ATP-binding cassette transporters in progression and clinical outcome of pancreatic cancer: what is the way forward?

Pancreatic ductal adenocarcinoma(PDAC) is one of the most aggressive diseases and is characterized by high chemoresistance, leading to the lack of effective therapeutic approaches and grim prognosis. Despite increasing understanding of the mechanisms of chemoresistance in cancer and the role of ATPbinding cassette(ABC) transporters in this resistance, the therapeutic potential of their pharmacological inhibition has not been successfully exploited yet. In spite of the discovery of potent pharmacological modulators of ABC transporters, the results obtained in clinical trials have been so far disappointing, with high toxicity levels impairing their successful administration to the patients. Critically, although ABC transporters have been mostly studied for their involvement in development of multidrug resistance(MDR), in recent years the contribution of ABC transporters to cancer initiation and progression has emerged as an important area of research, the understanding of which could significantly influence the development of more specific and efficient therapies. In this review, we explore the role of ABC transporters in the development and progression of malignancies, with focus on PDAC. Their established involvement in development of MDR will be also presented. Moreover, an emerging role for ABC transporters as prognostic tools for patients' survival will be discussed, demonstrating the therapeutic potential of ABC transporters in cancer therapy.

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.

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.

ATP-binding cassette subfamily B member 1 (ABCB1) and subfamily C member 10(ABCC1O) are not primary resistance factors for cabazitaxel

Introduction:ATP-binding cassette subfamily B member 1(ABCB1) and subfamily C member 10(ABCCIO) proteins are efflux transporters that couple the energy derived from ATP hydrolysis to the translocation of toxic substances and chemotherapeutic drugs out of cells.Cabazitaxel is a novel taxane that differs from paclitaxel by its lower affinity for ATP-binding cassette(ABC) transporters.Methods:We determined the effects of cabazitaxel,a novel tubulin-binding taxane,and paclitaxel on paclitaxelresistant,ABCB1-overexpressing KB-C2 and LLC-MDR1-WT cells and paclitaxel-resistant,ABCC10-overexpressing HEK293/ABCC10 cells by calculating the degree of drug resistance and measuring ATPase activity of the ABCB1 transporter.Results:Decreased resistance to cabazitaxel compared with paclitaxel was observed in KB-C2,LLC-MDR1-WT,and HEK293/ABCC10 cells.Moreover,cabazitaxel had low efficacy,whereas paclitaxel had high efficacy in stimulating the ATPase activity of ABCB1,indicating a direct interaction of both drugs with the transporter.Conclusion:ABCB1 and ABCC10 are not primary resistance factors for cabazitaxel compared with paclitaxel,suggesting that cabazitaxel may have a low affinity for these efflux transporters.

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.

Novel understanding of ABC transporters ABCB1/MDR/P-glycoprotein, ABCC2/MRP2, and ABCG2/BCRP in colorectal pathophysiology

AIM: To evaluate ATP-binding cassette(ABC) transporters in colonic pathophysiology as they had recently been related to colorectal cancer(CRC) development. METHODS: Literature search was conducted on Pub Med using combinations of the following terms: ABC transporters, ATP binding cassette transporter proteins, inflammatory bowel disease, ulcerative, colitis, Crohns disease, colorectal cancer, colitis, intestinal inflammation, intestinal carcinogenesis, ABCB1/P-glycoprotein(P-gp/CD243/MDR1), ABCC2/multidrug resistance protein 2(MRP2) and ABCG2/breast cancer resistance protein(BCRP), Abcb1/Mdr1 a, abcc2/Mrp2, abcg2/Bcrp, knock-out mice, tight junction, membrane lipid function. RESULTS: Recently, human studies reported thatchanges in the levels of ABC transporters were early events in the adenoma-carcinoma sequence leading to CRC. A link between ABCB1, high fat diet and gut microbes in relation to colitis was suggested by the animal studies. The finding that colitis was preceded by altered gut bacterial composition suggests that deletion of Abcb1 leads to fundamental changes of hostmicrobiota interaction. Also, high fat diet increases the frequency and severity of colitis in specific pathogenfree Abcb1 KO mice. The Abcb1 KO mice might thus serve as a model in which diet/environmental factors and microbes may be controlled and investigated in relation to intestinal inflammation. Potential molecular mechanisms include defective transport of inflammatory mediators and/or phospholipid translocation from one side to the other of the cell membrane lipid bilayer by ABC transporters affecting inflammatory response and/or function of tight junctions, phagocytosis and vesicle trafficking. Also, diet and microbes give rise to molecules which are potential substrates for the ABC transporters and which may additionally affect ABC transporter function through nuclear receptors and transcriptional regulation. Another critical role of ABCB1 was suggested by the finding that ABCB1 expression identifies a subpopulation of pro-inflammatory Th17 cells which were resistant to treatment with glucocorticoids. The evidence for the involvement of ABCC2 and ABCG2 in colonic pathophysiology was weak. CONCLUSION: ABCB1, diet, and gut microbes mutually interact in colonic inflammation, a well-known risk factor for CRC. Further insight may be translated into preventive and treatment strategies.

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.

ABC efflux transporters at blood-central nervous system barriers and their implications for treating spinal cord disorders

The barriers present in the interfaces between the blood and the central nervous system form a major hurdle for the pharmacological treatment of central nervous system injuries and diseases.The family of ATP-binding cassette(ABC)transporters has been widely studied regarding efflux of medications at blood-central nervous system barriers.These efflux transporters include P-glycoprotein(abcb1),‘breast cancer resistance protein'(abcg2)and the various‘multidrug resistance-associated proteins'(abccs).Understanding which efflux transporters are present at the blood-spinal cord,blood-cerebrospinal fluid and cerebrospinal fluid-spinal cord barriers is necessary to determine their involvement in limiting drug transfer from blood to the spinal cord tissue.Recent developments in the blood-brain barrier field have shown that barrier systems are dynamic and the profile of barrier defenses can alter due to conditions such as age,disease and environmental challenge.This means that a true understanding of ABC efflux transporter expression and localization should not be one static value but instead a range that represents the complex patient subpopulations that exist.In the present review,the blood-central nervous system barrier literature is discussed with a focus on the impact of ABC efflux transporters on:(i)protecting the spinal cord from adverse effects of systemically directed drugs,and(ii)limiting centrally directed drugs from accessing their active sites within the spinal cord.

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.

自然衰老型小鼠海马及肝脏组织中胆固醇转运相关蛋白表达的研究

目的研究自然衰老型小鼠海马及肝脏组织胆固醇转运相关蛋白表达变化,观察衰老对胆固醇转运的影响。方法选取清洁级雄性昆明小鼠1月龄10只,10月龄10只。1月龄小鼠为对照组,10月龄小鼠为老年组,饲养7 d后,采用Y字迷宫检测小鼠行为学及记忆,采用免疫组化检测肝脏脂肪酸合酶(FASN)蛋白表达变化、海马载脂蛋白E(ApoE)蛋白表达变化,采用ELISA法检测总胆固醇、三酰甘油、高密度胆固醇及低密度胆固醇含量变化,采用Western Blot法检测肝脏三磷酸腺苷结合盒转运体A1(ABCA1)、低密度脂蛋白受体(LDLR)蛋白和海马ABCA1蛋白、ApoE蛋白表达变化。结果老年组小鼠出现摄食量减少、懒动及反应较迟钝的表现。老年组小鼠的总进臂次数和交替次数少于对照组,差异有统计学意义(P<0.05)。老年组小鼠的高密度脂蛋白胆固醇含量低于对照组,三酰甘油和低密度脂蛋白胆固醇高于对照组,差异有统计学意义(P<0.05)。老年组小鼠肝脏的FASN、LDLR和ABCA1水平低于对照组,海马组织的ApoE蛋白表达高于对照组,ABCA1蛋白表达低于对照组,差异有统计学意义(P<0.05)。结论老年组小鼠外周及中枢胆固醇代谢出现异常,可能与肝脏及海马ABCA1蛋白、ApoE蛋白、LDLR蛋白表达异常有关。

建立检测猕猴三磷酸腺苷结合盒转运蛋白G2的mRNA相对表达水平的RT-qPCR方法

目的本研究旨在建立一种实时荧光定量PCR方法,用于检测猕猴三磷酸腺苷结合盒转运蛋白G2(adenosine triphosphate-binding cassette transporter protein G2,ABCG2)mRNA的基因转录水平。方法使用NCBI上GenBank数据库猕猴(Macaca mulatta)的ABCG2核苷酸序列号NM_001032919.1及内参GAPDH核苷酸序列号NM_001195426.1,借助Primer premier 5.0软件设计PCR引物。提取猕猴新鲜肾组织的总RNA,并反转录合成cDNA。接着,利用PCR引物进行实时荧光定量PCR扩增,并根据反应体系中荧光的变化情况定量分析ABCG2的mRNA相对表达水平。结果PCR产物测序结果显示,扩增的ABCG2和GAPDH核苷酸序列与NCBI上猕猴的序列同源性分别为90.91%和91.14%。ABCG2和GAPDH的扩增效率均达到80%~120%,实时荧光定量PCR标准曲线的熔解曲线为单峰,R2接近1。结论本研究建立的检测猕猴ABCG2 mRNA实时荧光定量检测方法,为研究高尿酸血症的发病机制以及新药开发奠定基础。

ATP-binding cassette transporter enhances tolerance to DDT in Tetrahymena

The reuse of dichlorodiphenyltrichloroethane(DDT) as an indoor residual spray was permitted by the World Health Organization in 2007, and approximately 14 countries still use DDT to control disease vectors. The extensive exposure of insects to DDT has resulted in the emergence of DDT resistance, especially in mosquitoes, and the mechanism for this resistance in mosquitoes has been widely reported. Spraying can also introduce DDT directly into surface water, and DDT can subsequently accumulate in microorganisms, but the mechanism for the resistance to DDT degradation in microorganisms is unclear. Using whole-genome microarray analysis, we detected an abcb15 gene that was up-regulated in a specific manner by DDT treatment in T. thermophile. The deduced ABCB15 peptide sequence had two transmembrane domains(TMDs) and two nucleotide-binding domains(NBDs) to form the structure TMD-NBD-TMD-NBD, and each NBD contained three conserved motifs: Walker-A, C-loop, and Walker-B, which indicated the T. thermophila abcb15 was a typical ABC transporter gene. The expression of ABCB15 fused with a C-terminal green fluorescent protein was found to be on the periphery of the cell, suggesting that ABCB15 was a membrane pump protein. In addition, cells with abcb15 partially knocked down(abcb15-KD) grew slower than wild-type cells in the presence of 256 mg L-1 DDT, indicating the tolerance of abcb15-KD strain to DDT exposure was decreased. Thus, we suggest that in Tetrahymena, the membrane pump protein encoded by ABCT gene abcb15 can enhance the tolerance to DDT and protect cells from this exogenous toxin by efficiently pumping it to the extracellular space.

荻草谷网蚜ABCG1基因的克隆及表达模式分析

荻草谷网蚜Sitobion miscanthi是严重威胁我国小麦生产安全的迁飞性害虫。蜕皮激素是参与蚜虫翅型分化调控的内激素,在有翅成蚜体内保持高滴度,且诱导后代产生更高比例的无翅蚜,其进出靶细胞需要经过细胞膜上特定蛋白的转运。ATP结合盒转运蛋白家族G亚家族(ATP-binding cassette transporter G, ABCG)中的ABCG1是通过跨膜转运昆虫类固醇、对蜕皮激素信号进行负调控的功能蛋白之一,在蚜虫中尚未见报道。本文克隆了荻草谷网蚜ABCG1(SmisABCG1)基因,并进行了序列比对、系统进化分析以及不同组织部位和发育时期表达模式分析。结果显示,SmisABCG1基因的开放阅读框全长为1 851 bp,编码616个氨基酸,含7个跨膜结构域,符合ABCG蛋白家族典型结构特性,基因登录ID:OP626323。昆虫间ABCG1较保守,该蛋白系统进化关系与各自物种间亲缘关系的远近保持一致。其中,SmisABCG1与来自豌豆蚜、禾谷缢管蚜、棉蚜、花生蚜和雪松长足大蚜等的ABCG1氨基酸序列高度一致(>87%),以上蚜虫聚为一支。与SmisABCG1亲缘关系最近的是豌豆蚜的ABCG1,其次是半翅目的褐飞虱、白背飞虱和灰飞虱,与膜翅目的新疆菜叶蜂、阿里山潜蝇茧蜂以及鞘翅目的赤拟谷盗、蜂箱小甲虫亲缘关系较远。该基因在伪胚胎和成蚜阶段高表达。包含伪胚胎的有翅、无翅成蚜整蚜SmisABCG1的转录水平无显著差异,但其在来自有翅成蚜的伪胚胎中的转录水平高于无翅成蚜伪胚胎,证实无翅成蚜自身的转录水平较高,而有翅成蚜较低。进一步分析显示这一差异主要是无翅蚜胸部显著高表达所导致。基于该蛋白对蜕皮激素负调控,与有翅成蚜转录水平低,但蜕皮激素水平更高相符合。

冠心病患者ABCG1、ANGPTL2启动子区甲基化与心力衰竭发生的关系研究

目的分析冠状动脉粥样硬化性心脏病(冠心病)患者三磷酸腺苷结合盒转运蛋白G1(ABCG1)、血管生成素样蛋白2(ANGPTL2)启动子区甲基化与心力衰竭(心衰)发生的关系。方法选取2020年3月至2022年3月于湖南省第二人民医院收治的冠心病患者120例。根据是否发生心衰,将患者分为合并心衰组(n=26)和不合并心衰组(n=94)。采用全自动生化仪检测血清总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C)。采用心脏超声检查患者左室射血分数(LVEF)、左心室舒张末期内径(LVEDD)、左室收缩末期内径(LVESD)水平。特异性PCR检测ABCG1和ANGPTL2基因甲基化。采用实时荧光定量聚合酶链反应检测ABCG1和ANGPTL2基因mRNA表达水平。Logistic回归分析探讨影响冠心病患者发生心衰的因素。结果两组患者LDL-C、LVEF、LVEDD、LVESD、ABCG1、ANGPTL2基因启动子区甲基化等方面比较,差异具有统计学意义(P<0.05)。LVESD、LVEF、ABCG1甲基化和ANGPTL2甲基化是冠心病患者发生心衰的危险因素。ABCG1甲基化、ANGPLT2甲基化患者中LVESD水平均高于未甲基化患者(P<0.05)。ABCG1甲基化、ANGPLT2甲基化患者中LVEF水平均低于未甲基化患者(P<0.05)。合并组ABCG1、ANGPTL2基因甲基化的患者mRNA的表达量明显低于非甲基化患者(P<0.05)。结论ABCG1和ANGPTL2基因甲基化是冠心病患者发生心衰的危险因素,检测上述两基因甲基化状态可为诊治冠心病心衰提供理论支持。

葛花提取物通过激活PPARγ上调ABCA1的表达而抑制THP-1源性泡沫细胞形成

[目的]探寻葛花提取物(PFE)对巨噬细胞源性泡沫细胞脂质蓄积的影响。[方法]通过MTT法筛选PFE对THP-1源性泡沫细胞的作用浓度,采用油红O染色和胆固醇检测试剂盒检测细胞内脂质蓄积情况,采用胆固醇流出试剂盒检测细胞的胆固醇流出水平,使用RT-qPCR和Western blot检测mRNA和蛋白表达。[结果]PFE显著降低THP-1源性泡沫细胞内的脂质蓄积。PFE不影响CD36、清道夫受体AⅠ(SR-AⅠ)、固醇调节元件结合蛋白2(SREBP2)及3-羟基-3-甲基戊二酰辅酶A还原酶(HMGCR)的mRNA表达,但能上调ATP结合盒转运体A1(ABCA1)的mRNA和蛋白表达水平(P<0.05),促进巨噬细胞源性泡沫细胞胆固醇流出(P<0.01)。PFE可以激活过氧化物酶体增殖物激活受体γ(PPARγ)的活性(P<0.01)及上调其mRNA和蛋白表达水平(P<0.05)。与PFE对照组相比,加入GW9662处理后PPARγ和ABCA1的蛋白表达水平均下降(P<0.01),胆固醇流出水平降低(P<0.01)。[结论]PFE可显著改善THP-1源性泡沫细胞内的脂质蓄积,通过PPARγ上调ABCA1表达及其介导的胆固醇流出抑制泡沫细胞形成。

ABCA3作为非小细胞肺癌的预后生物标志物及其与免疫细胞浸润的相关性

目的 本研究旨在基于生物信息学分析探讨ABCA3在非小细胞肺癌——肺腺癌(lung adenocarcinoma,LUAD)中的临床意义和生物学功能。方法 基于癌症基因组图谱(the Cancer Genome Atlas,TCGA),提取LUAD中ABCA3表达和相应的临床信息。使用R4.2.2软件进行统计分析。采用Wilcoxon符号秩和检验比较TCGA LUAD队列中肿瘤组织与对照组之间ABCA3的表达,以及临床病理参数与ABCA3表达水平之间的关系。根据ABCA3表达的中位数,将TCGA LUAD患者分为高表达组和低表达组。使用survival包和survminer包分析ABCA3与LUAD患者总生存(overall survival,OS)期和无进展生存(progression free survival,PFS)期的关系,并进行单因素和多因素Cox回归分析确定与LUAD预后相关的危险因素。使用rms包构建预测LUAD患者1年、2年和3年OS率的列线图模型。使用DESeq2包对高表达组和低表达组患者进行差异表达基因(differential expressed genes,DEGs)分析,并使用cluster Profil er包对DEGs进行基因本体(Gene Ontology,GO)数据库和基因组京都百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)富集分析。利用CIBERSORT算法预测LUAD肿瘤样本和正常样本中22种浸润性免疫细胞的丰度,并分析ABCA3表达与免疫浸润细胞和免疫检查点之间的相关性。结果 ABCA3基因在LUAD肿瘤组织中的表达均低于配对和非配对样本正常组织(P<0.05)。ABCA3高表达LUAD患者的OS (P=0.031)和PFS (P=0.044)明显高于低表达患者。T2分期(P=0.004)和T3分期(P=0.044)患者ABCA3的表达显著低于T1分期患者。多因素Cox回归分析显示,T分期、N分期和ABCA3表达是影响LUAD预后的独立影响因素(P<0.05)。基于ABCA3表达、T分期和N分期构建的列线图预测模型的C-index为0.86,提示模型与实际结果较为一致。校准曲线中的偏差修正线接近理想曲线,提示列线图模型的预测结果与观测结果较吻合。基因集富集分析显示ABCA3高表达组主要与花生四烯酸代谢、补体和凝血级联、肠道免疫网络免疫球蛋白A产生等有关。ABCA3的表达与NRP1、TRFRSF14、TNFSF15、CD40LG、HHLA2、CD28呈明显正相关,而与IDO1、CD70、TNFSF4、CD276和VTCN1呈明显负相关(P<0.05)。12种免疫浸润细胞在高表达组和低表达组存在明显差异(P<0.05)。此外,14种免疫浸润细胞与ABCA3表达呈现明显相关性(P<0.05),包括巨噬细胞、CD4+T细胞和树突细胞。结论 ABCA3的表达与LUAD患者预后和免疫细胞浸润有关,可能是预测非小细胞肺癌预后的有价值生物标志物。

microRNA在非渗出性年龄相关性黄斑变性氧化应激和脂质代谢中的作用

年龄相关性黄斑变性(ARMD)是一种与氧化应激相关的神经退行性疾病,其特征是光感受器和视网膜色素上皮(RPE)细胞的进行性死亡,是导致65岁以上人群不可逆中心视力丧失最常见的原因之一。microRNA(miRNA)是一类调节性短链非编码RNA,能够结合并抑制同一生物途径中的多个基因,这种独特的性质使其成为用于探索非渗出性ARMD发病机制、诊断和治疗的理想靶点。既往研究发现非渗出性ARMD的发病机制涉及年龄、遗传、环境、氧化应激、脂质代谢、自噬和免疫等多方面,但其发病机制尚未完全阐明。miRNA作为非渗出性ARMD的生物标志物在氧化应激和脂质代谢中发挥重要作用,本文总结了多种miRNA通过靶向Nrf2、HIF-1α抑制缺氧相关的血管生成信号影响氧化应激;miRNA通过调节脂蛋白的摄取、RPE和巨噬细胞中ABCA1的表达影响脂质代谢,加深了对miRNA在非渗出性ARMD氧化应激、脂质代谢方面的认识,为完善非渗出性ARMD发病机制和进一步预防提供了帮助。

Hepatocellular transport proteins and their role in liver disease

MOLECULAR PHYSIOLLGY OF HEPATOCELLULAR TRANSPORT PROTEINS Basolaferal transport systems Na+-dependent bile salt uptake Uptake of bile salts into the liver was first isolated perfused rat liver[1],isolated hepatocyte cultures and basolateral plasma membrane vesicles [2,4].

Drug-transporter interaction testing in drug discovery and development

The human body consists of several physiological barriers that express a number of membrane transporters. For an orally absorbed drug the intestinal, hepatic, renal and blood-brain barriers are of the greatest importance. The ATP-binding cassette(ABC) transporters that mediate cellular efflux and the solute carrier transporters that mostly mediate cellular uptake are the two superfamilies responsible for membrane transport of vast majority of drugs and drug metabolites. The total number of human transporters in the two superfamilies exceeds 400, and about 40-50 transporters have been characterized for drug transport. The latest Food and Drug Administration guidance focuses on P-glycoprotein, breast cancer resistance protein, organic anion transporting polypeptide 1B1(OATP1B1), OATP1B3, organic cation transporter 2(OCT2), and organic anion transporters 1(OAT1) and OAT3. The European Medicines Agency's shortlist additionally contains the bile salt export pump, OCT1, and the multidrug and toxin extrusion transporters, multidrug and toxin ex-trusion protein 1(MATE1) and MATE2/MATE2 K. A variety of transporter assays are available to test drugtransporter interactions, transporter-mediated drugdrug interactions, and transporter-mediated toxicity. The drug binding site of ABC transporters is accessible from the cytoplasm or the inner leaflet of the plasma membrane. Therefore, vesicular transport assays utilizing inside-out vesicles are commonly used assays, where the directionality of transport results in drugs being transported into the vesicle. Monolayer assays utilizing polarized cells expressing efflux transporters are the test systems suggested by regulatory agencies. However, in some monolayers, uptake transporters must be coexpressed with efflux transporters to assure detectable transport of low passive permeability drugs. For uptake transporters mediating cellular drug uptake, utilization of stable transfectants have been suggested. In vivo animal models complete the testing battery. Some issues, such as in vivo relevance, gender difference, age and ontogeny issues can only be addressed using in vivo models. Transporter specificity is provided by using knock-out or mutant models. Alternatively, chemical knock-outs can be employed. Compensatory changes are less likely when using chemical knockouts. On the other hand, specific inhibitors for some uptake transporters are not available, limiting the options to genetic knock-outs.