1
|
Nieto-Torres JL, Zaretski S, Liu T, Adams PD, Hansen M. Post-translational modifications of ATG8 proteins - an emerging mechanism of autophagy control. J Cell Sci 2023; 136:jcs259725. [PMID: 37589340 PMCID: PMC10445744 DOI: 10.1242/jcs.259725] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023] Open
Abstract
Autophagy is a recycling mechanism involved in cellular homeostasis with key implications for health and disease. The conjugation of the ATG8 family proteins, which includes LC3B (also known as MAP1LC3B), to autophagosome membranes, constitutes a hallmark of the canonical autophagy process. After ATG8 proteins are conjugated to the autophagosome membranes via lipidation, they orchestrate a plethora of protein-protein interactions that support key steps of the autophagy process. These include binding to cargo receptors to allow cargo recruitment, association with proteins implicated in autophagosome transport and autophagosome-lysosome fusion. How these diverse and critical protein-protein interactions are regulated is still not well understood. Recent reports have highlighted crucial roles for post-translational modifications of ATG8 proteins in the regulation of ATG8 functions and the autophagy process. This Review summarizes the main post-translational regulatory events discovered to date to influence the autophagy process, mostly described in mammalian cells, including ubiquitylation, acetylation, lipidation and phosphorylation, as well as their known contributions to the autophagy process, physiology and disease.
Collapse
Affiliation(s)
- Jose L. Nieto-Torres
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA 92037, USA
- Department of Biomedical Sciences, School of Health Sciences and Veterinary, Universidad Cardenal Herrera-CEU, CEU Universities, 46113 Moncada, Spain
| | - Sviatlana Zaretski
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA 92037, USA
| | - Tianhui Liu
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA 92037, USA
| | - Peter D. Adams
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA 92037, USA
| | - Malene Hansen
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA 92037, USA
- The Buck Institute for Aging Research, Novato, CA 94945, USA
| |
Collapse
|
2
|
Yang J, Yuan L, Liu F, Li L, Liu J, Chen Y, Lu Y, Yuan Y. Molecular mechanisms and physiological functions of autophagy in kidney diseases. Front Pharmacol 2022; 13:974829. [PMID: 36081940 PMCID: PMC9446454 DOI: 10.3389/fphar.2022.974829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 07/05/2022] [Indexed: 12/04/2022] Open
Abstract
Autophagy is a highly conserved cellular progress for the degradation of cytoplasmic contents including micromolecules, misfolded proteins, and damaged organelles that has recently captured attention in kidney diseases. Basal autophagy plays a pivotal role in maintaining cell survival and kidney homeostasis. Accordingly, dysregulation of autophagy has implicated in the pathologies of kidney diseases. In this review, we summarize the multifaceted role of autophagy in kidney aging, maladaptive repair, tubulointerstitial fibrosis and discuss autophagy-related drugs in kidney diseases. However, uncertainty still remains as to the precise mechanisms of autophagy in kidney diseases. Further research is needed to clarify the accurate molecular mechanism of autophagy in kidney diseases, which will facilitate the discovery of a promising strategy for the prevention and treatment of kidney diseases.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Yanrong Lu
- *Correspondence: Yanrong Lu, ; Yujia Yuan,
| | - Yujia Yuan
- *Correspondence: Yanrong Lu, ; Yujia Yuan,
| |
Collapse
|
3
|
Hou LS, Zhang YW, Li H, Wang W, Huan ML, Zhou SY, Zhang BL. The regulatory role and mechanism of autophagy in energy metabolism-related hepatic fibrosis. Pharmacol Ther 2022; 234:108117. [PMID: 35077761 DOI: 10.1016/j.pharmthera.2022.108117] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 02/06/2023]
Abstract
Hepatic fibrosis is a key pathological process of chronic liver diseases, caused by alcohol, toxic and aberrant energy metabolism. It progresses to cirrhosis or even hepatic carcinoma without effective treatment. Studies have shown that autophagy has important regulatory effects on hepatic stellate cells (HSCs) energy metabolism, and then affect the activation state of HSCs. Autophagy maintains hepatic energy homeostasis, and the dysregulation of autophagy can lead to the activation of HSCs and the occurrence and development of hepatic fibrosis. It is necessary to explore the mechanism of autophagy in energy metabolism-related hepatic fibrosis. Herein, the current study summarizes the regulating mechanisms of autophagy through different targets and signal pathways in energy metabolism-related hepatic fibrosis, and discusses the regulatory effect of autophagy by natural plant-derived, endogenous and synthetic compounds for the treatment of hepatic fibrosis. A better comprehension of autophagy in hepatic stellate cells energy metabolism-related hepatic fibrosis may provide effective intervention of hepatic fibrosis, explore the potential clinical strategies and promote the drug treatment of hepatic fibrosis.
Collapse
Affiliation(s)
- Li-Shuang Hou
- Department of Pharmaceutics, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China
| | - Yao-Wen Zhang
- Department of Pharmaceutics, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China
| | - Hua Li
- Key Laboratory of Pharmacology of the State Administration of Traditional Chinese Medicine, Fourth Military Medical University, Xi'an 710032, China; Department of Natural Medicine, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China
| | - Wei Wang
- Department of Pharmaceutics, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China
| | - Meng-Lei Huan
- Department of Pharmaceutics, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China; Key Laboratory of Pharmacology of the State Administration of Traditional Chinese Medicine, Fourth Military Medical University, Xi'an 710032, China
| | - Si-Yuan Zhou
- Department of Pharmaceutics, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China; Key Laboratory of Pharmacology of the State Administration of Traditional Chinese Medicine, Fourth Military Medical University, Xi'an 710032, China
| | - Bang-Le Zhang
- Department of Pharmaceutics, School of Pharmacy, Fourth Military Medical University, Xi'an 710032, China; Key Laboratory of Pharmacology of the State Administration of Traditional Chinese Medicine, Fourth Military Medical University, Xi'an 710032, China.
| |
Collapse
|
4
|
Fas BA, Maiani E, Sora V, Kumar M, Mashkoor M, Lambrughi M, Tiberti M, Papaleo E. The conformational and mutational landscape of the ubiquitin-like marker for autophagosome formation in cancer. Autophagy 2021; 17:2818-2841. [PMID: 33302793 PMCID: PMC8525936 DOI: 10.1080/15548627.2020.1847443] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 10/28/2020] [Accepted: 11/03/2020] [Indexed: 02/06/2023] Open
Abstract
Macroautophagy/autophagy is a cellular process to recycle damaged cellular components, and its modulation can be exploited for disease treatments. A key autophagy player is the ubiquitin-like protein MAP1LC3B/LC3B. Mutations and changes in MAP1LC3B expression occur in cancer samples. However, the investigation of the effects of these mutations on MAP1LC3B protein structure is still missing. Despite many LC3B structures that have been solved, a comprehensive study, including dynamics, has not yet been undertaken. To address this knowledge gap, we assessed nine physical models for biomolecular simulations for their capabilities to describe the structural ensemble of MAP1LC3B. With the resulting MAP1LC3B structural ensembles, we characterized the impact of 26 missense mutations from pan-cancer studies with different approaches, and we experimentally validated our prediction for six variants using cellular assays. Our findings shed light on damaging or neutral mutations in MAP1LC3B, providing an atlas of its modifications in cancer. In particular, P32Q mutation was found detrimental for protein stability with a propensity to aggregation. In a broader context, our framework can be applied to assess the pathogenicity of protein mutations or to prioritize variants for experimental studies, allowing to comprehensively account for different aspects that mutational events alter in terms of protein structure and function.Abbreviations: ATG: autophagy-related; Cα: alpha carbon; CG: coarse-grained; CHARMM: Chemistry at Harvard macromolecular mechanics; CONAN: contact analysis; FUNDC1: FUN14 domain containing 1; FYCO1: FYVE and coiled-coil domain containing 1; GABARAP: GABA type A receptor-associated protein; GROMACS: Groningen machine for chemical simulations; HP: hydrophobic pocket; LIR: LC3 interacting region; MAP1LC3B/LC3B microtubule associated protein 1 light chain 3 B; MD: molecular dynamics; OPTN: optineurin; OSF: open software foundation; PE: phosphatidylethanolamine, PLEKHM1: pleckstrin homology domain-containing family M 1; PSN: protein structure network; PTM: post-translational modification; SA: structural alphabet; SLiM: short linear motif; SQSTM1/p62: sequestosome 1; WT: wild-type.
Collapse
Affiliation(s)
- Burcu Aykac Fas
- Computational Biology Laboratory, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Emiliano Maiani
- Computational Biology Laboratory, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Valentina Sora
- Computational Biology Laboratory, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Mukesh Kumar
- Computational Biology Laboratory, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Maliha Mashkoor
- Computational Biology Laboratory, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Matteo Lambrughi
- Computational Biology Laboratory, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Matteo Tiberti
- Computational Biology Laboratory, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Elena Papaleo
- Computational Biology Laboratory, Danish Cancer Society Research Center, Copenhagen, Denmark
- Translational Disease Systems Biology, Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
5
|
Gauron MC, Newton AC, Colombo MI. PKCα Is Recruited to Staphylococcus aureus-Containing Phagosomes and Impairs Bacterial Replication by Inhibition of Autophagy. Front Immunol 2021; 12:662987. [PMID: 33815423 PMCID: PMC8013776 DOI: 10.3389/fimmu.2021.662987] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/03/2021] [Indexed: 11/24/2022] Open
Abstract
Hijacking the autophagic machinery is a key mechanism through which invasive pathogens such as Staphylococcus aureus replicate in their host cells. We have previously demonstrated that the bacteria replicate in phagosomes labeled with the autophagic protein LC3, before escaping to the cytoplasm. Here, we show that the Ca2+-dependent PKCα binds to S. aureus-containing phagosomes and that α-hemolysin, secreted by S. aureus, promotes this recruitment of PKCα to phagosomal membranes. Interestingly, the presence of PKCα prevents the association of the autophagic protein LC3. Live cell imaging experiments using the PKC activity reporter CKAR reveal that treatment of cells with S. aureus culture supernatants containing staphylococcal secreted factors transiently activates PKC. Functional studies reveal that overexpression of PKCα causes a marked inhibition of bacterial replication. Taken together, our data identify enhancing PKCα activity as a potential approach to inhibit S. aureus replication in mammalian cells.
Collapse
Affiliation(s)
- Maria Celeste Gauron
- Laboratorio de Mecanismos Moleculares Implicados en el Tráfico Vesicular y la Autofagia-Instituto de Histología y Embriología (IHEM)- Universidad Nacional de Cuyo, CONICET- Facultad de Ciencias Médicas, Mendoza, Argentina.,Department of Pharmacology, University of California San Diego, La Jolla, CA, United States
| | - Alexandra C Newton
- Department of Pharmacology, University of California San Diego, La Jolla, CA, United States
| | - María Isabel Colombo
- Laboratorio de Mecanismos Moleculares Implicados en el Tráfico Vesicular y la Autofagia-Instituto de Histología y Embriología (IHEM)- Universidad Nacional de Cuyo, CONICET- Facultad de Ciencias Médicas, Mendoza, Argentina
| |
Collapse
|
6
|
Wu JH, Tung SY, Ho CC, Su LH, Gan SW, Liao JY, Cho CC, Lin BC, Chiu PW, Pan YJ, Kao YY, Liu YC, Sun CH. A myeloid leukemia factor homolog involved in encystation-induced protein metabolism in Giardia lamblia. Biochim Biophys Acta Gen Subj 2021; 1865:129859. [PMID: 33581251 DOI: 10.1016/j.bbagen.2021.129859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/14/2021] [Accepted: 01/25/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Giardia lamblia differentiates into resistant cysts as an established model for dormancy. Myeloid leukemia factor (MLF) proteins are important regulators of cell differentiation. Giardia possesses a MLF homolog which was up-regulated during encystation and localized to unknown cytosolic vesicles named MLF vesicles (MLFVs). METHODS We used double staining for visualization of potential factors with role in protein metabolism pathway and a strategy that employed a deletion mutant, CDK2m3, to test the protein degradation pathway. We also explored whether autophagy or proteasomal degradation are regulators of Giardia encystation by treatment with MG132, rapamycin, or chloroquine. RESULTS Double staining of MLF and ISCU or CWP1 revealed no overlap between their vesicles. The aberrant CDK2m3 colocalized with MLFVs and formed complexes with MLF. MG132 increased the number of CDK2m3-localized vesicles and its protein level. We further found that MLF colocalized and interacted with a FYVE protein and an ATG8-like (ATG8L) protein, which were up-regulated during encystation and their expression induced Giardia encystation. The addition of MG132, rapamycin, or chloroquine, increased their levels and the number of their vesicles, and inhibited the cyst formation. MLF and FYVE were detected in exosomes released from culture. CONCLUSIONS The MLFVs are not mitosomes or encystation-specific vesicles, but are related with degradative pathway for CDK2m3. MLF, FYVE, and ATG8L play a positive role in encystation and function in protein clearance pathway, which is important for encystation and coordinated with Exosomes. GENERAL SIGNIFICANCE MLF, FYVE, and ATG8L may be involved an encystation-induced protein metabolism during Giardia differentiation.
Collapse
Affiliation(s)
- Jui-Hsuan Wu
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Szu-Yu Tung
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Chun-Che Ho
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Li-Hsin Su
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Soo-Wah Gan
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Jo-Yu Liao
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Chao-Cheng Cho
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Bo-Chi Lin
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Pei-Wei Chiu
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Yu-Jiao Pan
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Yu-Yun Kao
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Yu-Chen Liu
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC
| | - Chin-Hung Sun
- Department of Tropical Medicine and Parasitology, College of Medicine, National Taiwan University, Taipei 100, Taiwan, ROC.
| |
Collapse
|
7
|
Julku UH, Jäntti M, Svarcbahs R, Myöhänen TT. Prolyl Oligopeptidase Regulates Dopamine Transporter Oligomerization and Phosphorylation in a PKC- and ERK-Independent Manner. Int J Mol Sci 2021; 22:1777. [PMID: 33579026 PMCID: PMC7916783 DOI: 10.3390/ijms22041777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 12/18/2022] Open
Abstract
Prolyl oligopeptidase (PREP) is a serine protease that binds to alpha-synuclein (aSyn) and induces its aggregation. PREP inhibitors have been shown to have beneficial effects in Parkinson's disease models by enhancing the clearance of aSyn aggregates and modulating striatal dopamine. Additionally, we have shown that PREP regulates phosphorylation and internalization of dopamine transporter (DAT) in mice. In this study, we clarified the mechanism behind this by using HEK-293 and PREP knock-out HEK-293 cells with DAT transfection. We tested the effects of PREP, PREP inhibition, and alpha-synuclein on PREP-related DAT regulation by using Western blot analysis and a dopamine uptake assay, and characterized the impact of PREP on protein kinase C (PKC) and extracellular signal-regulated kinase (ERK) by using PKC assay and Western blot, respectively, as these kinases regulate DAT phosphorylation. Our results confirmed our previous findings that a lack of PREP can increase phosphorylation and internalization of DAT and decrease uptake of dopamine. PREP inhibition had a variable impact on phosphorylation of ERK dependent on the metabolic state of cells, but did not have an effect on phosphorylation or function of DAT. PREP modifications did not affect PKC activity either. Additionally, a lack of PREP elevated a DAT oligomerization that is associated with intracellular trafficking of DAT. Our results suggest that PREP-mediated phosphorylation, oligomerization, and internalization of DAT is not dependent on PKC or ERK.
Collapse
Affiliation(s)
- Ulrika H. Julku
- Division of Pharmacology and Pharmacotherapy/Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E (P.O. Box 56), FI-00014 Helsinki, Finland; (U.H.J.); (M.J.); (R.S.)
| | - Maria Jäntti
- Division of Pharmacology and Pharmacotherapy/Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E (P.O. Box 56), FI-00014 Helsinki, Finland; (U.H.J.); (M.J.); (R.S.)
| | - Reinis Svarcbahs
- Division of Pharmacology and Pharmacotherapy/Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E (P.O. Box 56), FI-00014 Helsinki, Finland; (U.H.J.); (M.J.); (R.S.)
| | - Timo T. Myöhänen
- Division of Pharmacology and Pharmacotherapy/Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E (P.O. Box 56), FI-00014 Helsinki, Finland; (U.H.J.); (M.J.); (R.S.)
- Integrative Physiology and Pharmacology Unit/Institute of Biomedicine, Faculty of Medicine, University of Turku, FI-20520 Turku, Finland
| |
Collapse
|
8
|
Jia R, Bonifacino JS. The ubiquitin isopeptidase USP10 deubiquitinates LC3B to increase LC3B levels and autophagic activity. J Biol Chem 2021; 296:100405. [PMID: 33577797 PMCID: PMC7960534 DOI: 10.1016/j.jbc.2021.100405] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/04/2021] [Accepted: 02/08/2021] [Indexed: 12/30/2022] Open
Abstract
Components of the autophagy machinery are subject to regulation by various posttranslational modifications. Previous studies showed that monoubiquitination of LC3B catalyzed by the ubiquitin-activating enzyme UBA6 and ubiquitin-conjugating enzyme/ubiquitin ligase BIRC6 targets LC3B for proteasomal degradation, thus reducing LC3B levels and autophagic activity under conditions of stress. However, mechanisms capable of counteracting this process are not known. Herein, we report that LC3B ubiquitination is reversed by the action of the deubiquitinating enzyme USP10. We identified USP10 in a CRISPR-Cas9 knockout screen for ubiquitination-related genes that regulate LC3B levels. Biochemical analyses showed that silencing of USP10 reduces the levels of both the LC3B-I and LC3B-II forms of LC3B through increased ubiquitination and proteasomal degradation. In turn, the reduced LC3B levels result in slower degradation of the autophagy receptors SQSTM1 and NBR1 and an increased accumulation of puromycin-induced aggresome-like structures. Taken together, these findings indicate that the levels of LC3B and autophagic activity are controlled through cycles of LC3B ubiquitination and deubiquitination.
Collapse
Affiliation(s)
- Rui Jia
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA.
| | - Juan S Bonifacino
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
9
|
Nieto-Torres JL, Leidal AM, Debnath J, Hansen M. Beyond Autophagy: The Expanding Roles of ATG8 Proteins. Trends Biochem Sci 2021; 46:673-686. [PMID: 33558127 DOI: 10.1016/j.tibs.2021.01.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 12/14/2022]
Abstract
The ATG8 family proteins are critical players in autophagy, a cytoprotective process that mediates degradation of cytosolic cargo. During autophagy, ATG8s conjugate to autophagosome membranes to facilitate cargo recruitment, autophagosome biogenesis, transport, and fusion with lysosomes, for cargo degradation. In addition to these canonical functions, recent reports demonstrate that ATG8s are also delivered to single-membrane organelles, which leads to highly divergent degradative or secretory fates, vesicle maturation, and cargo specification. The association of ATG8s with different vesicles involves complex regulatory mechanisms still to be fully elucidated. Whether individual ATG8 family members play unique canonical or non-canonical roles, also remains unclear. This review summarizes the many open molecular questions regarding ATG8s that are only beginning to be unraveled.
Collapse
Affiliation(s)
- Jose L Nieto-Torres
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA, USA
| | - Andrew M Leidal
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA
| | - Jayanta Debnath
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA.
| | - Malene Hansen
- Sanford Burnham Prebys Medical Discovery Institute, Program of Development, Aging, and Regeneration, La Jolla, CA, USA.
| |
Collapse
|
10
|
Yan X, Gao X, Niu Q, Peng X, Zhang J, Ma X, Wei Y, Wang H, Gao Y, Chang H. Differential protein metabolism and regeneration in hypertrophic diaphragm and atrophic gastrocnemius muscles in hibernating Daurian ground squirrels. Exp Physiol 2021; 106:958-971. [PMID: 33517584 DOI: 10.1113/ep089187] [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] [Received: 10/18/2020] [Accepted: 01/26/2021] [Indexed: 12/23/2022]
Abstract
NEW FINDINGS What is the central question of this study? The aim was to investigate whether diaphragm hypertrophy and gastrocnemius atrophy during hibernation of Daurian ground squirrels involve differential regulation of protein metabolism and regeneration. What is the main finding and its importance? We clarified the differences in protein metabolism and muscle regenerative potential in the diaphragm and gastrocnemius of hibernating ground squirrels, reflecting the different adaptability of muscles. ABSTRACT Are differences in the regulation of protein metabolism and regeneration involved in the different phenotypic adaptation mechanisms of muscle hypertrophy and atrophy in hibernators? Two fast-type muscles (diaphragm and gastrocnemius) in summer active and hibernating Daurian ground squirrels were selected to detect changes in cross-sectional area (CSA) and protein expression indicative of protein synthesis metabolism (protein expression of P-Akt, P-mTORC1, P-S6K1 and P-4E-BP1), protein degradation metabolism (MuRF1, atrogin-1, calpain-1, calpain-2, calpastatin, desmin, troponin T, Beclin1 and LC3-II) and muscle regeneration (MyoD, myogenin and myostatin). In the hibernation group compared with the summer active group, the CSA of the diaphragm muscle increased significantly by 26.1%, whereas the CSA of the gastrocnemius muscle decreased significantly by 20.4%. Our study also indicated that increased protein synthesis, decreased protein degradation and increased muscle regenerative potential contributed to diaphragm muscle hypertrophy, whereas decreased protein synthesis, increased protein degradation and decreased muscle regenerative potential contributed to gastrocnemius muscle atrophy. In conclusion, the differences in muscle regeneration and regulatory pattern of protein metabolism might contribute to the different adaptive changes observed in the diaphragm and gastrocnemius muscles of ground squirrels.
Collapse
Affiliation(s)
- Xia Yan
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, 710069, China
| | - Xuli Gao
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, 710069, China
| | - Qiaohua Niu
- Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, 710069, China
| | - Xin Peng
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, 710069, China
| | - Jie Zhang
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, 710069, China
| | - Xiufeng Ma
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, 710069, China
| | - Yanhong Wei
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, 710069, China.,School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, 750004, China
| | - Huiping Wang
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, 710069, China
| | - Yunfang Gao
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, 710069, China
| | - Hui Chang
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, 710069, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, 710069, China
| |
Collapse
|
11
|
Vishnupriya S, Priya Dharshini LC, Sakthivel KM, Rasmi RR. Autophagy markers as mediators of lung injury-implication for therapeutic intervention. Life Sci 2020; 260:118308. [PMID: 32828942 PMCID: PMC7442051 DOI: 10.1016/j.lfs.2020.118308] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 12/13/2022]
Abstract
Lung injury is characterized by inflammatory processes demonstrated as loss of function of the pulmonary capillary endothelial and alveolar epithelial cells. Autophagy is an intracellular digestion system that work as an inducible adaptive response to lung injury which is a resultant of exposure to various stress agents like hypoxia, ischemia-reperfusion and xenobiotics which may be manifested as acute lung injury (ALI), acute respiratory distress syndrome (ARDS), chronic lung injury (CLI), bronchopulmonary dysplasia (BPD), chronic obstructive pulmonary disease (COPD), asthma, ventilator-induced lung injury (VILI), ventilator-associated lung injury (VALI), pulmonary fibrosis (PF), cystic fibrosis (CF) and radiation-induced lung injury (RILI). Numerous regulators like LC3B-II, Beclin 1, p62, HIF1/BNIP3 and mTOR play pivotal role in autophagy induction during lung injury possibly for progression/inhibition of the disease state. The present review focuses on the critical autophagic mediators and their potential cross talk with the lung injury pathophysiology thereby bringing to limelight the possible therapeutic interventions.
Collapse
Affiliation(s)
- Selvaraj Vishnupriya
- Department of Biotechnology, PSG College of Arts and Science, Civil Aerodrome Post, Coimbatore 641 014, Tamil Nadu, India
| | | | - Kunnathur Murugesan Sakthivel
- Department of Biochemistry, PSG College of Arts and Science, Civil Aerodrome Post, Coimbatore 641 014, Tamil Nadu, India
| | - Rajan Radha Rasmi
- Department of Biotechnology, PSG College of Arts and Science, Civil Aerodrome Post, Coimbatore 641 014, Tamil Nadu, India.
| |
Collapse
|
12
|
Deng Q, Jiang L, Mao L, Song XH, He CQ, Li XL, Zhang ZH, Zeng HC, Chen JX, Long DX. The role of protein kinase C alpha in tri-ortho-cresyl phosphate-induced autophagy in human neuroblastoma SK-N-SH cells. J Appl Toxicol 2020; 40:1480-1490. [PMID: 33020912 DOI: 10.1002/jat.3999] [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] [Received: 02/09/2020] [Revised: 03/26/2020] [Accepted: 04/21/2020] [Indexed: 12/21/2022]
Abstract
As an organophosphorus ester, tri-ortho-cresyl phosphate (TOCP) has been widely used in agriculture and industry. It is reported that TOCP can induce organophosphate-induced delayed neuropathy (OPIDN) in sensitive animal and human species. However, the exact molecular mechanisms underlying TOCP-induced neurotoxicity are still unknown. In this study, we found that TOCP could induce autophagy by activating protein kinase C alpha (PKCα) signaling in neuroblastoma SK-N-SH cells. PKCα activators could positively regulate TOCP-induced autophagy by increasing the expression levels of neighbor BRCA1 gene protein 1 (NBR1), LC3 and P62 autophagic receptor protein. Furthermore, PKCα activation impaired the ubiquitin-proteasome system (UPS), resulting in inhibition of proteasome activity and accumulation of ubiquitinated proteins. UPS dysfunction could stimulate autophagy to serve as a compensatory pathway, which contributed to the accumulation of the abnormally hyperphosphorylated tau proteins and degradation of impaired proteins of the MAP 2 and NF-H families in neurodegenerative disorders.
Collapse
Affiliation(s)
- Qiang Deng
- School of Public Health, University of South China, Hengyang, China
| | - Lan Jiang
- School of Public Health, University of South China, Hengyang, China
| | - Liang Mao
- School of Public Health, University of South China, Hengyang, China
| | - Xiao-Hua Song
- School of Public Health, University of South China, Hengyang, China
| | - Chu-Qi He
- School of Public Health, University of South China, Hengyang, China
| | - Xiao-Ling Li
- School of Public Health, University of South China, Hengyang, China
| | - Zhao-Hui Zhang
- School of Public Health, University of South China, Hengyang, China
| | - Huai-Cai Zeng
- School of Public Health, University of South China, Hengyang, China
| | - Jia-Xiang Chen
- Jiangxi Medical College, Nanchang University, Nanchang, China
| | - Ding-Xin Long
- School of Public Health, University of South China, Hengyang, China
| |
Collapse
|
13
|
Wesch N, Kirkin V, Rogov VV. Atg8-Family Proteins-Structural Features and Molecular Interactions in Autophagy and Beyond. Cells 2020; 9:E2008. [PMID: 32882854 PMCID: PMC7564214 DOI: 10.3390/cells9092008] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 08/25/2020] [Accepted: 08/27/2020] [Indexed: 12/25/2022] Open
Abstract
Autophagy is a common name for a number of catabolic processes, which keep the cellular homeostasis by removing damaged and dysfunctional intracellular components. Impairment or misbalance of autophagy can lead to various diseases, such as neurodegeneration, infection diseases, and cancer. A central axis of autophagy is formed along the interactions of autophagy modifiers (Atg8-family proteins) with a variety of their cellular counter partners. Besides autophagy, Atg8-proteins participate in many other pathways, among which membrane trafficking and neuronal signaling are the most known. Despite the fact that autophagy modifiers are well-studied, as the small globular proteins show similarity to ubiquitin on a structural level, the mechanism of their interactions are still not completely understood. A thorough analysis and classification of all known mechanisms of Atg8-protein interactions could shed light on their functioning and connect the pathways involving Atg8-proteins. In this review, we present our views of the key features of the Atg8-proteins and describe the basic principles of their recognition and binding by interaction partners. We discuss affinity and selectivity of their interactions as well as provide perspectives for discovery of new Atg8-interacting proteins and therapeutic approaches to tackle major human diseases.
Collapse
Affiliation(s)
- Nicole Wesch
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany;
| | - Vladimir Kirkin
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research London, Sutton SM2 5NG, UK;
| | - Vladimir V. Rogov
- Institute of Biophysical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany;
- Structural Genomics Consortium, Buchmann Institute for Life Sciences, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany
- Institute of Pharmaceutical Chemistry, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany
| |
Collapse
|
14
|
Bello-Perez M, Sola I, Novoa B, Klionsky DJ, Falco A. Canonical and Noncanonical Autophagy as Potential Targets for COVID-19. Cells 2020; 9:E1619. [PMID: 32635598 PMCID: PMC7408018 DOI: 10.3390/cells9071619] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023] Open
Abstract
The SARS-CoV-2 pandemic necessitates a review of the molecular mechanisms underlying cellular infection by coronaviruses, in order to identify potential therapeutic targets against the associated new disease (COVID-19). Previous studies on its counterparts prove a complex and concomitant interaction between coronaviruses and autophagy. The precise manipulation of this pathway allows these viruses to exploit the autophagy molecular machinery while avoiding its protective apoptotic drift and cellular innate immune responses. In turn, the maneuverability margins of such hijacking appear to be so narrow that the modulation of the autophagy, regardless of whether using inducers or inhibitors (many of which are FDA-approved for the treatment of other diseases), is usually detrimental to viral replication, including SARS-CoV-2. Recent discoveries indicate that these interactions stretch into the still poorly explored noncanonical autophagy pathway, which might play a substantial role in coronavirus replication. Still, some potential therapeutic targets within this pathway, such as RAB9 and its interacting proteins, look promising considering current knowledge. Thus, the combinatory treatment of COVID-19 with drugs affecting both canonical and noncanonical autophagy pathways may be a turning point in the fight against this and other viral infections, which may also imply beneficial prospects of long-term protection.
Collapse
Affiliation(s)
- Melissa Bello-Perez
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autónoma de Madrid, Darwin 3, 28049 Madrid, Spain; (M.B.-P.); (I.S.)
| | - Isabel Sola
- Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Campus Universidad Autónoma de Madrid, Darwin 3, 28049 Madrid, Spain; (M.B.-P.); (I.S.)
| | - Beatriz Novoa
- Institute of Marine Research (IIM), National Research Council (CSIC), 36208 Vigo, Spain;
| | - Daniel J. Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Alberto Falco
- Institute of Research, Development, and Innovation in Healthcare Biotechnology in Elche (IDiBE), Miguel Hernández University (UMH), 03202 Elche, Spain
| |
Collapse
|
15
|
A Novel Cosegregating DCTN1 Splice Site Variant in a Family with Bipolar Disorder May Hold the Key to Understanding the Etiology. Genes (Basel) 2020; 11:genes11040446. [PMID: 32325768 PMCID: PMC7231292 DOI: 10.3390/genes11040446] [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: 03/10/2020] [Revised: 04/08/2020] [Accepted: 04/15/2020] [Indexed: 12/24/2022] Open
Abstract
A novel cosegregating splice site variant in the Dynactin-1 (DCTN1) gene was discovered by Next Generation Sequencing (NGS) in a family with a history of bipolar disorder (BD) and major depressive diagnosis (MDD). Psychiatric illness in this family follows an autosomal dominant pattern. DCTN1 codes for the largest dynactin subunit, namely p150Glued, which plays an essential role in retrograde axonal transport and in neuronal autophagy. A GT→TT transversion in the DCTN1 gene, uncovered in the present work, is predicted to disrupt the invariant canonical splice donor site IVS22 + 1G > T and result in intron retention and a premature termination codon (PTC). Thus, this splice site variant is predicted to trigger RNA nonsense-mediated decay (NMD) and/or result in a C-terminal truncated p150Glued protein (ct-p150Glued), thereby negatively impacting retrograde axonal transport and neuronal autophagy. BD prophylactic medications, and most antipsychotics and antidepressants, are known to enhance neuronal autophagy. This variant is analogous to the dominant-negative GLUED Gl1 mutation in Drosophila, which is responsible for a neurodegenerative phenotype. The newly identified variant may reflect an autosomal dominant cause of psychiatric pathology in this affected family. Factors that affect alternative splicing of the DCTN1 gene, leading to NMD and/or ct-p150Glued, may be of fundamental importance in contributing to our understanding of the etiology of BD as well as MDD.
Collapse
|
16
|
Maeyashiki C, Melhem H, Hering L, Baebler K, Cosin-Roger J, Schefer F, Weder B, Hausmann M, Scharl M, Rogler G, de Vallière C, Ruiz PA. Activation of pH-Sensing Receptor OGR1 (GPR68) Induces ER Stress Via the IRE1α/JNK Pathway in an Intestinal Epithelial Cell Model. Sci Rep 2020; 10:1438. [PMID: 31996710 PMCID: PMC6989664 DOI: 10.1038/s41598-020-57657-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 12/31/2019] [Indexed: 12/15/2022] Open
Abstract
Proton-sensing ovarian cancer G-protein coupled receptor (OGR1) plays an important role in pH homeostasis. Acidosis occurs at sites of intestinal inflammation and can induce endoplasmic reticulum (ER) stress and the unfolded protein response (UPR), an evolutionary mechanism that enables cells to cope with stressful conditions. ER stress activates autophagy, and both play important roles in gut homeostasis and contribute to the pathogenesis of inflammatory bowel disease (IBD). Using a human intestinal epithelial cell model, we investigated whether our previously observed protective effects of OGR1 deficiency in experimental colitis are associated with a differential regulation of ER stress, the UPR and autophagy. Caco-2 cells stably overexpressing OGR1 were subjected to an acidic pH shift. pH-dependent OGR1-mediated signalling led to a significant upregulation in the ER stress markers, binding immunoglobulin protein (BiP) and phospho-inositol required 1α (IRE1α), which was reversed by a novel OGR1 inhibitor and a c-Jun N-terminal kinase (JNK) inhibitor. Proton-activated OGR1-mediated signalling failed to induce apoptosis, but triggered accumulation of total microtubule-associated protein 1 A/1B-light chain 3, suggesting blockage of late stage autophagy. Our results show novel functions for OGR1 in the regulation of ER stress through the IRE1α-JNK signalling pathway, as well as blockage of autophagosomal degradation. OGR1 inhibition might represent a novel therapeutic approach in IBD.
Collapse
Affiliation(s)
- Chiaki Maeyashiki
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Hassan Melhem
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Larissa Hering
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Katharina Baebler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Jesus Cosin-Roger
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Fabian Schefer
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Bruce Weder
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Martin Hausmann
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Michael Scharl
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, Zurich, Switzerland
| | - Gerhard Rogler
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, Zurich, Switzerland
| | - Cheryl de Vallière
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
| | - Pedro A Ruiz
- Department of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
| |
Collapse
|
17
|
Shrestha BK, Skytte Rasmussen M, Abudu YP, Bruun JA, Larsen KB, Alemu EA, Sjøttem E, Lamark T, Johansen T. NIMA-related kinase 9–mediated phosphorylation of the microtubule-associated LC3B protein at Thr-50 suppresses selective autophagy of p62/sequestosome 1. J Biol Chem 2020. [DOI: 10.1016/s0021-9258(17)49883-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
18
|
Shrestha BK, Skytte Rasmussen M, Abudu YP, Bruun JA, Larsen KB, Alemu EA, Sjøttem E, Lamark T, Johansen T. NIMA-related kinase 9–mediated phosphorylation of the microtubule-associated LC3B protein at Thr-50 suppresses selective autophagy of p62/sequestosome 1. J Biol Chem 2020; 295:1240-1260. [DOI: https:/doi.org/10.1016/s0021-9258(17)49883-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2023] Open
|
19
|
Shrestha BK, Skytte Rasmussen M, Abudu YP, Bruun JA, Larsen KB, Alemu EA, Sjøttem E, Lamark T, Johansen T. NIMA-related kinase 9-mediated phosphorylation of the microtubule-associated LC3B protein at Thr-50 suppresses selective autophagy of p62/sequestosome 1. J Biol Chem 2019; 295:1240-1260. [PMID: 31857374 DOI: 10.1074/jbc.ra119.010068] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 12/11/2019] [Indexed: 12/21/2022] Open
Abstract
Human ATG8 family proteins (ATG8s) are active in all steps of the macroautophagy pathway, and their lipidation is essential for autophagosome formation. Lipidated ATG8s anchored to the outer surface of the phagophore serve as scaffolds for binding of other core autophagy proteins and various effector proteins involved in trafficking or fusion events, whereas those at the inner surface are needed for assembly of selective autophagy substrates. Their scaffolding role depends on specific interactions between the LC3-interacting region (LIR) docking site (LDS) in ATG8s and LIR motifs in various interaction partners. LC3B is phosphorylated at Thr-50 within the LDS by serine/threonine kinase (STK) 3 and STK4. Here, we identified LIR motifs in STK3 and atypical protein kinase Cζ (PKCζ) and never in mitosis A (NIMA)-related kinase 9 (NEK9). All three kinases phosphorylated LC3B Thr-50 in vitro A phospho-mimicking substitution of Thr-50 impaired binding of several LIR-containing proteins, such as ATG4B, FYVE, and coiled-coil domain-containing 1 (FYCO1), and autophagy cargo receptors p62/sequestosome 1 (SQSTM1) and neighbor of BRCA1 gene (NBR1). NEK9 knockdown or knockout enhanced degradation of the autophagy receptor and substrate p62. Of note, the suppression of p62 degradation was mediated by NEK9-mediated phosphorylation of LC3B Thr-50. Consistently, reconstitution of LC3B-KO cells with the phospho-mimicking T50E variant inhibited autophagic p62 degradation. PKCζ knockdown did not affect autophagic p62 degradation, whereas STK3/4 knockouts inhibited autophagic p62 degradation independently of LC3B Thr-50 phosphorylation. Our findings suggest that NEK9 suppresses LC3B-mediated autophagy of p62 by phosphorylating Thr-50 within the LDS of LC3B.
Collapse
Affiliation(s)
- Birendra Kumar Shrestha
- Molecular Cancer Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Mads Skytte Rasmussen
- Molecular Cancer Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Yakubu Princely Abudu
- Molecular Cancer Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Jack-Ansgar Bruun
- Molecular Cancer Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Kenneth Bowitz Larsen
- Molecular Cancer Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Endalkachew A Alemu
- Molecular Cancer Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Eva Sjøttem
- Molecular Cancer Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Trond Lamark
- Molecular Cancer Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Terje Johansen
- Molecular Cancer Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| |
Collapse
|
20
|
Robert G, Jacquel A, Auberger P. Chaperone-Mediated Autophagy and Its Emerging Role in Hematological Malignancies. Cells 2019; 8:E1260. [PMID: 31623164 PMCID: PMC6830112 DOI: 10.3390/cells8101260] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/04/2019] [Accepted: 10/11/2019] [Indexed: 12/19/2022] Open
Abstract
Chaperone-mediated autophagy (CMA) ensures the selective degradation of cellular proteins endowed with a KFERQ-like motif by lysosomes. It is estimated that 30% of all cellular proteins can be directed to the lysosome for CMA degradation, but only a few substrates have been formally identified so far. Mechanistically, the KFERQ-like motifs present in substrate proteins are recognized by the molecular chaperone Hsc70c (Heat shock cognate 71 kDa protein cytosolic), also known as HSPA8, and directed to LAMP2A, which acts as the CMA receptor at the lysosomal surface. Following linearization, the protein substrate is next transported to the lumen of the lysosomes, where it is degraded by resident proteases, mainly cathepsins and eventually recycled to sustain cellular homeostasis. CMA is induced by different stress conditions, including energy deprivation that also activates macro-autophagy (MA), that may make it difficult to decipher the relative impact of both pathways on cellular homeostasis. Besides common inducing triggers, CMA and MA might be induced as compensatory mechanisms when either mechanism is altered, as it is the often the case in different pathological settings. Therefore, CMA activation can compensate for alterations of MA and vice versa. In this context, these compensatory mechanisms, when occurring, may be targeted for therapeutic purposes. Both processes have received particular attention from scientists and clinicians, since modulation of MA and CMA may have a profound impact on cellular proteostasis, metabolism, death, differentiation, and survival and, as such, could be targeted for therapeutic intervention in degenerative and immune diseases, as well as in cancer, including hematopoietic malignancies. The role of MA in cancer initiation and progression is now well established, but whether and how CMA is involved in tumorigenesis has been only sparsely explored. In the present review, we encompass the description of the mechanisms involved in CMA, its function in the physiology and pathogenesis of hematopoietic cells, its emerging role in cancer initiation and development, and, finally, the potential therapeutic opportunity to target CMA or CMA-mediated compensatory mechanisms in hematological malignancies.
Collapse
Affiliation(s)
- Guillaume Robert
- Mediterranean Center for Molecular Medicine ,Université Nice Côte d'Azur, C3M/Inserm1065, 06100 Nice, France.
| | - Arnaud Jacquel
- Mediterranean Center for Molecular Medicine ,Université Nice Côte d'Azur, C3M/Inserm1065, 06100 Nice, France
| | - Patrick Auberger
- Mediterranean Center for Molecular Medicine ,Université Nice Côte d'Azur, C3M/Inserm1065, 06100 Nice, France.
| |
Collapse
|
21
|
Krichel C, Möckel C, Schillinger O, Huesgen PF, Sticht H, Strodel B, Weiergräber OH, Willbold D, Neudecker P. Solution structure of the autophagy-related protein LC3C reveals a polyproline II motif on a mobile tether with phosphorylation site. Sci Rep 2019; 9:14167. [PMID: 31578424 PMCID: PMC6775092 DOI: 10.1038/s41598-019-48155-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 07/26/2019] [Indexed: 11/09/2022] Open
Abstract
(Macro-)autophagy is a compartmental degradation pathway conserved from yeast to mammals. The yeast protein Atg8 mediates membrane tethering/hemifusion and cargo recruitment and is essential for autophagy. The human MAP1LC3/GABARAP family proteins show high sequence identity with Atg8, but MAP1LC3C is distinguished by a conspicuous amino-terminal extension with unknown functional significance. We have determined the high-resolution three-dimensional structure and measured the backbone dynamics of MAP1LC3C by NMR spectroscopy. From Ser18 to Ala120, MAP1LC3C forms an α-helix followed by the ubiquitin-like tertiary fold with two hydrophobic binding pockets used by MAP1LC3/GABARAP proteins to recognize targets presenting LC3-interacting regions (LIRs). Unlike other MAP1LC3/GABARAP proteins, the amino-terminal region of MAP1LC3C does not form a stable helix α1 but a "sticky arm" consisting of a polyproline II motif on a flexible linker. Ser18 at the interface between this linker and the structural core can be phosphorylated in vitro by protein kinase A, which causes additional conformational heterogeneity as monitored by NMR spectroscopy and molecular dynamics simulations, including changes in the LIR-binding interface. Based on these results we propose that the amino-terminal polyproline II motif mediates specific interactions with the microtubule cytoskeleton and that Ser18 phosphorylation modulates the interplay of MAP1LC3C with its various target proteins.
Collapse
Affiliation(s)
- Carsten Krichel
- ICS-6 (Strukturbiochemie) and JuStruct, Forschungszentrum Jülich, 52425, Jülich, Germany.,Institut für Physikalische Biologie and BMFZ, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany
| | - Christina Möckel
- ICS-6 (Strukturbiochemie) and JuStruct, Forschungszentrum Jülich, 52425, Jülich, Germany.,Institut für Physikalische Biologie and BMFZ, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany
| | - Oliver Schillinger
- ICS-6 (Strukturbiochemie) and JuStruct, Forschungszentrum Jülich, 52425, Jülich, Germany.,Institut für Theoretische Chemie und Computerchemie, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany
| | - Pitter F Huesgen
- ZEA-3 (Analytik), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Heinrich Sticht
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054, Erlangen, Germany
| | - Birgit Strodel
- ICS-6 (Strukturbiochemie) and JuStruct, Forschungszentrum Jülich, 52425, Jülich, Germany.,Institut für Theoretische Chemie und Computerchemie, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany
| | - Oliver H Weiergräber
- ICS-6 (Strukturbiochemie) and JuStruct, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Dieter Willbold
- ICS-6 (Strukturbiochemie) and JuStruct, Forschungszentrum Jülich, 52425, Jülich, Germany. .,Institut für Physikalische Biologie and BMFZ, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany.
| | - Philipp Neudecker
- ICS-6 (Strukturbiochemie) and JuStruct, Forschungszentrum Jülich, 52425, Jülich, Germany. .,Institut für Physikalische Biologie and BMFZ, Heinrich-Heine-Universität Düsseldorf, 40225, Düsseldorf, Germany.
| |
Collapse
|
22
|
Zhao G, Wang Y, Yang C, Zhao L, Guo L, Li L, Wei Z. Interplay Between Autophagy and Apoptosis in Lycorine Hydrochloride-Induced Cytotoxicity of HCT116 Cells. Nat Prod Commun 2019. [DOI: 10.1177/1934578x19862100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The aim of this study was to investigate the antitumor effect of lycorine hydrochloride (LH) and discuss the correlation between LH-induced apoptosis and autophagy in the human colorectal cancer cell line HCT116. Here the results by the Cell Counting Kit-8 and colony formation assays showed that LH concentration-dependently decreased cell viability and colony formation in HCT116 cells, suggesting inhibition of cell proliferation by LH. By flow cytometry, LH was found to increase apoptotic rate in HCT116 cells. Mechanistically, Western blot results revealed that LH increased the expression of the protein of Bax and Caspase-3, and decreased Bcl-2 proteins expression. Moreover, the reverse transcriptase quantitative polymerase chain reaction and Western blot analysis also showed that LH increased the expression of Beclin-1 and LC3B-II/LC3B-I ratio, indicating that autophagy was induced by LH. LH induced autophagy via downregulating phospho-mammalian target of rapamycin and upregulating phospho-AMPK (5′ adenosine monophosphate-activated protein kinase). Furthermore, to understand the role of LH-induced autophagy and its association with apoptosis, cells were analyzed after Beclin-1 small interfering RNA transfection. The results indicated that the proapoptotic ability of LH was increased by inhibition of autophagy. In conclusion, the present investigation suggested that LH induced apoptosis and autophagy in HCT116 cells via the mitochondrial and AMPK/mTOR pathways. The suppression of autophagy promoted LH-induced apoptosis by modulating Beclin-1 and Bcl-2.
Collapse
Affiliation(s)
- Ganting Zhao
- Department of Gastroenterology and Hepatology, Heping Hospital, Changzhi Medical College, Changzhi, China
| | - Yanjing Wang
- Department of Ultrasound, Beijing Anzhen Hospital, Capital Medical University, China
| | - Changqing Yang
- Department of Gastroenterology and Hepatology, Heping Hospital, Changzhi Medical College, Changzhi, China
| | - Li Zhao
- Department of Gastroenterology and Hepatology, Heping Hospital, Changzhi Medical College, Changzhi, China
| | - Lili Guo
- Department of Gastroenterology and Hepatology, Heping Hospital, Changzhi Medical College, Changzhi, China
| | - Lingmin Li
- Department of Pathology, Shanxi Medical University, Taiyuan, China
| | - Zibai Wei
- Department of Gastroenterology and Hepatology, Heping Hospital, Changzhi Medical College, Changzhi, China
| |
Collapse
|
23
|
Zech ATL, Singh SR, Schlossarek S, Carrier L. Autophagy in cardiomyopathies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1867:118432. [PMID: 30831130 DOI: 10.1016/j.bbamcr.2019.01.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/24/2019] [Accepted: 01/28/2019] [Indexed: 12/19/2022]
Abstract
Autophagy (greek auto: self; phagein: eating) is a highly conserved process within eukaryotes that degrades long-lived proteins and organelles within lysosomes. Its accurate and constant operation in basal conditions ensures cellular homeostasis by degrading damaged cellular components and thereby acting not only as a quality control but as well as an energy supplier. An increasing body of evidence indicates a major role of autophagy in the regulation of cardiac homeostasis and function. In this review, we describe the different forms of mammalian autophagy, their regulations and monitoring with a specific emphasis on the heart. Furthermore, we address the role of autophagy in several forms of cardiomyopathy and the options for therapy.
Collapse
Affiliation(s)
- Antonia T L Zech
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg, Hamburg, Germany; German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Sonia R Singh
- Division of Molecular Cardiovascular Biology, The Heart Institute, Cincinnati Children's Hospital, Cincinnati, OH, United States of America
| | - Saskia Schlossarek
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg, Hamburg, Germany; German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Lucie Carrier
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg, Hamburg, Germany; German Centre for Cardiovascular Research, Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany.
| |
Collapse
|
24
|
Autophagy: An Essential Degradation Program for Cellular Homeostasis and Life. Cells 2018; 7:cells7120278. [PMID: 30572663 PMCID: PMC6315530 DOI: 10.3390/cells7120278] [Citation(s) in RCA: 228] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 12/18/2018] [Accepted: 12/18/2018] [Indexed: 12/21/2022] Open
Abstract
Autophagy is a lysosome-dependent cellular degradation program that responds to a variety of environmental and cellular stresses. It is an evolutionarily well-conserved and essential pathway to maintain cellular homeostasis, therefore, dysfunction of autophagy is closely associated with a wide spectrum of human pathophysiological conditions including cancers and neurodegenerative diseases. The discovery and characterization of the kingdom of autophagy proteins have uncovered the molecular basis of the autophagy process. In addition, recent advances on the various post-translational modifications of autophagy proteins have shed light on the multiple layers of autophagy regulatory mechanisms, and provide novel therapeutic targets for the treatment of the diseases.
Collapse
|
25
|
Vuokila N, Lukasiuk K, Bot AM, van Vliet EA, Aronica E, Pitkänen A, Puhakka N. miR-124-3p is a chronic regulator of gene expression after brain injury. Cell Mol Life Sci 2018; 75:4557-4581. [PMID: 30155647 PMCID: PMC11105702 DOI: 10.1007/s00018-018-2911-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 08/02/2018] [Accepted: 08/22/2018] [Indexed: 02/06/2023]
Abstract
Traumatic brain injury (TBI) initiates molecular and cellular pathologies that underlie post-injury morbidities, including hippocampus-related memory decline and epileptogenesis. Non-coding small RNAs are master regulators of gene expression with the potential to affect multiple molecular pathways. To evaluate whether hippocampal gene expression networks are chronically regulated by microRNAs after TBI, we sampled the dentate gyrus of rats with severe TBI induced by lateral fluid-percussion injury 3 months earlier. Ingenuity pathway analysis revealed 30 upregulated miR-124-3p targets, suggesting that miR-124-3p is downregulated post-TBI (z-score = - 5.146, p < 0.05). Droplet digital polymerase chain reaction (ddPCR) and in situ hybridization confirmed the chronic downregulation of miR-124-3p (p < 0.05). Quantitative PCR analysis of two targets, Plp2 and Stat3, indicated that their upregulation correlated with the miR-124-3p downregulation (r = - 0.647, p < 0.05; r = - 0.629, p < 0.05, respectively). Immunohistochemical staining of STAT3 confirmed the increased protein expression. STRING analysis showed that 9 of the 30 miR-124-3p targets belonged to a STAT3 network. Reactome analysis and data mining connected the targets especially to inflammation and signal transduction. L1000CDS2 software revealed drugs (e.g., importazole, trichostatin A, and IKK-16) that could reverse the observed molecular changes. The translational value of our data was emphasized by in situ hybridization showing chronic post-traumatic downregulation of miR-124-3p in the dentate gyrus of TBI patients. Analysis of another brain injury model, status epilepticus, highlighted the fact that chronic downregulation of miR-124 is a common phenomenon after brain injury. Together, our findings indicate that miR-124-3p is a chronic modulator of molecular networks relevant to post-injury hippocampal pathologies in experimental models and in humans.
Collapse
Affiliation(s)
- Niina Vuokila
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, 70211, Kuopio, Finland
| | - Katarzyna Lukasiuk
- The Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Str, 02-093, Warsaw, Poland
| | - Anna Maria Bot
- The Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Str, 02-093, Warsaw, Poland
| | - Erwin A van Vliet
- Department of (Neuro)pathology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)pathology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Amsterdam, The Netherlands
| | - Asla Pitkänen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, 70211, Kuopio, Finland.
| | - Noora Puhakka
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, 70211, Kuopio, Finland.
| |
Collapse
|
26
|
Ribeiro KC, Campelo RP, Rodrigues DDRF, Mattos EC, Brandão IT, da Silva CL, Bouskela E, Martinez CG, Kurtenbach E. Immunization with plasmids encoding M2 acetylcholine muscarinic receptor epitopes impairs cardiac function in mice and induces autophagy in the myocardium. Autoimmunity 2018; 51:245-257. [PMID: 30424681 DOI: 10.1080/08916934.2018.1514389] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Autoantibodies against the M2 subtype of muscarinic acetylcholine receptors with functional activities have been found in the sera of patients with dilated cardiomyopathy (DCM), and the second extracellular loop has been established as the predominant epitope. However, it has been shown that the third intracellular loop is recognized by Chagas disease patients with severe cardiac dysfunction. In this work, BALB/c mice were immunized with plasmids encoding these two epitopes, and a control group received the empty plasmid (pcDNA3 vector). Serum from these DNA-immunized animals had elevated and persistent titres of antibodies against respective antigens. Heart echocardiography indicated diminished left ventricular wall thickness and reduced ejection fraction for both epitope-immunized groups, and ergospirometry tests showed a significant decrease in the exercise time and oxygen consumption. Transfer of serum from these immunized mice into naïve recipients induced the same alterations in cardiac structure and function. Furthermore, electron microscopy analysis of donor-immunized animals revealed several ultrastructural alterations suggestive of autophagy and mitophagy, suggesting novel roles for these autoantibodies. Overall, greater functional and structural impairment was observed in the donor and recipient epitope groups, implicating the third intracellular loop epitope in the pathological effects for the first-time. Therefore, the corresponding peptides could be useful for autoimmune DCM diagnosis and targeted therapy.
Collapse
Affiliation(s)
- Karla Consort Ribeiro
- a Programa de Biologia Molecular e Estrutural, Instituto de Biofísica Carlos Chagas Filho , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.,b Instituto Nacional de Propriedade Industrial , Rio de Janeiro , Brazil
| | - Roberto Perez Campelo
- a Programa de Biologia Molecular e Estrutural, Instituto de Biofísica Carlos Chagas Filho , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.,c Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil
| | - Daniela Del Rosário Flores Rodrigues
- a Programa de Biologia Molecular e Estrutural, Instituto de Biofísica Carlos Chagas Filho , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.,c Programa de Biologia Molecular e Biotecnologia, Instituto de Bioquímica Médica , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil
| | | | - Izaira Trincani Brandão
- e Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto , Universidade de São Paulo , Ribeirão Preto , Brazil
| | - Célio Lopes da Silva
- e Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto , Universidade de São Paulo , Ribeirão Preto , Brazil
| | - Eliete Bouskela
- f Lab. Pesq. Clínicas e Experimentais em Biologia Vascular - BioVasc Inst. De Biologia Roberto Alcântara Gomes e Fac. de Ciências Médicas , Universidade do Estado do Rio de Janeiro , Rio de Janeiro , Brazil
| | - Camila Guerra Martinez
- a Programa de Biologia Molecular e Estrutural, Instituto de Biofísica Carlos Chagas Filho , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.,g Instituto Nacional para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica , Conselho Nacional de Desenvolvimento Científico e Tecnológico/MCT , Rio de Janeiro , Brazil
| | - Eleonora Kurtenbach
- a Programa de Biologia Molecular e Estrutural, Instituto de Biofísica Carlos Chagas Filho , Universidade Federal do Rio de Janeiro , Rio de Janeiro , Brazil.,g Instituto Nacional para Pesquisa Translacional em Saúde e Ambiente na Região Amazônica , Conselho Nacional de Desenvolvimento Científico e Tecnológico/MCT , Rio de Janeiro , Brazil
| |
Collapse
|
27
|
Viret C, Faure M. Regulation of Syntaxin 17 during Autophagosome Maturation. Trends Cell Biol 2018; 29:1-3. [PMID: 30415939 DOI: 10.1016/j.tcb.2018.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 10/24/2018] [Indexed: 10/27/2022]
Abstract
During macroautophagy, cytosolic elements are confined in autophagosomes before fusion with endolysosomes for degradation or recycling. Recruitment of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) factor syntaxin 17 (STX17) is instrumental for this maturation step. Two recent studies indicate that the kinase ULK1 and the apoptosis modulator BRUCE both regulate STX17 engagement during autophagosome maturation in mammalian cells.
Collapse
Affiliation(s)
- Christophe Viret
- CIRI, International Center for Infectiology Research, Université de Lyon, France; INSERM, U1111, Lyon, France; CNRS, UMR5308, Lyon, France; Ecole Normale Supérieure de Lyon, Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 21 Av T. Garnier, 69007 Lyon, France.
| | - Mathias Faure
- CIRI, International Center for Infectiology Research, Université de Lyon, France; INSERM, U1111, Lyon, France; CNRS, UMR5308, Lyon, France; Ecole Normale Supérieure de Lyon, Lyon, France; Université Lyon 1, Centre International de Recherche en Infectiologie, 21 Av T. Garnier, 69007 Lyon, France; Equipe FRM (Fondation pour la Recherche Médicale), Paris, France.
| |
Collapse
|
28
|
Gutiérrez-López TY, Orduña-Castillo LB, Hernández-Vásquez MN, Vázquez-Prado J, Reyes-Cruz G. Calcium sensing receptor activates the NLRP3 inflammasome via a chaperone-assisted degradative pathway involving Hsp70 and LC3-II. Biochem Biophys Res Commun 2018; 505:1121-1127. [PMID: 30316511 DOI: 10.1016/j.bbrc.2018.10.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 10/05/2018] [Indexed: 01/21/2023]
Abstract
Calcium sensing receptor (CaSR) activates the NLRP3 inflammasome with consequences on homeostatic responses. However, little is known about how this process is orchestrated. Since proteolysis of critical regulators of NLRP3 inflammasome contribute to its activation, we aimed to understand how CaSR stimulates proteolytic pathways to activate the NLRP3 inflammasome. We found that proteasome and lysosome-dependent mechanisms are activated by CaSR to promote the degradation of important regulators of NLRP inflammasome. The pathway involves Gαq/PLC/PKC and Gβγ/PI3K signaling cascades and IRAK1 ubiquitination. In addition, CaSR stimulates Hsp70 expression activating a chaperone-assisted protein degradation that dictates the fate of ASC, NLRP3 (NOD-like receptor family protein 3), IRAK1 and TRAF6 proteins, turning on the NLRP3 inflammasome. In response to CaSR signaling, these proteins are degraded through the combination of CUPS (chaperone-assisted ubiquitin proteasome pathway) and CAEMI (chaperone-assisted endosomal microautophagy) systems being integrated by autophagosomes (chaperone-assisted macroautophagy, CAMA), as indicated by LC3-II, a classical marker for autophagy, that is induced in the process. Furthermore, CaSR triggers the proteolytic cleavage of pro-IL-1β (IL-1β, 31 kDa) into mature IL-1β (IL-1β, 17 kDa), via the proteasome. Taken together, our results indicate that CaSR promotes NLRP3 inflammasome activation and proteolytic maturation of IL-1β by inducing CUPS and CAEMI, chaperone-assisted degradation pathways. Overall, these results support the inclusion of CaSR as an activator of homeostasis-altering molecular processes.
Collapse
Affiliation(s)
- Tania Yareli Gutiérrez-López
- Departments of Cell Biology, Centro de Investigación y Estudios Avanzados del IPN (Cinvestav-IPN), Mexico City, Mexico
| | | | | | - José Vázquez-Prado
- Departments of Pharmacology, Centro de Investigación y Estudios Avanzados del IPN (Cinvestav-IPN), Mexico City, Mexico
| | - Guadalupe Reyes-Cruz
- Departments of Cell Biology, Centro de Investigación y Estudios Avanzados del IPN (Cinvestav-IPN), Mexico City, Mexico.
| |
Collapse
|
29
|
Mylka V, Deckers J, Ratman D, De Cauwer L, Thommis J, De Rycke R, Impens F, Libert C, Tavernier J, Vanden Berghe W, Gevaert K, De Bosscher K. The autophagy receptor SQSTM1/p62 mediates anti-inflammatory actions of the selective NR3C1/glucocorticoid receptor modulator compound A (CpdA) in macrophages. Autophagy 2018; 14:2049-2064. [PMID: 30215534 PMCID: PMC6984772 DOI: 10.1080/15548627.2018.1495681] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Glucocorticoids are widely used to treat inflammatory disorders; however, prolonged use of glucocorticoids results in side effects including osteoporosis, diabetes and obesity. Compound A (CpdA), identified as a selective NR3C1/glucocorticoid receptor (nuclear receptor subfamily 3, group C, member 1) modulator, exhibits an inflammation-suppressive effect, largely in the absence of detrimental side effects. To understand the mechanistic differences between the classic glucocorticoid dexamethasone (DEX) and CpdA, we looked for proteins oppositely regulated in bone marrow-derived macrophages using an unbiased proteomics approach. We found that the autophagy receptor SQSTM1 but not NR3C1 mediates the anti-inflammatory action of CpdA. CpdA drives SQSTM1 upregulation by recruiting the NFE2L2 transcription factor to its promoter. In contrast, the classic NR3C1 ligand dexamethasone recruits NR3C1 to the Sqstm1 promoter and other NFE2L2-controlled gene promoters, resulting in gene downregulation. Both DEX and CpdA induce autophagy, with marked different autophagy characteristics and morphology. Suppression of LPS-induced Il6 and Ccl2 genes by CpdA in macrophages is hampered upon Sqstm1 silencing, confirming that SQSTM1 is essential for the anti-inflammatory capacity of CpdA, at least in this cell type. Together, these results demonstrate how off-target mechanisms of selective NR3C1 ligands may contribute to a more efficient anti-inflammatory therapy.
Collapse
Affiliation(s)
- Viacheslav Mylka
- a Receptor Research Laboratories, Nuclear Receptor Lab , Ghent University , Ghent , Belgium.,c Department of Biochemistry , VIB-UGent Center for Medical Biotechnology , Ghent , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium
| | - Julie Deckers
- a Receptor Research Laboratories, Nuclear Receptor Lab , Ghent University , Ghent , Belgium.,c Department of Biochemistry , VIB-UGent Center for Medical Biotechnology , Ghent , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium.,f Inflammation Research Center , VIB, Ghent University , Ghent , Belgium
| | - Dariusz Ratman
- a Receptor Research Laboratories, Nuclear Receptor Lab , Ghent University , Ghent , Belgium.,c Department of Biochemistry , VIB-UGent Center for Medical Biotechnology , Ghent , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium
| | - Lode De Cauwer
- a Receptor Research Laboratories, Nuclear Receptor Lab , Ghent University , Ghent , Belgium.,c Department of Biochemistry , VIB-UGent Center for Medical Biotechnology , Ghent , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium
| | - Jonathan Thommis
- a Receptor Research Laboratories, Nuclear Receptor Lab , Ghent University , Ghent , Belgium.,c Department of Biochemistry , VIB-UGent Center for Medical Biotechnology , Ghent , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium
| | - Riet De Rycke
- f Inflammation Research Center , VIB, Ghent University , Ghent , Belgium.,g Department of Biomedical Molecular Biology , Ghent University , Ghent , Belgium.,h Department of Plant Systems Biology , VIB , Ghent , Belgium.,i Department of Plant Biotechnology and Bioinformatics , Ghent University , Ghent , Belgium
| | - Francis Impens
- c Department of Biochemistry , VIB-UGent Center for Medical Biotechnology , Ghent , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium.,j VIB Proteomics Core , VIB , Ghent , Belgium
| | - Claude Libert
- f Inflammation Research Center , VIB, Ghent University , Ghent , Belgium.,g Department of Biomedical Molecular Biology , Ghent University , Ghent , Belgium
| | - Jan Tavernier
- b Receptor Research Laboratories, Cytokine Receptor Lab , Ghent University , Ghent , Belgium.,c Department of Biochemistry , VIB-UGent Center for Medical Biotechnology , Ghent , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium
| | - Wim Vanden Berghe
- e PPES lab Protein Science, Proteomics & Epigenetic Signaling , Department Biomedical Sciences - University of Antwerp , Wilrijk , Belgium
| | - Kris Gevaert
- c Department of Biochemistry , VIB-UGent Center for Medical Biotechnology , Ghent , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium
| | - Karolien De Bosscher
- a Receptor Research Laboratories, Nuclear Receptor Lab , Ghent University , Ghent , Belgium.,c Department of Biochemistry , VIB-UGent Center for Medical Biotechnology , Ghent , Belgium.,d Department of Biochemistry , Ghent University , Ghent , Belgium
| |
Collapse
|
30
|
Pan H, Ding Y, Yan N, Nie Y, Li M, Tong L. Trehalose prevents sciatic nerve damage to and apoptosis of Schwann cells of streptozotocin-induced diabetic C57BL/6J mice. Biomed Pharmacother 2018; 105:907-914. [DOI: 10.1016/j.biopha.2018.06.069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/08/2018] [Accepted: 06/13/2018] [Indexed: 02/06/2023] Open
|
31
|
Phosphorylation of ULK1 affects autophagosome fusion and links chaperone-mediated autophagy to macroautophagy. Nat Commun 2018; 9:3492. [PMID: 30154410 PMCID: PMC6113293 DOI: 10.1038/s41467-018-05449-1] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/12/2018] [Indexed: 11/09/2022] Open
Abstract
The Unc-51 like autophagy activating kinase 1 (ULK1) complex plays a central role in the initiation stage of autophagy. However, the function of ULK1 in the late stage of autophagy is unknown. Here, we report that ULK1, a central kinase of the ULK1 complex involved in autophagy initiation, promotes autophagosome–lysosome fusion. PKCα phosphorylates ULK1 and prevents autolysosome formation. PKCα phosphorylation of ULK1 does not change its kinase activity; however, it decreases autophagosome–lysosome fusion by reducing the affinity of ULK1 for syntaxin 17 (STX17). Unphosphorylated ULK1 recruited STX17 and increased STX17′s affinity towards synaptosomal-associated protein 29 (SNAP29). Additionally, phosphorylation of ULK1 enhances its interaction with heat shock cognate 70 kDa protein (HSC70) and increases its degradation through chaperone-mediated autophagy (CMA). Our study unearths a key mechanism underlying autolysosome formation, a process in which the kinase activity of PKCα plays an instrumental role, and reveals the significance of the mutual regulation of macroautophagy and CMA in maintaining the balance of autophagy. The ULK complex plays a well-known role in initiating autophagy, to recycle cellular components in response to nutritional stress. Here, the authors demonstrate a late role for ULK in auotophagosome–lysosome fusion and provide a direct link between macroautophagy and chaperone mediated autophagy.
Collapse
|
32
|
Wang T, Liu C, Jia L. The roles of PKCs in regulating autophagy. J Cancer Res Clin Oncol 2018; 144:2303-2311. [PMID: 30116883 DOI: 10.1007/s00432-018-2731-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 08/02/2018] [Indexed: 12/15/2022]
Abstract
PURPOSE Autophagy, as a highly conserved cellular degradation and recycling process, plays an important part in maintaining cellular homeostasis. PKC signaling is involved in multiple pathways including cell cycle progression, tumorigenesis, migration and autophagy. METHODS Literatures about PKC and autophagy from PubMed databases were reviewed in this study. RESULTS Studies regarding the association of PKC and autophagy remain debatable. Different duration of the stimulation of autophagy and distinct cell contexts result in different function of PKC in regulating autophagy. The subcellular localization of PKCs and their downstream regulators may influence the autophagy regulation as well. As important intracellular components, the mitochondria play an important role in regulating autophagy, by metabolic modulation and structural derangement. CONCLUSION Phase II studies regarding PKC-β inhibitor, enzastaurin, showed promising results in MCL, DLBCL and recurrent high-grade gliomas. However, the detailed mechanism is still in need. The mechanism of PKC-β in mediating autophagy in lymphoma and high-grade gliomas remains elusive as well. Moreover, several studies were in agreement that rottlerin enhanced autophagy in breast cancer cells, which warrants further clinical studies to verify PKC-δ as a therapeutic target. Thus, identifying the function of PKC in modulating autophagy and conducting related clinical studies help find novel target for chemotherapy.
Collapse
Affiliation(s)
- Tianyi Wang
- NHC Key Laboratory of Radiobiology (Ministry of Health), School of Public Health, Jilin University, 1163 Xinmin Street, Changchun, 130021, People's Republic of China
| | - Conghe Liu
- NHC Key Laboratory of Radiobiology (Ministry of Health), School of Public Health, Jilin University, 1163 Xinmin Street, Changchun, 130021, People's Republic of China
| | - Lili Jia
- NHC Key Laboratory of Radiobiology (Ministry of Health), School of Public Health, Jilin University, 1163 Xinmin Street, Changchun, 130021, People's Republic of China.
| |
Collapse
|
33
|
Xue X, Ren J, Sun X, Gui Y, Feng Y, Shu B, Wei W, Lu Q, Liang Y, He W, Yang J, Dai C. Protein kinase Cα drives fibroblast activation and kidney fibrosis by stimulating autophagic flux. J Biol Chem 2018; 293:11119-11130. [PMID: 29794026 PMCID: PMC6052200 DOI: 10.1074/jbc.ra118.002191] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/20/2018] [Indexed: 12/25/2022] Open
Abstract
Kidney fibrosis is a histological hallmark of chronic kidney disease and arises in large part through extracellular matrix deposition by activated fibroblasts. The signaling protein complex mTOR complex 2 (mTORC2) plays a critical role in fibroblast activation and kidney fibrosis. Protein kinase Cα (PKCα) is one of the major sub-pathways of mTORC2, but its role in fibroblast activation and kidney fibrosis remains to be determined. Here, we found that transforming growth factor β1 (TGFβ1) activates PKCα signaling in cultured NRK-49F cells in a time-dependent manner. Blocking PKCα signaling with the chemical inhibitor Go6976 or by transfection with PKCα siRNA largely reduced expression of the autophagy-associated protein lysosomal-associated membrane protein 2 (LAMP2) and also inhibited autophagosome-lysosome fusion and autophagic flux in the cells. Similarly to chloroquine, Go6976 treatment and PKCα siRNA transfection also markedly inhibited TGFβ1-induced fibroblast activation. In murine fibrotic kidneys with unilateral ureteral obstruction (UUO) nephropathy, PKCα signaling is activated in the interstitial myofibroblasts. Go6976 administration largely blocked autophagic flux in fibroblasts in the fibrotic kidneys and attenuated the UUO nephropathy. Together, our findings suggest that blocking PKCα activity may retard autophagic flux and thereby prevent fibroblast activation and kidney fibrosis.
Collapse
Affiliation(s)
- Xian Xue
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| | - Jiafa Ren
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
- the Division of Nephrology, Department of Medicine, Duke University and Durham Veterans Affairs Medical Centers, Durham, North Carolina 27705
| | - Xiaoli Sun
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| | - Yuan Gui
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| | - Ye Feng
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| | - Bingyan Shu
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| | - Wei Wei
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| | - Qingmiao Lu
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| | - Yan Liang
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| | - Weichun He
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| | - Junwei Yang
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| | - Chunsun Dai
- From the Center for Kidney Disease, the Second Affiliated Hospital of Nanjing Medical University, 262 North Zhongshan Road, Nanjing, Jiangsu 210003, China and
| |
Collapse
|
34
|
Autophagy in cancer: a complex relationship. Biochem J 2018; 475:1939-1954. [DOI: 10.1042/bcj20170847] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 05/21/2018] [Accepted: 05/22/2018] [Indexed: 12/27/2022]
Abstract
Macroautophagy is the process by which cells package and degrade cytosolic components, and recycle the breakdown products for future use. Since its initial description by Christian de Duve in the 1960s, significant progress has been made in understanding the mechanisms that underlie this vital cellular process and its specificity. Furthermore, macroautophagy is linked to pathologic conditions such as cancer and is being studied as a therapeutic target. In this review, we will explore the connections between autophagy and cancer, which are tumor- and context-dependent and include the tumor microenvironment. We will highlight the importance of tumor compartment-specific autophagy in both cancer aggressiveness and treatment.
Collapse
|
35
|
Zientara-Rytter K, Subramani S. AIM/LIR-based fluorescent sensors-new tools to monitor mAtg8 functions. Autophagy 2018; 14:1074-1078. [PMID: 29749795 DOI: 10.1080/15548627.2018.1454238] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022] Open
Abstract
Macroautophagy/autophagy, a catabolic process by which cytoplasmic materials are degraded and recycled in lysosomes/vacuoles, remains a rapidly expanding research topic with the need for constantly improved methodologies to study each step of this pathway. Recently Lee and colleagues, as well as Stolz et al., independently reported the development of new AIM/LIR-based fluorescent sensors, which mark individual endogenous mammalian Atg8-family (mAtg8) proteins without affecting the autophagic flux. When expressed in cells, each sensor selectively recognizes individual mAtg8 isoforms and distinguishes mammalian MAP1LC3/LC3 proteins from the related GABARAPs. Such selectivity was achieved by using various LC3-interacting regions with high binding affinity to either a subgroup, or a specific, mAtg8 isoform as part of the sensor. Here we discuss the utility of these sensors in autophagy research and highlight their strengths, weaknesses and future directions.
Collapse
Affiliation(s)
- Katarzyna Zientara-Rytter
- a Section of Molecular Biology, Division of Biological Sciences , University of California San Diego , La Jolla , CA , USA
| | - Suresh Subramani
- a Section of Molecular Biology, Division of Biological Sciences , University of California San Diego , La Jolla , CA , USA
| |
Collapse
|
36
|
Lieberman OJ, McGuirt AF, Tang G, Sulzer D. Roles for neuronal and glial autophagy in synaptic pruning during development. Neurobiol Dis 2018; 122:49-63. [PMID: 29709573 DOI: 10.1016/j.nbd.2018.04.017] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 03/22/2018] [Accepted: 04/24/2018] [Indexed: 12/29/2022] Open
Abstract
The dendritic protrusions known as spines represent the primary postsynaptic location for excitatory synapses. Dendritic spines are critical for many synaptic functions, and their formation, modification, and turnover are thought to be important for mechanisms of learning and memory. At many excitatory synapses, dendritic spines form during the early postnatal period, and while many spines are likely being formed and removed throughout life, the net number are often gradually "pruned" during adolescence to reach a stable level in the adult. In neurodevelopmental disorders, spine pruning is disrupted, emphasizing the importance of understanding its governing processes. Autophagy, a process through which cytosolic components and organelles are degraded, has recently been shown to control spine pruning in the mouse cortex, but the mechanisms through which autophagy acts remain obscure. Here, we draw on three widely studied prototypical synaptic pruning events to focus on two governing principles of spine pruning: 1) activity-dependent synaptic competition and 2) non-neuronal contributions. We briefly review what is known about autophagy in the central nervous system and its regulation by metabolic kinases. We propose a model in which autophagy in both neurons and non-neuronal cells contributes to spine pruning, and how other processes that regulate spine pruning could intersect with autophagy. We further outline future research directions to address outstanding questions on the role of autophagy in synaptic pruning.
Collapse
Affiliation(s)
- Ori J Lieberman
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032, United States
| | - Avery F McGuirt
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032, United States
| | - Guomei Tang
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, United States
| | - David Sulzer
- Department of Psychiatry, Columbia University Medical Center, New York, NY 10032, United States; Department of Neurology, Columbia University Medical Center, New York, NY 10032, United States; Department of Pharmacology, Columbia University Medical Center, New York, NY 10032, United States; Research Foundation for Mental Hygiene, New York State Psychiatric Institute, New York, NY 10032, United States.
| |
Collapse
|
37
|
Selective autophagy: The new player in the fight against neurodegenerative diseases? Brain Res Bull 2018; 137:79-90. [DOI: 10.1016/j.brainresbull.2017.11.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 11/05/2017] [Accepted: 11/14/2017] [Indexed: 12/21/2022]
|
38
|
Wang F, Xu C, Reece EA, Li X, Wu Y, Harman C, Yu J, Dong D, Wang C, Yang P, Zhong J, Yang P. Protein kinase C-alpha suppresses autophagy and induces neural tube defects via miR-129-2 in diabetic pregnancy. Nat Commun 2017; 8:15182. [PMID: 28474670 PMCID: PMC5424165 DOI: 10.1038/ncomms15182] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 03/03/2017] [Indexed: 12/19/2022] Open
Abstract
Gene deletion-induced autophagy deficiency leads to neural tube defects (NTDs), similar to those in diabetic pregnancy. Here we report the key autophagy regulators modulated by diabetes in the murine developing neuroepithelium. Diabetes predominantly leads to exencephaly, induces neuroepithelial cell apoptosis and suppresses autophagy in the forebrain and midbrain of NTD embryos. Deleting the Prkca gene, which encodes PKCα, reverses diabetes-induced autophagy impairment, cellular organelle stress and apoptosis, leading to an NTD reduction. PKCα increases the expression of miR-129-2, which is a negative regulator of autophagy. miR-129-2 represses autophagy by directly targeting PGC-1α, a positive regulator for mitochondrial function, which is disturbed by maternal diabetes. PGC-1α supports neurulation by stimulating autophagy in neuroepithelial cells. These findings identify two negative autophagy regulators, PKCα and miR-129-2, which mediate the teratogenicity of hyperglycaemia leading to NTDs. We also reveal a function for PGC-1α in embryonic development through promoting autophagy and ameliorating hyperglycaemia-induced NTDs.
Collapse
Affiliation(s)
- Fang Wang
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Cheng Xu
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - E. Albert Reece
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
- Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Xuezheng Li
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Yanqing Wu
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Christopher Harman
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Jingwen Yu
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Daoyin Dong
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Cheng Wang
- Department of Obstetrics, Gynecology, Nebraska Medical Center, Omaha, Nebraska 68198, USA
| | - Penghua Yang
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Jianxiang Zhong
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| | - Peixin Yang
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
- Department of Biochemistry & Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
| |
Collapse
|
39
|
Yang M, Bai L, Yu W, Sun X, Xu G, Guan R, Yang Y, Qiu M, Zhang Y, Tian J, Fang H. Expression of autophagy-associated proteins in papillary thyroid carcinoma. Oncol Lett 2017; 14:411-415. [PMID: 28693184 DOI: 10.3892/ol.2017.6101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 03/21/2017] [Indexed: 12/16/2022] Open
Abstract
The present study was designed to assess the protein expression of the autophagy-associated genes, Beclin-1 and microtubule-associated protein 1 light chain 3 (LC3)-II, as well as the association with clinicopathological features in papillary thyroid carcinoma (PTC). A total of 50 subjects were recruited, including 50 human PTC samples and paired adjacent noncancerous tissue samples. The protein expression of Beclin-1 and LC3-II was analyzed using immunohistochemistry and western blotting. Beclin-1 and LC3-II expression in PTC tissues significantly reduced compared with normal tissues (P<0.05). Expression of Beclin-1 and LC3-II was associated with lymph node metastasis of PTC (P<0.05), but had no association with age, gender, tumor size, tumor number and Tumor-Node-Metastasis stage (P>0.05). Expression of Beclin-1 and LC3-II were positively correlated (r=0.327;P=0.020) in PTC. In conclusion, the activity of autophagy was declined in PTC; this decrease in autophagic capacity may be associated with tumorigenesis and the development of PTC.
Collapse
Affiliation(s)
- Meiliu Yang
- Department of Medical Experimental Center, North China University of Science and Technology, Tangshan, Hebei 063000, P.R. China
| | - Lu Bai
- Department of Medical Experimental Center, North China University of Science and Technology, Tangshan, Hebei 063000, P.R. China
| | - Wu Yu
- Department of Surgery, Qianan Yejituo Hospital, Qianan, Hebei 064400, P.R. China
| | - Xueling Sun
- Department of Endocrinology, Tangshan Worker Hospital, Tangshan, Hebei 063000, P.R. China
| | - Gang Xu
- Department of Burn, Tangshan Worker Hospital, Tangshan, Hebei 063000, P.R. China
| | - Ruhua Guan
- Department of Endocrinology, Hebei Yanda Hospital, San He, Hebei 065201, P.R. China
| | - Ying Yang
- Department of Endocrinology, Tangshan Worker Hospital, Tangshan, Hebei 063000, P.R. China
| | - Mingyue Qiu
- Department of Endocrinology, Tangshan Worker Hospital, Tangshan, Hebei 063000, P.R. China
| | - Yazhong Zhang
- Department of Endocrinology, Tangshan Worker Hospital, Tangshan, Hebei 063000, P.R. China
| | - Jinli Tian
- Department of Endocrinology, Tangshan Worker Hospital, Tangshan, Hebei 063000, P.R. China
| | - Hui Fang
- Department of Endocrinology, Tangshan Worker Hospital, Tangshan, Hebei 063000, P.R. China
| |
Collapse
|
40
|
Lou M, Zhang LN, Ji PG, Feng FQ, Liu JH, Yang C, Li BF, Wang L. Quercetin nanoparticles induced autophagy and apoptosis through AKT/ERK/Caspase-3 signaling pathway in human neuroglioma cells: In vitro and in vivo. Biomed Pharmacother 2016; 84:1-9. [DOI: 10.1016/j.biopha.2016.08.055] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/22/2016] [Accepted: 08/21/2016] [Indexed: 11/25/2022] Open
|
41
|
Graham CD, Kaza N, Klocke BJ, Gillespie GY, Shevde LA, Carroll SL, Roth KA. Tamoxifen Induces Cytotoxic Autophagy in Glioblastoma. J Neuropathol Exp Neurol 2016; 75:946-954. [PMID: 27516117 DOI: 10.1093/jnen/nlw071] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Glioblastomas (GBMs) are the most common and aggressive primary human malignant brain tumors. 4-Hydroxy tamoxifen (OHT) is an active metabolite of the tamoxifen (TMX) prodrug and a well-established estrogen receptor (ER) and estrogen-related receptor antagonist. A recent study from our laboratory demonstrated that OHT induced ER-independent malignant peripheral nerve sheath tumor (MPNST) cell death by autophagic degradation of the prosurvival protein Kirsten rat sarcoma viral oncogene homolog. Because both MPNST and GBM are glial in cell origin, we hypothesized that OHT could mediate similar effects in GBM. OHT induced a concentration-dependent reduction in cell viability that was largely independent of caspase activation in a human GBM cell line and 2 patient-derived xenolines. Further, OHT induced both cytotoxic autophagy and a concentration-dependent decrease in epidermal growth factor receptor (EGFR) protein levels. A GBM cell line expressing EGFR variant III (EGFRvIII) was relatively resistant to OHT-induced death and EGFRvIII was refractory to OHT-induced degradation. Thus, OHT induces GBM cell death through a caspase-independent, autophagy-related mechanism and should be considered as a potential therapeutic agent in patients with GBM whose tumors express wild-type EGFR.
Collapse
Affiliation(s)
- Christopher D Graham
- From the Department of Pathology (CDG, NK, BJK, LAS, SLC, KAR); and Department of Neurosurgery, University of Alabama at Birmingham (GYG), Birmingham, Alabama
| | - Niroop Kaza
- From the Department of Pathology (CDG, NK, BJK, LAS, SLC, KAR); and Department of Neurosurgery, University of Alabama at Birmingham (GYG), Birmingham, Alabama
| | - Barbara J Klocke
- From the Department of Pathology (CDG, NK, BJK, LAS, SLC, KAR); and Department of Neurosurgery, University of Alabama at Birmingham (GYG), Birmingham, Alabama
| | - G Yancey Gillespie
- From the Department of Pathology (CDG, NK, BJK, LAS, SLC, KAR); and Department of Neurosurgery, University of Alabama at Birmingham (GYG), Birmingham, Alabama
| | - Lalita A Shevde
- From the Department of Pathology (CDG, NK, BJK, LAS, SLC, KAR); and Department of Neurosurgery, University of Alabama at Birmingham (GYG), Birmingham, Alabama
| | - Steven L Carroll
- From the Department of Pathology (CDG, NK, BJK, LAS, SLC, KAR); and Department of Neurosurgery, University of Alabama at Birmingham (GYG), Birmingham, Alabama
| | - Kevin A Roth
- From the Department of Pathology (CDG, NK, BJK, LAS, SLC, KAR); and Department of Neurosurgery, University of Alabama at Birmingham (GYG), Birmingham, Alabama
| |
Collapse
|
42
|
Keta O, Bulat T, Golić I, Incerti S, Korać A, Petrović I, Ristić-Fira A. The impact of autophagy on cell death modalities in CRL-5876 lung adenocarcinoma cells after their exposure to γ-rays and/or erlotinib. Cell Biol Toxicol 2016; 32:83-101. [PMID: 27026538 DOI: 10.1007/s10565-016-9319-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 03/21/2016] [Indexed: 01/27/2023]
Abstract
In most patients with lung cancer radiation treatment is used either as single agent or in combination with radiosensitizing drugs. However, the mechanisms underlying combined therapy and its impact on different modes of cell death have not yet been fully elucidated. We aimed to examine effects of single and combined treatments with γ-rays and erlotinib on radioresistant CRL-5876 human lung adenocarcinoma cells with particular emphasis on cell death. CRL-5876 cells were treated with γ-rays and/or erlotinib and changes in cell cycle, DNA repair dynamics, ultrastructure, nuclear morphology and protein expression were monitored at different time points. To reveal the relationship between types of cell death that arise after these treatments, autophagy was blocked with chloroquine. We found that higher dose of γ-rays causes G2/M arrest while adding of erlotinib to this treatment decreases the number of cells in S phase. Impact of erlotinib on kinetics of disappearance of irradiation-induced DNA double strand breaks is reflected in the increase of residual γ-H2AX foci after 24 h. γ-rays provoke cytoprotective autophagy which precedes development of senescence. Erlotinib predominantly induces apoptosis and enlarges the number of apoptotic cells in the irradiated CRL-5876 cells. Chloroquine improved cytotoxicity induced by radiation and erlotinib, increased apoptosis and decreased senescence in the CRL-5876 cells. The results obtained on CRL-5876 cells indicate significant radiosensitizing effect of erlotinib and suggest that chloroquine in the combination with the above treatments may have an additional antitumor effect in lung adenocarcinoma.
Collapse
Affiliation(s)
- Otilija Keta
- Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11001, Belgrade, Serbia
| | - Tanja Bulat
- Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11001, Belgrade, Serbia
| | - Igor Golić
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Sebastien Incerti
- CNRS/IN2P3, Centre d'Etudes Nucléaires de Bordeaux Gradignan, CENBG, Université Bordeaux 1, 33175, Gradignan, France
| | | | - Ivan Petrović
- Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11001, Belgrade, Serbia
| | - Aleksandra Ristić-Fira
- Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11001, Belgrade, Serbia.
| |
Collapse
|
43
|
Toton E, Romaniuk A, Budzianowski J, Hofmann J, Rybczynska M. Zapotin (5,6,2',6'-tetramethoxyflavone) Modulates the Crosstalk Between Autophagy and Apoptosis Pathways in Cancer Cells with Overexpressed Constitutively Active PKCϵ. Nutr Cancer 2016; 68:290-304. [PMID: 26847268 DOI: 10.1080/01635581.2016.1134595] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Autophagy is important in the regulation of survival and death signaling pathways in cancer. PKCϵ revealed high transforming potential and the ability to increase cell migration, invasion, and metastasis. Zapotin (5,6,2',6'-tetramethoxyflavone), a natural flavonoid, showed chemopreventive and anticancer properties. Previously, we reported that downmodulation of induced PKCϵ level by zapotin was associated with decreased migration and increased apoptosis in HeLa cell line containing doxycycline-inducible constitutively active PKCϵ (PKCϵA/E, Ala(159) → Glu). Depending on the genetic and environmental content of cells, autophagy may either precede apoptosis or occur simultaneously. The purpose of this study was to assess the effect of zapotin on autophagy. Increasing concentration of zapotin (from 7.5 µM to 30 µM) caused an inhibition of the formation of autophagosomes and a decline in microtubule-associated protein 1 light chain 3 (LC3) protein levels. The gene expression level of major negative regulator of autophagy was noticeably increased. Moreover, the expression of the pivotal autophagy genes was decreased. These changes were accompanied by alternation in autophagy-related protein levels. In conclusion, our results implied that both the antiautophagic and the proapoptosis effect of zapotin in HeLaPKCϵA/E cells are associated with the protein kinase C epsilon signaling pathway and lead to programmed cell death.
Collapse
Affiliation(s)
- Ewa Toton
- a Department of Clinical Chemistry and Molecular Diagnostics , Poznan University of Medical Sciences , Poznan , Poland
| | - Aleksandra Romaniuk
- a Department of Clinical Chemistry and Molecular Diagnostics , Poznan University of Medical Sciences , Poznan , Poland
| | - Jaromir Budzianowski
- b Department of Pharmaceutical Botany , Poznan University of Medical Sciences , Poznan , Poland
| | - Johann Hofmann
- c Biocenter, Division of Medical Biochemistry, Innsbruck Medical University , Innsbruck , Austria
| | - Maria Rybczynska
- a Department of Clinical Chemistry and Molecular Diagnostics , Poznan University of Medical Sciences , Poznan , Poland
| |
Collapse
|
44
|
Jakhar R, Paul S, Bhardwaj M, Kang SC. Astemizole-Histamine induces Beclin-1-independent autophagy by targeting p53-dependent crosstalk between autophagy and apoptosis. Cancer Lett 2015; 372:89-100. [PMID: 26739061 DOI: 10.1016/j.canlet.2015.12.024] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 12/15/2015] [Accepted: 12/15/2015] [Indexed: 12/29/2022]
Abstract
Apoptosis and autophagy are genetically regulated, evolutionarily conserved processes that can jointly seal cancer cell fates, and numerous death stimuli are capable of activating either pathway. Although crosstalk between apoptosis and autophagy is quite complex and sometimes contradictory, it remains a key factor determining the outcomes of death-related pathologies such as cancer. In the present study, exposure of MCF-7 breast cancer cells to HIS and the H1 receptor antagonist AST both alone and together with HIS (AST-HIS) led to generation of intracellular ROS, which induced massive cellular vacuolization through dilation of the ER and mitochondria. Consequently, apoptosis by Bax translocation, cytochrome c release, and caspase activation were triggered. In addition, AST-HIS caused ER stress-induced autophagy in MCF-7 cells, as evidenced by an increased LC3-II/LC3-I ratio, with surprisingly no changes in Beclin-1 expression. Non-canonical autophagy was induced via p53 phosphorylation, which increased p53-p62 interactions to enhance Beclin-1-independent autophagy as evidenced by immunocytochemistry and immunoprecipitation. In the absence of Beclin-1, enhanced autophagy further activated apoptosis through caspase induction. In conclusion, these findings indicate that AST-HIS-induced apoptosis and autophagy can be regulated by ROS-mediated signaling pathways.
Collapse
Affiliation(s)
- Rekha Jakhar
- Department of Biotechnology, Daegu University, Kyoungsan, Kyoungbook 712-714, Republic of Korea
| | - Souren Paul
- Department of Biotechnology, Daegu University, Kyoungsan, Kyoungbook 712-714, Republic of Korea
| | - Monika Bhardwaj
- Department of Biotechnology, Daegu University, Kyoungsan, Kyoungbook 712-714, Republic of Korea
| | - Sun Chul Kang
- Department of Biotechnology, Daegu University, Kyoungsan, Kyoungbook 712-714, Republic of Korea.
| |
Collapse
|
45
|
Wesselborg S, Stork B. Autophagy signal transduction by ATG proteins: from hierarchies to networks. Cell Mol Life Sci 2015; 72:4721-57. [PMID: 26390974 PMCID: PMC4648967 DOI: 10.1007/s00018-015-2034-8] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 08/13/2015] [Accepted: 08/31/2015] [Indexed: 02/07/2023]
Abstract
Autophagy represents an intracellular degradation process which is involved in both cellular homeostasis and disease settings. In the last two decades, the molecular machinery governing this process has been characterized in detail. To date, several key factors regulating this intracellular degradation process have been identified. The so-called autophagy-related (ATG) genes and proteins are central to this process. However, several additional molecules contribute to the outcome of an autophagic response. Several review articles describing the molecular process of autophagy have been published in the recent past. In this review article we would like to add the most recent findings to this knowledge, and to give an overview of the network character of the autophagy signaling machinery.
Collapse
Affiliation(s)
- Sebastian Wesselborg
- Institute of Molecular Medicine I, Heinrich-Heine-University, Universitätsstr. 1, Building 23.12, 40225, Düsseldorf, Germany
| | - Björn Stork
- Institute of Molecular Medicine I, Heinrich-Heine-University, Universitätsstr. 1, Building 23.12, 40225, Düsseldorf, Germany.
| |
Collapse
|
46
|
Xie Y, Kang R, Sun X, Zhong M, Huang J, Klionsky DJ, Tang D. Posttranslational modification of autophagy-related proteins in macroautophagy. Autophagy 2015; 11:28-45. [PMID: 25484070 DOI: 10.4161/15548627.2014.984267] [Citation(s) in RCA: 239] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Macroautophagy is an intracellular catabolic process involved in the formation of multiple membrane structures ranging from phagophores to autophagosomes and autolysosomes. Dysfunction of macroautophagy is implicated in both physiological and pathological conditions. To date, 38 autophagy-related (ATG) genes have been identified as controlling these complicated membrane dynamics during macroautophagy in yeast; approximately half of these genes are clearly conserved up to human, and there are additional genes whose products function in autophagy in higher eukaryotes that are not found in yeast. The function of the ATG proteins, in particular their ability to interact with a number of macroautophagic regulators, is modulated by posttranslational modifications (PTMs) such as phosphorylation, glycosylation, ubiquitination, acetylation, lipidation, and proteolysis. In this review, we summarize our current knowledge of the role of ATG protein PTMs and their functional relevance in macroautophagy. Unraveling how these PTMs regulate ATG protein function during macroautophagy will not only reveal fundamental mechanistic insights into the regulatory process, but also provide new therapeutic targets for the treatment of autophagy-associated diseases.
Collapse
Affiliation(s)
- Yangchun Xie
- a Department of Oncology; Xiangya Hospital ; Central South University ; Changsha , Hunan , China
| | | | | | | | | | | | | |
Collapse
|
47
|
Dagda RK, Das Banerjee T. Role of protein kinase A in regulating mitochondrial function and neuronal development: implications to neurodegenerative diseases. Rev Neurosci 2015; 26:359-70. [PMID: 25741943 DOI: 10.1515/revneuro-2014-0085] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 01/08/2015] [Indexed: 11/15/2022]
Abstract
In neurons, enhanced protein kinase A (PKA) signaling elevates synaptic plasticity, promotes neuronal development, and increases dopamine synthesis. By contrast, a decline in PKA signaling contributes to the etiology of several brain degenerative diseases, including Alzheimer's disease and Parkinson's disease, suggesting that PKA predominantly plays a neuroprotective role. A-kinase anchoring proteins (AKAPs) are large multidomain scaffold proteins that target PKA and other signaling molecules to distinct subcellular sites to strategically localize PKA signaling at dendrites, dendritic spines, cytosol, and axons. PKA can be recruited to the outer mitochondrial membrane by associating with three different AKAPs to regulate mitochondrial dynamics, structure, mitochondrial respiration, trafficking, dendrite morphology, and neuronal survival. In this review, we survey the myriad of essential neuronal functions modulated by PKA but place a special emphasis on mitochondrially localized PKA. Finally, we offer an updated overview of how loss of PKA signaling contributes to the etiology of several brain degenerative diseases.
Collapse
|
48
|
Proton Channel Activity of Influenza A Virus Matrix Protein 2 Contributes to Autophagy Arrest. J Virol 2015; 90:591-8. [PMID: 26468520 DOI: 10.1128/jvi.00576-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 10/01/2015] [Indexed: 11/20/2022] Open
Abstract
Influenza A virus infection can arrest autophagy, as evidenced by autophagosome accumulation in infected cells. Here, we report that this autophagosome accumulation can be inhibited by amantadine, an antiviral proton channel inhibitor, in amantadine-sensitive virus infected cells or cells expressing influenza A virus matrix protein 2 (M2). Thus, M2 proton channel activity plays a role in blocking the fusion of autophagosomes with lysosomes, which might be a key mechanism for arresting autophagy.
Collapse
|
49
|
Popelka H, Klionsky DJ. Post-translationally-modified structures in the autophagy machinery: an integrative perspective. FEBS J 2015; 282:3474-88. [PMID: 26108642 DOI: 10.1111/febs.13356] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 06/11/2015] [Accepted: 06/19/2015] [Indexed: 01/10/2023]
Abstract
Autophagy is a self-cleaning process that occurs at a constitutive basal level, and is upregulated in response to stress. Macroautophagy (hereafter autophagy) is the most robust type of autophagy, where cargo (specific or nonspecific) is engulfed within a double-membrane structure termed an autophagosome. This process needs to be tightly regulated to maintain normal cellular homeostasis and prevent dysfunction; therefore, a fuller knowledge of the mechanisms of autophagy regulation is crucial for understanding the entire pathway. The autophagy-related proteins are the primary components that carry out autophagy. Many of these proteins are conserved from yeast to humans. A number of significant discoveries with regard to protein functional domains, protein-protein interactions or post-translational modifications of proteins involved in autophagy have been reported in parallel with, or followed by, solving the NMR or crystal structures of autophagy proteins or their protein domains. In the present review, we summarize structural insights gathered to date on the proteins of the autophagy machinery that are modulated by a post-translational modification, specifically phosphorylation, acetylation, ubiquitination and/or SUMOylation. For each protein, we link the reported results with information on the propensity of the corresponding amino acid sequence toward order/disorder. This integrative approach yields a comprehensive overview for each post-translationally modified protein, and also reveals areas for further investigation.
Collapse
Affiliation(s)
- Hana Popelka
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | | |
Collapse
|
50
|
Fernández-Araujo A, Alfonso A, Vieytes MR, Botana LM. Yessotoxin activates cell death pathways independent of Protein Kinase C in K-562 human leukemic cell line. Toxicol In Vitro 2015; 29:1545-54. [PMID: 26025416 DOI: 10.1016/j.tiv.2015.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 05/12/2015] [Accepted: 05/16/2015] [Indexed: 01/30/2023]
Abstract
Protein Kinase C (PKC) is a group of enzymes involved in pro-survival or pro-apoptotic events depending on the cellular model. Moreover, Yessotoxin (YTX) modulates its expression and activates different cell death pathways. In K-562 tumor cell line, YTX induces apoptosis and autophagy after 24 and 48 h of incubation, respectively, and the toxin carries out its action through the phosphodiesterase 4A (PDE4A). Therefore, the levels of two subtypes of PKC, conventional (cPKC) and δ isotype of novel PKC (PKCδ) were studied at these times after YTX incubation. Also their involvement in the cell death activated by the toxin and their relationship with PDE4A was checked. The expression of cPKC and PKCδ in cytosol, plasma membrane and nucleus was studied in normal and PDE4A-silenced cells. Furthermore, cell viability of normal cells, as well as cPKC-, PKCδ- and PDE4A-silenced cells was tested by Lactate Dehydrogenase (LDH) assay. As a result, PKCδ showed a key role in K-562 cell survive, since without this protein, K-562 cell decreased their viability. Furthermore, modulation of PKCs by YTX treatment was observed, however, the changes in the expression of these proteins are independent of cell death activated by the toxin. In addition, the modulation of PKCs detected is PDE4A-dependent, since the silencing of this protein change PKC expression pattern.
Collapse
Affiliation(s)
| | - Amparo Alfonso
- Dept. Farmacología, Facultad de Veterinaria, 27002 Lugo, Spain
| | | | - Luis M Botana
- Dept. Farmacología, Facultad de Veterinaria, 27002 Lugo, Spain.
| |
Collapse
|