title: Functional interaction between angiotensin II receptor type 1 and chemokine (C-C motif) receptor 2 with implications for chronic kidney disease.
abstract: Understanding functional interactions between G protein-coupled receptors is of great physiological and pathophysiological importance. Heteromerization provides one important potential mechanism for such interaction between different signalling pathways via macromolecular complex formation. Previous studies suggested a functional interplay between angiotensin II receptor type 1 (AT1) and Chemokine (C-C motif) Receptor 2 (CCR2). However the molecular mechanisms are not understood. We investigated AT1-CCR2 functional interaction in vitro using bioluminescence resonance energy transfer in HEK293 cells and in vivo using subtotal-nephrectomized rats as a well-established model for chronic kidney disease. Our data revealed functional heteromers of these receptors resulting in CCR2-Gαi1 coupling being sensitive to AT1 activation, as well as apparent enhanced β-arrestin2 recruitment with agonist co-stimulation that is synergistically reversed by combined antagonist treatment. Moreover, we present in vivo findings where combined treatment with AT1- and CCR2-selective inhibitors was synergistically beneficial in terms of decreasing proteinuria, reducing podocyte loss and preventing renal injury independent of blood pressure in the subtotal-nephrectomized rat model. Our findings further support a role for G protein-coupled receptor functional heteromerization in pathophysiology and provide insights into previous observations indicating the importance of AT1-CCR2 functional interaction in inflammation, renal and hypertensive disorders.
authors: Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia; Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, Australia.
authors: Mohammed Akli
authors: MA
authors: Ayoub
authors: Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia.
authors: Yuan
authors: Y
authors: Zhang
authors: Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia.
authors: Robyn S
authors: RS
authors: Kelly
authors: Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia; Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, Australia.
authors: Heng B
authors: HB
authors: See
authors: Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia; Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, Australia.
authors: Elizabeth K M
authors: EK
authors: Johnstone
authors: Dimerix Bioscience Limited, Nedlands, Western Australia, Australia.
authors: Elizabeth A
authors: EA
authors: McCall
authors: Dimerix Bioscience Limited, Nedlands, Western Australia, Australia.
authors: James H
authors: JH
authors: Williams
authors: Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia.
authors: Darren J
authors: DJ
authors: Kelly
authors: Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia; Centre for Medical Research, The University of Western Australia, Crawley, Western Australia, Australia; Dimerix Bioscience Limited, Nedlands, Western Australia, Australia.
authors: Kevin D G
authors: KD
authors: Pfleger
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D057809:HEK293 Cells; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D009392:Nephrectomy; D051381:Rats; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism; D054390:Receptors, CCR2 / Q000378:metabolism*; D051436:Renal Insufficiency, Chronic / Q000378:metabolism*
chemical_list: C515336:Ccr2 protein, rat; D007295:Inositol Phosphates; D044140:Receptor, Angiotensin, Type 1; D054390:Receptors, CCR2