Endothelial cell senescence and age-related vascular diseases

SIRT3 suppresses vascular endothelial senescence via DHRS2 and contributes to the anti-vascular aging effect of Bazi Bushen capsule

AIMS

Vascular and endothelial aging are significant causes of chronic diseases among the elderly. This study investigated the specific mechanism by which sirtuin 3 (SIRT3) regulates vascular endothelial senescence and the beneficial role of Bazi Bushen capsule (BZBS) in preventing vascular aging.

METHODS

Human umbilical vein endothelial cells and mouse aortic endothelial cells were cultured with D-galactose (D-gal) to induce aging and evaluate the beneficial effects of the SIRT3-dehydrogenase/reductase member 2 (DHRS2) axis on the inhibition of vascular endothelial aging. d-Gal was injected intraperitoneally into wild-type and Sirt3 knockout mice, while BZBS was administered orally. Histochemical staining, immunohistochemistry, and western blotting assays were used to explore the beneficial effects of BZBS against aging-associated vascular remodelling. Endothelial cell function assays were used to evaluate the role of BZBS in suppressing endothelial aging in vitro.

RESULTS

SIRT3 deacetylated DHRS2 and modulated the translation of DHRS2. The SIRT3-DHRS2 axis played an important role in preserving mitochondrial homeostasis and reducing reactive oxygen species generation through suppressing endothelial nitric oxide synthase (eNOS) translocating to mitochondria and eNOS-Thr495 phosphorylation mediated by protein kinase C δ (PKCδ). BZBS mitigated vascular remodelling and relieved endothelial oxidative stress via the SIRT3-DHRS2 axis.

CONCLUSION

SIRT3 activates DHRS2-PKCδ to stop aging in endothelial cells by inhibiting uncoupled eNOS translocating to mitochondria. BZBS rescued vascular aging and endothelial dysfunction via the SIRT3-DHRS2 axis. Revealing a protective mechanism by which SIRT3 inhibits endothelial senescence, this study provides evidence for BZBS in delaying vascular aging.

miR-34a-5p/MARCHF8/ADAM10 axis in the regulation of vascular endothelial cell dysfunction and senescence

Vascular aging is a key driver of age-related cardiovascular and metabolic diseases, with endothelial dysfunction and senescence as a central mechanism. In our recent study, we observed elevated ADAM10 protein levels in senescent endothelial cells, which worsened endothelial dysfunction and senescence. However, the regulatory mechanisms controlling ADAM10 expression are poorly understood. In this study, we show that ADAM10 undergoes post-transcriptional modification in senescent human umbilical vein endothelial cells (HUVECs), with the E3 ubiquitin ligase MARCHF8 predicted to facilitate its ubiquitination-dependent degradation. We also found that MARCHF8 expression was significantly reduced in senescent HUVECs. Knockdown of MARCHF8 in young HUVECs induced endothelial senescence and impaired key endothelial functions, including migration, proliferation, angiogenesis, and nitric oxide production. Conversely, overexpression of MARCHF8 in senescent HUVECs ameliorated senescence-associated dysfunctions. RNA sequencing analysis revealed that MARCHF8 knockdown disrupted pathways linked to cell senescence and atherosclerosis. In vivo, MARCHF8 overexpression in high-fat diet-fed apoE-/- mice reduced plasma interleukin-6 levels and attenuated atherosclerosis progression. Additionally, miR-34a-5p upregulation in senescence inhibited MARCHF8 expression, compromising its protective effects in delaying endothelial senescence. Collectively, these findings reveal a novel miR-34a-5p/MARCHF8/ADAM10 axis in vascular endothelial senescence, positioning MARCHF8 as a potential biomarker and therapeutic target for vascular aging and related diseases.

Advantages and disadvantages of targeting senescent endothelial cells in cardiovascular and cerebrovascular diseases based on small extracellular vesicles

INTRODUCTION

With the growth of the aging population, age-related diseases have become a heavy global burden, particularly cardiovascular and cerebrovascular diseases (CVDs). Endothelial cell (EC) senescence constitutes an essential factor in the development of CVDs, prompting increased focus on strategies to alleviate or reverse EC senescence.

AREAS COVERED

Small extracellular vesicles (sEVs) are cell-derived membrane structures, that contain proteins, lipids, RNAs, metabolites, growth factors and cytokines. They are widely used in treating CVDs, and show remarkable therapeutic potential in alleviating age-related CVDs by inhibiting or reversing EC senescence. However, unclear anti-senescence mechanism poses challenges for clinical application of sEVs, and a systematic review is lacking.

EXPERT OPINION

Targeting senescent ECs with sEVs in age-related CVDs treatment represents a promising therapeutic strategy, with modifying sEVs and their contents emerging as a prevalent approach. Nevertheless, challenges remain, such as identifying and selectively targeting senescent cells, understanding the consequences of removing senescent ECs and senescence-associated secretory phenotype (SASP), and assessing the side effects of therapeutic sEVs on CVDs. More substantial experimental and clinical data are needed to advance clinical practice.

Oxidized Low-Density Lipoprotein and Its Role in Immunometabolism

Modified cholesterols such as oxidized low-density lipoprotein (OxLDL) contribute to atherosclerosis and other disorders through the promotion of foam cell formation and inflammation. In recent years, it has become evident that immune cell responses to inflammatory molecules such as OxLDLs depend on cellular metabolic functions. This review examines the known effects of OxLDL on immunometabolism and immune cell responses in atherosclerosis and several other diseases. We additionally provide context on the relationship between OxLDL and aging/senescence and identify gaps in the literature and our current understanding in these areas.

Unraveling the role of HIF and epigenetic regulation in pulmonary arterial hypertension: implications for clinical research and its therapeutic approach

Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling with high pulmonary pressure, which ultimately leads to right heart failure and premature death. Emerging evidence suggests that both hypoxia and epigenetics play a pivotal role in the pathogenesis of PAH development. In this review article, we summarize the current developments in regulation of hypoxia inducible factor (HIF) isoforms in PAH vascular remodeling and the development of suitable animal models for discovery and testing of HIF pathway-targeting PAH therapeutics. In addition, we also discuss the epigenetic regulation of HIF-dependent isoforms in PAH and its therapeutic potential from a new perspective which highlights the importance of HIF isoform-specific targeting as a novel salutary strategy for PAH treatment.

Evaluations of secondary hypertension and laboratory data in the elderly population

Secondary hypertension in the elderly poses many challenges and requires a comprehensive diagnostic and management approach. This review explores the prevalence, diagnostic strategies, and treatment modalities for secondary hypertension in elderly patients, focusing on etiologies including primary aldosteronism, renal vascular disease, renal parenchymal disease, obstructive sleep apnea, thyroid disorders, Cushing's syndrome, pheochromocytomas and paragangliomas, and drug-induced hypertension. Key considerations include age-related changes in physiology and atypical presentations of underlying conditions necessitating thorough screening with a combination of clinical evaluation, laboratory tests, and imaging studies. Collaboration among healthcare providers is essential to ensure a timely diagnosis and personalized management tailored to the unique needs of elderly patients. Further research is needed to address knowledge gaps and optimize clinical strategies for managing secondary hypertension in this population.

Human Cord Blood Endothelial Progenitor Cells and Pregnancy Complications (Preeclampsia, Gestational Diabetes Mellitus, and Fetal Growth Restriction)

Hemangioblasts give rise to endothelial progenitor cells (EPCs), which also express the cell surface markers CD133 and c-kit. They may differentiate into the outgrowth endothelial cells (OECs) that control neovascularization in the developing embryo. According to numerous studies, reduced levels of EPCs in circulation have been linked to human cardiovascular disorders. Furthermore, preeclampsia and senescence have been linked to levels of EPCs produced from cord blood. Uncertainties surround how preeclampsia affects the way EPCs function. It is reasonable to speculate that preeclampsia may have an impact on the function of fetal EPCs during the in utero period; however, the present literature suggests that maternal vasculopathies, including preeclampsia, damage fetal circulation. Additionally, the differentiation potential and general activity of EPCs may serve as an indicator of the health of the fetal vascular system as they promote neovascularization and repair during pregnancy. Thus, the purpose of this review is to compare-through the assessment of their quantity, differentiation potency, angiogenic activity, and senescence-the angiogenic function of fetal EPCs obtained from cord blood for normal and pregnancy problems (preeclampsia, gestational diabetes mellitus, and fetal growth restriction). This will shed light on the relationship between the angiogenic function of fetal EPCs and pregnancy complications, which could have an effect on the management of long-term health issues like metabolic and cardiovascular disorders in offspring with abnormal vasculature development.

Aging in Ocular Blood Vessels: Molecular Insights and the Role of Oxidative Stress

Acknowledged as a significant pathogenetic driver for numerous diseases, aging has become a focal point in addressing the profound changes associated with increasing human life expectancy, posing a critical concern for global public health. Emerging evidence suggests that factors influencing vascular aging extend their impact to choroidal and retinal blood vessels. The objective of this work is to provide a comprehensive overview of the impact of vascular aging on ocular blood vessels and related diseases. Additionally, this study aims to illuminate molecular insights contributing to vascular cell aging, with a particular emphasis on the choroid and retina. Moreover, innovative molecular targets operating within the domain of ocular vascular aging are presented and discussed.

Targeting aging and age-related diseases with vaccines

Aging is a major risk factor for numerous chronic diseases. Vaccination offers a promising strategy to combat these age-related diseases by targeting specific antigens and inducing immune responses. Here, we provide a comprehensive overview of recent advances in vaccine-based interventions targeting these diseases, including Alzheimer's disease, type II diabetes, hypertension, abdominal aortic aneurysm, atherosclerosis, osteoarthritis, fibrosis and cancer, summarizing current approaches for identifying disease-associated antigens and inducing immune responses against these targets. Further, we reflect on the recent development of vaccines targeting senescent cells, as a strategy for more broadly targeting underlying causes of aging and associated pathologies. In addition to highlighting recent progress in these areas, we discuss important next steps to advance the therapeutic potential of these vaccines, including improving and robustly demonstrating efficacy in human clinical trials, as well as rigorously evaluating the safety and long-term effects of these vaccine strategies.

The Role of Sirtuin-1 (SIRT1) in the Physiology and Pathophysiology of the Human Placenta

Sirtuins, especially SIRT1, play a significant role in regulating inflammatory response, autophagy, and cell response to oxidative stress. Since their discovery, sirtuins have been regarded as anti-ageing and longevity-promoting enzymes. Sirtuin-regulated processes seem to participate in the most prevalent placental pathologies, such as pre-eclampsia. Furthermore, more and more research studies indicate that SIRT1 may prevent pre-eclampsia development or at least alleviate its manifestations. Having considered this, we reviewed recent studies on the role of sirtuins, especially SIRT1, in processes determining normal or abnormal development and functioning of the placenta.

Senescent Cells: Dual Implications on the Retinal Vascular System

Cellular senescence, a state of permanent cell cycle arrest in response to endogenous and exogenous stimuli, triggers a series of gradual alterations in structure, metabolism, and function, as well as inflammatory gene expression that nurtures a low-grade proinflammatory milieu in human tissue. A growing body of evidence indicates an accumulation of senescent neurons and blood vessels in response to stress and aging in the retina. Prolonged accumulation of senescent cells and long-term activation of stress signaling responses may lead to multiple chronic diseases, tissue dysfunction, and age-related pathologies by exposing neighboring cells to the heightened pathological senescence-associated secretory phenotype (SASP). However, the ultimate impacts of cellular senescence on the retinal vasculopathies and retinal vascular development remain ill-defined. In this review, we first summarize the molecular players and fundamental mechanisms driving cellular senescence, as well as the beneficial implications of senescent cells in driving vital physiological processes such as embryogenesis, wound healing, and tissue regeneration. Then, the dual implications of senescent cells on the growth, hemostasis, and remodeling of retinal blood vessels are described to document how senescent cells contribute to both retinal vascular development and the severity of proliferative retinopathies. Finally, we discuss the two main senotherapeutic strategies-senolytics and senomorphics-that are being considered to safely interfere with the detrimental effects of cellular senescence.

Aberrant hyper-expression of the RNA binding protein GIGYF2 in endothelial cells modulates vascular aging and function

Vascular endothelial cells (ECs) senescence plays a crucial role in vascular aging that promotes the initiation and progression of cardiovascular disease. The mutation of Grb10-interacting GYF protein 2 (GIGYF2) is strongly associated with the pathogenesis of aging-related diseases, whereas its role in regulating ECs senescence and dysfunction still remains elusive. In this study, we found aberrant hyperexpression of GIGYF2 in senescent human ECs and aortas of old mice. Silencing GIGYF2 in senescent ECs suppressed eNOS-uncoupling, senescence, and endothelial dysfunction. Conversely, in nonsenescent cells, overexpressing GIGYF2 promoted eNOS-uncoupling, cellular senescence, endothelial dysfunction, and activation of the mTORC1-SK61 pathway, which were ablated by rapamycin or antioxidant N-Acetyl-l-cysteine (NAC). Transcriptome analysis revealed that staufen double-stranded RNA binding protein 1 (STAU1) is remarkably downregulated in the GIGYF2-depleted ECs. STAU1 depletion significantly attenuated GIGYF2-induced cellular senescence, dysfunction, and inflammation in young ECs. Furthermore, we disclosed that GIGYF2 acting as an RNA binding protein (RBP) enhances STAU1 mRNA stability, and that the intron region of the late endosomal/lysosomal adaptor MAPK and mTOR activator 4 (LAMTOR4) could bind to STAU1 protein to upregulate LAMTOR4 expression. Immunofluorescence staining showed that GIGYF2 overexpression promoted the translocation of mTORC1 to lysosome. In the mice model, GIGYF2flox/flox Cdh-Cre+ mice protected aged mice from aging-associated vascular endothelium-dependent relaxation and arterial stiffness. Our work discloses that GIGYF2 serving as an RBP enhances the mRNA stability of STAU1 that upregulates LAMTOR4 expression through binding with its intron region, which activates the mTORC1-S6K1 signaling via recruitment of mTORC1 to the lysosomal membrane, ultimately leading to ECs senescence, dysfunction, and vascular aging. Disrupting the GIGYF2-STAU1-mTORC1 signaling cascade may represent a promising therapeutic approach against vascular aging and aging-related cardiovascular diseases.

Vascular Aging: Assessment and Intervention

Vascular aging represents a collection of structural and functional changes in a blood vessel with advancing age, including increased stiffness, vascular wall remodeling, loss of angiogenic ability, and endothelium-dependent vasodilation dysfunction. These age-related alterations may occur earlier in those who are at risk for or have cardiovascular diseases, therefore, are defined as early or premature vascular aging. Vascular aging contributes independently to cardio-cerebral vascular diseases (CCVDs). Thus, early diagnosis and interventions targeting vascular aging are of paramount importance in the delay or prevention of CCVDs. Here, we review the direct assessment of vascular aging by examining parameters that reflect changes in structure, function, or their compliance with age including arterial wall thickness and lumen diameter, endothelium-dependent vasodilation, arterial stiffness as well as indirect assessment through pathological studies of biomarkers including endothelial progenitor cell, lymphocytic telomeres, advanced glycation end-products, and C-reactive protein. Further, we evaluate how different types of interventions including lifestyle mediation, such as caloric restriction and salt intake, and treatments for hypertension, diabetes, and hyperlipidemia affect age-related vascular changes. As a single parameter or intervention targets only a certain vascular physiological change, it is recommended to use multiple parameters to evaluate and design intervention approaches accordingly to prevent systemic vascular aging in clinical practices or population-based studies.

A framework of biomarkers for vascular aging: a consensus statement by the Aging Biomarker Consortium

Aging of the vasculature, which is integral to the functioning of literally all human organs, serves as a fundamental physiological basis for age-related alterations as well as a shared etiological mechanism for various chronic diseases prevalent in the elderly population. China, home to the world's largest aging population, faces an escalating challenge in addressing the prevention and management of these age-related conditions. To meet this challenge, the Aging Biomarker Consortium of China has developed an expert consensus on biomarkers of vascular aging (VA) by synthesizing literature and insights from scientists and clinicians. This consensus provides a comprehensive assessment of biomarkers associated with VA and presents a systemic framework to classify them into three dimensions: functional, structural, and humoral. Within each dimension, the expert panel recommends the most clinically relevant VA biomarkers. For the functional domain, biomarkers reflecting vascular stiffness and endothelial function are highlighted. The structural dimension encompasses metrics for vascular structure, microvascular structure, and distribution. Additionally, proinflammatory factors are emphasized as biomarkers with the humoral dimension. The aim of this expert consensus is to establish a foundation for assessing the extent of VA and conducting research related to VA, with the ultimate goal of improving the vascular health of the elderly in China and globally.

CRTC1 is a potential target to delay aging-induced cognitive deficit by protecting the integrity of the blood-brain barrier via inhibiting inflammation

Aging can cause attenuation in the functioning of multiple organs, and blood-brain barrier (BBB) breakdown could promote the occurrence of disorders of the central nervous system during aging. Since inflammation is considered to be an important factor underlying BBB injury during aging, vascular endothelial cell senescence serves as a critical pathological basis for the destruction of BBB integrity. In the current review, we have first introduced the concepts related to aging-induced cognitive deficit and BBB integrity damage. Thereafter, we reviewed the potential relationship between disruption of BBB integrity and cognition deficit and the role of inflammation, vascular endothelial cell senescence, and BBB injury. We have also briefly introduced the function of CREB-regulated transcription co-activator 1 (CRTC1) in cognition and aging-induced CRTC1 changes as well as the critical roles of CRTC1/cyclooxygenase-2 (COX-2) in regulating inflammation, endothelial cell senescence, and BBB injury. Finally, the underlying mechanisms have been summarized and we propose that CRTC1 could be a promising target to delay aging-induced cognitive deficit by protecting the integrity of BBB through promoting inhibition of inflammation-mediated endothelial cell senescence.

Exploring disease interrelationships in older inpatients: a single-centre, retrospective study

Background

Comorbidity is a common phenomenon in the older population; it causes a heavy burden on societies and individuals. However, the relevant evidence, especially in the southwestern region of China, is insufficient.

Objectives

We aimed to examine current comorbidity characteristics as well as correlations among diseases in individuals aged >60 years.

Design

Retrospective study.

Methods

We included records of 2,995 inpatients treated at the Gerontological Department of Sichuan Geriatric Hospital from January 2018 to February 2022. The patients were divided into groups according to sex and age. Diseases were categorised based on the International Classification of Diseases and their Chinese names. We calculated the age-adjusted Charlson Comorbidity Index (ACCI), categorised diseases using the China Health and Retirement Longitudinal Study questionnaire, and visualised comorbidity using web graphs and the Apriori algorithm.

Results

The ACCI was generally high, and it increased with age. There were significant differences in the frequency of all diseases across age groups, especially in individuals aged ≥90 years. The most common comorbid diseases were liver diseases, stomach or other digestive diseases, and hypertension. Strong correlations between the most common digestive diseases and hypertension were observed.

Conclusion

Our findings provide insights into the current situation regarding comorbidity and the correlations among diseases in the older population. We expect our findings to inform future research directions as well as policies regarding general clinical practice and public health, especially for medical consortiums.

Biomarkers of aging

Aging biomarkers are a combination of biological parameters to (i) assess age-related changes, (ii) track the physiological aging process, and (iii) predict the transition into a pathological status. Although a broad spectrum of aging biomarkers has been developed, their potential uses and limitations remain poorly characterized. An immediate goal of biomarkers is to help us answer the following three fundamental questions in aging research: How old are we? Why do we get old? And how can we age slower? This review aims to address this need. Here, we summarize our current knowledge of biomarkers developed for cellular, organ, and organismal levels of aging, comprising six pillars: physiological characteristics, medical imaging, histological features, cellular alterations, molecular changes, and secretory factors. To fulfill all these requisites, we propose that aging biomarkers should qualify for being specific, systemic, and clinically relevant.

Canagliflozin Delays Aging of HUVECs Induced by Palmitic Acid via the ROS/p38/JNK Pathway

Vascular aging is an important factor contributing to cardiovascular diseases, such as hypertension and atherosclerosis. Hyperlipidemia or fatty accumulation may play an important role in vascular aging and cardiovascular diseases. Canagliflozin (CAN), a sodium-glucose cotransporter inhibitor, can exert a cardiovascular protection effect that is likely independent of its hypoglycemic activities; however, the exact mechanisms remain undetermined. We hypothesized that CAN might have protective effects on blood vessels by regulating vascular aging induced by hyperlipidemia or fatty accumulation in blood vessel walls. In this study, which was undertaken on the basis of aging and inflammation, we investigated the protective effects and mechanisms of CAN in human umbilical vein endothelial cells induced by palmitic acid. We found that CAN could delay vascular aging, reduce the secretion of the senescence-associated secretory phenotype (SASP) and protect DNA from damage, as well as exerting an effect on the cell cycle of senescent cells. These actions likely occur through the attenuation of the excess reactive oxygen species (ROS) produced in vascular endothelial cells and/or down-regulation of the p38/JNK signaling pathway. In summary, our study revealed a new role for CAN as one of the sodium-dependent glucose transporter 2 inhibitors in delaying lipotoxicity-induced vascular aging by targeting the ROS/p38/JNK pathway, giving new medicinal value to CAN and providing novel therapeutic ideas for delaying vascular aging in patients with dyslipidemia.

Phosphoglycerate dehydrogenase activates PKM2 to phosphorylate histone H3T11 and attenuate cellular senescence

Vascular endothelial cells (ECs) senescence correlates with the increase of cardiovascular diseases in ageing population. Although ECs rely on glycolysis for energy production, little is known about the role of glycolysis in ECs senescence. Here, we report a critical role for glycolysis-derived serine biosynthesis in preventing ECs senescence. During senescence, the expression of serine biosynthetic enzyme PHGDH is significantly reduced due to decreased transcription of the activating transcription factor ATF4, which leads to reduction of intracellular serine. PHGDH prevents premature senescence primarily by enhancing the stability and activity of pyruvate kinase M2 (PKM2). Mechanistically, PHGDH interacts with PKM2, which prevents PCAF-catalyzed PKM2 K305 acetylation and subsequent degradation by autophagy. In addition, PHGDH facilitates p300-catalyzed PKM2 K433 acetylation, which promotes PKM2 nuclear translocation and stimulates its activity to phosphorylate H3T11 and regulate the transcription of senescence-associated genes. Vascular endothelium-targeted expression of PHGDH and PKM2 ameliorates ageing in mice. Our findings reveal that enhancing serine biosynthesis could become a therapy to promote healthy ageing.

The landscape of aging

Aging is characterized by a progressive deterioration of physiological integrity, leading to impaired functional ability and ultimately increased susceptibility to death. It is a major risk factor for chronic human diseases, including cardiovascular disease, diabetes, neurological degeneration, and cancer. Therefore, the growing emphasis on "healthy aging" raises a series of important questions in life and social sciences. In recent years, there has been unprecedented progress in aging research, particularly the discovery that the rate of aging is at least partly controlled by evolutionarily conserved genetic pathways and biological processes. In an attempt to bring full-fledged understanding to both the aging process and age-associated diseases, we review the descriptive, conceptual, and interventive aspects of the landscape of aging composed of a number of layers at the cellular, tissue, organ, organ system, and organismal levels.

Endothelin A receptors contribute to senescence of brain microvascular endothelial cells

Cellular senescence plays a pivotal role in the aging and progression of neurodegenerative diseases, including vascular cognitive impairment and dementia (VCID). In postmortem brains from individuals with VCID, endothelin-1 (ET-1) levels closely correlate with blood barrier breakdown and cerebral hypoperfusion. Brain microvascular endothelial cells (BMVECs), previously thought to have exclusively endothelin B receptors, also possess endothelin A (ETA) receptors; however, the functional significance of this receptor in BMVECs is not known. We hypothesize that ETA receptors mediate BMVEC senescence. Serum-starved human BMVECs (HBEC5i) were incubated with ET-1 (1 µmol/L) in the presence/absence of ETA receptor antagonist BQ-123 (20 µmol/L). Cells were collected for Western blot and quantitative real-time PCR analyses. Treatment of ET-1 increased protein expression of ETA receptor, while it was prevented by the ETA receptor antagonist. ET-1 increased p21, p16, p53, LIF1 and cyclin D1 protein levels, and β-galactosidase accumulation, which were prevented in the presence of ETA blockade. While there was no change in tight junction proteins, ET-1 decreased adherent junction protein vascular endothelial cadherin (VE-cadherin) levels. In conclusion, ET-1 upregulates ETA receptors in BMVECs in an autocrine manner and triggers the activation of senescence. These in vitro findings need to be further studied in vivo to establish the role of ETA receptors in the progression of endothelial senescence in VCID.

Research progress in endothelial cell injury and repair

Endothelial cells, which are important metabolic and endocrine cells, play an important role in regulating vascular function. The occurrence and development of various cardiovascular and cerebrovascular diseases are associated with endothelial dysfunction. However, the underlying mechanism of vascular endothelial injury is not fully understood. It has been reported that the mechanism of endothelial injury mainly involves inflammation and oxidative stress. Moreover, endothelial progenitor cells are regarded as important contributors in repairing damaged endothelium. Multiple interventions (including chemical drugs and traditional Chinese medicines) exert endothelial protection by decreasing the release of inducing factors, suppressing inflammation and oxidative stress, and preventing endothelial cell senescence.

Factors and Pathways Modulating Endothelial Cell Senescence in Vascular Aging

Aging causes a progressive decline in the structure and function of organs. With advancing age, an accumulation of senescent endothelial cells (ECs) contributes to the risk of developing vascular dysfunction and cardiovascular diseases, including hypertension, diabetes, atherosclerosis, and neurodegeneration. Senescent ECs undergo phenotypic changes that alter the pattern of expressed proteins, as well as their morphologies and functions, and have been linked to vascular impairments, such as aortic stiffness, enhanced inflammation, and dysregulated vascular tone. Numerous molecules and pathways, including sirtuins, Klotho, RAAS, IGFBP, NRF2, and mTOR, have been implicated in promoting EC senescence. This review summarizes the molecular players and signaling pathways driving EC senescence and identifies targets with possible therapeutic value in age-related vascular diseases.

Chronological attenuation of NPRA/PKG/AMPK signaling promotes vascular aging and elevates blood pressure

Hypertension is common in elderly population. We designed to search comprehensively for genes that are chronologically shifted in their expressions and to define their contributions to vascular aging and hypertension. RNA sequencing was conducted to search for senescence-shifted transcripts in human umbilical vein endothelial cells (HUVECs). Small interfering RNA (siRNA), small-molecule drugs, CRISPR/Cas9 techniques, and imaging were used to determine genes' function and contributions to age-related phenotypes of the endothelial cell and blood vessel. Of 25 genes enriched in the term of "regulation of blood pressure," NPRA was changed most significantly. The decreased NPRA expression was replicated in aortas of aged mice. The knockdown of NPRA promoted HUVEC senescence and it decreased expressions of protein kinase cGMP-dependent 1 (PKG), sirtuin 1 (SIRT1), and endothelial nitric oxide synthase (eNOS). Suppression of NPRA also decreased the phosphorylation of AMP-activated protein kinase (AMPK) as well as the ratio of oxidized nicotinamide adenine dinucleotide (NAD⁺ )/reduced nicotinamide adenine dinucleotide (NADH) but increased the production of reactive oxygen species (ROS). 8-Br-cGMP (analog of cGMP), or AICAR (AMPK activator), counteracted the observed changes in HUVECs. The Npr1^+/- mice presented an elevated systolic blood pressure and their vessels became insensitive to endothelial-dependent vasodilators. Further, vessels from Npr1^+/- mice increased Cdkn1a but decreased eNos expressions. These phenotypes were rescued by intravenously administrated 8-Br-cGMP and viral overexpression of human PKG, respectively. In conclusion, we demonstrate NPRA/PKG/AMPK as a novel and critical signaling axis in the modulation of endothelial cell senescence, vascular aging, and hypertension.

Ganoderic acid D prevents oxidative stress-induced senescence by targeting 14-3-3ε to activate CaM/CaMKII/NRF2 signaling pathway in mesenchymal stem cells

Stem cell senescence is an important cause of aging. Delaying senescence may present a novel way to combat aging and age-associated diseases. This study provided a mechanistic insight into the protective effect of ganoderic acid D (GA-D) against human amniotic mesenchymal stem cell (hAMSCs) senescence. GA-D, a Ganoderma lucidum-derived triterpenoid, markedly prevented hAMSCs senescence via activating the Ca2+ calmodulin (CaM)/CaM-dependent protein kinase II (CaMKII)/nuclear erythroid 2-related factor 2 (Nrf2) axis, and 14-3-3ε was identified as a target of GA-D. 14-3-3ε-encoding gene (YWHAE) knockdown in hAMSCs reversed the activation of the CaM/CaMKII/Nrf2 signals to attenuate the GA-D anti-aging effect and increase senescence-associated β-galactosidase (SA-β-gal), p16 and p21 expression levels, including reactive oxygen species (ROS) production, thereby promoting cell cycle arrest and decreasing differentiation potential. YWHAE overexpression maintained or slightly enhanced the GA-D anti-aging effect. GA-D prevented d-galactose-caused aging in mice by significantly increasing the total antioxidant capacity, as well as superoxide dismutase and glutathione peroxidase activity, and reducing the formation of malondialdehyde, advanced glycation end products, and receptor of advanced glycation end products. Consistent with the protective mechanism of GA-D against hAMSCs senescence, GA-D delayed the senescence of bone-marrow mesenchymal stem cells in this aging model in vivo, reduced SA-β-gal and ROS production, alleviated cell cycle arrest, and enhanced cell viability and differentiation via regulating 14-3-3ε and CaM/CaMKII/Nrf2 axis. Therefore, GA-D retards hAMSCs senescence by targeting 14-3-3ε to activate the CaM/CaMKII/Nrf2 signaling pathway. Furthermore, the in vivo GA-D anti-aging effect may involve the regulation of stem cell senescence via the same signal axis.

A review of pathobiological mechanisms and potential application of medicinal plants for vascular aging: focus on endothelial cell senescence

Endothelial cell (EC) senescence plays a pivotal role in aging and is essential for the pathomechanism of aging-related diseases. Drugs targeting cellular senescence, such as senolytic or senomorphic drugs, may prevent aging and age-related diseases, but these bullets remain undeveloped to target EC senescence. Some medicinal plants may have an anti-senescence property but remain undiscovered. Deep learning has become an emerging approach for drug discovery by simply analyzing cellular morphology-based deep learning. This precious tool would be useful for screening the herb candidate in senescent EC rejuvenescence. Of note, several medicinal plants that can be found in Indonesia such as Curcuma longa L., Piper retrofractum, Guazuma ulmifolia Lam, Centella asiatica (L.) Urb., and Garcinia mangostana L. might potentially possess an anti-senescence effect. This review highlighted the importance of targeting EC senescence, the use of deep learning for medicinal plant screening, and some potential anti-senescence plants originating from Indonesia.

Long term high glucose exposure induces premature senescence in retinal endothelial cells

Purpose: Features of cellular senescence have been described in diabetic retinal vasculature. The aim of this study was to investigate how the high glucose microenvironment impacts on the senescence program of retinal endothelial cells. Methods: Human retinal microvascular endothelial cells were cultured under control and high glucose conditions of 5 mM and 25 mM D-glucose, respectively. Isomeric l-glucose was used as the osmotic control. Cells were counted using CASY technology until they reached their Hayflick limit. Senescence-associated β-Galactosidase was used to identify senescent cells. Endothelial cell functionality was evaluated by the clonogenic, 3D tube formation, and barrier formation assays. Cell metabolism was characterized using the Seahorse Bioanalyzer. Gene expression analysis was performed by bulk RNA sequencing. Retinal tissues from db/db and db/+ mice were evaluated for the presence of senescent cells. Publicly available scRNA-sequencing data for retinas from Akimba and control mice was used for gene set enrichment analysis. Results: Long term exposure to 25 mM D-Glucose accelerated the establishment of cellular senescence in human retinal endothelial cells when compared to 5 mM D-glucose and osmotic controls. This was shown from 4 weeks, by a significant slower growth, higher percentages of cells positive for senescence-associated β-galactosidase, an increase in cell size, and lower expression of pRb and HMGB2. These senescence features were associated with decreased clonogenic capacity, diminished tubulogenicity, and impaired barrier function. Long term high glucose-cultured cells exhibited diminished glycolysis, with lower protein expression of GLUT1, GLUT3, and PFKFB3. Transcriptomic analysis, after 4 weeks of culture, identified downregulation of ALDOC, PFKL, and TPI1, in cells cultured with 25 mM D-glucose when compared to controls. The retina from db/db mice showed a significant increase in acellular capillaries associated with a significant decrease in vascular density in the intermediate and deep retinal plexuses, when compared to db/+ mice. Senescent endothelial cells within the db/db retinal vasculature were identified by senescence-associated β-galactosidase staining. Analysis of single cell transcriptomics data for the Akimba mouse retina highlighted an enrichment of senescence and senescence-associated secretory phenotype gene signatures when compared to control mice. Conclusion: A diabetic-like microenvironment of 25 mM D-glucose was sufficient to accelerate the establishment of cellular senescence in human retinal microvascular endothelial cells.

Alteration of E2F2 Expression in Governing Endothelial Cell Senescence

Endothelial cell senescence has a vital implication for vascular dysfunction, leading to age-related cardiovascular disease, especially hypertension and atherosclerosis. E2F transcription factor 2 (E2F2) plays a critical role in cell proliferation, differentiation, and DNA damage response. Up to date, no study has ever connected E2F2 to vascular endothelial cell senescence. Here, we demonstrate that E2F2 is involved in endothelial cellular senescence. We found that E2F2 expression is decreased during the replicative senescence of human umbilical vein endothelial cells (HUVECs) and the aortas of aged mice. The knockdown of E2F2 in young HUVECs induces premature senescence characterized by an increase in senescence-associated β-galactosidase (SA-β-gal) activity, a reduction in phosphorylated endothelial nitric oxide synthase (p-eNOS) and sirtuin 1 (SIRT1), and the upregulation of senescence-associated secretory phenotype (SASP) IL-6 and IL-8. The lack of E2F2 promoted cell cycle arrest, DNA damage, and cell proliferation inhibition. Conversely, E2F2 overexpression reversed the senescence phenotype and enhanced the cellular function in the senescent cells. Furthermore, E2F2 deficiency downregulated downstream target genes including CNNA2, CDK1, and FOXM1, and overexpression restored the expression of these genes. Our findings demonstrate that E2F2 plays an indispensable role in endothelial cell senescence.

miR-335-5p regulates the proliferation, migration and phenotypic switching of vascular smooth muscle cells in aortic dissection by directly regulating SP1

Uncontrolled proliferation, migration and phenotypic switching of vascular smooth muscle cells (VSMCs) are important steps in the development and progression of aortic dissection (AD). The function and potential mechanism of miR-335-5p in the pathogenesis of AD are explored in this study. Specifically, the biological function of miR-335-5p is explored in vitro through CCK-8, Transwell, immunofluorescence, EdU, wound-healing, RT-qPCR and western blotting assays. In addition, an AD model induced by angiotensin II is used to investigate the function of miR-335-5p in vivo. A dual-luciferase assay is performed to verify the targeting relationship between miR-335-5p and specificity protein 1 (SP1). Experiments involving the loss of SP1 function are performed to demonstrate the function of SP1 in the miR-335-5p-mediated regulation of human aortic-VSMCs (HA-VSMCs). AD tissues and platelet-derived growth factor BB (PDGF-BB)-stimulated HA-VSMCs show significant downregulation of miR-335-5p expression and upregulated SP1 expression. Overexpression of miR-335-5p effectively suppresses cell proliferation, migration and synthetic phenotype markers and enhances contractile phenotype markers induced by PDGF-BB treatment. Additionally, SP1 is identified as a target gene downstream of miR-335-5p, and its expression is negatively correlated with miR-335-5p in AD. Upregulation of SP1 partially reverses the inhibitory effect of miR-335-5p on HA-VSMCs, whereas the downregulation of SP1 has the opposite effect. Furthermore, Ad-miR-335-5p clearly suppresses aorta dilatation and vascular media degeneration in the AD model. Our results suggest that miR-335-5p inhibits HA-VSMC proliferation, migration and phenotypic switching by negatively regulating SP1, and indicate that miR-335-5p may be a potential therapeutic target in AD.

Aldehyde Dehydrogenase 2 as a Therapeutic Target in Oxidative Stress-Related Diseases: Post-Translational Modifications Deserve More Attention

Aldehyde dehydrogenase 2 (ALDH2) has both dehydrogenase and esterase activity; its dehydrogenase activity is closely related to the metabolism of aldehydes produced under oxidative stress (OS). In this review, we recapitulate the enzyme activity of ALDH2 in combination with its protein structure, summarize and show the main mechanisms of ALDH2 participating in metabolism of aldehydes in vivo as comprehensively as possible; we also integrate the key regulatory mechanisms of ALDH2 participating in a variety of physiological and pathological processes related to OS, including tissue and organ fibrosis, apoptosis, aging, and nerve injury-related diseases. On this basis, the regulatory effects and application prospects of activators, inhibitors, and protein post-translational modifications (PTMs, such as phosphorylation, acetylation, S-nitrosylation, nitration, ubiquitination, and glycosylation) on ALDH2 are discussed and prospected. Herein, we aimed to lay a foundation for further research into the mechanism of ALDH2 in oxidative stress-related disease and provide a basis for better use of the ALDH2 function in research and the clinic.

Effects of Different Intensities and Durations of Aerobic Exercise on Vascular Endothelial Function in Middle-Aged and Elderly People: A Meta-analysis

Background

Previous studies have found that aerobic exercise was more effective in improving vascular endothelial function than resistance training, high-intensity interval training (HIIT), and other types of exercise, while the effects between different intensities and durations of aerobic exercise were unclear. Therefore, we performed this meta-analysis to investigate the effects of different intensities and durations of aerobic exercise on the vascular endothelial function of middle-aged and elderly people.

Methods:

Databases were searched up to April 2021 for studies evaluating the influences of different intensities and durations of aerobic exercise on endothelial function assessed by flow-mediated dilation (FMD) among healthy middle-aged and elderly people. Data were pooled using random-effects models to obtain the weighted mean difference (WMD) and 95% confidence intervals (CIs).

Results

A total of 9 studies involving 221 participants fulfilled the inclusion criteria. Aerobic exercise improved the overall FMD of healthy middle-aged and elderly people [WMD, 1.33 (95% CI, 0.37–2.28), P < 0.05]. Specifically, vigorous-intensity exercise increased FMD significantly in healthy middle-aged and elderly people [WMD, 1.10 (95% CI, 0.27–1.93), P < 0.05], while moderate-intensity exercise had no significant association with FMD [WMD, 1.49 (95% CI, −0.62 to 3.60), P = 0.17]. In addition, long-term (8 weeks or above) aerobic exercise increased the FMD in healthy middle-aged and elderly people [WMD, 1.63 (95% CI, 0.61–2.66), P < 0.05], while one-time acute aerobic exercise had no significant association with FMD of healthy middle-aged and elderly people [WMD, 0.89 (95% CI, −1.47 to 3.24), P = 0.46]. Specifically, 8 weeks or above of vigorous-intensity exercise increased FMD significantly in healthy middle-aged and elderly people [WMD, 1.48 (95% CI, 1.06–1.90), P < 0.01], while 8 weeks or above of moderate aerobic exercise had no significant association with FMD [WMD, 1.49 (95% CI, −0.62 to 3.60), P = 0.17].

Conclusion

Aerobic exercise, especially 8 weeks or above of vigorous-intensity aerobic exercise, improved the endothelial function in healthy middle-aged and elderly people.

The role of FGF21 in the pathogenesis of cardiovascular disease

ABSTRACT

The morbidity and mortality of cardiovascular diseases (CVDs) are increasing worldwide and seriously threaten human life and health. Fibroblast growth factor 21 (FGF21), a metabolic regulator, regulates glucose and lipid metabolism and may exert beneficial effects on the cardiovascular system. In recent years, FGF21 has been found to act directly on the cardiovascular system and may be used as an early biomarker of CVDs. The present review highlights the recent progress in understanding the relationship between FGF21 and CVDs including coronary heart disease, myocardial ischemia, cardiomyopathy, and heart failure and also explores the related mechanism of the cardioprotective effect of FGF21. FGF21 plays an important role in the prediction, treatment, and improvement of prognosis in CVDs. This cardioprotective effect of FGF21 may be achieved by preventing endothelial dysfunction and lipid accumulating, inhibiting cardiomyocyte apoptosis and regulating the associated oxidative stress, inflammation and autophagy. In conclusion, FGF21 is a promising target for the treatment of CVDs, however, its clinical application requires further clarification of the precise role of FGF21 in CVDs.

Senescence Alterations in Pulmonary Hypertension

Cellular senescence is the arrest of normal cell division and is commonly associated with aging. The interest in the role of cellular senescence in lung diseases derives from the observation of markers of senescence in chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (IPF), and pulmonary hypertension (PH). Accumulation of senescent cells and the senescence-associated secretory phenotype in the lung of aged patients may lead to mild persistent inflammation, which results in tissue damage. Oxidative stress due to environmental exposures such as cigarette smoke also promotes cellular senescence, together with additional forms of cellular stress such as mitochondrial dysfunction and endoplasmic reticulum stress. Growing recent evidence indicate that senescent cell phenotypes are observed in pulmonary artery smooth muscle cells and endothelial cells of patients with PH, contributing to pulmonary artery remodeling and PH development. In this review, we analyze the role of different senescence cell phenotypes contributing to the pulmonary artery remodeling process in different PH clinical entities. Different molecular pathway activation and cellular functions derived from senescence activation will be analyzed and discussed as promising targets to develop future senotherapies as promising treatments to attenuate pulmonary artery remodeling in PH.

Roles and functions of antisense lncRNA in vascular aging

Vascular aging is a major cause of morbidity and mortality in the elderly population. Endothelial cells (ECs) and vascular smooth muscle cells (VSMCs), forming the intima and media layers of the vessel wall respectively, are closely associated with the process of vascular aging and vascular aging-related diseases. Numerous studies have revealed the pathophysiologic mechanism through which lncRNA contributes to vascular aging, hence more attention is now paid to the role played by antisense long non-coding RNA (AS-lncRNA) in the pathogenesis of vascular aging. Nonetheless, only a small number of studies focus on the specific mechanism through which AS-lncRNA mediates vascular aging. In this review, we summarize the roles and functions of AS-lncRNA with regards to the development of vascular aging and vascular aging-related disease. We also aim to deepen our understanding of this process and provide alternative therapeutic modalities for vascular aging-related diseases.

C1q/TNF-Related Protein 9 Attenuates Atherosclerosis by Inhibiting Hyperglycemia-Induced Endothelial Cell Senescence Through the AMPKα/KLF4 Signaling Pathway

Hyperglycemia-induced endothelial cell senescence has been widely reported to be involved in the pathogenesis of type 2 diabetes mellitus‒accelerated atherosclerosis. Thus, understanding the underlying mechanisms and identifying potential therapeutic targets for endothelial cell senescence are valuable for attenuating atherosclerosis progression. C1q/tumor necrosis factor-related protein 9 (CTRP9), an emerging potential cardiokine, exerts a significant protective effect with respect to atherosclerosis, particularly in endothelial cells. However, the exact mechanism by which CTRP9 prevents endothelial cells from hyperglycemia-induced senescence remains unclear. This study aimed to investigate the effects of CTRP9 on hyperglycemia-induced endothelial cell senescence and atherosclerotic plaque formation in diabetic apolipoprotein E knockout (ApoE KO) mice. Human umbilical vein endothelial cells (HUVECs) were cultured in normal glucose (5.5 mM) and high glucose (40 mM) with or without recombinant human CTRP9 protein (3 μg/ml) for 48 h. Purified lentiviruses overexpressing CTRP9 (Lv-CTRP9) and control vectors containing green fluorescent protein (Lv-GFP) were injected via the tail vein into streptozotocin-induced diabetic ApoE KO mice. Results revealed that exposure of HUVECs to HG significantly increased the expression of Krüppel-like factor 4 (KLF4) and cyclin-dependent kinase inhibitor p21 (p21) and decreased that of telomerase reverse transcriptase (TERT). Treatment with recombinant human CTRP9 protein protected HUVECs from HG-induced premature senescence and dysfunction. CTRP9 promoted the phosphorylation of AMP-activated kinase (AMPK), attenuated the expression of KLF4 and p21 induced by HG, and increased the expression of TERT in HUVECs. Furthermore, in the background of AMPKα knockdown or KLF4 activation, the protective effects of CTRP9 were abolished. In-vivo experiments showed that the overexpression of CTRP9 inhibited vascular senescence and reduced atherosclerotic plaque formation in ApoE KO mice with diabetes. In conclusion, we demonstrate that KLF4 upregulation plays a crucial role in HG-induced endothelial senescence. This anti-atherosclerotic effect of CTRP9 may be partly attributed to the inhibition of HG-induced endothelial senescence through an AMPKα/KLF4-dependent mechanism, suggesting that CTRP9 could benefit further therapeutic approaches for type 2 diabetes mellitus‒accelerated atherosclerosis.

The Role of Short-Chain Fatty Acids of Gut Microbiota Origin in Hypertension

Hypertension is a significant risk factor for cardiovascular and cerebrovascular diseases, and its development involves multiple mechanisms. Gut microbiota has been reported to be closely linked to hypertension. Short-chain fatty acids (SCFAs)-the metabolites of gut microbiota-participate in hypertension development through various pathways, including specific receptors, immune system, autonomic nervous system, metabolic regulation and gene transcription. This article reviews the possible mechanisms of SCFAs in regulating blood pressure and the prospects of SCFAs as a target to prevent and treat hypertension.

Heme Oxygenase-1 at the Nexus of Endothelial Cell Fate Decision Under Oxidative Stress

Endothelial cells (ECs) form the inner lining of blood vessels and are central to sensing chemical perturbations that can lead to oxidative stress. The degree of stress is correlated with divergent phenotypes such as quiescence, cell death, or senescence. Each possible cell fate is relevant for a different aspect of endothelial function, and hence, the regulation of cell fate decisions is critically important in maintaining vascular health. This study examined the oxidative stress response (OSR) in human ECs at the boundary of cell survival and death through longitudinal measurements, including cellular, gene expression, and perturbation measurements. 0.5 mM hydrogen peroxide (HP) produced significant oxidative stress, placed the cell at this junction, and provided a model to study the effectors of cell fate. The use of systematic perturbations and high-throughput measurements provide insights into multiple regimes of the stress response. Using a systems approach, we decipher molecular mechanisms across these regimes. Significantly, our study shows that heme oxygenase-1 (HMOX1) acts as a gatekeeper of cell fate decisions. Specifically, HP treatment of HMOX1 knockdown cells reversed the gene expression of about 51% of 2,892 differentially expressed genes when treated with HP alone, affecting a variety of cellular processes, including anti-oxidant response, inflammation, DNA injury and repair, cell cycle and growth, mitochondrial stress, metabolic stress, and autophagy. Further analysis revealed that these switched genes were highly enriched in three spatial locations viz., cell surface, mitochondria, and nucleus. In particular, it revealed the novel roles of HMOX1 on cell surface receptors EGFR and IGFR, mitochondrial ETCs (MTND3, MTATP6), and epigenetic regulation through chromatin modifiers (KDM6A, RBBP5, and PPM1D) and long non-coding RNA (lncRNAs) in orchestrating the cell fate at the boundary of cell survival and death. These novel aspects suggest that HMOX1 can influence transcriptional and epigenetic modulations to orchestrate OSR affecting cell fate decisions.

Sex Differences in Molecular Mechanisms of Cardiovascular Aging

Cardiovascular disease (CVD) is still the leading cause of illness and death in the Western world. Cardiovascular aging is a progressive modification occurring in cardiac and vascular morphology and physiology where increased endothelial dysfunction and arterial stiffness are observed, generally accompanied by increased systolic blood pressure and augmented pulse pressure. The effects of biological sex on cardiovascular pathophysiology have long been known. The incidence of hypertension is higher in men, and it increases in postmenopausal women. Premenopausal women are protected from CVD compared with age-matched men and this protective effect is lost with menopause, suggesting that sex-hormones influence blood pressure regulation. In parallel, the heart progressively remodels over the course of life and the pattern of cardiac remodeling also differs between the sexes. Lower autonomic tone, reduced baroreceptor response, and greater vascular function are observed in premenopausal women than men of similar age. However, postmenopausal women have stiffer arteries than their male counterparts. The biological mechanisms responsible for sex-related differences observed in cardiovascular aging are being unraveled over the last several decades. This review focuses on molecular mechanisms underlying the sex-differences of CVD in aging.

The effects of bone morphogenetic protein 2 and thrombopoietin treatment on angiogenic properties of endothelial cells derived from the lung and bone marrow of young and aged, male and female mice

With an aging world population, there is an increased risk of fracture and impaired healing. One contributing factor may be aging-associated decreases in vascular function; thus, enhancing angiogenesis could improve fracture healing. Both bone morphogenetic protein 2 (BMP-2) and thrombopoietin (TPO) have pro-angiogenic effects. The aim of this study was to investigate the effects of treatment with BMP-2 or TPO on the in vitro angiogenic and proliferative potential of endothelial cells (ECs) isolated from lungs (LECs) or bone marrow (BMECs) of young (3-4 months) and old (22-24 months), male and female, C57BL/6J mice. Cell proliferation, vessel-like structure formation, migration, and gene expression were used to evaluate angiogenic properties. In vitro characterization of ECs generally showed impaired vessel-like structure formation and proliferation in old ECs compared to young ECs, but improved migration characteristics in old BMECs. Differential sex-based angiogenic responses were observed, especially with respect to drug treatments and gene expression. Importantly, these studies suggest that NTN1, ROBO2, and SLIT3, along with angiogenic markers (CD31, FLT-1, ANGPT1, and ANGP2) differentially regulate EC proliferation and functional outcomes based on treatment, sex, and age. Furthermore, treatment of old ECs with TPO typically improved vessel-like structure parameters, but impaired migration. Thus, TPO may serve as an alternative treatment to BMP-2 for fracture healing in aging owing to improved angiogenesis and fracture healing, and the lack of side effects associated with BMP-2.

Mechanical Fingerprint of Senescence in Endothelial Cells

Endothelial senescence entails alterations of the healthy cell phenotype, which accumulate over time and contribute to cardiovascular disease. Mechanical aspects regulating cell adhesion, force generation, and the response to flow contribute to the senescence-associated drift; however, they remain largely unexplored. Here, we exploit force microscopy to resolve variations of the cell anchoring to the substrate and the tractions generated upon aging in the nanonewton (nN) range. Senescent endothelial cells display a multifold increase in the levels of basal adhesion and force generation supported by mature and strong focal adhesions. The enhanced mechanical interaction with the substrate yields static endothelial monolayers that polarize in response to flow but fail the process of coordinated cell shape remodeling and reorientation. The emerging picture indicates that senescence reinforces the local cell interaction with the substrate and may therefore prevent endothelial denudation; however, it compromises the ability to functionally adapt to the local hemodynamic conditions.

Anthracycline chemotherapy-mediated vascular dysfunction as a model of accelerated vascular aging

Cardiovascular diseases (CVD) are the leading cause of death worldwide, and age is by far the greatest risk factor for developing CVD. Vascular dysfunction, including endothelial dysfunction and arterial stiffening, is responsible for much of the increase in CVD risk with aging. A key mechanism involved in vascular dysfunction with aging is oxidative stress, which reduces the bioavailability of nitric oxide (NO) and induces adverse changes to the extracellular matrix of the arterial wall (e.g., elastin fragmentation/degradation, collagen deposition) and an increase in advanced glycation end products, which form crosslinks in arterial wall structural proteins. Although vascular dysfunction and CVD are most prevalent in older adults, several conditions can "accelerate" these events at any age. One such factor is chemotherapy with anthracyclines, such as doxorubicin (DOXO), to combat common forms of cancer. Children, adolescents and young adults treated with these chemotherapeutic agents demonstrate impaired vascular function and an increased risk of future CVD development compared with healthy age-matched controls. Anthracycline treatment also worsens vascular dysfunction in mid-life (50-64 years of age) and older (65 and older) adults such that endothelial dysfunction and arterial stiffness are greater compared to age-matched controls. Collectively, these observations indicate that use of anthracycline chemotherapeutic agents induce a vascular aging-like phenotype and that the latter contributes to premature CVD in cancer survivors exposed to these agents. Here, we review the existing literature supporting these ideas, discuss potential mechanisms as well as interventions that may protect arteries from these adverse effects, identify research gaps and make recommendations for future research.

UNC5B Promotes Vascular Endothelial Cell Senescence via the ROS-Mediated P53 Pathway

Vascular endothelial cell senescence is involved in human aging and age-related vascular disorders. Guidance receptor UNC5B is implicated in oxidative stress and angiogenesis. Nonetheless, little is known about the role of UNC5B in endothelial cell senescence. Here, we cultured primary human umbilical vein endothelial cells to young and senescent phases. Subsequently, the expression of UNC5B was identified in replicative senescent cells, and then, its effect on endothelial cell senescence was confirmed by UNC5B-overexpressing lentiviral vectors and RNA interference. Overexpression of UNC5B in young endothelial cells significantly increased senescence-associated β-galactosidase-positive cells, upregulated the mRNAs expression of the senescence-associated secretory phenotype genes, reduced total cell number, and inhibited the potential for cell proliferation. Furthermore, overexpression of UNC5B promoted the generation of intracellular reactive oxygen species (ROS) and activated the P53 pathway. Besides, overexpression of UNC5B disturbed endothelial function by inhibiting cell migration and tube formation. Nevertheless, silencing UNC5B generated conflicting outcomes. Blocking ROS production or inhibiting the function of P53 rescued endothelial cell senescence induced by UNC5B. These findings suggest that UNC5B promotes endothelial cell senescence, potentially by activating the ROS-P53 pathway. Therefore, inhibiting UNC5B might reduce endothelial cell senescence and hinder age-related vascular disorders.

Vildagliptin improves vascular smooth muscle relaxation and decreases cellular senescence in the aorta of doxorubicin-treated rats

INTRODUCTION

Doxorubicin (DOX) is a chemotherapeutic agent used in cancer treatment. Its use is limited by later toxicity to the cardiovascular system (CVS). Cellular senescence has been proposed as one mechanism of DOX toxicity. It has also been suggested that senescence reduction can improve the condition in many pathologies. We hypothesised that vildagliptin treatment can reduce senescence and thus improve the relaxation of vascular smooth muscle (VSM) in the aorta of a rat DOX model.

METHODS

The rats received DOX and were treated with vildagliptin for 6 weeks. Thereafter, the rats were sacrificed, and the aorta prepared for measurements of VSM relaxation and RNA isolation to detect the level of senescence markers. To further prove the antisenescence effect of the main vildagliptin effector glucagon-like peptide 1(GLP-1), VSM cells (VSMCs) were incubated with DOX and treated with GLP-1. Subsequently, senescence was detected by senescence-associated beta-galactosidase (SA-β-gal) and by the presence of senescence markers.

RESULTS

DOX in rats caused diminished relaxation of VSM to sodium nitrate and caused an increase in the senescence mRNA markers p16Ink4a and p27Kip1 and the senescence-associated secretory phenotype (SASP) IL-6 and IL-8. Vildagliptin treatment led to improved relaxation and a reduction in senescence and SASP markers. Furthermore, in VSMCs DOX increased SA-β-gal activity, p16Ink4a, p27Kip1, IL-6 and IL-8, and GLP1 treatment led to a decrease of both senescence and SASP markers.

CONCLUSION

In summary we conclude that vildagliptin can reduce senescence and improve relaxation of vascular smooth muscle in the aorta of DOX-treated rats, and GLP-1 can reduce senescence of DOX-treated VSMCs. These data suggest that incretin-based drugs are promising candidates for patients suffering from late doxorubicin cardiovascular toxicity.

The mechanisms of vascular aging

Vascular senescence is one of the hotspots in current research. With global average life expectancy increasing, delaying or reducing aging and age-related diseases has become a pressing issue for improving quality of life. Vascular senescence is an independent risk factor for age-related cardiovascular diseases (CVD) and results in the deterioration of CVD. Nevertheless, the underlying mechanisms of the vascular senescence have not been expressly illustrated. In this review, we attempt to summarize the recent literature in the field and discuss the major mechanisms involved in vascular senescence. We also underline key molecular aspects of aging-associated vascular dysfunction in the attempt to highlight potential innovative therapeutic targets to delay the onset of age-related diseases.

Exosomes and Exosomal MicroRNAs in Age-Associated Stroke

Aging has been considered to be the most important non-modifiable risk factor for stroke and death. Changes in circulation factors in the systemic environment, cellular senescence and artery hypertension during human ageing have been investigated. Exosomes are nanosize membrane vesicles that can regulate target cell functions via delivering their carried bioactive molecules (e.g. protein, mRNA, and microRNAs). In the central nervous system, exosomes and exosomal microRNAs play a critical role in regulating neurovascular function, and are implicated in the initiation and progression of stroke. MicroRNAs are small non-coding RNAs that have been reported to play critical roles in various biological processes. Recently, evidence has shown that microRNAs are packaged into exosomes and can be secreted into the systemic and tissue environment. Circulating microRNAs participate in cellular senescence and contribute to age-associated stroke. Here, we provide an overview of current knowledge on exosomes and their carried microRNAs in the regulation of cellular and organismal ageing processes, demonstrating the potential role of exosomes and their carried microRNAs in age-associated stroke.

Mechanism of herbal medicine on hypertensive nephropathy (Review)

Hypertensive nephropathy is the most common complication of hypertension, and is one of the main causes of end-stage renal disease (ESRD) in numerous countries. The basic pathological feature of hypertensive nephropathy is arteriolosclerosis followed by renal parenchymal damage. The etiology of this disease is complex, and its pathogenesis is mainly associated with renal hemodynamic changes and vascular remodeling. Despite the increased knowledge on the pathogenesis of hypertensive nephropathy, the current clinical treatment methods are still not effective in preventing the development of the disease to ESRD. Herbal medicine, which is used to relieve symptoms, can improve hypertensive nephropathy through multiple targets. Since there are few clinical studies on the treatment of hypertensive nephropathy with herbal medicine, this article aims to review the progress on the basic research on the treatment of hypertensive nephropathy with herbal medicine, including regulation of the renin angiotensin system, inhibition of sympathetic excitation, antioxidant stress and anti-inflammatory protection of endothelial cells, and improvement of obesity-associated factors. Herbal medicine with different components plays a synergistic and multi-target role in the treatment of hypertensive nephropathy. The description of the mechanism of herbal medicine in the treatment of hypertensive nephropathy will contribute towards the progress of modern medicine.

Network Pharmacology-Based Prediction of Catalpol and Mechanisms against Stroke

Aim

To apply the network pharmacology method to screen the target of catalpol prevention and treatment of stroke, and explore the pharmacological mechanism of Catalpol prevention and treatment of stroke.

Methods

PharmMapper, GeneCards, DAVID, and other databases were used to find key targets. We selected hub protein and catalpol which were screened for molecular docking verification. Based on the results of molecular docking, the ITC was used to determine the binding coefficient between the highest scoring protein and catalpol. The GEO database and ROC curve were used to evaluate the correlation between key targets.

Results

27 key targets were obtained by mapping the predicted catalpol-related targets to the disease. Hub genes (ALB, CASP3, MAPK1 (14), MMP9, ACE, KDR, etc.) were obtained in the key target PPI network. The results of KEGG enrichment analysis showed that its signal pathway was involved in angiogenic remodeling such as VEGF, neurotrophic factors, and inflammation. The results of molecular docking showed that ACE had the highest docking score. Therefore, the ITC was used for the titration of ACE and catalpol. The results showed that catalpol had a strong binding force with ACE.

Conclusion

Network pharmacology combined with molecular docking predicts key genes, proteins, and signaling pathways for catalpol in treating stroke. The strong binding force between catalpol and ACE was obtained by using ITC, and the results of molecular docking were verified to lay the foundation for further research on the effect of catalpol on ACE. ROC results showed that the AUC values of the key targets are all >0.5. This article uses network pharmacology to provide a reference for a more in-depth study of catalpol's mechanism and experimental design.

MiR-217 promotes endothelial cell senescence through the SIRT1/p53 signaling pathway

Studies have shown that miR-217 can induce cell senescence, but its mechanism of action in vascular endothelial cell senescence is less reported. Therefore, this study aimed to investigate how miR-217 plays a role in endothelial cell senescence. Human umbilical vein endothelial cells (HUVECs) were used to replicate the aging model, and the population doubling levels (PDLs) during cell passage were counted. Senescence-associated β-galactosidase (SA-β-gal) staining, Real-time quantitative PCR (RT-qPCR), MTT assay, Transwell, and tube formation were used to detect the effects of miR-217 on young and senescent HUVECs. Targetscan7.2 and luciferase assay predicted and verified the relationship between miR-217 and the target gene, and the expression of silent information regulator 1 (SIRT1) and p53 was detected by RT-qPCR and western blot. In addition, SA-β-gal staining detected the effects of miR-217 inhibitor and SIRT1 on senescent HUVECs. MiR-217 was upregulated in senescent endothelial cells. Overexpression of miR-217 promoted the increase of SA-β-gal positive cells, and inhibited proliferation, migration and angiogenesis during endothelial cell growth. Furthermore, SIRT1 was a target gene of miR-217. Simultaneous silencing of SIRT1 reversed the effect of miR-217 inhibitor on the reduction of SA-β-gal positive-staining cells. Our data suggest that overexpression of miR-217 promoted vascular endothelial cell senescence by targeting the SIRT1/p53 signaling pathway, which may provide a new basis for studying the mechanism of action in vascular endothelial cell senescence.

Effects of cellular senescence on metabolic pathways in non-immune and immune cells

Many cellular stresses induce cellular senescence and the irreversible arrest of cell proliferation in different cell types. Although blocked in their capacity to divide, senescent cells are metabolically active and are characterized by a different metabolic phenotype as compared to non-senescent cells. Changes observed in senescent cells depend from the cell type and lead to an adaptative flexibility in the type of metabolism. This metabolic reprogramming is needed to cope with survival and with the energetic demands of the senescent program that include the increased secretion of senescence-associated secretory phenotype factors.