Impaired Endothelial Function Research Articles

Vasculoendothelial dysfunction and bone health in obese children: A connection with cancers

Obesity in children, a growing global epidemic, is not merely characterized by excessive body fat but also by a cascade of metabolic and functional derangements with significant musculoskeletal consequences. One of the key underpinnings of these detrimental effects is vasculoendothelial dysfunction (VED), a multifaceted pathological process characterized by impaired endothelial cell function. The endothelium, lining the vasculature, plays a pivotal role in regulating vascular tone, inflammation, and coagulation, and its dysfunction in obese children leads to a plethora of downstream complications with profound implications for musculoskeletal and bone health. Diagnosing VED in obese children remains a challenge. Traditional cardiovascular risk factors such as hypertension and dyslipidemia are often detected long after the occurrence of endothelial dysfunction. In the context of bone sarcoma, the interaction between cancer cells and vascular endothelium in the bone microenvironment is critical. The bone is a highly vascularized tissue, and the vascular endothelium plays a role in regulating bone homeostasis. In the presence of cancer cells, altered bone microenvironment provides a milieu favorable to tumor growth and invasion. The relationship between the vascular endothelium and cancer is complex and can vary depending on the type of cancer and its microenvironment. Understanding the interactions between vascular endothelium and bone sarcoma is crucial for developing targeted therapies. New molecular and cellular mechanisms involved in these interactions are awaiting to be uncovered, shedding light on potential therapeutic strategies for cancer treatment. On a relevant note, emerging vasculoendothelial markers hold promise for early detection and intervention. Early identification of VED, through the detection of vasculoendothelial markers, opens doors for timely interventions aimed at preventing its detrimental effects on musculoskeletal and bone health in obese children

#2810 Exploring non-renal vasculature: therapeutic implications of proton pump inhibitor and anthelmintic treatment in PCK rat model

Abstract Background and Aims Cystic kidney diseases represent ciliopathies that can cause vascular damage through renal hypertension. Additionally, there is growing experimental evidence of endothelial cell abnormalities associated with ciliary protein deficiencies. PCK rats, a strain derived from Sprague-Dawley (SD) rats that develops both polycystic kidney disease (PKD) and liver disease, serve as a model for recessive PKD. The PCK rat model also presents abnormalities in non-renal vascular function. Another study from our group suggests a potential therapeutic benefit of repurposed therapy with a proton pump inhibitor (PPi) and an anthelmintic agent in attenuating the progression of PKD in a PCK rat model. Here, we investigated whether these drugs can also improve endothelial function. Method The compounds were administered to 3-week-old male and female PCK rats (n = 5-6) for a total of 10 weeks. Untreated PCK rats and age-matched SD rats (n = 5-6) served as controls. After perfusion fixation, the aorta was harvested and its thoracic rings were used to evaluate the contraction/relaxation responses ex vivo by organ bath experiments. Additional rings were preserved for histological and molecular biological analyses. Results Male PCK rats exhibited impaired endothelial function compared to healthy controls. Endothelium-dependent relaxation to acetylcholine was improved by 10% after treatment with PPi, while the anthelmintic administration had no protective effect. PKD also impaired endothelial function in female PCK rats compared to healthy SD controls. There was an improvement in endothelium-dependent relaxation to acetylcholine after treatment with PPi by 5.5%, while administration of the anthelmintic agent further impaired endothelial function. Conclusion 13-week-old PCK rats show endothelial dysfunction in non-renal vasculature. Treatment with a proton pump inhibitor improved endothelial function in male PCK rats to the level of healthy SD controls. By contrast, in a parallel study, the anthelmintic had a positive effect on renal function but a detrimental impact on endothelial function. These intricate relationships underscore the need for further exploration to understand the underlying mechanisms and broader implications of our findings, illustrating the challenges and potential avenues for the development of effective treatments for PKD.

#2307 Serum NGAL, MMP-9 and suPAR in the assessment of kidney impairment and cardiovascular risk in children and adolescents with type 1 diabetes or obesity

Abstract Background and Aims Type 1 diabetes mellitus (DM1) and obesity represent two chronic paediatric diseases with worryingly rising incidence, characterized by chronic inflammation, endothelial dysfunction and increased risk for kidney impairment and cardiovascular disease. The aim of this cross-sectional study was to explore the potential usefulness of serum Neutrophil Gelatinase-Associated Lipocalin (NGAL), Matrix Metalloproteinase-9 (MMP-9) and Soluble Urokinase Plasminogen Activator Receptor (suPAR) for predicting early kidney injury or increased cardiovascular risk in children and adolescents with DM1 or obesity. Method Serum samples were obtained from children and adolescents aged <18 years old with DM1 (n=35) or obesity (n=38) and normal renal function with no history of albuminuria, as well as from healthy controls (n=23). Serum NGAL, MMP-9 and suPAR concentrations were measured using commercially available sandwich ELISA kits (NGAL: (DY1757-05), MMP-9: (DMP900); suPAR: (DUP00); R&D systems). All patients were evaluated for anthropometric indices (weight, height, BMI) while for different degrees of weight status we used the body mass index (BMI) z-score adjusted for age and sex. Estimated glomerular filtration rate (eGFR) was calculated according to the revised bedside Schwartz formula. Results Serum NGAL values were found significantly higher in patients with obesity but not in those with DM1. A positive correlation was found in patients with T1DM with diabetes duration (Spearman rho 0.364, p=0.044), and in all study participants with BMI z-score (Spearman rho 0.401, p=0.004). Furthermore, serum MMP-9 levels were significantly increased in patients with T1DM and in patients with obesity compared to controls. Mean serum suPAR levels were significantly higher in patients with obesity compared to patients with T1DM and controls, while children with T1DM had similar suPAR levels to controls (Table 1). Finally, serum suPAR levels showed a negative correlation with age (Spearman rho −0.359, p<0.001) and creatinine levels (Spearman rho −0.334, p=0.005), and a positive correlation with BMI z-score (Spearman rho 0.354, p=0.009). Conclusion Circulating NGAL, MMP-9 levels may prove useful as surrogate biomarkers to creatinine, GFR and albumin excretion rate for early detection of kidney injury, inflammation or endothelial dysfunction and cardiovascular complications in children and adolescents with T1DM or obesity. Children with obesity may have impaired inflammation status, kidney and endothelial function to a higher degree compared to children with T1DM, which may suggest that obesity may impose a greater health burden than T1DM, at least during childhood or the first years after T1DM diagnosis.

Pseudomonas aeruginosa N-3-Oxododecanoyl Homoserine Lactone Disrupts Endothelial Integrity by Activating the Angiopoietin-Tie System.

The activation of the angiopoietin (Angpt)-Tie system is linked to endothelial dysfunction during sepsis. Bacterial quorum-sensing molecules function as pathogen-associated molecular patterns. However, their impact on the endothelium and the Angpt-Tie system remains unclear. Therefore, this study investigated whether treatment with N-3-oxododecanoyl homoserine lactone (3OC12-HSL), a quorum-sensing molecule derived from Pseudomonas aeruginosa, impaired endothelial function in human umbilical vein endothelial cells. 3OC12-HSL treatment impaired tube formation even at sublethal concentrations, and immunocytochemistry analysis revealed that it seemed to reduce vascular endothelial-cadherin expression at the cell-cell interface. Upon assessing the mRNA expression patterns of genes associated with the Angpt-Tie axis, the expressions of Angpt2, Forkhead box protein O1, Tie1, and vascular endothelial growth factor 2 were found to be upregulated in the 3OC12-HSL-treated cells. Moreover, western blot analysis revealed that 3OC12-HSL treatment increased Angpt2 expression. A co-immunoprecipitation assay was conducted to assess the effect of 3OC12-HSL on the IQ motif containing GTPase activating protein 1 (IQGAP1) and Rac1 complex and the interaction between these proteins was consistently maintained regardless of 3OC12-HSL treatment. Next, recombinant human (rh)-Angpt1 was added to assess whether it modulated the effects of 3OC12-HSL treatment. rh-Angpt1 addition increased cellular viability, improved endothelial function, and reversed the overall patterns of mRNA and protein expression in endothelial cells treated with 3OC12-HSL. Additionally, it was related to the increased expression of phospho-Akt and the IQGAP1 and Rac1 complex. Collectively, our findings indicated that 3OC12-HSL from Pseudomonas aeruginosa can impair endothelial integrity via the activation of the Angpt-Tie axis, which appeared to be reversed by rh-Angpt1 treatment.

The clonal hematopoiesis mutation Jak2V617F aggravates endothelial injury and thrombosis in arteries with erosion-like intimas

BackgroundSuperficial plaque erosion causes many acute coronary syndromes. However, mechanisms of plaque erosion remain poorly understood, and we lack directed therapeutics for thrombotic complication. Human eroded plaques can harbor neutrophil extracellular traps (NETs) that propagate endothelial damage at experimental arterial lesions that recapitulate superficial erosion. Clonal Hematopoiesis of Indeterminate Potential (CHIP) denotes age-related clonal expansion of bone marrow-derived cells harboring somatic mutations in the absence of overt hematological disease. CHIP heightens the risk of cardiovascular disease, with the greatest increase seen in individuals with JAK2V617F. Neutrophils from mice and humans with JAK2V617F undergo NETosis more readily than Jak2WT (wild-type) cells. We hypothesized that JAK2V617F, by increasing propensity to NETosis, exacerbates aspects of superficial erosion. Methods and resultsWe generated Jak2V617F and Jak2WT mice with heterozygous Jak2V617F in myeloid cells. We induced areas of denuded endothelium that recapitulate features of superficial erosion and assessed endothelial integrity, cellular composition of the erosion, thrombosis rates, and response to ruxolitinib, a clinically available JAK1/2 inhibitor, in relation to genotype. Following experimental erosion, Jak2V617F mice have greater impairment of endothelial barrier function and increased rates of arterial thrombosis. Neointimas in Jak2V617F mice exhibit increased apoptosis, NETosis, and platelet recruitment. Jak2V617F mice treated with ruxolitinib show increased endothelial continuity and reduced apoptosis in the neointima comparable to levels in Jak2WT. ConclusionsThese observations provide new mechanistic insight into the pathophysiology of superficial erosion, the heightened risk for myocardial infarction in JAK2V617F CHIP, and point the way to personalized therapeutics based on CHIP status.

Placental Methylglyoxal in Preeclampsia: Vascular and Biomarker Implications.

Preeclampsia is a multifaceted syndrome that includes maternal vascular dysfunction. We hypothesize that increased placental glycolysis and hypoxia in preeclampsia lead to increased levels of methylglyoxal (MGO), consequently causing vascular dysfunction. Plasma samples and placentas were collected from uncomplicated and preeclampsia pregnancies. Uncomplicated placentas and trophoblast cells (BeWo) were exposed to hypoxia. The reactive dicarbonyl MGO and advanced glycation end products (Nε-(carboxymethyl)lysine [CML], Nε-(carboxyethyl)lysine [CEL], and MGO-derived hydroimidazolone [MG-H]) were quantified using liquid chromatography-tandem mass spectrometry. The activity of GLO1 (glyoxalase-1), that is, the enzyme detoxifying MGO, was measured. The impact of MGO on vascular function was evaluated using wire/pressure myography. The therapeutic potential of the MGO-quencher quercetin and mitochondrial-specific antioxidant mitoquinone mesylate (MitoQ) was explored. MGO, CML, CEL, and MG-H2 levels were elevated in preeclampsia-placentas (+36%, +36%, +25%, and +22%, respectively). Reduced GLO1 activity was observed in preeclampsia-placentas (-12%) and hypoxia-exposed placentas (-16%). Hypoxia-induced MGO accumulation in placentas was mitigated by the MGO-quencher quercetin. Trophoblast cells were identified as the primary source of MGO. Reduced GLO1 activity was also observed in hypoxia-exposed BeWo cells (-26%). Maternal plasma concentrations of CML and the MGO-derived MG-H1 increased as early as 12 weeks of gestation (+16% and +17%, respectively). MGO impaired endothelial barrier function, an effect mitigated by MitoQ, and heightened vascular responsiveness to thromboxane A2. This study reveals the accumulation of placental MGO in preeclampsia and upon exposure to hypoxia, demonstrates how MGO can contribute to vascular impairment, and highlights plasma CML and MG-H1 levels as promising early biomarkers for preeclampsia.

Endothelial dysfunction and complement activation are independently associated with disease duration in patients with systemic vasculitis

ObjectivesSystemic vasculitis is a heterogenous group of autoimmune diseases characterized by enhanced cardiovascular mortality. Endothelial dysfunction is associated with accelerated vascular damage, representing a core pathophysiologic mechanism contributing to excess CV risk. Recent studies have also shown that complement activation holds significant role in the pathogenesis of Anti-Neutrophilic Cytoplasmic Autoantibody (ANCA) -associated vasculitis (AAV). Given the potential crosstalk between the endothelium and complement, we aimed to assess, for the first time simultaneously, easily accessible biomarkers of endothelial dysfunction and complement activation in SV. MethodsWe measured circulating endothelial microvesicles (EMVs) and soluble complement components representative of alternative, classical and terminal activation (C5b-9, C1q, Bb fragments, respectively) in a meticulously selected group of patients with systemic vasculitis, but without cardiovascular disease. Individuals free from systemic diseases, who were matched with patients for cardiovascular risk factors(hypertension, diabetes, smoking, dyslipidemia), comprised the control group. ResultsWe studied 60 individuals (30 in each group). Patients with systemic vasculitis had elevated EMVs, higher levels of C5b-9 [536.4(463.4) vs 1200.94457.3), p = 0.003] and C1q [136.2(146.5 vs 204.2(232.9), p = 0.0129], compared to controls [232.0 (243.5) vs 139.3(52.1), p < 0.001]. In multivariate analysis both EMVs and C5b-9 were independently associated with disease duration (p = 0.005 and p = 0.004 respectively), yet not with disease activity. ConclusionPatients with systemic vasculitis exhibit impaired endothelial function and complement activation, both assessed by easily accessible biomarkers, even in the absence of cardiovascular disease manifestations. EMVs and soluble complement components such as C5b-9 and C1q could be used as early biomarkers of endothelial dysfunction and complement activation, respectively, in clinical practice during the course of SV, yet their predictive value in terms of future cardiovascular disease warrants further verification in appropriately designed studies.

TNF-TNFRI interaction impairs endothelial calcium signaling and elevates blood pressure in obesity

Endothelial dysfunction in small arteries plays a pivotal role in obesity-induced hypertension. Recent investigations have unveiled the detrimental impact of peroxynitrite, a reactive nitrogen species, on endothelium calcium signaling and vasodilation. Vascular inflammation has emerged as a crucial contributor to the pathogenesis of cardiovascular disorders. In this regard, the inflammatory cytokine, tumor necrosis factor (TNF), has been linked to peroxynitrite formation and endothelial dysfunction. Although TNF signaling in cardiovascular disorders is mainly attributed to immune cells, recent studies suggest that endothelial cells (ECs) and smooth muscle cells (SMCs) also produce TNF. We hypothesized that TNF derived from the vascular wall acts locally to inhibit endothelium-dependent vasodilation in obesity. Male C57BL6J mice fed a high-fat diet (HFD, 60% kcal fat) for 14 weeks showed higher blood pressures that normal chow diet (NCD)-fed mice. Flow cytometry and mRNA expression studies showed an increase in TNF levels in freshly isolated SMCs from small mesenteric arteries (MAs) in HFD mice compared to NCD mice. However, TNF levels in ECs were not different between HFD or NCD mice. Control and EC-specific TNF knockout (TNFECKO) mice showed a similar increase in blood pressure after HFD feeding. However, HFD feeding failed to elevate blood pressure in SMC-specific TNF knockout (TNFSMCKO) mice, suggesting a critical role for SMC TNF in blood pressure elevation in HFD mice. Both TNFSMCKO and TNFECKO showed a similar increase in body weight after HFD feeding when compared to control mice, suggesting that differences in weight gain did not contribute to lower blood pressure in obese TNFSMCKO mice. The pro-inflammatory effects of TNF are primarily attributed to TNF receptor-I (TNFRI) signaling. Therefore, we postulated that TNF released from SMCs acts locally on EC TNFRI to impair endothelium-dependent vasodilation. EC-specific TNFRI deletion (TNFRIECKO) reduced blood pressure, whereas SMC-specific TNFRI deletion (TNFRISMCKO) had no effect on blood pressure after HFD feeding. These findings collectively underline the critical role of SMC-derived TNF and endothelial TNFRI in driving blood pressure elevation in diet-induced obesity. Consistent with these data, endothelium-dependent vasodilation in response to acetylcholine markedly improved in obese TNFSMCKO and TNFRIECKO mice compared to obese control mice. Previous studies showed that decreased Ca2+ influx through endothelial TRPV4 (transient receptor potential vanilloid 4) channels contributes to endothelia dysfunction and blood pressure elevation in obese mice. The activity of TRPV4 channels was improved in ECs from HFD-fed TNFSMCKO and TNFRIECKO mice. Additionally, the levels of endothelial peroxynitrite were diminished in obese TNFSMCKO and TNFRIECKO mice, ameliorating the peroxynitrite-dependent impairment of endothelial function. Furthermore, treatment with a selective TNFRI signaling inhibitor (R7050, 10 mg/kg, intraperitoneally, once daily for 14 days) restored blood pressure to normal levels in HFD-fed obese mice but had no effect on the blood pressure in NCD-fed mice. R7050 treatment also restored endothelium-dependent dilation of MAs and the activity of TRPV4 channels in ECs. Collectively, our findings identify a critical role of local TNF-TNFRI signaling in the vascular wall in obesity-induced impairment of endothelial function and blood pressure elevation. The National Institutes of Health to SKS (HL146914, HL142808, and HL147555). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Ongoing, Chronic Stress Exposure Is Related to Impaired Vascular Endothelial Function Among Young Adults Irrespective of Subjective Appraisal of Stressor Severity

Introduction: Chronic stress is associated with cardiovascular morbidity independently of traditional cardiovascular risk factors. Vascular endothelial function (VEF) is predictive of cardiovascular risk and is reduced in response to transient and chronic psychosocial stress. While dominant stress theories (i.e., differential exposure model) posit that stress exposure explains health disparities, it has also been hypothesized that the subjective experience of these stressors — or stress appraisal — may also influence the effects of stress exposure on health. The purpose of this study was to investigate the associations of ongoing, chronic stress exposure and stress appraisal on VEF in young adults. Our hypothesis was that ongoing, chronic stress exposure, rather than stress appraisal, would be more strongly and inversely associated with VEF. We further conceptualized that stress appraisal would moderate the association between stress exposure and VEF. Methods: In 64, healthy young adults (75% Female; age = 25 ± 5 y), we assessed cumulative, chronic stress exposure with a measure that quantified ongoing exposure to 8 specific stressors over the last 12 months. For each chronic stress exposure reported, participants rated the perceived stressor severity using a 3-point Likert scale ( 1 = not upsetting, 2 = somewhat upsetting, 3 = very upsetting). The number of stressors was used as the indicator of ongoing, chronic stress exposure, while the average stressor severity was used as the indicator of stress appraisal. We assessed VEF using the brachial artery flow mediated dilation (FMD) technique normalized to the shear rate stimulus (%·[s1×10−2]) quantified as shear rate area under the curve. Using partial correlations, we examined relations among ongoing, chronic stress exposure and stress appraisal versus VEF, independently of sex. We then conducted an exploratory moderation analysis to assess whether stress appraisal moderated the effect of ongoing, chronic stress exposure on VEF. Results: Ongoing, chronic stress exposure (r=-0.32, p&lt;0.05), but not stress appraisal (r=-0.13, p=0.34) was related to VEF. Further, stress appraisal did not significantly moderate the association between ongoing, chronic stress exposure and VEF (p=0.69). However, the direct effect of ongoing, chronic stress exposure was statistically significant (β = -0.51; p=0.009), whereas the effect of stress appraisal was not (p=0.79), confirming our initial correlation analyses. Conclusions: Our findings indicate that ongoing, chronic stress exposure, rather than the subjective appraisal of this stress, significantly predicts impaired vascular endothelial function among young adults. Thus, our findings provide initial evidence indicating that stressor exposure is suffcient to increase cardiovascular risk independently of the perceived severity of the stressor(s) among young adults. However, the strength of our moderation analysis is limited by sample size, and future larger-scale studies may be necessary to fully understand the degree to which stress appraisal moderates the link between chronic stress and cardiovascular risk. Future studies may also seek to understand how potentially important, modifiable psychological processes influence this relationship, which may also be independent of stress appraisal. Funding provided by a grant from the Injury Prevention Research Center through the CDC (R49 CE003095; NDMJ and EBKT). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Low shear stress-induced blockage of autophagic flux impairs endothelial barrier and facilitates atherosclerosis in mice

Atherosclerosis preferentially occurs in areas with low shear stress (LSS) and oscillatory flow. LSS has been demonstrated to correlate with the development of atherosclerosis. The sphingosine 1-phosphate receptor 1 (S1PR1), involving intravascular blood flow sensing, regulates vascular development and vascular barrier function. However, whether LSS affects atherosclerosis via regulating S1PR1 remains incompletely clear. In this study, immunostaining results of F-actin, β-catenin, and VE-cadherin indicated that LSS impaired endothelial barrier function in human umbilical vein endothelial cells (HUVECs). Western blot analysis showed that LSS resulted in blockage of autophagic flux in HUVECs. In addition, autophagy agonist Rapamycin (Rapa) antagonized LSS-induced endothelial barrier dysfunction, whereas autophagic flux inhibitor Bafilomycin A1 (BafA1) exacerbated it, indicating that LSS promoted endothelial barrier dysfunction by triggering autophagic flux blockage. Notably, gene expression analysis revealed that LSS downregulated S1PR1 expression, which was antagonized by Rapa. Selective S1PR1 antagonist W146 impaired endothelial barrier function of HUVECs under high shear stress (HSS) conditions. Moreover, our data showed that expression of GAPARAPL2, a member of autophagy-related gene 8 (Atg8) proteins, was decreased in HUVECs under LSS conditions. Autophagic flux blockage induced by GAPARAPL2 knockdown inhibited S1PR1, aggravated endothelial barrier dysfunction of HUVECs in vitro, and promoted aortic atherosclerosis in ApoE−/− mice in vivo. Our study demonstrates that autophagic flux blockage induced by LSS downregulates S1PR1 expression and impairs endothelial barrier function. GABARAPL2 inhibition is involved in LSS-induced autophagic flux blockage, which impairs endothelial barrier function via downregulation of S1PR1.

Can the dietary inorganic nitrate supplementation mitigate the vascular dysfunction in elderly with Alzheimer’s disease?

Aging and Alzheimer disease (AD) are both characterized by progressive reduction in nitric oxide bioavailability and endothelial function impairment. Promising studies on young healthy individuals underly the positive effect of dietary nitrate supplementation on endothelial function. However, the pharmacokinetics of the plasma nitrate and nitrite (PN) and the accompanying endothelial responsiveness following the oral nitrate ingestion in healthy elderly (HE) and patients with AD is not clear. Our hypothesis was that due to the reduction of nitric oxide bioavailability during aging and AD, an equal dose of oral nitrate (ON) would ameliorate the endothelial responsiveness more in the HE and even more in patients with AD in comparison to healthy young subjects (HY). Therefore, with the aim of investigating the pharmacokinetics of PN and the time-course endothelial responsiveness in response to a single dose ON, 10 HY (25±4 YRS), 10 HE (72±8 YRS) and 13 AD (73±7 YRS) were recruited. PN levels and endothelial responsiveness (single-passive leg movement (ΔPLM)) were measured in the recruited individuals prior to (T0) and hourly for 4 hours (T1, T2, T3, and T4) after: a) a single dose of ON; and b) a single dose of placebo. As expected at T0 both PN and ΔPLM were significantly reduced in the HE and even more reduced in the AD in comparison to the HY (all p&lt;0.001). No changes in PN nor ΔPLM were detected in any group following placebo intake. PN increased significantly in all three groups at T1 (p&lt;0.001) and constantly increased up to T4, but no differences were detected between time points T1 to T4 in any group. ΔPLM increased significantly in all three groups at T2, reaching highest values at T4 (p&lt;0.001). However, AD exhibited significantly lower ΔPLM values at any time point compared to HY (p&lt;0.0001) and HE (p&lt;0.001). Significant correlation between PN and ΔPLM was found (p&lt;0.001, R2=0.1654). Contrary to our hypothesis, the results of this study suggest that the PN pharmacokinetics following a single dose of ON is similar in HY, HE and AD. Moreover, the expected time-course amelioration of the endothelial responsiveness was reduced in the HE and even more reduced in the AD, suggesting that other factors, rather than the nitric oxide bioavailability, are playing a role in the age- and AD-related vascular dysfunction. Ricerca di Base 2017 - RBVR17XRSA - Effectiveness of exercise and nitrate supplementation on progression of dementia in patients with Alzheimer’s disease. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Poor Sleep Quality Contributes to Vascular Endothelial Dysfunction in Young Adults with Adverse Childhood Experiences

Introduction: Adverse childhood experiences (ACEs) represent severe psychosocial stressors during the first 18 years of life that promote a dose-dependent, lifetime increase in cardiovascular disease risk. ACEs have been associated with impaired vascular endothelial function and poor sleep quality in young adults. However, whether poor sleep quality influences the association between ACEs and vascular endothelial function is unclear. We hypothesized that sleep quality would mediate the association of ACE exposure with impaired vascular function. Purpose: To examine the contribution of sleep quality to ACEs-related impairments in vascular endothelial function in young adults. Methods: We used a cross-sectional cohort study (Study 1) and a single-arm intervention (Study 2) to test our hypothesis. Sleep quality was characterized as sleep effciency (SE%) and calculated as total sleep duration relative to time-in-bed. Vascular endothelial function was assessed using the brachial artery flow mediated dilation technique (FMD). In Study 1, we examined the mediation effect of SE% in the association of ACE exposure with FMD in a cohort of young adults (n=56; age = 25 ± 5 y, BMI = 26 ± 5 kg/m2) using the bootstrapped (1,000 replications) bias-corrected percentile confidence interval method adjusted for sex, and depression and anxiety symptomology. The variance accounted for (VAF) was calculated as the ratio of the indirect effect to total effect β-coeffcients. In Study 2, with a separate sample (n=12; age = 21 ± 2 y, BMI = 23 ± 4 kg/m2) of young adults with high ACE exposure (5 ± 2 ACEs) and poor sleep quality (SE ≤ 90%), we manipulated SE% using 6-weeks of cognitive-behavioral therapy for insomnia (CBTi) and measured FMD before (PRE) and after (POST) the intervention. Change in weekly SE% from daily consensus sleep diary entries was analyzed using a one-way ANOVA with Tukey post hoc comparisons. PRE to POST change in FMD was analyzed with a paired samples t-test. The association between the change (Δ; POST-PRE) in SE% and FMD was examined using a Spearman’s correlation coeffcient (ρ). Results: In Study 1, SE% significantly, partially mediated the association between ACE exposure and FMD (indirect effect standardized β-estimate = -0.11 [95% CI = -0.29 – -0.02]; VAF = 27.4%). In Study 2, there was a treatment effect of CBTi on SE% ( p &lt; 0.001) where SE% improved from baseline to weeks 3, 4, 5, and 6 (weekly improvement range = 8.8 – 10.1%; all p ≤ 0.002). FMD increased PRE to POST (2.85 ± 0.58 to 3.65 ± 1.0 %/SR AUC·104; p = 0.017). There was a moderate, non-significant association between ΔSE% and ΔFMD (ρ = 0.46, p = 0.13). Conclusions: Our findings provide initial evidence that poor sleep quality may contribute to the previously described impairment in vascular endothelial dysfunction observed with increasing ACE exposure in young adults. Funding provided by a grant from the Injury Prevention Research Center through the CDC (R49 CE003095; NDMJ). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Influence of Resting Retrograde Shear Rate on Endothelial Function as Assessed by Flow Mediated Dilation

Shear stress profiles are an important determinant of endothelial function. Unidirectional blood flow enhances mean shear and protects endothelial function, whereas increased retrograde and oscillatory shear favors a proatherogenic environment. In this regard, acutely increasing retrograde shear has been shown to impair endothelial function. Also, previous studies have reported an elevation in retrograde shear in older adults that has been suggested to contribute to impaired endothelial function with age. However, the impact of having elevated retrograde shear at rest on endothelial function remains unclear. Therefore, we aimed to assess the associations between resting shear patterns and endothelial function, as measured by flow-mediated dilation (FMD) in a cohort of young and older adults. We hypothesized that higher retrograde shear rate and oscillatory shear index at rest would be related to a lower FMD value. Method: A total of 60 participants, 30 young adults (24 ± 5 years) and 30 older adults (62 ± 9 years), were studied. Resting brachial artery blood flow was measured using duplex Doppler ultrasound and retrograde shear rate and oscillatory shear index were calculated. Brachial artery FMD was used as a measure of endothelial function. Pearson correlations were used to investigate the associations between FMD, resting shear patterns, and age. Result: FMD was significantly lower in older compared to young adults (4.9 ± 2.7% vs. 7.6 ± 3.2%, p &lt; 0.01). Both retrograde shear rate and oscillatory shear index tended to be greater in older adults (-20.7 ± 15.1 s−1 vs. -15.2 ± 17 s−1, p = 0.062, and 10.7 ± 8% vs. 7.9 ± 8.0%, p = 0.056, respectively). FMD was not correlated with retrograde shear rate (r = -0.18, p = 0.17), or oscillatory shear index (r = -0.21, p = 0.11) in the entire cohort or in the young and older group alone. However, FMD, retrograde shear rate, and oscillatory index were moderately correlated with age: FMD (r = -0.45, p &lt; 0.01), retrograde shear rate (r = -0.32, p = 0.012), and oscillatory shear index (r = 0.33, p &lt; 0.01). Conclusion: These preliminary results suggest that resting retrograde shear and oscillatory shear index are not associated with reduced endothelial function in a cohort of young and old adults. Nevertheless, age-associated reductions in endothelial function and elevated retrograde shear were observed. This project was supported by the College of Nursing and Health Innovation. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effects of Myocardial Infarction-induced Heart Failure on Diaphragm Arteriolar Vasorelaxation

INTRODUCTION: Diaphragm atrophy and contractile dysfunction are prevalent in heart failure (HF), diminishing physical capacity and quality of life. The delivery of blood flow and oxygen necessary to support the metabolic demand of contractions is largely governed by the resistance vasculature (i.e., arterioles) with the endothelium playing a central role in arteriolar vasorelaxation. Adequate perfusion and blood flow distribution, and thus resistance vessel vasodilation, is a major determinate of diaphragm contractile function. While the mechanistic bases of HF-induced diaphragm dysfunction continue to be elucidated, the impact of HF on diaphragm vasomotor control has not been investigated. METHODS: Adult (6 mo) Sprague-Dawley rats (n=7) were divided into two groups: 1) Healthy Control (HC; n=4) and 2) MI-induced heart failure (HF; n=3). First-order arterioles (1A) from the medial costal diaphragm were isolated, cannulated, and pressurized at 90 cmH2O and allowed to equilibrate for 60 min to develop spontaneous tone. Thereafter, endothelium-dependent and -independent vasorelaxation responses to cumulative doses of acetylcholine (ACh; 10−9 to 10−4M) and sodium nitroprusside (SNP; 10−9 to 10−4M) were determined. RESULTS: There were no differences in spontaneous development (%) or maximal diameter (μm) between HC (20 ± 4%; 178 ± 11 μm) and HF (18 ± 2%; 184 ± 29 μm) diaphragm 1As ( P &gt; 0.05). Maximal ACh-mediated relaxation (%) was significantly reduced in HF rats compared to HC rats (52 ± 2 versus 68 ± 5%; P &lt; 0.05). Maximal endothelial-independent vasorelaxation with SNP, was not different between HC and HF rats (71 ± 3 versus 73 ± 1%; P &gt; 0.05). CONCLUSION: The preliminary data herein demonstrate that HF impaired endothelial function and vasomotor function in the medial costal diaphragm resistance vasculature. This suggests that, in HF, there may be a redistribution of blood flow to less effcient regions of the diaphragm (e.g., ventral costal) to sustain contractile function and compensate for the diminished medial costal vasomotor function demonstrated herein. Studies including a larger sample size are warranted to investigate the impact of HF on regional blood flow distribution and resistance vessel function in the diaphragm. Such investigations would yield novel mechanistic insights into HF-induced diaphragm dysfunction. National Institute of Aging 1R15AG078060, Ruth L. Kirschstein National Research Service Awards from the National Heart, Lung, and Blood Institute 1F31HL167618-01, and Sustained Momentum for Investigators with Laboratories Established (SMILE) Grants at Kansas State University. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Racial Disparities in Cardio-Oncology: Contributions of Anti-Cancer Therapy Induced Endothelial Dysfunction

Background: Major adverse cardiovascular (CV) events (MACE) related to anti-cancer therapy (CTx) represent the leading cause of non-cancer related mortality among breast cancer (BC) survivors. Most preclinical studies have focused on the heart, but increasing evidence suggests decreased endothelial function is predictive of CTx induced cardiac events. To date, the role of microvascular endothelial (dys)function, a well-established predictor of MACE, has been mostly ignored and few mechanistic studies exist in human subjects. CV disease in general, and CTx induced adverse events specifically, are significantly more prevalent in Black (B) relative to non-Hispanic White (NHW) patients. Despite the overwhelming clinical evidence supporting these health disparities, the underlying causes are poorly understood. Our lab and others have demonstrated that isolated vessels from human tissue samples can be used to understand the mechanisms contributing to CV disease. The overall goal of this study is to determine the effect of anti-cancer therapy on microvascular function and identify possible racial disparities. Hypothesis: Ex vivo treatment with CTx leads to impaired endothelial function, which is augmented in healthy donor vessels from B compared to NHW patients. Methods: Human adipose arterioles obtained from de-identified surgical discarded specimens of healthy B and NWH patients were used for video-microscopy. Vessels were incubated ex vivo 16–20 h with CTx (trastuzumab-TZM, doxorubicin-Dox, or paclitaxel-PTX). Response to endothelial dependent flow mediated dilation (FMD 5-100 cmH2O pressure gradient), acetylcholine (ACh; 10−9 to 10−5 M), and the endothelial independent dilator papaverine (Pap 10-4 M) were evaluated. Data are presented as %Max diameter ± SEM, N. Statistical significance was established with 2-way ANOVA RM *p&lt;0.05. Results: Exposure to Dox decreased FMD equally in vessels from B (19±3, n=8) vs. NHW patients (29±5 n=8). The TZM induced endothelial dysfunction in vessels from B patients (37±8*, n=11) was augmented compared to NHW patients (57±15, n=6). PTX did not impair FMD in NHW patients (93±0.9, n=7) but showed a significant reduction in vessels from B patients (49±10*, n=10). Similar results were observed with ACh dilation, but Max dilator capacity to papaverine was unchanged in either group (not shown). Conclusion: Our findings suggest that racial disparities may contribute to differences in microvascular function and clinical outcomes of BC patients. Since dysfunction of the microcirculation is a common predecessor to heart failure and other MACE, novel strategies designed to predict, manage, and treat these adverse effects are needed and should be tailored to individual patient populations. To date, we cannot differentiate between biological/genetic vs. social/environmental contributors to the observed microvascular responses to CTx; that will be the focus of future studies. This work was supported by the American Heart Association Scientific Focused Research Network grant (SFRN.). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Effects of BNT162b2 mRNA Covid-19 vaccine on vascular function.

The effects of Covid-19 vaccines on vascular function are still controversial. We evaluated the effects of BNT162b2 vaccine (BioNTech and Pfizer) on endothelial function assessed by flow-mediated vasodilation (FMD) and vascular smooth muscle function assessed by nitroglycerine-induced vasodilation (NID). This study was a prospective observational study. A total of 23 medical staff at Hiroshima University Hospital were enrolled in this study. FMD and NID were measured before vaccination and two weeks and six months after the 2nd dose of vaccination. FMD was significantly smaller two weeks after the 2nd dose of vaccination than before vaccination (6.5±2.4% and 8.2±2.6%, p = 0.03). FMD was significantly larger at six months than at two weeks after the 2nd dose of vaccination (8.2±3.0% and 6.5±2.4%, p = 0.03). There was no significant difference between FMD before vaccination and that at six months after the 2nd dose of vaccination (8.2±2.6% to 8.2±3.0%, p = 0.96). NID values were similar before vaccination and at two weeks, and six months after vaccination (p = 0.89). The BNT162b2 Covid-19 vaccine temporally impaired endothelial function but not vascular smooth muscle function, and the impaired endothelial function returned to the baseline level within six months after vaccination.

RNF213 variant and autophagic impairment: A pivotal link to endothelial dysfunction in moyamoya disease.

Moyamoya disease (MMD) is closely associated with the Ring Finger Protein 213 (RNF213), a susceptibility gene for MMD. However, its biological function remains unclear. We aimed to elucidate the role of RNF213 in the damage incurred by human endothelial cells under oxygen-glucose deprivation (OGD). We analyzed autophagy in peripheral blood mononuclear cells (PBMCs) derived from patients carrying either RNF213 wildtype (WT) or variant (p.R4810K). Subsequently, human umbilical vein endothelial cells (HUVECs) were transfected with RNF213 WT (HUVECWT) or p.R4810K (HUVECR4810K) and exposed to OGD for 2 h. Immunoblotting was used to analyze autophagy marker proteins, and endothelial function was analyzed by tube formation assay. Autophagic vesicles were observed using transmission electron microscopy. Post-OGD exposure, we administered rapamycin and cilostazol as potential autophagy inducers. The RNF213 variant group during post-OGD exposure (vs. pre-OGD) showed autophagy inhibition, increased protein expression of SQSTM1/p62 (p < 0.0001) and LC3-II (p = 0.0039), and impaired endothelial function (p = 0.0252). HUVECR4810K during post-OGD exposure (versus pre-OGD) showed a remarkable increase in autophagic vesicles. Administration of rapamycin and cilostazol notably restored the function of HUVECR4810K and autophagy. Our findings support the pivotal role of autophagy impaired by the RNF213 variant in MMD-induced endothelial cell dysfunction.

Endothelial function in patients with chronic myeloid leukemia treated with tyrosine kinase inhibitors is not related to cardiovascular risk assessed by SCORE2 algorithm.

Tyrosine kinase inhibitors (TKIs) revolutionized the treatment of chronic myeloid leukemia (CML) but are endowed with negative effects on endothelial function. To characterize endothelial function in patients with CML treated with various TKIs. Forty-eight patients diagnosed with chronic phase CML treated with TKIs, such as imatinib, bosutinib, nilotinib, ponatinib, and asciminib were included. Endothelial function was assessed in the brachial artery and microcirculation based on flow-mediated dilation (FMD), reactive hyperemia peripheral arterial tonometry (RH-PAT) and Flow Mediated Skin Fluorescence (FMSF). Reactive Hyperemia Index (RHI), FMD [%], Reactive Hyperemia Response (RHR [%]), Normoxia Oscillatory index (NOI [%]) and Hyperemic Response index (HR index [%]) did not differentiate between the group of patients with low / moderate risk in the Systemic Coronary Risk Estimation 2 (SCORE2), SCORE2-Older Persons (SCORE2-OP) and those with high / very high-risk scores. Among patients with low/intermediate risk based on the SCORE2 algorithms, some had lower (<Q1) values of endothelial parameters, reflecting impaired endothelial function, when compared with the whole population. Lower values of endothelial function parameters were associated with overall long-term treatment with TKIs or ponatinib treatment. Importantly, endothelial function assessed by FMSF (RHR [%]) negatively correlated with the total duration of TKI treatment, also after adjustment for age. Endothelial function in CML patients treated with TKIs was not related to cardiovascular risk based on SCORE2/SCORE2-OP algorithms but CML-specific factors, including duration of TKI treatment. FMSF-based assessment of skin microcirculation was a sensitive method for detecting the vascular effects of TKIs.

PREGNANT WOMEN STRUGGLING WITH HIGH BLOOD PRESSURE AND STRESS IN PREGNANCY AND ROLE OF NITRIC OXIDE SUPPLEMENTS L-ARGININE FOR PROLONG PERIOD

INTRODUCTION: Mental stress can contribute to the exacerbation of hypertension in pregnant women and preeclampsia by the release of stress hormones such as adrenaline and cortisol level. Less nitric oxide (NO)-dependent vasodilation and excess formation of reactive oxygen species could explain poor placenta perfusion already in PIH and Preeclampsia due to impaired endothelial function. Studies have indicated that Nitric oxide supplement L-arginine can lead to beneficial effects on various cardiometabolic markers, including blood pressure and vascular function especially in pregnant mothers. OBJECTIVE: The primary objective of this meta-analysis study of placebo-controlled trials was to assess and ascertain the evidence of effectiveness of L-arginine and its use in enhancing nitric oxide synthesis to translate into tangible improvement in Hypertension and preeclampsia management, Nitric oxide supplement L-arginine’s ubiquitous molecule’s role is a subject of debate and research with focus on both systolic and diastolic values, pregnancy outcomes and understanding of its role in Hypertension resistant to currently available therapies. METHODS: In this study focused on role of L-arginine on high blood pressure during pregnancy, we did a thorough research, effective communication of information from relevant and up-to-date research articles, studies from reputable sources and great places of academic database like PubMed, Google Scholar, medical journals. Around 16 trials were searched in Pub-Med and Google scholar. A total of six trials were included in this meta-analysis. RESULTS: Result of this meta-analysis shows Nitric Oxide L-arginine supplementation showed a mean decrease in diastolic blood pressure and can lead to beneficial effect on blood pressure and vascular function especially in pregnant mothers with stress, mean increase up to 1. 23 weeks (p = 0. 002) for gestation period to delivery but did not showed reduction in systolic blood pressure as compared to placebo. CONCLUSION: This meta-analysis study supports the notion that availability of this substrate for NO synthesis prolongs the latency to development of preeclampsia and decrease the hypertension in a high-risk pregnant woman with Hypertension and stress.

Role of the circulating milieu in age-related arterial dysfunction: a novel ex vivo approach.

The circulating milieu, bioactive molecules in the bloodstream, is altered with aging and interfaces constantly with the vasculature. This anatomic juxtaposition suggests that circulating factors may actively modulate arterial function. Here, we developed a novel, translational experimental model that allows for direct interrogation of the influence of the circulating milieu on age-related arterial dysfunction (aortic stiffening and endothelial dysfunction). To do so, we exposed young and old mouse arteries to serum from young and old mice and young and midlife/older (ML/O) adult humans. We found that old mouse and ML/O adult human, but not young, serum stiffened young mouse aortic rings, assessed via elastic modulus (mouse and human serum, P = 0.003 vs. young serum control), and impaired carotid artery endothelial function, assessed by endothelium-dependent dilation (EDD) (mouse serum, P < 0.001; human serum, P = 0.006 vs. young serum control). Furthermore, young mouse and human, but not old, serum reduced aortic elastic modulus (mouse serum, P = 0.009; human serum, P < 0.001 vs. old/MLO serum control) and improved EDD (mouse and human serum, P = 0.015 vs. old/MLO serum control) in old arteries. In human serum-exposed arteries, in vivo arterial function assessed in the human donors correlated with circulating milieu-modulated arterial function in young mouse arteries (aortic stiffness, r = 0.634, P = 0.005; endothelial function, r = 0.609, P = 0.004) and old mouse arteries (aortic stiffness, r = 0.664, P = 0.001; endothelial function, r = 0.637, P = 0.003). This study establishes novel experimental approaches for directly assessing the effects of the circulating milieu on arterial function and implicates changes in the circulating milieu as a mechanism of in vivo arterial aging.NEW & NOTEWORTHY Changes in the circulating milieu with advancing age may be a mechanism underlying age-related arterial dysfunction. Ex vivo exposure of young mouse arteries to the circulating milieu from old mice or midlife/older adults impairs arterial function whereas exposure of old mouse arteries to the circulating milieu from young mice or young adults improves arterial function. These findings establish that the circulating milieu directly influences arterial function with aging.