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Chen XJ, Bai YT, Xie JR, Zhou G. Lipid droplets' functional protein caveolin-2 is associated with lipid metabolism-related molecule FABP5 and EMT marker E-cadherin in oral epithelial dysplasia. J Clin Pathol 2024; 77:330-337. [PMID: 36854623 DOI: 10.1136/jcp-2022-208673] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 02/06/2023] [Indexed: 03/02/2023]
Abstract
AIMS To explore the accumulation of lipid droplets (LDs) and its relationship with lipid metabolism, and epithelial-mesenchymal transition (EMT) in the carcinogenesis processes in the oral cavity. METHODS LDs were stained by oil red O. Forty-eight oral squamous cell carcinomas (OSCC), 78 oral potentially malignant disorders (OPMDs) and 25 normal tissue sections were included to explore the LDs surface protein caveolin-2 and perilipin-3, lipid metabolism-related molecule FABP5 and EMT biomarker E-cadherin expression by immunohistochemical staining. RESULTS The accumulation of LDs was observed in OPMDs and OSCCs compared with normal tissues (p<0.05). In general, an increasing trend of caveolin-2, perilipin-3 and FABP5 expression was detected from the normal to OPMDs to OSCC groups (p<0.05). Additionally, caveolin-2, perilipin-3 and FABP5 expression were positively correlated with epithelial dysplasia in OPMDs, whereas E-cadherin positivity was negatively correlated with histopathological grade in both OPMDs and OSCC, respectively. A negative correlation of caveolin-2 (p<0.01, r =-0.1739), and FABP5 (p<0.01, r =-0.1880) with E-cadherin expression was detected. The caveolin-2 (p<0.0001, r=0.2641) and perilipin-3 (p<0.05, r=0.1408) staining was positively correlated with FABP5. Increased caveolin-2 expression was related to local recurrence and worse disease-free survival (p<0.05). CONCLUSION In the oral epithelial carcinogenesis process, LDs begin to accumulate early in the precancerous stage. LDs may be the regulator of FABP5-associated lipid metabolism and may closely related to the process of EMT; caveolin-2 could be the main functional protein.
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Affiliation(s)
- Xiao-Jie Chen
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Oral Medicine, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Yu-Ting Bai
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Ji-Rong Xie
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Gang Zhou
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Oral Medicine, School and Hospital of Stomatology, Wuhan University, Wuhan, China
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He Y, Liu L, Dong Y, Zhang X, Song Y, Jing Y, Ni Y, Wang Y, Wang Z, Ding L. Lipid droplets-related Perilipin-3: potential immune checkpoint and oncogene in oral squamous cell carcinoma. Cancer Immunol Immunother 2024; 73:78. [PMID: 38554152 PMCID: PMC10981595 DOI: 10.1007/s00262-024-03659-9] [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: 01/09/2024] [Accepted: 02/20/2024] [Indexed: 04/01/2024]
Abstract
BACKGROUND Lipid droplets (LDs) as major lipid storage organelles are recently reported to be innate immune hubs. Perilipin-3 (PLIN3) is indispensable for the formation and accumulation of LDs. Since cancer patients show dysregulated lipid metabolism, we aimed to elaborate the role of LDs-related PLIN3 in oral squamous cell carcinoma (OSCC). METHODS PLIN3 expression patterns (n = 87), its immune-related landscape (n = 74) and association with B7-H2 (n = 51) were assessed by immunohistochemistry and flow cytometry. Real-time PCR, Western blot, Oil Red O assay, immunofluorescence, migration assay, spheroid-forming assay and flow cytometry were performed for function analysis. RESULTS Spotted LDs-like PLIN3 staining was dominantly enriched in tumor cells than other cell types. PLIN3high tumor showed high proliferation index with metastasis potential, accompanied with less CD3+CD8+ T cells in peripheral blood and in situ tissue, conferring immunosuppressive microenvironment and shorter postoperative survival. Consistently, PLIN3 knockdown in tumor cells not only reduced LD deposits and tumor migration, but benefited for CD8+ T cells activation in co-culture system with decreased B7-H2. An OSCC subpopulation harbored PLIN3highB7-H2high tumor showed more T cells exhaustion, rendering higher risk of cancer-related death (95% CI 1.285-6.851). CONCLUSIONS LDs marker PLIN3 may be a novel immunotherapeutic target in OSCC.
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Affiliation(s)
- Yijia He
- Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Lingyun Liu
- Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Yuexin Dong
- Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Xiaoxin Zhang
- Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Yuxian Song
- Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Yue Jing
- Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Yanhong Ni
- Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Yi Wang
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
| | - Zhiyong Wang
- Department of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
| | - Liang Ding
- Central Laboratory of Stomatology, Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
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Stribny J, Schneiter R. Binding of perilipin 3 to membranes containing diacylglycerol is mediated by conserved residues within its PAT domain. J Biol Chem 2023; 299:105384. [PMID: 37898398 PMCID: PMC10694602 DOI: 10.1016/j.jbc.2023.105384] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 10/12/2023] [Accepted: 10/17/2023] [Indexed: 10/30/2023] Open
Abstract
Perilipins (PLINs) constitute an evolutionarily conserved family of proteins that specifically associate with the surface of lipid droplets (LDs). These proteins function in LD biogenesis and lipolysis and help to stabilize the surface of LDs. PLINs are typically composed of three different protein domains. They share an N-terminal PAT domain of unknown structure and function, a central region containing 11-mer repeats that form amphipathic helices, and a C-terminal domain that adopts a 4-helix bundle structure. How exactly these three distinct domains contribute to PLIN function remains to be determined. Here, we show that the N-terminal PAT domain of PLIN3 binds diacylglycerol (DAG), the precursor to triacylglycerol, a major storage lipid of LDs. PLIN3 and its PAT domain alone bind liposomes with micromolar affinity and PLIN3 binds artificial LDs containing low concentrations of DAG with nanomolar affinity. The PAT domain of PLIN3 is predicted to adopt an amphipathic triangular shaped structure. In silico ligand docking indicates that DAG binds to one of the highly curved regions within this domain. A conserved aspartic acid residue in the PAT domain, E86, is predicted to interact with DAG, and we found that its substitution abrogates high affinity binding of DAG as well as DAG-stimulated association with liposome and artificial LDs. These results indicate that the PAT domain of PLINs harbor specific lipid-binding properties that are important for targeting these proteins to the surface of LDs and to ER membrane domains enriched in DAG to promote LD formation.
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Affiliation(s)
- Jiri Stribny
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Roger Schneiter
- Department of Biology, University of Fribourg, Fribourg, Switzerland.
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4
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Bajpeyi S, Apaflo JN, Rosas V, Sepulveda-Rivera K, Varela-Ramirez A, Covington JD, Galgani JE, Ravussin E. Effect of an acute long-duration exercise bout on skeletal muscle lipid droplet morphology, GLUT 4 protein, and perilipin protein expression. Eur J Appl Physiol 2023; 123:2771-2778. [PMID: 37368137 DOI: 10.1007/s00421-023-05266-5] [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: 04/12/2023] [Accepted: 06/21/2023] [Indexed: 06/28/2023]
Abstract
PURPOSE Smaller lipid droplet morphology and GLUT 4 protein expression have been associated with greater muscle oxidative capacity and glucose uptake, respectively. The main purpose of this study was to determine the effect of an acute long-duration exercise bout on skeletal muscle lipid droplet morphology, GLUT4, perilipin 3, and perilipin 5 expressions. METHODS Twenty healthy men (age 24.0 ± 1.0 years, BMI 23.6 ± 0.4 kg/m2) were recruited for the study. The participants were subjected to an acute bout of exercise on a cycle ergometer at 50% VO2max until they reached a total energy expenditure of 650 kcal. The study was conducted after an overnight fast. Vastus lateralis muscle biopsies were obtained before and immediately after exercise for immunohistochemical analysis to determine lipid, perilipin 3, perilipin 5, and GLUT4 protein contents while GLUT 4 mRNA was quantified using RT-qPCR. RESULTS Lipid droplet size decreased whereas total intramyocellular lipid content tended to reduce (p = 0.07) after an acute bout of endurance exercise. The density of smaller lipid droplets in the peripheral sarcoplasmic region significantly increased (0.584 ± 0.04 to 0.638 ± 0.08 AU; p = 0.01) while larger lipid droplets significantly decreased (p < 0.05). GLUT4 mRNA tended to increase (p = 0.05). There were no significant changes in GLUT 4, perilipin 3, and perilipin 5 protein levels. CONCLUSION The study demonstrates that exercise may impact metabolism by enhancing the quantity of smaller lipid droplets over larger lipid droplets.
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Affiliation(s)
- Sudip Bajpeyi
- Metabolic, Nutrition, and Exercise Research (MiNER) Laboratory, Department of Kinesiology, The University of Texas at El Paso, 500 University Ave, El Paso, TX, 79968, USA.
| | - Jehu N Apaflo
- Metabolic, Nutrition, and Exercise Research (MiNER) Laboratory, Department of Kinesiology, The University of Texas at El Paso, 500 University Ave, El Paso, TX, 79968, USA
| | - Victoria Rosas
- Metabolic, Nutrition, and Exercise Research (MiNER) Laboratory, Department of Kinesiology, The University of Texas at El Paso, 500 University Ave, El Paso, TX, 79968, USA
| | - Keisha Sepulveda-Rivera
- Metabolic, Nutrition, and Exercise Research (MiNER) Laboratory, Department of Kinesiology, The University of Texas at El Paso, 500 University Ave, El Paso, TX, 79968, USA
| | - Armando Varela-Ramirez
- The Cellular Characterization and Biorepository (CCB) Core Facility, Border Biomedical Research Center, Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX, USA
| | - Jeffrey D Covington
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Jose E Galgani
- Faculty of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Eric Ravussin
- Laboratory of Skeletal Muscle Physiology, Pennington Biomedical Research Center, Baton Rouge, LA, USA
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5
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Choi YM, Ajjaji D, Fleming KD, Borbat PP, Jenkins ML, Moeller BE, Fernando S, Bhatia SR, Freed JH, Burke JE, Thiam AR, Airola MV. Structural insights into perilipin 3 membrane association in response to diacylglycerol accumulation. Nat Commun 2023; 14:3204. [PMID: 37268630 PMCID: PMC10238389 DOI: 10.1038/s41467-023-38725-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [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: 11/02/2022] [Accepted: 05/12/2023] [Indexed: 06/04/2023] Open
Abstract
Lipid droplets (LDs) are dynamic organelles that contain an oil core mainly composed of triglycerides (TAG) that is surrounded by a phospholipid monolayer and LD-associated proteins called perilipins (PLINs). During LD biogenesis, perilipin 3 (PLIN3) is recruited to nascent LDs as they emerge from the endoplasmic reticulum. Here, we analyze how lipid composition affects PLIN3 recruitment to membrane bilayers and LDs, and the structural changes that occur upon membrane binding. We find that the TAG precursors phosphatidic acid and diacylglycerol (DAG) recruit PLIN3 to membrane bilayers and define an expanded Perilipin-ADRP-Tip47 (PAT) domain that preferentially binds DAG-enriched membranes. Membrane binding induces a disorder to order transition of alpha helices within the PAT domain and 11-mer repeats, with intramolecular distance measurements consistent with the expanded PAT domain adopting a folded but dynamic structure upon membrane binding. In cells, PLIN3 is recruited to DAG-enriched ER membranes, and this requires both the PAT domain and 11-mer repeats. This provides molecular details of PLIN3 recruitment to nascent LDs and identifies a function of the PAT domain of PLIN3 in DAG binding.
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Affiliation(s)
- Yong Mi Choi
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Dalila Ajjaji
- Laboratoire de Physique de l'École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8N 1A1, Canada
| | - Peter P Borbat
- National Biomedical Resource for Advanced Electron Spin Resonance Technology (ACERT), Cornell University, Ithaca, NY, 14853, USA
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Meredith L Jenkins
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8N 1A1, Canada
| | - Brandon E Moeller
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8N 1A1, Canada
| | - Shaveen Fernando
- Department of Chemistry, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Surita R Bhatia
- Department of Chemistry, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Jack H Freed
- National Biomedical Resource for Advanced Electron Spin Resonance Technology (ACERT), Cornell University, Ithaca, NY, 14853, USA
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8N 1A1, Canada.
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
| | - Abdou Rachid Thiam
- Laboratoire de Physique de l'École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France.
| | - Michael V Airola
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, 11794, USA.
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6
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Lamprou I, Kakouratos C, Tsolou A, Pavlidis P, Xanthopoulou ET, Nanos C, Tsaroucha A, Sivridis E, Giatromanolaki A, Koukourakis MI. Lipophagy-related protein perilipin-3 (PLIN3) and resistance of prostate cancer to radiotherapy. Int J Radiat Oncol Biol Phys 2022; 113:401-414. [PMID: 35121129 DOI: 10.1016/j.ijrobp.2022.01.033] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 12/17/2021] [Accepted: 01/23/2022] [Indexed: 11/19/2022]
Abstract
PURPOSE Radiotherapy is a principal treatment modality for localized and locally advanced prostate cancer (PCa). Metabolic alterations, including lipid metabolism, may reduce treatment efficacy resulting in tumor relapse and poor therapeutic outcome. In the current study, we investigated the role of the lipophagy-related protein perilipin-3 (PLIN3) and the lysosomal acid lipase (LAL) in PCa response to radiotherapy. METHODS AND MATERIALS We explored the in vitro and xenograft (in NOD.SCID and R2G2 mice) response to radiation of either PLIN3-depleted or LAL-depleted hormone-refractory (DU145, PC3), and hormone-responsive 22Rv1 PCa cell lines. Moreover, we evaluated the clinical role of PLIN3 and LAL protein expression in a series of PCa tissue specimens from patients treated with radical radiotherapy. RESULTS In vitro and in vivo experiments showed reduced proliferation and strong radiosensitization of all studied PCa cell lines upon PLIN3 depletion. In vivo experiments demonstrated the significantly augmented radiotherapy efficacy upon PLIN3 depletion, resulting in extensive tissue necrosis. PLIN3 overexpression in tissue specimens was correlated with increased MIB1 proliferation index, increased autophagy flux, reduced response to radiotherapy and poor prognosis. The impact of LAL depletion on radiotherapy was of lesser importance. CONCLUSIONS Assessment of PLIN3 expression may identify subgroups of PCa patients less responsive to radiotherapy, and at high risk of relapse post irradiation. Whether radiotherapy efficacy may be enhanced by concurrent autophagy or PLIN3 inhibition in this sub-group of patients demands clinical evaluation.
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Affiliation(s)
| | | | | | | | | | | | | | - Efthimios Sivridis
- Department of Pathology, Democritus University of Thrace, Alexandroupolis, Greece
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Garcia-Macia M, Santos-Ledo A, Leslie J, Paish HL, Collins AL, Scott RS, Watson A, Burgoyne RA, White S, French J, Hammond J, Borthwick LA, Mann J, Bolaños JP, Korolchuk VI, Oakley F, Mann DA. A Mammalian Target of Rapamycin-Perilipin 3 (mTORC1-Plin3) Pathway is essential to Activate Lipophagy and Protects Against Hepatosteatosis. Hepatology 2021; 74:3441-3459. [PMID: 34233024 DOI: 10.1002/hep.32048] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 05/28/2021] [Accepted: 06/13/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND AIMS NAFLD is the most common hepatic pathology in western countries and no treatment is currently available. NAFLD is characterized by the aberrant hepatocellular accumulation of fatty acids in the form of lipid droplets (LDs). Recently, it was shown that liver LD degradation occurs through a process termed lipophagy, a form of autophagy. However, the molecular mechanisms governing liver lipophagy are elusive. Here, we aimed to ascertain the key molecular players that regulate hepatic lipophagy and their importance in NAFLD. APPROACH AND RESULTS We analyzed the formation and degradation of LD in vitro (fibroblasts and primary mouse hepatocytes), in vivo and ex vivo (mouse and human liver slices) and focused on the role of the autophagy master regulator mammalian target of rapamycin complex (mTORC) 1 and the LD coating protein perilipin (Plin) 3 in these processes. We show that the autophagy machinery is recruited to the LD on hepatic overload of oleic acid in all experimental settings. This led to activation of lipophagy, a process that was abolished by Plin3 knockdown using RNA interference. Furthermore, Plin3 directly interacted with the autophagy proteins focal adhesion interaction protein 200 KDa and autophagy-related 16L, suggesting that Plin3 functions as a docking protein or is involved in autophagosome formation to activate lipophagy. Finally, we show that mTORC1 phosphorylated Plin3 to promote LD degradation. CONCLUSIONS These results reveal that mTORC1 regulates liver lipophagy through a mechanism dependent on Plin3 phosphorylation. We propose that stimulating this pathway can enhance lipophagy in hepatocytes to help protect the liver from lipid-mediated toxicity, thus offering a therapeutic strategy in NAFLD.
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Affiliation(s)
- Marina Garcia-Macia
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- Institute of Biomedical Research of Salamanca, University Hospital of Salamanca, Salamanca, Spain
- Institute of Functional Biology and Genomics, University of Salamanca, CSIC, Salamanca, Spain
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Jack Leslie
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Hannah L Paish
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Amy L Collins
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Rebecca S Scott
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
- FibroFind Ltd, William Leech Building, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Abigail Watson
- FibroFind Ltd, William Leech Building, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Rachel A Burgoyne
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Steve White
- Department of Hepatobiliary Surgery, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Jeremy French
- Department of Hepatobiliary Surgery, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - John Hammond
- Department of Hepatobiliary Surgery, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, United Kingdom
| | - Lee A Borthwick
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Jelena Mann
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Juan P Bolaños
- Institute of Biomedical Research of Salamanca, University Hospital of Salamanca, Salamanca, Spain
- Institute of Functional Biology and Genomics, University of Salamanca, CSIC, Salamanca, Spain
- Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Viktor I Korolchuk
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Fiona Oakley
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Derek A Mann
- Newcastle Fibrosis Research Group, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
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Wilson MH, Ekker SC, Farber SA. Imaging cytoplasmic lipid droplets in vivo with fluorescent perilipin 2 and perilipin 3 knock-in zebrafish. eLife 2021; 10:e66393. [PMID: 34387191 PMCID: PMC8460263 DOI: 10.7554/elife.66393] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 08/10/2021] [Indexed: 12/26/2022] Open
Abstract
Cytoplasmic lipid droplets are highly dynamic storage organelles that are critical for cellular lipid homeostasis. While the molecular details of lipid droplet dynamics are a very active area of investigation, this work has been primarily performed in cultured cells. Taking advantage of the powerful transgenic and in vivo imaging opportunities available in zebrafish, we built a suite of tools to study lipid droplets in real time from the subcellular to the whole organism level. Fluorescently tagging the lipid droplet-associated proteins, perilipin 2 and perilipin 3, in the endogenous loci permits visualization of lipid droplets in the intestine, liver, and adipose tissue. Using these tools, we found that perilipin 3 is rapidly loaded on intestinal lipid droplets following a high-fat meal and later replaced by perilipin 2. These powerful new tools will facilitate studies on the role of lipid droplets in different tissues, under different genetic and physiological manipulations, and in a variety of human disease models.
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Affiliation(s)
- Meredith H Wilson
- Carnegie Institution for Science Department of EmbryologyBaltimoreUnited States
| | - Stephen C Ekker
- Department of Biochemistry and Molecular Biology, Mayo ClinicRochesterUnited States
| | - Steven A Farber
- Carnegie Institution for Science Department of EmbryologyBaltimoreUnited States
- Johns Hopkins University Department of BiologyBaltimoreUnited States
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9
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Hussain SS, Tran TM, Ware TB, Luse MA, Prevost CT, Ferguson AN, Kashatus JA, Hsu KL, Kashatus DF. RalA and PLD1 promote lipid droplet growth in response to nutrient withdrawal. Cell Rep 2021; 36:109451. [PMID: 34320341 PMCID: PMC8344381 DOI: 10.1016/j.celrep.2021.109451] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 06/04/2021] [Accepted: 07/02/2021] [Indexed: 01/22/2023] Open
Abstract
Lipid droplets (LDs) are dynamic organelles that undergo dynamic changes in response to changing cellular conditions. During nutrient depletion, LD numbers increase to protect cells against toxic fatty acids generated through autophagy and provide fuel for beta-oxidation. However, the precise mechanisms through which these changes are regulated have remained unclear. Here, we show that the small GTPase RalA acts downstream of autophagy to directly facilitate LD growth during nutrient depletion. Mechanistically, RalA performs this function through phospholipase D1 (PLD1), an enzyme that converts phosphatidylcholine (PC) to phosphatidic acid (PA) and that is recruited to lysosomes during nutrient stress in a RalA-dependent fashion. RalA inhibition prevents recruitment of the LD-associated protein perilipin 3, which is required for LD growth. Our data support a model in which RalA recruits PLD1 to lysosomes during nutrient deprivation to promote the localized production of PA and the recruitment of perilipin 3 to expanding LDs.
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Affiliation(s)
- Syed S Hussain
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Tuyet-Minh Tran
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Timothy B Ware
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
| | - Melissa A Luse
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Christopher T Prevost
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Ashley N Ferguson
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Jennifer A Kashatus
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Ku-Lung Hsu
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA; University of Virginia Cancer Center, University of Virginia Health System, Charlottesville, VA 22903, USA
| | - David F Kashatus
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA; University of Virginia Cancer Center, University of Virginia Health System, Charlottesville, VA 22903, USA.
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Jevons EFP, Gejl KD, Strauss JA, Ørtenblad N, Shepherd SO. Skeletal muscle lipid droplets are resynthesized before being coated with perilipin proteins following prolonged exercise in elite male triathletes. Am J Physiol Endocrinol Metab 2020; 318:E357-E370. [PMID: 31935113 DOI: 10.1152/ajpendo.00399.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Intramuscular triglycerides (IMTG) are a key substrate during prolonged exercise, but little is known about the rate of IMTG resynthesis in the postexercise period. We investigated the hypothesis that the distribution of the lipid droplet (LD)-associated perilipin (PLIN) proteins is linked to IMTG storage following exercise. Fourteen elite male triathletes (27 ± 1 yr, 66.5 ± 1.3 mL·kg-1·min-1) completed 4 h of moderate-intensity cycling. During the first 4 h of recovery, subjects received either carbohydrate or H2O, after which both groups received carbohydrate. Muscle biopsies collected pre- and postexercise and 4 and 24 h postexercise were analyzed using confocal immunofluorescence microscopy for fiber type-specific IMTG content and PLIN distribution with LDs. Exercise reduced IMTG content in type I fibers (-53%, P = 0.002), with no change in type IIa fibers. During the first 4 h of recovery, IMTG content increased in type I fibers (P = 0.014), but was not increased more after 24 h, where it was similar to baseline levels in both conditions. During recovery the number of LDs labeled with PLIN2 (70%), PLIN3 (63%), and PLIN5 (62%; all P < 0.05) all increased in type I fibers. Importantly, the increase in LDs labeled with PLIN proteins only occurred at 24 h postexercise. In conclusion, IMTG resynthesis occurs rapidly in type I fibers following prolonged exercise in highly trained individuals. Furthermore, increases in IMTG content following exercise preceded an increase in the number of LDs labeled with PLIN proteins. These data, therefore, suggest that the PLIN proteins do not play a key role in postexercise IMTG resynthesis.
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Affiliation(s)
- Emily F P Jevons
- Research Institute of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Kasper D Gejl
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Juliette A Strauss
- Research Institute of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Niels Ørtenblad
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Sam O Shepherd
- Research Institute of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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Chen Y, Frost S, Khushi M, Cantrill LC, Yu H, Arthur JW, Bright RK, Groblewski GE, Byrne JA. Delayed recruiting of TPD52 to lipid droplets - evidence for a "second wave" of lipid droplet-associated proteins that respond to altered lipid storage induced by Brefeldin A treatment. Sci Rep 2019; 9:9790. [PMID: 31278300 PMCID: PMC6611826 DOI: 10.1038/s41598-019-46156-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 06/18/2019] [Indexed: 12/27/2022] Open
Abstract
Tumor protein D52 (TPD52) is amplified and overexpressed in breast and prostate cancers which are frequently characterised by dysregulated lipid storage and metabolism. TPD52 expression increases lipid storage in mouse 3T3 fibroblasts, and co-distributes with the Golgi marker GM130 and lipid droplets (LDs). We examined the effects of Brefeldin A (BFA), a fungal metabolite known to disrupt the Golgi structure, in TPD52-expressing 3T3 cells, and in human AU565 and HMC-1-8 breast cancer cells that endogenously express TPD52. Five-hour BFA treatment reduced median LD numbers, but increased LD sizes. TPD52 knockdown decreased both LD sizes and numbers, and blunted BFA's effects on LD numbers. Following BFA treatment for 1-3 hours, TPD52 co-localised with the trans-Golgi network protein syntaxin 6, but after 5 hours BFA treatment, TPD52 showed increased co-localisation with LDs, which was disrupted by microtubule depolymerising agent nocodazole. BFA treatment also increased perilipin (PLIN) family protein PLIN3 but reduced PLIN2 detection at LDs in TPD52-expressing 3T3 cells, with PLIN3 recruitment to LDs preceding that of TPD52. An N-terminally deleted HA-TPD52 mutant (residues 40-184) almost exclusively targeted to LDs in both vehicle and BFA treated cells. In summary, delayed recruitment of TPD52 to LDs suggests that TPD52 participates in a temporal hierarchy of LD-associated proteins that responds to altered LD packaging requirements induced by BFA treatment.
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Affiliation(s)
- Yuyan Chen
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia.
- The University of Sydney Discipline of Child and Adolescent Health, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia.
| | - Sarah Frost
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
- The University of Sydney Discipline of Child and Adolescent Health, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
| | - Matloob Khushi
- Bioinformatics Unit, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
- The University of Sydney School of Information Technologies, Darlington, NSW, 2008, Australia
| | - Laurence C Cantrill
- The University of Sydney Discipline of Child and Adolescent Health, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
- Kids Research Microscope Facility, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia
| | - Hong Yu
- Cell Imaging Facility, Westmead Institute for Medical Research, Westmead, NSW, 2145, Australia
| | - Jonathan W Arthur
- Bioinformatics Unit, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, 2145, Australia
| | - Robert K Bright
- Department of Immunology and Molecular Microbiology and TTUHSC Cancer Center, Texas Tech University Health Sciences Center, Lubbock, Texas, 79430, USA
| | - Guy E Groblewski
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Jennifer A Byrne
- Molecular Oncology Laboratory, Children's Cancer Research Unit, Kids Research, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia.
- The University of Sydney Discipline of Child and Adolescent Health, The Children's Hospital at Westmead, Westmead, NSW, 2145, Australia.
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El-Ekiaby NM, Mekky RY, Riad SE, Elhelw DS, El-Sayed M, Esmat G, Abdelaziz AI. miR-148a and miR-30a limit HCV-dependent suppression of the lipid droplet protein, ADRP, in HCV infected cell models. J Med Virol 2017; 89:653-659. [PMID: 27591428 DOI: 10.1002/jmv.24677] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2016] [Indexed: 02/05/2023]
Abstract
Hepatitis C Virus (HCV) promotes lipid droplet (LD) formation and perturbs the expression of the LD associated PAT proteins ADRP and TIP47, to promote its own lifecycle. HCV enhances TIP47 and suppresses ADRP by displacing it from LD surface in infected cell models. We have previously shown that suppression of TIP47 by miR-148a and miR-30a decreased intracellular LDs and HCV RNA. Thus, this study aimed at examining whether this microRNA-mediated suppression of HCV would limit HCV-dependent displacement of ADRP from LDs. ADRP expression was examined in 21 HCV-infected liver biopsies and 9 healthy donor liver tissues as well as in HCV-infected Huh7 cells using qRT-PCR. miR-148a and miR-30a expression was manipulated using specific oligos in JFH-1 infected, oleic acid treated cells, to study their impact on ADRP expression using qRT-PCR, and immunofluorescence microscopy. Intracellular HCV RNA was assessed using qRT-PCR. ADRP is down regulated in patients as well as HCVcc-JFH-I infected cell models. Forcing the expression of both miRNAs induced ADRP on the mRNA and protein levels. This study shows that HCV suppresses hepatic ADRP expression in infected patients and cell lines. Forcing the expression of miR-148a and miR-30a limits the suppressive effect of HCV on ADRP. J. Med. Virol. 89:653-659, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Nada M El-Ekiaby
- Department of Pharmacology and Toxicology, Molecular Pathology Research Group, German University in Cairo, New Cairo City-Main Entrance Al Tagamoa Al Khames, Cairo, Egypt
- Scientific Affairs Unit, Egyptian Company for Biological Sciences, Giza, Egypt
| | - Radwa Y Mekky
- Department of Pharmacology and Toxicology, Molecular Pathology Research Group, German University in Cairo, New Cairo City-Main Entrance Al Tagamoa Al Khames, Cairo, Egypt
- Faculty of Biotechnology, October University of Modern Sciences and Arts, Giza, Egypt
| | - Sarah E Riad
- Department of Pharmacology and Toxicology, Molecular Pathology Research Group, German University in Cairo, New Cairo City-Main Entrance Al Tagamoa Al Khames, Cairo, Egypt
| | - Dalia S Elhelw
- Department of Pharmacology and Toxicology, Molecular Pathology Research Group, German University in Cairo, New Cairo City-Main Entrance Al Tagamoa Al Khames, Cairo, Egypt
| | | | - Gamal Esmat
- Endemic Medicine and Hepatology, Cairo University, Cairo, Egypt
| | - Ahmed I Abdelaziz
- Department of Pharmacology and Toxicology, Molecular Pathology Research Group, German University in Cairo, New Cairo City-Main Entrance Al Tagamoa Al Khames, Cairo, Egypt
- Biotechnology Graduate Program, American University in Cairo, AUC Avenue, New Cairo, Cairo, Egypt
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