Vascular Physiology Research Articles

Ion channel molecular complexes in vascular smooth muscle.

Ion channels that influence membrane potential and intracellular calcium concentration control vascular smooth muscle excitability. Voltage-gated calcium channels (VGCC), transient receptor potential (TRP) channels, voltage (KV), and Ca2+-activated K+ (BK) channels are key regulators of vascular smooth muscle excitability and contractility. These channels are regulated by various signaling cues, including protein kinases and phosphatases. The effects of these ubiquitous signaling molecules often depend on the formation of macromolecular complexes that provide a platform for targeting and compartmentalizing signaling events to specific substrates. This manuscript summarizes our current understanding of specific molecular complexes involving VGCC, TRP, and KV and BK channels and their contribution to regulating vascular physiology.

Retinal Vascular Physiology Biomarkers in a 5XFAD Mouse Model of Alzheimer's Disease.

Background: Alzheimer’s disease (AD) is a neurodegenerative disorder that affects the brain and retina and lacks reliable biomarkers for early diagnosis. As amyloid beta (Aβ) manifestations emerge prior to clinical symptoms and plaques of amyloid may cause vascular damage, identification of retinal vascular biomarkers may improve knowledge of AD pathophysiology and potentially serve as therapeutic targets. The purpose of the current study was to test the hypothesis that retinal hemodynamic and oxygen metrics are altered in 5XFAD mice. Methods: Thirty-two male mice were evaluated at 3 months of age: sixteen 5XFAD transgenic and sixteen wild-type mice. Spectral-domain optical coherence tomography, vascular oxygen tension, and blood flow imaging were performed in one eye of each mouse. After imaging, the imaged and fellow retinal tissues were submitted for histological sectioning and amyloid protein analysis, respectively. Protein analysis was also performed on the brain tissues. Results: Retinal physiological changes in venous diameter and blood velocity, arterial and venous oxygen contents, coupled with anatomical alterations in the thickness of retinal cell layers were detected in 5XFAD mice. Moreover, an increase in Aβ42 levels in both the retina and brain tissues was observed in 5XFAD mice. Significant changes in retinal oxygen delivery, metabolism, or extraction fraction were not detected. Based on compiled data from both groups, arterial oxygen content was inversely related to venous blood velocity and nerve fiber/ganglion cell layer thickness. Conclusions: Concurrent alterations in retinal hemodynamic and oxygen metrics, thickness, and tissue Aβ42 protein levels in 5XFAD mice at 3 months of age corresponded to previously reported findings in human AD. Overall, these results suggest that this mouse model can be utilized for studying pathophysiology of AD and evaluating potential therapies.

Vascular aging in adult congenital heart disease-a narrative review.

Background and ObjectiveMany studies about the high prevalence of cardiovascular disease in adults with congenital heart disease (CHD) have been published in response to the growing number of adult patients with CHD. The aging process leads to hypertension and cardiovascular disease, which is caused by a degenerative change in the systemic arterial system characterized by the stiffening of elastic arteries (known as arteriosclerosis) and the enlargement of aorta. In patients with CHD, aortic dilatation (so-called aortopathy) is one of the most frequent complications. It is well known the anatomical and histological changes in aortopathy are similar to those in aging process. The increase of pulse wave velocity (PWV) enhances pressure wave reflection, and it augments left ventricular afterload and impairs the coronary supply-workload balance in aging. This article reviews the aortic function in patients with CHD, aiming to provide a new direction for the management of their cardiovascular aging process.MethodsPapers on vascular physiology in CHD were retrieved. I searched all original papers and reviews about the vascular physiology in CHD using PubMed, published from January 1, 1973 to June 30, 2022, in English.Key Content and FindingsEnhancement of pressure wave reflection has been reported in many CHDs. Although PWV in whole aorta is not necessarily elevated, the abnormal arterial stiffness gradient is common in patients with CHD.ConclusionsMany reports concerning functional abnormalities of the aorta have been reported. The abnormalities can result in cardiovascular disease and organ damage. The practitioners should carefully treat patients with CHD while paying attention to their aging process.

A Review of Functional Analysis of Endothelial Cells in Flow Chambers

The vascular endothelial cells constitute the innermost layer. The cells are exposed to mechanical stress by the flow, causing them to express their functions. To elucidate the functions, methods involving seeding endothelial cells as a layer in a chamber were studied. The chambers are known as parallel plate, T-chamber, step, cone plate, and stretch. The stimulated functions or signals from endothelial cells by flows are extensively connected to other outer layers of arteries or organs. The coculture layer was developed in a chamber to investigate the interaction between smooth muscle cells in the middle layer of the blood vessel wall in vascular physiology and pathology. Additionally, the microfabrication technology used to create a chamber for a microfluidic device involves both mechanical and chemical stimulation of cells to show their dynamics in in vivo microenvironments. The purpose of this study is to summarize the blood flow (flow inducing) for the functions connecting to endothelial cells and blood vessels, and to find directions for future chamber and device developments for further understanding and application of vascular functions. The relationship between chamber design flow, cell layers, and microfluidics was studied.

Ang2-Targeted Combination Therapy for Cancer Treatment.

Angiopoietin-2 (Ang2), a member of the angiopoietin family, is widely involved in the process of vascular physiology, bone physiology, adipose tissue physiology and the occurrence and development of inflammation, cardiac hypertrophy, rheumatoid, tumor and other diseases under pathological conditions. Proliferation and metastasis of cancer largely depend on angiogenesis. Therefore, anti-angiogenesis has become the target of tumor therapy. Due to the Ang2 plays a key role in promoting angiogenesis and stability in vascular physiology, the imbalance of its expression is an important condition for the occurrence and development of cancer. It has been proved that blocking Ang2 can inhibit the growth, invasion and metastasis of cancer cells. In recent years, research has been constantly supplemented. We focus on the mechanisms that regulate the expression of Ang2 mRNA and protein levels in different cancers, contributing to a better understanding of how Ang2 exerts different effects in different cancers and stages, as well as facilitating more specific targeting of relevant molecules in cancer therapy. At the same time, the importance of Ang2 in cancer growth, metastasis, prognosis and combination therapy is pointed out. And finally, we will discuss the current investigations and future challenges of combining Ang2 inhibition with chemotherapy, immunotherapy, and radiotherapy to increase its efficacy in cancer patients. This review provides a theoretical reference for the development of new targets and effective combination therapy strategies for cancer treatment in the future.

The role of the autonomic nervous system in cerebral blood flow regulation in dementia: A review.

In this review we will examine the role of the autonomic nervous system in the control of cerebral blood flow (CBF) in dementia. Worldwide, 55 million people currently live with dementia, and this figure will increase as the global population ages. Understanding the changes in vascular physiology in dementia could pave the way for novel therapeutic approaches. Reductions in CBF have been demonstrated in multiple dementia sub-types, in addition to increased cerebrovascular resistance and reduced vasoreactivity. Cerebral autoregulation (CA) is a key mechanism for the maintenance of cerebral perfusion, but remains largely intact in cognitive disorders, despite reductions in global and regional CBF. However, the tight coupling between neuronal activity and CBF (neurovascular coupling - NVC) is lost in dementia, which may be a key driver of cognitive dysfunction. Despite numerous studies investigating disturbances in the control of CBF in dementia, less is known about the specific mechanisms responsible for the observed changes. Disturbances could be related to one of a number of pathways and mechanisms including disruption of the autonomic component. In this review we will explore clinical and animal studies, which specifically investigated the autonomic component of CBF control in dementia, drawing on the clinical implications and potential for novel biomarker and therapeutic targets.

Connexin and Pannexin Large-Pore Channels in Microcirculation and Neurovascular Coupling Function.

Microcirculation homeostasis depends on several channels permeable to ions and/or small molecules that facilitate the regulation of the vasomotor tone, hyperpermeability, the blood–brain barrier, and the neurovascular coupling function. Connexin (Cxs) and Pannexin (Panxs) large-pore channel proteins are implicated in several aspects of vascular physiology. The permeation of ions (i.e., Ca2+) and key metabolites (ATP, prostaglandins, D-serine, etc.) through Cxs (i.e., gap junction channels or hemichannels) and Panxs proteins plays a vital role in intercellular communication and maintaining vascular homeostasis. Therefore, dysregulation or genetic pathologies associated with these channels promote deleterious tissue consequences. This review provides an overview of current knowledge concerning the physiological role of these large-pore molecule channels in microcirculation (arterioles, capillaries, venules) and in the neurovascular coupling function.

3D Printed Bioreactor Enabling the Pulsatile Culture of Native and Angioplastied Large Arteries.

Routine interventions such as balloon angioplasty, result in vascular activation and remodeling, often requiring re-intervention. 2D in vitro models and small animal experiments have enabled the discovery of important mechanisms involved in this process, however the clinical translation is often underwhelming. There is a critical need for an ex vivo model representative of the human vascular physiology and encompassing the complexity of the vascular wall and the physical forces regulating its function. Vascular bioreactors for ex vivo culture of large vessels are viable alternatives, but their custom-made design and insufficient characterization often hinders the reproducibility of the experiments. The objective of the study was to design and validate a novel 3D printed cost-efficient and versatile perfusion system, capable of sustaining the viability and functionality of large porcine arteries for 7 days and enabling early post-injury evaluations. MultiJet Fusion 3D printing was used to engineer the EasyFlow insert, converting a conventional 50 ml centrifuge tube into a mini bioreactor. Porcine carotid arteries either left untreated or injured with an angioplasty balloon, were cultured under pulsatile flow for up to 7 days. Pressure, heart rate, medium viscosity and shear conditions were adjusted to resemble arterial in vivo hemodynamics. Tissue viability, cell activation and matrix remodeling were analyzed by immunohistochemistry, and vascular function was monitored by duplex ultrasound. Culture conditions in the EasyFlow bioreactor preserved endothelial coverage and smooth muscle organization and extracellular matrix structure in the vessel wall, as compared to static culture. Injured arteries presented hallmarks of early remodeling, such as intimal denudation, smooth muscle cell disarray and media/adventitia activation in flow culture. Duplex ultrasound confirmed continuous pulsatile blood flow conditions, dose-dependent vasodilator response to nitroglycerin in untreated vessels and impaired dilator response in angioplastied vessels. The scope of this work is to validate a low-cost, robust and reproducible system to explore the culture of native and injured large arteries under pulsatile flow. While the study of vascular pathology is beyond the scope of the present paper, our system enables future investigations and provides a platform to test novel therapies and devices ex vivo, in a patient relevant system.

Measurement of Layer-Specific Mechanical Properties of Intact Blood Vessels Based on Intravascular Optical Coherence Tomography.

The biomechanical analysis of stress and strain state of multilayered blood vessels has shown great importance in vascular pathology and physiology. However, there is a lack of method in measuring the mechanical property of each layer of a vascular sample without splitting up the wall. Here we develop a vascular inflation test method based on intravascular optical coherence tomography (IVOCT) imaging and inverse parametric estimation. We propose a three-step inverse parametric estimation method to solve the six constitutive parameters of the GOH models for the intima-media and adventitia of the coronaries simultaneously. A bilayer silicone vascular phantom inflation test and a virtual deformation test using finite element simulated data are conducted to evaluate the accuracy of the proposed method. The virtual deformation test demonstrates that the errors of the constitutive constants are less than 2.56% determined by the proposed inverse parametric estimation method. The stress-strain curves of a bilayer silicone vascular phantom obtained based on the parameters determined by the proposed method match well with those obtained by the uniaxial test. The proposed layer-specific vascular mechanical property measurement method provides a new experimental method for mechanical properties characterization of blood vessels. It also has the potential to be used for patient-specific mechanical properties estimation with IVOCT imaging in vivo.

Hazards of administration of benzodiazepines in patients with adaptive hyperventilation: a case rapport

IntroductionOnly three population-based observational human studies provided evidence that benzodiazepines (BZD) are associated with clinically adverse respiratory outcome. Striking was the finding that BZD drug exposure was associated with a 32% significantly increased adjusted risk of all-cause mortality, including, of note, the subgroup of individuals with no comorbidities. Causation, however, cannot be inferred in observational study design and, highly likely, recipients received BZD’s in these studies to help treating anxiety related to inter alia pre-existing respiratory symptoms.ObjectivesBased on one fatal particular case, authors of current rapport explain what can go wrong when BZD’s are given in patient with respiratory impairment.MethodsAuthors provide a model on how an increase in carbon dioxide can lead to impaired cerebral autoregulation in a person with pre-existing respiratory decompensation. Discussion of integrative metabolic and vascular physiology.ResultsCase rapport of a 18 y.o. otherwise healthy man, who was hospitalized with a novel episode of diabetic ketoacidosis accompanied by profound hypocapnia and anxiety, and who deteriorated and died shortly after airway management because of a clinically important acid-base balance disturbance caused by increased carbon dioxide. All the blood tests and results of respiratory monitoring were collected and carefully assessed.ConclusionsCurrent case suggests that the P(CO(2))--HCO(3) hypothesis is consistent with known data on impaired cerebral autoregulation in diabetic ketoacidosis, driven mainly by increased levels of pCO2. In our opinion, it indicates the recommendation not to administrate BZD’s in patients with pre-existing compensatory hyperventilation as it may counter to the logic of adaptive physiology.DisclosureNo significant relationships.

442-P: Sorbs2 Deficiency–Mediated Vascular BK Channel Dysfunction in Type 2 Diabetes

Vascular BK channels, composed of the pore-forming α-subunits (BK-α) and the regulatory β1 subunits (BK-β1) , is a key determinant of vasoreactivity, and its function is impaired in diabetes. However, our understanding of the mechanisms causing BK channel dysfunction in diabetic vessels is incomplete. The Sorbin and SH3 domain-containing protein 2 (Sorbs2) is abundantly expressed in vascular smooth muscle cells (SMCs) . We hypothesize that Sorbs2 is critical for vascular BK channel physiology. In this study, we compared vascular BK channel function between Sorbs2 KO and WT mice at 4 months of age. There was no difference in body weight and blood glucose between WT and Sorbs2 KO mice (body weight: 25.9±1.3 g of WT vs. 23.3±1.5 g of KO, n=14, p=N.S.; blood glucose: 166.4±7.7 mg/dL of WT vs. 152.2±12.2 mg/dL of KO, n=14, p=N.S.) . However, Sorbs2 KO mice have markedly reduced cell surface and cytoplasmic expression of BK-α and BK-β1, as well as BK channel-mediated vasodilation in carotid arteries with a maximal dilatation of 64.70±1.92% for WT mice (n=4) and 20.74±4.66% for KO mice (n=5, p<0.05) . Patch clamp experiments revealed that BK channel sensitivity to Ca2+ activation was impaired in the coronary SMCs of Sorbs2 KO mice (EC50: 2.87±0.68 µM, n=13, p<0.05) with decreased Hill coefficient (nH: 1.26) , compared to those of WT mice (EC50: 0.48±0.µM, nH: 2.70, n=13) . In vivo studies showed that Sorbs2 interacted with BK-α and BK-β1 protein in vascular SMCs. Silencing of Sorbs2 by shRNA decreased BK-α and BK-β1 expression, while adenoviral expression of Sorbs2 increased BK-α and BK-β1 expression in vascular SMCs. Most importantly, Sorbs2 expression was significantly reduced in the arteries of db/db type 2 diabetic mice and high fat diet-induced diabetic mice. Our results indicate that Sorbs2 plays an important role in regulating BK channel function and expression in vascular SMCs. Sorbs2 deficiency is a risk factor of BK channelopathy and vasculopathy in diabetes, independent of obesity and glucotoxicity. Disclosure T.Lu: None.

Acute and Long-Term Consequences of COVID-19 on Arterial Stiffness-A Narrative Review.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the ongoing global coronavirus (COVID-19) pandemic. Although initially viewed as an acute respiratory illness, COVID-19 is clearly a complex multisystemic disease with extensive cardiovascular involvement. Emerging evidence shows that the endothelium plays multiple roles in COVID-19 physiopathology, as both a target organ that can be directly infected by SARS-CoV-2 and a mediator in the subsequent inflammatory and thrombotic cascades. Arterial stiffness is an established marker of cardiovascular disease. The scope of this review is to summarize available data on the acute and long-term consequences of COVID-19 on vascular function. COVID-19 causes early vascular aging and arterial stiffness. Fast, noninvasive bedside assessment of arterial stiffness could optimize risk stratification in acute COVID-19, allowing for early escalation of treatment. Vascular physiology remains impaired at least 12 months after infection with SARS-CoV-2, even in otherwise healthy adults. This raises concerns regarding the extent of arterial remodeling in patients with preexisting vascular disease and the potential development of a persistent, chronic COVID-19 vasculopathy. Long-term follow up on larger cohorts is required to investigate the reversibility of COVID-19-induced vascular changes and their associated prognostic implications.

The Interplay of Endothelial P2Y Receptors in Cardiovascular Health: From Vascular Physiology to Pathology.

The endothelium plays a key role in blood vessel health. At the interface of the blood, it releases several mediators that regulate local processes that protect against the development of cardiovascular disease. In this interplay, there is increasing evidence for a role of extracellular nucleotides and endothelial purinergic P2Y receptors (P2Y-R) in vascular protection. Recent advances have revealed that endothelial P2Y1-R and P2Y2-R mediate nitric oxide-dependent vasorelaxation as well as endothelial cell proliferation and migration, which are processes involved in the regeneration of damaged endothelium. However, endothelial P2Y2-R, and possibly P2Y1-R, have also been reported to promote vascular inflammation and atheroma development in mouse models, with endothelial P2Y2-R also being described as promoting vascular remodeling and neointimal hyperplasia. Interestingly, at the interface with lipid metabolism, P2Y12-R has been found to trigger HDL transcytosis through endothelial cells, a process known to be protective against lipid deposition in the vascular wall. Better characterization of the role of purinergic P2Y-R and downstream signaling pathways in determination of the endothelial cell phenotype in healthy and pathological environments has clinical potential for the prevention and treatment of cardiovascular diseases.

Redox Mechanisms of Platelet Activation in Aging.

Aging is intrinsically linked with physiologic decline and is a major risk factor for a broad range of diseases. The deleterious effects of advancing age on the vascular system are evidenced by the high incidence and prevalence of cardiovascular disease in the elderly. Reactive oxygen species are critical mediators of normal vascular physiology and have been shown to gradually increase in the vasculature with age. There is a growing appreciation for the complexity of oxidant and antioxidant systems at the cellular and molecular levels, and accumulating evidence indicates a causal association between oxidative stress and age-related vascular disease. Herein, we review the current understanding of mechanistic links between oxidative stress and thrombotic vascular disease and the changes that occur with aging. While several vascular cells are key contributors, we focus on oxidative changes that occur in platelets and their mediation in disease progression. Additionally, we discuss the impact of comorbid conditions (i.e., diabetes, atherosclerosis, obesity, cancer, etc.) that have been associated with platelet redox dysregulation and vascular disease pathogenesis. As we continue to unravel the fundamental redox mechanisms of the vascular system, we will be able to develop more targeted therapeutic strategies for the prevention and management of age-associated vascular disease.

Putting Hemodynamics at the Center: A Systemic Approach to Teaching Vascular Ultrasound

A systemic framework for teaching vascular sonography that is centered on hemodynamics is useful to unify the initial test-by-test approach that developed with the pioneering and expansion of the field. Vascular sonography education is most powerful when taught with a system-level view of the circulation that connects how vascular anatomy (form) and physiology (function) are inextricably linked with hemodynamics (flow). Furthermore, understanding hemodynamic principles is key to using waveform morphology as a diagnostic tool. Teaching a system-based, hemodynamic-centered perspective aligns with the objectives of the recent Consensus Statement on Doppler Waveforms by the Society for Vascular Medicine and the Society for Vascular Ultrasound and equips the vascular sonography student to recognize, understand, and appropriately document vascular findings.

Significant role of long non-coding RNA MALAT1 in deep vein thrombosis via the regulation of vascular endothelial cell physiology through the microRNA-383-5p/BCL2L11 axis

ABSTRACT Deep vein thrombosis (DVT) is a vascular disease. The long non-coding RNA (lncRNA), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), is positively expressed in DVT tissues, and regulates the biological behavior of endothelial progenitor cells. Here, we explored whether MALAT1 affected the physiology of human vascular endothelial cells (HUVECs) and analyzed its underlying mechanism. To overexpress/silence the expression of MALAT1 in HUVECs, MALAT1-plasmid/MALAT1-small interfering RNA (siRNA) was used. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and flow cytometry analyses were performed to observe the cell viability and apoptosis. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to determine the apoptosis-related protein and gene expression levels. We used Starbase software to predict the associations among MALAT1, microRNA (miR)-383-5p, and BCL2-like 11 (BCL2L11). Luciferase reporter assay was used to validate their relationship. Compared to the control vector group, MALAT1-plasmid suppressed the viability and induced apoptosis of HUVECs, while improving Bcl-2-associated X protein (Bax) expression and decreasing Bcl-2 expression. There was an interaction between MALAT1 and miR-383-5p. Compared to the control siRNA group, MALAT1-siRNA increased the cell viability, reduced cell apoptosis, upregulated Bcl-2 expression, and suppressed Bax expression. These changes were reversed by the miR-383-5p inhibitor. Additionally, we verified that BCL2L11 is a target of miR-383-5p. miR-383-5p improved the cell proliferation, while decreasing cell apoptosis in HUVECs by targeting BCL2L11. Therefore, the lncRNA-MALAT1/miR-383-5p/BCL2L11 axis may be effective for DVT treatment.

Early life stress drives sustained reductions in circulating butyrate and propionate short‐chain fatty acids in pre‐pubertal and adult mice

Exposure to early life stress (ELS) is associated with a greater risk of developing cardiovascular disease (CVD) later in life. Using a mouse model of ELS, we have recently showed that 4‐week‐old pre‐pubertal mice exposed to ELS have lower microbial diversity and reduced abundances of Lachnospiraceae and Ruminococcaceae taxa, which are important producers of short‐chain fatty acids (SCFAs). An essential mechanism by which gut microbes influence host physiology is through the production of SCFAs that act as vasoactive mediators, histone deacetylase inhibitors, and immunomodulators. Therefore, we hypothesized that ELS‐induced changes in the gut microbiota would result in reduced circulating SCFAs. To test this hypothesis, we subjected mice to maternal separation (MaSep) in which pups underwent daily separation for 4 h on postnatal days (PDs) 2–5 and 8 h on PDs 6–16 until weaning on PD17. Normally reared (NR) mice remained undisturbed with dams until weaning on PD21. All mice were maintained on standard chow (NIH‐31) following weaning. Plasma was collected at PD28 (n=17 MaSep mice from 7 litters and 13 NR mice from 7 litters) and at PD84 (n=8 MaSep from 3 litters and 11 NR mice from 3 litters) for analysis of lactate and the SCFAs acetate, butyrate, isovalerate, propionate, and succinate by gas chromatography/mass spectrometry. Acetate, succinate, and lactate were not different between MaSep and NR mice at either timepoint. However, ELS exposure resulted in significantly reduced butyrate plasma concentrations at PD28 (14.38 ± 0.50 µM in MaSep mice compared to 18.58 ± 1.87 µM in NR mice; P = 0.02) and PD84 (11.94 ± 0.18 µM in MaSep mice compared to 15.03 ± 0.21 µM in NR mice; P < 0.001). ELS also reduced propionate plasma concentrations at PD28 (35.96 ± 1.47 µM in MaSep mice compared to 43.70 ± 1.44 µM in NR mice; P = 0.001) and PD84 (32.16 ± 0.92 µM in MaSep mice compared to 42.53 ± 1.05 µM in NR mice; P < 0.001). Isovalerate plasma concentration was greater in MaSep mice at PD84 (1.11 ± 0.13 µM) compared to NR mice (0.45 ± 0.11 µM; P = 0.002), while there was no difference in isovalerate between MaSep and NR mice at PD28. These data indicate that exposure to stress in early life can result in sustained reductions in butyrate (~22%) and propionate (~21%) concentrations in circulation. Recent advances have determined that butyrate and propionate are involved in blood pressure regulation and vascular physiology. Much less is known about the branched SCFA isovalerate. Future studies will determine if decreases in circulating butyrate and propionate, or increases in circulating isovalerate, play a role in ELS‐induced increased risk of CVD.

Content Reinforcement of the Cardiovascular Physiology Improves Knowledge Retention in Nursing Students

There is growing concern over the loss of anatomical and physiological knowledge in medical, allied‐health & nursing students over time (Narnaware & Neumeier, 2020a, Narnaware, Y. 2021). Numerous studies have demonstrated the difficulty of the students in these disciplines to retain and apply anatomical knowledge as they progress through their programs of study (Narnaware and Neumeier, 2020a). However, physiological knowledge retention has not been studied as extensively as anatomical knowledge retention in health care disciplines, with very few studies focusing on nursing students (Aari et al., 2004). Of those studies, most are carried out after graduation (Aari et al., 2004) or are focused on a single or limited number of organ systems (Pourshanazari et al., 2013). We have previously shown that physiology students retained approximately 86.6% of their first‐year physiological knowledge over four months (Narnaware et al., 2020b). To improve the acquisition and retention of physiological knowledge, the present study aims to develop an interventional strategy that includes the repeated assessment of cardiovascular physiology and defenses knowledge over eight weeks. Nursing students were quizzed on two components of cardiovascular physiology (vascular system and blood) and defenses using the online quizzing system Kahoot. Each Kahoot quiz included 9‐11 knowledge and comprehension level multiple‐choice questions, and new sets of questions were used for each week’s Kahoot quiz. Data were statistically analyzed using SPSS II, and means were compared using 2‐sample t‐tests. The scores are described as the mean and standard deviation (SD) and are presented in figure 1 and table 1. Statistical significance was set at P < 0.05 for all tests. Compared to week 1, repeating knowledge of the vascular physiology and defenses yielded a significantly higher (P<0.05) knowledge retention at week 2 (8.4% & 11.7%). However, this retention was highest at weeks 3 (18.7% & 16.9%) and weeks 4 (21.6% & 14.3%), P<0.001) in both organ systems, with less significant improvement (P<0.05) at week 6 (13.3%) and no significant difference in defenses (4.6%). No significant differences in knowledge retention were found between vascular and defenses at week 8. However, compared to vascular physiology and defenses, content reinforcement of blood was highly significant at all weeks. Compared to week 1, knowledge retention of blood was highest at week 4 (69.5%), week 6 (55.2%), and week 8 (54.7%), P<0.0001), with less significant retention at week 2 (27.8%) and week 3 (31.2%), P<0.001). Although organ system‐specific improvements in knowledge retention were found, the study results show that repeated knowledge assessment can significantly improve knowledge retention of cardiovascular physiology and defenses in nursing students and agrees with previously reported studies in medical students (Pourshanazari et al., 2013). Therefore, content reinforcement should be used as one of the interventional strategies to improve knowledge retention in nursing students, and further research should be conducted to explore effective ways to maintain increased retention over more extended periods.

Curbing High‐Fat Induced Perturbations in Aortic Perivascular Adipose Tissue in Adolescent Male Sprague‐Dawley Rats: Soil as Therapy?

Directly attached to the outer wall of blood vessels, perivascular adipose tissue (PVAT) is a unique variant of fat that is an important paracrine modulator of vascular physiology. Due to the proximity and endocrine‐like characteristics of this tissue, PVAT can contribute to the regulation vascular contractility and endothelial function. PVAT can also assume several properties of brown adipose tissue, including increased vascularization, small lipid droplet formation, mitochondrial density, and production of cardiometabolic signaling intermediates. Importantly, these properties promote the metabolic activity of this tissue which appear to be associated with improved vascular health. However, such properties may be diminished by chronic deleterious stimuli such as a high‐fat diet (HFD) and disease conditions like metabolic syndrome. Under such pressures, PVAT may serve a more insidious role in vascular dysfunction and promote the development of cardiovascular disease. Chronic diet‐induced changes in the vasculature and associated tissues like PVAT may be occurring early in the life cycle, promoting degeneration and disease‐associated remodeling. Currently, examination of these tissues early in life remain relatively unexplored and may offer important insight into the identification of prevention strategies and therapeutic targets. Previously, our lab identified increased expression of genes in the aorta of HFD fed adolescent Sprague‐Dawley rats, highlighting potential pathways and signaling intermediates that may impact the development of early vascular dysfunction. Moreover, we have demonstrated that an organic mineral complex (OMC) derived from plant and soil fractions prevented symptoms of metabolic syndrome in these animals. OMC is a complex of minerals, trace elements, organic acids (particularly fulvic acid), nitrates, and various microbial degradation products from plant and animal origins. The objective of the current study is to investigate the effects of a HFD and OMC on the expression of key proteins in aortic PVAT that play a role in adipose beiging, metabolism, and mitochondrial biogenesis, and are thus expected to provide critical insight into early mitigation of vascular disease progression. Six‐week‐old male Sprague‐Dawley rats (n = 36) were divided into two dietary groups: Chow or HFD fed for 10 weeks. Animals were further divided (n = 6/group) and administered 0, 0.6, or 3.0 mg/mL OMC in their drinking water. After the 10‐week intervention PVAT surrounding the aorta was extracted from the animals and Western blot analyses were performed using antibodies for the proteins UCP1, SDHA, PI3K, GLUT4, and b‐actin (as a loading control). Overall, we hypothesize that OMC supplementation will minimize decreases in these key proteins involved in health associated PVAT metabolism and function.

Insights Into the Role of Mitochondria in Vascular Calcification.

Vascular calcification (VC) is a growing burden in aging societies worldwide, and with a significant increase in all-cause mortality and atherosclerotic plaque rupture, it is frequently found in patients with aging, diabetes, atherosclerosis, or chronic kidney disease. However, the mechanism of VC is still not yet fully understood, and there are still no effective therapies for VC. Regarding energy metabolism factories, mitochondria play a crucial role in maintaining vascular physiology. Discoveries in past decades signifying the role of mitochondrial homeostasis in normal physiology and pathological conditions led to tremendous advances in the field of VC. Therapies targeting basic mitochondrial processes, such as energy metabolism, damage in mitochondrial DNA, or free-radical generation, hold great promise. The remarkably unexplored field of the mitochondrial process has the potential to shed light on several VC-related diseases. This review focuses on current knowledge of mitochondrial dysfunction, dynamics anomalies, oxidative stress, and how it may relate to VC onset and progression and discusses the main challenges and prerequisites for their therapeutic applications.