Supportive treatment of vascular dysfunction in pediatric subjects with obesity: the OBELIX study

Introduction Overweight or obese children develop abnormal endothelial cell dysfunction and arterial intima–media thickening with increased vasomotor tone and inflammation. Curcumin, resveratrol, zinc, magnesium, selenium, and vitamin D have shown beneficial effects on endothelial function. We test, among overweight and obese pediatric subjects, the effects on the endothelium of a combination of curcumin, resveratrol, zinc, magnesium, selenium, and vitamin D. Methods Forty-eight subjects (6–17 years) were randomized into two groups (placebo vs treatment) attended three visits at 0, 3, and 6 months (±15 days). Endothelial function was assessed by means of a post-occlusive release hyperemic (PORH) test for estimation of delta flow (DF) and hyperemic AUC index, and a heat provocation test (HPT) to measure DF HPT (DFHPT). Results Significant DF difference was noted at 6 months in both groups (p < 0.001). Overall time trend was significantly different between baseline, 3 months, and 6 months both in placebo (p < 0.05) and treatment (p < 0.001) groups and their comparison (p < 0.001). No differences were noted in hyperemic AUC index (3 and 6 months), whilst there were significant differences in time trends of rreatment (p < 0.001) and placebo (p < 0.05) groups and their comparison (p < 0.001). DFHPT difference between groups was significant at 3 and 6 months (p < 0.05). The overall time trend was significant exclusively in Treatment group between 3 and 6 months (p < 0.05). Correlation with anthropometrics was found for DF and body mass index (r = 0.677 6 months, p < 0.05), as well as for hyperemic AUC index and males (r = 0.348, p < 0.05), while DFHPT showed no correlation. Conclusion Curcumin, resveratrol, zinc, magnesium, selenium, and vitamin D appear to be promising in enhancing endothelial function by improvement of both DF in the PORH test and DF in the HPT, lowering the risk of developing cardiovascular diseases in overweight and obese pediatric subjects.

Upregulated PD-1 Signaling is an Important Antagonist to Glomerular Health in Aged Kidneys

Kidney aging and its contribution to disease and its underlying mechanisms are not well understood. With an aging population, kidney health becomes an important medical and socioeconomic factor. We previously showed that podocytes isolated from aged mice exhibit increased expression of Programed Cell Death Protein 1 (PD-1) surface receptor and its two ligands (PD-L1, PD-L2). PDCD1 transcript increases with age in micro-dissected human glomeruli, which correlates with lower eGFR, and higher segmental glomerulosclerosis and vascular arterial intima to lumen ratio. In vitro studies in podocytes demonstrate a critical role for PD-1 signaling in cell survival and induction of a Senescence-Associated Secretory Phenotype (SASP). To prove PD-1 signaling is critical to podocyte aging, aged mice were injected with anti-PD-1 antibody (aPD-1ab). Treatment significantly improved the aging phenotype in both kidney and liver. In the glomerulus, it increased the life-span of podocytes, but not parietal epithelial, mesangial or endothelial cells. Transcriptomic and immunohistochemistry studies demonstrate that anti-PD-1 treatment improved the health-span of podocytes. It restored the expression of canonical podocyte genes, transcription factors and gene regulatory networks, increased cellular metabolism signatures and lessened SASPs. These results suggest a critical contribution for increased PD-1 signaling towards both kidney and liver aging.

Impact of Interleukin-17 Inhibitor Therapy on Arterial Intima-media Thickness among Severe Psoriatic Patients

Background: Psoriasis is frequently accompanied by cardiovascular diseases based on the shared immunopathogenic pathway. Authors determined the effect of interleukin (IL)-17 inhibitor therapy on arterial intima-media thickness (IMT) among severe psoriatic patients. Methods: Thirty-one severe psoriatic patients were enrolled. Twenty received secukinumab and 11 received ixekizumab. Before treatment initiation and after 6 months, the carotid-brachial-femoral IMT, the Psoriasis Area Severity Index (PASI), the Dermatology Life Quality of Index (DLQI) and the EuroQol Visual Analogue Scale (EQ VAS) were evaluated. Results: After 6 months, significant ameliorations were observed in PASI (p < 0.001) from 18 to 0, in DLQI (p < 0.001) from 17 to 0, in EQ VAS (p < 0.001) from 60 to 90, in right carotid IMT (p < 0.001) from 1.1 mm to 0.8 mm, in left carotid IMT (p < 0.001) from 1.1 mm to 0.7 mm, in right brachial IMT (p < 0.001) from 0.75 mm to 0.6 mm, in left brachial IMT (p < 0.001) from 0.8 mm to 0.5 mm, in right femoral IMT (p < 0.001) from 0.9 mm to 0.7 mm and in left femoral IMT (p < 0.001) from 0.8 mm to 0.7 mm. Conclusions: By reducing the inflammation of the vascular wall, anti-IL-17 therapy may have a beneficial long-term effect on cardiovascular complications of systemic inflammation.

Apolipoprotein and LRP1-Based Peptides as New Therapeutic Tools in Atherosclerosis

Apolipoprotein (Apo)-based mimetic peptides have been shown to reduce atherosclerosis. Most of the ApoC-II and ApoE mimetics exert anti-atherosclerotic effects by improving lipid profile. ApoC-II mimetics reverse hypertriglyceridemia and ApoE-based peptides such as Ac-hE18A-NH2 reduce cholesterol and triglyceride (TG) levels in humans. Conversely, other classes of ApoE and ApoA-I mimetic peptides and, more recently, ApoJ and LRP1-based peptides, exhibit several anti-atherosclerotic actions in experimental models without influencing lipoprotein profile. These other mimetic peptides display at least one atheroprotective mechanism such as providing LDL stability against mechanical modification or conferring protection against the action of lipolytic enzymes inducing LDL aggregation in the arterial intima. Other anti-atherosclerotic effects exerted by these peptides also include protection against foam cell formation and inflammation, and induction of reverse cholesterol transport. Although the underlying mechanisms of action are still poorly described, the recent findings suggest that these mimetics could confer atheroprotection by favorably influencing lipoprotein function rather than lipoprotein levels. Despite the promising results obtained with peptide mimetics, the assessment of their stability, atheroprotective efficacy and tissue targeted delivery are issues currently under progress.

Influence of Disorders of Fatty Acid Metabolism, Arterial Wall Hypoxia, and Intraplaque Hemorrhages on Lipid Accumulation in Atherosclerotic Vessels

The review describes a number of competing views on the main causes of cholesterol accumulation in atherosclerotic vessels. On the one hand, unregulated cholesterol influx into arterial intima is primarily related to the increasing proportion of atherogenic lipoproteins in the lipoprotein spectrum of blood. On the other hand, the leading role in this process is assigned to the increased permeability of endothelium for atherogenic lipoproteins. The increased ability of arterial intima connective tissue to bind atherogenic blood lipoproteins is also considered to be the leading cause of cholesterol accumulation in the vascular wall. The key role in cholesterol accumulation is also assigned to unregulated (by a negative feedback mechanism) absorption of atherogenic lipoproteins by foam cells. It is suggested that the main cause of abundant cholesterol accumulation in atherosclerotic vessels is significant inflow of this lipid into the vascular wall during vasa vasorum hemorrhages.The article also provides arguments, according to which disorder of fatty acid metabolism in arterial wall cells can initiate accumulation of neutral lipids in them, contribute to the inflammation and negatively affect the mechanical conditions around the vasa vasorum in the arterial walls. As a result, the impact of pulse waves on the luminal surface of the arteries will lead to frequent hemorrhages of these microvessels. At the same time, adaptive-muscular intima hyperplasia, which develops in arterial channel areas subjected to high hemodynamic loads, causes local hypoxia in a vascular wall. As a result, arterial wall cells undergo even more severe lipid transformation. Hypoxia also stimulates vascularization of the arterial wall, which contributes to hemorrhages in it. With hemorrhages, free erythrocyte cholesterol penetrates into the forming atherosclerotic plaque, a part of this cholesterol forms cholesterol esters inside the arterial cells. The saturation of erythrocyte membranes with this lipid in conditions of hypercholesterolemia and atherogenic dyslipoproteinemia contributes to the process of cholesterol accumulation in arteries.

KLF2 Mediates the Suppressive Effect of Laminar Flow on Vascular Calcification by Inhibiting Endothelial BMP/SMAD1/5 Signaling

Rationale: Vascular calcification in arterial intima is closely associated with atherosclerosis. Endothelial cells (ECs) sense blood flow and respond to the mechanical cues generated by different flow patterns. Laminar flow (LF) induces an anti-atherosclerotic EC phenotype whereas disturbed flow (DF) exerts an atheroprone effect. However, the contribution of blood flow to calcification in atherosclerotic arteries remains to be evaluated. Objective: We aim to investigate whether blood flow plays a determinant role in the distribution of vascular calcification and the underlying mechanisms involved. Methods and Results: Computed tomography angiography analysis of human coronary arteries (n = 48) shows that calcification preferentially develops at flow perturbated sites. Similar phenomenon was observed in calcified human aortic valves and mouse arteries. Nonuniform shear stress produced in Y-shaped slide simulating live conditions in branched arteries promotes calcification in human umbilical vein ECs (HUVECs). The expression of Krüppel-like Factor 2 (KLF2), a transcription factor inducible by LF, is reduced in ECs of calcified human aortic valves and in endothelial calcification model, suggesting that KLF2 downregulation is likely involved in intimal calcification. Indeed, KLF2 silencing induces endothelial-to-mesenchymal transition and accelerates osteo-induction in both human aortic ECs and HUVECs. EC-specific KLF2 knockdown promotes whereas AAV9-mediated EC-KLF2 overexpression ameliorates vascular calcification in ApoE -/- mice. Global mRNA profiling in HUVECs reveals that KLF2 inhibits BMP/SMAD1/5 pathway which is critical in vascular calcification. Furthermore, KLF2 mediates LF-induced inhibition of the BMP/SMAD1/5 pathway. By contrast, DF-induced activation of BMP/SMAD1/5 pathway is suppressed by KLF2 overexpression. Mechanistically, KLF2 binds to the promoters of BMP4, BMPER and SMAD1 to directly regulate their expression in ECs. Conclusions: Vascular calcification prefers to occur at branched or bifurcated areas of vasculature. LF inhibits vascular calcification through KLF2-mediated inhibition of endothelial BMP/SMAD1/5 signaling. Targeting KLF2 may represent a novel therapeutic approach against vascular calcification.

Aggregation Susceptibility of Low-Density Lipoproteins—A Novel Modifiable Biomarker of Cardiovascular Risk

Circulating low-density lipoprotein (LDL) particles enter the arterial intima where they bind to the extracellular matrix and become modified by lipases, proteases, and oxidizing enzymes and agents. The modified LDL particles aggregate and fuse into larger matrix-bound lipid droplets and, upon generation of unesterified cholesterol, cholesterol crystals are also formed. Uptake of the aggregated/fused particles and cholesterol crystals by macrophages and smooth muscle cells induces their inflammatory activation and conversion into foam cells. In this review, we summarize the causes and consequences of LDL aggregation and describe the development and applications of an assay capable of determining the susceptibility of isolated LDL particles to aggregate when exposed to human recombinant sphingomyelinase enzyme ex vivo. Significant person-to-person differences in the aggregation susceptibility of LDL particles were observed, and such individual differences largely depended on particle lipid composition. The presence of aggregation-prone LDL in the circulation predicted future cardiovascular events in patients with atherosclerotic cardiovascular disease. We also discuss means capable of reducing LDL particles’ aggregation susceptibility that could potentially inhibit LDL aggregation in the arterial wall. Whether reductions in LDL aggregation susceptibility are associated with attenuated atherogenesis and a reduced risk of atherosclerotic cardiovascular diseases remains to be studied.