scholarly journals 280Red blood cells from patients with type 2 diabetes mellitus induce vascular endothelial dysfunction via a mechanism involving vascular arginase I and reactive oxygen species

2017 ◽  
Vol 38 (suppl_1) ◽  
Author(s):  
Z. Zhou ◽  
A. Mahdi ◽  
Y. Tratsiakovich ◽  
O. Kovamees ◽  
M. Alvarsson ◽  
...  
Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1712 ◽  
Author(s):  
Ali Mahdi ◽  
John Tengbom ◽  
Michael Alvarsson ◽  
Bernhard Wernly ◽  
Zhichao Zhou ◽  
...  

We recently showed that red blood cells (RBCs) from patients with type 2 diabetes mellitus (T2DM-RBCs) induce endothelial dysfunction through a mechanism involving arginase I and reactive oxygen species. Peroxynitrite is known to activate arginase in endothelial cells. Whether peroxynitrite regulates arginase activity in RBCs, and whether it is involved in the cross-talk between RBCs and the vasculature in T2DM, is unclear and elusive. The present study was designed to test the hypothesis that endothelial dysfunction induced by T2DM-RBCs is driven by peroxynitrite and upregulation of arginase. RBCs were isolated from patients with T2DM and healthy age matched controls. RBCs were co-incubated with aortae isolated from wild type rats for 18 h in the absence and presence of peroxynitrite scavenger FeTTPS. Evaluation of endothelial function in organ chambers by cumulative addition of acetylcholine as well as measurement of RBC and vessel arginase activity was performed. In another set of experiments, RBCs isolated from healthy subjects (Healthy RBCs) were incubated with the peroxynitrite donor SIN-1 with subsequent evaluation of endothelial function and arginase activity. T2DM-RBCs, but not Healthy RBCs, induced impairment in endothelial function, which was fully reversed by scavenging of RBC but not vascular peroxynitrite with FeTPPS. Arginase activity was up-regulated by the peroxynitrite donor SIN-1 in Healthy RBCs, an effect that was inhibited by FeTTPS. Healthy RBCs co-incubated with aortae in the presence of SIN-1 caused impairment of endothelial function, which was inhibited by FeTTPS or the arginase inhibitor ABH. T2DM-RBCs induced up-regulation of vascular arginase, an effect that was fully inhibited by FeTTPS. Collectively, our data indicate that RBCs impair endothelial function in T2DM via an effect that is driven by a peroxynitrite-mediated increase in arginase activity. This mechanism may be targeted in patients with T2DM for improvement in endothelial function.


2020 ◽  
Author(s):  
Miha Tibaut ◽  
Sara Mankoč Ramuš ◽  
Daniel Petrovič

Abstract Background We aimed to examine the role of the rs6060566 polymorphism of the reactive oxygen species modulator-1 (ROMO-1) gene in the development of myocardial infarction (MI) in Caucasians with type 2 diabetes mellitus (T2DM). Methods A total of 1072 subjects with T2DM were enrolled in cross-sectional case-control study: 335 subjects with MI and 737 subjects without clinical signs of coronary artery disease (CAD). Genetic analysis of the rs6060566 polymorphism was performed in all subjects. To assess the degree of coronary artery obstruction, a subpopulation of 128 subjects with T2DM underwent coronary computed tomography (CT) angiography. Next, endarterectomy samples were obtained during myocardial revascularization from diffusely diseased coronary arteries in 40 cases, which were analysed for ROMO-1 expression according to their genotype. Results There were no statistically significant associations between different genotypes or alleles of the rs6060566 polymorphism and MI in subjects with T2DM. The carriers of the C allele of the ROMO-1 rs6060566 had a threefold increased likelihood of having coronary artery stenosis (AOR = 3.27, 95% CI 1.16–9.20). Furthermore, the carriers of the C allele showed higher number of positive cells for ROMO-1 expression in endarterectomy samples of coronary arteries. Conclusions In accordance to our study, the rs6060566 polymorphism of the ROMO-1 gene is not the risk factor for MI in Caucasians with T2DM. However, we found that subjects carrying the C allele were at a 3.27-fold increased risk of developing severe CAD compared with those who had nonobstructive CAD. Moreover, The C allele carriers showed statistically higher number of cells positive for ROMO-1 compared with T allele carriers in coronary endarterectomy samples.


2007 ◽  
Vol 120 (4) ◽  
pp. 607-613 ◽  
Author(s):  
M.G. Signorello ◽  
G.L. Viviani ◽  
U. Armani ◽  
R. Cerone ◽  
G. Minniti ◽  
...  

2019 ◽  
Vol 317 (5) ◽  
pp. H1086-H1092 ◽  
Author(s):  
Ivan Merdzo ◽  
Ibolya Rutkai ◽  
Venkata N. L. R. Sure ◽  
Prasad V. G. Katakam ◽  
David W. Busija

One of the major characteristics of hyperglycemic states such as type 2 diabetes is increased reactive oxygen species (ROS) generation. Since mitochondria are a major source of ROS, it is vital to understand the involvement of these organelles in the pathogenesis of ROS-mediated conditions. Therefore, we investigated mitochondrial function and ROS production in cerebral blood vessels of 21-wk-old Zucker diabetic fatty obese rats and their lean controls. We have previously shown that in the early stages of insulin resistance, and short periods of type 2 diabetes mellitus, only mild differences exist in mitochondrial function. In the present study, we examined mitochondrial respiration, mitochondrial protein expression, and ROS production in large-surface cerebral arteries. We used 21-wk-old animals exposed to peak glucose levels for 7 wk and compared them with our previous studies on younger diabetic animals. We found that the same segments of mitochondrial respiration (basal respiration and proton leak) were diminished in diabetic groups as they were in younger diabetic animals. Levels of rattin, a rat humanin analog, tended to decrease in the diabetic group but did not reach statistical significance ( P = 0.08). Other mitochondrial proteins were unaffected, which might indicate the existence of compensatory mechanisms with extension of this relatively mild form of diabetes. Superoxide levels were significantly higher in large cerebral vessels of diabetic animals compared with the control group. In conclusion, prolonged dietary diabetes leads to stabilization, rather than deterioration, of metabolic status in the cerebral circulation, despite continued overproduction of ROS. NEW & NOTEWORTHY We have characterized for the first time the dynamics of mitochondrial function during the progression of type 2 diabetes mellitus with regard to mitochondrial respiration, protein expression, and reactive oxygen species production. In addition, this is the first measurement of rattin levels in the cerebral vasculature, which could potentially lead to novel treatment options.


Sign in / Sign up

Export Citation Format

Share Document