Endothelial Cell Senescence Research Articles

Sulodeksyd w leczeniu retinopatii cukrzycowej

Diabetes mellitus is causing dysfunction of the vascular endothelial cells, which results in various pathologies within the microvascular and macrovascular system including retinopathy, neuropathy, nephropathy, and angiopathy. Endothelial dysfunction is caused by hyperglycemia via different mechanisms, such as damage to the glycocalyx, activation of the inflammation, oxidative stress, stimulation of cellular senescence, induction of imbalance between coagulation and fibrinolysis. Many studies suggests that inhibition of retinal endothelial dysfunction may be an effective way of slowing the progress of diabetic retinopathy. Sulodexide (glycosaminoglycans composed from heparin-like and dermatan fractions)is associated with a protective and regenerating action on the glycocalyx, slows down senescence of human venous and arterial endothelial cells. Moreover its mechanism of action involves an anti-inflammatory, anti-proteolytic, and antioxidant effect, including interference with metabolic and non-metabolic stress. In present study sulodexide was chosen to evaluate its therapeutic properties for the treatment of diabetic retinopathy.

Canthaxanthin Attenuates the Vascular Aging or Endothelial Cell Senescence by Inhibiting Inflammation and Oxidative Stress in Mice.

Vascular endothelial dysfunction is an early phenotype of aging-related vascular dysfunction. Delaying vascular aging and preventing cardiovascular disease are major public health problems that urgently need to be solved. Scientists have studied various drugs to prevent the occurrence and progress of cardiovascular disease, but progress has been slow. Here, the antisenescence and anti-endothelial damage of canthaxanthin (CX, which is an active molecule from food) has been studied. This study was performed by adding CX to a model of cell senescence and oxidative damage induced by hydrogen peroxide. Cellular senescence markers (e.g., p16, p21, and p53) and oxidative damage markers (e.g., reactive oxygen species, nitric oxide, malondialdehyde, superoxide dismutase) were evaluated by the enzyme-linked immunosorbent assay, laser scanning confocal microscopy, and Western blotting. We found that CX downregulated the expression level of senescence-associated molecules, and significantly reduced the oxidative damage of vascular endothelial cells. These observations showed that CX effectively alleviated the senescence of vascular endothelial cells. Furthermore, CX treatment reduced the expression levels of interleukin-6 (IL-6), tumor necrosis factor alpha, and IL-1β. Finally, in vivo, CX significantly alleviated vascular senescence. The current study shows that CX has potential application value for treating vascular aging or endothelial cell senescence.

Gastrodin alleviates premature senescence of vascular endothelial cells by enhancing the Nrf2/HO-1 signalling pathway.

Endothelial dysfunction is an independent risk factor for stroke. The dysfunction of endothelial cells (EC) is closely concerned with EC senescence. Gastrodin (GAS) is an organic compound extracted from the dried root mass of the Orchidaceae plant Gastrodiae gastrodiae. It is used clinically to treat diseases such as vertebrobasilar insufficiency, vestibular neuronitis and vertigo. In the present study, we used hydrogen peroxide (H2 O2 )-induced human umbilical vein endothelial cells (HUVECs) to establish an invitro EC senescence model and to investigate the role and mechanism of GAS in EC senescence. It's found that H2 O2 -treated HUVECs increased the proportion of senescence-associated β-galactosidase (SA β-gal) positive cells and the relative protein expression levels of senescence-associated cyclin p16 and p21. In addition, GAS reduced the proportion of SA β-gal positive cells and the relative protein expression levels of p16 and p21, and increased the proliferation and migration ability of HUVECs. Meanwhile, GAS increased the expression of the anti-oxidative stress protein HO-1 and its nuclear expression level of Nrf2. The anti-senescence effect of GAS was blocked when HO-1 expression was inhibited by SnPPIX. Furthermore, absence of HO-1 abolished the effect of GAS on HUVEC proliferation and migration. In conclusion, GAS ameliorated H2 O2 -induced cellular senescence and enhanced cell proliferation and migration by enhancing Nrf2/HO-1 signalling in HUVECs. These findings of our study expanded the understanding of GAS pharmacology and suggested that GAS may offer a potential therapeutic agent for stroke.

Endothelial Dysfunction and Heart Failure with Preserved Ejection Fraction-An Updated Review of the Literature.

Heart failure (HF) is a clinical syndrome consisting of typical symptoms and signs due to structural and/or functional abnormalities of the heart, resulting in elevated intracardiac pressures and/or inadequate cardiac output. The vascular system plays a crucial role in the development and progression of HF regardless of ejection fraction, with endothelial dysfunction (ED) as one of the principal features of HF. The main ED manifestations (i.e., impaired endothelium-dependent vasodilation, increased oxidative stress, chronic inflammation, leukocyte adhesion, and endothelial cell senescence) affect the systemic and pulmonary haemodynamic and the renal and coronary circulation. The present review is aimed to discuss the contribution of ED to HF pathophysiology-in particular, HF with preserved ejection fraction-ED role in HF patients, and the possible effects of pharmacological and non-pharmacological approaches. For this purpose, relevant data from a literature search (PubMed, Scopus, EMBASE, and Medline) were reviewed. As a result, ED, assessed via venous occlusion plethysmography or flow-mediated dilation, was shown to be independently associated with poor outcomes in HF patients (e.g., mortality, cardiovascular events, and hospitalization due to worsening HF). In addition, SGLT2 inhibitors, endothelin antagonists, endothelial nitric oxide synthase cofactors, antioxidants, and exercise training were shown to positively modulate ED in HF. Despite the need for future research to better clarify the role of the vascular endothelium in HF, ED represents an interesting and promising potential therapeutic target.

Coptisine prevents angiotensin II‑induced endothelial cell injury and senescence via the lncRNA SNHG12/miR‑603/NAMPT pathway.

Atherosclerosis (AS) is a major health problem and targeting the associated molecular pathways is critical for developing therapies. The present study investigated the effect of coptisine on human umbilical vein endothelial cells (HUVECs) in response to angiotensin II (Ang II) induction by focusing on cellular senescence, apoptosis and inflammation. HUVECs were treated with different Ang II concentrations and long non-coding RNA small nucleolar RNA host gene 12 (SNHG12), microRNA (miRNA/miR)-603 and nicotinamide phosphoribosyltransferase (NAMPT) expressions were assessed. Cell viability, nicotinamide adenine dinucleotide (NAD+) levels, senescence, apoptosis and inflammation were assessed. The interactions among SNHG12, miR-603 and NAMPT were investigated using dual-luciferase reporter gene assays and RNA pull-down experiments. Coptisine treatment increased SNHG12 expression and attenuated Ang II-induced adverse effects in HUVECs. SNHG12 silencing abrogated coptisine's protective effects, indicating that SNHG12 is a key mediator. SNHG12 targets miR-603, which then directly targets NAMPT, an age-related gene involved in NAD(+) regulation. Coptisine modulated the SNHG12/miR-603/NAMPT pathway and miR-603 inhibition enhanced the protective effects of coptisine. NAMPT overexpression reversed the negative effects of miR-603 and enhanced the protective effect of the miR-603 inhibitor. Finally, the protective mechanism of coptisine is linked to the regulation of NAD(+), sirtuin 3 (SIRT3) and p53. Coptisine treatment counteracted the AngII-induced increase in SIRT3 and p53 protein levels, whereas the miR-603 inhibitor potentiated the effect of coptisine. SNHG12 knockdown partially abolished these effects, which were reversed by NAMPT overexpression. In conclusion, the present study revealed a novel protective mechanism involving the SNHG12/miR-603/NAMPT pathway in HUVECs exposed to Ang II, highlighting the potential therapeutic application of coptisine in treating atherosclerosis. These results suggested that coptisine exerts its protective effects by modulating the SNHG12/miR-603/NAMPT axis, which ultimately affects the regulation of NAD(+), SIRT3 and p53. Future studies should explore the potential of the SNHG12/miR-603/NAMPT pathway as a target for developing novel AS therapies.

Lipophilic Statins Eliminate Senescent Endothelial Cells by inducing Anoikis-Related Cell Death.

Pre-clinical studies from the recent past have indicated that senescent cells can negatively affect health and contribute to premature aging. Targeted eradication of these cells has been shown to improve the health of aged experimental animals, leading to a clinical interest in finding compounds that selectively eliminate senescent cells while sparing non-senescent ones. In our study, we identified a senolytic capacity of statins, which are lipid-lowering drugs prescribed to patients at high risk of cardiovascular events. Using two different models of senescence in human vascular endothelial cells (HUVECs), we found that statins preferentially eliminated senescent cells, while leaving non-senescent cells unharmed. We observed that the senolytic effect of statins could be negated with the co-administration of mevalonic acid and that statins induced cell detachment leading to anoikis-like apoptosis, as evidenced by real-time visualization of caspase-3/7 activation. Our findings suggest that statins possess a senolytic property, possibly also contributing to their described beneficial cardiovascular effects. Further studies are needed to explore the potential of short-term, high-dose statin treatment as a candidate senolytic therapy.

Endothelial deficiency of insulin-like growth factor-1 receptor leads to blood-brain barrier disruption and accelerated endothelial senescence in mice, mimicking aspects of the brain aging phenotype.

Age-related blood-brain barrier (BBB) disruption, cerebromicrovascular senescence, and microvascular rarefaction substantially contribute to the pathogenesis of vascular cognitive impairment (VCI) and Alzheimer's disease (AD). Previous studies established a causal link between age-related decline in circulating levels of insulin-like growth factor-1 (IGF-1), cerebromicrovascular dysfunction, and cognitive decline. The aim of our study was to determine the effect of IGF-1 signaling on senescence, BBB permeability, and vascular density in middle-age and old brains. Accelerated endothelial senescence was assessed in senescence reporter mice (VE-Cadherin-CreERT2 /Igf1rfl/fl × p16-3MR) using flow cytometry. To determine the functional consequences of impaired IGF-1 input to cerebromicrovascular endothelial cells, BBB integrity and capillary density were studied in mice with endothelium-specific knockout of IGF1R (VE-Cadherin-CreERT2 /Igf1rfl/fl ) using intravital two-photon microscopy. In VE-Cadherin-CreERT2 /Igf1rfl/fl mice: (1) there was an increased presence of senescent endothelial cells; (2) cumulative permeability of the microvessels to fluorescent tracers of different molecular weights (0.3-40 kDa) is significantly increased, as compared to that of control mice, whereas decline in cortical capillary density does not reach statistical significance. These findings support the notion that IGF-1 signaling plays a crucial role in preserving a youthful cerebromicrovascular endothelial phenotype and maintaining the integrity of the BBB.

Essential oil from Fructus Alpiniae zerumbet ameliorates vascular endothelial cell senescence in diabetes by regulating PPAR-γ signalling: A 4D label-free quantitative proteomics and network pharmacology study

Ethnopharmacological relevanceVascular endothelial cell senescence is associated with cardiovascular complications in diabetes. Essential oil from Fructus Alpiniae zerumbet (Pers.) B.L.Burtt & R.M.Sm. (EOFAZ) has potentially beneficial and promising diabetes-related vascular endothelial cell senescence-mitigating effects; however, the underlying molecular mechanisms remain unclear. Aim of the studyTo investigate the molecular effects of EOFAZ on vascular endothelial cell senescence in diabetes. Materials and methodsA diabetes mouse model was developed using a high-fat and high-glucose diet (HFD) combined with intraperitoneal injection of low-dose streptozotocin (STZ, 30 mg/kg) and oral treatment with EOFAZ. 4D label-free quantitative proteomics, network pharmacology, and molecular docking techniques were employed to explore the molecular mechanisms via which EOFAZ alleviates diabetes-related vascular endothelial cell senescence. A human aortic endothelial cells (HAECs) senescence model was developed using high palmitic acid and high glucose (PA/HG) concentrations in vitro. Western blotting, immunofluorescence, SA-β-galactosidase staining, cell cycle, reactive oxygen species (ROS), cell migration, and enzyme linked immunosorbent assays were performed to determine the protective role of EOFAZ against vascular endothelial cell senescence in diabetes. Moreover, the PPAR-γ agonist rosiglitazone, inhibitor GW9662, and siRNA were used to verify the underlying mechanism by which EOFAZ combats vascular endothelial cell senescence in diabetes. ResultsEOFAZ treatment ameliorated abnormal lipid metabolism, vascular histopathological damage, and vascular endothelial aging in diabetic mice. Proteomics and network pharmacology analysis revealed that the differentially expressed proteins (DEPs) and drug-disease targets were associated with the peroxisome proliferator-activated receptor gamma (PPAR-γ) signalling pathway, a key player in vascular endothelial cell senescence. Molecular docking indicated that the small-molecule compounds in EOFAZ had a high affinity for the PPAR-γ protein. Western blotting and immunofluorescence analyses confirmed the significance of DEPs and the involvement of the PPAR-γ signalling pathway. In vitro, EOFAZ and rosiglitazone treatment reversed the effects of PA/HG on the number of senescent endothelial cells, expression of senescence-related proteins, the proportion of cells in the G0/G1 phase, ROS levels, cell migration rate, and expression of pro-inflammatory factors. The protective effects of EOFAZ against vascular endothelial cell senescence in diabetes were aborted following treatment with GW9662 or PPAR-γ siRNA. ConclusionsEOFAZ ameliorates vascular endothelial cell senescence in diabetes by activating PPAR-γ signalling. The results of the present study highlight the potential beneficial and promising therapeutic effects of EOFAZ and provide a basis for its clinical application in diabetes-related vascular endothelial cell senescence.

Oligomeric tau enters brain vascular endothelial cells and induces cellular senescence and brain microvascular dysfunction in tauopathy

AbstractBackgroundVascular mechanisms of Alzheimer’s disease (AD) may constitute the most therapeutically addressable biological pathway underlying dementia. Soluble pathogenic forms of tau (tau oligomers) accumulate in brain microvasculature of AD and other tauopathies, particularly in microvascular endothelial cells.MethodsPrimary human brain microvascular endothelial cells (HBEC) were exposed to tau oligomers. Microtubule stability, eNOS activation, and markers of senescence were measured. Mice expressing P301S‐mutant human tau (P301S(PS19) mice), a model of tauopathy, were given immunotherapy to selectively remove tau oligomers, or non‐specific IgGs. After measurements of vascular reactivity, eNOS activity and markers of senescence were measured in microvasculature purified from brain.ResultOligomeric tau significantly decreased microtubule stability and eNOS activity, and induced cellular senescence in primary HBECs. Microtubule destabilization, reduced eNOS activity, and increased markers of cellular senescence in brain microvasculature of P301S(PS19) mice were associated with impaired vascular reactivity, and the latter was negated by immunotherapy that specifically removed oligomeric tau from brain.ConclusionBrain microvascular deficits in P301S(PS19) mice modeling tauopathy, mediated by tau oligomers, may arise from endothelial cell senescence and eNOS dysfunction triggered by internalization of tau oligomers. Pathogenic tau oligomers and senescent brain microvascular endothelial cells may thus be targets for intervention in AD and other tauopathies.

Colchicine prevents oxidative stress-induced endothelial cell senescence via blocking NF-κB and MAPKs: implications in vascular diseases

BackgroundSmoking, alcohol abuse, and hypertension are – among others, potential risk factors for cardiovascular diseases. These risk factors generate oxidative stress and cause oxidative stress-induced DNA damage, resulting in cellular senescence and senescence-associated secretory phenotype (SASP). The SASP factors in feed-forward response exacerbate inflammation and cause tissue remodeling, resulting in atherosclerotic plaque formation and rupture.ResultsColchicine inhibited ROS generation and mitigated oxidative stress-induced DNA damage. It dampened oxidative stress-induced endothelial cell senescence and improved the expression of DNA repair protein KU80 and aging marker Lamin B1. The drug attenuated the expression of senescence marker P21 at mRNA and protein levels. The pathway analysis showed that colchicine inhibited NF-κB and MAPKs pathways and subdued mTOR activation. Colchicine also attenuated mRNA expression of interleukin (IL)-1β, IL-6, IL-8, MCP-1, ICAM-1, and E-selectin. Furthermore, colchicine reduced the mRNA and protein expression of matrix metalloproteinase (MMP-2).ConclusionIn summary, colchicine blocked oxidative stress-induced senescence and SASP by inhibiting the activation of NF-κB and MAPKs pathways.Graphical

17β-Estradiol inhibits hydrogen peroxide-induced senescence and apoptosis in human umbilical vein endothelial cells by regulating the THBS1/TGF-β/Smad axis

Before menopause, females exhibit a lower incidence of cardiovascular disease than age-matched males, possibly owing to the protective effects of sex hormones. 17β-estradiol (17β-E2) protects against oxidative stress-induced injury by suppressing thrombospondin-1 (THBS1) expression in endothelial cells. Here, we examined the role of 17β-E2-mediated THBS1 suppression in preventing cell senescence and apoptosis. Human umbilical vein endothelial cells (HUVECs) were cultivated and treated with siRNA or overexpression plasmids to regulate THBS1. H2O2, estrogen-activity modulating drugs, and LY2109761 (a TGF-β kinase inhibitor) treatments were applied. THBS1 knockdown repressed, and its overexpression aggravated, H2O2-induced cell injury, affecting cell death, proliferation, senescence, and apoptosis. 17β-E2 inhibited THBS1 mRNA and protein expression time- and dose-dependently, by targeting ERβ. THBS1 overexpression blocked 17β-E2 from preventing H2O2-induced injury, significantly activating the TGF-β/Smad pathway. 17β-E2 inhibited H2O2-induced oxidative stress by downregulating THBS1 expression and TGF-β/Smad signaling in HUVECs. The THBS1/TGF-β/Smad axis could thus be a therapeutic target.

MiR-20b-5p involves in vascular aging induced by hyperhomocysteinemia

Hyperhomocysteinemia (HHcy) is an independent risk factor of atherosclerosis (AS). Some reports have shown that homocysteine (Hcy) could accelerate the development of AS by promoting endothelial cell senescence. miRNAs were widely involved in the pathophysiology of HHcy. However, few studies have focused on the changes of miRNA-mRNA networks in the artery of HHcy patients. For this reason, RNA-sequencing was adopted to investigate the expression of miRNA and mRNA in HHcy model mouse arteries. We found that the expression of 216 mRNAs and 48 miRNAs were significantly changed. Using TargetScan and miRDB web tools, 29 miRNA-mRNA pairs were predicted. Notably, miR-20b-5p and FJX1 shared the highest predicted score in TargetScan, and further study indicated that the miR-20b-5p inhibitor significantly upregulated the FJX1 expression in HHcy human umbilical vein endothelial cells (HUVECs) model. PPI analysis revealed an important sub-network which was centered on CDK1. Gene ontology (GO) enrichment analysis showed that HHcy had a significant effect on cell cycle. Further experiments found that Hcy management increased reactive oxygen species (ROS) generation, the activity of senescence associated β-galactosidase (SA-β-gal) and the protein expression of p16 and p21 in HUVECs, which were rescued by miR-20b-5p inhibitor. In general, our research indicated the important role of miR-20b-5p in HHcy-related endothelial cell senescence.

Age-related decline in spermatogenic activity accompanied with endothelial cell senescence in male mice

Age-related decline in spermatogenic activity accompanied with endothelial cell senescence in male mice

MTOR Inhibitor Rapalink-1 Prevents Ethanol-Induced Senescence in Endothelial Cells.

The cardiovascular risk factors, including smoking, ethanol, and oxidative stress, can induce cellular senescence. The senescent cells increase the expression and release of pro-inflammatory molecules and matrix metalloproteinase (MMPs). These pro-inflammatory molecules and MMPs promote the infiltration and accumulation of inflammatory cells in the vascular tissue, exacerbating vascular tissue inflammation. MMPs damage vascular tissue by degenerating the extracellular matrix. Consequently, these cellular and molecular events promote the initiation and progression of cardiovascular diseases. We used Rapalink-1, an mTOR inhibitor, to block ethanol-induced senescence. Rapalink-1 inhibited oxidative-stress-induced DNA damage and senescence in endothelial cells exposed to ethanol. It attenuated the relative protein expression of senescence marker P21 and improved the relative protein expression of DNA repair protein KU70 and aging marker Lamin B1. It inhibited the activation of NF-κB, MAPKs (P38 and ERK), and mTOR pathway proteins (mTOR, 4EBP-1, and S6). Moreover, Rapalink-1 suppressed ethanol-induced mRNA expression of ICAM-1, E-selectin, MCP-1, IL-8, MMP-2, and TIMP-2. Rapalink-1 also reduced the relative protein expression of MMP-2. In summary, Rapalink-1 prevented senescence, inhibited pro-inflammatory pathway activation, and ameliorated pro-inflammatory molecule expression and MMP-2.

Blockade of interleukin-6 trans-signaling prevents mitochondrial dysfunction and cellular senescence in retinal endothelial cells

Interleukin-6 (IL-6) is a multifaceted cytokine implicated in the pathogenesis of diabetic retinopathy (DR). Its activity extends through cis- and trans-signaling (TS) pathways, with cis-signaling limited to specific cell types possessing the membrane-bound IL-6 receptor, while trans-signaling broadly activates various cells without the membrane bound IL-6 receptor, including retinal endothelial cells. In this study, we determined the effects of interleukin-6 trans-signaling on mitochondrial dysfunction and cellular senescence in human retinal endothelial cells (HRECs). HRECs were cultured and treated with IL-6 + soluble IL-6R or Hyper IL-6 to activate trans-signaling, along with sgp130Fc for inhibition. RT-PCR was used to analyze gene expression changes associated with inflammation and senescence. Cellular senescence was assessed using SA β-gal staining. Mitochondrial function was evaluated using Seahorse XFe24 Bioanalyzer. IL-6 trans-signaling induced inflammatory gene expression as indicated by the upregulation of ICAM1, MCP1, and SERPINA3 levels. Additionally, it reduced mitochondrial respiration and oxidative phosphorylation, and these effects were counteracted by sgp130Fc. Moreover, IL-6 trans-signaling led to altered expression of apoptosis-associated genes, including downregulation of FIS1, BCL2, and MCL1, while promoting cellular senescence, a phenomenon mitigated by sgp130Fc. These results not only deepen our understanding of IL-6 in DR but also carry broader implications for age-related diseases and the aging process itself. This study underscores the potential therapeutic value of targeting IL-6 trans-signaling with sgp130Fc as a promising anti-inflammatory approach for DR and potentially other inflammatory conditions. Further in-vivo investigations are warranted to elucidate the function of IL-6 trans-signaling in aging-related pathologies and overall organismal health.

Vascular senescence controls the neuro-cardiac interface in the aging heart

Abstract Aging is a major risk factor for impaired cardiovascular function. The aging heart is characterized by vascular dysfunction, increased hypertrophy, fibrosis and electrophysiological alterations. Studies show impaired endothelial cell (EC) function associates with senescence in aging. Since vessels and nerves align, and this interplay is critical for tissue homeostasis, we studied whether an impairment of the neuro-vascular interface may contribute to age-associated pathologies in the heart. To study the innervation of the aging mouse heart, we histologically assessed the cardiac autonomic nervous system in 3- and 20-month old mice using the pan-neuronal marker Tuj1 and the sympathetic marker TH. Interestingly, sympathetic innervation of the left ventricle, especially around arteries, was reduced by 0.66±0.07-fold with aging (p<0.05) indicating that aging reduces innervation of the left ventricle. Similar findings were observed in premature aging models of TERT-KO and EC-transgenic progeria mice. Electrophysiological studies confirmed an increased incidence of ventricular arrhythmias and reduced heart rate variability in aged mice. To determine the potential contribution of neurovascular cells, we analyzed gene expression of isolated ECs in aging mouse hearts by bulk RNA sequencing. Aging significantly induced the expression of genes associated with GO-terms related to neuronal cell death and axon injury. Sema3a, an axon repelling factor, was significantly increased in ECs of aged mice hearts, which was confirmed by qPCR and by histology (p<0.05). Next we determined the mechanism of Sema3a regulation. We show that miR-145 acts as an up-stream regulator of Sema3a expression. miR-145-/- mice showed increased Sema3a expression and reduced cardiac innervation. We observed an increase in acidic β-gal activity as a marker for cellular senescence in the aging heart, particularly in the proximate arterial space. In addition, Sema3a expression was significantly increased in senescent ECs in vitro, thus suggesting a putative role for senescence to impair cardiac innervation. To test whether eliminating senescent cells may restore left ventricular axon density, we treated 18-month old mice with a combination of the two senolytic drugs dasatinib and quercetin, which are known to deplete senescent cells in vivo. After 2 months of treatment, cellular senescence was reduced by 0.4±0.1-fold (p<0.05) in aged hearts. Endothelial expression of Sema3a was also reduced. Importantly, senolytic treatment restored ventricular innervation, augmented heart rate variability, and normalized electrophysiological abnormalities (all p<0.05). In conclusion, we show that aging augments axon repelling signals in ECs and reduces left ventricular innervation. The depletion of senescent cells prevented age-induced impairment of innervation and normalized electrophysiological abnormalities suggesting a critical role of senescence-associated axon repulsion in the aging heart.

Abstract 13603: Inhibition of Exercise-Regulated Long Noncoding RNA SALTe1 Reverses Vascular Aging and Age-Related Cardiac Dysfunction

Rationale: Age is a major risk factor for cardiovascular disease. Recent work suggests vascular aging is an important determinant of longevity and end-organ function, although its role in age-related cardiac dysfunction and how exercise mitigates these phenotypes remain unclear. Objective: To identify exercise-regulated, cardiac long noncoding RNAs (lncRNAs) that modulate vascular aging. Methods and Results: Twenty-month-old mice underwent voluntary wheel running for eight weeks. RNAseq identified a novel set of lncRNAs altered in exercised aged hearts, termed S enescence A ssociated L ncRNA T ranscripts in E xercise (SALTes). SALTe1 was conserved and primarily expressed in endothelial cells (ECs). SALTe1 increased in aged hearts but decreased with exercise. Myocardial perfusion and CD31 positive cells were reduced in 20-month-old vs 10-week-old mice while EC senescence (CD31 and p16 or γH2AX double-positive cells) and cardiac diastolic dysfunction increased (p<0.05 for all). In 20-month-old mice, SALTe1 inhibition using antisense GapmeR or EC-specific knockdown in CAS9-mice reversed multiple hallmarks of vascular aging. Recovery from hindlimb ischemia improved (post-surgery day 28 perfusion ratio, Control: 0.58±0.03 vs GapmeR: 0.73±0.03, p=0.04, n=12/group) and aortic stiffness was reduced to levels seen in young animals. Myocardial perfusion (time-to-peak, Control: 2.585±0.08 vs GapmeR: 2.048±0.11 seconds, p=0.03, n=12/group) improved. Cardiac EC number increased, and EC senescence decreased (p<0.05 for all). Inhibition of SALTe1 reduced E/E’ (-20.16±1.60 vs -15.4±1.10, p=0.04, n=12/group) and increased global longitudinal strain (-15.88±0.84 vs 20.66±1.02, p=0.02, n=12/group). Mechanistic studies in vitro and in vivo revealed that SALTe1 works through regulation of Poly (ADP-Ribose) Polymerase Family Member 9 (PARP9) and RNA-binding protein with multiple splicing (RBPMS). Conclusions: SALTe1 regulates EC senescence through PARP9 and RBPMS. SALTe1 inhibition reverses multiple hallmarks of vascular aging and improves age-related cardiac dysfunction. These findings suggest a primary role for EC senescence in age-related cardiac dysfunction and identify SALTe1 as a potential new therapeutic target.

Abstract 15774: Cu Uptake Transporter CTR1 Cys189 Oxidation Protects Against Atherosclerosis via Limiting Mitochondrial Dysfunction and Endothelial Senescence

Background: Copper (Cu) is an essential micronutrient, but excess Cu is toxic. Role of copper in atherosclerosis remains unclear. The major Cu-uptake transporter CTR1 provides Cu to Cu chaperone/transcription factor Atox1 to promote inflammation as well as mitochondrial cytochrome C oxidase (COX) to regulate mitochondrial (mito)function. We reported that growth factor VEGF induced CTR1 Cys189 oxidation promotes VEGFR2/CTR1 internalization and angiogenesis in endothelial cells (ECs) while excess Cu induces CTR1 internalization to prevent Cu toxicity. However, role of CTR1-Cys189 in ROS-dependent mito dysfunction and senescence in ECs involved in atherosclerosis remains unknown. Results: Here we showed that inducible EC-specific Ctr1 -/- /ApoE -/- mice with high fat diet (HFD) reduced atherosclerosis (72%) and Mac3+ inflammatory cell (62%) vs. atherosclerotic ApoE -/- /HFD mice aorta which showed Ctr1-CysOH formation vs. control ApoE -/- mice. CRISPR-generated “redox-dead” Ctr1-Cys189A knock-in ApoE -/- /HFD mice aorta inhibited Ctr1-CysOH formation but enhanced atherosclerotic lesions and Cu accumulation (ICP-MS) vs. ApoE -/- /HFD mice. This in turn enhanced senescence (β-gal and markers), DNA oxidation, macrophage recruitment and mitochondrial hyperfusion (by TEM). In cultured human EC, proatherogenic cytokine TNFα stimulation rapidly induced CTR1-CysOH formation and CTR1 internalization, which were inhibited by CTR1-C189A or Nox4 shRNA. CTR1-C189A overexpression increased intracellular Cu and its downstream p-Drp1-S637 that promotes mitochondrial hyperfusion, mito dysfunction and mitoROS. This was associated with CTR1-C189A binding to mito Cu transporter SLC25A3, which might facilitate mito Cu overload and mito dysfunction. These CTR1-C189A-induced responses were inhibited by Cu chelator TTM and mito O 2 - scavenger Mito-TEMPO. Conclusions: CTR1-Cys189 oxidation-induced internalization limits excess Cu entry to protect against pro-atherogenic phenotype of CTR1/Cu. Preventing CTR1-Cys189 oxidation increases mito dysfunction via enhancing novel Cu-pS637-Drp1 axis as well as CTR1-SLC25A3 axis, which promotes mitoROS and EC senescence, thereby accelerating atherosclerosis.

Abstract 14459: Endothelial Cell Specific Expression of HIV-Nef Induces Endothelial Senescence and Reduced Cardiac Output

Introduction: People living with HIV experience increased cardiovascular comorbidities despite immediate prescription of combined antiviral therapy (ART) upon HIV diagnosis. Previously, we reported that the virally encoded HIV-Nef protein persists in extracellular vesicles (EV) of aviremic HIV patients on ART and endothelial-specific transgenic expression of HIV-Nef in murine models causes increased endothelial surface expression of the pro-apoptotic protein EMAPII. Co-culture with HIV-Nef expressing T cells induced endothelial senescence which could be completely abrogated by using EMAPII-neutralizing antibodies. Hypothesis: Here we hypothesize that endothelial Nef expression in transgenic mice induces EMAPII-associated endothelial senescence after intermittent exposure to hypoxia. Methods: Female (n=5) transgenic mice with endothelium-specific Nef expression using VE-Cadherin promoter were challenged with 4 weeks of mild hypoxia (10% O 2 ) followed by 8 weeks of normoxia and then evaluated for cardiac function using non-invasive echocardiography with INVEVO2100. Results: We observed decreased cardiac output (Nef= 15.10 ul/min vs WT= 21.46 ul/min, p<0.05). Subsequently, we observed a 3.5-fold increased frequency of senescent endothelial cells using the senescence-associated marker p16INK4α (Nef= 0.54% vs WT= 0.15%, p<0.05) from the heart using flow cytometry. Furthermore, we also observed a 3.5-fold increase in the frequency of EMAPII+/P16INK4α+ cells (Nef= 0.50% vs WT= 0.14%, p<0.05). Conclusions: Transgenic endothelial HIV-Nef expression leads to upregulation of endothelial cellular senescence and EMAPII expression. EMAPII-neutralizing antibodies and senolytic agents are likely tools to reduce HIV-Nef-induced senescence. Endothelial cell senescence could affect cardiac circulation to impair heart function. Future studies will evaluate sex differences in HIV-Nef induces cardiac output at various ages.

Abstract 12226: Aging Impairs the Neuro-Vascular Interface in the Heart

Aging is a major risk factor for impaired cardiovascular function. The aging heart is characterized by vascular dysfunction, increased hypertrophy, fibrosis and electrophysiological alterations. However, the interaction between the different age-associated changes in cardiac remodelling is poorly define. Since vessels are aligned with nerves, and this interplay is critical for tissue homeostasis, we investigated whether an impairment of the neuro-vascular interface may contribute to age-associated pathologies in the heart. We show that aging reduces sympathetic and sensory nerve fibers, which both align to arteries and arterioles. Aging induced a dysregulation of vascular-derived neuro-regulatory genes, especially the axon repellent factor Sema3A, which was augmented by 2.4±0.1-fold in old heart endothelial cells. Consistently, endothelial Sema3a overexpression reduced axon density in vivo, thus mimicking the observed aged heart phenotype. Since cellular senescence was induced at the same time point when nerve density declined (16 months of age) and senescence endothelial cells showed a higher expression of Sema3a, we hypothesized that endothelial senescence may contribute to cardiac denervation. Indeed, supernatants of senescent endothelial cells reduced neurite outgrowth in vitro in a Sema3A-dependent manner. In vivo studies further confirmed that endothelial-specific induction of senescence by overexpression of Progerin induced left ventricular denervation and induced Sema3a expression. By contrast, the pharmacological removal of senescent cells by the senolytic drugs dasatinib and quercetin rescued age-induced denervation and prevented the age-induced induction of endothelial Sema3a expression. Functional studies additionally demonstrated that endothelial senescence reduced heart rate variability, while senolytics preserved heart rate variability, restored age-associated declines in sympathetic and parasympathetic activity and reduced age-associated increase in arrhythmias. These data suggest that senescence-associated regulation of neuro-regulatory genes in endothelial cells is associated with reduced nerve density and, thereby, contributes to age-associated cardiac dysfunction.