Inhibition of MRP4 prevents and reverses pulmonary hypertension in mice

Hara, Yannis; Sassi, Yassine; Guibert, Christelle; Gambaryan, Natacha; Dorfmüller, Peter; Eddahibi, Saadia; Lompré, Anne‐Marie; Humbert, Marc; Hulot, Jean‐Sébastien

doi:10.1172/jci45023

Cited by 87 publications

(107 citation statements)

References 62 publications

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“…17 In platelets, MRP4 is located on the membrane of dense (d) granules and, to a lesser extent, the plasma membrane, and could therefore be involved in the transport of molecules, notably adenine nucleotides, from cytosol into dense granules. 18 Depletion of MRP4 on dense granules has been found in some Hermansky-Pudlak syndrome patients, correlating with defective adenine nucleotide storage.…”

Section: Introductionmentioning

confidence: 99%

Impaired platelet activation and cAMP homeostasis in MRP4-deficient mice

Decouture

Dreano

Belleville-Rolland

et al. 2015

Blood

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Key Points• In vivo and in vitro thrombus formation is altered in MRP4-deficient mice.• MRP4 modulates the cAMPprotein kinase A platelet signaling pathway.Molecules that reduce the level of cyclic adenosine 59-monophosphate (cAMP) in the platelet cytosol, such as adenosine 59-diphosphate (ADP) secreted from dense granules, trigger platelet activation. Therefore, any change in the distribution and/or availability of cyclic nucleotides or ADP may interfere with platelet reactivity. In this study, we evaluated the role of multidrug resistance protein 4 (MRP4, or ABCC4), a nucleotide transporter, in platelet functions in vivo and in vitro by investigating MRP4-deficient mice. MRP4 deletion resulted in a slight increase in platelet count but had no impact on platelet ultrastructure. In MRP4-deficient mice, the arterial occlusion was delayed and the tail bleeding time was prolonged. In a model of platelet depletion and transfusion mimicking a platelet-specific knockout, mice injected with MRP4 2/2 platelets also showed a significant increase in blood loss compared with mice injected with wild-type platelets.Defective thrombus formation and platelet activation were confirmed in vitro by studying platelet adhesion to collagen in flow conditions, integrin aIIbb3 activation, washed platelet secretion, and aggregation induced by low concentrations of proteinase-activated receptor 4-activating peptide, U46619, or ADP. We found no role of MRP4 in ADP dense-granule storage, but MRP4 redistributed cAMP from the cytosol to dense granules, as confirmed by increased vasodilator-stimulated phosphoprotein phosphorylation in MRP4-deficient platelets. These data suggest that MRP4 promotes platelet aggregation by modulating the cAMP-protein kinase A signaling pathway, suggesting that MRP4 might serve as a target for novel antiplatelet agents. (Blood. 2015;126(15):1823-1830

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Section: Introductionmentioning

confidence: 99%

Impaired platelet activation and cAMP homeostasis in MRP4-deficient mice

Decouture

Dreano

Belleville-Rolland

et al. 2015

Blood

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“…[27][28][29] For example, the cAMP-induced activation of mice. 29 Based on results from in vitro studies, Li et al 29 suggested that NHERF3 may mediate the association between CFTR and MRP4 in the gut.…”

Section: Discussionmentioning

confidence: 99%

Na+/H+ Exchanger Regulatory Factor 3 Is Critical for Multidrug Resistance Protein 4–Mediated Drug Efflux in the Kidney

Park

Kwak

Riederer

et al. 2014

Journal of the American Society of Nephrology

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Na+ /H + exchanger regulatory factor 3 (NHERF3) is a PSD-95/discs large/ZO-1 (PDZ)-based adaptor protein that regulates several membrane-transporting proteins in epithelia. However, the in vivo physiologic role of NHERF3 in transepithelial transport remains poorly understood. Multidrug resistance protein 4 (MRP4) is an ATP binding cassette transporter that mediates the efflux of organic molecules, such as nucleoside analogs, in the gastrointestinal and renal epithelia. Here, we report that Nherf3 knockout (Nherf3 2/2 ) mice exhibit profound reductions in Mrp4 expression and Mrp4-mediated drug transport in the kidney. A search for the binding partners of the COOH-terminal PDZ binding motif of MRP4 among several epithelial PDZ proteins indicated that MRP4 associated most strongly with NHERF3. When expressed in HEK293 cells, NHERF3 increased membrane expression of MRP4 by reducing internalization of cell surface MRP4 and consequently, augmented MRP4-mediated efflux of adefovir, a nucleoside-based antiviral agent and well known substrate of MRP4. Examination of wild-type and Nherf3 2/2 mice revealed that Nherf3 is most abundantly expressed in the kidney and has a prominent role in modulating Mrp4 levels. Deletion of Nherf3 in mice caused a profound reduction in Mrp4 expression at the apical membrane of renal proximal tubules and evoked a significant increase in the plasma and kidney concentrations of adefovir, with a corresponding decrease in the systemic clearance of this drug. These results suggest that NHERF3 is a key regulator of organic transport in the kidney, particularly MRP4-mediated clearance of drug molecules. Assembly of protein complexes by adaptor proteins with PSD-95/discs large/ZO-1 (PDZ) domains plays an important role in the regulation of many membrane proteins, especially in epithelial and neuronal tissues. 1,2 For example, PDZ-based adapter proteins in epithelia, such as Shank2, synaptic scaffolding molecule (S-SCAM), and Na + /H + exchanger regulatory factors (NHERFs), are known to be involved in the regulation of cell surface expression and the activity of many membrane transporters and receptors in the respiratory, digestive, urinary, and reproductive organs. [3][4][5][6] The four members of the NHERF proteins (NHERF1 to 4) contain either two or four PDZ domains and were the first family of PDZ-containing proteins shown

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“…ACE indicates angiotensin-converting enzyme; ALK-1, activin receptor-like kinase 1; AT-II, angiotensin II; BMPR2, bone morphogenetic protein receptor type 2; CAV, caveolin; ECM, extracellular matrix; EGF, epidermal growth factor; EPCs, endothelial progenitor cells; FGF, fibroblast growth factor; 5-HT, serotonin; MIF, macrophage migration-inhibitory factor; MMP, matrix metalloproteinase; MSCs, mesenchymal stem cells; PAH, pulmonary arterial hypertension; PDGF, platelet derived growth factor; RAAS, renin-angiotensin-aldosterone system; SERCA2a, sarcoplasmic reticulum Ca December 9/16, 2014 pulmonary vascular remodeling and also display reduced inflammatory cell recruitment to pulmonary arteries. 92 Taken together, inhibition of MRP4 might represent an interesting target for human PAH.…”

Section: Inhibition Of Cyclic Nucleotides Metabolismmentioning

confidence: 99%