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Fan Z, Zhang Y, Fang Y, Zhong H, Wei T, Akhtar H, Zhang J, Yang M, Li Y, Zhou X, Sun Z, Wang J. Polystyrene nanoplastics induce lipophagy via the AMPK/ULK1 pathway and block lipophagic flux leading to lipid accumulation in hepatocytes. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:134878. [PMID: 38897115 DOI: 10.1016/j.jhazmat.2024.134878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 06/07/2024] [Accepted: 06/09/2024] [Indexed: 06/21/2024]
Abstract
Micro- and nanoplastic pollution has emerged as a significant global concern due to their extensive presence in the environment and potential adverse effects on human health. Nanoplastics can enter the human circulatory system and accumulate in the liver, disrupting hepatic metabolism and causing hepatotoxicity. However, the precise mechanism remains uncertain. Lipophagy is an alternative mechanism of lipid metabolism involving autophagy. This study aims to explore how polystyrene nanoplastics (PSNPs) influence lipid metabolism in hepatocytes via lipophagy. Initially, it was found that PSNPs were internalized by human hepatocytes, resulting in decreased cell viability. PSNPs were found to induce the accumulation of lipid droplets (LDs), with autophagy inhibition exacerbating this accumulation. Then, PSNPs were proved to activate lipophagy by recruiting LDs into autophagosomes and block the lipophagic flux by impairing lysosomal function, inhibiting LD degradation. Ultimately, PSNPs were shown to activate lipophagy through the AMPK/ULK1 pathway, and knocking down AMPK exacerbated lipid accumulation in hepatocytes. Overall, these results indicated that PSNPs triggered lipophagy via the AMPK/ULK1 pathway and blocked lipophagic flux, leading to lipid accumulation in hepatocytes. Thus, this study identifies a novel mechanism underlying nanoplastic-induced lipid accumulation, providing a foundation for the toxicity study and risk assessments of nanoplastics.
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Affiliation(s)
- Zhuying Fan
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Yukang Zhang
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Shanxi Provincial Center for Disease Control and Prevention, Taiyuan 030012, Shanxi, China
| | - Yuting Fang
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Huiyuan Zhong
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China
| | - Tingting Wei
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Huraira Akhtar
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Jiahuai Zhang
- Center for Clinical Laboratory, Capital Medical University, Beijing 100069, China
| | - Man Yang
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Yanbo Li
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Xianqing Zhou
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Zhiwei Sun
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China
| | - Ji Wang
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, China.
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2
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Mansuri S, Mahalingavelar P, Soppina V, Kanvah S. A two-in-one probe: imaging lipid droplets and endoplasmic reticulum in tandem. J Mater Chem B 2024; 12:2028-2041. [PMID: 38319378 DOI: 10.1039/d4tb00026a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
The endoplasmic reticulum (ER) and lipid droplets (LDs) intricately interact in cellular processes, with the ER serving as a hub for lipid synthesis and LDs acting as storage organelles for lipids. Developing fluorescent probes that can simultaneously visualise the ER and LDs provides a means for real-time and specific visualisation of these subcellular organelles and elucidating their interaction. Herein, we present synthetically simple and novel donor-π-acceptor styryl fluorophores (PFC, PFN and PFB) incorporating pentafluorophenyl (PFP) to demonstrate exquisite discriminative imaging of ER and LD with a single excitation wavelength. The PFP moiety aids the ER selectivity, while the overall hydrophobicity of the molecule aids in the LD targeting. Furthermore, the fluorophores are utilised in studying the changes in size, distribution, and biogenesis of LDs within ER regions after treatment with oleic acid. Strong emission, lower concentrations ∼100 nM requirement, minimal cytotoxicity, and photostability make these fluorophores excellent tools for probing sub-cellular dynamics.
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Affiliation(s)
- Shabnam Mansuri
- Department of Chemistry, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat-382055, India.
| | - Paramasivam Mahalingavelar
- School of Chemistry and Biochemistry and School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Virupakshi Soppina
- Department of Biological Engineering, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat-382055, India.
| | - Sriram Kanvah
- Department of Chemistry, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat-382055, India.
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Skotland T, Llorente A, Sandvig K. Lipids in Extracellular Vesicles: What Can Be Learned about Membrane Structure and Function? Cold Spring Harb Perspect Biol 2023; 15:a041415. [PMID: 37277192 PMCID: PMC10411865 DOI: 10.1101/cshperspect.a041415] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Extracellular vesicles, such as exosomes, can be used as interesting models to study the structure and function of biological membranes as these vesicles contain only one membrane (i.e., one lipid bilayer). In addition to lipids, they contain proteins, nucleic acids, and various other molecules. The lipid composition of exosomes is here compared to HIV particles and detergent-resistant membranes, which also have a high content of sphingolipids, cholesterol, and phosphatidylserine (PS). We discuss interactions between the lipids in the two bilayers, and especially those between PS 18:0/18:1 in the inner leaflet and the very-long-chain sphingolipids in the outer leaflet, and the importance of cholesterol for these interactions. We also briefly discuss the involvement of ether-linked phospholipids (PLs) in such lipid raft-like structures, and the possible involvement of these and other lipid classes in the formation of exosomes. The urgent need to improve the quality of quantitative lipidomic studies is highlighted.
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Affiliation(s)
- Tore Skotland
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital-The Norwegian Radium Hospital, 0379 Oslo, Norway
- Centre for Cancer Cell Reprogramming, Faculty of Medicine, University of Oslo, 0379 Oslo, Norway
| | - Alicia Llorente
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital-The Norwegian Radium Hospital, 0379 Oslo, Norway
- Centre for Cancer Cell Reprogramming, Faculty of Medicine, University of Oslo, 0379 Oslo, Norway
- Department of Mechanical, Electronics and Chemical Engineering, Oslo Metropolitan University, 0167 Oslo, Norway
| | - Kirsten Sandvig
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital-The Norwegian Radium Hospital, 0379 Oslo, Norway
- Centre for Cancer Cell Reprogramming, Faculty of Medicine, University of Oslo, 0379 Oslo, Norway
- Department of Molecular Biosciences, University of Oslo, 0316 Oslo, Norway
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4
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Bianco V, Korbelius M, Vujic N, Akhmetshina A, Amor M, Kolb D, Pirchheim A, Bradic I, Kuentzel KB, Buerger M, Schauer S, Phan HTT, Bulfon D, Hoefler G, Zimmermann R, Kratky D. Impact of (intestinal) LAL deficiency on lipid metabolism and macrophage infiltration. Mol Metab 2023; 73:101737. [PMID: 37182562 PMCID: PMC10209539 DOI: 10.1016/j.molmet.2023.101737] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 03/01/2023] [Accepted: 05/08/2023] [Indexed: 05/16/2023] Open
Abstract
OBJECTIVE To date, the only enzyme known to be responsible for the hydrolysis of cholesteryl esters and triacylglycerols in the lysosome at acidic pH is lysosomal acid lipase (LAL). Lipid malabsorption in the small intestine (SI), accompanied by macrophage infiltration, is one of the most common pathological features of LAL deficiency. However, the exact role of LAL in intestinal lipid metabolism is still unknown. METHODS We collected three parts of the SI (duodenum, jejunum, ileum) from mice with a global (LAL KO) or intestine-specific deletion of LAL (iLAL KO) and corresponding controls. RESULTS We observed infiltration of lipid-associated macrophages into the lamina propria, where neutral lipids accumulate massively in the SI of LAL KO mice. In addition, LAL KO mice absorb less dietary lipids but have accelerated basolateral lipid uptake, secrete fewer chylomicrons, and have increased fecal lipid loss. Inflammatory markers and genes involved in lipid metabolism were overexpressed in the duodenum of old but not in younger LAL KO mice. Despite the significant reduction of LAL activity in enterocytes of enterocyte-specific (iLAL) KO mice, villous morphology, intestinal lipid concentrations, expression of lipid transporters and inflammatory genes, as well as lipoprotein secretion were comparable to control mice. CONCLUSIONS We conclude that loss of LAL only in enterocytes is insufficient to cause lipid deposition in the SI, suggesting that infiltrating macrophages are the key players in this process.
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Affiliation(s)
- Valentina Bianco
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Melanie Korbelius
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Nemanja Vujic
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Alena Akhmetshina
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Melina Amor
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Dagmar Kolb
- Core Facility Ultrastructure Analysis, Center for Medical Research, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Anita Pirchheim
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Ivan Bradic
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Katharina B Kuentzel
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Martin Buerger
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Silvia Schauer
- Diagnostics and Research Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Huyen T T Phan
- Diagnostics and Research Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Dominik Bulfon
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Gerald Hoefler
- Diagnostics and Research Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Robert Zimmermann
- BioTechMed-Graz, Graz, Austria; Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
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5
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Li X, Liu Q, Pan Y, Chen S, Zhao Y, Hu Y. New insights into the role of dietary triglyceride absorption in obesity and metabolic diseases. Front Pharmacol 2023; 14:1097835. [PMID: 36817150 PMCID: PMC9932209 DOI: 10.3389/fphar.2023.1097835] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 01/20/2023] [Indexed: 02/05/2023] Open
Abstract
The incidence of obesity and associated metabolic diseases is increasing globally, adversely affecting human health. Dietary fats, especially triglycerides, are an important source of energy for the body, and the intestine absorbs lipids through a series of orderly and complex steps. A long-term high-fat diet leads to intestinal dysfunction, inducing obesity and metabolic disorders. Therefore, regulating dietary triglycerides absorption is a promising therapeutic strategy. In this review, we will discuss diverse aspects of the dietary triglycerides hydrolysis, fatty acid uptake, triglycerides resynthesis, chylomicron assembly, trafficking, and secretion processes in intestinal epithelial cells, as well as potential targets in this process that may influence dietary fat-induced obesity and metabolic diseases. We also mention the possible shortcomings and deficiencies in modulating dietary lipid absorption targets to provide a better understanding of their administrability as drugs in obesity and related metabolic disorders.
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Affiliation(s)
- Xiaojing Li
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Qiaohong Liu
- Institute of Clinical Pharmacology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yuqing Pan
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Si Chen
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yu Zhao
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China,*Correspondence: Yu Zhao, ; Yiyang Hu,
| | - Yiyang Hu
- Key Laboratory of Liver and Kidney Diseases (Ministry of Education), Institute of Liver Diseases, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China,Institute of Clinical Pharmacology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China,*Correspondence: Yu Zhao, ; Yiyang Hu,
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6
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Wen J, Wang Y, Wang C, Yuan M, Chen F, Zou Q, Cai Z, Zhao B. Dietary High-Fat Promotes Cognitive Impairment by Suppressing Mitophagy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2023; 2023:4822767. [PMID: 36718278 PMCID: PMC9884172 DOI: 10.1155/2023/4822767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 01/06/2023] [Accepted: 01/11/2023] [Indexed: 01/22/2023]
Abstract
Dietary habits contribute to the characteristics of Alzheimer's disease (AD) and cognitive impairment, which are partly induced by the accumulation of hyperphosphorylated Tau, a microtubule-associated protein. In mice, a fat-rich diet facilitates cognitive dysfunction. However, the mechanism by which dietary fat damages the brain remains unclear. In this study, 13-month-old C57BL/6 mice were fed a normal or high-fat diet (HFD) for 6 months. Neuro-2a cells were incubated with the normal medium or palmitic acid (200 μM). Spatial memory was assessed utilizing a behavioral test. Further, western blotting and immunofluorescence techniques were used to determine the levels of mitophagy-related proteins. The synaptic morphology and phosphorylation of Tau proteins were also evaluated. Administration of HFD decreased the expression of synaptophysin and brain-derived neurotrophic factor expression, leading to significant damage to neurons. Tau protein hyperphosphorylation was detected at different loci both in vivo and in vitro. Significantly impaired learning and memory abilities, accompanied by impaired mitophagy-related processes, were observed in mice fed with HFD as compared to mice fed with normal food. In conclusion, high fatty-acid intake hinders mitophagy and upregulates Tau protein phosphorylation, including age-related synaptic dysfunction, which leads to cognitive decline.
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Affiliation(s)
- Jie Wen
- Department and Institute of Neurology, Guangdong Medical University, Zhanjiang, Guangdong 524001, China
- Guangdong Key Laboratory of Aging-Related Cardiac and Cerebral Diseases, Zhanjiang, Guangdong 524001, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Yuzhong District, Chongqing 400013, China
- Department of Neurology, Chongqing General Hospital, Yuzhong District, Chongqing 400013, China
| | - Yangyang Wang
- Chongqing Key Laboratory of Neurodegenerative Diseases, Yuzhong District, Chongqing 400013, China
- Department of Neurology, Chongqing General Hospital, Yuzhong District, Chongqing 400013, China
| | - Chuanling Wang
- Chongqing Key Laboratory of Neurodegenerative Diseases, Yuzhong District, Chongqing 400013, China
- Department of Neurology, Chongqing General Hospital, Yuzhong District, Chongqing 400013, China
- Chongqing Medical University, Yuzhong District, Chongqing 400016, China
| | - Minghao Yuan
- Chongqing Key Laboratory of Neurodegenerative Diseases, Yuzhong District, Chongqing 400013, China
- Department of Neurology, Chongqing General Hospital, Yuzhong District, Chongqing 400013, China
- Chongqing Medical University, Yuzhong District, Chongqing 400016, China
| | - Fei Chen
- Chongqing Key Laboratory of Neurodegenerative Diseases, Yuzhong District, Chongqing 400013, China
- Department of Neurology, Chongqing General Hospital, Yuzhong District, Chongqing 400013, China
- Chongqing Medical University, Yuzhong District, Chongqing 400016, China
| | - Qian Zou
- Chongqing Key Laboratory of Neurodegenerative Diseases, Yuzhong District, Chongqing 400013, China
- Department of Neurology, Chongqing General Hospital, Yuzhong District, Chongqing 400013, China
| | - Zhiyou Cai
- Chongqing Key Laboratory of Neurodegenerative Diseases, Yuzhong District, Chongqing 400013, China
- Department of Neurology, Chongqing General Hospital, Yuzhong District, Chongqing 400013, China
| | - Bin Zhao
- Department and Institute of Neurology, Guangdong Medical University, Zhanjiang, Guangdong 524001, China
- Guangdong Key Laboratory of Aging-Related Cardiac and Cerebral Diseases, Zhanjiang, Guangdong 524001, China
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7
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Chen WF, Wang HF, Wang Y, Liu ZG, Xu BH. AmAtg2B-Mediated Lipophagy Regulates Lipolysis of Pupae in Apis mellifera. Int J Mol Sci 2023; 24:2096. [PMID: 36768418 PMCID: PMC9916532 DOI: 10.3390/ijms24032096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/23/2022] [Accepted: 12/29/2022] [Indexed: 01/21/2023] Open
Abstract
Lipophagy plays an important role in regulating lipid metabolism in mammals. The exact function of autophagy-related protein 2 (Atg2) has been investigated in mammals, but research on the existence and functions of Atg2 in Apis mellifera (AmAtg2) is still limited. Here, autophagy occurred in honeybee pupae, which targeted lipid droplets (LDs) in fat body, namely lipophagy, which was verified by co-localization of LDs with microtubule-associated protein 1A/1B light chain 3 beta (LC3). Moreover, AmAtg2 homolog B (AmAtg2B) was expressed specifically in pupal fat body, which indicated that AmAtg2B might have special function in fat body. Further, AmAtg2B antibody neutralization and AmAtg2B knock-down were undertaken to verify the functions in pupae. Results showed that low expression of AmAtg2B at the protein and transcriptional levels led to lipophagy inhibition, which down-regulated the expression levels of proteins and genes related to lipolysis. Altogether, results in this study systematically revealed that AmAtg2B interfered with lipophagy and then caused abnormal lipolysis in the pupal stage.
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Affiliation(s)
| | | | | | | | - Bao-Hua Xu
- College of Animal Science and Technology, Shandong Agricultural University, Tai’an 271018, China
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8
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Jiang S, Miao Z. High-fat diet induces intestinal mucosal barrier dysfunction in ulcerative colitis: emerging mechanisms and dietary intervention perspective. Am J Transl Res 2023; 15:653-677. [PMID: 36915785 PMCID: PMC10006746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 01/09/2023] [Indexed: 03/16/2023]
Abstract
The incidence of ulcerative colitis (UC) is increasing worldwide, but its pathogenesis remains largely unclear. The intestinal mucosa is a barrier that maintains the stability of the body's internal environment, and dysfunction of this barrier leads to the occurrence and aggravation of UC. A high-fat diet (HFD) contains more animal fat and low fiber, and accumulating evidence has shown that long-term intake of an HFD is associated with UC. The mechanism linking an HFD with intestinal mucosal barrier disruption is multifactorial, and it typically involves microbiota dysbiosis and altered metabolism of fatty acids, bile acids, and tryptophan. Dysbiosis-induced metabolic changes can enhance intestinal permeability through multiple pathways. These changes modulate the programmed death of intestinal epithelial cells, inhibit the secretion of goblet cells and Paneth cells, and impair intercellular interactions. Gut metabolites can also induce intestinal immune imbalance by stimulating multiple proinflammatory signaling pathways and decreasing the effect of anti-inflammatory immune cells. In this review, we critically analyze the molecular mechanisms by which an HFD disrupts the intestinal mucosal barrier (IMB) and contributes to the development of UC. We also discuss the application and future direction of dietary intervention in the treatment of the IMB and prevention of UC.
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Affiliation(s)
- Shijing Jiang
- First Clinical Medical College, Nanjing University of Chinese Medicine Nanjing, Jiangsu, China
| | - Zhiwei Miao
- Department of Gastroenterology, Zhangjiagang TCM Hospital Affiliated to Nanjing University of Chinese Medicine Zhangjiagang, Suzhou, Jiangsu, China
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9
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Guyard V, Monteiro-Cardoso VF, Omrane M, Sauvanet C, Houcine A, Boulogne C, Ben Mbarek K, Vitale N, Faklaris O, El Khallouki N, Thiam AR, Giordano F. ORP5 and ORP8 orchestrate lipid droplet biogenesis and maintenance at ER-mitochondria contact sites. J Cell Biol 2022; 221:e202112107. [PMID: 35969857 PMCID: PMC9375143 DOI: 10.1083/jcb.202112107] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 05/30/2022] [Accepted: 07/05/2022] [Indexed: 12/29/2022] Open
Abstract
Lipid droplets (LDs) are the primary organelles of lipid storage, buffering energy fluctuations of the cell. They store neutral lipids in their core that is surrounded by a protein-decorated phospholipid monolayer. LDs arise from the endoplasmic reticulum (ER). The ER protein seipin, localizing at ER-LD junctions, controls LD nucleation and growth. However, how LD biogenesis is spatially and temporally coordinated remains elusive. Here, we show that the lipid transfer proteins ORP5 and ORP8 control LD biogenesis at mitochondria-associated ER membrane (MAM) subdomains, enriched in phosphatidic acid. We found that ORP5/8 regulates seipin recruitment to these MAM-LD contacts, and their loss impairs LD biogenesis. Importantly, the integrity of ER-mitochondria contact sites is crucial for ORP5/8 function in regulating seipin-mediated LD biogenesis. Our study uncovers an unprecedented ORP5/8 role in orchestrating LD biogenesis and maturation at MAMs and brings novel insights into the metabolic crosstalk between mitochondria, ER, and LDs at the membrane contact sites.
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Affiliation(s)
- Valentin Guyard
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
- Inserm U1280, Gif-sur-Yvette, France
| | - Vera Filipa Monteiro-Cardoso
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
- Inserm U1280, Gif-sur-Yvette, France
| | - Mohyeddine Omrane
- Laboratoire de Physique de l’École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, Paris, France
| | - Cécile Sauvanet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
- Inserm U1280, Gif-sur-Yvette, France
| | - Audrey Houcine
- Institut Jacques Monod, CNRS, UMR7592, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Claire Boulogne
- Imagerie-Gif, Electron Microscopy Facility, Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Kalthoum Ben Mbarek
- Laboratoire de Physique de l’École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, Paris, France
| | - Nicolas Vitale
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, UPR-321267000 Strasbourg, France
| | - Orestis Faklaris
- MRI, BioCampus Montpellier, CRBM, Univ. Montpellier, CNRS, Montpellier, France
| | - Naima El Khallouki
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
- Inserm U1280, Gif-sur-Yvette, France
| | - Abdou Rachid Thiam
- Laboratoire de Physique de l’École Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, Paris, France
| | - Francesca Giordano
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
- Inserm U1280, Gif-sur-Yvette, France
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10
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Ghanem M, Lewis GF, Xiao C. Recent advances in cytoplasmic lipid droplet metabolism in intestinal enterocyte. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159197. [PMID: 35820577 DOI: 10.1016/j.bbalip.2022.159197] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 06/03/2022] [Accepted: 06/14/2022] [Indexed: 11/30/2022]
Abstract
Processing of dietary fats in the intestine is a highly regulated process that influences whole-body energy homeostasis and multiple physiological functions. Dysregulated lipid handling in the intestine leads to dyslipidemia and atherosclerotic cardiovascular disease. In intestinal enterocytes, lipids are incorporated into lipoproteins and cytoplasmic lipid droplets (CLDs). Lipoprotein synthesis and CLD metabolism are inter-connected pathways with multiple points of regulation. This review aims to highlight recent advances in the regulatory mechanisms of lipid processing in the enterocyte, with particular focus on CLDs. In-depth understanding of the regulation of lipid metabolism in the enterocyte may help identify therapeutic targets for the treatment and prevention of metabolic disorders.
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Affiliation(s)
- Murooj Ghanem
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Gary F Lewis
- Departments of Medicine and Physiology, University of Toronto, and University Health Network, Toronto, ON, Canada
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
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11
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Wit M, Trujillo-Viera J, Strohmeyer A, Klingenspor M, Hankir M, Sumara G. When fat meets the gut-focus on intestinal lipid handling in metabolic health and disease. EMBO Mol Med 2022; 14:e14742. [PMID: 35437952 PMCID: PMC9081902 DOI: 10.15252/emmm.202114742] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 12/12/2022] Open
Abstract
The regular overconsumption of energy‐dense foods (rich in lipids and sugars) results in elevated intestinal nutrient absorption and consequently excessive accumulation of lipids in the liver, adipose tissue, skeletal muscles, and other organs. This can eventually lead to obesity and obesity‐associated diseases such as type 2 diabetes (T2D), non‐alcoholic fatty liver disease (NAFLD), cardiovascular disease, and certain types of cancer, as well as aggravate inflammatory bowel disease (IBD). Therefore, targeting the pathways that regulate intestinal nutrient absorption holds significant therapeutic potential. In this review, we discuss the molecular and cellular mechanisms controlling intestinal lipid handling, their relevance to the development of metabolic diseases, and emerging therapeutic strategies.
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Affiliation(s)
- Magdalena Wit
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland
| | - Jonathan Trujillo-Viera
- Rudolf-Virchow-Zentrum, Center for Integrative and Translational Bioimaging, University of Würzburg, Würzburg, Germany
| | - Akim Strohmeyer
- Chair for Molecular Nutritional Medicine, Technical University of Munich, TUM School of Life Sciences Weihenstephan, Freising, Germany.,EKFZ - Else Kröner-Fresenius-Center for Nutritional Medicine, Technical University of Munich, Munich, Germany.,ZIEL - Institute for Food & Health, Technical University of Munich, Freising, Germany
| | - Martin Klingenspor
- Chair for Molecular Nutritional Medicine, Technical University of Munich, TUM School of Life Sciences Weihenstephan, Freising, Germany.,EKFZ - Else Kröner-Fresenius-Center for Nutritional Medicine, Technical University of Munich, Munich, Germany.,ZIEL - Institute for Food & Health, Technical University of Munich, Freising, Germany
| | - Mohammed Hankir
- Department of General, Visceral, Transplant, Vascular and Pediatric Surgery, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Grzegorz Sumara
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warszawa, Poland
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12
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Li Y, Li Z, Ngandiri DA, Llerins Perez M, Wolf A, Wang Y. The Molecular Brakes of Adipose Tissue Lipolysis. Front Physiol 2022; 13:826314. [PMID: 35283787 PMCID: PMC8907745 DOI: 10.3389/fphys.2022.826314] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/10/2022] [Indexed: 12/11/2022] Open
Abstract
Adaptation to changes in energy availability is pivotal for the survival of animals. Adipose tissue, the body’s largest reservoir of energy and a major source of metabolic fuel, exerts a buffering function for fluctuations in nutrient availability. This functional plasticity ranges from energy storage in the form of triglycerides during periods of excess energy intake to energy mobilization via lipolysis in the form of free fatty acids for other organs during states of energy demands. The subtle balance between energy storage and mobilization is important for whole-body energy homeostasis; its disruption has been implicated as contributing to the development of insulin resistance, type 2 diabetes and cancer cachexia. As a result, adipocyte lipolysis is tightly regulated by complex regulatory mechanisms involving lipases and hormonal and biochemical signals that have opposing effects. In thermogenic brown and brite adipocytes, lipolysis stimulation is the canonical way for the activation of non-shivering thermogenesis. Lipolysis proceeds in an orderly and delicately regulated manner, with stimulation through cell-surface receptors via neurotransmitters, hormones, and autocrine/paracrine factors that activate various intracellular signal transduction pathways and increase kinase activity. The subsequent phosphorylation of perilipins, lipases, and cofactors initiates the translocation of key lipases from the cytoplasm to lipid droplets and enables protein-protein interactions to assemble the lipolytic machinery on the scaffolding perilipins at the surface of lipid droplets. Although activation of lipolysis has been well studied, the feedback fine-tuning is less well appreciated. This review focuses on the molecular brakes of lipolysis and discusses some of the divergent fine-tuning strategies in the negative feedback regulation of lipolysis, including delicate negative feedback loops, intermediary lipid metabolites-mediated allosteric regulation and dynamic protein–protein interactions. As aberrant adipocyte lipolysis is involved in various metabolic diseases and releasing the brakes on lipolysis in thermogenic adipocytes may activate thermogenesis, targeting adipocyte lipolysis is thus of therapeutic interest.
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13
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Zhang S, Peng X, Yang S, Li X, Huang M, Wei S, Liu J, He G, Zheng H, Yang L, Li H, Fan Q. The regulation, function, and role of lipophagy, a form of selective autophagy, in metabolic disorders. Cell Death Dis 2022; 13:132. [PMID: 35136038 PMCID: PMC8825858 DOI: 10.1038/s41419-022-04593-3] [Citation(s) in RCA: 80] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 01/07/2022] [Accepted: 01/27/2022] [Indexed: 12/15/2022]
Abstract
Autophagy is a conserved method of quality control in which cytoplasmic contents are degraded via lysosomes. Lipophagy, a form of selective autophagy and a novel type of lipid metabolism, has recently received much attention. Lipophagy is defined as the autophagic degradation of intracellular lipid droplets (LDs). Although much remains unknown, lipophagy appears to play a significant role in many organisms, cell types, metabolic states, and diseases. It participates in the regulation of intracellular lipid storage, intracellular free lipid levels (e.g., fatty acids), and energy balance. However, it remains unclear how intracellular lipids regulate autophagy. Impaired lipophagy can cause cells to become sensitive to death stimuli and may be responsible for the onset of a variety of diseases, including nonalcoholic fatty liver disease and metabolic syndrome. Like autophagy, the role of lipophagy in cancer is poorly understood, although analysis of specific autophagy receptors has helped to expand the diversity of chemotherapeutic targets. These studies have stimulated increasing interest in the role of lipophagy in the pathogenesis and treatment of cancer and other human diseases.
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Affiliation(s)
- Sheng Zhang
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Xueqiang Peng
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Shuo Yang
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Xinyu Li
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Mingyao Huang
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Shibo Wei
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Jiaxing Liu
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Guangpeng He
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Hongyu Zheng
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Liang Yang
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Hangyu Li
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China
| | - Qing Fan
- Department of General Surgery, The Fourth Affiliated Hospital, China Medical University, Shenyang, 110032, China.
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14
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A Decade of Mighty Lipophagy: What We Know and What Facts We Need to Know? OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:5539161. [PMID: 34777688 PMCID: PMC8589519 DOI: 10.1155/2021/5539161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 09/30/2021] [Accepted: 10/15/2021] [Indexed: 12/24/2022]
Abstract
Lipids are integral cellular components that act as substrates for energy provision, signaling molecules, and essential constituents of biological membranes along with a variety of other biological functions. Despite their significance, lipid accumulation may result in lipotoxicity, impair autophagy, and lysosomal function that may lead to certain diseases and metabolic syndromes like obesity and even cell death. Therefore, these lipids are continuously recycled and redistributed by the process of selective autophagy specifically termed as lipophagy. This selective form of autophagy employs lysosomes for the maintenance of cellular lipid homeostasis. In this review, we have reviewed the current literature about how lipid droplets (LDs) are recruited towards lysosomes, cross-talk between a variety of autophagy receptors present on LD surface and lysosomes, and lipid hydrolysis by lysosomal enzymes. In addition to it, we have tried to answer most of the possible questions related to lipophagy regulation at different levels. Moreover, in the last part of this review, we have discussed some of the pathological states due to the accumulation of these LDs and their possible treatments under the light of currently available findings.
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15
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Melatonin Attenuates Dextran Sodium Sulfate Induced Colitis in Obese Mice. Pharmaceuticals (Basel) 2021; 14:ph14080822. [PMID: 34451919 PMCID: PMC8399719 DOI: 10.3390/ph14080822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 01/03/2023] Open
Abstract
Epidemiological studies have indicated that obesity is an independent risk factor for colitis and that a high-fat diet (HFD) increases the deterioration of colitis-related indicators in mice. Melatonin has multiple anti-inflammatory effects, including inhibiting tumor growth and regulating immune defense. However, the mechanism of its activity in ameliorating obesity-promoted colitis is still unclear. This study explored the possibility that melatonin has beneficial functions in HFD-induced dextran sodium sulfate (DSS)-induced colitis in mice. Here, we revealed that HFD-promoted obesity accelerated DSS-induced colitis, while melatonin intervention improved colitis. Melatonin significantly alleviated inflammation by increasing anti-inflammatory cytokine release and reducing the levels of proinflammatory cytokines in HFD- and DSS-treated mice. Furthermore, melatonin expressed antioxidant activities and reversed intestinal barrier integrity, resulting in improved colitis in DSS-treated obese mice. We also found that melatonin could reduce the ability of inflammatory cells to utilize fatty acids and decrease the growth-promoting effect of lipids by inhibiting autophagy. Taken together, our study indicates that the inhibitory effect of melatonin on autophagy weakens the lipid-mediated prosurvival advantage, which suggests that melatonin-targeted autophagy may provide an opportunity to prevent colitis in obese individuals.
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16
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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: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [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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17
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Zembroski AS, Xiao C, Buhman KK. The Roles of Cytoplasmic Lipid Droplets in Modulating Intestinal Uptake of Dietary Fat. Annu Rev Nutr 2021; 41:79-104. [PMID: 34283920 DOI: 10.1146/annurev-nutr-110320-013657] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dietary fat absorption is required for health but also contributes to hyperlipidemia and metabolic disease when dysregulated. One step in the process of dietary fat absorption is the formation of cytoplasmic lipid droplets (CLDs) in small intestinal enterocytes; these CLDs serve as dynamic triacylglycerol storage organelles that influence the rate at which dietary fat is absorbed. Recent studies have uncovered novel factors regulating enterocyte CLD metabolism that in turn influence the absorption of dietary fat. These include peroxisome proliferator-activated receptor α activation, compartmentalization of different lipid pools, the gut microbiome, liver X receptor and farnesoid X receptor activation, obesity, and physiological factors stimulating CLD mobilization. Understanding how enterocyte CLD metabolism is regulated is key in modulating the absorption of dietary fat in the prevention of hyperlipidemia and its associated metabolic disorders. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Alyssa S Zembroski
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana 47907, USA;
| | - Changting Xiao
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, Indiana 47907, USA;
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18
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Filali-Mouncef Y, Hunter C, Roccio F, Zagkou S, Dupont N, Primard C, Proikas-Cezanne T, Reggiori F. The ménage à trois of autophagy, lipid droplets and liver disease. Autophagy 2021; 18:50-72. [PMID: 33794741 PMCID: PMC8865253 DOI: 10.1080/15548627.2021.1895658] [Citation(s) in RCA: 138] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Autophagic pathways cross with lipid homeostasis and thus provide energy and essential building blocks that are indispensable for liver functions. Energy deficiencies are compensated by breaking down lipid droplets (LDs), intracellular organelles that store neutral lipids, in part by a selective type of autophagy, referred to as lipophagy. The process of lipophagy does not appear to be properly regulated in fatty liver diseases (FLDs), an important risk factor for the development of hepatocellular carcinomas (HCC). Here we provide an overview on our current knowledge of the biogenesis and functions of LDs, and the mechanisms underlying their lysosomal turnover by autophagic processes. This review also focuses on nonalcoholic steatohepatitis (NASH), a specific type of FLD characterized by steatosis, chronic inflammation and cell death. Particular attention is paid to the role of macroautophagy and macrolipophagy in relation to the parenchymal and non-parenchymal cells of the liver in NASH, as this disease has been associated with inappropriate lipophagy in various cell types of the liver.Abbreviations: ACAT: acetyl-CoA acetyltransferase; ACAC/ACC: acetyl-CoA carboxylase; AKT: AKT serine/threonine kinase; ATG: autophagy related; AUP1: AUP1 lipid droplet regulating VLDL assembly factor; BECN1/Vps30/Atg6: beclin 1; BSCL2/seipin: BSCL2 lipid droplet biogenesis associated, seipin; CMA: chaperone-mediated autophagy; CREB1/CREB: cAMP responsive element binding protein 1; CXCR3: C-X-C motif chemokine receptor 3; DAGs: diacylglycerols; DAMPs: danger/damage-associated molecular patterns; DEN: diethylnitrosamine; DGAT: diacylglycerol O-acyltransferase; DNL: de novo lipogenesis; EHBP1/NACSIN (EH domain binding protein 1); EHD2/PAST2: EH domain containing 2; CoA: coenzyme A; CCL/chemokines: chemokine ligands; CCl4: carbon tetrachloride; ER: endoplasmic reticulum; ESCRT: endosomal sorting complexes required for transport; FA: fatty acid; FFAs: free fatty acids; FFC: high saturated fats, fructose and cholesterol; FGF21: fibroblast growth factor 21; FITM/FIT: fat storage inducing transmembrane protein; FLD: fatty liver diseases; FOXO: forkhead box O; GABARAP: GABA type A receptor-associated protein; GPAT: glycerol-3-phosphate acyltransferase; HCC: hepatocellular carcinoma; HDAC6: histone deacetylase 6; HECT: homologous to E6-AP C-terminus; HFCD: high fat, choline deficient; HFD: high-fat diet; HSCs: hepatic stellate cells; HSPA8/HSC70: heat shock protein family A (Hsp70) member 8; ITCH/AIP4: itchy E3 ubiquitin protein ligase; KCs: Kupffer cells; LAMP2A: lysosomal associated membrane protein 2A; LDs: lipid droplets; LDL: low density lipoprotein; LEP/OB: leptin; LEPR/OBR: leptin receptor; LIPA/LAL: lipase A, lysosomal acid type; LIPE/HSL: lipase E, hormone sensitive type; LIR: LC3-interacting region; LPS: lipopolysaccharide; LSECs: liver sinusoidal endothelial cells; MAGs: monoacylglycerols; MAPK: mitogen-activated protein kinase; MAP3K5/ASK1: mitogen-activated protein kinase kinase kinase 5; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MCD: methionine-choline deficient; MGLL/MGL: monoglyceride lipase; MLXIPL/ChREBP: MLX interacting protein like; MTORC1: mechanistic target of rapamycin kinase complex 1; NAFLD: nonalcoholic fatty liver disease; NAS: NAFLD activity score; NASH: nonalcoholic steatohepatitis; NPC: NPC intracellular cholesterol transporter; NR1H3/LXRα: nuclear receptor subfamily 1 group H member 3; NR1H4/FXR: nuclear receptor subfamily 1 group H member 4; PDGF: platelet derived growth factor; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PLIN: perilipin; PNPLA: patatin like phospholipase domain containing; PNPLA2/ATGL: patatin like phospholipase domain containing 2; PNPLA3/adiponutrin: patatin like phospholipase domain containing 3; PPAR: peroxisome proliferator activated receptor; PPARA/PPARα: peroxisome proliferator activated receptor alpha; PPARD/PPARδ: peroxisome proliferator activated receptor delta; PPARG/PPARγ: peroxisome proliferator activated receptor gamma; PPARGC1A/PGC1α: PPARG coactivator 1 alpha; PRKAA/AMPK: protein kinase AMP-activated catalytic subunit; PtdIns3K: class III phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; PTEN: phosphatase and tensin homolog; ROS: reactive oxygen species; SE: sterol esters; SIRT1: sirtuin 1; SPART/SPG20: spartin; SQSTM1/p62: sequestosome 1; SREBF1/SREBP1c: sterol regulatory element binding transcription factor 1; TAGs: triacylglycerols; TFE3: transcription factor binding to IGHM enhancer 3; TFEB: transcription factor EB; TGFB1/TGFβ: transforming growth factor beta 1; Ub: ubiquitin; UBE2G2/UBC7: ubiquitin conjugating enzyme E2 G2; ULK1/Atg1: unc-51 like autophagy activating kinase 1; USF1: upstream transcription factor 1; VLDL: very-low density lipoprotein; VPS: vacuolar protein sorting; WIPI: WD-repeat domain, phosphoinositide interacting; WDR: WD repeat domain.
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Affiliation(s)
- Yasmina Filali-Mouncef
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, AV Groningen, The Netherlands
| | - Catherine Hunter
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, Tuebingen, Germany.,International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Developmental Biology and Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Federica Roccio
- Institut Necker Enfants-Malades (INEM), INSERM U1151-CNRS UMR 8253, Université de Paris, Paris, France
| | - Stavroula Zagkou
- Adjuvatis, Lyon, France.,Laboratory of Tissue Biology and Therapeutic Engineering, CNRS UMR 5305, Université Claude Bernard Lyon 1, France
| | - Nicolas Dupont
- Institut Necker Enfants-Malades (INEM), INSERM U1151-CNRS UMR 8253, Université de Paris, Paris, France
| | | | - Tassula Proikas-Cezanne
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, Tuebingen, Germany.,International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Developmental Biology and Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Fulvio Reggiori
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, AV Groningen, The Netherlands
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19
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Li W, He P, Huang Y, Li YF, Lu J, Li M, Kurihara H, Luo Z, Meng T, Onishi M, Ma C, Jiang L, Hu Y, Gong Q, Zhu D, Xu Y, Liu R, Liu L, Yi C, Zhu Y, Ma N, Okamoto K, Xie Z, Liu J, He RR, Feng D. Selective autophagy of intracellular organelles: recent research advances. Theranostics 2021; 11:222-256. [PMID: 33391472 PMCID: PMC7681076 DOI: 10.7150/thno.49860] [Citation(s) in RCA: 234] [Impact Index Per Article: 78.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 09/04/2020] [Indexed: 12/11/2022] Open
Abstract
Macroautophagy (hereafter called autophagy) is a highly conserved physiological process that degrades over-abundant or damaged organelles, large protein aggregates and invading pathogens via the lysosomal system (the vacuole in plants and yeast). Autophagy is generally induced by stress, such as oxygen-, energy- or amino acid-deprivation, irradiation, drugs, etc. In addition to non-selective bulk degradation, autophagy also occurs in a selective manner, recycling specific organelles, such as mitochondria, peroxisomes, ribosomes, endoplasmic reticulum (ER), lysosomes, nuclei, proteasomes and lipid droplets (LDs). This capability makes selective autophagy a major process in maintaining cellular homeostasis. The dysfunction of selective autophagy is implicated in neurodegenerative diseases (NDDs), tumorigenesis, metabolic disorders, heart failure, etc. Considering the importance of selective autophagy in cell biology, we systemically review the recent advances in our understanding of this process and its regulatory mechanisms. We emphasize the 'cargo-ligand-receptor' model in selective autophagy for specific organelles or cellular components in yeast and mammals, with a focus on mitophagy and ER-phagy, which are finely described as types of selective autophagy. Additionally, we highlight unanswered questions in the field, helping readers focus on the research blind spots that need to be broken.
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20
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Schittmayer M, Vujic N, Darnhofer B, Korbelius M, Honeder S, Kratky D, Birner-Gruenberger R. Spatially Resolved Activity-based Proteomic Profiles of the Murine Small Intestinal Lipases. Mol Cell Proteomics 2020; 19:2104-2115. [PMID: 33023980 PMCID: PMC7710144 DOI: 10.1074/mcp.ra120.002171] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/28/2020] [Indexed: 01/05/2023] Open
Abstract
Despite the crucial function of the small intestine in nutrient uptake our understanding of the molecular events underlying the digestive function is still rudimentary. Recent studies demonstrated that enterocytes do not direct the entire dietary triacylglycerol toward immediate chylomicron synthesis. Especially after high-fat challenges, parts of the resynthesized triacylglycerol are packaged into cytosolic lipid droplets for transient storage in the endothelial layer of the small intestine. The reason for this temporary storage of triacylglycerol is not completely understood. To utilize lipids from cytosolic lipid droplets for chylomicron synthesis in the endoplasmic reticulum, stored triacylglycerol has to be hydrolyzed either by cytosolic lipolysis or lipophagy. Interestingly, triacylglycerol storage and chylomicron secretion rates are unevenly distributed along the small intestine, with the proximal jejunum exhibiting the highest intermittent storage capacity. We hypothesize that correlating hydrolytic enzyme activities with the reported distribution of triacylglycerol storage and chylomicron secretion in different sections of the small intestine is a promising strategy to determine key enzymes in triacylglycerol remobilization. We employed a serine hydrolase specific activity-based labeling approach in combination with quantitative proteomics to identify and rank hydrolases based on their relative activity in 11 sections of the small intestine. Moreover, we identified several clusters of enzymes showing similar activity distribution along the small intestine. Merging our activity-based results with substrate specificity and subcellular localization known from previous studies, carboxylesterase 2e and arylacetamide deacetylase emerge as promising candidates for triacylglycerol mobilization from cytosolic lipid droplets in enterocytes.
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Affiliation(s)
- Matthias Schittmayer
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria; Diagnostic and Research Institute of Pathology, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
| | - Nemanja Vujic
- Gottfried Schatz Research Center, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Barbara Darnhofer
- Diagnostic and Research Institute of Pathology, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Melanie Korbelius
- Gottfried Schatz Research Center, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Sophie Honeder
- Diagnostic and Research Institute of Pathology, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
| | - Ruth Birner-Gruenberger
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria; Diagnostic and Research Institute of Pathology, Medical University Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
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21
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Miceli C, Roccio F, Penalva-Mousset L, Burtin M, Leroy C, Nemazanyy I, Kuperwasser N, Pontoglio M, Friedlander G, Morel E, Terzi F, Codogno P, Dupont N. The primary cilium and lipophagy translate mechanical forces to direct metabolic adaptation of kidney epithelial cells. Nat Cell Biol 2020; 22:1091-1102. [PMID: 32868900 DOI: 10.1038/s41556-020-0566-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 07/28/2020] [Indexed: 12/19/2022]
Abstract
Organs and cells must adapt to shear stress induced by biological fluids, but how fluid flow contributes to the execution of specific cell programs is poorly understood. Here we show that shear stress favours mitochondrial biogenesis and metabolic reprogramming to ensure energy production and cellular adaptation in kidney epithelial cells. Shear stress stimulates lipophagy, contributing to the production of fatty acids that provide mitochondrial substrates to generate ATP through β-oxidation. This flow-induced process is dependent on the primary cilia located on the apical side of epithelial cells. The interplay between fluid flow and lipid metabolism was confirmed in vivo using a unilateral ureteral obstruction mouse model. Finally, primary cilium-dependent lipophagy and mitochondrial biogenesis are required to support energy-consuming cellular processes such as glucose reabsorption, gluconeogenesis and cytoskeletal remodelling. Our findings demonstrate how primary cilia and autophagy are involved in the translation of mechanical forces into metabolic adaptation.
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Affiliation(s)
- Caterina Miceli
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France.,Center for Autophagy Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Federica Roccio
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France
| | - Lucille Penalva-Mousset
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France
| | - Martine Burtin
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France
| | - Christine Leroy
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France
| | - Ivan Nemazanyy
- Platform for Metabolic Analyses, Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS 3633, Paris, France
| | - Nicolas Kuperwasser
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France
| | - Marco Pontoglio
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France
| | - Gérard Friedlander
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France
| | - Etienne Morel
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France
| | - Fabiola Terzi
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France
| | - Patrice Codogno
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France.
| | - Nicolas Dupont
- Institut Necker Enfants-Malades (INEM), INSERM U1151/CNRS UMR 8253, Université de Paris, Paris, France.
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22
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Masclaux-Daubresse C, d’Andrea S, Bouchez I, Cacas JL. Reserve lipids and plant autophagy. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2854-2861. [PMID: 32080724 PMCID: PMC7260719 DOI: 10.1093/jxb/eraa082] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/20/2020] [Indexed: 05/21/2023]
Abstract
Autophagy is a universal mechanism that facilitates the degradation of unwanted cytoplasmic components in eukaryotic cells. In this review, we highlight recent developments in the investigation of the role of autophagy in lipid homeostasis in plants by comparison with algae, yeast, and animals. We consider the storage compartments that form the sources of lipids in plants, and the roles that autophagy plays in the synthesis of triacylglycerols and in the formation and maintenance of lipid droplets. We also consider the relationship between lipids and the biogenesis of autophagosomes, and the role of autophagy in the degradation of lipids in plants.
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Affiliation(s)
| | - Sabine d’Andrea
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Isabelle Bouchez
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
| | - Jean-Luc Cacas
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, Versailles, France
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23
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Morel E. Endoplasmic Reticulum Membrane and Contact Site Dynamics in Autophagy Regulation and Stress Response. Front Cell Dev Biol 2020; 8:343. [PMID: 32548114 PMCID: PMC7272771 DOI: 10.3389/fcell.2020.00343] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/20/2020] [Indexed: 12/15/2022] Open
Abstract
Autophagy mobilizes a variety of intracellular endomembranes to ensure a proper stress response and the maintenance of cellular homeostasis. While the process of de novo biogenesis of pre-autophagic structures is not yet fully characterized, the role of the endoplasmic reticulum (ER) appears to be crucial in early steps of autophagic process. Here, I review and discuss various aspects of ER and ER-driven membrane contact site requirements and effects on mammalian organelles and endomembrane biogenesis, in particular during the early steps of autophagy-related membrane dynamics.
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Affiliation(s)
- Etienne Morel
- Cell Biology Department, Institut Necker-Enfants Malades (INEM), INSERM U1151-CNRS UMR 8253, Université de Paris, Paris, France
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24
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A Newly Identified LncRNA LncIMF4 Controls Adipogenesis of Porcine Intramuscular Preadipocyte through Attenuating Autophagy to Inhibit Lipolysis. Animals (Basel) 2020; 10:ani10060926. [PMID: 32466602 PMCID: PMC7341528 DOI: 10.3390/ani10060926] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/18/2020] [Accepted: 05/18/2020] [Indexed: 01/12/2023] Open
Abstract
Simple Summary Compared with lean-type pigs, the intramuscular fat content of fat-type Bamei pigs was greater. LncRNA, as a vital regular, plays an important role in numerous biological processes. However, there were a few studies on the role of lncRNAs during IMF development in pigs. Based on these, lncRNA sequencing in intramuscular adipocytes was performed to explore the effects of lncRNA on intramuscular fat deposition. RNA sequencing analysis of intramuscular adipocyte from Bamei pig (fat-type) and Yorkshire pig (lean-type) indicated that, a novel lncRNA, lncIMF4, was associated with intramuscular adipogenesis. In addition, further researches showed that knockdown lncIMF4 promoted proliferation and adipogenic differentiation of porcine intramuscular adipocytes, whereas inhibited autophagy. Moreover, knockdown lncIMF4 facilitated intramuscular adipogenesis through attenuating autophagy to repress the lipolysis. Our findings will contribute to better understand the mechanism of lncRNA controlling adipogenesis in pig. Furthermore, it also provides a new perspective to study the role of lncRNA in regulating porcine intramuscular adipogenesis for promoting pork quality. Abstract Intramuscular fat (IMF) is implicated in juiciness, tenderness, and flavor of pork. Meat quality of Chinese fat-type pig is much better than that of lean-type pig because of its higher IMF content. LncRNA is a vital regulator that contributes to adipogenesis. However, it is unknown about the regulation of lncRNA on IMF content. Here, by RNA sequence analysis of intramuscular adipocyte from Bamei pig (fat-type) and Yorkshire pig (lean-type), we found that a novel lncRNA, lncIMF4, was associated with adipogenesis. LncIMF4, abundant in adipose, differently expressed along with intramuscular preadipocyte proliferation and differentiation. Meanwhile, it is located both in cytoplasm and nucleus. Besides, lncIMF4 knockdown promoted proliferation and differentiation of porcine intramuscular preadipocytes, whereas inhibited autophagy. Moreover, lncIMF4 knockdown facilitated intramuscular adipogenesis through attenuating autophagy to repress the lipolysis. Our findings will contribute to understand better the mechanism of lncRNA controlling intramuscular adipogenesis for promoting pork quality.
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25
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Seo SH, Jung JY, Park K, Hossini AM, Zouboulis CC, Lee SE. Autophagy regulates lipid production and contributes to the sebosuppressive effect of retinoic acid in human SZ95 sebocytes. J Dermatol Sci 2020; 98:128-136. [PMID: 32354609 DOI: 10.1016/j.jdermsci.2020.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 03/20/2020] [Accepted: 04/06/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Autophagy is a catabolic process for eliminating damaged organelles or proteins to maintain cellular homeostasis. Recently, lipids have been demonstrated to be targets for autophagosomal degradation. Therefore, autophagy might be involved in sebaceous gland homeostasis, however, relevant data are lacking. OBJECTIVES We investigated the role of autophagy in sebaceous lipogenesis and its regulatory mechanisms in human SZ95 sebocytes. We also examined the possible role of autophagy in 13-cis-retinoic acid (13-cis-RA)-mediated sebosuppression. METHODS Autophagy markers expression was examined by immunohistochemistry in normal and acne lesional skin. SZ95 sebocytes were treated with autophagy inhibitors under starvation or treated with a combination of testosterone and linoleic acid (testosterone/LA), with or without autophagy inducer rapamycin or 13-cis-RA. Lipids were assessed by BODIPY and quantitative Nile Red staining. Autophagy-related gene 7 small interference RNA was used to confirm the role of autophagy on the sebosuppressive effect of rapamycin or 13-cis-RA. RESULTS Autophagy markers were strongly expressed in the maturing sebaceous gland cells in healthy skin, whereas downregulated in the acne-involved sebaceous glands. Testosterone/LA or insulin-like growth factor-1 inhibited starvation-induced sebocyte autophagy. Pharmacological inhibition of autophagy led to increased sebaceous lipid accumulation. Contrary, rapamycin inhibited the testosterone/LA-induced lipogenesis and expression of fatty acid synthesis genes via activating the autophagy pathway. 13-cis-RA increased autophagy in SZ95 sebocytes, partly via FoxO1 activation, and inhibition of autophagy abolished the sebosuppressive effect of 13-cis-RA. CONCLUSIONS Autophagy plays an important role in the modulation of lipogenesis in human sebocytes and is involved in the sebostatic effect of 13-cis-RA.
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Affiliation(s)
- Seong Hoon Seo
- Department of Dermatology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | | | | | - Amir M Hossini
- Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Brandenburg Medical School Theodor Fontane, Dessau, Germany
| | - Christos C Zouboulis
- Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Brandenburg Medical School Theodor Fontane, Dessau, Germany
| | - Sang Eun Lee
- Department of Dermatology, Yonsei University College of Medicine, Seoul, Republic of Korea.
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26
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Grasp55 -/- mice display impaired fat absorption and resistance to high-fat diet-induced obesity. Nat Commun 2020; 11:1418. [PMID: 32184397 PMCID: PMC7078302 DOI: 10.1038/s41467-020-14912-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 01/31/2020] [Indexed: 12/27/2022] Open
Abstract
The Golgi apparatus plays a central role in the intracellular transport of macromolecules. However, molecular mechanisms of Golgi-mediated lipid transport remain poorly understood. Here, we show that genetic inactivation of the Golgi-resident protein GRASP55 in mice reduces whole-body fat mass via impaired intestinal fat absorption and evokes resistance to high-fat diet induced body weight gain. Mechanistic analyses reveal that GRASP55 participates in the Golgi-mediated lipid droplet (LD) targeting of some LD-associated lipases, such as ATGL and MGL, which is required for sustained lipid supply for chylomicron assembly and secretion. Consequently, GRASP55 deficiency leads to reduced chylomicron secretion and abnormally large LD formation in intestinal epithelial cells upon exogenous lipid challenge. Notably, deletion of dGrasp in Drosophila causes similar defects of lipid accumulation in the midgut. These results highlight the importance of the Golgi complex in cellular lipid regulation, which is evolutionary conserved, and uncover potential therapeutic targets for obesity-associated diseases. The physiological roles of the Golgi reassembly-stacking protein 55 (GRASP55/GORASP55) remain largely elusive. Here, the authors show that the Golgi-resident protein GRASP55 plays a crucial role in lipid homeostasis by regulating intestinal lipid uptake.
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27
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Regulation of intestinal lipid metabolism: current concepts and relevance to disease. Nat Rev Gastroenterol Hepatol 2020; 17:169-183. [PMID: 32015520 DOI: 10.1038/s41575-019-0250-7] [Citation(s) in RCA: 241] [Impact Index Per Article: 60.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/02/2019] [Indexed: 12/21/2022]
Abstract
Lipids entering the gastrointestinal tract include dietary lipids (triacylglycerols, cholesteryl esters and phospholipids) and endogenous lipids from bile (phospholipids and cholesterol) and from shed intestinal epithelial cells (enterocytes). Here, we comprehensively review the digestion, uptake and intracellular re-synthesis of intestinal lipids as well as their packaging into pre-chylomicrons in the endoplasmic reticulum, their modification in the Golgi apparatus and the exocytosis of the chylomicrons into the lamina propria and subsequently to lymph. We also discuss other fates of intestinal lipids, including intestinal HDL and VLDL secretion, cytosolic lipid droplets and fatty acid oxidation. In addition, we highlight the applicability of these findings to human disease and the development of therapeutics targeting lipid metabolism. Finally, we explore the emerging role of the gut microbiota in modulating intestinal lipid metabolism and outline key questions for future research.
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Yu S, Wang Z, Ding L, Yang L. The regulation of TFEB in lipid homeostasis of non-alcoholic fatty liver disease: Molecular mechanism and promising therapeutic targets. Life Sci 2020; 246:117418. [PMID: 32057899 DOI: 10.1016/j.lfs.2020.117418] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 02/01/2020] [Accepted: 02/06/2020] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD), which is characterized by disruption of lipid homeostasis, has been the leading cause of chronic liver disease worldwide. However, currently there is no effective therapy for NAFLD. Consequently, it is extremely urgent to explore the specific and effective target functioned as lipids regulator during the pathological process of NAFLD for the drug development. Transcription factor EB (TFEB) plays a crucial role in the regulation of lipid homeostasis through linking autophagy to energy metabolism at the transcriptional level. In this review, we summarize the currently available information regarding the mediation of TFEB in lipid metabolism during the pathological process of NAFLD, and the specific regulatory mechanism of TFEB activity. We further recapitulate TFEB as a promising therapeutic target for NAFLD, primarily through the regulation of lipid homeostasis, energy metabolism as well as immune defense. A better understanding of these key issues will be helpful to promote the development of therapeutic agents which specifically target TFEB to halt or reverse the pathological progression of NAFLD.
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Affiliation(s)
- Shenglan Yu
- Shanghai Key Laboratory of Complex Prescription and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China; Shanghai R&D Center for Standardization of Traditional Chinese Medicines, Shanghai 201203, China; Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zhengtao Wang
- Shanghai Key Laboratory of Complex Prescription and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China; Shanghai R&D Center for Standardization of Traditional Chinese Medicines, Shanghai 201203, China
| | - Lili Ding
- Shanghai Key Laboratory of Complex Prescription and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China; Shanghai R&D Center for Standardization of Traditional Chinese Medicines, Shanghai 201203, China.
| | - Li Yang
- Shanghai Key Laboratory of Complex Prescription and MOE Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China; Shanghai R&D Center for Standardization of Traditional Chinese Medicines, Shanghai 201203, China; Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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Zienkiewicz K, Zienkiewicz A. Degradation of Lipid Droplets in Plants and Algae-Right Time, Many Paths, One Goal. FRONTIERS IN PLANT SCIENCE 2020; 11:579019. [PMID: 33014002 PMCID: PMC7509404 DOI: 10.3389/fpls.2020.579019] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/24/2020] [Indexed: 05/05/2023]
Abstract
In eukaryotic cells, lipids in the form of triacylglycerols (TAGs) are the major reservoir of cellular carbon and energy. These TAGs are packed into specialized organelles called lipid droplets (LDs). They can be found in most, if not all, types of cells, from bacteria to human. Recent data suggest that rather than being simple storage organelles, LDs are very dynamic structures at the center of cellular metabolism. This is also true in plants and algae, where LDs have been implicated in many processes including energy supply; membrane structure, function, trafficking; and signal transduction. Plant and algal LDs also play a vital role in human life, providing multiple sources of food and fuel. Thus, a lot of attention has been paid to metabolism and function of these organelles in recent years. This review summarizes the most recent advances on LDs degradation as a key process for TAGs release. While the initial knowledge on this process came from studies in oilseeds, the findings of the last decade revealed high complexity and specific mechanisms of LDs degradation in plants and algae. This includes identification of numerous novel proteins associated with LDs as well as a prominent role for autophagy in this process. This review outlines, systemizes, and discusses the most current data on LDs catabolism in plants and algae.
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30
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Hu Q, Mao Y, Liu M, Luo R, Jiang R, Guo F. The active nuclear form of SREBP1 amplifies ER stress and autophagy via regulation of PERK. FEBS J 2019; 287:2348-2366. [PMID: 31736227 DOI: 10.1111/febs.15144] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 09/10/2019] [Accepted: 11/15/2019] [Indexed: 12/11/2022]
Abstract
Endoplasmic reticulum (ER) stress and autophagy dysfunction contribute to the establishment and progression of diverse pathologies. Proteolytic activation of the transcription factor nSREBP1 is induced under ER stress; however, little is known about how SREBP1 and its nuclear active form nSREBP1 influence autophagy and unfolded protein response (UPR) activation in osteosarcoma cells. Our research focused on the effect of SREBP1/nSREBP1 upon apoptosis and autophagy during ER stress and the molecular mechanisms involved. Here, we showed that nSREBP1 binds to the promoter of protein kinase RNA-like endoplasmic reticulum kinase (PERK) and then regulates ER stress, cell growth, cell apoptosis, and autophagy through the PERK signaling pathway. nSREBP1 increased PERK gene expression and phosphorylation. nSREBP1 was further demonstrated to activate ER stress response through stimulatory effects on PERK signaling. Overexpression of SREBP1 increased its cleavage and release of nSREBP1; therefore, the effect of SREBP1 is achieved through the enhancement of the expression of nSREBP1. Overexpression of SREBP1/nSREBP1 amplifies PERK-associated cell cycle stagnation with G1 phase arresting, S phase reducing, and G2-M phase delaying. LV-SREBP1/nSREBP1 can also bolster PERK's ER stress-associated pro-apoptotic effects. LV-SREBP1/nSREBP1 and LV-PERK can activate autophagy in ER stress response, along with the overexpression of SREBP1/nSREBP1 and PERK. This resulted in amplification of PERK-related changes to cell proliferation and ER stress-mediated apoptosis and autophagy, with the biological effect of nSREBP1 relying on PERK, which makes up one of the three branches of the UPR signaling pathway. This study reveals important roles for SREBP1/nSREBP1 in PERK signaling under ER stress. Furthermore, nSREBP1, the nuclear active form of SREBP1, is able to robustly augment the effects of PERK. Description of the link between PERK and SREBP1/nSREBP1 function offers an improved understanding of the ER stress response and insight into the biological function of SREBP1/nSREBP1.
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Affiliation(s)
- Qin Hu
- Department of Cell Biology and Genetics, Core Facility of Development Biology, Chongqing Medical University, Chongqing, China
| | - Yu Mao
- Department of Cell Biology and Genetics, Core Facility of Development Biology, Chongqing Medical University, Chongqing, China
| | - Min Liu
- Department of Cell Biology and Genetics, Core Facility of Development Biology, Chongqing Medical University, Chongqing, China
| | - Rui Luo
- Department of Cell Biology and Genetics, Core Facility of Development Biology, Chongqing Medical University, Chongqing, China
| | - Rong Jiang
- Laboratory of Stem Cells and Tissue Engineering, Chongqing Medical University, Chongqing, China
| | - Fengjin Guo
- Department of Cell Biology and Genetics, Core Facility of Development Biology, Chongqing Medical University, Chongqing, China
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31
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Tan Y, Jin Y, Wu X, Ren Z. PSMD1 and PSMD2 regulate HepG2 cell proliferation and apoptosis via modulating cellular lipid droplet metabolism. BMC Mol Biol 2019; 20:24. [PMID: 31703613 PMCID: PMC6842266 DOI: 10.1186/s12867-019-0141-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 10/29/2019] [Indexed: 01/18/2023] Open
Abstract
Background Obesity and nonalcoholic steatohepatitis (NASH) are well-known risk factors of hepatocellular carcinoma (HCC). The lipid-rich environment enhances the proliferation and metastasis abilities of tumor cells. Previous studies showed the effect of the ubiquitin–proteasome system (UPS) on tumor cell proliferation. However, the underlying mechanism of UPS in regulating the proliferation of lipid-rich tumor cells is not totally clear. Results Here, we identify two proteasome 26S subunits, non-ATPase 1 and 2 (PSMD1 and PSMD2), which regulate HepG2 cells proliferation via modulating cellular lipid metabolism. Briefly, the knockdown of PSMD1 and/or PSMD2 decreases the formation of cellular lipid droplets, the provider of the energy and membrane components for tumor cell proliferation. Mechanically, PSMD1 and PSMD2 regulate the expression of genes related to de novo lipid synthesis via p38-JNK and AKT signaling. Moreover, the high expression of PSMD1 and PSMD2 is significantly correlated with poor prognosis of HCC. Conclusion We demonstrate that PSMD1 and PSMD2 promote the proliferation of HepG2 cells via facilitating cellular lipid droplet accumulation. This study provides a potential therapeutic strategy for the treatment of lipid-rich tumors.
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Affiliation(s)
- Yanjie Tan
- Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture & Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Yi Jin
- Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture & Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Xiang Wu
- Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture & Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Zhuqing Ren
- Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture & Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China. .,Bio-Medical Center of Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China.
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32
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Jarc E, Petan T. Lipid Droplets and the Management of Cellular Stress. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2019; 92:435-452. [PMID: 31543707 PMCID: PMC6747940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Lipid droplets are cytosolic fat storage organelles present in most eukaryotic cells. Long regarded merely as inert fat reservoirs, they are now emerging as major regulators of cellular metabolism. They act as hubs that coordinate the pathways of lipid uptake, distribution, storage, and use in the cell. Recent studies have revealed that they are also essential components of the cellular stress response. One of the hallmark characteristics of lipid droplets is their capacity to buffer excess lipids and to finely tune their subsequent release based on specific cellular requirements. This simple feature of lipid droplet biology, buffering and delayed release of lipids, forms the basis for their pleiotropic roles in the cellular stress response. In stressed cells, lipid droplets maintain energy and redox homeostasis and protect against lipotoxicity by sequestering toxic lipids into their neutral lipid core. Their mobility and dynamic interactions with mitochondria enable an efficient delivery of fatty acids for optimal energy production. Lipid droplets are also involved in the maintenance of membrane and organelle homeostasis by regulating membrane composition, preventing lipid peroxidation and removing damaged proteins and lipids. Finally, they also engage in a symbiotic relationship with autophagy and act as reservoirs of bioactive lipids that regulate inflammation and immunity. Thus, lipid droplets are central managers of lipid metabolism that function as safeguards against various types of cellular stress.
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Affiliation(s)
- Eva Jarc
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia,Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
| | - Toni Petan
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia,To whom all correspondence should be addressed: Toni Petan, Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; Tel: +386 1 477 3713, Fax: +386 1 477 3984,
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33
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Kim S, Kim N, Park S, Jeon Y, Lee J, Yoo SJ, Lee JW, Moon C, Yu SW, Kim EK. Tanycytic TSPO inhibition induces lipophagy to regulate lipid metabolism and improve energy balance. Autophagy 2019; 16:1200-1220. [PMID: 31469345 PMCID: PMC7469491 DOI: 10.1080/15548627.2019.1659616] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Hypothalamic glial cells named tanycytes, which line the 3rd ventricle (3V), are components of the hypothalamic network that regulates a diverse array of metabolic functions for energy homeostasis. Herein, we report that TSPO (translocator protein), an outer mitochondrial protein, is highly enriched in tanycytes and regulates homeostatic responses to nutrient excess as a potential target for an effective intervention in obesity. Administration of a TSPO ligand, PK11195, into the 3V, and tanycyte-specific deletion of Tspo reduced food intake and elevated energy expenditure, leading to negative energy balance in a high-fat diet challenge. Ablation of tanycytic Tspo elicited AMPK-dependent lipophagy, breaking down lipid droplets into free fatty acids, thereby elevating ATP in a lipid stimulus. Our findings suggest that tanycytic TSPO affects systemic energy balance through macroautophagy/autophagy-regulated lipid metabolism, and highlight the physiological significance of TSPO in hypothalamic lipid sensing and bioenergetics in response to overnutrition. Abbreviations 3V: 3rd ventricle; ACAC: acetyl-Coenzyme A carboxylase; AGRP: agouti related neuropeptide; AIF1/IBA1: allograft inflammatory factor 1; AMPK: AMP-activated protein kinase; ARC: arcuate nucleus; Atg: autophagy related; Bafilo: bafilomycin A1; CAMKK2: calcium/calmodulin-dependent protein kinase kinase 2, beta; CCCP: carbonyl cyanide m-chlorophenylhydrazone; CNS: central nervous system; COX4I1: cytochrome c oxidase subunit 4I1; FFA: free fatty acid; GFAP: glial fibrillary acidic protein; HFD: high-fat diet; ICV: intracerebroventricular; LAMP2: lysosomal-associated membrane protein 2; LD: lipid droplet; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MBH: mediobasal hypothalamus; ME: median eminence; MEF: mouse embryonic fibroblast; NCD: normal chow diet; NEFM/NFM: neurofilament medium; NPY: neuropeptide Y; OL: oleic acid; POMC: pro-opiomelanocortin-alpha; PRKN/Parkin: parkin RBR E3 ubiquitin protein ligase; Rax: retina and anterior neural fold homeobox; RBFOX3/NeuN: RNA binding protein, fox-1 homolog (C. elegans) 3; RER: respiratory exchange ratio; siRNA: small interfering RNA; SQSTM1: sequestosome 1; TG: triglyceride; TSPO: translocator protein; ULK1: unc-51 like kinase 1; VCO2: carbon dioxide production; VMH: ventromedial hypothalamus; VO2: oxygen consumption
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Affiliation(s)
- Seolsong Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea
| | - Nayoun Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea
| | - Seokjae Park
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea.,Neurometabolomics Research Center, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea
| | - Yoonjeong Jeon
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea.,Neurometabolomics Research Center, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea
| | - Jaemeun Lee
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea
| | - Seung-Jun Yoo
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea.,Convergence Research Advanced Centre for Olfaction, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea
| | - Ji-Won Lee
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea
| | - Cheil Moon
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea.,Convergence Research Advanced Centre for Olfaction, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea
| | - Seong-Woon Yu
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea.,Neurometabolomics Research Center, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea
| | - Eun-Kyoung Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea.,Neurometabolomics Research Center, Daegu Gyeongbuk Institute of Science and Technology , Daegu, Republic of Korea
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Saito T, Kuma A, Sugiura Y, Ichimura Y, Obata M, Kitamura H, Okuda S, Lee HC, Ikeda K, Kanegae Y, Saito I, Auwerx J, Motohashi H, Suematsu M, Soga T, Yokomizo T, Waguri S, Mizushima N, Komatsu M. Autophagy regulates lipid metabolism through selective turnover of NCoR1. Nat Commun 2019; 10:1567. [PMID: 30952864 PMCID: PMC6450892 DOI: 10.1038/s41467-019-08829-3] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 01/29/2019] [Indexed: 01/11/2023] Open
Abstract
Selective autophagy ensures the removal of specific soluble proteins, protein aggregates, damaged mitochondria, and invasive bacteria from cells. Defective autophagy has been directly linked to metabolic disorders. However how selective autophagy regulates metabolism remains largely uncharacterized. Here we show that a deficiency in selective autophagy is associated with suppression of lipid oxidation. Hepatic loss of Atg7 or Atg5 significantly impairs the production of ketone bodies upon fasting, due to decreased expression of enzymes involved in β-oxidation following suppression of transactivation by PPARα. Mechanistically, nuclear receptor co-repressor 1 (NCoR1), which interacts with PPARα to suppress its transactivation, binds to the autophagosomal GABARAP family proteins and is degraded by autophagy. Consequently, loss of autophagy causes accumulation of NCoR1, suppressing PPARα activity and resulting in impaired lipid oxidation. These results suggest that autophagy contributes to PPARα activation upon fasting by promoting degradation of NCoR1 and thus regulates β-oxidation and ketone bodies production. Defective autophagy has been associated with metabolic disorders. Here Saito et al. show that autophagy promotes the selective degradation of NCoR1, a repressor of lipid metabolism regulator PPARα, in response to starvation, and thus induces the expression of enzymes involved in lipid oxidation and the production of ketone bodies.
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Affiliation(s)
- Tetsuya Saito
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8510, Japan
| | - Akiko Kuma
- Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Department of Genetics, Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan.,Japan Science and Technology Agency, PRESTO, Saitama, 332-0012, Japan
| | - Yuki Sugiura
- Japan Science and Technology Agency, PRESTO, Saitama, 332-0012, Japan.,Department of Biochemistry, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Yoshinobu Ichimura
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8510, Japan
| | - Miki Obata
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8510, Japan
| | - Hiroshi Kitamura
- Department of Gene Expression Regulation, Institute of Development, Aging and Cancer, Tohoku University, Sendai, 980-8575, Japan
| | - Shujiro Okuda
- Bioinformatics Laboratory, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8510, Japan
| | - Hyeon-Cheol Lee
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Kazutaka Ikeda
- Laboratory for Metabolomics, RIKEN Center for Integrative Medical Sciences (IMS), Yokohama, Kanagawa, 230-0045, Japan
| | - Yumi Kanegae
- Core Research Facilities of Basic Science (Molecular Genetics), Research Center for Medical Science, Jikei University School of Medicine, Tokyo, 105-8461, Japan
| | - Izumu Saito
- Laboratory of Molecular Genetics, Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan.,Laboratory of Virology, Institute of Microbial Chemistry, Shinagawa-ku, Tokyo, 141-0021, Japan
| | - Johan Auwerx
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Hozumi Motohashi
- Department of Gene Expression Regulation, Institute of Development, Aging and Cancer, Tohoku University, Sendai, 980-8575, Japan
| | - Makoto Suematsu
- Department of Biochemistry, Keio University School of Medicine, Tokyo, 160-8582, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0052, Japan
| | - Takehiko Yokomizo
- Department of Biochemistry, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Satoshi Waguri
- Department of Anatomy and Histology, Fukushima Medical University School of Medicine, Hikarigaoka, Fukushima, 960-1295, Japan
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Masaaki Komatsu
- Department of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, 951-8510, Japan. .,Department of Physiology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, 113-8421, Japan.
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35
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Chen H, Huang Y, Yang P, Liu T, Ahmed N, Wang L, Wang T, Bai X, Haseeb A, Chen Q. Lipophagy contributes to long-term storage of spermatozoa in the epididymis of the Chinese soft-shelled turtle Pelodiscus sinensis. Reprod Fertil Dev 2019; 31:774-786. [DOI: 10.1071/rd18307] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/09/2018] [Indexed: 12/19/2022] Open
Abstract
Spermatozoa are known to be stored in the epididymis of the Chinese soft-shelled turtle Pelodiscus sinensis for long periods after spermiation from the testes, but the molecular mechanisms underlying this storage are largely unknown. In this study, epididymal spermatozoa were investigated to determine the potential molecular mechanism for long-term sperm storage in P. sinensis. Transmission electron microscopy (TEM) and Oil red O staining indicated that unusually large cytoplasmic droplets containing lipid droplets (LDs) were attached to the epididymal spermatozoa. However, the content of LDs decreased gradually with the sperm storage. LDs were surrounded by autophagic vesicles and sequestered as degradative cargo within autophagosome. Immunofluorescence and western blotting demonstrated that autophagy in spermatozoa increased gradually with the storage time. Invitro studies found that spermatozoa obtained from soft-shelled turtles in January can survive more than 40 days at 4°C. Furthermore, immunofluorescence and TEM showed that autophagy was involved in the degradation of LDs with the extension of sperm incubation. Inhibition of autophagy with 3-methyladenine significantly suppressed LD degradation. Moreover, adipose triglyceride lipase was involved in the metabolism of LDs. These findings indicate that lipophagy was activated to maximise LD breakdown, which contributes to long-term sperm storage in the epididymis of P. sinensis.
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36
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Li X, Xue Y, Pang L, Len B, Lin Z, Huang J, ShangGuan Z, Pan Y. Agaricus bisporus-derived β-glucan prevents obesity through PPAR γ downregulation and autophagy induction in zebrafish fed by chicken egg yolk. Int J Biol Macromol 2018; 125:820-828. [PMID: 30557642 DOI: 10.1016/j.ijbiomac.2018.12.122] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 12/07/2018] [Accepted: 12/14/2018] [Indexed: 01/06/2023]
Abstract
β-(1,4)-d-Glucan with (1,2) and (1,6)-linked branches (short for β-glucan), extracted from Agaricus bisporus (Lange) Sing, had significant anti-obesity and lowering-fat effect. FITC-β-glucan was absorbed by adipocytes of zebrafish larvae when stained by Nile Red. β-Glucan decreased the adiposity mass, reduced the expression of ppar g, mtp, L-fabp, ifabp in ISH, which was coincident as the results of RT-PCT. β-Glucan lowered the level of C/EBP α, c SREBP1, LXR α, PPAR γ by WB analysis, which were accompanied by an increase level in LC3 II/LC3 I and a decline level in p62 in dose-dependent manner. This study explored the effect and mechanisms of Agaricus bisporus derived-β-glucan to regulate lipid metabolism and prevent lipid deposits, and provided the experimental data for its use in diet food and food addictive.
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Affiliation(s)
- Xiumin Li
- The Engineering Technological Center of Mushroom Industry, Minnan Normal University, Zhangzhou, Fujian 363000, China.
| | - Yu Xue
- The Engineering Technological Center of Mushroom Industry, Minnan Normal University, Zhangzhou, Fujian 363000, China
| | - Liang Pang
- The College of Physical Education, Minnan Normal University, Zhangzhou, Fujian 363000, China
| | - Bo Len
- The Engineering Technological Center of Mushroom Industry, Minnan Normal University, Zhangzhou, Fujian 363000, China
| | - Zhichao Lin
- The Engineering Technological Center of Mushroom Industry, Minnan Normal University, Zhangzhou, Fujian 363000, China
| | - Jiafu Huang
- The Engineering Technological Center of Mushroom Industry, Minnan Normal University, Zhangzhou, Fujian 363000, China
| | - Zhaoshui ShangGuan
- Central Laboratory, the First Affiliated Hospital of Xiamen University, Xiamen 361003, China
| | - Yutian Pan
- The Engineering Technological Center of Mushroom Industry, Minnan Normal University, Zhangzhou, Fujian 363000, China.
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37
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Xiao C, Stahel P, Lewis GF. Regulation of Chylomicron Secretion: Focus on Post-Assembly Mechanisms. Cell Mol Gastroenterol Hepatol 2018; 7:487-501. [PMID: 30819663 PMCID: PMC6396431 DOI: 10.1016/j.jcmgh.2018.10.015] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/23/2018] [Accepted: 10/25/2018] [Indexed: 02/06/2023]
Abstract
Rapid and efficient digestion and absorption of dietary triglycerides and other lipids by the intestine, the packaging of those lipids into lipoprotein chylomicron (CM) particles, and their secretion via the lymphatic duct into the blood circulation are essential in maintaining whole-body lipid and energy homeostasis. Biosynthesis and assembly of CMs in enterocytes is a complex multistep process that is subject to regulation by intracellular signaling pathways as well as by hormones, nutrients, and neural factors extrinsic to the enterocyte. Dysregulation of this process has implications for health and disease, contributing to dyslipidemia and a potentially increased risk of atherosclerotic cardiovascular disease. There is increasing recognition that, besides intracellular regulation of CM assembly and secretion, regulation of postassembly pathways also plays important roles in CM secretion. This review examines recent advances in our understanding of the regulation of CM secretion in relation to mobilization of intestinal lipid stores, drawing particular attention to post-assembly regulatory mechanisms, including intracellular trafficking of triglycerides in enterocytes, CM mobilization from the lamina propria, and regulated transport of CM by intestinal lymphatics.
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Affiliation(s)
- Changting Xiao
- Changting Xiao, PhD, Princess Margaret Cancer Research Tower 10-203, Medical and Related Science Centre, 101 College Street, Toronto, Ontario M5G 1L7, Canada. fax: (416) 581-7487.
| | | | - Gary F. Lewis
- Correspondence Address correspondence to: Gary F. Lewis, MD, FRCPC, Toronto General Hospital, 200 Elizabeth Street, EN12-218, Toronto, Ontario M5G 2C4, Canada. fax: (416) 340-3314.
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38
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Zhang Y, Whaley-Connell AT, Sowers JR, Ren J. Autophagy as an emerging target in cardiorenal metabolic disease: From pathophysiology to management. Pharmacol Ther 2018; 191:1-22. [PMID: 29909238 PMCID: PMC6195437 DOI: 10.1016/j.pharmthera.2018.06.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/05/2018] [Indexed: 12/16/2022]
Abstract
Although advances in medical technology and health care have improved the early diagnosis and management for cardiorenal metabolic disorders, the prevalence of obesity, insulin resistance, diabetes, hypertension, dyslipidemia, and kidney disease remains high. Findings from numerous population-based studies, clinical trials, and experimental evidence have consolidated a number of theories for the pathogenesis of cardiorenal metabolic anomalies including resistance to the metabolic action of insulin, abnormal glucose and lipid metabolism, oxidative and nitrosative stress, endoplasmic reticulum (ER) stress, apoptosis, mitochondrial damage, and inflammation. Accumulating evidence has recently suggested a pivotal role for proteotoxicity, the unfavorable effects of poor protein quality control, in the pathophysiology of metabolic dysregulation and related cardiovascular complications. The ubiquitin-proteasome system (UPS) and autophagy-lysosomal pathways, two major although distinct cellular clearance machineries, govern protein quality control by degradation and clearance of long-lived or damaged proteins and organelles. Ample evidence has depicted an important role for protein quality control, particularly autophagy, in the maintenance of metabolic homeostasis. To this end, autophagy offers promising targets for novel strategies to prevent and treat cardiorenal metabolic diseases. Targeting autophagy using pharmacological or natural agents exhibits exciting new strategies for the growing problem of cardiorenal metabolic disorders.
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Affiliation(s)
- Yingmei Zhang
- Shanghai Institute of Cardiovascular Diseases, Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai 200032, China; Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA.
| | - Adam T Whaley-Connell
- Research Service, Harry S Truman Memorial Veterans' Hospital, University of Missouri-Columbia School of Medicine, Columbia, MO, USA; Diabetes and Cardiovascular Center, Department of Medicine, University of Missouri-Columbia School of Medicine, Columbia, MO, USA
| | - James R Sowers
- Research Service, Harry S Truman Memorial Veterans' Hospital, University of Missouri-Columbia School of Medicine, Columbia, MO, USA; Diabetes and Cardiovascular Center, Department of Medicine, University of Missouri-Columbia School of Medicine, Columbia, MO, USA
| | - Jun Ren
- Shanghai Institute of Cardiovascular Diseases, Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai 200032, China; Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA.
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39
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Hung YH, Buhman KK. DGAT1 deficiency disrupts lysosome function in enterocytes during dietary fat absorption. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:587-595. [PMID: 30342099 DOI: 10.1016/j.bbalip.2018.10.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 09/27/2018] [Accepted: 10/13/2018] [Indexed: 11/25/2022]
Abstract
Enterocytes, the absorptive cells of the small intestine, mediate the process of dietary fat absorption by secreting triacylglycerol (TAG) into circulation. When levels of dietary fat are high, TAG is stored in cytoplasmic lipid droplets (CLDs) and sequentially hydrolyzed for ultimate secretion. Mice with deficiency in acyl CoA: diacylglycerol acyltransferase 1 (Dgat1-/- mice) were previously reported to have a reduced rate of intestinal TAG secretion and abnormal TAG accumulation in enterocyte CLDs. This unique intestinal phenotype is critical to their resistance to diet-induced obesity; however, the underlying mechanism remains unclear. Emerging evidence shows that lysosomal TAG hydrolysis contributes to autophagy-mediated CLD mobilization termed lipophagy, and when disrupted results in CLD accumulation. In order to study how lipophagy contributes to the unique intestinal phenotype of Dgat1-/- mice, enterocytes from wild-type (WT) and Dgat1-/- mice were examined at 2 and 6 h after oral oil gavage. Through ultrastructural analysis we observed TAG present within autophagic vesicles (AVs) in mouse enterocytes, suggesting the role of lipophagy in intestinal CLD mobilization during dietary fat absorption. Furthermore, we found that Dgat1-/- mice had abnormal TAG accumulation within AVs and less acidic lysosomes compared to WT mice. Together these findings suggest that the delayed dietary fat absorption seen in Dgat1-/- mice is, in part, due to the dysregulated flux of autophagy-mediated CLD mobilization and impairment of lysosomal acidification in enterocytes. The present study highlights the critical role of lysosome in enterocyte CLD mobilization for proper dietary fat absorption.
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Affiliation(s)
- Yu-Han Hung
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States of America
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States of America.
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40
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Petan T, Jarc E, Jusović M. Lipid Droplets in Cancer: Guardians of Fat in a Stressful World. Molecules 2018; 23:molecules23081941. [PMID: 30081476 PMCID: PMC6222695 DOI: 10.3390/molecules23081941] [Citation(s) in RCA: 230] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 07/31/2018] [Accepted: 08/01/2018] [Indexed: 12/12/2022] Open
Abstract
Cancer cells possess remarkable abilities to adapt to adverse environmental conditions. Their survival during severe nutrient and oxidative stress depends on their capacity to acquire extracellular lipids and the plasticity of their mechanisms for intracellular lipid synthesis, mobilisation, and recycling. Lipid droplets, cytosolic fat storage organelles present in most cells from yeast to men, are emerging as major regulators of lipid metabolism, trafficking, and signalling in various cells and tissues exposed to stress. Their biogenesis is induced by nutrient and oxidative stress and they accumulate in various cancers. Lipid droplets act as switches that coordinate lipid trafficking and consumption for different purposes in the cell, such as energy production, protection against oxidative stress or membrane biogenesis during rapid cell growth. They sequester toxic lipids, such as fatty acids, cholesterol and ceramides, thereby preventing lipotoxic cell damage and engage in a complex relationship with autophagy. Here, we focus on the emerging mechanisms of stress-induced lipid droplet biogenesis; their roles during nutrient, lipotoxic, and oxidative stress; and the relationship between lipid droplets and autophagy. The recently discovered principles of lipid droplet biology can improve our understanding of the mechanisms that govern cancer cell adaptability and resilience to stress.
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Affiliation(s)
- Toni Petan
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana SI-1000, Slovenia.
| | - Eva Jarc
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana SI-1000, Slovenia.
- Jožef Stefan International Postgraduate School, Ljubljana SI-1000, Slovenia.
| | - Maida Jusović
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana SI-1000, Slovenia.
- Jožef Stefan International Postgraduate School, Ljubljana SI-1000, Slovenia.
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41
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Skotland T, Hessvik NP, Sandvig K, Llorente A. Exosomal lipid composition and the role of ether lipids and phosphoinositides in exosome biology. J Lipid Res 2018; 60:9-18. [PMID: 30076207 PMCID: PMC6314266 DOI: 10.1194/jlr.r084343] [Citation(s) in RCA: 413] [Impact Index Per Article: 68.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 07/24/2018] [Indexed: 12/11/2022] Open
Abstract
Exosomes are a type of extracellular vesicle released from cells after fusion of multivesicular bodies with the plasma membrane. These vesicles are often enriched in cholesterol, SM, glycosphingolipids, and phosphatidylserine. Lipids not only have a structural role in exosomal membranes but also are essential players in exosome formation and release to the extracellular environment. Our knowledge about the importance of lipids in exosome biology is increasing due to recent technological developments in lipidomics and a stronger focus on the biological functions of these molecules. Here, we review the available information about the lipid composition of exosomes. Special attention is given to ether lipids, a relatively unexplored type of lipids involved in membrane trafficking and abundant in some exosomes. Moreover, we discuss how the lipid composition of exosome preparations may provide useful information about their purity. Finally, we discuss the role of phosphoinositides, membrane phospholipids that help to regulate membrane dynamics, in exosome release and how this process may be linked to secretory autophagy. Knowledge about exosome lipid composition is important to understand the biology of these vesicles and to investigate possible medical applications.
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Affiliation(s)
- Tore Skotland
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital-Norwegian Radium Hospital, 0379 Oslo, Norway
| | - Nina P Hessvik
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital-Norwegian Radium Hospital, 0379 Oslo, Norway
| | - Kirsten Sandvig
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital-Norwegian Radium Hospital, 0379 Oslo, Norway.,Department of Biosciences, University of Oslo, 0316 Oslo, Norway
| | - Alicia Llorente
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital-Norwegian Radium Hospital, 0379 Oslo, Norway
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42
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Hu Z, Cai HY, Luo YY, Xiao JM, Li L, Guo T. Effect of varying hypoxia reoxygenation times on autophagy of cardiomyocytes. Acta Cir Bras 2018; 33:223-230. [PMID: 29668775 DOI: 10.1590/s0102-865020180030000004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/06/2018] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To investigate the impact of different hypoxia reoxygenation (HR) times on autophagy of rat cardiomyocytes (H9C2). METHODS Rat cardiomyocytes were randomly divided into normal control group (group A), hypoxia group (group B), 2 h HR group (group C), 12 h HR group (group D), and 24 h HR group (group E). LC3 II/LC3 I was determined via western blotting, and cell viabilities of cardiomyocytes were measured using methyl thiazolyl tetrazolium (MTT) assay. RESULTS Cell viabilities in HR model groups were significantly lower than those of group A (P<0.05). LC3 II/LC3 I levels in groups B to D were significantly higher than those of group A (P<0.05), and group D showed the highest LC3 II/LC3 I levels. Cell viabilities in groups B to D were significantly lower than those of group A (P<0.05), with group D showing the lowest cell viabilities (P<0.05). CONCLUSIONS Hypoxia can induce autophagy in rat cardiomyocytes, which can be further activated by reoxygenation; most notable after 12 h. Hypoxia-induced cell injury can be aggravated by reoxygenation. The lowest cell viability was observed at 12 h after reoxygenation; however, cell viability can be recovered after 24 h.
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Affiliation(s)
- Zhao Hu
- Department of Cardiology, First Affiliated Hospital, Kunming Medical University, Kunming, China
| | - Hong-Yan Cai
- Department of Cardiology, First Affiliated Hospital, Kunming Medical University, Kunming, China
| | - Yun-Yan Luo
- Department of Cardiology, First Affiliated Hospital, Kunming Medical University, Kunming, China
| | - Jian-Ming Xiao
- Department of Cardiology, First Affiliated Hospital, Kunming Medical University, Kunming, China
| | - Lin Li
- Department of Cardiology, First Affiliated Hospital, Kunming Medical University, Kunming, China
| | - Tao Guo
- Department of Cardiology, First Affiliated Hospital, Kunming Medical University, Kunming, China
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43
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Yang M, Zhang Y, Ren J. Autophagic Regulation of Lipid Homeostasis in Cardiometabolic Syndrome. Front Cardiovasc Med 2018; 5:38. [PMID: 29774216 PMCID: PMC5943591 DOI: 10.3389/fcvm.2018.00038] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/05/2018] [Indexed: 12/28/2022] Open
Abstract
As an important protein quality control process, autophagy is essential for the degradation and removal of long-lived or injured cellular components and organelles. Autophagy is known to participate in a number of pathophysiological processes including cardiometabolic syndrome. Recent findings have shown compelling evidence for the intricate interplay between autophagy and lipid metabolism. Autophagy serves as a major regulator of lipid homeostasis while lipid can also influence autophagosome formation and autophagic signaling. Lipophagy is a unique form of selective autophagy and functions as a fundamental mechanism for clearance of lipid excess in atherosclerotic plaques. Ample of evidence has denoted a novel therapeutic potential for autophagy in deranged lipid metabolism and management of cardiometabolic diseases such as atherosclerosis and diabetic cardiomyopathy. Here we will review the interplays between cardiac autophagy and lipid metabolism in an effort to seek new therapeutic options for cardiometabolic diseases.
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Affiliation(s)
- Mingjie Yang
- Department of Cardiology and Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yingmei Zhang
- Department of Cardiology and Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jun Ren
- Department of Cardiology and Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China.,Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY, United States
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44
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Xiao C, Stahel P, Carreiro AL, Buhman KK, Lewis GF. Recent Advances in Triacylglycerol Mobilization by the Gut. Trends Endocrinol Metab 2018; 29:151-163. [PMID: 29306629 DOI: 10.1016/j.tem.2017.12.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 11/30/2017] [Accepted: 12/04/2017] [Indexed: 11/26/2022]
Abstract
Dietary lipid absorption and lipoprotein secretion by the gut are important in maintaining whole-body energy homeostasis and have significant implications for health and disease. The processing of dietary lipids, including storage within and subsequent mobilization and transport from enterocyte cytoplasmic lipid droplets or other intestinal lipid storage pools (including the secretary pathway, lamina propria and lymphatics) and secretion of chylomicrons, involves coordinated steps that are subject to various controls. This review summarizes recent advances in our understanding of the mechanisms that underlie lipid storage and mobilization by small intestinal enterocytes and the intestinal lymphatic vasculature. Therapeutic targeting of lipid processing by the gut may provide opportunities for the treatment and prevention of dyslipidemia, and for improving health status.
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Affiliation(s)
- Changting Xiao
- Departments of Medicine and Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
| | - Priska Stahel
- Departments of Medicine and Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada
| | - Alicia L Carreiro
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Kimberly K Buhman
- Department of Nutrition Science, Purdue University, West Lafayette, IN 47907, USA
| | - Gary F Lewis
- Departments of Medicine and Physiology, Division of Endocrinology and Metabolism, Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, Canada.
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45
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Maan M, Peters JM, Dutta M, Patterson AD. Lipid metabolism and lipophagy in cancer. Biochem Biophys Res Commun 2018; 504:582-589. [PMID: 29438712 DOI: 10.1016/j.bbrc.2018.02.097] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 02/09/2018] [Indexed: 12/21/2022]
Abstract
The tumor microenvironment can be hypoxic, acidic, and deficient in nutrients, thus causing the metabolism of tumor cells as well as the neighboring stromal cells to be remodelled to facilitate tumor survival, proliferation, and metastasis. Abnormal tumor lipid metabolism is a fairly new field, which has received attention in the past few years. Cross-talk between tumor cells and tumor-associated stromal cells modulates the high metabolic needs of the tumor. Fatty acid turnover is high in tumor cells to meet the energy as well as synthetic requirements of the growing tumor. Lipolysis of lipids stored in lipid droplets was earlier considered to be solely carried out by cytosolic lipases. However recent studies demonstrate that lipophagy (autophagic degradation of lipids by acidic lipases) serves as an alternate pathway for the degradation of lipid droplets. Involvement of lipophagy in lipid turnover makes it a crucial player in tumorigenesis and metastasis. In this review we discuss the metabolic reprogramming of tumor cells with special focus on lipid metabolism. We also address the lipid turnover machinery in the tumor cell, especially the lipophagic pathway. Finally, we integrate the current understanding of lipophagy with tumor lipid metabolism.
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Affiliation(s)
- Meenu Maan
- School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Jeffrey M Peters
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary & Biomedical Sciences, Pennsylvania State University, University Park, PA 16802, United States
| | - Mainak Dutta
- Department of Biotechnology, BITS Pilani-Dubai Campus, Academic City, Dubai 345055, United Arab Emirates.
| | - Andrew D Patterson
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary & Biomedical Sciences, Pennsylvania State University, University Park, PA 16802, United States.
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Auclair N, Melbouci L, St-Pierre D, Levy E. Gastrointestinal factors regulating lipid droplet formation in the intestine. Exp Cell Res 2018; 363:1-14. [PMID: 29305172 DOI: 10.1016/j.yexcr.2017.12.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 12/22/2022]
Abstract
Cytoplasmic lipid droplets (CLD) are considered as neutral lipid reservoirs, which protect cells from lipotoxicity. It became clear that these fascinating dynamic organelles play a role not only in energy storage and metabolism, but also in cellular lipid and protein handling, inter-organelle communication, and signaling among diverse functions. Their dysregulation is associated with multiple disorders, including obesity, liver steatosis and cardiovascular diseases. The central aim of this review is to highlight the link between intra-enterocyte CLD dynamics and the formation of chylomicrons, the main intestinal dietary lipid vehicle, after overviewing the morphology, molecular composition, biogenesis and functions of CLD.
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Affiliation(s)
- N Auclair
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Nutrition, Université de Montréal, Montreal, Quebec, Canada H3T 1C5
| | - L Melbouci
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Department of Sciences and Physical Activities, UQAM, Quebec, Canada H2X 1Y4
| | - D St-Pierre
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Department of Sciences and Physical Activities, UQAM, Quebec, Canada H2X 1Y4
| | - E Levy
- Research Centre, CHU Sainte-Justine and Department of Montreal, Quebec, Canada H3T 1C5; Nutrition, Université de Montréal, Montreal, Quebec, Canada H3T 1C5; Institute of Nutrition and Functional Foods (INAF), Université Laval, Quebec, Quebec, Canada G1V 0A6.
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47
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Morel E, Ghezzal S, Lucchi G, Truntzer C, Pais de Barros JP, Simon-Plas F, Demignot S, Mineo C, Shaul PW, Leturque A, Rousset M, Carrière V. Cholesterol trafficking and raft-like membrane domain composition mediate scavenger receptor class B type 1-dependent lipid sensing in intestinal epithelial cells. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1863:199-211. [PMID: 29196159 DOI: 10.1016/j.bbalip.2017.11.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 11/13/2017] [Accepted: 11/27/2017] [Indexed: 02/02/2023]
Abstract
Scavenger receptor Class B type 1 (SR-B1) is a lipid transporter and sensor. In intestinal epithelial cells, SR-B1-dependent lipid sensing is associated with SR-B1 recruitment in raft-like/ detergent-resistant membrane domains and interaction of its C-terminal transmembrane domain with plasma membrane cholesterol. To clarify the initiating events occurring during lipid sensing by SR-B1, we analyzed cholesterol trafficking and raft-like domain composition in intestinal epithelial cells expressing wild-type SR-B1 or the mutated form SR-B1-Q445A, defective in membrane cholesterol binding and signal initiation. These features of SR-B1 were found to influence both apical cholesterol efflux and intracellular cholesterol trafficking from plasma membrane to lipid droplets, and the lipid composition of raft-like domains. Lipidomic analysis revealed likely participation of d18:0/16:0 sphingomyelin and 16:0/0:0 lysophosphatidylethanolamine in lipid sensing by SR-B1. Proteomic analysis identified proteins, whose abundance changed in raft-like domains during lipid sensing, and these included molecules linked to lipid raft dynamics and signal transduction. These findings provide new insights into the role of SR-B1 in cellular cholesterol homeostasis and suggest molecular links between SR-B1-dependent lipid sensing and cell cholesterol and lipid droplet dynamics.
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Affiliation(s)
- Etienne Morel
- Centre de Recherche des Cordeliers, INSERM, UMPC Université Paris 6, Université Paris Descartes Paris 5, CNRS, F-75006 Paris, France
| | - Sara Ghezzal
- Centre de Recherche des Cordeliers, INSERM, UMPC Université Paris 6, Université Paris Descartes Paris 5, CNRS, F-75006 Paris, France
| | - Géraldine Lucchi
- Clinical Innovation Proteomic Platform CLIPP, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Caroline Truntzer
- Clinical Innovation Proteomic Platform CLIPP, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Jean-Paul Pais de Barros
- Plateforme de Lipidomique, INSERM UMR1231, Université de Bourgogne Franche Comté, F-21000 Dijon, France
| | - Françoise Simon-Plas
- Agroécologie, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Sylvie Demignot
- Centre de Recherche des Cordeliers, INSERM, UMPC Université Paris 6, Université Paris Descartes Paris 5, CNRS, F-75006 Paris, France; EPHE, PSL Research University, F-75006 Paris, France
| | - Chieko Mineo
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas, Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Philip W Shaul
- Center for Pulmonary and Vascular Biology, Department of Pediatrics, University of Texas, Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Armelle Leturque
- Centre de Recherche des Cordeliers, INSERM, UMPC Université Paris 6, Université Paris Descartes Paris 5, CNRS, F-75006 Paris, France
| | - Monique Rousset
- Centre de Recherche des Cordeliers, INSERM, UMPC Université Paris 6, Université Paris Descartes Paris 5, CNRS, F-75006 Paris, France
| | - Véronique Carrière
- Centre de Recherche des Cordeliers, INSERM, UMPC Université Paris 6, Université Paris Descartes Paris 5, CNRS, F-75006 Paris, France.
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48
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Adipose tissue conditioned media support macrophage lipid-droplet biogenesis by interfering with autophagic flux. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1001-1012. [DOI: 10.1016/j.bbalip.2017.06.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 06/04/2017] [Accepted: 06/19/2017] [Indexed: 01/20/2023]
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49
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Kim SW, Ehrman J, Ahn MR, Kondo J, Lopez AAM, Oh YS, Kim XH, Crawley SW, Goldenring JR, Tyska MJ, Rericha EC, Lau KS. Shear stress induces noncanonical autophagy in intestinal epithelial monolayers. Mol Biol Cell 2017; 28:3043-3056. [PMID: 28855375 PMCID: PMC5662261 DOI: 10.1091/mbc.e17-01-0021] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 08/04/2017] [Accepted: 08/22/2017] [Indexed: 12/19/2022] Open
Abstract
Shear stress applied on the apical side of polarizing intestinal cells induces vacuole formation via the autophagy machinery. This response is relayed through apical microvilli that act as mechanosensors linking the physical environment to the intracellular trafficking pathways. Flow of fluids through the gut, such as milk from a neonatal diet, generates a shear stress on the unilaminar epithelium lining the lumen. We report that exposure to physiological levels of fluid shear stress leads to the formation of large vacuoles, containing extracellular contents within polarizing intestinal epithelial cell monolayers. These observations lead to two questions: how can cells lacking primary cilia transduce shear stress, and what molecular pathways support the formation of vacuoles that can exceed 80% of the cell volume? We find that shear forces are sensed by actin-rich microvilli that eventually generate the apical brush border, providing evidence that these structures possess mechanosensing ability. Importantly, we identified the molecular pathway that regulates large vacuole formation downstream from mechanostimulation to involve central components of the autophagy pathway, including ATG5 and LC3, but not Beclin. Together our results establish a novel link between the actin-rich microvilli, the macroscopic transport of fluids across cells, and the noncanonical autophagy pathway in organized epithelial monolayers.
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Affiliation(s)
- Sun Wook Kim
- Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, TN 37232.,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Jonathan Ehrman
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235
| | - Mok-Ryeon Ahn
- Department of Food Science and Nutrition, Dong-A University, Busan 604-714, Republic of Korea
| | - Jumpei Kondo
- Department of Biochemistry, Osaka International Cancer Institute, Osaka 541-8567, Japan
| | - Andrea A Mancheno Lopez
- Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, TN 37232.,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Yun Sik Oh
- Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, TN 37232.,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Xander H Kim
- Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, TN 37232.,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Scott W Crawley
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - James R Goldenring
- Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, TN 37232.,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232.,Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232.,Nashville VA Medical Center, Nashville, TN 37212
| | - Matthew J Tyska
- Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, TN 37232.,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
| | - Erin C Rericha
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235
| | - Ken S Lau
- Epithelial Biology Center, Vanderbilt University Medical Center, Nashville, TN 37232 .,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232
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50
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Minami S, Yamamoto T, Takabatake Y, Takahashi A, Namba T, Matsuda J, Kimura T, Kaimori JY, Matsui I, Hamano T, Takeda H, Takahashi M, Izumi Y, Bamba T, Matsusaka T, Niimura F, Isaka Y. Lipophagy maintains energy homeostasis in the kidney proximal tubule during prolonged starvation. Autophagy 2017; 13:1629-1647. [PMID: 28813167 DOI: 10.1080/15548627.2017.1341464] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Macroautophagy/autophagy is a self-degradation process that combats starvation. Lipids are the main energy source in kidney proximal tubular cells (PTCs). During starvation, PTCs increase fatty acid (FA) uptake, form intracellular lipid droplets (LDs), and hydrolyze them for use. The involvement of autophagy in lipid metabolism in the kidney remains largely unknown. Here, we investigated the autophagy-mediated regulation of renal lipid metabolism during prolonged starvation using PTC-specific Atg5-deficient (atg5-TSKO) mice and an in vitro serum starvation model. Twenty-four h of starvation comparably induced LD formation in the PTCs of control and atg5-TSKO mice; however, additional 24 h of starvation reduced the number of LDs in control mice, whereas increases were observed in atg5-TSKO mice. Autophagic degradation of LDs (lipophagy) in PTCs was demonstrated by electron microscopic observation and biochemical analysis. In vitro pulse-chase assays demonstrated that lipophagy mobilizes FAs from LDs to mitochondria during starvation, whereas impaired LD degradation in autophagy-deficient PTCs led to decreased ATP production and subsequent cell death. In contrast to the in vitro assay, despite impaired LD degradation, kidney ATP content was preserved in 48-h starved atg5-TSKO mice, probably due to increased utilization of ketone bodies. This compensatory mechanism was accompanied by a higher plasma FGF21 (fibroblast growth factor 21) level and its expression in the PTCs; however, this was not essential for the production of ketone bodies in the liver during prolonged starvation. In conclusion, lipophagy combats prolonged starvation in PTCs to avoid cellular energy depletion.
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Affiliation(s)
- Satoshi Minami
- a Department of Nephrology , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
| | - Takeshi Yamamoto
- a Department of Nephrology , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
| | - Yoshitsugu Takabatake
- a Department of Nephrology , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
| | - Atsushi Takahashi
- a Department of Nephrology , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
| | - Tomoko Namba
- a Department of Nephrology , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
| | - Jun Matsuda
- a Department of Nephrology , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
| | - Tomonori Kimura
- a Department of Nephrology , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
| | - Jun-Ya Kaimori
- b Department of Advanced Technology for Transplantation , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
| | - Isao Matsui
- a Department of Nephrology , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
| | - Takayuki Hamano
- c Department of Comprehensive Kidney Disease Research (CKDR) , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
| | - Hiroaki Takeda
- d Division of Metabolomics, Medical Institute of Bioregulation , Kyushu University , Higashi-ku , Fukuoka , Japan
| | - Masatomo Takahashi
- d Division of Metabolomics, Medical Institute of Bioregulation , Kyushu University , Higashi-ku , Fukuoka , Japan
| | - Yoshihiro Izumi
- d Division of Metabolomics, Medical Institute of Bioregulation , Kyushu University , Higashi-ku , Fukuoka , Japan
| | - Takeshi Bamba
- d Division of Metabolomics, Medical Institute of Bioregulation , Kyushu University , Higashi-ku , Fukuoka , Japan
| | - Taiji Matsusaka
- e Institute of Medical Sciences and Department of Molecular Life Sciences , Tokai University School of Medicine , Isehara , Kanagawa , Japan
| | - Fumio Niimura
- f Department of Pediatrics , Tokai University School of Medicine , Isehara , Kanagawa , Japan
| | - Yoshitaka Isaka
- a Department of Nephrology , Osaka University Graduate School of Medicine , Suita , Osaka , Japan
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