Transcriptomic Analysis of 3D Vasculature-On-A-Chip Reveals Paracrine Factors Affecting Vasculature Growth and Maturation

In vitro models of vasculature are of great importance for modelling vascular physiology and pathology. However, there is usually a lack of proper spatial patterning of interacting heterotypic cells in conventional vasculature dish models, which might confound results between contact and non-contact interactions. We use a microfluidic platform with structurally defined separation between human microvasculature and fibroblasts to probe their dynamic, paracrine interactions. We also develop a novel, versatile technique to retrieve cells embedded in extracellular matrix from the microfluidic device for downstream transcriptomic analysis, and uncover growth factor and cytokine expression profiles associated with improved vasculature growth. Paired receptor-ligand analysis further reveals paracrine signaling molecules that could be supplemented into the medium for vasculatures models where fibroblast co-culture is undesirable or infeasible. These findings also provide deeper insights into the molecular cues for more physiologically relevant vascular mimicry and vascularized organoid model for clinical applications such as drug screening and disease modeling.

Exercise capacity benefit in relation to endogenous testosterone, coronary and central vascular physiology, and the Mediterranean regime in hypertensive males with erectile dysfunction

Background The Mediterranean diet (Med-diet) benefits cardiovascular health, and erectile dysfunction (ED) often coexists in the hypertensive aging male population were endogenous testosterone (TT) typically declines. Coronary flow reserve (CFR) displays the ability of the coronary circulation to increase flow. Wave reflection amplification as expressed by augmentation index (AIx) exhibits a vital parameter of central vascular stiffness. Purpose To investigate the possible benefits of the Med-diet in exercise capacity, central physiology, CFR and erectile ability in relation to endogenous TT in the middle aged male hypertensive population with ED. Methods 250 hypertensive males (mean age 56 yo) with ED enrolled the study. All underwent a treadmill stress test (Bruce protocol). Exercise capacity was validated as metabolic equivalents (METs). We measured separately the CFR of the left anterior descending artery by an adenosine protocol (max dose 140μg/kg/min over 6 minutes). PW Doppler measurements were achieved at the middle/distal LAD segment under the guidance of color Doppler flow mapping. CFR was validated as ratio between peak diastolic flow velocity following drug infusion and rest. Ratios ≥2 are considered as non-ischemic response, higher values indicate microvascular coronary integrity. TT was measured on blood samples taken before 09:00 am. ED severity and adherence to the Med-diet were assessed by the SHIM-5 (range: 0–25) and the Med-diet (range: 0–55) scores. Higher values indicate a better erectile ability and Med-diet compliance respectively. Finally, central pulse pressure (cPP) and AIx were noninvasively estimated as parameters of central hemodynamic load and wave reflection amplification (Sphygmocor device). Results In bivariate analysis METs were positively associated to the Med-diet, CFR, TT and the SHIM-5 score (all p<0,005) and negatively to the AIx and cPP (both p<0,025). There was also positive association of the Med-diet to the CFR, TT and the SHIM-5 score (p<0,02) and negative to the AIx and cPP (p<0,025). By linear regression analysis association of METs to TT, CFR and Med-diet remained significant after adjustment for age, BMI, diabetes mellitus, use of statins and smoking status (p<0,005). We further subdivide our population according to the TT threshold of hypogonadism (≤3 ng/ml). Hypogonadism patients exhibit a lower exercise capacity comparing to the normal TT group (picture). Conclusion The Med-diet regime benefits exercise tolerance and erectile performance in hypertensive males with ED by enhancing endogenous testosterone and so coronary and central vascular physiology. We strongly recommend this culinary preference promoting thus vascular health and the sense of well being. FUNDunding Acknowledgement Type of funding sources: None.

Nuts: Natural Pleiotropic Nutraceuticals

Common nuts (tree nuts and peanuts) are energy-dense foods that nature has gifted with a complex matrix of beneficial nutrients and bioactives, including monounsaturated and polyunsaturated fatty acids, high-quality protein, fiber, non-sodium minerals, tocopherols, phytosterols, and antioxidant phenolics. These nut components synergize to favorably influence metabolic and vascular physiology pathways, ameliorate cardiovascular risk factors and improve cardiovascular prognosis. There is increasing evidence that nuts positively impact myriad other health outcomes as well. Nut consumption is correlated with lower cancer incidence and cancer mortality, and decreased all-cause mortality. Favorable effects on cognitive function and depression have also been reported. Randomized controlled trials consistently show nuts have a cholesterol-lowering effect. Nut consumption also confers modest improvements on glycemic control, blood pressure (BP), endothelial function, and inflammation. Although nuts are energy-dense foods, they do not predispose to obesity, and in fact may even help in weight loss. Tree nuts and peanuts, but not peanut butter, generally produce similar positive effects on outcomes. First level evidence from the PREDIMED trial shows that, in the context of a Mediterranean diet, consumption of 30 g/d of nuts (walnuts, almonds, and hazelnuts) significantly lowered the risk of a composite endpoint of major adverse cardiovascular events (myocardial infarction, stroke, and death from cardiovascular disease) by ≈30% after intervention for 5 y. Impressively, the nut-supplemented diet reduced stroke risk by 45%. As they are rich in salutary bioactive compounds and beneficially impact various health outcomes, nuts can be considered natural pleiotropic nutraceuticals.

Capillary-associated microglia regulate vascular structure and function through PANX1-P2RY12 coupling in mice

Microglia are brain-resident immune cells with a repertoire of functions in the brain. However, the extent of their interactions with the vasculature and potential regulation of vascular physiology has been insufficiently explored. Here, we document interactions between ramified CX3CR1 + myeloid cell somata and brain capillaries. We confirm that these cells are bona fide microglia by molecular, morphological and ultrastructural approaches. Then, we give a detailed spatio-temporal characterization of these capillary-associated microglia (CAMs) comparing them with parenchymal microglia (PCMs) in their morphological activities including during microglial depletion and repopulation. Molecularly, we identify P2RY12 receptors as a regulator of CAM interactions under the control of released purines from pannexin 1 (PANX1) channels. Furthermore, microglial elimination triggered capillary dilation, blood flow increase, and impaired vasodilation that were recapitulated in P2RY12−/− and PANX1−/− mice suggesting purines released through PANX1 channels play important roles in activating microglial P2RY12 receptors to regulate neurovascular structure and function.

Abstract P233: Microvascular Fingerprint Of Multi-Organ Imaging - New Insights In Preeclampsia Research

To establish the first protocol for high-resolution three-dimensional imaging of multiple organs in rodents, we performed microvasculature casting with Microfil silicone rubber substance in non-living rats and combined the method with advanced image analysis protocols after micro-CT scanning. This newly established method allows changes in individual organs to be visualized and examined in extraordinary detail as part of a multi-organ approach. Previously published protocols only address visualization of single organs or are insufficiently resolved with respect to vessel diameter analysis. With optimized staining protocols, samples can additionally be examined for possible structural changes such as inflammatory processes or fibrotic formation. Preeclampsia is a condition during pregnancy that leads to up to a 4-fold increased risk of maternal cardiovascular disease later in life, although symptoms usually resolve after delivery. In former preeclamptic rats, a reduction in microvascular density in the heart and brain with a simultaneous increase in retinal vessels has been described, even weeks after the disappearance of major features such as hypertension and albuminuria. The technique described will enhance studies of the vasculature in many other animal models and provide striking insights into vascular physiology necessary to drive translation.

The Vascular Circadian Clock in Chronic Kidney Disease

Chronic kidney disease is associated with extremely high cardiovascular mortality. The circadian rhythms (CR) have an impact on vascular function. The disruption of CR causes serious health problems and contributes to the development of cardiovascular diseases. Uremia may affect the master pacemaker of CR in the hypothalamus. A molecular circadian clock is also expressed in peripheral tissues, including the vasculature, where it regulates the different aspects of both vascular physiology and pathophysiology. Here, we address the impact of CKD on the intrinsic circadian clock in the vasculature. The expression of the core circadian clock genes in the aorta is disrupted in CKD. We propose a novel concept of the disruption of the circadian clock system in the vasculature of importance for the pathology of the uremic vasculopathy.

Mechanisms underlying the therapeutic potential of mesenchymal stem cells in atherosclerosis

Atherosclerosis is a chronic inflammatory condition resulting in the formation of fibrofatty plaques within the intimal layer of arterial walls. The identification of resident stem cells in the vascular wall has led to significant investigation into their contributions to health and disease, as well as their therapeutic potential. Of these, mesenchymal stem cells (MSCs) are the most widely studied in human clinical trials, which have demonstrated a modulatory role in vascular physiology and disease. This review highlights the most recent knowledge surrounding the cell biology of MSCs, including their origin, identification markers and differentiation potential. The limitations concerning the implementation of MSC therapy are considered and novel solutions to overcome these are proposed.

Aldosterone and Renin Concentration Abnormally Elevated in a Cohort of Normotensive Pregnant Women

During pregnancy the renin-angiotensin-aldosterone system (RAAS) undergo major changes to preserve normal blood pressure (BP), placenta blood flow and ensure a good pregnancy outcome. Abnormal aldosterone-renin metabolism is a risk factor for arterial hypertension and cardiovascular risk, but its association to pathological conditions in pregnancy remains unknown. Hence, clinical and subclinical novel biomarkers associated to these pathological conditions are encouraged to be identified. Aim: To study a cohort of normotensive pregnant women according to their serum aldosterone and plasma renin levels and assay their small extracellular vesicles (sEV) and a specific protein-cargo (LCN2, AT1R). Methods: A cohort of 54 normotensive pregnant women at term gestation. We determined the BP, serum aldosterone and plasma renin concentration. In a subgroup, we isolated their plasma sEVs and semi-quantify two EV-proteins (AT1R, LCN2). Results: We set a normal range of aldosterone and renin based in the interquartile range. We identified 5/54(9%) pregnant women with elevated aldosterone and low renin levels, and 5/54(9%) other pregnant women with low aldosterone and elevated renin levels. No differences were found in sEV-LCN2 nor sEV-AT1R. Conclusion: We found 18% normotensive pregnant women having either high aldosterone or high renin levels, suggesting a subclinical status similar to a primary aldosteronism or a hyperreninemia. Both would evolve to pathological conditions in presence a second challenge affecting the maternal vascular physiology or the BP. sEVs and its specific cargo are encouraged to be further studied in order to clarify its role as potential biomarkers of RAAS alterations in pregnant women.