ABCA1 transporter promotes the motility of human melanoma cells by modulating their plasma membrane organization

BACKGROUND: Melanoma is one of the most aggressive and deadliest skin tumor. Cholesterol content in melanoma cells is elevated, and a portion of it accumulates into lipid rafts. Therefore, the plasma membrane cholesterol and its lateral organization might be directly linked with tumor development. ATP Binding Cassette A1 (ABCA1) transporter modulates physico-chemical properties of the plasma membrane by modifying cholesterol distribution. Several studies linked the activity of the transporter with a different outcome of tumor progression depending on which type. However, no direct link between human melanoma progression and ABCA1 activity has been reported yet. METHODS: An immunohistochemical study on the ABCA1 level in 110 patients-derived melanoma tumors was performed to investigate the potential association of the transporter with melanoma stage of progression and prognosis. Furthermore, proliferation, migration and invasion assays, extracellular-matrix degradation assay, immunochemistry on proteins involved in migration processes and a combination of biophysical microscopy analysis of the plasma membrane organization of Hs294T human melanoma wild type, control (scrambled), ABCA1 Knockout ( ABCA1 KO) and ABCA1 chemically inactivated cells were used to study the impact of ABCA1 activity on human melanoma metastasis processes. RESULTS: The immunohistochemical analysis of clinical samples showed that high level of ABCA1 transporter in human melanoma is associated with a poor prognosis. Depletion or inhibition ofABCA1 impacts invasion capacities of aggressive melanoma cells. Loss of ABCA1 activity partially prevented cellular motility by affecting active focal adhesions formation via blocking clustering of phosphorylated focal adhesion kinases and active integrin ß3. Moreover, ABCA1 activity regulated the lateral organization of the plasma membrane in melanoma cells. Disrupting this organization, by increasing the content of cholesterol, also blocked active focal adhesion formation. CONCLUSION: Human melanoma cells reorganize their plasma membrane cholesterol content and organization via ABCA1 activity to promote motility processes and aggressiveness potential. Therefore, ABCA1 may contribute to tumor progression and poor prognosis, suggesting ABCA1 to be a potential metastatic marker in melanoma.

Caprylic Acid Improves Lipid Metabolism, Suppresses the Inflammatory Response and Activates the ABCA1/p-JAK2/p-STAT3 Signaling Pathway in C57BL/6J Mice and RAW264.7 Cells / 生物医学与环境科学（英文）

OBJECTIVE@#This study aimed to investigate the effects of caprylic acid (C8:0) on lipid metabolism and inflammation, and examine the mechanisms underlying these effects in mice and cells.@*METHODS@#Fifty-six 6-week-old male C57BL/6J mice were randomly allocated to four groups fed a high-fat diet (HFD) without or with 2% C8:0, palmitic acid (C16:0) or eicosapentaenoic acid (EPA). RAW246.7 cells were randomly divided into five groups: normal, lipopolysaccharide (LPS), LPS+C8:0, LPS+EPA and LPS+cAMP. The serum lipid profiles, inflammatory biomolecules, and ABCA1 and JAK2/STAT3 mRNA and protein expression were measured.@*RESULTS@#C8:0 decreased TC and LDL-C, and increased the HDL-C/LDL-C ratio after injection of LPS. Without LPS, it decreased TC in mice ( P < 0.05). Moreover, C8:0 decreased the inflammatory response after LPS treatment in both mice and cells ( P < 0.05). Mechanistic investigations in C57BL/6J mouse aortas after injection of LPS indicated that C8:0 resulted in higher ABCA1 and JAK2/STAT3 expression than that with HFD, C16:0 and EPA, and resulted in lower TNF-α, NF-κB mRNA expression than that with HFD ( P < 0.05). In RAW 264.7 cells, C8:0 resulted in lower expression of pNF-κBP65 than that in the LPS group, and higher protein expression of ABCA1, p-JAK2 and p-STAT3 than that in the LPS and LPS+cAMP groups ( P < 0.05).@*CONCLUSION@#Our studies demonstrated that C8:0 may play an important role in lipid metabolism and the inflammatory response, and the mechanism may be associated with ABCA1 and the p-JAK2/p-STAT3 signaling pathway.

MicroRNA-135a in ABCA1-labeled Exosome is a Serum Biomarker Candidate for Alzheimer's Disease / 生物医学与环境科学（英文）

Objective@#In the present study, the ABCA1 was used as a label to capture specific exosomes, the level of ABCA1-labeled exosomal microRNA-135a (miR-135a) was evaluated for the diagnosis of Alzheimer's disease (AD), especially in patients with early stages of AD.@*Methods@#This is a preliminary research focused on the levels of ABCA1 in WBCs, RBCs, HT-22 cells, and neuron cells. The diagnostic value of ABCA1-labeled exosomal miR-135a was examined using the CSF and serum of APP/PS1 double transgenic mice, and 152 patients with SCD, 131 patients with MCI, 198 patients with DAT, and 30 control subjects.@*Results@#The level of ABCA1 exosomes harvested from HT-22 cells and neuron culture medium was significantly higher compared to that of RBCs and WBCs ( @*Conclusion@#This study outlines a method to capture specific exosomes and detect them using immunological methods, which is more efficient for early diagnosis of AD.

Research progress on anti-atherosclerosis effect and mechanism of flavonoids compounds mediated by macrophages / 中国中药杂志

Flavonoids are important active ingredients of traditional Chinese medicine, mainly with cardiovascular, anti-liver injury, antioxidant, antispasmodic, and estrogen-like effects. These compounds have obvious effects on the cardiovascular and cerebrovascular diseases. Macrophage-derived foam cells are the key medium in the process of atherosclerosis(AS). In plaque, allserum lipids, serum lipoproteins, and various pro-or anti-inflammatory stimulating factors, chemokines, and small bioactive molecules can significantly affect the macrophage phenotype and induce stronger pro-inflammatory or anti-inflammatory properties. Studies have shown that some flavonoids can be used for macrophages through different pathways and mechanisms, playing an anti-atherosclerosis effect to different degrees, including promotion of cholesterol efflux from macrophages, anti-foaming of macrophages, inhibition of secretion of inflammatory factors, and antioxidant modified low density lipoprotein(ox-LDL)-induced apoptosis of macrophages. Related gene regulation inclu-ded ATP-binding cassette transporter A1(ABCA1), ATP-binding cassette transporter G1(ABCG1), Toll-like receptor(TLR), and scavenger receptor(SR). In this article, we would review the recent research progress of flavonoids on anti-atherosclerosis effect me-diated by macrophage. It is expected to provide new treatment strategies for AS-related cardiovascular and cerebrovascular diseases, and provide research ideas and development directions for the use of related natural medicines and design of new products.

Association of the ATP-binding Cassette Transporter A1 Gene Polymorphismo with Lipid Profile and Tye 2 Diabetes Mellitus

Diabetes remains unique among the main non-communicable ailments (NCDs) recognized by the World Health Organization (WHO), apart from the circulatory diseases, tumours, and long-lasting respiratory ailments. The current study aimed to determine the correlation between ABCA1 gene polymorphismo and lipid profile in type 2 diabetes mellitus patients. Serum samples from 100 type 2 diabetes mellitus patients (46 males and 54 females) and 50 standard subjects (26 males and 24 females) were colected from Najaf province/Irak. Fasting blood sugar (FBS), and lipid profiles (total cholesterol (TC), triglycerides (TH), HDL, LDL, and VLDL) were meassured. Plymerase chain reaction (PCR) with the Taq1 enzye was used for the amplification of the ABCA1 gene, which contains 525bp of the AABCA1 gene in the locus V825I. The present study revaled a positive corrrelation between FBS and body mass index (BMI) (r= 0.2390, p= 0.0463), TG (r = 0.1836, p= .01743), and VLDL (r = 0.1836, p = 0.1839). The frequencies of the GG genotype and the G allele were higher in the normal groups compared to the patientes (58% vs. 56% and 70% vs. 67%, respectively); conversely, the frequencies of the AA genotype (18% vs. 22%) and the A allele (30% vs. 33%) were higher in the patients compared to the normal groups. The data also showed a significant relationship between ABCA1 gene polymorphim and both TG and VLDL (P=0.007 for cach). There is relationship between the ABCA1 gene and HDL level. Additiionally, the G allele could be a defensive factor against diabetes mellitus in Iraqi peole (AU)

IL-17A, MCP-1, CCR-2, and ABCA1 polymorphisms in children with non-alcoholic fatty liver disease / Polimorfismos IL-17A, MCP-1, CCR-2 e ABCA1 em crianças com doença hepática gordurosa não alcoólica

Abstract Objective: The prevalence of non-alcoholic fatty liver disease in children has risen significantly, owing to the worldwide childhood obesity epidemic in the last two decades. Non-alcoholic fatty liver disease is closely linked to sedentary lifestyle, increased body mass index, and visceral adiposity. In addition, individual genetic variations also have a role in the development and progression of non-alcoholic fatty liver disease. The aim of this study was to investigate the gene polymorphisms of MCP-1 (-2518 A/G) (rs1024611), CCR-2 (190 G/A) (rs1799864), ABCA1 (883 G/A) (rs4149313), and IL-17A (-197 G/A) (rs2275913) in obese Turkish children with non-alcoholic fatty liver disease. Methods: The study recruited 186 obese children aged 10 -17 years, including 101 children with non-alcoholic fatty liver disease and 85 children without non-alcoholic fatty liver disease. Anthropometric measurements, insulin resistance, a liver panel, a lipid profile, liver ultrasound examination, and genotyping of the four variants were performed. Results: No difference was found between the groups in respect to age and gender, body mass index, waist/hip ratio, or body fat ratio. In addition to the elevated ALT levels, AST and GGT levels were found significantly higher in the non-alcoholic fatty liver disease group compared to the non non-alcoholic fatty liver disease group (p < 0.05). The A-allele of IL-17A (-197 G/A) (rs2275913) was associated with non-alcoholic fatty liver disease (odds ratio [OR] 2.05, 95% confidence interval: 1.12 -3.77, p = 0.02). Conclusions: The findings of this study suggest that there may be an association between IL-17A (-197 G/A) (rs2275913) polymorphism and non-alcoholic fatty liver disease development in obese Turkish children.

Resumo Objetivo: A prevalência de doença hepática gordurosa não alcoólica em crianças aumentou significativamente devido à epidemia de obesidade infantil em todo o mundo nas últimas duas décadas. A doença hepática gordurosa não alcoólica está intimamente ligada ao estilo de vida sedentário, ao aumento do índice de massa corporal e à adiposidade visceral. Além disso, variações genéticas individuais também têm um papel no desenvolvimento e na progressão da doença hepática gordurosa não alcoólica. O objetivo deste estudo foi investigar os polimorfismos genéticos MCP-1 (-2518 A/G) (rs1024611), CCR-2 (190 G/A) (rs1799864), ABCA1 (883 G/A) (rs4149313) e IL-17A (-197 G/A) (rs2275913) em crianças turcas obesas com doença hepática gordurosa não alcoólica. Métodos: O estudo recrutou 186 crianças obesas entre 10 e 17 anos, inclusive 101 crianças com doença hepática gordurosa não alcoólica e 85 crianças sem doença hepática gordurosa não alcoólica. Medidas antropométricas, resistência à insulina, painel hepático, perfil lipídico, exame ultrassonográfico do fígado e genotipagem de quatro variantes foram feitos. Resultados: Nenhuma diferença foi encontrada entre os grupos em relação à idade e sexo, índice de massa corporal, relação cintura/quadril ou proporção de gordura corporal. Além dos níveis elevados de ALT, os níveis de AST e GGT foram significativamente maiores no grupo doença hepática gordurosa não alcoólica em comparação com o grupo não doença hepática gordurosa não alcoólica (p < 0,05). O alelo A de IL-17A (-197 G/A) (rs2275913) foi associado à doença hepática gordurosa não alcoólica (odds ratio [OR] 2,05, intervalo de confiança de 95%: 1,12-3,77, p = 0,02). Conclusões: Os achados deste estudo sugerem que pode haver uma associação entre o polimorfismo IL-17A (-197 G/A) (rs2275913) e o desenvolvimento da doença hepática gordurosa não alcoólica em crianças turcas obesas.

Heparin-derived oligosaccharide inhibits vascular intimal hyperplasia in balloon-injured carotid artery / 中国天然药物

The aims of the present study were to determine the effects of heparin-derived oligosaccharides (HDOs) on vascular intimal hyperplasia (IH) in balloon-injured carotid artery and to elucidate the underlying mechanisms of action. An animal model was established by rubbing the endothelia within the common carotid artery (CCA) in male rabbits. The rabbits were fed a high-cholesterol diet. Arterial IH was determined by histopathological changes to the CCA. Serum lipids were detected using an automated biochemical analysis. Expressions of mRNAs for vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1 (MCP-1), scavenger receptor class B type I (SR-BI), and ATP-binding cassette transporter A1 (ABCA-1) were analyzed using reverse transcription polymerase chain reaction assays. Expressions of VEGF, VCAM-1, MCP-1, SR-BI and ABCA-1 proteins were analyzed by Western blotting. Enzyme-linked immunosorbent assays were used to quantify expression levels of VEGF and bFGF. Our results showed that administration of HDO significantly inhibited CCA histopathology and restenosis induced by balloon injury. The treatment with HDOs significantly decreased the mRNA and protein expression levels of VEGF, bFGF, VCAM-1, MCP-1, and SR-BI in the arterial wall; however, ABCA-1 expression level was elevated. HDO treatment led to a reduction in serum lipids (total cholesterol, triglycerides, high-density and low-density lipoproteins). Our results from the rabbit model indicated that HDOs could ameliorate IH and underlying mechanism might involve VEGF, bFGF, VCAM-1, MCP-1, SR-BI, and ABCA-1.

Association of ATP-binding cassette transporter A1 [ABCA1]-565 C/T gene polymorphism with hypoalphalipoproteinemia and serum lipids, IL-6 and CRP levels

Background: ATP-binding cassette transporter A1 [ABCA1] is a membrane integral protein which plays a vital role in High Density Lipoprotein [HDL] metabolism and exerts a protective effect against Hypoalphalipoproteinemia [HA] by mediation of rate-limiting step in HDL biogenesis. In addition, this protein possesses anti-inflammatory effects by inhibiting the production of some inflammatory cytokines in macrophages. This study investigated the association of ABCA1-565 C/T gene polymorphism with HA and serum lipids, IL-6 and CRP levels

Methods: A population which consisted of 101 HA and 95 normal subjects were genotyped for ABCA1-565C/T polymorphism by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism [PCR-RFLP]. The serum concentrations of lipids, IL-6 and high sensitive-CRP [hs-CRP] were measured by the relevant methods

Results: The frequency of T allele was significantly higher in the HA group than the controls [31.7 vs. 19.5%, p=0.002]. Thus, carriers of the T allele [CT and TT genotypes] had a higher risk for HA [p=0.016, OR=2.04, 95% CI=1.14-3.63]. T allele carriers demonstrated decreased HDL-C and increased triglyceride, IL-6 and CRP levels than those with the CC genotype

Conclusion: This study suggests that the-565 C/T polymorphism of ABCA1 gene is associated with an increased risk of HA, decreased HDL-C and increased TG, IL-6 and CRP

Effect of transcription activity regulated by VNTR-ZNF and -14C/T variants in the promoter region of ATP-binding cassette transporter 1 in HepG2 cells / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the effect of VNTR-ZNF and -14C/T variants of the promoter region of the ABCA1 gene on the transcription activity of genes in vitro.</p><p><b>METHODS</b>The recombinants were constructed by ligating DNA fragment containing VNTR-ZNF ACCCC inserted/deleted allele with or without -14C/T substitution fragments with a PGL2-basic vector containing luciferase reporter gene. The recombinants were then transfected into HepG2 cells using the cationic lipid method. After 48 h, transfected cells were collected and used to detect the luciferase activity.</p><p><b>RESULTS</b>Luciferase activity of PGL2-ZNF-ACCCCDel was greater than that of PGL2-ZNF-ACCCCIns. Luciferase activity of PGL2-ZNFDel-14C was greater than that of PGL2-ZNFDel-14T, PGL2-ZNFIns-14C, PGL2-ZNFIns-14T.</p><p><b>CONCLUSION</b>Compared with the insertion type, the ACCCC-deleted type of VNTR-ZNF can significantly enhance the transcription activity of ABCA1. And co-transfection of -14 C allele can further enhance this activity.</p>

High insulin level promotes the degradation of high density lipoprotein generation-related functional protein ABCA1 through calpain and proteasome pathway in 3T3-L1 adipocytes / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore effects and potential mechanisms of high insulin environment on high density lipoprotein (HDL) generation-related functional protein ABCA1.</p><p><b>METHODS</b>[(3)H] labeled cholesterol efflux from mature 3T3-L1 adipocytes was detected by liquid scintillation counting. ABCA1 mRNA and protein expression in mature 3T3-L1 adipocytes post stimulation with various concentrations of insulin was detected by real-time fluorescence-based quantitative techniques and Western blot, respectively, in the absence and presence of CHX (cycloheximide, CHX), calpeptin (calpain pathway inhibitor) or MG-132 (proteasome pathway inhibitor).</p><p><b>RESULTS</b>Cholesterol efflux rates were reduced post insulin stimulation in a dose-dependent manner ((7.06 ± 0.27)%, (6.59 ± 0.30)%, (6.34 ± 0.24)%, (5.07 ± 0.40)%, and (4.71 ± 0.40)% at 0, 1, 10, 10², and 10³ nmol/L of insulin, P < 0.05). Cholesterol efflux rates decreased in a time-dependent manner post 10³ nmol/L insulin stimulation (6.52 ± 0.30)%, (5.59 ± 0.71)%, (5.44 ± 0.37)%, (4.52 ± 0.32)%, and (4.38 ± 0.33)% at 0, 2, 4, 6, 12 h, respectively). ABCA1mRNA levels were not affected by insulin (P > 0.05). ABCA1 protein level was significantly downregulated in 10³ nmol/L insulin group compared to 0 nmol/L insulin group (P < 0.01). Compared with the 0 h group, ABCA1 protein level was significantly reduced in 6 h group (P < 0.05) and further reduced in 12 h group (P < 0.01). Both calpeptin and MG-132 could partly reduce insulin-induced degradation of ABCA1. Compared with the negative control group, ABCA1 protein levels were significantly upregulated by cotreatment with calpeptin and MG-132, respectively (both P < 0.01).</p><p><b>CONCLUSION</b>Our data suggest that high insulin level could promote the ABCA1 protein degradation and reduce cholesterol efflux from mature 3T3-L1 adipocytes through calpain and proteasome pathway, thus, produce a circumference not suitable for nascent HDL formation in 3T3-L1 adipocytes.</p>

Effect of ferulic acid on cholesterol efflux in macrophage foam cell formation and potential mechanism / 中国中药杂志

The formation of macrophage-derived foam cells is a typical feature of atherosclerosis (AS). Reverse cholesterol efflux (RCT) is one of important factors for the formation of macrophage foam cells. In this study, macrophage form cells were induced by oxidized low density lipoprotein (ox-LDL) and then treated with different concentrations of ferulic acid, so as to observe the effect of ferulic acid on the intracellular lipid metabolism in the ox-LDL-induced macrophage foam cell formation, the cholesterol efflux and the mRNA expression and protein levels of ATP binding cassette transporter A1 (ABCA1) and ATP binding cassette transporter G1 (ABCG1) that mediate cholesterol efflux, and discuss the potential mechanism of ferulic acid in resisting AS. According to the findings, compared with the control group, the ox-LDL-treated group showed significant increase in intracellular lipid content, especially for the cholesterol content; whereas the intracellular lipid accumulation markedly decreased, after the treatment with ferulic acid. The data also demonstrated that the mRNA and protein expressions of ABCA1 and ABCG1 significantly increased after macrophage foam cells were treated with different concentrations of ferulic acid. In summary, ferulic acid may show the anti-atherosclerosis effect by increasing the surface ABCA1 and ABCG1 expressions of macrophage form cells and promoting cholesterol efflux.

The in vitro anti-atherosclerotic activity of compound E0869 / 药学学报

ATP-binding cassette transporter A1 (ABCA1) and scavenger receptor class B type I (SR-BI/CLA-1) are the key proteins in reverse cholesterol transport (RCT). The high expression of ABCA1 and SR-BI/CLA-1 can decrease the danger of atherosclerosis. The purpose of the study is to find ABCA1 and CLA-1up-regulators for treating atherosclerosis by using cell-based high throughput screening models. Among 20 000 compounds screened, E0869 [1-(3, 4-dimethylphenyl)-1-oxopropan-2-yll4-((methylsulfonyl)methyl)benzoate] was found as the positive hit. The up-regulated activities of E0869 in ABCAl1-LUC and bCA-l1-LUC HepG2 cell were 160% and 175%, respectively. The EC50 values of E0869 in ABCAl1-LUC and CLA-l1-LUC HepG2 cell were 3.79 and 1.42 pμol- x ,(-1) respectively. E0869 could upregulate the mRNA and protein levels of ABCA1, SR-BI/CLA-1 and ABCGJ1genes in HepG2 and RAW264.7 cells by Real-Time Quantitative PCR and Western blotting analysis, but could not influence the expression of FAS, SREBP-l1 and CD36. Foam cell assay showed that E0869 could inhibit lipids accumulation in mouse peritoneal macrophages RAW264.7. Cholesterol efflux assay showed that E0869 could induce HDL-mediated cholesterol efflux in mouse peritoneal macrophages RAW264.7. In conclusion, E0869 could up-regulate ABCA1 and CLA-1 activity, and had good anti-atherosclerotic activity in vitro.

Effect of ligustrazine on reverse cholesterol transport in foam cells / 中国中药杂志

<p><b>OBJECTIVE</b>To discuss the intervention effect of ligustrazine on ox-LDL-induced foam cells from the perspective of reverse cholesterol transport.</p><p><b>METHOD</b>RAW264.7 cultured in vitro was induced with 20 mg x L(-1) ox-LDL to establish the foam cell model, and intervened with ligustrazine. The lipid accumulation in cells was observed by the oil red O dyeing. The changes in total cholesterol and cholesterol ester in the cells were detected with the colorimetric method. The fluorescent quantitative PCR and Western blot were used to detect the mRNA expressions of PPARgamma, LXRalpha and ABCA1.</p><p><b>RESULT</b>Ligustrazine could reduce total cholesterol and cholesterol ester in foam cells, inhibit the lipid accumulation, and increase the mRNA and protein expressions of PPARgamma, LXRalpha and ABCA1.</p><p><b>CONCLUSION</b>Ligustrazine can promote the reverse cholesterol transport by increasing the gene expressions of PPARgamma, LXRalpha and ABCA1.</p>

Atorvastatin inhibits macrophage-derived foam cell formation by suppressing the activation of PPARγ and NF-κB pathway / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate whether atorvastatin inhibits oxidized low-density lipoproteins (Ox-LDL)-stimulated foam cell formation from THP-1 macrophages by regulating the activation of peroxisome proliferator-activated receptor γ (PPARγ) and nuclear factor-κB (NF-κB). Methods THP-1 macrophages were pretreated with 10, 20, or 40 µmol/L atorvastatin for 2 h, and after washing with PBS twice, the cells were incubated with 60 µg/ml of Ox-LDL for 48 h. The quantity of intracellular lipid of the cells was detected with Oil red O staining and enzymatic fluorometric method. The expression of the scavenger receptors of CD36 and SRA were analyzed with Western blotting. We also examined the effect of atorvastatin on adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) expression and the activation of PPARγ and p-iκB, and further assessed the capacity of the macrophages to bind to Dil-oxLDL.</p><p><b>RESULTS</b>Atorvastatin potently inhibited ox-LDL-induced macrophage-derived foam cell formation, down-regulated the expression of CD36 and SRA, and up-regulated the expression of ABCA1. Atorvastatin markedly suppressed the activation of PPARγ and p-iκB in ox-LDL-stimulated THP-1 macrophages (P<0.05) and significantly decreased the Dil-oxLDL-binding capacity of the macrophages (P<0.05).</p><p><b>CONCLUSION</b>Atorvastatin as an effective anti-atherosclerosis agent can suppress the activation of PPARγ and p-iκB to reduce lipid accumulation in macrophages.</p>

Thymic stromal lmphopoietin pomotes macrophage-derived foam cell formation / 华中科技大学学报（医学）（英德文版）

The effect of thymic stromal lymphopoietin (TSLP) on macrophage-derived foam cell formation and the underlying mechanism were studied. Macrophages isolated from C57BL/6 mice were co-cultured in vitro with different concentrations of TSLP or TSLPR-antibody in the presence of oxidized low density lipoprotein (ox-LDL). The effects of TSLP on macrophage-derived foam cell formation were observed by using oil red O staining and intracellular lipid determination. The expression levels of foam cell scavenger receptors (CD36 and SRA) as well as ABCA1 and TSLPR were detected by using RT-PCR and Western blotting. As compared with the control group, TSLP treatment significantly promoted lipid accumulation in macrophages, significantly increased protein expression of CD36 and TSLPR in a dose-dependent manner, and significantly reduced the expression of ABCA1 protein in a dose-dependent manner. No significant differences were noted between the TSLPR-antibody group and the control group. TSLP may down-regulate the expression of cholesterol efflux receptor ABCA1 and up-regulate scavenger receptor expression via the TSLPR signaling pathway, thereby promoting macrophage-derived foam cell formation.

Ac-hE-18A-NH2 inhibits the inflammatory response induced by ox-LDL via inhibiting NF-κB activation in RAW264.7 macrophages / 中南大学学报(医学版)

OBJECTIVE@#To evaluate the effect of Ac-hE-18A-NH2 on TNF-α secretion and mRNA expression in ox-LDL-stimulated RAW264.7 macrophages and to elucidate the possible mechanisms.@*METHODS@#Macrophages were incubated in the medium containing various concentrations of Ac-hE18A-NH2 (1-50 μg/mL) with ox-LDL (50 μg/mL) stimulated. The TNF-α level and intracellular cholesterol content were measured by commercially available quantitation kits following the manufacturer's instructions. TNF-α and ATP-binding cassette transporter A1 (ABCA1) mRNA expression were detected by real-time PCR. ABCA1 and IκB protein -expression in the macrophages were determined by Western blot. NF-κB activity was evaluated by electrophoretic mobility shift assay (EMSA).@*RESULTS@#Ox-LDL stimulation induced a significant increase in TNF-α secretion, mRNA expression, cholesterol accumulation and nuclear factor-κB (NF-κB) activity in RAW264.7 macrophages. Ac-hE-18A-NH2 reduced TNF-α secretion and mRNA expression, up-regulated the ABCA1 mRNA and protein expression, reduced the intracellular cholesterol content, and inhibited NF- κB activation in a dose-dependent manner. Under the same condition and the same concentration, Ac-hE-18A-NH2 was more efficient than D-4F (apoA-I mimetic peptide) in inhibiting the inflammatory response induced by ox-LDL in the macrophages.@*CONCLUSION@#Ac-hE-18A-NH2 may suppress TNF-α secretion and mRNA expression in ox-LDL stimulated RAW264.7 macrophages via IκB-NF-κB signaling pathway. The anti-inflammatory effect of Ac-hE-18A-NH2 is better than that of apoA-I mimic peptide D-4F.

Effect of garlic extract on some serum biochemical parameters and expression of npc1l1, abca1, abcg5 and abcg8 genes in the intestine of hypercholesterolemic mice.

Some compounds in the garlic inhibit cholesterol synthesis, resulting in lowering of serum cholesterol and triglycerides and increase in HDL level. However, the mechanism of this specific effect is not fully understood. In the small intestine, ATP-binding cassette transporters G5, G8 and A1 (ABCG5, ABCG8 and ABCA1), as well as Niemann-Pick C1 like 1 (NPC1L1) protein have important roles in cholesterol metabolism. In this study, we evaluated the beneficial effect of aqueous extract of garlic on lipid profile and also expression of npc1l1, abca1, abcg5 and abcg8 genes in the intestine of N-Marry mice fed a high cholesterol diet as a possible mechanism of garlic effect. Twenty-four mice were randomly divided into three groups: Group 1: hypercholesterolmic (received chow + 2% cholesterol + 0.5% cholic acid); Group 2: garlic (received chow + 4% (w/w) garlic extract + 2% cholesterol + 0.5% cholic acid); and Group 3: received chow only. After one month, mice were anesthetized and blood was collected from their heart. The jejunum was removed, washed with PBS and entrocytes were scraped and used for the experiments. Serum lipids were measured enzymatically and expression of mRNA levels for the above-mentioned proteins was determined by semi-quantitative RT-PCR. Garlic extract significantly reduced serum lipids (p<0.05), compared with the hypercholesterolemic group. Expression of the intestinal npc1l1 was significantly decreased (p<0.01) in the garlic group, compared with the chow group, while abcg5 (p<0.01), abcg8 (p<0.01) and abca1 (p<0.05) expressions were significantly increased. In conclusion, this study reveals a possible mechanism for the beneficial effects of the garlic in lowering serum lipids by decreasing the intestinal lipid absorption and increasing excretion of cholesterol back into the intestinal lumen.

An evaluation of the mechanism of ABCA7 on cellular lipid release in ABCA7-HEC293 cell / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>ABCA7 is a member of the ABCA subfamily that shows a high degree of homology to ABCA1 and, like ABCA1, mediates cellular cholesterol and phospholipid release by apolipoproteins when transfected in vitro. However, expression of ABCA7 has been shown to be downregulated by increased cellular cholesterol while ABCA1 was upregulated.</p><p><b>METHODS</b>The underlying mechanism for this effect was examined in ABCA1 or ABCA7-transfected HEC293. Lipid content in the medium and cells was determined by enzymatic assays. Gene expression was quantitated by real time PCR, and protein content was determined by Western blotting.</p><p><b>RESULTS</b>While ABCA7 mRNA was decreased by 25-hydroxycholesterol treatment, ABCA1 was apparently increased. Treatment with the synthetic LXR agonist T0901317 (T09) upregulated ABCA1 expression and apoAI-mediated cellular lipid release in ABCA1-transfected HEC293 cells, but ABCA7 expression and cellular lipid release in ABCA7-transfected HEC293 cells showed no obvious changes.</p><p><b>CONCLUSION</b>The ABCA7 gene is regulated by sterol in a direction opposite to that of ABCA1.</p>

Mitofusin2 decreases intracellular cholesterol of oxidized LDL-induced foam cells from rat vascular smooth muscle cells / 华中科技大学学报（医学）（英德文版）

Mitofusin2 (Mfn2) plays a pivotal role in the proliferation and apoptosis of vascular smooth muscle cells (VSMCs). The purpose of this study was to investigate the effects of Mfn2 on the trafficking of intracellular cholesterol in the foam cells derived from rat VSMCs (rVSMCs) and also to investigate the effects of Mfn2 on the expression of adenosine triphosphate-binding cassette subfamily A member 1 (ABCA1), adenosine triphosphate-binding cassette subfamily G member 1 (ABCG1) and peroxisome proliferator-activated receptor gamma (PPARγ). The rVSMCs were co-cultured with oxidized low density lipoprotein (LDL, 80 μg/mL) to produce foam cells and cholesterol accumulation in cells. Before oxidized LDL treatment, different titers (20, 40 and 60 pfu/cell) of recombinant adenovirus containing Mfn2 gene (Adv-Mfn2) were added into the culture medium for 24 h to transfect the Mfn2 gene into the rVSMCs. Then the cells were harvested for analyses. The protein expression of Mfn2 was significantly higher in Adv-Mfn2-transfected group than in untransfected group (P<0.05), and the expression levels significantly increased when the titer of Adv-Mfn2 increased (P<0.05). At 24 or 48 h after oxidized LDL treatment, rVSMCs became irregular and their nuclei became larger, and their plasma abounded with red lipid droplets. However, the number of red lipid droplets was significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group. At 48 h after oxidized LDL treatment, the intracellular cholesterol in rVSMCs was significantly increased (P<0.05), but it was significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05), and it also significantly decreased when the titer of Adv-Mfn2 increased (P<0.05). The mRNA and protein expression levels of ABCA1 and ABCG1 were significantly increased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05). Though the mRNA and protein expression levels of PPARγ was not significantly increased (P>0.05), the phosporylation levels of PPARγ were significantly decreased in Adv-Mfn2-transfected group as compared with untransfected group (P<0.05). These results suggest that the transfection of Adv-Mfn2 can significantly reduce intracellular cholesterol in oxidized LDL-induced rVSMCs possibly by decreasing PPARγ phosporylation and then increasing protein expression levels of ABCA1 and ABCG1, which may be helpful to suppress the formation of foam cells.

Regulatory functions of electroacupuncture at fenglong (ST40) on blood lipids and hepatic ABCA1 and PPARalpha in hyperlipidemia rats / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the effects of electroacupuncture (EA) at Fenglong (ST40) on blood lipids, mRNA and protein expression of ATP binding cassette transporter A1 (ABCA1) and peroxisome proliferator-activated receptor a (PPARalpha) in hyperlipidemia rats.</p><p><b>METHODS</b>Thirty-two SD rats of SPF grade were selected to prepare the hyperlipidemia model. After successful modeling, they were randomly divided into the model group, the treatment group, the control group, and the treatment control group, 8 in each group. Another 8 rats were selected as the normal control group. Rats in the treatment group and the treatment control group received EA at Fenglong (ST40), once daily for 30 successive days. Rats in the model group and the treatment group were administered with high fat forage, while rats in the normal control group, the control group, and the treatment control group were administered with common forage. The contents of the total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were detected in every group. The mRNA and protein expressions of ABCA1 and PPARalpha were detected using RT-PCR and Western blot.</p><p><b>RESULTS</b>The levels of TC and LDL-C increased, and the mRNA and protein expressions of ABCA1 and PPARalpha decreased in the model group when compared with the normal group, showing statistical difference (P<0.01, P<0.05). But there was no obvious change in TG or HDL-C (P>0.05). Compared with the model group, the levels of TC and LDL-C decreased in each intervention group with statistical difference (P<0.01). The mRNA and protein expression of ABCA1 and PPARa in the treatment group and the treatment control group increased. The mRNA and protein expressions of PPARalpha increased in the control group with statistical difference (P<0.01, P<0.05). Compared with the control group, the levels of TC and LDL-C decreased, the mRNA and protein expressions of ABCA1 and PPARa increased in the treatment control group with statistical difference (P<0.01). But there was no obvious change in TG or HDL-C (P>0.05).</p><p><b>CONCLUSIONS</b>EA at ST40 could obviously down-regulate the levels of TC and LDL-C in hyperlipidemia rats, up-regulate the expressions of ABCA1 and PPARalpha, thus promoting counter transport of cholesterol. It had some therapeutic effects on hyperlipidemia.</p>