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Zhang X, Evans TD, Chen S, Sergin I, Stitham J, Jeong SJ, Rodriguez-Velez A, Yeh YS, Park A, Jung IH, Diwan A, Schilling JD, Rom O, Yurdagul A, Epelman S, Cho J, Lodhi IJ, Mittendorfer B, Razani B. Loss of Macrophage mTORC2 Drives Atherosclerosis via FoxO1 and IL-1β Signaling. Circ Res 2023; 133:200-219. [PMID: 37350264 PMCID: PMC10527041 DOI: 10.1161/circresaha.122.321542] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 06/12/2023] [Indexed: 06/24/2023]
Abstract
BACKGROUND The mTOR (mechanistic target of rapamycin) pathway is a complex signaling cascade that regulates cellular growth, proliferation, metabolism, and survival. Although activation of mTOR signaling has been linked to atherosclerosis, its direct role in lesion progression and in plaque macrophages remains poorly understood. We previously demonstrated that mTORC1 (mTOR complex 1) activation promotes atherogenesis through inhibition of autophagy and increased apoptosis in macrophages. METHODS Using macrophage-specific Rictor- and mTOR-deficient mice, we now dissect the distinct functions of mTORC2 pathways in atherogenesis. RESULTS In contrast to the atheroprotective effect seen with blockade of macrophage mTORC1, macrophage-specific mTORC2-deficient mice exhibit an atherogenic phenotype, with larger, more complex lesions and increased cell death. In cultured macrophages, we show that mTORC2 signaling inhibits the FoxO1 (forkhead box protein O1) transcription factor, leading to suppression of proinflammatory pathways, especially the inflammasome/IL (interleukin)-1β response, a key mediator of vascular inflammation and atherosclerosis. In addition, administration of FoxO1 inhibitors efficiently rescued the proinflammatory response caused by mTORC2 deficiency both in vitro and in vivo. Interestingly, collective deletion of macrophage mTOR, which ablates mTORC1- and mTORC2-dependent pathways, leads to minimal change in plaque size or complexity, reflecting the balanced yet opposing roles of these signaling arms. CONCLUSIONS Our data provide the first mechanistic details of macrophage mTOR signaling in atherosclerosis and suggest that therapeutic measures aimed at modulating mTOR need to account for its dichotomous functions.
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Affiliation(s)
- Xiangyu Zhang
- Department of Medicine and Vascular Medicine Institute, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Trent D. Evans
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Sunny Chen
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Ismail Sergin
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Jeremiah Stitham
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St Louis, MO, USA
| | - Se-Jin Jeong
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | | | - Yu-Sheng Yeh
- Department of Medicine and Vascular Medicine Institute, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Arick Park
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - In-Hyuk Jung
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Abhinav Diwan
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
- John Cochran VA Medical Center, St. Louis, MO, USA
| | - Joel D. Schilling
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
| | - Oren Rom
- Department of Pathology and Translational Pathobiology and Department of Molecular and Cellular Physiology, Louisiana State University, Shreveport, LA
| | - Arif Yurdagul
- Department of Pathology and Translational Pathobiology and Department of Molecular and Cellular Physiology, Louisiana State University, Shreveport, LA
| | - Slava Epelman
- Ted Rogers Centre for Heart Research, Peter Munk Cardiac Center, Toronto General Hospital Research Institute, University Health Network and University of Toronto, Toronto, Canada
| | - Jaehyung Cho
- Division of Hematology, Department of Medicine, Washington University School of Medicine, St Louis, MO, USA
- Department of Pathology & Immunology, Washington University School of Medicine, St Louis, MO, USA
| | - Irfan J. Lodhi
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St Louis, MO, USA
| | - Bettina Mittendorfer
- Division of Geriatrics and Nutritional Science, and Washington University School of Medicine, St Louis, MO, USA
| | - Babak Razani
- Department of Medicine and Vascular Medicine Institute, University of Pittsburgh School of Medicine and UPMC, Pittsburgh, PA
- Pittsburgh VA Medical Center, Pittsburgh, PA
- Cardiovascular Division, Washington University School of Medicine, St Louis, MO, USA
- Department of Pathology & Immunology, Washington University School of Medicine, St Louis, MO, USA
- John Cochran VA Medical Center, St. Louis, MO, USA
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Wu Q, Lv Q, Liu X, Ye X, Cao L, Wang M, Li J, Yang Y, Li L, Wang S. Natural compounds from botanical drugs targeting mTOR signaling pathway as promising therapeutics for atherosclerosis: A review. Front Pharmacol 2023; 14:1083875. [PMID: 36744254 PMCID: PMC9894899 DOI: 10.3389/fphar.2023.1083875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 01/05/2023] [Indexed: 01/22/2023] Open
Abstract
Atherosclerosis (AS) is a chronic inflammatory disease that is a major cause of cardiovascular diseases (CVDs), including coronary artery disease, hypertension, myocardial infarction, and heart failure. Hence, the mechanisms of AS are still being explored. A growing compendium of evidence supports that the activity of the mechanistic/mammalian target of rapamycin (mTOR) is highly correlated with the risk of AS. The mTOR signaling pathway contributes to AS progression by regulating autophagy, cell senescence, immune response, and lipid metabolism. Various botanical drugs and their functional compounds have been found to exert anti- AS effects by modulating the activity of the mTOR signaling pathway. In this review, we summarize the pathogenesis of AS based on the mTOR signaling pathway from the aspects of immune response, autophagy, cell senescence, and lipid metabolism, and comb the recent advances in natural compounds from botanical drugs to inhibit the mTOR signaling pathway and delay AS development. This review will provide a new perspective on the mechanisms and precision treatments of AS.
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Affiliation(s)
- Qian Wu
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Qianyu Lv
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Xiao’an Liu
- Capital University of Medical, Beijing, China
| | - Xuejiao Ye
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Linlin Cao
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Manshi Wang
- Beijing Xicheng District Guangwai Hospital, Beijing, China
| | - Junjia Li
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Yingtian Yang
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Lanlan Li
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Shihan Wang
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China,*Correspondence: Shihan Wang,
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3
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Li H, Zhou WY, Liu YX, Xia YY, Xia CL, Pan DR, Li Z, Shi Y, Chen SL, Zhang JX. Rictor maintains endothelial integrity under shear stress. Front Cell Dev Biol 2022; 10:963866. [PMID: 36438564 PMCID: PMC9685313 DOI: 10.3389/fcell.2022.963866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 10/26/2022] [Indexed: 11/12/2022] Open
Abstract
Background: Endothelial injury induced by low shear stress (LSS) is an initiating factor in the pathogenesis of various cardiovascular diseases, including atherosclerosis, hypertension, and thrombotic diseases. Low shear stress activates the mammalian target of rapamycin complex 2 (mTORC2) signaling pathway. Rictor, the main constituent protein of mTORC2, is involved in vascular development. However, the impact of conditional Rictor ablation on endothelial homeostasis, especially on endothelial-specific markers, such as vascular endothelial-cadherin (VE-cadherin) and von Willebrand factor (VWF), under blood flow stimulation is unclear. Objective: We aimed to investigate whether endothelial Rictor is involved in maintaining vascular endothelial integrity and the potential role of Rictor in atheroprone blood flow-mediated endothelial injury. Methods and results: Immunofluorescence staining showed that endothelial Rictor was successfully knocked out in a mouse model. Scanning electron microscopy (EM) detection revealed disruption of the endothelial monolayer in the thoracic aorta of Rictor-deficient mice. Furthermore, scanning electron microscopy and transmission electron microscopy showed that Rictor deletion disrupted endothelial integrity and expanded cell junctions in the left common carotid artery region. In vitro, low shear stress disrupted actin filament polarity and the promoted the translocation of vascular endothelial-cadherin, the key component of adherens junctions (AJs) in human umbilical vein endothelial cells. After Rictor downregulation by small interfering RNA, the translocation of vascular endothelial-cadherin and stress fibers increased. Rictor knockdown inhibited low shear stress-induced von Willebrand factor upregulation, and downregulation of vascular endothelial-cadherin decreased low shear stress-induced von Willebrand factor expression. These results suggest that vascular endothelial-cadherin/von Willebrand factor is a possible mechanism mediated by Rictor in the pathological process of low shear stress-induced endothelial injury. Conclusion: Rictor is a key protein that regulates endothelial integrity under vascular physiological homeostasis, and Rictor mediates low shear stress-induced endothelial injury by regulating adherens junctions and von Willebrand factor.
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Affiliation(s)
- Hui Li
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Wen-Ying Zhou
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Yi-Xian Liu
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Yi-Yuan Xia
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Chun-Lei Xia
- Department of Intensive Medicine, The Affiliated Jiangning Hospital of Nanjing Medical University, Nanjing, China
| | - Dao-Rong Pan
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Zheng Li
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Yi Shi
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
| | - Shao-Liang Chen
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
- *Correspondence: Jun-Xia Zhang, ; Shao-Liang Chen,
| | - Jun-Xia Zhang
- Department of Cardiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China
- *Correspondence: Jun-Xia Zhang, ; Shao-Liang Chen,
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Mahmoudi A, Butler AE, Jamialahmadi T, Sahebkar A. The role of exosomal miRNA in nonalcoholic fatty liver disease. J Cell Physiol 2022; 237:2078-2094. [PMID: 35137416 DOI: 10.1002/jcp.30699] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 12/14/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) impacts more than one-third of the population and is linked with other metabolic diseases. The term encompasses a wide spectrum of diseases, from modest steatosis to nonalcoholic steatohepatitis, fibrosis and, ultimately, cirrhosis with the potential for development of hepatocellular carcinoma. Currently, available methods for diagnosing NAFLD are invasive or lack accuracy, and monitoring to determine response to therapeutic interventions is challenging. Exosomes are nano-scaled extracellular vesicles that are secreted by a variety of cells. They convey proteins, mRNA, miRNA, and other bioactive molecules between cells and are involved in an extensive range of biological processes, particularly cell-cell communication. Several reports suggest that exosomes mediate miRNAs and, thus, they have potential clinical utility for diagnosis, prognosis, and therapeutics in liver diseases. In view of the vital role of exosomal microRNA in disease, we here synthesized current knowledge about the biogenesis of exosomal miRNA and exosome-mediated microRNA transfer. We then discuss the potential of exosomal miRNA in diagnosis and therapeutics of NAFLD.
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Affiliation(s)
- Ali Mahmoudi
- Department of Medical Biotechnology and Nanotechnology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | - Tannaz Jamialahmadi
- Surgical Oncology Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Amirhossein Sahebkar
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.,School of Medicine, The University of Western Australia, Perth, Australia.,Department of Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
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5
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AKT Isoforms in Macrophage Activation, Polarization, and Survival. Curr Top Microbiol Immunol 2022; 436:165-196. [DOI: 10.1007/978-3-031-06566-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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6
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Efferocytosis induces macrophage proliferation to help resolve tissue injury. Cell Metab 2021; 33:2445-2463.e8. [PMID: 34784501 PMCID: PMC8665147 DOI: 10.1016/j.cmet.2021.10.015] [Citation(s) in RCA: 108] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/17/2021] [Accepted: 10/26/2021] [Indexed: 01/01/2023]
Abstract
Apoptotic cell clearance by macrophages (efferocytosis) promotes resolution signaling pathways, which can be triggered by molecules derived from the phagolysosomal degradation of apoptotic cells. We show here that nucleotides derived from the hydrolysis of apoptotic cell DNA by phagolysosomal DNase2a activate a DNA-PKcs-mTORC2/Rictor pathway that increases Myc to promote non-inflammatory macrophage proliferation. Efferocytosis-induced proliferation expands the pool of resolving macrophages in vitro and in mice, including zymosan-induced peritonitis, dexamethasone-induced thymocyte apoptosis, and atherosclerosis regression. In the dexamethasone-thymus model, hematopoietic Rictor deletion blocked efferocytosing macrophage proliferation, apoptotic cell clearance, and tissue resolution. In atherosclerosis regression, silencing macrophage Rictor or DNase2a blocked efferocyte proliferation, apoptotic cell clearance, and plaque stabilization. In view of previous work showing that other types of apoptotic cell cargo can promote resolution in individual efferocytosing macrophages, the findings here suggest that signaling-triggered apoptotic cell-derived nucleotides can amplify this benefit by increasing the number of these macrophages.
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7
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Rosario FJ, Kelly AC, Gupta MB, Powell TL, Cox L, Jansson T. Mechanistic Target of Rapamycin Complex 2 Regulation of the Primary Human Trophoblast Cell Transcriptome. Front Cell Dev Biol 2021; 9:670980. [PMID: 34805133 PMCID: PMC8599300 DOI: 10.3389/fcell.2021.670980] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 09/23/2021] [Indexed: 01/04/2023] Open
Abstract
Mechanistic Target of Rapamycin Complex 2 (mTORC2) regulates placental amino acid and folate transport. However, the role of mTORC2 in modulating other placental functions is largely unexplored. We used a gene array following the silencing of rictor to identify genes regulated by mTORC2 in primary human trophoblast (PHT) cells. Four hundred and nine genes were differentially expressed; 102 genes were down-regulated and 307 up-regulated. Pathway analyses demonstrated that inhibition of mTORC2 resulted in increased expression of genes encoding for pro-inflammatory IL-6, VEGF-A, leptin, and inflammatory signaling (SAPK/JNK). Furthermore, down-regulated genes were functionally enriched in genes involved in angiogenesis (Osteopontin) and multivitamin transport (SLC5A6). In addition, the protein expression of leptin, VEGFA, IL-6 was increased and negatively correlated to mTORC2 signaling in human placentas collected from pregnancies complicated by intrauterine growth restriction (IUGR). In contrast, the protein expression of Osteopontin and SLC5A6 was decreased and positively correlated to mTORC2 signaling in human IUGR placentas. In conclusion, mTORC2 signaling regulates trophoblast expression of genes involved in inflammation, micronutrient transport, and angiogenesis, representing novel links between mTOR signaling and multiple placental functions necessary for fetal growth and development.
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Affiliation(s)
- Fredrick J Rosario
- Division of Reproductive Sciences, Department of OB/GYN University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Amy Catherine Kelly
- Division of Reproductive Sciences, Department of OB/GYN University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Madhulika B Gupta
- Children's Health Research Institute and Department of Pediatrics and Biochemistry, University of Western Ontario, London, ON, Canada
| | - Theresa L Powell
- Division of Reproductive Sciences, Department of OB/GYN University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Section of Neonatology, Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Laura Cox
- Section of Molecular Medicine, Department of Internal Medicine, Center for Precision Medicine, Wake Forest School of Medicine, Winston-Salem, NC, United States
| | - Thomas Jansson
- Division of Reproductive Sciences, Department of OB/GYN University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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8
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O'Morain VL, Chan Y, Williams JO, Alotibi R, Alahmadi A, Rodrigues NP, Plummer SF, Hughes TR, Michael DR, Ramji DP. The Lab4P Consortium of Probiotics Attenuates Atherosclerosis in LDL Receptor Deficient Mice Fed a High Fat Diet and Causes Plaque Stabilization by Inhibiting Inflammation and Several Pro-Atherogenic Processes. Mol Nutr Food Res 2021; 65:e2100214. [PMID: 34216185 PMCID: PMC9373067 DOI: 10.1002/mnfr.202100214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/07/2021] [Indexed: 12/17/2022]
Abstract
SCOPE Previous studies show that Lab4 probiotic consortium plus Lactobacillus plantarum CUL66 (Lab4P) reduces diet-induced weight gain and plasma cholesterol levels in C57BL/6J mice fed a high fat diet (HFD). The effect of Lab4P on atherosclerosis is not known and is therefore investigated. METHODS AND RESULTS Atherosclerosis-associated parameters are analyzed in LDL receptor deficient mice fed HFD for 12 weeks alone or supplemented with Lab4P. Lab4P increases plasma HDL and triglyceride levels and decreases LDL/VLDL levels. Lab4P also reduces plaque burden and content of lipids and macrophages, indicative of dampened inflammation, and increases smooth muscle cell content, a marker of plaque stabilization. Atherosclerosis arrays show that Lab4P alters the liver expression of 19 key disease-associated genes. Lab4P also decreases the frequency of macrophages and T-cells in the bone marrow. In vitro assays using conditioned media from probiotic bacteria demonstrates attenuation of several atherosclerosis-associated processes in vitro such as chemokine-driven monocytic migration, proliferation of monocytes and macrophages, foam cell formation and associated changes in expression of key genes, and proliferation and migration of vascular smooth muscle cells. CONCLUSION This study provides new insights into the anti-atherogenic actions of Lab4P together with the underlying mechanisms and supports further assessments in human trials.
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Affiliation(s)
- Victoria L. O'Morain
- Cardiff School of BiosciencesCardiff UniversitySir Martin Evans Building, Museum AvenueCardiffCF10 3AXUK
| | - Yee‐Hung Chan
- Cardiff School of BiosciencesCardiff UniversitySir Martin Evans Building, Museum AvenueCardiffCF10 3AXUK
| | - Jessica O. Williams
- Cardiff School of BiosciencesCardiff UniversitySir Martin Evans Building, Museum AvenueCardiffCF10 3AXUK
| | - Reem Alotibi
- Cardiff School of BiosciencesCardiff UniversitySir Martin Evans Building, Museum AvenueCardiffCF10 3AXUK
| | - Alaa Alahmadi
- Cardiff School of BiosciencesCardiff UniversitySir Martin Evans Building, Museum AvenueCardiffCF10 3AXUK
| | - Neil P. Rodrigues
- European Cancer Stem Cell Research Institute, Cardiff School of BiosciencesCardiff UniversityHadyn Ellis Building, Maindy RoadCardiffCF24 4HQUK
| | - Sue F. Plummer
- Cultech LimitedUnit 2 Christchurch Road, Baglan Industrial ParkPort TalbotSA12 7BZUK
| | - Timothy R. Hughes
- Systems Immunity Research Institute, School of MedicineCardiff UniversityCardiffCF14 4XNUK
| | - Daryn R. Michael
- Cultech LimitedUnit 2 Christchurch Road, Baglan Industrial ParkPort TalbotSA12 7BZUK
| | - Dipak P. Ramji
- Cardiff School of BiosciencesCardiff UniversitySir Martin Evans Building, Museum AvenueCardiffCF10 3AXUK
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9
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Liu XL, Pan Q, Cao HX, Xin FZ, Zhao ZH, Yang RX, Zeng J, Zhou H, Fan JG. Lipotoxic Hepatocyte-Derived Exosomal MicroRNA 192-5p Activates Macrophages Through Rictor/Akt/Forkhead Box Transcription Factor O1 Signaling in Nonalcoholic Fatty Liver Disease. Hepatology 2020; 72:454-469. [PMID: 31782176 PMCID: PMC10465073 DOI: 10.1002/hep.31050] [Citation(s) in RCA: 155] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 11/18/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Hepatic macrophages can be activated by many factors such as gut-derived bacterial components and factors released from damaged hepatocytes. Macrophage polarization toward a proinflammatory phenotype (M1) represents an important event in the disease progression of nonalcoholic fatty liver disease (NAFLD). However, the underlying molecular mechanisms remain incompletely understood. Exosomes have been identified as important mediators for cell-cell communication by transferring various biological components such as microRNAs (miRs), proteins, and lipids. The role of exosomes in crosstalk between hepatocytes and macrophages in disease progression of NAFLD is yet to be explored. APPROACH AND RESULTS In the present study, we reported that lipotoxic injury-induced release of hepatocyte exosomes enriched with miR-192-5p played a critical role in the activation of M1 macrophages and hepatic inflammation. Serum miR-192-5p levels in patients with NAFLD positively correlated with hepatic inflammatory activity score and disease progression. Similarly, the serum miR-192-5p level and the number of M1 macrophages, as well as the expression levels of the hepatic proinflammatory mediators, were correlated with disease progression in high-fat high-cholesterol diet-fed rat models. Lipotoxic hepatocytes released more miR-192-5p-enriched exosomes than controls, which induced M1 macrophage (cluster of differentiation 11b-positive [CD11b+ ]/CD86+ ) activation and increase of inducible nitric oxide synthase, interleukin 6, and tumor necrosis factor alpha expression. Furthermore, hepatocyte-derived exosomal miR-192-5p inhibited the protein expression of the rapamycin-insensitive companion of mammalian target of rapamycin (Rictor), which further inhibited the phosphorylation levels of Akt and forkhead box transcription factor O1 (FoxO1) and resulted in activation of FoxO1 and subsequent induction of the inflammatory response. CONCLUSIONS Hepatocyte-derived exosomal miR-192-5p plays a critical role in the activation of proinflammatory macrophages and disease progression of NAFLD through modulating Rictor/Akt/FoxO1 signaling. Serum exosomal miR-192-5p represents a potential noninvasive biomarker and therapeutic target for nonalcoholic steatohepatitis.
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Affiliation(s)
- Xiao-Lin Liu
- Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
- Department of Gastroenterology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, China
| | - Qin Pan
- Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Hai-Xia Cao
- Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Feng-Zhi Xin
- Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Ze-Hua Zhao
- Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Rui-Xu Yang
- Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Jing Zeng
- Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Huiping Zhou
- Department of Microbiology and Immunology, Medical College of Virginia, Virginia Commonwealth University; McGuire VA Medical Center, Richmond, VA, 23298, USA
| | - Jian-Gao Fan
- Department of Gastroenterology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
- Shanghai Key Laboratory of Children’s Digestion and Nutrition, Shanghai 200092, China
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10
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Leonard F, Curtis LT, Hamed AR, Zhang C, Chau E, Sieving D, Godin B, Frieboes HB. Nonlinear response to cancer nanotherapy due to macrophage interactions revealed by mathematical modeling and evaluated in a murine model via CRISPR-modulated macrophage polarization. Cancer Immunol Immunother 2020; 69:731-744. [PMID: 32036448 PMCID: PMC7186159 DOI: 10.1007/s00262-020-02504-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 01/24/2020] [Indexed: 12/11/2022]
Abstract
Tumor-associated macrophages (TAMs) have been shown to both aid and hinder tumor growth, with patient outcomes potentially hinging on the proportion of M1, pro-inflammatory/growth-inhibiting, to M2, growth-supporting, phenotypes. Strategies to stimulate tumor regression by promoting polarization to M1 are a novel approach that harnesses the immune system to enhance therapeutic outcomes, including chemotherapy. We recently found that nanotherapy with mesoporous particles loaded with albumin-bound paclitaxel (MSV-nab-PTX) promotes macrophage polarization towards M1 in breast cancer liver metastases (BCLM). However, it remains unclear to what extent tumor regression can be maximized based on modulation of the macrophage phenotype, especially for poorly perfused tumors such as BCLM. Here, for the first time, a CRISPR system is employed to permanently modulate macrophage polarization in a controlled in vitro setting. This enables the design of 3D co-culture experiments mimicking the BCLM hypovascularized environment with various ratios of polarized macrophages. We implement a mathematical framework to evaluate nanoparticle-mediated chemotherapy in conjunction with TAM polarization. The response is predicted to be not linearly dependent on the M1:M2 ratio. To investigate this phenomenon, the response is simulated via the model for a variety of M1:M2 ratios. The modeling indicates that polarization to an all-M1 population may be less effective than a combination of both M1 and M2. Experimental results with the CRISPR system confirm this model-driven hypothesis. Altogether, this study indicates that response to nanoparticle-mediated chemotherapy targeting poorly perfused tumors may benefit from a fine-tuned M1:M2 ratio that maintains both phenotypes in the tumor microenvironment during treatment.
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Affiliation(s)
- Fransisca Leonard
- Department of Nanomedicine, Houston Methodist Research Institute, R8-213, 6670 Bertner St., Houston, TX, 77030, USA
| | - Louis T Curtis
- Department of Bioengineering, University of Louisville, Louisville, KY, USA
| | - Ahmed R Hamed
- Department of Nanomedicine, Houston Methodist Research Institute, R8-213, 6670 Bertner St., Houston, TX, 77030, USA
- Pharmaceutical and Drug Industries Research Division, National Research Centre, Giza, Egypt
| | - Carolyn Zhang
- Department of Nanomedicine, Houston Methodist Research Institute, R8-213, 6670 Bertner St., Houston, TX, 77030, USA
| | - Eric Chau
- Department of Nanomedicine, Houston Methodist Research Institute, R8-213, 6670 Bertner St., Houston, TX, 77030, USA
| | - Devon Sieving
- Department of Nanomedicine, Houston Methodist Research Institute, R8-213, 6670 Bertner St., Houston, TX, 77030, USA
| | - Biana Godin
- Department of Nanomedicine, Houston Methodist Research Institute, R8-213, 6670 Bertner St., Houston, TX, 77030, USA.
- Department of Obstetrics and Gynecology, Houston Methodist Hospital, Houston, TX, USA.
| | - Hermann B Frieboes
- Department of Bioengineering, University of Louisville, Lutz Hall 419, Louisville, KY, 40292, USA.
- James Graham Brown Cancer Center, University of Louisville, Louisville, KY, USA.
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, USA.
- Center for Predictive Medicine, University of Louisville, Louisville, KY, USA.
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11
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Kiss T, Tarantini S, Csipo T, Balasubramanian P, Nyúl-Tóth Á, Yabluchanskiy A, Wren JD, Garman L, Huffman DM, Csiszar A, Ungvari Z. Circulating anti-geronic factors from heterochonic parabionts promote vascular rejuvenation in aged mice: transcriptional footprint of mitochondrial protection, attenuation of oxidative stress, and rescue of endothelial function by young blood. GeroScience 2020; 42:727-748. [PMID: 32172434 PMCID: PMC7205954 DOI: 10.1007/s11357-020-00180-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 03/04/2020] [Indexed: 12/15/2022] Open
Abstract
Aging-induced functional and phenotypic alterations of the vasculature (e.g., endothelial dysfunction, oxidative stress) have a central role in morbidity and mortality of older adults. It has become apparent in recent years that cell autonomous mechanisms alone are inadequate to explain all aspects of vascular aging. The present study was designed to test the hypothesis that age-related changes in circulating anti-geronic factors contribute to the regulation of vascular aging processes in a non-cell autonomous manner. To test this hypothesis, through heterochronic parabiosis we determined the extent, if any, to which endothelial function, vascular production of ROS, and shifts in the vascular transcriptome (RNA-seq) are modulated by the systemic environment. We found that in aortas isolated from isochronic parabiont aged (20-month-old) C57BL/6 mice [A-(A); parabiosis for 8 weeks] acetylcholine-induced endothelium-dependent relaxation was impaired and ROS production (dihydroethidium fluorescence) was increased as compared with those in aortas from young isochronic parabiont (6-month-old) mice [Y-(Y)]. The presence of young blood derived from young parabionts significantly improved endothelium-dependent vasorelaxation and attenuated ROS production in vessels of heterochronic parabiont aged [A-(Y)] mice. In aortas derived from heterochronic parabiont young [Y-(A)] mice, acetylcholine-induced relaxation and ROS production were comparable with those in aortas derived from Y-(Y) mice. Using RNA-seq we assessed transcriptomic changes in the aortic arch associated with aging and heterochronic parabiosis. We identified 347 differentially expressed genes in A-(A) animals compared with Y-(Y) controls. We have identified 212 discordant genes, whose expression levels differed in the aged phenotype, but have shifted back toward the young phenotype by the presence of young blood in aged A-(Y) animals. Pathway analysis shows that vascular protective effects mediated by young blood-regulated genes include mitochondrial rejuvenation. In conclusion, a relatively short-term exposure to young blood can rescue vascular aging phenotypes, including attenuation of oxidative stress, mitochondrial rejuvenation, and improved endothelial function. Our findings provide additional evidence supporting the significant plasticity of vascular aging and evidence for the existence of anti-geronic factors capable of exerting rejuvenating effects on the aging vasculature.
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Affiliation(s)
- Tamas Kiss
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK 73104 USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK 73104 USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
| | - Tamas Csipo
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK 73104 USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Department of Cardiology, Division of Clinical Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Priya Balasubramanian
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK 73104 USA
| | - Ádám Nyúl-Tóth
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK 73104 USA
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Andriy Yabluchanskiy
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK 73104 USA
| | - Jonathan D. Wren
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK 73104 USA
- Oklahoma Medical Research Foundation, Genes & Human Disease Research Program, Oklahoma City, OK USA
| | - Lori Garman
- Oklahoma Medical Research Foundation, Genes & Human Disease Research Program, Oklahoma City, OK USA
| | - Derek M. Huffman
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461 USA
- Institute for Aging Research, Albert Einstein College of Medicine, Bronx, NY USA
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY USA
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK 73104 USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
- The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104 USA
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK 73104 USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA
- The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104 USA
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12
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Huang J, Wang D, Huang LH, Huang H. Roles of Reconstituted High-Density Lipoprotein Nanoparticles in Cardiovascular Disease: A New Paradigm for Drug Discovery. Int J Mol Sci 2020; 21:ijms21030739. [PMID: 31979310 PMCID: PMC7037452 DOI: 10.3390/ijms21030739] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/19/2020] [Accepted: 01/21/2020] [Indexed: 02/08/2023] Open
Abstract
Epidemiological results revealed that there is an inverse correlation between high-density lipoprotein (HDL) cholesterol levels and risks of atherosclerotic cardiovascular disease (ASCVD). Mounting evidence supports that HDLs are atheroprotective, therefore, many therapeutic approaches have been developed to increase HDL cholesterol (HDL-C) levels. Nevertheless, HDL-raising therapies, such as cholesteryl ester transfer protein (CETP) inhibitors, failed to ameliorate cardiovascular outcomes in clinical trials, thereby casting doubt on the treatment of cardiovascular disease (CVD) by increasing HDL-C levels. Therefore, HDL-targeted interventional studies were shifted to increasing the number of HDL particles capable of promoting ATP-binding cassette transporter A1 (ABCA1)-mediated cholesterol efflux. One such approach was the development of reconstituted HDL (rHDL) particles that promote ABCA1-mediated cholesterol efflux from lipid-enriched macrophages. Here, we explore the manipulation of rHDL nanoparticles as a strategy for the treatment of CVD. In addition, we discuss technological capabilities and the challenge of relating preclinical in vivo mice research to clinical studies. Finally, by drawing lessons from developing rHDL nanoparticles, we also incorporate the viabilities and advantages of the development of a molecular imaging probe with HDL nanoparticles when applied to ASCVD, as well as gaps in technology and knowledge required for putting the HDL-targeted therapeutics into full gear.
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Affiliation(s)
- Jiansheng Huang
- Department of Medicine, Vanderbilt University Medical Center, 318 Preston Research Building, 2200 Pierce Avenue, Nashville, TN 37232, USA
- Correspondence:
| | - Dongdong Wang
- Institute of Clinical Chemistry, University Hospital Zurich, Wagistrasse 14, 8952 Schlieren, Switzerland;
| | - Li-Hao Huang
- Pathology and Immunology Department, Washington University School of Medicine, St. Louis, MO 63110-1093, USA;
| | - Hui Huang
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232, USA;
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13
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Wang D, Huang J, Gui T, Yang Y, Feng T, Tzvetkov NT, Xu T, Gai Z, Zhou Y, Zhang J, Atanasov AG. SR-BI as a target of natural products and its significance in cancer. Semin Cancer Biol 2020; 80:18-38. [PMID: 31935456 DOI: 10.1016/j.semcancer.2019.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/25/2019] [Accepted: 12/30/2019] [Indexed: 02/07/2023]
Abstract
Scavenger receptor class B type I (SR-BI) protein is an integral membrane glycoprotein. SR-BI is emerging as a multifunctional protein, which regulates autophagy, efferocytosis, cell survival and inflammation. It is well known that SR-BI plays a critical role in lipoprotein metabolism by mediating cholesteryl esters selective uptake and the bi-directional flux of free cholesterol. Recently, SR-BI has also been identified as a potential marker for cancer diagnosis, prognosis, or even a treatment target. Natural products are a promising source for the discovery of new drug leads. Multiple natural products were identified to regulate SR-BI protein expression. There are still a number of challenges in modulating SR-BI expression in cancer and in using natural products for modulation of such protein expression. In this review, our purpose is to discuss the relationship between SR-BI protein and cancer, and the molecular mechanisms regulating SR-BI expression, as well as to provide an overview of natural products that regulate SR-BI expression.
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Affiliation(s)
- Dongdong Wang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Jiansheng Huang
- Department of Medicine, Vanderbilt University Medical Center, 318 Preston Research Building, 2200 Pierce Avenue, Nashville, Tennessee, 37232, USA
| | - Ting Gui
- Key Laboratory of Traditional Chinese Medicine for Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Yaxin Yang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Tingting Feng
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China
| | - Nikolay T Tzvetkov
- Department of Biochemical Pharmacology and Drug Design, Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, 21 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria
| | - Tao Xu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Zhibo Gai
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Ying Zhou
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China.
| | - Jingjie Zhang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China.
| | - Atanas G Atanasov
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, 05-552, Jastrzębiec, Poland; Department of Pharmacognosy, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria; Institute of Neurobiology, Bulgarian Academy of Sciences, 23 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria; Ludwig Boltzmann Institute for Digital Health and Patient Safety, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
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14
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Katholnig K, Schütz B, Fritsch SD, Schörghofer D, Linke M, Sukhbaatar N, Matschinger JM, Unterleuthner D, Hirtl M, Lang M, Herac M, Spittler A, Bergthaler A, Schabbauer G, Bergmann M, Dolznig H, Hengstschläger M, Magnuson MA, Mikula M, Weichhart T. Inactivation of mTORC2 in macrophages is a signature of colorectal cancer that promotes tumorigenesis. JCI Insight 2019; 4:124164. [PMID: 31619583 PMCID: PMC6824305 DOI: 10.1172/jci.insight.124164] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 09/06/2019] [Indexed: 12/30/2022] Open
Abstract
The mechanistic target of rapamycin complex 2 (mTORC2) is a potentially novel and promising anticancer target due to its critical roles in proliferation, apoptosis, and metabolic reprogramming of cancer cells. However, the activity and function of mTORC2 in distinct cells within malignant tissue in vivo is insufficiently explored. Surprisingly, in primary human and mouse colorectal cancer (CRC) samples, mTORC2 signaling could not be detected in tumor cells. In contrast, only macrophages in tumor-adjacent areas showed mTORC2 activity, which was downregulated in stromal macrophages residing within human and mouse tumor tissues. Functionally, inhibition of mTORC2 by specific deletion of Rictor in macrophages stimulated tumorigenesis in a colitis-associated CRC mouse model. This phenotype was driven by a proinflammatory reprogramming of mTORC2-deficient macrophages that promoted colitis via the cytokine SPP1/osteopontin to stimulate tumor growth. In human CRC patients, high SPP1 levels and low mTORC2 activity in tumor-associated macrophages correlated with a worsened clinical prognosis. Treatment of mice with a second-generation mTOR inhibitor that inhibits mTORC2 and mTORC1 exacerbated experimental colorectal tumorigenesis in vivo. In conclusion, mTORC2 activity is confined to macrophages in CRC and limits tumorigenesis. These results suggest activation but not inhibition of mTORC2 as a therapeutic strategy for colitis-associated CRC.
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Affiliation(s)
- Karl Katholnig
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics
| | - Birgit Schütz
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics
| | | | - David Schörghofer
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics
| | - Monika Linke
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics
| | | | | | | | - Martin Hirtl
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics
| | - Michaela Lang
- Department of Internal Medicine III, Division of Gastroenterology and Hepatology
| | | | - Andreas Spittler
- Core Facility Flow Cytometry & Surgical Research Laboratories, Medical University of Vienna, Vienna, Austria
| | - Andreas Bergthaler
- CeMM Research Center for Molecular Medicine, Austrian Academy of Sciences, Vienna, Austria
| | - Gernot Schabbauer
- Institute for Physiology, Center for Physiology and Pharmacology, and
| | - Michael Bergmann
- Division of General Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Helmut Dolznig
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics
| | | | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics and Center for Stem Cell Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Mario Mikula
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics
| | - Thomas Weichhart
- Center of Pathobiochemistry and Genetics, Institute of Medical Genetics
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15
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Zhang Q, Hu J, Wu Y, Luo H, Meng W, Xiao B, Xiao X, Zhou Z, Liu F. Rheb (Ras Homolog Enriched in Brain 1) Deficiency in Mature Macrophages Prevents Atherosclerosis by Repressing Macrophage Proliferation, Inflammation, and Lipid Uptake. Arterioscler Thromb Vasc Biol 2019; 39:1787-1801. [DOI: 10.1161/atvbaha.119.312870] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Objective:
Macrophage foam cell formation is an important process in atherosclerotic plaque development. The small GTPase Rheb (Ras homolog enriched in brain 1) regulates endocytic trafficking that is critical for foam cell formation. However, it is unclear whether and how macrophage Rheb regulates atherogenesis, which are the focuses of the current study.
Approach and Results:
Immunofluorescence study confirmed the colocalization of Rheb in F4/80 and Mac-2 (galectin-3)–labeled lesional macrophages. Western blot and fluorescence-activated cell sorting analysis showed that Rheb expression was significantly increased in atherosclerotic lesions of atherosclerosis-prone (apoE
−/−
[apolipoprotein E deficient]) mice fed with Western diet. Increased Rheb expression was also observed in oxidized LDL (low-density lipoprotein)–treated macrophages. To investigate the in vivo role of macrophage Rheb, we established mature Rheb
mKO
(macrophage-specific Rheb knockout) mice by crossing the Rheb floxed mice with
F4/80-cre
mice. Macrophage-specific knockout of Rheb in mice reduced Western diet–induced atherosclerotic lesion by 32%, accompanied with a decrease in macrophage content in plaque. Mechanistically, loss of Rheb in macrophages repressed oxidized LDL–induced lipid uptake, inflammation, and macrophage proliferation. On the contrary, lentivirus-mediated overexpression of Rheb in macrophages increased oxidized LDL–induced lipid uptake and inflammation, and the stimulatory effect of Rheb was suppressed by the mTOR (mammalian target of rapamycin) inhibitor rapamycin or the PKA (protein kinase A) activator forskolin.
Conclusions:
Macrophage Rheb plays important role in Western diet–induced atherosclerosis by promoting macrophage proliferation, inflammation, and lipid uptake. Inhibition of expression and function of Rheb in macrophages is beneficial to prevent diet-induced atherosclerosis.
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Affiliation(s)
- Qinghai Zhang
- From the Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China (Q.Z., J.H., Y.W., H.L., W.M., B.X., Z.Z., F.L.)
- Department of Metabolism and Endocrinology, First Affiliated Hospital of University of South China, Hengyang, Hunan (Q.Z.)
| | - Jie Hu
- From the Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China (Q.Z., J.H., Y.W., H.L., W.M., B.X., Z.Z., F.L.)
| | - Yan Wu
- From the Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China (Q.Z., J.H., Y.W., H.L., W.M., B.X., Z.Z., F.L.)
| | - Hairong Luo
- From the Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China (Q.Z., J.H., Y.W., H.L., W.M., B.X., Z.Z., F.L.)
| | - Wen Meng
- From the Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China (Q.Z., J.H., Y.W., H.L., W.M., B.X., Z.Z., F.L.)
| | - Bo Xiao
- From the Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China (Q.Z., J.H., Y.W., H.L., W.M., B.X., Z.Z., F.L.)
- Department of Biology, Southern University of Science and Technology, Shenzhen, China (B.X.)
| | - Xianzhong Xiao
- Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China (X.X.)
| | - Zhiguang Zhou
- From the Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China (Q.Z., J.H., Y.W., H.L., W.M., B.X., Z.Z., F.L.)
| | - Feng Liu
- From the Department of Metabolism and Endocrinology, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, National Clinical Research Center for Metabolic Diseases, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China (Q.Z., J.H., Y.W., H.L., W.M., B.X., Z.Z., F.L.)
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16
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Linton MF, Moslehi JJ, Babaev VR. Akt Signaling in Macrophage Polarization, Survival, and Atherosclerosis. Int J Mol Sci 2019; 20:ijms20112703. [PMID: 31159424 PMCID: PMC6600269 DOI: 10.3390/ijms20112703] [Citation(s) in RCA: 137] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 12/15/2022] Open
Abstract
The PI3K/Akt pathway plays a crucial role in the survival, proliferation, and migration of macrophages, which may impact the development of atherosclerosis. Changes in Akt isoforms or modulation of the Akt activity levels in macrophages significantly affect their polarization phenotype and consequently atherosclerosis in mice. Moreover, the activity levels of Akt signaling determine the viability of monocytes/macrophages and their resistance to pro-apoptotic stimuli in atherosclerotic lesions. Therefore, elimination of pro-apoptotic factors as well as factors that antagonize or suppress Akt signaling in macrophages increases cell viability, protecting them from apoptosis, and this markedly accelerates atherosclerosis in mice. In contrast, inhibition of Akt signaling by the ablation of Rictor in myeloid cells, which disrupts mTORC2 assembly, significantly decreases the viability and proliferation of blood monocytes and macrophages with the suppression of atherosclerosis. In addition, monocytes and macrophages exhibit a threshold effect for Akt protein levels in their ability to survive. Ablation of two Akt isoforms, preserving only a single Akt isoform in myeloid cells, markedly compromises monocyte and macrophage viability, inducing monocytopenia and diminishing early atherosclerosis. These recent advances in our understanding of Akt signaling in macrophages in atherosclerosis may have significant relevance in the burgeoning field of cardio-oncology, where PI3K/Akt inhibitors being tested in cancer patients can have significant cardiovascular and metabolic ramifications.
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Affiliation(s)
- MacRae F Linton
- Atherosclerosis Research Unit, Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University School of Medicine, 2220 Pierce Avenue, Nashville, TN 37232-6300, USA.
- Department of Pharmacology, Vanderbilt University School of Medicine, 2220 Pierce Avenue, Nashville, TN 37232-6300, USA.
| | - Javid J Moslehi
- Atherosclerosis Research Unit, Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University School of Medicine, 2220 Pierce Avenue, Nashville, TN 37232-6300, USA.
| | - Vladimir R Babaev
- Atherosclerosis Research Unit, Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University School of Medicine, 2220 Pierce Avenue, Nashville, TN 37232-6300, USA.
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17
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Dai H, Thomson AW. The "other" mTOR complex: New insights into mTORC2 immunobiology and their implications. Am J Transplant 2019; 19:1614-1621. [PMID: 30801921 PMCID: PMC6538441 DOI: 10.1111/ajt.15320] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/10/2019] [Accepted: 02/15/2019] [Indexed: 01/25/2023]
Abstract
A central role of the mechanistic target of rapamycin (mTOR) in regulation of fundamental cell processes is well recognized. mTOR functions in two distinct complexes: rapamycin-sensitive mTOR complex (C) 1 and rapamycin-insensitive mTORC2. While the role of mTORC1 in shaping immune responses, including transplant rejection, and the influence of its antagonism in promoting allograft tolerance have been studied extensively using rapamycin, lack of selective small molecule inhibitors has limited understanding of mTORC2 biology. Within the past few years, however, intracellular localization of mTORC2, its contribution to mitochondrial fitness, cell metabolism, cytoskeletal modeling and cell migration, and its role in differentiation and function of immune cells have been described. Studies in mTORC2 knockdown/knockout mouse models and a new class of dual mTORC1/2 inhibitors, have shed light on the immune regulatory functions of mTORC2. These include regulation of antigen-presenting cell, NK cell, T cell subset, and B cell differentiation and function. mTORC2 has been implicated in regulation of ischemia/reperfusion injury and graft rejection. Potential therapeutic benefits of antagonizing mTORC2 to inhibit chronic rejection have also been described, while selective in vivo targeting strategies using nanotechnology have been developed. We briefly review and discuss these developments and their implications.
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Affiliation(s)
- Helong Dai
- Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA,Department of Urological Organ Transplantation, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China
| | - Angus W. Thomson
- Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA,Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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18
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Malik N, Sansom OJ, Michie AM. The role of mTOR-mediated signals during haemopoiesis and lineage commitment. Biochem Soc Trans 2018; 46:1313-1324. [PMID: 30154096 PMCID: PMC6195642 DOI: 10.1042/bst20180141] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 12/11/2022]
Abstract
The serine/threonine protein kinase mechanistic target of rapamycin (mTOR) has been implicated in the regulation of an array of cellular functions including protein and lipid synthesis, proliferation, cell size and survival. Here, we describe the role of mTOR during haemopoiesis within the context of mTORC1 and mTORC2, the distinct complexes in which it functions. The use of conditional transgenic mouse models specifically targeting individual mTOR signalling components, together with selective inhibitors, have generated a significant body of research emphasising the critical roles played by mTOR, and individual mTOR complexes, in haemopoietic lineage commitment and development. This review will describe the profound role of mTOR in embryogenesis and haemopoiesis, underscoring the importance of mTORC1 at the early stages of haemopoietic cell development, through modulation of stem cell potentiation and self-renewal, and erythroid and B cell lineage commitment. Furthermore, the relatively discrete role of mTORC2 in haemopoiesis will be explored during T cell development and B cell maturation. Collectively, this review aims to highlight the functional diversity of mTOR signalling and underline the importance of this pathway in haemopoiesis.
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Affiliation(s)
- Natasha Malik
- Institute of Cancer Sciences, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow, U.K
| | - Owen J Sansom
- Institute of Cancer Sciences, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow, U.K
- Cancer Research UK Beatson Institute, Garscube Estate, Glasgow, U.K
| | - Alison M Michie
- Institute of Cancer Sciences, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow, U.K.
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