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1.
Cell ; 185(19): 3501-3519.e20, 2022 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-36041436

RESUMEN

How intestinal microbes regulate metabolic syndrome is incompletely understood. We show that intestinal microbiota protects against development of obesity, metabolic syndrome, and pre-diabetic phenotypes by inducing commensal-specific Th17 cells. High-fat, high-sugar diet promoted metabolic disease by depleting Th17-inducing microbes, and recovery of commensal Th17 cells restored protection. Microbiota-induced Th17 cells afforded protection by regulating lipid absorption across intestinal epithelium in an IL-17-dependent manner. Diet-induced loss of protective Th17 cells was mediated by the presence of sugar. Eliminating sugar from high-fat diets protected mice from obesity and metabolic syndrome in a manner dependent on commensal-specific Th17 cells. Sugar and ILC3 promoted outgrowth of Faecalibaculum rodentium that displaced Th17-inducing microbiota. These results define dietary and microbiota factors posing risk for metabolic syndrome. They also define a microbiota-dependent mechanism for immuno-pathogenicity of dietary sugar and highlight an elaborate interaction between diet, microbiota, and intestinal immunity in regulation of metabolic disorders.


Asunto(s)
Síndrome Metabólico , Microbiota , Animales , Dieta Alta en Grasa , Azúcares de la Dieta , Interleucina-17 , Mucosa Intestinal , Lípidos , Ratones , Ratones Endogámicos C57BL , Obesidad , Células Th17
2.
Physiol Rev ; 104(2): 727-764, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-37882731

RESUMEN

The multifunctional membrane glycoprotein CD36 is expressed in different types of cells and plays a key regulatory role in cellular lipid metabolism, especially in cardiac muscle. CD36 facilitates the cellular uptake of long-chain fatty acids, mediates lipid signaling, and regulates storage and oxidation of lipids in various tissues with active lipid metabolism. CD36 deficiency leads to marked impairments in peripheral lipid metabolism, which consequently impact on the cellular utilization of multiple different fuels because of the integrated nature of metabolism. The functional presence of CD36 at the plasma membrane is regulated by its reversible subcellular recycling from and to endosomes and is under the control of mechanical, hormonal, and nutritional factors. Aberrations in this dynamic role of CD36 are causally associated with various metabolic diseases, in particular insulin resistance, diabetic cardiomyopathy, and cardiac hypertrophy. Recent research in cardiac muscle has disclosed the endosomal proton pump vacuolar-type H+-ATPase (v-ATPase) as a key enzyme regulating subcellular CD36 recycling and being the site of interaction between various substrates to determine cellular substrate preference. In addition, evidence is accumulating that interventions targeting CD36 directly or modulating its subcellular recycling are effective for the treatment of metabolic diseases. In conclusion, subcellular CD36 localization is the major adaptive regulator of cellular uptake and metabolism of long-chain fatty acids and appears a suitable target for metabolic modulation therapy to mend failing hearts.


Asunto(s)
Resistencia a la Insulina , Metabolismo de los Lípidos , Humanos , Miocardio/metabolismo , Corazón , Ácidos Grasos/metabolismo , Antígenos CD36/metabolismo
3.
Immunity ; 54(9): 2101-2116.e6, 2021 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-34469775

RESUMEN

Tissue macrophages are immune cells whose phenotypes and functions are dictated by origin and niches. However, tissues are complex environments, and macrophage heterogeneity within the same organ has been overlooked so far. Here, we used high-dimensional approaches to characterize macrophage populations in the murine liver. We identified two distinct populations among embryonically derived Kupffer cells (KCs) sharing a core signature while differentially expressing numerous genes and proteins: a major CD206loESAM- population (KC1) and a minor CD206hiESAM+ population (KC2). KC2 expressed genes involved in metabolic processes, including fatty acid metabolism both in steady-state and in diet-induced obesity and hepatic steatosis. Functional characterization by depletion of KC2 or targeted silencing of the fatty acid transporter Cd36 highlighted a crucial contribution of KC2 in the liver oxidative stress associated with obesity. In summary, our study reveals that KCs are more heterogeneous than anticipated, notably describing a subpopulation wired with metabolic functions.


Asunto(s)
Antígenos CD36/metabolismo , Macrófagos del Hígado/metabolismo , Hígado/metabolismo , Obesidad/metabolismo , Estrés Oxidativo/fisiología , Animales , Ratones
4.
Immunity ; 54(7): 1561-1577.e7, 2021 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-34102100

RESUMEN

A common metabolic alteration in the tumor microenvironment (TME) is lipid accumulation, a feature associated with immune dysfunction. Here, we examined how CD8+ tumor infiltrating lymphocytes (TILs) respond to lipids within the TME. We found elevated concentrations of several classes of lipids in the TME and accumulation of these in CD8+ TILs. Lipid accumulation was associated with increased expression of CD36, a scavenger receptor for oxidized lipids, on CD8+ TILs, which also correlated with progressive T cell dysfunction. Cd36-/- T cells retained effector functions in the TME, as compared to WT counterparts. Mechanistically, CD36 promoted uptake of oxidized low-density lipoproteins (OxLDL) into T cells, and this induced lipid peroxidation and downstream activation of p38 kinase. Inhibition of p38 restored effector T cell functions in vitro, and resolution of lipid peroxidation by overexpression of glutathione peroxidase 4 restored functionalities in CD8+ TILs in vivo. Thus, an oxidized lipid-CD36 axis promotes intratumoral CD8+ T cell dysfunction and serves as a therapeutic avenue for immunotherapies.


Asunto(s)
Antígenos CD36/metabolismo , Linfocitos T CD8-positivos/metabolismo , Peroxidación de Lípido/fisiología , Lipoproteínas LDL/metabolismo , Neoplasias/metabolismo , Receptores Depuradores/metabolismo , Animales , Transporte Biológico/fisiología , Línea Celular Tumoral , Células HEK293 , Humanos , Leucocitos Mononucleares/metabolismo , Linfocitos Infiltrantes de Tumor/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Microambiente Tumoral/fisiología
5.
Immunity ; 48(5): 923-936.e4, 2018 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-29752065

RESUMEN

The development of T cell tolerance in the thymus requires the presentation of host proteins by multiple antigen-presenting cell (APC) types. However, the importance of transferring host antigens from transcription factor AIRE-dependent medullary thymic epithelial cells (mTECs) to bone marrow (BM) APCs is unknown. We report that antigen was primarily transferred from mTECs to CD8α+ dendritic cells (DCs) and showed that CD36, a scavenger receptor selectively expressed on CD8α+ DCs, mediated the transfer of cell-surface, but not cytoplasmic, antigens. The absence of CD8α+ DCs or CD36 altered thymic T cell selection, as evidenced by TCR repertoire analysis and the loss of allo-tolerance in murine allogeneic BM transplantation (allo-BMT) studies. Decreases in these DCs and CD36 expression in peripheral blood of human allo-BMT patients correlated with graft-versus-host disease. Our findings suggest that CD36 facilitates transfer of mTEC-derived cell-surface antigen on CD8α+ DCs to promote tolerance to host antigens during homeostasis and allo-BMT.


Asunto(s)
Antígenos de Superficie/inmunología , Antígenos CD36/inmunología , Tolerancia Inmunológica/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Linfocitos T Reguladores/inmunología , Timo/inmunología , Animales , Antígenos de Superficie/metabolismo , Trasplante de Médula Ósea , Antígenos CD36/genética , Antígenos CD36/metabolismo , Antígenos CD8/inmunología , Antígenos CD8/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Ratones Endogámicos BALB C , Ratones Noqueados , Ratones Transgénicos , Receptores de Antígenos de Linfocitos T/metabolismo , Linfocitos T Reguladores/metabolismo , Timo/metabolismo , Trasplante Homólogo
6.
Annu Rev Physiol ; 85: 317-337, 2023 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-36347219

RESUMEN

Long-chain fatty acids (FAs) are components of plasma membranes and an efficient fuel source and also serve as metabolic regulators through FA signaling mediated by membrane FA receptors. Impaired tissue FA uptake has been linked to major complications of obesity, including insulin resistance, cardiovascular disease, and type 2 diabetes. Fatty acid interactions with a membrane receptor and the initiation of signaling can modify pathways related to nutrient uptake and processing, cell proliferation or differentiation, and secretion of bioactive factors. Here, we review the major membrane receptors involved in FA uptake and FA signaling. We focus on two types of membrane receptors for long-chain FAs: CD36 and the G protein-coupled FA receptors FFAR1 and FFAR4. We describe key signaling pathways and metabolic outcomes for CD36, FFAR1, and FFAR4 and highlight the parallels that provide insight into FA regulation of cell function.


Asunto(s)
Diabetes Mellitus Tipo 2 , Humanos , Transducción de Señal/fisiología , Receptores Acoplados a Proteínas G/metabolismo , Ácidos Grasos/metabolismo , Membrana Celular/metabolismo , Antígenos CD36/metabolismo
7.
Circulation ; 150(9): 710-723, 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39186525

RESUMEN

BACKGROUND: Exosome therapy shows potential for cardiac repair after injury. However, intrinsic challenges such as short half-life and lack of clear targets hinder the clinical feasibility. Here, we report a noninvasive and repeatable method for exosome delivery through inhalation after myocardial infarction (MI), which we called stem cell-derived exosome nebulization therapy (SCENT). METHODS: Stem cell-derived exosomes were characterized for size distribution and surface markers. C57BL/6 mice with MI model received exosome inhalation treatment through a nebulizer for 7 consecutive days. Echocardiographies were performed to monitor cardiac function after SCENT, and histological analysis helped with the investigation of myocardial repair. Single-cell RNA sequencing of the whole heart was performed to explore the mechanism of action by SCENT. Last, the feasibility, efficacy, and general safety of SCENT were demonstrated in a swine model of MI, facilitated by 3-dimensional cardiac magnetic resonance imaging. RESULTS: Recruitment of exosomes to the ischemic heart after SCENT was detected by ex vivo IVIS imaging and fluorescence microscopy. In a mouse model of MI, SCENT ameliorated cardiac repair by improving left ventricular function, reducing fibrotic tissue, and promoting cardiomyocyte proliferation. Mechanistic studies using single-cell RNA sequencing of mouse heart after SCENT revealed a downregulation of Cd36 in endothelial cells (ECs). In an EC-Cd36fl/- conditional knockout mouse model, the inhibition of CD36, a fatty acid transporter in ECs, led to a compensatory increase in glucose utilization in the heart and higher ATP generation, which enhanced cardiac contractility. In pigs, cardiac magnetic resonance imaging showed an enhanced ejection fraction (Δ=11.66±5.12%) and fractional shortening (Δ=5.72±2.29%) at day 28 after MI by SCENT treatment compared with controls, along with reduced infarct size and thickened ventricular wall. CONCLUSIONS: In both rodent and swine models, our data proved the feasibility, efficacy, and general safety of SCENT treatment against acute MI injury, laying the groundwork for clinical investigation. Moreover, the EC-Cd36fl/- mouse model provides the first in vivo evidence showing that conditional EC-CD36 knockout can ameliorate cardiac injury. Our study introduces a noninvasive treatment option for heart disease and identifies new potential therapeutic targets.


Asunto(s)
Exosomas , Ratones Endogámicos C57BL , Infarto del Miocardio , Animales , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/terapia , Infarto del Miocardio/fisiopatología , Exosomas/metabolismo , Ratones , Administración por Inhalación , Modelos Animales de Enfermedad , Porcinos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Masculino , Función Ventricular Izquierda , Humanos , Miocardio/metabolismo , Miocardio/patología , Células Madre/metabolismo , Antígenos CD36/metabolismo , Antígenos CD36/genética
8.
Circulation ; 149(20): 1578-1597, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38258575

RESUMEN

BACKGROUND: Calcification of the aortic valve leads to increased leaflet stiffness and consequently results in the development of calcific aortic valve disease (CAVD). However, the underlying molecular and cellular mechanisms of calcification remain unclear. Here, we identified a novel aortic valve calcification-associated PIWI-interacting RNA (piRNA; AVCAPIR) that increases valvular calcification and promotes CAVD progression. METHODS: Using piRNA sequencing, we identified piRNAs contributing to the pathogenesis of CAVD that we termed AVCAPIRs. High-cholesterol diet-fed ApoE-/- mice with AVCAPIR knockout were used to examine the role of AVCAPIR in aortic valve calcification (AVC). Gain- and loss-of-function assays were conducted to determine the role of AVCAPIR in the induced osteogenic differentiation of human valvular interstitial cells. To dissect the mechanisms underlying AVCAPIR-elicited procalcific effects, we performed various analyses, including an RNA pulldown assay followed by liquid chromatography-tandem mass spectrometry, methylated RNA immunoprecipitation sequencing, and RNA sequencing. RNA pulldown and RNA immunoprecipitation assays were used to study piRNA interactions with proteins. RESULTS: We found that AVCAPIR was significantly upregulated during AVC and exhibited potential diagnostic value for CAVD. AVCAPIR deletion markedly ameliorated AVC in high-cholesterol diet-fed ApoE-/- mice, as shown by reduced thickness and calcium deposition in the aortic valve leaflets, improved echocardiographic parameters (decreased peak transvalvular jet velocity and mean transvalvular pressure gradient, as well as increased aortic valve area), and diminished levels of osteogenic markers (Runx2 and Osterix) in aortic valves. These results were confirmed in osteogenic medium-induced human valvular interstitial cells. Using unbiased protein-RNA screening and molecular validation, we found that AVCAPIR directly interacts with FTO (fat mass and obesity-associated protein), subsequently blocking its N6-methyladenosine demethylase activity. Further transcriptomic and N6-methyladenosine modification epitranscriptomic screening followed by molecular validation confirmed that AVCAPIR hindered FTO-mediated demethylation of CD36 mRNA transcripts, thus enhancing CD36 mRNA stability through the N6-methyladenosine reader IGF2BP1 (insulin-like growth factor 2 mRNA binding protein 1). In turn, the AVCAPIR-dependent increase in CD36 stabilizes its binding partner PCSK9 (proprotein convertase subtilisin/kexin type 9), a procalcific gene, at the protein level, which accelerates the progression of AVC. CONCLUSIONS: We identified a novel piRNA that induced AVC through an RNA epigenetic mechanism and provide novel insights into piRNA-directed theranostics in CAVD.


Asunto(s)
Estenosis de la Válvula Aórtica , Válvula Aórtica , Calcinosis , ARN Interferente Pequeño , Animales , Calcinosis/metabolismo , Calcinosis/genética , Calcinosis/patología , Válvula Aórtica/metabolismo , Válvula Aórtica/patología , Válvula Aórtica/anomalías , Humanos , Ratones , Estenosis de la Válvula Aórtica/metabolismo , Estenosis de la Válvula Aórtica/genética , Estenosis de la Válvula Aórtica/patología , ARN Interferente Pequeño/metabolismo , ARN Interferente Pequeño/genética , Masculino , Osteogénesis , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Animales de Enfermedad , Enfermedad de la Válvula Aórtica/metabolismo , Enfermedad de la Válvula Aórtica/genética , Enfermedad de la Válvula Aórtica/patología , ARN de Interacción con Piwi
9.
J Cell Sci ; 136(15)2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37461827

RESUMEN

Protein palmitoylation is a post-translational lipid modification of proteins. Accumulating evidence reveals that palmitoylation functions as a sorting signal to direct proteins to destinations; however, the sorting mechanism remains largely unknown. Here, we show that ARF6 plays a general role in targeting palmitoylated proteins from the Golgi to the plasma membrane (PM). Through shRNA screening, we identified ARF6 as the key small GTPase in targeting CD36, a palmitoylated protein, from the Golgi to the PM. We found that the N-terminal myristoylation of ARF6 is required for its binding with palmitoylated CD36, and the GTP-bound form of ARF6 facilitates the delivery of CD36 to the PM. Analysis of stable isotope labeling by amino acids in cell culture revealed that ARF6 might facilitate the sorting of 359 of the 531 palmitoylated PM proteins, indicating a general role of ARF6. Our study has thus identified a sorting mechanism for targeting palmitoylated proteins from the Golgi to the PM.


Asunto(s)
Aparato de Golgi , Proteínas de la Membrana , Membrana Celular/metabolismo , Aparato de Golgi/metabolismo , Proteínas de la Membrana/metabolismo , Transporte de Proteínas
10.
Stem Cells ; 42(8): 763-776, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38733123

RESUMEN

Endometrium fibrosis is the leading cause of uterine infertility. Macrophages participated in the occurrence and development of endometrial fibrosis. We previously reported that human umbilical cord multipotent stromal cells (hUC-MSCs) exerted their therapeutic effect in a macrophage-dependent manner in endometrial fibrosis. However precise mechanisms by which hUC-MSCs may influence macrophages in endometrial fibrosis remain largely unexplored. Here, we demonstrated that abnormal iron and lipid metabolism occurred in patients with intrauterine adhesions (IUA) and murine models. Ferroptosis has been proven to contribute to the progression of fibrotic diseases. Our results revealed that pharmacological activation of ferroptosis by Erastin aggravated endometrial fibrosis, while inhibition of ferroptosis by Ferrostatin-1 ameliorated endometrial fibrosis in vivo. Moreover, ferroptosis of macrophages was significantly upregulated in endometria of IUA murine models. Of note, transcriptome profiles revealed that CD36 gene expression was significantly increased in patients with IUA and immunofluorescence analysis showed CD36 protein was mainly located in macrophages. Silencing CD36 in macrophages could reverse cell ferroptosis. Dual luciferase reporter assay revealed that CD36 was the direct target of activation transcription factor 3 (ATF3). Furthermore, through establishing coculture system and IUA murine models, we found that hUC-MSCs had a protective role against macrophage ferroptosis and alleviated endometrial fibrosis related to decreased CD36 and ATF3. The effect of hUC-MSCs on macrophage ferroptosis was attributed to the upregulation of amphiregulin (AREG). Our data highlighted that macrophage ferroptosis occurred in endometrial fibrosis via the ATF3-CD36 pathway and hUC-MSCs protected against macrophage ferroptosis to alleviate endometrial fibrosis via secreting AREG. These findings provided a potential target for therapeutic implications of endometrial fibrosis.


Asunto(s)
Anfirregulina , Antígenos CD36 , Endometrio , Ferroptosis , Fibrosis , Macrófagos , Cordón Umbilical , Femenino , Humanos , Cordón Umbilical/citología , Cordón Umbilical/metabolismo , Animales , Macrófagos/metabolismo , Ratones , Anfirregulina/metabolismo , Anfirregulina/genética , Endometrio/metabolismo , Endometrio/patología , Antígenos CD36/metabolismo , Antígenos CD36/genética , Factor de Transcripción Activador 3/metabolismo , Factor de Transcripción Activador 3/genética , Células Madre Multipotentes/metabolismo
11.
Exp Cell Res ; 435(2): 113947, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38301989

RESUMEN

Cancer-associated fibroblasts (CAFs) are the main components in the tumor microenvironment. Tumors activate fibroblasts from quiescent state into activated state by secreting cytokines, and activated CAFs may in turn promote tumor progression and metastasis. Therefore, studies targeting CAFs could enrich the therapeutic options for tumor treatment. In this study, we demonstrate that the content of lipid droplets and the expression of autophagosomes were higher in CAFs than in peri-tumor fibroblasts (PTFs), which was inhibited by 5-(tetradecyloxy)-2-furoic acid(TOFA). The expression of CD36 in CAFs was higher than that in PTFs at both mRNA and protein levels. Inhibition of CD36 activity using either the CD36 inhibitor SSO or siRNA had a significant negative impact on the proliferation and migration abilities of CAFs, which was associated with reduced levels of relevant activated genes (α-SMA, FAP, Vimentin) and cytokines (IL-6, TGF-ß and VEGF-α). SSO also inhibited HCC growth and tumorigenesis in nude mice orthotopically implanted with CAFs and HCC cells. Our data further show that CD36+CAFs affected the expression of PD-1 in CTLs leading to CTL exhaustion, and that patients with high CD36 expression in CAFs were correlated with shorter overall survival (OS). Together, our data demonstrate that CAFs were active in lipid metabolism with increased lipid content and lipophagy activity. CD36 may play a key role in the regulation of the biological behaviors of CAFs, which may influence the proliferation and migration of tumor cells by reprograming the lipid metabolism in tumor cells. Thus, CD36 could be an effective therapeutic target for the treatment of HCC.


Asunto(s)
Fibroblastos Asociados al Cáncer , Carcinoma Hepatocelular , Neoplasias Hepáticas , Animales , Ratones , Humanos , Carcinoma Hepatocelular/patología , Fibroblastos Asociados al Cáncer/patología , Neoplasias Hepáticas/patología , Ratones Desnudos , Reprogramación Metabólica , Línea Celular Tumoral , Fibroblastos/metabolismo , Citocinas/metabolismo , Microambiente Tumoral , Proliferación Celular
12.
Am J Respir Cell Mol Biol ; 70(1): 11-25, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37725486

RESUMEN

The generation of bioactive truncated oxidized phospholipids (Tr-OxPLs) from oxidation of cell-membrane or circulating lipoproteins is a common feature of various pathological states. Scavenger receptor CD36 is involved in lipid transport and acts as a receptor for Tr-OxPLs. Interestingly, Tr-OxPLs and CD36 are involved in endothelial dysfunction-derived acute lung injury, but the precise mechanistic connections remain unexplored. In the present study, we investigated the role of CD36 in mediating pulmonary endothelial cell (EC) dysfunction caused by Tr-OxPLs. Our results demonstrated that the Tr-OxPLs KOdia-PC, Paz-PC, PGPC, PON-PC, POV-PC, and lysophosphocholine caused an acute EC barrier disruption as revealed by measurements of transendothelial electrical resistance and VE-cadherin immunostaining. More importantly, a synthetic amphipathic helical peptide, L37pA, targeting human CD36 strongly attenuated Tr-OxPL-induced EC permeability. L37pA also suppressed Tr-OxPL-induced endothelial inflammatory activation monitored by mRNA expression of inflammatory cytokines/chemokines and adhesion molecules. In addition, L37pA blocked Tr-OxPL-induced NF-κB activation and tyrosine phosphorylation of Src kinase and VE-cadherin. The Src inhibitor SU6656 attenuated KOdia-PC-induced EC permeability and inflammation, but inhibition of the Toll-like receptors (TLRs) TLR1, TLR2, TLR4, and TLR6 had no such protective effects. CD36-knockout mice were more resistant to Tr-OxPL-induced lung injury. Treatment with L37pA was equally effective in ameliorating Tr-OxPL-induced vascular leak and lung inflammation as determined by an Evans blue extravasation assay and total cell and protein content in BAL fluid. Altogether, these results demonstrate an essential role of CD36 in mediating Tr-OxPL-induced EC dysfunction and suggest a strong therapeutic potential of CD36 inhibitory peptides in mitigating lung injury and inflammation.


Asunto(s)
Lesión Pulmonar Aguda , Fosfolípidos , Animales , Ratones , Humanos , Fosfolípidos/metabolismo , Lesión Pulmonar Aguda/patología , Inflamación , Péptidos , Pulmón/patología
13.
Am J Physiol Cell Physiol ; 326(5): C1543-C1555, 2024 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-38586877

RESUMEN

Obesity imposes deficits on adipose tissue and vascular endothelium, yet the role that distinct adipose depots play in mediating endothelial dysfunction in local arteries remains unresolved. We recently showed that obesity impairs endothelial Kir2.1 channels, mediators of nitric oxide production, in arteries of visceral adipose tissue (VAT), while Kir2.1 function in subcutaneous adipose tissue (SAT) endothelium remains intact. Therefore, we determined if VAT versus SAT from lean or diet-induced obese mice affected Kir2.1 channel function in vitro. We found that VAT from obese mice reduces Kir2.1 function without altering channel expression whereas AT from lean mice and SAT from obese mice had no effect on Kir2.1 function as compared to untreated control cells. As Kir2.1 is well known to be inhibited by fatty acid derivatives and obesity is strongly associated with elevated circulating fatty acids, we next tested the role of the fatty acid translocase CD36 in mediating VAT-induced Kir2.1 dysfunction. We found that the downregulation of CD36 restored Kir2.1 currents in endothelial cells exposed to VAT from obese mice. In addition, endothelial cells exposed to VAT from obese mice exhibited a significant increase in CD36-mediated fatty acid uptake. The importance of CD36 in obesity-induced endothelial dysfunction of VAT arteries was further supported in ex vivo pressure myography studies where CD36 ablation rescued the endothelium-dependent response to flow via restoring Kir2.1 and endothelial nitric oxide synthase function. These findings provide new insight into the role of VAT in mediating obesity-induced endothelial dysfunction and suggest a novel role for CD36 as a mediator of endothelial Kir2.1 impairment.NEW & NOTEWORTHY Our findings suggest a role for visceral adipose tissue (VAT) in the dysfunction of endothelial Kir2.1 in obesity. We further reveal a role for CD36 as a major contributor to VAT-mediated Kir2.1 and endothelial dysfunction, suggesting that CD36 offers a potential target for preventing the early development of obesity-associated cardiovascular disease.


Asunto(s)
Antígenos CD36 , Células Endoteliales , Grasa Intraabdominal , Ratones Endogámicos C57BL , Obesidad , Canales de Potasio de Rectificación Interna , Animales , Ratones , Antígenos CD36/metabolismo , Antígenos CD36/genética , Dieta Alta en Grasa , Células Endoteliales/metabolismo , Endotelio Vascular/metabolismo , Grasa Intraabdominal/metabolismo , Ratones Obesos , Obesidad/metabolismo , Canales de Potasio de Rectificación Interna/metabolismo , Canales de Potasio de Rectificación Interna/genética , Grasa Subcutánea/metabolismo
14.
J Lipid Res ; 65(2): 100499, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38218337

RESUMEN

Ferroptosis is a novel cell death mechanism that is mediated by iron-dependent lipid peroxidation. It may be involved in atherosclerosis development. Products of phospholipid oxidation play a key role in atherosclerosis. 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine (PGPC) is a phospholipid oxidation product present in atherosclerotic lesions. It remains unclear whether PGPC causes atherosclerosis by inducing endothelial cell ferroptosis. In this study, human umbilical vein endothelial cells (HUVECs) were treated with PGPC. Intracellular levels of ferrous iron, lipid peroxidation, superoxide anions (O2•-), and glutathione were detected, and expression of fatty acid binding protein-3 (FABP3), glutathione peroxidase 4 (GPX4), and CD36 were measured. Additionally, the mitochondrial membrane potential (MMP) was determined. Aortas from C57BL6 mice were isolated for vasodilation testing. Results showed that PGPC increased ferrous iron levels, the production of lipid peroxidation and O2•-, and FABP3 expression. However, PGPC inhibited the expression of GPX4 and glutathione production and destroyed normal MMP. These effects were also blocked by ferrostatin-1, an inhibitor of ferroptosis. FABP3 silencing significantly reversed the effect of PGPC. Furthermore, PGPC stimulated CD36 expression. Conversely, CD36 silencing reversed the effects of PGPC, including PGPC-induced FABP3 expression. Importantly, E06, a direct inhibitor of the oxidized 1-palmitoyl-2-arachidonoyl-phosphatidylcholine IgM natural antibody, inhibited the effects of PGPC. Finally, PGPC impaired endothelium-dependent vasodilation, ferrostatin-1 or FABP3 inhibitors inhibited this impairment. Our data demonstrate that PGPC impairs endothelial function by inducing endothelial cell ferroptosis through the CD36 receptor to increase FABP3 expression. Our findings provide new insights into the mechanisms of atherosclerosis and a therapeutic target for atherosclerosis.


Asunto(s)
Aterosclerosis , Ciclohexilaminas , Ferroptosis , Fenilendiaminas , Animales , Ratones , Humanos , Fosfolípidos , Fosforilcolina , Éteres Fosfolípidos/metabolismo , Éteres Fosfolípidos/farmacología , Ratones Endogámicos C57BL , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Endotelio/metabolismo , Glutatión/metabolismo , Hierro/metabolismo , Proteína 3 de Unión a Ácidos Grasos
15.
J Biol Chem ; 299(12): 105463, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37977221

RESUMEN

Ferroptosis, characterized by iron-dependent cell death, has recently emerged as a critical defense mechanism against microbial infections. The present study aims to investigate the involvement of exosomes in the induction of ferroptosis and the inhibition of bacterial infection in crustaceans. Our findings provide compelling evidence for the pivotal role of exosomes in the immune response of crustaceans, wherein they facilitate intracellular iron accumulation and activate the ferroptotic pathways. Using RNA-seq and bioinformatic analysis, we demonstrate that cytochrome P450 (CYP) can effectively trigger ferroptosis. Moreover, by conducting an analysis of exosome cargo proteins, we have identified the participation of six-transmembrane epithelial antigen of prostate 4 in the regulation of hemocyte ferroptotic sensitivity. Subsequent functional investigations unveil that six-transmembrane epithelial antigen of prostate 4 enhances cellular Fe2+ levels, thereby triggering Fenton reactions and accelerating CYP-mediated lipid peroxidation, ultimately culminating in ferroptotic cell death. Additionally, the Fe2+-dependent CYP catalyzes the conversion of arachidonic acid into 20-hydroxyeicosatetraenoic acid, which activates the peroxisome proliferator-activated receptor. Consequently, the downstream target of peroxisome proliferator-activated receptor, cluster of differentiation 36, promotes intracellular fatty acid accumulation, lipid peroxidation, and ferroptosis. These significant findings shed light on the immune defense mechanisms employed by crustaceans and provide potential strategies for combating bacterial infections in this species.


Asunto(s)
Bacterias , Crustáceos , Exosomas , Ferroptosis , Hierro , Sistema Enzimático del Citocromo P-450/metabolismo , Exosomas/metabolismo , Ferroptosis/fisiología , Hierro/metabolismo , Peroxidación de Lípido , Receptores Activados del Proliferador del Peroxisoma/metabolismo , Oxidorreductasas/metabolismo , Proteínas de la Membrana/metabolismo , Antígenos CD36/metabolismo , RNA-Seq , Compuestos Ferrosos/metabolismo , Crustáceos/citología , Crustáceos/genética , Crustáceos/metabolismo , Crustáceos/microbiología , Ácidos Hidroxieicosatetraenoicos , Ácido Araquidónico/metabolismo , Ácidos Grasos/metabolismo , Bacterias/metabolismo
16.
Circulation ; 148(4): 336-353, 2023 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-37232170

RESUMEN

BACKGROUND: PCSK9 (proprotein convertase subtilisin/kexin 9), which is mainly secreted by the liver, is not only a therapeutic target for hyperlipidemia and cardiovascular disease, but also has been implicated in the immune regulation of infections and tumors. However, the role of PCSK9 and the liver in heart transplant rejection (HTR) and the underlying mechanisms remain unclear. METHODS: We assessed serum PCSK9 expression in both murine and human recipients during HTR and investigated the effect of PCSK9 ablation on HTR by using global knockout mice and a neutralizing antibody. Moreover, we performed multiorgan histological and transcriptome analyses, and multiomics and single-cell RNA-sequencing studies of the liver during HTR, as well. We further used hepatocyte-specific Pcsk9 knockout mice to investigate whether the liver regulated HTR through PCSK9. Last, we explored the regulatory effect of the PCSK9/CD36 pathway on the phenotype and function of macrophages in vitro and in vivo. RESULTS: Here, we report that murine and human recipients have high serum PCSK9 levels during HTR. PCSK9 ablation prolonged cardiac allograft survival and attenuated the infiltration of inflammatory cells in the graft and the expansion of alloreactive T cells in the spleen. Next, we demonstrated that PCSK9 was mainly produced and significantly upregulated in the recipient liver, which also showed a series of signaling changes, including changes in the TNF-α (tumor necrosis factor α) and IFN-γ (interferon γ) signaling pathways and the bile acid and fatty acid metabolism pathways. We found mechanistically that TNF-α and IFN-γ synergistically promoted PCSK9 expression in hepatocytes through the transcription factor SREBP2 (sterol regulatory element binding protein 2). Moreover, in vitro and in vivo studies indicated that PCSK9 inhibited CD36 expression and fatty acid uptake by macrophages and strengthened the proinflammatory phenotype, which facilitated their ability to promote proliferation and IFN-γ production by donor-reactive T cells. Last, we found that the protective effect of PCSK9 ablation against HTR is dependent on the CD36 pathway in the recipient. CONCLUSIONS: This study reveals a novel mechanism for immune regulation by the liver through the PCSK9/CD36 pathway during HTR, which influences the phenotype and function of macrophages and suggests that the modulation of this pathway may be a potential therapeutic target to prevent HTR.


Asunto(s)
Trasplante de Corazón , Proproteína Convertasa 9 , Humanos , Ratones , Animales , Proproteína Convertasa 9/genética , Proproteína Convertasa 9/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Células Hep G2 , Hígado/metabolismo , Ácidos Grasos/metabolismo , Ratones Noqueados , Trasplante de Corazón/efectos adversos , Receptores de LDL/genética
17.
Artículo en Inglés | MEDLINE | ID: mdl-39196801

RESUMEN

Consumption of a Western diet (WD) increases CD36 expression in vascular, hepatic, and skeletal muscle tissues promoting lipid metabolic disorders and insulin resistance. We further examined the role of endothelial cell specific CD36 (ECCD36) signaling in contributing to skeletal muscle lipid metabolic disorders, insulin resistance, and their underlying molecular mechanisms. Female ECCD36 wild type (ECCD36+/+) and knock out (ECCD36-/-) mice, aged six weeks, were provided with either a WD or a standard chow diet for a duration of 16 weeks. ECCD36+/+ WD mice were characterized by elevated fasting plasma glucose and insulin levels, increased homeostatic model assessment for insulin resistance, and glucose intolerance that were blunted in ECCD36-/- mice. Improved insulin sensitivity in ECCD36-/- mice was characterized by increased phosphoinositide 3-kinases/protein kinase B signaling that further augmented glucose transporter type 4 expression and glucose uptake. Meanwhile, 16 weeks of WD feeding also increased skeletal muscle free fatty acid (FFA) and lipid accumulation, without any observed changes in plasma FFA levels. These lipid metabolic disorders were blunted in ECCD36-/- mice. Moreover, ECCD36 also mediated in vitro palmitic acid-induced lipid accumulation in cultured ECs, subsequently leading to the release of FFAs into the culture media. Furthermore, consumption of a WD increased FFA oxidation, mitochondrial dysfunction, impaired mitochondrial respiratory, skeletal muscle fiber type transition, and fibrosis. These WD-induced abnormalities were blunted in ECCD36-/- mice. These findings demonstrate that endothelial specific ECCD36 signaling participates in skeletal muscle FFA uptake, ectopic lipid accumulation, mitochondrial dysfunction, insulin resistance, and associated skeletal muscle dysfunction in diet-induced obesity.

18.
Clin Immunol ; 260: 109914, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38286173

RESUMEN

OBJECTIVE: To investigate CD36 in ANCA-associated vasculitis (AAV), a condition characterized by monocyte/macrophage activation and vascular damage. METHODS: CD36 expression was assessed in AAV patients and healthy controls (HC). The impact of palmitic acid (PA) stimulation on multinucleate giant cell (MNGC) formation, macrophage, and endothelial cell activation, with or without CD36 knockdown, was examined. RESULTS: CD36 was overexpressed on AAV patients' monocytes compared to HC, regardless of disease activity. AAV patients exhibited elevated soluble CD36 levels in serum and plasma and PR3-ANCA patients' monocytes demonstrated increased MNGC formation following PA stimulation compared to HC. PA stimulation of macrophages or endothelial cells resulted in heightened CD36 expression, cell activation, increased macrophage migration inhibitory factor (MIF) production, and c-Myc expression, with attenuation upon CD36 knockdown. CONCLUSION: CD36 participates in macrophage and endothelial cell activation and MNGC formation, features of AAV pathogenesis. AAV treatment may involve targeting CD36 or MIF.


Asunto(s)
Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos , Anticuerpos Anticitoplasma de Neutrófilos , Humanos , Anticuerpos Anticitoplasma de Neutrófilos/metabolismo , Células Endoteliales/patología , Macrófagos/patología , Células Gigantes , Citoplasma/patología
19.
Biochem Biophys Res Commun ; 707: 149781, 2024 05 07.
Artículo en Inglés | MEDLINE | ID: mdl-38492244

RESUMEN

BACKGROUND & AIMS: CD36, a membrane protein widely present in various tissues, is crucial role in regulating energy metabolism. The rise of HCC as a notable outcome of NAFLD is becoming more apparent. Patients with hereditary CD36 deficiency are at increased risk of NAFLD. However, the impact of CD36 deficiency on NAFLD-HCC remains unclear. METHODS: Global CD36 knockout mice (CD36KO) and wild type mice (WT) were induced to establish NAFLD-HCC model by N-nitrosodiethylamine (DEN) plus high fat diet (HFD). Transcriptomics was employed to examine genes that were expressed differentially. RESULTS: Compared to WT mice, CD36KO mice showed more severe HFD-induced liver issues and increased tumor malignancy. The MEK1/2-ERK1/2 pathway activation was detected in the liver tissues of CD36KO mice using RNA sequencing and Western blot analysis. CONCLUSION: Systemic loss of CD36 leaded to the advancement of NAFLD to HCC by causing lipid disorders and metabolic inflammation, a process that involves the activation of MAPK signaling pathway. We found that CD36 contributes significantly to the maintenance of metabolic homeostasis in NAFLD-HCC.


Asunto(s)
Trastornos de las Plaquetas Sanguíneas , Carcinoma Hepatocelular , Enfermedades Genéticas Congénitas , Neoplasias Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Humanos , Animales , Ratones , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Sistema de Señalización de MAP Quinasas , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Hígado/metabolismo , Transducción de Señal , Antígenos CD36/genética , Antígenos CD36/metabolismo , Dieta Alta en Grasa/efectos adversos , Ratones Endogámicos C57BL , Ratones Noqueados
20.
Biochem Biophys Res Commun ; 708: 149786, 2024 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-38493545

RESUMEN

Ectopic lipid deposition (ELD) and mitochondrial dysfunction are common causes of metabolic disorders in humans. Consuming too much fructose can result in mitochondrial dysfunction and metabolic disorders. 6-Gingerol, the main component of ginger (Zingiber officinale Roscoe), has been proven to alleviate metabolic disorders. This study seeks to examine the effects of 6-gingerol on metabolic disorders caused by fructose and uncover the underlying molecular mechanisms. In this study, the results showed that 6-Gingerol ameliorated high-fructose-induced metabolic disorders. Moreover, it inhibited CD36 membrane translocation, increased CD36 expression in the mitochondria, and decreased the O-GlcNAc modification of CD36 and OGT expression in vitro and vivo. In addition, 6-Gingerol enhanced the performance of mitochondria in the skeletal muscle and boosted the respiratory capability of L6 myotubes. This study provides a theoretical basis and new insights for the development of lipid-lowering drugs in clinical practice.


Asunto(s)
Enfermedades Metabólicas , Enfermedades Mitocondriales , Humanos , Músculo Esquelético/metabolismo , Mitocondrias/metabolismo , Alcoholes Grasos/farmacología , Alcoholes Grasos/metabolismo , Catecoles/farmacología , Fructosa/metabolismo , Enfermedades Metabólicas/metabolismo , Enfermedades Mitocondriales/metabolismo
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