Vascular Dysfunction Research Articles

CORRIGENDUM: Optical coherence tomography angiography features in Waldenström macroglobulinemia patients without Hyperviscosity syndrome: A pilot prospective study

PurposeTo evaluate the retinal vessel density (VD) with optical coherence tomography angiography (OCTA) in asymptomatic patients affected by Waldenström macroglobulinemia (WM) without hyperviscosity syndrome (HVS) and to highlight the presence of microvascular damage in theese clinically asymptomatic WD patients. DesignProspective study. MethodsA total of 43 eyes from 43 WM patients (24 females, 19 males, mean age 55.1 ± 13.6 years) were enrolled from January 2023 to December 2023 in the Eye Clinic of the University of Naples Federico II. .Along with WM patients, 40 healthy subjects (HS) (20 females, 20 males, mean age 52.3 ± 15.6 years) with a normal ophthalmic examination and no history of intraocular surgery or retinal pathologic features were included as control group All patients and controls underwent OCTA. ResultsThe two groups were not significantly different for age and sex Visual acuity examination showed no statistically significant difference in BCVA between controls and patients Compared to HS, WD patients showed lower VD values in the SCP in the whole image (47.95 ± 5.17 % vs. 52.99 ± 2.52%; p < 0.001), as well as in the parafovea (53.01 ± 6.69 % vs. 55.30 ± 2.61%; p = 0.002), and fovea (21.38 ± 9.01 % vs. 30.31 ± 5.84 %; p < 0.001). On the other hand, in the DCP VD values were significantly higher in patients compared to controls in the whole image (55.82 ± 8.07 % vs. 50.83 ± 5.46%; p = 0.005), as well as in the parafovea (56.76 ± 6.26 % vs. 52.59 ± 5.46%; p = 0.001), and fovea (38.75 ± 8.59 % vs. 33.43 ± 8.68 %; p < 0.001). ConclusionThe finding that OCTA confirmed the presence of widespread microvascular damage in WD patients clinically silent. Thus, OCTA is a safe rapid imaging technique that could represent a valid biomarker of systemic vascular dysfunction.

A Novel Preclinical Murine Model of Systemic Lupus Erythematosus-Like Cardiovascular Disease.

Systemic lupus erythematosus (SLE) affects nine women to every man worldwide, and these patients are at greater risk for cardiovascular disease (CVD) morbidity and mortality. Clinical studies have demonstrated that patients with SLE are more likely to develop CVD, including cardiac and vascular dysfunction. Although many preclinical models of SLE are available, including treatment with Toll-like receptor (TLR) 7/8 agonists, a consistent preclinical model of SLE-like CVD with systemic, cardiac, renal, and cerebral endothelial activation and cardiac dysfunction has yet to be described. Here, we hypothesize that acceleration of SLE with the TLR7/8 agonist resiquimod (R848) will promote cardiac and endothelial activation with subsequent end-stage organ damage in the SLE-prone B6.Nba2 mouse model. Female and male SLE-prone B6.Nba2 mice were treated with R848 or acetone, administered topically twice weekly over a four-week period, to accelerate the development of SLE-like pathophysiology. Echocardiography was performed at baseline, 4 weeks, and 16 weeks. At 16 weeks, tissues were harvested, weighed, and analyzed by histology, immunofluorescence, real-time quantitative polymerase chain reaction, and enzyme-linked immunosorbent assays. We found that female R848-treated mice had increased serum anti-Smith and immunoglobulin G complex deposition in the kidney, heart, and brain consistent with SLE-like etiology. Tissue analysis revealed significant enlargement of the spleen in both female and male R848-treated mice, with only cardiac and renal enlargement in females compared to their respective controls. Echocardiographic imaging revealed left ventricular wall thickening by 4 weeks that was followed by a progressive increase in left ventricular internal diameters and subsequent decrease in ejection fraction over the 16-week time course in female mice. We found that circulating levels of soluble vascular adhesion molecule-1 and soluble intracellular adhesion molecule-1 were increased in both female and male R848-treated mice, whereas cardiac and renal fibrosis were significantly increased in only female R848-treated mice. Our data demonstrate that R848 treatment of SLE-prone B6.Nba2 mice is a novel preclinical model to study the sex-dependent pathophysiologic mechanisms of SLE-like CVD.

Characterizing Vascular and Hormonal Changes in Women Across the Lifespan: A Cross-Sectional Analysis.

Vascular dysfunction, marked by lower endothelial function and increased aortic stiffness, are non-traditional risk factors that precede the development of CVD. However, the age at which these changes in vascular function occur in women and the degree to which reproductive hormones mediate these changes has not been characterized. Women free from major disease were enrolled across the adult lifespan (aged 18-70, n=140). Endothelial function was assessed as flow-mediated dilation (FMD) of the brachial artery during reactive hyperemia using duplex ultrasound and expressed as percent dilation. Aortic stiffness was measured by carotid-femoral pulse wave velocity (cfPWV). Blood samples were obtained to quantify reproductive hormone concentration. Regression models determined age-related breakpoints and mediating factors between age and vascular outcomes. FMD declined with age with a breakpoint and steeper decline occurring at age 47. Thereafter, age was independently associated with lower FMD (B=-0.13, P<0.001). cfPWV was relatively stable until a breakpoint at age 48, and age was independently associated with higher cfPWV thereafter (B=0.10, P<0.001). Path analysis revealed that the association between age and FMD was partially mediated by follicle stimulating hormone (abind=0.051, P=0.01) and progesterone (abind=0.513, P<0.001) but not estradiol (abind=-0.004, P=0.08). No mediation was present for cfPWV. Age was associated with endothelial dysfunction and aortic stiffness in women beginning at 47 and 48 years, respectively, 3-4 years prior to the average age of menopause. The association between age and endothelial dysfunction was explained in part by elevations in follicle stimulating hormone and progesterone, but not declining estradiol.

Dexrazoxane prevents vascular toxicity in doxorubicin-treated mice

BackgroundDoxorubicin (DOX) is used for breast cancer and lymphoma, but can cause cardiotoxicity, arterial stiffness, and endothelial dysfunction. We recently reported SERPINA3N as biomarker of cardiovascular toxicity in patients and mice. Dexrazoxane (DEXRA) is an FDA-approved drug that prevents DOX-induced cardiac toxicity in high-risk patients. However, the effect of DEXRA on vascular dysfunction during DOX treatment has not been documented. Therefore, here we investigated whether DEXRA protects against DOX-induced arterial stiffness, endothelial dysfunction, and SERPINA3N upregulation in tissue and plasma from mice.MethodsMale C57BL6/J mice were treated with DOX (4 mg/kg), DEXRA (40 mg/kg), a combination (DEXRA + DOX), or VEHICLE (0.9% NaCl) weekly i.p. for 6 weeks (n = 8 per group). Cardiovascular function was measured in vivo by ultrasound imaging at baseline, weeks 2 and 6. Vascular reactivity was analyzed ex vivo in the thoracic aorta at week 6 and molecular analysis was performed.ResultsDEXRA prevented left ventricular ejection fraction decline by DOX (DEXRA + DOX: 62 ± 2% vs DOX: 51 ± 2%). Moreover, DEXRA prevented the increase in pulse wave velocity by DOX (DEXRA + DOX: 2.1 ± 0.2 m/s vs DOX: 4.5 ± 0.3 m/s) and preserved endothelium-dependent relaxation (DEXRA + DOX: 82 ± 3% vs DOX: 62 ± 3%). In contrast to DOX-treated mice, SERPINA3N did not increase in the DEXRA + DOX group.ConclusionOur results not only confirm the cardioprotective effects of DEXRA against DOX-induced cardiotoxicity but also add preservation of vascular endothelial cell function as an important mechanism. Moreover, the study demonstrates the potential of SERPINA3N as a biomarker for monitoring cardiovascular complications of DOX in high-risk patients.

Acetaminophen Overdose Reveals PAR4 as a Low-Expressing but Potent Receptor on the Hepatic Endothelium in Mice.

The protease thrombin, which elicits multiple physiological and pathological effects on vascular endothelial cells (ECs), can signal through PARs (protease-activated receptors) 1 and 4. PAR1 is a high-affinity thrombin receptor known to signal on ECs, whereas PAR4 is a low-affinity thrombin receptor, and evidence for its expression and function on ECs is mixed. This study aims to exploit the high levels of thrombin generation and hepatic vascular dysfunction that occur during acetaminophen (APAP) overdose to determine (1) whether hepatic endothelial PAR4 is a functional receptor, and (2) the endothelial-specific functions for PAR1 and PAR4 in a high thrombin and pathological setting. We generated mice with conditional deletion of Par1/Par4 in ECs and overdosed them with APAP. Hepatic vascular permeability, erythrocyte accumulation in the liver, thrombin generation, and liver function were assessed following overdose. Additionally, we investigated the expression levels of endothelial PARs and how they influence transcription in APAP-overdosed liver ECs using endothelial translating ribosome affinity purification followed by next-generation sequencing. We found that mice deficient in high-expressing endothelial Par1 or low-expressing Par4 had equivalent reductions in APAP-induced hepatic vascular instability, although mice deficient for both receptors had lower vascular permeability at an earlier timepoint after APAP overdose than either of the single mutants. Additionally, mice with loss of both endothelial Par1 and Par4 had reduced thrombin generation after APAP overdose, suggesting decreased hypercoagulability. Last, we found that endothelial PAR1-but not PAR4-can regulate transcription in hepatic ECs. Low-expressing PAR4 can react similarly to high-expressing PAR1 in APAP-overdosed hepatic ECs, demonstrating that PAR4 is a potent thrombin receptor. Additionally, these receptors are functionally redundant but act divergently in their expression and ability to influence transcription in hepatic ECs.

Complex regulation of tau phosphorylation by the endothelin system in brain microvascular endothelial cells (BMVECs): link to barrier function.

Endothelin-1 (ET-1), the most potent vasoconstrictor identified to date, contributes to cerebrovascular dysfunction. ET-1 levels in postmortem brain specimens from individuals diagnosed with Alzheimer's disease (AD) and related dementias (ADRD) were shown to be related to cerebral hypoxia and disease severity. ET-1-mediated vascular dysfunction and ensuing cognitive deficits have also been reported in experimental models of AD and ADRD. Moreover, studies also showed that ET-1 secreted from brain microvascular endothelial cells (BMVECs) can affect neurovascular unit integrity in an autocrine and paracrine manner. Vascular contributions to cognitive impairment and dementia (VCID) is a leading ADRD cause known to be free of neuronal tau pathology, a hallmark of AD. However, a recent study reported cytotoxic hyperphosphorylated tau (p-tau) accumulation, which fails to bind or stabilize microtubules in BMVECs in VCID. Thus, the study aimed to determine the impact of ET-1 on tau pathology, microtubule organization, and barrier function in BMVECs. Cells were stimulated with 1 μM ET-1 for 24 h in the presence/absence of ETA (BQ123; 20 μM) or ETB (BQ788; 20 μM) receptor antagonists. Cell lysates were assayed for an array of phosphorylation site-specific antibodies and microtubule organization/stabilization markers. ET-1 stimulation increased p-tau Thr231 but decreased p-tau Ser199, Ser262, Ser396, and Ser214 levels only in the presence of ETA or ETB antagonism. ET-1 also impaired barrier function in the presence of ETA antagonism. These novel findings suggest that (1) dysregulation of endothelial tau phosphorylation may contribute to cerebral microvascular dysfunction and (2) the ET system may be an early intervention target to prevent hyperphosphorylated tau-mediated disruption of BMVEC barrier function.

SCAR-6 elncRNA locus epigenetically regulates PROZ and modulates coagulation and vascular function.

In this study, we characterize a novel lncRNA-producing gene locus that we name Syntenic Cardiovascular Conserved Region-Associated lncRNA-6 (scar-6) and functionally validate its role in coagulation and cardiovascular function. A 12-bp deletion of the scar-6 locus in zebrafish (scar-6gib007Δ12/Δ12) results in cranial hemorrhage and vascular permeability. Overexpression, knockdown and rescue with the scar-6 lncRNA modulates hemostasis in zebrafish. Molecular investigation reveals that the scar-6 lncRNA acts as an enhancer lncRNA (elncRNA), and controls the expression of prozb, an inhibitor of factor Xa, through an enhancer element in the scar-6 locus. The scar-6 locus suppresses loop formation between prozb and scar-6 sequences, which might be facilitated by the methylation of CpG islands via the prdm14-PRC2 complex whose binding to the locus might be stabilized by the scar-6 elncRNA transcript. Binding of prdm14 to the scar-6 locus is impaired in scar-6gib007Δ12/Δ12 zebrafish. Finally, activation of the PAR2 receptor in scar-6gib007Δ12/Δ12 zebrafish triggers NF-κB-mediated endothelial cell activation, leading to vascular dysfunction and hemorrhage. We present evidence that the scar-6 locus plays a role in regulating the expression of the coagulation cascade gene prozb and maintains vascular homeostasis.

Calciprotein particles induce arterial stiffening ex vivo and impair vascular cell function

Calciprotein particles (CPPs) are an endogenous buffering system, clearing excessive amounts of Ca2+ and PO43- from the circulation and thereby preventing ectopic mineralization. CPPs circulate as primary CPPs (CPP1), which are small spherical colloidal particles, and can aggregate to form large, crystalline, secondary CPPs (CPP2). Even though it has been reported that CPPs are toxic to vascular smooth muscle cells (VSMC) in vitro, their effect(s) on the vasculature remain unclear. Here we have shown that CPP1, but not CPP2, increased arterial stiffness ex vivo. Interestingly, the effects were more pronounced in the abdominal infrarenal aorta compared to the thoracic descending aorta. Further, we demonstrated that CPP1 affected both endothelial and VSMC function, impairing vasorelaxation and contraction respectively. Concomitantly, arterial glycosaminoglycan accumulation was observed as well, which is indicative of an increased extracellular matrix stiffness. However, these effects were not observed in vivo. Hence, we concluded that CPP1 can induce vascular dysfunction.

DDAH1 deficiency exacerbates cerebral vascular endothelial dysfunction by aggravating BBB disruption and oxidative stress in thoracic blast-induced brain injury

As terrorist incidents and underground explosion events have become more frequent around the world, brain injury caused by thoracic blast exposure has been more highlighted due to its injured organ, subsequent social and economic burden. It has been reported dimethylarginine dimethylaminohydrolase 1 (DDAH1) plays important roles in regulating vascular endothelial injury repair and angiogenesis, but its role in thoracic blast-induced brain injury remains to be explained. This study seeks to investigate the mechanism of DDAH1 on thoracic blast-induced brain injury. 40 C57BL/6 wild type mice and 40 DDAH1 knockout mice were randomly and equally divided into control group and blast group, respectively. The integrity of blood-brain barrier (BBB) was detected by Evans blue test. The serum inflammatory factors, nitric oxide (NO) contents, and asymmetric dimethylarginine (ADMA) levels were determined through ELISA. HE staining and reactive oxygen species (ROS) detection were performed for histopathological changes. Western blot was used to detect the proteins related to oxidative stress, tight junction, focal adhesion, vascular endothelial injury, and the DDAH1/ADMA/eNOS signaling pathway. DDAH1 deficiency aggravated thoracic blast-induced BBB leakage, inflammatory response, and the increased levels of inflammatory-related factors. Additionally, DDAH1 deficiency also increased ROS generation, MDA and IRE-α expression. Regarding cerebral vascular endothelial dysfunction, DDAH1 deficiency increased the expression of MCAM, FN1, LIMK1, VEGF, MMP9, Vimentin and N-cadherin, while lowering the expression of FMR1, Occludin, claudin-3, claudin-5, Lyn, LIMA1, Glrb, Sez6, Dystrophin, and phosphorylation of VASP. Also, DDAH1 deficiency exacerbated explosion-induced increase of ADMA and decrease of eNOS activity and NO contents. Thus, we conclude that DDAH1 could prevent cerebral vascular endothelial dysfunction and related injury by inhibiting ADMA signaling and increasing eNOS activity in thoracic blast induced brain injury.

Ginsenoside Rg1 improves hypoxia-induced pulmonary vascular endothelial dysfunction through TXNIP/NLRP3 pathway-modulated mitophagy

BackgroundVascular endothelial dysfunction (VED) is one of the main pathogenic events in pulmonary arterial hypertension (PAH). Previous studies have demonstrated that the ginsenoside Rg1 (Rg1) can ameliorate PAH, but the mechanism by which Rg1 affects pulmonary VED in hypoxia-induced PAH remains unclear. MethodsNetwork pharmacology, molecular docking and other experiments were used to explore the mechanisms by which Rg1 affects PAH. A PAH mouse model was established via hypoxia combined with the vascular endothelial growth factor (VEGFR) inhibitor su5416 (SuHx), and a cell model was established via hypoxia. The functions of Rg1 in VED, oxidative stress, inflammation, mitophagy, and TXNIP and NLRP3 expression were examined. ResultsIn hypoxia-induced VED, progressive exacerbation of oxidative stress, inflammation, and mitophagy were observed, and were associated with elevated TXNIP and NLRP3 expression in vivo and in vitro. Rg1 improved hypoxia-induced impaired endothelium-dependent vasodilation and increased nitric oxide (NO) and endothelial NO synthase (eNOS) expression. Rg1, SRI37330 (a TXNIP inhibitor), MCC950 (an NLRP3 inhibitor), and Liensinine (a mitophagy inhibitor) attenuated oxidative stress, inflammation, and mitophagy by reducing the expression of TXNIP and NLRP3 in mice and cells. Furthermore, the combination of SB203580 (a mitophagy agonist) with Rg1 disrupted the protective effect of Rg1 on hypoxia-induced pulmonary artery and human pulmonary artery endothelial cells (HPAECs). ConclusionRg1 improves hypoxia-induced pulmonary vascular endothelial dysfunction through TXNIP/NLRP3 pathway-modulated oxidative stress, inflammation and mitophagy.

Impact of peripheral venoarterial extracorporeal membrane oxygenation support for heart failure on systemic hemodynamics and aortic blood flow

Peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) is an advanced temporary life support system for patients with refractory cardiogenic shock or severe cardiopulmonary failure. However, the reperfusion of oxygenated blood into the arterial system via a peripheral artery will induce substantial hemodynamic changes that might contribute to the development of complications. In this study, we developed two types of computational models to quantify the hemodynamic changes induced by the peripheral VA-ECMO support for systolic heart failure (HF) of various severities. One was a lumped-parameter model used for exploring the optimal workload of extracorporeal membrane oxygenation (ECMO) for a specific severity of HF, whereas the other one was a geometrical multiscale model capable of simulating the detailed flow field in the aorta while accounting for the hemodynamic coupling of VA-ECMO with the cardiovascular system. Numerical results revealed that the retrograde transmission of ECMO-supplied blood flow toward the heart not only considerably inhibited cardiac output but also induced marked flow disturbance and regionally high or oscillatory wall shear stress (WSS) in the aorta that may increase the risk of thrombosis and vascular dysfunction. The major characteristics of flow disturbance and spatial distribution of abnormal WSS were codetermined by the cardiac function and workload of ECMO while less influenced by the morphology of aorta. These findings emphasized the importance of tuning the workload of ECMO based on patient-specific cardiac function to balance the amount of blood oxygenation support by ECMO against the risk of complications associated with hemodynamic abnormalities.

Glucose and pH dual-responsive hydrogels with antibacterial, reactive oxygen species scavenging, and angiogenesis properties for promoting the healing of infected diabetic foot ulcers

The healing process of diabetic foot ulcers is challenging due to the presence of a complex and severe inflammatory microenvironment, characterized by hyperglycemia, low pH, susceptibility to infection, vascular dysfunction, and over-expression of reactive oxygen species (ROS), which can potentially lead to amputation or even mortality. Herein, a glucose and pH dual-responsive hydrogel was designed and prepared by crosslinking phenylboronic acid-grafted quaternary chitosan (QF, 4 wt%) with dopamine-grafted oxidized hyaluronic acid (OD, 5 wt%) through phenylboronation, schiff-base reaction, and other techniques. The multifunctional QO/@PV@AB7 hydrogel was prepared by incorporating pravastatin-loaded chitosan nanoparticles (CSNPs@PV, 2 mg/mL) and antimicrobial peptide AMP-AB7 loaded silica nanoparticles (SiO2NPs@AB7, 0.5 mg/mL). The results demonstrate that the QO/@PV@AB7 hydrogel exhibits good responsiveness to acidic conditions and high glucose levels, while effectively scavenging various types of ROS. Moreover, it exerted protective effects against oxidative stress on cells, enhanced HUVECs viability, and promoted angiogenesis. Notably, the QO/@PV@AB7 hydrogel displayed potent antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli. Additionally, in an MRSA-infected rat model of diabetic foot wounds, administration of the QO/@PV@AB7 hydrogel led to increased secretion of pro-angiogenic factors such as vascular endothelial nitric oxide synthase (eNOS), vascular endothelial-generating factor (VEGF), and endothelial cell adhesion molecule (CD31). Furthermore, the hydrogel significantly reduced the levels of inflammatory factors such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), while simultaneously increasing the levels of anti-inflammatory cytokines such as interleukin-10 (IL-10). The findings suggest that multifunctional hydrogels incorporating PV@CSNPs and SiO2NPs@AB7 demonstrate promising potential as a therapeutic approach for the treatment of diabetic foot. Statement of SignificanceHere, a glucose and pH dual-responsive QO/@PV@AB7 hydrogel with antimicrobial and angiogenesis-promoting properties was developed for the treatment of infected wounds in diabetic feet. Our findings demonstrate that the proposed hydrogel exhibits good responsiveness, effectively scavenges various types of reactive oxygen species (DPPH, O2-, -OH, and ABTS+), provides protection against oxidative stress, enhances HUVECs cell viability, and promotes angiogenesis. Notably, it also demonstrates potent antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli. Additionally, in vivo experiments demonstrated that the hydrogel exhibited accelerated wound healing in MRSA-infected diabetic foot ulcers, with a reduction of four days compared to the control group.

Insight in the (Phospho)proteome of Vascular Smooth Muscle Cells Derived From Patients With Abdominal Aortic Aneurysm Reveals Novel Disease Mechanisms.

Abdominal aortic aneurysm (AAA) is characterized by weakening and dilatation of the aortic wall in the abdomen. The aim of this study was to gain insight into cell-specific mechanisms involved in AAA pathophysiology by analyzing the (phospho)proteome of vascular smooth muscle cells derived from patients with AAA compared with those of healthy donors. A (phospho)proteomics analysis based on tandem mass spectrometry was performed on vascular smooth muscle cells derived from patients with AAA (n=24) and healthy, control individuals (C-SMC, n=8). Following protein identification and quantification using MaxQuant, integrative inferred kinase activity analysis was used to calculate kinase activity scores. Expression differences between vascular smooth muscle cells derived from patients with AAA and healthy, control individuals were predominantly found in proteins involved in ECM (extracellular matrix) remodeling (THSD4 [thrombospondin type-1 domain-containing protein 4] and ADAMTS1 [A disintegrin and metalloproteinase with thrombospondin motifs 1]), energy metabolism (GYS1 [glycogen synthase 1] and PCK2 [phosphoenolpyruvate carboxykinase 2, mitochondrial]), and contractility (CACNA2D1 [calcium voltage-dependent channel subunit α-2/δ-1] and TPM1 [tropomyosin α-1 chain]). Phosphorylation patterns on proteins related to actin cytoskeleton organization dominated the phosphoproteome of vascular smooth muscle cells derived from patients with AAA . Besides, phosphorylation changes on proteins related to energy metabolism (GYS1), contractility (PARVA [α-parvin], PPP1R12A [protein phosphatase 1 regulatory subunit 12A], and CALD1 [caldesmon 1]), and intracellular communication (GJA1 [gap junction α-1 protein]) were seen. Kinase activity of NUAK1 (NUAK family SNF1-like kinase 1), FYN (tyrosine-protein kinase Fyn), MAPK7 (mitogen-activated protein kinase 7), and STK10 (serine/threonine kinase 10) was different in vascular smooth muscle cells derived from patients with AAA compared with those from healthy, control individuals. This study revealed changes in expression and phosphorylation levels of proteins involved in various processes responsible for AAA progression and development (eg, energy metabolism, ECM remodeling, actin cytoskeleton organization, contractility, intracellular communication, and cell adhesion). These newly identified proteins, phosphosites, and related kinases provide further insight into the underlying mechanism of vascular smooth muscle cell dysfunction within the aneurysmal wall. Our omics data thereby offer the opportunity to study the relevance, either as drug target or biomarker, of these proteins in AAA development.

Dietary protein in a challenge meal does not alleviate postprandial impairments in vascular endothelial function in healthy older adults with cardiometabolic risk: a randomized crossover-controlled trial

BackgroundPostprandial vascular endothelial dysfunction is an early marker of atherosclerosis. Meal protein has been reported to reduce endothelial dysfunction in adults and the effect could be mediated by the amino acid content. ObjectiveThis trial aims to assess the effect of a specifically designed plant protein blend that contains high leucine, arginine and cysteine on postprandial endothelial function in the elderly. MethodsIn a randomized, double-blind, 3-period crossover (2-wk washout), controlled trial, we compared the vascular effects of 3 high-saturated-fat high-sucrose (HFHS) meals based on either our specific plant-protein blend, milk protein, or without added protein. The trial was conducted on 29 healthy adults >65y presenting at least 2 cardiometabolic risk factors. Postprandial vascular function was evaluated at fasting, 3 hours, and 5 hours postprandially, using brachial flow-mediated dilation (FMD), hand microvascular reactivity (by Flowmetry Laser Doppler, FLD), and finger reactive hyperemia index (using Peripheral Arterial Tonometry, RHI). Immune cells count and gene expression in peripheral blood mononuclear cells (PBMC) was also assessed postprandially. Data were analyzed using mixed linear models with repeated measurements on participants for meal composition and time of sampling. This trial was registered at clinicaltrials.gov as NCT04923555. ResultsFMD iAUC decreased after meals (time effect P<0.01), with no significant differences between meals. RHI also decreased with time (P<0.01). PBMC count and MCP1, IL-1b, IL-6 expression increased after meals showing postprandial endothelial activation (P<0.05). Overall, meal composition had no effect on any of the postprandial changes (Ps>0.10). ConclusionsIn healthy adults over 65 years presenting cardiometabolic risk, adding protein to an HFHS challenge meal does not mitigate postprandial impairments in vascular endothelial function and inflammatory activation. Further studies are needed to explore the potential differences with younger adults.

Comprehensive analysis of the m6A demethylase FTO in endothelial dysfunction by MeRIP sequencing

N6-methyladenosine (m6A) is the most general post-transcriptional modification of eukaryotic mRNAs and long-stranded non-coding RNAs. In this process, It has been shown that FTO associates with the m6A mRNA demethylase and plays a role in diabetic vascular endothelial dysfunction. In the present study, we detected FTO protein expression in HUVECs by Western blot and found that FTO was highly expressed in all disease groups relative to the control group. To explore the mechanism of FTO in T2DM vasculopathy, we performed an analysis by methylated RNA immunoprecipitation sequencing (MeRIP-seq) to elucidate the role of aberrant m6A modification and mRNA expression in endothelial dysfunction. The results showed 202 overlapping genes with varying m6A modifications and varied mRNA expression, and GO and KEGG enrichment analysis revealed that these genes were predominantly enriched in pathways associated with T2DM complications and endothelial dysfunction. By an integrated analysis of MeRIP-seq and RNA-seq results, the IGV plots showed elevated kurtosis of downstream candidate gene modifications, which may be downstream targets for FTO to exercise biological functions. HOXA9 and PLAU mRNA expression levels were significantly down after FTO inhibition. In the current work, we set up a typological profile of the m6A genes among HUVECs as well as uncovered a hidden relationship between RNA methylation modifications for T2DM vasculopathy-associated genes. Taken together, this study indicates that endothelial functional impairment is present in T2DM patients and may be related to aberrant expression of FTO.

Relationship between peripheral and intracoronary blood flow in patients with angina and nonobstructive coronary arteries.

Coronary vasomotor dysfunction, an important underlying cause of angina and nonobstructive coronary arteries (ANOCA), encompassing coronary vasospasm, coronary endothelial dysfunction, and/or coronary microvascular dysfunction, is clinically assessed by invasive coronary function testing (ICFT). As ICFT imposes a high burden on patients and carries risks, developing noninvasive alternatives is important. We evaluated whether coronary vasomotor dysfunction is a component of systemic microvascular endothelial and smooth muscle dysfunction and can be detected using laser speckle contrast analysis (LASCA). Forty-three consecutive patients with ANOCA underwent ICFT, with intracoronary acetylcholine, adenosine, and flow measurements, to assess coronary vasomotor dysfunction. Cutaneous microvascular function was assessed using LASCA in the forearm, combined with vasodilators acetylcholine, sodium nitroprusside, and insulin and using EndoPAT, by measuring the reactive hyperemia index (RHI). Of the 43 included patients with ANOCA (79% women, 59 ± 9 yr old), 38 patients had coronary vasomotor dysfunction, including 28 with coronary vasospasm, 26 with coronary endothelial dysfunction, and 18 with coronary microvascular dysfunction, with overlapping endotypes. Patients with and without coronary vasomotor dysfunction had similar peripheral flow responses to acetylcholine, insulin, and RHI. In contrast, coronary vasomotor dysfunction was associated with lower peripheral flow responses to sodium nitroprusside (P < 0.001). An absolute flow response to sodium nitroprusside of 83.95 APU resulted in 86.1% sensitivity and 80.0% specificity for coronary vasomotor dysfunction (area under the ROC curve, 0.883; P = 0.006). In conclusion, this study provides evidence of systemic vascular smooth muscle dysfunction in patients with ANOCA with coronary vasomotor dysfunction and the diagnostic value of peripheral microvascular function testing as a noninvasive tool for detecting coronary vasomotor dysfunction.NEW & NOTEWORTHY This study provides proof of concept that assessment of the peripheral vasculature, particularly vascular smooth muscle cells measured using the LASCA technology holds potential as a noninvasive tool for detecting coronary vasomotor dysfunction. This finding highlights the potential of the LASCA technology in, for example, medication studies for coronary vasomotor dysfunction, especially when investigating whether medication improves vascular function, as repeated peripheral measurements are less invasive than invasive coronary function testing, the current gold standard.

High-Intensity Interval Training and Moderate-Intensity Continuous Training Alleviate Vascular Dysfunction in Spontaneously Hypertensive Rats through the Inhibition of Pyroptosis

High-Intensity Interval Training and Moderate-Intensity Continuous Training Alleviate Vascular Dysfunction in Spontaneously Hypertensive Rats through the Inhibition of Pyroptosis

Coadministration of PEGylated apohemoglobin and haptoglobin can limit vascular dysfunction in the microcirculation and prevent acute inflammation.

Unfortunately, during pathological conditions resulting in chronic hemolysis cell-free hemoglobin (Hb) is released into the circulation that releases free heme, resulting in several complications. One approach to prevent these toxicities is the administration of supplemental scavenger proteins, haptoglobin (Hp) and hemopexin (Hpx). The goal of this body of work is to objectively measure the levels of vascular reactivity and inflammatory profiles after an infusion of acellular hemoglobin in animals that were given a coadministration of PEGylated human apohemoglobin (PEG-apoHb), a hemopexin (Hpx)-mimetic that can scavenge free heme from hemoglobin, together with human plasma-derived Hp that can scavenge dimerized Hb. Using intravital microscopy, Golden Syrian hamsters instrumented with a dorsal window chamber were used to evaluate the in vivo effects of four experimental groups that were then challenged with a hypovolemic injection (10% of the animal's blood volume) of human Hb (hHb, 5 g/dL). The four experimental groups consisted of: 1) lactated Ringer's solution (control), 2) PEG-apoHb only, 3) Hp only, and 4) PEG-apoHb + Hp. The microvascular hemodynamics (diameter and flow) in arterioles and venules were recorded at baseline, 20 min after treatment, and 20 min after hHb challenge. Systemic parameters (blood pressure and heart rate), blood gases (pH, Pco2, and Po2), blood parameters (Hb concentration and hematocrit), and multiorgan functionality/inflammation were also measured. Our results suggest that coadministration of PEG-apoHb + Hp as a booster before the infusion of acellular hemoglobin significantly prevented vasoconstriction in the microcirculation, significantly increased the number of functional capillaries, and significantly reduced inflammation.NEW & NOTEWORTHY Coadministration of PEGylated human apohemoglobin (PEG-apoHb)-a hemopexin (Hpx) mimetic that can scavenge free heme-and human plasma-derived haptoglobin (Hp) that can scavenge hemoglobin (Hb), reduces microcirculatory dysfunction and cardiac and kidney inflammation in a Hb-challenge model.

Gestational influenza A virus infection elicits nonresolving vascular dysfunction and T-cell accumulation in the aorta of mice.

T-cell accumulation within the aorta promotes endothelial dysfunction and the genesis of cardiovascular disease, including hypertension and atherosclerosis. Viral infection during pregnancy is also known to mediate marked acute endothelial dysfunction, but it is not clear whether T cells are recruited to the aorta and whether the dysfunction persists postpartum. Here, we demonstrate that influenza A virus (IAV) infection during pregnancy in a murine model resulted in endothelial dysfunction of the aorta, which persisted for up to 60 days postinfection and was associated with higher levels of IFN-γ mRNA expression within the tissue. In the absence of infection, low numbers of naïve CD4+ and CD8+ T cells, central memory T cells, and effector memory T cells were observed in the aorta. However, with IAV infection, these T-cell subsets were significantly increased with a notable accumulation of IAV-specific CD8+ effector memory T cells. Critically, this increase was maintained out to at least 60 days. In contrast, IAV infection in nonpregnant female mice resulted in modest endothelial dysfunction with no accumulation of T cells within the aorta. These data, therefore, demonstrate that the aorta is a site of T-cell recruitment and retention after IAV infection during pregnancy. Although IAV-specific memory T cells could theoretically confer protection against future influenza infection, nonspecific memory T-cell activation and IFN-γ production in the aorta could also contribute to future endothelial dysfunction and cardiovascular disease.NEW & NOTEWORTHY Pregnancy is a risk factor for cardiovascular complications to influenza A virus (IAV) infection. We demonstrate that gestational IAV infection caused endothelial dysfunction of the maternal aorta, which persisted for 60 days postinfection in mice. Various T cells accumulated within the aorta at 60 days because of the infection, and this was associated with elevated levels of the proinflammatory cytokine, IFN-γ. Our study demonstrates a novel "long influenza" cardiovascular phenotype in female mice.

Pde3a and Pde3b regulation of murine pulmonary artery smooth muscle cell growth and metabolism.

A role for metabolically active adipose tissue in pulmonary hypertension (PH) pathogenesis is emerging. Alterations in cellular metabolism in metabolic syndrome are triggers of PH-related vascular dysfunction. Metabolic reprogramming in proliferative pulmonary vascular cells causes a metabolic switch from oxidative phosphorylation to glycolysis. PDE3A and PDE3B subtypes in the regulation of metabolism in pulmonary artery smooth muscle cells (PASMC) are poorly understood. We previously found that PDE3A modulates the cellular energy sensor, AMPK, in human PASMC. We demonstrate that global Pde3a knockout mice have right ventricular (RV) hypertrophy, elevated RV systolic pressures, and metabolic dysfunction with elevated serum free fatty acids (FFA). Therefore, we sought to delineate Pde3a/Pde3b regulation of metabolic pathways in PASMC. We found that PASMC Pde3a deficiency, and to a lesser extent Pde3b deficiency, downregulates AMPK, CREB and PPARγ, and upregulates pyruvate kinase dehydrogenase expression, suggesting decreased oxidative phosphorylation. Interestingly, siRNA Pde3a knockdown in adipocytes led to elevated FFA secretion. Furthermore, PASMC exposed to siPDE3A-transfected adipocyte media led to decreased α-SMA, AMPK and CREB phosphorylation, and greater viable cell numbers compared to controls under the same conditions. These data demonstrate that deficiencies of Pde3a and Pde3b alter pathways that affect cell growth and metabolism in PASMC.