AUTHOR=Mesquita Thássio R. R. , Campos-Mota Gianne P. , Lemos Virgínia S. , Cruz Jader S. , de Jesus Itamar C. G. , Camargo Enilton A. , Pesquero Jorge L. , Pesquero João B. , Capettini Luciano Dos Santos A. , Lauton-Santos Sandra 

TITLE=Vascular Kinin B1 and B2 Receptors Determine Endothelial Dysfunction through Neuronal Nitric Oxide Synthase

JOURNAL=Frontiers in Physiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2017.00228

DOI=10.3389/fphys.2017.00228

ISSN=1664-042X

ABSTRACT=<p>B<sub>1</sub>- and B<sub>2</sub>-kinin receptors are G protein-coupled receptors that play an important role in the vascular function. Therefore, the present study was designed to evaluate the participation of kinin receptors in the acetylcholine (ACh)-induced vascular relaxation, focusing on the protein-protein interaction involving kinin receptors with endothelial and neuronal nitric oxide synthases (eNOS and nNOS). Vascular reactivity, nitric oxide (NO·) and reactive oxygen species (ROS) generation, co-immunoprecipitation were assessed in thoracic aorta from male wild-type (WT), B<sub>1</sub>- (B<sub>1</sub>R<sup>−/−</sup>), B<sub>2</sub>- (B<sub>2</sub>R<sup>−/−</sup>) knockout mice. Some vascular reactivity experiments were also performed in a double kinin receptors knockout mice (B<sub>1</sub>B<sub>2</sub>R<sup>−/−</sup>). For pharmacological studies, selective B<sub>1</sub>- and B<sub>2</sub>-kinin receptors antagonists, NOS inhibitors and superoxide dismutase (SOD) mimetic were used. First, we show that B<sub>1</sub>- and B<sub>2</sub>-kinin receptors form heteromers with nNOS and eNOS in thoracic aorta. To investigate the functionality of these protein-protein interactions, we took advantage of pharmacological tools and knockout mice. Importantly, our results show that kinin receptors regulate ACh-induced relaxation via nNOS signaling in thoracic aorta with no changes in NO· donor-induced relaxation. Interestingly, B<sub>1</sub>B<sub>2</sub>R<sup>−/−</sup> presented similar level of vascular dysfunction as found in B<sub>1</sub>R<sup>−/−</sup> or B<sub>2</sub>R<sup>−/−</sup> mice. In accordance, aortic rings from B<sub>1</sub>R<sup>−/−</sup> or B<sub>2</sub>R<sup>−/−</sup> mice exhibit decreased NO· bioavailability and increased superoxide generation compared to WT mice, suggesting the involvement of excessive ROS generation in the endothelial dysfunction of B<sub>1</sub>R<sup>−/−</sup> and B<sub>2</sub>R<sup>−/−</sup> mice. Alongside, we show that impaired endothelial vasorelaxation induced by ACh in B<sub>1</sub>R<sup>−/−</sup> or B<sub>2</sub>R<sup>−/−</sup> mice was rescued by the SOD mimetic compound. Taken together, our findings show that B<sub>1</sub>- and B<sub>2</sub>-kinin receptors regulate the endothelium-dependent vasodilation of ACh through nNOS activity and indicate that molecular disturbance of short-range interaction between B<sub>1</sub>- and B<sub>2</sub>-kinin receptors with nNOS might be involved in the oxidative pathogenesis of endothelial dysfunction.</p>