulating cellular physiology. Supraphysiological (>1 mM) concentrations of H(2)O(2) are cytotoxic, but lower concentrations (250 μM) sufficient to induce transient fragmentation do not lower cell viability. H(2)O(2)-induced mitochondrial fragmentation is preceded by decreases in inner mitochondrial membrane potential and maximal respiratory rate, suggesting a possible mechanism. Because H(2)O(2) is produced in contracting muscle, our results raise the possibility that ROS generation may contribute to exercise-induced changes in mitochondrial morphology in vivo.
Collapse
Affiliation(s)
- Xiying Fan
- Department of Integrative Biology, University of California, Berkeley, CA 94720-3140, USA
| | | | | |
Collapse
|