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Yang J, Zhang Y, Jiang L, Li C, Sun Z, Zhang Y, Lin T, Jiang Y, Liu B. A triple combination strategy of UHPLC-MS n, hypolipidemic activity and transcriptome sequencing to unveil the hypolipidemic mechanism of Nelumbo nucifera alkaloids. JOURNAL OF ETHNOPHARMACOLOGY 2022; 282:114608. [PMID: 34517059 DOI: 10.1016/j.jep.2021.114608] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/31/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Nelumbo nucifera (N. nucifera), a kind of edible Chinese herbal, has been studied in treating hyperlipidemia. However, the hypolipidemic mechanism of N. nucifera remains unknown. Aims of this review: We aimed to screen the effective constituent of N. nucifera alkaloids and elucidated the potential mechanism for treating hyperlipidemia. A triple combination strategy of UHPLC-MSn, hypolipidemic activity and transcriptome sequencing was built to unveil the hypolipidemic mechanism of Nelumbo nucifera alkaloid. MATERIALS AND METHODS We comprehensively investigated the characterization of N. nucifera alkaloids by using UHPLC-LTQ-Orbitrap MSn. And the hypolipidemic activity of candidate active ingredients were evaluated on sodium oleate-induced HepG2 cell. Finally, O-nornuciferine and N. nucifera alkaloid extraction were analyzed by RNA sequence (RNA-seq) to decipher the underlying hypolipidemic mechanism and were verified by qRT-PCR. RESULTS 35 compounds were identified from N. nucifera alkaloid extraction by UHPLC-LTQ-Orbitrap MSn. Among them, O-nornuciferine and N. nucifera alkaloid extraction which showed significant hypolipidemic activity were analyzed by transcriptome sequencing. After the intervention of O-nornuciferine and N. nucifera alkaloid extraction, 1 and 158 differentially expressed genes (DEGs) were identified, severally. The enrichment analysis indicated that the hypolipidemic effect was adjusted by the expression of numerous key DEGs involved in bile secretion, glycerolipid and sphingolipid metabolism, PPAR signaling pathway. CONCLUSIONS O-nornuciferine and N. nucifera alkaloids had exibited significant effects in hyperlipidemia. The candidate genes were LDLR, LPL and ANGPTL4, etc. It was most likely that they adjusted lipid metabolism by modulating expression levels of various key factors which were involved in bile secretion, glycerolipid metabolism, sphingolipid metabolism and PPAR signaling pathway, and so on. This study clarified the hypolipidemic mechanism of the alkaloids in N. nucifera, and laid a foundation for the subsequent development of clinical application and better quality of N. nucifera.
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Affiliation(s)
- Jiaying Yang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Yu Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Lijuan Jiang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Caixia Li
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Zhenxiao Sun
- School of Life Science, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Yan Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Tianfeng Lin
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Yanyan Jiang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China.
| | - Bin Liu
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China.
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Devi Kt R, Sivalingam N. Cichorium intybus attenuates Streptozotocin-induced pancreatic β-cell damage by inhibiting NF-κB activation and oxidative stress. J Appl Biomed 2020; 18:70-79. [PMID: 34907728 DOI: 10.32725/jab.2020.010] [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: 01/21/2019] [Accepted: 07/11/2020] [Indexed: 11/05/2022] Open
Abstract
The aqueous extract of Cichorium intybus (CIE) leaves have shown the properties of protecting against pancreatic β-cell damage by streptozotocin (STZ), but the molecular mechanisms of its protection are not completely elucidated yet. Our current study focuses on elucidating the mechanisms of these preventive effects of CIE in MIN6 cells and an in-vivo model of Wistar rats. CIE offers protection against STZ in MIN6 cells by reducing the pro-oxidants and increasing the activity of the antioxidant enzymes. In vitro results also indicated that CIE inhibited cytotoxicity, reduced Reactive oxygen species (ROS), maintained glucose-stimulated insulin secretion and reduced NF-κB p65 translocation into the nucleus. The group administered with a 250 mg/kg dose of CIE in vivo has shown an ability to maintain blood glucose level and also to preserve the number and morphology of pancreatic islets when compared to the diabetic group treated with STZ. Probably, active compounds like quercetin, rutin, and catechin present in CIE, preserve the integrity of pancreatic islets thereby protecting β-cells from the adverse effects of STZ.
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Affiliation(s)
- Ramya Devi Kt
- SRM Institute of Science and Technology, Faculty of Engineering and Technology, School of Bioengineering, Department of Biotechnology, Tamil Nadu, India
| | - Nageswaran Sivalingam
- SRM Institute of Science and Technology, Faculty of Engineering and Technology, School of Bioengineering, Department of Biotechnology, Tamil Nadu, India
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Chen YQ, Pottanat TG, Siegel RW, Ehsani M, Qian YW, Zhen EY, Regmi A, Roell WC, Guo H, Luo MJ, Gimeno RE, Van't Hooft F, Konrad RJ. Angiopoietin-like protein 8 differentially regulates ANGPTL3 and ANGPTL4 during postprandial partitioning of fatty acids. J Lipid Res 2020; 61:1203-1220. [PMID: 32487544 PMCID: PMC7397750 DOI: 10.1194/jlr.ra120000781] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/09/2020] [Indexed: 12/11/2022] Open
Abstract
Angiopoietin-like protein (ANGPTL)8 has been implicated in metabolic syndrome and reported to regulate adipose FA uptake through unknown mechanisms. Here, we studied how complex formation of ANGPTL8 with ANGPTL3 or ANGPTL4 varies with feeding to regulate LPL. In human serum, ANGPTL3/8 and ANGPTL4/8 complexes both increased postprandially, correlated negatively with HDL, and correlated positively with all other metabolic syndrome markers. ANGPTL3/8 also correlated positively with LDL-C and blocked LPL-facilitated hepatocyte VLDL-C uptake. LPL-inhibitory activity of ANGPTL3/8 was >100-fold more potent than that of ANGPTL3, and LPL-inhibitory activity of ANGPTL4/8 was >100-fold less potent than that of ANGPTL4. Quantitative analyses of inhibitory activities and competition experiments among the complexes suggested a model in which localized ANGPTL4/8 blocks the LPL-inhibitory activity of both circulating ANGPTL3/8 and localized ANGPTL4, allowing lipid sequestration into fat rather than muscle during the fed state. Supporting this model, insulin increased ANGPTL3/8 secretion from hepatocytes and ANGPTL4/8 secretion from adipocytes. These results suggest that low ANGPTL8 levels during fasting enable ANGPTL4-mediated LPL inhibition in fat tissue to minimize adipose FA uptake. During feeding, increased ANGPTL8 increases ANGPTL3 inhibition of LPL in muscle via circulating ANGPTL3/8, while decreasing ANGPTL4 inhibition of LPL in adipose tissue through localized ANGPTL4/8, thereby increasing FA uptake into adipose tissue. Excessive caloric intake may shift this system toward the latter conditions, possibly predisposing to metabolic syndrome.
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Affiliation(s)
- Yan Q Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Thomas G Pottanat
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Robert W Siegel
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Mariam Ehsani
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Yue-Wei Qian
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Eugene Y Zhen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Ajit Regmi
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - William C Roell
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Haihong Guo
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - M Jane Luo
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Ruth E Gimeno
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Ferdinand Van't Hooft
- Division of Cardiovascular Medicine, Department of Medicine Solna, Karolinska Institutet Karolinska University Hospital Solna, Stockholm, Sweden
| | - Robert J Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
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Li J, Li L, Guo D, Li S, Zeng Y, Liu C, Fu R, Huang M, Xie W. Triglyceride metabolism and angiopoietin-like proteins in lipoprotein lipase regulation. Clin Chim Acta 2020; 503:19-34. [PMID: 31923423 DOI: 10.1016/j.cca.2019.12.029] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 12/31/2019] [Accepted: 12/31/2019] [Indexed: 12/21/2022]
Abstract
Hypertriglyceridemia is a risk factor for a series of diseases, such as cardiovascular disease (CVD), diabetes and nonalcoholic fatty liver disease (NAFLD). Angiopoietin-like proteins (ANGPTLs) family, especially ANGPTL3, ANGPTL4 and ANGPTL8, which regulate lipoprotein lipase (LPL) activity, play pivotal roles in triglyceride (TG) metabolism and related diseases/complications. There are many transcriptional and post-transcriptional factors that participate in physiological and pathological regulation of ANGPTLs to affect triglyceride metabolism. This review is intended to focus on the similarity and difference in the expression, structural features, regulation profile of the three ANGPTLs and inhibitory models for LPL. Description of the regulatory factors of ANGPTLs and the properties in regulating the lipid metabolism involved in the underlying mechanisms in pathological effects on diseases will provide potential therapeutic approaches for the treatment of dyslipidemia related diseases.
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Affiliation(s)
- Jing Li
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China; 2016 Class of Clinical Medicine, University of South China, Hengyang 421001, Hunan, China
| | - Liang Li
- Department of Pathophysiology, University of South China, Hengyang 421001, Hunan, China
| | - DongMing Guo
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China
| | - SuYun Li
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China
| | - YuXin Zeng
- 2018 Class of Excellent Doctor, University of South China, Hengyang 421001, Hunan, China
| | - ChuHao Liu
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China; 2016 Class of Clinical Medicine, University of South China, Hengyang 421001, Hunan, China
| | - Ru Fu
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China; 2016 Class of Clinical Medicine, University of South China, Hengyang 421001, Hunan, China
| | - MengQian Huang
- 2015 Class of Clinical Medicine, Fuxing Hospital, Capital Medical University, Beijing 100038, China.
| | - Wei Xie
- Clinical Anatomy & Reproductive Medicine Application Institute, University of South China, Hengyang 421001, Hunan, China.
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Vendrame F, Olops L, Saad STO, Costa FF, Fertrin KY. Hypocholesterolemia and dysregulated production of angiopoietin-like proteins in sickle cell anemia patients. Cytokine 2019; 120:88-91. [PMID: 31054480 DOI: 10.1016/j.cyto.2019.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/05/2019] [Accepted: 04/19/2019] [Indexed: 12/24/2022]
Abstract
Angiopoietin-like proteins (ANGPTL) are responsible for inhibiting lipoprotein lipase activity, and ANGPTL3 and ANGPTL4 deficiencies have been shown to lower lipoprotein levels in animal models and in humans carrying loss-of-function mutations. Sickle cell anemia (SCA) is a hereditary hemolytic anemia characterized by vaso-occlusive crises and end-organ damage, which is curiously associated with hypocholesterolemia and a low incidence of atherosclerosis, whose underlying mechanisms are unclear. We hypothesized that ANGPTL3 and ANGPTL4 dysregulation is responsible for the hypolipidemic phenotype in SCA. We measured circulating concentrations of ANGPTL3 and ANGPTL4 and correlated them with hemolytic biomarkers and lipoproteins in 40 patients with SCA and 30 control individuals. The association between hemolysis and low cholesterol levels in SCA was confirmed along with surprisingly higher levels of ANGPTL3 and ANGPTL4 in SCA patients than in controls. ANGPTL3 correlated with hemolysis markers LDH and reticulocyte counts, while ANGPTL4 did not. Our data show a paradoxical increase in production of ANGPTL3 and ANGPTL4 in SCA, which would be expected to cause hyperlipidemia, due to increased inhibition of lipoprotein lipase. ANGPTL3, exclusively produced by the liver, correlated with hemolysis markers, suggesting a possible hepatic response to hemolysis. Further functional studies and replication in larger cohorts are warranted to investigate the dysregulation of lipid metabolism in SCA.
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Affiliation(s)
- Felipe Vendrame
- Hematology and Hemotherapy Center, University of Campinas - UNICAMP, Campinas, Brazil
| | - Leticia Olops
- Hematology and Hemotherapy Center, University of Campinas - UNICAMP, Campinas, Brazil
| | | | | | - Kleber Yotsumoto Fertrin
- Hematology and Hemotherapy Center, University of Campinas - UNICAMP, Campinas, Brazil; Division of Hematology, University of Washington, Seattle, WA, USA.
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Yu B, Zhang M, Chen J, Wang L, Peng X, Zhang X, Wang H, Wang A, Zhao D, Pang D, OuYang H, Tang X. Abnormality of hepatic triglyceride metabolism in Apc Min/+ mice with colon cancer cachexia. Life Sci 2019; 227:201-211. [PMID: 31002917 DOI: 10.1016/j.lfs.2019.04.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/10/2019] [Accepted: 04/16/2019] [Indexed: 01/01/2023]
Abstract
AIMS Colorectal cancer syndrome has been one of the greatest concerns in the world. Although several epidemiological studies have shown that hepatic low lipoprotein lipase (LPL) mRNA expression may be associated with dyslipidemia and tumor progression, it is still not known whether the liver plays an essential role in hyperlipidemia of ApcMin/+ mice. MAIN METHODS We measured the expression of metabolic enzymes that involved fatty acid uptake, de novo lipogenesis (DNL), β-oxidation and investigated hepatic triglyceride production in the liver of wild-type and ApcMin/+ mice. KEY FINDINGS We found that hepatic fatty acid uptake and DNL decreased, but there was no significant difference in fatty acid β-oxidation. Interestingly, the production of hepatic very low-density lipoprotein-triglyceride (VLDL-TG) decreased at 20 weeks of age, but marked steatosis was observed in the livers of the ApcMin/+ mouse. To further explore hypertriglyceridemia, we assessed the function of hepatic glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 (GPIHBP1) for the first time. GPIHBP1 is governed by the transcription factor octamer-binding transcription factor-1 (Oct-1) which are involved in the nuclear factor-κB (NF-κB) signaling pathway in the liver of ApcMin/+ mice. Importantly, it was also confirmed that sn50 (100 μg/mL, an inhibitor of the NF-κB) reversed the tumor necrosis factor α (TNFα)-induced Oct-1 and GPIHBP1 reduction in HepG2 cells. SIGNIFICANCE Altogether, these findings highlighted a novel role of GPIHBP1 that might be responsible for hypertriglyceridemia in ApcMin/+ mice. Hypertriglyceridemia in these mice may be associated with their hepatic lipid metabolism development.
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Affiliation(s)
- Biao Yu
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Mingjun Zhang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Jiahuan Chen
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Lingyu Wang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Xiaohuan Peng
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Xinwei Zhang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - He Wang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Anbei Wang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Dazhong Zhao
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Daxin Pang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Hongsheng OuYang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China
| | - Xiaochun Tang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, No.5333 Xi'an Road, Lvyuan District, Changchun 130062, Jilin Province, China.
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Sheng L, Jena PK, Liu HX, Hu Y, Nagar N, Bronner DN, Settles ML, Bäumler AJ, Wan YJY. Obesity treatment by epigallocatechin-3-gallate-regulated bile acid signaling and its enriched Akkermansia muciniphila. FASEB J 2018; 32:fj201800370R. [PMID: 29882708 PMCID: PMC6219838 DOI: 10.1096/fj.201800370r] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 05/14/2018] [Indexed: 12/21/2022]
Abstract
Dysregulated bile acid (BA) synthesis is accompanied by dysbiosis, leading to compromised metabolism. This study analyzes the effect of epigallocatechin-3-gallate (EGCG) on diet-induced obesity through regulation of BA signaling and gut microbiota. The data revealed that EGCG effectively reduced diet-increased obesity, visceral fat, and insulin resistance. Gene profiling data showed that EGCG had a significant impact on regulating genes implicated in fatty acid uptake, adipogenesis, and metabolism in the adipose tissue. In addition, metabolomics analysis revealed that EGCG altered the lipid and sugar metabolic pathways. In the intestine, EGCG reduced the FXR agonist chenodeoxycholic acid, as well as the FXR-regulated pathway, suggesting intestinal FXR deactivation. However, in the liver, EGCG increased the concentration of FXR and TGR-5 agonists and their regulated signaling. Furthermore, our data suggested that EGCG activated Takeda G protein receptor (TGR)-5 based on increased GLP-1 release and elevated serum PYY level. EGCG and antibiotics had distinct antibacterial effects. They also differentially altered body weight and BA composition. EGCG, but not antibiotics, increased Verrucomicrobiaceae, under which EGCG promoted intestinal bloom of Akkermansia muciniphila. Excitingly, A. muciniphila was as effective as EGCG in treating diet-induced obesity. Together, EGCG shifts gut microbiota and regulates BA signaling thereby having a metabolic beneficial effect.-Sheng, L., Jena, P. K., Liu, H.-X., Hu, Y., Nagar, N., Bronner, D. N., Settles, M. L., Bäumler, A. J. Wan, Y.-J. Y. Obesity treatment by epigallocatechin-3-gallate-regulated bile acid signaling and its enriched Akkermansia muciniphila.
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Affiliation(s)
- Lili Sheng
- Department of Pathology and Laboratory Medicine, University of California, Davis, Sacramento, California, USA
| | - Prasant Kumar Jena
- Department of Pathology and Laboratory Medicine, University of California, Davis, Sacramento, California, USA
| | - Hui-Xin Liu
- Department of Pathology and Laboratory Medicine, University of California, Davis, Sacramento, California, USA
| | - Ying Hu
- Department of Pathology and Laboratory Medicine, University of California, Davis, Sacramento, California, USA
| | - Nidhi Nagar
- Department of Pathology and Laboratory Medicine, University of California, Davis, Sacramento, California, USA
| | - Denise N. Bronner
- Department of Medical Microbiology and Immunology, University of California, Davis, Davis, California, USA
| | - Matthew L. Settles
- Bioinformatics Core Facility in the Genome Center, University of California, Davis, Davis, California, USA
| | - Andreas J. Bäumler
- Department of Medical Microbiology and Immunology, University of California, Davis, Davis, California, USA
| | - Yu-Jui Yvonne Wan
- Department of Pathology and Laboratory Medicine, University of California, Davis, Sacramento, California, USA
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Abstract
PURPOSE OF REVIEW Cardiovascular disease is the leading cause of morbidity and mortality in the United States and therapies aimed at lipid modification are important for the reduction of cardiovascular risk. There have been many exciting advances in lipid management over the recent years. This review discusses these recent advances as well as the direction of future studies. RECENT FINDINGS Several recent clinical trials support low-density lipoprotein cholesterol (LDL-c) reduction beyond maximal statin therapy for improved cardiovascular outcomes. Ezetimibe reduced LDL-c beyond maximal statin therapy and was associated with improved cardiovascular outcomes for high-risk populations. Further LDL-c reduction may also be achieved with proprotein convertase subtilisin/kexin type-9 (PCSK9) inhibition and a recent trial, Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk (FOURIER), was the first to show reduction in cardiovascular events for evolocumab. Additional outcome studies of monoclonal antibody and RNA-targeted PCSK9 inhibitors are underway. Quantitative high-density lipoprotein cholesterol (HDL-c) improvements have failed to have clinical impact to date; most recently, cholesteryl ester transfer protein inhibitors and apolipoprotein infusions have demonstrated disappointing results. There are still ongoing trials in both of these areas, but some newer therapies are focusing on HDL functionality and not just the absolute HDL-c levels. There are several ongoing studies in triglyceride reduction including fatty acid therapy, inhibition of apolipoprotein C-3 or ANGTPL3 and peroxisome proliferator-activated receptor-α agonists. SUMMARY Lipid management continues to evolve and these advances have the potential to change clinical practice in the coming years.
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Angptl4 does not control hyperglucagonemia or α-cell hyperplasia following glucagon receptor inhibition. Proc Natl Acad Sci U S A 2017; 114:2747-2752. [PMID: 28143927 DOI: 10.1073/pnas.1620989114] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Genetic disruption or pharmacologic inhibition of glucagon signaling effectively lowers blood glucose but results in compensatory glucagon hypersecretion involving expansion of pancreatic α-cell mass. Ben-Zvi et al. recently reported that angiopoietin-like protein 4 (Angptl4) links glucagon receptor inhibition to hyperglucagonemia and α-cell proliferation [Ben-Zvi et al. (2015) Proc Natl Acad Sci USA 112:15498-15503]. Angptl4 is a secreted protein and inhibitor of lipoprotein lipase-mediated plasma triglyceride clearance. We report that Angptl4-/- mice treated with an anti-glucagon receptor monoclonal antibody undergo elevation of plasma glucagon levels and α-cell expansion similar to wild-type mice. Overexpression of Angptl4 in liver of mice caused a 8.6-fold elevation in plasma triglyceride levels, but did not alter plasma glucagon levels or α-cell mass. Furthermore, administration of glucagon receptor-blocking antibody to healthy individuals increased plasma glucagon and amino acid levels, but did not change circulating Angptl4 concentration. These data show that Angptl4 does not link glucagon receptor inhibition to compensatory hyperglucagonemia or expansion of α-cell mass, and that it cannot be given to induce such secretion and growth. The reduction of plasma triglyceride levels in Angptl4-/- mice and increase following Angptl4 overexpression suggest that changes in plasma triglyceride metabolism do not regulate α-cells in the pancreas. Our findings corroborate recent data showing that increased plasma amino acids and their transport into α-cells link glucagon receptor blockage to α-cell hyperplasia.
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Aryal B, Rotllan N, Araldi E, Ramírez CM, He S, Chousterman BG, Fenn AM, Wanschel A, Madrigal-Matute J, Warrier N, Martín-Ventura JL, Swirski FK, Suárez Y, Fernández-Hernando C. ANGPTL4 deficiency in haematopoietic cells promotes monocyte expansion and atherosclerosis progression. Nat Commun 2016; 7:12313. [PMID: 27460411 PMCID: PMC4974469 DOI: 10.1038/ncomms12313] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 06/21/2016] [Indexed: 12/27/2022] Open
Abstract
Lipid accumulation in macrophages has profound effects on macrophage gene expression and contributes to the development of atherosclerosis. Here, we report that angiopoietin-like protein 4 (ANGPTL4) is the most highly upregulated gene in foamy macrophages and it's absence in haematopoietic cells results in larger atherosclerotic plaques, characterized by bigger necrotic core areas and increased macrophage apoptosis. Furthermore, hyperlipidemic mice deficient in haematopoietic ANGPTL4 have higher blood leukocyte counts, which is associated with an increase in the common myeloid progenitor (CMP) population. ANGPTL4-deficient CMPs have higher lipid raft content, are more proliferative and less apoptotic compared with the wild-type (WT) CMPs. Finally, we observe that ANGPTL4 deficiency in macrophages promotes foam cell formation by enhancing CD36 expression and reducing ABCA1 localization in the cell surface. Altogether, these findings demonstrate that haematopoietic ANGPTL4 deficiency increases atherogenesis through regulating myeloid progenitor cell expansion and differentiation, foam cell formation and vascular inflammation. Angiopoietin-like 4 protein (ANGPTL4) is a regulator of lipoprotein metabolism whose role in atherosclerosis has been controversial. Here the authors show that ANGPTL4 deficiency in haematopoietic cells increases atherogenesis by promoting myeloid progenitor cell expansion and differentiation, foam cell formation and vascular inflammation.
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Affiliation(s)
- Binod Aryal
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Integrative Cell Signaling and Neurobiology of Metabolism Program, Section of Comparative Medicine and Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Departments of Medicine and Cell Biology, Leon H. Charney Division of Cardiology and Cell Biology, New York University School of Medicine, New York, New York 10016, USA
| | - Noemi Rotllan
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Integrative Cell Signaling and Neurobiology of Metabolism Program, Section of Comparative Medicine and Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Elisa Araldi
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Integrative Cell Signaling and Neurobiology of Metabolism Program, Section of Comparative Medicine and Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Cristina M Ramírez
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Integrative Cell Signaling and Neurobiology of Metabolism Program, Section of Comparative Medicine and Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Shun He
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Benjamin G Chousterman
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Ashley M Fenn
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Amarylis Wanschel
- Departments of Medicine and Cell Biology, Leon H. Charney Division of Cardiology and Cell Biology, New York University School of Medicine, New York, New York 10016, USA
| | - Julio Madrigal-Matute
- Departments of Medicine and Cell Biology, Leon H. Charney Division of Cardiology and Cell Biology, New York University School of Medicine, New York, New York 10016, USA
| | - Nikhil Warrier
- Departments of Medicine and Cell Biology, Leon H. Charney Division of Cardiology and Cell Biology, New York University School of Medicine, New York, New York 10016, USA
| | - Jose L Martín-Ventura
- Vascular Research Lab, IIS-Fundación Jimenez-Díaz, Universidad Autónoma de Madrid, Madrid 28040, Spain
| | - Filip K Swirski
- Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Yajaira Suárez
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Integrative Cell Signaling and Neurobiology of Metabolism Program, Section of Comparative Medicine and Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Carlos Fernández-Hernando
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Integrative Cell Signaling and Neurobiology of Metabolism Program, Section of Comparative Medicine and Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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11
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Tate M, Robinson E, Green BD, McDermott BJ, Grieve DJ. Exendin-4 attenuates adverse cardiac remodelling in streptozocin-induced diabetes via specific actions on infiltrating macrophages. Basic Res Cardiol 2015; 111:1. [PMID: 26597728 PMCID: PMC4656717 DOI: 10.1007/s00395-015-0518-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 10/27/2015] [Indexed: 02/06/2023]
Abstract
In addition to its' established metabolic and cardioprotective effects, glucagon-like peptide-1 (GLP-1) reduces post-infarction heart failure via preferential actions on the extracellular matrix (ECM). Here, we investigated whether the GLP-1 mimetic, exendin-4, modulates cardiac remodelling in experimental diabetes by specifically targeting inflammatory/ECM pathways, which are characteristically dysregulated in this setting. Adult mice were subjected to streptozotocin (STZ) diabetes and infused with exendin-4/insulin/saline from 0 to 4 or 4–12 weeks. Exendin-4 and insulin improved metabolic parameters in diabetic mice after 12 weeks, but only exendin-4 reduced cardiac diastolic dysfunction and interstitial fibrosis in parallel with altered ECM gene expression. Whilst myocardial inflammation was not evident at 12 weeks, CD11b-F4/80++ macrophage infiltration at 4 weeks was increased and reduced by exendin-4, together with an improved cytokine profile. Notably, media collected from high glucose-treated macrophages induced cardiac fibroblast differentiation, which was prevented by exendin-4, whilst several cytokines/chemokines were differentially expressed/secreted by exendin-4-treated macrophages, some of which were modulated in STZ exendin-4-treated hearts. Our findings suggest that exendin-4 preferentially protects against ECM remodelling and diastolic dysfunction in experimental diabetes via glucose-dependent modulation of paracrine communication between infiltrating macrophages and resident fibroblasts, thereby indicating that cell-specific targeting of GLP-1 signalling may be a viable therapeutic strategy in this setting.
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Affiliation(s)
- Mitchel Tate
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7AE, UK
| | - Emma Robinson
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7AE, UK
| | - Brian D Green
- Institute for Global Food Security, School of Biological Sciences, Belfast, BT9 5HN, UK
| | - Barbara J McDermott
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7AE, UK
| | - David J Grieve
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7AE, UK.
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12
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Uno K, Yamada T, Ishigaki Y, Imai J, Hasegawa Y, Sawada S, Kaneko K, Ono H, Asano T, Oka Y, Katagiri H. A hepatic amino acid/mTOR/S6K-dependent signalling pathway modulates systemic lipid metabolism via neuronal signals. Nat Commun 2015; 6:7940. [PMID: 26268630 PMCID: PMC4557134 DOI: 10.1038/ncomms8940] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 06/30/2015] [Indexed: 12/15/2022] Open
Abstract
Metabolism is coordinated among tissues and organs via neuronal signals. Levels of circulating amino acids (AAs), which are elevated in obesity, activate the intracellular target of rapamycin complex-1 (mTORC1)/S6kinase (S6K) pathway in the liver. Here we demonstrate that hepatic AA/mTORC1/S6K signalling modulates systemic lipid metabolism via a mechanism involving neuronal inter-tissue communication. Hepatic expression of an AA transporter, SNAT2, activates the mTORC1/S6K pathway, and markedly elevates serum triglycerides (TGs), while downregulating adipose lipoprotein lipase (LPL). Hepatic Rheb or active-S6K expression have similar metabolic effects, whereas hepatic expression of dominant-negative-S6K inhibits TG elevation in SNAT2 mice. Denervation, pharmacological deafferentation and β-blocker administration suppress obesity-related hypertriglyceridemia with adipose LPL upregulation, suggesting that signals are transduced between liver and adipose tissue via a neuronal pathway consisting of afferent vagal and efferent sympathetic nerves. Thus, the neuronal mechanism uncovered here serves to coordinate amino acid and lipid levels and contributes to the development of obesity-related hypertriglyceridemia.
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Affiliation(s)
- Kenji Uno
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Tetsuya Yamada
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Yasushi Ishigaki
- Division of Diabetes and Metabolism, Iwate Medical University, Morioka 020-8505, Japan
| | - Junta Imai
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Yutaka Hasegawa
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Shojiro Sawada
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Keizo Kaneko
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Hiraku Ono
- The Fourth Department of Internal Medicine, Saitama Medical University, Saitama 350-0495, Japan
| | - Tomoichiro Asano
- Department of Medical Science, Graduate School of Medicine, University of Hiroshima, Hiroshima 734-8553, Japan
| | - Yoshitomo Oka
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Hideki Katagiri
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan.,Japan Science and Technology Agency, CREST, Sendai 980-8575, Japan
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13
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Wang Y, Gusarova V, Banfi S, Gromada J, Cohen JC, Hobbs HH. Inactivation of ANGPTL3 reduces hepatic VLDL-triglyceride secretion. J Lipid Res 2015; 56:1296-307. [PMID: 25954050 DOI: 10.1194/jlr.m054882] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Indexed: 02/01/2023] Open
Abstract
Humans and mice lacking angiopoietin-like protein 3 (ANGPTL3) have pan-hypolipidemia. ANGPTL3 inhibits two intravascular lipases, LPL and endothelial lipase, and the low plasma TG and HDL-cholesterol levels in ANGPTL3 deficiency reflect increased activity of these enzymes. The mechanism responsible for the low LDL-cholesterol levels associated with ANGPTL3 deficiency is not known. Here we used an anti-ANGPTL3 monoclonal antibody (REGN1500) to inactivate ANGPTL3 in mice with genetic deficiencies in key proteins involved in clearance of ApoB-containing lipoproteins. REGN1500 treatment consistently reduced plasma cholesterol levels in mice in which Apoe, Ldlr, Lrp1, and Sdc1 were inactivated singly or in combination, but did not alter clearance of rabbit (125)I-βVLDL or mouse (125)I-LDL. Despite a 61% reduction in VLDL-TG production, VLDL-ApoB-100 production was unchanged in REGN1500-treated animals. Hepatic TG content, fatty acid synthesis, and fatty acid oxidation were similar in REGN1500 and control antibody-treated animals. Taken together, our findings indicate that inactivation of ANGPTL3 does not affect the number of ApoB-containing lipoproteins secreted by the liver but alters the particles that are made such that they are cleared more rapidly from the circulation via a noncanonical pathway(s). The increased clearance of lipolytic remnants results in decreased production of LDL in ANGPTL3-deficient animals.
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Affiliation(s)
- Yan Wang
- Departments of Molecular Genetics University of Texas Southwestern Medical Center, Dallas, TX Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX
| | | | - Serena Banfi
- Departments of Molecular Genetics University of Texas Southwestern Medical Center, Dallas, TX
| | | | - Jonathan C Cohen
- Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Helen H Hobbs
- Departments of Molecular Genetics University of Texas Southwestern Medical Center, Dallas, TX Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX
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14
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Differential effects of angiopoietin-like 4 in brain and muscle on regulation of lipoprotein lipase activity. Mol Metab 2014; 4:144-50. [PMID: 25685701 PMCID: PMC4314546 DOI: 10.1016/j.molmet.2014.11.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 11/03/2014] [Accepted: 11/05/2014] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE Lipoprotein lipase (LPL) is a key regulator of circulating triglyceride rich lipoprotein hydrolysis. In brain LPL regulates appetite and energy expenditure. Angiopoietin-like 4 (Angptl4) is a secreted protein that inhibits LPL activity and, thereby, triglyceride metabolism, but the impact of Angptl4 on central lipid metabolism is unknown. METHODS We induced type 1 diabetes by streptozotocin (STZ) in whole-body Angptl4 knockout mice (Angptl4(-/-) ) and their wildtype littermates to study the role of Angptl4 in central lipid metabolism. RESULTS In type 1 (streptozotocin, STZ) and type 2 (ob/ob) diabetic mice, there is a ~2-fold increase of Angptl4 in the hypothalamus and skeletal muscle. Intracerebroventricular insulin injection into STZ mice at levels which have no effect on plasma glucose restores Angptl4 expression in hypothalamus. Isolation of cells from the brain reveals that Angptl4 is produced in glia, whereas LPL is present in both glia and neurons. Consistent with the in vivo experiment, in vitro insulin treatment of glial cells causes a 50% reduction of Angptl4 and significantly increases LPL activity with no change in LPL expression. In Angptl4(-/-) mice, LPL activity in skeletal muscle is increased 3-fold, and this is further increased by STZ-induced diabetes. By contrast, Angptl4(-/-) mice show no significant difference in LPL activity in hypothalamus or brain independent of diabetic and nutritional status. CONCLUSION Thus, Angptl4 in brain is produced in glia and regulated by insulin. However, in contrast to the periphery, central Angptl4 does not regulate LPL activity, but appears to participate in the metabolic crosstalk between glia and neurons.
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Key Words
- ARC, arcuate nucleus
- AgRP, agouti-related protein
- Angptl4
- Angptl4, angiopoietin-like 4
- CART, cocaine-and-amphetamine-regulated transcript
- CNS, central nervous system
- FFA, free fatty acid
- LPL, lipoprotein lipase
- Lipid metabolism
- Lipoprotein lipase
- NPY, neuropeptide-Y
- POMC, pro-opiomelanocortin
- STZ, streptozotocin
- TG, triglyceride
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15
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Application of RPTEC/TERT1 cells for investigation of repeat dose nephrotoxicity: A transcriptomic study. Toxicol In Vitro 2014; 30:106-16. [PMID: 25450743 DOI: 10.1016/j.tiv.2014.10.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/30/2014] [Accepted: 10/03/2014] [Indexed: 12/14/2022]
Abstract
The kidney is a major target organ for toxicity. Incidence of chronic kidney disease (CKD) is increasing at an alarming rate due to factors such as increasing population age and increased prevalence of heart disease and diabetes. There is a major effort ongoing to develop superior predictive models of renal injury and early renal biomarkers that can predict onset of CKD. In the EU FP7 funded project, Predict-IV, we investigated the human renal proximal tubule cells line, RPTEC/TERT1 for their applicability to long term nephrotoxic mechanistic studies. To this end, we used a tiered strategy to optimise dosing regimes for 9 nephrotoxins. Our final testing protocol utilised differentiated RPTEC/TERT1 cells cultured on filter inserts treated with compounds at both the apical and basolateral side, at concentrations not exceeding IC10, for 14 days in a 24 h repeat application. Transepithelial electrical resistance and supernatant lactate were measured over the duration of the experiments and genome wide transcriptomic profiles were assayed at day 1, 3 and 14. The effect of hypoxia was investigated for a subset of compounds. The transcriptomic data were analysed to investigate compound-specific effects, global responses and mechanistically informative signatures. In addition, several potential clinically useful renal injury biomarkers were identified.
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16
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Li X, Zhu M, Penfold ME, Koenen RR, Thiemann A, Heyll K, Akhtar S, Koyadan S, Wu Z, Gremse F, Kiessling F, van Zandvoort M, Schall TJ, Weber C, Schober A. Activation of CXCR7 limits atherosclerosis and improves hyperlipidemia by increasing cholesterol uptake in adipose tissue. Circulation 2013; 129:1244-53. [PMID: 24374972 DOI: 10.1161/circulationaha.113.006840] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND The aim of this study was to determine the role of the chemokine receptor CXCR7 in atherosclerosis and vascular remodeling. CXCR7 is the alternative receptor of CXCL12, which regulates stem cell-mediated vascular repair and limits atherosclerosis via its receptor, CXCR4. METHODS AND RESULTS Wire-induced injury of the carotid artery was performed in mice with a ubiquitous, conditional deletion of CXCR7 and in mice treated with the synthetic CXCR7 ligand CCX771. The effect of CCX771 treatment on atherosclerosis was studied in apolipoprotein E-deficient (Apoe(-/-)) mice fed a high-fat diet for 12 weeks. Lipoprotein fractions were quantified in the plasma of Apoe(-/-) mice by fast protein liquid chromatography. Uptake of DiI-labeled very low-density lipoprotein to adipose tissue was determined by 2-photon microscopy. We show that genetic deficiency of Cxcr7 increased neointima formation and lesional macrophage accumulation in hyperlipidemic mice after vascular injury. This was related to increased serum cholesterol levels and subsequent hyperlipidemia-induced monocytosis. Conversely, administration of the CXCR7 ligand CCX771 to Apoe(-/-) mice inhibited lesion formation and ameliorated hyperlipidemia after vascular injury and during atherosclerosis. Treatment with CCX771 reduced circulating very low-density lipoprotein levels but not low-density lipoprotein or high-density lipoprotein levels and increased uptake of very low-density lipoprotein into Cxcr7-expressing white adipose tissue. This effect of CCX771 was associated with an enhanced lipase activity and reduced expression of Angptl4 in adipose tissue. CONCLUSIONS CXCR7 regulates blood cholesterol by promoting its uptake in adipose tissue. This unexpected cholesterol-lowering effect of CXCR7 is beneficial for atherosclerotic vascular diseases, presumably via amelioration of hyperlipidemia-induced monocytosis, and can be augmented with a synthetic CXCR7 ligand.
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Affiliation(s)
- Xiaofeng Li
- Institute for Molecular Cardiovascular Research (X.L., R.R.K., A.T., K.H., S.A., Z.W., M.v.Z., C.W., A.S.), Core Facility Two-Photon Imaging, Interdisciplinary Center for Clinical Research Aachen (S.K.), and Experimental Molecular Imaging (F.G., F.K.), RWTH Aachen University, Aachen, Germany; Institute for Cardiovascular Prevention, Ludwig Maximilians University Munich, Munich, Germany (M.Z., R.R.K., K.H., C.W., A.S.); ChemoCentryx Inc, Mountain View, CA (M.E.P., T.J.S.); Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands (M.v.Z., C.W.); and Munich Heart Alliance, Munich, Germany (C.W., A.S.)
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17
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Navab M, Hough G, Buga GM, Su F, Wagner AC, Meriwether D, Chattopadhyay A, Gao F, Grijalva V, Danciger JS, Van Lenten BJ, Org E, Lusis AJ, Pan C, Anantharamaiah GM, Farias-Eisner R, Smyth SS, Reddy ST, Fogelman AM. Transgenic 6F tomatoes act on the small intestine to prevent systemic inflammation and dyslipidemia caused by Western diet and intestinally derived lysophosphatidic acid. J Lipid Res 2013; 54:3403-18. [PMID: 24085744 DOI: 10.1194/jlr.m042051] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We recently reported that levels of unsaturated lysophosphatidic acid (LPA) in the small intestine significantly correlated with the extent of aortic atherosclerosis in LDL receptor-null (LDLR⁻/⁻) mice fed a Western diet (WD). Here we demonstrate that WD increases unsaturated (but not saturated) LPA levels in the small intestine of LDLR⁻/⁻ mice and causes changes in small intestine gene expression. Confirmation of microarray analysis by quantitative RT-PCR showed that adding transgenic tomatoes expressing the apoA-I mimetic peptide 6F (Tg6F) to WD prevented many WD-mediated small intestine changes in gene expression. If instead of feeding WD, unsaturated LPA was added to chow and fed to the mice: i) levels of LPA in the small intestine were similar to those induced by feeding WD; ii) gene expression changes in the small intestine mimicked WD-mediated changes; and iii) changes in plasma serum amyloid A, total cholesterol, triglycerides, HDL-cholesterol levels, and the fast-performance liquid chromatography lipoprotein profile mimicked WD-mediated changes. Adding Tg6F (but not control tomatoes) to LPA-supplemented chow prevented the LPA-induced changes. We conclude that: i) WD-mediated systemic inflammation and dyslipidemia may be in part due to WD-induced increases in small intestine LPA levels; and ii) Tg6F reduces WD-mediated systemic inflammation and dyslipidemia by preventing WD-induced increases in LPA levels in the small intestine.
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Affiliation(s)
- Mohamad Navab
- Departments of Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095
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18
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Clasen BFF, Krusenstjerna-Hafstrøm T, Vendelbo MH, Thorsen K, Escande C, Møller N, Pedersen SB, Jørgensen JOL, Jessen N. Gene expression in skeletal muscle after an acute intravenous GH bolus in human subjects: identification of a mechanism regulating ANGPTL4. J Lipid Res 2013; 54:1988-97. [PMID: 23606725 DOI: 10.1194/jlr.p034520] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Growth hormone (GH) acutely stimulates lipolysis and fat oxidation, a process that operates postabsorptively and involves activation of the JAK-STAT pathway in the target tissue; no in vivo data exist regarding subsequent GH-regulated gene transcription. We obtained serum samples and muscle biopsies in human subjects before and 2 h after administration of a GH bolus. A significant (~75%) elevation in serum FFA levels was recorded post GH. Microarray identified 79 GH-regulated genes in muscle. With qRT-PCR, we then examined the expression of selected genes in the presence and absence of glucose-induced suppression of lipolysis. Four genes involved in the JAK-STAT5 signaling pathway were regulated by GH, including SOCS1-3 and CISH, in addition to three genes associated with insulin action: NFκB1A, PIK3C2B, and PRKAG2. The gene encoding ANGPTL4, a protein involved in lipolysis and suppression of LPL activity, exhibited the most pronounced upregulation (5.6-fold) after GH, which was abrogated by concomitant suppression of lipolysis. Therefore, the GH-induced stimulation of ANGPTL4 gene expression seems secondary to induction of lipolysis. This new concept implies that abundant supply of circulating FFA decreases the need for alternative triglyceride-derived FFA through distinct inhibition of LPL mediated by increased ANGPTL4 gene expression in human muscle.
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Affiliation(s)
- Berthil F F Clasen
- Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
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19
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Jonker JT, Smit JWA, Hammer S, Snel M, van der Meer RW, Lamb HJ, Mattijssen F, Mudde K, Jazet IM, Dekkers OM, de Roos A, Romijn JA, Kersten S, Rensen PCN. Dietary modulation of plasma angiopoietin-like protein 4 concentrations in healthy volunteers and in patients with type 2 diabetes. Am J Clin Nutr 2013; 97:255-60. [PMID: 23283507 DOI: 10.3945/ajcn.112.043687] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Angiopoietin-like protein 4 (ANGPTL4) has been identified as an inhibitor of lipoprotein lipase. Preliminary data suggest that plasma nonesterified fatty acids (NEFAs) raise plasma ANGPTL4 concentrations in humans. OBJECTIVE The objective was to assess plasma ANGPTL4 concentrations after various nutritional interventions that increase NEFA concentrations in healthy subjects and in patients with type 2 diabetes mellitus. DESIGN We studied 4 groups, both at baseline and after 3 d of either fasting (n = 22 healthy men), a very-low-calorie diet (VLCD; n = 10 healthy men and n = 10 patients with diabetes), or a high-fat, high-energy diet (HFED; n = 15 healthy men). Plasma ANGPTL4, NEFA, and triglyceride concentrations were measured. RESULTS In healthy men, a VLCD increased ANGPTL4 from 13.2 (IQR: 8.1-24.2) at baseline to 18.2 (16.7-33.4) ng/mL (P < 0.05), fasting increased ANGPTL4 from 10.6 (7.6-17.6) to 28.0 (23.1-35.0) ng/mL (P < 0.05), and an HFED increased ANGPTL4 from 13.9 (8.2-22.0) to 17.2 (11.2-23.6) ng/mL (P < 0.05). In men with diabetes, a VLCD also increased ANGPTL4, from 10.9 ± 2.4 to 19.2 ± 3.2 ng/mL (P < 0.05). All interventions significantly increased plasma NEFAs in both healthy men and patients with diabetes. The change in ANGPTL4 positively correlated with the change in NEFA concentrations (β = 0.048, P < 0.001) and negatively correlated with the change in plasma triglycerides (β = -0.051, P = 0.01). CONCLUSIONS Three days of either fasting, a VLCD, or an HFED increased plasma ANGPTL4 concentrations in healthy men, concomitantly with increased plasma NEFA concentrations. Similarly, a VLCD in patients with diabetes increased ANGPTL4 concentrations, concomitantly with increased NEFA concentrations.
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Affiliation(s)
- Jacqueline T Jonker
- Departments of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Leiden, Netherlands
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20
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Tan MJ, Teo Z, Sng MK, Zhu P, Tan NS. Emerging roles of angiopoietin-like 4 in human cancer. Mol Cancer Res 2012; 10:677-88. [PMID: 22661548 DOI: 10.1158/1541-7786.mcr-11-0519] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Angiopoietin-like 4 (ANGPTL4) is best known for its role as an adipokine involved in the regulation of lipid and glucose metabolism. The characterization of ANGPTL4 as an adipokine is largely due to our limited understanding of the interaction partners of ANGPTL4 and how ANGPTL4 initiates intracellular signaling. Recent findings have revealed a critical role for ANGPTL4 in cancer growth and progression, anoikis resistance, altered redox regulation, angiogenesis, and metastasis. Emerging evidence suggests that ANGPTL4 function may be drastically altered depending on the proteolytic processing and posttranslational modifications of ANGPTL4, which may clarify several conflicting roles of ANGPTL4 in different cancers. Although the N-terminal coiled-coil region of ANGPTL4 has been largely responsible for the endocrine regulatory role in lipid metabolism, insulin sensitivity, and glucose homeostasis, it has now emerged that the COOH-terminal fibrinogen-like domain of ANGPTL4 may be a key regulator in the multifaceted signaling during cancer development. New insights into the mechanistic action of this functional domain have opened a new chapter into the possible clinical application of ANGPTL4 as a promising candidate for clinical intervention in the fight against cancer. This review summarizes our current understanding of ANGPTL4 in cancer and highlights areas that warrant further investigation. A better understanding of the underlying cellular and molecular mechanisms of ANGPTL4 will reveal novel insights into other aspects of tumorigenesis and the potential therapeutic value of ANGPTL4.
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Affiliation(s)
- Ming Jie Tan
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551
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21
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Ruge T, Sukonina V, Kroupa O, Makoveichuk E, Lundgren M, Svensson MK, Olivecrona G, Eriksson JW. Effects of hyperinsulinemia on lipoprotein lipase, angiopoietin-like protein 4, and glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 in subjects with and without type 2 diabetes mellitus. Metabolism 2012; 61:652-60. [PMID: 22078753 DOI: 10.1016/j.metabol.2011.09.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 09/27/2011] [Indexed: 11/22/2022]
Abstract
Our aims were to compare the systemic effects of insulin on lipoprotein lipase (LPL) in tissues from subjects with different degrees of insulin sensitivity. The effects of insulin on LPL during a 4-hour hyperinsulinemic, euglycemic clamp were studied in skeletal muscle, adipose tissue, and postheparin plasma from young healthy subjects (YS), older subjects with type 2 diabetes mellitus (DS), and older control subjects (CS). In addition, we studied the effects of insulin on the expression of 2 recently recognized candidate genes for control of LPL activity: angiopoietin-like protein 4 (ANGPTL4) and glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1. As an effect of insulin, LPL activity decreased by 20% to 25% in postheparin plasma and increased by 20% to 30% in adipose tissue in all groups. In YS, the levels of ANGPTL4 messenger RNA in adipose tissue decreased 3-fold during the clamp. In contrast, there was no significant change in DS or CS. Regression analysis showed that the ability of insulin to reduce the expression of ANGPTL4 was positively correlated with M-values and inversely correlated with factors linked to the metabolic syndrome. Expression of glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 tended to be higher in YS than in DS or CS, but the expression was not affected by insulin in any of the groups. Our data imply that the insulin-mediated regulation of LPL is not directly linked to the control of glucose turnover by insulin or to ANGPTL4 expression in adipose tissue or plasma. Interestingly, the response of ANGPTL4 expression in adipose tissue to insulin was severely blunted in both DS and CS.
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Affiliation(s)
- Toralph Ruge
- Department of Surgery and Peri-Operative Sciences/Surgery, Umeå University, SE-901 85 Umeå, Sweden.
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22
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Current world literature. Curr Opin Lipidol 2012; 23:156-63. [PMID: 22418573 DOI: 10.1097/mol.0b013e3283521229] [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] [Indexed: 11/26/2022]
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