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Aytekin A, Yazir Y, Duruksu G, Öztürk A. Comparison of aquaporin profile of advanced passage mesenchymal stem cells with early passage mesenchymal stem cells and determination of its effect on adipogenic differentiation efficiency. Tissue Cell 2024; 89:102448. [PMID: 38917601 DOI: 10.1016/j.tice.2024.102448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/11/2024] [Accepted: 06/14/2024] [Indexed: 06/27/2024]
Abstract
OBJECTIVE Our study aimed to compare aquaporin profiles in advanced and early passage bone marrow-derived mesenchymal stem cells (BM-MSCs) and assess the impact of aquaporin changes after adipogenic differentiation. Aquaporins are crucial for stem cell survival and differentiation during their life cycle. We focused on the role of aquaporins in the cell structures of advanced and early passage stem cells. METHODS In our study, BM-MSCs were used for our objectives. Characterization of the cells was evaluated via flow cytometry using stem cell surface markers. The characterized BM-MSCs were divided into control and differentiation groups at passages 3 (P3) and 8 (P8). AQP1, AQP3, AQP7, AQP9, and AQP10 expression levels on days 0, 1, 3, 7, 14, and 21 were evaluated using Real Time-PCR, ELISA, and immunofluorescence studies. RESULTS The cells were characterized by flow cytometry and confirmed to exhibit BM-MSC characteristics. At P3 and P8, differentiation was initiated, and AQP protein expression was observed to initially increase and then decrease on subsequent days. The increase in AQP protein expression at P3 occurred earlier than that at P8. Gene expression analysis demonstrated a statistically significant increase in AQP gene expression on days when AQP protein expression decreased. Moreover, statistical differences were observed between late and early passage AQP profiles. CONCLUSION Our study examined the composition of AQPs in BM-MSCs in association with cell passage, and found that AQPs play a role in the differentiation process. The connection between the AQP profile and aging might be related to differentiation capacity, which could have implications for slowing down cellular aging and developing new therapeutic approaches.
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Affiliation(s)
- Ayşegül Aytekin
- Department of Histology and Embryology, Faculty of Medicine, Kocaeli University, Kocaeli, Turkey
| | - Yusufhan Yazir
- Department of Stem Cell, Institute of Health Sciences, Kocaeli University, Kocaeli, Turkey; Center for Stem Cell and Gene Therapies Research and Practice, Kocaeli University, Kocaeli, Turkey; Department of Histology and Embryology, Faculty of Medicine, Kocaeli University, Kocaeli, Turkey.
| | - Gökhan Duruksu
- Department of Stem Cell, Institute of Health Sciences, Kocaeli University, Kocaeli, Turkey; Center for Stem Cell and Gene Therapies Research and Practice, Kocaeli University, Kocaeli, Turkey
| | - Ahmet Öztürk
- Department of Stem Cell, Institute of Health Sciences, Kocaeli University, Kocaeli, Turkey; Center for Stem Cell and Gene Therapies Research and Practice, Kocaeli University, Kocaeli, Turkey; Department of Histology and Embryology, Faculty of Medicine, Kocaeli University, Kocaeli, Turkey
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Chakraborty S, Anand S, Bhandari RK. Medaka liver developed Human NAFLD-NASH transcriptional signatures in response to ancestral bisphenol A exposure. RESEARCH SQUARE 2024:rs.3.rs-4585175. [PMID: 39070641 PMCID: PMC11275980 DOI: 10.21203/rs.3.rs-4585175/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
The progression of fatty liver disease to non-alcoholic steatohepatitis (NASH) is a leading cause of death in humans. Lifestyles and environmental chemical exposures can increase the susceptibility of humans to NASH. In humans, the presence of bisphenol A (BPA) in urine is associated with fatty liver disease, but whether ancestral BPA exposure leads to the activation of human NAFLD-NASH-associated genes in the unexposed descendants is unclear. In this study, using medaka fish as an animal model for human NAFLD, we investigated the transcriptional signatures of human NAFLD-NASH and their associated roles in the pathogenesis of the liver of fish that were not directly exposed, but their ancestors were exposed to BPA during embryonic and perinatal development three generations prior. Comparison of bulk RNA-Seq data of the liver in BPA lineage male and female medaka with publicly available human NAFLD-NASH patient data revealed transgenerational alterations in the transcriptional signature of human NAFLD-NASH in medaka liver. Twenty percent of differentially expressed genes (DEGs) were upregulated in both human NAFLD patients and medaka. Specifically in females, among the total shared DEGs in the liver of BPA lineage fish and NAFLD patient groups, 27.69% were downregulated, and 20% were upregulated. Of all DEGs, 52.31% of DEGs were found in ancestral BPA-lineage females, suggesting that NAFLD in females shared the majority of human NAFLD gene networks. Pathway analysis revealed beta-oxidation, lipoprotein metabolism, and HDL/LDL-mediated transport processes linked to downregulated DEGs in BPA lineage males and females. In contrast, the expression of genes encoding lipogenesis-related proteins was significantly elevated in the liver of BPA lineage females only. BPA lineage females exhibiting activation of myc, atf4, xbp1, stat4, and cancerous pathways, as well as inactivation of igf1, suggest their possible association with an advanced NAFLD phenotype. The present results suggest that gene networks involved in the progression of human NAFLD and the transgenerational NAFLD in medaka are conserved and that medaka can be an excellent animal model to understand the development and progression of liver disease and environmental influences in the liver.
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Chakraborty S, Anand S, Bhandari RK. Sex-specific expression of the human NAFLD-NASH transcriptional signatures in the liver of medaka with a history of ancestral bisphenol A exposure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.19.594843. [PMID: 38826193 PMCID: PMC11142124 DOI: 10.1101/2024.05.19.594843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
The progression of fatty liver disease to non-alcoholic steatohepatitis (NASH) is a leading cause of death in humans. Lifestyles and environmental chemical exposures can increase the susceptibility of humans to NASH. In humans, the presence of bisphenol A (BPA) in urine is associated with fatty liver disease, but whether ancestral BPA exposure leads to the activation of human NAFLD-NASH-associated genes in the unexposed descendants is unclear. In this study, using medaka fish as an animal model for human NAFLD, we investigated the transcriptional signatures of human NAFLD-NASH and their associated roles in the pathogenesis of the liver of fish who were not directly exposed but their ancestors were exposed to BPA during embryonic and perinatal development three generations prior. Comparison of bulk RNA-Seq data of the liver in BPA lineage male and female medaka with publicly available human NAFLD-NASH patient data revealed transgenerational alterations in the transcriptional signature of human NAFLD-NASH in medaka liver. Twenty percent of differentially expressed genes (DEGs) were upregulated in both human NAFLD patients and medaka. Specifically in females, among the total shared DEGs in the liver of BPA lineage fish and NAFLD patient groups, 27.69% DEGs were downregulated and 20% DEGs were upregulated. Off all DEGs, 52.31% DEGs were found in ancestral BPA-lineage females, suggesting that NAFLD in females shared majority of human NAFLD gene networks. Pathway analysis revealed beta-oxidation, lipoprotein metabolism, and HDL/LDL-mediated transport processes linked to downregulated DEGs in BPA lineage males and females. In contrast, the expression of genes encoding lipogenesis-related proteins was significantly elevated in the liver of BPA lineage females only. BPA lineage females exhibiting activation of myc, atf4, xbp1, stat4, and cancerous pathways, as well as inactivation of igf1, suggest their possible association with an advanced NAFLD phenotype. The present results suggest that gene networks involved in the progression of human NAFLD and the transgenerational NAFLD in medaka are conserved and that medaka can be an excellent animal model to understand the development and progression of liver disease and environmental influences in the liver.
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Affiliation(s)
- Sourav Chakraborty
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211, U.S.A
| | - Santosh Anand
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211, U.S.A
| | - Ramji Kumar Bhandari
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211, U.S.A
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Moreto F, Garcia JL, Ferreira ALDA, Radrezza S, Costa MR, Romualdo GR, Grandini NA, Aldini G, Correa CR, D'Amato A. Quantitative proteomics study of carnosine effect in an animal model of Western diet-induced nonalcoholic fatty liver disease. J Biochem Mol Toxicol 2024; 38:e23644. [PMID: 38348714 DOI: 10.1002/jbt.23644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 12/20/2023] [Accepted: 01/09/2024] [Indexed: 02/15/2024]
Abstract
The nonalcoholic fatty liver disease (NAFLD), which is closely related to westernized dietary (WD) patterns, displays a rising epidemiological and economic burden. Since there is no pharmacological therapy approved for this disease, mechanistic studies are warranted. In this work, we investigated the action of carnosine (CAR), a natural dipeptide with several protection roles against oxidative stress in the liver of NAFLD rats. NAFLD was induced by WD-rich sugars and fat, verifying the histological evidence of steatosis. As intraperitoneal administration of CAR reversed liver steatosis, the protein profiles of NAFLD liver and CAR NAFLD liver were evaluated by label-free proteomics approach. A total of 2531 proteins were identified and the 230 and 276 were significantly up- and downregulated, respectively, by CAR treatment of NAFLD rats and involved in fundamental pathways such as oxidative stress and lipid metabolism. Perilipin 2 and apolipoprotein E, components of the plasma membrane of vesicle, resulted in highly downregulated in the CAR-treated NAFLD liver. The advanced bioanalytical approach demonstrated the efficacy of CAR in overcoming the main symptoms of NAFLD, ameliorating the steatosis in the liver.
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Affiliation(s)
- Fernando Moreto
- Medical School, Sao Paulo State University, Botucatu, Brazil
| | | | | | - Silvia Radrezza
- Molecular Cell Biology and Genetics Division, Max Planck Institute, Dresden, Germany
| | | | | | | | - Giancarlo Aldini
- Department of Pharmaceutical Sciences, University of Milan, Milan, Italy
| | | | - Alfonsina D'Amato
- Department of Pharmaceutical Sciences, University of Milan, Milan, Italy
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Doncheva AI, Li Y, Khanal P, Hjorth M, Kolset SO, Norheim FA, Kimmel AR, Dalen KT. Altered hepatic lipid droplet morphology and lipid metabolism in fasted Plin2-null mice. J Lipid Res 2023; 64:100461. [PMID: 37844775 PMCID: PMC10716011 DOI: 10.1016/j.jlr.2023.100461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 10/18/2023] Open
Abstract
Perilipin 2 (Plin2) binds to the surface of hepatic lipid droplets (LDs) with expression levels that correlate with triacylglyceride (TAG) content. We investigated if Plin2 is important for hepatic LD storage in fasted or high-fat diet-induced obese Plin2+/+ and Plin2-/- mice. Plin2-/- mice had comparable body weights, metabolic phenotype, glucose tolerance, and circulating TAG and total cholesterol levels compared with Plin2+/+ mice, regardless of the dietary regime. Both fasted and high-fat fed Plin2-/- mice stored reduced levels of hepatic TAG compared with Plin2+/+ mice. Fasted Plin2-/- mice stored fewer but larger hepatic LDs compared with Plin2+/+ mice. Detailed hepatic lipid analysis showed substantial reductions in accumulated TAG species in fasted Plin2-/- mice compared with Plin2+/+ mice, whereas cholesteryl esters and phosphatidylcholines were increased. RNA-Seq revealed minor differences in hepatic gene expression between fed Plin2+/+ and Plin2-/- mice, in contrast to marked differences in gene expression between fasted Plin2+/+ and Plin2-/- mice. Our findings demonstrate that Plin2 is required to regulate hepatic LD size and storage of neutral lipid species in the fasted state, while its role in obesity-induced steatosis is less clear.
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Affiliation(s)
- Atanaska I Doncheva
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Yuchuan Li
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Hepato-Pancreato-Biliary Surgery, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Prabhat Khanal
- Faculty of Biosciences and Aquaculture, Nord University, Steinkjer, Norway
| | - Marit Hjorth
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Svein O Kolset
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Frode A Norheim
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Alan R Kimmel
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, The National Institutes of Health, Bethesda, MD, USA
| | - Knut Tomas Dalen
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway; The Norwegian Transgenic Center, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
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Hu Y, Wang R, Liu J, Wang Y, Dong J. Lipid droplet deposition in the regenerating liver: A promoter, inhibitor, or bystander? Hepatol Commun 2023; 7:e0267. [PMID: 37708445 PMCID: PMC10503682 DOI: 10.1097/hc9.0000000000000267] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 07/29/2023] [Indexed: 09/16/2023] Open
Abstract
Liver regeneration (LR) is a complex process involving intricate networks of cellular connections, cytokines, and growth factors. During the early stages of LR, hepatocytes accumulate lipids, primarily triacylglycerol, and cholesterol esters, in the lipid droplets. Although it is widely accepted that this phenomenon contributes to LR, the impact of lipid droplet deposition on LR remains a matter of debate. Some studies have suggested that lipid droplet deposition has no effect or may even be detrimental to LR. This review article focuses on transient regeneration-associated steatosis and its relationship with the liver regenerative response.
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Affiliation(s)
- Yuelei Hu
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Ruilin Wang
- Department of Cadre’s Wards Ultrasound Diagnostics. Ultrasound Diagnostic Center, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Juan Liu
- Research Unit of Precision Hepatobiliary Surgery Paradigm, Chinese Academy of Medical Sciences, Beijing, China
- Hepatopancreatobiliary Center, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
- Institute for Organ Transplant and Bionic Medicine, Tsinghua University, Beijing, China
- Clinical Translational Science Center, Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, China
| | - Yunfang Wang
- Research Unit of Precision Hepatobiliary Surgery Paradigm, Chinese Academy of Medical Sciences, Beijing, China
- Hepatopancreatobiliary Center, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
- Institute for Organ Transplant and Bionic Medicine, Tsinghua University, Beijing, China
- Clinical Translational Science Center, Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, China
| | - Jiahong Dong
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Jilin University, Changchun, China
- Research Unit of Precision Hepatobiliary Surgery Paradigm, Chinese Academy of Medical Sciences, Beijing, China
- Hepatopancreatobiliary Center, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
- Institute for Organ Transplant and Bionic Medicine, Tsinghua University, Beijing, China
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7
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Wei X, Lin L, Yuan QQ, Wang XY, Zhang Q, Zhang XM, Tang KC, Guo MY, Dong TY, Han W, Huang DK, Qi YL, Zhang M, Zhang HB. Bavachin protects against diet-induced hepatic steatosis and obesity in mice. Acta Pharmacol Sin 2023; 44:1416-1428. [PMID: 36721007 PMCID: PMC10310714 DOI: 10.1038/s41401-023-01056-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 01/13/2023] [Indexed: 02/02/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a major health concern worldwide, and the incidence of metabolic disorders associated with NAFLD is rapidly increasing because of the obesity epidemic. There are currently no approved drugs that prevent or treat NAFLD. Recent evidence shows that bavachin, a flavonoid isolated from the seeds and fruits of Psoralea corylifolia L., increases the transcriptional activity of PPARγ and insulin sensitivity during preadipocyte differentiation, but the effect of bavachin on glucose and lipid metabolism remains unclear. In the current study we investigated the effects of bavachin on obesity-associated NAFLD in vivo and in vitro. In mouse primary hepatocytes and Huh7 cells, treatment with bavachin (20 μM) significantly suppressed PA/OA or high glucose/high insulin-induced increases in the expression of fatty acid synthesis-related genes and the number and size of lipid droplets. Furthermore, bavachin treatment markedly elevated the phosphorylation levels of AKT and GSK-3β, improving the insulin signaling activity in the cells. In HFD-induced obese mice, administration of bavachin (30 mg/kg, i.p. every other day for 8 weeks) efficiently attenuated the increases in body weight, liver weight, blood glucose, and liver and serum triglyceride contents. Moreover, bavachin administration significantly alleviated hepatic inflammation and ameliorated HFD-induced glucose intolerance and insulin resistance. We demonstrated that bavachin protected against HFD-induced obesity by inducing fat thermogenesis and browning subcutaneous white adipose tissue (subWAT). We revealed that bavachin repressed the expression of lipid synthesis genes in the liver of obese mice, while promoting the expression of thermogenesis, browning, and mitochondrial respiration-related genes in subWAT and brown adipose tissue (BAT) in the mice. In conclusion, bavachin attenuates hepatic steatosis and obesity by repressing de novo lipogenesis, inducing fat thermogenesis and browning subWAT, suggesting that bavachin is a potential drug for NAFLD therapy.
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Affiliation(s)
- Xiang Wei
- Department of Biochemistry and Molecular Biology, Metabolic Disease Research Center, School of Basic Medicine, Anhui Medical University, Hefei, 230032, China
- Department of Hyperbaric Oxygen, The Second People's Hospital of Hefei, Hefei Hospital Affiliated to Anhui Medical University, Hefei, 230011, China
| | - Li Lin
- Department of Biochemistry and Molecular Biology, Metabolic Disease Research Center, School of Basic Medicine, Anhui Medical University, Hefei, 230032, China
| | - Qian-Qian Yuan
- Department of Biochemistry and Molecular Biology, Metabolic Disease Research Center, School of Basic Medicine, Anhui Medical University, Hefei, 230032, China
| | - Xiu-Yun Wang
- Department of Biochemistry and Molecular Biology, Metabolic Disease Research Center, School of Basic Medicine, Anhui Medical University, Hefei, 230032, China
| | - Qing Zhang
- Department of Biochemistry and Molecular Biology, Metabolic Disease Research Center, School of Basic Medicine, Anhui Medical University, Hefei, 230032, China
| | - Xiao-Min Zhang
- Department of Biochemistry and Molecular Biology, Metabolic Disease Research Center, School of Basic Medicine, Anhui Medical University, Hefei, 230032, China
| | - Ke-Chao Tang
- Department of Biochemistry and Molecular Biology, Metabolic Disease Research Center, School of Basic Medicine, Anhui Medical University, Hefei, 230032, China
| | - Man-Yu Guo
- Department of Biochemistry and Molecular Biology, Metabolic Disease Research Center, School of Basic Medicine, Anhui Medical University, Hefei, 230032, China
| | - Ting-Yu Dong
- The Second Clinical Medical College of Anhui Medical University, Hefei, 230032, China
| | - Wei Han
- Department of Gastroenterology, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China
| | - Da-Ke Huang
- Synthetic Laboratory of School of Basic Medicine Sciences, Anhui Medical University, Hefei, 230032, China
| | - Yin-Liang Qi
- Department of Hyperbaric Oxygen, The Second People's Hospital of Hefei, Hefei Hospital Affiliated to Anhui Medical University, Hefei, 230011, China
| | - Mei Zhang
- Health Management Center, The First Affiliated Hospital of the University of Sciences and Technology of China (Anhui Provincial Hospital), Hefei, 230001, China.
| | - Hua-Bing Zhang
- Department of Biochemistry and Molecular Biology, Metabolic Disease Research Center, School of Basic Medicine, Anhui Medical University, Hefei, 230032, China.
- The Affiliated Chuzhou Hospital of Anhui Medical University (The First People's Hospital of Chuzhou), Chuzhou, 239001, China.
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Che L, Huang J, Lin JX, Xu CY, Wu XM, Du ZB, Wu JS, Lin ZN, Lin YC. Aflatoxin B1 exposure triggers hepatic lipotoxicity via p53 and perilipin 2 interaction-mediated mitochondria-lipid droplet contacts: An in vitro and in vivo assessment. JOURNAL OF HAZARDOUS MATERIALS 2023; 445:130584. [PMID: 37055989 DOI: 10.1016/j.jhazmat.2022.130584] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/17/2022] [Accepted: 12/07/2022] [Indexed: 06/19/2023]
Abstract
Aflatoxin B1 (AFB1) is one of the most toxic mycotoxins widely found in food contaminants, and its target organ is the liver. It poses a major food security and public health threat worldwide. However, the lipotoxicity mechanism of AFB1 exposure-induced liver injury remains unclear and requires further elucidation. Herein, we investigated the potential hepatic lipotoxicity of AFB1 exposure using in vitro and in vivo models to assess the public health hazards of high dietary AFB1 exposure. We demonstrated that low-dose of AFB1 (1.25 μM for 48 h, about one-fifth of the IC50 in HepG2 and HepaRG cells, IC50 are 5.995 μM and 5.266 μM, respectively) exposure significantly induced hepatic lipotoxicity, including abnormal lipid droplets (LDs) growth, mitochondria-LDs contacts increase, lipophagy disruption, and lipid accumulation. Mechanistically, we showed that AFB1 exposure promoted the mitochondrial p53 (mito-p53) and LDs-associated protein perilipin 2 (PLIN2) interaction-mediated mitochondria-LDs contacts, resulting in lipid accumulation in hepatocytes. Mito-p53-targeted inhibition, knockdown of PLIN2, and rapamycin application efficiently promoted the lysosome-dependent lipophagy and alleviated the hepatic lipotoxicity and liver injury induced by AFB1 exposure. Overall, our study found that mito-p53 and PLIN2 interaction mediates three organelles-mitochondria, LDs, and lysosomal networks to regulate lipid homeostasis in AFB1 exposure-induced hepatotoxicity, revealing how this unique trio of organelles works together and provides a novel insight into the targeted intervention in inter-organelle lipid sensing and trafficking for alleviating hazardous materials-induced hepatic lipotoxicity.
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Affiliation(s)
- Lin Che
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Jing Huang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Jin-Xian Lin
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Chi-Yu Xu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Xin-Mou Wu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Ze-Bang Du
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Jia-Shen Wu
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China
| | - Zhong-Ning Lin
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China.
| | - Yu-Chun Lin
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen 361102, China.
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Li H, Xu C, Meng F, Yao Z, Fan Z, Yang Y, Meng X, Zhan Y, Sun Y, Ma F, Yang J, Yang M, Yang J, Wu Z, Cai G, Zheng E. Genome-Wide Association Studies for Flesh Color and Intramuscular Fat in (Duroc × Landrace × Large White) Crossbred Commercial Pigs. Genes (Basel) 2022; 13:2131. [PMID: 36421806 PMCID: PMC9690869 DOI: 10.3390/genes13112131] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/12/2022] [Accepted: 11/12/2022] [Indexed: 07/30/2023] Open
Abstract
The intuitive impression of pork is extremely important in terms of whether consumers are enthusiastic about purchasing it. Flesh color and intramuscular fat (IMF) are indispensable indicators in meat quality assessment. In this study, we determined the flesh color and intramuscular fat at 45 min and 12 h after slaughter (45 mFC, 45 mIMF, 12 hFC, and 12 hIMF) of 1518 commercial Duroc × Landrace × Large White (DLY) pigs. We performed a single nucleotide polymorphism (SNP) genome-wide association study (GWAS) analysis with 28,066 SNPs. This experiment found that the correlation between 45 mFC and 12 hFC was 0.343. The correlation between 45 mIMF and 12 hIMF was 0.238. The heritability of the traits 45 mFC, 12 hFC, 45 mIMF, and 12 hIMF was 0.112, 0.217, 0.139, and 0.178, respectively, and we identified seven SNPs for flesh color and three SNPs for IMF. Finally, several candidate genes regulating these four traits were identified. Three candidate genes related to flesh color were provided: SNCAIP and PRR16 on SSC2, ST3GAL4 on SSC5, and GALR1 on SSC1. A total of three candidate genes related to intramuscular fat were found, including ABLIM3 on SSC2, DPH5 on SSC4, and DOCK10 on SSC15. Furthermore, GO and KEGG analysis revealed that these genes are involved in the regulation of apoptosis and are implicated in functions such as pigmentation and skeletal muscle metabolism. This study applied GWAS to analyze the scoring results of flesh color and IMF in different time periods, and it further revealed the genetic structure of flesh color and IMF traits, which may provide important genetic loci for the subsequent improvement of pig meat quality traits.
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Affiliation(s)
- Hao Li
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
- State Key Laboratory of Livestock and Poultry Breeding, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Cineng Xu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
| | - Fanming Meng
- State Key Laboratory of Livestock and Poultry Breeding, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Zekai Yao
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
- State Key Laboratory of Livestock and Poultry Breeding, Guangdong Key Laboratory of Animal Breeding and Nutrition, Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Zhenfei Fan
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
| | - Yingshan Yang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
| | - Xianglun Meng
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
| | - Yuexin Zhan
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
| | - Ying Sun
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
| | - Fucai Ma
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
| | - Jifei Yang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
| | - Ming Yang
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Jie Yang
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou 510642, China
| | - Zhenfang Wu
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou 510642, China
- Yunfu Subcenter of Guangdong Laboratory for Lingnan Modern Agriculture, Yunfu 527400, China
| | - Gengyuan Cai
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou 510642, China
| | - Enqin Zheng
- College of Animal Science and National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China
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10
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Perilipin 2 Protects against Lipotoxicity-Induced Islet Fibrosis by Inducing Islet Stellate Cell Activation Phenotype Changes. BIOMED RESEARCH INTERNATIONAL 2022; 2022:4581405. [PMID: 35845956 PMCID: PMC9279040 DOI: 10.1155/2022/4581405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 06/20/2022] [Indexed: 11/17/2022]
Abstract
Aims We explored whether and how perilipin 2 (Plin2) protected islets against lipotoxicity-induced islet dysfunction by regulating islet stellate cells (ISCs) activation. Methods Six-week-old male rats were given a high-fat diet or a control diet for 28 weeks. Glucose metabolic phenotypes were assessed using glucose/insulin tolerance tests, masson, and immunohistochemical staining. ISCs activation levels were assessed from rats and palmitic acid- (PA-) treated cultured ISCs by immunofluorescence, Oil red O staining, electron microscopy, quantitative PCR, and western blotting. Changes in ISCs phenotype of activation degree and its underlying mechanisms were assessed by target gene lentiviral infection, high-performance liquid chromatography (HPLC), and western blotting. Results Obese rats showed glucose intolerance, decreased endocrine hormone profiles, and elevated expression of α-smooth muscle actin (α-SMA), a polygonal appearance without cytoplasmic lipid droplets of ISCs in rats and isolated islets. PA-treated cultured ISCs exhibited faster proliferation and migration abilities with the induction of mRNA levels of lipid metabolism proteins, especially Plin2. The overexpression of Plin2 resulted in ISCs “re-quiescent” phenotypes associated with inhibition of the Smad3-TGF-β signaling pathways. Conclusions Our observations suggest a protective role of Plin2 in weakening ISCs activation. It may serve as a novel therapeutic target for preventing islet fibrosis for T2DM.
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11
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Preventive Effects of Ilex Cornuta Aqueous Extract on High-Fat Diet-Induced Fatty Liver of Mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:7183471. [PMID: 35432557 PMCID: PMC9010189 DOI: 10.1155/2022/7183471] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 03/09/2022] [Indexed: 12/26/2022]
Abstract
Objective To investigate the preventive effects of Ilex cornuta aqueous extract (ICAE) on high-fat diet (HFD)-induced fatty liver of mice and its mechanisms. Materials and Methods Twenty-six male KM (Kunming) mice were divided into 3 groups, including the control group (n = 9), fed with normal diet; HFD group (n = 9), fed with HFD; ICAE + HFD group (n = 8), fed with HFD and administered with ICAE (3 g·kg-1·d-1) at the same time for 10 weeks. Body weight, liver weight, intra-abdominal and subcutaneous fat weight, serum triglyceride (TG), total cholesterol (TC), and blood glucose were determined to evaluate the preventive effects of ICAE on obesity. The average 24 h food consumption of the mice was monitored for 5 times in the 9th week of the experiment to investigate the effects of ICAE on food intake. Serum alanine transaminase (ALT) and aspartate aminotransferase (AST) were assayed to observe the influences of HFD and ICAE on liver function. HE staining was adopted to observe the influence of ICAE on the morphology of adipose tissue and liver tissue. Hepatic TG and TC content assay and oil red O staining were used to evaluate the influences of ICAE on HFD-induced fatty liver, and the protein expression of peroxisome proliferator-activated receptors γ (PPARγ) and adipose differentiation-related protein (ADRP) in liver were examined by immunoblotting. Results ICAE treatment significantly reduced the increase of body weight, intra-abdominal, and subcutaneous fat and liver weight induced by HFD (P < 0.001), but has no influence on food intake; ICAE treatment attenuated the elevation of serum TG, TC, and glucose, as well as serum ALT and AST (P < 0.01, P < 0.05, P < 0.001) and dramatically decreased the content of TG in liver (P < 0.01), but has no influence on hepatic TC content. HE staining and oil red O staining showed that ICAE significantly reduced HFD-induced white adipocyte hypertrophy and significantly inhibited lipid accumulation in liver. Immunoblotting showed that the protein levels of PPARγ and ADRP were significantly increased by HFD induction, which can be dramatically reduced by ICAE treatment (P < 0.05, P < 0.0001). Conclusion ICAE has preventive effects on HFD-induced obesity and fatty liver in mice, exerted beneficial effects upon HFD-induced hepatic injury. The preventive effects of ICAE on fatty liver are concerned with the downregulation of PPARγ and ADRP protein expression in liver.
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12
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Antony R, Aby K, Gao H, Eichholz M, Srinivasan R, Li Y. UCHL1 Regulates Lipid and Perilipin 2 Level in Skeletal Muscle. Front Physiol 2022; 13:855193. [PMID: 35464088 PMCID: PMC9021748 DOI: 10.3389/fphys.2022.855193] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/21/2022] [Indexed: 11/14/2022] Open
Abstract
Ubiquitin C-terminal hydrolase L1 (UCHL1) is a deubiquitinating enzyme that was originally found in neurons. We found that UCHL1 is highly expressed in slow oxidative skeletal muscles, but its functions remain to be fully understood. In this study, we observed that UCHL1 protein levels in skeletal muscle and C2C12 myotubes were downregulated by fasting or glucose starvation respectively. Skeletal muscle selective knockout (smKO) of UCHL1 resulted in a significant reduction of lipid content in skeletal muscle and improved glucose tolerance. UCHL1 smKO did not significantly change the levels of key proteins involved in oxidative metabolism such as SDHA, Akt, or PDH. Interestingly, while the levels of the major lipases and lipid transporters were unchanged, perilipin 2 was significantly downregulated in UCHL1 smKO muscle. Consistently, in C2C12 myotubes, UCHL1 siRNA knockdown also reduced perilipin 2 protein level. This data suggests that UCHL1 may stabilize perilipin 2 and thus lipid storage in skeletal muscle.
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Affiliation(s)
| | | | | | | | | | - Yifan Li
- Division of Basic Biomedical Sciences, University of South Dakota Sanford School of Medicine, Vermillion, SD, United States
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13
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Amelioration of hepatic steatosis by dietary essential amino acid-induced ubiquitination. Mol Cell 2022; 82:1528-1542.e10. [PMID: 35245436 DOI: 10.1016/j.molcel.2022.01.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/14/2021] [Accepted: 01/25/2022] [Indexed: 12/30/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a global health concern with no approved drugs. High-protein dietary intervention is currently the most effective treatment. However, its underlying mechanism is unknown. Here, using Drosophila oenocytes, the specialized hepatocyte-like cells, we find that dietary essential amino acids ameliorate hepatic steatosis by inducing polyubiquitination of Plin2, a lipid droplet-stabilizing protein. Leucine and isoleucine, two branched-chain essential amino acids, strongly bind to and activate the E3 ubiquitin ligase Ubr1, targeting Plin2 for degradation. We further show that the amino acid-induced Ubr1 activity is necessary to prevent steatosis in mouse livers and cultured human hepatocytes, providing molecular insight into the anti-NAFLD effects of dietary protein/amino acids. Importantly, split-intein-mediated trans-splicing expression of constitutively active UBR2, an Ubr1 family member, significantly ameliorates obesity-induced and high fat diet-induced hepatic steatosis in mice. Together, our results highlight activation of Ubr1 family proteins as a promising strategy in NAFLD treatment.
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14
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Wang G, Li M, Yu S, Guan M, Ma S, Zhong Z, Guo Y, Leng X, Huang H. Tandem mass tag-based proteomics analysis of type 2 diabetes mellitus with non-alcoholic fatty liver disease in mice treated with acupuncture. Biosci Rep 2022; 42:BSR20212248. [PMID: 34981123 PMCID: PMC8762347 DOI: 10.1042/bsr20212248] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/01/2021] [Accepted: 12/23/2021] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE To explore the proteomics profiles of hepatocytes of mice treated with acupuncture for type 2 diabetes mellitus (T2DM) with non-alcoholic fatty liver disease (NAFLD). METHODS We used a Tandem mass tag (TMT)-based quantitative proteomics approach to identify proteins with potential molecular mechanisms associated with acupuncture interventions for T2DM with NAFLD. RESULTS Acupuncture effectively improved body weight, blood glucose, and insulin levels in T2DM with NAFLD mouse models and reversed steatosis within hepatocytes. Quantitative TMT-based proteomics analysis identified a total of 4710 quantifiable proteins and 1226 differentially expressed proteins (DEPs) in the model control group (MCG) compared with the normal control group (NCG). The Acupuncture Treatment Group (ATG) presented in 122 DEPs was compared with the MCG group. We performed a bioinformatics analysis, which revealed that DEPs enriched in the KEGG pathway after acupuncture treatment were mainly involved in the PPAR signaling pathway, fatty acid biosynthesis, fatty acid metabolism, fatty acid elongation, fat digestion and absorption. We used parallel reaction monitoring (PRM) technology to explore the association of aldehyde oxidase 1 (Aox1), acyl-coenzyme A thioesterase 2 (Acot2), perilipin-2 (Plin2), acetyl-CoA carboxylase 1 (Acc), NADP-dependent malic enzyme (Me1), fatty acid synthase (Fasn), ATP-citrate synthase (Acly), fatty acid-binding protein, intestinal (Fabp2) with lipid synthesis, fatty acid oxidation, and hepatocyte steatosis. CONCLUSIONS Our results show that acupuncture can regulate the protein expression of T2DM in the NAFLD mice model, and can effectively improve hepatocyte steatosis, and has potential benefits for the clinical treatment of this disease.
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Affiliation(s)
- Guan Wang
- College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun 130117, China
| | - Mengyuan Li
- College of Acupuncture and Massage, Changchun University of Chinese Medicine, Changchun, 130117, China
| | - Shuo Yu
- College of Acupuncture and Massage, Changchun University of Chinese Medicine, Changchun, 130117, China
| | - Mengqi Guan
- College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun 130117, China
| | - Shiqi Ma
- College of Acupuncture and Massage, Changchun University of Chinese Medicine, Changchun, 130117, China
| | - Zhen Zhong
- College of Acupuncture and Massage, Changchun University of Chinese Medicine, Changchun, 130117, China
| | - Yihui Guo
- College of Integrated Traditional Chinese and Western Medicine, Changchun University of Chinese Medicine, Changchun 130117, China
| | - Xiangyang Leng
- College of Traditional Chinese Medicine, Changchun University of Chinese Medicine, Changchun 130117, China
| | - Haipeng Huang
- College of Acupuncture and Massage, Changchun University of Chinese Medicine, Changchun, 130117, China
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15
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Chen Q, Fang W, Cui K, Chen Q, Xiang X, Zhang J, Zhang Y, Mai K, Ai Q. Endoplasmic reticulum stress induces hepatic steatosis by transcriptional upregulating lipid droplet protein perilipin2. FASEB J 2021; 35:e21900. [PMID: 34547130 DOI: 10.1096/fj.202100739rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 08/12/2021] [Accepted: 08/19/2021] [Indexed: 12/13/2022]
Abstract
Previous studies have shown that endoplasmic reticulum (ER) stress contributes to hepatic steatosis in several manners. However, how lipid droplet (LD) proteins participate in this process has rarely been reported. In the present study, ER stress was induced at both in vitro and in vivo levels with tunicamycin in large yellow croaker (Larimichthys crocea). Effects of LD protein perilipin2 (PLIN2) on hepatic lipid accumulation and lipoprotein transport under normal physiological condition and ER stress were then explored using dsRNA mediated knockdown. Subsequently, the transcriptional regulation of plin2 expression by transcription factors generated in the unfolded protein response (UPR) was determined by dual-luciferase reporter assays, chromatin immunoprecipitation and electrophoretic mobility-shift assay. We demonstrated that ER stress could promote LDs accumulation and inhibit lipoprotein transport by transcriptionally upregulating PLIN2 in liver. Among the transcription factors generated by UPR, spliced X-box binding protein1 can directly upregulated the expression of plin2, whereas C/EBP homologous protein can upregulate the expression of plin2 through peroxisome proliferator activated-receptor α. These results revealed that the LD protein PLIN2 played an important role in ER stress-induced hepatic steatosis, which might be a novel mechanism explaining hepatic steatosis triggered by ER stress.
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Affiliation(s)
- Qiuchi Chen
- Key laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture and Rural Affairs, and The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, People's Republic of China
| | - Wei Fang
- Key laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture and Rural Affairs, and The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, People's Republic of China
| | - Kun Cui
- Key laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture and Rural Affairs, and The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, People's Republic of China
| | - Qiang Chen
- Key laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture and Rural Affairs, and The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, People's Republic of China
| | - Xiaojun Xiang
- Key laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture and Rural Affairs, and The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, People's Republic of China
| | - Junzhi Zhang
- Key laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture and Rural Affairs, and The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, People's Republic of China
| | - Yunqiang Zhang
- Key laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture and Rural Affairs, and The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, People's Republic of China
| | - Kangsen Mai
- Key laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture and Rural Affairs, and The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, People's Republic of China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, People's Republic of China
| | - Qinghui Ai
- Key laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture and Rural Affairs, and The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, People's Republic of China.,Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, People's Republic of China
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16
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Serum Perilipin 2 (PLIN2) Predicts Multiple Organ Dysfunction in Critically Ill Patients. Biomedicines 2021; 9:biomedicines9091210. [PMID: 34572396 PMCID: PMC8468514 DOI: 10.3390/biomedicines9091210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/03/2021] [Accepted: 09/07/2021] [Indexed: 12/24/2022] Open
Abstract
Perilipin 2 (PLIN2) is a lipid droplet protein with various metabolic functions. However, studies investigating PLIN2 in the context of inflammation, especially in systemic and acute inflammation, are lacking. Hence, we assessed the relevance of serum PLIN2 in critically ill patients. We measured serum PLIN2 serum in 259 critically ill patients (166 with sepsis) upon admission to a medical intensive care unit (ICU) compared to 12 healthy controls. A subset of 36 patients underwent computed tomography to quantify body composition. Compared to controls, serum PLIN2 concentrations were elevated in critically ill patients at ICU admission. Interestingly, PLIN2 independently indicated multiple organ dysfunction (MOD), defined as a SOFA score > 9 points, at ICU admission, and was also able to independently predict MOD after 48 h. Moreover, serum PLIN2 levels were associated with severe respiratory failure potentially reflecting a moribund state. However, PLIN2 was neither a predictor of ICU mortality nor did it reflect metabolic dysregulation. Conclusively, the first study assessing serum PLIN2 in critical illness proved that it may assist in risk stratification because it is capable of independently indicating MOD at admission and predicting MOD 48 h after PLIN2 measurement. Further evaluation regarding the underlying mechanisms is warranted.
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17
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Conte M, Santoro A, Collura S, Martucci M, Battista G, Bazzocchi A, Morsiani C, Sevini F, Capri M, Monti D, Franceschi C, Salvioli S. Circulating perilipin 2 levels are associated with fat mass, inflammatory and metabolic markers and are higher in women than men. Aging (Albany NY) 2021; 13:7931-7942. [PMID: 33735111 PMCID: PMC8034884 DOI: 10.18632/aging.202840] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 03/04/2021] [Indexed: 02/06/2023]
Abstract
Perilipin 2 (PLIN2) is a protein involved in lipid storage and metabolism in non-adipose tissues. Detectable levels of circulating PLIN2 (cPLIN2) have been reported to be associated with some types of cancer, but no systematic analysis of age-related modifications in cPLIN2 levels has ever been performed. We measured serum cPLIN2 in a group of old people including centenarians in comparison with young subjects and tested possible correlations with parameters of body composition, fat and glucose metabolism, and inflammation. We found that: i. levels of cPLIN2 do not change with age, but women have higher levels of cPLIN2 with respect to men; ii. cPLIN2 levels strongly correlate to BMI, as well as fat and lean mass; iii. cPLIN2 levels strongly correlate with the proinflammatory adipokine leptin. Due to the adipogenic activity of leptin, it is hypothesized that cPLIN2 is affected and possibly regulated by this pleiotropic adipokine. Moreover, these results suggest that cPLIN2 (possibly together with leptin) could be assumed as a proxy for body adiposity.
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Affiliation(s)
- Maria Conte
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy.,Interdepartmental Center "Alma Mater Research Institute on Global Challenges and Climate Change (Alma Climate)", University of Bologna, Bologna, Italy
| | - Aurelia Santoro
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Salvatore Collura
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Morena Martucci
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Giuseppe Battista
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Alberto Bazzocchi
- Diagnostic and Interventional Radiology, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Cristina Morsiani
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Federica Sevini
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy
| | - Miriam Capri
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy.,Interdepartmental Center "Alma Mater Research Institute on Global Challenges and Climate Change (Alma Climate)", University of Bologna, Bologna, Italy
| | - Daniela Monti
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Claudio Franceschi
- Laboratory of Systems Medicine of Healthy Aging and Department of Applied Mathematics, Lobachevsky University, Nizhny Novgorod, Russia
| | - Stefano Salvioli
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy.,Interdepartmental Center "Alma Mater Research Institute on Global Challenges and Climate Change (Alma Climate)", University of Bologna, Bologna, Italy
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18
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Angelini G, Castagneto-Gissey L, Casella-Mariolo J, Caristo ME, Russo MF, Lembo E, Verrastro O, Stefanizzi G, Marini PL, Casella G, Bornstein SR, Rubino F, Mingrone G. Duodenal-jejunal bypass improves nonalcoholic fatty liver disease independently of weight loss in rodents with diet-induced obesity. Am J Physiol Gastrointest Liver Physiol 2020; 319:G502-G511. [PMID: 32812775 DOI: 10.1152/ajpgi.00357.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver-related mortality. NAFLD is associated with obesity, hepatic fat accumulation, and insulin resistance, all of which contribute to its pathophysiology. Weight-loss is the main therapy for NAFLD, and metabolic surgery is the most effective treatment for morbid obesity and its metabolic comorbidities. Although has been reported that Roux-en-Y gastric bypass can reverse NAFLD, it is unclear whether such effects result from reduced weight, from a lower calorie-intake, or from the direct influence of surgery on mechanisms contributing to NAFLD. We aimed to investigate whether gastrointestinal (GI) bypass surgery could induce direct effects on hepatic fat accumulation and insulin resistance, independently of weight reduction. Twenty Wistar rats on a high-fat diet underwent duodenal-jejunal-bypass (DJB) or sham operation and were pair fed (PF) for 15 wk after surgery to obtain a matched weight. Outcome measures include ectopic fat deposition, expression of genes and proteins involved in fat metabolism, insulin-signaling, and gluconeogenesis in liver and muscle. Despite no differences in body weight and calorie intake, DJB showed lower ectopic fat accumulation, improved peripheral and hepatic insulin sensitivity, and enhanced lipid droplet degradation. In both tissues, DJB increased insulin signaling, whereas hepatic key enzymes involved in gluconeogenesis and de novo lipogenesis were decreased. These findings suggest that DJB can reverse, independently of weight loss, ectopic fat deposition and insulin resistance, two features of NAFLD that share a mutual pathway, in which perilipin-2 (PLIN2) seems to be the main player, supporting further investigation into strategies that target the gut to treat metabolic liver diseases.NEW & NOTEWORTHY Our findings suggest that duodenal-jejunal bypass can reverse, independently of weight loss, ectopic fat deposition and insulin resistance, two features of nonalcoholic fatty liver disease that share a mutual pathway, in which perilipin-2 seems to be the main player. Our study supports further investigation into the role of proximal small intestine exclusion in the pathophysiology of nonalcoholic fatty liver disease to uncover less invasive treatments that mimic the effects of metabolic surgery and aims to prevent and treat metabolic liver disease.
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Affiliation(s)
- Giulia Angelini
- Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico, Università Cattolica del S. Cuore, Rome, Italy
| | | | | | - Maria Emiliana Caristo
- Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico, Università Cattolica del S. Cuore, Rome, Italy
| | - Maria Francesca Russo
- Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico, Università Cattolica del S. Cuore, Rome, Italy
| | - Erminia Lembo
- Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico, Università Cattolica del S. Cuore, Rome, Italy
| | - Ornella Verrastro
- Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico, Università Cattolica del S. Cuore, Rome, Italy
| | - Gianluigi Stefanizzi
- Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico, Università Cattolica del S. Cuore, Rome, Italy
| | - Pier Luigi Marini
- Department of Surgery, Azienda Ospedaliera S. Camillo Forlanini, Rome, Italy
| | - Giovanni Casella
- Department of Surgical Sciences, Sapienza University of Rome, Rome, Italy
| | - Stefan R Bornstein
- Department of Medicine III, Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Dresden, Germany.,Diabetes and Nutritional Sciences, King's College London, London, United Kingdom
| | - Francesco Rubino
- Diabetes and Nutritional Sciences, King's College London, London, United Kingdom
| | - Geltrude Mingrone
- Fondazione Policlinico Universitario A. Gemelli Istituto di Ricovero e Cura a Carattere Scientifico, Università Cattolica del S. Cuore, Rome, Italy.,Diabetes and Nutritional Sciences, King's College London, London, United Kingdom
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19
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Arumugam MK, Talawar S, Listenberger L, Donohue TM, Osna NA, Kharbanda KK. Role of Elevated Intracellular S-Adenosylhomocysteine in the Pathogenesis of Alcohol-Related Liver Disease. Cells 2020; 9:cells9061526. [PMID: 32585865 PMCID: PMC7349643 DOI: 10.3390/cells9061526] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/19/2020] [Accepted: 06/21/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The earliest manifestation of alcohol-related liver disease (ALD) is steatosis, characterized by the accumulation of lipid droplets (LDs) in hepatocytes. Findings from our laboratory have indicated that many pathological changes, including steatosis, correlate with the alcohol-induced hepatocellular increases in S-adenosylhomocysteine (SAH). Based on these considerations, we hypothesized that an experimental increase in intracellular SAH alone will result in similar steatotic changes to those seen after alcohol exposure. METHODS Freshly isolated rat hepatocytes grown on collagen-coated plates were exposed to serum-free medium containing 50 µmol/L oleic acid and varying concentrations of 3-deazaadenosine (DZA) to experimentally elevate intracellular SAH levels. RESULTS Overnight exposure to DZA treatment dose-dependently increased hepatocellular triglyceride accumulation, which was also evident by morphological visualization of larger-sized LDs. The rise in triglycerides and LDs accompanied increases in mRNA and protein levels of several LD-associated proteins known to regulate LD number and size. Furthermore, DZA treatment caused a decline in the levels of lipases that prevent fat accumulation as well as increased the expression of factors involved in lipogenesis and fatty acid mobilization. Collectively, our results indicate that the elevation of intracellular SAH is sufficient to promote fat accumulation in hepatocytes, which is similar to that seen after alcohol exposure.
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Affiliation(s)
- Madan Kumar Arumugam
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (M.K.A.); (S.T.); (T.M.D.J.); (N.A.O.)
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Sharanappa Talawar
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (M.K.A.); (S.T.); (T.M.D.J.); (N.A.O.)
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Laura Listenberger
- Departments of Biology and Chemistry, St. Olaf College, Northfield, MN 55057, USA;
| | - Terrence M. Donohue
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (M.K.A.); (S.T.); (T.M.D.J.); (N.A.O.)
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Natalia A. Osna
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (M.K.A.); (S.T.); (T.M.D.J.); (N.A.O.)
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Kusum K. Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE 68105, USA; (M.K.A.); (S.T.); (T.M.D.J.); (N.A.O.)
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
- Correspondence: ; Tel.: +1-402-995-3752; Fax: +1-402-995-4600
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20
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Kirpich IA, Warner DR, Feng W, Joshi-Barve S, McClain CJ, Seth D, Zhong W, Zhou Z, Osna NA, Kharbanda KK. Mechanisms, biomarkers and targets for therapy in alcohol-associated liver injury: From Genetics to nutrition: Summary of the ISBRA 2018 symposium. Alcohol 2020; 83:105-114. [PMID: 31129175 PMCID: PMC7043088 DOI: 10.1016/j.alcohol.2019.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/13/2019] [Accepted: 05/14/2019] [Indexed: 02/06/2023]
Abstract
The symposium "Mechanisms, Biomarkers and Targets for Therapy in Alcohol-associated Liver Injury: From Genetics to Nutrition" was held at the 19th Congress of International Society for Biomedical Research on Alcoholism on September 13th, 2018 in Kyoto, Japan. The goal of the symposium was to discuss the importance of genetics and nutrition in alcoholic liver disease (ALD) development from mechanistic and therapeutic perspectives. The following is a summary of this session addressing the gene polymorphisms in ALD, the role of zinc in gut-liver axis perturbations associated with ALD, highlighting the importance of dietary fat in ALD pathogenesis, the hepatic n6 and n3 PUFA oxylipin pattern associated with ethanol-induced liver injury, and finally deliberating on new biomarkers for alcoholic hepatitis and their implications for diagnosis and therapy. This summary of the symposium will benefit junior and senior faculty currently investigating alcohol-induced organ pathology as well as undergraduate, graduate, and post-graduate students and fellows.
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Affiliation(s)
- Irina A Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA; University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, USA; Robley Rex Veterans Medical Center, Louisville, KY, USA; Hepatobiology & Toxicology Program, University of Louisville, Louisville, KY, USA
| | - Dennis R Warner
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, USA
| | - Wenke Feng
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA; University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, USA; Hepatobiology & Toxicology Program, University of Louisville, Louisville, KY, USA
| | - Swati Joshi-Barve
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA; University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, USA; Hepatobiology & Toxicology Program, University of Louisville, Louisville, KY, USA
| | - Craig J McClain
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville, Louisville, KY, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA; University of Louisville Alcohol Center, University of Louisville School of Medicine, Louisville, KY, USA; Robley Rex Veterans Medical Center, Louisville, KY, USA; Hepatobiology & Toxicology Program, University of Louisville, Louisville, KY, USA
| | - Devanshi Seth
- Drug Health Services, Royal Prince Alfred Hospital, Camperdown, NSW, Australia, And Centenary Institute of Cancer Medicine and Cell Biology, The University of Sydney, Sydney, NSW, Australia
| | - Wei Zhong
- Center for Translational Biomedical Research, Department of Nutrition, University of North Carolina at Greensboro, Kannapolis, NC, 28081, USA
| | - Zhanxiang Zhou
- Center for Translational Biomedical Research, Department of Nutrition, University of North Carolina at Greensboro, Kannapolis, NC, 28081, USA
| | - Natalia A Osna
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - Kusum K Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry & Molecular Biology, University of Nebraska Medical Center, Omaha, NE, USA.
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21
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Choi K, Jin M, Zouboulis CC, Lee Y. Increased Lipid Accumulation under Hypoxia in SZ95 Human Sebocytes. Dermatology 2020; 237:131-141. [PMID: 32088721 DOI: 10.1159/000505537] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 12/19/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Excessive sebum is produced by specialized cells called sebocytes and is considered a cause or consequence of acne, sebaceous cysts, hyperplasia, and sebaceous adenoma. OBJECTIVE To report changes in lipid accumulation in human sebocytes under hypoxia, which occurs under conditions of seborrhea. METHODS Sebocytes from the immortalized human gland cell line SZ95 were cultured under conditions of hypoxia for 48 h; lipid formation was confirmed by Nile red and Oil Red O staining. To investigate whether HIF-1α plays a role in lipid accumulation, SZ95 cells transfected or treated with dimethyloxalylglycine (DMOG) were assessed by Nile red. For protein expression of the sterol regulatory element-binding protein-1 (SREBP-1) and perilipin 2 (PLIN2), Western blot analysis was performed. Differentially expressed genes (DEGs) in SZ95 sebocytes under hypoxia were revealed by RNA-Seq analyses, and the statistical significance of the correlation between hypoxic and acne/non-acne skin was evaluated using gene set enrichment analysis. RESULTS Hypoxia induces lipid accumulation in SZ95 sebocytes. In addition, the levels of SREBP-1 and PLIN2 were regulated by HIF-1α in SZ95 sebocytes under hypoxia. RNA-Seq analyses of DEGs in SZ95 sebocytes under hypoxia revealed 256 DEGs, including several lipid droplet-associated genes. DEGs between acne and non-acne skin are significantly enriched in hypoxia gene sets. We also detected 93 differentially expressed inflammatory mediators. CONCLUSIONS To the best of our knowledge, this study is the first to show that a hypoxic microenvironment can increase lipogenesis and provides a link between seborrhea and inflammation.
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Affiliation(s)
- KeunOh Choi
- Department of Bioscience and Biotechnology, Sejong University, Seoul, Republic of Korea
| | - Mirim Jin
- Department of Microbiology, College of Medicine, Gachon University, Incheon, Republic of Korea.,Department of Health Science and Technology, GAHIST, Gachon University, Incheon, Republic of Korea
| | - Christos C Zouboulis
- Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Brandenburg Medical School Theodor Fontane, Dessau, Germany
| | - YoungJoo Lee
- Department of Bioscience and Biotechnology, Sejong University, Seoul, Republic of Korea,
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Fan H, Diao H, Lu Y, Xie J, Cheng X. The relation between serum adipose differentiation-related protein and non-alcoholic fatty liver disease in type 2 diabetes mellitus. Ther Adv Endocrinol Metab 2020; 11:2042018820969025. [PMID: 33194172 PMCID: PMC7607795 DOI: 10.1177/2042018820969025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 10/06/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Adipose differentiation-related protein (ADRP) is an adipokine. In vitro and animal studies have verified the role of ADRP in lipid metabolism and non-alcoholic fatty liver disease (NAFLD). The aim of this study was to evaluate the interaction between levels of ADRP and NAFLD in type 2 diabetes mellitus (T2DM). METHODS Cross-sectional design. A total of 142 patients with T2DM were assigned to NAFLD (Group-I) and non-NAFLD (Group-II). Anthropometric data were collected. Serum ADRP levels and biochemical parameters were also determined. t test or χ2 test was conducted to compare the data between two groups. Receiver operating characteristic (ROC) curve analysis and logistic regression models were used to assess the interaction between ADRP levels and NAFLD in T2DM. Pearson correlation analysis and linear regression model were used to assess the correlations between serum ADRP levels and other parameters. RESULTS The serum ADRP level was higher in Group-I than in Group-II. Further, binary logistic regression models demonstrated that ADRP was an independent risk factor related to NAFLD in patients with T2DM. Moreover, as the ADRP level elevated across its tertiles, the percentage of NAFLD in T2DM increased. Multivariate logistic regression models demonstrated that the odds ratio of NAFLD was 8.831 in the highest tertile of ADRP, after adjustment for potential confounders. Area under THE ROC curve of ADRP for predicting the presence of NAFLD in T2DM was 0.738. Finally, multiple stepwise regression analysis indicated that age, waist circumference (WC), homeostasis model assessment of insulin resistance index (HOMA-IR) and triglyceride (TG) were independent factors associated with ADRP levels. CONCLUSION High serum ADRP level may be used as an independent risk factor for NAFLD in T2DM. The expression of ADRP may be affected by age, WC, HOMA-IR and TG.
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Affiliation(s)
- Huaying Fan
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Hongjie Diao
- XieTang Community Health Service Center, Suzhou, Jiangsu, China
| | | | | | - Xingbo Cheng
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
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23
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Bauer R, Tondl P, Schneider WJ. A differentiation program induced by bone morphogenetic proteins 4 and 7 in endodermal epithelial cells provides the molecular basis for efficient nutrient transport by the chicken yolk sac. Dev Dyn 2019; 249:222-236. [PMID: 31691430 PMCID: PMC7028021 DOI: 10.1002/dvdy.129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 10/17/2019] [Accepted: 10/29/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The mammalian yolk sac provides nutrients for the growing fetus during critical early developmental processes such as neural tube closure, which precedes the functional maturation of the placenta. In contrast, oviparous species such as the chicken rely solely on the yolk sac for transfer of nutrients from the yolk to the developing embryo. However, the molecular mechanisms that provide the yolk sac with nutrient transfer competence remain poorly understood. RESULTS We demonstrate that the chicken endodermal epithelial cells (EEC), which are in close contact with the yolk, gain their nutrient-transport competence by a paracrine crosstalk with the blood-vessel forming mesodermal cell layer. Bone morphogenetic proteins (BMP) 4 and 7 produced by ectodermal and mesodermal cell layers likely initiate a differentiation program of EECs during the transition from the area vitellina to the area vasculosa. BMPs, by inducing SMAD signaling, promote the up-regulation of endocytic receptor expression and thereby provide the EECs with the molecular machinery to produce triglyceride-rich lipoprotein particles. CONCLUSION This paracrine signaling cascade may constitute the basis for the EEC-mediated mechanism underlying the efficient uptake, degradation, resynthesis, and transfer of yolk-derived nutrients into the embryonic circulation, which assures proper energy supply and development of the growing fetus.
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Affiliation(s)
- Raimund Bauer
- Center for Pathobiochemistry and Genetics, Institute of Medical Chemistry, Medical University of Vienna, Vienna, Austria
| | - Philipp Tondl
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Wolfgang J Schneider
- Department of Medical Biochemistry, Max Perutz Labs, Medical University of Vienna, Vienna, Austria
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24
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Fu S, Meng Y, Lin S, Zhang W, He Y, Huang L, Du H. Transcriptomic responses of hypothalamus to acute exercise in type 2 diabetic Goto-Kakizaki rats. PeerJ 2019; 7:e7743. [PMID: 31579613 PMCID: PMC6764357 DOI: 10.7717/peerj.7743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/25/2019] [Indexed: 12/21/2022] Open
Abstract
The hypothalamus has an integral role in energy homeostasis regulation, and its dysfunctions lead to the development of type 2 diabetes (T2D). Physical activity positively affects the prevention and treatment of T2D. However, there is not much information on the adaptive mechanisms of the hypothalamus. In this study, RNA sequencing was used to determine how acute exercise affects hypothalamic transcriptome from both type 2 diabetic Goto-Kakizaki (GK) and control Wistar rats with or without a single session of running (15 m/min for 60 min). Through pairwise comparisons, we identified 957 differentially expressed genes (DEGs), of which 726, 197, and 98 genes were found between GK and Wistar, exercised GK and GK, and exercised Wistar and Wistar, respectively. The results of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment revealed that lipid metabolism-related terms and pathways were enriched in GK and exercised GK rats, and nervous system related terms and pathways were enriched in exercised GK and Wistar rats. Furthermore, 45 DEGs were associated with T2D and related phenotypes according to the annotations in the Rat Genome Database. Among these 45 DEGs, several genes (Plin2, Cd36, Lpl, Wfs1, Cck) related to lipid metabolism or the nervous system are associated with the exercise-induced benefits in the hypothalamus of GK rats. Our findings might assist in identifying potential therapeutic targets for T2D prevention and treatment.
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Affiliation(s)
- Shuying Fu
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Yuhuan Meng
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Shudai Lin
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Wenlu Zhang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Yuting He
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Lizhen Huang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
| | - Hongli Du
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, China
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26
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Cansby E, Kulkarni NM, Magnusson E, Kurhe Y, Amrutkar M, Nerstedt A, Ståhlman M, Sihlbom C, Marschall HU, Borén J, Blüher M, Mahlapuu M. Protein kinase MST3 modulates lipid homeostasis in hepatocytes and correlates with nonalcoholic steatohepatitis in humans. FASEB J 2019; 33:9974-9989. [PMID: 31173506 DOI: 10.1096/fj.201900356rr] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ectopic lipid storage in the liver is considered the main risk factor for nonalcoholic steatohepatitis (NASH). Understanding the molecular networks controlling hepatocellular lipid deposition is therefore essential for developing new strategies to effectively prevent and treat this complex disease. Here, we describe a new regulator of lipid partitioning in human hepatocytes: mammalian sterile 20-like (MST) 3. We found that MST3 protein coats lipid droplets in mouse and human liver cells. Knockdown of MST3 attenuated lipid accumulation in human hepatocytes by stimulating β-oxidation and triacylglycerol secretion while inhibiting fatty acid influx and lipid synthesis. We also observed that lipogenic gene expression and acetyl-coenzyme A carboxylase protein abundance were reduced in MST3-deficient hepatocytes, providing insight into the molecular mechanisms underlying the decreased lipid storage. Furthermore, MST3 expression was positively correlated with key features of NASH (i.e., hepatic lipid content, lobular inflammation, and hepatocellular ballooning) in human liver biopsies. In summary, our results reveal a role of MST3 in controlling the dynamic metabolic balance of liver lipid catabolism vs. lipid anabolism. Our findings highlight MST3 as a potential drug target for the prevention and treatment of NASH and related complex metabolic diseases.-Cansby, E., Kulkarni, N. M., Magnusson, E., Kurhe, Y., Amrutkar, M., Nerstedt, A., Ståhlman, M., Sihlbom, C., Marschall, H.-U., Borén, J., Blüher, M., Mahlapuu, M. Protein kinase MST3 modulates lipid homeostasis in hepatocytes and correlates with nonalcoholic steatohepatitis in humans.
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Affiliation(s)
- Emmelie Cansby
- Department of Chemistry and Molecular Biology, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Nagaraj M Kulkarni
- Department of Chemistry and Molecular Biology, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Elin Magnusson
- Department of Chemistry and Molecular Biology, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Yeshwant Kurhe
- Department of Chemistry and Molecular Biology, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Manoj Amrutkar
- Department of Hepato-Pancreato-Biliary Surgery, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Annika Nerstedt
- Department of Chemistry and Molecular Biology, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Marcus Ståhlman
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Carina Sihlbom
- Proteomics Core Facility, University of Gothenburg, Gothenburg, Sweden
| | - Hanns-Ulrich Marschall
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Jan Borén
- Department of Molecular and Clinical Medicine/Wallenberg Laboratory, Institute of Medicine, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Matthias Blüher
- Department of Medicine, University of Leipzig, Leipzig, Germany
| | - Margit Mahlapuu
- Department of Chemistry and Molecular Biology, University of Gothenburg and Sahlgrenska University Hospital, Gothenburg, Sweden
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Jin Y, Tan Y, Chen L, Liu Y, Ren Z. Reactive Oxygen Species Induces Lipid Droplet Accumulation in HepG2 Cells by Increasing Perilipin 2 Expression. Int J Mol Sci 2018; 19:ijms19113445. [PMID: 30400205 PMCID: PMC6274801 DOI: 10.3390/ijms19113445] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/16/2018] [Accepted: 10/29/2018] [Indexed: 12/20/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) has become the world's most common liver disease. The disease can develop liver fibrosis or even carcinomas from the initial hepatic steatosis, and this process is influenced by many factors. Reactive oxygen species (ROS), as potent oxidants in cells, have been reported previously to play an important role in the development of NAFLD progression via promoting neutral lipid accumulation. Here, we found that ROS can promote lipid droplet formation in hepatocytes by promoting perilipin2 (PLIN2) expression. First, we used different concentrations of hydrogen peroxide to treat HepG2 cells and found that the number of lipid droplets in the cells increased, however also that this effect was dose-independent. Then, the mRNA level of several lipid droplet-associated genes was detected with hydrogen peroxide treatment and the expression of PLIN2, PLIN5, and FSP27 genes was significantly up-regulated (p < 0.05). We overexpressed PLIN2 in HepG2 cells and found that the lipid droplets in the cells were markedly increased. Interference with PLIN2 inhibits ROS-induced lipid droplet formation, revealing that PLIN2 is a critical factor in this process. We subsequently analyzed the regulatory pathway and protein interaction network that is involved in PLIN2 and found that PLIN2 can regulate intracellular lipid metabolism through the PPARα/RXRA and CREB/CREBBP signaling pathways. The majority of the data indicated the correlation between hydrogen peroxide-induced PLIN2 and lipid droplet upregulation. In conclusion, ROS up-regulates the expression of PLIN2 in hepatocytes, whereas PLIN2 promotes the formation of lipid droplets resulting in lipid accumulation in liver tissues.
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Affiliation(s)
- Yi Jin
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science, Huazhong Agricultural University, Wuhan 430070, China.
| | - Yanjie Tan
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science, Huazhong Agricultural University, Wuhan 430070, China.
| | - Lupeng Chen
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science, Huazhong Agricultural University, Wuhan 430070, China.
| | - Yan Liu
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science, Huazhong Agricultural University, Wuhan 430070, China.
| | - Zhuqing Ren
- Key Laboratory of Agriculture Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science, Huazhong Agricultural University, Wuhan 430070, China.
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China.
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28
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Tuazon MA, Campbell SC, Klein DJ, Shapses SA, Anacker KR, Anthony TG, Uzumcu M, Henderson GC. Effects of ovariectomy and exercise training intensity on energy substrate and hepatic lipid metabolism, and spontaneous physical activity in mice. Metabolism 2018. [PMID: 29522773 DOI: 10.1016/j.metabol.2018.02.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Menopause is associated with fatty liver, glucose dysregulation, increased body fat, and impaired bone quality. Previously, it was demonstrated that single sessions of high-intensity interval exercise (HIIE) are more effective than distance- and duration-matched continuous exercise (CE) on altering hepatic triglyceride (TG) metabolism and very-low density lipoprotein-TG (VLDL-TG) secretion. METHODS Six weeks training using these modalities was examined for effects on hepatic TG metabolism/secretion, glucose tolerance, body composition, and bone mineral density (BMD) in ovariectomized (OVX) and sham-operated (SHAM) mice. OVX and SHAM were assigned to distance- and duration-matched CE and HIIE, or sedentary control. RESULTS Energy expenditure during exercise was confirmed to be identical between CE and HIIE and both similarly reduced post-exercise absolute carbohydrate oxidation and spontaneous physical activity (SPA). OVX vs. SHAM displayed impaired glucose tolerance and greater body fat despite lower hepatic TG, and these outcomes were not affected by training. Only HIIE increased hepatic AMPK in OVX and SHAM, but neither training type impacted VLDL-TG secretion. As expected, BMD was lower in OVX, and training did not affect long bones. CONCLUSIONS The results reveal intensity-dependent effects on hepatic AMPK expression and general exercise effects on subsequent SPA and substrate oxidation that is independent of estrogen status. These findings support the notion that HIIE can impact aspects of liver physiology in females while the effects of exercise on whole body substrate selection appear to be independent of training intensity. However, neither exercise approach mitigated the impairment in glucose tolerance and elevated body fat occurring in OVX mice.
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Affiliation(s)
- Marc A Tuazon
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ, United States; Center for Lipid Research, Rutgers University, New Brunswick, NJ, United States
| | - Sara C Campbell
- Department of Kinesiology and Health, Rutgers University, New Brunswick, NJ, United States; Center for Lipid Research, Rutgers University, New Brunswick, NJ, United States.
| | - Dylan J Klein
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ, United States
| | - Sue A Shapses
- Department of Kinesiology and Health, Rutgers University, New Brunswick, NJ, United States; Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ, United States
| | - Keith R Anacker
- Department of Kinesiology and Health, Rutgers University, New Brunswick, NJ, United States
| | - Tracy G Anthony
- Department of Nutritional Sciences, Rutgers University, New Brunswick, NJ, United States; Center for Lipid Research, Rutgers University, New Brunswick, NJ, United States
| | - Mehmet Uzumcu
- Department of Animal Sciences, Rutgers University, New Brunswick, NJ, United States
| | - Gregory C Henderson
- Department of Kinesiology and Health, Rutgers University, New Brunswick, NJ, United States; Center for Lipid Research, Rutgers University, New Brunswick, NJ, United States
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29
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Grasselli E, Canesi L, Portincasa P, Voci A, Vergani L, Demori I. Models of non-Alcoholic Fatty Liver Disease and Potential Translational Value: the Effects of 3,5-L-diiodothyronine. Ann Hepatol 2018; 16:707-719. [PMID: 28809727 DOI: 10.5604/01.3001.0010.2713] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder in industrialized countries and is associated with increased risk of cardiovascular, hepatic and metabolic diseases. Molecular mechanisms on the root of the disrupted lipid homeostasis in NAFLD and potential therapeutic strategies can benefit of in vivo and in vitro experimental models of fatty liver. Here, we describe the high fat diet (HFD)-fed rat in vivo model, and two in vitro models, the primary cultured rat fatty hepatocytes or the FaO rat hepatoma fatty cells, mimicking human NAFLD. Liver steatosis was invariably associated with increased number/size of lipid droplets (LDs) and modulation of expression of genes coding for key genes of lipid metabolism such as peroxisome proliferator-activated receptors (Ppars) and perilipins (Plins). In these models, we tested the anti-steatotic effects of 3,5-L-diiodothyronine (T2), a metabolite of thyroid hormones. T2 markedly reduced triglyceride content and LD size acting on mRNA expression of both Ppars and Plins. T2 also stimulated mitochondrial oxidative metabolism of fatty acids. We conclude that in vivo and especially in vitro models of NAFLD are valuable tools to screen a large number of compounds counteracting the deleterious effect of liver steatosis. Because of the high and negative impact of liver steatosis on human health, ongoing experimental studies from our group are unravelling the ultimate translational value of such cellular models of NAFLD.
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Affiliation(s)
- Elena Grasselli
- University of Genoa, Genoa, Italy Department of Earth, Environmental and Life Sciences-DISTAV
| | - Laura Canesi
- University of Genoa, Genoa, Italy Department of Earth, Environmental and Life Sciences-DISTAV
| | - Piero Portincasa
- University of Bari Medical School, Bari, Italy Department of Biomedical Sciences and Human Oncology Clinica Medica "A. Murri"
| | - Adriana Voci
- University of Genoa, Genoa, Italy Department of Earth, Environmental and Life Sciences-DISTAV
| | - Laura Vergani
- University of Genoa, Genoa, Italy Department of Earth, Environmental and Life Sciences-DISTAV
| | - Ilaria Demori
- University of Genoa, Genoa, Italy Department of Earth, Environmental and Life Sciences-DISTAV
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Feng YZ, Lund J, Li Y, Knabenes IK, Bakke SS, Kase ET, Lee YK, Kimmel AR, Thoresen GH, Rustan AC, Dalen KT. Loss of perilipin 2 in cultured myotubes enhances lipolysis and redirects the metabolic energy balance from glucose oxidation towards fatty acid oxidation. J Lipid Res 2017; 58:2147-2161. [PMID: 28822960 DOI: 10.1194/jlr.m079764] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Indexed: 02/07/2023] Open
Abstract
Lipid droplet (LD) coating proteins are essential for the formation and stability of intracellular LDs. Plin2 is an abundant LD coating protein in skeletal muscle, but its importance for muscle function is unclear. We show that myotubes established from Plin2-/- mice contain reduced content of LDs and accumulate less oleic acid (OA) in triacylglycerol (TAG) due to elevated LD hydrolysis in comparison with Plin2+/+ myotubes. The reduced ability to store TAG in LDs in Plin2-/- myotubes is accompanied by a shift in energy metabolism. Plin2-/- myotubes are characterized by increased oxidation of OA, lower glycogen synthesis, and reduced glucose oxidation in comparison with Plin2+/+ myotubes, perhaps reflecting competition between FAs and glucose as part of the Randle cycle. In accord with these metabolic changes, Plin2-/- myotubes have elevated expression of Ppara and Ppargc1a, transcription factors that stimulate expression of genes important for FA oxidation, whereas genes involved in glucose uptake and oxidation are suppressed. Loss of Plin2 had no impact on insulin-stimulated Akt phosphorylation. Our results suggest that Plin2 is essential for protecting the pool of skeletal muscle LDs to avoid an uncontrolled hydrolysis of stored TAG and to balance skeletal muscle energy metabolism.
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Affiliation(s)
- Yuan Z Feng
- Department of Pharmaceutical Biosciences, School of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Jenny Lund
- Department of Pharmaceutical Biosciences, School of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Yuchuan Li
- Department of Nutrition, University of Oslo, Oslo, Norway
| | - Irlin K Knabenes
- Department of Pharmaceutical Biosciences, School of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Siril S Bakke
- Department of Pharmaceutical Biosciences, School of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Eili T Kase
- Department of Pharmaceutical Biosciences, School of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Yun K Lee
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Alan R Kimmel
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - G Hege Thoresen
- Department of Pharmaceutical Biosciences, School of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway.,Department of Pharmacology, Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Arild Christian Rustan
- Department of Pharmaceutical Biosciences, School of Pharmacy, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Knut Tomas Dalen
- Department of Nutrition, University of Oslo, Oslo, Norway .,The Norwegian Transgenic Center, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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Kimmel AR, Sztalryd C. The Perilipins: Major Cytosolic Lipid Droplet-Associated Proteins and Their Roles in Cellular Lipid Storage, Mobilization, and Systemic Homeostasis. Annu Rev Nutr 2017; 36:471-509. [PMID: 27431369 DOI: 10.1146/annurev-nutr-071813-105410] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The discovery by Dr. Constantine Londos of perilipin 1, the major scaffold protein at the surface of cytosolic lipid droplets in adipocytes, marked a fundamental conceptual change in the understanding of lipolytic regulation. Focus then shifted from the enzymatic activation of lipases to substrate accessibility, mediated by perilipin-dependent protein sequestration and recruitment. Consequently, the lipid droplet became recognized as a unique, metabolically active cellular organelle and its surface as the active site for novel protein-protein interactions. A new area of investigation emerged, centered on lipid droplets' biology and their role in energy homeostasis. The perilipin family is of ancient origin and has expanded to include five mammalian genes and a growing list of evolutionarily conserved members. Universally, the perilipins modulate cellular lipid storage. This review provides a summary that connects the perilipins to both cellular and whole-body homeostasis.
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Affiliation(s)
- Alan R Kimmel
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, The National Institutes of Health, Bethesda, Maryland 20892;
| | - Carole Sztalryd
- The Geriatric Research Education and Clinical Center, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland 21201.,Division of Endocrinology, Department of Medicine, School of Medicine, University of Maryland, Baltimore, Maryland 21201;
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32
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New insight into inter-organ crosstalk contributing to the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Protein Cell 2017. [PMID: 28643267 PMCID: PMC5818366 DOI: 10.1007/s13238-017-0436-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver dysfunction and a significant global health problem with substantial rise in prevalence over the last decades. It is becoming increasingly clear that NALFD is not only predominantly a hepatic manifestation of metabolic syndrome, but also involves extra-hepatic organs and regulatory pathways. Therapeutic options are limited for the treatment of NAFLD. Accordingly, a better understanding of the pathogenesis of NAFLD is critical for gaining new insight into the regulatory network of NAFLD and for identifying new targets for the prevention and treatment of NAFLD. In this review, we emphasize on the current understanding of the inter-organ crosstalk between the liver and peripheral organs that contributing to the pathogenesis of NAFLD.
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Tsai TH, Chen E, Li L, Saha P, Lee HJ, Huang LS, Shelness GS, Chan L, Chang BHJ. The constitutive lipid droplet protein PLIN2 regulates autophagy in liver. Autophagy 2017; 13:1130-1144. [PMID: 28548876 DOI: 10.1080/15548627.2017.1319544] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Excess triglyceride (TG) accumulation in the liver underlies fatty liver disease, a highly prevalent ailment. TG occurs in the liver sequestered in lipid droplets, the major lipid storage organelle. Lipid droplets are home to the lipid droplet proteins, the most abundant of which are the perilipins (PLINs), encoded by 5 different genes, Plin1 to Plin5. Of the corresponding gene products, PLIN2 is the only constitutive and ubiquitously expressed lipid droplet protein that has been used as a protein marker for lipid droplets. We and others reported that plin2-/- mice have an ∼60% reduction in TG content, and are protected against fatty liver disease. Here we show that PLIN2 overexpression protects lipid droplets against macroautophagy/autophagy, whereas PLIN2 deficiency enhances autophagy and depletes hepatic TG. The enhanced autophagy in plin2-/- mice protects against severe ER stress-induced hepatosteatosis and hepatocyte apoptosis. In contrast, hepatic TG depletion resulting from other genetic and pharmacological manipulations has no effect on autophagy. Importantly, PLIN2 deficiency lowers cellular TG content in wild-type mouse embryonic fibroblasts (MEFs) via enhanced autophagy, but does not affect cellular TG content in atg7-/- MEFs that are devoid of autophagic function. Conversely, adenovirus-shAtg7-mediated hepatic Atg7 knockdown per se does not alter the hepatic TG level, suggesting a more complex regulation in vivo. In sum, PLIN2 guards its own house, the lipid droplet. PLIN2 overexpression protects against autophagy, and its downregulation stimulates TG catabolism via autophagy.
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Affiliation(s)
- Tsung-Huang Tsai
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA
| | - Elaine Chen
- b Molecular and Cellular Biology , Baylor College of Medicine , Houston , TX , USA
| | - Lan Li
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA
| | - Pradip Saha
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA.,b Molecular and Cellular Biology , Baylor College of Medicine , Houston , TX , USA
| | - Hsiao-Ju Lee
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA
| | - Li-Shin Huang
- c Department of Medicine , Columbia University , New York , NY , USA
| | - Gregory S Shelness
- d Department of Internal Medicine , Section on Molecular Medicine, Wake Forest School of Medicine , Winston-Salem , NC , USA
| | - Lawrence Chan
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA.,b Molecular and Cellular Biology , Baylor College of Medicine , Houston , TX , USA
| | - Benny Hung-Junn Chang
- a Departments of Medicine, Baylor College of Medicine , Houston , TX , USA.,b Molecular and Cellular Biology , Baylor College of Medicine , Houston , TX , USA
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Zhang J, Zamani M, Thiele C, Taher J, Amir Alipour M, Yao Z, Adeli K. AUP1 (Ancient Ubiquitous Protein 1) Is a Key Determinant of Hepatic Very-Low-Density Lipoprotein Assembly and Secretion. Arterioscler Thromb Vasc Biol 2017; 37:633-642. [PMID: 28183703 DOI: 10.1161/atvbaha.117.309000] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 01/23/2017] [Indexed: 12/14/2022]
Abstract
OBJECTIVE AUP1 (ancient ubiquitous protein 1) is an endoplasmic reticulum-associated protein that also localizes to the surface of lipid droplets (LDs), with dual role in protein quality control and LD regulation. Here, we investigated the role of AUP1 in hepatic lipid mobilization and demonstrate critical roles in intracellular biogenesis of apoB100 (apolipoprotein B-100), LD mobilization, and very-low-density lipoprotein (VLDL) assembly and secretion. APPROACH AND RESULTS: siRNA (short/small interfering RNA) knockdown of AUP1 significantly increased secretion of VLDL-sized apoB100-containing particles from HepG2 cells, correcting a key metabolic defect in these cells that normally do not secrete much VLDL. Secreted particles contained higher levels of metabolically labeled triglyceride, and AUP1-deficient cells displayed a larger average size of LDs, suggesting a role for AUP1 in lipid mobilization. Importantly, AUP1 was also found to directly interact with apoB100, and this interaction was enhanced with proteasomal inhibition. Knockdown of AUP1 reduced apoB100 ubiquitination, decreased intracellular degradation of newly synthesized apoB100, and enhanced extracellular apoB100 secretion. Interestingly, the stimulatory effect of AUP1 knockdown on VLDL assembly was reminiscent of the effect previously observed after MEK-ERK (mitogen-activated protein kinase kinase-extracellular signal-regulated kinase) inhibition; however, further studies indicated that the AUP1 effect was independent of MEK-ERK signaling. CONCLUSIONS In summary, our findings reveal an important role for AUP1 as a regulator of apoB100 stability, hepatic LD metabolism, and intracellular lipidation of VLDL particles. AUP1 may be a crucial factor in apoB100 quality control, determining the rate at which apoB100 is degraded or lipidated to enable VLDL particle assembly and secretion.
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Affiliation(s)
- Jing Zhang
- From the Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada (J.Z., M.Z., J.T., K.A.); Department of Biochemistry (M.Z., K.A.) and Department of Laboratory Medicine and Pathobiology (J.T., K.A.), University of Toronto, Ontario, Canada; Biochemistry and Cell Biology of Lipids Unit, LIMES Institute, University of Bonn, Germany (C.T.); and Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ontario, Canada (M.A.A., Z.Y.)
| | - Mostafa Zamani
- From the Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada (J.Z., M.Z., J.T., K.A.); Department of Biochemistry (M.Z., K.A.) and Department of Laboratory Medicine and Pathobiology (J.T., K.A.), University of Toronto, Ontario, Canada; Biochemistry and Cell Biology of Lipids Unit, LIMES Institute, University of Bonn, Germany (C.T.); and Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ontario, Canada (M.A.A., Z.Y.)
| | - Christoph Thiele
- From the Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada (J.Z., M.Z., J.T., K.A.); Department of Biochemistry (M.Z., K.A.) and Department of Laboratory Medicine and Pathobiology (J.T., K.A.), University of Toronto, Ontario, Canada; Biochemistry and Cell Biology of Lipids Unit, LIMES Institute, University of Bonn, Germany (C.T.); and Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ontario, Canada (M.A.A., Z.Y.)
| | - Jennifer Taher
- From the Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada (J.Z., M.Z., J.T., K.A.); Department of Biochemistry (M.Z., K.A.) and Department of Laboratory Medicine and Pathobiology (J.T., K.A.), University of Toronto, Ontario, Canada; Biochemistry and Cell Biology of Lipids Unit, LIMES Institute, University of Bonn, Germany (C.T.); and Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ontario, Canada (M.A.A., Z.Y.)
| | - Mohsen Amir Alipour
- From the Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada (J.Z., M.Z., J.T., K.A.); Department of Biochemistry (M.Z., K.A.) and Department of Laboratory Medicine and Pathobiology (J.T., K.A.), University of Toronto, Ontario, Canada; Biochemistry and Cell Biology of Lipids Unit, LIMES Institute, University of Bonn, Germany (C.T.); and Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ontario, Canada (M.A.A., Z.Y.)
| | - Zemin Yao
- From the Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada (J.Z., M.Z., J.T., K.A.); Department of Biochemistry (M.Z., K.A.) and Department of Laboratory Medicine and Pathobiology (J.T., K.A.), University of Toronto, Ontario, Canada; Biochemistry and Cell Biology of Lipids Unit, LIMES Institute, University of Bonn, Germany (C.T.); and Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ontario, Canada (M.A.A., Z.Y.)
| | - Khosrow Adeli
- From the Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada (J.Z., M.Z., J.T., K.A.); Department of Biochemistry (M.Z., K.A.) and Department of Laboratory Medicine and Pathobiology (J.T., K.A.), University of Toronto, Ontario, Canada; Biochemistry and Cell Biology of Lipids Unit, LIMES Institute, University of Bonn, Germany (C.T.); and Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ontario, Canada (M.A.A., Z.Y.).
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35
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Chen E, Tsai TH, Li L, Saha P, Chan L, Chang BHJ. PLIN2 is a Key Regulator of the Unfolded Protein Response and Endoplasmic Reticulum Stress Resolution in Pancreatic β Cells. Sci Rep 2017; 7:40855. [PMID: 28102311 PMCID: PMC5244387 DOI: 10.1038/srep40855] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/09/2016] [Indexed: 11/09/2022] Open
Abstract
Progressive pancreatic β cell failure underlies the transition of impaired glucose tolerance to overt diabetes; endoplasmic reticulum (ER) stress expedites β cell failure in this situation. ER stress can be elicited by lipotoxicity and an increased demand for insulin in diabetes. We previously reported that the lipid droplet protein perilipin 2 (PLIN2) modulates lipid homeostasis in the liver. Here, we show that PLIN2 modulates the unfolded protein response (UPR) and ER stress in pancreatic β cells. PLIN2 expression goes up when β cells are exposed to a lipid load or to chemical ER stress inducers. Downregulation of PLIN2 ameliorates the effects of fatty acid- and chemical-induced ER stress, whereas PLIN2 overexpression exacerbates them. Diabetic Akita mice, which carry a heterozygous C96Y Ins2 mutation, exhibit elevated PLIN2 expression and ER stress in their β cells. Genetic ablation of Plin2 in Akita mice leads to mitigation of ER stress, forestalling β cell apoptosis, partially restoring β cell mass, and ameliorating diabetes. Mechanistic experiments showed that PLIN2 downregulation is associated with enhanced autophagic flux and accelerated ER stress resolution. In sum, we have identified a crucial role for PLIN2 in modulating autophagy, ER stress resolution, and β cell apoptosis and survival.
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Affiliation(s)
- Elaine Chen
- Department of Molecular &Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Tsung Huang Tsai
- Department of Medicine, Division of Diabetes, Endocrinology &Metabolism, Diabetes Research Center, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Lan Li
- Department of Medicine, Division of Diabetes, Endocrinology &Metabolism, Diabetes Research Center, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Pradip Saha
- Department of Molecular &Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Lawrence Chan
- Department of Molecular &Cellular Biology, Baylor College of Medicine, Houston, TX, USA.,Department of Medicine, Division of Diabetes, Endocrinology &Metabolism, Diabetes Research Center, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
| | - Benny Hung-Junn Chang
- Department of Molecular &Cellular Biology, Baylor College of Medicine, Houston, TX, USA.,Department of Medicine, Division of Diabetes, Endocrinology &Metabolism, Diabetes Research Center, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
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36
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Conte M, Franceschi C, Sandri M, Salvioli S. Perilipin 2 and Age-Related Metabolic Diseases: A New Perspective. Trends Endocrinol Metab 2016; 27:893-903. [PMID: 27659144 DOI: 10.1016/j.tem.2016.09.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/01/2016] [Accepted: 09/01/2016] [Indexed: 12/20/2022]
Abstract
Perilipin 2 (Plin2), a protein associated with the metabolism of intracellular lipid droplets (LDs), has long been considered only for its role in lipid storage. However, the manipulation of its expression affects the severity of a variety of metabolic and age-related diseases, such as fatty liver, insulin resistance and type 2 diabetes (T2D), cardiovascular disease, atherosclerosis, sarcopenia, and cancer, suggesting that this protein may play a role in these pathological conditions. In particular, its downregulation in mice prevents or mitigates some of the above mentioned diseases. Conversely, in humans high levels of Plin2 are present in sarcopenia, hepatic steatosis, atherosclerosis, and some types of cancer. We propose that inhibition of Plin2 might be a strategy to counteract several metabolic and age-related diseases.
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Affiliation(s)
- Maria Conte
- Department of Experimental, Diagnostic, and Specialty Medicine (DIMES), University of Bologna, 40126 Bologna, Italy; Interdepartmental Centre 'L. Galvani' (CIG), University of Bologna, 40126 Bologna, Italy.
| | - Claudio Franceschi
- IRCCS, Institute of Neurological Sciences of Bologna, 40139 Bologna, Italy
| | - Marco Sandri
- Department of Biomedical Science, University of Padova, 35121 Padova, Italy; Venetian Institute of Molecular Medicine, 35129 Padova, Italy
| | - Stefano Salvioli
- Department of Experimental, Diagnostic, and Specialty Medicine (DIMES), University of Bologna, 40126 Bologna, Italy; Interdepartmental Centre 'L. Galvani' (CIG), University of Bologna, 40126 Bologna, Italy
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37
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Libby AE, Bales E, Orlicky DJ, McManaman JL. Perilipin-2 Deletion Impairs Hepatic Lipid Accumulation by Interfering with Sterol Regulatory Element-binding Protein (SREBP) Activation and Altering the Hepatic Lipidome. J Biol Chem 2016; 291:24231-24246. [PMID: 27679530 DOI: 10.1074/jbc.m116.759795] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Indexed: 12/16/2022] Open
Abstract
Perilipin-2 (PLIN2) is a constitutively associated cytoplasmic lipid droplet coat protein that has been implicated in fatty liver formation in non-alcoholic fatty liver disease. Mice with or without whole-body deletion of perilipin-2 (Plin2-null) were fed either Western or control diets for 30 weeks. Perilipin-2 deletion prevents obesity and insulin resistance in Western diet-fed mice and dramatically reduces hepatic triglyceride and cholesterol levels in mice fed Western or control diets. Gene and protein expression studies reveal that PLIN2 deletion suppressed SREBP-1 and SREBP-2 target genes involved in de novo lipogenesis and cholesterol biosynthetic pathways in livers of mice on either diet. GC-MS lipidomics demonstrate that this reduction correlated with profound alterations in the hepatic lipidome with significant reductions in both desaturation and elongation of hepatic neutral lipid species. To examine the possibility that lipidomic actions of PLIN2 deletion contribute to suppression of SREBP activation, we isolated endoplasmic reticulum membrane fractions from long-term Western diet-fed wild type (WT) and Plin2-null mice. Lipidomic analyses reveal that endoplasmic reticulum membranes from Plin2-null mice are markedly enriched in ω-3 and ω-6 long-chain polyunsaturated fatty acids, which others have shown inhibit SREBP activation and de novo lipogenesis. Our results identify PLIN2 as a determinant of global changes in the hepatic lipidome and suggest the hypothesis that these actions contribute to SREBP-regulated de novo lipogenesis involved in non-alcoholic fatty liver disease.
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Affiliation(s)
- Andrew E Libby
- From the Integrated Physiology Graduate Program.,Division of Reproductive Sciences, and
| | | | - David J Orlicky
- Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - James L McManaman
- From the Integrated Physiology Graduate Program, .,Division of Reproductive Sciences, and
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38
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Sentinelli F, Capoccia D, Incani M, Bertoccini L, Severino A, Pani MG, Manconi E, Cossu E, Leonetti F, Baroni MG. The perilipin 2 (PLIN2) gene Ser251Pro missense mutation is associated with reduced insulin secretion and increased insulin sensitivity in Italian obese subjects. Diabetes Metab Res Rev 2016; 32:550-6. [PMID: 26443937 DOI: 10.1002/dmrr.2751] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 09/07/2015] [Accepted: 10/05/2015] [Indexed: 01/23/2023]
Abstract
BACKGROUND Perilipin 2 (PLIN2), a member of the family of perilipin lipid droplets coating proteins, is very widely expressed. The Ser251Pro (rs35568725) missense mutation in exon 6 of PLIN2 gene was previously associated with increased lipid accumulation, decreased lipolysis and increased number of small lipid droplets per cell. Furthermore, the Pro251 mutation was associated with decreased plasma triglyceride and very low density lipoprotein concentrations in population studies. The aim of this study was to evaluate the effect of the Ser251Pro mutation of PLIN2 gene in a cohort with a higher predisposition to obesity-associated metabolic alterations, such as insulin resistance, decreased insulin-secretion, hyperglycaemia, and dyslipidaemia. METHODS A large cohort (N = 1692) of Italian obese subjects (mean body mass index = 41 kg/m(2) ) was genotyped for the Ser251Pro mutation. All participants underwent oral glucose tolerance tests (OGTT), with measurement of glucose and insulin levels. Indices of insulin resistance and of insulin secretion were also calculated. Clinical and biochemical parameters were collected for all participants. RESULTS We observed that insulin concentration was significantly reduced at 120 min after the administration of glucose in Pro251 allele carriers, whereas glucose levels were similar in Pro251 allele carriers and non-carriers throughout the OGTT. Furthermore, the CIR120 index of insulin secretion was significantly lower (P < 0.035) and the ISI index of insulin-sensitivity was significantly higher (P < 0.031) in carriers of the Pro251 allele. When we analysed men and women separately to test for gender-specific associations, we observed that in women insulin levels were significantly lower in Pro251 allele carriers compared with wild-type subjects throughout the whole OGTT. In men, we confirmed a significant reduction in insulin concentration only at 120 min after the OGTT. No significant differences between genotype groups regarding triglyceride levels and anyother clinical and metabolic parameters were observed. CONCLUSION We observed a strong significant association between the PLIN2 Pro251 mutation and lower insulin secretion associated with an increased insulin sensitivity. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Federica Sentinelli
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Danila Capoccia
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Michela Incani
- Endocrinology and Diabetes, Department of Medical Sciences, University of Cagliari, Cagliari, Italy
| | - Laura Bertoccini
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Anna Severino
- Institute of Cardiology, Catholic University, Rome, Italy
| | - Maria Grazia Pani
- Endocrinology and Diabetes, Department of Medical Sciences, University of Cagliari, Cagliari, Italy
| | - Ettore Manconi
- Endocrinology and Diabetes, Department of Medical Sciences, University of Cagliari, Cagliari, Italy
| | - Efisio Cossu
- Endocrinology and Diabetes, Department of Medical Sciences, University of Cagliari, Cagliari, Italy
| | - Frida Leonetti
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Marco G Baroni
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
- Endocrinology and Diabetes, Department of Medical Sciences, University of Cagliari, Cagliari, Italy
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Liu X, Yao Z. Chronic over-nutrition and dysregulation of GSK3 in diseases. Nutr Metab (Lond) 2016; 13:49. [PMID: 27493677 PMCID: PMC4972972 DOI: 10.1186/s12986-016-0108-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 07/21/2016] [Indexed: 12/16/2022] Open
Abstract
Loss of cellular response to hormonal regulation in maintaining metabolic homeostasis is common in the process of aging. Chronic over-nutrition may render cells insensitive to such a hormonal regulation owing to overstimulation of certain signaling pathways, thus accelerating aging and causing diseases. The glycogen synthase kinase 3 (GSK3) plays a pivotal role in relaying various extracellular and intracellular regulatory signals critical to cell growth, survival, regeneration, or death. The main signaling pathway regulating GSK3 activity through serine-phosphorylation is the phosphoinositide 3-kinase (PI3K)/phosphoinositide-dependent kinase-1 (PDK1)/Akt relay that catalyzes serine-phosphorylation and thus inactivation of GSK3. In addition, perilipin 2 (PLIN2) has recently been shown to regulate GSK3 activation through direct association with GSK3. This review summarizes current understanding on environmental and nutritional factors contributing to GSK3 regulation (or dysregulation) through the PI3K/PDK1/Akt/GSK3 axis, and highlights the newly discovered role that PLIN2 plays in regulating GSK3 activity and GSK3 downstream pathways.
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Affiliation(s)
- Xunxian Liu
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5 Canada
| | - Zemin Yao
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5 Canada
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40
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The histone deacetylase inhibiting drug Entinostat induces lipid accumulation in differentiated HepaRG cells. Sci Rep 2016; 6:28025. [PMID: 27320682 PMCID: PMC4913258 DOI: 10.1038/srep28025] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/19/2016] [Indexed: 12/19/2022] Open
Abstract
Dietary overload of toxic, free metabolic intermediates leads to disrupted insulin signalling and fatty liver disease. However, it was recently reported that this pathway might not be universal: depletion of histone deacetylase (HDAC) enhances insulin sensitivity alongside hepatic lipid accumulation in mice, but the mechanistic role of microscopic lipid structure in this effect remains unclear. Here we study the effect of Entinostat, a synthetic HDAC inhibitor undergoing clinical trials, on hepatic lipid metabolism in the paradigmatic HepaRG liver cell line. Specifically, we statistically quantify lipid droplet morphology at single cell level utilizing label-free microscopy, coherent anti-Stokes Raman scattering, supported by gene expression. We observe Entinostat efficiently rerouting carbohydrates and free-fatty acids into lipid droplets, upregulating lipid coat protein gene Plin4, and relocating droplets nearer to the nucleus. Our results demonstrate the power of Entinostat to promote lipid synthesis and storage, allowing reduced systemic sugar levels and sequestration of toxic metabolites within protected protein-coated droplets, suggesting a potential therapeutic strategy for diseases such as diabetes and metabolic syndrome.
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41
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Najt CP, Senthivinayagam S, Aljazi MB, Fader KA, Olenic SD, Brock JRL, Lydic TA, Jones AD, Atshaves BP. Liver-specific loss of Perilipin 2 alleviates diet-induced hepatic steatosis, inflammation, and fibrosis. Am J Physiol Gastrointest Liver Physiol 2016; 310:G726-38. [PMID: 26968211 PMCID: PMC4867327 DOI: 10.1152/ajpgi.00436.2015] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 03/08/2016] [Indexed: 01/31/2023]
Abstract
Hepatic inflammation and fibrosis are key elements in the pathogenesis of nonalcoholic steatohepatitis (NASH), a progressive liver disease initiated by excess hepatic lipid accumulation. Lipid droplet protein Perilipin 2 (Plin2) alleviates dietary-induced hepatic steatosis when globally ablated; however, its role in the progression of NASH remains unknown. To investigate this further, we challenged Plin2 liver-specific knockout mice (designated L-KO) and their respective wild-type (WT) controls with a methionine-choline-deficient (MCD) diet for 15 days to induce a NASH phenotype of increased hepatic triglyceride levels through impaired phosphatidylcholine (PC) synthesis and very-low-density lipoprotein (VLDL) secretion. Results on liver weights, body weights, fat tissue mass, and histology in WT and L-KO mice fed the MCD diet revealed signs of hepatic steatosis, fibrosis, and inflammation; however, these effects were blunted in L-KO mice. In addition, levels of PC and VLDL were unchanged, and hepatic steatosis was reduced in L-KO mice fed the MCD diet, due in part to an increase in remodeling of PE to PC via the enzyme phosphatidylethanolamine N-methyltransferase (PEMT). These mice also exhibited decreased hepatic expression of proinflammatory markers cyclooxygenase 2, IL-6, TNF-α, IL-1β, and reduced expression of endoplasmic reticulum (ER) stress proteins C/EBP homologous protein and cleaved caspase-1. Taken together, these results suggest that Plin2 liver-specific ablation alleviates diet-induced hepatic steatosis and inflammation via a PEMT-mediated mechanism that involves compensatory changes in proteins involved in phospholipid remodeling, inflammation, and ER stress that work to alleviate diet-induced NASH. Overall, these findings support a role for Plin2 as a target for NASH therapy.
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Affiliation(s)
- Charles P. Najt
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
| | | | - Mohammad B. Aljazi
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
| | - Kelly A. Fader
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
| | - Sandra D. Olenic
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
| | - Julienne R. L. Brock
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
| | - Todd A. Lydic
- 2Department of Physiology, Michigan State University, East Lansing, Michigan; and
| | - A. Daniel Jones
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan; ,3Department of Chemistry, Michigan State University, East Lansing, Michigan
| | - Barbara P. Atshaves
- 1Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan;
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Natural Functions of PLIN2 Mediating Wnt/LiCl Signaling and Glycogen Synthase Kinase 3 (GSK3)/GSK3 Substrate-Related Effects Are Modulated by Lipid. Mol Cell Biol 2015; 36:421-37. [PMID: 26598603 DOI: 10.1128/mcb.00510-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 10/02/2015] [Indexed: 12/28/2022] Open
Abstract
Belonging to the PLIN family, PLIN2 associates with lipid storage droplets (LSDs), but other functions of PLIN2 remain unclear. Here, we suggest that PLIN2 mediates Wnt signaling because PLIN2 small interfering RNA (siRNA) suppresses activation of Wnt/coreceptor pathways. The mediation in the Wnt/Frizzled pathway seems to occur from Dishevelleds to axin/glycogen synthase kinase 3(GSK3)/β-catenin complexes (AGβC) as Wnt decreases Dishevelled/PLIN2 but increases AGβC/PLIN2 associations. Augmenting cellular LSDs that affect PLIN2 associations with these proteins, oleic acid (OA) treatment inhibits Wnt-increased AGβC/PLIN2 associations and β-catenin T-cell factor signaling (β-CTS). Revealing that PLIN2 is a GSK3-associated protein, the study explored PLIN2-mediated effects on GSK3/GSK3 substrates. PLIN2 siRNA reduces inhibitory GSK3 levels and lithium chloride (LiCl)-upregulated β-catenin or CCAAT/enhancer binding protein α (c/EBPα) expression. OA treatment decreases LiCl-increased c/EBPα via PLIN2-c/EBPα dissociation. In addition to PLIN2 overexpression increasing β-CTS, PLIN2 depletion or overexpression drops or adds expression of GSK3 substrates, such as β-catenin, c/EBPα,c-Myc, cyclin D1, and insulin receptor substrate 1, and cell growth/survival. PLIN2 N or C terminus overexpression that is associated with higher levels of the substrates suggests that those substrates bind to specific regions of PLIN2. Mimicking the possible high lipid concentrations in cells in the human body under conditions of hyperlipidemia/obesity, OA-treated cells gain or reduce GSK3 substrate expression in parallel with a decrease (a Wnt-like effect) or increase in GSK3 activity, likely regulated by GSK3/PLIN2/GSK3 substrate associations.
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Carr RM, Ahima RS. Pathophysiology of lipid droplet proteins in liver diseases. Exp Cell Res 2015; 340:187-92. [PMID: 26515554 DOI: 10.1016/j.yexcr.2015.10.021] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 10/21/2015] [Accepted: 10/23/2015] [Indexed: 02/07/2023]
Abstract
Cytosolic lipid droplets (LDs) are present in most cell types, and consist of a core comprising neutral lipids, mainly triglycerides and sterol esters, surrounded by a monolayer of phospholipids. LDs are heterogeneous in their structure, chemical composition, and tissue distribution. LDs are coated by several proteins, including perilipins and other structural proteins, lipogenic enzymes, lipases and membrane-trafficking proteins. Five proteins of the perilipin (PLIN) family (PLIN1 (perilipin), PLIN2 (adipose differentiation-related protein), PLIN3 (tail-interacting protein of 47kDa), PLIN4 (S3-12), and PLIN5 (myocardial lipid droplet protein)), are associated with LD formation. More recently, the CIDE family of proteins, hypoxia-inducible protein 2 (HIG2), and patanin-like phospholipase domain-containing 3 (PNPLA3) have also gained attention in hepatic LD biology. Evidence suggests that LD proteins are involved in the pathophysiology of fatty liver diseases characterized by excessive lipid accumulation in hepatocytes. This review article will focus on how hepatic LDs and their associated proteins are involved in the pathogenesis of three chronic liver conditions: hepatitis C virus infection, non-alcoholic fatty liver disease, and alcoholic liver disease.
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Affiliation(s)
- Rotonya M Carr
- Department of Medicine, Gastroenterology and Hepatology Division, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Rexford S Ahima
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
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44
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Son SH, Goo YH, Choi M, Saha PK, Oka K, Chan LCB, Paul A. Enhanced atheroprotection and lesion remodelling by targeting the foam cell and increasing plasma cholesterol acceptors. Cardiovasc Res 2015; 109:294-304. [PMID: 26487692 DOI: 10.1093/cvr/cvv241] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 10/06/2015] [Indexed: 11/13/2022] Open
Abstract
AIMS Atherosclerosis development can be ameliorated by promoting reverse cholesterol transport (RCT) from arteries. The process involves cholesterol efflux from foam cells to extracellular acceptors such as apolipoprotein A-I (apoA-I) and high-density lipoprotein (HDL) that mediate transport to the liver. Perilipin-2 (PLIN2) is a lipid droplet (LD)-associated protein that in macrophages facilitates cholesterol storage and prevents efflux. We hypothesized that atheroprotection would be enhanced by concurrently targeting PLIN2 to increase the efflux capacity of foam cells and increasing plasma apoA-I and HDL. METHODS AND RESULTS PLIN2-knockout and wild-type mice lacking apolipoprotein E (PLIN2(-/-)/apoE(-/-) and PLIN2(+/+)/apoE(-/-)) were treated with a helper-dependent adenoviral vector encoding human apoA-I (HDAd-AI) or with control empty vector. Treatment with HDAd-AI increased hepatic apoA-I production, plasma apoA-I and HDL-cholesterol (HDL-C), and apoA-I deposition in lesions to a similar extent in PLIN2(-/-)/apoE(-/-) and PLIN2(+/+)/apoE(-/-) mice. However, atherosclerosis development at the aortic sinus was considerably lower in HDAd-AI-treated PLIN2(-/-)/apoE(-/-) mice. A more stable lesion phenotype, with increased collagen content, was primarily associated to treatment with HDAd-AI, but was enhanced under PLIN2 deficiency. PLIN2 deficiency and apoA-I cumulatively reduced LDs and cholesterol ester content in cultured macrophages. Neutral lipid in atheroma was significantly reduced in HDAd-AI-treated PLIN2(-/-)/apoE(-/-) mice, and RCT from macrophages to feces was enhanced in PLIN2(-/-) macrophages. CONCLUSION These studies demonstrate a mutually beneficial relationship between PLIN2 deficiency and elevated apoA-I/HDL-C in preventing atherosclerosis development. The data support that targeting foam cell components to mobilize cholesterol may be a promising strategy to enhance the atheroprotection of plasma cholesterol acceptors.
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Affiliation(s)
- Se-Hee Son
- Center for Cardiovascular Sciences, Albany Medical College, 47 New Scotland Avenue, MC-8, Albany, NY 12208, USA
| | - Young-Hwa Goo
- Center for Cardiovascular Sciences, Albany Medical College, 47 New Scotland Avenue, MC-8, Albany, NY 12208, USA
| | - Mihyun Choi
- Center for Cardiovascular Sciences, Albany Medical College, 47 New Scotland Avenue, MC-8, Albany, NY 12208, USA
| | - Pradip K Saha
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Kazuhiro Oka
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Lawrence C B Chan
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Antoni Paul
- Center for Cardiovascular Sciences, Albany Medical College, 47 New Scotland Avenue, MC-8, Albany, NY 12208, USA
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45
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Schneider WJ. Lipid transport to avian oocytes and to the developing embryo. J Biomed Res 2015; 30:174-80. [PMID: 26585559 PMCID: PMC4885163 DOI: 10.7555/jbr.30.20150048] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/12/2015] [Accepted: 07/03/2015] [Indexed: 11/25/2022] Open
Abstract
Studies of receptor-mediated lipoprotein metabolic pathways in avian species have revealed that physiological intricacies of specific cell types are highly analogous to those in mammals. A prime example for the power of comparative studies across different animal kingdoms, elucidated in the chicken, is that the expression of different lipoprotein receptors in somatic cells and oocytes are the key to oocyte growth. In avian species, yolk precursor transport from the hen's liver to rapidly growing oocytes and the subsequent transfer of yolk nutrients via the yolk sac to the developing embryo are highly efficient processes. Oocytes grow from a diameter of 5 mm to 2.5-3 cm in only 7 days, and the yolk sac transfers nutrients from the yolk stored in the mature oocyte to the embryo within just 2 weeks. The underlying key transport mechanism is receptor-mediated endocytosis of macromolecules, i.e., of hepatically synthesized yolk precursors for oocyte growth, and of mature yolk components for embryo nutrition, respectively. Recently, the receptors involved, as well as the role of lipoprotein synthesis in the yolk sac have been identified. As outlined here, lipoprotein degradation/resynthesis cycles and the expression of lipoprotein receptors are not only coordinated with the establishment of the follicular architecture embedding the oocyte, but also with the generation of the yolk sac vasculature essential for nutrient transfer to the embryo.
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Affiliation(s)
- Wolfgang J Schneider
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University and Biocenter Vienna, Austria.
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Microsomal Triglyceride Transfer Protein (MTP) Associates with Cytosolic Lipid Droplets in 3T3-L1 Adipocytes. PLoS One 2015; 10:e0135598. [PMID: 26267806 PMCID: PMC4534446 DOI: 10.1371/journal.pone.0135598] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 07/16/2015] [Indexed: 12/18/2022] Open
Abstract
Lipid droplets are intracellular energy storage organelles composed of a hydrophobic core of neutral lipid, surrounded by a monolayer of phospholipid and a diverse array of proteins. The function of the vast majority of these proteins with regard to the formation and/or turnover of lipid droplets is unknown. Our laboratory was the first to report that microsomal triglyceride transfer protein (MTP), a lipid transfer protein essential for the assembly of triglyceride-rich lipoproteins, was expressed in adipose tissue of humans and mice. In addition, our studies suggested that MTP was associated with lipid droplets in both brown and white fat. Our observations led us to hypothesize that MTP plays a key role in lipid droplet formation and/or turnover. The objective of these studies was to gain insight into the function of MTP in adipocytes. Using molecular, biochemical, and morphologic approaches we have shown: 1) MTP protein levels increase nearly five-fold as 3T3-L1 cells differentiate into adipocytes. 2) As 3T3-L1 cells undergo differentiation, MTP moves from the juxtanuclear region of the cell to the surface of lipid droplets. MTP and perilipin 2, a major lipid droplet surface protein, are found on the same droplets; however, MTP does not co-localize with perilipin 2. 3) Inhibition of MTP activity has no effect on the movement of triglyceride out of the cell either as a lipid complex or via lipolysis. 4) MTP is found associated with lipid droplets within hepatocytes from human fatty livers, suggesting that association of MTP with lipid droplets is not restricted to adipocytes. In summary, our data demonstrate that MTP is a lipid droplet-associated protein. Its location on the surface of the droplet in adipocytes and hepatocytes, coupled with its known function as a lipid transfer protein and its increased expression during adipocyte differentiation suggest a role in lipid droplet biology.
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47
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D'Andrea S. Lipid droplet mobilization: The different ways to loosen the purse strings. Biochimie 2015; 120:17-27. [PMID: 26187474 DOI: 10.1016/j.biochi.2015.07.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 07/11/2015] [Indexed: 01/25/2023]
Abstract
Cytosolic lipid droplets are dynamic lipid-storage organelles that play a crucial role as reservoirs of metabolic energy and membrane precursors. These organelles are present in virtually all cell types, from unicellular to pluricellular organisms. Despite similar structural organization, lipid droplets are heterogeneous in morphology, distribution and composition. The protein repertoire associated to lipid droplet controls the organelle dynamics. Distinct structural lipid droplet proteins are associated to specific lipolytic pathways. The role of these structural lipid droplet-associated proteins in the control of lipid droplet degradation and lipid store mobilization is discussed. The control of the strictly-regulated lipolysis in lipid-storing tissues is compared between mammals and plants. Differences in the cellular regulation of lipolysis between lipid-storing tissues and other cell types are also discussed.
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Affiliation(s)
- Sabine D'Andrea
- INRA, Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France; AgroParisTech, Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France.
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48
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Amrutkar M, Cansby E, Nuñez-Durán E, Pirazzi C, Ståhlman M, Stenfeldt E, Smith U, Borén J, Mahlapuu M. Protein kinase STK25 regulates hepatic lipid partitioning and progression of liver steatosis and NASH. FASEB J 2015; 29:1564-76. [PMID: 25609431 DOI: 10.1096/fj.14-264937] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/08/2014] [Indexed: 12/21/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common form of liver disease, and 10% to 20% of NAFLD patients progress to nonalcoholic steatohepatitis (NASH). The molecular pathways controlling progression to NAFLD/NASH remain poorly understood. We recently identified serine/threonine protein kinase 25 (STK25) as a regulator of whole-body insulin and glucose homeostasis. This study investigates the role of STK25 in liver lipid accumulation and NASH. Stk25 transgenic mice challenged with a high-fat diet displayed a dramatic increase in liver steatosis and hepatic insulin resistance compared to wild-type siblings. Focal fibrosis, hepatocellular damage, and inflammation were readily seen in transgenic but not wild-type livers. Transgenic livers displayed reduced β-oxidation and triacylglycerol secretion, while lipid uptake and synthesis remained unchanged. STK25 was associated with lipid droplets, colocalizing with the main hepatic lipid droplet-coating protein adipose differentiation-related protein, the level of which was increased 3.8 ± 0.7-fold in transgenic livers (P < 0.01), while a key hepatic lipase, adipose triacylglycerol lipase, was translocated from the lipid droplets surface to the cytoplasm, providing the likely mechanism underlying the effect of STK25. In summary, STK25 is a lipid droplet-associated protein that promotes NAFLD through control of lipid release from the droplets for β-oxidation and triacylglycerol secretion. STK25 also drives pathogenesis of NASH.
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Affiliation(s)
- Manoj Amrutkar
- *Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, and Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Emmelie Cansby
- *Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, and Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Esther Nuñez-Durán
- *Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, and Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Carlo Pirazzi
- *Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, and Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Marcus Ståhlman
- *Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, and Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Elin Stenfeldt
- *Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, and Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Ulf Smith
- *Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, and Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Jan Borén
- *Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, and Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Margit Mahlapuu
- *Lundberg Laboratory for Diabetes Research, Department of Molecular and Clinical Medicine, and Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
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Tuazon MA, McConnell TR, Wilson GJ, Anthony TG, Henderson GC. Intensity-dependent and sex-specific alterations in hepatic triglyceride metabolism in mice following acute exercise. J Appl Physiol (1985) 2015; 118:61-70. [PMID: 25257878 PMCID: PMC6195669 DOI: 10.1152/japplphysiol.00440.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 09/24/2014] [Indexed: 01/14/2023] Open
Abstract
Precise regulation of hepatic triglyceride (TG) metabolism and secretion is critical for health, and exercise could play a significant role. We compared one session of high-intensity interval exercise (HIIE) vs. continuous exercise (CE) on hepatic TG metabolism. Female and male mice were assigned to CE, HIIE, or sedentary control (CON). HIIE was a 30-min session of 30-s running intervals (30 m/min) interspersed with 60-s walking periods (5 m/min). CE was a distance- and duration-matched run at 13.8 m/min. Hepatic content of TG and TG secretion rates, as well as expression of relevant genes/proteins, were measured at 3 h (day 1) and 28 h (day 2) postexercise. On day 1, hepatic [TG] in CE and HIIE were both elevated vs. CON in both sexes with an approximately twofold greater elevation in HIIE vs. CE in females. In both sexes, hepatic perilipin 2 (PLIN2) protein on day 1 was increased significantly by both exercise types with a significantly greater increase with HIIE than CE, whereas the increase in mRNA reached significance only after HIIE. On day 2 in both sexes the increases in hepatic TG and PLIN2 with exercise declined toward CON levels. Only HIIE on day 2 resulted in reduced hepatic TG secretion by ∼20% in females with no effect in males. Neither exercise modality altered AMPK signaling or microsomal triglyceride transfer protein expression. Females exhibited higher hepatic TG secretion than males in association with different expression levels of related metabolic enzymes. These intensity-dependent and sex-specific alterations following exercise may have implications for sex-based exercise prescription.
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Affiliation(s)
- Marc A Tuazon
- Department of Exercise Science, Rutgers University, New Brunswick, New Jersey; Center for Lipid Research, Rutgers University, New Brunswick, New Jersey
| | - Taylor R McConnell
- Department of Exercise Science, Rutgers University, New Brunswick, New Jersey; Center for Lipid Research, Rutgers University, New Brunswick, New Jersey
| | - Gabriel J Wilson
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey; and Center for Lipid Research, Rutgers University, New Brunswick, New Jersey
| | - Tracy G Anthony
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey; and Center for Lipid Research, Rutgers University, New Brunswick, New Jersey
| | - Gregory C Henderson
- Department of Exercise Science, Rutgers University, New Brunswick, New Jersey; Center for Lipid Research, Rutgers University, New Brunswick, New Jersey
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50
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Najt CP, Lwande JS, McIntosh AL, Senthivinayagam S, Gupta S, Kuhn LA, Atshaves BP. Structural and functional assessment of perilipin 2 lipid binding domain(s). Biochemistry 2014; 53:7051-66. [PMID: 25338003 PMCID: PMC4238800 DOI: 10.1021/bi500918m] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/22/2014] [Indexed: 12/18/2022]
Abstract
Although perilipin 2 (Plin2) has been shown to bind lipids with high affinity, the Plin2 lipid binding site has yet to be defined. This is of interest since Plin2's affinity for lipids has been suggested to be important for lipid droplet biogenesis and intracellular triacylglycerol accumulation. To define these regions, mouse Plin2 and several deletion mutants expressed as recombinant proteins and in mammalian cells were assessed by molecular modeling, fluorescence binding, circular dichroic, and fluorescence resonance energy transfer techniques to identify the structural and functional requirements for lipid binding. Major findings of this study indicate (1) the N-terminal PAT domain does not bind cholesterol or stearic acid; (2) Plin2 residues 119-251, containing helix α4, the α-β domain, and part of helix α6 form a Plin3-like cleft found to be important for highest affinity lipid binding; (3) both stearic acid and cholesterol interact favorably with the Plin2 cleft formed by conserved residues in helix α6 and adjacent strands, which is common to all the active lipid-binding constructs; and (4) discrete targeting of the Plin2 mutants to lipid droplets supports Plin2 containing two independent, nonoverlapping lipid droplet targeting domains in its central and C-terminal sequences. Thus, the current work reveals specific domains responsible for Plin2-lipid interactions that involves the protein's lipid binding and targeting functions.
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Affiliation(s)
- Charles P. Najt
- Department
of Biochemistry and Molecular Biology and Department of Computer Science
and Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | - Joel S. Lwande
- Department
of Biochemistry and Molecular Biology and Department of Computer Science
and Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | - Avery L. McIntosh
- Physiology and Pharmacology, Texas A&M
University, TVMC College Station, Texas 77843-4466, United States
| | - Subramanian Senthivinayagam
- Department
of Biochemistry and Molecular Biology and Department of Computer Science
and Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | - Shipra Gupta
- Department
of Biochemistry and Molecular Biology and Department of Computer Science
and Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | - Leslie A. Kuhn
- Department
of Biochemistry and Molecular Biology and Department of Computer Science
and Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | - Barbara P. Atshaves
- Department
of Biochemistry and Molecular Biology and Department of Computer Science
and Engineering, Michigan State University, East Lansing, Michigan 48824, United States
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