1
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Ullah Khan S, Daniela Hernández-González K, Ali A, Shakeel Raza Rizvi S. Diabetes and the fabkin complex: A dual-edged sword. Biochem Pharmacol 2024; 223:116196. [PMID: 38588831 DOI: 10.1016/j.bcp.2024.116196] [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: 11/21/2023] [Revised: 03/27/2024] [Accepted: 04/05/2024] [Indexed: 04/10/2024]
Abstract
The Fabkin complex, composed of FABP4, ADK, and NDPKs, emerges as a novel regulator of insulin-producing beta cells, offering promising prospects for diabetes treatment. Our approach, which combines literature review and database analysis, sets the stage for future research. These findings hold significant implications for both diabetes treatment and research, as they present potential therapeutic targets for personalized treatment, leading to enhanced patient outcomes and a deeper comprehension of the disease. The multifaceted role of the Fabkin complex in glucose metabolism, insulin resistance, anti-inflammation, beta cell proliferation, and vascular function underscores its therapeutic potential, reshaping diabetes management and propelling advancements in the field.
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Affiliation(s)
- Safir Ullah Khan
- Department of Zoology, Wildlife & Fisheries, Faculty of sciences, Pir Mehr Ali Shah Arid Agriculture University, P.C. 46300, Rawalpindi, Pakistan
| | - Karla Daniela Hernández-González
- Facultad de Biología, Universidad Veracruzana, Circuito Gonzalo Aguirre Beltrán s/n, Zona Universitaria, C.P. 91000 Xalapa, Veracruz, México
| | - Amir Ali
- Nanoscience and Nanotechnology Program, Center for Research and Advanced Studies of the IPN, Mexico City, Mexico
| | - Syed Shakeel Raza Rizvi
- Department of Zoology, Wildlife & Fisheries, Faculty of sciences, Pir Mehr Ali Shah Arid Agriculture University, P.C. 46300, Rawalpindi, Pakistan.
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2
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Yu HC, Jeon YG, Na AY, Han CY, Lee MR, Yang JD, Yu HC, Son JB, Kim ND, Kim JB, Lee S, Bae EJ, Park BH. p21-activated kinase 4 counteracts PKA-dependent lipolysis by phosphorylating FABP4 and HSL. Nat Metab 2024; 6:94-112. [PMID: 38216738 DOI: 10.1038/s42255-023-00957-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 11/30/2023] [Indexed: 01/14/2024]
Abstract
Adipose tissue lipolysis is mediated by cAMP-protein kinase A (PKA)-dependent intracellular signalling. Here, we show that PKA targets p21-activated kinase 4 (PAK4), leading to its protein degradation. Adipose tissue-specific overexpression of PAK4 in mice attenuates lipolysis and exacerbates diet-induced obesity. Conversely, adipose tissue-specific knockout of Pak4 or the administration of a PAK4 inhibitor in mice ameliorates diet-induced obesity and insulin resistance while enhancing lipolysis. Pak4 knockout also increases energy expenditure and adipose tissue browning activity. Mechanistically, PAK4 directly phosphorylates fatty acid-binding protein 4 (FABP4) at T126 and hormone-sensitive lipase (HSL) at S565, impairing their interaction and thereby inhibiting lipolysis. Levels of PAK4 and the phosphorylation of FABP4-T126 and HSL-S565 are enhanced in the visceral fat of individuals with obesity compared to their lean counterparts. In summary, we have uncovered an important role for FABP4 phosphorylation in regulating adipose tissue lipolysis, and PAK4 inhibition may offer a therapeutic strategy for the treatment of obesity.
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Affiliation(s)
- Hwang Chan Yu
- Department of Biochemistry and Molecular Biology, Jeonbuk National University Medical School, Jeonju, Korea
| | - Yong Geun Jeon
- School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Ann-Yae Na
- School of Pharmacy, Sungkyunkwan University, Suwon, Korea
| | - Chang Yeob Han
- School of Pharmacy, Jeonbuk National University, Jeonju, Korea
| | - Mi Rin Lee
- Department of Surgery, Jeonbuk National University Hospital, Jeonju, Korea
| | - Jae Do Yang
- Department of Surgery, Jeonbuk National University Hospital, Jeonju, Korea
| | - Hee Chul Yu
- Department of Surgery, Jeonbuk National University Hospital, Jeonju, Korea
| | | | | | - Jae Bum Kim
- School of Biological Sciences, Seoul National University, Seoul, Korea
| | - Sangkyu Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, Korea.
| | - Eun Ju Bae
- School of Pharmacy, Jeonbuk National University, Jeonju, Korea.
| | - Byung-Hyun Park
- Department of Biochemistry and Molecular Biology, Jeonbuk National University Medical School, Jeonju, Korea.
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3
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Baru A, Devi C, Mukhopadhyay T, Dogra N. Anti bacterial function of secreted human FABP3. Biochim Biophys Acta Gen Subj 2023; 1867:130472. [PMID: 37788726 DOI: 10.1016/j.bbagen.2023.130472] [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: 03/14/2023] [Revised: 09/12/2023] [Accepted: 09/28/2023] [Indexed: 10/05/2023]
Abstract
FABP3 belongs to a large family of cytoplasmic fatty acid binding proteins that are expressed in a tissue-specific manner. It is predominantly expressed in breast, muscle and heart. During our exploratory studies on the role of FABP3 in tumorigenesis and our consequent attempts to study the molecular mechanism responsible for the oncogenic potential of FABP3, we came across an unexpected role of FABP3 as an anti-bacterial protein. Presence of the protein was detected in culture media of cell lines stably over-expressing human FABP3. Conditioned medium from these FABP3 over-expressing cells exerted a distinct anti-bacterial activity against E. coli. Our results indicate that binding of FABP3 to the bacterial cell surface contributes to its anti-bacterial activity. Incubation of E. coli bacterial cells with FABP3 protein led to disruption of the physical integrity of bacterial cell membrane causing leakage of cellular components. Further, in silico analysis predicted strong binding of FABP3 to the antibiotic binding sites on the bacterial ribosome. Interestingly, we found that FABP3 is a naturally occurring secretory protein present in milk in abundance as confirmed by western blot and ELISA. Thus, our experimental data together with in silico analysis suggests that FABP3 is secreted in milk, has an anti-bacterial function, shows activity against E. coli by disrupting bacterial membrane and targeting the ribosome, and may play a protective role against bacterial infection in newborns.
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Affiliation(s)
- Ambica Baru
- National Centre for Human Genome Studies and Research, Panjab University, Sector-14, Chandigarh-160014, India
| | - Chandra Devi
- National Centre for Human Genome Studies and Research, Panjab University, Sector-14, Chandigarh-160014, India
| | - Tapas Mukhopadhyay
- National Centre for Human Genome Studies and Research, Panjab University, Sector-14, Chandigarh-160014, India.
| | - Nilambra Dogra
- National Centre for Human Genome Studies and Research, Panjab University, Sector-14, Chandigarh-160014, India.
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4
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Abstract
Fatty acid-binding proteins (FABPs) are small lipid-binding proteins abundantly expressed in tissues that are highly active in fatty acid (FA) metabolism. Ten mammalian FABPs have been identified, with tissue-specific expression patterns and highly conserved tertiary structures. FABPs were initially studied as intracellular FA transport proteins. Further investigation has demonstrated their participation in lipid metabolism, both directly and via regulation of gene expression, and in signaling within their cells of expression. There is also evidence that they may be secreted and have functional impact via the circulation. It has also been shown that the FABP ligand binding repertoire extends beyond long-chain FAs and that their functional properties also involve participation in systemic metabolism. This article reviews the present understanding of FABP functions and their apparent roles in disease, particularly metabolic and inflammation-related disorders and cancers.
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Affiliation(s)
- Judith Storch
- Department of Nutritional Sciences and Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey, United States;
| | - Betina Corsico
- Instituto de Investigaciones Bioquímicas de La Plata, CONICET-UNLP, Facultad de Ciencias Médicas, La Plata, Argentina;
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5
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Inouye KE, Prentice KJ, Lee A, Wang ZB, Dominguez-Gonzalez C, Chen MX, Riveros JK, Burak MF, Lee GY, Hotamışlıgil GS. Endothelial-derived FABP4 constitutes the majority of basal circulating hormone and regulates lipolysis-driven insulin secretion. JCI Insight 2023; 8:e164642. [PMID: 37279064 PMCID: PMC10443803 DOI: 10.1172/jci.insight.164642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 05/31/2023] [Indexed: 06/07/2023] Open
Abstract
Fatty acid binding protein 4 (FABP4) is a lipid chaperone secreted from adipocytes upon stimulation of lipolysis. Circulating FABP4 levels strongly correlate with obesity and metabolic pathologies in experimental models and humans. While adipocytes have been presumed to be the major source of hormonal FABP4, this question has not been addressed definitively in vivo. We generated mice with Fabp4 deletion in cells known to express the gene - adipocytes (Adipo-KO), endothelial cells (Endo-KO), myeloid cells (Myeloid-KO), and the whole body (Total-KO) - to examine the contribution of these cell types to basal and stimulated plasma FABP4 levels. Unexpectedly, baseline plasma FABP4 was not significantly reduced in Adipo-KO mice, whereas Endo-KO mice showed ~87% reduction versus WT controls. In contrast, Adipo-KO mice exhibited ~62% decreased induction of FABP4 responses to lipolysis, while Endo-KO mice showed only mildly decreased induction, indicating that adipocytes are the main source of increases in FABP4 during lipolysis. We did not detect any myeloid contribution to circulating FABP4. Surprisingly, despite the nearly intact induction of FABP4, Endo-KO mice showed blunted lipolysis-induced insulin secretion, identical to Total-KO mice. We conclude that the endothelium is the major source of baseline hormonal FABP4 and is required for the insulin response to lipolysis.
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Affiliation(s)
- Karen E. Inouye
- Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, Massachusetts, USA
| | - Kacey J. Prentice
- Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, Massachusetts, USA
| | - Alexandra Lee
- Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, Massachusetts, USA
| | - Zeqiu B. Wang
- Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, Massachusetts, USA
| | - Carla Dominguez-Gonzalez
- Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, Massachusetts, USA
| | - Mu Xian Chen
- Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, Massachusetts, USA
| | - Jillian K. Riveros
- Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, Massachusetts, USA
| | - M. Furkan Burak
- Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, Massachusetts, USA
| | - Grace Y. Lee
- Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, Massachusetts, USA
| | - Gökhan S. Hotamışlıgil
- Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Department of Molecular Metabolism, Boston, Massachusetts, USA
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA
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Prentice KJ, Lee A, Cedillo P, Inouye KE, Ertunc ME, Riveros JK, Lee GY, Hotamisligil GS. Sympathetic tone dictates the impact of lipolysis on FABP4 secretion. J Lipid Res 2023; 64:100386. [PMID: 37172691 PMCID: PMC10248869 DOI: 10.1016/j.jlr.2023.100386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 04/19/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023] Open
Abstract
Levels of circulating fatty acid binding protein 4 (FABP4) protein are strongly associated with obesity and metabolic disease in both mice and humans, and secretion is stimulated by β-adrenergic stimulation both in vivo and in vitro. Previously, lipolysis-induced FABP4 secretion was found to be significantly reduced upon pharmacological inhibition of adipose triglyceride lipase (ATGL) and was absent from adipose tissue explants from mice specifically lacking ATGL in their adipocytes (ATGLAdpKO). Here, we find that upon activation of β-adrenergic receptors in vivo, ATGLAdpKO mice unexpectedly exhibited significantly higher levels of circulating FABP4 as compared with ATGLfl/fl controls, despite no corresponding induction of lipolysis. We generated an additional model with adipocyte-specific deletion of both FABP4 and ATGL (ATGL/FABP4AdpKO) to evaluate the cellular source of this circulating FABP4. In these animals, there was no evidence of lipolysis-induced FABP4 secretion, indicating that the source of elevated FABP4 levels in ATGLAdpKO mice was indeed from the adipocytes. ATGLAdpKO mice exhibited significantly elevated corticosterone levels, which positively correlated with plasma FABP4 levels. Pharmacological inhibition of sympathetic signaling during lipolysis using hexamethonium or housing mice at thermoneutrality to chronically reduce sympathetic tone significantly reduced FABP4 secretion in ATGLAdpKO mice compared with controls. Therefore, activity of a key enzymatic step of lipolysis mediated by ATGL, per se, is not required for in vivo stimulation of FABP4 secretion from adipocytes, which can be induced through sympathetic signaling.
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Affiliation(s)
- Kacey J Prentice
- Department of Molecular Metabolism; Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Alexandra Lee
- Department of Molecular Metabolism; Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Paulina Cedillo
- Department of Molecular Metabolism; Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Karen E Inouye
- Department of Molecular Metabolism; Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Meric Erikci Ertunc
- Department of Molecular Metabolism; Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Jillian K Riveros
- Department of Molecular Metabolism; Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Grace Yankun Lee
- Department of Molecular Metabolism; Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Gökhan S Hotamisligil
- Department of Molecular Metabolism; Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Broad Institute of Harvard and MIT, Cambridge, MA, USA.
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7
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I'Anson H, Archer HR, Choi HJ, Ko TB, Rodriguez CL, Samuel MA, Bezold KA, Whitworth GB. Resting metabolic rate, abdominal fat pad and liver metabolic gene expression in female rats provided a snacking diet from weaning to adulthood. Physiol Behav 2022; 256:113962. [PMID: 36100110 DOI: 10.1016/j.physbeh.2022.113962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/22/2022] [Accepted: 09/09/2022] [Indexed: 10/31/2022]
Abstract
Our female rat model with continuous, ad libitum access to snacks and chow from weaning to adulthood closely mimics human feeding behavior from childhood onwards. It causes weight gain, enlarged abdominal fat pads, reduced insulin sensitivity and leptin resistance without an increase in total caloric intake. Our current study investigated if this change in energy partitioning is due to a decrease in resting metabolic rate (RMR). In addition, we determined if carbohydrate and lipid metabolism changes in abdominal fat pads and liver. RMR, using indirect calorimetry, was determined in control and snacking rats every two weeks from Days 28-29 to Days 76-77. RMR decreased with age in both groups, but there was no difference between snacking and control rats at any age. At termination, abdominal fat pads (parametrial, retroperitoneal and mesenteric) and liver samples were collected for determination of gene expression for 21 genes involved in carbohydrate and lipid metabolism using RT-qPCR. Analysis of gene expression data showed a striking difference between metabolic profiles of control and snacking rats in abdominal fat pads and liver, with a distinct segregation of genes for both lipid and carbohydrate metabolism that correlated with an increase in body weight and fat pad weights. Genes involved in lipogenesis were upregulated in abdominal fat pads, while genes involved in adipogenesis, and lipid recycling were upregulated in the liver. In conclusion, snacking in addition to chow from weaning in female rats causes a repartitioning of energy that is not due to depressed RMR in snacking rats. Rather, snacking from weaning causes a shift in gene expression resulting in energy partitioning toward enhanced abdominal fat pad lipogenesis, and adipogenesis and lipid recycling in liver.
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Affiliation(s)
- Helen I'Anson
- Department of Biology, Washington & Lee University, Lexington VA 24450, United States.
| | - Hannah R Archer
- Department of Biology, Washington & Lee University, Lexington VA 24450, United States
| | - Hannah J Choi
- Department of Biology, Washington & Lee University, Lexington VA 24450, United States
| | - Tiffany B Ko
- Department of Biology, Washington & Lee University, Lexington VA 24450, United States
| | - Carissa L Rodriguez
- Department of Biology, Washington & Lee University, Lexington VA 24450, United States
| | - Mariam A Samuel
- Department of Biology, Washington & Lee University, Lexington VA 24450, United States
| | - Kelly A Bezold
- Department of Biology, Washington & Lee University, Lexington VA 24450, United States
| | - Gregg B Whitworth
- Department of Biology, Washington & Lee University, Lexington VA 24450, United States
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8
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Targeting Fatty Acid-Binding Protein 4 Improves Pathologic Features of Aortic Stenosis. Int J Mol Sci 2022; 23:ijms23158439. [PMID: 35955575 PMCID: PMC9369247 DOI: 10.3390/ijms23158439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022] Open
Abstract
Aortic stenosis (AS) is a fibrocalcific disease of the aortic valves (AVs). Sex-differences in AS pathophysiology have recently been described. High levels of fatty acid-binding protein 4 (FAPB4) in atherosclerotic plaques have been associated with increased local inflammation, endothelial dysfunction, and plaque vulnerability. FABP4 pharmacological blockade has been shown to be effective for the treatment of atherosclerosis by modulating metabolic and inflammatory pathways. We aimed to analyze the sex-specific expression of FABP4 in AS and its potential role as a therapeutic target. A total of 226 patients (61.5% men) with severe AS undergoing surgical AV replacement were recruited. The FABP4 levels were increased in the AVs of AS patients compared to the control subjects, showing greater expression in the fibrocalcific regions. Male AVs exhibited higher levels of FABP4 compared to females, correlating with markers of inflammation (IL-6, Rantes), apoptosis (Bax, caspase-3, Bcl-2), and calcification (IL-8, BMP-2 and BMP-4). VICs derived from AS patients showed the basal expression of FABP4 in vitro. Osteogenic media induced upregulation of intracellular and secreted FABP4 levels in male VICs after 7 days, along with increased levels of inflammatory, pro-apoptotic, and osteogenic markers. Treatment with BMS309403, a specific inhibitor of FABP4, prevented from all of these changes. Thus, we propose FABP4 as a new sex-specific pharmacological therapeutic target in AS.
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9
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Iglesia RP, Prado MB, Alves RN, Escobar MIM, Fernandes CFDL, Fortes ACDS, Souza MCDS, Boccacino JM, Cangiano G, Soares SR, de Araújo JPA, Tiek DM, Goenka A, Song X, Keady JR, Hu B, Cheng SY, Lopes MH. Unconventional Protein Secretion in Brain Tumors Biology: Enlightening the Mechanisms for Tumor Survival and Progression. Front Cell Dev Biol 2022; 10:907423. [PMID: 35784465 PMCID: PMC9242006 DOI: 10.3389/fcell.2022.907423] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/26/2022] [Indexed: 11/28/2022] Open
Abstract
Non-canonical secretion pathways, collectively known as unconventional protein secretion (UPS), are alternative secretory mechanisms usually associated with stress-inducing conditions. UPS allows proteins that lack a signal peptide to be secreted, avoiding the conventional endoplasmic reticulum-Golgi complex secretory pathway. Molecules that generally rely on the canonical pathway to be secreted may also use the Golgi bypass, one of the unconventional routes, to reach the extracellular space. UPS studies have been increasingly growing in the literature, including its implication in the biology of several diseases. Intercellular communication between brain tumor cells and the tumor microenvironment is orchestrated by various molecules, including canonical and non-canonical secreted proteins that modulate tumor growth, proliferation, and invasion. Adult brain tumors such as gliomas, which are aggressive and fatal cancers with a dismal prognosis, could exploit UPS mechanisms to communicate with their microenvironment. Herein, we provide functional insights into the UPS machinery in the context of tumor biology, with a particular focus on the secreted proteins by alternative routes as key regulators in the maintenance of brain tumors.
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Affiliation(s)
- Rebeca Piatniczka Iglesia
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil,The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Mariana Brandão Prado
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Rodrigo Nunes Alves
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Maria Isabel Melo Escobar
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Camila Felix de Lima Fernandes
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ailine Cibele dos Santos Fortes
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Maria Clara da Silva Souza
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Jacqueline Marcia Boccacino
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Giovanni Cangiano
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Samuel Ribeiro Soares
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - João Pedro Alves de Araújo
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Deanna Marie Tiek
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Anshika Goenka
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Xiao Song
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Jack Ryan Keady
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Bo Hu
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Shi Yuan Cheng
- The Robert H. Lurie Comprehensive Cancer Center, The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute at Northwestern Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Marilene Hohmuth Lopes
- Laboratory of Neurobiology and Stem Cells, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil,*Correspondence: Marilene Hohmuth Lopes,
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10
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Prentice KJ, Saksi J, Robertson LT, Lee GY, Inouye KE, Eguchi K, Lee A, Cakici O, Otterbeck E, Cedillo P, Achenbach P, Ziegler AG, Calay ES, Engin F, Hotamisligil GS. A hormone complex of FABP4 and nucleoside kinases regulates islet function. Nature 2021; 600:720-726. [PMID: 34880500 DOI: 10.1038/s41586-021-04137-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/14/2021] [Indexed: 11/09/2022]
Abstract
The liberation of energy stores from adipocytes is critical to support survival in times of energy deficit; however, uncontrolled or chronic lipolysis associated with insulin resistance and/or insulin insufficiency disrupts metabolic homeostasis1,2. Coupled to lipolysis is the release of a recently identified hormone, fatty-acid-binding protein 4 (FABP4)3. Although circulating FABP4 levels have been strongly associated with cardiometabolic diseases in both preclinical models and humans4-7, no mechanism of action has yet been described8-10. Here we show that hormonal FABP4 forms a functional hormone complex with adenosine kinase (ADK) and nucleoside diphosphate kinase (NDPK) to regulate extracellular ATP and ADP levels. We identify a substantial effect of this hormone on beta cells and given the central role of beta-cell function in both the control of lipolysis and development of diabetes, postulate that hormonal FABP4 is a key regulator of an adipose-beta-cell endocrine axis. Antibody-mediated targeting of this hormone complex improves metabolic outcomes, enhances beta-cell function and preserves beta-cell integrity to prevent both type 1 and type 2 diabetes. Thus, the FABP4-ADK-NDPK complex, Fabkin, represents a previously unknown hormone and mechanism of action that integrates energy status with the function of metabolic organs, and represents a promising target against metabolic disease.
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Affiliation(s)
- Kacey J Prentice
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Jani Saksi
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Lauren T Robertson
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Grace Y Lee
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Karen E Inouye
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Kosei Eguchi
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Alexandra Lee
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Ozgur Cakici
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Emily Otterbeck
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Paulina Cedillo
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Peter Achenbach
- Institute of Diabetes Research, Helmholtz Zentrum Munchen, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Anette-Gabriele Ziegler
- Institute of Diabetes Research, Helmholtz Zentrum Munchen, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Ediz S Calay
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Feyza Engin
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA.,Departments of Biomolecular Chemistry and Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Gökhan S Hotamisligil
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA. .,Broad Institute of Harvard and MIT, Cambridge, MA, USA.
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11
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Sánchez JC, Valencia-Vásquez A, García AM. Role of TRPV4 Channel in Human White Adipocytes Metabolic Activity. Endocrinol Metab (Seoul) 2021; 36:997-1006. [PMID: 34648704 PMCID: PMC8566118 DOI: 10.3803/enm.2021.1167] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 08/19/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Intracellular calcium (Ca2+) homeostasis plays an essential role in adipocyte metabolism and its alteration is associated with obesity and related disorders. Transient receptor potential vanilloid 4 (TRPV4) channels are an important Ca2+ pathway in adipocytes and their activity is regulated by metabolic mediators such as insulin. In this study, we evaluated the role of TRPV4 channels in metabolic activity and adipokine secretion in human white adipocytes. METHODS Human white adipocytes were freshly cultured and the effects of the activation and inhibition of TRPV4 channels on lipolysis, glucose uptake, lactate production, and leptin and adiponectin secretion were evaluated. RESULTS Under basal and isoproterenol-stimulated conditions, TRPV4 activation by GSK1016709A decreased lipolysis whereas HC067047, an antagonist, increased lipolysis. The activation of TRPV4 resulted in increased glucose uptake and lactate production under both basal conditions and insulin-stimulated conditions; in contrast HC067047 decreased both parameters. Leptin production was increased, and adiponectin production was diminished by TRPV4 activation and its inhibition had the opposite effect. CONCLUSION Our results suggested that TRPV4 channels are metabolic mediators involved in proadipogenic processes and glucose metabolism in adipocyte biology. TRPV4 channels could be a potential pharmacological target to treat metabolic disorders.
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Affiliation(s)
- Julio C Sánchez
- Faculty of Health Sciences, Technological University of Pereira, La Julita, Pereira, Colombia
| | - Aníbal Valencia-Vásquez
- Faculty of Health Sciences, Technological University of Pereira, La Julita, Pereira, Colombia
| | - Andrés M García
- Faculty of Health Sciences, Technological University of Pereira, La Julita, Pereira, Colombia
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12
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Scaglia N, Frontini-López YR, Zadra G. Prostate Cancer Progression: as a Matter of Fats. Front Oncol 2021; 11:719865. [PMID: 34386430 PMCID: PMC8353450 DOI: 10.3389/fonc.2021.719865] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 07/12/2021] [Indexed: 12/11/2022] Open
Abstract
Advanced prostate cancer (PCa) represents the fifth cause of cancer death worldwide. Although survival has improved with second-generation androgen signaling and Parp inhibitors, the benefits are not long-lasting, and new therapeutic approaches are sorely needed. Lipids and their metabolism have recently reached the spotlight with accumulating evidence for their role as promoters of PCa development, progression, and metastasis. As a result, interest in targeting enzymes/transporters involved in lipid metabolism is rapidly growing. Moreover, the use of lipogenic signatures to predict prognosis and resistance to therapy has been recently explored with promising results. Despite the well-known association between obesity with PCa lethality, the underlying mechanistic role of diet/obesity-derived metabolites has only lately been unveiled. Furthermore, the role of lipids as energy source, building blocks, and signaling molecules in cancer cells has now been revisited and expanded in the context of the tumor microenvironment (TME), which is heavily influenced by the external environment and nutrient availability. Here, we describe how lipids, their enzymes, transporters, and modulators can promote PCa development and progression, and we emphasize the role of lipids in shaping TME. In a therapeutic perspective, we describe the ongoing efforts in targeting lipogenic hubs. Finally, we highlight studies supporting dietary modulation in the adjuvant setting with the purpose of achieving greater efficacy of the standard of care and of synthetic lethality. PCa progression is "a matter of fats", and the more we understand about the role of lipids as key players in this process, the better we can develop approaches to counteract their tumor promoter activity while preserving their beneficial properties.
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Affiliation(s)
- Natalia Scaglia
- Biochemistry Research Institute of La Plata "Professor Doctor Rodolfo R. Brenner" (INIBIOLP), National University of La Plata/National Council of Scientific and Technical Research of Argentina, La Plata, Argentina
| | - Yesica Romina Frontini-López
- Biochemistry Research Institute of La Plata "Professor Doctor Rodolfo R. Brenner" (INIBIOLP), National University of La Plata/National Council of Scientific and Technical Research of Argentina, La Plata, Argentina
| | - Giorgia Zadra
- Institute of Molecular Genetics, National Research Council, Pavia, Italy
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13
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Aung MT, Yu Y, Ferguson KK, Cantonwine DE, Zeng L, McElrath TF, Pennathur S, Mukherjee B, Meeker JD. Cross-Sectional Estimation of Endogenous Biomarker Associations with Prenatal Phenols, Phthalates, Metals, and Polycyclic Aromatic Hydrocarbons in Single-Pollutant and Mixtures Analysis Approaches. ENVIRONMENTAL HEALTH PERSPECTIVES 2021; 129:37007. [PMID: 33761273 PMCID: PMC7990518 DOI: 10.1289/ehp7396] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
BACKGROUND Humans are exposed to mixtures of toxicants that can impact several biological pathways. We investigated the associations between multiple classes of toxicants and an extensive panel of biomarkers indicative of lipid metabolism, inflammation, oxidative stress, and angiogenesis. METHODS We conducted a cross-sectional study of 173 participants (median 26 wk gestation) from the LIFECODES birth cohort. We measured exposure analytes of multiple toxicant classes [metals, phthalates, phenols, and polycyclic aromatic hydrocarbons (PAHs)] in urine samples. We also measured endogenous biomarkers (eicosanoids, cytokines, angiogenic markers, and oxidative stress markers) in either plasma or urine. We estimated pair-wise associations between exposure analytes and endogenous biomarkers using multiple linear regression after adjusting for covariates. We used adaptive elastic net regression, hierarchical Bayesian kernel machine regression, and sparse-group LASSO regression to evaluate toxicant mixtures associated with individual endogenous biomarkers. RESULTS After false-discovery adjustment (q<0.2), single-pollutant models yielded 19 endogenous biomarker signals associated with phthalates, 13 with phenols, 17 with PAHs, and 18 with trace metals. Notably, adaptive elastic net revealed that phthalate metabolites were selected for several positive signals with the cyclooxygenase (n=7), cytochrome p450 (n=7), and lipoxygenase (n=8) pathways. Conversely, the toxicant classes that exhibited the greatest number of negative signals overall in adaptive elastic net were phenols (n=20) and metals (n=21). DISCUSSION This study characterizes cross-sectional endogenous biomarker signatures associated with individual and mixtures of prenatal toxicant exposures. These results can help inform the prioritization of specific pairs or clusters of endogenous biomarkers and exposure analytes for investigating health outcomes. https://doi.org/10.1289/EHP7396.
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Affiliation(s)
- Max T. Aung
- Department of Biostatistics, University of Michigan (U-M) School of Public Health, Ann Arbor, Michigan, USA
| | - Youfei Yu
- Department of Biostatistics, University of Michigan (U-M) School of Public Health, Ann Arbor, Michigan, USA
| | - Kelly K. Ferguson
- Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - David E. Cantonwine
- Division of Maternal and Fetal Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Lixia Zeng
- Department of Internal Medicine-Nephrology, U-M, Ann Arbor, Michigan, USA
| | - Thomas F. McElrath
- Division of Maternal and Fetal Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Subramaniam Pennathur
- Department of Internal Medicine-Nephrology, U-M, Ann Arbor, Michigan, USA
- Michigan Regional Comprehensive Metabolomics Resource Core, U-M, Ann Arbor, Michigan, USA
- Department of Molecular and Integrative Physiology, U-M, Ann Arbor, Michigan, USA
| | - Bhramar Mukherjee
- Department of Biostatistics, University of Michigan (U-M) School of Public Health, Ann Arbor, Michigan, USA
- Department of Epidemiology, U-M School of Public Health, Ann Arbor, Michigan, USA
| | - John D. Meeker
- Department of Environmental Health Sciences, U-M School of Public Health, Ann Arbor, Michigan, USA
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14
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Hepatic Lipidomics and Molecular Imaging in a Murine Non-Alcoholic Fatty Liver Disease Model: Insights into Molecular Mechanisms. Biomolecules 2020; 10:biom10091275. [PMID: 32899418 PMCID: PMC7563600 DOI: 10.3390/biom10091275] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/28/2020] [Accepted: 09/01/2020] [Indexed: 12/11/2022] Open
Abstract
An imbalance between hepatic fatty acid uptake and removal results in ectopic fat accumulation, which leads to non-alcoholic fatty liver disease (NAFLD). The amount and type of accumulated triglycerides seem to play roles in NAFLD progression; however, a complete understanding of how triglycerides contribute to NAFLD evolution is lacking. Our aim was to evaluate triglyceride accumulation in NAFLD in a murine model and its associations with molecular mechanisms involved in liver damage and adipose tissue-liver cross talk by employing lipidomic and molecular imaging techniques. C57BL/6J mice fed a high-fat diet (HFD) for 12 weeks were used as a NAFLD model. Standard-diet (STD)-fed animals were used as controls. Standard liver pathology was assessed using conventional techniques. The liver lipidome was analyzed by liquid chromatography–mass spectrometry (LC–MS) and laser desorption/ionization–mass spectrometry (LDI–MS) tissue imaging. Liver triglycerides were identified by MS/MS. The transcriptome of genes involved in intracellular lipid metabolism and inflammation was assessed by RT-PCR. Plasma leptin, resistin, adiponectin, and FABP4 levels were determined using commercial kits. HFD-fed mice displayed increased liver lipid content. LC–MS analyses identified 14 triglyceride types that were upregulated in livers from HFD-fed animals. Among these 14 types, 10 were identified in liver cross sections by LDI–MS tissue imaging. The accumulation of these triglycerides was associated with the upregulation of lipogenesis and inflammatory genes and the downregulation of β-oxidation genes. Interestingly, the levels of plasma FABP4, but not of other adipokines, were positively associated with 8 of these triglycerides in HFD-fed mice but not in STD-fed mice. Our findings suggest a putative role of FABP4 in the liver-adipose tissue cross talk in NAFLD.
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15
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Inoue H, Inazu M, Konishi M, Yokoyama U. Functional expression of TRPM7 as a Ca 2+ influx pathway in adipocytes. Physiol Rep 2020; 7:e14272. [PMID: 31650715 PMCID: PMC6813326 DOI: 10.14814/phy2.14272] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 09/20/2019] [Accepted: 10/04/2019] [Indexed: 02/01/2023] Open
Abstract
In adipocytes, intracellular Ca2+ and Mg2+ modulates physiological functions, such as insulin action and the secretion of adipokines. TRPM7 is a Ca2+/Mg2+‐permeable non‐selective cation channel. TRPM7 mRNA is highly expressed in adipose tissue, however, its functional expression in adipocytes remains to be elucidated. In this study, we demonstrated for the first time that TRPM7 was functionally expressed in both freshly isolated white adipocytes and in 3T3‐L1 adipocytes differentiated from a 3T3‐L1 pre‐adipocyte cell line by whole‐cell patch‐clamp recordings. Consistent with known properties of TRPM7 current, the current in adipocytes was activated by the elimination of extracellular divalent cations and the reduction of intracellular free Mg2+ concentrations, and was inhibited by the TRPM7 inhibitors, 2‐aminoethyl diphenylborinate (2‐APB), hydrogen peroxide (H2O2), N‐methyl maleimide (NMM), NS8593, and 2‐amino‐2‐[2‐(4‐octylphenyl)ethyl]‐1,3‐propanediol (FTY720). Treatment with small‐interfering (si) RNA targeting TRPM7 resulted in a reduction in the current to 23 ± 7% of nontargeting siRNA‐treated adipocytes. Moreover a TRPM7 activator, naltriben, increased the TRPM7‐like current and [Ca2+]i in 3T3‐L1 adipocytes but not in TRPM7‐knockdown adipocytes. These findings indicate that TRPM7 is functionally expressed, and plays a role as a Ca2+ influx pathway in adipocytes.
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Affiliation(s)
- Hana Inoue
- Department of Physiology, Tokyo Medical University, Tokyo, Japan
| | - Masato Inazu
- Institute of Medical Science, Tokyo Medical University, Tokyo, Japan
| | - Masato Konishi
- Department of Physiology, Tokyo Medical University, Tokyo, Japan
| | - Utako Yokoyama
- Department of Physiology, Tokyo Medical University, Tokyo, Japan
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16
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Scherschel K, Gosau N. EAT: What role does the fat around the heart play? Int J Cardiol 2020; 301:121-122. [PMID: 31668656 DOI: 10.1016/j.ijcard.2019.08.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/06/2019] [Accepted: 08/09/2019] [Indexed: 11/17/2022]
Affiliation(s)
- Katharina Scherschel
- Department of Cardiology - Electrophysiology, University Heart & Vascular Centre, University Hospital Hamburg-Eppendorf, Germany; DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Nils Gosau
- Department of Cardiology, Asklepios Klinik St. Georg, Lohmühlenstr. 5, 20099 Hamburg, Germany.
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17
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Walenna NF, Kurihara Y, Chou B, Ishii K, Soejima T, Hiromatsu K. Chlamydia pneumoniae infection-induced endoplasmic reticulum stress causes fatty acid-binding protein 4 secretion in murine adipocytes. J Biol Chem 2020; 295:2713-2723. [PMID: 31992597 DOI: 10.1074/jbc.ra119.010683] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 01/23/2020] [Indexed: 12/28/2022] Open
Abstract
Fatty acid-binding protein 4 (FABP4) is predominantly expressed in adipocytes and macrophages and regulates metabolic and inflammatory pathways. FABP4 is secreted from adipocytes during lipolysis, and elevated circulating FABP4 levels are associated with obesity, metabolic disease, and cardiac dysfunction. We previously reported that the bacterial respiratory pathogen Chlamydia pneumoniae infects murine adipocytes and exploits host FABP4 to mobilize fat and replicate within adipocytes. However, whether C. pneumoniae induces FABP4 secretion from adipocytes has not been determined. Here, we show that FABP4 is actively secreted by murine adipocytes upon C. pneumoniae infection. Chemical inhibition of lipase activity and genetic deficiency of hormone-sensitive lipase blocked FABP4 secretion from C. pneumoniae-infected adipocytes. Mechanistically, C. pneumoniae infection induced endoplasmic reticulum (ER) stress and the unfolded protein response (UPR), resulting in elevated levels of mitochondrial reactive oxygen species and cytosolic Ca2+ Of note, exposure to a mitochondrial reactive oxygen species-specific scavenger, MitoTEMPO, reduced FABP4 release from C. pneumoniae-infected adipocytes. Furthermore, treatment with azoramide, which protects cells against ER stress, decreased FABP4 release from C. pneumoniae-infected adipocytes. Using gene silencing of CHOP (C/EBP homologous protein), a central regulator of ER stress, we further validated the role of C. pneumoniae infection-induced ER stress/UPR in promoting FABP4 secretion. Overall, these results indicate that C. pneumoniae infection robustly induces FABP4 secretion from adipocytes by stimulating ER stress/UPR. Our findings shed additional light on the etiological link between C. pneumoniae infection and metabolic syndrome.
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Affiliation(s)
- Nirwana Fitriani Walenna
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan; Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yusuke Kurihara
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan
| | - Bin Chou
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan
| | - Kazunari Ishii
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan
| | - Toshinori Soejima
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan
| | - Kenji Hiromatsu
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan.
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18
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Josephrajan A, Hertzel AV, Bohm EK, McBurney MW, Imai SI, Mashek DG, Kim DH, Bernlohr DA. Unconventional Secretion of Adipocyte Fatty Acid Binding Protein 4 Is Mediated By Autophagic Proteins in a Sirtuin-1-Dependent Manner. Diabetes 2019; 68:1767-1777. [PMID: 31171562 PMCID: PMC6702637 DOI: 10.2337/db18-1367] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 05/29/2019] [Indexed: 12/11/2022]
Abstract
Fatty acid binding protein 4 (FABP4) is a leaderless lipid carrier protein primarily expressed by adipocytes and macrophages that not only functions intracellularly but is also secreted. The secretion is mediated via unconventional mechanism(s), and in a variety of species, metabolic dysfunction is correlated with elevated circulating FABP4 levels. In diabetic animals, neutralizing antibodies targeting serum FABP4 increase insulin sensitivity and attenuate hepatic glucose output, suggesting the functional importance of circulating FABP4. Using animal and cell-based models, we show that FABP4 is secreted from white, but not brown, adipose tissue in response to lipolytic stimulation in a sirtuin-1 (SIRT1)-dependent manner via a mechanism that requires some, but not all, autophagic components. Silencing of early autophagic genes such as Ulk1/2, Fip200, or Beclin-1 or chemical inhibition of ULK1/2 or VPS34 attenuated secretion, while Atg5 knockdown potentiated FABP4 release. Genetic knockout of Sirt1 diminished secretion, and serum FABP4 levels were undetectable in Sirt1 knockout mice. In addition, blocking SIRT1 by EX527 attenuated secretion while activating SIRT1 by resveratrol-potentiated secretion. These studies suggest that FABP4 secretion from adipocytes is regulated by SIRT1 and requires early autophagic components.
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Affiliation(s)
- Ajeetha Josephrajan
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN
| | - Ann V Hertzel
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN
| | - Ellie K Bohm
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN
| | - Michael W McBurney
- Department of Biochemistry, Microbiology and Immunology, The University of Ottawa, Ottawa, Ontario, Canada
| | - Shin-Ichiro Imai
- Department of Developmental Biology, Washington University in St. Louis, St. Louis, MO
| | - Douglas G Mashek
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN
| | - Do-Hyung Kim
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN
| | - David A Bernlohr
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN
- Department of Developmental Biology, Washington University in St. Louis, St. Louis, MO
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19
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Samimi A, Ghanavat M, Shahrabi S, Azizidoost S, Saki N. Role of bone marrow adipocytes in leukemia and chemotherapy challenges. Cell Mol Life Sci 2019; 76:2489-2497. [PMID: 30715556 PMCID: PMC11105633 DOI: 10.1007/s00018-019-03031-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/01/2019] [Accepted: 01/28/2019] [Indexed: 12/25/2022]
Abstract
Adipose tissue (AT) is an extramedullary reservoir of normal hematopoietic stem cells (HSCs). Adipocytes prevent the production of normal HSCs via secretion of inflammatory factors, and adipocyte-derived free fatty acids may contribute to the development and progression of leukemia via providing energy for leukemic cells. In addition, adipocytes are able to metabolize and inactivate therapeutic agents, reducing the concentrations of active drugs in adipocyte-rich microenvironments. The aim of this study was to detect the role of adipocytes in the progression and treatment of leukemia. Relevant literature was identified through a PubMed search (2000-2018) of English-language papers using the following terms: leukemia, adipocyte, leukemic stem cell, chemotherapy, and bone marrow. Findings suggest the striking interplay between leukemic cells and adipocytes to create a unique microenvironment supporting the metabolic demands and survival of leukemic cells. Based on these findings, targeting lipid metabolism of leukemic cells and adipocytes in combination with standard therapeutic agents might present novel treatment options.
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Affiliation(s)
- Azin Samimi
- Department of Pharmacology and Toxicology, School of Pharmacy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Majid Ghanavat
- Child Growth and Development Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Saeid Shahrabi
- Department of Biochemistry and Hematology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Shirin Azizidoost
- Thalassemia and Hemoglobinopathy Research Center, Research Institute of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Najmaldin Saki
- Thalassemia and Hemoglobinopathy Research Center, Research Institute of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
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20
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Klusóczki Á, Veréb Z, Vámos A, Fischer-Posovszky P, Wabitsch M, Bacso Z, Fésüs L, Kristóf E. Differentiating SGBS adipocytes respond to PPARγ stimulation, irisin and BMP7 by functional browning and beige characteristics. Sci Rep 2019; 9:5823. [PMID: 30967578 PMCID: PMC6456729 DOI: 10.1038/s41598-019-42256-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/26/2019] [Indexed: 12/24/2022] Open
Abstract
Brown and beige adipocytes are enriched in mitochondria with uncoupling protein-1 (UCP1) to generate heat instead of ATP contributing to healthy energy balance. There are few human cellular models to reveal regulatory networks in adipocyte browning and key targets for enhancing thermogenesis in obesity. The Simpson-Golabi-Behmel syndrome (SGBS) preadipocyte line has been a useful tool to study human adipocyte biology. Here we report that SGBS cells, which are comparable to subcutaneous adipose-derived stem cells, carry an FTO risk allele. Upon sustained PPARγ stimulation or irisin (a myokine released in response to exercise) treatment, SGBS cells differentiated into beige adipocytes exhibiting multilocular lipid droplets, high UCP1 content with induction of typical browning genes (Cidea, Elovl3) and the beige marker Tbx1. The autocrine mediator BMP7 led to moderate browning with the upregulation of the classical brown marker Zic1 instead of Tbx1. Thermogenesis potential resulted from PPARγ stimulation, irisin and BMP7 can be activated in UCP1-dependent and the beige specific, creatine phosphate cycle mediated way. The beige phenotype, maintained under long-term (28 days) conditions, was partially reversed by withdrawal of PPARγ ligand. Thus, SGBS cells can serve as a cellular model for both white and sustainable beige adipocyte differentiation and function.
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Affiliation(s)
- Ágnes Klusóczki
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zoltán Veréb
- Regenerative Medicine and Cellular Pharmacology Research Laboratory, Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Attila Vámos
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | | | - Martin Wabitsch
- Division of Pediatric Endocrinology and Diabetes, University Medical Center Ulm, Ulm, Germany
| | - Zsolt Bacso
- Department of Biophysics and Cell Biology, Faculties of Medicine and Pharmacology, University of Debrecen, Debrecen, Hungary
| | - László Fésüs
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
| | - Endre Kristóf
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
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21
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Prentice KJ, Saksi J, Hotamisligil GS. Adipokine FABP4 integrates energy stores and counterregulatory metabolic responses. J Lipid Res 2019; 60:734-740. [PMID: 30705117 PMCID: PMC6446704 DOI: 10.1194/jlr.s091793] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Indexed: 12/15/2022] Open
Abstract
Although counterregulatory hormones and mediators of the fight-or-flight responses are well defined at many levels, how energy stores per se are integrated into this system remains an enigmatic question. Recent years have seen the adipose tissue become a central focus for mediating intracellular signaling and communication through the release of a variety of bioactive lipids and substrates, as well as various adipokines. A critical integration node among these mediators and responses is controlled by FA binding protein 4 (FABP4), also known as adipocyte protein 2 (aP2), which is highly expressed in adipose tissue and functions as a lipid chaperone protein. Recently, it was demonstrated that FABP4 is a secreted hormone that has roles in maintaining glucose homeostasis, representing a key juncture facilitating communication between energy-storage systems and distant organs to respond to life-threatening situations. However, chronic engagement of FABP4 under conditions of immunometabolic stress, such as obesity, exacerbates a number of immunometabolic diseases, including diabetes, asthma, cancer, and atherosclerosis. In both preclinical mouse models and humans, levels of circulating FABP4 have been correlated with metabolic disease incidence, and reducing FABP4 levels or activity is associated with improved metabolic health. In this review, we will discuss the intriguing emerging biology of this protein, including potential therapeutic options for targeting circulating FABP4.
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Affiliation(s)
- Kacey J Prentice
- Sabri Ülker Center for Metabolic Research Harvard T. H. Chan School of Public Health, Boston, MA; Department of Genetics and Complex Diseases Harvard T. H. Chan School of Public Health, Boston, MA
| | - Jani Saksi
- Sabri Ülker Center for Metabolic Research Harvard T. H. Chan School of Public Health, Boston, MA; Department of Genetics and Complex Diseases Harvard T. H. Chan School of Public Health, Boston, MA
| | - Gökhan S Hotamisligil
- Sabri Ülker Center for Metabolic Research Harvard T. H. Chan School of Public Health, Boston, MA; Department of Genetics and Complex Diseases Harvard T. H. Chan School of Public Health, Boston, MA; Broad Institute of Harvard and MIT Cambridge, MA.
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22
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Abstract
Fatty acid-binding proteins (FABPs), a family of lipid chaperones, contribute to systemic metabolic regulation via several lipid signaling pathways. Fatty acid-binding protein 4 (FABP4), known as adipocyte FABP (A-FABP) or aP2, is mainly expressed in adipocytes and macrophages and plays important roles in the development of insulin resistance and atherosclerosis in relation to metabolically driven low-grade and chronic inflammation, referred to as ‘metaflammation’. FABP4 is secreted from adipocytes in a non-classical pathway associated with lipolysis and acts as an adipokine for the development of insulin resistance and atherosclerosis. Circulating FABP4 levels are associated with several aspects of metabolic syndrome and cardiovascular disease. Ectopic expression and function of FABP4 in cells and tissues are also related to the pathogenesis of several diseases. Pharmacological modification of FABP4 function by specific inhibitors, neutralizing antibodies or antagonists of unidentified receptors would be novel therapeutic strategies for several diseases, including obesity, diabetes mellitus, atherosclerosis and cardiovascular disease. Significant roles of FABP4 as a lipid chaperone in physiological and pathophysiological conditions and the possibility of FABP4 being a therapeutic target for metabolic and cardiovascular diseases are discussed in this review.
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Affiliation(s)
- Masato Furuhashi
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine
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23
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Martínez-Micaelo N, Rodríguez-Calvo R, Guaita-Esteruelas S, Heras M, Girona J, Masana L. Extracellular FABP4 uptake by endothelial cells is dependent on cytokeratin 1 expression. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:234-244. [PMID: 30521939 DOI: 10.1016/j.bbalip.2018.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 11/14/2018] [Accepted: 11/30/2018] [Indexed: 12/21/2022]
Abstract
AIMS The aim of this study is to determine the physical and functional interplay between fatty acid-binding protein 4 (FABP4) and its membrane receptor-like candidate protein, cytokeratin 1 (CK1), and to determine the effect of hindering CK1-mediated FABP4 cellular uptake on non-disturbed or metabolically stressed endothelial cells. METHODS We monitored the direct interaction between FABP4 and CK1 using surface plasmon resonance, and the effects of blocking exogenous FABP4 (eFABP4) cellular uptake were determined by using specific siRNA to knock down the expression of CK1 in human umbilical vein endothelial cells (HUVECs). The expression and nuclear translocation of transcription factors involved in oxidative stress (NRF2) and inflammation (p65 subunit of NF-ĸB transcription factor) were determined by Western blotting analysis. RESULTS Our data showed that FABP4 and CK1 bind to each other and that the putative FABP4 binding domain would be within the 151GIQEVTINQSLLQPLNVEID170 CK1 sequence. We determined that in non-disturbed or metabolically stressed endothelial cells, eFABP4 regulates the cellular response to oxidative stress. In addition, we also found that in the presence of palmitate, eFABP4 increases the pro-inflammatory effects induced by palmitate per se, probably due to an increase in the transport of palmitate inside cells, suggesting that these FABP4-mediated pro-oxidative and pro-inflammatory effects are dependent on CK1 expression. CONCLUSIONS We demonstrated that CK1 facilitates eFABP4 cellular uptake in endothelial cells. Therefore, the CK1-targeted inhibition of exogenous FABP4 cellular uptake might be a potential therapeutic strategy to protect endothelial cells against FABP4-induced activation of inflammation and oxidative stress.
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Affiliation(s)
- N Martínez-Micaelo
- Lipids and Atherosclerosis Research Unit, Hospital Universitari Sant Joan, Institut d'Investigació Sanitària Pere Virgili (IISPV), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Universitat Rovira i Virgili, Reus, Spain
| | - R Rodríguez-Calvo
- Lipids and Atherosclerosis Research Unit, Hospital Universitari Sant Joan, Institut d'Investigació Sanitària Pere Virgili (IISPV), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Universitat Rovira i Virgili, Reus, Spain
| | - S Guaita-Esteruelas
- Lipids and Atherosclerosis Research Unit, Hospital Universitari Sant Joan, Institut d'Investigació Sanitària Pere Virgili (IISPV), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Universitat Rovira i Virgili, Reus, Spain; Grup d'Investigació en Oncologia Translacional, Epidemiològica i Clínica (GIOTEC), Institut d'Investigació Sanitària Pere Virgili (IISPV), Spain
| | - M Heras
- Lipids and Atherosclerosis Research Unit, Hospital Universitari Sant Joan, Institut d'Investigació Sanitària Pere Virgili (IISPV), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Universitat Rovira i Virgili, Reus, Spain
| | - J Girona
- Lipids and Atherosclerosis Research Unit, Hospital Universitari Sant Joan, Institut d'Investigació Sanitària Pere Virgili (IISPV), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Universitat Rovira i Virgili, Reus, Spain
| | - L Masana
- Lipids and Atherosclerosis Research Unit, Hospital Universitari Sant Joan, Institut d'Investigació Sanitària Pere Virgili (IISPV), Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Universitat Rovira i Virgili, Reus, Spain.
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24
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Shrestha S, Sunaga H, Hanaoka H, Yamaguchi A, Kuwahara S, Umbarawan Y, Nakajima K, Machida T, Murakami M, Saito A, Tsushima Y, Kurabayashi M, Iso T. Circulating FABP4 is eliminated by the kidney via glomerular filtration followed by megalin-mediated reabsorption. Sci Rep 2018; 8:16451. [PMID: 30401801 PMCID: PMC6219568 DOI: 10.1038/s41598-018-34902-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 10/28/2018] [Indexed: 01/15/2023] Open
Abstract
Circulating fatty acid binding protein 4 (FABP4), secreted from adipocytes, is a potential biomarker for metabolic and cardiovascular diseases. Circulating FABP4 levels are positively associated with adiposity and adrenergic stimulation, but negatively with renal function. In this study, we addressed the issue of how the kidney regulates clearance of circulating FABP4. Tracing study revealed remarkable accumulation of 125I-labeled FABP4 in the kidney. Exogenous FABP4 was exclusively detected in the apical membrane of proximal tubule epithelial cells (PTECs). Bilateral nephrectomy resulted in marked elevation of circulating FABP4 levels. Accelerated lipolysis by β-3 adrenergic stimulation led to a marked elevation in circulating FABP4 in mice with severe renal dysfunction. Megalin, an endocytic receptor expressed in PTECs, plays a major role in reabsorption of proteins filtered through glomeruli. Quartz-crystal microbalance study revealed that FABP4 binds to megalin. In kidney-specific megalin knockout mice, a large amount of FABP4 was excreted in urine while circulating FABP4 levels were significantly reduced. Our data suggest that circulating FABP4 is processed by the kidney via the glomerular filtration followed by megalin-mediated reabsorption. Thus, it is likely that circulating FABP4 levels are determined mainly by balance between secretion rate of FABP4 from adipocytes and clearance rate of the kidney.
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Affiliation(s)
- Suman Shrestha
- Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Hiroaki Sunaga
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Hirofumi Hanaoka
- Department of Bioimaging Information Analysis, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Aiko Yamaguchi
- Department of Bioimaging Information Analysis, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Shoji Kuwahara
- Department of Applied Molecular Medicine, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8585, Japan
| | - Yogi Umbarawan
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan.,Department of Internal Medicine, Faculty of Medicine Universitas Indonesia, Jl. Salemba Raya No. 6, Jakarta, 10430, Indonesia
| | - Kiyomi Nakajima
- Department of Clinical Laboratory Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Tetsuo Machida
- Department of Clinical Laboratory Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Masami Murakami
- Department of Clinical Laboratory Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Akihiko Saito
- Department of Applied Molecular Medicine, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8585, Japan
| | - Yoshito Tsushima
- Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan.,Research Program for Diagnostic and Molecular Imaging, Division of Integrated Oncology Research, Gunma University Initiative for Advanced Research (GIAR), 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Masahiko Kurabayashi
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan.,Program for obesity-related cardiovascular disease, Division of Endocrinology, Metabolism and Signaling, Gunma University Initiative for Advanced Research (GIAR), 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
| | - Tatsuya Iso
- Department of Cardiovascular Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan.
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25
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Bishnoi M, Khare P, Brown L, Panchal SK. Transient receptor potential (TRP) channels: a metabolic TR(i)P to obesity prevention and therapy. Obes Rev 2018; 19:1269-1292. [PMID: 29797770 DOI: 10.1111/obr.12703] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/26/2018] [Accepted: 04/11/2018] [Indexed: 12/13/2022]
Abstract
Cellular transport of ions, especially by ion channels, regulates physiological function. The transient receptor potential (TRP) channels, with 30 identified so far, are cation channels with high calcium permeability. These ion channels are present in metabolically active tissues including adipose tissue, liver, gastrointestinal tract, brain (hypothalamus), pancreas and skeletal muscle, which suggests a potential role in metabolic disorders including obesity. TRP channels have potentially important roles in adipogenesis, obesity development and its prevention and therapy because of their physiological properties including calcium permeability, thermosensation and taste perception, involvement in cell metabolic signalling and hormone release. This wide range of actions means that organ-specific actions are unlikely, thus increasing the possibility of adverse effects. Delineation of responses to TRP channels has been limited by the poor selectivity of available agonists and antagonists. Food constituents that can modulate TRP channels are of interest in controlling metabolic status. TRP vanilloid 1 channels modulated by capsaicin have been the most studied, suggesting that this may be the first target for effective pharmacological modulation in obesity. This review shows that most of the TRP channels are potential targets to reduce metabolic disorders through a range of mechanisms.
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Affiliation(s)
- M Bishnoi
- Department of Food and Nutritional Biotechnology, National Agri-Food Biotechnology Institute, S.A.S. Nagar (Mohali), Punjab, India.,Functional Foods Research Group, Institute for Agriculture and the Environment, University of Southern Queensland, Toowoomba, QLD, Australia
| | - P Khare
- Department of Food and Nutritional Biotechnology, National Agri-Food Biotechnology Institute, S.A.S. Nagar (Mohali), Punjab, India
| | - L Brown
- Functional Foods Research Group, Institute for Agriculture and the Environment, University of Southern Queensland, Toowoomba, QLD, Australia.,School of Health and Wellbeing, University of Southern Queensland, Toowoomba, QLD, Australia
| | - S K Panchal
- Functional Foods Research Group, Institute for Agriculture and the Environment, University of Southern Queensland, Toowoomba, QLD, Australia
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26
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Chan PC, Wu TN, Chen YC, Lu CH, Wabitsch M, Tian YF, Hsieh PS. Targeted inhibition of CD74 attenuates adipose COX-2-MIF-mediated M1 macrophage polarization and retards obesity-related adipose tissue inflammation and insulin resistance. Clin Sci (Lond) 2018; 132:1581-1596. [DOI: 10.1042/cs20180041] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Adipose tissue (AT) inflammation is crucial to the development of obesity-associated insulin resistance. Our aim was to investigate the contribution of cyclooxygenase-2 (COX-2)/macrophage migration inhibitory factor (MIF)-mediated cross-talk between hypertrophic adipocytes and macrophages to the etiology of AT inflammation and the involvement of CD74 using human SGBS adipocytes, THP-1 macrophages and mice fed a high-fat (HF) diet. The MIF and CD74 mRNA levels in the adipocytes and stromal vascular cells (SVCs) of white fat were highly correlated with body weight (BW), homeostatic model assessment for insulin resistance (HOMA-IR), and adipose macrophage marker expression levels, especially those in SVCs. COX-2 inhibition suppressed the elevation of MIF production in HF white adipocytes as well as palmitate and hypoxic-treated SGBS adipocytes. Treatment of adipocytes transfected with shCOX-2 and siMIF or subjected to MIF depletion in the medium reversed the pro-inflammatory responses in co-incubated THP-1 cells. Inhibition of NF-κB activation reversed the COX2-dependent MIF secretion from treated adipocytes. The targeted inhibition of macrophage CD74 prevented M1 macrophage polarization in the above co-culture model. The COX-2-dependent increases in CD74 gene expression and MIF release in M1-polarized macrophages facilitated the expression of COX-2 and MIF in co-cultured SGBS adipocytes. CD74 shRNA intravenous injection suppressed HF-induced AT M1 macrophage polarization and inflammation as well as insulin resistance in mice. The present study suggested that COX-2-mediated MIF secretion through NF-κB activation from hypertrophic and hypoxic adipocytes as well as M1 macrophages might substantially contribute to the phenotypic switch of AT macrophages through CD74 in obesity. Inhibition of CD74 could attenuate AT inflammation and insulin resistance in the development of HF diet-induced obesity.
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Affiliation(s)
- Pei-Chi Chan
- Department of Physiology and Biophysics, National Defense Medical Center (NDMC), Taipei, Taiwan
| | - Ting-Ni Wu
- Department of Physiology and Biophysics, National Defense Medical Center (NDMC), Taipei, Taiwan
| | - Ying-Chuan Chen
- Department of Physiology and Biophysics, National Defense Medical Center (NDMC), Taipei, Taiwan
- Headquater, Institute of Preventive Medicine, NDMC, Taipei, Taiwan
| | - Chieh-Hua Lu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, NDMC, Taipei, Taiwan
| | - Martin Wabitsch
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, Ulm University, Ulm, Germany
| | - Yu-Feng Tian
- Division of General Surgery, Department of Surgery, Yung Kung Campus, Chi-Mei Medical Center, Tainan, Taiwan
- Department of Health & Nutrition, Chia Nan University of Pharmacy and Science, Tainan, Taiwan
| | - Po-Shiuan Hsieh
- Department of Physiology and Biophysics, National Defense Medical Center (NDMC), Taipei, Taiwan
- Headquater, Institute of Preventive Medicine, NDMC, Taipei, Taiwan
- Department of Medical Research, Tri-Service General Hospital, NDMC, Taipei, Taiwan
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27
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Guaita-Esteruelas S, Gumà J, Masana L, Borràs J. The peritumoural adipose tissue microenvironment and cancer. The roles of fatty acid binding protein 4 and fatty acid binding protein 5. Mol Cell Endocrinol 2018; 462:107-118. [PMID: 28163102 DOI: 10.1016/j.mce.2017.02.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 01/11/2017] [Accepted: 02/01/2017] [Indexed: 02/08/2023]
Abstract
The adipose tissue microenvironment plays a key role in tumour initiation and progression because it provides fatty acids and adipokines to tumour cells. The fatty acid-binding protein (FABP) family is a group of small proteins that act as intracellular fatty acid transporters. Adipose-derived FABPs include FABP4 and FABP5. Both have an important role in lipid-related metabolic processes and overexpressed in many cancers, such as breast, prostate, colorectal and ovarian. Moreover, their expression in peritumoural adipose tissue is deregulated, and their circulating levels are upregulated in some tumours. In this review, we discuss the role of the peritumoural adipose tissue and the related adipokines FABP4 and FABP5 in cancer initiation and progression and the possible pathways implicated in these processes.
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Affiliation(s)
- S Guaita-Esteruelas
- Institut d'Investigació Sanitària Pere Virgili (IISPV), Centre d'R+D+I en Nutrició i Salut, Avda. de la Universitat, 43204 Reus, Spain; Research Unit on Lipids and Atherosclerosis, Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Universitat Rovira i Virgili, Sant Llorenç, 21 43201 Reus, Spain; Institut d'Oncologia de la Catalunya Sud (IOCS), Hospital Universitari Sant Joan de Reus, IISPV, Universitat Rovira i Virgili, Av. del Dr, Josep Laporte, 2, 43204 Reus, Spain.
| | - J Gumà
- Institut d'Oncologia de la Catalunya Sud (IOCS), Hospital Universitari Sant Joan de Reus, IISPV, Universitat Rovira i Virgili, Av. del Dr, Josep Laporte, 2, 43204 Reus, Spain; Department of Medicine and Surgery, Universitat Rovira i Virgili, Sant Llorenç, 21, 43201 Reus, Spain
| | - L Masana
- Research Unit on Lipids and Atherosclerosis, Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Universitat Rovira i Virgili, Sant Llorenç, 21 43201 Reus, Spain
| | - J Borràs
- Institut d'Oncologia de la Catalunya Sud (IOCS), Hospital Universitari Sant Joan de Reus, IISPV, Universitat Rovira i Virgili, Av. del Dr, Josep Laporte, 2, 43204 Reus, Spain; Department of Medicine and Surgery, Universitat Rovira i Virgili, Sant Llorenç, 21, 43201 Reus, Spain
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28
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Villeneuve J, Bassaganyas L, Lepreux S, Chiritoiu M, Costet P, Ripoche J, Malhotra V, Schekman R. Unconventional secretion of FABP4 by endosomes and secretory lysosomes. J Cell Biol 2017; 217:649-665. [PMID: 29212659 PMCID: PMC5800802 DOI: 10.1083/jcb.201705047] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 10/09/2017] [Accepted: 11/14/2017] [Indexed: 01/30/2023] Open
Abstract
Adipocytes secrete fatty acid binding protein 4, which influences glucose production in hepatocytes and insulin secretion in pancreatic β-cells, but the mechanisms of its secretion are unclear. Villeneuve et al. show that FABP4 is secreted unconventionally through enclosure within endosomes and secretory lysosomes. An appreciation of the functional properties of the cytoplasmic fatty acid binding protein 4 (FABP4) has advanced with the recent demonstration that an extracellular form secreted by adipocytes regulates a wide range of physiological functions. Little, however, is known about the mechanisms that mediate the unconventional secretion of FABP4. Here, we demonstrate that FABP4 secretion is mediated by a membrane-bounded compartment, independent of the conventional endoplasmic reticulum–Golgi secretory pathway. We show that FABP4 secretion is also independent of GRASP proteins, autophagy, and multivesicular bodies but involves enclosure within endosomes and secretory lysosomes. We highlight the physiological significance of this pathway with the demonstration that an increase in plasma levels of FABP4 is inhibited by chloroquine treatment of mice. These findings chart the pathway of FABP4 secretion and provide a potential therapeutic means to control metabolic disorders associated with its dysregulated secretion.
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Affiliation(s)
- Julien Villeneuve
- Center for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.,Department of Molecular and Cell Biology and Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA
| | - Laia Bassaganyas
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA.,Institute for Human Genetics, University of California, San Francisco, San Francisco, CA
| | - Sebastien Lepreux
- Institut National de la Santé et de la Recherche Médicale U1026, Université de Bordeaux, Bordeaux, France
| | - Marioara Chiritoiu
- Center for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Pierre Costet
- Service des Animaleries, Université de Bordeaux, Bordeaux, France
| | - Jean Ripoche
- Institut National de la Santé et de la Recherche Médicale U1026, Université de Bordeaux, Bordeaux, France
| | - Vivek Malhotra
- Center for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain .,Universitat Pompeu Fabra, Barcelona, Spain.,Institutio Catalana de Recerca i Estudis Avancats, Barcelona, Spain
| | - Randy Schekman
- Department of Molecular and Cell Biology and Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA
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29
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Walenna NF, Kurihara Y, Chou B, Ishii K, Soejima T, Itoh R, Shimizu A, Ichinohe T, Hiromatsu K. Chlamydia pneumoniae exploits adipocyte lipid chaperone FABP4 to facilitate fat mobilization and intracellular growth in murine adipocytes. Biochem Biophys Res Commun 2017; 495:353-359. [PMID: 29108997 DOI: 10.1016/j.bbrc.2017.11.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 11/02/2017] [Indexed: 11/28/2022]
Abstract
Fatty acid-binding protein 4 (FABP4), a cytosolic lipid chaperone predominantly expressed in adipocytes and macrophages, modulates lipid fluxes, trafficking, signaling, and metabolism. Recent studies have demonstrated that FABP4 regulates metabolic and inflammatory pathways, and in mouse models its inhibition can improve type 2 diabetes mellitus and atherosclerosis. However, the role of FABP4 in bacterial infection, metabolic crosstalk between host and pathogen, and bacterial pathogenesis have not been studied. As an obligate intracellular pathogen, Chlamydia pneumoniae needs to obtain nutrients such as ATP and lipids from host cells. Here, we show that C. pneumoniae successfully infects and proliferates in murine adipocytes by inducing hormone sensitive lipase (HSL)-mediated lipolysis. Chemical inhibition or genetic manipulation of HSL significantly abrogated the intracellular growth of C. pneumoniae in adipocytes. Liberated free fatty acids were utilized to generate ATP via β-oxidation, which C. pneumoniae usurped for its replication. Strikingly, chemical inhibition or genetic silencing of FABP4 significantly abrogated C. pneumoniae infection-induced lipolysis and mobilization of liberated FFAs, resulting in reduced bacterial growth in adipocytes. Collectively, these results demonstrate that C. pneumoniae exploits host FABP4 to facilitate fat mobilization and intracellular replication in adipocytes. This work uncovers a novel strategy used by intracellular pathogens for acquiring energy via hijacking of the host lipid metabolism pathway.
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Affiliation(s)
- Nirwana Fitriani Walenna
- Department of Microbiology & Immunology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan; Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yusuke Kurihara
- Department of Microbiology & Immunology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Bin Chou
- Department of Microbiology & Immunology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Kazunari Ishii
- Department of Microbiology & Immunology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Toshinori Soejima
- Department of Microbiology & Immunology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Ryota Itoh
- Department of Microbiology & Immunology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Akinori Shimizu
- Department of Microbiology & Immunology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Takeshi Ichinohe
- Division of Viral Infection, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Kenji Hiromatsu
- Department of Microbiology & Immunology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
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30
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Chang CC, Chen CY, Wen HC, Huang CY, Hung MS, Lu HC, Chen WL, Chang CH. Caveolin-1 Secreted from Adipose Tissues and Adipocytes Functions as an Adipogenesis Enhancer. Obesity (Silver Spring) 2017; 25:1932-1940. [PMID: 28944626 DOI: 10.1002/oby.21970] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 07/11/2017] [Accepted: 07/24/2017] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Caveolin-1 (Cav-1) is expressed abundantly in adipose tissue and involved in many physiological processes. While Cav-1 has been reported to be secreted in pancreatic acinar cells and LNCaP prostate cancer cells, its secretion from adipose tissue awaits investigation. METHODS Cav-1 secretion from 3T3-L1 adipocytes and fat tissues from normal chow diet- and high-fat diet (HFD)-fed mice was measured. Functions and uptake of secreted Cav-1 proteins were assessed by adding Cav-1 back to preadipocytes and LNCaP cells. RESULTS Cav-1 secretion was evident in adipose tissues and were substantially promoted in HFD-fed mice. Cav-1 was detectable in the conditioned media of 3T3-L1 adipocytes but not preadipocytes. Hypertrophied adipocytes induced by glucose and fatty acids secreted more Cav-1, suggesting that hypertrophied adipocytes were responsible for enhanced Cav-1 secretion in obese mice. Secreted Cav-1 was taken up by preadipocytes and LNCaP cells. 3T3-L1 preadipocytes overexpressing Cav-1 were better differentiated, suggesting that secreted Cav-1 may promote adipogenesis. Hypertrophied 3T3-L1 adipocytes enhanced ERK1/2 activation, and the attenuation of ERK1/2 activity by PD98059 inhibited Cav-1 secretion. CONCLUSIONS Cav-1 is actively secreted from adipocytes as a putative adipogenesis enhancer. Hypertrophied adipocytes secrete Cav-1 via ERK1/2-dependent mechanisms to promote adipogenesis, thus establishing a vicious cycle.
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Affiliation(s)
- Chia-Chu Chang
- PhD Program for Aging, China Medical University, Taichung, Taiwan, Republic of China
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan, Republic of China
- Environmental and Precision Medicine Laboratory, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan, Republic of China
| | - Chen-Yu Chen
- Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Miaoli, Taiwan, Republic of China
| | - Hui-Chin Wen
- Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Miaoli, Taiwan, Republic of China
| | - Chih-Yang Huang
- PhD Program for Aging, China Medical University, Taichung, Taiwan, Republic of China
| | - Ming-Shiu Hung
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli, Taiwan, Republic of China
| | - Hsi-Chi Lu
- Department of Food Science, Tunghai University, Taichung, Taiwan, Republic of China
| | - Woan-Ling Chen
- Environmental and Precision Medicine Laboratory, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan, Republic of China
- Department of Food Science, Tunghai University, Taichung, Taiwan, Republic of China
| | - Chung-Ho Chang
- PhD Program for Aging, China Medical University, Taichung, Taiwan, Republic of China
- Environmental and Precision Medicine Laboratory, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan, Republic of China
- Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Miaoli, Taiwan, Republic of China
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31
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RNA-seq analysis of the kidneys of broiler chickens fed diets containing different concentrations of calcium. Sci Rep 2017; 7:11740. [PMID: 28924246 PMCID: PMC5603577 DOI: 10.1038/s41598-017-11379-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 08/23/2017] [Indexed: 01/13/2023] Open
Abstract
Calcium (Ca) is required for normal growth and is involved in cellular physiology, signal transduction, and bone mineralization. In humans, inadequate Ca intake causes hypocalcaemia, and excessive Ca intake causes hypercalcemia. In chicken, Ca is also required for body weight gain and eggshell formation. However, transcriptomic responses to low/high Ca intake, and mechanisms affecting body weight have not been explored. In this study, we performed comparative RNA sequencing (RNA-seq) using the kidney of broiler chickens fed diets containing 0.8, 1.0, and 1.2% Ca. Annotation of RNA-seq data revealed a significant number of differentially expressed genes (DEGs) in the kidney via pairwise comparison using Cufflinks and edgeR. Using edgeR, we identified 12 DEGs; seven overlapped with those found by cufflinks. Seven DEGs were validated by real-time quantitative-PCR (qRT-PCR) in Ca-supplemented kidneys, and the results correlated with the RNA-seq data. DEGs identified by cufflinks/edgeR were subjected to pathway enrichment, protein/protein interaction, and co-occurrence analyses to determine their involvement in disease. The National Research Council (NRC) recommended Ca intake for 21-day post-hatch broilers is about 1.0%. Our findings suggest that higher-than-recommended Ca intake (1.2%) could reduce body weight gain in broilers, and that affected DEGs are related to stress-induced diseases, such as hypertension.
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Yeo CR, Agrawal M, Hoon S, Shabbir A, Shrivastava MK, Huang S, Khoo CM, Chhay V, Yassin MS, Tai ES, Vidal-Puig A, Toh SA. SGBS cells as a model of human adipocyte browning: A comprehensive comparative study with primary human white subcutaneous adipocytes. Sci Rep 2017; 7:4031. [PMID: 28642596 PMCID: PMC5481408 DOI: 10.1038/s41598-017-04369-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 05/19/2017] [Indexed: 01/20/2023] Open
Abstract
The Simpson Golabi Behmel Syndrome (SGBS) pre-adipocyte cell strain is widely considered to be a representative in vitro model of human white pre-adipocytes. A recent study suggested that SGBS adipocytes exhibit an unexpected transient brown phenotype. Here, we comprehensively examined key differences between SGBS adipocytes and primary human white subcutaneous (PHWSC) adipocytes. RNA-Seq analysis revealed that extracellular matrix (ECM)-receptor interaction and metabolic pathways were the top two KEGG pathways significantly enriched in SGBS adipocytes, which included positively enriched mitochondrial respiration and oxidation pathways. Compared to PHWSC adipocytes, SGBS adipocytes showed not only greater induction of adipogenic gene expression during differentiation but also increased levels of UCP1 mRNA and protein expression. Functionally, SGBS adipocytes displayed higher ISO-induced basal leak respiration and overall oxygen consumption rate, along with increased triglyceride accumulation and insulin-stimulated glucose uptake. In conclusion, we confirmed that SGBS adipocytes, which are considered of white adipose tissue origin can shift towards a brown/beige adipocyte phenotype. These differences indicate SGBS cells may help to identify mechanisms leading to browning, and inform our understanding for the use of SGBS vis-à-vis primary human subcutaneous adipocytes as a human white adipocyte model, guiding the selection of appropriate cell models in future metabolic research.
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Affiliation(s)
- Chia Rou Yeo
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 117599, Singapore, Singapore
| | - Madhur Agrawal
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 117599, Singapore, Singapore
| | - Shawn Hoon
- Molecular Engineering Laboratory, Biomedical Sciences Institutes, A*Star, 138668, Singapore, Singapore
| | - Asim Shabbir
- Department of Surgery, National University Hospital, 119074, Singapore, Singapore
| | - Manu Kunaal Shrivastava
- Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Shiqi Huang
- Food Science and Technology Program, Department of Chemistry, National University of Singapore, Singapore, 117542, Singapore
| | - Chin Meng Khoo
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 117599, Singapore, Singapore
- Department of Medicine, National University Health System, 119228, Singapore, Singapore
| | - Vanna Chhay
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 117599, Singapore, Singapore
| | - M Shabeer Yassin
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 117599, Singapore, Singapore
| | - E Shyong Tai
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 117599, Singapore, Singapore
- Department of Medicine, National University Health System, 119228, Singapore, Singapore
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Sue-Anne Toh
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 117599, Singapore, Singapore.
- Department of Medicine, National University Health System, 119228, Singapore, Singapore.
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Leukemic blasts program bone marrow adipocytes to generate a protumoral microenvironment. Blood 2017; 129:1320-1332. [PMID: 28049638 DOI: 10.1182/blood-2016-08-734798] [Citation(s) in RCA: 214] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 12/22/2016] [Indexed: 02/07/2023] Open
Abstract
Despite currently available therapies, most patients diagnosed with acute myeloid leukemia (AML) die of their disease. Tumor-host interactions are critical for the survival and proliferation of cancer cells; accordingly, we hypothesize that specific targeting of the tumor microenvironment may constitute an alternative or additional strategy to conventional tumor-directed chemotherapy. Because adipocytes have been shown to promote breast and prostate cancer proliferation, and because the bone marrow adipose tissue accounts for up to 70% of bone marrow volume in adult humans, we examined the adipocyte-leukemia cell interactions to determine if they are essential for the growth and survival of AML. Using in vivo and in vitro models of AML, we show that bone marrow adipocytes from the tumor microenvironment support the survival and proliferation of malignant cells from patients with AML. We show that AML blasts alter metabolic processes in adipocytes to induce phosphorylation of hormone-sensitive lipase and consequently activate lipolysis, which then enables the transfer of fatty acids from adipocytes to AML blasts. In addition, we report that fatty acid binding protein-4 (FABP4) messenger RNA is upregulated in adipocytes and AML when in coculture. FABP4 inhibition using FABP4 short hairpin RNA knockdown or a small molecule inhibitor prevents AML proliferation on adipocytes. Moreover, knockdown of FABP4 increases survival in Hoxa9/Meis1-driven AML model. Finally, knockdown of carnitine palmitoyltransferase IA in an AML patient-derived xenograft model improves survival. Here, we report the first description of AML programming bone marrow adipocytes to generate a protumoral microenvironment.
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Yamamoto T, Furuhashi M, Sugaya T, Oikawa T, Matsumoto M, Funahashi Y, Matsukawa Y, Gotoh M, Miura T. Transcriptome and Metabolome Analyses in Exogenous FABP4- and FABP5-Treated Adipose-Derived Stem Cells. PLoS One 2016; 11:e0167825. [PMID: 27936164 PMCID: PMC5148007 DOI: 10.1371/journal.pone.0167825] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 11/21/2016] [Indexed: 12/30/2022] Open
Abstract
Adipose-derived stem cells (ADSC), which exist near adipocytes in adipose tissue, have been used as a potential tool of regenerative medicine. Lipid chaperones, fatty acid-binding protein 4 (FABP4) and 5 (FABP5), are abundantly expressed in adipocytes. FABP4 has recently been shown to be secreted from adipocytes during lipolysis in a non-classical pathway and may act as an adipokine. Here, we investigated the role of exogenous FABP4 and FABP5 in transcriptional and metabolic regulation in ADSC. FABP4 and FABP5 were little expressed in ADSC. However, both FABP4 and FABP5 were significantly induced after adipocyte differentiation of ADSC and were secreted from the differentiated adipocytes. Analysis of microarray data, including gene ontology enrichment analysis and cascade analysis of the protein-protein interaction network using a transcription factor binding site search, demonstrated that treatment of ADSC with FABP4 or FABP5 affected several kinds of genes related to inflammatory and metabolic responses and the process of cell differentiation. Notably, myogenic factors, including myocyte enhancer factors, myogenic differentiation 1 and myogenin, were modulated by treatment of ADSC with FABP4, indicating that exogenous FABP4 treatment is partially associated with myogenesis in ADSC. Metabolome analysis showed that treatment of ADSC with FABP4 and with FABP5 similarly, but differently in extent, promoted hydrolysis and/or uptake of lipids, consequentially together with enhancement of β oxidation, inhibition of downstream of the glycolysis pathway, accumulation of amino acids, reduction of nucleic acid components and increase in the ratio of reduced and oxidized nicotinamide adenine dinucleotide phosphates (NADPH/NADP+), an indicator of reducing power, and the ratio of adenosine triphosphate and adenosine monophosphate (ATP/AMP), an indicator of the energy state, in ADSC. In conclusion, secreted FABP4 and FABP5 from adipocytes as adipokines differentially affect transcriptional and metabolic regulation in ADSC near adipocytes. The adiposity condition in the host of regenerative medicine may affect characteristics of ADSC by exposure of the balance of FABP4 and FABP5.
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Affiliation(s)
- Tokunori Yamamoto
- Department of Urology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masato Furuhashi
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Japan
| | - Takeshi Sugaya
- Department of Nephrology and Hypertension, St. Marianna University School of Medicine, Sugao, Miyamae-ku, Kawasaki, Kanagawa, Japan
- CIMIC Co., Ltd; Mass Building Yushima, Bunkyo-ku, Tokyo, Japan
| | - Tsuyoshi Oikawa
- CIMIC Co., Ltd; Mass Building Yushima, Bunkyo-ku, Tokyo, Japan
| | - Megumi Matsumoto
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Japan
| | - Yasuhito Funahashi
- Department of Urology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshihisa Matsukawa
- Department of Urology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Momokazu Gotoh
- Department of Urology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tetsuji Miura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo, Japan
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Zhang J, Qiao C, Chang L, Guo Y, Fan Y, Villacorta L, Chen YE, Zhang J. Cardiomyocyte Overexpression of FABP4 Aggravates Pressure Overload-Induced Heart Hypertrophy. PLoS One 2016; 11:e0157372. [PMID: 27294862 PMCID: PMC4905683 DOI: 10.1371/journal.pone.0157372] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 05/28/2016] [Indexed: 12/23/2022] Open
Abstract
Fatty acid binding protein 4 (FABP4) is a member of the intracellular lipid-binding protein family, responsible for the transportation of fatty acids. It is considered to express mainly in adipose tissues, and be strongly associated with inflammation, obesity, diabetes and cardiovasculardiseases. Here we report that FABP4 is also expressed in cardiomyocytes and plays an important role in regulating heart function under pressure overload. We generated heart-specific transgenic FABP4 (FABP4-TG) mice using α myosin-heavy chain (α-MHC) promoter and human FABP4 sequence, resulting in over-expression of FABP4 in cardiomyocytes. The FABP4-TG mice displayed normal cardiac morphology and contractile function. When they were subjected to the transverse aorta constriction (TAC) procedure, the FABP4-TG mice developed more cardiac hypertrophy correlated with significantly increased ERK phosphorylation, compared with wild type controls. FABP4 over-expression in cardiomyocytes activated phosphor-ERK signal and up-regulate the expression of cardiac hypertrophic marker genes. Conversely, FABP4 induced phosphor-ERK signal and hypertrophic gene expressions can be markedly inhibited by an ERK inhibitor PD098059 as well as the FABP4 inhibitor BMS309403. These results suggest that FABP4 over-expression in cardiomyocytes can aggravate the development of cardiac hypertrophy through the activation of ERK signal pathway.
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Affiliation(s)
- Ji Zhang
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
- * E-mail: (JZ); (YEC)
| | - Congzhen Qiao
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Lin Chang
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Yanhong Guo
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Yanbo Fan
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Luis Villacorta
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Y. Eugene Chen
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
- * E-mail: (JZ); (YEC)
| | - Jifeng Zhang
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
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Guaita-Esteruelas S, Bosquet A, Saavedra P, Gumà J, Girona J, Lam EWF, Amillano K, Borràs J, Masana L. Exogenous FABP4 increases breast cancer cell proliferation and activates the expression of fatty acid transport proteins. Mol Carcinog 2016; 56:208-217. [PMID: 27061264 DOI: 10.1002/mc.22485] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 02/22/2016] [Accepted: 03/18/2016] [Indexed: 11/11/2022]
Abstract
Adipose tissue plays an important role in tumor progression, because it provides nutrients and adipokines to proliferating cells. Fatty acid binding protein 4 (FABP4) is a key adipokine for fatty acid transport. In metabolic pathologies, plasma levels of FABP4 are increased. However, the role of this circulating protein is unknown. Recent studies have demonstrated that FABP4 might have a role in tumor progression, but the molecular mechanisms involved are still unclear. In this study, we analysed the role of eFABP4 (exogenous FABP4) in breast cancer progression. MCF-7 and MDA-MB-231 breast cancer cells did not express substantial levels of FABP4 protein, but intracellular FABP4 levels increased after eFABP4 incubation. Moreover, eFABP4 enhanced the proliferation of these breast cancer cells but did not have any effect on MCF-7 and MDA-MB-231 cell migration. Additionally, eFABP4 induced the AKT and MAPK signaling cascades in breast cancer cells, and the inhibition of these pathways reduced the eFBAP4-mediated cell proliferation. Interestingly, eFABP4 treatment in MCF-7 cells increased levels of the transcription factor FoxM1 and the fatty acid transport proteins CD36 and FABP5. In summary, we showed that eFABP4 plays a key role in tumor proliferation and activates the expression of fatty acid transport proteins in MCF-7 breast cancer cells. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Sandra Guaita-Esteruelas
- Institut d'Investigació Sanitària Pere Virgili (IISPV), Centre d'R+D+I en Nutrició i Salut. Avda. de la Universitat, Reus, Spain.,Research Unit on Lipids and Atherosclerosis, Universitat Rovira i Virgili, carrer Sant Llorenç, Reus, Spain.,Oncology Research Group, "Sant Joan" University Hospital, Oncology Institute of Southern Catalonia (IOCS), Av. del Dr. Josep Laporte, Reus, Spain
| | - Alba Bosquet
- Institut d'Investigació Sanitària Pere Virgili (IISPV), Centre d'R+D+I en Nutrició i Salut. Avda. de la Universitat, Reus, Spain.,Research Unit on Lipids and Atherosclerosis, Universitat Rovira i Virgili, carrer Sant Llorenç, Reus, Spain
| | - Paula Saavedra
- Research Unit on Lipids and Atherosclerosis, Universitat Rovira i Virgili, carrer Sant Llorenç, Reus, Spain
| | - Josep Gumà
- Oncology Research Group, "Sant Joan" University Hospital, Oncology Institute of Southern Catalonia (IOCS), Av. del Dr. Josep Laporte, Reus, Spain
| | - Josefa Girona
- Research Unit on Lipids and Atherosclerosis, Universitat Rovira i Virgili, carrer Sant Llorenç, Reus, Spain
| | - Eric W-F Lam
- Department of Surgery and Cancer, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College London, London W12 0NN, United Kingdom
| | - Kepa Amillano
- Oncology Research Group, "Sant Joan" University Hospital, Oncology Institute of Southern Catalonia (IOCS), Av. del Dr. Josep Laporte, Reus, Spain
| | - Joan Borràs
- Oncology Research Group, "Sant Joan" University Hospital, Oncology Institute of Southern Catalonia (IOCS), Av. del Dr. Josep Laporte, Reus, Spain
| | - Lluís Masana
- Research Unit on Lipids and Atherosclerosis, Universitat Rovira i Virgili, carrer Sant Llorenç, Reus, Spain
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Hu R, Huffman KE, Chu M, Zhang Y, Minna JD, Yu Y. Quantitative Secretomic Analysis Identifies Extracellular Protein Factors That Modulate the Metastatic Phenotype of Non-Small Cell Lung Cancer. J Proteome Res 2016; 15:477-86. [PMID: 26736068 DOI: 10.1021/acs.jproteome.5b00819] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Lung cancer is the leading cause of cancer-related deaths for men and women in the United States, with non-small cell lung cancer (NSCLC) representing 85% of all diagnoses. Late stage detection, metastatic disease and lack of actionable biomarkers contribute to the high mortality rate. Proteins in the extracellular space are known to be critically involved in regulating every stage of the pathogenesis of lung cancer. To investigate the mechanism by which secreted proteins contribute to the pathogenesis of NSCLC, we performed quantitative secretomic analysis of two isogenic NSCLC cell lines (NCI-H1993 and NCI-H2073) and an immortalized human bronchial epithelial cell line (HBEC3-KT) as control. H1993 was derived from a chemo-naïve metastatic tumor, while H2073 was derived from the primary tumor after etoposide/cisplatin therapy. From the conditioned media of these three cell lines, we identified and quantified 2713 proteins, including a series of proteins involved in regulating inflammatory response, programmed cell death and cell motion. Gene Ontology (GO) analysis indicates that a number of proteins overexpressed in H1993 media are involved in biological processes related to cancer metastasis, including cell motion, cell-cell adhesion and cell migration. RNA interference (RNAi)-mediated knock down of a number of these proteins, including SULT2B1, CEACAM5, SPRR3, AGR2, S100P, and S100A14, leads to dramatically reduced migration of these cells. In addition, meta-analysis of survival data indicates NSCLC patients whose tumors express higher levels of several of these secreted proteins, including SULT2B1, CEACAM5, SPRR3, S100P, and S100A14, have a worse prognosis. Collectively, our results provide a potential molecular link between deregulated secretome and NSCLC cell migration/metastasis. In addition, the identification of these aberrantly secreted proteins might facilitate the development of biomarkers for early detection of this devastating disease.
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Affiliation(s)
- Rongkuan Hu
- Department of Biochemistry and ‡Hamon Center for Therapeutic Oncology Research, Simmons Comprehensive Cancer Center, Pharmacology and Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas 75235, United States
| | - Kenneth E Huffman
- Department of Biochemistry and ‡Hamon Center for Therapeutic Oncology Research, Simmons Comprehensive Cancer Center, Pharmacology and Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas 75235, United States
| | - Michael Chu
- Department of Biochemistry and ‡Hamon Center for Therapeutic Oncology Research, Simmons Comprehensive Cancer Center, Pharmacology and Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas 75235, United States
| | - Yajie Zhang
- Department of Biochemistry and ‡Hamon Center for Therapeutic Oncology Research, Simmons Comprehensive Cancer Center, Pharmacology and Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas 75235, United States
| | - John D Minna
- Department of Biochemistry and ‡Hamon Center for Therapeutic Oncology Research, Simmons Comprehensive Cancer Center, Pharmacology and Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas 75235, United States
| | - Yonghao Yu
- Department of Biochemistry and ‡Hamon Center for Therapeutic Oncology Research, Simmons Comprehensive Cancer Center, Pharmacology and Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas 75235, United States
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38
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Burak MF, Inouye KE, White A, Lee A, Tuncman G, Calay ES, Sekiya M, Tirosh A, Eguchi K, Birrane G, Lightwood D, Howells L, Odede G, Hailu H, West S, Garlish R, Neale H, Doyle C, Moore A, Hotamisligil GS. Development of a therapeutic monoclonal antibody that targets secreted fatty acid–binding protein aP2 to treat type 2 diabetes. Sci Transl Med 2015; 7:319ra205. [DOI: 10.1126/scitranslmed.aac6336] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 11/04/2015] [Indexed: 12/13/2022]
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Abstract
Intracellular and extracellular interactions with proteins enables the functional and mechanistic diversity of lipids. Fatty acid-binding proteins (FABPs) were originally described as intracellular proteins that can affect lipid fluxes, metabolism and signalling within cells. As the functions of this protein family have been further elucidated, it has become evident that they are critical mediators of metabolism and inflammatory processes, both locally and systemically, and therefore are potential therapeutic targets for immunometabolic diseases. In particular, genetic deficiency and small molecule-mediated inhibition of FABP4 (also known as aP2) and FABP5 can potently improve glucose homeostasis and reduce atherosclerosis in mouse models. Further research has shown that in addition to their intracellular roles, some FABPs are found outside the cells, and FABP4 undergoes regulated, vesicular secretion. The circulating form of FABP4 has crucial hormonal functions in systemic metabolism. In this Review we discuss the roles and regulation of both intracellular and extracellular FABP actions, highlighting new insights that might direct drug discovery efforts and opportunities for management of chronic metabolic diseases.
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Affiliation(s)
- Gökhan S Hotamisligil
- Department of Genetics and Complex Diseases and Sabri Ülker Center, Harvard T.H. Chan School of Public Health, 677 Huntington Avenue, Boston, MA 02115, USA
| | - David A Bernlohr
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 321 Church Street SE, Minneapolis, MN 55455, USA
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Llobet L, Toivonen JM, Montoya J, Ruiz-Pesini E, López-Gallardo E. Xenobiotics that affect oxidative phosphorylation alter differentiation of human adipose-derived stem cells at concentrations that are found in human blood. Dis Model Mech 2015; 8:1441-55. [PMID: 26398948 PMCID: PMC4631789 DOI: 10.1242/dmm.021774] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 09/03/2015] [Indexed: 12/17/2022] Open
Abstract
Adipogenesis is accompanied by differentiation of adipose tissue-derived stem cells to adipocytes. As part of this differentiation, biogenesis of the oxidative phosphorylation system occurs. Many chemical compounds used in medicine, agriculture or other human activities affect oxidative phosphorylation function. Therefore, these xenobiotics could alter adipogenesis. We have analyzed the effects on adipocyte differentiation of some xenobiotics that act on the oxidative phosphorylation system. The tested concentrations have been previously reported in human blood. Our results show that pharmaceutical drugs that decrease mitochondrial DNA replication, such as nucleoside reverse transcriptase inhibitors, or inhibitors of mitochondrial protein synthesis, such as ribosomal antibiotics, diminish adipocyte differentiation and leptin secretion. By contrast, the environmental chemical pollutant tributyltin chloride, which inhibits the ATP synthase of the oxidative phosphorylation system, can promote adipocyte differentiation and leptin secretion, leading to obesity and metabolic syndrome as postulated by the obesogen hypothesis. Summary: Some medical drugs and environmental chemical pollutants acting on the oxidative phosphorylation system can alter adipocyte differentiation and adipogenesis and, thus, have important consequences for human health.
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Affiliation(s)
- Laura Llobet
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013-Zaragoza, Spain Instituto de Investigación Sanitaria de Aragón, Universidad de Zaragoza, 50013-Zaragoza, Spain CIBER de Enfermedades Raras (CIBERER), Universidad de Zaragoza, 50013-Zaragoza, Spain
| | - Janne M Toivonen
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013-Zaragoza, Spain Instituto de Investigación Sanitaria de Aragón, Universidad de Zaragoza, 50013-Zaragoza, Spain
| | - Julio Montoya
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013-Zaragoza, Spain Instituto de Investigación Sanitaria de Aragón, Universidad de Zaragoza, 50013-Zaragoza, Spain CIBER de Enfermedades Raras (CIBERER), Universidad de Zaragoza, 50013-Zaragoza, Spain
| | - Eduardo Ruiz-Pesini
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013-Zaragoza, Spain Instituto de Investigación Sanitaria de Aragón, Universidad de Zaragoza, 50013-Zaragoza, Spain CIBER de Enfermedades Raras (CIBERER), Universidad de Zaragoza, 50013-Zaragoza, Spain Fundación ARAID, Universidad de Zaragoza, 50013-Zaragoza, Spain
| | - Ester López-Gallardo
- Departamento de Bioquímica, Biología Molecular y Celular, Universidad de Zaragoza, 50013-Zaragoza, Spain Instituto de Investigación Sanitaria de Aragón, Universidad de Zaragoza, 50013-Zaragoza, Spain CIBER de Enfermedades Raras (CIBERER), Universidad de Zaragoza, 50013-Zaragoza, Spain
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Saavedra P, Girona J, Bosquet A, Guaita S, Canela N, Aragonès G, Heras M, Masana L. New insights into circulating FABP4: Interaction with cytokeratin 1 on endothelial cell membranes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2966-74. [PMID: 26343611 DOI: 10.1016/j.bbamcr.2015.09.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 08/07/2015] [Accepted: 09/03/2015] [Indexed: 01/12/2023]
Abstract
Fatty acid-binding protein 4 (FABP4) is an adipose tissue-secreted adipokine that is involved in the regulation of energetic metabolism and inflammation. Increased levels of circulating FABP4 have been detected in individuals with cardiovascular risk factors. Recent studies have demonstrated that FABP4 has a direct effect on peripheral tissues, specifically promoting vascular dysfunction; however, its mechanism of action is unknown. The objective of this work was to assess the specific interactions between exogenous FABP4 and the plasma membranes of endothelial cells. Immunofluorescence assays showed that exogenous FABP4 localized along the plasma membranes of human umbilical vein endothelial cells (HUVECs), interacting specifically with plasma membrane proteins. Anti-FABP4 immunoblotting revealed two covalent protein complexes containing FABP4 and its putative receptor; these complexes were approximately 108 kDa and 77 kDa in size. Proteomics and mass spectrometry experiments revealed that cytokeratin 1 (CK1) was the FABP4-binding protein. An anti-CK1 immunoblot confirmed the presence of CK1. FABP4-CK1 complexes were also detected in HAECs, HCASMCs, HepG2 cells and THP-1 cells. Pharmacological FABP4 inhibition by BMS309403 results in a slight decrease in the formation of these complexes, indicating that fatty acids may play a role in FABP4 functionality. In addition, we demonstrated that exogenous FABP4 crosses the plasma membrane to enter the cytoplasm and nucleus in HUVECs. These findings indicate that exogenous FABP4 interacts with plasma membrane proteins, specifically CK1. These data contribute to our current knowledge regarding the mechanism of action of circulating FABP4.
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Affiliation(s)
- Paula Saavedra
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Josefa Girona
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Alba Bosquet
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Sandra Guaita
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Núria Canela
- Centre for Omics Science, Universitat Rovira i Virgili, Reus, Spain
| | - Gemma Aragonès
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Mercedes Heras
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Lluís Masana
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain.
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Abstract
A number of chronic metabolic pathologies, including obesity, diabetes, cardiovascular disease, asthma, and cancer, cluster together to present the greatest threat to human health. As research in this field has advanced, it has become clear that unresolved metabolic inflammation, organelle dysfunction, and other cellular and metabolic stresses underlie the development of these chronic metabolic diseases. However, the relationship between these systems and pathological mechanisms is poorly understood. Here we discuss the role of cellular Ca(2+) homeostasis as a critical mechanism integrating the myriad of cellular and subcellular dysfunctional networks found in metabolic tissues such as liver and adipose tissue in the context of metabolic disease, particularly in obesity and diabetes.
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Baraban E, Chavakis T, Hamilton BS, Sales S, Wabitsch M, Bornstein SR, Ehrhart-Bornstein M. Anti-inflammatory properties of bone morphogenetic protein 4 in human adipocytes. Int J Obes (Lond) 2015; 40:319-27. [PMID: 26228459 DOI: 10.1038/ijo.2015.141] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 07/05/2015] [Accepted: 07/05/2015] [Indexed: 12/30/2022]
Abstract
BACKGROUND Obesity is characterized by increased adipocyte number and size as well as white adipose tissue (WAT) inflammation, which is fundamental for the development of insulin resistance and type-2 diabetes. These processes, regulated by various endocrine, paracrine and autocrine factors, are extensively studied with the hope to interfere and to inhibit weight gain and related complications in obese patients. Recent data suggest an important role of bone morphogenic protein 4 (BMP4) in the regulation of adipogenesis and development of obesity. BMP4 is a growth factor of the transforming growth factor-β superfamily. Initially, BMPs were identified as inducers of ectopic bone formation. It is now apparent, however, that these proteins have different pleiotropic developmental actions and including playing a role in white adipogenesis. METHODS AND RESULTS Here, we demonstrate that the expression of BMP4 in human WAT is negatively correlated to body mass index and to the expression of pro-inflammatory cytokines. In vitro, BMP4 expression in cultured human adipocytes is upregulated after induction of differentiation. Cells treated with exogenous BMP4 increased peroxisome proliferator-activated receptor γ (PPARγ) expression and significantly reduced the expression of pro-inflammatory cytokines including tumor necrosis factor α (TNF-α) and monocyte chemoattractant protein 1. TNF-α treatment of fully differentiated adipocytes resulted in downregulation of the expression of adipogenic genes and elevated expression of pro-inflammatory cytokines. Exogenous BMP4 addition significantly reduced the negative effect of TNF-α on the expression profile of adipocytes. Finally, treatment of human adipocytes with exogenous BMP4 reduced the adipocytes' chemoattractant potential and the migration of monocytes toward adipocyte-conditioned medium. CONCLUSIONS These results indicate that BMP4 is an important anti-inflammatory molecule, which may act through PPARγ and reduces TNF-α-mediated pro-inflammatory cytokine production in human adipocytes. Through its anti-inflammatory potential, BMP4 may serve as a protective factor for inflammation-related diseases such as insulin-tolerance or type-2 diabetes.
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Affiliation(s)
- E Baraban
- Division of Molecular Endocrinology, Medical Clinic III, Technische Universität Dresden, Dresden, Germany
| | - T Chavakis
- Division of Molecular Endocrinology, Medical Clinic III, Technische Universität Dresden, Dresden, Germany.,Department of Clinical Pathobiochemistry, Institute of Clinical Chemistry and Laboratory Medicine, University Clinic, Technische Universität Dresden, Dresden, Germany
| | - B S Hamilton
- CardioMetabolic Diseases Research, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach an der Riß, Germany
| | - S Sales
- Division of Molecular Endocrinology, Medical Clinic III, Technische Universität Dresden, Dresden, Germany.,Max Planck Institute of Molecular Cell Biology and Genetics, Shevchenko Lab, Dresden, Germany
| | - M Wabitsch
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, University of Ulm, Ulm, Germany
| | - S R Bornstein
- Division of Molecular Endocrinology, Medical Clinic III, Technische Universität Dresden, Dresden, Germany
| | - M Ehrhart-Bornstein
- Division of Molecular Endocrinology, Medical Clinic III, Technische Universität Dresden, Dresden, Germany
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Kralisch S, Klöting N, Ebert T, Kern M, Hoffmann A, Krause K, Jessnitzer B, Lossner U, Sommerer I, Stumvoll M, Fasshauer M. Circulating adipocyte fatty acid-binding protein induces insulin resistance in mice in vivo. Obesity (Silver Spring) 2015; 23:1007-13. [PMID: 25865078 DOI: 10.1002/oby.21057] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 01/29/2015] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Circulating levels of the adipokine adipocyte fatty acid-binding protein (AFABP) are increased in obesity. However, the influence of circulating AFABP on insulin sensitivity in vivo remains unclear. METHODS C57BL/6NTac mice (10 weeks) were treated over 8 weeks i.p. with saline (control) or recombinant AFABP (0.5 mg/kg/d). A comprehensive characterization of metabolic parameters, body composition, and energy expenditure was performed. Furthermore, the effect of AFABP on pancreatic β-cell responsiveness, hepatic glycogen content, and peroxisome proliferator-activated receptor (PPAR) γ protein expression was elucidated. RESULTS In male mice, AFABP treatment induced insulin resistance with significantly increased fasting insulin, C-peptide, and homeostasis model assessment of insulin resistance. In female animals, a similar trend was observed. In both genders, no difference in body weight, lipid parameters, body composition, or energy expenditure could be detected between AFABP-treated and control mice. Insulin resistance in male AFABP-treated mice was accompanied by decreased PPARγ protein content in perigonadal adipose tissue and diminished circulating adiponectin. AFABP treatment did not affect pancreatic β-cell responsiveness and hepatic glycogen content. CONCLUSIONS Circulating AFABP induces insulin resistance in male mice. AFABP-mediated degradation of PPARγ in adipose tissue and subsequently decreased expression of insulin-sensitizing adiponectin are potential mechanisms for this effect.
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Affiliation(s)
- Susan Kralisch
- Department of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany; Leipzig University Medical Center, IFB AdiposityDiseases, Leipzig, Germany
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Huber W, Sinopoli A, Kohler J, Hug M, Ruf A, Huber S. Elucidation of direct competition and allosteric modulation of small-molecular-weight protein ligands using surface plasmon resonance methods. J Mol Recognit 2015; 28:480-91. [DOI: 10.1002/jmr.2465] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 01/16/2015] [Accepted: 01/16/2015] [Indexed: 01/01/2023]
Affiliation(s)
- Walter Huber
- Molecular Design and Chemical Biology (MDCB); F. Hoffmann La Roche, Roche Innovation Center Basel; Grenzacherstrasse 124 4070 Basel Switzerland
| | | | - Josiane Kohler
- Molecular Design and Chemical Biology (MDCB); F. Hoffmann La Roche, Roche Innovation Center Basel; Grenzacherstrasse 124 4070 Basel Switzerland
| | - Melanie Hug
- Molecular Design and Chemical Biology (MDCB); F. Hoffmann La Roche, Roche Innovation Center Basel; Grenzacherstrasse 124 4070 Basel Switzerland
| | - Armin Ruf
- Molecular Design and Chemical Biology (MDCB); F. Hoffmann La Roche, Roche Innovation Center Basel; Grenzacherstrasse 124 4070 Basel Switzerland
| | - Sylwia Huber
- Molecular Design and Chemical Biology (MDCB); F. Hoffmann La Roche, Roche Innovation Center Basel; Grenzacherstrasse 124 4070 Basel Switzerland
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Furuhashi M, Saitoh S, Shimamoto K, Miura T. Fatty Acid-Binding Protein 4 (FABP4): Pathophysiological Insights and Potent Clinical Biomarker of Metabolic and Cardiovascular Diseases. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2015; 8:23-33. [PMID: 25674026 PMCID: PMC4315049 DOI: 10.4137/cmc.s17067] [Citation(s) in RCA: 196] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 12/16/2014] [Accepted: 12/16/2014] [Indexed: 12/13/2022]
Abstract
Over the past decade, evidences of an integration of metabolic and inflammatory pathways, referred to as metaflammation in several aspects of metabolic syndrome, have been accumulating. Fatty acid-binding protein 4 (FABP4), also known as adipocyte FABP (A-FABP) or aP2, is mainly expressed in adipocytes and macrophages and plays an important role in the development of insulin resistance and atherosclerosis in relation to metaflammation. Despite lack of a typical secretory signal peptide, FABP4 has been shown to be released from adipocytes in a non-classical pathway associated with lipolysis, possibly acting as an adipokine. Elevation of circulating FABP4 levels is associated with obesity, insulin resistance, diabetes mellitus, hypertension, cardiac dysfunction, atherosclerosis, and cardiovascular events. Furthermore, ectopic expression and function of FABP4 in several types of cells and tissues have been recently demonstrated. Here, we discuss both the significant role of FABP4 in pathophysiological insights and its usefulness as a biomarker of metabolic and cardiovascular diseases.
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Affiliation(s)
- Masato Furuhashi
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Shigeyuki Saitoh
- Department of Nursing, Division of Medical and Behavioral Subjects, Sapporo Medical University School of Health Sciences, Sapporo, Japan
| | | | - Tetsuji Miura
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
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Mita T, Furuhashi M, Hiramitsu S, Ishii J, Hoshina K, Ishimura S, Fuseya T, Watanabe Y, Tanaka M, Ohno K, Akasaka H, Ohnishi H, Yoshida H, Saitoh S, Shimamoto K, Miura T. FABP4 is secreted from adipocytes by adenyl cyclase-PKA- and guanylyl cyclase-PKG-dependent lipolytic mechanisms. Obesity (Silver Spring) 2015; 23:359-67. [PMID: 25521833 DOI: 10.1002/oby.20954] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 10/05/2014] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Fatty acid-binding protein 4 (FABP4) is expressed in adipocytes, and elevated plasma FABP4 level is associated with obesity-mediated metabolic phenotype. Postprandial regulation and secretory signaling of FABP4 has been investigated. METHODS Time courses of FABP4 levels were examined during an oral glucose tolerance test (OGTT; n=53) or a high-fat test meal eating (n=35). Effects of activators and inhibitors of adenyl cyclase (AC)-protein kinase A (PKA) signaling and guanylyl cyclase (GC)-protein kinase G (PKG) signaling on FABP4 secretion from mouse 3T3-L1 adipocytes were investigated. RESULTS FABP4 level significantly declined after the OGTT or a high-fat meal eating, while insulin level was increased. Treatment with low and high glucose concentration or palmitate for 2 h did not affect FABP4 secretion from 3T3-L1 adipocytes. FABP4 secretion was increased by stimulation of lipolysis using isoproterenol, a β3 -adrenoceptor agonist (CL316243), forskolin, dibutyryl-cAMP and atrial natriuretic peptide, and the induced FABP4 secretion was suppressed by insulin or an inhibitor of PKA (H-89), PKG (KT5823) or hormone sensitive lipase (CAY10499). CONCLUSIONS FABP4 is secreted from adipocytes in association with lipolysis regulated by AC-PKA- and GC-PKG-mediated signal pathways. Plasma FABP4 level declines postprandially, and suppression of FABP4 secretion by insulin-induced anti-lipolytic signaling may be involved in this decline in FABP4 level.
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Affiliation(s)
- Tomohiro Mita
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, 060-8543, Japan
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Ebert T, Hopf LM, Wurst U, Bachmann A, Kralisch S, Lössner U, Platz M, Kratzsch J, Stolzenburg JU, Dietel A, Grisk O, Beige J, Anders M, Bast I, Klöting N, Blüher M, Stumvoll M, Fasshauer M. Circulating adipocyte fatty acid binding protein is increased in chronic and acute renal dysfunction. Nutr Metab Cardiovasc Dis 2014; 24:1027-1034. [PMID: 24813306 DOI: 10.1016/j.numecd.2014.03.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 03/14/2014] [Accepted: 03/17/2014] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND AIMS The adipokine adipocyte fatty acid binding protein (AFABP) is positively associated with the development of the metabolic syndrome, diabetes mellitus, and cardiovascular disease. We hypothesized that AFABP also increases with deteriorating renal function. METHODS AND RESULTS Serum AFABP levels were quantified by enzyme linked immunosorbent assay in 532 patients with chronic kidney disease (CKD) covering the whole spectrum of estimated glomerular filtration rate (eGFR) categories from G1 to G5 (study population 1). Furthermore, AFABP was measured in 32 patients before and within 30 h after elective unilateral nephrectomy, a model of acute kidney dysfunction (AKD) (study population 2). Moreover, circulating AFABP was investigated in rats undergoing bilateral nephrectomy (BNE) as compared to sham-operated animals. Median serum AFABP levels adjusted for age, gender, and body mass index significantly increased with increasing eGFR category (G1: 22.0 μg/l; G2: 34.6 μg/l; G3: 56.7 μg/l; G4: 95.2 μg/l; and G5: 173.9 μg/l). Furthermore, renal dysfunction remained positively associated with AFABP in multivariate analysis in this cohort. In patients undergoing unilateral nephrectomy, AFABP increased significantly after surgery (42.1 μg/l) as compared to pre-surgical values (29.3 μg/l). Furthermore, relative changes of post-to-pre-surgical AFABP levels were independently associated with relative changes of post-to-pre-surgical creatinine concentrations. After BNE in rats, AFABP increased significantly as compared to sham-operated animals. CONCLUSIONS We show that AFABP is significantly elevated in CKD and AKD patients. Furthermore, measures of renal function are associated with circulating AFABP. Moreover, animal experiments indicate that AFABP levels strongly depend on renal function.
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Affiliation(s)
- T Ebert
- University of Leipzig, Department of Endocrinology and Nephrology, 04103 Leipzig, Germany; Leipzig University Medical Center, IFB AdiposityDiseases, 04103 Leipzig, Germany.
| | - L M Hopf
- University of Leipzig, Department of Endocrinology and Nephrology, 04103 Leipzig, Germany; Leipzig University Medical Center, IFB AdiposityDiseases, 04103 Leipzig, Germany
| | - U Wurst
- University of Leipzig, Department of Endocrinology and Nephrology, 04103 Leipzig, Germany; Leipzig University Medical Center, IFB AdiposityDiseases, 04103 Leipzig, Germany
| | - A Bachmann
- University of Leipzig, Department of Endocrinology and Nephrology, 04103 Leipzig, Germany
| | - S Kralisch
- University of Leipzig, Department of Endocrinology and Nephrology, 04103 Leipzig, Germany; Leipzig University Medical Center, IFB AdiposityDiseases, 04103 Leipzig, Germany
| | - U Lössner
- University of Leipzig, Department of Endocrinology and Nephrology, 04103 Leipzig, Germany; Leipzig University Medical Center, IFB AdiposityDiseases, 04103 Leipzig, Germany
| | - M Platz
- University of Leipzig, Department of Endocrinology and Nephrology, 04103 Leipzig, Germany; Leipzig University Medical Center, IFB AdiposityDiseases, 04103 Leipzig, Germany
| | - J Kratzsch
- University of Leipzig, Institute of Laboratory Medicine, 04103 Leipzig, Germany
| | - J U Stolzenburg
- University of Leipzig, Department of Urology, 04103 Leipzig, Germany
| | - A Dietel
- University of Leipzig, Department of Urology, 04103 Leipzig, Germany
| | - O Grisk
- University of Greifswald, Department of Physiology, 17495 Greifswald, Karlsburg, Germany
| | - J Beige
- Hospital St. Georg, Division of Nephrology and KfH Renal Unit, 04129 Leipzig, Germany
| | - M Anders
- Outpatient Nephrology Care Unit, 04107 and 04178 Leipzig, Germany
| | - I Bast
- Outpatient Nephrology Care Unit, 04107 and 04178 Leipzig, Germany
| | - N Klöting
- Leipzig University Medical Center, IFB AdiposityDiseases, 04103 Leipzig, Germany
| | - M Blüher
- University of Leipzig, Department of Endocrinology and Nephrology, 04103 Leipzig, Germany
| | - M Stumvoll
- University of Leipzig, Department of Endocrinology and Nephrology, 04103 Leipzig, Germany
| | - M Fasshauer
- University of Leipzig, Department of Endocrinology and Nephrology, 04103 Leipzig, Germany; Leipzig University Medical Center, IFB AdiposityDiseases, 04103 Leipzig, Germany
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Kralisch S, Ebert T, Lossner U, Jessnitzer B, Stumvoll M, Fasshauer M. Adipocyte fatty acid-binding protein is released from adipocytes by a non-conventional mechanism. Int J Obes (Lond) 2013; 38:1251-4. [PMID: 24445660 DOI: 10.1038/ijo.2013.232] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 11/18/2013] [Accepted: 12/08/2013] [Indexed: 01/22/2023]
Abstract
Adipocyte fatty acid-binding protein (AFABP) is an adipokine, which induces insulin resistance. However, AFABP does not possess any secretion-directed signals and the mechanisms for AFABP release have not been thoroughly assessed so far. In the current study, mechanisms for AFABP secretion were elucidated in 3T3-L1 adipocytes in vitro in the presence or absence of hormonal stimulation, calcium ionophore and secretion inhibitors by cell fractionation experiments, immunoblotting and ELISAs. We demonstrate that AFABP secretion is upregulated during adipocyte differentiation. AFABP secretion is not influenced by treatment with protein secretion inhibitors that block vesicular traffic at the endoplasmic reticulum and the Golgi apparatus. AFABP is secreted partially by adipocyte-derived microvesicles (ADMs), an established mechanism for unconventional secretion from adipocytes. Both total and ADM-secreted AFABP are downregulated by insulin and upregulated by the calcium ionophore ionomycin. Furthermore, murine RAW 264.7 macrophages secrete AFABP and AFABP release from these cells is upregulated by lipopolysaccharide treatment. Taken together, these results suggest that AFABP is actively released by unconventional mechanisms and by ADMs from 3T3-L1 adipocytes. Furthermore, AFABP secretion from fat cells is regulated by insulin and intracellular calcium.
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Affiliation(s)
- S Kralisch
- 1] Department of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany [2] IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - T Ebert
- 1] Department of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany [2] IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - U Lossner
- 1] Department of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany [2] IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - B Jessnitzer
- Department of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
| | - M Stumvoll
- Department of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany
| | - M Fasshauer
- 1] Department of Endocrinology and Nephrology, University of Leipzig, Leipzig, Germany [2] IFB Adiposity Diseases, University of Leipzig, Leipzig, Germany
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