Chronic nitric oxide deprivation induces an adaptive antioxidant status in human endothelial cells

Sex-dependent differences in the secretome of human endothelial cells

Background

Cellular sex has rarely been considered as a biological variable in preclinical research, even when the pathogenesis of diseases with predictable sex differences is studied. In this perspective, proteomics, and “omics” approaches in general, can provide powerful tools to obtain comprehensive cellular maps, thus favoring the discovery of still unknown sex-biased physio-pathological mechanisms.

Methods

We performed proteomic and Gene Ontology (GO) analyses of the secretome from human serum-deprived male and female endothelial cells (ECs) followed by ELISA validation. Apoptosis was detected by FACS and Western blot techniques and efferocytosis through the ability of the macrophage cell line RAW 264.7 to engulf apoptotic ECs. PTX3 mRNA levels were measured by RT-qPCR.

Results

Proteomic and GO analyses of the secretome from starved human male and female ECs demonstrated a significant enrichment in proteins related to cellular responses to stress and to the regulation of apoptosis in the secretome of male ECs. Accordingly, a higher percentage of male ECs underwent apoptosis in response to serum deprivation in comparison with female ECs. Among the secreted proteins, we reliably found higher levels of PTX3 in the male EC secretome. The silencing of PTX3 suggested that male ECs were dependent on its expression to properly carry out the efferocytotic process. At variance, female EC efferocytosis seemed to be independent on PTX3 expression.

Conclusions

Our results demonstrated that serum-starved male and female ECs possess different secretory phenotypes that might take part in the sex-biased response to cellular stress. We identified PTX3 as a crucial player in the male-specific endothelial response to an apoptotic trigger. This novel and sex-related role for secreted proteins, and mainly for PTX3, may open the way to the discovery of still unknown sex-specific mechanisms and pharmacological targets for the prevention and treatment of endothelial dysfunction at the onset of atherosclerosis and cardiovascular disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13293-020-00350-3.

[Impact of endothelial dysfunction on the course of acute ST-elevation myocardial infarction and its correction by remote ischemic preconditioning]

Aim of the study - to assess the effect of remote ischemic preconditioning (RIPC) on the incidence of endothelial dysfunction (ED) and its impact on hospital prognosis in patients with ST segment elevation acute myocardial infarction (STEMI).

MATERIALS AND METHODS

We conducted a single - centre, open - label prospective study that included 173 patients with STEMI who underwent primary percutaneous coronary intervention within the first 24 hours of the symptoms onset. Before the PCI, patients were randomized into two groups. In the first group (n=86) during the preparation for PCI, we performed RIPC procedure by inflation of the cuff of the tonometer to 200 mm Hg and its further deflation on patient's shoulder, thus creating short cycles of controlled ischemia/reperfusion in hand (4 cycles of ischemia/reperfusion for 5/5 minutes respectively). In the second, control group (n=87), the standard primary PCI was performed without the previous RIPC. Evaluation of the endothelial function was performed on the 2-7th day after admission using the endothelium - dependent flow - mediated dilatation test (FMD) of the brachial artery. Primary endpoints in this study included the presence of ED, in - hospital mortality, life - threatening arrhythmias (ventricular fibrillation/ventricular tachycardia after first 24 hours upon admission), stent thrombosis, clinical signs of heart failure, and a combined endpoint consisting of all the listed above.

RESULTS

The median values for FMD-test did not differ significantly between the study groups upon admission. Assessment of the FMD of the brachial artery on the 2-7th day after PCI showed that among the patients who underwent RIPC there was a significantly lower percentage of patients with ED than in the patients with STEMI who did not undergo RIPC before PCI (43.1% vs. 75.8% respectively, p=0.0001). We found a significant reduction in the incidence of heart failure and of combined endpoint in the group of patients without ED compared with patients with ED: 0% vs. 9.3% (n=7; p=0.023) and 3.8% (n=2) vs. 16% (n=12; p=0.032) respectively. When assessing the effect of RIPC on hospital prognosis, we also found a significant decrease in the incidence of heart failure and a trend towards a decrease in the combined endpoint in the group of patients who underwent RIPC compared to the control group: 1.5% (n=1) vs. 9.7% (n=6; p=0.045) and 6.2% (n=4) vs. 16.1% (n=10; p=0.073) respectively.

CONCLUSION

Performance of RIPC before the primary PCI significantly reduces the incidence of ED in patients with STEMI on the 2-7th day of the disease onset. The presence of ED in patients with STEMI is associated with a significant increase in the incidence of heart failure and of the combined endpoint during in - hospital period. RIPC significantly reduces the incidence of heart failure in patients with STEMI during in - hospital period.

The role of nitric oxide and oxidative stress in intestinal damage induced by selenium deficiency in chickens

Nitric oxide (NO) is an essential messenger molecule and is associated with inflammation and oxidative stress. Although NO has important biological functions in mammals, its role in the mechanism that occurs after intestinal injuries in chickens remains unknown. The objective of the present study was to investigate the real role of NO and oxidative stress in the intestinal injuries of chickens induced by selenium (Se) deficiency. A total 150 chickens were randomly divided into the following two groups: a low-Se group (L group, fed a Se-deficient diet containing 0.020 mg/kg Se) and a control group (C group, fed a commercial diet containing 0.2 mg/kg Se). The activities and mRNA levels of glutathione peroxidase (GSH-Px), the production of glutathione (GSH) and NO, and the protein and mRNA levels of inducible nitric oxide synthase (iNOS) were examined in the intestinal tissues (duodenum, jejunum, and rectum) at 15, 25, 35, 45, and 55 days. Methane dicarboxylic aldehyde (MDA) levels were also detected by assay kits. Then, the morphologies of the tissues were observed under the microscope after hematoxylin and eosin staining (H&E staining). The results showed that Se deficiency induced higher inflammatory damage and MDA levels (P < 0.05), which were accompanied by higher levels of iNOS and NO but lower levels of GSH and GSH-Px (P < 0.05). Our results indicated that Se deficiency induced oxidative damage in the intestinal tracts of chickens and that low levels of GSH-Px and high contents of NO may exert a major role in the injury of the intestinal tract induced by Se deficiency.

Remote ischemic preconditioning and endothelial function in patients with acute myocardial infarction and primary PCI

BACKGROUND

Remote ischemic preconditioning by transient limb ischemia reduces myocardial ischemia-reperfusion injury in patients undergoing percutaneous coronary intervention. The aim of the study we report here was to assess the effect of remote ischemic preconditioning on endothelial function in patients with acute myocardial infarction who underwent primary percutaneous coronary intervention.

METHODS

Forty-eight patients with acute myocardial infarction were enrolled. All participants were randomly divided into 2 groups. In Group I (n = 23), remote ischemic preconditioning was performed before primary percutaneous coronary intervention (intermittent arm ischemia-reperfusion through 4 cycles of 5-minute inflation and 5-minute deflation of a blood-pressure cuff to 200 mm Hg). In Group II (n = 25), standard percutaneous coronary intervention without preconditioning was performed. We assessed endothelial function using the flow-mediated dilation test on baseline, then within 1-3 hours after percutaneous coronary intervention, and again on days 2 and 7 after percutaneous coronary intervention.

RESULTS

The brachial artery flow-mediated dilation results were significantly higher on the first day after primary percutaneous coronary intervention in the preconditioning group (Group I) than in the control group (Group II) (12.1% vs 0.0%, P = .03, and 11.1% vs 6.3%, P = .016, respectively), and this difference remained on the seventh day (12.3% vs 7.4%, P = .0005, respectively).

CONCLUSION

We demonstrated for the first time that remote ischemic preconditioning before primary percutaneous coronary intervention significantly improves endothelial function in patients with acute myocardial infarction, and this effect remains constant for at least a week. We suppose that the improvement of endothelial function may be one of the possible explanations of the effect of remote ischemic preconditioning.

Enhancing vascular relaxing effects of nitric oxide-donor ruthenium complexes

Ruthenium-derived complexes have emerged as new nitric oxide (NO) donors that may help circumvent the NO deficiency that impairs vasodilation. NO in vessels can be produced by the endothelial cells and/or released by NO donors. NO interacts with soluble guanylyl-cyclase to produce cGMP to activate the kinase-G pathway. As a result, conductance arteries, veins and resistance arteries dilate, whereas the cytosolic Ca2+ levels in the smooth muscle cells decrease. NO also reacts with oxygen or the superoxide anion, to generate reactive oxygen species that modulate NO-induced vasodilation. In this article, we focus on NO production by NO synthase and discuss the vascular changes taking place during hypertension originating from endothelial dysfunction. We will describe how the NO released from ruthenium-derived complexes enhances the vascular effects arising from failed NO generation or lack of NO bioavailability. In addition, how ruthenium-derived NO donors induce the hypotensive effect by vasodilation is also discussed.