1
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Ropert B, Gallrein C, Schumacher B. DNA repair deficiencies and neurodegeneration. DNA Repair (Amst) 2024; 138:103679. [PMID: 38640601 DOI: 10.1016/j.dnarep.2024.103679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/03/2024] [Accepted: 04/11/2024] [Indexed: 04/21/2024]
Abstract
Neurodegenerative diseases are the second most prevalent cause of death in industrialized countries. Alzheimer's Disease is the most widespread and also most acknowledged form of dementia today. Together with Parkinson's Disease they account for over 90 % cases of neurodegenerative disorders caused by proteopathies. Far less known are the neurodegenerative pathologies in DNA repair deficiency syndromes. Such diseases like Cockayne - or Werner Syndrome are described as progeroid syndromes - diseases that cause the premature ageing of the affected persons, and there are clear implications of such diseases in neurologic dysfunction and degeneration. In this review, we aim to draw the attention on commonalities between proteopathy-associated neurodegeneration and neurodegeneration caused by DNA repair defects and discuss how mitochondria are implicated in the development of both disorder classes. Furthermore, we highlight how nematodes are a valuable and indispensable model organism to study conserved neurodegenerative processes in a fast-forward manner.
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Affiliation(s)
- Baptiste Ropert
- Institute for Genome Stability in Aging and Disease, Medical Faculty, University and University Hospital of Cologne, Joseph-Stelzmann-Str. 26, Cologne 50931, Germany; Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, Cologne 50931, Germany
| | - Christian Gallrein
- Institute for Genome Stability in Aging and Disease, Medical Faculty, University and University Hospital of Cologne, Joseph-Stelzmann-Str. 26, Cologne 50931, Germany; Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, Cologne 50931, Germany; Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Beutenbergstraße 11, Jena 07745, Germany
| | - Björn Schumacher
- Institute for Genome Stability in Aging and Disease, Medical Faculty, University and University Hospital of Cologne, Joseph-Stelzmann-Str. 26, Cologne 50931, Germany; Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, Cologne 50931, Germany.
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2
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Chen M, Zhu Z, Wu S, Huang A, Xie Z, Cai J, Huang R, Yu S, Liu M, Zhang J, Tse Y, Wu Q, Wang J, Ding Y. SKN-1 is indispensable for protection against Aβ-induced proteotoxicity by a selenopeptide derived from Cordyceps militaris. Redox Biol 2024; 70:103065. [PMID: 38340636 PMCID: PMC10869277 DOI: 10.1016/j.redox.2024.103065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 01/26/2024] [Accepted: 01/28/2024] [Indexed: 02/12/2024] Open
Abstract
Oxidative stress (OS) and disruption of proteostasis caused by aggregated proteins are the primary causes of cell death in various diseases. Selenopeptides have shown the potential to control OS and alleviate inflammatory damage, suggesting promising therapeutic applications. However, their potential function in inhibiting proteotoxicity is not yet fully understood. To address this gap in knowledge, this study aimed to investigate the effects and underlying mechanisms of the selenopeptide VPRKL(Se)M on amyloid β protein (Aβ) toxicity in transgenic Caenorhabditis elegans. The results revealed that supplementation with VPRKL(Se)M can alleviate Aβ-induced toxic effects in the transgenic C. elegans model. Moreover, the addition of VPRKL(Se)M inhibited the Aβ aggregates formation, reduced the reactive oxygen species (ROS) levels, and ameliorated the overall proteostasis. Importantly, we found that the inhibitory effects of VPRKL(Se)M on Aβ toxicity and activation of the unfolded protein are dependent on skinhead-1 (SKN-1). These findings suggested that VPRKL(Se)M is a potential bioactive agent for modulating SKN-1, which subsequently improves proteostasis and reduces OS. Collectively, the findings from the current study suggests VPRKL(Se)M may play a critical role in preventing protein disorder and related diseases.
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Affiliation(s)
- Mengfei Chen
- Department of Food Science and Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China; Institute of Microbiology, Guangdong Academy of Sciences, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Safety and Health, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangzhou, 510070, China
| | - Zhenjun Zhu
- Department of Food Science and Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Shujian Wu
- Department of Food Science and Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Aohuan Huang
- Department of Food Science and Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China; Institute of Microbiology, Guangdong Academy of Sciences, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Safety and Health, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangzhou, 510070, China
| | - Zhiqing Xie
- Department of Food Science and Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Jie Cai
- Department of Food Science and Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China; Institute of Microbiology, Guangdong Academy of Sciences, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Safety and Health, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangzhou, 510070, China
| | - Rong Huang
- Department of Food Science and Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China; Institute of Microbiology, Guangdong Academy of Sciences, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Safety and Health, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangzhou, 510070, China
| | - Shubo Yu
- Institute of Microbiology, Guangdong Academy of Sciences, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Safety and Health, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangzhou, 510070, China
| | - Ming Liu
- Institute of Microbiology, Guangdong Academy of Sciences, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Safety and Health, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangzhou, 510070, China
| | - Jumei Zhang
- Institute of Microbiology, Guangdong Academy of Sciences, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Safety and Health, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangzhou, 510070, China
| | - Yuchung Tse
- Core Research Facilities, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Qingping Wu
- Institute of Microbiology, Guangdong Academy of Sciences, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Safety and Health, National Health Commission Science and Technology Innovation Platform for Nutrition and Safety of Microbial Food, Guangzhou, 510070, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou, 510642, China
| | - Yu Ding
- Department of Food Science and Engineering, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China.
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3
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Feng D, Qu L, Powell-Coffman JA. Transcriptome analyses describe the consequences of persistent HIF-1 over-activation in Caenorhabditis elegans. PLoS One 2024; 19:e0295093. [PMID: 38517909 PMCID: PMC10959373 DOI: 10.1371/journal.pone.0295093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 02/20/2024] [Indexed: 03/24/2024] Open
Abstract
Metazoan animals rely on oxygen for survival, but during normal development and homeostasis, animals are often challenged by hypoxia (low oxygen). In metazoans, many of the critical hypoxia responses are mediated by the evolutionarily conserved hypoxia-inducible transcription factors (HIFs). The stability and activity of HIF complexes are strictly regulated. In the model organism C. elegans, HIF-1 stability and activity are negatively regulated by VHL-1, EGL-9, RHY-1 and SWAN-1. Importantly, C. elegans mutants carrying strong loss-of-function mutations in these genes are viable, and this provides opportunities to interrogate the molecular consequences of persistent HIF-1 over-activation. We find that the genome-wide gene expression patterns are compellingly similar in these mutants, supporting models in which RHY-1, VHL-1 and EGL-9 function in common pathway(s) to regulate HIF-1 activity. These studies illuminate the diversified biological roles played by HIF-1, including metabolism and stress response. Genes regulated by persistent HIF-1 over-activation overlap with genes responsive to pathogens, and they overlap with genes regulated by DAF-16. As crucial stress regulators, HIF-1 and DAF-16 converge on key stress-responsive genes and function synergistically to enable hypoxia survival.
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Affiliation(s)
- Dingxia Feng
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
| | - Long Qu
- Department of Statistics, Iowa State University, Ames, Iowa, United States of America
| | - Jo Anne Powell-Coffman
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
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4
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Campbell D, Zuryn S. The mechanisms and roles of mitochondrial dynamics in C. elegans. Semin Cell Dev Biol 2024; 156:266-275. [PMID: 37919144 DOI: 10.1016/j.semcdb.2023.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 10/15/2023] [Accepted: 10/26/2023] [Indexed: 11/04/2023]
Abstract
If mitochondria are the powerhouses of the cell, then mitochondrial dynamics are the power grid that regulates how that energy output is directed and maintained in response to unique physiological demands. Fission and fusion dynamics are highly regulated processes that fine-tune the mitochondrial networks of cells to enable appropriate responses to intrinsic and extrinsic stimuli, thereby maintaining cellular and organismal homeostasis. These dynamics shape many aspects of an organism's healthspan including development, longevity, stress resistance, immunity, and response to disease. In this review, we discuss the latest findings regarding the mechanisms and roles of mitochondrial dynamics by focussing on the nematode Caenorhabditis elegans. Whole live-animal studies in C. elegans have enabled a true organismal-level understanding of the impact that mitochondrial dynamics play in homeostasis over a lifetime.
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Affiliation(s)
- Daniel Campbell
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Steven Zuryn
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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5
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Hu L, Wang N, Bryant JD, Liu L, Xie L, West AP, Walsh AJ. Label-free spatially maintained measurements of metabolic phenotypes in cells. Front Bioeng Biotechnol 2023; 11:1293268. [PMID: 38090715 PMCID: PMC10715269 DOI: 10.3389/fbioe.2023.1293268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 11/14/2023] [Indexed: 02/01/2024] Open
Abstract
Metabolic reprogramming at a cellular level contributes to many diseases including cancer, yet few assays are capable of measuring metabolic pathway usage by individual cells within living samples. Here, autofluorescence lifetime imaging is combined with single-cell segmentation and machine-learning models to predict the metabolic pathway usage of cancer cells. The metabolic activities of MCF7 breast cancer cells and HepG2 liver cancer cells were controlled by growing the cells in culture media with specific substrates and metabolic inhibitors. Fluorescence lifetime images of two endogenous metabolic coenzymes, reduced nicotinamide adenine dinucleotide (NADH) and oxidized flavin adenine dinucleotide (FAD), were acquired by a multi-photon fluorescence lifetime microscope and analyzed at the cellular level. Quantitative changes of NADH and FAD lifetime components were observed for cells using glycolysis, oxidative phosphorylation, and glutaminolysis. Conventional machine learning models trained with the autofluorescence features classified cells as dependent on glycolytic or oxidative metabolism with 90%-92% accuracy. Furthermore, adapting convolutional neural networks to predict cancer cell metabolic perturbations from the autofluorescence lifetime images provided improved performance, 95% accuracy, over traditional models trained via extracted features. Additionally, the model trained with the lifetime features of cancer cells could be transferred to autofluorescence lifetime images of T cells, with a prediction that 80% of activated T cells were glycolytic, and 97% of quiescent T cells were oxidative. In summary, autofluorescence lifetime imaging combined with machine learning models can detect metabolic perturbations between glycolysis and oxidative metabolism of living samples at a cellular level, providing a label-free technology to study cellular metabolism and metabolic heterogeneity.
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Affiliation(s)
- Linghao Hu
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States
| | - Nianchao Wang
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States
| | - Joshua D. Bryant
- Microbial Pathogenesis and Immunology, Health Science Center, Texas A&M University, College Station, TX, United States
| | - Lin Liu
- Department of Nutrition, Texas A&M University, College Station, TX, United States
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX, United States
| | - Linglin Xie
- Department of Nutrition, Texas A&M University, College Station, TX, United States
| | - A. Phillip West
- Microbial Pathogenesis and Immunology, Health Science Center, Texas A&M University, College Station, TX, United States
| | - Alex J. Walsh
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States
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6
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Feng D, Qu L. Transcriptome analyses describe the consequences of persistent HIF-1 over-activation in Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.15.567311. [PMID: 38014086 PMCID: PMC10680707 DOI: 10.1101/2023.11.15.567311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Metazoan animals rely on oxygen for survival, but during normal development and homeostasis, animals are often challenged by hypoxia (low oxygen). In metazoans, many of the critical hypoxia responses are mediated by the evolutionarily conserved hypoxia-inducible transcription factors (HIFs). The stability and activity of HIF complexes are strictly regulated. In the model organism C. elegans, HIF-1 stability and activity are negatively regulated by VHL-1, EGL-9, RHY-1 and SWAN-1. Importantly, C. elegans mutants carrying strong loss-of-function mutations in these genes are viable, and this provides opportunities to interrogate the molecular consequences of persistent HIF-1 over-activation. We find that the genome-wide gene expression patterns are compellingly similar in these mutants, supporting models in which RHY-1, SWAN-1 and EGL-9 function in common pathway(s) to regulate HIF-1 activity. These studies illuminate the diversified biological roles played by HIF-1, including metabolism, hypoxia and other stress responses, reproduction and development. Genes regulated by persistent HIF-1 over-activation overlap with genes responsive to pathogens, and they overlap with genes regulated by DAF-16. As crucial stress regulators, HIF-1 and DAF-16 converge on key stress-responsive genes and function synergistically to enable hypoxia survival.
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Affiliation(s)
- Dingxia Feng
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, United States of America
| | - Long Qu
- Department of Statistics, Iowa State University, Ames, Iowa, United States of America
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7
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Xin Y, Zhao L, Peng R. HIF-1 signaling: an emerging mechanism for mitochondrial dynamics. J Physiol Biochem 2023:10.1007/s13105-023-00966-0. [PMID: 37178248 DOI: 10.1007/s13105-023-00966-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 05/02/2023] [Indexed: 05/15/2023]
Abstract
A growing emphasis has been paid to the function of mitochondria in tumors, neurodegenerative disorders (NDs), and cardiovascular diseases. Mitochondria are oxygen-sensitive organelles whose function depends on their structural basis. Mitochondrial dynamics are critical in regulating the structure. Mitochondrial dynamics include fission, fusion, motility, cristae remodeling, and mitophagy. These processes could alter mitochondrial morphology, number, as well as distribution, to regulate complicated cellular signaling processes like metabolism. Meanwhile, they also could modulate cell proliferation and apoptosis. The initiation and progression of several diseases, such as tumors, NDs, cardiovascular disease, were all interrelated with mitochondrial dynamics. HIF-1 is a nuclear protein presented as heterodimers, and its transcriptional activity is triggered by hypoxia. It plays an important role in numerous physiological processes including the development of cardiovascular system, immune system, and cartilage. Additionally, it could evoke compensatory responses in cells during hypoxia through upstream and downstream signaling networks. Moreover, the alteration of oxygen level is a pivotal factor to promote mitochondrial dynamics and HIF-1 activation. HIF-1α might be a promising target for modulating mitochondrial dynamics to develop therapeutic approaches for NDs, immunological diseases, and other related diseases. Here, we reviewed the research progress of mitochondrial dynamics and the potential regulatory mechanism of HIF-1 in mitochondrial dynamics.
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Affiliation(s)
- Yu Xin
- Beijing Institute of Radiation Medicine, Beijing, 100850, People's Republic of China
| | - Li Zhao
- Beijing Institute of Radiation Medicine, Beijing, 100850, People's Republic of China.
| | - Ruiyun Peng
- Beijing Institute of Radiation Medicine, Beijing, 100850, People's Republic of China.
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8
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Chen J, Wang D, Xu R, Yao T, Guo Y, Liu Q, Yang E, Wu Z, Xu Z. SLP-2 regulates the generation of reactive oxygen species and the ERK pathway to promote papillary thyroid carcinoma motility and angiogenesis. Tissue Cell 2023; 80:101997. [PMID: 36527788 DOI: 10.1016/j.tice.2022.101997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/05/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
Although papillary thyroid cancer (PTC) has a generally decent prognosis, approximately 10% of patients experience recurrence, which is frequently associated with distant metastasis. Stomatin-like protein 2 (SLP-2), a protein located in the mitochondrial intermembrane space, is thought to be a possible cancer promoter. This study aimed to discover the involvement of SLP-2 in PTC motility and angiogenesis, and to initially explore its mechanism. According to the CCLE database, SLP-2 was universally increased in various cancers. Then SLP-2 expression in PTC cell lines was evaluated. Thereafter the influences of SLP-2 knockdown on cell migration, invasion, epithelial-mesenchymal transition (EMT), and angiogenesis were assessed, respectively. The mediated roles of reactive oxygen species (ROS) and MAPKs in the SLP-2 regulation were likewise determined. SLP-2 was discovered to be upregulated in PTC cells, and its knockdown could suppress cell migration, invasion, EMT, and angiogenesis. Declined SLP-2 expression also facilitated ROS generation and inhibited phosphorylation of MAPKs. Moreover, ERK agonist and ROS scavenger treatment partially reversed the impacts of SLP-2 knockdown on cells, indicating SLP-2 regulated generation of ROS and ERK pathway to promote PTC motility and angiogenesis. Generally, SLP-2 appears to be one of the major genes in the pathogenesis of PTC. Silencing its expression may have an impact on the onset and evolution of PTC. The fact that SLP-2 has a considerable influence on ROS levels implies that PTC can be treated by boosting ROS levels.
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Affiliation(s)
- Jianping Chen
- Department of Breast and Thyroid Surgery, Yijishan Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, China
| | - Duting Wang
- Department of Breast and Thyroid Surgery, Yijishan Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, China
| | - Rui Xu
- Department of Breast and Thyroid Surgery, Yijishan Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, China
| | - Ting Yao
- Department of Breast and Thyroid Surgery, Yijishan Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, China
| | - Yu Guo
- Department of Breast and Thyroid Surgery, Yijishan Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, China
| | - Qi Liu
- Department of Breast and Thyroid Surgery, Yijishan Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, China
| | - Erlong Yang
- Department of Breast and Thyroid Surgery, Yijishan Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, China
| | - Zhengqing Wu
- Department of Breast and Thyroid Surgery, Yijishan Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, China
| | - Zhenyu Xu
- Precision Medicine Centre, Yijishan Affiliated Hospital of Wannan Medical College, Wuhu, Anhui 241001, China.
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9
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Vora M, Pyonteck SM, Popovitchenko T, Matlack TL, Prashar A, Kane NS, Favate J, Shah P, Rongo C. The hypoxia response pathway promotes PEP carboxykinase and gluconeogenesis in C. elegans. Nat Commun 2022; 13:6168. [PMID: 36257965 PMCID: PMC9579151 DOI: 10.1038/s41467-022-33849-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 10/05/2022] [Indexed: 12/31/2022] Open
Abstract
Actively dividing cells, including some cancers, rely on aerobic glycolysis rather than oxidative phosphorylation to generate energy, a phenomenon termed the Warburg effect. Constitutive activation of the Hypoxia Inducible Factor (HIF-1), a transcription factor known for mediating an adaptive response to oxygen deprivation (hypoxia), is a hallmark of the Warburg effect. HIF-1 is thought to promote glycolysis and suppress oxidative phosphorylation. Here, we instead show that HIF-1 can promote gluconeogenesis. Using a multiomics approach, we reveal the genomic, transcriptomic, and metabolomic landscapes regulated by constitutively active HIF-1 in C. elegans. We use RNA-seq and ChIP-seq under aerobic conditions to analyze mutants lacking EGL-9, a key negative regulator of HIF-1. We integrate these approaches to identify over two hundred genes directly and functionally upregulated by HIF-1, including the PEP carboxykinase PCK-1, a rate-limiting mediator of gluconeogenesis. This activation of PCK-1 by HIF-1 promotes survival in response to both oxidative and hypoxic stress. Our work identifies functional direct targets of HIF-1 in vivo, comprehensively describing the metabolome induced by HIF-1 activation in an organism.
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Affiliation(s)
- Mehul Vora
- The Waksman Institute, Rutgers The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Stephanie M Pyonteck
- The Waksman Institute, Rutgers The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Tatiana Popovitchenko
- The Waksman Institute, Rutgers The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Tarmie L Matlack
- The Waksman Institute, Rutgers The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Aparna Prashar
- The Department of Genetics, Rutgers The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Nanci S Kane
- The Waksman Institute, Rutgers The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - John Favate
- The Department of Genetics, Rutgers The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Premal Shah
- The Department of Genetics, Rutgers The State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Christopher Rongo
- The Waksman Institute, Rutgers The State University of New Jersey, Piscataway, NJ, 08854, USA. .,The Department of Genetics, Rutgers The State University of New Jersey, Piscataway, NJ, 08854, USA.
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10
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Ryan KC, Laboy JT, Norman KR. Deregulation of Mitochondrial Calcium Handling Due to Presenilin Loss Disrupts Redox Homeostasis and Promotes Neuronal Dysfunction. Antioxidants (Basel) 2022; 11:antiox11091642. [PMID: 36139715 PMCID: PMC9495597 DOI: 10.3390/antiox11091642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/19/2022] [Accepted: 08/21/2022] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial dysfunction and oxidative stress are major contributors to the pathophysiology of neurodegenerative diseases, including Alzheimer’s disease (AD). However, the mechanisms driving mitochondrial dysfunction and oxidative stress are unclear. Familial AD (fAD) is an early onset form of AD caused primarily by mutations in the presenilin-encoding genes. Previously, using Caenorhabditis elegans as a model system to study presenilin function, we found that loss of C. elegans presenilin orthologue SEL-12 results in elevated mitochondrial and cytosolic calcium levels. Here, we provide evidence that elevated neuronal mitochondrial generated reactive oxygen species (ROS) and subsequent neurodegeneration in sel-12 mutants are a consequence of the increase of mitochondrial calcium levels and not cytosolic calcium levels. We also identify mTORC1 signaling as a critical factor in sustaining high ROS in sel-12 mutants in part through its repression of the ROS scavenging system SKN-1/Nrf. Our study reveals that SEL-12/presenilin loss disrupts neuronal ROS homeostasis by increasing mitochondrial ROS generation and elevating mTORC1 signaling, which exacerbates this imbalance by suppressing SKN-1/Nrf antioxidant activity.
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11
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Hawrysh PJ, Myrka AM, Buck LT. Review: A history and perspective of mitochondria in the context of anoxia tolerance. Comp Biochem Physiol B Biochem Mol Biol 2022; 260:110733. [PMID: 35288242 DOI: 10.1016/j.cbpb.2022.110733] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 01/01/2023]
Abstract
Symbiosis is found throughout nature, but perhaps nowhere is it more fundamental than mitochondria in all eukaryotes. Since mitochondria were discovered and mechanisms of oxygen reduction characterized, an understanding gradually emerged that these organelles were involved not just in the combustion of oxygen, but also in the sensing of oxygen. While multiple hypotheses exist to explain the mitochondrial involvement in oxygen sensing, key elements are developing that include potassium channels and reactive oxygen species. To understand how mitochondria contribute to oxygen sensing, it is informative to study a model system which is naturally adapted to survive extended periods without oxygen. Amongst air-breathing vertebrates, the most highly adapted are western painted turtles (Chrysemys picta bellii), which overwinter in ice-covered and anoxic water bodies. Through research of this animal, it was postulated that metabolic rate depression is key to anoxic survival and that mitochondrial regulation is a key aspect. When faced with anoxia, excitatory neurotransmitter receptors in turtle brain are inhibited through mitochondrial calcium release, termed "channel arrest". Simultaneously, inhibitory GABAergic signalling contributes to the "synaptic arrest" of excitatory action potential firing through a pathway dependent on mitochondrial depression of ROS generation. While many pathways are implicated in mitochondrial oxygen sensing in turtles, such as those of adenosine, ATP turnover, and gaseous transmitters, an apparent point of intersection is the mitochondria. In this review we will explore how an organelle that was critical for organismal complexity in an oxygenated world has also become a potentially important oxygen sensor.
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Affiliation(s)
- Peter John Hawrysh
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Alexander Morley Myrka
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Leslie Thomas Buck
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3G5, Canada.
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12
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Mello DF, Maurer LL, Ryde IT, Song DH, Marinakos SM, Jiang C, Wiesner MR, Hsu-Kim H, Meyer JN. In Vivo Effects of Silver Nanoparticles on Development, Behavior, and Mitochondrial Function are Altered by Genetic Defects in Mitochondrial Dynamics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1113-1124. [PMID: 35038872 PMCID: PMC8802983 DOI: 10.1021/acs.est.1c05915] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Silver nanoparticles (AgNPs) are extensively used in consumer products and biomedical applications, thus guaranteeing both environmental and human exposures. Despite extensive research addressing AgNP safety, there are still major knowledge gaps regarding AgNP toxicity mechanisms, particularly in whole organisms. Mitochondrial dysfunction is frequently described as an important cytotoxicity mechanism for AgNPs; however, it is still unclear if mitochondria are the direct targets of AgNPs. To test this, we exposed the nematodeCaenorhabditis elegans to sublethal concentrations of AgNPs and assessed specific mitochondrial parameters as well as organismal-level endpoints that are highly reliant on mitochondrial function, such as development and chemotaxis behavior. All AgNPs tested significantly delayed nematode development, disrupted mitochondrial bioenergetics, and blocked chemotaxis. However, silver was not preferentially accumulated in mitochondria, indicating that these effects are likely not due to direct mitochondria-AgNP interactions. Mutant nematodes with deficiencies in mitochondrial dynamics displayed both greater and decreased susceptibility to AgNPs compared to wild-type nematodes, which was dependent on the assay and AgNP type. Our study suggests that AgNPs indirectly promote mitochondrial dysfunction, leading to adverse outcomes at the organismal level, and reveals a role of gene-environment interactions in the susceptibility to AgNPs. Finally, we propose a novel hypothetical adverse outcome pathway for AgNP effects to guide future research.
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Affiliation(s)
- Danielle F. Mello
- Center for the Environmental Implications of Nanotechnology, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
- To whom correspondence should be addressed: and
| | - Laura L. Maurer
- Center for the Environmental Implications of Nanotechnology, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Ian T. Ryde
- Center for the Environmental Implications of Nanotechnology, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Dong Hoon Song
- Simulation Group, Samsung SDI, Suwon-si, Gyeonggi-do, Republic of Korea
| | - Stella M. Marinakos
- Center for the Environmental Implications of Nanotechnology, Department of Civil & Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Chuanjia Jiang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, P. R. China
| | - Mark R. Wiesner
- Center for the Environmental Implications of Nanotechnology, Department of Civil & Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Heileen Hsu-Kim
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300350, P. R. China
| | - Joel N. Meyer
- Center for the Environmental Implications of Nanotechnology, Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
- To whom correspondence should be addressed: and
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13
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Ding C, Wu Y, Dabas H, Hammarlund M. Activation of the CaMKII-Sarm1-ASK1-p38 MAP kinase pathway protects against axon degeneration caused by loss of mitochondria. eLife 2022; 11:73557. [PMID: 35285800 PMCID: PMC8920508 DOI: 10.7554/elife.73557] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 01/25/2022] [Indexed: 12/22/2022] Open
Abstract
Mitochondrial defects are tightly linked to axon degeneration, yet the underlying cellular mechanisms remain poorly understood. In Caenorhabditis elegans, PVQ axons that lack mitochondria degenerate spontaneously with age. Using an unbiased genetic screen, we found that cell-specific activation of CaMKII/UNC-43 suppresses axon degeneration due to loss of mitochondria. Unexpectedly, CaMKII/UNC-43 activates the conserved Sarm1/TIR-1-ASK1/NSY-1-p38 MAPK pathway and eventually the transcription factor CEBP-1 to protect against degeneration. In addition, we show that disrupting a trafficking complex composed of calsyntenin/CASY-1, Mint/LIN-10, and kinesin suppresses axon degeneration. Further analysis indicates that disruption of this trafficking complex activates the CaMKII-Sarm1-MAPK pathway through L-type voltage-gated calcium channels. Our findings identify CaMKII as a pivot point between mitochondrial defects and axon degeneration, describe how it is regulated, and uncover a surprising neuroprotective role for the Sarm1-p38 MAPK pathway in this context.
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Affiliation(s)
- Chen Ding
- Department of Neuroscience, Yale University School of MedicineNew HavenUnited States
| | - Youjun Wu
- Department of Genetics, Yale University School of MedicineNew HavenUnited States
| | - Hadas Dabas
- Department of Genetics, Yale University School of MedicineNew HavenUnited States
| | - Marc Hammarlund
- Department of Neuroscience, Yale University School of MedicineNew HavenUnited States,Department of Genetics, Yale University School of MedicineNew HavenUnited States
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14
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Myrka A, Buck L. Cytoskeletal Arrest: An Anoxia Tolerance Mechanism. Metabolites 2021; 11:metabo11080561. [PMID: 34436502 PMCID: PMC8401981 DOI: 10.3390/metabo11080561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/13/2021] [Accepted: 08/14/2021] [Indexed: 12/16/2022] Open
Abstract
Polymerization of actin filaments and microtubules constitutes a ubiquitous demand for cellular adenosine-5′-triphosphate (ATP) and guanosine-5′-triphosphate (GTP). In anoxia-tolerant animals, ATP consumption is minimized during overwintering conditions, but little is known about the role of cell structure in anoxia tolerance. Studies of overwintering mammals have revealed that microtubule stability in neurites is reduced at low temperature, resulting in withdrawal of neurites and reduced abundance of excitatory synapses. Literature for turtles is consistent with a similar downregulation of peripheral cytoskeletal activity in brain and liver during anoxic overwintering. Downregulation of actin dynamics, as well as modification to microtubule organization, may play vital roles in facilitating anoxia tolerance. Mitochondrial calcium release occurs during anoxia in turtle neurons, and subsequent activation of calcium-binding proteins likely regulates cytoskeletal stability. Production of reactive oxygen species (ROS) formation can lead to catastrophic cytoskeletal damage during overwintering and ROS production can be regulated by the dynamics of mitochondrial interconnectivity. Therefore, suppression of ROS formation is likely an important aspect of cytoskeletal arrest. Furthermore, gasotransmitters can regulate ROS levels, as well as cytoskeletal contractility and rearrangement. In this review we will explore the energetic costs of cytoskeletal activity, the cellular mechanisms regulating it, and the potential for cytoskeletal arrest being an important mechanism permitting long-term anoxia survival in anoxia-tolerant species, such as the western painted turtle and goldfish.
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Affiliation(s)
- Alexander Myrka
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada;
| | - Leslie Buck
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada;
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
- Correspondence: ; Tel.: +1-416-978-3506
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15
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Tissue Imaging and Quantification Relying on Endogenous Contrast. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 3233:257-288. [PMID: 34053031 DOI: 10.1007/978-981-15-7627-0_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Cell-matrix interactions play an important role in regulating a variety of essential processes in multicellular organisms, and are closely associated with numerous diseases. Modified interactions have major effects upon key features of both cells and extracellular matrix (ECM), and a thorough understanding of changes in these features can lead to critically important insights of diseases as well as the identification of effective therapeutic targets. Here, we summarize recent advances in quantitative, optical imaging of cellular metabolism and ECM spatial organization using endogenous sources of contrast. Specifically, we focus on the two-photon excited fluorescence (TPEF) imaging of autofluorescent cellular coenzymes, NAD(P)H and FAD, for the extraction of metabolic information described by optical biomarkers including cellular redox state, NAD(P)H fluorescence lifetime, and mitochondrial clustering. We show representative applications in assessing adipose tissue function and detecting malignant lesions in human skin, and further demonstrate that a combination of these optical metrics can provide complementary insights into the underlying biological mechanisms. In addition, we review the development of quantitative analysis methods to extract spatial orientation and organization metrics of collagen fibers, a major ECM component, and demonstrate applications of these approaches in two and three dimensions in several diseases, including would healing, osteoarthritis and cancer, as well as assessments of matrix remodeling in hormone-regulated engineered breast tissues. Finally, we summarize this chapter and discuss important research directions that we expect will evolve in the near future.
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16
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Chao D, Ariake K, Sato S, Ohtsuka H, Takadate T, Ishida M, Masuda K, Maeda S, Miura T, Mitachi K, Yu XJ, Fujishima F, Mizuma M, Nakagawa K, Morikawa T, Kamei T, Unno M. Stomatin‑like protein 2 induces metastasis by regulating the expression of a rate‑limiting enzyme of the hexosamine biosynthetic pathway in pancreatic cancer. Oncol Rep 2021; 45:90. [PMID: 33846782 PMCID: PMC8042670 DOI: 10.3892/or.2021.8041] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/08/2021] [Indexed: 01/05/2023] Open
Abstract
Stomatin-like protein 2 (SLP-2) is associated with poor prognosis in several types of cancer, including pancreatic cancer (PC); however, the molecular mechanism of its involvement remains elusive. The present study aimed to elucidate the role of this protein in the development of PC. Human PC cell lines AsPC-1 and PANC-1 were transfected by a vector expressing SLP-2 shRNA. Analyses of cell proliferation, migration, invasion, chemosensitivity, and glucose uptake were conducted, while a mouse xenograft model was used to evaluate the functional role of SLP-2 in PC. Immunohistochemical analysis was retrospectively performed on human tissue samples to compare expression between the primary site (n=279) and the liver metastatic site (n=22). Furthermore, microarray analysis was conducted to identify the genes correlated with SLP-2. In vitro analysis demonstrated that cells in which SLP-2 was suppressed exhibited reduced cell motility and glucose uptake, while in vivo analysis revealed a marked decrease in the number of liver metastases. Immunohistochemistry revealed that SLP-2 was increased in liver metastatic sites. Microarray analysis indicated that this protein regulated the expression of glutamine-fructose-6-phosphate transaminase 2 (GFPT2), a rate-limiting enzyme of the hexosamine biosynthesis pathway. SLP-2 contributed to the malignant character of PC by inducing liver metastasis. Cell motility and glucose uptake may be induced via the hexosamine biosynthesis pathway through the expression of GFPT2. The present study revealed a new mechanism of liver metastasis and indicated that SLP-2 and its downstream pathway could provide novel therapeutic targets for PC.
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Affiliation(s)
- Dang Chao
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Kyohei Ariake
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Satoko Sato
- Department of Pathology, Tohoku University Hospital, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Hideo Ohtsuka
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Tatsuyuki Takadate
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Masaharu Ishida
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Kunihiro Masuda
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Shimpei Maeda
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Takayuki Miura
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Katsutaka Mitachi
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Xun Jing Yu
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Fumiyoshi Fujishima
- Department of Pathology, Tohoku University Hospital, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Masamichi Mizuma
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Kei Nakagawa
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Takanori Morikawa
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Takashi Kamei
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Michiaki Unno
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
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17
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Tataridas-Pallas N, Thompson MA, Howard A, Brown I, Ezcurra M, Wu Z, Silva IG, Saunter CD, Kuerten T, Weinkove D, Blackwell TK, Tullet JMA. Neuronal SKN-1B modulates nutritional signalling pathways and mitochondrial networks to control satiety. PLoS Genet 2021; 17:e1009358. [PMID: 33661901 PMCID: PMC7932105 DOI: 10.1371/journal.pgen.1009358] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 01/17/2021] [Indexed: 12/14/2022] Open
Abstract
The feeling of hunger or satiety results from integration of the sensory nervous system with other physiological and metabolic cues. This regulates food intake, maintains homeostasis and prevents disease. In C. elegans, chemosensory neurons sense food and relay information to the rest of the animal via hormones to control food-related behaviour and physiology. Here we identify a new component of this system, SKN-1B which acts as a central food-responsive node, ultimately controlling satiety and metabolic homeostasis. SKN-1B, an ortholog of mammalian NF-E2 related transcription factors (Nrfs), has previously been implicated with metabolism, respiration and the increased lifespan incurred by dietary restriction. Here we show that SKN-1B acts in two hypothalamus-like ASI neurons to sense food, communicate nutritional status to the organism, and control satiety and exploratory behaviours. This is achieved by SKN-1B modulating endocrine signalling pathways (IIS and TGF-β), and by promoting a robust mitochondrial network. Our data suggest a food-sensing and satiety role for mammalian Nrf proteins. Deciding when and how much to eat is important for maintaining health and preventing disease. It requires an intricate molecular level of communication between our nervous, physiological, and metabolic systems. These signals stimulate food intake, and afterwards the feeling of satiety which makes us stop eating. We have studied these phenomena using the simple nematode worm C. elegans which has a fully mapped nervous system and quantifiable food-related behaviours. In C. elegans, chemosensory neurons sense food and communicate this to the rest of the animal via hormones to control food-related behaviour and associated physiological changes. Here we identify a new central node of this system, the C. elegans gene SKN-1B, which acts in two sensory neurons to sense food, communicate food-status to the rest of the worm, and control satiety and exploratory behaviours. It does this by altering hormonal signalling (Insulin and Transforming Growth Factor-β), and by promoting a strong mitochondrial network. The mammalian equivalents of SKN-1B are the NF-E2 related transcription factors (Nrfs), which have previously been implicated with metabolism and respiration. Our data suggest a new food-sensing and satiety role for mammalian Nrf proteins.
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Affiliation(s)
| | | | - Alexander Howard
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Ian Brown
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Marina Ezcurra
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Ziyun Wu
- Joslin Diabetes Center, One Joslin Place, Boston, Massachusetts, United States of America
| | | | | | - Timo Kuerten
- School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - David Weinkove
- Magnitude Biosciences Ltd, NETPark Plexus, Sedgefield, United Kingdom
| | - T. Keith Blackwell
- Joslin Diabetes Center, One Joslin Place, Boston, Massachusetts, United States of America
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18
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Okoye CN, Stevens D, Kamunde C. Modulation of mitochondrial site-specific hydrogen peroxide efflux by exogenous stressors. Free Radic Biol Med 2021; 164:439-456. [PMID: 33383085 DOI: 10.1016/j.freeradbiomed.2020.12.234] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/18/2020] [Accepted: 12/21/2020] [Indexed: 12/16/2022]
Abstract
Oxygen (O2) deprivation and metals are common environmental stressors and their exposure to aquatic organisms can induce oxidative stress by disrupting cellular reactive oxygen species (ROS) homeostasis. Mitochondria are a major source of ROS in the cell wherein a dozen sites located on enzymes of the electron transport system (ETS) and substrate oxidation produce superoxide anion radicals (O2˙‾) or hydrogen peroxide (H2O2). Sites located on ETS enzymes can generate ROS by forward electron transfer (FET) and reverse electron transfer (RET) reactions; however, knowledge of how exogenous stressors modulate site-specific ROS production is limited. We investigated the effects of anoxia-reoxygenation and cadmium (Cd) on H2O2 emission in fish liver mitochondria oxidizing glutamate-malate, succinate or palmitoylcarnitine-malate. We find that anoxia-reoxygenation attenuates H2O2 emission while the effect of Cd depends on the substrate, with monotonic responses for glutamate-malate and palmitoylcarnitine-malate, and a biphasic response for succinate. Anoxia-reoxygenation exerts a substrate-dependent inhibition of mitochondrial respiration which is more severe with palmitoylcarnitine-malate compared with succinate or glutamate-malate. Additionally, specific mitochondrial ROS-emitting sites were sequestered using blockers of electron transfer and the effects of anoxia-reoxygenation and Cd on H2O2 emission were evaluated. Here, we find that site-specific H2O2 emission capacities depend on the substrate and the direction of electron flow. Moreover, anoxia-reoxygenation alters site-specific H2O2 emission rates during succinate and glutamate-malate oxidation whereas Cd imposes monotonic or biphasic H2O2 emission responses depending on the substrate and site. Contrary to our expectation, anoxia-reoxygenation blunts the effect of Cd. These results suggest that the effect of exogenous stressors on mitochondrial oxidant production is governed by their impact on energy conversion reactions and mitochondrial redox poise. Moreover, direct increased ROS production seemingly does not explain the increased adverse effects associated with combined exposure of aquatic organisms to Cd and low dissolved oxygen levels.
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Affiliation(s)
- Chidozie N Okoye
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, C1A 4P3, Canada; Department of Veterinary Obstetrics and Reproductive Diseases. Faculty of Veterinary Medicine, University of Nigeria, Nsukka, Nigeria
| | - Don Stevens
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, C1A 4P3, Canada
| | - Collins Kamunde
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, PE, C1A 4P3, Canada.
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19
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Larrick JW, Larrick JW, Mendelsohn AR. SUMO Wrestles with Mitophagy to Extend Lifespan. Rejuvenation Res 2020; 23:527-532. [PMID: 33256568 DOI: 10.1089/rej.2020.2406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
SUMOylation, a conserved protein post-translational modification that performs multiple functions including regulation of nuclear transport and transcription, is implicated in numerous biological processes including aging. RNAi knockdown of the sole Small Ubiquitin-like MOdifier (SUMO) gene, smo-1, in Caenorhabditis elegans shortened lifespan, whereas overexpression in the intestine modestly increased lifespan. Smo-1 is required for mitochondrial fission in a tissue-specific manner. Fission, in turn, is needed for mitophagy to maintain mitochondrial homeostasis during aging. SUMOlyation affects DAuer Formation (DAF)-16, which can be directly SUMOylated, and SKN-1, the homolog of mammalian Nrf2. These regulators play key roles in maintaining mitochondrial homeostasis. However, given the modest effect of overexpressing smo-1 on lifespan enhancement and potential interference with other genes that can promote increased lifespan, caution is advised in the translation of this study based on C. elegans. Although inhibitors of SUMOlyation have been developed for cancer and activators also have been identified, broad-acting biochemical pathway modifiers such as SUMO are often suboptimal drug targets and may not be as promising for antiaging applications as they first appear.
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Affiliation(s)
- James W Larrick
- Panorama Research Institute, Sunnyvale, California, USA.,Regenerative Sciences Institute, Sunnyvale, California, USA
| | | | - Andrew R Mendelsohn
- Panorama Research Institute, Sunnyvale, California, USA.,Regenerative Sciences Institute, Sunnyvale, California, USA
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20
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Princz A, Pelisch F, Tavernarakis N. SUMO promotes longevity and maintains mitochondrial homeostasis during ageing in Caenorhabditis elegans. Sci Rep 2020; 10:15513. [PMID: 32968203 PMCID: PMC7511317 DOI: 10.1038/s41598-020-72637-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 08/24/2020] [Indexed: 12/12/2022] Open
Abstract
The insulin/IGF signalling pathway impacts lifespan across distant taxa, by controlling the activity of nodal transcription factors. In the nematode Caenorhabditis elegans, the transcription regulators DAF-16/FOXO and SKN-1/Nrf function to promote longevity under conditions of low insulin/IGF signalling and stress. The activity and subcellular localization of both DAF-16 and SKN-1 is further modulated by specific posttranslational modifications, such as phosphorylation and ubiquitination. Here, we show that ageing elicits a marked increase of SUMO levels in C. elegans. In turn, SUMO fine-tunes DAF-16 and SKN-1 activity in specific C. elegans somatic tissues, to enhance stress resistance. SUMOylation of DAF-16 modulates mitochondrial homeostasis by interfering with mitochondrial dynamics and mitophagy. Our findings reveal that SUMO is an important determinant of lifespan, and provide novel insight, relevant to the complexity of the signalling mechanisms that influence gene expression to govern organismal survival in metazoans.
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Affiliation(s)
- Andrea Princz
- Department of Biology, University of Crete, Heraklion, Greece.,Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Federico Pelisch
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, Scotland, UK
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece. .,Department of Basic Sciences, Faculty of Medicine, University of Crete, Heraklion, Greece.
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21
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Arnold ML, Cooper J, Grant BD, Driscoll M. Quantitative Approaches for Scoring in vivo Neuronal Aggregate and Organelle Extrusion in Large Exopher Vesicles in C. elegans. J Vis Exp 2020:10.3791/61368. [PMID: 33016946 PMCID: PMC7805482 DOI: 10.3791/61368] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Toxicity of misfolded proteins and mitochondrial dysfunction are pivotal factors that promote age-associated functional neuronal decline and neurodegenerative disease across species. Although these neurotoxic challenges have long been considered to be cell-intrinsic, considerable evidence now supports that misfolded human disease proteins originating in one neuron can appear in neighboring cells, a phenomenon proposed to promote pathology spread in human neurodegenerative disease. C. elegans adult neurons that express aggregating proteins can extrude large (~4 µm) membrane-surrounded vesicles that can include the aggregated protein, mitochondria, and lysosomes. These large vesicles are called "exophers" and are distinct from exosomes (which are about 100x smaller and have different biogenesis). Throwing out cellular debris in exophers may occur by a conserved mechanism that constitutes a fundamental, but formerly unrecognized, branch of neuronal proteostasis and mitochondrial quality control, relevant to processes by which aggregates spread in human neurodegenerative diseases. While exophers have been mostly studied in animals that express high copy transgenic mCherry within touch neurons, these protocols are equally useful in the study of exophergenesis using fluorescently tagged organelles or other proteins of interest in various classes of neurons. Described here are the physical features of C. elegans exophers, strategies for their detection, identification criteria, optimal timing for quantitation, and animal growth protocols that control for stresses that can modulate exopher production levels. Together, details of protocols outlined here should serve to establish a standard for quantitative analysis of exophers across laboratories. This document seeks to serve as a resource in the field for laboratories seeking to elaborate molecular mechanisms by which exophers are produced and by which exophers are reacted to by neighboring and distant cells.
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Affiliation(s)
- Meghan Lee Arnold
- Department of Molecular Biology and Biochemistry, Rutgers University
| | - Jason Cooper
- Department of Molecular Biology and Biochemistry, Rutgers University
| | - Barth D Grant
- Department of Molecular Biology and Biochemistry, Rutgers University
| | - Monica Driscoll
- Department of Molecular Biology and Biochemistry, Rutgers University;
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22
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Zhang X, Li BY, Fu LJ, Adu-Gyamfi EA, Xu BR, Liu TH, Chen XM, Lan X, Wang YX, Xu HB, Ding YB. Stomatin-like protein 2 (SLP2) regulates the proliferation and invasion of trophoblast cells by modulating mitochondrial functions. Placenta 2020; 100:13-23. [PMID: 32814233 DOI: 10.1016/j.placenta.2020.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 06/01/2020] [Accepted: 07/08/2020] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Stomatin-like protein 2 (SLP2) is highly expressed in human first trimester trophoblast cells, but its functions in placental morpho-physiology remain unknown. This study aimed to determine the role of SLP2 in the proliferation and invasion of human first trimester trophoblast cells. METHODS Immunofluorescence was used to determine the expression and localization of SLP2 in normal and miscarriage human first trimester placenta. Western blot was used to determine the expression of SLP2, PCNA, Cyclin D3, N-cadherin, Vimentin, PGC1α and PPARα in HTR-8/SVneo cells. SLP2 was knocked down in the HTR-8/SVneo cells by using si-Slp2. Wound healing and migration assays were used to determine the effect of SLP2 knockdown on the migration and invasion in the HTR-8/SVneo cells. Mitochondrial membrane potential, reactive oxygen species (ROS), ATP production and biogenesis were measured to assess the effects of SLP2 knockdown on mitochondrial functions. RESULT SLP2 was strongly expressed in the cytotrophoblasts (CTB), syncytiotrophoblast (STB) and extravillous trophoblasts (EVT) of normal pregnancy placenta as compared to miscarriage placenta. SLP2 was highly expressed in the invasive EVT cell lines, HTR-8/SVneo and HPT-8 compared to the CTB cell line JAR. Knockdown of SLP2 significantly inhibited the migration and invasion of HTR-8/SVneo cells and placental villous explants, and repressed mitochondrial biogenesis and functions in HTR-8/SVneo cells. DISCUSSION Silencing of SLP2 inhibited the proliferation, migration and invasion of HTR-8/SVneo cells via the impairment of mitochondrial functions. This indicates that the downregulation of SLP2 in miscarriage placenta could be part of the pathogenesis and pathophysiology of the disease.
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Affiliation(s)
- Xue Zhang
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China; The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China
| | - Bing-Yi Li
- Department of Obstetrics and Gyaanecology, the First Affiliated Hospital, Chongqing Medical University, Chongqing, 400016, PR China; Wuhan Medical & Healthcare for Woman and Children, Wuhan, 430015, PR China
| | - Li-Juan Fu
- The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China; School of Traditional Chinese Medicine, Chongqing Medical University, Chongqing, 400016, PR China
| | - Enoch Appiah Adu-Gyamfi
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China
| | - Bai-Ruo Xu
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China
| | - Tai-Hang Liu
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China; The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China
| | - Xue-Mei Chen
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China; The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China
| | - Xi Lan
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China
| | - Ying-Xiong Wang
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China; The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China
| | - Hong-Bing Xu
- Department of Obstetrics and Gyaanecology, the First Affiliated Hospital, Chongqing Medical University, Chongqing, 400016, PR China.
| | - Yu-Bin Ding
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China; The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China.
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23
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Leboutet R, Chen Y, Legouis R, Culetto E. Mitophagy during development and stress in C. elegans. Mech Ageing Dev 2020; 189:111266. [DOI: 10.1016/j.mad.2020.111266] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/13/2022]
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Berry BJ, Trewin AJ, Milliken AS, Baldzizhar A, Amitrano AM, Lim Y, Kim M, Wojtovich AP. Optogenetic control of mitochondrial protonmotive force to impact cellular stress resistance. EMBO Rep 2020; 21:e49113. [PMID: 32043300 PMCID: PMC7132214 DOI: 10.15252/embr.201949113] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/26/2019] [Accepted: 01/15/2020] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial respiration generates an electrochemical proton gradient across the mitochondrial inner membrane called protonmotive force (PMF) to drive diverse functions and synthesize ATP. Current techniques to manipulate the PMF are limited to its dissipation; yet, there is no precise and reversible method to increase the PMF. To address this issue, we aimed to use an optogenetic approach and engineered a mitochondria-targeted light-activated proton pump that we name mitochondria-ON (mtON) to selectively increase the PMF in Caenorhabditis elegans. Here we show that mtON photoactivation increases the PMF in a dose-dependent manner, supports ATP synthesis, increases resistance to mitochondrial toxins, and modulates energy-sensing behavior. Moreover, transient mtON activation during hypoxic preconditioning prevents the well-characterized adaptive response of hypoxia resistance. Our results show that optogenetic manipulation of the PMF is a powerful tool to modulate metabolism and cell signaling.
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Affiliation(s)
- Brandon J Berry
- Department of Pharmacology and PhysiologyUniversity of Rochester Medical CenterRochesterNYUSA
| | - Adam J Trewin
- Department of Anesthesiology and Perioperative MedicineUniversity of Rochester Medical CenterRochesterNYUSA
| | - Alexander S Milliken
- Department of Pharmacology and PhysiologyUniversity of Rochester Medical CenterRochesterNYUSA
| | - Aksana Baldzizhar
- Department of Anesthesiology and Perioperative MedicineUniversity of Rochester Medical CenterRochesterNYUSA
| | - Andrea M Amitrano
- Department of PathologyUniversity of Rochester Medical CenterRochesterNYUSA
- Department of Microbiology and ImmunologyUniversity of Rochester Medical CenterRochesterNYUSA
| | - Yunki Lim
- Nephrology DivisionDepartment of MedicineSchool of Medicine and DentistryUniversity of Rochester Medical CenterRochesterNYUSA
| | - Minsoo Kim
- Department of PathologyUniversity of Rochester Medical CenterRochesterNYUSA
- Department of Microbiology and ImmunologyUniversity of Rochester Medical CenterRochesterNYUSA
| | - Andrew P Wojtovich
- Department of Pharmacology and PhysiologyUniversity of Rochester Medical CenterRochesterNYUSA
- Department of Anesthesiology and Perioperative MedicineUniversity of Rochester Medical CenterRochesterNYUSA
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25
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Sisalli MJ, Ianniello G, Savoia C, Cuomo O, Annunziato L, Scorziello A. Knocking-out the Siah2 E3 ubiquitin ligase prevents mitochondrial NCX3 degradation, regulates mitochondrial fission and fusion, and restores mitochondrial function in hypoxic neurons. Cell Commun Signal 2020; 18:42. [PMID: 32164721 PMCID: PMC7066748 DOI: 10.1186/s12964-020-0529-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 02/05/2020] [Indexed: 11/10/2022] Open
Abstract
Background Na+/Ca2+ exchanger isoform 3 (NCX3) regulates mitochondrial Ca2+ handling through the outer mitochondrial membrane (OMM) and promotes neuronal survival during oxygen and glucose deprivation (OGD). Conversely, Seven In-Absentia Homolog 2 (Siah2), an E3-ubiquitin ligase, which is activated under hypoxic conditions, causes proteolysis of mitochondrial and cellular proteins. In the present study, we investigated whether siah2, upon its activation during hypoxia, interacts with NCX3 and whether such interaction could regulate the molecular events underlying changes in mitochondrial morphology, i.e., fusion and fission, and function, in neurons exposed to anoxia and anoxia/reoxygenation. Methods To answer these questions, after exposing cortical neurons from siah2 KO mice (siah2 −/−) to OGD and OGD/Reoxygenation, we monitored the changes in mitochondrial fusion and fission protein expression, mitochondrial membrane potential (ΔΨm), and mitochondrial calcium concentration ([Ca2+]m) by using specific fluorescent probes, confocal microscopy, and Western Blot analysis. Results As opposed to congenic wild-type neurons, in neurons from siah2−/− mice exposed to OGD, form factor (FF), an index of the complexity and branching aspect of mitochondria, and aspect ratio (AR), an index reflecting the “length-to-width ratio” of mitochondria, maintained low expression. In KO siah2 neurons exposed to OGD, downregulation of mitofusin 1 (Mfn1), a protein involved in mitochondrial fusion and upregulation of dynamin-related protein 1 (Drp1), a protein involved in the mitochondrial fission, were prevented. Furthermore, under OGD conditions, whereas [Ca2+]m was reduced, ΔΨm, mitochondrial oxidative capacity and ATP production were improved. Interestingly, our immunoprecipitation assay revealed that Siah2 interacted with NCX3. Indeed, siah2 knock-out prevented NCX3 degradation in neurons exposed to OGD. Finally, when siah2−/− neurons were exposed to OGD/reoxygenation, FF, AR, and Mfn1 expression increased, and mitochondrial function improved compared to siah2+/+ neurons. Conclusions Collectively, these findings indicate that hypoxia-induced SIAH2-E3 ligase activation influences mitochondrial fusion and fission, as well as function, by inducing NCX3 degradation. Video Abstract
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Affiliation(s)
- Maria Josè Sisalli
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Via S. Pansini 5, 80131, Naples, Italy
| | - Gaetano Ianniello
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Via S. Pansini 5, 80131, Naples, Italy
| | - Claudia Savoia
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Via S. Pansini 5, 80131, Naples, Italy
| | - Ornella Cuomo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Via S. Pansini 5, 80131, Naples, Italy
| | | | - Antonella Scorziello
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Via S. Pansini 5, 80131, Naples, Italy.
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26
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Doshi S, Price E, Landis J, Barot U, Sabatella M, Lans H, Kalb RG. Neuropeptide signaling regulates the susceptibility of developing C. elegans to anoxia. Free Radic Biol Med 2019; 131:197-208. [PMID: 30529384 DOI: 10.1016/j.freeradbiomed.2018.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/05/2018] [Accepted: 12/05/2018] [Indexed: 02/04/2023]
Abstract
Inadequate delivery of oxygen to organisms during development can lead to cell dysfunction/death and life-long disabilities. Although the susceptibility of developing cells to low oxygen conditions changes with maturation, the cellular and molecular pathways that govern responses to low oxygen are incompletely understood. Here we show that developing Caenorhabditis elegans are substantially more sensitive to anoxia than adult animals and that this sensitivity is controlled by nervous system generated hormones (e.g., neuropeptides). A screen of neuropeptide genes identified and validated nlp-40 and its receptor aex-2 as a key regulator of anoxic survival in developing worms. The survival-promoting action of impaired neuropeptide signaling does not rely on five known stress resistance pathways and is specific to anoxic insult. Together, these data highlight a novel cell non-autonomous pathway that regulates the susceptibility of developing organisms to anoxia.
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Affiliation(s)
- Shachee Doshi
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Emma Price
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Justin Landis
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Urva Barot
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Mariangela Sabatella
- Department of Molecular Genetics, Erasmus Medical Centre, Oncode Institute, Cancer Genomics Netherlands, Rotterdam 3015 CN, the Netherlands
| | - Hannes Lans
- Department of Molecular Genetics, Erasmus Medical Centre, Oncode Institute, Cancer Genomics Netherlands, Rotterdam 3015 CN, the Netherlands
| | - Robert G Kalb
- Division of Neurology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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27
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Vozdek R, Long Y, Ma DK. The receptor tyrosine kinase HIR-1 coordinates HIF-independent responses to hypoxia and extracellular matrix injury. Sci Signal 2018; 11:11/550/eaat0138. [DOI: 10.1126/scisignal.aat0138] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Inadequate tissue oxygen, or hypoxia, is a central concept in the pathophysiology of ischemic disorders and cancer. Hypoxia promotes extracellular matrix (ECM) remodeling, cellular metabolic adaptation, and cancer cell metastasis. To discover new pathways through which cells respond to hypoxia, we performed a large-scale forward genetic screen inCaenorhabditis elegansand identified a previously uncharacterized receptor tyrosine kinase named HIR-1. Loss of function inhir-1phenocopied the impaired ECM integrity associated with hypoxia or deficiency in the oxygen-dependent dual oxidase, heme peroxidases, or cuticular collagens involved in ECM homeostasis. Genetic suppressor screens identified NHR-49 and MDT-15 as transcriptional regulators downstream of HIR-1. Furthermore,hir-1mutants showed defects in adapting to and recovering from prolonged severe hypoxia. We propose thatC. elegansHIR-1 coordinates hypoxia-inducible factor–independent responses to hypoxia and hypoxia-associated ECM remodeling through mechanisms that are likely conserved in other organisms.
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28
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Markaki M, Palikaras K, Tavernarakis N. Novel Insights Into the Anti-aging Role of Mitophagy. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 340:169-208. [PMID: 30072091 DOI: 10.1016/bs.ircmb.2018.05.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aging is a complex biological process affecting almost all living organisms. Although its detrimental effects on animals' physiology have been extensively documented, several aspects of the biology of aging are insufficiently understood. Mitochondria, the central energy producers of the cell, play vital roles in a wide range of cellular processes, including regulation of bioenergetics, calcium signaling, metabolic responses, and cell death, among others. Thus, proper mitochondrial function is a prerequisite for the maintenance of cellular and organismal homeostasis. Several mitochondrial quality control mechanisms have evolved to allow adaptation to different metabolic conditions, thereby preserving cellular homeostasis and survival. A tight coordination between mitochondrial biogenesis and mitochondrial selective autophagy, known as mitophagy, is a common characteristic of healthy biological systems. The balanced interplay between these two opposing cellular processes dictates stress resistance, healthspan, and lifespan extension. Mitochondrial biogenesis and mitophagy efficiency decline with age, leading to progressive accumulation of damaged and/or unwanted mitochondria, deterioration of cellular function, and ultimately death. Several regulatory factors that contribute to energy homeostasis have been implicated in the development and progression of many pathological conditions, such as neurodegenerative, metabolic, and cardiovascular disorders, among others. Therefore, mitophagy modulation may serve as a novel potential therapeutic approach to tackle age-associated pathologies. Here, we review the molecular signaling pathways that regulate and coordinate mitophagy with mitochondrial biogenesis, highlighting critical factors that hold promise for the development of pharmacological interventions toward enhancing human health and quality of life throughout aging.
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Affiliation(s)
- Maria Markaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas
| | - Konstantinos Palikaras
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas; Department of Basic Sciences, Medical School, University of Crete, Heraklion, Greece
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29
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Liu Z, Pouli D, Alonzo CA, Varone A, Karaliota S, Quinn KP, Münger K, Karalis KP, Georgakoudi I. Mapping metabolic changes by noninvasive, multiparametric, high-resolution imaging using endogenous contrast. SCIENCE ADVANCES 2018; 4:eaap9302. [PMID: 29536043 PMCID: PMC5846284 DOI: 10.1126/sciadv.aap9302] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Monitoring subcellular functional and structural changes associated with metabolism is essential for understanding healthy tissue development and the progression of numerous diseases, including cancer, diabetes, and cardiovascular and neurodegenerative disorders. Unfortunately, established methods for this purpose either are destructive or require the use of exogenous agents. Recent work has highlighted the potential of endogenous two-photon excited fluorescence (TPEF) as a method to monitor subtle metabolic changes; however, mechanistic understanding of the connections between the detected optical signal and the underlying metabolic pathways has been lacking. We present a quantitative approach to detecting both functional and structural metabolic biomarkers noninvasively, relying on endogenous TPEF from two coenzymes, NADH (reduced form of nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide). We perform multiparametric analysis of three optical biomarkers within intact, living cells and three-dimensional tissues: cellular redox state, NADH fluorescence lifetime, and mitochondrial clustering. We monitor the biomarkers in cells and tissues subjected to metabolic perturbations that trigger changes in distinct metabolic processes, including glycolysis and glutaminolysis, extrinsic and intrinsic mitochondrial uncoupling, and fatty acid oxidation and synthesis. We demonstrate that these optical biomarkers provide complementary insights into the underlying biological mechanisms. Thus, when used in combination, these biomarkers can serve as a valuable tool for sensitive, label-free identification of changes in specific metabolic pathways and characterization of the heterogeneity of the elicited responses with single-cell resolution.
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Affiliation(s)
- Zhiyi Liu
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
| | - Dimitra Pouli
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
| | - Carlo A. Alonzo
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
| | - Antonio Varone
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
| | | | - Kyle P. Quinn
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
- Department of Biomedical Engineering, University of Arkansas, Fayetteville, AR 72701, USA
| | - Karl Münger
- Developmental, Molecular and Chemical Biology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Katia P. Karalis
- Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Irene Georgakoudi
- Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA
- Corresponding author.
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30
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Pouli D, Balu M, Alonzo CA, Liu Z, Quinn KP, Rius-Diaz F, Harris RM, Kelly KM, Tromberg BJ, Georgakoudi I. Imaging mitochondrial dynamics in human skin reveals depth-dependent hypoxia and malignant potential for diagnosis. Sci Transl Med 2017; 8:367ra169. [PMID: 27903865 DOI: 10.1126/scitranslmed.aag2202] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 05/25/2016] [Accepted: 10/18/2016] [Indexed: 12/29/2022]
Abstract
Active changes in mitochondrial structure and organization facilitate cellular homeostasis. Because aberrant mitochondrial dynamics are implicated in a variety of human diseases, their assessment is potentially useful for diagnosis, therapy, and disease monitoring. Because current techniques for evaluating mitochondrial morphology are invasive or necessitate mitochondria-specific dyes, their clinical translation is limited. We report that mitochondrial dynamics can be monitored in vivo, within intact human skin by relying entirely on endogenous two-photon-excited fluorescence from the reduced metabolic coenzyme nicotinamide adenine dinucleotide (NADH). We established the sensitivity of this approach with in vivo, fast temporal studies of arterial occlusion-reperfusion, which revealed acute changes in the mitochondrial metabolism and dynamics of the lower human epidermal layers. In vitro hypoxic-reperfusion studies validated that the in vivo outcomes were a result of NADH fluorescence changes. To demonstrate the diagnostic potential of this approach, we evaluated healthy and cancerous human skin epithelia. Healthy tissues displayed consistent, depth-dependent morphological and mitochondrial organization patterns that varied with histological stratification and intraepithelial mitochondrial protein expression. In contrast, these consistent patterns were absent in cancerous skin lesions. We exploited these differences to successfully differentiate healthy from cancerous tissues using a predictive classification approach. Collectively, these results demonstrate that our label-free, automated, near real-time assessments of mitochondrial organization-relying solely on endogenous contrast-could be useful for accurate, noninvasive in vivo diagnosis.
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Affiliation(s)
- Dimitra Pouli
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
| | - Mihaela Balu
- Laser Microbeam and Medical Program, Beckman Laser Institute, University of California, Irvine, Irvine, CA 92612, USA
| | - Carlo A Alonzo
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
| | - Zhiyi Liu
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
| | - Kyle P Quinn
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.,Department of Biomedical Engineering, University of Arkansas, 120 John A. White Jr. Engineering Hall, Fayetteville, AR 72701, USA
| | - Francisca Rius-Diaz
- Department of Preventive Medicine and Public Health, Faculty of Medicine, University of Malaga, 32 Louis Pasteur Boulevard, 29071 Málaga, Spain
| | - Ronald M Harris
- Department of Dermatology, University of California, Irvine, 1 Medical Plaza Drive, Irvine, CA 92697, USA
| | - Kristen M Kelly
- Department of Dermatology, University of California, Irvine, 1 Medical Plaza Drive, Irvine, CA 92697, USA
| | - Bruce J Tromberg
- Laser Microbeam and Medical Program, Beckman Laser Institute, University of California, Irvine, Irvine, CA 92612, USA
| | - Irene Georgakoudi
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.
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31
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Zanon A, Kalvakuri S, Rakovic A, Foco L, Guida M, Schwienbacher C, Serafin A, Rudolph F, Trilck M, Grünewald A, Stanslowsky N, Wegner F, Giorgio V, Lavdas AA, Bodmer R, Pramstaller PP, Klein C, Hicks AA, Pichler I, Seibler P. SLP-2 interacts with Parkin in mitochondria and prevents mitochondrial dysfunction in Parkin-deficient human iPSC-derived neurons and Drosophila. Hum Mol Genet 2017; 26:2412-2425. [PMID: 28379402 DOI: 10.1093/hmg/ddx132] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/16/2017] [Indexed: 12/26/2022] Open
Abstract
Mutations in the Parkin gene (PARK2) have been linked to a recessive form of Parkinson's disease (PD) characterized by the loss of dopaminergic neurons in the substantia nigra. Deficiencies of mitochondrial respiratory chain complex I activity have been observed in the substantia nigra of PD patients, and loss of Parkin results in the reduction of complex I activity shown in various cell and animal models. Using co-immunoprecipitation and proximity ligation assays on endogenous proteins, we demonstrate that Parkin interacts with mitochondrial Stomatin-like protein 2 (SLP-2), which also binds the mitochondrial lipid cardiolipin and functions in the assembly of respiratory chain proteins. SH-SY5Y cells with a stable knockdown of Parkin or SLP-2, as well as induced pluripotent stem cell-derived neurons from Parkin mutation carriers, showed decreased complex I activity and altered mitochondrial network morphology. Importantly, induced expression of SLP-2 corrected for these mitochondrial alterations caused by reduced Parkin function in these cells. In-vivo Drosophila studies showed a genetic interaction of Parkin and SLP-2, and further, tissue-specific or global overexpression of SLP-2 transgenes rescued parkin mutant phenotypes, in particular loss of dopaminergic neurons, mitochondrial network structure, reduced ATP production, and flight and motor dysfunction. The physical and genetic interaction between Parkin and SLP-2 and the compensatory potential of SLP-2 suggest a functional epistatic relationship to Parkin and a protective role of SLP-2 in neurons. This finding places further emphasis on the significance of Parkin for the maintenance of mitochondrial function in neurons and provides a novel target for therapeutic strategies.
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Affiliation(s)
- Alessandra Zanon
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Sreehari Kalvakuri
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | | | - Luisa Foco
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Marianna Guida
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Christine Schwienbacher
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Alice Serafin
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Franziska Rudolph
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany
| | - Michaela Trilck
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany
| | - Anne Grünewald
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany.,Molecular and Functional Neurobiology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux, Luxembourg
| | - Nancy Stanslowsky
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany
| | - Florian Wegner
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany
| | | | - Alexandros A Lavdas
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Rolf Bodmer
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Peter P Pramstaller
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy.,Department of Neurology, General Central Hospital, 39100 Bolzano, Italy.,Department of Neurology, University of Lübeck, 23562 Lübeck, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany
| | - Andrew A Hicks
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Irene Pichler
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Philip Seibler
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany
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32
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Dues DJ, Andrews EK, Schaar CE, Bergsma AL, Senchuk MM, Van Raamsdonk JM. Aging causes decreased resistance to multiple stresses and a failure to activate specific stress response pathways. Aging (Albany NY) 2017; 8:777-95. [PMID: 27053445 PMCID: PMC4925828 DOI: 10.18632/aging.100939] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 03/17/2016] [Indexed: 12/14/2022]
Abstract
In this work, we examine the relationship between stress resistance and aging. We find that resistance to multiple types of stress peaks during early adulthood and then declines with age. To dissect the underlying mechanisms, we use C. elegans transcriptional reporter strains that measure the activation of different stress responses including: the heat shock response, mitochondrial unfolded protein response, endoplasmic reticulum unfolded protein response, hypoxia response, SKN-1-mediated oxidative stress response, and the DAF-16-mediated stress response. We find that the decline in stress resistance with age is at least partially due to a decreased ability to activate protective mechanisms in response to stress. In contrast, we find that any baseline increase in stress caused by the advancing age is too mild to detectably upregulate any of the stress response pathways. Further exploration of how worms respond to stress with increasing age revealed that the ability to mount a hormetic response to heat stress is also lost with increasing age. Overall, this work demonstrates that resistance to all types of stress declines with age. Based on our data, we speculate that the decrease in stress resistance with advancing age results from a genetically-programmed inactivation of stress response pathways, not accumulation of damage.
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Affiliation(s)
- Dylan J Dues
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Emily K Andrews
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Claire E Schaar
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Alexis L Bergsma
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Megan M Senchuk
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Jeremy M Van Raamsdonk
- Laboratory of Aging and Neurodegenerative Disease, Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI 49503, USA.,Department of Translational Science and Molecular Medicine, Michigan State University, Grand Rapids, MI 49503, USA.,Department of Genetics, Michigan State University, East Lansing, MI 48824, USA
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33
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van der Bliek AM, Sedensky MM, Morgan PG. Cell Biology of the Mitochondrion. Genetics 2017; 207:843-871. [PMID: 29097398 PMCID: PMC5676242 DOI: 10.1534/genetics.117.300262] [Citation(s) in RCA: 245] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 09/05/2017] [Indexed: 01/19/2023] Open
Abstract
Mitochondria are best known for harboring pathways involved in ATP synthesis through the tricarboxylic acid cycle and oxidative phosphorylation. Major advances in understanding these roles were made with Caenorhabditiselegans mutants affecting key components of the metabolic pathways. These mutants have not only helped elucidate some of the intricacies of metabolism pathways, but they have also served as jumping off points for pharmacology, toxicology, and aging studies. The field of mitochondria research has also undergone a renaissance, with the increased appreciation of the role of mitochondria in cell processes other than energy production. Here, we focus on discoveries that were made using C. elegans, with a few excursions into areas that were studied more thoroughly in other organisms, like mitochondrial protein import in yeast. Advances in mitochondrial biogenesis and membrane dynamics were made through the discoveries of novel functions in mitochondrial fission and fusion proteins. Some of these functions were only apparent through the use of diverse model systems, such as C. elegans Studies of stress responses, exemplified by mitophagy and the mitochondrial unfolded protein response, have also benefitted greatly from the use of model organisms. Recent developments include the discoveries in C. elegans of cell autonomous and nonautonomous pathways controlling the mitochondrial unfolded protein response, as well as mechanisms for degradation of paternal mitochondria after fertilization. The evolutionary conservation of many, if not all, of these pathways ensures that results obtained with C. elegans are equally applicable to studies of human mitochondria in health and disease.
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Affiliation(s)
- Alexander M van der Bliek
- Department of Biological Chemistry, Jonsson Comprehensive Cancer Center and Molecular Biology Institute, David Geffen School of Medicine at UCLA, Los Angeles, California 90024
| | - Margaret M Sedensky
- Department of Anesthesiology and Pain Medicine, University of Washington and Center for Developmental Therapeutics, Seattle Children's Research Institute, Washington 98101
| | - Phil G Morgan
- Department of Anesthesiology and Pain Medicine, University of Washington and Center for Developmental Therapeutics, Seattle Children's Research Institute, Washington 98101
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Ivanina AV, Nesmelova I, Leamy L, Sokolov EP, Sokolova IM. Intermittent hypoxia leads to functional reorganization of mitochondria and affects cellular bioenergetics in marine molluscs. ACTA ACUST UNITED AC 2017; 219:1659-74. [PMID: 27252455 DOI: 10.1242/jeb.134700] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 03/14/2016] [Indexed: 12/11/2022]
Abstract
Fluctuations in oxygen (O2) concentrations represent a major challenge to aerobic organisms and can be extremely damaging to their mitochondria. Marine intertidal molluscs are well-adapted to frequent O2 fluctuations, yet it remains unknown how their mitochondrial functions are regulated to sustain energy metabolism and prevent cellular damage during hypoxia and reoxygenation (H/R). We used metabolic control analysis to investigate the mechanisms of mitochondrial responses to H/R stress (18 h at <0.1% O2 followed by 1 h of reoxygenation) using hypoxia-tolerant intertidal clams Mercenaria mercenaria and hypoxia-sensitive subtidal scallops Argopecten irradians as models. We also assessed H/R-induced changes in cellular energy balance, oxidative damage and unfolded protein response to determine the potential links between mitochondrial dysfunction and cellular injury. Mitochondrial responses to H/R in scallops strongly resembled those in other hypoxia-sensitive organisms. Exposure to hypoxia followed by reoxygenation led to a strong decrease in the substrate oxidation (SOX) and phosphorylation (PHOS) capacities as well as partial depolarization of mitochondria of scallops. Elevated mRNA expression of a reactive oxygen species-sensitive enzyme aconitase and Lon protease (responsible for degradation of oxidized mitochondrial proteins) during H/R stress was consistent with elevated levels of oxidative stress in mitochondria of scallops. In hypoxia-tolerant clams, mitochondrial SOX capacity was enhanced during hypoxia and continued rising during the first hour of reoxygenation. In both species, the mitochondrial PHOS capacity was suppressed during hypoxia, likely to prevent ATP wastage by the reverse action of FO,F1-ATPase. The PHOS capacity recovered after 1 h of reoxygenation in clams but not in scallops. Compared with scallops, clams showed a greater suppression of energy-consuming processes (such as protein turnover and ion transport) during hypoxia, indicated by inactivation of the translation initiation factor EIF-2α, suppression of 26S proteasome activity and a dramatic decrease in the activity of Na(+)/K(+)-ATPase. The steady-state levels of adenylates were preserved during H/R exposure and AMP-dependent protein kinase was not activated in either species, indicating that the H/R exposure did not lead to severe energy deficiency. Taken together, our findings suggest that mitochondrial reorganizations sustaining high oxidative phosphorylation flux during recovery, combined with the ability to suppress ATP-demanding cellular functions during hypoxia, may contribute to high resilience of clams to H/R stress and help maintain energy homeostasis during frequent H/R cycles in the intertidal zone.
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Affiliation(s)
- Anna V Ivanina
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Irina Nesmelova
- Department of Physics, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Larry Leamy
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Eugene P Sokolov
- Department of General Surgery, Carolinas Medical Center, Charlotte, NC 28232, USA
| | - Inna M Sokolova
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
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Mitochondria and mitochondria-induced signalling molecules as longevity determinants. Mech Ageing Dev 2017; 165:115-128. [DOI: 10.1016/j.mad.2016.12.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/28/2016] [Accepted: 12/07/2016] [Indexed: 12/21/2022]
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Abstract
The balance of oxidants and antioxidants within the cell is crucial for maintaining health, and regulating physiological processes such as signalling. Consequently, imbalances between oxidants and antioxidants are now understood to lead to oxidative stress, a physiological feature that underlies many diseases. These processes have spurred the field of chemical biology to develop a plethora of sensors, both small-molecule and fluorescent protein-based, for the detection of specific oxidizing species and general redox balances within cells. The mitochondrion, in particular, is the site of many vital redox reactions. There is therefore a need to target redox sensors to this particular organelle. It has been well established that targeting mitochondria can be achieved by the use of a lipophilic cation-targeting group, or by utilizing natural peptidic mitochondrial localization sequences. Here, we review how these two approaches have been used by a number of researchers to develop mitochondrially localized fluorescent redox sensors that are already proving useful in providing insights into the roles of reactive oxygen species in the mitochondria.
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Affiliation(s)
| | | | - Elizabeth J. New
- School of Chemistry, The University of Sydney, New South Wales 2006, Australia
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C. elegans neurons jettison protein aggregates and mitochondria under neurotoxic stress. Nature 2017; 542:367-371. [PMID: 28178240 PMCID: PMC5336134 DOI: 10.1038/nature21362] [Citation(s) in RCA: 250] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 01/03/2017] [Indexed: 12/12/2022]
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Braeckman BP, Smolders A, Back P, De Henau S. In Vivo Detection of Reactive Oxygen Species and Redox Status in Caenorhabditis elegans. Antioxid Redox Signal 2016; 25:577-92. [PMID: 27306519 PMCID: PMC5041511 DOI: 10.1089/ars.2016.6751] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 06/14/2016] [Indexed: 12/21/2022]
Abstract
SIGNIFICANCE Due to its large families of redox-active enzymes, genetic amenability, and complete transparency, the nematode Caenorhabditis elegans has the potential to become an important model for the in vivo study of redox biology. RECENT ADVANCES The recent development of several genetically encoded ratiometric reactive oxygen species (ROS) and redox sensors has revolutionized the quantification and precise localization of ROS and redox signals in living organisms. Only few exploratory studies have applied these sensors in C. elegans and undoubtedly much remains to be discovered in this model. As a follow-up to our recent findings that the C. elegans somatic gonad uses superoxide and hydrogen peroxide (H2O2) signals to communicate with the germline, we here analyze the patterns of H2O2 inside the C. elegans germline. CRITICAL ISSUES Despite the advantages of genetically encoded ROS and redox sensors over classic chemical sensors, still several general as well as C. elegans-specific issues need to be addressed. The major concerns for the application of these sensors in C. elegans are (i) decreased vitality of some reporter strains, (ii) interference of autofluorescent compartments with the sensor signal, and (iii) the use of immobilization methods that do not influence the worm's redox physiology. FUTURE DIRECTIONS We propose that several of the current issues may be solved by designing reporter strains carrying single copies of codon-optimized sensors. Preferably, these sensors should have their emission wavelengths in the red region, where autofluorescence is absent. Worm analysis could be optimized using four-dimensional ratiometric fluorescence microscopy of worms immobilized in microfluidic chips. Antioxid. Redox Signal. 25, 577-592.
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Affiliation(s)
| | - Arne Smolders
- Biology Department, Ghent University, Ghent, Belgium
| | - Patricia Back
- Biology Department, Ghent University, Ghent, Belgium
| | - Sasha De Henau
- Biology Department, Ghent University, Ghent, Belgium
- Biomedical Genetics, University Medical Center Untrecht, Utrecht, The Netherlands
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Schwarzländer M, Dick TP, Meyer AJ, Morgan B. Dissecting Redox Biology Using Fluorescent Protein Sensors. Antioxid Redox Signal 2016; 24:680-712. [PMID: 25867539 DOI: 10.1089/ars.2015.6266] [Citation(s) in RCA: 191] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
SIGNIFICANCE Fluorescent protein sensors have revitalized the field of redox biology by revolutionizing the study of redox processes in living cells and organisms. RECENT ADVANCES Within one decade, a set of fundamental new insights has been gained, driven by the rapid technical development of in vivo redox sensing. Redox-sensitive yellow and green fluorescent protein variants (rxYFP and roGFPs) have been the central players. CRITICAL ISSUES Although widely used as an established standard tool, important questions remain surrounding their meaningful use in vivo. We review the growing range of thiol redox sensor variants and their application in different cells, tissues, and organisms. We highlight five key findings where in vivo sensing has been instrumental in changing our understanding of redox biology, critically assess the interpretation of in vivo redox data, and discuss technical and biological limitations of current redox sensors and sensing approaches. FUTURE DIRECTIONS We explore how novel sensor variants may further add to the current momentum toward a novel mechanistic and integrated understanding of redox biology in vivo. Antioxid. Redox Signal. 24, 680-712.
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Affiliation(s)
- Markus Schwarzländer
- 1 Plant Energy Biology Lab, Department Chemical Signalling, Institute of Crop Science and Resource Conservation (INRES), University of Bonn , Bonn, Germany
| | - Tobias P Dick
- 2 Division of Redox Regulation, German Cancer Research Center (DKFZ) , DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Andreas J Meyer
- 3 Department Chemical Signalling, Institute of Crop Science and Resource Conservation (INRES), University of Bonn , Bonn, Germany
| | - Bruce Morgan
- 2 Division of Redox Regulation, German Cancer Research Center (DKFZ) , DKFZ-ZMBH Alliance, Heidelberg, Germany .,4 Cellular Biochemistry, Department of Biology, University of Kaiserslautern , Kaiserslautern, Germany
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Morsci NS, Hall DH, Driscoll M, Sheng ZH. Age-Related Phasic Patterns of Mitochondrial Maintenance in Adult Caenorhabditis elegans Neurons. J Neurosci 2016; 36:1373-85. [PMID: 26818523 PMCID: PMC4728731 DOI: 10.1523/jneurosci.2799-15.2016] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 12/11/2015] [Accepted: 12/18/2015] [Indexed: 12/22/2022] Open
Abstract
Aging is associated with cognitive decline and increasing risk of neurodegeneration. Perturbation of mitochondrial function, dynamics, and trafficking are implicated in the pathogenesis of several age-associated neurodegenerative diseases. Despite this fundamental importance, the critical understanding of how organismal aging affects lifetime neuronal mitochondrial maintenance remains unknown, particularly in a physiologically relevant context. To address this issue, we performed a comprehensive in vivo analysis of age-associated changes in mitochondrial morphology, density, trafficking, and stress resistance in individual Caenorhabditis elegans neurons throughout adult life. Adult neurons display three distinct stages of increase, maintenance, and decrease in mitochondrial size and density during adulthood. Mitochondrial trafficking in the distal neuronal processes declines progressively with age starting from early adulthood. In contrast, long-lived daf-2 mutants exhibit delayed age-associated changes in mitochondrial morphology, constant mitochondrial density, and maintained trafficking rates during adulthood. Reduced mitochondrial load at late adulthood correlates with decreased mitochondrial resistance to oxidative stress. Revealing aging-associated changes in neuronal mitochondria in vivo is an essential precedent that will allow future elucidation of the mechanistic causes of mitochondrial aging. Thus, our study establishes the critical foundation for the future analysis of cellular pathways and genetic and pharmacological factors regulating mitochondrial maintenance in aging- and disease-relevant conditions. SIGNIFICANCE STATEMENT Using Caenorhabditis elegans as a model, we address long-standing questions: How does aging affect neuronal mitochondrial morphology, density, trafficking, and oxidative stress resistance? Are these age-related changes amenable to genetic manipulations that slow down the aging process? Our study illustrates that mitochondrial trafficking declines progressively from the first day of adulthood, whereas mitochondrial size, density, and resistance to oxidative stress undergo three distinct stages: increase in early adulthood, maintenance at high levels during mid-adulthood, and decline during late adulthood. Thus, our study characterizes mitochondrial aging profile at the level of a single neuron in its native environment and establishes the critical foundation for the future genetic and pharmacological dissection of factors that influence long-term mitochondrial maintenance in neurons.
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Affiliation(s)
- Natalia S Morsci
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
| | - David H Hall
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, and
| | - Monica Driscoll
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey 08855
| | - Zu-Hang Sheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892,
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Park EC, Rongo C. The p38 MAP kinase pathway modulates the hypoxia response and glutamate receptor trafficking in aging neurons. eLife 2016; 5. [PMID: 26731517 PMCID: PMC4775213 DOI: 10.7554/elife.12010] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 01/04/2016] [Indexed: 01/07/2023] Open
Abstract
Neurons are sensitive to low oxygen (hypoxia) and employ a conserved pathway to combat its effects. Here, we show that p38 MAP Kinase (MAPK) modulates this hypoxia response pathway in C. elegans. Mutants lacking p38 MAPK components pmk-1 or sek-1 resemble mutants lacking the hypoxia response component and prolyl hydroxylase egl-9, with impaired subcellular localization of Mint orthologue LIN-10, internalization of glutamate receptor GLR-1, and depression of GLR-1-mediated behaviors. Loss of p38 MAPK impairs EGL-9 protein localization in neurons and activates the hypoxia-inducible transcription factor HIF-1, suggesting that p38 MAPK inhibits the hypoxia response pathway through EGL-9. As animals age, p38 MAPK levels decrease, resulting in GLR-1 internalization; this age-dependent downregulation can be prevented through either p38 MAPK overexpression or removal of CDK-5, an antagonizing kinase. Our findings demonstrate that p38 MAPK inhibits the hypoxia response pathway and determines how aging neurons respond to hypoxia through a novel mechanism. DOI:http://dx.doi.org/10.7554/eLife.12010.001 The brain accounts for 2% of our body weight, but consumes about 20% of our oxygen intake. This oxygen gluttony is due to the tremendous appetite of brain cells for energy, which neurons satisfy through oxygen-dependent (aerobic) metabolism. As a result, the loss of oxygen to the brain during a stroke, heart attack, or due to another medical condition can be very damaging to cells in the brain. Human and other animal cells use a communication system called the hypoxia response pathway to sense oxygen and trigger a protective response when oxygen is low. This pathway includes an enzyme called prolyl hydroxylase, which senses oxygen and modifies another protein in the pathway that regulates the production of enzymes involved in metabolism. This alters the balance of enzymes involved in aerobic and oxygen-independent (anaerobic) metabolism in the cell. However, it is not clear how the activity of the prolyl hydroxylase is regulated. Much of our knowledge about the hypoxia response pathway has been gained from studies using a small worm called C. elegans. This worm uses the pathway to cope with hypoxia in the harsh environment of the soil. Mutant worms that lack the prolyl hydroxylase have several abnormalities including higher levels of anaerobic metabolism even in the presence of oxygen, and defects in the connections between neurons. Park and Rongo used C. elegans to study the pathway in more detail. The experiments show that another enzyme called p38 MAPK activates the prolyl hydroxylase. Mutant worms that lack this enzyme have similar abnormalities in the hypoxia response pathway as animals that lack the prolyl hydroxylase. In normal worms, decreasing levels of p38 MAPK as the animals grow older contribute to the decline in the nervous system. The p38 MAPK enzyme appears to work by regulating the activity of the prolyl hydroxylase and its location inside neurons. These findings provide a new target for the development of drugs that may help to protect us from tissue damage caused by hypoxia. Future challenges are to find out what activates p38 MAPK, and how it influences the location of prolyl hydroxylase in neurons. DOI:http://dx.doi.org/10.7554/eLife.12010.002
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Affiliation(s)
- Eun Chan Park
- The Waksman Institute, Rutgers The State University of New Jersey, New Jersey, United States.,Department of Genetics, Rutgers The State University of New Jersey, New Jersey, United States
| | - Christopher Rongo
- The Waksman Institute, Rutgers The State University of New Jersey, New Jersey, United States.,Department of Genetics, Rutgers The State University of New Jersey, New Jersey, United States
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Palikaras K, Lionaki E, Tavernarakis N. Coordination of mitophagy and mitochondrial biogenesis during ageing in C. elegans. Nature 2015; 521:525-8. [PMID: 25896323 DOI: 10.1038/nature14300] [Citation(s) in RCA: 514] [Impact Index Per Article: 57.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 02/09/2015] [Indexed: 12/14/2022]
Abstract
Impaired mitochondrial maintenance in disparate cell types is a shared hallmark of many human pathologies and ageing. How mitochondrial biogenesis coordinates with the removal of damaged or superfluous mitochondria to maintain cellular homeostasis is not well understood. Here we show that mitophagy, a selective type of autophagy targeting mitochondria for degradation, interfaces with mitochondrial biogenesis to regulate mitochondrial content and longevity in Caenorhabditis elegans. We find that DCT-1 is a key mediator of mitophagy and longevity assurance under conditions of stress in C. elegans. Impairment of mitophagy compromises stress resistance and triggers mitochondrial retrograde signalling through the SKN-1 transcription factor that regulates both mitochondrial biogenesis genes and mitophagy by enhancing DCT-1 expression. Our findings reveal a homeostatic feedback loop that integrates metabolic signals to coordinate the biogenesis and turnover of mitochondria. Uncoupling of these two processes during ageing contributes to overproliferation of damaged mitochondria and decline of cellular function.
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Affiliation(s)
- Konstantinos Palikaras
- 1] Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Nikolaou Plastira 100, Heraklion 70013, Crete, Greece [2] Department of Biology, University of Crete, Heraklion 70013, Crete, Greece
| | - Eirini Lionaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Nikolaou Plastira 100, Heraklion 70013, Crete, Greece
| | - Nektarios Tavernarakis
- 1] Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Nikolaou Plastira 100, Heraklion 70013, Crete, Greece [2] Department of Basic Sciences, Faculty of Medicine, University of Crete, Heraklion 71110, Crete, Greece
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Barbosa DJ, Serrat R, Mirra S, Quevedo M, de Barreda EG, Àvila J, Ferreira LM, Branco PS, Fernandes E, Lourdes Bastos MD, Capela JP, Soriano E, Carvalho F. The mixture of "ecstasy" and its metabolites impairs mitochondrial fusion/fission equilibrium and trafficking in hippocampal neurons, at in vivo relevant concentrations. Toxicol Sci 2014; 139:407-20. [PMID: 24595818 DOI: 10.1093/toxsci/kfu042] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
3,4-Methylenedioxymethamphetamine (MDMA; "ecstasy") is a potentially neurotoxic recreational drug of abuse. Though the mechanisms involved are still not completely understood, formation of reactive metabolites and mitochondrial dysfunction contribute to MDMA-related neurotoxicity. Neuronal mitochondrial trafficking, and their targeting to synapses, is essential for proper neuronal function and survival, rendering neurons particularly vulnerable to mitochondrial dysfunction. Indeed, MDMA-associated disruption of Ca(2+) homeostasis and ATP depletion have been described in neurons, thus suggesting possible MDMA interference on mitochondrial dynamics. In this study, we performed real-time functional experiments of mitochondrial trafficking to explore the role of in situ mitochondrial dysfunction in MDMA's neurotoxic actions. We show that the mixture of MDMA and six of its major in vivo metabolites, each compound at 10μM, impaired mitochondrial trafficking and increased the fragmentation of axonal mitochondria in cultured hippocampal neurons. Furthermore, the overexpression of mitofusin 2 (Mfn2) or dynamin-related protein 1 (Drp1) K38A constructs almost completely rescued the trafficking deficits caused by this mixture. Finally, in hippocampal neurons overexpressing a Mfn2 mutant, Mfn2 R94Q, with impaired fusion and transport properties, it was confirmed that a dysregulation of mitochondrial fission/fusion events greatly contributed to the reported trafficking phenotype. In conclusion, our study demonstrated, for the first time, that the mixture of MDMA and its metabolites, at concentrations relevant to the in vivo scenario, impaired mitochondrial trafficking and increased mitochondrial fragmentation in hippocampal neurons, thus providing a new insight in the context of "ecstasy"-induced neuronal injury.
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Affiliation(s)
- Daniel José Barbosa
- REQUIMTE (Rede de Química e Tecnologia), Toxicology Laboratory, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
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