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Xu N, Qiao Q, Fang X, Wang G, An K, Jiang W, Li J, Xu Z. Solvatochromic Buffering Fluorescent Probe Resolves the Lipid Transport and Morphological Changes during Lipid Droplet Fusion by Super-Resolution Imaging. Anal Chem 2024; 96:4709-4715. [PMID: 38457637 DOI: 10.1021/acs.analchem.4c00292] [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: 03/10/2024]
Abstract
The varied functions of lipid droplets, which encompass the regulation of lipid and energy homeostasis, as well as their association with the occurrence of various metabolic diseases, are intricately linked to their dynamic properties. Super-resolution imaging techniques have emerged to decipher physiological processes and molecular mechanisms on the nanoscale. However, achieving long-term dynamic super-resolution imaging faces challenges due to the need for fluorescent probes with high photostability. This paper introduces LD-CF, a "buffering probe" for imaging lipid droplet dynamics using structured illumination microscopy (SIM). The polarity-sensitive LD-CF eliminates background fluorescence with a "cyan filter" strategy, enabling wash-free imaging of lipid droplets. In the fluorescent "off" state outside droplets, the probes act as a "buffering pool", replacing photobleached probes inside droplets and enabling photostable long-term SIM imaging. With this probe, three modes of lipid droplet fusion were observed, including the discovery of fusion from large to small lipid droplets. Fluorescence intensity tracking also revealed the direction of lipid transport during the lipid droplet fusion.
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Affiliation(s)
- Ning Xu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- School of Chemistry, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Qinglong Qiao
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Xiangning Fang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Guangying Wang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Kai An
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Wenchao Jiang
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Jin Li
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
| | - Zhaochao Xu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
- School of Chemistry, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
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Zhang M, Fu T, Huang Q, Xing Z, Yang J, Lu W, Hu M, Han LQ, Loor JJ, Gao TY. Size, number and phospholipid composition of milk fat globules are affected by dietary conjugated linoleic acid. J Anim Physiol Anim Nutr (Berl) 2022. [DOI: 10.1111/jpn.13788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 09/07/2022] [Accepted: 10/14/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Menglu Zhang
- Department of Animal Production and Husbandry, College of Animal Science and Technology Henan Agricultural University Zhengzhou P.R. China
| | - Tong Fu
- Department of Animal Production and Husbandry, College of Animal Science and Technology Henan Agricultural University Zhengzhou P.R. China
| | - Qixue Huang
- Department of Veterinary Biotechnology, College of Veterinary Medicine Henan Agricultural University Zhengzhou P.R. China
| | - Zhiyang Xing
- Department of Veterinary Biotechnology, College of Veterinary Medicine Henan Agricultural University Zhengzhou P.R. China
| | - Jingna Yang
- Department of Veterinary Biotechnology, College of Veterinary Medicine Henan Agricultural University Zhengzhou P.R. China
| | - Wenyan Lu
- Department of Veterinary Biotechnology, College of Veterinary Medicine Henan Agricultural University Zhengzhou P.R. China
| | - Mingyue Hu
- Department of Veterinary Biotechnology, College of Veterinary Medicine Henan Agricultural University Zhengzhou P.R. China
| | - Li Qiang Han
- Department of Veterinary Biotechnology, College of Veterinary Medicine Henan Agricultural University Zhengzhou P.R. China
| | - Juan J. Loor
- Department of Animal Science, Division of Nutritional Sciences University of Illinois Urbana Illinois USA
| | - Teng Yun Gao
- Department of Animal Production and Husbandry, College of Animal Science and Technology Henan Agricultural University Zhengzhou P.R. China
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Deregulation of Lipid Homeostasis: A Fa(c)t in the Development of Metabolic Diseases. Cells 2020; 9:cells9122605. [PMID: 33291746 PMCID: PMC7761975 DOI: 10.3390/cells9122605] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 02/06/2023] Open
Abstract
Lipids are important molecules for human health. The quantity and quality of fats consumed in the diet have important effects on the modulation of both the natural biosynthesis and degradation of lipids. There is an important number of lipid-failed associated metabolic diseases and an increasing number of studies suggesting that certain types of lipids might be beneficial to the treatment of many metabolic diseases. The aim of the present work is to expose an overview of de novo biosynthesis, storage, and degradation of lipids in mammalian cells, as well as, to review the published data describing the beneficial effects of these processes and the potential of some dietary lipids to improve metabolic diseases.
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Leyland B, Boussiba S, Khozin-Goldberg I. A Review of Diatom Lipid Droplets. BIOLOGY 2020; 9:biology9020038. [PMID: 32098118 PMCID: PMC7168155 DOI: 10.3390/biology9020038] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 12/20/2022]
Abstract
The dynamic nutrient availability and photon flux density of diatom habitats necessitate buffering capabilities in order to maintain metabolic homeostasis. This is accomplished by the biosynthesis and turnover of storage lipids, which are sequestered in lipid droplets (LDs). LDs are an organelle conserved among eukaryotes, composed of a neutral lipid core surrounded by a polar lipid monolayer. LDs shield the intracellular environment from the accumulation of hydrophobic compounds and function as a carbon and electron sink. These functions are implemented by interconnections with other intracellular systems, including photosynthesis and autophagy. Since diatom lipid production may be a promising objective for biotechnological exploitation, a deeper understanding of LDs may offer targets for metabolic engineering. In this review, we provide an overview of diatom LD biology and biotechnological potential.
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Price AM, Doner NM, Gidda SK, Jambunathan S, James CN, Schami A, Yurchenko O, Mullen RT, Dyer JM, Puri V, Chapman KD. Mouse Fat-Specific Protein 27 (FSP27) expressed in plant cells localizes to lipid droplets and promotes lipid droplet accumulation and fusion. Biochimie 2020; 169:41-53. [PMID: 31400447 DOI: 10.1016/j.biochi.2019.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/05/2019] [Indexed: 10/26/2022]
Abstract
Fat-Specific Protein 27 (FSP27) belongs to a small group of vertebrate proteins containing a Cell-death Inducing DNA fragmentation factor-α-like Effector (CIDE)-C domain and is involved in lipid droplet (LD) accumulation and energy homeostasis. FSP27 is predominantly expressed in white and brown adipose tissues, as well as liver, and plays a key role in mediating LD-LD fusion. No orthologs have been identified in invertebrates or plants. In this study, we tested the function of mouse FSP27 in stably-transformed Arabidopsis thaliana leaves and seeds, as well as through transient expression in Nicotiana tabacum suspension-cultured cells and N. benthamiana leaves. Confocal microscopic analysis of plant cells revealed that, similar to ectopic expression in mammalian cells, FSP27 produced in plants 1) correctly localized to LDs, 2) accumulated at LD-LD contact sites, and 3) induced an increase in the number and size of LDs and also promoted LD clustering and fusion. Furthermore, FSP27 increased oil content in transgenic A. thaliana seeds. Given that plant oils have uses in human and animal nutrition as well as industrial uses such as biofuels and bioplastics, our results suggest that ectopic expression of FSP27 in plants represents a potential strategy for increasing oil content and energy density in bioenergy or oilseed crops.
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Affiliation(s)
- Ann M Price
- BioDiscovery Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Nathan M Doner
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Satinder K Gidda
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Srikarthika Jambunathan
- Department of Medicine, Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, MA, USA
| | - Christopher N James
- BioDiscovery Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Alyssa Schami
- BioDiscovery Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA
| | - Olga Yurchenko
- USDA-ARS, US Arid-Land Agricultural Research Center, Maricopa, AZ, USA
| | - Robert T Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - John M Dyer
- USDA-ARS, US Arid-Land Agricultural Research Center, Maricopa, AZ, USA
| | - Vishwajeet Puri
- Department of Biomedical Sciences and the Diabetes Institute, Ohio University, Athens, OH, USA
| | - Kent D Chapman
- BioDiscovery Institute, Department of Biological Sciences, University of North Texas, Denton, TX, USA.
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Mitra R, Le TT, Gorjala P, Goodman OB. Positive regulation of prostate cancer cell growth by lipid droplet forming and processing enzymes DGAT1 and ABHD5. BMC Cancer 2017; 17:631. [PMID: 28877685 PMCID: PMC5588693 DOI: 10.1186/s12885-017-3589-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 08/22/2017] [Indexed: 12/30/2022] Open
Abstract
Background Neoplastic cells proliferate rapidly and obtain requisite building blocks by reprogramming metabolic pathways that favor growth. Previously, we observed that prostate cancer cells uptake and store lipids in the form of lipid droplets, providing building blocks for membrane synthesis, to facilitate proliferation and growth. Mechanisms of lipid uptake, lipid droplet dynamics and their contribution to cancer growth have yet to be defined. This work is focused on elucidating the prostate cancer-specific modifications in lipid storage pathways so that these modified gene products can be identified and therapeutically targeted. Methods To identify genes that promote lipid droplet formation and storage, the expression profiles of candidate genes were assessed and compared between peripheral blood mononuclear cells and prostate cancer cells. Subsequently, differentially expressed genes were inhibited and growth assays performed to elucidate their role in the growth of the cancer cells. Cell cycle, apoptosis and autophagy assays were performed to ascertain the mechanism of growth inhibition. Results Our results indicate that DGAT1, ABHD5, ACAT1 and ATGL are overexpressed in prostate cancer cells compared to PBMCs and of these overexpressed genes, DGAT1 and ABHD5 aid in the growth of the prostate cancer cells. Blocking the expression of both DGAT1 and ABHD5 results in inhibition of growth, cell cycle block and cell death. DGAT1 siRNA treatment inhibits lipid droplet formation and leads to autophagy where as ABHD5 siRNA treatment promotes accumulation of lipid droplets and leads to apoptosis. Both the siRNA treatments reduce AMPK phosphorylation, a key regulator of lipid metabolism. While DGAT1 siRNA reduces phosphorylation of ACC, the rate limiting enzyme in de novo fat synthesis and triggers phosphorylation of raptor and ULK-1 inducing autophagy and cell death, ABHD5 siRNA decreases P70S6 phosphorylation, leading to PARP cleavage, apoptosis and cell death. Interestingly, DGAT-1 is involved in the synthesis of triacylglycerol where as ABHD5 is a hydrolase and participates in the fatty acid oxidation process, yet inhibition of both enzymes similarly promotes prostate cancer cell death. Conclusion Inhibition of either DGAT1 or ABHD5 leads to prostate cancer cell death. Both DGAT1 and ABHD5 can be selectively targeted to block prostate cancer cell growth.
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Affiliation(s)
- Ranjana Mitra
- College of Medicine, Roseman University of Health Sciences, 10530 Discovery drive, Las Vegas, NV, 89135, USA.
| | - Thuc T Le
- College of Medicine, Roseman University of Health Sciences, 10530 Discovery drive, Las Vegas, NV, 89135, USA
| | - Priyatham Gorjala
- College of Medicine, Roseman University of Health Sciences, 10530 Discovery drive, Las Vegas, NV, 89135, USA
| | - Oscar B Goodman
- College of Medicine, Roseman University of Health Sciences, 10530 Discovery drive, Las Vegas, NV, 89135, USA. .,Comprehensive Cancer Centers of Nevada, 9280 W Sunset Road, Las Vegas, NV, 89148, USA.
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Cornell RB, Ridgway ND. CTP:phosphocholine cytidylyltransferase: Function, regulation, and structure of an amphitropic enzyme required for membrane biogenesis. Prog Lipid Res 2015; 59:147-71. [PMID: 26165797 DOI: 10.1016/j.plipres.2015.07.001] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/07/2015] [Accepted: 07/07/2015] [Indexed: 12/12/2022]
Abstract
CTP:phosphocholine cytidylyltransferase (CCT) catalyzes a rate-limiting and regulated step in the CDP-choline pathway for the synthesis of phosphatidylcholine (PC) and PC-derived lipids. Control of CCT activity is multi-layered, and includes direct regulation by reversible membrane binding involving a built-in lipid compositional sensor. Thus CCT contributes to phospholipid compositional homeostasis. CCT also modifies the curvature of its target membrane. Knowledge of CCT structure and regulation of its catalytic function are relatively advanced compared to many lipid metabolic enzymes, and are reviewed in detail. Recently the genetic origins of two human developmental and lipogenesis disorders have been traced to mutations in the gene for CCTα.
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Affiliation(s)
- Rosemary B Cornell
- Department of Molecular Biology and Biochemistry and the Department of Chemistry, Simon Fraser University, Burnaby, B.C. V5A-1S6, Canada.
| | - Neale D Ridgway
- Departments of Pediatrics, and Biochemistry and Molecular Biology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia B3H-4H7, Canada
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Gross DA, Silver DL. Cytosolic lipid droplets: from mechanisms of fat storage to disease. Crit Rev Biochem Mol Biol 2015; 49:304-26. [PMID: 25039762 DOI: 10.3109/10409238.2014.931337] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The lipid droplet (LD) is a phylogenetically conserved organelle. In eukaryotes, it is born from the endoplasmic reticulum, but unlike its parent organelle, LDs are the only known cytosolic organelles that are micellar in structure. LDs are implicated in numerous physiological and pathophysiological functions. Many aspects of the LD has captured the attention of diverse scientists alike and has recently led to an explosion in information on the LD biogenesis, expansion and fusion, identification of LD proteomes and diseases associated with LD biology. This review will provide a brief history of this fascinating organelle and provide some contemporary views of unanswered questions in LD biogenesis.
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Affiliation(s)
- David A Gross
- Program in Cardiovascular & Metabolic Disorders, Duke-NUS Graduate Medical School Singapore , Singapore , and
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Hashimoto T, Segawa H, Okuno M, Kano H, Hamaguchi HO, Haraguchi T, Hiraoka Y, Hasui S, Yamaguchi T, Hirose F, Osumi T. Active involvement of micro-lipid droplets and lipid-droplet-associated proteins in hormone-stimulated lipolysis in adipocytes. J Cell Sci 2012; 125:6127-36. [PMID: 23108672 DOI: 10.1242/jcs.113084] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The regulation of lipolysis in adipocytes involves coordinated actions of many lipid droplet (LD)-associated proteins such as perilipin, hormone sensitive lipase (HSL), adipose triglyceride lipase (ATGL), and its activator protein, CGI-58. Here, we describe the cellular origin and physiological significance of micro LDs (mLDs) that emerge in the cytoplasm during active lipolysis, as well as the roles of key lipolytic proteins on mLDs in differentiated 3T3-L1 adipocytes. Multiplex coherent anti-Stokes Raman scattering (CARS) microscopy demonstrated that mLDs receive the fatty acid (FA) moiety of triglyceride from pre-existing LDs during lipolysis. However, when FA re-esterification was blocked, mLDs did not emerge. Time-lapse imaging of GFP-tagged LD-associated proteins and immunocytochemical analyses showed that particulate structures carrying LD-associated proteins emerged throughout the cells upon lipolytic stimulation, but not when FA re-esterification was blocked. Overall lipolysis, as estimated by glycerol release, was significantly lowered by blocking re-esterification, whereas release of free FAs was enhanced. ATGL was co-immunoprecipitated with CGI-58 from the homogenates of lipolytically stimulated cells. Following CGI-58 knockdown or ATGL inhibition with bromoenol lactone, release of both glycerol and FA was significantly lowered. AICAR, an activator of AMP-activated protein kinase, significantly increased FA release, in accordance with increased expression of ATGL, even in the absence of CGI-58. These results suggest that, besides on the surface of pre-existing central LDs, LD-associated proteins are actively involved in lipolysis on mLDs that are formed by FA re-esterification. Regulation of mLDs and LD-associated proteins may be an attractive therapeutic target against lipid-associated metabolic diseases.
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Affiliation(s)
- Takeshi Hashimoto
- Faculty of Sport and Health Science, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan.
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