Inhibiting NF-κB increases cholesterol efflux from THP-1 derived-foam cells treated with AngⅡ via up-regulating the expression of ATP-binding cassette transporter A1

Objective： To study the role of nuclear factor-kappa B（NF- κB） in cholesterol efflux from THP-1 derived-foam cells treated with Angiotensin Ⅱ（Ang Ⅱ ）. Methods：Cultured THP-1 derived-foam cells were treated with Ang Ⅱ or preincubated with tosyl-phenylalanine chloromethyl-ketone（TPCK） NF- κB inhibitor. The levels of activated NF- κB in the cells were examined by sandwich ELISA, Cellular cholesterol content was studied by electron microscopy scanning and zymochemistry via fluorospectrophotometer and cholesterol effiux was detected by scintillation counting technique. ABCA1 mRNA and protein were quantified by RT-PCR and Western blotting. Results：Addition of TPCK to the cells before Ang Ⅱ stimulation attenuated the response of NF- κB p65 nuclear translocation induced by Ang Ⅱ and showed no peak in foam cells group and caused a reduction in cholesterol content and an increase in cholesterol efflux by 24.1%（P〈 0.05） and 41.1%（P〈 0.05） respectively, when compared with Ang Ⅱ group. In accordance, the ABCA1 mRNA and protein were increased by 30% and 19%（P 〈 0.05） respectively, when compared with Ang Ⅱ group. Conclusion：Ang Ⅱ can downregulate ABCA1 in THP-1 derived-foam cells via NF- K B, which leads to less cholesterol effiux and the increase of cholesterol content with the consequence of the promotion of atherosclerosis.

ZBM30 suppresses atherosclerosis through up-regulating ATP-binding cassette A1 and G1

Atherosclerosis is the most common cause of cardiovascular diseases, such as myocardial infarction and stroke. The aim of this study was to investigate the effects of a novel compound ZBM30 on atherosclerosis in ApoE- deficient mice and its associated mechanism. ApoE-deficient mice （6 weeks old）, fed an atherogenic high-fat and high cholesterol diet for 8 weeks, were divided into three groups. Two groups were orally administrated ZBM30 （10, 30 nag ~ kg-1） daily for 12 weeks, while the control group was administered saline. Atherosclerotic lesions with en face aortas were evaluated by Sudan IV staining, and lesion areas in aortic sinuses were evaluated by oil red O staining. Necrotic core areas and fibrous cap areas in the lesion were evaluated by henaatoxylin and eosin （HE） staining and Masson＇ s trichronae staining in the aorta sinuses. The effects of ZBM30 on cholesterol accumulation in naacrophages and cholesterol transporters： ATP binding cassette A1 （ABCA1） and ATP binding cassette G1 （AB- CG1） were evaluated by oil red O assay, 3H-cholesterol efflux assay, Western blot, and real-time PCR on macro- phage cell lines： Raw 264.7 and THP-1. Inanauno-fluoresces was used to determine the ABCA1 expression in naac- rophage in aorta sinuses. Luciferase reporters of wild type and mutant types of ABCA1 promoter were constructed to determine the regulatory domain of ZBM30 on ABCA1 promoter. Results showed that, compared with the control group, en face lesions in ZBM30 group （ 10, 30 mg · kg^-1 ） were reduced 54.96 ± 10.06% and 71.50 ± 15.37% respectively, and aorta sinus lesions were reduced 41.85 ± 11.21% and 82.23 ± 8.25% respectively. Necrotic core areas in the ZBM30 group were markedly reduced and fibrous cap areas were not changed. Oil red O staining and 3 H-cholesterol efflux assays on Raw 264.7 cell line revealed that ZBM30 significantly attenuated the cholesterol accumulation in naacrophages by enhancing apolipoprotein AI and HDL mediated cholesterol efflux. Furthermore, ZBM30 induced the protein and naRNA expression of cholesterol transporters such as ABCA1 and ABCG1. Inanauno- fluoresces experiment revealed that ZBM30 induced the ABCA1 expression in naacrophage in the lesion, which is consistent with the results in vitro. Luciferase reporter assay revealed that ZBM30 exerted its effect on ABCA1 via liver X receptor （LXR） binding domain. In conclusion, ZBM30 suppresses atherosclerosis through up-regulating cholesterol efflux via ABCA1 and ABCG1 transporters in ApoE-deficient mice.

GPRC5A调控的ABCB1表达对肺腺癌增殖的影响

目的ATP结合盒B亚家族成员1(ATP binding cassette subfamily B member 1,ABCB1)的异常表达在多种癌症的发生发展中发挥关键作用。然而,G蛋白偶联受体C家族5组A型(G protein coupled receptor family C group5 type A,GPRC5A)调控的ABCB1表达对肺腺癌增殖的影响仍不清楚。本研究探讨了GPRC5A调控的ABCB1表达对肺腺癌增殖的影响。方法我们采用RT-PCR、Western-blot或免疫组化实验,分析ABCB1在肺腺癌细胞系、人肺腺癌组织以及GPRC5A基因敲除小鼠和野生型小鼠的气管上皮细胞和肺组织中的表达。采用细胞计数试剂盒-8(CCK-8)分析GPRC5A基因敲除小鼠气管上皮细胞对化疗药物的敏感性。采用皮下肿瘤形成实验探讨下调ABCB1表达是否可抑制体内肺腺癌增殖。采用免疫荧光和免疫沉淀实验研究GPRC5A和ABCB1之间潜在的调控关系。结果ABCB1在肺腺癌细胞系和人类肺腺癌组织中表达上调。GPRC5A基因敲除小鼠的气管上皮细胞及肺组织的ABCB1表达高于野生型小鼠。与GPRC5A野生型小鼠的气管上皮细胞相比,GPRC5A基因敲除小鼠的气管上皮细胞对塔立奇达和多柔比星更敏感。注射移植细胞28天后,接受ABCB1基因敲除细胞移植的GPRC5A-/-C57BL/6小鼠的肺肿瘤的体积和重量均明显低于野生型细胞移植小鼠(P=0.0043,P=0.0060)。此外,免疫荧光和免疫沉淀实验表明,GPRC5A通过直接结合方式调控ABCB1的表达。结论GPRC5A通过抑制ABCB1表达降低肺腺癌增殖。GPRC5A调节ABCB1表达的途径有待研究。

High-density lipoprotein and atherosclerosis: Roles of lipid transporters

Various previous studies have found a negative cor-relation between the risk of cardiovascular events and serum high-density lipoprotein(HDL) cholesterol levels. The reverse cholesterol transport, a pathway of choles-terol from peripheral tissue to liver which has several potent antiatherogenic properties. For instance, the particles of HDL mediate to transport cholesterol from cells in arterial tissues, particularly from atherosclerotic plaques, to the liver. Both ATP-binding cassette trans-porters(ABC) A1 and ABCG1 are membrane cholesterol transporters and have been implicated in mediating cholesterol effluxes from cells in the presence of HDL and apolipoprotein A-I, a major protein constituent of HDL. Previous studies demonstrated that ABCA1 and ABCG1 or the interaction between ABCA1 and ABCG1 exerted antiatherosclerotic effects. As a therapeutic approach for increasing HDL cholesterol levels, much focus has been placed on increasing HDL cholesterol levels as well as enhancing HDL biochemical functions. HDL therapies that use injections of reconstituted HDL, apoA-I mimetics, or full-length apoA-I have shown dramatic effectiveness. In particular, a novel apoA-I mi-metic peptide, Fukuoka University ApoA-I Mimetic Pep-tide, effectively removes cholesterol via specific ABCA1 and other transporters, such as ABCG1, and has an an-tiatherosclerotic effect by enhancing the biological func-tions of HDL without changing circulating HDL choles-terol levels. Thus, HDL-targeting therapy has significant atheroprotective potential, as it uses lipid transporter-targeting agents, and may prove to be a therapeutic tool for atherosclerotic cardiovascular diseases.

Roles of sulfonylurea receptor 1 and multidrug resistance protein 1 in modulating insulin secretion in human insulinoma

BACKGROUND:Sulfonylurea receptor 1(SUR1)and multidrug resistance protein 1(MRP1)are two prominent members of multidrug resistance proteins associated with insulin secretion. The aims of this study were to investigate their expression in insulinomas and their sole and synergistic effects in modulating abnormal insulin secretion. METHODS:Fasting glucose,insulin and C-peptide were measured in 11 insulinoma patients and 11 healthy controls. Prolonged oral glucose tolerance tests were performed in 6 insulinoma patients.Insulin content,SUR1 and MRP1 were detected in 11 insulinoma patients by immunohistochemistry. SUR1 and MRP1 were also detected in 6 insulinoma patients by immunofluorescence. RESULTS:Insulinoma patients presented the typical demons-trations of Whipple’s triad.Fasting glucose of each insulinoma patient was lower than 2.8 mmol/L,and simultaneous insulin and C-peptide were increased in insulinoma patients. Prolonged oral glucose tolerance tests showed that insulin secretion in insulinoma patients were also stimulated by high glucose.Immunohistochemistry and immunofluorescence staining showed that SUR1 increased,but MRP1 decreased in insulinoma compared with the adjacent islets. CONCLUSIONS:The hypersecretion of insulin in insulinomas might be,at least partially,due to the enrichment of SUR1. In contrast,MRP1,which is down-regulated in insulinomas, might reflect a negative feedback in insulin secretion.

Role of apolipoproteins,ABCA1 and LCAT in the biogenesis of normal and aberrant high density lipoproteins

In this review, we focus on the pathway of biogenesis of HDL, the essential role of apoA-I, ATP binding cassette transporter A1（ABCA1）, and lecithin： cholesterol acyltransferase（LCAT） in the formation of plasma HDL; the generation of aberrant forms of HDL containing mutant apoA-I forms and the role of apoA-IV and apoE in the formation of distinct HDL subpopulations. The biogenesis of HDL requires functional interactions of the ABCA1 with apoA-I（and to a lesser extent with apoE and apoA-IV） and subsequent interactions of the nascent HDL species thus formed with LCAT. Mutations in apoA-I, ABCA1 and LCAT either prevent or impair the formation of HDL and may also affect the functionality of the HDL species formed. Emphasis is placed on three categories of apoA-I mutations. The first category describes a unique bio-engineered apoA-I mutation that disrupts interactions between apoA-I and ABCA1 and generates aberrant prep HDL subpopulations that cannot be converted efficiently to a subpopulations by LCAT. The second category describes natural and bio-engineered apoA-I mutations that generate preβ and small size a4 HDL subpopulations, and are associated with low plasma HDL levels. These phenotypes can be corrected by excess LCAT. The third category describes bio-engineered apoA-I mutations that induce hypertriglyceridemia that can be corrected by excess lipoprotein lipase and also have defective maturation of HDL.The HDL phenotypes described here may serve in the future for diagnosis, prognoses and potential treatment of abnormalities that affect the biogenesis and functionality of HDL.

Overexpression of the steroidogenic acute regulatory protein increases the expression of ATP-binding cassette transporters in microvascular endothelial cells(bEnd.3)

Objective:To determine the effect of steroidogenic acute regulatory protein(StAR) overexpression on the levels of adenosine triphosphate(ATP)-binding cassette transporter A1(ABCA1) and ATP-binding cassette transporter G1(ABCG1) in an endothelial cell line(bEnd.3).Methods:The StAR gene was induced in bEnd.3 cells with adenovirus infection.The infection efficiency was detected by fluorescence activated cell sorter(FACS) and fluorescence microscopy.The expressions of StAR gene and protein levels were detected by real-time polymerase chain reaction(PCR) and Western blot.The gene and protein levels of ABCA1 and ABCG1 were detected by real-time PCR and Western blot after StAR overexpression.Results:The result shows that StAR was successfully overexpressed in bEnd.3 cells by adenovirus infection.The mRNA and protein expressions of ABCA1 and ABCG1 were greatly increased by StAR overexpression in bEnd.3 cells.Conclusion:Overexpression of StAR increases ABCA1 and ABCG1 expressions in endothelial cells.

How to overcome ATP-binding cassette drug efflux transporter-mediated drug resistance?

P-glycoprotein(ABCB1),multidrug resistance protein-1(ABCC1)and breast cancer resistance protein(ABCG2)belong to the ATP-binding cassette(ABC)superfamily of proteins that play an important physiological role in protection of the body from toxic xenobiotics and endogenous metabolites.Beyond this,these transporters determine the toxicity profile of many drugs,and confer multidrug resistance(MDR)in cancer cells associated with a poor treatment outcome of cancer patients.It has long been hypothesized that inhibition of ABC drug efflux transporters will increase drug accumulation and thereby overcome MDR,but until now no approved inhibitor of these transporters is available in the clinic.In this review we present molecular strategies to overcome this type of drug resistance and discuss for each of these strategies their promising value or indicate underlying reasons for their limited success.

G蛋白偶联受体81、单羧酸转运体1和4在宫颈鳞癌中的表达及其临床意义

目的:通过检测G蛋白偶联受体81(G protein-coupled receptor 81,GPR81)、单羧酸转运体(monocarboxylate transporter,MCT)1和4在宫颈鳞癌中的表达,探讨GPR81,MCT1,MCT4在宫颈鳞癌发病中的作用。方法:采用免疫组织化学法(SP二步法)检测GPR81,MCT1,MCT4在16例正常宫颈组织、44例宫颈鳞癌组织中的表达情况,分析其表达水平与宫颈鳞癌临床分期和病理的关系,研究GPR81,MCT1,MCT4在宫颈鳞癌组织中表达的相关性。结果:宫颈鳞癌组中的GPR81,MCT1,MCT4表达水平均明显高于正常宫颈组(P<0.01)。在宫颈鳞癌组中,临床分期为I^II期宫颈鳞癌组织中的GPR81,MCT1,MCT4表达低于临床分期为III^IV期者,其中GPR81的表达差异有统计学意义(P<0.05),MCT1和MCT4的表达差异无统计学意义(P>0.05);中分化肿瘤组的GPR81,MCT1,MCT4表达低于低分化肿瘤组,但差异无统计学意义(P>0.05);无淋巴结转移的宫颈鳞癌组与有淋巴结转移的宫颈鳞癌组的GPR81,MCT1,MCT4表达无明显差异(P>0.05)。GPR81,MCT1,MCT4在宫颈鳞癌组织中的表达无明显相关关系(P>0.05)。结论:GPR81,MCT1,MCT4可能与宫颈鳞癌的发病有关,GPR81可能与宫颈鳞癌的病情进展有关。

乳腺癌组织中ALDH1、CXCR4及ABCG2与其分子亚型的关系

目的探讨乳腺癌组织中乙醛脱氢酶1(ALDH1)、CXCR4及三磷酸腺苷结合转运蛋白G超家族成员2(ABCG2)的表达情况,并分析三者与乳腺癌分子亚型的关系。方法采用免疫组化S-P法检测90例乳腺癌组织中ALDH1、CXCR4、ABCG2以及ER、PR、HER-2的表达情况,根据后三者的表达情况将乳腺癌分为Luminal A型(35例,38.9%)、Luminal B型(16例,17.8%)、HER-2过表达型(22例,24.4%)和Basal-like型(17例,18.9%)4个亚型,并分析三者与分子亚型的关系。结果 90例乳腺癌组织中,ALDH1、CXCR4、ABCG2的阳性表达率分别为32.2%、60.0%、32.2%。不同亚型乳腺癌组织中ALDH1、CXCR4及ABCG2的表达比较差异有统计学意义(χ2=20.157,P<0.001;χ2=12.088,P=0.007;χ2=18.760,P<0.001)。结论不同亚型乳腺癌组织的ALDH1、CXCR4及ABCG2表达具有差异性,三者检测有助于乳腺癌分子亚型的预后评估。

Single Nucleotide Polymorphisms (SNPs) of URAT1 (rs7932775) and ABCG2 (rs3825016) on Chronic Kidney Disease Patients with Hyperuricemia

Background: More and more chronic kidney disease (CKD) patients are accompanied with hyperuricaemia. As is known, hyperuricaemia is an independent hazard of both cardiovascular diseases (CVD) and chronic kidney diseases. We aim at identifying Single Nucleotide Polymorphism (SNP) difference of hURAT1 (rs7932775) and ABCG2 (rs3825016) on CKD patient with hyperuricemia and/or gout. Methods: All forty-two CKD patients were divided into two groups: hyperuricemia, and control group. 24 hours urine sample and serum were prepared for testing biochemistry parameters. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method is used to analyze hURAT1 and ABCG2 single nucleotide polymorphisms in different groups. Results: 17 patients have CT SNP of hURAT1 (rs7932775) and 13 patients have CT SNP of ABCG2 (rs3825016) in hyperuricemia group, while only 5 persons and 6 persons have the same mutations in control group respectively. 7 patients have CT SNP of both hURAT1 (rs7932775) and ABCG2 (rs3825016) in hyperuricemia group, while only 2 persons have the same mutations in control group. CT mutation rates of hURAT1 (rs7932775) and ABCG2 (rs3825016) in hyperuricemia group were 60.7% (17/28) and 50% (13/28) respectively, higher than that of control group (35.7% (5/14) and 42.8% (6/14)). What is more, Double SNP mutations in both hURAT1 (rs7932775) and ABCG2 (rs3825016) in hyperuricemia group were 25% (7/28), higher than that of control group (14.2%, 2/14). Conclusion: There are higher mutation rates of CT SNP in hURAT1 (rs7932775) and/or ABCG2 (rs3825016) in hyperuricemia group. We can conclude that hyperuricemia is a high risk factor in progress of CKD, which is necessary to take measures of decreasing serum uric acid to delay CKD progress.

High nuclear ABCG1 expression is a poor predictor for hepatocellular carcinoma patient survival

Background:ATP-binding cassette transporter G1(ABCG1)regulates cellular cholesterol homeostasis and plays a significant role in tumor immunity.But,for hepatocellular carcinoma(HCC),the role of ABCG1 has not been investigated.Thus,the aim of this study was to evaluate the prognostic value and clinicopathological significance of ABCG1 in HCC.Methods:One hundred and four adult patients with HCC were enrolled,and ABCG1 expression in paired HCC specimens was determined by immunohistochemistry.All these patients were stratified by ABCG1 expression,Kaplan-Meier analysis was used to compare the overall survival(OS)and recurrence-free survival(RFS),and Cox regression analysis was used to determine independent predictors of tumor recurrence.Results:Upregulation of ABCG1 was observed in HCC samples compared to matched tumor-adjacent tissues.Patients with high nuclear ABCG1 expression had lower OS and RFS(P=0.012 and P=0.020,respectively).High nuclear ABCG1 expression was related to larger tumor size(P=0.004)and tumor recurrence(P=0.027).Although ABCG1 was expressed in the cytoplasm,cytosolic expression could not predict the outcome in patients with HCC.A new stratification pattern was established based on the heterogenous ABCG1 expression pattern:high risk(High^(nucleus)/Low^(cytosol)),moderate risk(High^(nucleus)/High^(cytosol) or Low^(nucleus)/Low^(cytosol)),and low risk(Low^(nucleus)/High^(cytosol)).This ABCG1-based risk stratification could distinguish the different OS and RFS in patients with HCC.Multivariate Cox regression analysis indicated that ABCG1 high risk was an independent predictor of poor RFS(P=0.015).Conclusions:High nuclear ABCG1 expression indicates poor prognosis in patients with HCC.Asymmetric distribution of ABCG1 in the nucleus and cytoplasm may have an important role in tumor recurrence.

A Possible Mechanism Linking Hyperglycemia and Reduced High-density Lipoprotein Cholesterol Levels in Diabetes

This study investigated the role of glucose in the biogenesis of high-density lipoprotein cholesterol(HDL-C).Mouse primary peritoneal macrophages were harvested and maintained in Dulbecco’s modified Eagle’s medium(DMEM) containing glucose of various concentrations.The cells were divided into 3 groups in terms of different glucose concentrations in the cultures:Control group(5.6 mmol/L glucose),high glucose concentration groups(16.7 mmol/L and 30 mmol/L glucose).ATP-binding cassette transporter A1(ABCA1) mRNA expression in the macrophages was detected by semi-quantitative RT-PCR 24,48 and 72 h after glucose treatment.The results showed that ABCA1 mRNA expression in the 16.7 mmol/L glucose group was not significantly different from that in the control group at all testing time points(P>0.05 for each).In the 30 mmol/L glucose group,macrophage ABCA1 mRNA expression was not changed significantly at 24 h(P=0.14),but was substantially decreased by 40.4% at 48 h(P=0.009) and by 48.1% at 72 h(P=0.015) as compared with that in the control group.It was concluded that ABCA1 is of vital importance for HDL-C biogenesis.High glucose may hamper HDL-C biogenesis by decreasing ABCA1 expression,which contributes to low HDL-C level in diabetes.

A <i>wzt</i>Mutant <i>Burkholderia mallei</i>Is Attenuated and Partially Protects CD1 Mice against Glanders

Burkholderia mallei is the etiologic agent of glanders in solipeds and humans. Lipopolysaccharide (LPS) is a major component of cell envelop of this pathogen. O-antigen, the most external component of LPS, is a virulence factor and a protective antigen in many pathogenic bacteria. Two putative proteins named Wzm (integral membrane protein) and Wzt (hydrophilic ATP-binding protein) are believed to make up an ABC-2 transporter of B. mallei that facilitates transport of components of O-antigen from cytosol to outer-membrane. We studied the importance of wzt (encoding Wzt) to growth, LPS O-antigen profile, and pathogenicity of B. mallei. A wzt mutant strain was generated by deleting a portion of the wzt in B. mallei wild type strain ATCC 23344 by gene replacement. Compared to the wild type strain, the wzt mutant displayed slower growth in vitro and less lethality in CD1 mice when inoculated intraperitoneally. The 50% lethal doses (LD50) of the wild type and the wzt mutant strains were 5.9 × 105 and 9.1 × 105 cfu, respectively. CD1 mice inoculated with a non-lethal dose of the wzt mutant produced specific serum immunoglobulins IgG1 and IgG2a and were partially protected against challenge with 11.2 times LD50 of the wild type strain. These findings suggest that the wzt is required for optimal in vitro growth and pathogenesis of B. mallei, and a wzt mutant protects CD1 mice against glanders.

Protective Effect of Irbesartan on ATP Binding Cassette Transporter A1 in THP-1 Derived Macrophages

Objectives To explore the protective effect of irbesartan （lrb） under the interference with angiotensin II （Ang II） on ABCA1. Methods Electron microscopy was used to detect the morphous of foam cells. The expression of ABCA1 mRNA and its protein were determined by RT-PCR and Western blotting, respectively. The variance of cellular cholesterol content was measured by zymochemistry via-fluorospeetrophotometer. Results A positive facilitative effect of Ang II on the formation of foam cells was observed. Total cholesterol was increased significantly by Ang II, the expression of ABCA1 was down-regulated obviously by Ang II; Irb could protect ABCA1 against the lesion of Ang II; Total cellular cholesterol content was reduced significantly in Irb ＋ Ang II group; However, considerable alteration about the cholesterol content and the expression of ABCA1 were not observed in Irb group without incubation with Ang II. Conclusions Irb could protect ABCA1 against the lesion of Ang II, which may contribute to its anti-atherosclerotic properties. （ S Chin J Cardiol 2009; 10（4） ： 227 -233）

姜黄素对APP/PS1双转基因鼠海马ABCA1、apoA1的表达和血清TC、HDL含量的影响

目的:探讨姜黄素对APP/PS1双转基因鼠海马组织中三磷酸腺苷结合盒转运子A1(ATP binding cassette transport protein A1,ABCA1)和载脂蛋白A1(apolipoprotein A1,apoA1)的表达及血清中总胆固醇(total cholesterol,TC)和高密度脂蛋白(high-density lipoprotein,HDL)含量的影响。方法:用APP/PS1双转基因鼠建立阿尔茨海默病(Alzheimer’s disease,AD)模型,不同浓度姜黄素饲料喂养6个月。免疫组化SP法检测转基因鼠的海马组织CA1区ABCA1和apoA1的表达变化。胆固醇酶法比色法检测血清中TC和HDL的含量。结果:经过不同浓度姜黄素饲喂转基因鼠后,其海马组织CA1区ABCA1和apoA1的表达增加(P=0.005和0.003;P=0.025和0.001),且血清中HDL的含量也随之增加,TC的含量逐渐减少,其差异均有统计学意义(P=0.041和0.010;P=0.046和0.002)。结论:ABCA1在AD的发生发展中起着重要的作用,姜黄素可能是通过增加ABCA1表达和升高apoA1和HDL含量降低胆固醇水平。

可溶性Klotho蛋白抑制THP-1源性泡沫细胞形成

目的:探讨可溶性Klotho(KL)蛋白对THP-1源性泡沫细胞形成的影响。方法:THP-1单核细胞与160 nmol/L佛波酯孵育48 h后,诱导分化为THP-1源性巨噬细胞,给予THP-1源性巨噬细胞不同浓度(25、50、100和200μg/L)的可溶性KL蛋白预处理后,再由氧化型低密度脂蛋白(ox-LDL)诱导其转变为泡沫细胞。油红O染色观察细胞内脂滴形成情况,通过液体闪烁计数法测定THP-1源性泡沫细胞内胆固醇流出情况,酶荧光法检测细胞内游离胆固醇及胆固醇酯的含量,并分别用Western blot法及RT-qPCR法检测酰基辅酶A:胆固醇酰基转移酶1(ACAT1)和ATP结合盒转运体A1(ABCA1)的蛋白及mRNA表达。结果:可溶性KL蛋白能增加THP-1源性巨噬细胞内胆固醇流出,抑制THP-1源性泡沫细胞形成,且可溶性KL蛋白呈一定浓度依赖性地抑制ox-LDL诱导的泡沫细胞形成过程中ACAT1表达的上调和ABCA1表达的下调(P<0.05)。结论:可溶性KL蛋白能够抑制THP-1源性泡沫细胞形成,其机制可能与靶向调控细胞内ACAT1和ABCA1的表达有关。

丹红注射液对U937细胞SR-AⅠ及ABCA1 mRNA表达的影响

目的以人单核细胞株U937细胞为研究对象,观察不同浓度丹红注射液对U937细胞清道夫受体AⅠ(SR-AⅠ)和ATP结合盒转运体A1(ABCA1)mRNA表达的影响,探讨其抗动脉粥样硬化的机制。方法以100nmol/L佛波酯诱导U937细胞48h使其分化为巨噬细胞,再以50mg/L ox-LDL(氧化低密度脂蛋白)孵育细胞的同时加入不同浓度丹红注射液或其他干预因素处理24h,用实时荧光定量PCR方法检测其SR-AⅠ和ABCA1mR-NA的表达量。结果与50mg/L ox-LDL组比较,LXR-a(肝X受体激动剂)(T-090137)干预组U937细胞SR-AⅠmRNA表达下降、ABCA1mRNA表达升高,但SR-AⅠmRNA的表达无统计学意义(P>0.05),而ABCA1mRNA的表达有统计学意义(P<0.01);3.0mL/L丹红注射液干预组U937细胞SR-AⅠmRNA的表达升高,10.0、30.0、60.0mL/L丹红注射液干预组U937细胞SR-AⅠmRNA的表达逐渐下降,但各浓度组均无统计学意义(P>0.05);丹红注射液干预组ABCA1mRNA的表达则呈浓度依赖性升高,但于60.0mL/L浓度时出现表达下降,3.0、10.0、30.0mL/L干预组有统计学意义(P<0.05)。与LXR-a(肝X受体激动剂)(T-090137)干预组比较,丹红注射液各浓度干预组ABCA1mRNA表达降低,10.0、30.0mL/L丹红注射液干预组ABCA1mRNA的表达无统计学意义(P>0.05)。结论丹红注射液各浓度组对50mg/L ox-LDL干预的U937细胞SR-AⅠmRNA的表达无影响,而明显增加U937细胞ABCA1mRNA表达,尤其在浓度10.0、30.0mL/L时增加ABCA1mRNA表达明显。增加U937细胞ABCA1mRNA表达可能是其抗动脉粥样硬化的重要机制。

载脂蛋白A-Ⅰ对巨噬细胞源泡沫细胞单核细胞趋化蛋白-1、血管细胞黏附分子-1和三磷酸腺苷结合盒转运子1表达的影响

目的探讨载脂蛋白A-Ⅰ(apoA-Ⅰ)对巨噬细胞源泡沫细胞单核细胞趋化因子-1(MCP-1)、血管细胞黏附分子-1(VCAM-1)及三磷酸腺苷结合盒转运子(ABCA1)表达的影响。方法以佛波酯(PMA)及氧化型低密度脂蛋白(ox-LDL)诱导人急性单核细胞白血病细胞株(THP-1),使其分化为负脂的泡沫细胞,然后用apoA-Ⅰ(10 mg/L)或ABCA1抗体(10 mg/L)孵育泡沫细胞24 h。采用免疫荧光法检测巨噬细胞及经apoA-Ⅰ及ABCA1抗体干预前后泡沫细胞MCP-1、VCAM-1及ABCA1的表达,并行半定量分析。结果①经ox-LDL50 mg/L干预后,与巨噬细胞相比,泡沫细胞内MCP-1、VCAM-1及ABCA1表达均明显增强。②与未干预组相比,经apoA-Ⅰ10 mg/L干预后,泡沫细胞内MCP-1及VCAM-1表达显著减少(P值均<0.05),而ABCA1表达明显增加(P值均<0.05);经ABCA1抗体10 mg/L干预后,泡沫细胞内MCP-1的表达显著增加(P值均<0.05),VCAM-1表达有增加趋势,但差异无统计学意义(P>0.05)。结论apoA-Ⅰ可能通过增加泡沫细胞ABCA1和降低MCP-1及VCAM-1蛋白的表达发挥其抗动脉粥样硬化和抗炎作用,ABCA1通道可能在降低泡沫细胞内MCP-1表达方面发挥一定作用。

New insights into renal lipid dysmetabolism in diabetic kidney disease

Lipid dysmetabolism is one of the main features of diabetes mellitus and manifests by dyslipidemia as well as the ectopic accumulation of lipids in various tissues and organs,including the kidney.Research suggests that impaired cholesterol metabolism,increased lipid uptake or synthesis,increased fatty acid oxidation,lipid droplet accumulation and an imbalance in biologically active sphingolipids(such as ceramide,ceramide-1-phosphate and sphingosine-1-phosphate)contribute to the development of diabetic kidney disease(DKD).Currently,the literature suggests that both quality and quantity of lipids are associated with DKD and contribute to increased reactive oxygen species production,oxidative stress,inflammation,or cell death.Therefore,control of renal lipid dysmetabolism is a very important therapeutic goal,which needs to be archived.This article will review some of the recent advances leading to a better understanding of the mechanisms of dyslipidemia and the role of particular lipids and sphingolipids in DKD.