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Li Z, Yin X, Lyu C, Wang J, Liu K, Cui S, Ding S, Wang Y, Wang J, Guo D, Xu R. Zinc Oxide Nanoparticles Trigger Autophagy in the Human Multiple Myeloma Cell Line RPMI8226: an In Vitro Study. Biol Trace Elem Res 2024; 202:913-926. [PMID: 37432567 DOI: 10.1007/s12011-023-03737-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 06/18/2023] [Indexed: 07/12/2023]
Abstract
Multiple myeloma (MM) is a malignant clonal proliferative plasma cell tumor. Zinc oxide nanoparticles (ZnO NPs) are used for antibacterial and antitumor applications in the biomedical field. This study investigated the autophagy-induced effects of ZnO NPs on the MM cell line RPMI8226 and the underlying mechanism. After RPMI8226 cells were exposed to various concentrations of ZnO NPs, the cell survival rate, morphological changes, lactate dehydrogenase (LDH) levels, cell cycle arrest, and autophagic vacuoles were monitored. Moreover, we investigated the expression of Beclin 1 (Becn1), autophagy-related gene 5 (Atg5), and Atg12 at the mRNA and protein levels, as well as the level of light chain 3 (LC3). The results showed that ZnO NPs could effectively inhibit the proliferation and promote the death of RPMI8226 cells in vitro in a dose- and time-dependent manner. ZnO NPs increased LDH levels, enhanced monodansylcadaverine (MDC) fluorescence intensity, and induced cell cycle arrest at the G2/M phases in RPMI8226 cells. Moreover, ZnO NPs significantly increased the expression of Becn1, Atg5, and Atg12 at the mRNA and protein levels and stimulated the production of LC3. We further validated the results using the autophagy inhibitor 3-methyladenine (3‑MA). Overall, we observed that ZnO NPs can trigger autophagy signaling in RPMI8226 cells, which may be a potential therapeutic approach for MM.
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Affiliation(s)
- Zonghong Li
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, China
| | - Xuewei Yin
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, China
| | - Chunyi Lyu
- Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, China
| | - Jingyi Wang
- Department of Hematology, the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, No. 16369#, Jingshi Road, Jinan, 250014, Shandong Province, China
| | - Kui Liu
- Department of Hematology, the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, No. 16369#, Jingshi Road, Jinan, 250014, Shandong Province, China
| | - Siyuan Cui
- Department of Hematology, the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, No. 16369#, Jingshi Road, Jinan, 250014, Shandong Province, China
| | - Shumin Ding
- Department of Hematology, the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, No. 16369#, Jingshi Road, Jinan, 250014, Shandong Province, China
| | - Yingying Wang
- Department of Hematology, the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, No. 16369#, Jingshi Road, Jinan, 250014, Shandong Province, China
| | - Jinxin Wang
- Department of Hematology, the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, No. 16369#, Jingshi Road, Jinan, 250014, Shandong Province, China
| | - Dadong Guo
- Shandong Provincial Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular Diseases, Shandong Academy of Eye Disease Prevention and Therapy, Affiliated Eye Hospital of Shandong, University of Traditional Chinese Medicine, No. 48#, Yingxiongshan Road, Jinan, Shandong Province, China.
| | - Ruirong Xu
- Department of Hematology, the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, No. 16369#, Jingshi Road, Jinan, 250014, Shandong Province, China.
- Key Laboratory of Integrated Traditional Chinese and Western Medicine for Hematology, Health Commission of Shandong Province, Jinan, 250014, China.
- Institute of Hematology, Shandong University of Traditional Chinese Medicine, Jinan, 250014, China.
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2
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Tian L, Guo S, Zhao Z, Chen Y, Wang C, Li Q, Li Y. miR-30a-3p Regulates Autophagy in the Involution of Mice Mammary Glands. Int J Mol Sci 2023; 24:14352. [PMID: 37762652 PMCID: PMC10531886 DOI: 10.3390/ijms241814352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/17/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023] Open
Abstract
The mammary gland undergoes intensive remodeling during the lactation cycle, and the involution process of mammary gland contains extensive epithelial cells involved in the process of autophagy. Our studies of mice mammary glands suggest that miR-30a-3p expression was low during involution compared with its high expression in the mammary glands of lactating mice. Then, we revealed that miR-30a-3p negatively regulated autophagy by autophagy related 12 (Atg12) in mouse mammary gland epithelial cells (MMECs). Restoring ATG12, knocking down autophagy related 5 (Atg5), starvation, and Rapamycin were used to further confirm this conclusion. Overexpression of miR-30a-3p inhibited autophagy and altered mammary structure in the involution of the mammary glands of mice, which was indicative of alteration in mammary remodeling. Taken together, these results elucidated the molecular mechanisms of miR-30a-3p as a key induction mediator of autophagy by targeting Atg12 within the transition period between lactation and involution in mammary glands.
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Affiliation(s)
- Lei Tian
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (L.T.); (S.G.); (Z.Z.); (Y.C.)
| | - Shancheng Guo
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (L.T.); (S.G.); (Z.Z.); (Y.C.)
| | - Zhiye Zhao
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (L.T.); (S.G.); (Z.Z.); (Y.C.)
| | - Yuxu Chen
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (L.T.); (S.G.); (Z.Z.); (Y.C.)
| | - Chunmei Wang
- Key Laboratory of Dairy Science of Education Ministry, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China;
| | - Qingzhang Li
- Key Laboratory of Dairy Science of Education Ministry, College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China;
| | - Ye Li
- School of Medicine, Kunming University of Science and Technology, Kunming 650500, China
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3
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Sengupta S, Pick E. The Ubiquitin-like Proteins of Saccharomyces cerevisiae. Biomolecules 2023; 13:biom13050734. [PMID: 37238603 DOI: 10.3390/biom13050734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/18/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
In this review, we present a comprehensive list of the ubiquitin-like modifiers (Ubls) of Saccharomyces cerevisiae, a common model organism used to study fundamental cellular processes that are conserved in complex multicellular organisms, such as humans. Ubls are a family of proteins that share structural relationships with ubiquitin, and which modify target proteins and lipids. These modifiers are processed, activated and conjugated to substrates by cognate enzymatic cascades. The attachment of substrates to Ubls alters the various properties of these substrates, such as function, interaction with the environment or turnover, and accordingly regulate key cellular processes, including DNA damage, cell cycle progression, metabolism, stress response, cellular differentiation, and protein homeostasis. Thus, it is not surprising that Ubls serve as tools to study the underlying mechanism involved in cellular health. We summarize current knowledge on the activity and mechanism of action of the S. cerevisiae Rub1, Smt3, Atg8, Atg12, Urm1 and Hub1 modifiers, all of which are highly conserved in organisms from yeast to humans.
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Affiliation(s)
- Swarnab Sengupta
- Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa Mount Carmel, Haifa 3498838, Israel
| | - Elah Pick
- Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa Mount Carmel, Haifa 3498838, Israel
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Tivon 3600600, Israel
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Liu YL, Hsiao IH, Lin YH, Lin CL, Jan MS, Hung HC, Liu GY. Ornithine decarboxylase functions in both autophagy and apoptosis in response to ultraviolet B radiation injury. J Cell Physiol 2022; 237:2140-2154. [PMID: 35019151 DOI: 10.1002/jcp.30678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 12/17/2021] [Accepted: 12/22/2021] [Indexed: 12/11/2022]
Abstract
We present a mechanism for how ornithine decarboxylase (ODC) regulates the crosstalk between autophagy and apoptosis. In cancer cells, low-intensity ultraviolet B (UVBL ) induces autophagy while high-intensity UVB (UVBH ) induces apoptosis. Overexpression of ODC decreases UVBL -induced autophagy by inhibiting Atg5-Atg12 conjugation and suppressing the expression of autophagy markers LC3, Atg7, Atg12, and BECN1 proteins. In contrast, when ODC-overexpressing cells are exposed to UVBH radiation, the levels of LC3-II, Atg5-Atg12 conjugate, BECN1, Atg7, and Atg12 increase, while the apoptosis marker cleaved-PARP proteins decrease, indicating that ODC overexpression induced UVBH -induced autophagy but inhibited UVBH -induced cellular apoptosis. Additionally, when exposed to UVBH radiation, silencing BECN1, Atg5, and Atg12 genes results in a decrease in the level of LC3-II proteins but an increase in the level of cleaved-PARP proteins, and apoptotic bodies were significantly increased while autophagosomes were significantly decreased. These findings imply that ODC inhibits apoptosis in cells via the autophagy pathway. The role of Atg12 in ODC-overexpressing cells exposed to UVBH radiation is investigated using site-directed mutagenesis. Our results indicate that the Atg12-D111S mutant has increased cell survival. The Atg12-ΔG186 mutant impairs autophagy and enhances apoptosis. We demonstrate that when ODC-overexpressing cells are silenced for the Atg12 protein, autophagy and apoptosis are strongly affected, and ODC-induced autophagy protects against UVBH -induced apoptosis via the Atg12 protein.
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Affiliation(s)
- Yi-Liang Liu
- Department of Life Sciences, National Chung Hsing University (NCHU), Taichung, Taiwan.,Institute of Medicine, College of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - I-Hsin Hsiao
- Department of Life Sciences, National Chung Hsing University (NCHU), Taichung, Taiwan
| | - Yen-Hung Lin
- Department of Life Sciences, National Chung Hsing University (NCHU), Taichung, Taiwan.,Institute of Medicine, College of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Chih-Li Lin
- Institute of Medicine, College of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Ming-Shiou Jan
- Institute of Medicine, College of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Hui-Chih Hung
- Department of Life Sciences, National Chung Hsing University (NCHU), Taichung, Taiwan.,College of Life Sciences, Institute of Genomics and Bioinformatics, National Chung Hsing University (NCHU), Taichung, Taiwan.,iEGG and Animal Biotechnology Center, National Chung Hsing University (NCHU), Taichung, Taiwan
| | - Guang-Yaw Liu
- Institute of Medicine, College of Medicine, Chung Shan Medical University, Taichung, Taiwan.,Division of Allergy, Immunology, and Rheumatology, Chung Shan Medical University Hospital, Taichung, Taiwan
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Giordano F, Montalto FI, Panno ML, Andò S, De Amicis F. A Notch inhibitor plus Resveratrol induced blockade of autophagy drives glioblastoma cell death by promoting a switch to apoptosis. Am J Cancer Res 2021; 11:5933-5950. [PMID: 35018234 PMCID: PMC8727809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 10/23/2021] [Indexed: 06/14/2023] Open
Abstract
Glioblastoma multiforme (GBM) is the most common and aggressive form of brain tumors and the hardest type of cancer to treat. Therapies targeting developmental pathways, such as Notch, eliminate neoplastic glioma cells, but their efficacy can be limited by various mechanisms. Combination regimens may represent a good opportunity for effective therapies with durable effects. We used low doses of the γ-secretase inhibitor RO4929097 (GSI), to block the Notch pathway activity, in combination with Resveratrol (RSV) and we evidenced the mechanisms of autophagy/apoptosis transition in GBM cells. Resveratrol and GSI combination results in the synergistic induction of cell death together with the block of the autophagic flux evidenced by a sustained increase of LC3-II and p62 protein content, due to the dramatic reduction of CDK4, an important regulator of lysosomal function. The ectopic overexpression of the constitutive active CDK4 mutant, greatly counteracted the RSV+GSI induced block of the autophagy. Triggering autophagy in RSV+GSI-treated cells, which have impaired lysosomal function, caused the collapse of the system and a following apoptosis. For instance, by combining the CDK4 mutant as well as the early stage autophagy inhibitor, 3-methyladenina, abolished the RSV+GSI induced caspases activation. The initiator caspases (caspases-8 and -9), effector caspase (caspase-3) and its downstream substrate PARP were induced after RSV+GSI exposure as well as the percentage of the TUNEL positive cells. Moreover, the pro-apoptotic signaling MAPK p38 was activated while the pro-survival MAPK p42/p44 signaling was inhibited. In short, we establish the role of CDK4 in the regulation of autophagy/apoptosis transition induced by RSV and GSI in GBM cells. This new synergistic therapeutic combination, increasing the accumulation of autophagosomes, may have therapeutic value for GBM patients.
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Affiliation(s)
- Francesca Giordano
- Department of Pharmacy, Health and Nutritional Sciences, University of CalabriaItaly
| | - Francesca Ida Montalto
- Department of Pharmacy, Health and Nutritional Sciences, University of CalabriaItaly
- Health Center, University of CalabriaItaly
| | - Maria Luisa Panno
- Department of Pharmacy, Health and Nutritional Sciences, University of CalabriaItaly
| | - Sebastiano Andò
- Department of Pharmacy, Health and Nutritional Sciences, University of CalabriaItaly
- Health Center, University of CalabriaItaly
| | - Francesca De Amicis
- Department of Pharmacy, Health and Nutritional Sciences, University of CalabriaItaly
- Health Center, University of CalabriaItaly
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Xu X, Huang CY, Oka SI. LncRNA KCNQ1OT1 promotes Atg12-mediated autophagy via inhibiting miR-26a-5p in ischemia reperfusion. Int J Cardiol 2021; 339:132-3. [PMID: 34265311 DOI: 10.1016/j.ijcard.2021.07.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 07/07/2021] [Indexed: 11/22/2022]
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Okada T, Ogura T. Scanning Electron-Assisted Dielectric Microscopy Reveals Autophagosome Formation by LC3 and ATG12 in Cultured Mammalian Cells. Int J Mol Sci 2021; 22:ijms22041834. [PMID: 33673233 PMCID: PMC7917705 DOI: 10.3390/ijms22041834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 01/01/2023] Open
Abstract
Autophagy is an intracellular self-devouring system that plays a central role in cellular recycling. The formation of functional autophagosomes depends on several autophagy-related proteins, including the microtubule-associated proteins 1A/1B light chain 3 (LC3) and the conserved autophagy-related gene 12 (Atg12). We have recently developed a novel scanning electron-assisted dielectric microscope (SE-ADM) for nanoscale observations of intact cells. Here, we used the SE-ADM system to observe LC3- and Atg12-containing autophagosomes in cells labelled in the culture medium with antibodies conjugated to colloidal gold particles. We observed that, during autophagosome formation, Atg12 localized along the actin meshwork structure, whereas LC3 formed arcuate or circular alignments. Our system also showed a difference in the distribution of LC3 and Atg12; Atg12 was broadly distributed while LC3 was more localized. The difference in the spatial distribution demonstrated by our system explains the difference in the size of fluorescent spots due to the fluorescently labelled antibodies observed using optical microscopy. The direct SE-ADM observation of cells should thus be effective in analyses of autophagosome formation.
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Zhang H, Li S, Xu H, Sun L, Zhu Z, Yao Z. Interference of miR-107 with Atg12 is inhibited by HULC to promote metastasis of hepatocellular carcinoma. MedComm (Beijing) 2020; 1:165-177. [PMID: 34766115 PMCID: PMC8491224 DOI: 10.1002/mco2.25] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 01/13/2023] Open
Abstract
Highly upregulated in liver cancer (HULC) had a significant predictive effect on tumor growth and metastasis of hepatocellular carcinoma (HCC); however, the mechanisms of HULC on HCC still need to be clarified. We attempted to determine the roles of HULC and miR-107 in autophagy and invasion of HCC. HULC siRNA reduced the level of autophagy. The impact of HULC siRNA on invasion can be reversed by activating autophagy in HCC cell lines. Further studies on HULC and autophagy were conducted. An interacting sequence between HULC and miR-107, as well as miR-107 and Atg12, was predicted by software. The relationship of each pair of molecules was confirmed by luciferase reporter assays. The negative impacts of miR-107 on autophagy and invasion were proved in HCC cell lines. The inhibitor of miR-107-promoted invasion can also be reversed by Atg12 siRNA. The changes of miR-107, Atg12, epithelial-mesenchymal transition, and autophagy in transplanted tumors of mouse models also confirmed the results in HCC cell lines. Finally, we find that HULC acts as an endogenous sponge, which abolishes the binding of miR-107 on the Atg12 3'-UTR and promotes autophagy and metastasis of HCC.
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Affiliation(s)
- Haiming Zhang
- Liver Transplantation CenterNational Clinical Research Center for Digestive Diseases and Beijing Key Laboratory of Tolerance Induction and Organ Protection in TransplantationBeijing Friendship HospitalCapital Medical UniversityBeijingChina
| | - Shipeng Li
- Department of General SurgeryJiaozuo People's HospitalXinxiang Medical UniversityJiaozuoChina
| | - Haixu Xu
- Department of ImmunologyTianjin Key Laboratory of Cellular and Molecular ImmunologyTianjin Medical UniversityTianjinChina
| | - Liying Sun
- Liver Transplantation CenterNational Clinical Research Center for Digestive Diseases and Beijing Key Laboratory of Tolerance Induction and Organ Protection in TransplantationBeijing Friendship HospitalCapital Medical UniversityBeijingChina
| | - Zhijun Zhu
- Liver Transplantation CenterNational Clinical Research Center for Digestive Diseases and Beijing Key Laboratory of Tolerance Induction and Organ Protection in TransplantationBeijing Friendship HospitalCapital Medical UniversityBeijingChina
| | - Zhi Yao
- Department of ImmunologyTianjin Key Laboratory of Cellular and Molecular ImmunologyTianjin Medical UniversityTianjinChina
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Nie Y, Liang X, Liu S, Guo F, Fang N, Zhou F. WASF3 Knockdown Sensitizes Gastric Cancer Cells to Oxaliplatin by Inhibiting ATG12-Mediated Autophagy. Am J Med Sci 2020; 359:287-295. [PMID: 32359534 DOI: 10.1016/j.amjms.2020.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/23/2020] [Accepted: 02/26/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Gastric cancer is one of the most aggressive tumors, usually resulting in metastasis, and therapies for advanced gastric cancer remain limited. Drug resistance is the main reason for chemotherapeutic failure in gastric cancer. Wiskott-Aldrich syndrome protein family member 3 (WASF3) is required for invasion and metastasis of different cancers. However, there has been little study of WASF3 expression involvement in gastric cancer. In this study, we explored the role of WASF3 in the sensitivity of gastric cancer to oxaliplatin, and the underlying mechanisms. METHODS We silenced WASF3 using WASF3-siRNA in MGC803 cells. Then, CCK-8, flow cytometry and transwell assay were performed to study the effect of WASF3 silencing on proliferation, migration, invasiveness and apoptosis of MGC803 cells. Moreover, we evaluated the potential mechanism in vitro to determine the sensitization to oxaliplatin induced by WASF3. RESULTS WASF3 silencing by small interfering RNA inhibited the proliferation, migration and invasiveness of gastric cancer cells. We also observed that WASF3 knockdown promoted cell apoptosis and enhanced oxaliplatin sensitivity. Furthermore, the sensitization to oxaliplatin induced by WASF3 knockdown depended on the inhibition of Atg12-mediated autophagy. CONCLUSIONS Our analysis demonstrates WASF3 targeting is a new potential therapeutic strategy for gastric cancer.
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Affiliation(s)
- Yanli Nie
- Department of Radiation Oncology and Medical Oncology, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Hubei Key Laboratory of Tumor Biological Behaviors, Wuhan, China; Department of Gastrointestinal Medical Oncology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xinjun Liang
- Department of Gastrointestinal Medical Oncology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sanhe Liu
- Department of Gastrointestinal Medical Oncology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fang Guo
- Department of Pathology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Na Fang
- Department of Pathology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fuxiang Zhou
- Department of Radiation Oncology and Medical Oncology, Zhongnan Hospital of Wuhan University, Hubei Cancer Clinical Study Center, Hubei Key Laboratory of Tumor Biological Behaviors, Wuhan, China.
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Zhao J, Chen F, Ma W, Zhang P. Suppression of long noncoding RNA NEAT1 attenuates hypoxia-induced cardiomyocytes injury by targeting miR-378a-3p. Gene 2020; 731:144324. [PMID: 31904498 DOI: 10.1016/j.gene.2019.144324] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 12/22/2019] [Accepted: 12/30/2019] [Indexed: 01/23/2023]
Abstract
BACKGROUND/AIMS lncRNA NEAT1 is involved in the development of many diseases. However, the function of lncRNA NEAT1 in myocardial infarction is unclear. Therefore, this experimental design based on lncRNA NEAT1 to explore the pathogenesis of myocardial infarction. METHODS RT-qPCR was used to detect the expression of lncRNA NEAT1 and miR-378a-3p in peripheral blood and mouse cardiomyocytes of patients with myocardial infarction. MTT assay, flow cytometry, Caspase-3 kit and transwell assay were used to detect the effects of lncRNA NEAT1 and miR-378a-3p on cardiomyocyte proliferation, apoptosis and migration. Target gene prediction and screening, luciferase reporter assays were used to verify downstream target genes for lncRNA NEAT1 and miR-378a-3p. Western blotting was used to detect the protein expression of Atg12 and related autophagy genes. RESULTS lncRNA NEAT1 was highly expressed in peripheral blood and mouse cardiomyocytes of patients with myocardial infarction. Moreover, lncRNA NEAT1 significantly promoted cell proliferation and migration of cardiomyocytes. In addition, lncRNA NEAT1 inhibited miR-378a-3p expression, and miR-378a-3p inhibited Atg12 expression, while lncRNA NEAT1 regulated expression of Atg12 and related autophagic factors via miR-378a-3p. Knockout of microRNA-378-3p reversed the effects of NEAT1 silencing on cell damage. CONCLUSION lncRNA NEAT1 can regulate the proliferation of cardiomyocytes by regulating miR-378-3p/Atg12 axis, thus accelerating the occurrence and development of cardiomyocytes.
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Affiliation(s)
- Jiali Zhao
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan City, Shandong Province 250021, PR China
| | - Fudi Chen
- Department of Emergency, Shandong Provincial Hospital Affiliated to Shandong University, Jinan City, Shandong Province 250021, PR China.
| | - Wei Ma
- Department of Emergency, Shandong Provincial Hospital Affiliated to Shandong University, Jinan City, Shandong Province 250021, PR China
| | - Peng Zhang
- Department of Critical Care Medicine, Shandong Provincial Hospital Affiliated to Shandong University, Jinan City, Shandong Province 250021, PR China
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Li C, Yu Y, Zhang X, Wei J, Qin Q. Grouper Atg12 negatively regulates the antiviral immune response against Singapore grouper iridovirus (SGIV) infection. Fish Shellfish Immunol 2019; 93:702-710. [PMID: 31421242 DOI: 10.1016/j.fsi.2019.08.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
Autophagy is an evolutionarily conserved, multi-step lysosomal degradation process used to maintain cell survival and homeostasis. A series of autophagy-related genes (Atgs) are involved in the autophagic pathway. In mammals, a growing number of studies have attributed functions to some Atgs that are distinct from their classical role in autophagosome biogenesis, such as resistance to pathogens. However, little is known about the functions of fish Atgs. In this study, we cloned and characterized an atg12 homolog from orange spotted grouper (Epinephelus coioides) (Ecatg12). Ecatg12 encodes a 117 amino acid protein that shares 94.0% and 76.8% identity with gourami (Anabas_testudineus) and humans (Homo sapiens), respectively. The transcription level of Ecatg12 was lower in cells infected with Singapore grouper iridovirus (SGIV) than in non-infected cells. Fluorescence microscopy revealed that EcAtg12 localized in the cytoplasm and nucleus in grouper spleen cells. Overexpression of EcAtg12 significantly increased the replication of SGIV, as evidenced by increased severity of the cytopathic effect, transcription levels of viral genes, levels of viral proteins, and progeny virus yield. Further studies showed that EcAtg12 overexpression decreased the expression levels of interferon (IFN) related molecules and pro-inflammatory factors and inhibited the promoter activity of IFN-3, interferon-stimulated response element, and nuclear factor-κB. Together, these results demonstrate that EcAtg12 plays crucial roles in SGIV replication by downregulating antiviral immune responses.
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Affiliation(s)
- Chen Li
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Yepin Yu
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Xin Zhang
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China
| | - Jingguang Wei
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China; Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, 510642, PR China.
| | - Qiwei Qin
- Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, PR China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266000, PR China.
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Fultz R, Engevik MA, Shi Z, Hall A, Herrmann B, Ganesh BP, Major A, Haag A, Mori-Akiyama Y, Versalovic J. Phagocytosis by macrophages depends on histamine H2 receptor signaling and scavenger receptor 1. Microbiologyopen 2019; 8:e908. [PMID: 31369218 PMCID: PMC6813435 DOI: 10.1002/mbo3.908] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/19/2019] [Accepted: 06/30/2019] [Indexed: 12/11/2022] Open
Abstract
The histamine H2 receptor (H2R) is a G protein‐coupled receptor that mediates cyclic AMP production, protein kinase A activation, and MAP kinase signaling. In order to explore the multifaceted effects of histamine signaling on immune cells, phagocytosis was evaluated using primary mouse‐derived macrophages. Phagocytosis is initiated by signaling via surface‐bound scavenger receptors and can be regulated by autophagy. Absence of H2R signaling resulted in diminished phagocytosis of live bacteria and synthetic microspheres by primary macrophages from histamine H2 receptor gene (Hrh2)‐deficient mice. Flow cytometry and immunofluorescence microscopy were used to quantify phagocytosis of phylogenetically diverse bacteria as well as microspheres of defined chemical composition. Autophagy and scavenger receptor gene expression were quantified in macrophages after exposure to Escherichia coli. Expression of the autophagy genes, Becn1 and Atg12, was increased in Hrh2−/− macrophages, indicating upregulation of autophagy pathways. Expression of the Macrophage Scavenger Receptor 1 gene (Msr1) was diminished in Hrh2‐deficient macrophages, supporting the possible importance of histamine signaling in scavenger receptor abundance and macrophage function. Flow cytometry confirmed diminished MSR1 surface abundance in Hrh2−/− macrophages. These data suggest that H2R signaling is required for effective phagocytosis by regulating the process of autophagy and scavenger receptor MSR1 abundance in macrophages.
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Affiliation(s)
- Robert Fultz
- Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Integrative Program in Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Melinda A Engevik
- Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
| | - Zhongcheng Shi
- Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
| | - Anne Hall
- Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Molecular Virology & Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Beatrice Herrmann
- Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, PA, USA
| | - Bhanu P Ganesh
- Department of Neurology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Angela Major
- Department of Pathology, Texas Children's Hospital, Houston, TX, USA
| | - Anthony Haag
- Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
| | - Yuko Mori-Akiyama
- Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
| | - James Versalovic
- Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX, USA
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Huang S, Lin Y, Liang Z, Wu Z, Chen Y, Chen C. Erythropoietin helix B surface peptide modulates miR-21/ Atg12 axis to alleviates cardiomyocyte hypoxia-reoxygenation injury. Am J Transl Res 2019; 11:2422-2430. [PMID: 31105848 PMCID: PMC6511769 DOI: pmid/31105848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 03/25/2019] [Indexed: 02/05/2023]
Abstract
BACKGROUND The erythropoietin helix B surface peptide (HBSP) has been shown to have neuroprotective and repair-damaging myocardium effects similar to erythropoietin (EPO). However, the protective mechanism of HBSP on cardiomyocyte hypoxia-reoxygenation (H/R) injury is not clear. METHODS H9C2 cells were pretreated with HBSP and subjected to hypoxia/reoxygenation (H/R), changes in cell function, autophagy and apoptosis were assessed, respectively. Cells were transfected with miR-21 mimic and miR-NC, and the relative expression of miR-21 and Atg12 were detected by qRT-PCR. The target role of miR-21 and Atg12 was evaluated by dual-luciferase reporter. After transfected with si-Atg12 and si-NC, western blot was used to assess autophagy and apoptosis proteins, flow cytometry assay was used to detect apoptosis rate. RESULTS We found the expression of miR-21 was significantly down-regulated, accompanied by remarkably activated of autophagy and apoptosis in H9C2 cells during H/R injury. Pleasantly, HBSP pretreatment has a similar effect as transfection of miR-21 mimic, which is to evidently inhibit autophagy and apoptosis by up-regulating miR-21 expression. Moreover, Bioinformatics analysis and luciferase reporter assay revealed that Atg12 was directly bond to miR-21. To further understand whether Atg12 is involved in the process of miR-21 regulating autophagy, si-Atg12 and si-NC were transfected into H9C2 cell, the results showed that knockdown of Atg12 enhances the inhibition autophagy and apoptosis effect of HBSP. CONCLUSION These results demonstrate that HBSP inhibits myocardial H/R injury induced by autophagy over-activation and apoptosis via miR-21/Atg12 axis.
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Affiliation(s)
- Song Huang
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical CollegeShantou 515041, Guangdong, China
| | - Yongluan Lin
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical CollegeShantou 515041, Guangdong, China
| | - Zhanbo Liang
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical CollegeShantou 515041, Guangdong, China
| | - Zhuomin Wu
- Department of Pharmacy, The First Affiliated Hospital of Shantou University Medical CollegeShantou 515041, Guangdong, China
| | - Yequn Chen
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical CollegeShantou 515041, Guangdong, China
| | - Chang Chen
- Department of Cardiology, The First Affiliated Hospital of Shantou University Medical CollegeShantou 515041, Guangdong, China
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Murrow L, Debnath J. Atg12-Atg3 Coordinates Basal Autophagy, Endolysosomal Trafficking, and Exosome Release. Mol Cell Oncol 2018; 5:e1039191. [PMID: 30263931 PMCID: PMC6154856 DOI: 10.1080/23723556.2015.1039191] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 04/04/2015] [Accepted: 04/06/2015] [Indexed: 12/21/2022]
Abstract
We recently identified an interaction between Atg12-Atg3, a complex between 2 core autophagy regulators, and the ESCRT-associated protein Pdcd6ip (programmed cell death 6 interacting protein, commonly known as Alix), which coordinately regulates basal autophagy, late endosome-to-lysosome trafficking, and exosome release. Because these processes all serve fundamental roles in cancer progression and therapy, Atg12-Atg3 may be an attractive anticancer target.
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Affiliation(s)
- Lyndsay Murrow
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center; University of California San Francisco, San Francisco, California 94143 USA
- Present address: Pharmaceutical Chemistry and Center for Systems and Synthetic Biology; University of California, San Francisco, California 94143 USA
| | - Jayanta Debnath
- Department of Pathology and Helen Diller Family Comprehensive Cancer Center; University of California San Francisco, San Francisco, California 94143 USA
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15
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Abstract
Selective macroautophagy/autophagy mediates the selective delivery of cytoplasmic cargo material via autophagosomes into the lytic compartment for degradation. This selectivity is mediated by cargo receptor molecules that link the cargo to the phagophore (the precursor of the autophagosome) membrane via their simultaneous interaction with the cargo and Atg8 proteins on the membrane. Atg8 proteins are attached to membrane in a conjugation reaction and the cargo receptors bind them via short peptide motifs called Atg8-interacting motifs/LC3-interacting regions (AIMs/LIRs). We have recently shown for the yeast Atg19 cargo receptor that the AIM/LIR motifs also serve to recruit the Atg12-Atg5-Atg16 complex, which stimulates Atg8 conjugation, to the cargo. We could further show in a reconstituted system that the recruitment of the Atg12-Atg5-Atg16 complex is sufficient for cargo-directed Atg8 conjugation. Our results suggest that AIM/LIR motifs could have more general roles in autophagy.
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Affiliation(s)
- Dorotea Fracchiolla
- a Department of Biochemistry and Cell Biology , Max F. Perutz Laboratories (MFPL), University of Vienna, Vienna Biocenter (VBC) , Vienna , Austria
| | - Justyna Sawa-Makarska
- a Department of Biochemistry and Cell Biology , Max F. Perutz Laboratories (MFPL), University of Vienna, Vienna Biocenter (VBC) , Vienna , Austria
| | - Sascha Martens
- a Department of Biochemistry and Cell Biology , Max F. Perutz Laboratories (MFPL), University of Vienna, Vienna Biocenter (VBC) , Vienna , Austria
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Abstract
Macroautophagy is a physiological process that is implicated in various pathological conditions, including neurodegenerative diseases and cancer. The execution of canonical autophagy is regulated by a core signaling cascade and it involves two well-characterized, ubiquitin-like conjugation systems-the Atg5/Atg12/Atg16L1 and the Atg8-phosphatidyl ethanolamine (PE), which are both catalyzed by Atg7. The conjugation of Atg5-Atg12 and the subsequent interaction with the positive regulator Atg16L1 are essential for the conjugation of Atg8 to PE and the subsequent formation of autophagosomes. The interaction between Atg5-Atg12 complex and Atg16L1 is highly dynamic, induced upon activation of the autophagic process, and required for the recruitment of the At5-Atg12 complex to sites of autophagosome formation. Monitoring the Atg5-Atg12-Atg16L1 aggregation and deaggregation may be used not only as means to study the dynamics of autophagy, but in another important point, it may provide important insights on the basic molecular mechanisms of autophagy in physiological and pathological settings. In this chapter, we describe methods of monitoring the Atg5-Atg12-Atg16L1 aggregation and deaggregation, with emphasis on prostate cancer.
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Affiliation(s)
- P Kharaziha
- Cancer Centrum Karolinska, Karolinska Institutet and University Hospital, Stockholm, Sweden
| | - T Panaretakis
- Cancer Centrum Karolinska, Karolinska Institutet and University Hospital, Stockholm, Sweden.
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Zhang Y, Li Q, Liu C, Gao S, Ping H, Wang J, Wang P. MiR-214-3p attenuates cognition defects via the inhibition of autophagy in SAMP8 mouse model of sporadic Alzheimer's disease. Neurotoxicology 2016; 56:139-149. [PMID: 27397902 DOI: 10.1016/j.neuro.2016.07.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 05/28/2016] [Accepted: 07/06/2016] [Indexed: 11/30/2022]
Abstract
The autophagy process is the major cellular degradation pathway for long-lived proteins and organelles. Dysfunction of autophagy may lead to several neurodegenerative disorders. However, the regulation and function of autophagy in sporadic Alzheimer's disease (SAD) remain unclear. In this study, we established SAMP8 mouse as a suitable SAD model and performed microarray profiling to identify miR-214-3p as a SAD associated microRNA that was downregulated in hippocampal neurons of SAMP8 mice upon the induction of autophagy. Furthermore, decreased miR-214-3p level was detected in cerebrospinal fluid from SAD patients. Overexpression of miR-214-3p in primary neurons from SAMP8 mice inhibited autophagy, demonstrated by decreased levels of LC3βII and Beclin1, and reduced number of GFP-LC3-positive autophagosome vesicles, and led to increased viability and decreased caspase-mediated apoptosis. Conversely, antagomiR-214-3p promoted autophagy and apoptosis in neurons from SAMP8 mice. Mechanistically, miR-214-3p negatively regulated Atg12 expression by targeting the 3'-untranslated region of Atg12. Treatment of SAMP8 mice with miR-214-3p attenuated neuronal apoptosis and improved behavioral performance. Taken together, these results suggest that miR-214-3p suppresses autophagy and alleviates hippocampal neuron apoptosis, which indicates that miR-214-3p represents a new potential neuroprotective factor for SAD.
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Affiliation(s)
- Yueqi Zhang
- Department of Neurology of Weifang People's Hospital, Weifang 261041, Shandong, PR China
| | - Qiliang Li
- Department of Medical Laboratory of Beijing Children's Hospital, Capital Medical University, Beijing 100053, PR China
| | - Chengeng Liu
- Clinical Laboratory of Xuanwu Hospital, Capital Medical University, Beijing 100053, PR China
| | - Shichao Gao
- Clinical Laboratory of Xuanwu Hospital, Capital Medical University, Beijing 100053, PR China
| | - Hong Ping
- Clinical Laboratory of Xuanwu Hospital, Capital Medical University, Beijing 100053, PR China
| | - Jinling Wang
- Clinical Laboratory of Xuanwu Hospital, Capital Medical University, Beijing 100053, PR China
| | - Peichang Wang
- Clinical Laboratory of Xuanwu Hospital, Capital Medical University, Beijing 100053, PR China.
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Abstract
Atg8 lipidation can be efficiently reconstituted in vitro. Lipidation and de-lipidation of Atg8 by Atg4 can be analyzed. Reconstitution of Atg8-lipidation using giant unilamellar vesicles offers spatial insights. These assays allow determining the effect of modifications on Atg8 lipidation/de-lipidation.
Macroautophagy is a major bulk degradation pathway for cytoplasmic material in eukaryotic cells. During macroautophagy, double membrane-bound organelles called autophagosomes are formed in a de novo manner. In the course of their formation autophagosomes capture cytoplasmic material, which is subsequently degraded upon fusion with the lysosomal system in complex eukaryotes or the vacuole in yeast. Several proteins are required for autophagosome formation. Among these are the components of two ubiquitin-like conjugation reactions that collectively mediate the conjugation of the ubiquitin-like Atg12 to the Atg5 protein and of the ubiquitin-like protein Atg8 to the headgroup of the membrane lipid phosphatidylethanolamine. The lipidated form of Atg8 is membrane-bound and marks the growing autophagosomal membrane as well as the completed autophagosome. Here we describe assays for the in vitro reconstitution of the Atg8 lipidation reaction using recombinantly expressed and purified proteins derived from Saccharomycescerevisiae in combination with small and giant unilamellar vesicles. The assays enable the study of the biochemical mechanisms of action of the Atg8 lipidation machinery and to analyze the impact of mutations and post-translational modifications of the conjugation machinery on Atg8 lipidation.
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Affiliation(s)
- Bettina Zens
- Max F. Perutz Laboratories, University of Vienna, Dr. Bohr-Gasse 9/3, 1030 Vienna, Austria
| | - Justyna Sawa-Makarska
- Max F. Perutz Laboratories, University of Vienna, Dr. Bohr-Gasse 9/3, 1030 Vienna, Austria
| | - Sascha Martens
- Max F. Perutz Laboratories, University of Vienna, Dr. Bohr-Gasse 9/3, 1030 Vienna, Austria.
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19
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Nowag H, Guhl B, Thriene K, Romao S, Ziegler U, Dengjel J, Münz C. Macroautophagy Proteins Assist Epstein Barr Virus Production and Get Incorporated Into the Virus Particles. EBioMedicine 2014; 1:116-25. [PMID: 26137519 PMCID: PMC4457436 DOI: 10.1016/j.ebiom.2014.11.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 11/04/2014] [Accepted: 11/06/2014] [Indexed: 01/16/2023] Open
Abstract
Epstein Barr virus (EBV) persists as a latent herpes virus infection in the majority of the adult human population. The virus can reactivate from this latent infection into lytic replication for virus particle production. Here, we report that autophagic membranes, which engulf cytoplasmic constituents during macroautophagy and transport them to lysosomal degradation, are stabilized by lytic EBV replication in infected epithelial and B cells. Inhibition of autophagic membrane formation compromises infectious particle production and leads to the accumulation of viral DNA in the cytosol. Vice versa, pharmacological stimulation of autophagic membrane formation enhances infectious virus production. Atg8/LC3, an essential macroautophagy protein and substrate anchor on autophagic membranes, was found in virus preparations, suggesting that EBV recruits Atg8/LC3 coupled membranes to its envelope in the cytosol. Our data indicate that EBV subverts macroautophagy and uses autophagic membranes for efficient envelope acquisition during lytic infection. Macroautophagic membranes are stabilized during lytic EBV replication. Inhibition of macroautophagic membrane formation reduces EBV production. Stimulation of macroautophagic membrane formation boosts EBV production. Without macroautophagic membranes EBV DNA accumulates in the cytosol. Macroautophagic membranes get incorporated into EBV particles.
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Key Words
- Atg, autophagy related gene
- Atg12
- Atg16
- Atg8/LC3
- B cell
- BALF1, BamH1 A fragment leftward reading frame 1
- BALF4, BamH1 A fragment leftward reading frame 4
- BHRF1, BamH1 H fragment rightward reading frame 1
- BMRF1, BamH1 M fragment rightward reading frame 1
- BNRF1, BamH1 N fragment rightward reading frame 1
- BRLF1, BamH1 R fragment leftward reading frame 1
- BZLF1
- BZLF1, BamH1 Z fragment leftward reading frame 1
- EBNA1, Epstein Barr virus nuclear antigen 1
- EBV, Epstein Barr virus
- Epithelial cell
- LMP1, latent membrane protein 1
- Lytic EBV replication
- vFLIP, viral FLICE-like inhibitor protein
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Affiliation(s)
- Heike Nowag
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland
| | - Bruno Guhl
- Center for Microscopy and Image Analysis, University of Zürich, 8057 Zürich, Switzerland
| | - Kerstin Thriene
- Department of Dermatology, Medical Center, University of Freiburg, Hauptstr. 7, 79104 Freiburg, Germany
- Freiburg Institute for Advanced Studies, University of Freiburg, Albertstr. 19, 79104 Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestr. 18, 79104 Freiburg, Germany
- ZBSA Center for Biological Systems Analysis, University of Freiburg, Habsburgerstr. 49, 79104 Freiburg, Germany
| | - Susana Romao
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland
| | - Urs Ziegler
- Center for Microscopy and Image Analysis, University of Zürich, 8057 Zürich, Switzerland
| | - Joern Dengjel
- Department of Dermatology, Medical Center, University of Freiburg, Hauptstr. 7, 79104 Freiburg, Germany
- Freiburg Institute for Advanced Studies, University of Freiburg, Albertstr. 19, 79104 Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestr. 18, 79104 Freiburg, Germany
- ZBSA Center for Biological Systems Analysis, University of Freiburg, Habsburgerstr. 49, 79104 Freiburg, Germany
| | - Christian Münz
- Viral Immunobiology, Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland
- Corresponding author at: Institute of Experimental Immunology, University of Zürich, 8057 Zürich, Switzerland.
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Kaiser SE, Qiu Y, Coats JE, Mao K, Klionsky DJ, Schulman BA. Structures of Atg7-Atg3 and Atg7-Atg10 reveal noncanonical mechanisms of E2 recruitment by the autophagy E1. Autophagy 2013; 9:778-80. [PMID: 23388412 DOI: 10.4161/auto.23644] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Central to most forms of autophagy are two ubiquitin-like proteins (UBLs), Atg8 and Atg12, which play important roles in autophagosome biogenesis, substrate recruitment to autophagosomes, and other aspects of autophagy. Typically, UBLs are activated by an E1 enzyme that (1) catalyzes adenylation of the UBL C terminus, (2) transiently covalently captures the UBL through a reactive thioester bond between the E1 active site cysteine and the UBL C terminus, and (3) promotes transfer of the UBL C terminus to the catalytic cysteine of an E2 conjugating enzyme. The E2, and often an E3 ligase enzyme, catalyzes attachment of the UBL C terminus to a primary amine group on a substrate. Here, we summarize our recent work reporting the structural and mechanistic basis for E1-E2 protein interactions in autophagy.
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Affiliation(s)
- Stephen E Kaiser
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
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Abstract
The activity of the conserved Atg12-Atg5-Atg16 complex is essential for autophagosome formation. However, little is known about its mechanism of action during this process. In our study we employed in vitro systems consisting of purified proteins and giant unilamellar vesicles (GUVs) or small liposomes to investigate membrane binding by the Atg12-Atg5-Atg16 complex and its interplay with the Atg8 conjugation system. We showed that Atg5 directly binds membranes and that this membrane binding is negatively regulated by Atg12 conjugation but activated by Atg16. Membrane binding by the Atg12-Atg5-Atg16 complex is required for efficient promotion of Atg8 lipidation. Additionally, we found that the Atg12-Atg5-Atg16 complex tethered vesicles in an Atg8-independent manner. In yeast, membrane binding by Atg5 is not required for its recruitment to the phagophore assembly site (PAS) but is essential for efficient promotion of autophagy and the cytoplasm-to-vacuole targeting (Cvt) pathway at a stage preceding Atg8 lipidation and autophagosome closure. Our findings provide new insights into the role of the Atg12-Atg5-Atg16 complex during autophagosome formation.
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Affiliation(s)
- Marta Walczak
- Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
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