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Komiya Y, Iseki S, Ochiai M, Takahashi Y, Yokoyama I, Suzuki T, Tatsumi R, Sawano S, Mizunoya W, Arihara K. Dietary oleic acid intake increases the proportion of type 1 and 2X muscle fibers in mice. Sci Rep 2024; 14:755. [PMID: 38191891 PMCID: PMC10774392 DOI: 10.1038/s41598-023-50464-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 12/20/2023] [Indexed: 01/10/2024] Open
Abstract
Skeletal muscle is one of the largest metabolic tissues in mammals and is composed of four different types of muscle fibers (types 1, 2A, 2X, and 2B); however, type 2B is absent in humans. Given that slow-twitch fibers are superior to fast-twitch fibers in terms of oxidative metabolism and are rich in mitochondria, shift of muscle fiber types in direction towards slower fiber types improves metabolic disorders and endurance capacity. We previously had reported that oleic acid supplementation increases type 1 fiber formation in C2C12 myotubes; however, its function still remains unclear. This study aimed to determine the effect of oleic acid on the muscle fiber types and endurance capacity. An in vivo mouse model was used, and mice were fed a 10% oleic acid diet for 4 weeks. Two different skeletal muscles, slow soleus muscle with the predominance of slow-twitch fibers and fast extensor digitorum longus (EDL) muscle with the predominance of fast-twitch fibers, were used. We found that dietary oleic acid intake improved running endurance and altered fiber type composition of muscles, the proportion of type 1 and 2X fibers increased in the soleus muscle and type 2X increased in the EDL muscle. The fiber type shift in the EDL muscle was accompanied by an increased muscle TAG content. In addition, blood triacylglycerol (TAG) and non-esterified fatty acid levels decreased during exercise. These changes suggested that lipid utilization as an energy substrate was enhanced by oleic acid. Increased proliferator-activated receptor γ coactivator-1β protein levels were observed in the EDL muscle, which potentially enhanced the fiber type transitions towards type 2X and muscle TAG content. In conclusion, dietary oleic acid intake improved running endurance with the changes of muscle fiber type shares in mice. This study elucidated a novel functionality of oleic acid in skeletal muscle fiber types. Further studies are required to elucidate the underlying mechanisms. Our findings have the potential to contribute to the field of health and sports science through nutritional approaches, such as the development of supplements aimed at improving muscle function.
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Affiliation(s)
- Yusuke Komiya
- Laboratory of Food Function and Safety, Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan.
| | - Shugo Iseki
- Laboratory of Food Function and Safety, Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Masaru Ochiai
- Laboratory of Animal and Human Nutritional Physiology, Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Yume Takahashi
- Laboratory of Food Function and Safety, Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Issei Yokoyama
- Laboratory of Food Function and Safety, Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Takahiro Suzuki
- Laboratory of Muscle and Meat Science, Department of Animal and Marine Bioresource Sciences, Faculty of Agriculture, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan
| | - Ryuichi Tatsumi
- Laboratory of Muscle and Meat Science, Department of Animal and Marine Bioresource Sciences, Faculty of Agriculture, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan
| | - Shoko Sawano
- Laboratory of Food Health Science, Department of Food and Life Science, School of Life and Environmental Science, Azabu University, Sagamihara, Japan
| | - Wataru Mizunoya
- Laboratory of Food Science, Department of Animal Science and Biotechnology, School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Keizo Arihara
- Laboratory of Food Function and Safety, Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
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Zhang C. Coherent Raman scattering microscopy of lipid droplets in cells and tissues. JOURNAL OF RAMAN SPECTROSCOPY : JRS 2023; 54:988-1000. [PMID: 38076450 PMCID: PMC10707480 DOI: 10.1002/jrs.6540] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/03/2023] [Indexed: 09/03/2024]
Abstract
Lipid droplets (LDs) play a key role as the hub for lipid metabolism to maintain cellular metabolic homeostasis. Understanding the functions and changes of LDs in different pathological conditions is crucial for identifying new markers for diagnosis and discovering new targets for treatment. In recent years, coherent Raman scattering (CRS) microscopy has been popularized for the imaging and quantification of LDs in live cells. Compared to spontaneous Raman scattering microscopy, CRS microscopy offers a much higher imaging speed while maintaining similar chemical information. Due to the high lipid density, LDs usually have strong CRS signals and therefore are the most widely studied organelle in the CRS field. In this review, we discuss recent achievements using CRS to study the quantity, distribution, composition, and dynamics of LDs in various systems.
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Affiliation(s)
- Chi Zhang
- Department of Chemistry, Purdue Center for Cancer Research, Purdue Institute of Inflammation Immunology and Infectious Disease, Purdue University, West Lafayette, IN
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3
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Guo P, Yao X, Jin X, Xv Y, Zhang J, Li Q, Yan C, Li X, Kim N. Interference with DGAT Gene Inhibited TAG Accumulation and Lipid Droplet Synthesis in Bovine Preadipocytes. Animals (Basel) 2023; 13:2223. [PMID: 37444021 DOI: 10.3390/ani13132223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 06/30/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Triacylglycerol (TGA) is the primary component of intramuscular fat. Expression of diacylglyceryl transferase (DGAT) determines the polyester differentiation ability of precursor adipocytes. The two DGAT isoforms (DGAT1 and DGAT2) play different roles in TAG metabolism. This study investigates the roles of DGAT1 and DGAT2 in signaling pathways related to differentiation and lipid metabolism in Yanbian bovine preadipocytes. sh-DGAT1 (sh-1), sh-DGAT2 (sh-2), and sh-DGAT1 + sh-DGAT2 (sh-1 + 2) were prepared using short interfering RNA (siRNA) interference technique targeting DGAT1 and DGAT2 genes and infected bovine preadipocytes. Molecular and transcriptomic techniques, including differentially expressed genes (DEGs) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis, were used to investigate the effects on the differentiation of Yanbian bovine preadipocytes. After interference with DGAT1 and DGAT2 genes, the contents of TAG and adiponectin were decreased. The TAG content in the sh-2 and sh-1 + 2 groups was significantly lower than that in the sh-NC group. RNA sequencing (RNA-seq) results showed 2070, 2242, and 2446 DEGs in the sh-1, sh-2, and sh-1 + 2 groups, respectively. The DEGs of the sh-2 group were mainly concentrated in the PPAR, AMPK, and Wnt signaling pathways associated with adipocyte proliferation and differentiation. These results demonstrated that at the mRNA level, DGAT2 plays a more important role in lipid metabolism than DGAT1.
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Affiliation(s)
- Panpan Guo
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, China
- International Healthcare Innovation Institute, Jiangmen 529020, China
- Engineering Research Centre of North-East Cold Region Beef Cattle Science & Technology Innovation, Ministry of Education, Department of Animal Science, College of Agriculture, Yanbian University, Yanji 133002, China
| | - Xuerui Yao
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, China
- International Healthcare Innovation Institute, Jiangmen 529020, China
| | - Xin Jin
- Engineering Research Centre of North-East Cold Region Beef Cattle Science & Technology Innovation, Ministry of Education, Department of Animal Science, College of Agriculture, Yanbian University, Yanji 133002, China
- Laboratory Animal Center, Yanbian University, Yanji 133002, China
| | - Yongnan Xv
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, China
| | - Junfang Zhang
- Engineering Research Centre of North-East Cold Region Beef Cattle Science & Technology Innovation, Ministry of Education, Department of Animal Science, College of Agriculture, Yanbian University, Yanji 133002, China
| | - Qiang Li
- Engineering Research Centre of North-East Cold Region Beef Cattle Science & Technology Innovation, Ministry of Education, Department of Animal Science, College of Agriculture, Yanbian University, Yanji 133002, China
| | - Changguo Yan
- Yanbian Hongchao Wisdom Animal Husbandry Co., Ltd., Yanji 133002, China
| | - Xiangzi Li
- Engineering Research Centre of North-East Cold Region Beef Cattle Science & Technology Innovation, Ministry of Education, Department of Animal Science, College of Agriculture, Yanbian University, Yanji 133002, China
| | - Namhyung Kim
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529020, China
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Guo PP, Jin X, Zhang JF, Li Q, Yan CG, Li XZ. Overexpression of DGAT2 Regulates the Differentiation of Bovine Preadipocytes. Animals (Basel) 2023; 13:ani13071195. [PMID: 37048451 PMCID: PMC10093762 DOI: 10.3390/ani13071195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/25/2023] [Accepted: 03/27/2023] [Indexed: 04/01/2023] Open
Abstract
Triacylglycerols (TAGs) are a major component of intramuscular fat. Diacylglycerol O-acyltransferase 2(DGAT2) expression determines the rate of TAG synthesis. The purpose of this study was to investigate the role of DGAT2 in the differentiation of Yanbian cattle preadipocytes and lipid metabolism-related signalling pathways. Bovine preadipocytes were infected with overexpression and interfering adenovirus vectors of DGAT2. The effects on the differentiation of Yanbian cattle preadipocytes were examined using molecular and transcriptomic techniques, including differentially expressed genes (DEGs) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis. DGAT2 overexpression significantly increased (p < 0.05) intracellular TAG, adiponectin, and lipid droplet (LD) contents. Moreover, it upregulated (p < 0.05) peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer binding protein α, and fatty acid binding protein 4 mRNA expression. In contrast, DGAT2 knockdown reduced intracellular TAG and LD content and downregulated (p < 0.05) C/EBPβ, mannosyl (alpha-1,3-)-glycoproteinbeta-1,2-N-acetylglucosaminyltransferase, lipin 1,1-acylglycerol-3-phosphate O-acyltransferase 4, and acetyl-CoA carboxylase alpha mRNA expression. Between DGAT2-overexpressing preadipocytes and normal cells, 208 DEGs were identified, including 106 upregulated and 102 downregulated genes. KEGG pathway analysis revealed DEGs mainly enriched in PPAR signalling and AMP-activated protein kinase pathways, cholesterol metabolism, and fatty acid biosynthesis. These results demonstrated that DGAT2 regulated preadipocyte differentiation and LD and TAG accumulation by mediating the expression of adipose differentiation-, lipid metabolism-, and fatty acid synthesis-related genes.
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Al Saedi A, Debruin DA, Hayes A, Hamrick M. Lipid metabolism in sarcopenia. Bone 2022; 164:116539. [PMID: 36007811 DOI: 10.1016/j.bone.2022.116539] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/10/2022] [Accepted: 08/18/2022] [Indexed: 11/29/2022]
Abstract
Sarcopenia is an age-related disease associated with loss of muscle mass and strength. This geriatric syndrome predisposes elderly individuals to a disability, falls, fractures, and death. Fat infiltration in muscle is one of the hallmarks of sarcopenia and aging. Alterations in fatty acid (FA) metabolism are evident in aging, type 2 diabetes, and obesity, with the accumulation of lipids inside muscle cells contributing to muscle insulin resistance and ceramide accumulation. These lipids include diacylglycerol, lipid droplets, intramyocellular lipids, intramuscular triglycerides, and polyunsaturated fatty acids (PUFAs). In this review, we examine the regulation of lipid metabolism in skeletal muscle, including lipid metabolization and storage, intervention, and the types of lipases expressed in skeletal muscle responsible for the breakdown of adipose triglyceride fats. In addition, we address the role of FAs in sarcopenia and the potential benefits of PUFAs.
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Affiliation(s)
- Ahmed Al Saedi
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia; Institute of Health and Sport (IHeS), Victoria University, Melbourne, VIC, Australia.
| | - Danielle A Debruin
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia; Institute of Health and Sport (IHeS), Victoria University, Melbourne, VIC, Australia
| | - Alan Hayes
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, VIC, Australia; Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, St. Albans, VIC, Australia; Institute of Health and Sport (IHeS), Victoria University, Melbourne, VIC, Australia
| | - Mark Hamrick
- Department of Cellular Biology & Anatomy, Medical College of Georgia, Augusta University, Laney Walker Blvd. CB2915, Augusta, GA 30912, USA
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Boildieu D, Guerenne-Del Ben T, Duponchel L, Sol V, Petit JM, Champion É, Kano H, Helbert D, Magnaudeix A, Leproux P, Carré P. Coherent anti-Stokes Raman scattering cell imaging and segmentation with unsupervised data analysis. Front Cell Dev Biol 2022; 10:933897. [PMID: 36051442 PMCID: PMC9424763 DOI: 10.3389/fcell.2022.933897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 07/11/2022] [Indexed: 11/17/2022] Open
Abstract
Coherent Raman imaging has been extensively applied to live-cell imaging in the last 2 decades, allowing to probe the intracellular lipid, protein, nucleic acid, and water content with a high-acquisition rate and sensitivity. In this context, multiplex coherent anti-Stokes Raman scattering (MCARS) microspectroscopy using sub-nanosecond laser pulses is now recognized as a mature and straightforward technology for label-free bioimaging, offering the high spectral resolution of conventional Raman spectroscopy with reduced acquisition time. Here, we introduce the combination of the MCARS imaging technique with unsupervised data analysis based on multivariate curve resolution (MCR). The MCR process is implemented under the classical signal non-negativity constraint and, even more originally, under a new spatial constraint based on cell segmentation. We thus introduce a new methodology for hyperspectral cell imaging and segmentation, based on a simple, unsupervised workflow without any spectrum-to-spectrum phase retrieval computation. We first assess the robustness of our approach by considering cells of different types, namely, from the human HEK293 and murine C2C12 lines. To evaluate its applicability over a broader range, we then study HEK293 cells in different physiological states and experimental situations. Specifically, we compare an interphasic cell with a mitotic (prophase) one. We also present a comparison between a fixed cell and a living cell, in order to visualize the potential changes induced by the fixation protocol in cellular architecture. Next, with the aim of assessing more precisely the sensitivity of our approach, we study HEK293 living cells overexpressing tropomyosin-related kinase B (TrkB), a cancer-related membrane receptor, depending on the presence of its ligand, brain-derived neurotrophic factor (BDNF). Finally, the segmentation capability of the approach is evaluated in the case of a single cell and also by considering cell clusters of various sizes.
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Affiliation(s)
- Damien Boildieu
- University of Limoges, CNRS, XLIM, UMR 7252, Limoges, France
- University of Poitiers, CNRS, XLIM, UMR 7252, Poitiers, France
| | | | - Ludovic Duponchel
- University of Lille, CNRS, UMR 8516, LASIRE - Laboratoire de Spectroscopie Pour Les Interactions, La Réactivité et L’Environnement, Lille, France
| | - Vincent Sol
- University of Limoges, PEIRENE, UR 22722, Limoges, France
| | | | - Éric Champion
- University of Limoges, CNRS, Institut de Recherche sur Les Céramiques, UMR 7315, Limoges, France
| | - Hideaki Kano
- Department of Chemistry, Faculty of Science, Kyushu University, Fukuoka, Japan
| | - David Helbert
- University of Poitiers, CNRS, XLIM, UMR 7252, Poitiers, France
| | - Amandine Magnaudeix
- University of Limoges, CNRS, Institut de Recherche sur Les Céramiques, UMR 7315, Limoges, France
| | - Philippe Leproux
- University of Limoges, CNRS, XLIM, UMR 7252, Limoges, France
- *Correspondence: Philippe Leproux,
| | - Philippe Carré
- University of Poitiers, CNRS, XLIM, UMR 7252, Poitiers, France
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Overexpression of DGAT2 Stimulates Lipid Droplet Formation and Triacylglycerol Accumulation in Bovine Satellite Cells. Animals (Basel) 2022; 12:ani12141847. [PMID: 35883393 PMCID: PMC9312262 DOI: 10.3390/ani12141847] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 07/14/2022] [Accepted: 07/19/2022] [Indexed: 12/12/2022] Open
Abstract
Intramuscular fat (IMF) is closely related to the tenderness, juiciness, and flavor of beef, and is an important indicator for beef quality assessment internationally. The main components of skeletal intramuscular fat (IMF) are phospholipids and triacylglycerols (TAG), and the final step of TAG biosynthesis is catalyzed by diacylglycerol acyltransferase 2 (DGAT2). To explore the effect of DGAT2 on the differentiation of bovine muscle satellite cells (BSCs) and its role in the signaling pathway related to lipid metabolism, the adenovirus overexpression and interference vector of the DGAT2 gene was constructed in this study, and the overexpression adenovirus Ad-DGAT2 and interfering adenovirus sh-DGAT2 were used to infect BSCs. Overexpression of DGAT2 resulted in a significant increase in the contents of TAG and ADP, and the mRNA and protein expression levels of PPARγ, C/EBPα, and SREBF1 (p < 0.05). Interfering with the expression of DGAT2 reduced the intracellular TAG content and lipid droplet accumulation. Furthermore, the mRNA and protein expression levels of PPARγ, C/EBPα, and SREBF1 (p < 0.05) were significantly downregulated. Transcriptome sequencing showed that a total of 598 differentially expressed genes (DEGs) were screened in BSCs infected with Ad-DGAT2, and these DEGs included 292 upregulated genes and 306 downregulated genes. A total of 49 DEGs were screened in BSCs infected with sh-DGAT2, and these DEGs included 25 upregulated and 24 downregulated genes. KEGG enrichment analysis showed that the DEGs, after overexpression of DGAT2, were mainly enriched in the PPAR signaling pathway, and the fat digestion and absorption, glycerophospholipid metabolism, fatty acid biosynthesis, and AMPK signaling pathways. The DEGs obtained after interfering with DGAT2 were mainly enriched in the metabolic pathways, such as the PPAR signaling pathway and PI3K/AKT signaling pathway. In summary, our study demonstrated that the lipid droplet formation, TAG accumulation, and adipogenic gene expression in BSCs overexpressing DGAT2 were higher than those in the control cells. These results highlight the important role of DGAT2 in regulating BSCs during adipogenic transdifferentiation and underscore the complexity of intramuscular adipogenesis.
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An X, Zhang S, Li T, Chen N, Wang X, Zhang B, Ma Y. Transcriptomics analysis reveals the effect of Broussonetia papyrifera L. fermented feed on meat quality traits in fattening lamb. PeerJ 2021; 9:e11295. [PMID: 33987003 PMCID: PMC8086582 DOI: 10.7717/peerj.11295] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 03/27/2021] [Indexed: 11/20/2022] Open
Abstract
To date, utilization of feed grains is increasing, which competes for human food. It is imperative to develop and utilize unconventional feed materials. Broussonetia papyrifera L. (B. papyrifera) is a good feeding material with high crude protein, crude fat, and low crude fiber, which is widely distributed in China. In this study, 12 Dorper ♂×Hu ♀ crossbred weaned male lambs were seleted into four groups based on the feed that ratio of the B. papyrifera fermented feed in the total mixed diet (0%, 6%, 18%, and 100%), to character the lambs' longissimus dorsi (LD) fatty acids, morphology and transcriptome. Results showed that the muscle fiber's diameter and area were the smallest in the 100% group. The highest content of beneficial fatty acids and the lowest content of harmful fatty acids in group 18%. RNA-seq identified 443 differentially expressed genes (DEGs) in the LD of lambs from 4 groups. Among these genes, 169 (38.1%) were up-regulated and 274 (61.9%) were down-regulated. The DEGs were mostly enriched in in fatty acid metabolism, arginine and proline metabolism, and PPAR signaling pathways. Our results provide knowledge to understand effect of different ratios of B. papyrifera fermented feed on sheep meat quality traits, also a basis for understanding of the molecular regulation mechanism of B. papyrifera fermented feed affecting on sheep meat quality.
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Affiliation(s)
- Xuejiao An
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Shengwei Zhang
- Gansu Provincial Farmer Education and Training Station, Lanzhou, China
| | - Taotao Li
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Nana Chen
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Xia Wang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Baojun Zhang
- Gansu Provincial Farmer Education and Training Station, Lanzhou, China
| | - Youji Ma
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, Gansu, China
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Daemen S, Gemmink A, Paul A, Billecke N, Rieger K, Parekh SH, Hesselink MKC. Label-free CARS microscopy reveals similar triacylglycerol acyl chain length and saturation in myocellular lipid droplets of athletes and individuals with type 2 diabetes. Diabetologia 2020; 63:2654-2664. [PMID: 32880685 PMCID: PMC7641925 DOI: 10.1007/s00125-020-05266-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/17/2020] [Indexed: 01/17/2023]
Abstract
AIMS/HYPOTHESIS Intramyocellular lipid (IMCL) content associates with development of insulin resistance, albeit not in insulin-sensitive endurance-trained athletes (trained). Qualitative and spatial differences in muscle lipid composition may underlie this so-called athlete's paradox. Here we studied triacylglycerol (TAG) composition of individual myocellular lipid droplets (LDs) in trained individuals and individuals with type 2 diabetes mellitus. METHODS Trained ([Formula: see text] 71.0 ± 1.6 ml O2 [kg lean body mass (LBM)]-1 min-1), normoglycaemic (fasting glucose 5.1 ± 0.1 mmol/l) individuals and untrained ([Formula: see text] 36.8 ± 1.5 ml O2 [kg LBM]-1 min-1) individuals with type 2 diabetes (fasting glucose 7.4 ± 0.5 mmol/l), with similar IMCL content (3.5 ± 0.7% vs 2.5 ± 0.3%, p = 0.241), but at opposite ends of the insulin sensitivity spectrum (glucose infusion rate 93.8 ± 6.6 vs 25.7 ± 5.3 μmol [kg LBM]-1 min-1 for trained individuals and those with type 2 diabetes, respectively) were included from our database in the present study. We applied in situ label-free broadband coherent anti-Stokes Raman scattering (CARS) microscopy to sections from skeletal muscle biopsies to measure TAG acyl chain length and saturation of myocellular LDs. This approach uniquely permits examination of individual LDs in their native environment, in a fibre-type-specific manner, taking into account LD size and subcellular location. RESULTS Despite a significant difference in insulin sensitivity, we observed remarkably similar acyl chain length and saturation in trained and type 2 diabetic individuals (chain length: 18.12 ± 0.61 vs 18.36 ± 0.43 number of carbons; saturation: 0.37 ± 0.05 vs 0.38 ± 0.06 number of C=C bonds). Longer acyl chains or higher saturation (lower C=C number) could be detected in subpopulations of LDs, i.e. large LDs (chain length: 18.11 ± 0.48 vs 18.63 ± 0.57 carbon number) and subsarcolemmal LDs (saturation: 0.34 ± 0.02 vs 0.36 ± 0.04 C=C number), which are more abundant in individuals with type 2 diabetes. CONCLUSIONS/INTERPRETATION In contrast to reports of profound differences in the lipid composition of lipids extracted from skeletal muscle from trained and type 2 diabetic individuals, our in situ, LD-specific approach detected only modest differences in TAG composition in LD subpopulations, which were dependent on LD size and subcellular location. If, and to what extent, these modest differences can impact insulin sensitivity remains to be elucidated. Graphical abstract.
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Affiliation(s)
- Sabine Daemen
- Department of Nutrition and Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Anne Gemmink
- Department of Nutrition and Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Alexandra Paul
- Department of Biology and Biological Engineering, Division of Chemical Biology, Chalmers University of Technology, Gothenburg, Sweden
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA
| | - Nils Billecke
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Mainz, Germany
| | - Katrina Rieger
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Mainz, Germany
| | - Sapun H Parekh
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX, USA.
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Mainz, Germany.
| | - Matthijs K C Hesselink
- Department of Nutrition and Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands.
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Tracey TJ, Kirk SE, Steyn FJ, Ngo ST. The role of lipids in the central nervous system and their pathological implications in amyotrophic lateral sclerosis. Semin Cell Dev Biol 2020; 112:69-81. [PMID: 32962914 DOI: 10.1016/j.semcdb.2020.08.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/11/2020] [Accepted: 08/31/2020] [Indexed: 12/12/2022]
Abstract
Lipids play an important role in the central nervous system (CNS). They contribute to the structural integrity and physical characteristics of cell and organelle membranes, act as bioactive signalling molecules, and are utilised as fuel sources for mitochondrial metabolism. The intricate homeostatic mechanisms underpinning lipid handling and metabolism across two major CNS cell types; neurons and astrocytes, are integral for cellular health and maintenance. Here, we explore the various roles of lipids in these two cell types. Given that changes in lipid metabolism have been identified in a number of neurodegenerative diseases, we also discuss changes in lipid handling and utilisation in the context of amyotrophic lateral sclerosis (ALS), in order to identify key cellular processes affected by the disease, and inform future areas of research.
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Affiliation(s)
- T J Tracey
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia.
| | - S E Kirk
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia
| | - F J Steyn
- Centre for Clinical Research, The University of Queensland, Brisbane, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - S T Ngo
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Australia; Centre for Clinical Research, The University of Queensland, Brisbane, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, Australia.
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11
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Lipid droplets in prostate cancer cells and effect of irradiation studied by Raman microspectroscopy. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158753. [DOI: 10.1016/j.bbalip.2020.158753] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/26/2020] [Accepted: 05/29/2020] [Indexed: 12/21/2022]
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12
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Quantitative Mapping of Triacylglycerol Chain Length and Saturation Using Broadband CARS Microscopy. Biophys J 2019; 116:2346-2355. [PMID: 31153590 DOI: 10.1016/j.bpj.2019.04.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 03/25/2019] [Accepted: 04/25/2019] [Indexed: 01/15/2023] Open
Abstract
Lipid droplets (LDs), present in many cell types, are highly dynamic organelles that store neutral lipids, primarily triacylglycerols (TAGs). With the discovery of new LD functions (e.g., in immune response, protein clearage, and occurrence with disease), new methods to study LD chemical composition in situ are necessary. We present an approach for in situ, quantitative TAG analysis using label-free, coherent Raman microscopy that allows deciphering LD TAG composition in different biochemically complex samples with submicrometer spatial resolution. Employing a set of standard TAGs, we generate a spectral training matrix capturing the variation caused in Raman-like spectra by TAG backbone, chain length, and number of double bonds per chain, as well as the presence of proteins or other diluting molecules. Comparing our fitting approach to gas chromatography measurements for mixtures of standard TAGs and food oils, we find the root mean-square error for the prediction of TAG chemistry to be 0.69 CH2 and 0.15 #C=C. When progressing to more complex samples such as oil emulsions and LDs in various eukaryotic cells, we find good agreement with bulk gas chromatography measurements. For differentiated adipocytes, we find a significant increase in the number of double bonds in small LDs (below 2 μm in diameter) compared to large LDs (above 2 μm in diameter). Coupled with a relatively limited sample preparation requirement, this approach should enable rapid and accurate TAG LD analysis for a variety of cell biology and technological applications.
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13
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Schnell DM, Walton RG, Vekaria HJ, Sullivan PG, Bollinger LM, Peterson CA, Thomas DT. Vitamin D produces a perilipin 2-dependent increase in mitochondrial function in C2C12 myotubes. J Nutr Biochem 2018; 65:83-92. [PMID: 30658160 DOI: 10.1016/j.jnutbio.2018.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/11/2018] [Accepted: 11/10/2018] [Indexed: 02/08/2023]
Abstract
Vitamin D has been connected with increased intramyocellular lipid (IMCL) and has also been shown to increase mitochondrial function and insulin sensitivity. Evidence suggests that perilipin 2 (PLIN2), a perilipin protein upregulated with calcitriol treatment, may be integral to managing increased IMCL capacity and lipid oxidation in skeletal muscle. Therefore, we hypothesized that PLIN2 is required for vitamin D induced IMCL accumulation and increased mitochondrial oxidative function. To address this hypothesis, we treated C2C12 myotubes with 100 nM calcitriol (the active form of vitamin D) and/or PLIN2 siRNA in a four group design and analyzed markers of IMCL accumulation and metabolism using qRT-PCR, cytochemistry, and oxygen consumption assay. Expression of PLIN2, but not PLIN3 or PLIN5 mRNA was increased with calcitriol, and PLIN2 induction was prevented with siRNA knockdown without compensation by other perilipins. PLIN2 knockdown did not appear to prevent lipid accumulation. Calcitriol treatment increased mRNA expression of triglyceride synthesizing genes DGAT1 and DGAT2 and also lipolytic genes ATGL and CGI-58. PLIN2 knockdown decreased the expression of CGI-58 and CPT1, and was required for calcitriol-induced upregulation of DGAT2. Calcitriol increased oxygen consumption rate while PLIN2 knockdown decreased oxygen consumption rate. PLIN2 was required for a calcitriol-induced increase in oxygen consumption driven by mitochondrial complex II. We conclude that calcitriol increases mitochondrial function in myotubes and that this increase is at least in part mediated by PLIN2.
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Affiliation(s)
| | - R Grace Walton
- Department of Rehabilitation Sciences; Center for Muscle Biology.
| | | | | | | | | | - D Travis Thomas
- Department of Clinical Sciences, University of Kentucky, Lexington, KY 40536.
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14
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Metcalfe LK, Smith GC, Turner N. Defining lipid mediators of insulin resistance - controversies and challenges. J Mol Endocrinol 2018; 62:JME-18-0023. [PMID: 30068522 DOI: 10.1530/jme-18-0023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 07/04/2018] [Accepted: 07/31/2018] [Indexed: 12/31/2022]
Abstract
Essential elements of all cells, lipids play important roles in energy production, signalling and as structural components. Despite these critical functions, excessive availability and intracellular accumulation of lipid is now recognised as a major factor contributing to many human diseases, including obesity and diabetes. In the context of these metabolic disorders, ectopic deposition of lipid has been proposed to have deleterious effects of insulin action. While this relationship has been recognised for some time now, there is currently no unifying mechanism to explain how lipids precipitate the development of insulin resistance. This review summarises the evidence linking specific lipid molecules to the induction of insulin resistance, describing some of the current controversies and challenges for future studies in this field.
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Affiliation(s)
- Louise K Metcalfe
- L Metcalfe, Department of Pharmacology, School of Medical Sciences, UNSW Australia, Kensington, Australia
| | - Greg C Smith
- G Smith, Department of Pharmacology, School of Medical Sciences, UNSW Australia, Kensington, Australia
| | - Nigel Turner
- N Turner, Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
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15
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Gemmink A, Daemen S, Brouwers B, Huntjens PR, Schaart G, Moonen-Kornips E, Jörgensen J, Hoeks J, Schrauwen P, Hesselink MKC. Dissociation of intramyocellular lipid storage and insulin resistance in trained athletes and type 2 diabetes patients; involvement of perilipin 5? J Physiol 2017; 596:857-868. [PMID: 29110300 DOI: 10.1113/jp275182] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 10/25/2017] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS Intramyocellular lipid storage is negatively associated with insulin sensitivity. However, endurance trained athletes and type 2 diabetes mellitus (T2DM) patients store similar amounts of lipids in their muscle; the so-called athlete's paradox. Compared to T2DM, trained athletes possess higher levels of perilipin 5 (PLIN5), a lipid droplet (LD) coating protein. We examined whether coating LD with PLIN5 affects the pattern of muscle lipid (LD size and number) in relation to the athlete's paradox. Despite differences in PLIN5 protein content, we observed that coating the LD with PLIN5 could not explain the observed differences in LD size and number between athletes and T2DM. PLIN5-coated LDs were positively associated with oxidative capacity but not with insulin sensitivity. We conclude that coating of LDs with PLIN5 cannot causally explain the athlete's paradox. ABSTRACT Intramyocellular lipid (IMCL) hampers insulin sensitivity, albeit not in endurance-trained athletes (Trained). Compared to type 2 diabetes mellitus (T2DM) patients, Trained subjects have high levels of perilipin 5 (PLIN5). In the present study, we tested whether the fraction of PLIN5-coated lipid droplets (LDs) is a determinant of skeletal muscle insulin sensitivity and contributes to the athlete's paradox. Muscle biopsies were taken from eight Trained, Lean sedentary, Obese and T2DM subjects. Trained, Obese and T2DM subjects were matched for total IMCL content. Confocal images were analysed for lipid area fraction, LD size and number and PLIN5+ and PLIN5- LDs were measured. A stepwise linear regression was performed to identify factors explaining observed variance in glucose infusion rate (GIR). Trained and T2DM subjects stored IMCL differently; Trained subjects had a higher number of LDs compared to T2DM subjects (0.037 ± 0.004 μm-2 vs. 0.023 ± 0.003 μm-2 , P = 0.024) that were non-significantly smaller (0.27 ± 0.01 μm2 vs. 0.32 ± 0.02 μm2 , P = 0.197, Trained vs. T2DM). Even though total PLIN5 protein content was almost double in Trained vs. T2DM subjects (1.65 ± 0.21 AU vs. 0.89 ± 0.09 AU, P = 0.004), PLIN5 coating did not affect LD number or size significantly. Of the observed variance in GIR, the largest fraction by far (70.2%) was explained by maximal oxygen uptake. Adding PLIN5 protein content or PLIN5+ LDs increased the explained variance in GIR (74.7% and 80.7% for PLIN5 protein content and PLIN5+ LDs, respectively). Thus, the putative relationship between PLIN5 and insulin sensitivity is at best indirect and is apparent only in conjunction with maximal oxygen uptake. Hence, PLIN5 abundance cannot be causally linked to the athlete's paradox.
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Affiliation(s)
- Anne Gemmink
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Sabine Daemen
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Bram Brouwers
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands.,Current affiliation: Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Orlando, FL, USA
| | - Peter R Huntjens
- Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Gert Schaart
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Esther Moonen-Kornips
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Johanna Jörgensen
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Joris Hoeks
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Patrick Schrauwen
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Matthijs K C Hesselink
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
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16
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Baer A, Schmidt S, Haensch S, Eder M, Mayer G, Harrington MJ. Mechanoresponsive lipid-protein nanoglobules facilitate reversible fibre formation in velvet worm slime. Nat Commun 2017; 8:974. [PMID: 29042549 PMCID: PMC5645397 DOI: 10.1038/s41467-017-01142-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 08/22/2017] [Indexed: 12/23/2022] Open
Abstract
Velvet worms eject a fluid capture slime that can be mechanically drawn into stiff biopolymeric fibres. Remarkably, these fibres can be dissolved by extended exposure to water, and new regenerated fibres can be drawn from the dissolved fibre solution-indicating a fully recyclable process. Here, we perform a multiscale structural and compositional investigation of this reversible fabrication process with the velvet worm Euperipatoides rowelli, revealing that biopolymeric fibre assembly is facilitated via mono-disperse lipid-protein nanoglobules. Shear forces cause nanoglobules to self-assemble into nano- and microfibrils, which can be drawn into macroscopic fibres with a protein-enriched core and lipid-rich coating. Fibre dissolution in water leads to re-formation of nanoglobules, suggesting that this dynamic supramolecular assembly of mechanoresponsive protein-building blocks is mediated by reversible non-covalent interactions. These findings offer important mechanistic insights into the role of mechanochemical processes in bio-fibre formation, providing potential avenues for sustainable material fabrication processes.Velvet worms expel a fluid slime that, under shear force, forms stiff fibres that can be dissolved and then regenerated. Here, the authors reveal that the recyclability of these biopolymers relies on mechanoresponsive lipid-protein nanoglobules in the slime that reversibly self-assemble into fibrils.
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Affiliation(s)
- Alexander Baer
- Department of Zoology, Institute of Biology, University of Kassel, Heinrich-Plett-Str. 40, 34132, Kassel, Germany.
| | - Stephan Schmidt
- Institute of Organic and Macromolecular Chemistry, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Sebastian Haensch
- Center for Advanced Imaging (CAi), Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225, Düsseldorf, Germany
| | - Michaela Eder
- Dept. of Biomaterials, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424, Potsdam, Germany
| | - Georg Mayer
- Department of Zoology, Institute of Biology, University of Kassel, Heinrich-Plett-Str. 40, 34132, Kassel, Germany
| | - Matthew J Harrington
- Dept. of Biomaterials, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424, Potsdam, Germany. .,Dept. of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC, H3A 0B8, Canada.
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17
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Gemmink A, Goodpaster BH, Schrauwen P, Hesselink MKC. Intramyocellular lipid droplets and insulin sensitivity, the human perspective. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1242-1249. [PMID: 28739280 DOI: 10.1016/j.bbalip.2017.07.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/18/2017] [Accepted: 07/19/2017] [Indexed: 11/19/2022]
Abstract
Skeletal muscle can store excess fat as subcellular lipid droplets (LDs). While originally viewed as uninteresting static balls of triacylglycerol, it is now clear that myocellular LDs play an active role in myocellular (patho)physiology. In this review we aim to discuss the role of LDs in muscle cell insulin sensitivity and identify parameters which appear to affect this relationship. Moreover, we discuss the application of novel tools permitting detailed examination of these parameters. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.
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Affiliation(s)
- Anne Gemmink
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands
| | - Bret H Goodpaster
- Translational Research Institute for Metabolism and Diabetes, Orlando, FL, USA
| | - Patrick Schrauwen
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands
| | - Matthijs K C Hesselink
- Department of Human Biology and Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD Maastricht, The Netherlands.
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18
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Imaging and lipidomics methods for lipid analysis in metabolic and cardiovascular disease. J Dev Orig Health Dis 2017; 8:566-574. [PMID: 28697812 DOI: 10.1017/s2040174417000496] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cardiometabolic diseases exhibit changes in lipid biology, which is important as lipids have critical roles in membrane architecture, signalling, hormone synthesis, homoeostasis and metabolism. However, Developmental Origins of Health and Disease studies of cardiometabolic disease rarely include analysis of lipids. This short review highlights some examples of lipid pathology and then explores the technology available for analysing lipids, focussing on the need to develop imaging modalities for intracellular lipids. Analytical methods for studying interactions between the complex endocrine and intracellular signalling pathways that regulate lipid metabolism have been critical in expanding our understanding of how cardiometabolic diseases develop in association with obesity and dietary factors. Biochemical methods can be used to generate detailed lipid profiles to establish links between lifestyle factors and metabolic signalling pathways and determine how changes in specific lipid subtypes in plasma and homogenized tissue are associated with disease progression. New imaging modalities enable the specific visualization of intracellular lipid traffic and distribution in situ. These techniques provide a dynamic picture of the interactions between lipid storage, mobilization and signalling, which operate during normal cell function and are altered in many important diseases. The development of methods for imaging intracellular lipids can provide a dynamic real-time picture of how lipids are involved in complex signalling and other cell biology pathways; and how they ultimately regulate metabolic function/homoeostasis during early development. Some imaging modalities have the potential to be adapted for in vivo applications, and may enable the direct visualization of progression of pathogenesis of cardiometabolic disease after poor growth in early life.
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19
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Morales PE, Bucarey JL, Espinosa A. Muscle Lipid Metabolism: Role of Lipid Droplets and Perilipins. J Diabetes Res 2017; 2017:1789395. [PMID: 28676863 PMCID: PMC5476901 DOI: 10.1155/2017/1789395] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 04/19/2017] [Accepted: 04/26/2017] [Indexed: 02/07/2023] Open
Abstract
Skeletal muscle is one of the main regulators of carbohydrate and lipid metabolism in our organism, and therefore, it is highly susceptible to changes in glucose and fatty acid (FA) availability. Skeletal muscle is an extremely complex tissue: its metabolic capacity depends on the type of fibers it is made up of and the level of stimulation it undergoes, such as acute or chronic contraction. Obesity is often associated with increased FA levels, which leads to the accumulation of toxic lipid intermediates, oxidative stress, and autophagy in skeletal fibers. This lipotoxicity is one of the most common causes of insulin resistance (IR). In this scenario, the "isolation" of certain lipids in specific cell compartments, through the action of the specific lipid droplet, perilipin (PLIN) family of proteins, is conceived as a lifeguard compensatory strategy. In this review, we summarize the cellular mechanism underlying lipid mobilization and metabolism inside skeletal muscle, focusing on the function of lipid droplets, the PLIN family of proteins, and how these entities are modified in exercise, obesity, and IR conditions.
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Affiliation(s)
- Pablo Esteban Morales
- Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Jose Luis Bucarey
- CIDIS-AC, Escuela de Medicina, Universidad de Valparaiso, Valparaiso, Chile
| | - Alejandra Espinosa
- Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- *Alejandra Espinosa:
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20
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Laurens C, Bourlier V, Mairal A, Louche K, Badin PM, Mouisel E, Montagner A, Marette A, Tremblay A, Weisnagel JS, Guillou H, Langin D, Joanisse DR, Moro C. Perilipin 5 fine-tunes lipid oxidation to metabolic demand and protects against lipotoxicity in skeletal muscle. Sci Rep 2016; 6:38310. [PMID: 27922115 PMCID: PMC5138838 DOI: 10.1038/srep38310] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/07/2016] [Indexed: 11/09/2022] Open
Abstract
Lipid droplets (LD) play a central role in lipid homeostasis by controlling transient fatty acid (FA) storage and release from triacylglycerols stores, while preventing high levels of cellular toxic lipids. This crucial function in oxidative tissues is altered in obesity and type 2 diabetes. Perilipin 5 (PLIN5) is a LD protein whose mechanistic and causal link with lipotoxicity and insulin resistance has raised controversies. We investigated here the physiological role of PLIN5 in skeletal muscle upon various metabolic challenges. We show that PLIN5 protein is elevated in endurance-trained (ET) subjects and correlates with muscle oxidative capacity and whole-body insulin sensitivity. When overexpressed in human skeletal muscle cells to recapitulate the ET phenotype, PLIN5 diminishes lipolysis and FA oxidation under basal condition, but paradoxically enhances FA oxidation during forskolin- and contraction- mediated lipolysis. Moreover, PLIN5 partly protects muscle cells against lipid-induced lipotoxicity. In addition, we demonstrate that down-regulation of PLIN5 in skeletal muscle inhibits insulin-mediated glucose uptake under normal chow feeding condition, while paradoxically improving insulin sensitivity upon high-fat feeding. These data highlight a key role of PLIN5 in LD function, first by finely adjusting LD FA supply to mitochondrial oxidation, and second acting as a protective factor against lipotoxicity in skeletal muscle.
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Affiliation(s)
- Claire Laurens
- INSERM, UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.,University of Toulouse, Paul Sabatier University, France
| | - Virginie Bourlier
- INSERM, UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.,University of Toulouse, Paul Sabatier University, France
| | - Aline Mairal
- INSERM, UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.,University of Toulouse, Paul Sabatier University, France
| | - Katie Louche
- INSERM, UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.,University of Toulouse, Paul Sabatier University, France
| | - Pierre-Marie Badin
- INSERM, UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.,University of Toulouse, Paul Sabatier University, France
| | - Etienne Mouisel
- INSERM, UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.,University of Toulouse, Paul Sabatier University, France
| | - Alexandra Montagner
- University of Toulouse, Paul Sabatier University, France.,INRA, UMR 1331, TOXALIM, Toulouse, France
| | - André Marette
- Department of Medicine, Laval University, Quebec City, Canada.,Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Quebec City, Canada
| | - Angelo Tremblay
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Quebec City, Canada.,Department of Kinesiology, Laval University, Quebec City, Canada
| | | | - Hervé Guillou
- University of Toulouse, Paul Sabatier University, France.,INRA, UMR 1331, TOXALIM, Toulouse, France
| | - Dominique Langin
- INSERM, UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.,University of Toulouse, Paul Sabatier University, France.,Toulouse University Hospitals, Department of Clinical Biochemistry, Toulouse, France
| | - Denis R Joanisse
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Quebec City, Canada.,Department of Kinesiology, Laval University, Quebec City, Canada
| | - Cedric Moro
- INSERM, UMR1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France.,University of Toulouse, Paul Sabatier University, France
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21
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Waschatko G, Billecke N, Schwendy S, Jaurich H, Bonn M, Vilgis TA, Parekh SH. Label-free in situ imaging of oil body dynamics and chemistry in germination. J R Soc Interface 2016; 13:20160677. [PMID: 27798279 PMCID: PMC5095225 DOI: 10.1098/rsif.2016.0677] [Citation(s) in RCA: 10] [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: 08/23/2016] [Accepted: 09/28/2016] [Indexed: 02/06/2023] Open
Abstract
Plant oleosomes are uniquely emulsified lipid reservoirs that serve as the primary energy source during seed germination. These oil bodies undergo significant changes regarding their size, composition and structure during normal seedling development; however, a detailed characterization of these oil body dynamics, which critically affect oil body extractability and nutritional value, has remained challenging because of a limited ability to monitor oil body location and composition during germination in situ Here, we demonstrate via in situ, label-free imaging that oil bodies are highly dynamic intracellular organelles that are morphologically and biochemically remodelled extensively during germination. Label-free, coherent Raman microscopy (CRM) combined with bulk biochemical measurements revealed the temporal and spatial regulation of oil bodies in native soya bean cotyledons during the first eight days of germination. Oil bodies undergo a cycle of growth and shrinkage that is paralleled by lipid and protein compositional changes. Specifically, the total protein concentration associated with oil bodies increases in the first phase of germination and subsequently decreases. Lipids contained within the oil bodies change in saturation and chain length during germination. Our results show that CRM is a well-suited platform to monitor in situ lipid dynamics and local chemistry and that oil bodies are actively remodelled during germination. This underscores the dynamic role of lipid reservoirs in plant development.
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Affiliation(s)
- Gustav Waschatko
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Mainz, Germany
| | - Nils Billecke
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Mainz, Germany
| | - Sascha Schwendy
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Mainz, Germany
| | - Henriette Jaurich
- Department of Polymer Theory, Max Planck Institute for Polymer Research, Mainz, Germany
| | - Mischa Bonn
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Mainz, Germany
| | - Thomas A Vilgis
- Department of Polymer Theory, Max Planck Institute for Polymer Research, Mainz, Germany
| | - Sapun H Parekh
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Mainz, Germany
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22
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Cicerone M. Molecular imaging with CARS micro-spectroscopy. Curr Opin Chem Biol 2016; 33:179-85. [PMID: 27400394 PMCID: PMC5018446 DOI: 10.1016/j.cbpa.2016.05.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 04/14/2016] [Accepted: 05/10/2016] [Indexed: 10/21/2022]
Abstract
After more than a decade of instrument and method development, broadband coherent anti-Stokes Raman scattering (CARS) micro-spectroscopy is beginning to live up to its potential as a label-free imaging modality that can rapidly generate high resolution images with full vibrational spectra at each image pixel. Presently these instruments are able to obtain quantitative, spatially resolved information on lipids from the CH stretch region of the Raman spectrum, and some instrument designs facilitate acquisition of high quality fingerprint spectra, containing information on a host of molecular species including structural proteins, nucleotides, and metabolites. While most of the existing instruments are research projects themselves, it appears that the relevant technologies are maturing so that commercially available instruments may not be too far in the future, making this remarkable imaging modality widely available.
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Affiliation(s)
- Marcus Cicerone
- NIST, 100 Bureau Drive, Gaithersburg, MD 20899, United States.
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23
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Gemmink A, Bosma M, Kuijpers HJH, Hoeks J, Schaart G, van Zandvoort MAMJ, Schrauwen P, Hesselink MKC. Decoration of intramyocellular lipid droplets with PLIN5 modulates fasting-induced insulin resistance and lipotoxicity in humans. Diabetologia 2016; 59:1040-8. [PMID: 26864436 PMCID: PMC4826431 DOI: 10.1007/s00125-016-3865-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 12/14/2015] [Indexed: 12/24/2022]
Abstract
AIMS/HYPOTHESIS In contrast to insulin-resistant individuals, insulin-sensitive athletes possess high intramyocellular lipid content (IMCL), good mitochondrial function and high perilipin 5 (PLIN5) levels, suggesting a role for PLIN5 in benign IMCL storage. We hypothesised a role for PLIN5 in modulating fasting-mediated insulin resistance. METHODS Twelve men were fasted for 60 h, before and after which muscle biopsies were taken and stained for lipid droplets (LDs), PLIN5 and laminin. Confocal microscopy images were analysed for LD size, number, PLIN5 association and subcellular distribution. RESULTS Fasting elevated IMCL content 2.8-fold and reduced insulin sensitivity (by 55%). Individuals with the most prominent increase in IMCL showed the least reduction in insulin sensitivity (r = 0.657; p = 0.028) and mitochondrial function (r = 0.896; p = 0.006). During fasting, PLIN5 gene expression or PLIN5 protein content in muscle homogenates was unaffected, microscopy analyses revealed that the fraction of PLIN5 associated with LDs (PLIN5+) increased significantly (+26%) upon fasting, suggesting PLIN5 redistribution. The significant increase in LD number (+23%) and size (+23%) upon fasting was entirely accounted for by PLIN5+ LDs, not by LDs devoid of PLIN5. Also the association between IMCL storage capacity and insulin resistance and mitochondrial dysfunction was only apparent for PLIN5+ LDs. CONCLUSIONS/INTERPRETATION Fasting results in subcellular redistribution of PLIN5 and promotes the capacity to store excess fat in larger and more numerous PLIN5-decorated LDs. This associates with blunting of fasting-induced insulin resistance and mitochondrial dysfunction, suggesting a role for PLIN5 in the modulation of fasting-mediated lipotoxicity. TRIAL REGISTRATION trialregister.nl NTR 2042.
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Affiliation(s)
- Anne Gemmink
- Department of Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD, Maastricht, the Netherlands
| | - Madeleen Bosma
- Department of Human Biology, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Helma J H Kuijpers
- Department of Genetics and Cell Biology-Molecular Cell Biology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Joris Hoeks
- Department of Human Biology, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Gert Schaart
- Department of Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD, Maastricht, the Netherlands
| | - Marc A M J van Zandvoort
- Department of Genetics and Cell Biology-Molecular Cell Biology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre+, Maastricht, the Netherlands
- Institute for Molecular Cardiovascular Research IMCAR, Universitätsklinikum Aachen, Aachen, Germany
| | - Patrick Schrauwen
- Department of Human Biology, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Matthijs K C Hesselink
- Department of Human Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, 6200MD, Maastricht, the Netherlands.
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Daemen S, van Zandvoort MAMJ, Parekh SH, Hesselink MKC. Microscopy tools for the investigation of intracellular lipid storage and dynamics. Mol Metab 2015; 5:153-163. [PMID: 26977387 PMCID: PMC4770264 DOI: 10.1016/j.molmet.2015.12.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 12/19/2015] [Accepted: 12/27/2015] [Indexed: 12/01/2022] Open
Abstract
Background Excess storage of lipids in ectopic tissues, such as skeletal muscle, liver, and heart, seems to associate closely with metabolic abnormalities and cardiac disease. Intracellular lipid storage occurs in lipid droplets, which have gained attention as active organelles in cellular metabolism. Recent developments in high-resolution microscopy and microscopic spectroscopy have opened up new avenues to examine the physiology and biochemistry of intracellular lipids. Scope of review The aim of this review is to give an overview of recent technical advances in microscopy, and its application for the visualization, identification, and quantification of intracellular lipids, with special focus to lipid droplets. In addition, we attempt to summarize the probes currently available for the visualization of lipids. Major conclusions The continuous development of lipid probes in combination with the rapid development of microscopic techniques can provide new insights in the role and dynamics of intracellular lipids. Moreover, in situ identification of intracellular lipids is now possible and promises to add a new dimensionality to analysis of lipid biochemistry, and its relation to (patho)physiology.
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Key Words
- BODIPY, Boron-dipyrromethene
- CARS, coherent anti-stokes Raman scattering
- CLEM, correlative light electron microscopy
- CLSM, confocal laser scanning microscopy
- DIC, differential interference microscopy
- FA, fatty acid
- FIB-SEM, focused ion beam scanning electron microscopy
- FLIP, fluorescence loss in photobleaching
- FRAP, fluorescent recovery after photobleaching
- FRET, fluorescence resonance energy transfer
- Fluorescent lipid probes
- GFP, green fluorescent protein
- HCV, hepatitis C virus
- LD, lipid droplet
- Lipid droplets
- Live-cell imaging
- Metabolic disease
- NBD, nitro-benzoxadiazolyl
- PALM, photoactivation localization microscopy
- SBEM, serial block face scanning electron microscopy
- SIMS, Secondary Ion Mass Spectrometry
- SRS, Stimulated Raman Scattering
- STED, stimulated emission depletion
- STORM, stochastic optical reconstruction microscopy
- Super-resolution
- TAG, triacylglycerol
- TEM, transmission electron microscopy
- TOF-SIMS, time-of-flight SIMS
- TPLSM, two-photon laser scanning microscopy
- Vibrational microscopy
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Affiliation(s)
- Sabine Daemen
- Department of Human Movement Sciences and Human Biology, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands.
| | - Marc A M J van Zandvoort
- Department of Genetics and Molecular Cell Biology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands; Institute for Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany.
| | - Sapun H Parekh
- Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Mainz, Germany.
| | - Matthijs K C Hesselink
- Department of Human Movement Sciences and Human Biology, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands.
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Bosma M. Lipid droplet dynamics in skeletal muscle. Exp Cell Res 2015; 340:180-6. [PMID: 26515552 DOI: 10.1016/j.yexcr.2015.10.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/20/2015] [Accepted: 10/23/2015] [Indexed: 02/07/2023]
Abstract
The skeletal muscle is subjected to high mechanical and energetic demands. Lipid droplets are an important source of energy substrates for the working muscle. Muscle cells contain a variety of lipid droplets, which are fundamentally smaller than those found in adipocytes. This translates into a greater lipid droplet surface area serving as the interface for intracellular lipid metabolism. The skeletal muscle has a high plasticity, it is subjected to major remodeling following training and detraining. This coincides with adaptations in lipid droplet characteristics and dynamics. The majority of lipid droplets in skeletal muscle are located in the subsarcolemmal region or in-between the myofibrils, in close vicinity to mitochondria. The vastly organized nature of skeletal muscle fibers limits organelle mobility. The high metabolic rate and substrate turnover in skeletal muscle demands a strict coordination of intramyocellular lipid metabolism and LD dynamics, in which lipid droplet coat proteins play an important role. This review provides insights into the characteristics, diversity and dynamics of skeletal muscle lipid droplets.
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Affiliation(s)
- Madeleen Bosma
- Department of Cell and Molecular Biology, Karolinska Institutet, P.O. Box 285, SE-171 77 Stockholm, Sweden.
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