scholarly journals ATP-binding cassette transporter Abcg2 lineage contributes to the cardiac vasculature after oxidative stress

2014 ◽  
Vol 306 (12) ◽  
pp. H1610-H1618 ◽  
Author(s):  
Travis J. Maher ◽  
Yi Ren ◽  
Qinglu Li ◽  
Elizabeth Braunlin ◽  
Mary G. Garry ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Immunohistochemical Analysis ◽  
Atp Binding ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Systemic Oxidative Stress ◽  
Atp Binding Cassette Transporter ◽  
Atp Binding Cassette

Due to their specialized location, stem and progenitor cells are often exposed to oxidative stress. Although ATP-binding cassette transporter subfamily G member 2 (Abcg2)-expressing cells have been implicated in cardiac protective mechanisms involving oxidative stress, there remains a lack of understanding regarding the behavior of cardiac Abcg2-expressing cells when exposed to ROS. The aim of the present study was to characterize the response of the cardiac Abcg2 lineage to oxidative stress. In vitro analysis demonstrated that the antioxidant program regulated by Abcg2 is dependent on a functional transporter. Delivery of paraquat dichloride (PQ), a systemic oxidative stress-inducing agent, to mice confirmed that Abcg2 provides a survival benefit. When exposed to PQ, reporter mice showed an increase in the Abcg2 lineage. Transcriptional and immunohistochemical analysis of Abcg2 lineage-positive cells revealed an enhanced vascular commitment after stress. Finally, preconditioning with PQ demonstrated a reduction in scar size and an increase in angiogenesis after permanent left coronary artery ligation. In conclusion, the data suggest that Abcg2 plays a cytoprotective role in response to in vivo oxidative stress. The contribution of the Abcg2 lineage to the vasculature in the heart is increased after PQ delivery.

scholarly journals Aucubin Protects against Myocardial Infarction-Induced Cardiac Remodeling via nNOS/NO-Regulated Oxidative Stress

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Zheng Yang ◽  
Qing-Qing Wu ◽  
Yang Xiao ◽  
Ming Xia Duan ◽  
Chen Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Cardiac Remodeling ◽  
Coronary Artery Ligation ◽  
No Production ◽  
Protective Effects ◽  
Artery Ligation ◽  
Nos Inhibitors

Whether aucubin could protect myocardial infarction- (MI-) induced cardiac remodeling is not clear. In this study, in a mouse model, cardiac remodeling was induced by left anterior descending coronary artery ligation surgery. Mice were intraperitoneally injected with aucubin (10 mg/kg) 3 days post-MI. Two weeks post-MI, mice in the aucubin treatment group showed decreased mortality, decreased infarct size, and improved cardiac function. Aucubin also decreased cardiac remodeling post-MI. Consistently, aucubin protected cardiomyocytes against hypoxic injury in vitro. Mechanistically, we found that aucubin inhibited the ASK1/JNK signaling. These effects were abolished by the JNK activator. Moreover, we found that the oxidative stress was attenuated in both in vivo aucubin-treated mice heart and in vitro-treated cardiomyocytes, which caused decreased thioredoxin (Trx) consumption, leading to ASK1 forming the inactive complex with Trx. Aucubin increased nNOS-derived NO production in vivo and vitro. The protective effects of aucubin were reversed by the NOS inhibitors L-NAME and L-VINO in vitro. Furthermore, nNOS knockout mice also reversed the protective effects of aucubin on cardiac remodeling. Taken together, aucubin protects against cardiac remodeling post-MI through activation of the nNOS/NO pathway, which subsequently attenuates the ROS production, increases Trx preservation, and leads to inhibition of the ASK1/JNK pathway.

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 Water-Pipe Smoke Exposure-Induced Circulatory Disturbances in Mice, and the Influence of Betaine Supplementation Thereon

2017 ◽  
Vol 41 (3) ◽  
pp. 1098-1112 ◽  
Author(s):  
Abderrahim Nemmar ◽  
Suhail Al-Salam ◽  
Sumaya Beegam ◽  
Priya Yuvaraju ◽  
Abderrahim Oulhaj ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Plasma Concentrations ◽  
Immunohistochemical Analysis ◽  
Plasminogen Activator Inhibitor ◽  
Water Pipe ◽  
Plasminogen Activator Inhibitor 1 ◽  
Factor Α ◽  
Air Control

Background/Aims: It has been shown, both experimentally and clinically, that water-pipe smoke (WPS) exposure adversely affects the cardiovascular system (CVS) through the generation of oxidative stress and inflammation. Betaine, a naturally occurring compound in common foods, has antioxidant and anti-inflammatory actions. However, its potential to mitigate the adverse effect of WPS on the CVS has never been reported before. This is the subject of this study in mice. Methods: Mice were exposed daily for 30 min to either normal air (control), or to WPS for two consecutive weeks. Betaine was administered daily by gavage at a dose of 10mg/kg, 1h before either air or WPS exposure. Results: Betaine mitigated the in vivo prothrombotic effect of WPS in pial arterioles and venules. Moreover, it reversed the WPS-induced decrease in circulating platelets. Likewise, betaine alleviated platelet aggregation in vitro, and the shortening of activated partial thromboplastin time and prothrombin time induced by WPS. Betaine reduced the increase of plasminogen activator inhibitor-1 and fibrinogen concentrations in plasma induced by WPS. Betaine also diminished the WPS-induced increase of plasma concentrations of interleukin 6 and tumor necrosis factor α, and attenuated the increase of lipid peroxidation and superoxide dismutase. Immunohistochemical analysis of the heart revealed an increase in the expression of inducible nitric oxide synthase and cytochrome C by cardiomyocytes of the WPS-exposed mice. These effects were averted by betaine. Conclusion: Our findings suggest that betaine treatment significantly mitigated WPS-induced hypercoagulability, and inflammation, as well as systemic and cardiac oxidative stress.

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.

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