scholarly journals Lactobacillus plantarum CUL66 can impact cholesterol homeostasis in Caco-2 enterocytes

2016 ◽  
Vol 7 (3) ◽  
pp. 443-451 ◽  
Author(s):  
D.R. Michael ◽  
J.W.E. Moss ◽  
D. Lama Calvente ◽  
I. Garaiova ◽  
S.F. Plummer ◽  
...  
Keyword(s):  
Lactobacillus Plantarum ◽  
Cholesterol Metabolism ◽  
Culture Media ◽  
Cholesterol Homeostasis ◽  
In Vivo Studies ◽  
Western Society ◽  
Bile Salt Hydrolase ◽  
Atp Binding ◽  
Atp Binding Cassette

Hypercholesterolemia drives the development of cardiovascular disease, the leading cause of mortality in western society. Supplementation with probiotics that interfere with cholesterol metabolism may provide a contribution to disease prevention. Lactobacillus plantarum CUL66 (NCIMB 30280) has been assessed in vitro for its ability to impact cholesterol absorption. L. plantarum CUL66 tested positive for bile salt hydrolase activity and the ability to assimilate cholesterol from culture media. RT-qPCR analysis showed that the bacterium significantly decreased the expression of Niemann-Pick C1-like 1 and ATP-binding cassette transporter-1 in polarised Caco-2 cells after 6 h exposure. Conversely, the expression of ATP-binding cassette sub-family G member (ABCG)-5 and ABCG-8, and 3-hydroxy-3-methylglutaryl-CoA reductase were significantly increased. Using a radiolabelled assay, we also observed significant reductions in the uptake and basolateral efflux of cholesterol by Caco-2 cells exposed to L. plantarum CUL66. This in vitro study identified L. plantarum CUL66 as a cholesterol lowering bacteria by highlighting its ability to beneficially regulate multiple in vitro events associated with intestinal cholesterol metabolism and provides evidence of efficacy for its inclusion in future in vivo studies.

scholarly journals A Selective ATP-Binding Cassette Subfamily G Member 2 Efflux Inhibitor Revealed via High-Throughput Flow Cytometry

2012 ◽  
Vol 18 (1) ◽  
pp. 26-38 ◽  
Author(s):  
J. Jacob Strouse ◽  
Irena Ivnitski-Steele ◽  
Hadya M. Khawaja ◽  
Dominique Perez ◽  
Jerec Ricci ◽  
...  
Keyword(s):  
Molecular Probes ◽  
Atp Binding ◽  
Specific Substrate ◽  
Tumor Resistance ◽  
Drug Concentrations ◽  
Efflux Inhibition ◽  
Substrate Inhibitor ◽  
Atp Binding Cassette

Chemotherapeutics tumor resistance is a principal reason for treatment failure, and clinical and experimental data indicate that multidrug transporters such as ATP-binding cassette (ABC) B1 and ABCG2 play a leading role by preventing cytotoxic intracellular drug concentrations. Functional efflux inhibition of existing chemotherapeutics by these pumps continues to present a promising approach for treatment. A contributing factor to the failure of existing inhibitors in clinical applications is limited understanding of specific substrate/inhibitor/pump interactions. We have identified selective efflux inhibitors by profiling multiple ABC transporters against a library of small molecules to find molecular probes to further explore such interactions. In our primary screening protocol using JC-1 as a dual-pump fluorescent reporter substrate, we identified a piperazine-substituted pyrazolo[1,5-a]pyrimidine substructure with promise for selective efflux inhibition. As a result of a focused structure-activity relationship (SAR)–driven chemistry effort, we describe compound 1 (CID44640177), an efflux inhibitor with selectivity toward ABCG2 over ABCB1. Compound 1 is also shown to potentiate the activity of mitoxantrone in vitro as well as preliminarily in vivo in an ABCG2-overexpressing tumor model. At least two analogues significantly reduce tumor size in combination with the chemotherapeutic topotecan. To our knowledge, low nanomolar chemoreversal activity coupled with direct evidence of efflux inhibition for ABCG2 is unprecedented.

scholarly journals Endocrine Disruptors Differentially Target ATP-Binding Cassette Transporters in the Blood-Testis Barrier and Affect Leydig Cell Testosterone Secretion In Vitro

2013 ◽  
Vol 136 (2) ◽  
pp. 382-391 ◽  
Author(s):  
Anita C. A. Dankers ◽  
Maarke J. E. Roelofs ◽  
Aldert H. Piersma ◽  
Fred C. G. J. Sweep ◽  
Frans G. M. Russel ◽  
...  
Keyword(s):  
Endocrine Disruptors ◽  
Leydig Cell ◽  
Atp Binding ◽  
Testosterone Secretion ◽  
Atp Binding Cassette Transporters ◽  
Blood Testis Barrier ◽  
Atp Binding Cassette

Evaluation of Annona muricata (Graviola) leaves activity against experimental trichinellosis: in vitro and in vivo studies

2021 ◽  
Vol 95 ◽  
Author(s):  
E.S. El-Wakil ◽  
H.F. Abdelmaksoud ◽  
T.S. AbouShousha ◽  
M.M.I. Ghallab
Keyword(s):  
Culture Media ◽  
Trichinella Spiralis ◽  
Drug Effects ◽  
In Vivo Studies ◽  
Control Group ◽  
Annona Muricata ◽  
Group I ◽  
Small Intestinal

Abstract Our work aimed to evaluate the possible effect of Annona muricata (Graviola) leaf extract on Trichinella spiralis in in vitro and in vivo studies. Trichinella spiralis worms were isolated from infected mice and transferred to three culture media – group I (with no drugs), group II (contained Graviola) and group III (contained albendazole) – then they were examined using the electron microscope. In the in vivo study, mice were divided into five groups: GI (infected untreated), GII (prophylactically treated with Graviola for seven days before infection), GIII (infected and treated with Graviola), GIV (infected and treated with albendazole) and GV (infected and treated with a combination of Graviola plus albendazole in half doses). Drug effects were assessed by adults and larvae load beside the histopathological small intestinal and muscular changes. A significant reduction of adult and larval counts occurred in treated groups in comparison to the control group. Histopathologically, marked improvement in the small intestinal and muscular changes was observed in treated groups. Also, massive destruction of the cultured adults’ cuticle was detected in both drugs. This study revealed that Graviola leaves have potential activity against trichinellosis, especially in combination with albendazole, and could serve as an adjuvant to anti-trichinellosis drug therapy.

scholarly journals Dichlorodiphenyltrichloroethane Impairs Amyloid Beta Clearance by Decreasing Liver X Receptor α Expression

2021 ◽  
Vol 13 ◽  
Author(s):  
Dongmei Wu ◽  
Yang Hu ◽  
Min Song ◽  
Gongbo Li
Keyword(s):  
Amyloid Beta ◽  
Critical Role ◽  
Liver X Receptor ◽  
Dynamics Simulation ◽  
Atp Binding ◽  
Atp Binding Cassette Transporter ◽  
Liver X Receptor Α ◽  
Aβ Clearance ◽  
Atp Binding Cassette

Abnormal amyloid beta (Aβ) clearance is a distinctive pathological mechanism for Alzheimer’s disease (AD). ATP-binding cassette transporter A1 (ABCA1), which mediates the lipidation of apolipoprotein E, plays a critical role in Aβ clearance. As an environmental factor for AD, dichlorodiphenyltrichloroethane (DDT) can decrease ATP-binding cassette transporter A1 (ABCA1) expression and disrupt Aβ clearance. Liver X receptor α (LXRα) is an autoregulatory transcription factor for ABCA1 and a target of some environmental pollutants, such as organophosphate pesticides. In this study, we aimed to investigate whether DDT could affect Aβ clearance by targeting LXRα. The DDT-pretreated H4 human neuroglioma cells and immortalized astrocytes were incubated with exogenous Aβ to evaluate Aβ consumption. Meanwhile, cytotoxicity and LXRα expression were determined in the DDT-treated cells. Subsequently, the antagonism of DDT on LXRα agonist T0901317 was determined in vitro. The interaction between DDT and LXRα was predicted by molecular docking and molecular dynamics simulation technology. We observed that DDT could inhibit Aβ clearance and decrease the levels of LXRα mRNA and LXRα protein. Moreover, DDT is supposed to strongly bind to LXRα and exert antagonistic effects on LXRα. In conclusion, this study firstly presented that DDT could inhibit LXRα expression, which would contribute to Aβ clearance decline in vitro. It provides an experimental basis to search for potential therapeutic targets of AD.

scholarly journals NtcA-Dependent Expression of the devBCAOperon, Encoding a Heterocyst-Specific ATP-Binding Cassette Transporter in Anabaena spp

2001 ◽  
Vol 183 (12) ◽  
pp. 3795-3799 ◽  
Author(s):  
Gabriele Fiedler ◽  
Alicia M. Muro-Pastor ◽  
Enrique Flores ◽  
Iris Maldener
Keyword(s):  
Nitrogen Deficiency ◽  
Transcriptional Regulator ◽  
Atp Binding ◽  
Translation Start Site ◽  
Atp Binding Cassette Transporter ◽  
Translation Start ◽  
Transcriptional Start Point ◽  
Pcc 7120 ◽  
Atp Binding Cassette

ABSTRACT The devBCA operon, encoding subunits of an ATP-binding cassette exporter, is essential for differentiation of N2-fixing heterocysts in Anabaena spp. Nitrogen deficiency-dependent transcription of the operon and the use of its transcriptional start point, located 762 (Anabaena variabilis strain ATCC 29413-FD) or 704 (Anabaena sp. strain PCC 7120) bp upstream of the translation start site, were found to require the global nitrogen transcriptional regulator NtcA. Furthermore, NtcA was shown to bind in vitro to the promoter ofdevBCA.

scholarly journals Role of ATP-Binding-Cassette Transporter Genes in High-Frequency Acquisition of Resistance to Azole Antifungals in Candida glabrata

2001 ◽  
Vol 45 (4) ◽  
pp. 1174-1183 ◽  
Author(s):  
Dominique Sanglard ◽  
Francoise Ischer ◽  
Jacques Bille
Keyword(s):  
Abc Transporter ◽  
High Frequency ◽  
Candida Glabrata ◽  
Antifungal Agents ◽  
Clinical Isolates ◽  
Azole Resistance ◽  
Atp Binding ◽  
Transporter Gene ◽  
Atp Binding Cassette

ABSTRACT Candida glabrata has been often isolated from AIDS patients with oropharyngeal candidiasis treated with azole antifungal agents, especially fluconazole. We recently showed that the ATP-binding-cassette (ABC) transporter gene CgCDR1 was upregulated in C. glabrata clinical isolates resistant to azole antifungal agents (D. Sanglard, F. Ischer, D. Calabrese, P. A. Majcherczyk, and J. Bille, Antimicrob. Agents Chemother. 43:2753–2765, 1999). Deletion of CgCDR1 in C. glabrata rendered the null mutant hypersusceptible to azole derivatives and showed the importance of this gene in mediating azole resistance. We observed that wild-type C. glabrata exposed to fluconazole in a medium containing the drug at 50 μg/ml developed resistance to this agent and other azoles at a surprisingly high frequency (2 × 10−4 to 4 × 10−4). We show here that this high-frequency azole resistance (HFAR) acquired in vitro was due, at least in part, to the upregulation ofCgCDR1. The CgCDR1 deletion mutant DSY1041 could still develop HFAR but in a medium containing fluconazole at 5 μg/ml. In the HFAR strain derived from DSY1041, a distinct ABC transporter gene similar to CgCDR1, calledCgCDR2, was upregulated. This gene was slightly expressed in clinical isolates but was upregulated in strains with the HFAR phenotype. Deletion of both CgCDR1 and CgCDR2suppressed the development of HFAR in a medium containing fluconazole at 5 μg/ml, showing that both genes are important mediators of resistance to azole derivatives in C. glabrata. We also show here that the HFAR phenomenon was linked to the loss of mitochondria in C. glabrata. Mitochondrial loss could be obtained by treatment with ethidium bromide and resulted in acquisition of resistance to azole derivatives without previous exposure to these agents. Azole resistance obtained in vitro by HFAR or by agents stimulating mitochondrial loss was at least linked to the upregulation of both CgCDR1 and CgCDR2.

scholarly journals Evidence for a Role of the Adenosine 5′-Triphosphate-Binding Cassette Transporter A1 in the Externalization of Annexin I from Pituitary Folliculo-Stellate Cells

Endocrinology ◽  
2003 ◽  
Vol 144 (3) ◽  
pp. 1062-1073 ◽  
Author(s):  
Lee P. Chapman ◽  
Matthew J. Epton ◽  
Julia C. Buckingham ◽  
John F. Morris ◽  
Helen C. Christian
Keyword(s):  
Abc Transporters ◽  
Anterior Pituitary ◽  
Signal Sequence ◽  
Atp Binding ◽  
Annexin I ◽  
Adenocarcinoma Cells ◽  
Inhibitory Feedback ◽  
Immunofluorescence Labeling ◽  
Atp Binding Cassette

Annexin 1 (ANXA1) has a well-demonstrated role in early delayed inhibitory feedback of glucocorticoids in the pituitary. ANXA1 is located in folliculo-stellate (FS) cells, and glucocorticoids act on these cells to externalize and stimulate the synthesis of ANXA1. However, ANXA1 lacks a signal sequence so the mechanism by which ANXA1 is externalized from FS cells was unknown and has been investigated. The ATP-binding cassette (ABC) transporters are a large group of transporters with varied roles that include the externalization of proteins. Glucocorticoid-induced externalization of ANXA1 from an FS cell line (TtT/GF) and rat anterior pituitary was blocked by glyburide, which inhibits ABC transporters. Glyburide also blocked the glucocorticoid inhibition of forskolin-stimulated ACTH release from pituitary tissue in vitro. RT-PCR revealed mRNA and Western blotting demonstrated protein for the ATP binding cassette A1 (ABCA1) transporter in mouse FS, TtT/GF, and A549 lung adenocarcinoma cells from which glucocorticoids also induce externalization of ANXA1. In TtT/GF cells, immunofluorescence labeling revealed a near total colocalization of cell surface ANXA1 and ABCA1. We conclude that ANXA1, which mediates the early delayed feedback of glucocorticoids in the anterior pituitary, is externalized from FS cells by an ABC transporter and that the ABCA1 transporter is a likely candidate.

scholarly journals Human Lupus Plasma Pro-Atherogenic Effects on Cultured Macrophages Are Not Mitigated by Statin Therapy: A Mechanistic LAPS Substudy

Medicina ◽  
2019 ◽  
Vol 55 (9) ◽  
pp. 514 ◽  
Author(s):  
Reiss ◽  
Arain ◽  
Kasselman ◽  
Renna ◽  
Zhen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lupus Erythematosus ◽  
Cholesterol Metabolism ◽  
Lipid Lowering ◽  
Cholesterol Transport ◽  
Atp Binding ◽  
Peroxisome Proliferator ◽  
Atherosclerotic Cardiovascular Disease ◽  
Peroxisome Proliferator Activated Receptor ◽  
Atp Binding Cassette

Background and Objectives: Atherosclerotic cardiovascular disease (CVD) remains a major cause of morbidity and mortality in persons with systemic lupus erythematosus (SLE, lupus). Atherosclerosis, which involves interplay between cholesterol metabolism and cellular inflammatory pathways, is primarily treated with statins since statins have lipid-lowering and anti-inflammatory properties. The Lupus Atherosclerosis Prevention Study (LAPS) was designed to investigate the efficacy of statins against CVD in SLE patients. LAPS demonstrated that 2 years of atorvastatin administration did not reduce atherosclerosis progression in lupus patients. In this LAPs substudy, we use cultured macrophages to explore the atherogenic properties of plasma from LAPS subjects to explain the mechanistic rationale for the inability of statins to reduce CVD in lupus. Materials and Methods: THP-1 differentiated macrophages were treated for 18 h with 10% SLE patient plasma obtained pre- and post-atorvastatin therapy or placebo. Gene expression of the following cholesterol transport genes was measured by qRT-PCR. For efflux—ATP binding cassette transporter (ABC)A1 and ABCG1, 27-hydroxylase, peroxisome proliferator-activated receptor (PPAR)γ, and liver X receptor (LXR)α; and for influx—cluster of differentiation 36 (CD36) and scavenger receptor (ScR)A1. Results: Macrophages exposed to plasma from both statin-treated and placebo-treated groups showed a significant decrease in cholesterol efflux proteins ATP binding cassette (ABC) transporters A1 and ABCG1, an increase in 27-hydroxylase, an increase in the LDL receptor and a decrease in intracellular free cholesterol. No change in influx receptors ScRA1 and CD36, nor nuclear proteins LXRα and PPARγ was observed. Conclusions: Statins do not normalize pro-atherogenic changes induced by lupus and these changes continue to worsen over time. This study provides mechanistic insight into LAPS findings by demonstrating that statins are overall ineffective in altering the balance of cholesterol transport gene expression in human macrophages. Furthermore, our study suggests that statins as a CVD treatment may not be useful in attenuating lipid overload in the SLE environment.

scholarly journals Liver X Receptor β (LXRβ) Interacts Directly with ATP-binding Cassette A1 (ABCA1) to Promote High Density Lipoprotein Formation during Acute Cholesterol Accumulation

2011 ◽  
Vol 286 (22) ◽  
pp. 20117-20124 ◽  
Author(s):  
Masako Hozoji-Inada ◽  
Youichi Munehira ◽  
Kohjiro Nagao ◽  
Noriyuki Kioka ◽  
Kazumitsu Ueda
Keyword(s):  
Translational Regulation ◽  
Cholesterol Efflux ◽  
Density Lipoprotein ◽  
Transcriptional Response ◽  
Liver X Receptor ◽  
Cholesterol Homeostasis ◽  
Atp Binding ◽  
Transcriptional Level ◽  
Cholesterol Accumulation ◽  
Atp Binding Cassette

Cells have evolved multiple mechanisms for maintaining cholesterol homeostasis, and, among these, ATP-binding cassette protein A1 (ABCA1)-mediated cholesterol efflux is highly regulated at the transcriptional level through the activity of the nuclear receptor liver X receptor (LXR). Here, we show that in addition to its well defined role in transcription, LXRβ directly binds to the C-terminal region (2247LTSFL2251) of ABCA1 to mediate its post-translational regulation. In the absence of cholesterol accumulation in the macrophage-like cell line THP-1, the ABCA1-LXRβ complex stably localizes to the plasma membrane, but apolipoprotein A-I (apoA-I) binding or cholesterol efflux does not occur. Exogenously added LXR ligands, which mimic cholesterol accumulation, cause LXRβ to dissociate from ABCA1, thus freeing ABCA1 for apoA-I binding and subsequent cholesterol efflux. Photoaffinity labeling experiments with 8-azido-[α-32P]ATP showed that the interaction of LXRβ with ABCA1 inhibits ATP binding by ABCA1. This is the first study to show that a protein-protein interaction with the endogenous protein suppresses the function of ABC proteins by inhibiting ATP binding. LXRβ can cause a post-translational response by binding directly to ABCA1, as well as a transcriptional response, to maintain cholesterol homeostasis.

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