Arginase Inhibition Restores Peroxynitrite-Induced Endothelial Dysfunction via L-Arginine-Dependent Endothelial Nitric Oxide Synthase Phosphorylation

Abstract

PurposePeroxynitrite plays a critical role in vascular pathophysiology by increasing arginase activity and decreasing endothelial nitric oxide synthase (eNOS) activity. Therefore, the aims of this study were to investigate whether arginase inhibition and L-arginine supplement could restore peroxynitrite-induced endothelial dysfunction and determine the involved mechanism.Materials and MethodsHuman umbilical vein endothelial cells (HUVECs) were treated with SIN-1, a peroxynitrite generator, and arginase activity, nitrite/nitrate production, and expression levels of proteins were measured. eNOS activation was evaluated via Western blot and dimer blot analysis. We also tested nitric oxide (NO) and reactive oxygen species (ROS) production and performed a vascular tension assay.ResultsSIN-1 treatment increased arginase activity in a time- and dose-dependent manner and reciprocally decreased nitrite/nitrate production that was prevented by peroxynitrite scavenger in HUVECs. Furthermore, SIN-1 induced an increase in the expression level of arginase I and II, though not in eNOS protein. The decreased eNOS phosphorylation at Ser1177 and the increased at Thr495 by SIN-1 were restored with arginase inhibitor and L-arginine. The changed eNOS phosphorylation was consistent in the stability of eNOS dimers. SIN-1 decreased NO production and increased ROS generation in the aortic endothelium, all of which was reversed by arginase inhibitor or L-arginine. NG-Nitro-L-arginine methyl ester (L-NAME) prevented SIN-1-induced ROS generation. In the vascular tension assay, SIN-1 enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxant responses to acetylcholine that were reversed by arginase inhibition.ConclusionThese findings may explain the beneficial effect of arginase inhibition and L-arginine supplement on endothelial dysfunction under redox imbalance-dependent pathophysiological conditions.

Semen Cuscutae Administration Improves Hepatic Lipid Metabolism and Adiposity in High Fat Diet-Induced Obese Mice

“…Our findings show that the hepatic NO level in HFD-fed mice supplemented with SC, as natural arginase inhibitor, was dramatically higher than those in HFD-only mice (HF group) and glucose levels in the SC group were significantly decreased compared to those in the CTL and HF groups. The possible mechanism may be further supported by our previous work and that of others [7,14,[34][35][36][37][38]. Arginase inhibition promotes the expression of eNOS, which leads to the generation of NO in the HFD-fed mice livers and HepG2 cells [1,7,34].…”

Correction of morphofunctional disorders of the cardiovascular system with asialized erythropoietin and arginase II selective inhibitors KUD 974 and KUD 259 in experimental preeclampsia

“…The potential effects of the blockade of this enzyme have been confirmed in many experiments (Xiong et al 2014;Sobolev et al 2018). It was fair to expect that the positive effects obtained in the correction of morphofunctional disorders of ADMA-like preeclampsia by other arginase II inhibitors would be found in the studied pharmacological agents Nguyen et al 2016;Severinova et al 2019).…”

“…One of the promising groups of drugs for the treatment of preeclampsia are arginase inhibitors. At present, a great deal of data has been accumulated on their pronounced endothelial protective properties, including those obtained using various experimental models of preeclampsia (Gureev 2016;Nguyen et al 2016). Arginase II inhibitors are of particular interest, as being more selective.…”

“…Arginase II inhibitors are of particular interest, as being more selective. The preclinical studies of the selective arginase II inhibitor ZB49-0010 in various pathology models showed its pronounced endothelial protective properties that are superior to those for the non-selective inhibitor of L-norvaline Nguyen et al 2016;Severinova et al 2019). The literature contains data on the endothelial protective properties of arginase II selective inhibitors KUD-259 and KUD-974 on the functional state of vascular endothelium (Pokrovskii et al 2017); however, to date, studies of their effectiveness have not been conducted in experimental preeclampsia yet.…”

“…Preclinical studies in L-NAME induced preeclampsia in rats demonstrated the positive effects of resveratrol (Zou et al 2014), recombinant erythropoietin (Gureev 2016) and tadalafil (Yoshikawa et al 2017). Another promising group of drugs for the treatment of hypertensive conditions in pregnant women is arginase inhibitors (Nguyen et al 2016;Severinova et al 2019). At the same time, arginase II inhibitors as being more selective are of particular interest (Pokrovskii et al 2017;Gureev et al 2015).…”