WonMo Ahn , Faith N. Burnett , Kamila Wojnar-Lason , Jaser Doja , Amritha Sreekumar , Pushpankur Ghoshal , Bhupesh Singla , Graydon Gonsalvez , Ryan A. Harris , Xiaoling Wang , Joseph M. Miano , Gábor Csányi
{"title":"受体不依赖的液相胞饮作用的激活促进动脉粥样硬化小鼠泡沫单核细胞的形成","authors":"WonMo Ahn , Faith N. Burnett , Kamila Wojnar-Lason , Jaser Doja , Amritha Sreekumar , Pushpankur Ghoshal , Bhupesh Singla , Graydon Gonsalvez , Ryan A. Harris , Xiaoling Wang , Joseph M. Miano , Gábor Csányi","doi":"10.1016/j.redox.2024.103423","DOIUrl":null,"url":null,"abstract":"<div><div>Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death worldwide. Clinical and experimental data demonstrated that circulating monocytes internalize plasma lipoproteins and become lipid-laden foamy cells in hypercholesterolemic subjects. This study was designed to identify the endocytic mechanisms responsible for foamy monocyte formation, perform functional and transcriptomic analysis of foamy and non-foamy monocytes relevant to ASCVD, and characterize specific monocyte subsets isolated from the circulation of normocholesterolemic controls and hypercholesterolemic patients. We hypothesized that activation of fluid-phase macropinocytosis contributes to foamy monocyte formation <em>in vitro</em> and in hypercholesterolemic mice <em>in vivo</em>. High resolution scanning electron microscopy (SEM) and quantification of FITC/TRITC-dextran internalization demonstrated macropinocytosis stimulation in human (THP-1) and <em>wild type</em> murine monocytes. Stimulation of macropinocytosis induced foamy monocyte formation in the presence of unmodified, native LDL (nLDL) and oxidized LDL (ox-LDL) <em>in vitro</em>. Genetic blockade of macropinocytosis (<em><strong>LysMCre</strong></em><em><strong>+</strong></em> <em>Nhe1</em><sup><em>f/f</em></sup>) inhibited foamy monocyte formation in hypercholesterolemic mice <em>in vivo</em> and attenuated monocyte adhesion to atherosclerotic aortas <em>ex vivo</em>. Mechanistic studies identified NADPH oxidase 2 (Nox2)-derived superoxide anion (O<sub>2</sub><sup>⋅−</sup>) as an important downstream signaling molecule stimulating macropinocytosis in monocytes. qRT-PCR identified CD36 as a major scavenger receptor that increases in response to lipid loading in monocytes and deletion of CD36 (<em>Cd36</em><sup>−/−</sup>) inhibited foamy monocyte formation in hypercholesterolemic mice. Bulk RNA-sequencing characterized transcriptional differences between non-foamy and foamy monocytes versus macrophages. Finally, flow cytometry analysis of CD14 and CD16 expression demonstrated a significant increase in intermediate monocytes in hypercholesterolemic patients compared to normocholesterolemic controls. These results provide novel insights into the mechanisms of foamy monocyte formation and potentially identify new therapeutic targets for the treatment of atherosclerosis.</div></div>","PeriodicalId":20998,"journal":{"name":"Redox Biology","volume":"78 ","pages":"Article 103423"},"PeriodicalIF":10.7000,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Activation of receptor-independent fluid-phase pinocytosis promotes foamy monocyte formation in atherosclerotic mice\",\"authors\":\"WonMo Ahn , Faith N. Burnett , Kamila Wojnar-Lason , Jaser Doja , Amritha Sreekumar , Pushpankur Ghoshal , Bhupesh Singla , Graydon Gonsalvez , Ryan A. Harris , Xiaoling Wang , Joseph M. Miano , Gábor Csányi\",\"doi\":\"10.1016/j.redox.2024.103423\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death worldwide. Clinical and experimental data demonstrated that circulating monocytes internalize plasma lipoproteins and become lipid-laden foamy cells in hypercholesterolemic subjects. This study was designed to identify the endocytic mechanisms responsible for foamy monocyte formation, perform functional and transcriptomic analysis of foamy and non-foamy monocytes relevant to ASCVD, and characterize specific monocyte subsets isolated from the circulation of normocholesterolemic controls and hypercholesterolemic patients. We hypothesized that activation of fluid-phase macropinocytosis contributes to foamy monocyte formation <em>in vitro</em> and in hypercholesterolemic mice <em>in vivo</em>. High resolution scanning electron microscopy (SEM) and quantification of FITC/TRITC-dextran internalization demonstrated macropinocytosis stimulation in human (THP-1) and <em>wild type</em> murine monocytes. Stimulation of macropinocytosis induced foamy monocyte formation in the presence of unmodified, native LDL (nLDL) and oxidized LDL (ox-LDL) <em>in vitro</em>. Genetic blockade of macropinocytosis (<em><strong>LysMCre</strong></em><em><strong>+</strong></em> <em>Nhe1</em><sup><em>f/f</em></sup>) inhibited foamy monocyte formation in hypercholesterolemic mice <em>in vivo</em> and attenuated monocyte adhesion to atherosclerotic aortas <em>ex vivo</em>. Mechanistic studies identified NADPH oxidase 2 (Nox2)-derived superoxide anion (O<sub>2</sub><sup>⋅−</sup>) as an important downstream signaling molecule stimulating macropinocytosis in monocytes. qRT-PCR identified CD36 as a major scavenger receptor that increases in response to lipid loading in monocytes and deletion of CD36 (<em>Cd36</em><sup>−/−</sup>) inhibited foamy monocyte formation in hypercholesterolemic mice. Bulk RNA-sequencing characterized transcriptional differences between non-foamy and foamy monocytes versus macrophages. Finally, flow cytometry analysis of CD14 and CD16 expression demonstrated a significant increase in intermediate monocytes in hypercholesterolemic patients compared to normocholesterolemic controls. These results provide novel insights into the mechanisms of foamy monocyte formation and potentially identify new therapeutic targets for the treatment of atherosclerosis.</div></div>\",\"PeriodicalId\":20998,\"journal\":{\"name\":\"Redox Biology\",\"volume\":\"78 \",\"pages\":\"Article 103423\"},\"PeriodicalIF\":10.7000,\"publicationDate\":\"2024-12-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Redox Biology\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2213231724004014\",\"RegionNum\":1,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"BIOCHEMISTRY & MOLECULAR BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Redox Biology","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2213231724004014","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
Activation of receptor-independent fluid-phase pinocytosis promotes foamy monocyte formation in atherosclerotic mice
Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death worldwide. Clinical and experimental data demonstrated that circulating monocytes internalize plasma lipoproteins and become lipid-laden foamy cells in hypercholesterolemic subjects. This study was designed to identify the endocytic mechanisms responsible for foamy monocyte formation, perform functional and transcriptomic analysis of foamy and non-foamy monocytes relevant to ASCVD, and characterize specific monocyte subsets isolated from the circulation of normocholesterolemic controls and hypercholesterolemic patients. We hypothesized that activation of fluid-phase macropinocytosis contributes to foamy monocyte formation in vitro and in hypercholesterolemic mice in vivo. High resolution scanning electron microscopy (SEM) and quantification of FITC/TRITC-dextran internalization demonstrated macropinocytosis stimulation in human (THP-1) and wild type murine monocytes. Stimulation of macropinocytosis induced foamy monocyte formation in the presence of unmodified, native LDL (nLDL) and oxidized LDL (ox-LDL) in vitro. Genetic blockade of macropinocytosis (LysMCre+Nhe1f/f) inhibited foamy monocyte formation in hypercholesterolemic mice in vivo and attenuated monocyte adhesion to atherosclerotic aortas ex vivo. Mechanistic studies identified NADPH oxidase 2 (Nox2)-derived superoxide anion (O2⋅−) as an important downstream signaling molecule stimulating macropinocytosis in monocytes. qRT-PCR identified CD36 as a major scavenger receptor that increases in response to lipid loading in monocytes and deletion of CD36 (Cd36−/−) inhibited foamy monocyte formation in hypercholesterolemic mice. Bulk RNA-sequencing characterized transcriptional differences between non-foamy and foamy monocytes versus macrophages. Finally, flow cytometry analysis of CD14 and CD16 expression demonstrated a significant increase in intermediate monocytes in hypercholesterolemic patients compared to normocholesterolemic controls. These results provide novel insights into the mechanisms of foamy monocyte formation and potentially identify new therapeutic targets for the treatment of atherosclerosis.
期刊介绍:
Redox Biology is the official journal of the Society for Redox Biology and Medicine and the Society for Free Radical Research-Europe. It is also affiliated with the International Society for Free Radical Research (SFRRI). This journal serves as a platform for publishing pioneering research, innovative methods, and comprehensive review articles in the field of redox biology, encompassing both health and disease.
Redox Biology welcomes various forms of contributions, including research articles (short or full communications), methods, mini-reviews, and commentaries. Through its diverse range of published content, Redox Biology aims to foster advancements and insights in the understanding of redox biology and its implications.