1
|
Müller L, Hoppe T. UPS-dependent strategies of protein quality control degradation. Trends Biochem Sci 2024:S0968-0004(24)00149-X. [PMID: 38945729 DOI: 10.1016/j.tibs.2024.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 05/29/2024] [Accepted: 06/10/2024] [Indexed: 07/02/2024]
Abstract
The degradation of damaged proteins is critical for tissue integrity and organismal health because damaged proteins have a high propensity to form aggregates. E3 ubiquitin ligases are key regulators of protein quality control (PQC) and mediate the selective degradation of damaged proteins, a process termed 'PQC degradation' (PQCD). The degradation signals (degrons) that trigger PQCD are based on hydrophobic sites that are normally buried within the native protein structure. However, an open question is how PQCD-specialized E3 ligases distinguish between transiently misfolded proteins, which can be efficiently refolded, and permanently damaged proteins, which must be degraded. While significant progress has been made in characterizing degradation determinants, understanding the key regulatory signals of cellular and organismal PQCD pathways remains a challenge.
Collapse
Affiliation(s)
- Leonie Müller
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital of Cologne, 50931 Cologne, Germany
| | - Thorsten Hoppe
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital of Cologne, 50931 Cologne, Germany.
| |
Collapse
|
2
|
Diaz Escarcega R, Murambadoro K, Valencia R, Moruno-Manchon JF, Furr Stimming EE, Jung SY, Tsvetkov AS. Sphingosine kinase 2 regulates protein ubiquitination networks in neurons. Mol Cell Neurosci 2024; 130:103948. [PMID: 38909878 DOI: 10.1016/j.mcn.2024.103948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 05/31/2024] [Accepted: 06/17/2024] [Indexed: 06/25/2024] Open
Abstract
Two sphingosine kinase isoforms, sphingosine kinase 1 (SPHK1) and sphingosine kinase 2 (SPHK2), synthesize the lipid sphingosine-1-phosphate (S1P) by phosphorylating sphingosine. SPHK1 is a cytoplasmic kinase, and SPHK2 is localized to the nucleus and other organelles. In the cytoplasm, the SPHK1/S1P pathway modulates autophagy and protein ubiquitination, among other processes. In the nucleus, the SPHK2/S1P pathway regulates transcription. Here, we hypothesized that the SPHK2/S1P pathway governs protein ubiquitination in neurons. We found that ectopic expression of SPHK2 increases ubiquitinated substrate levels in cultured neurons and pharmacologically inhibiting SPHK2 decreases protein ubiquitination. With mass spectrometry, we discovered that inhibiting SPHK2 affects lipid and synaptic protein networks as well as a ubiquitin-dependent protein network. Several ubiquitin-conjugating and hydrolyzing proteins, such as the E3 ubiquitin-protein ligases HUWE1 and TRIP12, the E2 ubiquitin-conjugating enzyme UBE2Z, and the ubiquitin-specific proteases USP15 and USP30, were downregulated by SPHK2 inhibition. Using RNA sequencing, we found that inhibiting SPHK2 altered lipid and neuron-specific gene networks, among others. Genes that encode the corresponding proteins from the ubiquitin-dependent protein network that we discovered with mass spectrometry were not affected by inhibiting SPHK2, indicating that the SPHK2/S1P pathway regulates ubiquitination at the protein level. We also show that both SPHK2 and HUWE1 were upregulated in the striatum of a mouse model of Huntington's disease, the BACHD mice, indicating that our findings are relevant to neurodegenerative diseases. Our results identify SPHK2/S1P as a novel regulator of protein ubiquitination networks in neurons and provide a new target for developing therapies for neurodegenerative diseases.
Collapse
Affiliation(s)
- Rocio Diaz Escarcega
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America
| | - Karen Murambadoro
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America
| | - Ricardo Valencia
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America
| | - Jose Felix Moruno-Manchon
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America
| | - Erin E Furr Stimming
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America
| | - Sung Yun Jung
- Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, United States of America.
| | - Andrey S Tsvetkov
- Department of Neurology, University of Texas McGovern Medical School, Houston, TX 77030, United States of America; The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, United States of America; UTHealth Consortium on Aging, the University of Texas McGovern Medical School, Houston, TX 77030, United States of America.
| |
Collapse
|
3
|
Liu J, Wang L, He H, Liu Y, Jiang Y, Yang J. The Complex Role of Chaperone-Mediated Autophagy in Cancer Diseases. Biomedicines 2023; 11:2050. [PMID: 37509689 PMCID: PMC10377530 DOI: 10.3390/biomedicines11072050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/08/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
Chaperone-mediated autophagy (CMA) is a process that rapidly degrades proteins labeled with KFERQ-like motifs within cells via lysosomes to terminate their cellular functioning. Meanwhile, CMA plays an essential role in various biological processes correlated with cell proliferation and apoptosis. Previous studies have shown that CMA was initially found to be procancer in cancer cells, while some theories suggest that it may have an inhibitory effect on the progression of cancer in untransformed cells. Therefore, the complex relationship between CMA and cancer has aroused great interest in the application of CMA activity regulation in cancer therapy. Here, we describe the basic information related to CMA and introduce the physiological functions of CMA, the dual role of CMA in different cancer contexts, and its related research progress. Further study on the mechanism of CMA in tumor development may provide novel insights for tumor therapy targeting CMA. This review aims to summarize and discuss the complex mechanisms of CMA in cancer and related potential strategies for cancer therapy.
Collapse
Affiliation(s)
- Jing Liu
- Department of Basic Medicine, School of Medicine, Hunan Normal University, Changsha 410013, China
| | - Lijuan Wang
- Department of Anesthesiology, Hunan Cancer Hospital/The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha 410013, China
| | - Hua He
- Department of Basic Medicine, School of Medicine, Hunan Normal University, Changsha 410013, China
| | - Yueying Liu
- Department of Basic Medicine, School of Medicine, Hunan Normal University, Changsha 410013, China
| | - Yiqun Jiang
- Department of Basic Medicine, School of Medicine, Hunan Normal University, Changsha 410013, China
- The Key Laboratory of Model Animal and Stem Cell Biology in Hunan Province, Hunan Normal University, Changsha 410013, China
| | - Jinfeng Yang
- Department of Anesthesiology, Hunan Cancer Hospital/The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha 410013, China
| |
Collapse
|
4
|
Semisynthesis and biological evaluation of (+)-sclerotiorin derivatives as antitumor agents for the treatment of hepatocellular carcinoma. Eur J Med Chem 2022; 232:114166. [DOI: 10.1016/j.ejmech.2022.114166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/27/2022] [Accepted: 01/29/2022] [Indexed: 11/22/2022]
|
5
|
Morey TM, Esmaeili MA, Duennwald ML, Rylett RJ. SPAAC Pulse-Chase: A Novel Click Chemistry-Based Method to Determine the Half-Life of Cellular Proteins. Front Cell Dev Biol 2021; 9:722560. [PMID: 34557490 PMCID: PMC8452969 DOI: 10.3389/fcell.2021.722560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
Assessing the stability and degradation of proteins is central to the study of cellular biological processes. Here, we describe a novel pulse-chase method to determine the half-life of cellular proteins that overcomes the limitations of other commonly used approaches. This method takes advantage of pulse-labeling of nascent proteins in living cells with the bioorthogonal amino acid L-azidohomoalanine (AHA) that is compatible with click chemistry-based modifications. We validate this method in both mammalian and yeast cells by assessing both over-expressed and endogenous proteins using various fluorescent and chemiluminescent click chemistry-compatible probes. Importantly, while cellular stress responses are induced to a limited extent following live-cell AHA pulse-labeling, we also show that this response does not result in changes in cell viability and growth. Moreover, this method is not compromised by the cytotoxicity evident in other commonly used protein half-life measurement methods and it does not require the use of radioactive amino acids. This new method thus presents a versatile, customizable, and valuable addition to the toolbox available to cell biologists to determine the stability of cellular proteins.
Collapse
Affiliation(s)
- Trevor M Morey
- Molecular Medicine Research Group, Robarts Research Institute, Western University, London, ON, Canada.,Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | - Mohammad Ali Esmaeili
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Martin L Duennwald
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - R Jane Rylett
- Molecular Medicine Research Group, Robarts Research Institute, Western University, London, ON, Canada.,Department of Physiology and Pharmacology, Western University, London, ON, Canada
| |
Collapse
|
6
|
Rong H, Wang C, Liu H, Zhang M, Yuan Y, Pu Y, Huang J, Yu J. Biochemical Toxicity and Potential Detoxification Mechanisms in Earthworms Eisenia fetida Exposed to Sulfamethazine and Copper. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2020; 105:255-260. [PMID: 32632463 DOI: 10.1007/s00128-020-02927-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 06/27/2020] [Indexed: 06/11/2023]
Abstract
The present study investigated the biochemical toxicity and potential detoxification mechanisms in earthworms Eisenia fetida exposed to sulfamethazine (SMZ) (7.5, 15 and 30 mg kg-1) either alone or in combination with Copper (Cu) (100 mg kg-1) in soil. The results showed that increasing concentrations of SMZ in soil activated superoxide dismutase, catalase and glutathione peroxidase isozymes, suggesting reactive oxygen species (ROS) burst in earthworms. Treatment with SMZ and Cu separately or in combination caused protein oxidation and damage, elevating the synthesis of ubiquitin, the 20S proteasome, cytochrome P450 (CYP450), and heat shock protein 70 (HSP70). Such treatments also induced the activities of proteases, endoproteinase (EP) and glutathione S-transferases (GSTs). The results suggested that the ubiquitin-20S proteasome, proteases, EP and HSP70 were involved in degradation or remediation of oxidatively damaged proteins. Elevated levels of CYP450 and GSTs also participated in the detoxification of the earthworms.
Collapse
Affiliation(s)
- Hong Rong
- School of Biological Engineering, Huainan Normal University, Huainan, China
- Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, China
| | - Chengrun Wang
- School of Biological Engineering, Huainan Normal University, Huainan, China.
- Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, China.
| | - Haitao Liu
- School of Biological Engineering, Huainan Normal University, Huainan, China
- Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, China
| | - Min Zhang
- School of Biological Engineering, Huainan Normal University, Huainan, China
- Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, China
| | - Yueting Yuan
- School of Biological Engineering, Huainan Normal University, Huainan, China
- Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, China
| | - Yanjie Pu
- School of Biological Engineering, Huainan Normal University, Huainan, China
- Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, China
| | - Jin Huang
- School of Biological Engineering, Huainan Normal University, Huainan, China
- Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, China
| | - Jinyu Yu
- School of Biological Engineering, Huainan Normal University, Huainan, China
- Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes, Huainan Normal University, Huainan, China
| |
Collapse
|
7
|
Degradation of group V secretory phospholipase A 2 in lung endothelium is mediated by autophagy. Microvasc Res 2019; 129:103954. [PMID: 31730773 DOI: 10.1016/j.mvr.2019.103954] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 09/18/2019] [Accepted: 11/10/2019] [Indexed: 02/07/2023]
Abstract
Group V secretory phospholipase A2 (gVPLA2) is a potent inflammatory mediator in mammalian tissues that hydrolyzes phospholipids and initiates eicosanoid biosynthesis. Previous work has demonstrated that multiple inflammatory stimuli induce its expression and secretion in several cell types, including the lung endothelium. However, little is known about the mechanism(s) by which gVPLA2 inflammatory signaling is subsequently downregulated. Therefore, in this study we characterized potential clearance mechanisms for gVPLA2 in lung endothelial cells (EC). We observed that exogenous gVPLA2 is taken up rapidly by nutrient-starved human pulmonary artery EC (HPAEC) in vitro, and its cellular expression subsequently is reduced over several hours. In parallel experiments performed in pulmonary vascular EC isolated from mice genetically deficient in gVPLA2, the degradation of exogenously applied gVPLA2 occurs in a qualitatively similar fashion. This degradation is significantly attenuated in EC treated with ammonium chloride or chloroquine, which are lysosomal inhibitors that block autophagic flux. In contrast, the proteasomal inhibitor MG132 fails to prevent the clearance of gVPLA2. Both immunofluorescence microscopy and proximity ligation assay demonstrate the co-localization of LC3 and gVPLA2 during this process, indicating the association of gVPLA2 with autophagosomes. Nutrient starvation, a known inducer of autophagy, is sufficient to stimulate gVPLA2 degradation. These results suggest that a lysosome-mediated autophagy pathway contributes to gVPLA2 clearance from lung EC. These novel observations advance our understanding of the mechanism by which this key inflammatory enzyme is downregulated in the lung vasculature.
Collapse
|
8
|
Wang M, Li S, Zhang P, Wang Y, Wang C, Bai D, Jiang X. EMP2 acts as a suppressor of melanoma and is negatively regulated by mTOR-mediated autophagy. J Cancer 2019; 10:3582-3592. [PMID: 31333775 PMCID: PMC6636303 DOI: 10.7150/jca.30342] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 05/07/2019] [Indexed: 02/06/2023] Open
Abstract
Cutaneous melanoma is one of the most common malignant skin tumors and advanced melanoma is usually associated with a poor prognosis. In the current study, we demonstrated the tumor suppressing role of epithelial membrane protein-2 (EMP2) by inducing apoptosis in a A375 human melanoma cell line. Mechanistically, the low expression of EMP2 in melanoma is partially due to autophagic protein degradation mediated by the mTOR pathway. These results suggest there is regulation of autophagy as well as EMP2 levels might be an interesting novel targeted therapeutic strategy for melanoma. Although the further investigation is needed to deeply understand the regulatory mechanisms of EMP2 in melanoma progression and metastasis, our results clarify the functions and mechanisms of autophagy in melanoma, and shed new light on novel targeted therapeutics for melanoma.
Collapse
Affiliation(s)
- Manyi Wang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, Department of Orthodontics and Paediatrics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, PR China
| | - Sijia Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, Department of Orthodontics and Paediatrics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, PR China
| | - Peng Zhang
- Department of Radiation Oncology, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Radiation Oncology Key Laboratory of Sichuan Province, Chengdu 610041, PR China
| | - Yujia Wang
- Department of Dermatology and State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, PR China
| | - Chunting Wang
- Department of Dermatology and State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, PR China
| | - Ding Bai
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Disease, Department of Orthodontics and Paediatrics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, PR China
| | - Xian Jiang
- Department of Dermatology and State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, PR China
| |
Collapse
|
9
|
Grosso RA, Caldarone PVS, Sánchez MC, Chiabrando GA, Colombo MI, Fader CM. Hemin induces autophagy in a leukemic erythroblast cell line through the LRP1 receptor. Biosci Rep 2019; 39:BSR20181156. [PMID: 30523204 PMCID: PMC6328880 DOI: 10.1042/bsr20181156] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 10/31/2018] [Accepted: 11/07/2018] [Indexed: 01/04/2023] Open
Abstract
Hemin is an erythropoietic inductor capable of inducing autophagy in erythroid-like cell lines. Low-density lipoprotein receptor-related protein 1 (LRP1) is a transmembrane receptor involved in a wide range of cellular processes, such as proliferation, differentiation, and metabolism. Our aim was to evaluate whether LRP1 is responsible for hemin activity in K562 cells, with the results demonstrating a three-fold increase in LRP1 gene expression levels (P-values <0.001) when assessed by quantitative real-time RT-PCR (qRT-PCR). Moreover, a 70% higher protein amount was observed compared with control condition (P-values <0.01) by Western blot (WB). Time kinetic assays demonstrated a peak in light chain 3 (LC3) II (LC3II) levels after 8 h of hemin stimulation and the localization of LRP1 in the autophagosome structures. Silencing LRP1 by siRNA decreased drastically the hemin-induced autophagy activity by almost 80% compared with control cells (P-values <0.01). Confocal localization and biochemical analysis indicated a significant redistribution of LRP1 from early endosomes and recycling compartments to late endosomes and autophagolysosomes, where the receptor is degraded. We conclude that LRP1 is responsible for hemin-induced autophagy activity in the erythroblastic cell line and that hemin-LRP1 complex activation promotes a self-regulation of the receptor. Our results suggest that hemin, via the LRP1 receptor, favors erythroid maturation by inducing an autophagic response, making it a possible therapeutic candidate to help in the treatment of hematological disorders.
Collapse
Affiliation(s)
- Ruben Adrian Grosso
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Paula Virginia Subirada Caldarone
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5016, Argentina
| | - María Cecilia Sánchez
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5016, Argentina
| | - Gustavo Alberto Chiabrando
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5016, Argentina
| | - María Isabel Colombo
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Claudio Marcelo Fader
- Universidad Nacional de Cuyo, Facultad de Odontología, Mendoza, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| |
Collapse
|
10
|
Lin Y, Kong F, Li Y, Wang Y, Song L, Zhao C. The tumor suppressor OVCA1 is a short half-life protein degraded by the ubiquitin-proteasome pathway. Oncol Lett 2019; 17:2328-2334. [PMID: 30675298 PMCID: PMC6341780 DOI: 10.3892/ol.2018.9852] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 11/19/2018] [Indexed: 12/14/2022] Open
Abstract
Ovarian cancer gene 1 (OVCA1) is a tumor suppressor associated with ovarian cancer, which is involved in cell proliferation regulation, embryonic development and tumorigenesis. Loss of heterozygosity in the OVCA1 gene occurs in 50-86% of cases of ovarian cancer; however, the physiological and biochemical functions of OVCA1 are not yet clear. In the present study, the stability and degradation of OVCA1 were investigated in A2780, Hela and 293 cells. The results revealed that the OVCA1 protein was unstable by MG132 inhibiting proteasome mediated degradation, co-immunoprecipitation and half-life measurement experiments. The cellular protein levels of endogenous OVCA1 were too low to be detected by western blotting. In addition, carbobenzoxy-L-leucyl-L-leucyl-L-leucinal inhibited the degradation of OVCA1 in cells. The co-immunoprecipitation assay revealed that the OVCA1 protein interacted with ubiquitin to form a poly-ubiquitinated complex in cells. The half-life of OVCA1, measured by inhibiting protein synthesis with cycloheximide, was <2 h. The present study demonstrated that OVCA1 may be degraded by the ubiquitin-mediated proteasome pathway and may be considered a short half-life protein. In conclusion, the regulation of OVCA1 protein degradation via the ubiquitin-proteasome pathway may represent a novel direction in the development of ovarian cancer therapy.
Collapse
Affiliation(s)
- Yingwei Lin
- Department of Clinical Laboratory, The Second Hospital of Dalian Medical University, Dalian, Liaoning 116023, P.R. China
| | - Fandou Kong
- Department of Gynecology and Obstetrics, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
| | - Yan Li
- College of Laboratory Medicine, Dalian Medical University, Dalian, Liaoning 116044, P.R. China
| | - Yinghui Wang
- College of Laboratory Medicine, Dalian Medical University, Dalian, Liaoning 116044, P.R. China
| | - Ling Song
- College of Laboratory Medicine, Dalian Medical University, Dalian, Liaoning 116044, P.R. China
| | - Chunyan Zhao
- College of Laboratory Medicine, Dalian Medical University, Dalian, Liaoning 116044, P.R. China
| |
Collapse
|
11
|
Chu CW, Ko HJ, Chou CH, Cheng TS, Cheng HW, Liang YH, Lai YL, Lin CY, Wang C, Loh JK, Cheng JT, Chiou SJ, Su CL, Huang CYF, Hong YR. Thioridazine Enhances P62-Mediated Autophagy and Apoptosis Through Wnt/β-Catenin Signaling Pathway in Glioma Cells. Int J Mol Sci 2019; 20:ijms20030473. [PMID: 30678307 PMCID: PMC6386927 DOI: 10.3390/ijms20030473] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 01/18/2019] [Indexed: 12/12/2022] Open
Abstract
Thioridazine (THD) is a common phenothiazine antipsychotic drug reported to suppress growth in several types of cancer cells. We previously showed that THD acts as an antiglioblastoma and anticancer stem-like cell agent. However, the signaling pathway underlying autophagy and apoptosis induction remains unclear. THD treatment significantly induced autophagy with upregulated AMPK activity and engendered cell death with increased sub-G1 in glioblastoma multiform (GBM) cell lines. Notably, through whole gene expression screening with THD treatment, frizzled (Fzd) proteins, a family of G-protein-coupled receptors, were found, suggesting the participation of Wnt/β-catenin signaling. After THD treatment, Fzd-1 and GSK3β-S9 phosphorylation (inactivated form) was reduced to promote β-catenin degradation, which attenuated P62 inhibition. The autophagy marker LC3-II markedly increased when P62 was released from β-catenin inhibition. Additionally, the P62-dependent caspase-8 activation that induced P53-independent apoptosis was confirmed by inhibiting T-cell factor/β-catenin and autophagy flux. Moreover, treatment with THD combined with temozolomide (TMZ) engendered increased LC3-II expression and caspase-3 activity, indicating promising drug synergism. In conclusion, THD induces autophagy in GBM cells by not only upregulating AMPK activity, but also enhancing P62-mediated autophagy and apoptosis through Wnt/β-catenin signaling. Therefore, THD is a potential alternative therapeutic agent for drug repositioning in GBM.
Collapse
Affiliation(s)
- Cheng-Wei Chu
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (C.-W.C.); (H.-J.K.); (C.-H.C.); (Y.-L.L.); (C.-Y.L.); (J.-K.L.); (S.-J.C.)
- Division of Neurosurgery, Department of Surgery, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung 801, Taiwan
| | - Huey-Jiun Ko
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (C.-W.C.); (H.-J.K.); (C.-H.C.); (Y.-L.L.); (C.-Y.L.); (J.-K.L.); (S.-J.C.)
| | - Chia-Hua Chou
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (C.-W.C.); (H.-J.K.); (C.-H.C.); (Y.-L.L.); (C.-Y.L.); (J.-K.L.); (S.-J.C.)
| | - Tai-Shan Cheng
- Department of Biotechnology and Laboratory Science in Medicine, Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei 112, Taiwan; (T.-S.C.); (H.-W.C.); (Y.-H.L.)
| | - Hui-Wen Cheng
- Department of Biotechnology and Laboratory Science in Medicine, Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei 112, Taiwan; (T.-S.C.); (H.-W.C.); (Y.-H.L.)
| | - Yu-Hsin Liang
- Department of Biotechnology and Laboratory Science in Medicine, Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei 112, Taiwan; (T.-S.C.); (H.-W.C.); (Y.-H.L.)
| | - Yun-Ling Lai
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (C.-W.C.); (H.-J.K.); (C.-H.C.); (Y.-L.L.); (C.-Y.L.); (J.-K.L.); (S.-J.C.)
| | - Chen-Yen Lin
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (C.-W.C.); (H.-J.K.); (C.-H.C.); (Y.-L.L.); (C.-Y.L.); (J.-K.L.); (S.-J.C.)
| | - Chihuei Wang
- Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan;
| | - Joon-Khim Loh
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (C.-W.C.); (H.-J.K.); (C.-H.C.); (Y.-L.L.); (C.-Y.L.); (J.-K.L.); (S.-J.C.)
- Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
| | - Jiin-Tsuey Cheng
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan;
| | - Shean-Jaw Chiou
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (C.-W.C.); (H.-J.K.); (C.-H.C.); (Y.-L.L.); (C.-Y.L.); (J.-K.L.); (S.-J.C.)
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
- Department of Biochemistry & Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Chun-Li Su
- Department of Human Development and Family Studies, National Taiwan Normal University, Taipei 106, Taiwan;
| | - Chi-Ying F. Huang
- Department of Biotechnology and Laboratory Science in Medicine, Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei 112, Taiwan; (T.-S.C.); (H.-W.C.); (Y.-H.L.)
- Department of Biochemistry & Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Correspondence: (C.-Y.F.H.); (Y.-R.H.)
| | - Yi-Ren Hong
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan; (C.-W.C.); (H.-J.K.); (C.-H.C.); (Y.-L.L.); (C.-Y.L.); (J.-K.L.); (S.-J.C.)
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan;
- Department of Biochemistry & Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
- Correspondence: (C.-Y.F.H.); (Y.-R.H.)
| |
Collapse
|
12
|
Song X, Guo C, Zheng Y, Wang Y, Jin Z, Yin Y. Post-transcriptional regulation of cancer/testis antigen MAGEC2 expression by TRIM28 in tumor cells. BMC Cancer 2018; 18:971. [PMID: 30309319 PMCID: PMC6182782 DOI: 10.1186/s12885-018-4844-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 09/21/2018] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Cancer/testis antigen MAGEC2 (also known as HCA587) is highly expressed in a wide variety of tumors and plays an active role in promoting growth and metastasis of tumor cells. However, little is known for the regulation of MAGEC2 expression in cancer cells. METHODS Western blotting and quantitative RT-PCR were performed to analyze MAGEC2 expression. Co-immunoprecipitation assay was applied for detecting the endogenous interaction of MAGEC2 and TRIM28 in tumor cells. Overexpression and knockdown assays were used to examine the effects of TRIM28 on the expression of MAGEC2 protein. Immunohistochemistry (IHC) staining was performed in hepatocellular carcinoma patients to evaluate the association between the expression of MAGEC2 and TRIM28. Proteasome inhibitors MG132 or PS-341 and lysosome inhibitor Chloroquine (CQ) were used to inhibit proteasomal or lysosomal-mediated protein degradation respectively. RESULTS We demonstrate that MAGEC2 interacts with TRIM28 in melanoma cells and MAGEC2 expression in tumor cells depends on the expression of TRIM28. The expression level of MAGEC2 protein was significantly reduced when TRIM28 was depleted in tumor cells, and no changes were observed in MAGEC2 mRNA level. Furthermore, expression levels of MAGEC2 and TRIM28 are positively correlated in MAGEC2-positive human hepatocellular carcinoma tissues (p = 0.0011). Mechanistic studies indicate that the regulatory role of TRIM28 on MAGEC2 protein expression in tumor cells depends on proteasome-mediated pathway. CONCLUSIONS Our findings show that TRIM28 is necessary for MAGEC2 expression in cancer cells, and TRIM28 may serve as a new potential target for immunotherapy of cancer.
Collapse
Affiliation(s)
- Xiao Song
- Department of Immunology, School of Basic Medical Sciences, Key Laboratory of Medical Immunology of Ministry of Health, Peking University, Beijing, 100191, China
| | - Chengli Guo
- Department of Immunology, School of Basic Medical Sciences, Key Laboratory of Medical Immunology of Ministry of Health, Peking University, Beijing, 100191, China
| | - Yutian Zheng
- Department of Immunology, School of Basic Medical Sciences, Key Laboratory of Medical Immunology of Ministry of Health, Peking University, Beijing, 100191, China
| | - Ying Wang
- Department of Immunology, School of Basic Medical Sciences, Key Laboratory of Medical Immunology of Ministry of Health, Peking University, Beijing, 100191, China
| | - Zhongtian Jin
- Department of Hepatobiliary Surgery, Peking University People's Hospital, Beijing, 100044, China.
| | - Yanhui Yin
- Department of Immunology, School of Basic Medical Sciences, Key Laboratory of Medical Immunology of Ministry of Health, Peking University, Beijing, 100191, China.
| |
Collapse
|
13
|
Campbell P, Morris H, Schapira A. Chaperone-mediated autophagy as a therapeutic target for Parkinson disease. Expert Opin Ther Targets 2018; 22:823-832. [DOI: 10.1080/14728222.2018.1517156] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Philip Campbell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Huw Morris
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, UK
| | | |
Collapse
|
14
|
Calmodulin promotes matrix metalloproteinase 9 production and cell migration by inhibiting the ubiquitination and degradation of TBC1D3 oncoprotein in human breast cancer cells. Oncotarget 2018; 8:36383-36398. [PMID: 28422741 PMCID: PMC5482662 DOI: 10.18632/oncotarget.16756] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 03/22/2017] [Indexed: 11/25/2022] Open
Abstract
The hominoid oncoprotein TBC1D3 enhances growth factor (GF) signaling and GF signaling, conversely, induces the ubiquitination and subsequent degradation of TBC1D3. However, little is known regarding the regulation of this degradation, and the role of TBC1D3 in the progression of tumors has also not been defined. In the present study, we demonstrated that calmodulin (CaM), a ubiquitous cellular calcium sensor, specifically interacted with TBC1D3 in a Ca2+-dependent manner and inhibited GF signaling-induced ubiquitination and degradation of the oncoprotein in both cytoplasm and nucleus of human breast cancer cells. The CaM-interacting site of TBC1D3 was mapped to amino acids 157~171, which comprises two 1–14 hydrophobic motifs and one lysine residue (K166). Deletion of these motifs was shown to abolish interaction between TBC1D3 and CaM. Surprisingly, this deletion mutation caused inability of GF signaling to induce the ubiquitination and subsequent degradation of TBC1D3. In agreement with this, we identified lysine residue 166 within the CaM-interacting motifs of TBC1D3 as the actual site for the GF signaling-induced ubiquitination using mutational analysis. Point mutation of this lysine residue exhibited the same effect on TBC1D3 as the deletion mutant, suggesting that CaM inhibits GF signaling-induced degradation of TBC1D3 by occluding its ubiquitination at K166. Notably, we found that TBC1D3 promoted the expression and activation of MMP-9 and the migration of MCF-7 cells. Furthermore, interaction with CaM considerably enhanced such effect of TBC1D3. Taken together, our work reveals a novel model by which CaM promotes cell migration through inhibiting the ubiquitination and degradation of TBC1D3.
Collapse
|
15
|
Autophagy in dendritic cells. Cell Mol Immunol 2018; 15:944-952. [PMID: 29578531 PMCID: PMC6207777 DOI: 10.1038/cmi.2018.2] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 12/24/2017] [Accepted: 12/24/2017] [Indexed: 12/15/2022] Open
Abstract
Autophagy and immunity share the property of being auto-protective for the organism. Autophagy is an important degradation pathway that buffers nutrient deprivation by recycling macromolecules in organisms from yeast to man. Perturbations in autophagy are associated with inflammation and cancer development. Emerging studies have characterized the molecular details regarding how autophagy is controlled by immune cells. Among these, dendritic cells (DCs) are one of the most potent professional antigen-presenting cells critical for the activation of naïve T cells to maintain immune tolerance and drive protective immunity to infection and cancer. DCs undergo functional maturation that can either lead to an immunostimulatory phenotype, as in the context of infection, or to a tolerogenic phenotype associated with immunosuppression to self-antigens, as well as to cancer. An increasing number of recent studies has characterized the involvement of autophagy in DC functions in various physiological and pathological contexts. Here, we provide a comprehensive review of these outcomes and discuss the limitation of the models used and the forefront of the knowledge concerning the crosstalk between autophagy and DC biology.
Collapse
|
16
|
Li TY, Chiang BH. 6-shogaol induces autophagic cell death then triggered apoptosis in colorectal adenocarcinoma HT-29 cells. Biomed Pharmacother 2017; 93:208-217. [PMID: 28641163 DOI: 10.1016/j.biopha.2017.06.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/23/2017] [Accepted: 06/12/2017] [Indexed: 12/12/2022] Open
Abstract
6-shogaol is a phytochemical of dietary ginger, we found that 6-shogaol could induced both autophagic and apoptotic death in human colon adenocarcinoma (HT-29) cells. Results of this study showed that 6-shogal induced cell cycle arrest, autophagy, and apoptosis in HT-29 cells in a time sequence. After 6h, 6-shogal induced apparent G2/M arrest, then the HT-29 cells formed numerous autophagosomes in each phase of the cell cycle. After 18h, increases in acidic vesicles and LAMP-1 (Lysosome-associated membrane proteins 1) showed that 6-shogaol had caused autophagic cell death. After 24h, cell shrinkage and Caspase-3/7 activities rising, suggesting that apoptotic cell death had increased. And after 48h, the result of TUNEL assay indicated the highest occurrence of apoptosis upon 6-shogaol treatment. It appeared that apoptosis is triggered by autophagy in 6-shogaol treated HT-29 cells, the damage of autophagic cell death initiated apoptosis program.
Collapse
Affiliation(s)
- Ting-Yi Li
- Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| | - Been-Huang Chiang
- Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
| |
Collapse
|
17
|
Sun F, Xu X, Wang X, Zhang B. Regulation of autophagy by Ca 2. Tumour Biol 2016; 37:10.1007/s13277-016-5353-y. [PMID: 27864685 PMCID: PMC5250648 DOI: 10.1007/s13277-016-5353-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 09/07/2016] [Indexed: 01/20/2023] Open
Abstract
Autophagy is an evolutionarily conserved lysosomal catabolic process used as an internal engine in response to nutrient starvation or metabolic stress. A number of protein complexes and an intricate network of stress signaling cascades impinge on the regulation of autophagy; the mammalian target of rapamycin serves as a canonical player. Ca2+, as a major intracellular second messenger, regulates multiple physiological and pathological functions. Although significant information is already well-established about the role of Ca2+ in apoptosis, its role in autophagy has been recently determined and is poorly understood. Intracellular Ca2+ positively and negatively affects autophagy. In this review, evidence for both views and the interplay of Ca2+ between autophagy and apoptosis induction are discussed. The available data revealed the bidirectional role of Ca2+ in the regulation of autophagy. Moreover, the data also indicated that this role probably depends on the context of time, space, Ca2+ source, and cell state, thus either preventing or enhancing autophagy.
Collapse
Affiliation(s)
- Fang Sun
- Department of Clinical Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, 221000, China
- Department of Obstetrics and Gynecology, Xuzhou Central Hospital, Xuzhou, Jiangsu, 221009, China
| | - Xia Xu
- Department of Obstetrics and Gynecology, Xuzhou Hospital of Traditional Chinese Medicine, Xuzhou, Jiangsu, 221002, China
| | - Xiaohong Wang
- Department of Obstetrics and Gynecology, Xuzhou Hospital of Traditional Chinese Medicine, Xuzhou, Jiangsu, 221002, China
| | - Bei Zhang
- Department of Clinical Medicine, Xuzhou Medical University, Xuzhou, Jiangsu, 221000, China.
- Department of Obstetrics and Gynecology, Xuzhou Central Hospital, Xuzhou, Jiangsu, 221009, China.
- Department of Obstetrics and Gynecology, Xuzhou Central Hospital, Xuzhou, Jiangsu, 221002, China.
| |
Collapse
|
18
|
Enrich C, Rentero C, Grewal T. Annexin A6 in the liver: From the endocytic compartment to cellular physiology. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:933-946. [PMID: 27984093 DOI: 10.1016/j.bbamcr.2016.10.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 12/15/2022]
Abstract
Annexin A6 (AnxA6) belongs to the conserved annexin family - a group of Ca2+-dependent membrane binding proteins. AnxA6 is the largest of all annexins and highly expressed in smooth muscle, hepatocytes, endothelial cells and cardiomyocytes. Upon activation, AnxA6 binds to negatively charged phospholipids in a wide range of intracellular localizations, in particular the plasma membrane, late endosomes/pre-lysosomes, but also synaptic vesicles and sarcolemma. In these cellular sites, AnxA6 is believed to contribute to the organization of membrane microdomains, such as cholesterol-rich lipid rafts and confer multiple regulatory functions, ranging from vesicle fusion, endocytosis and exocytosis to programmed cell death and muscle contraction. Growing evidence supports that Ca2+ and Ca2+-binding proteins control endocytosis and autophagy. Their regulatory role seems to operate at the level of the signalling pathways that initiate autophagy or at later stages, when autophagosomes fuse with endolysosomal compartments. The convergence of the autophagic and endocytic vesicles to lysosomes shares several features that depend on Ca2+ originating from lysosomes/late endosomes and seems to depend on proteins that are subsequently activated by this cation. However, the involvement of Ca2+ and its effector proteins in these autophagic and endocytic stages still remains poorly understood. Although AnxA6 makes up almost 0.25% of total protein in the liver, little is known about its function in hepatocytes. Within the endocytic route, we identified AnxA6 in endosomes and autophagosomes of hepatocytes. Hence, AnxA6 and possibly other annexins might represent new Ca2+ effectors that regulate converging steps of autophagy and endocytic trafficking in hepatocytes. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.
Collapse
Affiliation(s)
- Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cellular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain.
| | - Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cellular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Thomas Grewal
- Faculty of Pharmacy A15, University of Sydney, Sydney, NSW 2006, Australia
| |
Collapse
|
19
|
O'Brien KM. New Lessons from an Old Fish: What Antarctic Icefishes May Reveal about the Functions of Oxygen-Binding Proteins. Integr Comp Biol 2016; 56:531-41. [PMID: 27252192 DOI: 10.1093/icb/icw062] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The loss of expression of the oxygen-binding protein hemoglobin (Hb) in the family Channichthyidae (suborder Notothenioidei) of Antarctic fishes is considered a disaptation that has persisted because of the unusual conditions prevailing in the Southern Ocean during the evolution of the family. The loss of expression of the intracellular oxygen-binding protein myoglobin (Mb) in heart ventricles is more of a conundrum because it occurred at four points during the radiation of the family, suggesting weakened selective pressure maintaining expression of the protein. Yet, studies have shown that when present, Mb enhances function. Here, I discuss potential reasons for weakened selective pressure maintaining Mb expression in light of the multiple functions proposed for Mb. Additionally, I discuss results from recent studies exploring the possibility that the loss of Hb and Mb may be advantageous because it reduces the production of reactive oxygen species, levels of oxidized proteins, and the energetic costs associated with replacing oxidatively damaged proteins.
Collapse
Affiliation(s)
- Kristin M O'Brien
- University of Alaska Fairbanks, Institute of Arctic Biology, Department of Biology and Wildlife, Fairbanks, AK 99775, USA
| |
Collapse
|
20
|
Fader CM, Salassa BN, Grosso RA, Vergara AN, Colombo MI. Hemin induces mitophagy in a leukemic erythroblast cell line. Biol Cell 2016; 108:77-95. [PMID: 26773440 DOI: 10.1111/boc.201500058] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 01/11/2016] [Indexed: 12/29/2022]
Abstract
BACKGROUND INFORMATION In eukaryotic cells, autophagy is considered a lysosomal catabolic process which participates in the degradation of intracellular components in a vacuolar structure termed autolysosome. This pathway plays a significant role in the erythropoiesis process, contributing to the clearance of some organelles (such as mitochondria) that are not necessary in the mature red blood cells. Nevertheless, the role of autophagy in erythrocyte maturation has not been fully established. RESULTS Here, we have demonstrated that hemin (a physiological erythroid maturation stimulator) is able to induce the expression of critical autophagic genes (i.e., Map1a1b (LC3), Beclin-1 gen, Atg5) in an erythroleukemia cell type. We have also shown that hemin increased the size of autophagic vacuoles which were labelled with LC3 and the degradative lysosomal marker dye quenched-bovine serum albumin. In addition, we have determined by Western blot a rise in the lipidated form of the autophagic protein LC3 (i.e., LC3-II) upon hemin treatment. Moreover, we provide evidence that hemin induces mitochondrial membrane depolarisation and that mitochondria sequestration by autophagy requires the active form of the NIX protein. CONCLUSIONS We have found that the physiological erythroid maturation stimulator hemin is able to induce mitophagy in K562 cells, and that the autophagy adaptor NIX is necessary for mitophagy progression. K562 cells have been used as a relevant model to determine the possible therapeutic role of new differentiating compounds. SIGNIFICANCE It has been proposed that autophagy induction is a feasible new therapeutic key in fighting cancer. Our results suggest that hemin is favoring erythroid maturation by inducing an autophagic response in K562 cells, being a possible therapeutic candidate that may help in the chronic myelogenous leukemia (CML) treatment.
Collapse
Affiliation(s)
- Claudio Marcelo Fader
- Facultad de Farmacia y Bioquímica, Universidad Juan Agustín Maza, Mendoza, Argentina.,Instituto de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | - Betiana Nebaí Salassa
- Facultad de Farmacia y Bioquímica, Universidad Juan Agustín Maza, Mendoza, Argentina
| | - Rubén Adrián Grosso
- Instituto de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | | | - María Isabel Colombo
- Facultad de Farmacia y Bioquímica, Universidad Juan Agustín Maza, Mendoza, Argentina.,Instituto de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| |
Collapse
|
21
|
Aguado C, Pérez-Jiménez E, Lahuerta M, Knecht E. Isolation of Lysosomes from Mammalian Tissues and Cultured Cells. Methods Mol Biol 2016; 1449:299-311. [PMID: 27613045 DOI: 10.1007/978-1-4939-3756-1_19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Lysosomes participate within the cells in the degradation of organelles, macromolecules, and a wide variety of substrates. In any study on specific roles of lysosomes, both under physiological and pathological conditions, it is advisable to include methods that allow their reproducible and reliable isolation. However, purification of lysosomes is a difficult task, particularly in the case of cultured cells. This is mainly because of the heterogeneity of these organelles, along with their low number and high fragility. Also, isolation methods, while disrupting plasma membranes, have to preserve the integrity of lysosomes, as the breakdown of their membranes releases enzymes that could damage all cell organelles, including themselves. The protocols described below have been routinely used in our laboratory for the specific isolation of lysosomes from rat liver, NIH/3T3, and other cultured cells, but can be adapted to other mammalian tissues or cell lines.
Collapse
Affiliation(s)
- Carmen Aguado
- Intracellular Protein Degradation and Rare Diseases Laboratory, Centro de Investigación Príncipe Felipe, C./Eduardo Primo Yúfera, 3, Valencia, 46012, Spain. .,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain.
| | - Eva Pérez-Jiménez
- Intracellular Protein Degradation and Rare Diseases Laboratory, Centro de Investigación Príncipe Felipe, C./Eduardo Primo Yúfera, 3, Valencia, 46012, Spain
| | - Marcos Lahuerta
- Intracellular Protein Degradation and Rare Diseases Laboratory, Centro de Investigación Príncipe Felipe, C./Eduardo Primo Yúfera, 3, Valencia, 46012, Spain
| | - Erwin Knecht
- Intracellular Protein Degradation and Rare Diseases Laboratory, Centro de Investigación Príncipe Felipe, C./Eduardo Primo Yúfera, 3, Valencia, 46012, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| |
Collapse
|
22
|
Romá-Mateo C, Aguado C, García-Giménez JL, Knecht E, Sanz P, Pallardó FV. Oxidative stress, a new hallmark in the pathophysiology of Lafora progressive myoclonus epilepsy. Free Radic Biol Med 2015; 88:30-41. [PMID: 25680286 DOI: 10.1016/j.freeradbiomed.2015.01.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 01/16/2015] [Accepted: 01/28/2015] [Indexed: 12/12/2022]
Abstract
Lafora disease (LD; OMIM 254780, ORPHA501) is a devastating neurodegenerative disorder characterized by the presence of glycogen-like intracellular inclusions called Lafora bodies and caused, in most cases, by mutations in either the EPM2A or the EPM2B gene, encoding respectively laforin, a phosphatase with dual specificity that is involved in the dephosphorylation of glycogen, and malin, an E3-ubiquitin ligase involved in the polyubiquitination of proteins related to glycogen metabolism. Thus, it has been reported that laforin and malin form a functional complex that acts as a key regulator of glycogen metabolism and that also plays a crucial role in protein homeostasis (proteostasis). Regarding this last function, it has been shown that cells are more sensitive to ER stress and show defects in proteasome and autophagy activities in the absence of a functional laforin-malin complex. More recently, we have demonstrated that oxidative stress accompanies these proteostasis defects and that various LD models show an increase in reactive oxygen species and oxidative stress products together with a dysregulated antioxidant enzyme expression and activity. In this review we discuss possible connections between the multiple defects in protein homeostasis present in LD and oxidative stress.
Collapse
Affiliation(s)
- Carlos Romá-Mateo
- Fundación Investigación Clinico de Valencia, Instituto de Investigación Sanitaria, Valencia, Spain; Department of Physiology, School of Medicine and Dentistry, University of Valencia, E46010 Valencia, Spain
| | - Carmen Aguado
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Valencia, Spain; Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - José Luis García-Giménez
- Fundación Investigación Clinico de Valencia, Instituto de Investigación Sanitaria, Valencia, Spain; Department of Physiology, School of Medicine and Dentistry, University of Valencia, E46010 Valencia, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, Valencia, Spain
| | - Erwin Knecht
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Valencia, Spain; Centro de Investigación Príncipe Felipe, Valencia, Spain
| | - Pascual Sanz
- Centro de Investigación Biomédica en Red de Enfermedades Raras, Valencia, Spain; Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Federico V Pallardó
- Fundación Investigación Clinico de Valencia, Instituto de Investigación Sanitaria, Valencia, Spain; Department of Physiology, School of Medicine and Dentistry, University of Valencia, E46010 Valencia, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, Valencia, Spain.
| |
Collapse
|
23
|
Amaya C, Fader CM, Colombo MI. Autophagy and proteins involved in vesicular trafficking. FEBS Lett 2015; 589:3343-53. [PMID: 26450776 DOI: 10.1016/j.febslet.2015.09.021] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/19/2015] [Accepted: 09/22/2015] [Indexed: 12/16/2022]
Abstract
Autophagy is an intracellular degradation system that, as a basic mechanism it delivers cytoplasmic components to the lysosomes in order to maintain adequate energy levels and cellular homeostasis. This complex cellular process is activated by low cellular nutrient levels and other stress situations such as low ATP levels, the accumulation of damaged proteins or organelles, or pathogen invasion. Autophagy as a multistep process involves vesicular transport events leading to tethering and fusion of autophagic vesicles with several intracellular compartments. This review summarizes our current understanding of the autophagic pathway with emphasis in the trafficking machinery (i.e. Rabs GTPases and SNAP receptors (SNAREs)) involved in specific steps of the pathway.
Collapse
Affiliation(s)
- Celina Amaya
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, Centro Universitario, Parque General San Martín, 5500 Mendoza, Argentina
| | - Claudio Marcelo Fader
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, Centro Universitario, Parque General San Martín, 5500 Mendoza, Argentina
| | - María Isabel Colombo
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, Centro Universitario, Parque General San Martín, 5500 Mendoza, Argentina.
| |
Collapse
|
24
|
Cai Z, Zeng W, Tao K, E Z, Wang B, Yang Q. Chaperone-mediated autophagy: roles in neuroprotection. Neurosci Bull 2015. [PMID: 26206599 DOI: 10.1007/s12264-015-1540-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Chaperone-mediated autophagy (CMA), one of the main pathways of lysosomal proteolysis, is characterized by the selective targeting and direct translocation into the lysosomal lumen of substrate proteins containing a targeting motif biochemically related to the pentapeptide KFERQ. Along with the other two lysosomal pathways, macro- and micro-autophagy, CMA is essential for maintaining cellular homeostasis and survival by selectively degrading misfolded, oxidized, or damaged cytosolic proteins. CMA plays an important role in pathologies such as cancer, kidney disorders, and neurodegenerative diseases. Neurons are post-mitotic and highly susceptible to dysfunction of cellular quality-control systems. Maintaining a balance between protein synthesis and degradation is critical for neuronal functions and homeostasis. Recent studies have revealed several new mechanisms by which CMA protects neurons through regulating factors critical for their viability and homeostasis. In the current review, we summarize recent advances in the understanding of the regulation and physiology of CMA with a specific focus on its possible roles in neuroprotection.
Collapse
Affiliation(s)
- Zhibiao Cai
- Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | | | | | | | | | | |
Collapse
|
25
|
Rubio-Villena C, Sanz P, Garcia-Gimeno MA. Structure-Function Analysis of PPP1R3D, a Protein Phosphatase 1 Targeting Subunit, Reveals a Binding Motif for 14-3-3 Proteins which Regulates its Glycogenic Properties. PLoS One 2015; 10:e0131476. [PMID: 26114292 PMCID: PMC4482762 DOI: 10.1371/journal.pone.0131476] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/01/2015] [Indexed: 01/20/2023] Open
Abstract
Protein phosphatase 1 (PP1) is one of the major protein phosphatases in eukaryotic cells. It plays a key role in regulating glycogen synthesis, by dephosphorylating crucial enzymes involved in glycogen homeostasis such as glycogen synthase (GS) and glycogen phosphorylase (GP). To play this role, PP1 binds to specific glycogen targeting subunits that, on one hand recognize the substrates to be dephosphorylated and on the other hand recruit PP1 to glycogen particles. In this work we have analyzed the functionality of the different protein binding domains of one of these glycogen targeting subunits, namely PPP1R3D (R6) and studied how binding properties of different domains affect its glycogenic properties. We have found that the PP1 binding domain of R6 comprises a conserved RVXF motif (R102VRF) located at the N-terminus of the protein. We have also identified a region located at the C-terminus of R6 (W267DNND) that is involved in binding to the PP1 glycogenic substrates. Our results indicate that although binding to PP1 and glycogenic substrates are independent processes, impairment of any of them results in lack of glycogenic activity of R6. In addition, we have characterized a novel site of regulation in R6 that is involved in binding to 14-3-3 proteins (RARS74LP). We present evidence indicating that when binding of R6 to 14-3-3 proteins is prevented, R6 displays hyper-glycogenic activity although is rapidly degraded by the lysosomal pathway. These results define binding to 14-3-3 proteins as an additional pathway in the control of the glycogenic properties of R6.
Collapse
Affiliation(s)
- Carla Rubio-Villena
- Instituto de Biomedicina de Valencia, CSIC, and Centro de Investigación en Red de Enfermedades Raras (CIBERER), Jaime Roig 11, Valencia, Spain
| | - Pascual Sanz
- Instituto de Biomedicina de Valencia, CSIC, and Centro de Investigación en Red de Enfermedades Raras (CIBERER), Jaime Roig 11, Valencia, Spain
- * E-mail:
| | - Maria Adelaida Garcia-Gimeno
- Instituto de Biomedicina de Valencia, CSIC, and Centro de Investigación en Red de Enfermedades Raras (CIBERER), Jaime Roig 11, Valencia, Spain
| |
Collapse
|
26
|
Yang Y, Ma Y, Chen X, Guo X, Yan B, Du A. Screening and analysis of Hc-ubq and Hc-gst related to desiccation survival of infective Haemonchus contortus larvae. Vet Parasitol 2015; 210:179-85. [DOI: 10.1016/j.vetpar.2015.03.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 03/18/2015] [Accepted: 03/22/2015] [Indexed: 01/18/2023]
|
27
|
Ye Y, Tan S, Zhou X, Li X, Jundt MC, Lichter N, Hidebrand A, Dhasarathy A, Wu M. Inhibition of p-IκBα Ubiquitylation by Autophagy-Related Gene 7 to Regulate Inflammatory Responses to Bacterial Infection. J Infect Dis 2015; 212:1816-26. [PMID: 26022442 DOI: 10.1093/infdis/jiv301] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/14/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Klebsiella pneumoniae causes serious infections and healthcare burdens in humans. We have previously reported that the deficiency of autophagy-related gene (Atg) 7 in macrophages (murine alveolar macrophage cell line [MH-S]) induced irregular host immunity against K. pneumoniae and worsened pathologic effects in the lung. In the current study, we investigated the molecular mechanism by which Atg7 influenced K. pneumoniae-induced inflammatory responses. METHODS Expression levels of Atg7, ubiquitin (Ub), and tumor necrosis factor (TNF) α and phosphorylation of IκBα (p-IκBα) were determined with immunoblotting. Ubiquitylation of p-IκBα was determined with immunoprecipitation. RESULTS We noted an interaction between Atg7 and p-IκBα, which was decreased in MH-S after K. pneumoniae infection, whereas the interaction between Ub and p-IκBα was increased. Knock-down of Atg7 with small interfering RNA increased p-IκBα ubiquitylation, promoted nuclear factor κB translocation into the nucleus, and increased the production of TNF-α. Moreover, knock-down of Ub with lentivirus-short hairpin RNA Ub particles decreased binding of p-IκBα to Ub and inhibited TNF-α expression in the primary alveolar macrophages and lung tissue of atg7-knockout mice on K. pneumoniae infection. CONCLUSIONS Loss of Atg7 switched binding of p-IκBα from Atg7 to Ub, resulting in increased ubiquitylation of p-IκBα and intensified inflammatory responses against K. pneumoniae. Our findings not only reveal a regulatory role of Atg7 in ubiquitylation of p-IκBα but also indicate potential therapeutic targets for K. pneumoniae control.
Collapse
Affiliation(s)
- Yan Ye
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks
| | - Shirui Tan
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks Laboratory of Biochemistry and Molecular Biology, School of Life Sciences, Yunnan University, Kunming
| | - Xikun Zhou
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
| | - Xuefeng Li
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China
| | - Michael C Jundt
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks
| | - Natalie Lichter
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks
| | - Alec Hidebrand
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks
| | - Archana Dhasarathy
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks
| | - Min Wu
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks
| |
Collapse
|
28
|
Abstract
The formal oxidation state of carbon atoms in organic molecules depends on the covalent structure. In proteins, the average oxidation state of carbon (Z(C)) can be calculated as an elemental ratio from the chemical formula. To investigate oxidation-reduction (redox) patterns, groups of proteins from different subcellular locations and phylogenetic groups were selected for comparison. Extracellular proteins of yeast have a relatively high oxidation state of carbon, corresponding with oxidizing conditions outside of the cell. However, an inverse relationship between Z(C) and redox potential occurs between the endoplasmic reticulum and cytoplasm. This trend provides support for the hypothesis that protein transport and turnover are ultimately coupled to the maintenance of different glutathione redox potentials in subcellular compartments. There are broad changes in Z(C) in whole-genome protein compositions in microbes from different environments, and in Rubisco homologues, lower Z(C) tends to occur in organisms with higher optimal growth temperature. Energetic costs calculated from thermodynamic models are consistent with the notion that thermophilic organisms exhibit molecular adaptation to not only high temperature but also the reducing nature of many hydrothermal fluids. Further characterization of the material requirements of protein metabolism in terms of the chemical conditions of cells and environments may help to reveal other linkages among biochemical processes with implications for changes on evolutionary time scales.
Collapse
Affiliation(s)
- Jeffrey M Dick
- Department of Chemistry, Curtin University, Perth, Western Australia, Australia Department of Applied Geology, Curtin University, Perth, Western Australia, Australia
| |
Collapse
|
29
|
Jung ES, Hong H, Kim C, Mook-Jung I. Acute ER stress regulates amyloid precursor protein processing through ubiquitin-dependent degradation. Sci Rep 2015; 5:8805. [PMID: 25740315 PMCID: PMC5390087 DOI: 10.1038/srep08805] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 02/05/2015] [Indexed: 12/15/2022] Open
Abstract
Beta-amyloid (Aβ), a major pathological hallmark of Alzheimer's disease (AD), is derived from amyloid precursor protein (APP) through sequential cleavage by β-secretase and γ-secretase enzymes. APP is an integral membrane protein, and plays a key role in the pathogenesis of AD; however, the biological function of APP is still unclear. The present study shows that APP is rapidly degraded by the ubiquitin-proteasome system (UPS) in the CHO cell line in response to endoplasmic reticulum (ER) stress, such as calcium ionophore, A23187, induced calcium influx. Increased levels of intracellular calcium by A23187 induces polyubiquitination of APP, causing its degradation. A23187-induced reduction of APP is prevented by the proteasome inhibitor MG132. Furthermore, an increase in levels of the endoplasmic reticulum-associated degradation (ERAD) marker, E3 ubiquitin ligase HRD1, proteasome activity, and decreased levels of the deubiquitinating enzyme USP25 were observed during ER stress. In addition, we found that APP interacts with USP25. These findings suggest that acute ER stress induces degradation of full-length APP via the ubiquitin-proteasome proteolytic pathway.
Collapse
Affiliation(s)
- Eun Sun Jung
- Department of Biochemistry &Biomedical Science, Seoul National University College of Medicine, Seoul, 110-799, Republic of Korea
| | - HyunSeok Hong
- Medifron DBT, Inc., Gyeongi, 425-838, Republic of Korea
| | - Chaeyoung Kim
- Department of Biochemistry &Biomedical Science, Seoul National University College of Medicine, Seoul, 110-799, Republic of Korea
| | - Inhee Mook-Jung
- Department of Biochemistry &Biomedical Science, Seoul National University College of Medicine, Seoul, 110-799, Republic of Korea
| |
Collapse
|
30
|
Choi SW, Song JK, Yim YS, Yun HG, Chun KH. Glucose deprivation triggers protein kinase C-dependent β-catenin proteasomal degradation. J Biol Chem 2015; 290:9863-73. [PMID: 25691573 PMCID: PMC4392283 DOI: 10.1074/jbc.m114.606756] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Indexed: 11/07/2022] Open
Abstract
Autophagy is a conserved process that contributes to cell homeostasis. It is well known that induction mainly occurs in response to nutrient starvation, such as starvation of amino acids and insulin, and its mechanisms have been extensively characterized. However, the mechanisms behind cellular glucose deprivation-induced autophagy are as of now poorly understood. In the present study, we determined a mechanism by which glucose deprivation induced the PKC-dependent proteasomal degradation of β-catenin, leading to autophagy. Glucose deprivation was shown to cause a sub-G1 transition and enhancement of the LC3-II protein levels, whereas β-catenin protein underwent degradation in a proteasome-dependent manner. Moreover, the inhibition of GSK3β was unable to abolish the glucose deprivation-mediated β-catenin degradation or up-regulation of LC3-II protein levels, which suggested GSK3β-independent protein degradation. Intriguingly, the inhibition of PKCα using a pharmacological inhibitor and transfection of siRNA for PKCα was observed to effectively block glucose deprivation-induced β-catenin degradation as well as the increase in LC3-II levels and the accumulation of a sub-G1 population. Together, our results demonstrated a molecular mechanism by which glucose deprivation can induce the GSK3β-independent protein degradation of β-catenin, leading to autophagy.
Collapse
Affiliation(s)
- Seung-Won Choi
- From the Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea and
| | - Jun-Kyu Song
- From the Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea and the Brain Korea 21 Plus Project for Medical Science, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Ye-Seal Yim
- From the Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea and the Brain Korea 21 Plus Project for Medical Science, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Ho-Geun Yun
- From the Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea and the Brain Korea 21 Plus Project for Medical Science, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Kyung-Hee Chun
- From the Department of Biochemistry and Molecular Biology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea and the Brain Korea 21 Plus Project for Medical Science, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| |
Collapse
|
31
|
GDF15 regulates Kv2.1-mediated outward K+ current through the Akt/mTOR signalling pathway in rat cerebellar granule cells. Biochem J 2014; 460:35-47. [PMID: 24597762 PMCID: PMC4000135 DOI: 10.1042/bj20140155] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
GDF15 (growth/differentiation factor 15), a novel member of the TGFβ (transforming growth factor β) superfamily, plays critical roles in the central and peripheral nervous systems, but the signal transduction pathways and receptor subtypes involved are not well understood. In the present paper, we report that GDF15 specifically increases the IK (delayed-rectifier outward K+ current) in rat CGNs (cerebellar granule neurons) in time- and concentration-dependent manners. The GDF15-induced amplification of the IK is mediated by the increased expression and reduced lysosome-dependent degradation of the Kv2.1 protein, the main α-subunit of the IK channel. Exposure of CGNs to GDF15 markedly induced the phosphorylation of ERK (extracellular-signal-regulated kinase), Akt and mTOR (mammalian target of rapamycin), but the GDF15-induced IK densities and increased expression of Kv2.1 were attenuated only by Akt and mTOR, and not ERK, inhibitors. Pharmacological inhibition of the Src-mediated phosphorylation of TGFβR2 (TGFβ receptor 2), not TGFβR1, abrogated the effect of GDF15 on IK amplification and Kv2.1 induction. Immunoprecipitation assays showed that GDF15 increased the tyrosine phosphorylation of TGFβRII in the CGN lysate. The results of the present study reveal a novel regulation of Kv2.1 by GDF15 mediated through the TGFβRII-activated Akt/mTOR pathway, which is a previously uncharacterized Smad-independent mechanism of GDF15 signalling.
Collapse
|
32
|
Ghislat G, Knecht E. Ca²⁺-sensor proteins in the autophagic and endocytic traffic. Curr Protein Pept Sci 2014; 14:97-110. [PMID: 23305313 PMCID: PMC3664516 DOI: 10.2174/13892037112139990033] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 09/19/2012] [Accepted: 11/28/2012] [Indexed: 12/21/2022]
Abstract
Autophagy and endocytosis are two evolutionarily conserved catabolic processes that comprise vesicle trafficking events for the clearance of the sequestered intracellular and extracellular cargo. Both start differently but end in the same compartment, the lysosome. Mounting evidences from the last years have established the involvement of proteins sensitive to intracellular Ca2+ in the control of the early autophagic steps and in the traffic of autophagic, endocytic and lysosomal vesicles. However, this knowledge is based on dispersed outcomes that do not set up a consensus model of the Ca2+-dependent control of autophagy and endocytosis. Here, we will provide a critical synopsis of insights from the last decade on the involvement of Ca2+-sensor proteins in the activation of autophagy and in fusion events of endocytic vesicles, autophagosomes and lysosomes.
Collapse
Affiliation(s)
- Ghita Ghislat
- Laboratorio de Biología Celular, Centro de Investigación Príncipe Felipe, C/ Eduardo Primo Yúfera 3, Valencia 46012, Spain and CIBERER, Valencia, Spain
| | | |
Collapse
|
33
|
PTEN increases autophagy and inhibits the ubiquitin-proteasome pathway in glioma cells independently of its lipid phosphatase activity. PLoS One 2013; 8:e83318. [PMID: 24349488 PMCID: PMC3862694 DOI: 10.1371/journal.pone.0083318] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 11/01/2013] [Indexed: 12/30/2022] Open
Abstract
Two major mechanisms of intracellular protein degradation, autophagy and the ubiquitin-proteasome pathway, operate in mammalian cells. PTEN, which is frequently mutated in glioblastomas, is a tumor suppressor gene that encodes a dual specificity phosphatase that antagonizes the phosphatidylinositol 3-kinase class I/AKT/mTOR pathway, which is a key regulator of autophagy. Here, we investigated in U87MG human glioma cells the role of PTEN in the regulation of autophagy and the ubiquitin-proteasome pathway, because both are functionally linked and are relevant in cancer progression. Since U87MG glioma cells lack a functional PTEN, we used stable clones that express, under the control of a tetracycline-inducible system (Tet-on), wild-type PTEN and two of its mutants, G129E-PTEN and C124S-PTEN, which, respectively, lack the lipid phosphatase activity only and both the lipid and the protein phosphatase activities of this protein. Expression of PTEN in U87MG glioma cells decreased proteasome activity and also reduced protein ubiquitination. On the contrary, expression of PTEN increased the autophagic flux and the lysosomal mass. Interestingly, and although PTEN negatively regulates the phosphatidylinositol 3-kinase class I/AKT/mTOR signaling pathway by its lipid phosphatase activity, both effects in U87MG cells were independent of this activity. These results suggest a new mTOR-independent signaling pathway by which PTEN can regulate in opposite directions the main mechanisms of intracellular protein degradation.
Collapse
|
34
|
Agholme L, Nath S, Domert J, Marcusson J, Kågedal K, Hallbeck M. Proteasome inhibition induces stress kinase dependent transport deficits--implications for Alzheimer's disease. Mol Cell Neurosci 2013; 58:29-39. [PMID: 24270002 DOI: 10.1016/j.mcn.2013.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/10/2013] [Accepted: 11/14/2013] [Indexed: 01/21/2023] Open
Abstract
Alzheimer's disease (AD) is characterized by accumulation of two misfolded and aggregated proteins, β-amyloid and hyperphosphorylated tau. Both cellular systems responsible for clearance of misfolded and aggregated proteins, the lysosomal and the proteasomal, have been shown to be malfunctioning in the aged brain and more so in patients with neurodegenerative diseases, including AD. This malfunction could be contributing to β-amyloid and tau accumulation, eventually aggregating in plaques and tangles. We have investigated the impact of decreased proteasome activity on tau phosphorylation as well as on microtubule stability and transport. To do this, we used our recently developed neuronal model where human SH-SY5Y cells obtain neuronal morphology and function through differentiation. We found that exposure to low doses of the proteasome inhibitor MG-115 caused tau phosphorylation, microtubule destabilization and disturbed neuritic transport. Furthermore, reduced proteasome activity activated several proteins implicated in tau phosphorylation and AD pathology, including c-Jun N-terminal kinase, c-Jun and extracellular signal-regulated protein kinase (ERK) 1/2. Restoration of the microtubule transport was achieved by inhibiting ERK 1/2 activation, and simultaneous inhibition of both ERK 1/2 and c-Jun reversed the proteasome inhibition-induced tau phosphorylation. Taken together, this study suggests that a decrease in proteasome activity can, through activation of c-Jun and ERK 1/2, result in several events related to neurodegenerative diseases. Restoration of proteasome activity or modulation of ERK 1/2 and c-Jun function can open new treatment possibilities against neurodegenerative diseases such as AD.
Collapse
Affiliation(s)
- Lotta Agholme
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Sangeeta Nath
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Jakob Domert
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Jan Marcusson
- Geriatric, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Katarina Kågedal
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Martin Hallbeck
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden; Department of Clinical Pathology, County Council of Östergötland, Linköping, Sweden.
| |
Collapse
|
35
|
Pooley NJ, Tacchi L, Secombes CJ, Martin SAM. Inflammatory responses in primary muscle cell cultures in Atlantic salmon (Salmo salar). BMC Genomics 2013; 14:747. [PMID: 24180744 PMCID: PMC3819742 DOI: 10.1186/1471-2164-14-747] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 10/26/2013] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The relationship between fish health and muscle growth is critical for continued expansion of the aquaculture industry. The effect of immune stimulation on the expression of genes related to the energy balance of fish is poorly understood. In mammals immune stimulation results in major transcriptional changes in muscle, potentially to allow a reallocation of amino acids for use in the immune response and energy homeostasis. The aim of this study was to investigate the effects of immune stimulation on fish muscle gene expression. RESULTS Atlantic salmon (Salmo salar) primary muscle cell cultures were stimulated with recombinant (r)IL-1β, a major proinflammatory cytokine, for 24 h in order to simulate an acute immune response. The transcriptomic response was determined by RNA hybridization to a 4 × 44 K Agilent Atlantic salmon microarray platform. The rIL-1β stimulation induced the expression of genes related to both the innate and adaptive immune systems. In addition there were highly significant changes in the expression of genes related to regulation of the cell cycle, growth/structural proteins, proteolysis and lipid metabolism. Of interest were a number of IGF binding proteins that were differentially expressed, which may demonstrate cross talk between the growth and immune systems. CONCLUSION We show rIL-1β modulates the expression of not only immune related genes, but also that of genes involved in processes related to growth and metabolism. Co-stimulation of muscle cells with both rIGF-I and rIL-1β demonstrates cross talk between these pathways providing potential avenues for further research. This study highlights the potential negative effects of inflammation on muscle protein deposition and growth in fish and extends our understanding of energy allocation in ectothermic animals.
Collapse
Affiliation(s)
- Nicholas J Pooley
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - Luca Tacchi
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
- Current address: Centre for Evolutionary and Theoretical Immunology, University of New Mexico, Albuquerque, NM 87131-0001, USA
| | - Christopher J Secombes
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - Samuel AM Martin
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| |
Collapse
|
36
|
Glucose induces autophagy under starvation conditions by a p38 MAPK-dependent pathway. Biochem J 2013; 449:497-506. [PMID: 23116132 DOI: 10.1042/bj20121122] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Autophagy is a natural process of 'self-eating' that occurs within cells and can be either pro-survival or can cause cell death. As a pro-survival mechanism, autophagy obtains energy by recycling cellular components such as macromolecules or organelles. In response to nutrient deprivation, e.g. depletion of amino acids or serum, autophagy is induced and most of these signals converge on the kinase mTOR (mammalian target of rapamycin). It is commonly accepted that glucose inhibits autophagy, since its deprivation from cells cultured in full medium induces autophagy by a mechanism involving AMPK (AMP-activated protein kinase), mTOR and Ulk1. However, we show in the present study that under starvation conditions addition of glucose produces the opposite effect. Specifically, the results of the present study demonstrate that the presence of glucose induces an increase in the levels of LC3 (microtubule-associated protein 1 light chain)-II, in the number and volume density of autophagic vacuoles and in protein degradation by autophagy. Addition of glucose also increases intracellular ATP, which is in turn necessary for the induction of autophagy because the glycolysis inhibitor oxamate inhibits it, and there is also a good correlation between LC3-II and ATP levels. Moreover, we also show that, surprisingly, the induction of autophagy by glucose is independent of AMPK and mTOR and mainly relies on p38 MAPK (mitogen-activated protein kinase).
Collapse
|
37
|
Vidal-Donet JM, Cárcel-Trullols J, Casanova B, Aguado C, Knecht E. Alterations in ROS activity and lysosomal pH account for distinct patterns of macroautophagy in LINCL and JNCL fibroblasts. PLoS One 2013; 8:e55526. [PMID: 23408996 PMCID: PMC3567113 DOI: 10.1371/journal.pone.0055526] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 12/27/2012] [Indexed: 12/21/2022] Open
Abstract
Neuronal ceroid lipofuscinoses (NCL) are lysosomal storage disorders characterized by the accumulation of lipofuscin within lysosomes. Late infantile (LINCL) and juvenile (JNCL) are their most common forms and are caused by loss-of-function mutations in tripeptidyl peptidase 1 (TPP1), a lysosomal endopeptidase, and CLN3 protein (CLN3p), whose location and function is still controversial. LINCL patients suffer more severely from NCL consequences than JNCL patients, in spite of having in common an abnormal accumulation of material with a similar composition in the lysosomes. To identify distinctive characteristics that could explain the differences in the severity of LINCL and JNCL pathologies, we compared the protein degradation mechanisms in patientś fibroblasts. Pulse-chase experiments show a significant decrease in protein degradation by macroautophagy in fibroblasts bearing TPP1 (CLN2) and CLN3p (CLN3) mutations. In CLN2 fibroblasts, LC3-II levels and other procedures indicate an impaired formation of autophagosomes, which confirms the pulse-chase experiments. This defect is linked to an accumulation of reactive oxygen species (ROS), an upregulation of the Akt-mTOR signalling pathway and increased activities of the p38α and ERK1/2 MAPKs. In CLN3 fibroblasts, LC3-II analysis indicates impairment in autophagosome maturation and there is also a defect in fluid phase endocytosis, two alterations that can be related to an observed increase of 0.5 units in lysosomal pH. CLN3 fibroblasts also accumulate ROS but to a lower extent than CLN2. TPP1 activity is completely abrogated in CLN2 and partially diminished in CLN3 fibroblasts. TPP1 cleaves small hydrophobic proteins like subunit c of mitochondrial ATP synthase and the lack or a lower activity of this enzyme can contribute to lipofuscin accumulation. These alterations in TPP1 activity lead to an increased ROS production, especially in CLN2 in which it is aggravated by a decrease in catalase activity. This could explain the earlier appearance of the symptoms in the LINCL form.
Collapse
Affiliation(s)
| | - Jaime Cárcel-Trullols
- Laboratory of Cellular Biology, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | | | - Carmen Aguado
- Laboratory of Cellular Biology, Centro de Investigación Príncipe Felipe, Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Erwin Knecht
- Laboratory of Cellular Biology, Centro de Investigación Príncipe Felipe, Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
- * E-mail:
| |
Collapse
|
38
|
Engelfriet PM, Jansen EHJM, Picavet HSJ, Dollé MET. Biochemical markers of aging for longitudinal studies in humans. Epidemiol Rev 2013; 35:132-51. [PMID: 23382477 PMCID: PMC4707878 DOI: 10.1093/epirev/mxs011] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/19/2013] [Indexed: 12/21/2022] Open
Abstract
Much progress has been made in the past decades in unraveling the mechanisms that are responsible for aging. The discovery that particular gene mutations in experimental species such as yeast, flies, and nematodes are associated with longevity has led to many important insights into pathways that regulate aging processes. However, extrapolating laboratory findings in experimental species to knowledge that is valid for the complexity of human physiology remains a major challenge. Apart from the restricted experimental possibilities, studying aging in humans is further complicated by the development of various age-related diseases. The availability of a set of biomarkers that really reflect underlying aging processes would be of much value in disentangling age-associated pathology from specific aging mechanisms. In this review, we survey the literature to identify promising biochemical markers of aging, with a particular focus on using them in longitudinal studies of aging in humans that entail repeated measurements on easily obtainable material, such as blood samples. Our search strategy was a 2-pronged approach, one focused on general mechanisms of aging and one including studies on clinical biomarkers of age-related diseases.
Collapse
Affiliation(s)
- Peter M. Engelfriet
- Correspondence to Dr. Peter M. Engelfriet, National Institute for Public Health and the Environment (RIVM), Centre for Prevention and Health Services Research, P.O. Box 1, 3720 BA Bilthoven, The Netherlands (e-mail: )
| | | | | | | |
Collapse
|
39
|
Montioli R, Oppici E, Cellini B, Roncador A, Dindo M, Voltattorni CB. S250F variant associated with aromatic amino acid decarboxylase deficiency: molecular defects and intracellular rescue by pyridoxine. Hum Mol Genet 2013; 22:1615-24. [PMID: 23321058 DOI: 10.1093/hmg/ddt011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Dopa or aromatic amino acid decarboxylase (DDC, AADC) is a pyridoxal 5'-phosphate-dependent enzyme that catalyses the production of the neurotransmitters dopamine and serotonin. Among the so far identified mutations associated with AADC deficiency, an inherited rare neurometabolic disease, the S250F mutation is the most frequent one. Here, for the first time, the molecular basis of the deficit of the S250F variant was investigated both in vitro and in cellular systems. Ser250 is not essential for the catalytic activity of the enzyme. However, its mutation to Phe causes a ~7-fold reduction of catalytic efficiency and a conformational change in the proximity of the mutated residue that is transmitted to the active site. In cellular extracts of E. coli and mammalian cells, both the specific activity and the protein level of the variant decrease with respect to the wild-type. The results with mammalian cells indicate that the mutation does not affect intracellular mRNA levels, and are consistent with a model where S250F undergoes a degradation process via the proteasome, possibly through an ubiquitination process occurring faster than in the wild-type. Overall, biochemical and cell biology experiments show that loss of function of S250F occurs by two distinct but not exclusive mechanisms affecting activity and folding. Importantly, 4-phenylbutirric acid (4-PBA) or, to a major extent, pyridoxine increase the expression level and, in a dose-dependent manner, the decarboxylase specific activity of mutant-expressing cells. This strongly suggests that 4-PBA and/or pyridoxine administration may be of important value in therapy of patients bearing the S250F mutation.
Collapse
Affiliation(s)
- Riccardo Montioli
- Department of Life Sciences and Reproduction, University of Verona, Verona, Italy
| | | | | | | | | | | |
Collapse
|
40
|
Aguilar-Melero P, Prieto-Álamo MJ, Jurado J, Holmgren A, Pueyo C. Proteomics in HepG2 hepatocarcinoma cells with stably silenced expression of PRDX1. J Proteomics 2012; 79:161-71. [PMID: 23277276 DOI: 10.1016/j.jprot.2012.12.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 11/12/2012] [Accepted: 12/08/2012] [Indexed: 12/13/2022]
Abstract
Peroxiredoxin 1 (PRDX1) is a member of the peroxiredoxin family. Aberrant expression of PRDX1 has been described in various cancers. We investigated the significance of this up-regulation in non-challenged hepatocellularcarcinoma (HCC) cells by establishing a HepG2 cell line stably expressing a Prdx1 shRNA. Prdx1 silencing reversed, at least partially, the tumoural phenotype of HepG2 cells, resulting in morphological changes, delayed cell growth, down-regulation of transcripts for AFP, osteopontin and β-catenin and decreased γ-glutamyl transpeptidase activity, and oppositely up-regulation of transcripts for E-cadherin and proapoptotic proteins (BAX, CASP3) and increased alkaline phosphatase and CASP3 activities. Proteomic profiling identified 16 spots differentially expressed in Prdx1-silenced cells. Most of the variations involved the down-regulation of proteins with pivotal roles in cell proliferation and differentiation, in agreement with the observed phenotypic changes. We also investigated the effect of Prdx1 silencing on thiol protein oxidation. Proteins prone to reversible cysteine oxidation play major physiological functions. Notably, the down-regulation and altered redox status of key enzymes of carbohydrate and amino acid metabolism suggested a disturbance of the Warburg effect and glutamine utilization, two major pathways in the proliferation of tumour cells. Overall, these observations suggest that PRDX1 acts as a pro-cancer protein in HCC HepG2 cells.
Collapse
Affiliation(s)
- Patricia Aguilar-Melero
- Department of Biochemistry and Molecular Biology, University of Córdoba, Campus de Rabanales, Edificio Severo Ochoa, planta 2(a)ª, Carretera Madrid-Cádiz Km 396-a, 14071-Córdoba, Spain
| | | | | | | | | |
Collapse
|
41
|
Abstract
Autophagy is a membrane trafficking pathway responsible for the breakdown of unwanted intracellular materials and crucial for the cell healthiness and survival. In the autophagic flux, various dynamic membrane rearrangements occurs starting with the elongation of the phagophore and its closure to build an autophagosome and ending with its fusion with late endosomes and lysosomes to form an autolysosome. Although Ca2+ is a well established regulator of membrane fusion events, little is known about its role in these processes during autophagy. Recent studies, based on proteomic analyses of lysosomal membranes, have provided new insights into this field of study. Thus, the levels on lysosomal membranes of annexin A1, annexin A5 and copine 1, three proteins that bind to phospholipid membranes in a Ca2+-dependent manner, increased under nutrient deprivation, a condition that promotes autophagic degradation. In addition, two different studies showed that annexin A5 and annexin A1 are involved in autophagosome maturation. Here, we discuss the molecular mechanisms by which the fusion of autophagosomes with endosomes and lysosomes could be regulated by these three proteins and Ca2+.
Collapse
Affiliation(s)
- Ghita Ghislat
- Laboratorio de Biología Celular; Centro de Investigación Príncipe; Valencia, Spain
| | | |
Collapse
|
42
|
Ghislat G, Patron M, Rizzuto R, Knecht E. Withdrawal of essential amino acids increases autophagy by a pathway involving Ca2+/calmodulin-dependent kinase kinase-β (CaMKK-β). J Biol Chem 2012; 287:38625-36. [PMID: 23027865 DOI: 10.1074/jbc.m112.365767] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Autophagy is the main lysosomal catabolic process that becomes activated under stress conditions, such as amino acid starvation and cytosolic Ca(2+) upload. However, the molecular details on how both conditions control autophagy are still not fully understood. Here we link essential amino acid starvation and Ca(2+) in a signaling pathway to activate autophagy. We show that withdrawal of essential amino acids leads to an increase in cytosolic Ca(2+), arising from both extracellular medium and intracellular stores, which induces the activation of adenosine monophosphate-activated protein kinase (AMPK) via Ca(2+)/calmodulin-dependent kinase kinase-β (CaMKK-β). Furthermore, we show that autophagy induced by amino acid starvation requires AMPK, as this induction is attenuated in its absence. Subsequently, AMPK activates UNC-51-like kinase (ULK1), a mammalian autophagy-initiating kinase, through phosphorylation at Ser-555 in a process that requires CaMKK-β. Finally, the mammalian target of rapamycin complex C1 (mTORC1), a negative regulator of autophagy downstream of AMPK, is inhibited by amino acid starvation in a Ca(2+)-sensitive manner, and CaMKK-β appears to be important for mTORC1 inactivation, especially in the absence of extracellular Ca(2+). All these results highlight that amino acid starvation regulates autophagy in part through an increase in cellular Ca(2+) that activates a CaMKK-β-AMPK pathway and inhibits mTORC1, which results in ULK1 stimulation.
Collapse
Affiliation(s)
- Ghita Ghislat
- Laboratorio de Biología Celular, Centro de Investigación Príncipe Felipe and CIBERER, C/Eduardo Primo Yúfera 3, 46012 Valencia, Spain
| | | | | | | |
Collapse
|
43
|
Fader CM, Aguilera MO, Colombo MI. ATP is released from autophagic vesicles to the extracellular space in a VAMP7-dependent manner. Autophagy 2012; 8:1741-56. [PMID: 22951367 DOI: 10.4161/auto.21858] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Autophagy is a normal degradative pathway that involves the sequestration of cytoplasmic components and organelles in a vacuole called autophagosome. SNAREs proteins are key molecules of the vesicle fusion machinery. Our results indicate that in a mammalian tumor cell line a subset of VAMP7 (V-SNARE)-positive vacuoles colocalize with LC3 at the cell periphery (focal adhesions) upon starvation. The re-distribution of VAMP7 positive structures is a microtubule-dependent event, with the participation of the motor protein KIF5 and the RAB7 effector RILP. Interestingly, most of the VAMP7-labeled vesicles were loaded with ATP. Moreover, in cells subjected to starvation, these structures fuse with the plasma membrane to release the nucleotide to the extracellular medium. Summarizing, our results show the molecular components involved in the release of ATP to extracellular space, which is recognized as an important autocrine/paracrine signal molecule that participates in the regulation of several cellular functions such as immunogenicity of cancer cell death or inflammation.
Collapse
Affiliation(s)
- Claudio Marcelo Fader
- Laboratorio de Biología Celular y Molecular-Instituto de Histología y Embriología (IHEM), Facultad de Ciencias Médicas, Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
| | | | | |
Collapse
|
44
|
Regulation of autophagy by glucose in Mammalian cells. Cells 2012; 1:372-95. [PMID: 24710481 PMCID: PMC3901114 DOI: 10.3390/cells1030372] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 06/22/2012] [Accepted: 07/13/2012] [Indexed: 02/07/2023] Open
Abstract
Autophagy is an evolutionarily conserved process that contributes to maintain cell homeostasis. Although it is strongly regulated by many extracellular factors, induction of autophagy is mainly produced by starvation of nutrients. In mammalian cells, the regulation of autophagy by amino acids, and also by the hormone insulin, has been extensively investigated, but knowledge about the effects of other autophagy regulators, including another nutrient, glucose, is more limited. Here we will focus on the signalling pathways by which environmental glucose directly, i.e., independently of insulin and glucagon, regulates autophagy in mammalian cells, but we will also briefly mention some data in yeast. Although glucose deprivation mainly induces autophagy via AMPK activation and the subsequent inhibition of mTORC1, we will also comment other signalling pathways, as well as evidences indicating that, under certain conditions, autophagy can be activated by glucose. A better understanding on how glucose regulates autophagy not only will expand our basic knowledge of this important cell process, but it will be also relevant to understand common human disorders, such as cancer and diabetes, in which glucose levels play an important role.
Collapse
|
45
|
The role of the ubiquitin-proteasome system in kidney diseases. Clin Exp Nephrol 2012; 16:507-17. [PMID: 22684356 DOI: 10.1007/s10157-012-0643-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 04/30/2012] [Indexed: 12/22/2022]
Abstract
Proteins in mammalian cells are continually being degraded and synthesized. Protein degradation via the ubiquitin-proteasome system (UPS) is the major pathway for non-lysosomal proteolysis of intracellular proteins and plays important roles in a variety of fundamental cellular processes such as regulation of cell cycle progression, differentiation, apoptosis, sodium channel function, and modulation of inflammatory responses. The central element of this system is the covalent linkage of ubiquitins to targeted proteins, which are then recognized by the 26S proteasome composed of adenosine triphosphate-dependent, multi-catalytic proteases. Damaged or misfolded proteins, as well as regulatory proteins that control many critical cellular functions, are among the targets of this degradation process. Consequently, aberration of the system leads to dysregulation of cellular homeostasis and development of many diseases. Based on the findings, it is not surprising that abnormalities of the system are also associated with the pathogenesis of kidney diseases. In this review, I discuss (1) the basic mechanism of the UPS, and (2) the association between the pathogenesis of kidney diseases and the UPS. Diverse roles of the UPS are implicated in the development of kidney diseases, and further studies on this system may reveal new strategies for overcoming kidney diseases.
Collapse
|
46
|
Ghislat G, Aguado C, Knecht E. Annexin A5 stimulates autophagy and inhibits endocytosis. J Cell Sci 2012; 125:92-107. [PMID: 22266906 DOI: 10.1242/jcs.086728] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Macroautophagy is a major lysosomal catabolic process activated particularly under starvation in eukaryotic cells. A new organelle, the autophagosome, engulfs cytoplasmic substrates, which are degraded after fusion with endosomes and/or lysosomes. During a shotgun proteome analysis of purified lysosomal membranes from mouse fibroblasts, a Ca(2+)-dependent phospholipid-binding protein, annexin A5, was found to increase on lysosomal membranes under starvation. This suggests a role for this protein, an abundant annexin with a still unknown intracellular function, in starvation-induced lysosomal degradation. Transient overexpression and silencing experiments showed that annexin A5 increased lysosomal protein degradation, and colocalisation experiments, based on GFP sensitivity to lysosomal acidic pH, indicated that this was mainly the result of inducing autophagosome-lysosome fusion. Annexin A5 also inhibited the endocytosis of a fluid-phase marker and cholera toxin, but not receptor-mediated endocytosis. Therefore, we propose a double and opposite role of annexin A5 in regulating the endocytic and autophagic pathways and the fusion of autophagosomes with lysosomes and endosomes.
Collapse
Affiliation(s)
- Ghita Ghislat
- Laboratorio de Biología Celular, Centro de Investigación Príncipe Felipe, Valencia, Spain
| | | | | |
Collapse
|
47
|
|
48
|
Esteve JM, Knecht E. Mechanisms of autophagy and apoptosis: Recent developments in breast cancer cells. World J Biol Chem 2011; 2:232-8. [PMID: 22031846 PMCID: PMC3202127 DOI: 10.4331/wjbc.v2.i10.232] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 09/26/2011] [Accepted: 10/03/2011] [Indexed: 02/05/2023] Open
Abstract
Autophagy, the pathway whereby cell components are degraded by lysosomes, is involved in the cell response to environmental stresses, such as nutrient deprivation, hypoxia or exposition to chemotherapeutic agents. Under these conditions, which are reminiscent of certain phases of tumor development, autophagy either promotes cell survival or induces cell death. This strengthens the possibility that autophagy could be an important target in cancer therapy, as has been proposed. Here, we describe the regulation of survival and death by autophagy and apoptosis, especially in cultured breast cancer cells. In particular, we discuss whether autophagy represents an apoptosis-independent process and/or if they share common pathways. We believe that understanding in detail the molecular mechanisms that underlie the relationships between autophagy and apoptosis in breast cancer cells could improve the available treatments for this disease.
Collapse
Affiliation(s)
- Juan M Esteve
- Juan M Esteve, Erwin Knecht, Laboratorio de Biología Celular, Centro de Investigación Príncipe Felipe, Avda. Autopista del Saler 16, 46012-Valencia, Spain and CIBERER, Valencia, Spain
| | | |
Collapse
|
49
|
The increased activity of liver lysosomal lipase in nonalcoholic Fatty liver disease contributes to the development of hepatic insulin resistance. Biochem Res Int 2011; 2012:135723. [PMID: 21904679 PMCID: PMC3163129 DOI: 10.1155/2012/135723] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 05/10/2011] [Accepted: 06/02/2011] [Indexed: 12/15/2022] Open
Abstract
We tested the hypothesis that TAG accumulation in the liver induced by short-term high-fat diet (HFD) in rats leads to the dysregulation of endogenous TAG degradation by lysosomal lipase (LIPA) via lysosomal pathway and is causally linked with the onset of hepatic insulin resistance. We found that LIPA could be translocated between qualitatively different depots (light and dense lysosomes). In contrast to dense lysosomal fraction, LIPA associated with light lysosomes exhibits high activity on both intracellular TAG and exogenous substrate and prandial- or diet-dependent regulation. On standard diet, LIPA activity was upregulated in fasted and downregulated in fed animals. In the HFD group, we demonstrated an increased TAG content, elevated LIPA activity, enhanced production of diacylglycerol, and the abolishment of prandial-dependent LIPA regulation in light lysosomal fraction. The impairment of insulin signalling and increased activation of PKCε was found in liver of HFD-fed animals. Lipolysis of intracellular TAG, mediated by LIPA, is increased in steatosis probably due to the enhanced formation of phagolysosomes. Consequent overproduction of diacylglycerol may represent the causal link between HFD-induced hepatic TAG accumulation and hepatic insulin resistance via PKCε activation.
Collapse
|
50
|
|