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Xu J, Guo Y, Huang X, Ma X, Li P, Wang Y, Wang X, Yuan L. Effects of DHA dietary intervention on hepatic lipid metabolism in apolipoprotein E-deficient and C57BL/6J wild-type mice. Biomed Pharmacother 2021; 144:112329. [PMID: 34653759 DOI: 10.1016/j.biopha.2021.112329] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/05/2021] [Accepted: 10/08/2021] [Indexed: 02/08/2023] Open
Abstract
Lipid metabolic disorder occurs when ApoE gene is deficient. However, the role of Docosahexaenoic acid (DHA) in relieving hepatic lipid metabolic disorder in apolipoprotein E-deficient (ApoE -/-) mice remains unknown. We fed 3-month-old C57BL/6J wild-type (C57 wt) and ApoE -/- mice respectively with normal or DHA fortified diet for 5 months. We found ApoE gene deficiency caused hepatic lipid deposition and increased lipid levels in plasma and liver. Hepatic gene expression of SRB1, CD36 and FABP5 in ApoE -/- mice, protein expression of HMGCR, LRP1 in C57 wt mice and protein expression of LRP1 in ApoE -/- mice increased after DHA intervention. In DHA-fed ApoE -/- mice, LXRα/β and PPARα protein expression down-regulated in cytoplasm, but LXRα/β protein expression up-regulated in nucleus. DHA treatment decreased RXRα and RXRβ expression in C57 wt and ApoE -/- female mice. Deletion of ApoE gene caused lipid metabolism disorder in liver of mice. DHA treatment efficiently meliorated lipid metabolism caused by ApoE deficient through the regulation of gene and protein expressions of molecules involved in liver fatty acids transport and lipid metabolism.
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Affiliation(s)
- Jingjing Xu
- School of Public Health, Capital Medical University, Beijing 100069, PR China
| | - Yujie Guo
- School of Public Health, Capital Medical University, Beijing 100069, PR China
| | - Xiaochen Huang
- School of Public Health, Capital Medical University, Beijing 100069, PR China
| | - Xiaojun Ma
- School of Public Health, Capital Medical University, Beijing 100069, PR China
| | - Pengfei Li
- School of Public Health, Capital Medical University, Beijing 100069, PR China
| | - Ying Wang
- The Affiliated Suzhou Science and Technology Town Hospital of Nanjing Medical University, Suzhou, Jiangsu 215153, PR China
| | - Xixiang Wang
- School of Public Health, Capital Medical University, Beijing 100069, PR China
| | - Linhong Yuan
- School of Public Health, Capital Medical University, Beijing 100069, PR China.
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2
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Egger AN, Rajabi‐Estarabadi A, Williams NM, Resnik SR, Fox JD, Wong LL, Jozic I. The importance of caveolins and caveolae to dermatology: Lessons from the caves and beyond. Exp Dermatol 2020; 29:136-148. [PMID: 31845391 PMCID: PMC7028117 DOI: 10.1111/exd.14068] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/25/2019] [Accepted: 11/28/2019] [Indexed: 12/15/2022]
Abstract
Caveolae are flask-shaped invaginations of the cell membrane rich in cholesterol and sphingomyelin, with caveolin proteins acting as their primary structural components that allow compartmentalization and orchestration of various signalling molecules. In this review, we discuss how pleiotropic functions of caveolin-1 (Cav1) and its intricate roles in numerous cellular functions including lipid trafficking, signalling, cell migration and proliferation, as well as cellular senescence, infection and inflammation, are integral for normal development and functioning of skin and its appendages. We then examine how disruption of the homeostatic levels of Cav1 can lead to development of various cutaneous pathophysiologies including skin cancers, cutaneous fibroses, psoriasis, alopecia, age-related changes in skin and aberrant wound healing and propose how levels of Cav1 may have theragnostic value in skin physiology/pathophysiology.
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Affiliation(s)
- Andjela N. Egger
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Ali Rajabi‐Estarabadi
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Natalie M. Williams
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Sydney R. Resnik
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Joshua D. Fox
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Lulu L. Wong
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Ivan Jozic
- Wound Healing and Regenerative Medicine Research ProgramDr. Phillip Frost Department of Dermatology and Cutaneous SurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
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Role of Caveolin-1 in Diabetes and Its Complications. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:9761539. [PMID: 32082483 PMCID: PMC7007939 DOI: 10.1155/2020/9761539] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 12/10/2019] [Accepted: 12/26/2019] [Indexed: 12/25/2022]
Abstract
It is estimated that in 2017 there were 451 million people with diabetes worldwide. These figures are expected to increase to 693 million by 2045; thus, innovative preventative programs and treatments are a necessity to fight this escalating pandemic disorder. Caveolin-1 (CAV1), an integral membrane protein, is the principal component of caveolae in membranes and is involved in multiple cellular functions such as endocytosis, cholesterol homeostasis, signal transduction, and mechanoprotection. Previous studies demonstrated that CAV1 is critical for insulin receptor-mediated signaling, insulin secretion, and potentially the development of insulin resistance. Here, we summarize the recent progress on the role of CAV1 in diabetes and diabetic complications.
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Kagawa Y, Umaru BA, Ariful I, Shil SK, Miyazaki H, Yamamoto Y, Ogata M, Owada Y. Role of FABP7 in tumor cell signaling. Adv Biol Regul 2019; 71:206-218. [PMID: 30245263 DOI: 10.1016/j.jbior.2018.09.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 09/13/2018] [Accepted: 09/13/2018] [Indexed: 06/08/2023]
Abstract
Lipids are major molecules for the function of organisms and are involved in the pathophysiology of various diseases. Fatty acids (FAs) signaling and their metabolism are some of the most important pathways in tumor development, as lipids serve as energetic sources during carcinogenesis. Fatty acid binding proteins (FABPs) facilitate FAs transport to different cell organelles, modulating their metabolism along with mediating other physiological activities. FABP7, brain-typed FABP, is thought to be an important molecule for cell proliferation in healthy as well as diseased organisms. Several studies on human tumors and tumor-derived cell lines put FABP7 in the center of tumorigenesis, and its high expression level has been reported to correlate with poor prognosis in different tumor types. Several types of FABP7-expressing tumors have shown an up-regulation of cell signaling activity, but molecular mechanisms of FABP7 involvement in tumorigenesis still remain elusive. In this review, we focus on the expression and function of FABP7 in different tumors, and possible mechanisms of FABP7 in tumor proliferation and migration.
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Affiliation(s)
- Yoshiteru Kagawa
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Banlanjo A Umaru
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Islam Ariful
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, Sendai, Japan; Department of Pharmacy, University of Rajshahi, Rajshahi, Bangladesh
| | - Subrata Kumar Shil
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Hirofumi Miyazaki
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Yui Yamamoto
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, Sendai, Japan; Department of Anatomy, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Masaki Ogata
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, Sendai, Japan; Department of Anatomy, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Yuji Owada
- Department of Organ Anatomy, Tohoku University Graduate School of Medicine, Sendai, Japan.
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Parthasarathi K. The Pulmonary Vascular Barrier: Insights into Structure, Function, and Regulatory Mechanisms. MOLECULAR AND FUNCTIONAL INSIGHTS INTO THE PULMONARY VASCULATURE 2018; 228:41-61. [DOI: 10.1007/978-3-319-68483-3_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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VLDL/LDL acts as a drug carrier and regulates the transport and metabolism of drugs in the body. Sci Rep 2017; 7:633. [PMID: 28377633 PMCID: PMC5428859 DOI: 10.1038/s41598-017-00685-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 03/08/2017] [Indexed: 01/01/2023] Open
Abstract
Only free drugs have been believed to be carried into tissues through active or passive transport. However, considering that lipoproteins function as carriers of serum lipids such as cholesterol and triglycerides, we hypothesized that lipoproteins can associate with certain drugs and mediate their transport into tissues in lipid-associated form. Here, in vitro and in vivo studies with low density lipoprotein receptor (LDLR)-overexpressing or -knockdown cells and wild-type or LDLR-mutant mice were used to show the association of various drugs with lipoproteins and the uptake of lipoprotein-associated drugs through a lipoprotein receptor-mediated process. In clinical studies, investigation of the effect of lipoprotein apheresis on serum drug concentrations in patients with familial hypercholesterolemia demonstrated that lipoprotein-mediated drug transport occurs in humans as well as in mice. These findings represent a new concept regarding the transport and metabolism of drugs in the body and suggest that the role of lipoprotein-mediated drug transport should be considered when developing effective and safe pharmacotherapies.
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Otis JP, Shen MC, Quinlivan V, Anderson JL, Farber SA. Intestinal epithelial cell caveolin 1 regulates fatty acid and lipoprotein cholesterol plasma levels. Dis Model Mech 2017; 10:283-295. [PMID: 28130355 PMCID: PMC5374320 DOI: 10.1242/dmm.027300] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 01/23/2017] [Indexed: 12/16/2022] Open
Abstract
Caveolae and their structural protein caveolin 1 (CAV1) have roles in cellular lipid processing and systemic lipid metabolism. Global deletion of CAV1 in mice results in insulin resistance and increases in atherogenic plasma lipids and cholesterol, but protects from diet-induced obesity and atherosclerosis. Despite the fundamental role of the intestinal epithelia in the regulation of dietary lipid processing and metabolism, the contributions of CAV1 to lipid metabolism in this tissue have never been directly investigated. In this study the cellular dynamics of intestinal Cav1 were visualized in zebrafish and the metabolic contributions of CAV1 were determined with mice lacking CAV1 in intestinal epithelial cells (CAV1IEC-KO). Live imaging of Cav1–GFP and fluorescently labeled caveolae cargos shows localization to the basolateral and lateral enterocyte plasma membrane (PM), suggesting Cav1 mediates transport between enterocytes and the submucosa. CAV1IEC-KO mice are protected from the elevation in circulating fasted low-density lipoprotein (LDL) cholesterol associated with a high-fat diet (HFD), but have increased postprandial LDL cholesterol, total free fatty acids (FFAs), palmitoleic acid, and palmitic acid. The increase in circulating FAs in HFD CAV1IEC-KO mice is mirrored by decreased hepatic FAs, suggesting a non-cell-autonomous role for intestinal epithelial cell CAV1 in promoting hepatic FA storage. In conclusion, CAV1 regulates circulating LDL cholesterol and several FA species via the basolateral PM of enterocytes. These results point to intestinal epithelial cell CAV1 as a potential therapeutic target to lower circulating FFAs and LDL cholesterol, as high levels are associated with development of type II diabetes and cardiovascular disease. Summary: Caveolin 1, which forms caveolae, localizes to the basolateral membrane of zebrafish intestinal epithelial cells and regulates circulating murine fatty acid and lipoprotein cholesterol levels.
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Affiliation(s)
- Jessica P Otis
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA
| | - Meng-Chieh Shen
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA
| | - Vanessa Quinlivan
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA.,Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA
| | - Jennifer L Anderson
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA
| | - Steven A Farber
- Carnegie Institution for Science, Department of Embryology, Baltimore, MD 21218, USA .,Johns Hopkins University, Department of Biology, Baltimore, MD 21218, USA
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Mo ZC, Ren K, Liu X, Tang ZL, Yi GH. A high-density lipoprotein-mediated drug delivery system. Adv Drug Deliv Rev 2016; 106:132-147. [PMID: 27208399 DOI: 10.1016/j.addr.2016.04.030] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 04/13/2016] [Accepted: 04/27/2016] [Indexed: 01/08/2023]
Abstract
High-density lipoprotein (HDL) is a comparatively dense and small lipoprotein that can carry lipids as a multifunctional aggregate in plasma. Several studies have shown that increasing the levels or improving the functionality of HDL is a promising target for treating a wide variety of diseases. Among lipoproteins, HDL particles possess unique physicochemical properties, including naturally synthesized physiological components, amphipathic apolipoproteins, lipid-loading and hydrophobic agent-incorporating characteristics, specific protein-protein interactions, heterogeneity, nanoparticles, and smaller size. Recently, the feasibility and superiority of using HDL particles as drug delivery vehicles have been of great interest. In this review, we summarize the structure, constituents, biogenesis, remodeling, and reconstitution of HDL drug delivery systems, focusing on their delivery capability, characteristics, applications, manufacturing, and drug-loading and drug-targeting characteristics. Finally, the future prospects are presented regarding the clinical application and challenges of using HDL as a pharmacodelivery carrier.
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Affiliation(s)
- Zhong-Cheng Mo
- Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang City 421001, Hunan Province, China; Department of Histology and Embryology, University of South China, Hengyang, Hunan 421001, China
| | - Kun Ren
- Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang City 421001, Hunan Province, China
| | - Xing Liu
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, 100005 Beijing, China
| | - Zhen-Li Tang
- Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang City 421001, Hunan Province, China
| | - Guang-Hui Yi
- Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, University of South China, Hengyang City 421001, Hunan Province, China.
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Caveolin-1 facilitates internalization and degradation of ABCA1 and probucol oxidative products interfere with this reaction to increase HDL biogenesis. Atherosclerosis 2016; 253:54-60. [PMID: 27579791 DOI: 10.1016/j.atherosclerosis.2016.08.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 08/01/2016] [Accepted: 08/23/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND AND AIMS Expression of ATP binding cassette transporter (ABC) A1, a key membrane protein for biogenesis of high-density lipoprotein (HDL), is regulated not only by its gene transcription but also by its intracellular degradation to modulate plasma HDL concentration. We previously showed that inhibition of ABCA1 degradation by probucol oxidative products, spiroquinone (SQ) and diphenoquinone (DQ), increased HDL biogenesis and reverse cholesterol transport, and achieved reduction of atherosclerosis in animal models. The background mechanism has thus been investigated. METHODS Involvement of caveolin-1, a protein of multiple functions in cell biology, particularly in cholesterol trafficking, has been examined for its roles in ABCA1 degradation as well as the effects of SQ and DQ on the reaction. RESULTS ABCA1 protein was increased in caveolin-1-deficient mouse embryonic fibroblasts, not by increase of transcription but by decrease in its internalization and degradation. Transfection and expression of caveolin-1 normalized the protein level and the rate of degradation of ABCA1. Immunoprecipitation experiments demonstrated association between ABCA1 and caveolin-1 and SQ and DQ disrupted this interaction. The effects of SQ and DQ to increase ABCA1 and cell cholesterol release induced by apolipoprotein A-I were dependent on expression of caveolin-1. Fluorescence imaging of ABCA1 and caveolin-1 in cultured cells demonstrated their co-localization as well as its disruption by SQ and DQ, being consistent with the biochemical findings. CONCLUSIONS Caveolin-1 enhances internalization and degradation of ABCA1 by its association with ABCA1. Interference of this interaction by probucol oxidative products suppresses ABCA1 degradation and increase HDL biogenesis.
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Chen YH, Lin WW, Liu CS, Hsu LS, Lin YM, Su SL. Caveolin-1 Expression Ameliorates Nephrotic Damage in a Rabbit Model of Cholesterol-Induced Hypercholesterolemia. PLoS One 2016; 11:e0154210. [PMID: 27124120 PMCID: PMC4849769 DOI: 10.1371/journal.pone.0154210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 04/10/2016] [Indexed: 01/14/2023] Open
Abstract
Caveolin-1 (CAV-1) participates in regulating vesicular transport, signal transduction, tumor progression, and cholesterol homeostasis. In the present study, we tested the hypothesis that CAV-1 improves dyslipidemia, inhibits cyclophilin A (CypA)- mediated ROS production, prevents mitochondrial compensatory action and attenuates oxidative stress responses in cholesterol-induced hypercholesterolemia. To determine the role of CAV-1 in mediating oxidative and antioxidative as well as cholesterol homeostasis, hypercholesterolemic rabbits were intravenously administered antenapedia-CAV-1 (AP-CAV-1) peptide for 2 wk. AP-CAV-1 enhanced CAV-1 expression by ˃15%, inhibited CypA expression by ˃50% (P < 0.05) and significantly improved dyslipidemia, thus reducing neutral lipid peroxidation. Moreover, CAV-1 attenuated hypercholesterolemia-induced changes in mitochondrial morphology and biogenesis and preserved mitochondrial respiratory function. In addition, CAV-1 protected against hypercholesterol-induced oxidative stress responses by reducing the degree of oxidative damage and enhancing the expression of antioxidant enzymes. CAV-1 treatment significantly suppressed apoptotic cell death, as evidenced by the reduction in the number of terminal deoxynucleotidyl transferase dUTP nick end-labeling-positive cells. We concluded that CAV-1 plays a critical role in inhibiting CypA-mediated ROS production, improving dyslipidemia, maintaining mitochondrial function, and suppressing oxidative stress responses that are vital for cell survival in hypercholesterol-affected renal organs.
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Affiliation(s)
- Ya-Hui Chen
- Vascular and Genomic Center, Changhua Christian Hospital, Changhua, Taiwan
- Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Wei-Wen Lin
- Department of Internal Medicine, Division of Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Chin-San Liu
- Vascular and Genomic Center, Changhua Christian Hospital, Changhua, Taiwan
- Graduate Institute of Integrative Medicine, China Medical University, Taichung, Taiwan
| | - Li-Sung Hsu
- Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Yueh-Min Lin
- Department of Pathology, Changhua Christian Hospital, Changhua, Taiwan
- Department of Medical Technology, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan
| | - Shih-Li Su
- Vascular and Genomic Center, Changhua Christian Hospital, Changhua, Taiwan
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Changhua Christian Hospital, Changhua, Taiwan
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
- * E-mail:
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Hebel T, Eisinger K, Neumeier M, Rein-Fischboeck L, Pohl R, Meier EM, Boettcher A, Froehner SC, Adams ME, Liebisch G, Krautbauer S, Buechler C. Lipid abnormalities in alpha/beta2-syntrophin null mice are independent from ABCA1. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:527-36. [PMID: 25625330 DOI: 10.1016/j.bbalip.2015.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 01/12/2015] [Accepted: 01/19/2015] [Indexed: 01/27/2023]
Abstract
The syntrophins alpha (SNTA) and beta 2 (SNTB2) are molecular adaptor proteins shown to stabilize ABCA1, an essential regulator of HDL cholesterol. Furthermore, SNTB2 is involved in glucose stimulated insulin release. Hyperglycemia and dyslipidemia are characteristic features of the metabolic syndrome, a serious public health problem with rising prevalence. Therefore, it is important to understand the role of the syntrophins herein. Mice deficient for both syntrophins (SNTA/B2-/-) have normal insulin and glucose tolerance, hepatic ABCA1 protein and cholesterol. When challenged with a HFD, wild type and SNTA/B2-/- mice have similar weight gain, adiposity, serum and liver triglycerides. Hepatic ABCA1, serum insulin and insulin sensitivity are normal while glucose tolerance is impaired. Liver cholesterol is reduced, and expression of SREBP2 and HMG-CoA-R is increased in the knockout mice. Scavenger receptor-BI (SR-BI) protein is strongly diminished in the liver of SNTA/B2-/- mice while SR-BI binding protein NHERF1 is not changed and PDZK1 is even induced. Knock-down of SNTA, SNTB2 or both has no effect on hepatocyte SR-BI and PDZK1 proteins. Further, SR-BI levels are not reduced in brown adipose tissue of SNTA/B2-/- mice excluding that syntrophins directly stabilize SR-BI. SR-BI stability is regulated by MAPK and phosphorylated ERK2 is induced in the liver of the knock-out mice. Blockage of ERK activity upregulates hepatocyte SR-BI showing that increased MAPK activity contributes to low SR-BI. Sphingomyelin which is well described to regulate cholesterol metabolism is reduced in the liver and serum of the knock-out mice while the size of serum lipoproteins is not affected. Current data exclude a major function of these syntrophins in ABCA1 activity and insulin release but suggest a role in regulating glucose uptake, ERK and SR-BI levels, and sphingomyelin metabolism in obesity.
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Affiliation(s)
- Tobias Hebel
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Kristina Eisinger
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Markus Neumeier
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Lisa Rein-Fischboeck
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Rebekka Pohl
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Elisabeth M Meier
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Alfred Boettcher
- Institute for Clinical Chemistry and Laboratory Medicine, Regensburg University Hospital, Regensburg, Germany
| | - Stanley C Froehner
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Marvin E Adams
- Department of Physiology and Biophysics, University of Washington, WA, USA
| | - Gerhard Liebisch
- Institute for Clinical Chemistry and Laboratory Medicine, Regensburg University Hospital, Regensburg, Germany
| | - Sabrina Krautbauer
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Christa Buechler
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany.
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12
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Kagawa Y, Yasumoto Y, Sharifi K, Ebrahimi M, Islam A, Miyazaki H, Yamamoto Y, Sawada T, Kishi H, Kobayashi S, Maekawa M, Yoshikawa T, Takaki E, Nakai A, Kogo H, Fujimoto T, Owada Y. Fatty acid-binding protein 7 regulates function of caveolae in astrocytes through expression of caveolin-1. Glia 2015; 63:780-94. [PMID: 25601031 DOI: 10.1002/glia.22784] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 12/16/2014] [Indexed: 12/28/2022]
Abstract
Fatty acid-binding proteins (FABPs) bind and solubilize long-chain fatty acids, controlling intracellular lipid dynamics. FABP7 is expressed by astrocytes in the developing brain, and suggested to be involved in the control of astrocyte lipid homeostasis. In this study, we sought to examine the role of FABP7 in astrocytes, focusing on plasma membrane lipid raft function, which is important for receptor-mediated signal transduction in response to extracellular stimuli. In FABP7-knockout (KO) astrocytes, the ligand-dependent accumulation of Toll-like receptor 4 (TLR4) and glial cell-line-derived neurotrophic factor receptor alpha 1 into lipid raft was decreased, and the activation of mitogen-activated protein kinases and nuclear factor-κB was impaired after lipopolysaccharide (LPS) stimulation when compared with wild-type astrocytes. In addition, the expression of caveolin-1, not cavin-1, 2, 3, caveolin-2, and flotillin-1, was found to be decreased at the protein and transcriptional levels. FABP7 re-expression in FABP7-KO astrocytes rescued the decreased level of caveolin-1. Furthermore, caveolin-1-transfection into FABP7-KO astrocytes significantly increased TLR4 recruitment into lipid raft and tumor necrosis factor-α production after LPS stimulation. Taken together, these data suggest that FABP7 controls lipid raft function through the regulation of caveolin-1 expression and is involved in the response of astrocytes to the external stimuli. GLIA 2015;63:780-794.
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Affiliation(s)
- Yoshiteru Kagawa
- Department of Organ Anatomy, Yamaguchi University Graduate School of Medicine, Ube, Japan
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13
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Astudillo AM, Pérez-Chacón G, Meana C, Balgoma D, Pol A, Del Pozo MA, Balboa MA, Balsinde J. Altered arachidonate distribution in macrophages from caveolin-1 null mice leading to reduced eicosanoid synthesis. J Biol Chem 2011; 286:35299-307. [PMID: 21852231 DOI: 10.1074/jbc.m111.277137] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
In this work we have studied the effect of caveolin-1 deficiency on the mechanisms that regulate free arachidonic acid (AA) availability. The results presented here demonstrate that macrophages from caveolin-1-deficient mice exhibit elevated fatty acid incorporation and remodeling and a constitutively increased CoA-independent transacylase activity. Mass spectrometry-based lipidomic analyses reveal stable alterations in the profile of AA distribution among phospholipids, manifested by reduced levels of AA in choline glycerophospholipids but elevated levels in ethanolamine glycerophospholipids and phosphatidylinositol. Furthermore, macrophages from caveolin-1 null mice show decreased AA mobilization and prostaglandin E(2) and LTB(4) production upon cell stimulation. Collectively, these results provide insight into the role of caveolin-1 in AA homeostasis and suggest an important role for this protein in the eicosanoid biosynthetic response.
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Affiliation(s)
- Alma M Astudillo
- Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas, 47003 Valladolid, Spain
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Scherer M, Böttcher A, Liebisch G. Lipid profiling of lipoproteins by electrospray ionization tandem mass spectrometry. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1811:918-24. [PMID: 21745591 DOI: 10.1016/j.bbalip.2011.06.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 05/30/2011] [Accepted: 06/14/2011] [Indexed: 10/18/2022]
Abstract
Lipoproteins are of fundamental importance for the lipid transport and cardiovascular disease. The function and metabolism of lipoproteins is intimately linked to the biophysical properties of their surface lipids. Although a number of disease associations were found for lipid species in plasma, only a few studies reported lipid profiles of lipoproteins. Here, we provide an overview of techniques for lipoprotein separation, methods for lipid species analysis based on electrospray ionization tandem mass spectrometry (ESI-MS/MS) as well as data from recent lipidomic studies on lipoprotein fractions. We also discuss the different analytical strategies and how lipid profiling can expand our understanding of the biology and structures of lipoproteins.
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Mattsson CL, Csikasz RI, Shabalina IG, Nedergaard J, Cannon B. Caveolin-1-ablated mice survive in cold by nonshivering thermogenesis despite desensitized adrenergic responsiveness. Am J Physiol Endocrinol Metab 2010; 299:E374-83. [PMID: 20530737 DOI: 10.1152/ajpendo.00071.2010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Caveolin-1 (Cav1)-ablated mice display impaired lipolysis in white adipose tissue. They also seem to have an impairment in brown adipose tissue function, implying that Cav1-ablated mice could encounter problems in surviving longer periods in cold temperatures. To investigate this, Cav1-ablated mice and wild-type mice were transferred to cold temperatures for extended periods of time, and parameters related to metabolism and thermogenesis were investigated. Unexpectedly, the Cav1-ablated mice survived in the cold. There were no differences between Cav1-ablated and wild-type mice with regard to food intake, in behavior related to shivering, or in body temperature. The Cav1-ablated mice had a halved total fat content independently of acclimation temperature. There was no difference in brown adipose tissue uncoupling protein-1 (UCP1) protein amount, and isolated brown fat mitochondria were thermogenically competent but displayed 30% higher thermogenic capacity. However, the beta(3)-adrenergic receptor amount was reduced by about one-third in the Cav1-ablated mice at all acclimation temperatures. Principally in accordance with this, a higher than standard dose of norepinephrine was needed to obtain full norepinephrine-induced thermogenesis in the Cav1-ablated mice; the higher dose was also needed for the Cav1-ablated mice to be able to utilize fat as a substrate for thermogenesis. In conclusion, the ablation of Cav1 impairs brown adipose tissue function by a desensitization of the adrenergic response; however, the desensitization is not evident in the animal as it is overcome physiologically, and Cav1-ablated mice can therefore survive in prolonged cold by nonshivering thermogenesis.
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Parker S, Baylis HA. Overexpression of caveolins in Caenorhabditis elegans induces changes in egg-laying and fecundity. Commun Integr Biol 2010; 2:382-4. [PMID: 19907693 DOI: 10.4161/cib.2.5.8715] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Accepted: 04/07/2009] [Indexed: 02/06/2023] Open
Abstract
Caveolae are small plasma membrane-associated invaginations that are enriched in proteins of the caveolin family in addition to, sphingolipids, glycosphingolipids and cholesterol. Caveolae have been implicated in several endocytic and trafficking mechanisms. Mutations in caveolins have been shown to cause disease and caveolae offer one site for pathogen entry. The Caenorhabditis elegans genome encodes two caveolins (cav-1 and cav-2); we have shown that these two proteins have distinct expression patterns. CAV-1 is found in the majority of cells in embryos and in the body-wall muscles, neurons and germ line of adult worms. CAV-2 is expressed in the intestine and is required for apical lipid trafficking. In the course of our studies, we generated several constructs to overexpress caveolins in C. elegans. Here we show that overexpression of cav-1 protects against the decrease in brood size associated with the effects of heat shock and the presence of extrachromosomal arrays in heat-shocked animals. Furthermore, we show that overexpression of cav-2 in the nervous system increases the rate of egg-laying and total number of eggs laid.
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Affiliation(s)
- Scott Parker
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
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Selective enrichment of phosphatidylcholines from food and biological matrices using metal oxides as solid-phase extraction materials prior to analysis by HPLC–ESI-MS/MS. Anal Bioanal Chem 2010; 396:2965-75. [DOI: 10.1007/s00216-010-3527-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 02/01/2010] [Accepted: 02/02/2010] [Indexed: 01/11/2023]
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18
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Parker S, Walker DS, Ly S, Baylis HA. Caveolin-2 is required for apical lipid trafficking and suppresses basolateral recycling defects in the intestine of Caenorhabditis elegans. Mol Biol Cell 2009; 20:1763-71. [PMID: 19158391 PMCID: PMC2655242 DOI: 10.1091/mbc.e08-08-0837] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 12/08/2008] [Accepted: 01/13/2009] [Indexed: 12/30/2022] Open
Abstract
Caveolins are plasma membrane-associated proteins that colocalize with, and stabilize caveolae. Their functions remain unclear although they are known to be involved in specific events in cell signaling and endocytosis. Caenorhabditis elegans encodes two caveolin genes, cav-1 and cav-2. We show that cav-2 is expressed in the intestine where it is localized to the apical membrane and in intracellular bodies. Using the styryl dye FM4-64 and BODIPY-labeled lactosylceramide, we show that the intestinal cells of cav-2 animals are defective in the apical uptake of lipid markers. These results suggest parallels with the function of caveolins in lipid homeostasis in mammals. We also show that CAV-2 depletion suppresses the abnormal accumulation of vacuoles that result from defective basolateral recycling in rme-1 and rab-10 mutants. Analysis of fluorescent markers of basolateral endocytosis and recycling suggest that endocytosis is normal in cav-2 mutants and thus, that the suppression of basolateral recycling defects in cav-2 mutants is due to changes in intracellular trafficking pathways. Finally, cav-2 mutants also have abnormal trafficking of yolk proteins. Taken together, these data indicate that caveolin-2 is an integral component of the trafficking network in the intestinal cells of C. elegans.
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Affiliation(s)
- Scott Parker
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom
| | - Denise S. Walker
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom
| | - Sung Ly
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom
| | - Howard A. Baylis
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom
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Le Lay S, Li Q, Proschogo N, Rodriguez M, Gunaratnam K, Cartland S, Rentero C, Jessup W, Mitchell T, Gaus K. Caveolin-1-dependent and -independent membrane domains. J Lipid Res 2008; 50:1609-20. [PMID: 19074371 PMCID: PMC2724060 DOI: 10.1194/jlr.m800601-jlr200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipid rafts defined as cholesterol- and sphingomyelin-rich domains have been isolated from different cell types that vary greatly in their lipid profiles. Here, we investigated the contribution of the structural protein caveolin-1 (Cav1) to the overall lipid composition and domain abundance in mouse embryonic fibroblasts (MEFs) from wild-type (WT) or Cav1-deficient (Cav1−/−) animals. Our findings show that Cav1 expression had no effect on free (membrane-associated) cholesterol levels. However, Cav1−/−-deficient cells did have a higher proportion of sphingomyelin, decreased abundance of unsaturated phospholipids, and a trend toward shorter fatty acid chains in phosphatidylcholine. We isolated detergent-resistant membranes (DRMs), nondetergent raft domains (NDR), and cholesterol oxidase (CO)-sensitive domains and assessed the abundance of ordered domains in intact cells using the fluorescent dye Laurdan. Despite differences in phospholipid composition, we found that cholesterol levels in DRMs, NDR, and CO-sensitive domains were similar in both cell types. The data suggest that Cav1 is not required to target cholesterol to lipid rafts and that CO does not specifically oxidize caveolar cholesterol. In contrast, the abundance of ordered domains in adherent cells is reduced in Cav1−/− compared with WT MEFs, suggesting that cell architecture is critical in maintaining Cav1-induced lipid rafts.
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Affiliation(s)
- Soazig Le Lay
- Centre de Recherche des Cordeliers, INSERM, U872, Université Pierre et Marie Curie, Paris 6, France
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