Vascular Endothelial Cell Senescence Research Articles

Photobiomodulation Inhibits Ischemia-Induced Brain Endothelial Senescence via Endothelial Nitric Oxide Synthase

Recent research suggests that photobiomodulation therapy (PBMT) positively impacts the vascular function associated with various cerebrovascular diseases. Nevertheless, the specific mechanisms by which PBMT improves vascular function remain ambiguous. Since endothelial nitric oxide synthase (eNOS) is crucial in regulating vascular function following cerebral ischemia, we investigated whether eNOS is a key element controlling cerebrovascular function and the senescence of vascular endothelial cells following PBMT treatment. Both rat photothrombotic (PT) stroke and in vitro oxygen–glucose deprivation (OGD)-induced vascular endothelial injury models were utilized. We demonstrated that treatment with PBMT (808 nm, 350 mW/cm2, 2 min/day) for 7 days significantly reduced PT-stroke-induced vascular permeability. Additionally, PBMT inhibited the levels of endothelial senescence markers (senescence green and p21) and antiangiogenic factor (endostatin), while increasing the phospho-eNOS (Ser1177) in the peri-infarct region following PT stroke. In vitro study further indicated that OGD increased p21, endostatin, and DNA damage (γH2AX) levels in the brain endothelial cell line, but they were reversed by PBMT. Intriguingly, the beneficial effects of PBMT were attenuated by a NOS inhibitor. In summary, these findings provide novel insights into the role of eNOS in PBMT-mediated protection against cerebrovascular senescence and endothelial dysfunction following ischemia. The use of PBMT as a therapeutic is a promising strategy to improve endothelial function in cerebrovascular disease.

Increased Prolylcarboxypeptidase Expression Can Serve as a Biomarker of Senescence in Culture.

Prolylcarboxypeptidase (PRCP, PCP, Lysosomal Pro-X-carboxypeptidase, Angiotensinase C) controls angiotensin- and kinin-induced cell signaling. Elevation of PRCP appears to be activated in chronic inflammatory diseases [cardiovascular disease (CVD), diabetes] in proportion to severity. Vascular endothelial cell senescence and mitochondrial dysfunction have consistently been shown in models of CVD in aging. Cellular senescence, a driver of age-related dysfunction, can differentially alter the expression of lysosomal enzymes due to lysosomal membrane permeability. There is a lack of data demonstrating the effect of age-related dysfunction on the expression and function of PRCP. To explore the changes in PRCP, the PRCP-dependent prekallikrein (PK) pathway was characterized in early- and late-passage human pulmonary artery endothelial cells (HPAECs). Detailed kinetic analysis of cells treated with high molecular weight kininogen (HK), a precursor of bradykinin (BK), and PK revealed a mechanism by which senescent HPAECs activate the generation of kallikrein upon the assembly of the HK-PK complex on HPAECs in parallel with an upregulation of PRCP and endothelial nitric oxide (NO) synthase (eNOS) and NO formation. The NO production and expression of both PRCP and eNOS increased in early-passage HPAECs and decreased in late-passage HPAECs. Low activity of PRCP in late-passage HPAECs was associated with rapid decreased telomerase reverse transcriptase mRNA levels. We also found that, with an increase in the passage number of HPAECs, reduced PRCP altered the respiration rate. These results indicated that aging dysregulates PRCP protein expression, and further studies will shed light into the complexity of the PRCP-dependent signaling pathway in aging.

High Glucose Promotes and Aggravates the Senescence and Dysfunction of Vascular Endothelial Cells in Women with Hyperglycemia in Pregnancy.

Hyperglycemia in pregnancy (HIP) is linked to fetoplacental endothelial dysfunction, which might be a result of hyperglycemia. Hyperglycemia is associated with cell senescence; however, the role and mechanism of high glucose and cell senescence in HIP endothelial cell failure are largely unknown. Our study discovered that human umbilical vein endothelial cells (HUVECs) obtained from HIP pregnant women exhibit excessive senescence, with significantly elevated expression of senescence markers senescence-associated beta-galactosidase (SA-β-gal), p16, p21, and p53. Subsequently, we found that exposing primary HUVECs and cell lines to high glucose resulted in an increase in the synthesis of these senescence indicators, similar to what had been observed in pregnant women with HIP. A replicate senescence model and stress-induced premature senescence (SIPS) model showed higher amounts of vascular damage indicators, including von Willebrand factor (vWF), chemotactic C-C motif chemokine ligand 2 (CCL2), intercellular adhesion molecule 1 (ICAM-1), along with the anti-apoptotic protein BCL2. However, lower expressions of the pro-apoptotic component BAX, in addition to defective proliferation and tubulogenesis, were seen. Further studies indicated that hyperglycemia can not only induce these alterations in HUVECs but also exacerbate the aforementioned changes in both aging HUVECs. The experiments outlined above have also been validated in pregnant women with HIP. Collectively, these data suggest that exposure to high glucose accelerates cell senescence-mediated vein endothelial cell dysfunction, including excessive inflammation, cell adhesion, impaired angiogenesis, and cell proliferation possibly contributing to pregnancy complications and adverse pregnancy outcomes.

Involvement of retinoic acid‑inducible gene‑I in radiation‑induced senescence of human umbilical vein endothelial cells.

In 2012, the threshold radiation dose (0.5 Gy) for cardiovascular and cerebrovascular diseases was revised, and this threshold dose may be exceeded during procedures involving radiation such as interventional radiology. Therefore, in addition to regulating radiation dose, it is necessary to develop strategies to prevent and mitigate the development of cardiovascular disease. Cellular senescence is irreversible arrest of cell proliferation. Although cellular senescence is one of the mechanisms for suppressing cancer, it also has adverse effects. For example, senescence of vascular endothelial cells is involved in development of vascular disorders. However, the mechanisms underlying induction of cellular senescence are not fully understood. Therefore, the present study explored the factors involved in the radiation-induced senescence in human umbilical vein endothelial cells (HUVECs). The present study reanalyzed the gene expression data of senescent normal human endothelial cells and fibroblast after irradiation (NCBI Gene Expression Omnibus accession no. GSE130727) and microarray data of HUVECs 24 h after irradiation (NCBI Gene Expression Omnibus accession no. GSE76484). Numerous genes related to viral infection and inflammation were upregulated in radiation-induced senescent cells. In addition, the gene group involved in the retinoic acid-inducible gene-I (RIG-I)-like receptor (RLR) signaling pathway, which plays an important role to induce anti-viral response, was altered in irradiated HUVECs. Therefore, to investigate the involvement of RIG-I and melanoma differentiation-associated gene 5 (MDA5), which are RLRs, in radiation-induced senescence of HUVECs, the protein expression of RIG-I and MDA5 and the activity of senescence-associated β-galactosidase (SA-β-gal), a representative senescence marker, were analyzed. Of note, knockdown of RIG-I in HUVECs significantly decreased radiation-increased proportion of cells with high SA-β-gal activity (i.e., senescent cells), whereas this phenomenon was not observed in MDA5-knockdown cells. Taken together, the present results suggested that RIG-I, but not MDA5, was associated with radiation-induced senescence in HUVECs.

DHCR24 Insufficiency Promotes Vascular Endothelial Cell Senescence and Endothelial Dysfunction via Inhibition of Caveolin-1/ERK Signaling.

Endothelial cells (ECs) senescence is critical for vascular dysfunction, which leads to age-related disease. DHCR24, a 3β-hydroxysterol δ 24 reductase with multiple functions other than enzymatic activity, has been involved in age-related disease. However, little is known about the relationship between DHCR24 and vascular ECs senescence. We revealed that DHCR24 expression is chronologically decreased in senescent human umbilical vein endothelial cells (HUVECs) and the aortas of aged mice. ECs senescence in endothelium-specific DHCR24 knockout mice was characterized by increased P16 and senescence-associated secretory phenotype, decreased SIRT1 and cell proliferation, impaired endothelium-dependent relaxation, and elevated blood pressure. In vitro, DHCR24 knockdown in young HUVECs resulted in a similar senescence phenotype. DHCR24 deficiency impaired endothelial migration and tube formation and reduced nitric oxide (NO) levels. DHCR24 suppression also inhibited the caveolin-1/ERK signaling, probably responsible for increased reactive oxygen species production and decreased eNOS/NO. Conversely, DHCR24 overexpression enhanced this signaling pathway, blunted the senescence phenotype, and improved cellular function in senescent cells, effectively blocked by the ERK inhibitor U0126. Moreover, desmosterol accumulation induced by DHCR24 deficiency promoted HUVECs senescence and inhibited caveolin-1/ERK signaling. Our findings demonstrate that DHCR24 is essential in ECs senescence.

PM2.5-induced premature senescence in HUVECs through the SIRT1/PGC-1α/SIRT3 pathway

Vascular endothelial cell senescence plays a pivotal role in the development of atherosclerosis. Recent studies have demonstrated that ambient fine particulate matter (PM2.5) induces stress-induced premature senescence (SIPS) in vascular endothelial cells. However, the precise mechanisms underlying this process remain to be fully elucidated. Cellular senescence is closely associated with reactive oxygen species (ROS), and emerging research has established a strong connection between the SIRT1/PGC-1α/SIRT3 signaling pathway and the antioxidant system in vascular endothelial cells. In this study, we aimed to investigate the impact of PM2.5 on vascular endothelial cell senescence and to elucidate the underlying mechanisms. Our findings revealed that PM2.5 exposure led to an increase in senescence-associated β-galactosidase (SA-β-gal) activity and the expression of the cell cycle-blocking proteins P53/P21 and P16 in human umbilical vein endothelial cells (HUVECs). Flow cytometry analysis demonstrated an elevated proportion of cells arrested in the G0/G1 phase after PM2.5 exposure. In addition, PM2.5-induced cellular senescence was attributed to the disruption of the cellular antioxidative defense system through the SIRT1/PGC-1α/SIRT3 signaling pathway. The expression of cellular senescence markers was reduced after targeted scavenging of mitochondrial ROS using MitoQ. Moreover, treatment with SRT1720, a SIRT1-specific activator, upregulated the SIRT1/PGC-1α/SIRT3 signaling pathway, restored the antioxidant system, and attenuated the expression of cellular senescence markers. Taken together, our results suggest that PM2.5 downregulates the SIRT1/PGC-1α/SIRT3 signaling pathway, resulting in impaired antioxidant defenses in HUVECs. This, in turn, allows for the accumulation of ROS, leading to inhibition of endothelial cell cycle progression and the onset of stress-induced senescence in HUVECs.

Dendrobine regulates STAT3 to attenuate mitochondrial dysfunction and senescence in vascular endothelial cells triggered by oxidized low-density lipoprotein.

Our previous studies have highlighted the potential therapeutic efficacy of dendrobine, an alkaloid, in atherosclerosis (AS), nevertheless, the underlying mechanism remains unclear. This study employs a combination of network pharmacology and in vitro experiments to explore the regulatory pathways involved. Through network pharmacology, the biological function for intersection targets between dendrobine and AS were identified. Molecular docking was conducted to investigate the interaction between the dominant target and dendrobine. Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low-density lipoprotein (ox-LDL) to mimic AS, and the effects of dendrobine on cell viability, lipid deposition, mitochondrial function, and cellular senescence were evaluated. Subsequently, cells were treated with the mitophagy inhibitor Mdivi-1 and the STAT3 agonist colivelin to assess the role of mitophagy and STAT3 signaling in dendrobine regulation. Intersection targets were associated with biological processes, including reactive oxygen species production. Dendrobine attenuated the effects of ox-LDL treatment on HUVECs, mitigating changes in cell activity, lipid deposition, mitochondrial function, and cellular senescence. Both Mdivi-1 and colivelin treatments resulted in decreased cell viability and increased cellular senescence, with colivelin suppressing mitophagy. Cotreatment with Mdivi-1 and colivelin further aggravated cellular senescence and inhibited FoxO signaling. Together, this study indicated that dendrobine regulated the STAT3/FoxO signaling pathway, alleviating mitochondrial dysfunction and cellular senescence. This study contributes valuable insights to the potential clinical application of dendrobine.

BANP Participates in the Chronic Intermittent Hypoxia-Induced Senescence of Vascular Endothelial Cells by Promoting P53 Phosphorylation and Nuclear Retention

Introduction: The objective of this study was to examine the potential induction of senescence in vascular endothelial cells (VECs) by chronic intermittent hypoxia (CIH), a defining characteristic of obstructive sleep apnea (OSA). This investigation seeks to elucidate the underlying mechanisms that contribute to the development of cardiovascular diseases in patients with OSA, with a particular focus on CIH-induced vascular aging. Methods: The BioSpherix-OxyCycler system was used to establish models of CIH in both rats and human umbilical vein endothelial cells (HUVECs). To assess VECs’ senescence, various methods were employed including EdU incorporation assay, cell cycle analysis, senescence-associated β-galactosidase (SA-β-gal) staining, and senescence protein testing. Vascular aging was evaluated through measurements of carotid-femoral pulse wave velocity, intima-media thickness, and Ki67 immunohistochemical staining. In order to identify the molecular mechanisms associated with CIH-induced senescence in VECs, a bioinformatics study was conducted utilizing the Gene Expression Omnibus database. Results: Under conditions of CIH, HUVECs exhibited inhibited proliferation, arrested cell cycle, increased activity of SA-β-gal, and elevated expression levels of p53 and p21 compared to HUVECs under normoxic conditions. Similarly, rats exposed to CIH displayed increased carotid-femoral pulse wave velocity, intima-media thickness, vascular permeability, and SA-β-gal activity in VECs, along with decreased expression of arterial Ki67. BTG3-associated protein (BANP) was found to be highly expressed in CIH-induced VECs. Furthermore, the overexpression of BANP resulted in the senescence of VECs, along with elevated levels of p53 phosphorylation and nuclear localization. Conclusions: These findings demonstrate that CIH can induce VECs senescence and contribute to vascular aging. Additionally, BANP can induce VECs senescence by promoting p53 phosphorylation and nuclear retention. These discoveries offer novel insights into the increased cardiovascular risk associated with OSA, thereby presenting new possibilities for therapeutic intervention.

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.

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.

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.

Counteracting Age-Related Netrin-1 Signaling Insufficiency Ameliorates Endothelial Cell Senescence and Angiogenesis Impairment.

Senescent cells that accumulate are regarded as promising therapeutic targets. However, senolytic therapy failed to achieve satisfactory results. We previously discovered that young human plasma improved vascular endothelial cell senescence, and UNC5B might be a novel intervention target. Netrin-1, as a natural ligand of UNC5B, plays roles in multiple age-related vascular disorders, but its involvement in aging is still unclear. Here, we observed a significant decrease in plasma Netrin-1 levels in old healthy subjects compared to the young. In vivo, adeno-associated-virus-mediated delivery of Netrin-1 into aged mice significantly improved functional recovery in a model of hindlimb ischemia, promoted angiogenesis in ischemic tissues, and activated the endothelial nitric oxide synthase. Furthermore, we revealed that low-dose Netrin-1 recombinant protein significantly reduced senescence-associated-β-galactosidase-positive cells, inhibited the P53 pathway, promoted cell migration, increased tubule formation, and elevated nitric oxide production in senescent endothelial cells. However, UNC5B inhibition blocked the pro-angiogenesis effect of low-dose Netrin-1 on senescent cells or aortic rings. In summary, this study depicts that modulating Netrin-1 signaling can result in improved vascular health and Netrin-1 may have therapeutic potential for age-related ischemic diseases.

A Novel Role of Hyaluronic Acid and Proteoglycan Link Protein 1 (HAPLN1) in Delaying Vascular Endothelial Cell Senescence.

Cardiovascular diseases (CVDs) are the most common cardiovascular system disorders. Cellular senescence is a key mechanism associated with dysfunction of aged vascular endothelium. Hyaluronic acid and proteoglycan link protein 1 (HAPLN1) has been known to non-covalently link hyaluronic acid (HA) and proteoglycans (PGs), and forms and stabilizes HAPLN1-containing aggregates as a major component of extracellular matrix. Our previous study showed that serum levels of HAPLN1 decrease with aging. Here, we found that the HAPLN1 gene expression was reduced in senescent human umbilical vein endothelial cells (HUVECs). Moreover, a recombinant human HAPLN1 (rhHAPLN1) decreased the activity of senescence-associated β-gal and inhibited the production of senescence-associated secretory phenotypes, including IL-1β, CCL2, and IL-6. rhHAPLN1 also down-regulated IL-17A levels, which is known to play a key role in vascular endothelial senescence. In addition, rhHAPLN1 protected senescent HUVECs from oxidative stress by reducing cellular reactive oxygen species levels, thus promoting the function and survival of HUVECs and leading to cellular proliferation, migration, and angiogenesis. We also found that rhHAPLN1 not only increases the sirtuin 1 (SIRT1) levels, but also reduces the cellular senescence markers levels, such as p53, p21, and p16. Taken together, our data indicate that rhHAPLN1 delays or inhibits the endothelial senescence induced by various aging factors, such as replicative, IL-17A, and oxidative stress-induced senescence, thus suggesting that rhHAPLN1 may be a promising therapeutic for CVD and atherosclerosis.

Hydrogen sulfide ameliorates senescence in vascular endothelial cells through ameliorating inflammation and activating PPARδ/SGLT2/STAT3 signaling pathway.

Mounting evidence demonstrates that hydrogen sulfide (H 2S) promotes anti-inflammatory molecules and inhibits pro-inflammatory cytokines in endothelial cells (ECs). This study aims to investigate the favorable action of H 2S on endothelial function in senescence by inhibiting the production of inflammatory molecules. Senescent ECs exhibit a reduction in H 2S, endothelial nitric oxide synthase (eNOS) and peroxisome proliferator-activated receptor δ (PPARδ), coupled with increased inflammatory molecules, sodium glucose transporter type 2 (SGLT2) and phosphorylation of STAT3, which could be reversed by the administration of a slow but sustained release agent of H 2S, GYY4137. Decreased production of eNOS and upregulated p-STAT3 and SGLT2 levels in senescent ECs are reversed by replenishment of the SGLT2 inhibitor EMPA and the PPARδ agonist GW501516. The PPARδ antagonist GSK0660 attenuates eNOS expression and increases the production of p-STAT3 and SGLT2. However, supplementation with GYY4137 has no beneficial effect on GSK0660-treated ECs. GYY4137, GW501516 and EMPA preserve endothelial-dependent relaxation (EDR) in D-gal-treated aortae, while GSK0660 destroys aortic relaxation even with GYY4137 supplementation. In summary, senescent ECs manifest aggravated the expressions of the inflammatory molecules SGLT2 and p-STAT3 and decreased the productions of PPARδ, eNOS and CSE. H 2S ameliorates endothelial dysfunction through the anti-inflammatory effect of the PPARδ/SGLT2/p-STAT3 signaling pathway in senescent ECs and may be a potential therapeutic target for anti-ageing treatment.

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.

Autophagy in homocysteine‑induced HUVEC senescence.

The senescence of vascular endothelial cells (VECs) drives the occurrence and development of cardiovascular disease (CVD). Homocysteine (HCY) is a general risk factor for age-associated CVDs. Autophagy, an evolutionarily conserved lysosomal protein degradation pathway, serves a part in VEC senescence. The purpose of this study was to investigate the role of autophagy in HCY-induced endothelial cell senescence and explore novel mechanisms and therapeutic approaches for related CVDs. Human umbilical vein endothelial cells (HUVECs) were isolated from fresh umbilical cords of healthy pregnancies. Cell Counting Kit-8, flow cytometry and senescence-associated (SA) β-galactosidase (Gal) staining demonstrated that HCY induced HUVEC senescence by decreasing cell proliferation, arresting cell cycle and increasing the number of SA-β-Gal-positive cells. Stub-RFP-Sens-GFP-LC3 autophagy-related double fluorescence lentivirus revealed that HCY increased autophagic flux. Further, inhibition of autophagy using 3-methyladenine increased HCY-induced HUVEC senescence. By contrast, the induction of autophagy via rapamycin alleviated HCY-induced HUVEC senescence. Finally, the detection of reactive oxygen species (ROS) with ROS kit showed that HCY increased intracellular ROS, whereas induction of autophagy reduced intracellular ROS. In conclusion, HCY increased HUVEC senescence and upregulated autophagy; moderate autophagy could reverse HCY-induced cell senescence. Autophagy may alleviate HCY-induced cell senescence by decreasing intracellular ROS. This provides insight into the underlying mechanism of HCY-induced VEC senescence and potential treatments for age-associated CVDs.

Exosomal miR-214-3p from senescent osteoblasts accelerates endothelial cell senescence

BackgroundOsteoporosis is a common systemic bone disease that leads to bone fragility and increases the risk of fracture. However, the pathogenesis of osteoporosis is considered to be highly complex. The exosomes can regulate the communication between cells. The specific mechanism of information transmission between osteoblasts and endothelial cells is worthy of further study.MethodsExosomes were isolated and verified from senescent osteoblasts. The source and properties of exosomes were determined by TEM, particle size analysis and western blot. We established the co-culture model of endothelial cells and senescent osteoblasts. We used qRT-PCR to identify differentially expressed miRNAs. The functional changes of vascular endothelial cells were verified by cell transfection. β-Galactosidase cell senescence assay, Hoechst cell apoptosis assay, Ki67 cell proliferation assay and Transwell migration assay were used to verify cell senescence, apoptosis, proliferation, and migration. The potential target gene of miRNA was detected by bio-informatics pathway and double luciferase report.ResultsWe discovered that senescent osteoblasts could promote the senescence and apoptosis of vascular endothelial cells and inhibit their proliferation and migration. miR-214-3p was upregulated in senescent osteoblast-derived exosomes. miR-214-3p could effectively promote senescence and apoptosis of endothelial cells and inhibit proliferation and migration ability. L1CAM is a miR-214-3p direct target gene determined by bio-informatics and double luciferase report.ConclusionsIn conclusion, senescent osteoblast-derived exosomes can accelerate endothelial cell senescence through miR-214-3p/L1CAM pathway. Our experiments reveal the role of exosomes in the skeletal microenvironment.

Pro-inflammatory cytokines mediating senescence of vascular endothelial cells in atherosclerosis.

Atherosclerosis (AS) is a chronic inflammatory vascular disease, and aging is a major risk factor. The accumulation of senescent vascular endothelial cells (VECs) often leads to chronic inflammation and oxidative stress and induces endothelial dysfunction, contributing to the occurrence and development of AS. Senescent cells can secrete a variety of pro-inflammatory cytokines to induce the senescence of adjacent cells in a paracrine manner, leading to the transmission of signaling of cellular senescence to neighboring cells and the accumulation of senescent cells. Recent studies have demonstrated that several pro-inflammatory cytokines, including IL-17, TNF-α, and IFN-γ, can induce the senescence of VECs. This review summarizes and focuses on the pro-inflammatory cytokines that often induce the senescence of VECs and the molecular mechanisms of these pro-inflammatory cytokines inducing senescence of VECs. Targeting the senescence of VECs induced by pro-inflammatory cytokines may provide a potential and novel strategy for the prevention and treatment of AS.

Parishin alleviates vascular ageing in mice by upregulation ofKlotho.

Senescence of vascular endothelial cells is the major risk of vascular dysfunction and disease among elderly people. Parishin, which is a phenolic glucoside derived from Gastrodia elata, significantly prolonged yeast lifespan. However, the action of parishin in vascular ageing remains poorly understood. Here, we treated human coronary artery endothelial cells (HCAEC) and naturally aged mice by parishin. Parishin alleviated HCAEC senescence and general age-related features in vascular tissue in naturally aged mice. Network pharmacology approach was applied to determine the compound-target networks of parishin. Our analysis indicated that parishin had a strong binding affinity for Klotho. Expression of Klotho, a protein of age-related declines, was upregulated by parishin in serum and vascular tissue in naturally aged mice. Furthermore, FoxO1, on Klotho/FoxO1 signalling pathway, was increased in the parishin-intervened group, accompanied by the downregulated phosphorylated FoxO1. Taken together, parishin can increase Klotho expression to alleviate vascular endothelial cell senescence and vascular ageing.