Original articleHomocysteine accelerates atherosclerosis by inhibiting scavenger receptor class B member1 via DNMT3b/SP1 pathway
Introduction
Atherosclerosis, a complex chronic disease characterized by lipid deposition in the arterial wall, is a major contributor to morbidity and mortality worldwide [1]. Emerging evidence demonstrated that homocysteine (Hcy), a key intermediate in the metabolism of sulfur-containing amino acid, has been recognized as an independent risk factor for atherosclerosis [2]. Although it was reported that Hcy-induced oxidative stress, endothelium dysfunction and vascular smooth muscle cells (VSMCs) proliferation also played important roles in the pathogenesis of atherosclerosis [[3], [4], [5]], the underlying mechanisms regarding Hcy-accelerated lipid deposition in atherosclerosis still need to be further elucidated.
Scavenger receptor class B type 1 (SCARBI) is a cell-surface glycoprotein which belongs to the CD36 superfamily together with scavenger receptor CD36 and lysosomal membrane protein 2 [6]. It was evidenced that SCARB1 is widely expressed in mammals including macrophages and endothelial cells. Additionally, SCARB1 was reported to play a vital role in cholesterol homeostasis [7,8]. Ubiquitous deletion of SCARB1 can disturb HDL metabolism which reverses the transportation of cholesterol [6,9]. On the other hand, overexpression of SCARB1 in SCARB1-deficient animals can reduce plasma HDL cholesterol levels [10]. Thus, it is reasonable to suspect that SCARB1 might be involved in atherosclerosis due to its regulating role in the metabolism of LDL and HDL which maintain cellular cholesterol balance.
Gene transcriptional regulation involves epigenetics-transcriptional factor interaction, which plays a pivotal role in gene regulation processes and disease development at the molecular level [11]. DNA methylation is the most highly studied epigenetic marker in the modulation of gene transcription, which was regulated by DNA methyltransferases (DNMTs) and intermediate metabolites of the one-carbon pathway including Hcy. Meantime, several studies have suggested the tight correlation between plasma Hcy and DNA methylation [12]. In our previous study, it was found that Hcy-mediated FABP4 gene demethylation via DNMT1 can accelerate atherosclerosis in ApoE-/- mice [13]. However, a variety of DNA methylation aberrations at a genome-wide level and particular loci under similar pathological conditions was observed [14]. Besides, aberrant expression of DNMT3b, one kind of functional DNMTs in mammals, can inhibit gene expression and onset the bladder cancer by decreasing global DNA methylation [15]. More importantly, several investigations have documented that epigenetic modification including DNA methylation is initiated by the specific transcription factor that binds to the promoter of the gene [16]. As a member of the family of SP/KLF transcription factors, specificity protein 1 (SP1) can drive various cellular processes, such as development, proliferation, apoptosis, as well as lipid metabolism [17]. Meanwhile, it can trigger gene expression through binding to the GC-rich motifs present in the proximal promoter of a gene [18]. In breast cancer, Sp1-induced DNMT1 activity increase was responsible for p53-induced expression inhibition of p125 and the methylation of POLD1 gene promoter [19], while little is known about the association between SP1 and DNMT3b during the development of in atherosclerosis.
Therefore, this study is aimed to elucidate the role of SCARB1 in Hcy-mediated atherosclerosis. The evidence indicated that the decreased recruitment of SP1 to SCARB1 promoter mediated by DNMT3b was responsible for the downregulation of SCARB1, which finally result in the lipid accumulation in foam cells. These findings provide new insight into Hcy-associated lipid accumulation and a new potential molecular target of SCARB1 for the therapy of Hcy-related cardiovascular diseases.
Section snippets
Chemicals and reagents
Wizard® Genomic DNA Purification Kit was from Promega (Madison, USA), DL-Homocysteic Acid (DL-Hcy), PMA, ox-LDL,5-aza-2′-deoxycytidine (5-AZC), Nile Red, DC_05, TFD, and NanaomycinA, anti-SP1 antibodies were from Sigma-Aldrich (St. Louis, USA), anti-β-actin antibody was from Zsbio (Beijing, China), antibodies against SCARB1, DNMT3b, MOMA-2 and perilipin were from Abcam (MA, USA), HRP conjugated goat anti-rabbit IgG and goat anti-mouse-IgG were from Jackson ImmunoResearch (West Grove, USA), DNA
High methionine diet results in hyperhomocysteinemia (HHcy) and promotes atherosclerosis progression in ApoE-/- mice
To confirm the atherogenic effects of HHcy, we firstly administered the ApoE-/- mice with a high-methionine diet for 20 weeks to induce hyperhomocysteinemia (Fig. 1A). The results indicated that the atherosclerotic lesion area in the aortic root was significantly increased in ApoE-/- mice fed with a high-methionine diet as well as the lesion percentage of aortic sinus, while folate and vitamin B12 significantly attenuated the increase of atherosclerotic lesion (Fig. 1B, C). Pearson correlation
Discussion
Atherosclerosis is a chronic lipid-driven disease in large and medium arterial walls [31]. As the major component of atherosclerotic lesions, macrophages played a critical role in the development of atherosclerosis by uptaking ox-LDL into foam cells [32]. Recently, various risk factors including Hcy in atherosclerosis have been identified [33]. In this study, we found that DNMT3b-mediated inhibition of SCARB1 facilitated lipid accumulation in foam cells in the presence of Hcy, which did not
Declaration of Competing Interest
The authors declare that they have no conflict of interest.
Acknowledgments
This work was supported by the National Natural Science Foundation of China (81560288, 81560084, 81700404, 81570452, 81560086), Key Research and Development Projects in Ningxia Province (2018BEG02004), West China first-Class Disciplines Basic Medical Sciences at Ningxia Medical University (NXYLXK2017B07), Ningxia Chunhui Planning project (Z2016050), Ningxia Natural Science Foundation of China (2019AAC03075).
References (50)
- et al.
Activation of NLRP3 inflammasomes contributes to hyperhomocysteinemia-aggravated inflammation and atherosclerosis in apoE-deficient mice
Lab. Invest.
(2017) - et al.
miR-125b targets DNMT3b and mediates p53 DNA methylation involving in the vascular smooth muscle cells proliferation induced by homocysteine
Exp. Cell Res.
(2016) - et al.
Ovarian granulosa cells utilize scavenger receptor SR-BI to evade cellular cholesterol homeostatic control for steroid synthesis
J. Lipid Res.
(2013) - et al.
Scavenger receptor B1 (SR-B1) profoundly excludes high density lipoprotein (HDL) apolipoprotein AII as it nibbles HDL-cholesteryl ester
J. Biol. Chem.
(2017) - et al.
Mechanistic insights into the interaction between transcription factors and epigenetic modifications and the contribution to the development of obesity
Front. Endocrinol.
(2018) - et al.
High-methionine diets accelerate atherosclerosis by HHcy-mediated FABP4 gene demethylation pathway via DNMT1 in ApoE(-/-) mice
FEBS Lett.
(2015) - et al.
Low-density lipoprotein upregulate SR-BI through Sp1 Ser702 phosphorylation in hepatic cells
Biochim. Biophys. Acta
(2016) - et al.
Quantitative assessment of atherosclerotic lesions in mice
Atherosclerosis
(1987) - et al.
Modulation of FABP4 hypomethylation by DNMT1 and its inverse interaction with miR-148a/152 in the placenta of preeclamptic rats and HTR-8 cells
Placenta
(2016) - et al.
Spontaneous necrosis of the skin associated with cryofibrinogenemia, cryoglobulinemia, and homocystinuria
Ann. Vasc. Surg.
(1996)
The polyphenol PGG enhances expression of SR-BI and ABCA1 in J774 and THP-1 macrophages
Atherosclerosis
Allele-specific DNA methylation and its interplay with repressive histone marks at promoter-mutant TERT genes
Cell Rep.
DNA demethylation by DNMT3A and DNMT3B in vitro and of methylated episomal DNA in transiently transfected cells
Biochim. et Biophys. Acta
Activation of NLRP3 inflammasomes contributes to hyperhomocysteinemia-aggravated inflammation and atherosclerosis in apoE-deficient mice
Lab. Investig.
Thrombophilic risk factors in patients with severe carotid atherosclerosis
J. Thromb. Haemostas.
Aged garlic extract inhibits homocysteine-induced scavenger receptor CD36 expression and oxidized low-density lipoprotein cholesterol uptake in human macrophages in vitro
J. Ethnopharmacol.
Homocysteine accelerates atherosclerosis via inhibiting LXRalpha-mediated ABCA1/ABCG1-dependent cholesterol efflux from macrophages
Life Sci.
Up-regulated expression of scavenger receptor class B type 1 (SR-B1) is associated with malignant behaviors and poor prognosis of breast cancer
Pathol. Res. Pract.
High density lipoprotein phospholipid composition is a major determinant of the bi-directional flux and net movement of cellular free cholesterol mediated by scavenger receptor BI
J. Biol. Chem.
Autocrine TGF-beta1/miR-200s/miR-221/DNMT3B regulatory loop maintains CAF status to fuel breast cancer cell proliferation
Cancer Lett.
Zinc-fingers and homeoboxes 1 (ZHX1) binds DNA methyltransferase (DNMT) 3B to enhance DNMT3B-mediated transcriptional repression
Biochem. Biophys. Res. Commun.
Inflammation and beyond: new directions and emerging drugs for treating atherosclerosis
Expert Opin. Emerging Drugs
Aberrant promoter methylation of multiple genes in VSMC proliferation induced by Hcy
Mol. Med. Rep.
Homocysteineinduced oxidative stress through TLR4/NFkappaB/DNMT1mediated LOX1 DNA methylation in endothelial cells
Mol. Med. Rep.
Pediococcus acidilactici LAB4 and Lactobacillus plantarum LAB12 assimilate cholesterol and modulate ABCA1, CD36, NPC1L1 and SCARB1 in vitro
Benefic. Microbes
Cited by (29)
Combining metabolomics and OCT to reveal plasma metabolic profiling and biomarkers of plaque erosion and plaque rupture in STEMI patients
2023, International Journal of CardiologyRap1A accelerates homocysteine-induced ANA-1 cells inflammation via synergy of FoxO1 and DNMT3a
2023, Cellular SignallingDifferential expression of placental 11β-HSD2 induced by high maternal glucocorticoid exposure mediates sex differences in placental and fetal development
2022, Science of the Total EnvironmentCitation Excerpt :It is known that the expression of 11β-HSD2 is regulated by a variety of transcription factors such as Sp1, Egr1, NF-κB and PPAR (α/β/γ/δ) (He et al., 2014; Heiniger et al., 2003; Julan et al., 2005; Kostadinova et al., 2005; Li et al., 2011). Sp1 is widely expressed and participates in various cellular functions, including cell growth, differentiation, apoptosis, immune response, DNA damage response, and chromatin remodeling (Guo et al., 2020; Iwahori et al., 2008; Thakur et al., 2016; Vizcaino et al., 2015). HSD11B2 gene promoter region has multiple overlapping Sp1 binding sites that play a critical role in regulating its expression (Li et al., 2011; Nawrocki et al., 2002).
SNF5 promotes IL-1β expression via H3K4me1 in atherosclerosis induced by homocysteine
2021, International Journal of Biochemistry and Cell BiologyCitation Excerpt :All animals received humane care in compliance with the Institutional Authority for Laboratory Animal Care of Ningxia Medical University in accordance with the Guide for the Care and Use of Laboratory Animals published by the United States National Institutes of Health. Hcy concentrations in serum were measured by fluorescence immunoassay (Abbott IMx analyzer, Abbott Laboratories, Berkshire, UK) as previously reported (Guo et al., 2020). Hematoxylin-eosin (HE) staining and Oil Red O staining were used to stain tissues in accordance with the instructions of the reagent manufacturer.
Relationship between homocysteine and chronic total coronary occlusion: A cross-sectional study from southwest China
2023, Cardiology in the Young
- 1
These authors contributed equally to this work.