ALDH2 deficiency inhibits Ox-LDL induced foam cell formation via suppressing CD36 expression

Aldehyde Dehydrogenase 2 rs671 G/A and a/A Genotypes are Associated with the Risk of Acute Myocardial Infarction

Background

Aldehyde dehydrogenase 2 (ALDH2) is a key catalytic enzyme involved in the aldehyde metabolism that plays an important role in the occurrence and development of acute myocardial infarction (AMI). However, the relationship of ALDH2 polymorphism and susceptibility to AMI may differ among different regions and populations, and it has not yet been reported in Hakka population. The purpose of the present study was to investigate it in this population.

Methods

Four hundred and nineteen AMI patients and 636 individuals without AMI were included in the present study. The ALDH2 rs671 polymorphism was genotyped using polymerase chain reaction (PCR)-microarray. Differences in ALDH2 rs671 genotypes and alleles between patients and controls were compared, and the relationship between ALDH2 rs671 genotypes and AMI risk was analyzed.

Results

Patients with AMI had a lower frequency of ALDH2 rs671 G/G genotype (43.2% vs 52.7%, p=0.003), and a higher G/A genotype (45.6% vs 38.5%, p=0.025) than controls. And AMI patients had a lower frequency of ALDH2 rs671 G allele (66.0% vs 71.9%), and a higher A allele (34.0% vs 28.1%) (p=0.004) than controls. Logistic regression analysis showed that overweight (body mass index (BMI)≥24.0 kg/m2 vs BMI 18.5-23.9 kg/m2: odds ratio (OR) 2.046, 95% confidence interval (CI): 1.520-2.754, p<0.001), history of hypertension (yes vs no: OR 3.464, 95% CI: 2.515-4.770, p<0.001), ALDH2 rs671 G/A genotype (G/A vs G/G: OR 1.476, 95% CI: 1.102-1.976, p=0.009), and A/A genotype (A/A vs G/G: OR 1.656, 95% CI: 1.027-2.668, p=0.038) maybe the independent risk factors for AMI.

Conclusion

Overweight (BMI≥24.0 kg/m2), a history of hypertension, and ALDH2 rs671 G/A or A/A genotypes increased the risk of developing AMI in Hakka population.

ALDH2 deficiency augments atherosclerosis through the USP14-cGAS-dependent polarization of proinflammatory macrophages

The aldehyde dehydrogenase 2 (ALDH2) rs671 polymorphism commonly exists in the East Asian populations and is associated with high risks of cardiovascular disease (CVD). However, the cellular and molecular mechanisms that underlie the ALDH2 rs671 mutant-linked high CVD remain elusive. Here, we show that macrophages derived from human ALDH2 rs671 carriers and ALDH2 knockout mice exhibited an enhanced pro-inflammatory macrophage phenotype and an impaired anti-inflammatory macrophage phenotype. Transplanting bone marrow from ALDH2-/-ApoE-/- to ApoE-/- mice significantly increased atherosclerotic plaque growth and pro-inflammatory macrophage polarization in vivo. Mechanistically, ALDH2 inhibited activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway in macrophages. Pharmacological inhibition of cGAS by RU.521 completely neutralized ALDH2-deficiency-induced macrophage polarization. In-depth mechanistic investigation showed that ALDH2 accelerated cGAS K48-linked polyubiquitination degradation at lysine 282 in macrophages by reducing the interaction between ubiquitin-specific protease 14 (USP14) and cGAS, mainly through its enzymatic role in mitigating 4-hydroxy-2-nonenal (4-HNE) accumulation. Consistently, USP14 knockdown in bone marrow cells alleviated proinflammatory responses in macrophages and protected against atherosclerosis. Our findings provide new mechanistic insights of ALDH2 deficiency-associated proinflammation and atherosclerosis and new therapeutic and preventive paradigms for treatment of atherosclerosis-associated CVD.

Cannabidiol (CBD) Inhibits Foam Cell Formation via Regulating Cholesterol Homeostasis and Lipid Metabolism

SCOPE

The cannabidiol (CBD) in hemp oil has important pharmacological activities. Accumulating evidence suggests that CBD is beneficial in the cardiovascular system and has been applied as a health supplement for atherosclerosis. However, the mechanism remains unclear.

METHODS AND RESULTS

This study investigates the impact of CBD on foam cell formation, cholesterol homeostasis, and lipid metabolism in macrophages. CBD elevates the levels of peroxisome proliferator-activated receptor gamma (PPARγ) and its associated targets, such as ATP binding transporter A1/G1 (ABCA1/ABCG1), thus reducing foam cell formation, and increasing cholesterol efflux within macrophages. Notably, the upregulation of ABCA1 and ABCG1 expression induced by CBD is found to be attenuated by both a PPARγ inhibitor and PPARγ small interfering RNA (siRNA). Moreover, transfection of PPARγ siRNA results in a decrease in the inhibitory effect of CBD on foam cell formation and promotion of cholesterol efflux. Through lipidomics analysis, the study finds that CBD significantly reverses the enhancement of ceramide (Cer). Correlation analysis indicates a negative association between Cer level and the expression of ABCA1/ABCG1.

CONCLUSION

This study confirms that CBD can be an effective therapeutic candidate for atherosclerosis treatment by activating PPARγ, up-regulating ABCA1/ABCG1 expression, and down-regulating Cer level.

Factors associated with treatment responses to pioglitazone in patients with steatotic liver disease: A 3-year prospective cohort study

AIM

The response rate to pioglitazone and the predictive factors for its effects on improving liver biochemistry in patients with steatotic liver disease (SLD) remain elusive, so we aimed to investigate these issues.

METHODS

A 3-year prospective cohort study of 126 Taiwanese patients with SLD treated with pioglitazone (15-30 mg/day) was conducted. Phospholipase domain-containing protein 3 I148M rs738409, methylenetetrahydrofolate reductase rs1801133, aldehyde dehydrogenase 2 (ALDH2) rs671 and lipoprotein lipase rs10099160 single nucleotide polymorphisms were assessed in the patients.

RESULTS

Of 126 patients, 78 (61.9%) were men, and the mean and median ages were 54.3 and 56.5 years, respectively. Pioglitazone responders were defined as those with decreased alanine aminotransferase (ALT) levels at 6 months post-treatment, and 105 (83.3%) patients were responders. Compared with non-responders, responders were more frequently women and had higher baseline ALT levels. The proportion of patients with the ALDH2 rs671 GG genotype was lower among responders (38.6% vs. 66.6%, p = .028). Female sex [odds ratio (OR): 4.514, p = .023] and baseline ALT level (OR: 1.015, p = .046; cut-off level: ≥82 U/L) were associated with pioglitazone response. Among responders, the liver biochemistry and homeostasis model assessment of insulin resistance improved from 6 to 24 months post-treatment. The total cholesterol levels decreased within 6 months, while increases in high-density lipoprotein cholesterol levels and decreases in triglyceride levels and fibrosis-4 scores were noted only at 24 months post-treatment. The 2-year cumulative incidences of cardiovascular events, cancers and hepatic events were similar between responders and non-responders.

CONCLUSIONS

Regarding liver biochemistry, over 80% of Taiwanese patients with SLD had a pioglitazone response, which was positively associated with female sex and baseline ALT levels. Insulin resistance improved as early as 6 months post-treatment, while liver fibrosis improvement was not observed until 24 months post-treatment. The link between the pioglitazone response and the ALDH2 genotype warrants further investigation.

Aldehyde dehydrogenase 2 rs671 a/A Genotype is Associated with an Increased Risk of Early Onset Coronary Artery Stenosis

Background

The role of aldehyde dehydrogenase 2 (ALDH2) in cardiovascular diseases has been gradually studied. However, it is unclear whether ALDH2 polymorphism is associated with the risk of early onset (onset age ≤55 years old in men and ≤65 years old in women) coronary artery stenosis (CAS). The association between ALDH2 single nucleotide polymorphism (SNP) rs671 and risk in patients with early onset CAS was investigated in this study.

Methods

The study included 213 early onset CAS patients and 352 individuals without CAS were set as controls. The ALDH2 rs671 polymorphism was genotyped by polymerase chain reaction (PCR) - microarray. Differences in ALDH2 rs671 genotypes and alleles between patients and controls were compared. Multiple logistic regression analysis was performed after adjusting for gender, body mass index (BMI), smoking history, drinking history, and diabetes mellitus to assess the relationship between ALDH2 rs671 genotypes and early onset CAS risk.

Results

The frequency of the ALDH2 rs671 G/G genotype was lower in the early onset CAS patients (43.7% vs 55.3%, p=0.007) than that in the controls. The frequency of the ALDH2 rs671 A allele was higher (32.9% vs 25.0%) than that in the controls (p=0.005). After adjusting for other confounding factors, multivariate logistic regression showed that ALDH2 rs671 A/A genotype (A/A vs G/G: odds ratio (OR) 2.508, 95% confidence interval (CI): 1.130-5.569, p=0.024), overweight (BMI≥24.0 vs 18.5-23.9: OR 5.047, 95% CI: 3.275-7.777, p<0.001), history of smoking (yes vs no: OR 2.813, 95% CI: 1.595-4.961, p<0.001), and diabetes mellitus (yes vs no: OR 2.191, 95% CI: 1.397-3.437, p=0.001) were the independent risk factors of early onset CAS.

Conclusion

In men ≤55 years old and women ≤65 years old, individuals with ALDH2 rs671 A/A genotype, overweight (BMI ≥24.0 kg/m2), smoking history, and diabetes mellitus increased risk of developing CAS.

The role of aldehyde dehydrogenase 2 in cardiovascular disease

Aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme involved in the detoxification of alcohol-derived acetaldehyde and endogenous aldehydes. The inactivating ALDH2 rs671 polymorphism, present in up to 8% of the global population and in up to 50% of the East Asian population, is associated with increased risk of cardiovascular conditions such as coronary artery disease, alcohol-induced cardiac dysfunction, pulmonary arterial hypertension, heart failure and drug-induced cardiotoxicity. Although numerous studies have attributed an accumulation of aldehydes (secondary to alcohol consumption, ischaemia or elevated oxidative stress) to an increased risk of cardiovascular disease (CVD), this accumulation alone does not explain the emerging protective role of ALDH2 rs671 against ageing-related cardiac dysfunction and the development of aortic aneurysm or dissection. ALDH2 can also modulate risk factors associated with atherosclerosis, such as cholesterol biosynthesis and HDL biogenesis in hepatocytes and foam cell formation and efferocytosis in macrophages, via non-enzymatic pathways. In this Review, we summarize the basic biology and the clinical relevance of the enzymatic and non-enzymatic, tissue-specific roles of ALDH2 in CVD, and discuss the future directions in the research and development of therapeutic strategies targeting ALDH2. A thorough understanding of the complex roles of ALDH2 in CVD will improve the diagnosis, management and prognosis of patients with CVD who harbour the ALDH2 rs671 polymorphism.

ALDH2 rs671 and MTHFR rs1801133 polymorphisms are risk factors for arteriosclerosis in multiple arteries

BACKGROUND

Arteriosclerosis in multiple arteries has long been associated with heightened cardiovascular risk. Acetaldehyde dehydrogenase 2 (ALDH2) and methylenetetrahydrofolate reductase (MTHFR) play an important role in the pathogenesis of arteriosclerosis by participating in the oxidation and reduction reactions in vascular endothelial cells. The purpose was to investigate the relationship of ALDH2 and MTHFR gene polymorphisms with arteriosclerosis in multiple arteries.

METHODS

410 patients with arteriosclerosis in single artery and 472 patients with arteriosclerosis in multiple arteries were included. The relationship between ALDH2 rs671 and MTHFR rs1801133 polymorphisms and arteriosclerosis in single artery and arteriosclerosis in multiple arteries was analyzed.

RESULTS

The proportion of ALDH2 rs671 A allele (35.6% vs. 30.9%, P = 0.038) and MTHFR rs1801133 T allele (32.6% vs. 27.1%, P = 0.012) in patients with arteriosclerosis in multiple arteries was significantly higher than that in arteriosclerosis in single artery, respectively. The proportion of history of alcohol consumption in patients with ALDH2 rs671 G/G genotype was higher than those in ALDH2 rs671 G/A genotype and A/A genotype (P < 0.001). The results of logistic regression analysis indicated that ALDH2 rs671 A/A genotype (A/A vs. G/G: OR 1.996, 95% CI: 1.258-3.166, P = 0.003) and MTHFR rs1801133 T/T genotype (T/T vs. C/C: OR 1.943, 95% CI: 1.179-3.203, P = 0.009) may be independent risk factors for arteriosclerosis in multiple arteries (adjusted for age, sex, smoking, drinking, hypertension, and diabetes).

CONCLUSIONS

ALDH2 rs671 A/A and MTHFR rs1801133 T/T genotypes may be independent risk factors for arteriosclerosis in multiple arteries.

Targeting PPARs for therapy of atherosclerosis: A review

Atherosclerosis, a chief pathogenic factor of cardiovascular disease, is associated with many factors including inflammation, dyslipidemia, and oxidative stress. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors and are widely expressed with tissue- and cell-specificity. They control multiple genes that are involved in lipid metabolism, inflammatory response, and redox homeostasis. Given the diverse biological functions of PPARs, they have been extensively studied since their discovery in 1990s. Although controversies exist, accumulating evidence have demonstrated that PPAR activation attenuates atherosclerosis. Recent advances are valuable for understanding the mechanisms of action of PPAR activation. This article reviews the recent findings, mainly from the year of 2018 to present, including endogenous molecules in regulation of PPARs, roles of PPARs in atherosclerosis by focusing on lipid metabolism, inflammation, and oxidative stress, and synthesized PPAR modulators. This article provides information valuable for researchers in the field of basic cardiovascular research, for pharmacologists that are interested in developing novel PPAR agonists and antagonists with lower side effects as well as for clinicians.

Multi-functional plant flavonoids regulate pathological microenvironments for vascular stent surface engineering

In-stent restenosis (ISR) and late thrombosis, usually caused by excessive smooth muscle cell (SMC) proliferation and delayed endothelial layer repair, respectively, are the main risks for the failure of vascular stent implantation. For years, modification of stents with biomolecules that could selectively inhibit SMC proliferation and support endothelial cell (EC) growth had drawn extensive attention. However, the modulatory effect of these biomolecules faces the impact of oxidative stress, inflammation, and hyperlipidemia of the pathological vascular microenvironment, which is caused by the stent implantation injury and atherosclerosis lesions. Here, we modified stents with a natural and multi-functional flavonoid, baicalin (BCL), using poly-dopamine (PDA) coating technology to combat the harmful impact of the pathological microenvironment. Stent with an appropriate BCL immobilization density (approximately 2.03 μg/cm2) successfully supported ECs growth while inhibited SMC proliferation. Furthermore, baicalin-modified surfaces regulated the oxidative stress, inflammation, and high-lipid of the pathological microenvironment to inhibit endothelial dysfunction and the oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cells formation. In vivo results showed that baicalin-modified stents exhibited significant anti-ISR, anti-inflammatory, and endothelialization-promoting functions. Our study suggests that the multi-functional baicalin with pathological microenvironment-regulation (PMR) effect has potential use in the surface engineering of cardiovascular devices. STATEMENT OF SIGNIFICANCE: Empowering vascular stents with selective modulation of smooth muscle cells and endothelial cells by surface technology has become an important research direction for stent surface engineering. However, stent coatings that can furthermodulate the pathological microenvironment of blood vessels have been rarely reported. In this study, we constructed a multifunctional coating based on a flavonoid, baicalin, which can selectively modulate vascular wall cells and improve the pathological microenvironment. This study may provide a reference for developing advanced vascular stents.

Aldehyde dehydrogenase 2 and NOD-like receptor thermal protein domain associated protein 3 inflammasome in atherosclerotic cardiovascular diseases: A systematic review of the current evidence

Inflammation and dyslipidemia underlie the pathological basis of atherosclerosis (AS). Clinical studies have confirmed that there is still residual risk of atherosclerotic cardiovascular diseases (ASCVD) even after intense reduction of LDL. Some of this residual risk can be explained by inflammation as anti-inflammatory therapy is effective in improving outcomes in subjects treated with LDL-lowering agents. NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome activation is closely related to early-stage inflammation in AS. Aldehyde dehydrogenase 2 (ALDH2) is an important enzyme of toxic aldehyde metabolism located in mitochondria and works in the metabolism of toxic aldehydes such as 4-HNE and MDA. Despite studies confirming that ALDH2 can negatively regulate NLRP3 inflammasome and delay the development of atherosclerosis, the mechanisms involved are still poorly understood. Reactive Oxygen Species (ROS) is a common downstream pathway activated for NLRP3 inflammasome. ALDH2 can reduce the multiple sources of ROS, such as oxidative stress, inflammation, and mitochondrial damage, thereby reducing the activation of NLRP3 inflammasome. Further, according to the downstream of ALDH2 and the upstream of NLRP3, the molecules and related mechanisms of ALDH2 on NLRP3 inflammasome are comprehensively expounded as possible. The potential mechanism may provide potential inroads for treating ASCVD.

Aldehyde dehydrogenase 2 deficiency promotes skeletal muscle atrophy in aged mice

Aldehyde dehydrogenase 2 (ALDH2) detoxifies acetaldehyde produced from ethanol. A missense single nucleotide polymorphism (SNP) rs671 in ALDH2 exhibits a dominant-negative form of the ALDH2 protein. Nearly 40% of people in East Asia carry an inactive ALDH2*2 mutation. Previous studies reported that ALDH2*2 is associated with increased risk of several diseases. In this study, we examined the effect of ALDH2 deficiency on age-related muscle atrophy and its underlying mechanisms. We found that ALDH2 deficiency promotes age-related loss of muscle fiber cross-sectional areas, especially in oxidative fibers. Furthermore, ALDH2 deficiency exacerbated age-related accumulation of 4-hydroxy-2-nonenal (4-HNE), a marker of oxidative stress in the gastrocnemius muscle. Similarly, mitochondrial reactive oxygen species (ROS) production increased in aged ALDH2-knockout mice, indicating that ALDH2 deficiency induced mitochondrial dysfunction. In summary, ALDH2 deficiency promotes age-related muscle loss, especially in oxidative fibers, which may be associated with an increased accumulation of oxidative stress via mitochondrial dysfunction.

Lipid Oxidation Products on Inflammation-Mediated Hypertension and Atherosclerosis: A Mini Review

Cardiovascular diseases such as hypertension and atherosclerosis are the common causes of mortality in developed and developing countries. Repeated heating of the dietary oil is a common practice to reduce cost during food preparation. When the cooking oil is heated at high temperatures, production of free radicals augments the oxidative degradation of lipids and depletes the natural antioxidant contents of the cooking oil. Chronic intake of foods prepared using reheated oil could impair antioxidant capacity, leading to oxidative stress and inflammation. This review aims to summarize the current evidence of lipid oxidation products on hypertension and atherosclerosis via inflammatory pathway. In particular, toxic lipid oxidation products such as malondialdehyde and 4-hydroxy-2-nonenal are taken into account. Understanding the signaling pathways underlying the pathology associated with the lipid oxidation-derived aldehydes may be useful to develop therapeutic strategies for the prevention of inflammatory-related cardiovascular complications.

HSP60 Regulates Lipid Metabolism in Human Ovarian Cancer

Accumulating evidence demonstrates that cancer is an oxidative stress-related disease, and oxidative stress is closely linked with heat shock proteins (HSPs). Lipid oxidative stress is derived from lipid metabolism dysregulation that is closely associated with the development and progression of malignancies. This study sought to investigate regulatory roles of HSPs in fatty acid metabolism abnormality in ovarian cancer. Pathway network analysis of 5115 mitochondrial expressed proteins in ovarian cancer revealed various lipid metabolism pathway alterations, including fatty acid degradation, fatty acid metabolism, butanoate metabolism, and propanoate metabolism. HSP60 regulated the expressions of lipid metabolism proteins in these lipid metabolism pathways, including ADH5, ECHS1, EHHADH, HIBCH, SREBP1, ACC1, and ALDH2. Further, interfering HSP60 expression inhibited migration, proliferation, and cell cycle and induced apoptosis of ovarian cancer cells in vitro. In addition, mitochondrial phosphoproteomics and immunoprecipitation-western blot experiments identified and confirmed that phosphorylation occurred at residue Ser70 in protein HSP60, which might regulate protein folding of ALDH2 and ACADS in ovarian cancers. These findings clearly demonstrated that lipid metabolism abnormality occurred in oxidative stress-related ovarian cancer and that HSP60 and its phosphorylation might regulate this lipid metabolism abnormality in ovarian cancer. It opens a novel vision in the lipid metabolism reprogramming in human ovarian cancer.

Elevated Secretion of Aldosterone Increases TG/HDL-C Ratio and Potentiates The Ox-LDL-Induced Dysfunction of HUVEC

Objective

Atherosclerosis (AS) is one of the most common causes of human death and disability. This study is designed to investigate the roles of aldosterone (Aldo) and oxidized low-density lipoprotein (Ox-LDL) in this disease by clinical data and cell model.

Materials and Methods

In this experimental study, clinical data were collected to investigate the Aldo role for the patients with primary aldosteronism or adrenal tumors. Cell viability assay, fluorescence-activated cell sorting (FACS) assay, apoptosis assay, cell aging analysis, and matrigel tube formation assay were performed to detect effects on human umbilical vein endothelial cells (HUVECs) treated with Aldo and/or Ox-LDL. Quantitative polymerase chain reaction (qPCR) and Western blot analysis were performed to figure out critical genes in the process of endothelial cells dysfunction induced by Aldo and/or Ox-LDL.

Results

We found that the Aldo level had a positive correlation with the TG/HDL-C ratio. Endothelial cell growth, angiogenesis, senescence, and apoptosis were significantly affected, and eNOS/Sirt1, the value of Bcl-2/Bax and Angiopoietin1/2 were significantly affected when cells were co-treated by Aldo and Ox-LDL.

Conclusion

Elevated Aldo with high Ox-LDL together may accelerate the dysfunction of HUVEC, and the Ox-LDL, especially for those patients with high Aldo should be well controlled. The assessment of the role of Aldo may provide a theoretical basis for the effective prevention and investigation of a new treatment of AS.

A small-molecule activator of mitochondrial aldehyde dehydrogenase 2 reduces the severity of cerulein-induced acute pancreatitis

Acute pancreatitis (AP) is one of the leading causes of hospital admission for gastrointestinal disorders. Although lipid peroxides are produced in AP, it is unknown if targeting lipid peroxides prevents AP. This study aimed to investigate the role of mitochondrial aldehyde dehydrogenase 2 (ALDH2), a critical enzyme for lipid peroxide degradation, in AP and the possible underlying mechanisms. Cerulein was used to induce AP in C57BL/6 J male mice and pancreatic acinar cells were used to elucidate underlying mechanisms in vitro. Pancreatic enzymes in the serum, lipid peroxidation products malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), and Bcl-2, Bax and cleaved caspase-3 were measured. ALDH2 activation with a small-molecule activator, Alda-1, reduced the levels of the pancreatic enzymes in the serum and the lipid peroxidation products MDA and 4-HNE. In addition, Alda-1 decreased Bax and cleaved caspase-3 expression and increased Bcl-2 expression in vivo and in vitro. In conclusion, ALDH2 activation by Alda-1 has a protective effect in cerulein-induced AP by mitigating apoptosis in pancreatic acinar cells by alleviating lipid peroxidation.

Effects of β2/aβ2 on oxLDL-induced CD36 activation in THP-1 macrophages

AIMS

β2-glycoprotein I/anti-β2-glycoprotein I antibody complex (β2/aβ2) could promote oxLDL-induced endothelial inflammation through Toll-like receptor 4 (TLR4), therefore accelerates atherosclerosis in patients with anti-phospholipid syndrome (APS). However, effects of β2/aβ2 and TLR4 on oxLDL-induced CD36 activation in macrophages remain to be elucidated and are currently under investigation.

MATERIALS AND METHODS

THP-1 macrophages with or without the pre-treatment of TAK-242, a TLR4 inhibitor, were treated with RPMI 1640, oxLDL, oxLDL+β2/aβ2 or oxLDL + LPS.CD36 expression and subsequent intracellular lipid accumulation, cholesterol-transportation-related proteins (ACAT1, ABCG1 and ABCA1) expression, inflammatory cytokines (IL-1β, TNF-α and IL-6) secretion, focal adhesion kinases (FAK) activation and matrix metalloproteinases (MMP-2 and MMP-9) expression by these THP-1 macrophages were evaluated. Moreover, effects of TLR4 on oxLDL+β2/aβ2-induced peroxisome proliferators-activated receptor-γ (PPAR-γ) expression and CD36 translocation have also been observed.

KEY FINDINGS

Compared with oxLDL-treated ones, CD36 expression, intracellular lipid accumulation and FAK activation were inhibited, whereas the levels of inflammatory cytokines and MMPs were upregulated in THP-1 macrophages treated with oxLDL+β2/aβ2 (p < 0.05). Moreover, observed differences between oxLDL-treated and oxLDL+β2/aβ2-treated THP-1 macrophages could be reversed by TAK-242 pre-treatment (p < 0.05). Furthermore, oxLDL+β2/aβ2 promoted PPAR-γ expression and CD36 cytoplasmic translocation in THP-1 macrophages, these effects could also be attenuated by TAK-242 (p < 0.05).

SIGNIFICANCE

Through a TLR4 dependent manner, β2/aβ2 inhibited oxLDL-induced CD36 expression, lipid accumulation and FAK activation, while promoted inflammatory cytokines and MMPs expression in THP-1 macrophages, indicating the novel dual roles played by β2/aβ2 in APS-related atherosclerosis.