Effect of aging on the vascular system plus monitoring and support

Integrated Bioinformatic Analysis of the Shared Molecular Mechanisms Between Osteoporosis and Atherosclerosis

Background

Osteoporosis and atherosclerosis are common in the elderly population, conferring a heavy worldwide burden. Evidence links osteoporosis and atherosclerosis but the exact underlying common mechanism of its occurrence is unclear. The purpose of this study is to further explore the molecular mechanism between osteoporosis and atherosclerosis through integrated bioinformatic analysis.

Methods

The microarray data of osteoporosis and atherosclerosis in the Gene Expression Omnibus (GEO) database were downloaded. The Weighted Gene Co-Expression Network Analysis (WGCNA) and differentially expressed genes (DEGs) analysis were used to identify the co-expression genes related to osteoporosis and atherosclerosis. In addition, the common gene targets of osteoporosis and atherosclerosis were analyzed and screened through three public databases (CTD, DISEASES, and GeneCards). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed by Metascape. Then, the common microRNAs (miRNAs) in osteoporosis and atherosclerosis were screened out from the Human microRNA Disease Database (HMDD) and the target genes of whom were predicted through the miRTarbase. Finally, the common miRNAs-genes network was constructed by Cytoscape software.

Results

The results of common genes analysis showed that immune and inflammatory response may be a common feature in the pathophysiology of osteoporosis and atherosclerosis. Six hub genes (namely, COL1A1, IBSP, CTSD, RAC2, MAF, and THBS1) were obtained via taking interaction of different analysis results. The miRNAs-genes network showed that has-let-7g might play an important role in the common mechanisms between osteoporosis and atherosclerosis.

Conclusion

This study provides new sights into shared molecular mechanisms between osteoporosis and atherosclerosis. These common pathways and hub genes may offer promising clues for further experimental studies.

Correlation between Coronary Artery Calcium- and Different Cardiovascular Risk Score-Based Methods for the Estimation of Vascular Age in Caucasian Patients

Vascular age can be derived from cardiovascular (CV) risk scores such as the Framingham Risk Score (FRS) and the Systematic Coronary Risk Evaluation (SCORE). Recently, coronary artery calcium score (CACS) was proposed as a means of assessing arterial age. We aimed to compare these approaches for the assessment of vascular age. FRS-, SCORE-, and CACS-based vascular ages of 241 consecutive Caucasian patients undergoing coronary CT angiography were defined according to previously published methods. Vascular ages based on FRS, SCORE, and CACS were 68.0 (IQR: 55.0–82.0), 63.0 (IQR: 53.0–75.0), and 47.1 (IQR: 39.1–72.3) years, respectively, (p < 0.001). FRS- and SCORE-based biological age showed strong correlation [ICC: 0.91 (95%CI: 0.88–0.93)], while CACS-based vascular age moderately correlated with FRS- and SCORE-based vascular age [ICC: 0.66 (95%CI: 0.56–0.73) and ICC: 0.65 (95%CI: 0.56–0.73), respectively, both p < 0.001)]. Based on FRS, SCORE, and CACS, 83.4%, 93.8%, and 42.3% of the subjects had higher vascular age than their documented chronological age (FRS+, SCORE+, CACS+), and 53.2% of the FRS+ (107/201) and 57.1% of the SCORE+ (129/226) groups were classified as CACS-. Traditional risk equations demonstrate a tendency of overestimating vascular age in low- to intermediate-risk patients compared to CACS. Prospective studies are warranted to further evaluate the contribution of different vascular age calculations to CV preventive strategies.

A biomimetic shock model on the effect of endothelial aging on vascular barrier properties

BACKGROUND

Aging is characterized by a decline in cellular function, which has an adverse effect on the biologic response to injury. Both aging and trauma/hemorrhagic shock (T/HS) increase oxidative stress which impairs the vascular endothelium (EC) and glycocalyx (EG). The additive effect of aging on EC and EG damage following T/HS are unknown. This was studied in an in vitro model.

METHODS

Confluent endothelial cell monolayers from primary aortic endothelial cells from 10-week-old mice ("young" cells) or primary aortic cells from 65-week-old mice ("aged" cells) were established in microfluidic devices (MFDs) and perfused at constant shear conditions overnight. Mouse endothelial cell monolayers were then exposed to hypoxia/reoxygenation alone and/or epinephrine or norepinephrine. Endothelial glycocalyx degradation was indexed as well as subsequent endothelial injury/activation.

RESULTS

Aged endothelial cells showed increase glycocalyx shedding and subsequent loss of glycocalyx thickness. This lead to a more pronounced level of EC injury/activation compared with young endothelial cells. Although exposure to biomimetic shock conditions exacerbated both endothelial glycocalyx shedding and endothelial injury in both aged and young endothelial cells, the effect was significantly more pronounced in aged cells.

CONCLUSION

Advanced age is associated with worse outcomes in severely injured trauma patients. Our study demonstrates that there is increased EG shedding and a diminished EG layer in aged compared to "young" endothelial cell layers. Biomimetic shock conditions lead to an even greater impairment of the endothelial glycocalyx in aged versus young endothelial cell monolayers. It appears that these effects are a consequence of aging related oxidative stress at both baseline and shock conditions. This exacerbates shock-induced endotheliopathy and may contribute to untoward effects on patient outcomes in this population.

BK channel-forming slo1 proteins mediate the brain artery constriction evoked by the neurosteroid pregnenolone

Pregnenolone is a neurosteroid that modulates glial growth and differentiation, neuronal firing, and several brain functions, these effects being attributed to pregnenolone actions on the neurons and glial cells themselves. Despite the vital role of the cerebral circulation for brain function and the fact that pregnenolone is a vasoactive agent, pregnenolone action on brain arteries remain unknown. Here, we obtained in vivo concentration response curves to pregnenolone on middle cerebral artery (MCA) diameter in anesthetized male and female C57BL/6J mice. In both male and female animals, pregnenolone (1 nM-100 μM) constricted MCA in a concentration-dependent manner, its maximal effect reaching ~22-35% decrease in diameter. Pregnenolone action was replicated in intact and de-endothelialized, in vitro pressurized MCA segments with pregnenolone evoking similar constriction in intact and de-endothelialized MCA. Neurosteroid action was abolished by 1 μM paxilline, a selective blocker of Ca2+ - and voltage-gated K+ channels of large conductance (BK). Cell-attached, patch-clamp recordings on freshly isolated smooth muscle cells from mouse MCAs demonstrated that pregnenolone at concentrations that constricted MCAs in vitro and in vivo (10 μM), reduced BK activity (NPo), with an average decrease in NPo reaching 24.2%. The concentration-dependence of pregnenolone constriction of brain arteries and inhibition of BK activity in intact cells were paralleled by data obtained in cell-free, inside-out patches, with maximal inhibition reached at 10 μM pregnenolone. MCA smooth muscle BKs include channel-forming α (slo1 proteins) and regulatory β1 subunits, encoded by KCNMA1 and KCNMB1, respectively. However, pregnenolone-driven decrease in NPo was still evident in MCA myocytes from KCNMB1-/- mice. Following reconstitution of slo1 channels into artificial, binary phospholipid bilayers, 10 μM pregnenolone evoked slo1 NPo inhibition which was similar to that seen in native membranes. Lastly, pregnenolone failed to constrict MCA from KCNMA1-/- mice. In conclusion, pregnenolone constricts MCA independently of neuronal, glial, endothelial and circulating factors, as well as of cell integrity, organelles, complex membrane cytoarchitecture, and the continuous presence of cytosolic signals. Rather, this action involves direct inhibition of SM BK channels, which does not require β1 subunits but is mediated through direct sensing of the neurosteroid by the channel-forming α subunit.

Celastrol Dilates and Counteracts Ethanol-Induced Constriction of Cerebral Arteries

The increasing recognition of the role played by cerebral artery dysfunction in brain disorders has fueled the search for new cerebrovascular dilators. Celastrol, a natural triterpene undergoing clinical trials for treating obesity, exerts neuroprotection, which was linked to its antioxidant/anti-inflammatory activities. We previously showed that celastrol fit pharmacophore criteria for activating calcium- and voltage-gated potassium channels of large conductance (BK channels) made of subunits cloned from cerebrovascular smooth muscle (SM). These recombinant BK channels expressed in a heterologous system were activated by celastrol. Activation of native SM BK channels is well known to evoke cerebral artery dilation. Current data demonstrate that celastrol (1-100 µM) dilates de-endothelialized, ex vivo pressurized middle cerebral arteries (MCAs) from rats, with EC₅₀ = 45 µM and maximal effective concentration (E_max)= 100 µM and with MCA diameter reaching a 10% increase over vehicle-containing, time-matched values (P < 0.05). A similar vasodilatory efficacy is achieved when celastrol is probed on MCA segments with intact endothelium. Selective BK blocking with 1 μM paxilline blunts celastrol vasodilation. Similar blunting is achieved with 0.8 mM 4-aminopirydine, which blocks voltage-gated K⁺ channels other than BK. Using an in vivo rat cranial window, we further demonstrate that intracarotid injections of 45 μM celastrol into pial arteries branching from MCA mimics celastrol ex vivo action. MCA constriction by ethanol concentrations reached in blood during moderate-heavy alcohol drinking (50 mM), which involves SM BK inhibition, is both prevented and reverted by celastrol. We conclude that celastrol could be an effective cerebrovascular dilator and antagonist of alcohol-induced cerebrovascular constriction, with its efficacy being uncompromised by conditions that disrupt endothelial and/or BK function. SIGNIFICANCE STATEMENT: Our study demonstrates for the first time that celastrol significantly dilates rat cerebral arteries both ex vivo and in vivo and both prevents and reverses ethanol-induced cerebral artery constriction. Celastrol actions are endothelium-independent but mediated through voltage-gated (K_V) and calcium- and voltage-gated potassium channel of large conductance (BK) K⁺ channels. This makes celastrol an appealing new agent to evoke cerebrovascular dilation under conditions in which endothelial and/or BK channel function are impaired.

A Comprehensive Investigation of Comorbidities, Mechanisms, Injury Patterns, and Outcomes in Geriatric Blunt Trauma Patients

The geriatric population is growing and trauma providers are often tasked with caring for injuries in the elderly. There is limited information regarding injury patterns in geriatric trauma patients stratified by mechanism of injury. This study intends to investigate the comorbidities, mechanisms, injury patterns, and outcomes in geriatric blunt trauma patients. A retrospective study of the 2012 National Trauma Databank was performed. Adult blunt trauma patients were identified; geriatric (>/=65) patients were compared with younger (<65) patients regarding admission demographics and vital signs, mechanism and severity of injury, and comorbidities. The primary outcome was injuries sustained and secondary outcomes included mortality, length of stay in the intensive care unit and hospital, and ventilator days. There were 589,830 blunt trauma patients who met the inclusion criteria, including 183,209 (31%) geriatric and 406,621 (69%) nongeriatric patients. Falls were more common in geriatric patients (79 vs 29%, P < 0.0001). Geriatric patients less often had an Injury Severity Score >/=16 (18 vs 20%, P < 0.0001) but more often a head Abbreviated Injury Scale >/=3 (24 vs 18%, P < 0.0001) and lower extremity Abbreviated Injury Scale >/=3 (24% vs 8%, P < 0.0001). After logistic regression older age was an independent risk factor for mortality for the overall population and across all mechanisms. Falls are the most common mechanism for geriatric trauma patients. Geriatric patients overall present with a lower Injury Severity Score, but more often sustain severe injuries to the head and lower extremities. Injury patterns vary significantly between older and younger patients when stratified by mechanism. Mortality is significantly higher for geriatric trauma patients and older age is independently associated with mortality across all mechanisms.

Association between different risk factors and vascular accelerated ageing (EVA study): study protocol for a cross-sectional, descriptive observational study

INTRODUCTION

The process of population ageing that is occurring in developed societies represents a major challenge for the health system. The aim of this study is to analyse factors that have an influence on early vascular ageing (EVA), estimated by carotid-femoral pulse wave velocity (cf-PWV) and Cardio Ankle Vascular Index (CAVI), and to determine differences by gender in a Spanish population.

METHODS AND ANALYSIS

An observational, descriptive, cross-sectional study.

STUDY POPULATION

From the population assigned to the participating healthcare centres, a cluster random sampling stratified by age and gender will be performed to obtain 500 participants aged between 35 and 75. Those who meet the inclusion criteria and give written informed consent will be included in the study.

MEASUREMENTS

Main dependent variables: cf-PWV determined using the SphygmoCor System and CAVI estimated using VASERA. Secondary dependent variables: telomere length, carotid intima-media thickness, central and peripheral augmentation index, ankle-brachial pulse wave velocity, ankle-brachial index, retinal arteriovenous index, and renal and cardiac organ damage.

INDEPENDENT VARIABLES

lifestyles (physical activity, adherence to the Mediterranean diet, alcohol and tobacco consumption); psychological factors (depression, anxiety and chronic stress); inflammatory factors and oxidative stress.

ETHICS AND DISSEMINATION

The study has been approved by the clinical research ethics committee of the healthcare area of Salamanca. All study participants will sign an informed consent form agreeing to participate in the study in compliance with the Declaration of Helsinki and the WHO standards for observational studies. The results of this study will allow the understanding of the relationship of the different influencing factors and their relative weight in the development of EVA. At least 5 publications in first-quartile scientific journals are planned.

TRIAL REGISTRATION NUMBER

NCT02623894; Pre-results.

Osteoporosis and cardiovascular disease: an update

Osteoporosis (OP) and cardiovascular diseases (CVD) are the most important causes of mortality and morbility in the elderly. Lots of studies showed a correlation between bone loss and cardiovascular risk mediated by the vascular calcification. The relationship between OP and CVD could be firstly explained by their common risk factors such as age, smoking, alcohol consumption, physical activity and menopause. However, other different hypotheses were proposed to clarify this link. Multiple factors, for example bone morphogenetic proteins, osteoprotegerin, receptor activator of nuclear factor κB ligand, parathyroid hormone, phosphate, oxidized lipids and vitamins D and K seemed to be involved in both conditions, indicating a possible common pathophysiologic mechanism. We review and discuss the available data describing this association. Further studies are necessary to better investigate similarities between OP and CVD.