Background—Endothelial dysfunction plays an important role in the early development of atherosclerosis and vascular complications in type 2 diabetes mellitus. Increased expression and activity of arginase, metabolizing the nitric oxide substrate L-arginine, may result in reduced production of nitric oxide and thereby endothelial dysfunction. We hypothesized that inhibition of arginase activity ...

RATIONALE AND OBJECTIVE Arginase-1 is an important component of the intricate mechanism regulating arginine availability during immune responses and nitric oxide synthase (NOS) activity. In this study Arg1(fl/fl)/Tie2-Cre(tg/-) mice were developed to investigate the effect of arginase-1 related arginine depletion on NOS2- and NOS3-dependent NO production and jejunal microcirculation under resti...

Selenium plays an important role in biological system due to its incorporation in glutathione peroxidases and thioredoxin reductase as prosthetic group, the pharmacological studies of synthetic organoseleno-compounds revealed these molecules to be used as antioxidants, enzyme inhibitors, neuroprotectors, antitumor, anti-infectious agents, cytokine inducers and immuno-modulators. The present stu...

Lung fibrosis is characterized by increased deposition of ECM, especially collagens, and enhanced proliferation of fibroblasts. l-arginine is a key precursor of nitric oxide, asymmetric dimethylarginine, and proline, an amino acid enriched in collagen. We hypothesized that l-arginine metabolism is altered in pulmonary fibrosis, ultimately affecting collagen synthesis. Expression analysis of key...

This special issue, entitled “the role of arginase in endothelial dysfunction,” assembles original contributions (1–4), as well as timely reviews (5–12) broadly related to the deleterious activities of the manganese-containing enzyme arginase in the vascular endothelium. The arginase 1 isoform is cytosolic and is mainly localized in the liver, where it performs a crucial role in eliminating nit...

Human arginase I is a potential target for therapeutic intervention in diseases linked to compromised l-arginine homeostasis. Here, we report high-affinity binding of the reaction coordinate analogue inhibitors 2(S)-amino-6-boronohexanoic acid (ABH, Kd = 5 nM) and S-(2-boronoethyl)-l-cysteine (BEC, Kd = 270 nM) to human arginase I, and we report x-ray crystal structures of the respective enzyme...

Complex regulation of T cell functions during pregnancy is required to ensure materno-fetal tolerance. Here we reveal a novel pathway for the temporary suppression of maternal T cell responses in uncomplicated human pregnancies. Our results show that arginase activity is significantly increased in the peripheral blood of pregnant women and remarkably high arginase activities are expressed in te...

Arginase, a manganese-dependent enzyme that widely distributed in almost all creatures, is a urea cycle enzyme that catalyzes the hydrolysis of L-arginine to generate L-ornithine and urea. Compared with the well-studied arginases from animals and yeast, only a few eubacterial arginases have been characterized, such as those from H. pylori and B. anthracis. However, these enzymes used for argina...

Upregulated arginase activity, which competes with nitric oxide synthase (NOS), impairs nitric oxide production and has been implicated in various metabolic disorders. This study examined whether circulating amino acid metabolite ratios are associated with arginase and NOS activities and whether arginine bioavailability is associated with metabolic syndrome (MetS). Data related to arginase and ...

Myeloid-derived suppressor cells (MDSCs) are a well-defined population of cells that accumulate in the tissue of tumor-bearing animals and are known to inhibit immune responses. Within 4 days, bone marrow cells cultured in granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor resulted in the generation of CD11b(+)Ly6G(lo)Ly6C(+) MDSCs, the majority of which ...