151
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Chung JY, Chen H, Papadopoulos V, Zirkin B. Cholesterol accumulation, lipid droplet formation, and steroid production in Leydig cells: Role of translocator protein (18-kDa). Andrology 2019; 8:719-730. [PMID: 31738001 DOI: 10.1111/andr.12733] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 11/06/2019] [Accepted: 11/14/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Cholesterol import into the mitochondria of steroid-producing cells is the rate-determining step in steroidogenesis. Numerous studies have provided evidence that the cholesterol-binding translocator protein (18 kDa TSPO) plays an important role in cholesterol translocation into mitochondria and that it also might act on cholesterol homeostasis. Several TSPO-specific ligands have been shown to increase steroid production in vitro and in vivo. OBJECTIVES The present study assessed the effects of the TSPO drug ligand FGIN-1-27 on cholesterol accumulation and lipid droplet formation in relationship to steroid formation. MATERIALS AND METHODS Using MA-10 and primary Leydig cells, immunocytochemical and molecular methods were used to examine cholesterol accumulation, the formation of lipid droplets, and steroid formation in response to LH and FGIN-1-27. Additionally, we determined the effects of Tspo knockout by CRISPR/Cas9, and of siRNA knockdowns of Tspo and Plin2 (Perilipin 2; also known as adipose differentiation-related protein, ADFP) on LH- and FGIN-1-27-induced steroidogenesis. RESULTS In response to LH and FGIN-1-27, cultured MA-10 cells and primary Leydig cells increased steroid formation, cholesterol accumulation, and lipid droplet formation. Cholesterol accumulation in the lipid droplets also was increased in Tspo knockout cells. Knockout of Tspo or its knockdown in MA-10 cells resulted in reduced progesterone formation in response to both LH and FGIN-1-27, as did knockdown of Plin2. Steroid production also was inhibited by the cholesteryl ester hydrolase inhibitor diethylumbelliferyl phosphate. DISCUSSION AND CONCLUSION These results support the conclusion that FGIN-1-27 stimulates steroid formation by increasing TSPO-mediated cholesterol translocation into the inner mitochondria for steroidogenesis, as well as into the cytosol for lipid droplet formation. FGIN-1-27 also increased steroid formation at least in part by inducing the conversion of cholesteryl ester located in lipid droplets to cholesterol, thus making available more substrate for steroid formation.
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Affiliation(s)
- Jin-Yong Chung
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Haolin Chen
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Department of Anesthesiology, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Science, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Barry Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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152
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Gao J, Huang T, Li J, Guo X, Xiao H, Gu J, Tang J, Cai W, Li D. Beneficial Effects of n-3 Polyunsaturated Fatty Acids on Offspring's Pancreas of Gestational Diabetes Rats. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:13269-13281. [PMID: 31725275 DOI: 10.1021/acs.jafc.9b05739] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We studied the long-term influence of gestational diabetes mellitus (GDM) on the pancreas of offspring and the effect of omega-3 polyunsaturated fatty acids (n-3 PUFAs) on offspring's pancreas. GDM offspring were divided into three groups: GDM offspring, n-3 PUFA-adequate-GDM offspring, and n-3 PUFA-deficient GDM offspring. All healthy and GDM offspring were fed up to 11 months old. The pancreas of GDM offspring exhibited fatty infiltration at 11 months old, whereas n-3 PUFA improved the pancreatic fatty infiltration. n-3 PUFA lowered the pancreatic oxidative stress and inflammation. Surprisingly, n-3 PUFA postponed pancreatic telomere shortening of GDM offspring at old age. Nontargeted metabolomics showed that many metabolites were altered in the pancreas of GDM offspring at old age, including l-valine, ceramide, acylcarnitines, tocotrienol, cholesteryl acetate, and biotin. n-3 PUFA modulated some altered metabolites and metabolic pathways. Therefore, GDM caused the long-term effects on offspring's pancreas, whereas n-3 PUFA played a beneficial role.
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Affiliation(s)
- Jinlong Gao
- Department of Food Science and Nutrition , Zhejiang University , 866 Yuhangtang Road , Hangzhou 310058 , China
| | - Tao Huang
- Department of Epidemiology and Biostatistics , Peking University , 5 Yiheyuan Road , Beijing 100871 , China
| | - Jiaomei Li
- Institute of Nutrition and Health , Qingdao University , 308 Ningxia Road , Qingdao 266071 , China
| | - Xiaofei Guo
- Institute of Nutrition and Health , Qingdao University , 308 Ningxia Road , Qingdao 266071 , China
| | - Hailong Xiao
- Department of Food Inspection , Hangzhou Institute for Food and Drug Control , 198 Yonghua Street , Hangzhou 310022 , China
| | - Jiaojiao Gu
- School of Nursing , Zhejiang Chinese Medical University , 548 Binwen Road , Hangzhou 310053 , China
| | - Jun Tang
- Department of Food Science and Nutrition , Zhejiang University , 866 Yuhangtang Road , Hangzhou 310058 , China
| | - Wenwen Cai
- Department of Food Science and Nutrition , Zhejiang University , 866 Yuhangtang Road , Hangzhou 310058 , China
| | - Duo Li
- Department of Food Science and Nutrition , Zhejiang University , 866 Yuhangtang Road , Hangzhou 310058 , China
- Institute of Nutrition and Health , Qingdao University , 308 Ningxia Road , Qingdao 266071 , China
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153
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Choi SY, Park JS, Shon CH, Lee CY, Ryu JM, Son DJ, Hwang BY, Yoo HS, Cho YC, Lee J, Kim JW, Roh YS. Fermented Korean Red Ginseng Extract Enriched in Rd and Rg3 Protects against Non-Alcoholic Fatty Liver Disease through Regulation of mTORC1. Nutrients 2019; 11:nu11122963. [PMID: 31817227 PMCID: PMC6949916 DOI: 10.3390/nu11122963] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/28/2019] [Accepted: 12/02/2019] [Indexed: 12/13/2022] Open
Abstract
The fermentation of Korean red ginseng (RG) increases the bioavailability and efficacy of RG, which has a protective role in various diseases. However, the ginsenoside-specific molecular mechanism of the fermented RG with Cordyceps militaris (CRG) has not been elucidated in non-alcoholic fatty liver disease (NAFLD). A mouse model of NAFLD was induced by a fast-food diet (FFD) and treated with CRG (100 or 300 mg/kg) for the last 8 weeks. CRG-mediated signaling was assessed in the liver cells isolated from mice. CRG administration significantly reduced the FFD-induced steatosis, liver injury, and inflammation, indicating that CRG confers protective effects against NAFLD. Of note, an extract of CRG contains a significantly increased amount of ginsenosides (Rd and Rg3) after bioconversion compared with that of conventional RG. Moreover, in vitro treatment with Rd or Rg3 produced anti-steatotic effects in primary hepatocytes. Mechanistically, CRG protected palmitate-induced activation of mTORC1 and subsequent inhibition of mitophagy and PPARα signaling. Similar to that noted in hepatocytes, CRG exerted anti-inflammatory activity through mTORC1 inhibition-mediated M2 polarization. In conclusion, CRG inhibits lipid-mediated pathologic activation of mTORC1 in hepatocytes and macrophages, which in turn prevents NAFLD development. Thus, the administration of CRG may be an alternative for the prevention of NAFLD.
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Affiliation(s)
- Su-Yeon Choi
- College of Pharmacy and Medical Research Center, Chungbuk National University, Cheongju 28160, Korea; (S.-Y.C.); (J.-S.P.); (C.-H.S.); (C.-Y.L.); (D.-J.S.)
| | - Jeong-Su Park
- College of Pharmacy and Medical Research Center, Chungbuk National University, Cheongju 28160, Korea; (S.-Y.C.); (J.-S.P.); (C.-H.S.); (C.-Y.L.); (D.-J.S.)
| | - Chang-Ho Shon
- College of Pharmacy and Medical Research Center, Chungbuk National University, Cheongju 28160, Korea; (S.-Y.C.); (J.-S.P.); (C.-H.S.); (C.-Y.L.); (D.-J.S.)
| | - Chae-Young Lee
- College of Pharmacy and Medical Research Center, Chungbuk National University, Cheongju 28160, Korea; (S.-Y.C.); (J.-S.P.); (C.-H.S.); (C.-Y.L.); (D.-J.S.)
| | - Jae-Myun Ryu
- NOVA K-MED Co., Ltd., 1646 Yuseong-daero, HNU Innobiz Park Suite 403, Yuseong-gu, Daejeon 34054, Korea;
| | - Dong-Ju Son
- College of Pharmacy and Medical Research Center, Chungbuk National University, Cheongju 28160, Korea; (S.-Y.C.); (J.-S.P.); (C.-H.S.); (C.-Y.L.); (D.-J.S.)
| | - Bang-Yeon Hwang
- College of Pharmacy and Medical Research Center, Chungbuk National University, Cheongju 28160, Korea; (S.-Y.C.); (J.-S.P.); (C.-H.S.); (C.-Y.L.); (D.-J.S.)
| | - Hwan-Soo Yoo
- College of Pharmacy and Medical Research Center, Chungbuk National University, Cheongju 28160, Korea; (S.-Y.C.); (J.-S.P.); (C.-H.S.); (C.-Y.L.); (D.-J.S.)
| | - Young-Chang Cho
- College of Pharmacy, Chonnam National University, Gwangju 61186, Korea
| | - Jin Lee
- Department of Pathology, School of Medicine, University of California, San Diego, CA 92093, USA;
| | - Jong-Won Kim
- Biosafety Research Institute and College of Veterinary Medicine, Jeonbuk National University, Deokjin-gu, Jeonju-si 54596, Korea
- Correspondence: (J.-W.K.); (Y.-S.R.); Tel.: +82-63-850-0953 (J.-W.K.); +82-43-261-2819 (Y.-S.R.)
| | - Yoon-Seok Roh
- College of Pharmacy and Medical Research Center, Chungbuk National University, Cheongju 28160, Korea; (S.-Y.C.); (J.-S.P.); (C.-H.S.); (C.-Y.L.); (D.-J.S.)
- Correspondence: (J.-W.K.); (Y.-S.R.); Tel.: +82-63-850-0953 (J.-W.K.); +82-43-261-2819 (Y.-S.R.)
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154
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Gao G, Sheng Y, Yang H, Chua BT, Xu L. DFCP1 associates with lipid droplets. Cell Biol Int 2019; 43:1492-1504. [PMID: 31293035 DOI: 10.1002/cbin.11199] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 07/07/2019] [Indexed: 01/24/2023]
Abstract
Double FYVE-containing protein 1 (DFCP1) is ubiquitously expressed, participates in intracellular membrane trafficking and labels omegasomes through specific interactions with phosphatidylinositol-3-phosphate (PI3P). Previous studies showed that subcellular DFCP1 proteins display multi-organelle localization, including in the endoplasmic reticulum (ER), Golgi apparatus and mitochondria. However, its localization and function on lipid droplets (LDs) remain unclear. Here, we demonstrate that DFCP1 localizes to the LD upon oleic acid incubation. The ER-targeted domain of DFCP1 is indispensable for its LD localization, which is further enhanced by double FYVE domains. Inhibition of PI3P binding at the FYVE domain through wortmannin treatment or double mutation at C654S and C770S have no effect on DFCP1's LD localization. These show that the mechanisms for DFCP1 targeting the omegasome and LDs are different. DFCP1 deficiency in MEF cells causes an increase in LD number and reduces LD size. Interestingly, DFCP1 interacts with GTP-bound Rab18, an LD-associated protein. Taken together, our work demonstrates the dynamic localization of DFCP1 is regulated by nutritional status in response to cellular metabolism.
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Affiliation(s)
- Guangang Gao
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Yuanyuan Sheng
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, 2052 New South Wales, Sydney, Australia
| | - Boon Tin Chua
- The Institute of Metabolism and Integrative Biology, Fudan University, 200438, Shanghai, China
| | - Li Xu
- State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing, China
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155
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Lecoutre S, Montel V, Vallez E, Pourpe C, Delmont A, Eury E, Verbanck M, Dickes-Coopman A, Daubersies P, Lesage J, Laborie C, Tailleux A, Staels B, Froguel P, Breton C, Vieau D. Transcription profiling in the liver of undernourished male rat offspring reveals altered lipid metabolism pathways and predisposition to hepatic steatosis. Am J Physiol Endocrinol Metab 2019; 317:E1094-E1107. [PMID: 31638854 DOI: 10.1152/ajpendo.00291.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Clinical and animal studies have reported an association between low birth weight and the development of nonalcoholic fatty liver disease (NAFLD) in offspring. Using a model of prenatal maternal 70% food restriction diet (FR30) in the rat, we previously showed that maternal undernutrition predisposes offspring to altered lipid metabolism in adipose tissue, especially on a high-fat (HF) diet. Here, using microarray-based expression profiling combined with metabolic, endocrine, biochemical, histological, and lipidomic approaches, we assessed whether FR30 procedure sensitizes adult male offspring to impaired lipid metabolism in the liver. No obvious differences were noted in the concentrations of triglycerides, cholesterol, and bile acids in the liver of 4-mo-old FR30 rats whichever postweaning diet was used. However, several clues suggest that offspring's lipid metabolism and steatosis are modified by maternal undernutrition. First, lipid composition was changed (i.e., higher total saturated fatty acids and lower elaidic acid) in the liver, whereas larger triglyceride droplets were observed in hepatocytes of undernourished rats. Second, FR30 offspring exhibited long-term impact on hepatic gene expression and lipid metabolism pathways on a chow diet. Although the transcriptome profile was globally modified by maternal undernutrition, cholesterol and bile acid biosynthesis pathways appear to be key targets, indicating that FR30 animals were predisposed to impaired hepatic cholesterol metabolism. Third, the FR30 protocol markedly modifies hepatic gene transcription profiles in undernourished offspring in response to postweaning HF. Overall, FR30 offspring may exhibit impaired metabolic flexibility, which does not enable them to properly cope with postweaning nutritional challenges influencing the development of nonalcoholic fatty liver.
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Affiliation(s)
- Simon Lecoutre
- Université Lille, EA4489, Equipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, Lille, France
| | - Valérie Montel
- Université Lille, EA4489, Equipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, Lille, France
| | - Emmanuelle Vallez
- Université Lille, Centre Hospitalier Universitaire de Lille, Institut Pasteur de Lille, INSERM U1011-European Genomic Institute for Diabetes, Lille, France
| | - Charlène Pourpe
- Université Lille, EA4489, Equipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, Lille, France
| | | | - Elodie Eury
- Université Lille, UMR 8199, European Genomic Institute for Diabetes, Lille, France
| | - Marie Verbanck
- Université Lille, UMR 8199, European Genomic Institute for Diabetes, Lille, France
| | - Anne Dickes-Coopman
- Université Lille, EA4489, Equipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, Lille, France
| | | | - Jean Lesage
- Université Lille, EA4489, Equipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, Lille, France
| | - Christine Laborie
- Université Lille, EA4489, Equipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, Lille, France
| | - Anne Tailleux
- Université Lille, Centre Hospitalier Universitaire de Lille, Institut Pasteur de Lille, INSERM U1011-European Genomic Institute for Diabetes, Lille, France
| | - Bart Staels
- Université Lille, Centre Hospitalier Universitaire de Lille, Institut Pasteur de Lille, INSERM U1011-European Genomic Institute for Diabetes, Lille, France
| | - Philippe Froguel
- Université Lille, UMR 8199, European Genomic Institute for Diabetes, Lille, France
| | - Christophe Breton
- Université Lille, EA4489, Equipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, Lille, France
| | - Didier Vieau
- Université Lille, EA4489, Equipe Malnutrition Maternelle et Programmation des Maladies Métaboliques, Lille, France
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156
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Ladinsky MS, Mardones GA, Orlicky DJ, Howell KE, McManaman JL. Electron Tomography Revels that Milk Lipids Originate from Endoplasmic Reticulum Domains with Novel Structural Features. J Mammary Gland Biol Neoplasia 2019; 24:293-304. [PMID: 31709487 PMCID: PMC7976053 DOI: 10.1007/s10911-019-09438-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 10/16/2019] [Indexed: 12/11/2022] Open
Abstract
Lipid droplets (LD) are dynamically-regulated organelles that originate from the endoplasmic reticulum (ER), and function in the storage, trafficking and metabolism of neutral lipids. In mammary epithelial cells (MEC) of lactating animals, intact LD are secreted intact into milk to form milk lipids by a novel apocrine mechanism. The secretion of intact LD and the relatively large amounts of lipid secreted by lactating MEC increase demands on the cellular processes responsible for lipid synthesis and LD formation. As yet these processes are poorly defined due to limited understanding of LD-ER interactions. To overcome these limitations, we used rapid-freezing and freeze-substitution methods in conjunction with 3D electron tomography and high resolution immunolocalization to define interactions between LD with ER in MEC of pregnant and lactating rats. Using these approaches, we identified distinct ER domains that contribute to lipid droplet formation and stabilization and which possess unique features previously unrecognized or not fully appreciated. Our results show nascent lipid droplets within the ER lumen and the association of both forming and mature droplets with structurally unique regions of ER cisternae, characterized by the presence of perilipin-2, a protein implicated in lipid droplet formation, and enzymes involved in lipid synthesis. These data demonstrate that milk lipids originate from LD-ER domains with novel structural features and suggest a mechanism for initial droplet formation in the ER lumen and subsequent maturation of the droplets in association with ER cisternae.
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Affiliation(s)
- Mark S Ladinsky
- Boulder Laboratory for 3D Electron Microscopy of Cells, University of Colorado, Boulder, CO, 80309, USA
- Division of Biology, California Institute of Technology, Pasadena, CA, USA
| | - Gonzalo A Mardones
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
- Instituto de Fisiologia, Universidad Austral de Chile, Valdiva, Chile
| | - David J Orlicky
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Kathryn E Howell
- Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - James L McManaman
- Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, 12700 E. 19th Ave., Aurora, CO, 80045, USA.
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157
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Liu Y, Bao H, Wang W, Lim HY. Cardiac Snail family of transcription factors directs systemic lipid metabolism in Drosophila. PLoS Genet 2019; 15:e1008487. [PMID: 31725726 PMCID: PMC6879157 DOI: 10.1371/journal.pgen.1008487] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 11/26/2019] [Accepted: 10/21/2019] [Indexed: 12/30/2022] Open
Abstract
Maintenance of normal lipid homeostasis is crucial to heart function. On the other hand, the heart is now recognized to serve an important role in regulating systemic lipid metabolism; however, the molecular basis remains unclear. In this study, we identify the Drosophila Snail family of transcription factors (herein termed Sna TFs) as new mediators of the heart control of systemic lipid metabolism. Overexpression of Sna TF genes specifically in the heart promotes whole-body leanness whereas their knockdown in the heart promotes obesity. In addition, flies that are heterozygous for a snail deficiency chromosome also exhibit systemic obesity, and that cardiac-specific overexpression of Sna substantially reverses systemic obesity in these flies. We further show that genetically manipulating Sna TF levels in the fat body and intestine do not affect systemic lipid levels. Mechanistically, we find that flies bearing the overexpression or inhibition of Sna TFs in the postnatal heart only exhibit systemic lipid metabolic defects but not heart abnormalities. Cardiac-specific alterations of Sna TF levels also do not perturb cardiac morphology, viability, lipid metabolism or fly food intake. On the other hand, cardiac-specific manipulations of Sna TF levels alter lipogenesis and lipolysis gene expression, mitochondrial biogenesis and respiration, and lipid storage droplet 1 and 2 (Lsd-1 and Lsd-2) levels in the fat body. Together, our results reveal a novel and specific role of Sna TFs in the heart on systemic lipid homeostasis maintenance that is independent of cardiac development and function and involves the governance of triglyceride synthesis and breakdown, energy utilization, and lipid droplet dynamics in the fat body.
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Affiliation(s)
- Ying Liu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Hong Bao
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Weidong Wang
- Department of Medicine, Section of Endocrinology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail: (WW); (H-YL)
| | - Hui-Ying Lim
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail: (WW); (H-YL)
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158
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Yang JW, Yeo HK, Yun JH, Lee JU. Theracurmin (Highly Bioavailable Curcumin) Prevents High Fat Diet-Induced Hepatic Steatosis Development in Mice. Toxicol Res 2019; 35:403-410. [PMID: 31636851 PMCID: PMC6791664 DOI: 10.5487/tr.2019.35.4.403] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 02/27/2019] [Accepted: 03/08/2019] [Indexed: 12/11/2022] Open
Abstract
Curcumin, a hydrophobic polyphenol isolated from the Curcuma longa L. plant, has many pharmacological properties, including antioxidant, anti-inflammatory, and chemo-preventive activities. Curcumin has been shown to have potential in preventing nonalcoholic fatty liver disease (NAFLD). However, the low bioavailability of curcumin has proven to be a major limiting factor in its clinical adoption. Theracurmin, a highly bioavailable curcumin that utilizes micronized technology showed improved biological absorbability in vivo. The aim of this study was to investigate the role of theracurmin in modulating hepatic lipid metabolism in vivo. A fatty liver mouse model was produced by feeding mice a high fat diet (HFD; 60% fat) for 12 weeks. We found that treatment for 12 weeks with theracurmin significantly lowered plasma triacylglycerol (TG) levels and reduced HFD-induced liver fat accumulation. Theracurmin treatment lowered hepatic TG and total cholesterol (T-CHO) levels in HFD-fed mice compared to controls. In addition, theracurmin administration significantly reduced lipid peroxidation and cellular damage caused by reactive oxygen species in HFD-fed mice. Overall, these results suggest that theracurmin has the ability to control lipid metabolism and can potentially serve as an effective therapeutic remedy for the prevention of fatty liver.
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Affiliation(s)
- Jin Won Yang
- College of Pharmacy, Woosuk University, Wanju, Korea
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159
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Jarc E, Petan T. Lipid Droplets and the Management of Cellular Stress. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2019; 92:435-452. [PMID: 31543707 PMCID: PMC6747940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Lipid droplets are cytosolic fat storage organelles present in most eukaryotic cells. Long regarded merely as inert fat reservoirs, they are now emerging as major regulators of cellular metabolism. They act as hubs that coordinate the pathways of lipid uptake, distribution, storage, and use in the cell. Recent studies have revealed that they are also essential components of the cellular stress response. One of the hallmark characteristics of lipid droplets is their capacity to buffer excess lipids and to finely tune their subsequent release based on specific cellular requirements. This simple feature of lipid droplet biology, buffering and delayed release of lipids, forms the basis for their pleiotropic roles in the cellular stress response. In stressed cells, lipid droplets maintain energy and redox homeostasis and protect against lipotoxicity by sequestering toxic lipids into their neutral lipid core. Their mobility and dynamic interactions with mitochondria enable an efficient delivery of fatty acids for optimal energy production. Lipid droplets are also involved in the maintenance of membrane and organelle homeostasis by regulating membrane composition, preventing lipid peroxidation and removing damaged proteins and lipids. Finally, they also engage in a symbiotic relationship with autophagy and act as reservoirs of bioactive lipids that regulate inflammation and immunity. Thus, lipid droplets are central managers of lipid metabolism that function as safeguards against various types of cellular stress.
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Affiliation(s)
- Eva Jarc
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia,Jožef Stefan International Postgraduate School, Ljubljana, Slovenia
| | - Toni Petan
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia,To whom all correspondence should be addressed: Toni Petan, Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; Tel: +386 1 477 3713, Fax: +386 1 477 3984,
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160
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Abstract
PURPOSE OF REVIEW Obesity is a pandemic, yet preventable healthcare problem. Insulin resistance, diabetes mellitus, dyslipidemia, and cardiovascular complications are core manifestation of obesity. While adipose tissue is a primary site of energy storage, it is also an endocrine organ, secreting a large number of adipokines and cytokines. Nonetheless in obesity, the secretion of cytokines and free fatty acids increases significantly and is associated with the degree of adiposity and insulin resistance. Fat-specific protein 27 (FSP27) has emerged as one of the major proteins that promote physiological storage of fat in adipose tissue. RECENT FINDINGS Review of number of recent findings suggests that FSP27 plays a crucial role in physiological storage of fat within the adipose tissue especially in humans. However, in disease conditions such as obesity, FSP27 may contribute to ectopic fat accumulation in non-adipose tissue. More studies are required to highlight the tissue-specific role of FSP27, especially in humans.
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Affiliation(s)
- Shakun Karki
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, 88 East Newton St, Boston, MA, 02118, USA.
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161
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la Fuente FPD, Quezada L, Sepúlveda C, Monsalves-Alvarez M, Rodríguez JM, Sacristán C, Chiong M, Llanos M, Espinosa A, Troncoso R. Exercise regulates lipid droplet dynamics in normal and fatty liver. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:158519. [PMID: 31473346 DOI: 10.1016/j.bbalip.2019.158519] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 08/19/2019] [Accepted: 08/26/2019] [Indexed: 12/20/2022]
Abstract
Lipids droplets (LD) are dynamics organelles that accumulate neutral lipids during nutrient surplus. LD alternates between periods of growth and consumption through regulated processes including as de novo lipogenesis, lipolysis and lipophagy. The liver is a central tissue in the regulation of lipid metabolism. Non-Alcoholic Fatty Liver Diseases (NAFLD) is result of the accumulation of LD in liver. Several works have been demonstrated a positive effect of exercise on reduction of liver fat. However, the study of the exercise on liver LD dynamics is far from being understood. Here we investigated the effect of chronic exercise in the regulation of LD dynamics using a mouse model of high fat diet-induced NAFLD. Mice were fed with a high-fat diet or control diet for 12 weeks; then groups were divided into chronic exercise or sedentary for additional 8 weeks. Our results showed that exercise reduced fasting glycaemia, insulin and triacylglycerides, also liver damage. However, exercise did not affect the intrahepatic triacylglycerides levels and the number of LD but reduced their size. In addition, exercise decreased the SREBP-1c levels, without changes in lipolysis, mitochondrial proteins or autophagy/lipophagy markers. Unexpectedly in the control mice, exercise increased the number of LD, also PLIN2, SREBP-1c, FAS, ATGL, HSL and MTTP levels. Our findings show that exercise rescues the liver damage in a model of NAFLD reducing the size of LD and normalizing protein markers of de novo lipogenesis and lipolysis. Moreover, exercise increases proteins associated to LD dynamics in the control mice.
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Affiliation(s)
- Francisco Pino-de la Fuente
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Laura Quezada
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Carlos Sepúlveda
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile; Laboratorio de Ciencias del Ejercicio, Clínica MEDS, Santiago, Chile
| | - Matías Monsalves-Alvarez
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Juan M Rodríguez
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Camila Sacristán
- Departamento de Tecnología Medica, Facultad de Medicina, Universidad de Chile, Chile
| | - Mario Chiong
- Advanced Center for Chronic Disease (ACCDiS), Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Miguel Llanos
- Laboratorio de Nutrición y Regulación Metabólica, INTA, Universidad de Chile, Chile
| | - Alejandra Espinosa
- Departamento de Tecnología Medica, Facultad de Medicina, Universidad de Chile, Chile.
| | - Rodrigo Troncoso
- Laboratorio de Investigación en Nutrición y Actividad Física (LABINAF), Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile; Advanced Center for Chronic Disease (ACCDiS), Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile; Autophagy Research Center (ARC), Universidad de Chile, Santiago, Chile.
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162
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Abstract
Significance: Alterations in adipose tissue function have profound consequences on whole body energy homeostasis because this tissue is central for fat accumulation, energy expenditure, glucose and insulin metabolism, and hormonal regulation. With the obesity reaching epidemic proportions globally, it is important to understand the mechanisms leading to adipose tissue malfunction. Recent Advances: Autophagy has originally been viewed as an adaptive response to cellular stress, but in recent years this process was shown to regulate important cellular processes. In adipose tissue, autophagy is a key regulator of white adipose tissue (WAT) and brown adipose tissue (BAT) adipogenesis, and dysregulated autophagy impairs fat accumulation both in vitro and in vivo. Animal studies have also suggested an important role for autophagy and mitophagy during the transition from beige to white fat. Human studies have provided evidence for altered autophagy in WAT, and these alterations correlated with the degree of insulin resistance. Critical Issues: Despite these important advances in the study of autophagy in adipose tissue, we still do not understand the physiological role of autophagy in mature white and brown adipocytes. Furthermore, several human studies involving autophagy assessment were performed on whole adipose tissue, which complicates the interpretation of the results considering the cellular heterogeneity of this tissue. Future Directions: Future studies will undoubtedly expand our understanding of the role of autophagy in fully differentiated adipocytes, and uncover novel cross-talks between this tissue and other organs in regulating lipid metabolism, redox signaling, energy homeostasis, and insulin sensitivity.
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Affiliation(s)
- Maroua Ferhat
- Program in Molecular Medicine, Department of Nutrition and Integrative Physiology, College of Health, University of Utah, Salt Lake City, Utah
| | - Katsuhiko Funai
- Program in Molecular Medicine, Department of Nutrition and Integrative Physiology, College of Health, University of Utah, Salt Lake City, Utah
| | - Sihem Boudina
- Program in Molecular Medicine, Department of Nutrition and Integrative Physiology, College of Health, University of Utah, Salt Lake City, Utah
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163
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Hsieh CM, Liu PY, Chin LK, Zhang JB, Wang K, Sung KB, Ser W, Bourouina T, Leprince-Wang Y, Liu AQ. Regulation of lipid droplets in live preadipocytes using optical diffraction tomography and Raman spectroscopy. OPTICS EXPRESS 2019; 27:22994-23008. [PMID: 31510584 DOI: 10.1364/oe.27.022994] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 05/24/2019] [Indexed: 06/10/2023]
Abstract
Lipid droplets have gained strong interest in recent years to comprehend how they function and coordinate with other parts of the cell. However, it remains challenging to study the regulation of lipid droplets in live preadipocytes using conventional microscopic techniques. In this paper, we study the effects of fatty acid stimulation and cell starvation on lipid droplets using optical diffraction tomography and Raman spectroscopy by measuring size, refractive index, volume, dry mass and degree of unsaturation. The increase of fatty acids causes an increase in the number and dry mass of lipid droplets. During starvation, the number of lipid droplets increases drastically, which are released to mitochondria to release energy. Studying lipid droplets under different chemical stimulations could help us understand the regulation of lipid droplets for metabolic disorders, such as obesity and diabetes.
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164
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Bose D, Banerjee S, Chatterjee N, Das S, Saha M, Saha KD. Inhibition of TGF-β induced lipid droplets switches M2 macrophages to M1 phenotype. Toxicol In Vitro 2019; 58:207-214. [DOI: 10.1016/j.tiv.2019.03.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 03/12/2019] [Accepted: 03/27/2019] [Indexed: 01/17/2023]
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165
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Single-molecule localization microscopy and tracking with red-shifted states of conventional BODIPY conjugates in living cells. Nat Commun 2019; 10:3400. [PMID: 31363088 PMCID: PMC6667493 DOI: 10.1038/s41467-019-11384-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 07/11/2019] [Indexed: 11/09/2022] Open
Abstract
Single-molecule localization microscopy (SMLM) is a rapidly evolving technique to resolve subcellular structures and single-molecule dynamics at the nanoscale. Here, we employ conventional BODIPY conjugates for live-cell SMLM via their previously reported red-shifted ground-state dimers (DII), which transiently form through bi-molecular encounters and emit bright single-molecule fluorescence. We employ the versatility of DII-state SMLM to resolve the nanoscopic spatial regulation and dynamics of single fatty acid analogs (FAas) and lipid droplets (LDs) in living yeast and mammalian cells with two colors. In fed cells, FAas localize to the endoplasmic reticulum and LDs of ~125 nm diameter. Upon fasting, however, FAas form dense, non-LD clusters of ~100 nm diameter at the plasma membrane and transition from free diffusion to confined immobilization. Our reported SMLM capability of conventional BODIPY conjugates is further demonstrated by imaging lysosomes in mammalian cells and enables simple and versatile live-cell imaging of sub-cellular structures at the nanoscale. Single-molecule localization microscopy (SMLM) requires the use of fluorophores with specific sets of properties. Here the authors employ conventional BODIPY dyes as SMLM fluorophores by making use of rarely reported red-shifted ground state BODIPY dimers to image fatty acids, lipid droplets and lysosomes at single-molecule resolution.
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166
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167
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Milon A, Kaczmarczyk M, Pawlicki P, Bilinska B, Duliban M, Gorowska-Wojtowicz E, Tworzydlo W, Kotula-Balak M. Do estrogens regulate lipid status in testicular steroidogenic Leydig cell? Acta Histochem 2019; 121:611-618. [PMID: 31126612 DOI: 10.1016/j.acthis.2019.04.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/26/2019] [Accepted: 04/26/2019] [Indexed: 12/24/2022]
Abstract
In this study mouse Leydig cell (MA-10) were treated with G-protein coupled membrane estrogen receptor antagonist (G-15; 10 nM). Cells were analyzed by Western blotting for expression of estrogen-related receptors (ERRα, β and γ), steroidogenic markers (lutropin receptor; LHR and 3β-hydroxysteroid dehydrogenase; 3β-HSD) and lipid droplet markers (perilipin; PLIN and microtubule-associated protein 1 A/1B-light chain 3; LC3). Concomitantly, microscopic analyses by light microscope (immunofluorescent staining for lipid droplets, PLIN and LC3) as well as by electron microscope (for lipid droplet ultrastructure) were utilized. For analysis of cholesterol content, cAMP level and progesterone secretion, G-15, estrogen receptor (ER) antagonist (ICI 182,780; 10 μM), 17β-estradiol (10 mM) and, bisphenol A (BPA; 10 nM) were used alone or in combinations. We revealed no changes in ERRs expression but alterations in ERRβ and γ localization in G-15-treated cells when compared to control. Partial translocation of ERRβ and γ from the cell nucleus to cytoplasm was observed. Decreased expression of LHR, 3β-HSD, PLIN and LC3 was detected. Moreover, in treated cells large lipid droplets and differences in their distribution were found. Very strong signal of co-localization for PLIN and LC3 was found in treated cells when compared to control. In ultrastructure of treated cells, degenerating lipid droplets and double membrane indicating on presence of lipophagosome were observed. We found, that only (i) BPA and G-15 did not effect on cholesterol content, (ii) BPA, G-15 and ICI did not effect on cAMP level and (iii) BPA, ICI alone and in combination, and BPA with G-15 did not modulate progesterone secretion. These findings showed complex and diverse estrogen effects on mouse Leydig cells at various steps of steroid hormone production (cholesterol storage, release and processing). Lipid homeostasis and metabolism in these cells were affected by endogenous and exogenous estrogen, interactions of receptors (GPER, ER and ERR) and GPER and ER antagonists.
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Affiliation(s)
- A Milon
- Department of Endocrinology, Institute of Zoology and Biomedical Research, Jagiellonian University in Kraków, Gronostajowa 9, 30-387, Krakow, Poland
| | - M Kaczmarczyk
- Department of Endocrinology, Institute of Zoology and Biomedical Research, Jagiellonian University in Kraków, Gronostajowa 9, 30-387, Krakow, Poland
| | - P Pawlicki
- Department of Endocrinology, Institute of Zoology and Biomedical Research, Jagiellonian University in Kraków, Gronostajowa 9, 30-387, Krakow, Poland
| | - B Bilinska
- Department of Endocrinology, Institute of Zoology and Biomedical Research, Jagiellonian University in Kraków, Gronostajowa 9, 30-387, Krakow, Poland
| | - M Duliban
- Department of Endocrinology, Institute of Zoology and Biomedical Research, Jagiellonian University in Kraków, Gronostajowa 9, 30-387, Krakow, Poland
| | - E Gorowska-Wojtowicz
- Department of Endocrinology, Institute of Zoology and Biomedical Research, Jagiellonian University in Kraków, Gronostajowa 9, 30-387, Krakow, Poland
| | - W Tworzydlo
- Department of Developmental Biology and Invertebrate Morphology Institute of Zoology and Biomedical Research, Jagiellonian University in Kraków, Gronostajowa 9, 30-387, Krakow, Poland
| | - M Kotula-Balak
- Department of Endocrinology, Institute of Zoology and Biomedical Research, Jagiellonian University in Kraków, Gronostajowa 9, 30-387, Krakow, Poland.
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168
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Liu N, Yun Y, Yin Y, Hahn M, Ma Z, Chen Y. Lipid droplet biogenesis regulated by the FgNem1/Spo7-FgPah1 phosphatase cascade plays critical roles in fungal development and virulence in Fusarium graminearum. THE NEW PHYTOLOGIST 2019; 223:412-429. [PMID: 30767239 DOI: 10.1111/nph.15748] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 02/08/2019] [Indexed: 06/09/2023]
Abstract
Lipid droplets (LDs) control lipid metabolism in eukaryotic cells in general. However, the biogenesis regulation and biological functions of LDs are largely unknown in pathogenic fungi. Rapamycin treatment results in a significant increase of LD biogenesis in Fusarium graminearum. Molecular mechanisms of the target of rapamycin (TOR) pathway in regulating LD biogenesis and the functions of LD in virulence of F. graminearum were investigated in depth by combining genetic, cytological and phenotypic strategies. TOR in Fusarium graminearum (FgTOR) inhibition by rapamycin induces LD biogenesis through the FgPpg1/Sit4 signaling branch. FgPpg1 promotes phosphorylation of protein phosphatase FgNem1 by the protein kinase FgCak1. The phosphorylated FgNem1 dephosphorylates the phosphatidate phosphatase FgPah1. Dephosphorylated FgPah1 is active and stimulates LD biogenesis. Moreover, deletion of FgNem1/Spo7 or FgPah1 leads to serious defects in vegetative growth, sexual development and virulence. The results of this study provide novel insights into the regulatory mechanism and biological functions of the LDs in the devastating pathogenic fungus F. graminearum.
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Affiliation(s)
- Na Liu
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yingzi Yun
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yanni Yin
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Matthias Hahn
- Department of Biology, Kaiserslautern University, 67663, Kaiserslautern, Germany
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yun Chen
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
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169
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Development of Technetium-99m-Labeled BODIPY-Based Probes Targeting Lipid Droplets Toward the Diagnosis of Hyperlipidemia-Related Diseases. Molecules 2019; 24:molecules24122283. [PMID: 31248199 PMCID: PMC6631856 DOI: 10.3390/molecules24122283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/16/2019] [Accepted: 06/17/2019] [Indexed: 01/23/2023] Open
Abstract
Hyperlipidemia causes systemic lipid disorder, which leads to hepatic steatosis and atherosclerosis. Thus, it is necessary to detect these syndromes early and precisely to improve prognosis. In the affected regions, abnormal formation and growth of lipid droplets is observed; therefore, lipid droplets may be a suitable target for the diagnosis of hyperlipidemia-related syndromes. In this study, we designed and synthesized [99mTc]Tc-BOD and [99mTc]Tc-MBOD composed of one technetium-99m and two BODIPY scaffolds with hydroxamamide (Ham) or N-methylated hydroxamamide (MHam) in radiochemical yields of 54 and 35%, respectively, with a radiochemical purity of over 95%. [99mTc]Tc-BOD showed significantly higher accumulation levels in foam cells than in non-foam cells (foam cells: 213.8 ± 64.8, non-foam cell: 126.2 ± 26.9 %dose/mg protein, p < 0.05) 2 h after incubation. In contrast, [99mTc]Tc-MBOD showed similar accumulation levels in foam cells and non-foam cells (foam cells: 92.2 ± 23.3, non-foam cell: 83.8 ± 19.8 %dose/mg protein). In normal mice, [99mTc]Tc-BOD exhibited gradual blood clearance (0.5 h: 4.98 ± 0.35, 6 h: 1.94 ± 0.12 %ID/g) and relatively high accumulation in the liver 6 h after administration (15.22 ± 1.72 %ID/g). Therefore, [99mTc]Tc-BOD may have potential as an imaging probe for detecting lipid droplets in disease lesions of hyperlipidemia.
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170
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Watch What You (Self-) Eat: Autophagic Mechanisms that Modulate Metabolism. Cell Metab 2019; 29:803-826. [PMID: 30943392 PMCID: PMC6450419 DOI: 10.1016/j.cmet.2019.03.003] [Citation(s) in RCA: 188] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/07/2019] [Accepted: 03/04/2019] [Indexed: 02/07/2023]
Abstract
Autophagy is an evolutionarily conserved lysosome- or vacuole-dependent catabolic pathway in eukaryotes. Autophagy functions basally for cellular quality control and is induced to act as an alternative source of basic metabolites during nutrient deprivation. These functions of autophagy are intimately connected to the regulation of metabolism, and the metabolic status of the cell in turn controls the nature and extent of autophagic induction. Here, we highlight the co-regulation of autophagy and metabolism with a special focus on selective autophagy that, along with bulk autophagy, plays a central role in regulating and rewiring metabolic circuits. We outline the metabolic signals that activate these pathways, the mechanisms involved, and the downstream effects and implications while recognizing yet unanswered questions. We also discuss the role of autophagy in the development and maintenance of adipose tissue, an emerging player in systemic metabolic homeostasis, and describe what is currently known about the complex relationship between autophagy and cancer.
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171
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From sugar to liver fat and public health: systems biology driven studies in understanding non-alcoholic fatty liver disease pathogenesis. Proc Nutr Soc 2019; 78:290-304. [PMID: 30924429 DOI: 10.1017/s0029665119000570] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is now a major public health concern with an estimated prevalence of 25-30% of adults in many countries. Strongly associated with obesity and the metabolic syndrome, the pathogenesis of NAFLD is dependent on complex interactions between genetic and environmental factors that are not completely understood. Weight loss through diet and lifestyle modification underpins clinical management; however, the roles of individual dietary nutrients (e.g. saturated and n-3 fatty acids; fructose, vitamin D, vitamin E) in the pathogenesis or treatment of NAFLD are only partially understood. Systems biology offers valuable interdisciplinary methods that are arguably ideal for application to the studying of chronic diseases such as NAFLD, and the roles of nutrition and diet in their molecular pathogenesis. Although present in silico models are incomplete, computational tools are rapidly evolving and human metabolism can now be simulated at the genome scale. This paper will review NAFLD and its pathogenesis, including the roles of genetics and nutrition in the development and progression of disease. In addition, the paper introduces the concept of systems biology and reviews recent work utilising genome-scale metabolic networks and developing multi-scale models of liver metabolism relevant to NAFLD. A future is envisioned where individual genetic, proteomic and metabolomic information can be integrated computationally with clinical data, yielding mechanistic insight into the pathogenesis of chronic diseases such as NAFLD, and informing personalised nutrition and stratified medicine approaches for improving prognosis.
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172
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Levchenko SM, Kuzmin AN, Ohulchanskyy TY, Pliss A, Qu J, Prasad PN. Near-Infrared Irradiation Affects Lipid Metabolism in Neuronal Cells, Inducing Lipid Droplets Formation. ACS Chem Neurosci 2019; 10:1517-1523. [PMID: 30499655 DOI: 10.1021/acschemneuro.8b00508] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
It is known that lipids play an outstanding role in cellular regulation, and their dysfunction has been linked to many diseases. Thus, modulation of lipid metabolism may provide new pathways for disease treatment or prevention. In this work, near-infrared (NIR) light was applied to modulate lipid metabolism and increase intracellular lipid content in rat cortical neurons (RCN). Using label-free CARS microscopy, we have monitored the intracellular lipid content in RCN at a single-cell level. A major increase in average level of lipid per cell after treatment with laser diode at 808 nm was found, nonlinearly dependent on the irradiation dose. Moreover, a striking formation of lipid droplets (LDs) in the irradiated RCN was discovered. Further experiments and analysis reveal a strong correlation between NIR light induced generation of reactive oxygen species (ROS), lipids level, and LDs formation in RCN. Our findings can contribute to a development of therapeutic approaches for neurological disorders via NIR light control of lipid metabolism in neuronal cells.
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Affiliation(s)
- Svitlana M. Levchenko
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong Province 518060, China
| | - Andrey N. Kuzmin
- Institute for Lasers, Photonics and Biophotonics, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
- Advanced
Cytometry
Instrumentation Systems, LLC, 640 Ellicott Street − Suite 499, Buffalo, New York 14203, United States
| | - Tymish Y. Ohulchanskyy
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong Province 518060, China
| | - Artem Pliss
- Institute for Lasers, Photonics and Biophotonics, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
- Advanced
Cytometry
Instrumentation Systems, LLC, 640 Ellicott Street − Suite 499, Buffalo, New York 14203, United States
| | - Junle Qu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong Province 518060, China
| | - Paras N. Prasad
- Institute for Lasers, Photonics and Biophotonics, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, United States
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173
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Skeletal Muscle Lipid Droplets and the Athlete's Paradox. Cells 2019; 8:cells8030249. [PMID: 30875966 PMCID: PMC6468652 DOI: 10.3390/cells8030249] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/07/2019] [Accepted: 03/12/2019] [Indexed: 12/17/2022] Open
Abstract
The lipid droplet (LD) is an organelle enveloped by a monolayer phospholipid membrane with a core of neutral lipids, which is conserved from bacteria to humans. The available evidence suggests that the LD is essential to maintaining lipid homeostasis in almost all organisms. As a consequence, LDs also play an important role in pathological metabolic processes involving the ectopic storage of neutral lipids, including type 2 diabetes mellitus (T2DM), atherosclerosis, steatosis, and obesity. The degree of insulin resistance in T2DM patients is positively correlated with the size of skeletal muscle LDs. Aerobic exercise can reduce the occurrence and development of various metabolic diseases. However, trained athletes accumulate lipids in their skeletal muscle, and LD size in their muscle tissue is positively correlated with insulin sensitivity. This phenomenon is called the athlete’s paradox. This review will summarize previous studies on the relationship between LDs in skeletal muscle and metabolic diseases and will discuss the paradox at the level of LDs.
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174
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Slayton M, Gupta A, Balakrishnan B, Puri V. CIDE Proteins in Human Health and Disease. Cells 2019; 8:cells8030238. [PMID: 30871156 PMCID: PMC6468517 DOI: 10.3390/cells8030238] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/07/2019] [Accepted: 03/09/2019] [Indexed: 12/14/2022] Open
Abstract
Cell death-Inducing DNA Fragmentation Factor Alpha (DFFA)-like Effector (CIDE) proteins have emerged as lipid droplet-associated proteins that regulate fat metabolism. There are three members in the CIDE protein family—CIDEA, CIDEB, and CIDEC (also known as fat-specific protein 27 (FSP27)). CIDEA and FSP27 are primarily expressed in adipose tissue, while CIDEB is expressed in the liver. Originally, based upon their homology with DNA fragmentation factors, these proteins were identified as apoptotic proteins. However, recent studies have changed the perception of these proteins, redefining them as regulators of lipid droplet dynamics and fat metabolism, which contribute to a healthy metabolic phenotype in humans. Despite various studies in humans and gene-targeting studies in mice, the physiological roles of CIDE proteins remains elusive. This review will summarize the known physiological role and metabolic pathways regulated by the CIDE proteins in human health and disease.
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Affiliation(s)
- Mark Slayton
- Department of Biomedical Sciences and Diabetes Institute, Ohio University Heritage College of Osteopathic Medicine, Athens, OH 45701, USA.
| | - Abhishek Gupta
- Department of Biomedical Sciences and Diabetes Institute, Ohio University Heritage College of Osteopathic Medicine, Athens, OH 45701, USA.
| | - Bijinu Balakrishnan
- Department of Biomedical Sciences and Diabetes Institute, Ohio University Heritage College of Osteopathic Medicine, Athens, OH 45701, USA.
| | - Vishwajeet Puri
- Department of Biomedical Sciences and Diabetes Institute, Ohio University Heritage College of Osteopathic Medicine, Athens, OH 45701, USA.
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175
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Orlicky DJ, Libby AE, Bales ES, McMahan RH, Monks J, La Rosa FG, McManaman JL. Perilipin-2 promotes obesity and progressive fatty liver disease in mice through mechanistically distinct hepatocyte and extra-hepatocyte actions. J Physiol 2019; 597:1565-1584. [PMID: 30536914 PMCID: PMC6418763 DOI: 10.1113/jp277140] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 12/05/2018] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS Wild-type mice and mice with hepatocyte-specific or whole-body deletions of perilipin-2 (Plin2) were used to define hepatocyte and extra-hepatocyte effects of altered cellular lipid storage on obesity and non-alcoholic fatty liver disease (NAFLD) pathophysiology in a Western-diet (WD) model of these disorders. Extra-hepatocyte actions of Plin2 are responsible for obesity, adipose inflammation and glucose clearance abnormalities in WD-fed mice. Hepatocyte and extra-hepatic actions of Plin2 mediate fatty liver formation in WD-fed mice through distinct mechanisms. Hepatocyte-specific actions of Plin2 are primary mediators of immune cell infiltration and fibrotic injury in livers of obese mice. ABSTRACT Non-alcoholic fatty liver disease (NAFLD) is an obesity- and insulin resistance-related metabolic disorder with progressive pathology. Perilipin-2 (Plin2), a ubiquitously expressed cytoplasmic lipid droplet scaffolding protein, is hypothesized to contribute to NAFLD in humans and rodent models through effects on cellular lipid metabolism. In this study, we delineate hepatocyte-specific and extra-hepatocyte Plin2 mechanisms regulating the effects of obesity and insulin resistance on NAFLD pathophysiology in mice fed an obesogenic Western-style diet (WD). Total Plin2 deletion (Plin2-Null) fully protected WD-fed mice from obesity, insulin resistance, adipose inflammation, steatohepatitis (NASH) and liver fibrosis found in WT animals. Hepatocyte-specific Plin2 deletion (Plin2-HepKO) largely protected against NASH and fibrosis and partially protected against steatosis in WD-fed animals, but it did not protect against obesity, insulin resistance, or adipose inflammation. Significantly, total or hepatocyte-specific Plin2 deletion impaired WD-induced monocyte recruitment and pro-inflammatory macrophage polarization found in livers of WT mice. Analyses of the molecular and cellular processes mediating steatosis, inflammation and fibrosis identified differences in total and hepatocyte-specific actions of Plin2 on the mechanisms promoting NAFLD pathophysiology. Our results demonstrate that hepatocyte-specific actions of Plin2 are central to the initiation and pathological progression of NAFLD in obese and insulin-resistant mice through effects on immune cell recruitment and fibrogenesis. Conversely, extra-hepatocyte Plin2 actions promote NAFLD pathophysiology through effects on obesity, inflammation and insulin resistance. Our findings provide new insight into hepatocyte and extra-hepatocyte mechanisms underlying NAFLD development and progression.
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Affiliation(s)
- David J. Orlicky
- Department of PathologyUniversity of Colorado School of MedicineAuroraCOUSA
| | - Andrew E. Libby
- Graduate Program in Integrated PhysiologyUniversity of Colorado School of MedicineAuroraCOUSA
- Division of Reproductive SciencesUniversity of Colorado School of MedicineAuroraCOUSA
| | - Elise S. Bales
- Division of Reproductive SciencesUniversity of Colorado School of MedicineAuroraCOUSA
| | - Rachel H. McMahan
- Division of Gastroenterology and HepatologyUniversity of Colorado School of MedicineAuroraCOUSA
| | - Jenifer Monks
- Division of Reproductive SciencesUniversity of Colorado School of MedicineAuroraCOUSA
| | | | - James L. McManaman
- Graduate Program in Integrated PhysiologyUniversity of Colorado School of MedicineAuroraCOUSA
- Division of Reproductive SciencesUniversity of Colorado School of MedicineAuroraCOUSA
- Center for Human NutritionUniversity of Colorado School of MedicineAuroraCOUSA
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176
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Abstract
Lipid droplets are storage organelles at the centre of lipid and energy homeostasis. They have a unique architecture consisting of a hydrophobic core of neutral lipids, which is enclosed by a phospholipid monolayer that is decorated by a specific set of proteins. Originating from the endoplasmic reticulum, lipid droplets can associate with most other cellular organelles through membrane contact sites. It is becoming apparent that these contacts between lipid droplets and other organelles are highly dynamic and coupled to the cycles of lipid droplet expansion and shrinkage. Importantly, lipid droplet biogenesis and degradation, as well as their interactions with other organelles, are tightly coupled to cellular metabolism and are critical to buffer the levels of toxic lipid species. Thus, lipid droplets facilitate the coordination and communication between different organelles and act as vital hubs of cellular metabolism.
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Affiliation(s)
- James A Olzmann
- Department of Nutritional Sciences and Toxicology, University of California-Berkeley, Berkeley, CA, USA.
| | - Pedro Carvalho
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
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177
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A novel lipid droplets-targeting ratiometric fluorescence probe for hypochlorous acid in living cells. Talanta 2019; 194:308-313. [DOI: 10.1016/j.talanta.2018.10.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/29/2018] [Accepted: 10/07/2018] [Indexed: 01/15/2023]
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178
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Cholesterol and the Safety Factor for Neuromuscular Transmission. Int J Mol Sci 2019; 20:ijms20051046. [PMID: 30823359 PMCID: PMC6429197 DOI: 10.3390/ijms20051046] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/23/2019] [Accepted: 02/24/2019] [Indexed: 12/12/2022] Open
Abstract
A present review is devoted to the analysis of literature data and results of own research. Skeletal muscle neuromuscular junction is specialized to trigger the striated muscle fiber contraction in response to motor neuron activity. The safety factor at the neuromuscular junction strongly depends on a variety of pre- and postsynaptic factors. The review focuses on the crucial role of membrane cholesterol to maintain a high efficiency of neuromuscular transmission. Cholesterol metabolism in the neuromuscular junction, its role in the synaptic vesicle cycle and neurotransmitter release, endplate electrogenesis, as well as contribution of cholesterol to the synaptogenesis, synaptic integrity, and motor disorders are discussed.
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179
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Zhou J, Qu G, Zhang G, Wu Z, Liu J, Yang D, Li J, Chang M, Zeng H, Hu J, Fang T, Song Y, Bai C. Glycerol kinase 5 confers gefitinib resistance through SREBP1/SCD1 signaling pathway. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2019; 38:96. [PMID: 30791926 PMCID: PMC6385389 DOI: 10.1186/s13046-019-1057-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 01/27/2019] [Indexed: 01/07/2023]
Abstract
Background Drug resistance is common in cancer chemotherapy. This study investigates the role of Glycerol kinase 5 (GK5) in mediating gefitinib resistance in NSCLC. Methods The exosomal mRNA of GK5 was detected using a tethered cationic lipoplex nanoparticle (TCLN) biochip. Real-time PCR and Western blot were used to examine the expression of GK5 mRNA and protein in gefitinib-sensitive and -resistant human lung adenocarcinoma cells. The cell counting kit-8, EdU assay, flow cytometry, and JC-1 dye were used to measure cell proliferation, cell cycle, and the mitochondrial membrane potential. Results We found that the exosomal mRNA of GK5 in the plasma of patients with gefitinib-resistant adenocarcinoma was significantly higher compared with that of gefitinib-sensitive patients. The mRNA and protein levels of GK5 were significantly upregulated in gefitinib-resistant human lung adenocarcinoma PC9R and H1975 cells compared with gefitinib-sensitive PC9 cells. Silencing GK5 in PC9R cells induced mitochondrial damage, caspase activation, cell cycle arrest, and apoptosis via SREBP1/SCD1 signaling pathway. Conclusions We demonstrated that GK5 confers gefitinib resistance in lung cancer by inhibiting apoptosis and cell cycle arrest. GK5 could be a novel therapeutic target for treatment of NSCLC with resistance to EGFR tyrosine kinase inhibitors.
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Affiliation(s)
- Jian Zhou
- Department of Pulmonary Medicine, Shanghai Respiratory Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Guimei Qu
- Department of Pathology, The Affiliated Yantai Yuhuangding Hospital, Qingdao University, Yantai, China
| | - Ge Zhang
- Department of Pulmonary Medicine, Shanghai Respiratory Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zuoren Wu
- Hangzhou Dixiang Co. Ltd., Hangzhou, China
| | - Jing Liu
- Department of Pathology, The Affiliated Yantai Yuhuangding Hospital, Qingdao University, Yantai, China
| | - Dawei Yang
- Department of Pulmonary Medicine, Shanghai Respiratory Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jing Li
- Department of Pulmonary Medicine, Shanghai Respiratory Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Meijia Chang
- Department of Pulmonary Medicine, Shanghai Respiratory Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | | | - Jie Hu
- Department of Pulmonary Medicine, Shanghai Respiratory Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Tao Fang
- Department of Oncology, Shengli Oilfield Central Hospital, Dongying, Shandong Province, China.
| | - Yuanlin Song
- Department of Pulmonary Medicine, Shanghai Respiratory Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China.
| | - Chunxue Bai
- Department of Pulmonary Medicine, Shanghai Respiratory Research Institute, Zhongshan Hospital, Fudan University, Shanghai, China.
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180
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Neutral Lipid Storage Diseases as Cellular Model to Study Lipid Droplet Function. Cells 2019; 8:cells8020187. [PMID: 30795549 PMCID: PMC6406896 DOI: 10.3390/cells8020187] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/14/2019] [Accepted: 02/19/2019] [Indexed: 01/10/2023] Open
Abstract
Neutral lipid storage disease with myopathy (NLSDM) and with ichthyosis (NLSDI) are rare autosomal recessive disorders caused by mutations in the PNPLA2 and in the ABHD5/CGI58 genes, respectively. These genes encode the adipose triglyceride lipase (ATGL) and α-β hydrolase domain 5 (ABHD5) proteins, which play key roles in the function of lipid droplets (LDs). LDs, the main cellular storage sites of triacylglycerols and sterol esters, are highly dynamic organelles. Indeed, LDs are critical for both lipid metabolism and energy homeostasis. Partial or total PNPLA2 or ABHD5/CGI58 knockdown is characteristic of the cells of NLSD patients; thus, these cells are natural models with which one can unravel LD function. In this review we firstly summarize genetic and clinical data collected from NLSD patients, focusing particularly on muscle, skin, heart, and liver damage due to impaired LD function. Then, we discuss how NLSD cells were used to investigate and expand the current structural and functional knowledge of LDs.
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181
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Li X, Li Y, Jiang M, Wu W, He S, Chen C, Qin Z, Tang BZ, Mak HY, Qu JY. Quantitative Imaging of Lipid Synthesis and Lipolysis Dynamics in Caenorhabditis elegans by Stimulated Raman Scattering Microscopy. Anal Chem 2019; 91:2279-2287. [PMID: 30589537 DOI: 10.1021/acs.analchem.8b04875] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Quantitative methods to precisely measure cellular states in vivo have become increasingly important and desirable in modern biology. Recently, stimulated Raman scattering (SRS) microscopy has emerged as a powerful tool to visualize small biological molecules tagged with alkyne (C≡C) or carbon-deuterium (C-D) bonds in the cell-silent region. In this study, we developed a technique based on SRS microscopy of vibrational tags for quantitative imaging of lipid synthesis and lipolysis in live animals. The technique aims to overcome the major limitations of conventional fluorescent staining and lipid extraction methods that do not provide the capability of in vivo quantitative analysis. Specifically, we used three bioorthogonal lipid molecules (the alkyne-tagged fatty acid 17-ODYA, deuterium-labeled saturated fatty acid PA-D31, and unsaturated fatty acid OA-D34) to investigate the metabolic dynamics of lipid droplets (LDs) in live Caenorhabditis elegans ( C. elegans). Using a hyperspectral SRS (hsSRS) microscope and subtraction method, the interfering non-Raman background was eliminated to improve the accuracy of lipid quantification. A linear relationship between SRS signals and fatty acid molar concentrations was accurately established. With this quantitative analysis tool, we imaged and determined the changes in concentration of the three fatty acids in LDs of fed or starved adult C. elegans. Using the hsSRS imaging mode, we also observed the desaturation of fatty acids in adult C. elegans via spectral analysis on the SRS signals from LDs. The results demonstrated the unique capability of hsSRS microscopy in quantitative analysis of lipid metabolism in vivo.
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Affiliation(s)
- Xuesong Li
- Department of Electronic and Computer Engineering , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China.,Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China
| | - Yan Li
- Division of Life Science , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China
| | - Meijuan Jiang
- Department of Chemistry , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China
| | - Wanjie Wu
- Department of Electronic and Computer Engineering , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China.,Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China
| | - Sicong He
- Department of Electronic and Computer Engineering , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China.,Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China
| | - Congping Chen
- Department of Electronic and Computer Engineering , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China.,Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China
| | - Zhongya Qin
- Department of Electronic and Computer Engineering , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China.,Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China
| | - Ben Zhong Tang
- Department of Chemistry , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China
| | - Ho Yi Mak
- Division of Life Science , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China
| | - Jianan Y Qu
- Department of Electronic and Computer Engineering , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China.,Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study , Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong 999077 , China
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182
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Mallela SK, Patel DM, Ducasa GM, Merscher S, Fornoni A, Al-Ali H. Detection and Quantification of Lipid Droplets in Differentiated Human Podocytes. Methods Mol Biol 2019; 1996:199-206. [PMID: 31127558 PMCID: PMC7941729 DOI: 10.1007/978-1-4939-9488-5_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Lipid droplets (LDs) are dynamic organelles that regulate the storage and homeostasis of intracellular triglycerides and other neutral lipids. Studies show that the number, morphology, and subcellular localization of LDs are altered in a growing number of diseases. As such, methodologies for imaging and quantifying LDs have become essential tools for detecting changes in cellular lipid metabolism, which could be an important indicator of disease onset or progression. We previously reported on the accumulation of LDs in podocytes of the kidney glomerulus in nephrological diseases of metabolic and non-metabolic origin. Here, we describe a high-content analysis (HCA) method for automated detection and quantification of LDs in differentiated human podocytes.
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Affiliation(s)
- Shamroop Kumar Mallela
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Devang Maheshkumar Patel
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Gloria Michelle Ducasa
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Sandra Merscher
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA.
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Hassan Al-Ali
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA.
- Peggy and Harold Katz Family Drug Discovery Center, University of Miami Miller School of Medicine, Miami, FL, USA.
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
- The Miami Project to Cure Paralysis, University of Miami, Miller School of Medicine, Miami, FL, USA.
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183
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Zhao N, Li Y, Yang W, Zhuang J, Li Y, Li N. Multifunctional pyrazoline based AIEgens: real-time tracking and specific protein “fishing” of lipid droplets. Chem Sci 2019. [DOI: 10.1039/c9sc03111a] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
A series of multifunctional pyrazoline based AIEgens were developed for real-time tracking of lipid metabolism, reversibly monitoring intracellular pH in dual-color mode and specific labeling of lipid droplet related protein.
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Affiliation(s)
- Na Zhao
- Key Laboratory of Macromolecular Science of Shaanxi Province
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- 710119 Xi'an
| | - Yan Li
- Key Laboratory of Macromolecular Science of Shaanxi Province
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- 710119 Xi'an
| | - Weiyao Yang
- Key Laboratory of Macromolecular Science of Shaanxi Province
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- 710119 Xi'an
| | - Jiabao Zhuang
- Key Laboratory of Macromolecular Science of Shaanxi Province
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- 710119 Xi'an
| | - Yue Li
- Key Laboratory of Macromolecular Science of Shaanxi Province
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- 710119 Xi'an
| | - Nan Li
- Key Laboratory of Macromolecular Science of Shaanxi Province
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education
- School of Chemistry & Chemical Engineering
- Shaanxi Normal University
- 710119 Xi'an
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184
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Levchenko SM, Peng X, Liu L, Qu J. The impact of cell fixation on coherent anti-stokes Raman scattering signal intensity in neuronal and glial cell lines. JOURNAL OF BIOPHOTONICS 2019; 12:e201800203. [PMID: 30039928 DOI: 10.1002/jbio.201800203] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Revised: 07/07/2018] [Accepted: 07/20/2018] [Indexed: 06/08/2023]
Abstract
A number of studies require sample fixation, aimed to preserve cells in a physiological state with minimal changes of morphology and intracellular molecular content. Sample fixation may significantly distort experimental data, which makes the data interpretation process more challenging. It is particularly important for study of lipid-related diseases, where the biochemical and morphological characteristics of the cells need to be well preserved for an accurate data analysis. This study investigates the effects of formaldehyde and ethanol (EtOH) fixatives on coherent anti-stokes Raman scattering (CARS) signal of proteins and lipids in major cellular compartments of neuronal and glial cells. We found that both fixatives induce alteration of proteins and lipids signal in studied cell lines. Furthermore, the impact of sample preservation methods on CARS signal varies between cell lines. For instance, our data reveals that EtOH fixation induces ~45% increase of CARS signal of proteins in the nucleolus of neuronal cells and ~35% decrease of CARS signal in glial cells. The results indicate that aldehyde fixation is a preferable method for preservation of neuronal and glial cells prior to CARS imaging, as it less affects both CARS signal and intracellular distribution of proteins and lipids.
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Affiliation(s)
- Svitlana M Levchenko
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education/Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Xiao Peng
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education/Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Liwei Liu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education/Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
| | - Junle Qu
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education/Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, China
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185
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α-Cedrene protects rodents from high-fat diet-induced adiposity via adenylyl cyclase 3. Int J Obes (Lond) 2018; 43:202-216. [PMID: 30568259 DOI: 10.1038/s41366-018-0176-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 06/27/2018] [Accepted: 07/02/2018] [Indexed: 11/08/2022]
Abstract
OBJECTIVE The increasing global prevalence of obesity and its associated disorders points to an urgent need for the development of novel and effective strategies for the prevention of weight gain. Here, we investigated the potential of α-cedrene, a volatile sesquiterpene compound derived from cedarwood oil, in regulation of obesity and delineated the mechanisms involved. METHODS For the prevention of obesity, C57BL/6 N mice were fed a high-fat diet (HFD) and were orally administered either with vehicle or α-cedrene for 8 weeks. For the therapy of obesity, obese Sprague Dawley rats, induced by a HFD for 8 weeks, were orally treated either with vehicle or α-cedrene for 12 weeks. To determine whether the action of α-cedrene was Adcy3 dependent, Adcy3 heterozygous null mice (Adcy3+/-) and wild-type controls were fed either HFD or α-cedrene supplemented HFD for 17 weeks. RESULTS Oral α-cedrene administration prevented or reversed HFD-induced obesity and abnormal metabolic aberrations in rodents, without affecting their food intake. Downregulation of Adcy3 expression by small interfering RNA abrogated the beneficial effects of α-cedrene on the oxygen consumption rate and intracellular lipid accumulation in 3T3-L1 adipocytes. Similarly, in Adcy3+/- mice, the α-cedrene-driven suppression of body weight gain observed in wild-type mice was substantially (~50%) attenuated. Expression of thermogenic and lipid oxidation genes was increased in adipose tissues of α-cedrene-treated mice, with concomitant downregulation of adipogenic gene expression. These beneficial molecular changes elicited by α-cedrene were blunted in adipose tissues of Adcy3+/- mice. CONCLUSIONS Our results highlight the potential of α-cedrene for antiobesity interventions and suggest that the antiobesity effect of α-cedrene is mediated by Adcy3 in adipose tissues.
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186
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Zhang X, Liu H, Hao Y, Xu L, Zhang T, Liu Y, Guo L, Zhu L, Pei Z. Coenzyme Q10 protects against hyperlipidemia-induced cardiac damage in apolipoprotein E-deficient mice. Lipids Health Dis 2018; 17:279. [PMID: 30526612 PMCID: PMC6286539 DOI: 10.1186/s12944-018-0928-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/26/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Hyperlipidemia is a well-established risk factor for cardiac damage, which can lead to cardiovascular diseases. Many studies have shown that Coenzyme Q10(CoQ10) protects against cardiac damage in vivo. The aim of this study was to investigate the possible protective effects of CoQ10 against cardiac damage in apolipoprotein E-deficient (ApoE-/-) mice. METHODS Eight-week-old male C57BL/6 and ApoE-/- mice were randomly divided into four groups: C57BL/6 mice fed a normal diet (C57BL/6 group); C57BL/6 mice fed a normal diet + CoQ10 (C57BL/6 + CoQ10 group); ApoE-/- mice fed a high-fat diet (ApoE-/- HD group), and ApoE-/- mice fed a high-fat diet + CoQ10 (ApoE-/- HD + CoQ10 group). All groups were fed the different diets for 16 weeks. Blood samples were obtained from the inferior vena cava and collected in serum tubes. The samples were then stored at - 80 °C until used. Coronal sections of heart tissues were fixed in 10% formalin and then embedded in paraffin for histological evaluation. The remainder of the heart tissues was snap-frozen in liquid nitrogen for mRNA or immunohistochemical analysis. RESULTS The metabolic parameters such as total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-c), and triglycerides (TG) levels were lower in ApoE-/-HD + CoQ10 mice than in ApoE-/- HD mice. There were significant pathophysiological changes (H&E, PAS, Masson and CD68 staining) in ApoE-/- mice in the HD group compared with those in the HD + CoQ10 group. CoQ10 reduced HD-induced cardiac tissue damage via autophagy (p62 and LC3), as evidenced by immunoblotting, immunohistochemistry, and RT-qPCR. CoQ10 also inhibited inflammation (IL-6 and TNF-α) gene expression in ApoE-/- mice. CONCLUSIONS These results indicate that CoQ10 is a potential therapeutic target for cardiac damage caused by hyperlipidemia.
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Affiliation(s)
- Xiaoqing Zhang
- Department of Infection, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, China
| | - Hongyang Liu
- Department of Heart Intensive Care Unit, the First Affiliated Hospital of Dalian Medical University, No.193 Lianhe Road, Dalian, China
| | - Yuhua Hao
- Department of Infection, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, China
| | - Lulu Xu
- Department of Infection, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, China
| | - Tiemei Zhang
- Department of Infection, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, China
| | - Yingshu Liu
- Department of Endocrinology, Dalian Municipal Central Hospital, 42 Xuegong Road, Dalian, China
| | - Lipeng Guo
- Department of Cardiology, Dalian Third People' Hospital Affiliated to Dalian Medical University, No.40 Qianshan Road, Dalian, China
| | - Liyue Zhu
- Rehabilitation Center, Zhejiang Hospital, 12 Lingyin Road, Hangzhou, Zhejiang, China
| | - Zuowei Pei
- Department of Cardiology, Affiliated Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Dalian, China.
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187
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Xu H, Zhang H, Liu G, Kong L, Zhu X, Tian X, Zhang Z, Zhang R, Wu Z, Tian Y, Zhou H. Coumarin-Based Fluorescent Probes for Super-resolution and Dynamic Tracking of Lipid Droplets. Anal Chem 2018; 91:977-982. [DOI: 10.1021/acs.analchem.8b04079] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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188
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Sharma L, Lone NA, Knott RM, Hassan A, Abdullah T. Trigonelline prevents high cholesterol and high fat diet induced hepatic lipid accumulation and lipo-toxicity in C57BL/6J mice, via restoration of hepatic autophagy. Food Chem Toxicol 2018; 121:283-296. [PMID: 30208301 DOI: 10.1016/j.fct.2018.09.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 12/19/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is often linked with impaired hepatic autophagy. Here, we studied the alterations in hepatocellular autophagy by high cholesterol and high-fat diet (HC-HF) diet in C57BL/6J mice, and by palmitic acid (PA), in AML-12 and HepG2 cells. Further, we analysed role of Trigonelline (TG), a plant alkaloid, in preventing NAFLD, by modulating autophagy. For this, C57BL/6J mice were fed with Standard Chow (SC) or HC-HF diet, with and without TG for 16 weeks. In-vitro; AML-12 cells and HepG2 cells, were exposed to PA with and without TG, for 24 h. Cellular events related to autophagy, lipogenesis, and lipo-toxicity were studied. The HC-HF diet fed mice showed hepatic autophagy blockade, increased triglycerides and steatosis. PA exposure to AML-12 cells and HepG2 cells induced impaired autophagy, ER stress, resulting in lipotoxicity. TG treatment in HC-HF fed mice, restored hepatic autophagy, and prevented steatosis. TG treated AML-12, and HepG2 cells exposed to PA showed autophagy restoration, and reduced lipotoxicity, however, these effects were diminished in Atg7-/- HepG2 cells, and in the presence of chloroquine. This study shows that HC-HF diet-induced impaired autophagy, and steatosis is prevented by TG, which attributes to its novel mechanism in treating NAFLD.
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Affiliation(s)
- Love Sharma
- Academy of Scientific and Innovative Research (AcSIR), Jammu Campus, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, Jammu and Kashmir, India; PK-PD and Toxicology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, Jammu and Kashmir, India
| | - Nazir A Lone
- Academy of Scientific and Innovative Research (AcSIR), Jammu Campus, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, Jammu and Kashmir, India; PK-PD and Toxicology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, Jammu and Kashmir, India
| | - Rachel M Knott
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, Scotland, UK
| | - Adil Hassan
- Department of Pathology, Government Medical College, Srinagar, Jammu and Kashmir, India
| | - Tasduq Abdullah
- Academy of Scientific and Innovative Research (AcSIR), Jammu Campus, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, Jammu and Kashmir, India; PK-PD and Toxicology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi, Jammu and Kashmir, India.
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189
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Wang J, Yan C, Xu C, Chua BT, Li P, Chen FJ. Polybasic RKKR motif in the linker region of lipid droplet (LD)-associated protein CIDEC inhibits LD fusion activity by interacting with acidic phospholipids. J Biol Chem 2018; 293:19330-19343. [PMID: 30361435 DOI: 10.1074/jbc.ra118.004892] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/24/2018] [Indexed: 12/17/2022] Open
Abstract
Lipid droplets (LDs) are intracellular organelles and a central site for lipid synthesis, storage, and mobilization. The size of LDs reflects the dynamic regulation of lipid metabolism in cells. Previously, we found that cell death-inducing DFFA-like effector C (CIDEC) mediates LD fusion and growth by lipid transfer through LD-LD contact sites in adipocytes and hepatocytes. The CIDE-N domains of CIDEC molecules form homodimers, whereas the CIDE-C domain plays an important role in LD targeting and enrichment. Here, using targeted protein deletions and GFP expression coupled with fluorescence microscopy, we identified a polybasic RKKR motif in the linker region that connects the CIDE-N and CIDE-C domains of CIDEC and functions as a regulatory motif for LD fusion. We found that deletion of the linker region or mutation of the RKKR motif increases the formation of supersized LDs compared with LD formation in cells with WT CIDEC. This enhanced LD fusion activity required the interaction between CIDE-N domains. Mechanistically, we found that the RKKR motif interacts with acidic phospholipids via electrostatic attraction. Loss of this motif disrupted the protein-lipid interaction, resulting in enhanced lipid droplet fusion activity and thus formation of larger LDs. In summary, we have uncovered a CIDEC domain that regulates LD fusion activity, a finding that provides insights into the inhibitory regulation of LD fusion through CIDEC-lipid interactions.
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Affiliation(s)
- Jia Wang
- From the State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084
| | - Chengsong Yan
- the State Key Laboratory of Molecular Biology, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, and
| | - Chenqi Xu
- the State Key Laboratory of Molecular Biology, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, and
| | - Boon Tin Chua
- the Institute of Metabolism and Integrative Biology, Fudan University, Shanghai 200438, China
| | - Peng Li
- From the State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084,
| | - Feng-Jung Chen
- From the State Key Laboratory of Membrane Biology and Tsinghua-Peking Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, .,the Institute of Metabolism and Integrative Biology, Fudan University, Shanghai 200438, China
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190
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de Carvalho CCCR, Caramujo MJ. The Various Roles of Fatty Acids. Molecules 2018; 23:molecules23102583. [PMID: 30304860 PMCID: PMC6222795 DOI: 10.3390/molecules23102583] [Citation(s) in RCA: 306] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 10/01/2018] [Accepted: 10/06/2018] [Indexed: 12/31/2022] Open
Abstract
Lipids comprise a large group of chemically heterogeneous compounds. The majority have fatty acids (FA) as part of their structure, making these compounds suitable tools to examine processes raging from cellular to macroscopic levels of organization. Among the multiple roles of FA, they have structural functions as constituents of phospholipids which are the "building blocks" of cell membranes; as part of neutral lipids FA serve as storage materials in cells; and FA derivatives are involved in cell signalling. Studies on FA and their metabolism are important in numerous research fields, including biology, bacteriology, ecology, human nutrition and health. Specific FA and their ratios in cellular membranes may be used as biomarkers to enable the identification of organisms, to study adaptation of bacterial cells to toxic compounds and environmental conditions and to disclose food web connections. In this review, we discuss the various roles of FA in prokaryotes and eukaryotes and highlight the application of FA analysis to elucidate ecological mechanisms. We briefly describe FA synthesis; analyse the role of FA as modulators of cell membrane properties and FA ability to store and supply energy to cells; and inspect the role of polyunsaturated FA (PUFA) and the suitability of using FA as biomarkers of organisms.
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Affiliation(s)
- Carla C C R de Carvalho
- Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
| | - Maria José Caramujo
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Edifício C2-5º Piso, 1749-016 Lisboa, Portugal.
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191
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Mele C, Tagliaferri MA, Saraceno G, Mai S, Vietti R, Zavattaro M, Aimaretti G, Scacchi M, Marzullo P. Serum uric acid potentially links metabolic health to measures of fuel use in lean and obese individuals. Nutr Metab Cardiovasc Dis 2018; 28:1029-1035. [PMID: 30139687 DOI: 10.1016/j.numecd.2018.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/04/2018] [Accepted: 06/12/2018] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND AIMS Uric acid (UA) is a byproduct of the high-energy purine metabolism and is conventionally regarded as a marker of cardio-metabolic impairment. Its potential relationship with energy homeostasis is unknown to date. METHODS AND RESULTS In a cross-sectional study on 121 otherwise healthy obese and 99 sex- and-age-matched lean subjects, UA levels were analyzed in relation to metabolic health, inflammatory markers, respiratory quotient (RQ) and resting energy expenditure (REE) as assessed by indirect calorimetry, fat mass (%FM) and fat-free mass (FFM) as determined by bioimpedance analysis. As expected, obese and lean subjects differed in BMI, glucolipid homeostasis, leptin and insulin levels, inflammatory markers, %FM and FFM (p < 0.001 for all). Likewise, UA levels (p < 0.001) and rates of hyperuricaemia (40.5% vs 3.0%, p < 0.0001) were also higher in obese than lean controls. Further, indirect calorimetry confirmed that obesity increased REE and decreased RQ significantly (p < 0.001). Beyond the expected metabolic correlates, in individual and merged groups UA levels were associated negatively with RQ and positively with REE (p < 0.0001 for both). In multivariable regression analysis, significant independent predictors of UA were BMI and sex. When BMI was replaced by measures of body composition, %FM and FFM emerged as significant predictors of serum UA (p < 0.0001). CONCLUSIONS A potential link relates serum UA to measures of resting energy expenditure and their determinants.
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Affiliation(s)
- C Mele
- Division of General Medicine, Ospedale S. Giuseppe, Istituto Auxologico Italiano, via Cadorna 90, 28824, Piancavallo di Oggebbio (VB), Italy; Department of Translational Medicine, University of Piemonte Orientale, via Solaroli 17, 28100, Novara, Italy
| | - M A Tagliaferri
- Division of General Medicine, Ospedale S. Giuseppe, Istituto Auxologico Italiano, via Cadorna 90, 28824, Piancavallo di Oggebbio (VB), Italy
| | - G Saraceno
- Division of General Medicine, Ospedale S. Giuseppe, Istituto Auxologico Italiano, via Cadorna 90, 28824, Piancavallo di Oggebbio (VB), Italy
| | - S Mai
- Laboratory of Metabolic Research, Ospedale S. Giuseppe, Istituto Auxologico Italiano, via Cadorna 90, 28824, Piancavallo di Oggebbio (VB), Italy
| | - R Vietti
- Laboratory of Metabolic Research, Ospedale S. Giuseppe, Istituto Auxologico Italiano, via Cadorna 90, 28824, Piancavallo di Oggebbio (VB), Italy
| | - M Zavattaro
- Department of Translational Medicine, University of Piemonte Orientale, via Solaroli 17, 28100, Novara, Italy
| | - G Aimaretti
- Department of Translational Medicine, University of Piemonte Orientale, via Solaroli 17, 28100, Novara, Italy
| | - M Scacchi
- Division of General Medicine, Ospedale S. Giuseppe, Istituto Auxologico Italiano, via Cadorna 90, 28824, Piancavallo di Oggebbio (VB), Italy
| | - P Marzullo
- Division of General Medicine, Ospedale S. Giuseppe, Istituto Auxologico Italiano, via Cadorna 90, 28824, Piancavallo di Oggebbio (VB), Italy; Department of Translational Medicine, University of Piemonte Orientale, via Solaroli 17, 28100, Novara, Italy.
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192
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Zheng Z, Zhang T, Liu H, Chen Y, Kwok RTK, Ma C, Zhang P, Sung HHY, Williams ID, Lam JWY, Wong KS, Tang BZ. Bright Near-Infrared Aggregation-Induced Emission Luminogens with Strong Two-Photon Absorption, Excellent Organelle Specificity, and Efficient Photodynamic Therapy Potential. ACS NANO 2018; 12:8145-8159. [PMID: 30074773 DOI: 10.1021/acsnano.8b03138] [Citation(s) in RCA: 192] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Far-red and near-infrared (NIR) fluorescent materials possessing the characteristics of strong two-photon absorption and aggregation-induced emission (AIE) as well as specific targeting capability are much-sought-after for bioimaging and therapeutic applications due to their deep penetration depth and high resolution. Herein, a series of dipolar far-red and NIR AIE luminogens with a strong push-pull effect are designed and synthesized. The obtained fluorophores display bright far-red and NIR solid-state fluorescence with a high quantum yield of up to 30%, large Stokes shifts of up to 244 nm, and large two-photon absorption cross-sections of up to 887 GM. A total of three neutral AIEgens show specific lipid droplet (LD)-targeting capability, while the one with cationic and lipophilic characteristics tends to target the mitochondria specifically. All of the molecules demonstrate good biocompatibility, high brightness, and superior photostability. They also serve as efficient two-photon fluorescence-imaging agents for the clear visualization of LDs or mitochondria in living cells and tissues with deep tissue penetration (up to 150 μm) and high contrast. These AIEgens can efficiently generate singlet oxygen upon light irradiation for the photodynamic ablation of cancer cells. All of these intriguing results prove that these far-red and NIR AIEgens are excellent candidates for the two-photon fluorescence imaging of LDs or mitochondria and organelle-targeting photodynamic cancer therapy.
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Affiliation(s)
- Zheng Zheng
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute for Advanced Study, Department of Chemical and Biological Engineering and Division of Life Science, The Hong Kong University of Science and Technology (HKUST) , Clear Water Bay, Kowloon , Hong Kong , China
| | - Tianfu Zhang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute for Advanced Study, Department of Chemical and Biological Engineering and Division of Life Science, The Hong Kong University of Science and Technology (HKUST) , Clear Water Bay, Kowloon , Hong Kong , China
| | - Haixiang Liu
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute for Advanced Study, Department of Chemical and Biological Engineering and Division of Life Science, The Hong Kong University of Science and Technology (HKUST) , Clear Water Bay, Kowloon , Hong Kong , China
| | - Yuncong Chen
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute for Advanced Study, Department of Chemical and Biological Engineering and Division of Life Science, The Hong Kong University of Science and Technology (HKUST) , Clear Water Bay, Kowloon , Hong Kong , China
| | - Ryan T K Kwok
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute for Advanced Study, Department of Chemical and Biological Engineering and Division of Life Science, The Hong Kong University of Science and Technology (HKUST) , Clear Water Bay, Kowloon , Hong Kong , China
| | - Chao Ma
- Department of Physics , HKUST , Clear Water Bay, Kowloon , Hong Kong , China
| | - Pengfei Zhang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute for Advanced Study, Department of Chemical and Biological Engineering and Division of Life Science, The Hong Kong University of Science and Technology (HKUST) , Clear Water Bay, Kowloon , Hong Kong , China
| | - Herman H Y Sung
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute for Advanced Study, Department of Chemical and Biological Engineering and Division of Life Science, The Hong Kong University of Science and Technology (HKUST) , Clear Water Bay, Kowloon , Hong Kong , China
| | - Ian D Williams
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute for Advanced Study, Department of Chemical and Biological Engineering and Division of Life Science, The Hong Kong University of Science and Technology (HKUST) , Clear Water Bay, Kowloon , Hong Kong , China
| | - Jacky W Y Lam
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute for Advanced Study, Department of Chemical and Biological Engineering and Division of Life Science, The Hong Kong University of Science and Technology (HKUST) , Clear Water Bay, Kowloon , Hong Kong , China
| | - Kam Sing Wong
- Department of Physics , HKUST , Clear Water Bay, Kowloon , Hong Kong , China
| | - Ben Zhong Tang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute for Advanced Study, Department of Chemical and Biological Engineering and Division of Life Science, The Hong Kong University of Science and Technology (HKUST) , Clear Water Bay, Kowloon , Hong Kong , China
- HKUST-Shenzhen Research Institute , No. 9 Yuexing First Road , South Area, Hi-Tech Park, Nanshan , Shenzhen 518057 , China
- NSFC Center for Luminescence from Molecular Aggregates , SCUT-HKUST Joint Research Institute, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology , Guangzhou 510640 , China
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193
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Martins AS, Martins IC, Santos NC. Methods for Lipid Droplet Biophysical Characterization in Flaviviridae Infections. Front Microbiol 2018; 9:1951. [PMID: 30186265 PMCID: PMC6110928 DOI: 10.3389/fmicb.2018.01951] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 08/02/2018] [Indexed: 01/14/2023] Open
Abstract
Lipid droplets (LDs) are intracellular organelles for neutral lipid storage, originated from the endoplasmic reticulum. They play an essential role in lipid metabolism and cellular homeostasis. In fact, LDs are complex organelles, involved in many more cellular processes than those initially proposed. They have been extensively studied in the context of LD-associated pathologies. In particular, LDs have emerged as critical for virus replication and assembly. Viruses from the Flaviviridae family, namely dengue virus (DENV), hepatitis C virus (HCV), West Nile virus (WNV), and Zika virus (ZIKV), interact with LDs to usurp the host lipid metabolism for their own viral replication and pathogenesis. In general, during Flaviviridae infections it is observed an increasing number of host intracellular LDs. Several viral proteins interact with LDs during different steps of the viral life cycle. The HCV core protein and DENV capsid protein, extensively interact with LDs to regulate their replication and assembly. Detailed studies of LDs in viral infections may contribute for the development of possible inhibitors of key steps of viral replication. Here, we reviewed different techniques that can be used to characterize LDs isolated from infected or non-infected cells. Microscopy studies have been commonly used to observe LDs accumulation and localization in infected cell cultures. Fluorescent dyes, which may affect LDs directly, are widely used to probe LDs but there are also approaches that do not require the use of fluorescence, namely stimulated Raman scattering, electron and atomic force microscopy-based approaches. These three are powerful techniques to characterize LDs morphology. Raman scattering microscopy allows studying LDs in a single cell. Electron and atomic force microscopies enable a better characterization of LDs in terms of structure and interaction with other organelles. Other biophysical techniques, such as dynamic light scattering and zeta potential are also excellent to characterize LDs in terms of size in a simple and fast way and test possible LDs interaction with viral proteins. These methodologies are reviewed in detail, in the context of viral studies.
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Affiliation(s)
- Ana S Martins
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Ivo C Martins
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Nuno C Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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194
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Zhao W, Feng X, Liu B, Xian J, Zhang N. Er-Miao-Fang Extracts Inhibits Adipose Lipolysis and Reduces Hepatic Gluconeogenesis via Suppression of Inflammation. Front Physiol 2018; 9:1041. [PMID: 30154727 PMCID: PMC6102449 DOI: 10.3389/fphys.2018.01041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 07/12/2018] [Indexed: 01/07/2023] Open
Abstract
High-fat-diet (HFD) feeding induces adipose dysfunction. This study aims to explore whether the Traditional Chinese Medical prescription Er-Miao-Fang could ameliorate adipose dysfunction and prevent hepatic glucose output. Short-term HFD feeding induced adipose lipolysis accompanied with enhanced hepatic glucose output in mice. Adipose lipolysis is initiated by cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling. Oral administration Er-Miao-Fang inhibited inflammation in adipose tissue by dephosphorylation of JNK and reducing TNF-α and IL-1β production, and thus preserved phosphodiesterase 3B (PDE3B) induction, contributing to preventing cAMP accumulation. As a result, from suppression of PKA activation, Er-Miao-Fang reduced fatty acids and glycerol release from adipose tissue due to the inhibition hormone-sensitive lipase (HSL). By blocking the traffic of fatty acids and inflammatory mediators from adipose tissue to the liver, Er-Miao-Fang attenuated hepatic cAMP/PKA signaling by protecting phosphodiesterase 4B (PDE4B) induction from inflammatory insult, and thereby reduced hepatic glucose production by suppression of hepatic glucagon response in HFD-fed mice. In conclusion, Er-Miao-Fang prevented adipose lipolysis by suppression of inflammation, contributing to reducing excessive hepatic glucose output. These findings present a new view of regulating gluconeogenesis and provide the guiding significance for the regulation of multi-link targets with Traditional Chinese Medicine.
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Affiliation(s)
- Wenjun Zhao
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
| | - Xin Feng
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Baolin Liu
- Clinical Metabolomics Centre, China Pharmaceutical University, Nanjing, China
| | - Jiechen Xian
- Engineering Research Center of Modern Preparation Technology of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ning Zhang
- Experiment Center for Science and Technology, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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195
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Petan T, Jarc E, Jusović M. Lipid Droplets in Cancer: Guardians of Fat in a Stressful World. Molecules 2018; 23:molecules23081941. [PMID: 30081476 PMCID: PMC6222695 DOI: 10.3390/molecules23081941] [Citation(s) in RCA: 217] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 07/31/2018] [Accepted: 08/01/2018] [Indexed: 12/12/2022] Open
Abstract
Cancer cells possess remarkable abilities to adapt to adverse environmental conditions. Their survival during severe nutrient and oxidative stress depends on their capacity to acquire extracellular lipids and the plasticity of their mechanisms for intracellular lipid synthesis, mobilisation, and recycling. Lipid droplets, cytosolic fat storage organelles present in most cells from yeast to men, are emerging as major regulators of lipid metabolism, trafficking, and signalling in various cells and tissues exposed to stress. Their biogenesis is induced by nutrient and oxidative stress and they accumulate in various cancers. Lipid droplets act as switches that coordinate lipid trafficking and consumption for different purposes in the cell, such as energy production, protection against oxidative stress or membrane biogenesis during rapid cell growth. They sequester toxic lipids, such as fatty acids, cholesterol and ceramides, thereby preventing lipotoxic cell damage and engage in a complex relationship with autophagy. Here, we focus on the emerging mechanisms of stress-induced lipid droplet biogenesis; their roles during nutrient, lipotoxic, and oxidative stress; and the relationship between lipid droplets and autophagy. The recently discovered principles of lipid droplet biology can improve our understanding of the mechanisms that govern cancer cell adaptability and resilience to stress.
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Affiliation(s)
- Toni Petan
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana SI-1000, Slovenia.
| | - Eva Jarc
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana SI-1000, Slovenia.
- Jožef Stefan International Postgraduate School, Ljubljana SI-1000, Slovenia.
| | - Maida Jusović
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana SI-1000, Slovenia.
- Jožef Stefan International Postgraduate School, Ljubljana SI-1000, Slovenia.
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196
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Liu Y, Xu S, Zhang C, Zhu X, Hammad MA, Zhang X, Christian M, Zhang H, Liu P. Hydroxysteroid dehydrogenase family proteins on lipid droplets through bacteria, C. elegans, and mammals. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:881-894. [DOI: 10.1016/j.bbalip.2018.04.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 04/18/2018] [Accepted: 04/21/2018] [Indexed: 02/08/2023]
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197
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Khosravi M, Hosseini-Fard R, Najafi M. Circulating low density lipoprotein (LDL). Horm Mol Biol Clin Investig 2018; 35:/j/hmbci.ahead-of-print/hmbci-2018-0024/hmbci-2018-0024.xml. [PMID: 30059347 DOI: 10.1515/hmbci-2018-0024] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/22/2018] [Indexed: 12/13/2022]
Abstract
Low-density lipoprotein (LDL) particles are known as atherogenic agents in coronary artery diseases. They modify to other electronegative forms and may be the subject for improvement of inflammatory events in vessel subendothelial spaces. The circulating LDL value is associated with the plasma PCSK-9 level. They internalize into macrophages using the lysosomal receptor-mediated pathways. LDL uptake is related to the membrane scavenger receptors, modifications of lipid and protein components of LDL particles, vesicular maturation and lipid stores of cells. Furthermore, LDL vesicular trafficking is involved with the function of some proteins such as Rab and Lamp families. These proteins also help in the transportation of free cholesterol from lysosome into the cytosol. The aggregation of lipids in the cytosol is a starting point for the formation of foam cells so that they may participate in the primary core of atherosclerosis plaques. The effects of macrophage subclasses are different in the formation and remodeling of plaques. This review is focused on the cellular and molecular events involved in cholesterol homeostasis.
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Affiliation(s)
- Mohsen Khosravi
- Biochemistry Department, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Hosseini-Fard
- Biochemistry Department, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Najafi
- Cellular and Molecular Research Center, Biochemistry Department, Iran University of Medical Sciences, Tehran, Iran, Phone: 09155192401
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198
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Joseph JS, Ayeleso AO, Mukwevho E. Importance of CaMKII activation in the regulation of adiposomes and ATP concentration in rat skeletal muscle. ACTA ACUST UNITED AC 2018. [DOI: 10.1080/0035919x.2018.1476421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Jitcy S. Joseph
- Department of Biochemistry, University of Johannesburg, Auckland Park 2006, South Africa
| | - Ademola O. Ayeleso
- Department of Biochemistry, North-West University, Mafikeng Campus, Mmabatho, 2735, South Africa
| | - Emmanuel Mukwevho
- Department of Biochemistry, North-West University, Mafikeng Campus, Mmabatho, 2735, South Africa
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199
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The utrophin-beta 2 syntrophin complex regulates adipocyte lipid droplet size independent of adipogenesis. Mol Cell Biochem 2018; 452:29-39. [PMID: 30014220 DOI: 10.1007/s11010-018-3409-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 07/13/2018] [Indexed: 02/06/2023]
Abstract
Utrophin is a widely expressed cytoskeleton protein and is associated with lipid droplets (LDs) in adipocytes. The scaffold protein beta 2 syntrophin (SNTB2) controls signaling events by recruiting distinct membrane and cytoskeletal proteins, and binds to utrophin. Here we show that SNTB2 forms a complex with utrophin in adipocytes. SNTB2 protein is strongly diminished when utrophin is low. Of note, knock-down of utrophin or SNTB2 enhances LD growth during adipogenesis. SNTB2 reduction has no effect on basal and induced lipolysis, and insulin-stimulated phosphorylation of Akt is normal. The antilipolytic activity of insulin is enhanced in adipocytes with low SNTB2, while knock-down of utrophin has no effect. Uptake of exogenously supplied oleate and linoleate is comparable in scrambled and SNTB2 siRNA-treated cells. In the fibroblasts, diminished SNTB2 is associated with lower proliferation. CCAAT/enhancer-binding protein alpha and sterol regulatory element-binding proteins which are critical transcription factors for adipogenesis are normally expressed. Consequently, maturation of cells with SNTB2 knock-down is not grossly impaired. In fibroblasts, SNTB2 is localized to filamentous and vesicular structures which are distinct from beta actin, alpha tubulin, endoplasmic reticulum, early endosomes, lysosomes and mitochondria. Collectively, our data provide evidence that the utrophin-SNTB2 complex regulates LD size without affecting adipogenesis.
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Dietary fat-associated osteoarthritic chondrocytes gain resistance to lipotoxicity through PKCK2/STAMP2/FSP27. Bone Res 2018; 6:20. [PMID: 30002945 PMCID: PMC6033867 DOI: 10.1038/s41413-018-0020-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 12/18/2022] Open
Abstract
Free fatty acids (FFAs), which are elevated with metabolic syndrome, are considered the principal offender exerting lipotoxicity. Few previous studies have reported a causal relationship between FFAs and osteoarthritis pathogenesis. However, the molecular mechanism by which FFAs exert lipotoxicity and induce osteoarthritis remains largely unknown. We here observed that oleate at the usual clinical range does not exert lipotoxicity while oleate at high pathological ranges exerted lipotoxicity through apoptosis in articular chondrocytes. By investigating the differential effect of oleate at toxic and nontoxic concentrations, we revealed that lipid droplet (LD) accumulation confers articular chondrocytes, the resistance to lipotoxicity. Using high fat diet-induced osteoarthritis models and articular chondrocytes treated with oleate alone or oleate plus palmitate, we demonstrated that articular chondrocytes gain resistance to lipotoxicity through protein kinase casein kinase 2 (PKCK2)—six-transmembrane protein of prostate 2 (STAMP2)—and fat-specific protein 27 (FSP27)-mediated LD accumulation. We further observed that the exertion of FFAs-induced lipotoxicity was correlated with the increased concentration of cellular FFAs freed from LDs, whether FFAs are saturated or not. In conclusion, PKCK2/STAMP2/FSP27-mediated sequestration of FFAs in LD rescues osteoarthritic chondrocytes. PKCK2/STAMP2/FSP27 should be considered for interventions against metabolic OA. Cartilage tissue deals with the stress of exposure to free fatty acids by sequestering the toxic molecules into sub-cellular oil droplets. Young Hyun Yoo from Dong-A University College of Medicine in Busan, South Korea, and coworkers exposed rat cartilage cells to increasing levels of a fatty acid called oleate, a by-product of fat metabolism, and observed that the accumulation of oil droplets conferred resistance to oleate-induced toxicity. In these rat cells and in experiments involving mouse models of osteoarthritis fed a high-fat diet, the researchers then identified three of the protective proteins needed for cartilage tissue to properly quarantine fatty acids into oil droplets. Those proteins — and their connected regulatory networks — could now serve as drug targets for treating metabolic syndrome-associated osteoarthritis.
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