Molecular cloning of a novel scavenger receptor for oxidized low density lipoprotein, SR-PSOX, on macrophages

Receptor-mediated endocytosis of oxidized low density lipoprotein (OxLDL) by macrophages has been implicated in foam cell transformation in the process of atherogenesis. Although several scavenger receptor molecules, including class A scavenger receptors and CD36, have been identified as OxLDL receptors on macrophages, additional molecules on macrophages may also be involved in the recognition of OxLDL. From a cDNA library of phorbol 12-myristate 13-acetate-stimulated THP-1 cells, we isolated a cDNA encoding a novel protein designated SR-PSOX (scavenger receptor that binds phosphatidylserine and oxidized lipoprotein), which acts as a receptor for OxLDL. SR-PSOX was a type I membrane protein consisting of 254 amino acids, expression of which was shown on human and murine macrophages with a molecular mass of 30 kDa. SR-PSOX could specifically bind with high affinity, internalize, and degrade OxLDL. The recognition of OxLDL was blocked by polyinosinic acid and dextran sulfate but not by acetylated low density lipoprotein. Taken together, SR-PSOX is a novel class of molecule belonging to the scavenger receptor family, which may play important roles in pathophysiology including atherogenesis.     

Oxidized low density lipoprotein exposure alters the transcriptional response of macrophages to inflammatory stimulus

Macrophage-derived foam cells in atherosclerotic lesions are generally thought to play a major role in the pathology of the disease. Because macrophages play a central role in the inflammatory response, and the atherosclerotic lesion has features associated with chronic inflammatory settings, we investigated foam cell inflammatory potential. THP-1-derived macrophages were treated with oxidized low density lipoprotein (OxLDL) for 3 days to lipid load the macrophages and establish a foam cell-like phenotype. The cells were then activated by treatment with lipopolysaccharide (LPS), and RNA was harvested at 0, 1, and 6 h after LPS addition. RNA from treated and control cells was hybridized to microarrays containing approximately 16,000 human cDNAs. Genes that exhibited a 4-fold or greater increase or decrease at either 1 or 6 h after LPS treatment were counted as LPS-responsive genes. Employing these criteria, 127 LPS-responsive genes were identified. Prior treatment of THP-1 macrophages with OxLDL affected the expression of 57 of these 127 genes. Among these 57 genes was a group of chemokine, cytokine, and signal transduction genes with pronounced expression changes. OxLDL pretreatment resulted in a significant perturbation of LPS-induced NF kappa B activation. Furthermore, some of the OxLDL effects appear to be mediated by the nuclear receptors retinoid X receptor and peroxisomal proliferator-activated receptor gamma because pretreatment of THP-1 macrophages with ligands for these receptors, followed by LPS treatment, recapitulates the OxLDL plus LPS results for several of the most significantly modulated genes.     

Galectin-3 expression in macrophages is signaled by Ras/MAP kinase pathway and up-regulated by modified lipoproteins

To study the signaling pathway involved in the regulation of galectin-3 expression we used phorbol ester to stimulate macrophage differentiation of THP-1 cells. Treatment with phorbol 12-myristate 13-acetate (PMA) increased significantly the level of expression of galectin-3 in THP-1 cells. PMA-induced galectin-3 overexpression was blocked by: protein kinase C inhibitors staurosporine, calphostin C, and apigenin; tyrosine-specific protein kinase inhibitors genistein and tyrphostin A25; PD 98059, a selective inhibitor of mitogen-activated protein kinase (MAPK) kinase 1 (MEK1 or MKK1); and SB 203580, a specific inhibitor of p38 MAPK. Galectin-3 up-regulation was not affected by exposure to two inhibitors of cAMP-dependent protein kinase (PKA), H-89 and KT5720. Co-transfection of pPG3.5, a plasmid vector containing the rabbit galectin-3 promoter and the constructs pMCL-MKK1 N3 or pRC-RSV-MKK3Glu that constitutively express MKK1 and MKK3, raised the activity of galectin-3 promoter by 185% and 110%, respectively. Co-transfection with a Ha-Ras expression vector stimulated galectin-3 promoter activity approximately 10-fold. Expression of c-Jun or v-Jun raised the level of galectin-3 promoter activity more the three- and fourfold, respectively. Co-transfection of c-Jun and pPG3.5 5'-upstream deletion mutants resulted in a reduction of the galectin-3 promoter activity by 50% to 80%. Transfection of c-Jun, v-Jun or Ha-Ras increased significantly galectin-3 protein in THP-1 cells. These findings indicated that Ras/MEKK1/MKK1-dependent/AP-1 signal transduction pathway plays an important role in the expression of galectin-3 in PMA-stimulated macrophages. We further investigated the effect of modified lipoproteins on galectin-3 expression in macrophages. Murine resident peritoneal macrophages loaded with acetylated low-density lipoprotein (AcLDL) or oxidized LDL (OxLDL) showed increased galectin-3 protein and mRNA. These results showed that treatment of macrophages with PMA or modified lipoproteins results in galectin-3 overexpression. These findings may explain the enhanced expression of galectin-3 in atherosclerotic foam cells and suggest that Ras/MAPK signal transduction pathway is involved in controlling this gene.     

Inhibition of the NLRP3 inflammasome attenuates foam cell formation of THP-1 macrophages by suppressing ox-LDL uptake and promoting cholesterol efflux

The NOD-like receptor family, pyrin domain–containing protein 3 (NLRP3) inflammasome plays an important role in the development of atherosclerosis. The activated NLRP3 inflammasome has been reported to promote macrophage foam cell formation, but not all studies have obtained the same result, and how NLRP3 inflammasome is involved in the formation of foam cells remains elusive. We used selective NLRP3 inflammasome inhibitors and NLRP3-deficient THP-1 cells to assess the effect of NLRP3 inflammasome inhibition on macrophage foam cell formation, oxidized low-density lipoprotein (ox-LDL) uptake, esterification, and cholesterol efflux, as well as the expression of associated proteins. Inhibition of the NLRP3 inflammasome attenuated foam cell formation, diminished ox-LDL uptake, and promoted cholesterol efflux from THP-1 macrophages. Moreover, it downregulated CD36, acyl coenzyme A: cholesterol acyltransferase-1 and neutral cholesterol ester hydrolase expression; upregulated ATP-binding cassette transporter A1 (ABCA1) and scavenger receptor class B type I (SR-BI) expression; but had no effect on the expression of scavenger receptor class A and ATP-binding cassette transporter G1. Collectively, our findings show that inhibition of the NLRP3 inflammasome decreases foam cell formation of THP-1 macrophages via suppression of ox-LDL uptake and enhancement of cholesterol efflux, which may be due to downregulation of CD36 expression and upregulation of ABCA1 and SR-BI expression, respectively.     

Oxidized low density lipoprotein decreases macrophage expression of scavenger receptor B-I

Scavenger receptor class B type I (SR-BI) has recently been identified as a high density lipoprotein (HDL) receptor that mediates bidirectional flux of cholesterol across the plasma membrane. We have previously demonstrated that oxidized low density lipoprotein (OxLDL) will increase expression of another class B scavenger receptor, CD36 (Han, J., Hajjar, D. P., Febbraio, M., and Nicholson, A. C. (1997) J. Biol. Chem. 272, 21654-21659). In studies reported herein, we evaluated the effects of OxLDL on expression of SR-BI in macrophages to determine how exposure to this modified lipoprotein could alter SR-BI expression and cellular lipid flux. OxLDL decreased SR-BI expression in a dose- and time-dependent manner. Incubation with OxLDL had no effect on the membrane distribution of SB-BI, and it decreased expression of both cytosolic and membrane protein. Consistent with its effect on SR-BI protein expression, OxLDL decreased SR-BI mRNA in a dose-dependent manner. The ability of OxLDL to decrease SR-BI expression was dependent on the degree of LDL oxidation. OxLDL decreased both [(14)C]cholesteryl oleate/HDL uptake and efflux of [(14)C]cholesterol to HDL in a time-dependent manner. Incubation of macrophages with 7-ketocholesterol, but not free cholesterol, also inhibited expression of SR-BI. Finally, we demonstrate that the effect of OxLDL on SR-BI is dependent on the differentiation state of the monocyte/macrophage. These results imply that in addition to its effect in inducing foam cell formation in macrophages through increased uptake of oxidized lipids, OxLDL may also enhance foam cell formation by altering SR-BI-mediated lipid flux across the cell membrane.     

Binding and uptake of differently oxidized low density lipoprotein in mouse peritoneal macrophages and THP-1 macrophages: involvement of negative charges as well as oxidation-specific epitopes

Oxidatively modified low-density lipoprotein (LDL) has been found in vivo, and oxidized LDL (oxLDL) could bind to scavenger receptors, leading to foam cell formation. Macrophages bear a number of different scavenger receptors for oxLDL, and macrophages of different origins may have a different scavenger receptor repertoire. In addition, LDL oxidized to different degrees may differ in the ability to bind macrophage scavenger receptors. In this study, we characterized the patterns of the binding and uptake of differently oxidized LDL in mouse peritoneal macrophages (MPM) and human THP-1 macrophages, and the influence of negative charge and oxidation-specific epitopes in oxLDL on these processes. Thresholds of increased binding and uptake in MPM were found when LDL was oxidized to the degrees with a relative electrophoretic mobility (REM) of 2.6 (minor threshold) and 3.0 (major threshold), corresponding to 49 and 57%, respectively, of the loss of free amino groups in these oxLDL. There was no threshold for the binding of oxLDL to THP-1 macrophages, while for uptake, a major threshold with REM of 3.0 (57% free amino groups lost) was found. The presence of the F(ab')(2) fragments of the monoclonal antibody OB/04, which was raised against copper-oxidized LDL, led to the reduction of the binding and uptake, respectively, of Eu(3+)-oxLDL (REM:3.6) in MPM by 31 and 29%, and by 19 and 22% in THP-1 macrophages. It is concluded that LDL oxidized to different degrees binds differently to macrophages, and the patterns of binding and uptake are different for MPM and human THP-1 macrophages. Both, the negative charge and the oxidation-specific epitopes of oxLDL are involved in these processes.     

Low-density lipoproteins induce the renin-angiotensin system and their receptors in human endothelial cells.

Increased levels of low-density lipoproteins are well-established risk factors of endothelial dysfunction and the metabolic syndrome. In this study, we evaluated the effect of native low-density lipoprotein (nLDL) and oxidized LDL (oxLDL) on the expression of genes of the renin-angiotensin system (angiotensin-converting enzyme, ACE; angiotensin II type 1 receptor, AT(1)) and their receptors (low-density lipoprotein receptor: LDLR; lectin-like oxLDL receptor: LOX-1; toll-like receptor 4: TLR4) in primary cultures of human umbilical vein endothelial cells. ACE and AT(1) expressions were significantly increased after stimulation with nLDL and oxLDL. OxLDL receptor LOX-1 showed a maximum induction after 7 hours. Increased LOX-1 protein expression in response to oxLDL could be blocked by a LOX-1-specific antibody. TLR4 expression was increased by nLDL and oxLDL as well. We conclude that LDL and oxLDL can activate the renin-angiotensin system and their receptors LDLR, LOX-1, and TLR4 in human endothelial cells. These data suggest a novel link between hypercholesterolemia and hypertension in patients with the metabolic syndrome.     

A macrophage Fc receptor for IgG is also a receptor for oxidized low density lipoprotein.

The internalization of oxidized low density lipoprotein (OxLDL) by macrophages is hypothesized to contribute to foam cell formation and eventually to atherosclerotic lesion formation. OxLDL is a ligand for the acetylated low density lipoprotein (AcLDL) receptor, however, our data show that this receptor accounts for less than half of OxLDL uptake by mouse macrophages, suggesting additional receptors for OxLDL. We have developed a novel expression cloning strategy in order to isolate clones encoding OxLDL receptors. In addition to the AcLDL receptor, we isolated a molecular clone for a structurally unrelated receptor capable of mediating the high affinity uptake of OxLDL following transfection into cells. This receptor has been identified as the mouse Fc gamma RII-B2, a member of a family of receptors known to mediate immune complex uptake through recognition of the Fc region of IgG. The uptake of OxLDL by cells transfected with the Fc gamma RII-B2 clone is not blocked by AcLDL but is blocked by the anti-Fc gamma RII monoclonal antibody, 2.4G2.     

氧化低密度脂蛋白对THP-1巨噬细胞吞噬和分泌功能的影响

目的:探讨氧化低密度脂蛋白(oxidized low density lipoprotein,ox-LDL)对巨噬细胞源性泡沫细胞吞噬功能和炎症相关因子分泌功能的影响。方法:利用佛波酯(phorbol ester,PMA)诱导THP-1细胞分化形成巨噬细胞,之后采用ox-LDL处理48小时后,诱导其形成泡沫细胞。利用中性红吞噬实验,分析泡沫细胞形成前后吞噬功能的变化;通过ELISA法,检测细胞培养上清中肿瘤坏死因子α(tumor necrosis factorα,TNF-α)含量,观察ox-LDL对THP-1巨噬细胞功能的影响。结果:细胞形态学结果表明,我们成功利用ox-LDL诱导THP-1巨噬细胞形成泡沫细胞;进一步发现ox-LDL诱导THP-1巨噬细胞表面的清道夫受体CD36表达升高,并促进细胞吞噬功能增加,进一步促进细胞内胆固醇含量显著升高(P0.05);同时,ox-LDL能够刺激巨噬细胞大量分泌TNF-α(P0.05)。结论:ox-LDL通过增强清道夫受体CD36表达,提高巨噬细胞的吞噬功能,引起大量胆固醇聚集,产生细胞毒性损伤,并促进TNF-α炎性因子的大量分泌。     

Toll-like receptor 4 is up-regulated by mTOR activation during THP-1 macrophage foam cells formation

Macrophage foam cells formation is the most important process in atherosclerotic plaque formation and development. Toll-like receptor 4 (TLR4) is one of the important innate immune sensors of endogenous damage signals and crucial for regulating inflammation. Growing evidence indicates that TLR4 plays a very important role in macrophage foam cells formation. However, the underlying mechanisms regulating TLR4 expression in macrophage are not fully understood. In this study, we induced THP-1 macrophage foam cells formation with oxidative modified low-density lipoprotein (ox-LDL). We observed that TLR4 mRNA and protein expression were markedly up-regulated, and the phosphorylation of mammalian target of rapamycin (mTOR) and its downstream target p70S6K were promoted during foam cells formation. The mTOR inhibitor rapamycin blocked mTOR phosphorylation and inhibited TLR4 expression induced by ox-LDL. Silencing mTOR, rictor or raptor protein expression by small interfering RNA, also inhibited the up-regulation of TLR4 expression, respectively. Inhibition of mTOR with rapamycin reversed the down-regulation of cellular lipid efflux mediator ABCA1, which resulted from the activation of TLR4 by ligands. These data suggested that TRL4 expression was up-regulated by a mechanism dependent on mTOR signal pathway activation during THP-1 macrophage foam cells formation. Inhibition of ox-LDL induced mTOR activation reduced TLR4 expression, and improved the impaired lipid efflux.     

Lipoprotein aggregation protects human monocyte-derived macrophages from OxLDL-induced cytotoxicity

Oxidative modifications render low density lipoprotein cytotoxic and enhance its propensity to aggregate and fuse into particles similar to those found in atherosclerotic lesions. We showed previously that aggregation of oxidized LDL (OxLDL) promotes the transformation of human macrophages into lipid-laden foam cells (Asmis, R., and J. Jelk. 2000. Large variations in human foam cell formation in individuals. A fully autologous in vitro assay based on the quantitative analysis of cellular neutral lipids. Atherosclerosis. 148: 243-253). Here, we tested the hypothesis that aggregation of OxLDL enhances its clearance by human macrophages and thus may protect macrophages from OxLDL-induced cytotoxicity. We found that increased aggregation of OxLDL correlated with decreased macrophage injury. Using 3H-labeled and Alexa546-labeled OxLDL, we found that aggregation enhanced OxLDL uptake and increased cholesteryl ester accumulation but did not alter free cholesterol levels in macrophages. Acetylated LDL was a potent competitor of aggregated oxidized LDL (AggOxLDL) uptake, suggesting that scavenger receptor A plays an important role in the clearance of AggOxLDL. Inhibitors of actin polymerization, cytochalasin B, cytochalasin D, and latrunculin A, also prevented AggOxLDL uptake and restored OxLDL-induced cytotoxicity. This suggests that OxLDL-induced macrophage injury does not require OxLDL uptake and may occur on the cell surface. Our data demonstrate that aggregation of cytotoxic OxLDL enhances its clearance by macrophages without damage to the cells, thus allowing macrophages to avoid OxLDL-induced cell injury.     

Advanced glycation end products serve as ligands for lectin-like oxidized low-density lipoprotein receptor-1(LOX-1): biochemical and binding characterizations assay

Advanced glycation end products (AGEs) are a class of complex heterogeneous compounds which accumulate with age and is known to be involved in the pathogenesis of several diseases from diabetes to atherosclerosis. AGEs serve as ligands for multiple receptors including scavenger receptor (SR-A), CD36, and SR-BIota. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) plays an important role in both atherosclerosis and is found to be an endothelial cell receptor for AGEs. To explore the binding characterization of AGEs to LOX-1, AGEs were prepared by three different reducing sugars (d-glucose, d-fructose, and d-ribose) and the biochemical characterization including, free amino groups, free amine content, fructosamine residues, carbonyl content, fluorescence, and absorbance were determined. The binding activity was determined by FITC labeled AGEs using Chinese hamster ovary-K1 cells stably transfected with human LOX-1 gene. The obtained AGEs showed significant differences in the extent of side chain modifications, carbonyl content, fluorescence, and absorption models. All of the AGEs showed specific and saturable binding to hLOX-1-CHO-K1 cells. Furthermore, dose-dependent binding processes were observed. However, the maximal cellular binding of AGEs differs between the sugars (glucose > ribose > fructose). In addition, oxidized low-density lipoprotein (ox-LDL) could significantly inhibit the binding of AGEs to LOX-1 with different inhibitory efficiency. LOX-1 serves as receptor for AGEs which may give some insight into the role of LOX-1 in the pathogenesis of diabetes and related disorders.     

Distinct mechanisms for OxLDL uptake and cellular trafficking by class B scavenger receptors CD36 and SR-BI

Modified forms of LDL, including oxidized low density lipoprotein (OxLDL), contribute to macrophage lipid accumulation in the vessel wall. Despite the pathophysiological importance of uptake pathways for OxLDL, the molecular details of OxLDL endocytosis by macrophages are not well understood. Studies in vitro demonstrate that the class B scavenger receptor CD36 mediates macrophage uptake and degradation of OxLDL. Although the closely related scavenger receptor class B type I (SR-BI) binds OxLDL with high affinity, evidence that SR-BI plays a role in OxLDL metabolism is lacking. In this study, we directly compared OxLDL uptake and degradation by CD36 and SR-BI. Our results indicate that although CD36 and SR-BI internalize OxLDL, SR-BI mediates significantly less OxLDL degradation. Endocytosis of OxLDL by both SR-BI and CD36 is independent of caveolae, microtubules, and actin cytoskeleton. However, OxLDL uptake by CD36, but not SR-BI, is dependent on dynamin. The analysis of chimeric SR-BI/CD36 receptors shows that the CD36 C-terminal cytoplasmic tail is necessary and sufficient for dynamin-dependent OxLDL internalization by class B scavenger receptors. These findings indicate that different mechanisms are involved in OxLDL uptake by SR-BI and CD36, which may segregate these two structurally homologous receptors at the cell surface, leading to differences in intracellular trafficking and degradation.     

TGF-beta1 downregulates CD36 and scavenger receptor A but upregulates LOX-1 in human macrophages

Transforming growth factor-beta1 (TGF-beta1), a key cytokine for control of cell growth, extracellular matrix formation, and inflammation control, is secreted by many cells present in the arteriosclerotic plaque. Lipid accumulation in the vessel wall is regarded as an early step in atherogenesis and depends on uptake of modified low-density lipoprotein (LDL) by macrophages through scavenger receptors and their transformation into foam cells. Prominent members of the scavenger receptor family are the class A type I and II receptors (ScR-A), the class B receptor CD36, and the recently detected lectin-like oxidized LDL receptor-1 (LOX-1), which, unlike the native LDL receptor (LDL-R), are not feedback controlled. CD36 is responsible for >50% of modified LDL uptake into human monocyte-derived macrophages. We therefore studied whether TGF-beta1 influences expression and function of ScR-A, CD36, and LOX-1 in monocytes using RT-PCR and flow cytometry. Total uptake of oxidized LDL by monocytoid cells, reflecting the combined function of all scavenger receptors, was significantly reduced by TGF-beta1. At initially low picomolar concentrations, TGF-beta1 decreased CD36 mRNA and protein surface expression and ScR-A mRNA levels in the human monocytic cell line THP-1 and in freshly isolated and cultivated human monocytes, whereas LOX-1 mRNA was increased. Expression of LDL-R and beta-actin was not affected by TGF-beta1. In conclusion, depression of scavenger receptor function in monocytes by TGF-beta1 in low concentrations reduces foam cell formation. Together with matrix control by TGF-beta1, this may be important for atherogenesis and plaque stabilization.     

Lysophosphatidic acid-induced oxidized low-density lipoprotein uptake is class A scavenger receptor-dependent in macrophages

Lysophosphatidic acid (LPA) is a low-molecular-weight lysophospholipid enriched in platelets and mildly oxidized low-density lipoprotein (OxLDL). It is suggested that LPA is involved in atherosclerosis, and our previous studies showed that LPA regulates inflammation in multiple cell types. The main aim of this study was to investigate the effects of LPA on the uptake of OxLDL by mouse J774A.1 macrophages. We observed that LPA upregulated fluorescence-labeled DiI-OxLDL uptake in J774A.1 cells. Meanwhile, expression of the class A scavenger receptor (SR-A), a receptor for modified LDL, was also enhanced. Furthermore, pertussis toxin (PTx) or Ki16425 significantly abolished LPA's effects, indicating that G(i) and LPA(3) are involved in OxLDL uptake and SR-A expression. Of most importance, the LPA-induced OxLDL uptake could be inhibited when cells were incubated with a functional blocking antibody of SR-A. Our results suggest that LPA-enhanced OxLDL uptake is mediated via LPA(3)-G(i) activation and subsequent SR-A expression.     

Chaperonin-containing TCP-1 complex directly binds to the cytoplasmic domain of the LOX-1 receptor

Lectin-like oxidized low-density lipoprotein receptor (LOX-1) is a scavenger receptor that binds oxidized low-density lipoprotein (OxLDL) and has a role in atherosclerosis development. The N-terminus intracellular region (cytoplasmic domain) of LOX-1 mediates receptor internalization and trafficking, potentially through intracellular protein interactions. Using affinity isolation, we identified 6 of the 8 components of the chaperonin-containing TCP-1 (CCT) complex bound to LOX-1 cytoplasmic domain, which we verified by coimmunoprecipitation and immunostaining in human umbilical vein endothelial cells. We found that the interaction between CCT and LOX-1 is direct and ATP-dependent and that OxLDL suppressed this interaction. Understanding the association between LOX-1 and the CCT complex may facilitate the design of novel therapies for cardiovascular disease.     

Association between monocyte Fcγ subclass expression and acute coronary syndrome

Background  

Atherosclerosis lesions contain abundant immunoglobulins complexed with oxidized LDL (OxLDL) that are endocytosed by macrophages to form foam cells. While recent evidence supports a role for the macrophage scavenger receptor pathway in 75–90% of OxLDL uptake, in vitro evidence suggests another potential uptake pathway could involve autoantibody binding to IgG subclass-specific Fc receptors.     

Specific Kv1.3 blockade modulates key cholesterol-metabolism-associated molecules in human macrophages exposed to ox-LDL

Cholesterol-metabolism-associated molecules, including scavenger receptor class A (SR-A), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), CD36, ACAT1, ABCA1, ABCG1, and scavenger receptor class B type I, can modulate cholesterol metabolism in the transformation from macrophages to foam cells. Voltage-gated potassium channel Kv1.3 has increasingly been demonstrated to play an important role in the modulation of macrophage function. Here, we investigate the role of Kv1.3 in modulating cholesterol-metabolism-associated molecules in human acute monocytic leukemia cell-derived macrophages (THP-1 macrophages) and human monocyte-derived macrophages exposed to oxidized LDL (ox-LDL). Human Kv1.3 and Kv1.5 channels (hKv1.3 and hKv1.5) are expressed in macrophages and form a heteromultimeric channel. The hKv1.3-E314 antibody that we had generated as a specific hKv1.3 blocker inhibited outward delayed rectifier potassium currents, whereas the hKv1.5-E313 antibody that we had generated as a specific hKv1.5 blocker failed. Accordingly, the hKv1.3-E314 antibody reduced percentage of cholesterol ester and enhanced apoA-I-mediated cholesterol efflux in THP-1 macrophages and human monocyte-derived macrophages exposed to ox-LDL. The hKv1.3-E314 antibody downregulated SR-A, LOX-1, and ACAT1 expression and upregulated ABCA1 expression in THP-1 macrophages and human monocyte-derived macrophages. Our results reveal that specific Kv1.3 blockade represents a novel strategy modulating cholesterol metabolism in macrophages, which benefits the treatment of atherosclerotic lesions.