Endothelial Cell Apoptosis Research Articles

Intravenous iron administration in patients with heart failure alters endothelial homeostasis with early release of endothelial microvesicles and subsequent mobilization of endothelial progenitor cell

Abstract Background Intravenous iron supplementation is an established therapy for patients with heart failure (HF) with reduced ejection fraction (LV-EF<50%) and iron deficiency, resulting in reduced risk of HF hospitalization. Since iron may induce oxidative stress, inflammation and apoptosis in endothelial cells, concerns persist regarding potential adverse vascular effects of iron therapy. To evaluate endothelial health following ferric carboxymaltose (FCM) administration, we assessed the profile of circulating endothelial microvesicles (EMVs) and endothelial progenitor cells (EPCs) in a cohort of 23 HF patients using flow cytometry. Results Compared to healthy control subjects (HC; n=15), baseline levels of CD31+/CD41- EMVs were significantly higher and EMVs featured a more apoptotic phenotype in HF patients. Following administration of 1000mg FCM, EMV levels showed an early but transient increase (Fig. 1) and displayed an altered phenotype profile with dominant augmentation of EMVs expressing the inducible markers CD62E and CD54, indicating endothelial activation and injury. Levels of circulating vasoregenerative CD45lowCD34+KDR+ EPCs were lower in HF patients and FCM application resulted in an early decrease of EPCs followed by substantial mobilization into the circulation after one week (Fig. 2). Levels of EMVs and EPCs returned to baseline values within two and four weeks, respectively. Compared to HF patients with preserved renal function, the EMV/EPC ratio was higher in HF patients whereas EPC mobilization was diminished with additional chronic kidney disease, suggesting impaired vascular repair capacity. In vitro experiments with cultured endothelial cells revealed that FCM at therapeutic concentrations dose-dependently promotes endothelial apoptosis, increases expression of adhesion molecules and CXCL12, and triggers the generation of EMVs. Conclusion Intravenous iron supplementation with FCM in HF patients provokes a biphasic response with early release of CD62E+ and CD54+ enriched EMVs and subsequent mobilization of EPCs, suggesting temporary aggravation of endothelial dysfunction upon FCM supplementation and consecutive engagement of a vascular defense program.

Apolipoprotein C3-rich low-density lipoprotein (AC3RL) increases BBB permeability and deteriorates cerebral ischemic stroke injury

Abstract Background Ischaemic stroke causes disability due to brain damage resulting from blood supply obstruction or increased permeability of the blood-brain barrier (BBB) that exposes the blood to toxic substances during reperfusion. Apolipoprotein C3 is a crucial triglyceride transport modulator, and its overexpression raises the risk of dyslipidemia and cardiovascular disease. Clinically, we observed that stroke patients have higher levels of apolipoprotein C3-rich low-density lipoprotein (AC3RL) expression than healthy individuals, and they also have worse prognoses. Simultaneously, we found that an increase in AC3RL is involved in endothelial cell apoptosis and inflammatory response, which may be linked to the occurrence of brain injury after stroke. Purpose This study aimed to explore whether the high expression of AC3RL would increase the permeability of the blood-brain barrier, and aggravate brain damage. Methods The intraluminal monofilament model of middle cerebral artery occlusion (MCAO) experiment was carried out using C57BL/6 and apolipoprotein E gene knockout mice (ApoE-/-). WT receive an IV injection of AC3RL, which was separate from stroke patients' plasma. APOE-/- was fed a high-fat diet to promote AC3RL higher expression. We performed 60-minute ischaemic and 7-day reperfusion. The modified neurological severity score (mNSS) method was used to assess motor and neurological scores. Evans blue dye was injected through the tail vein one hour before euth (A) AC3RL, which was separated from stroke patients' plasma. (B) AC3RL concentration in individuals. (C) The white portion of the mice brains TTC stain indicates the site of the injury. (D) Evans blue dye leakage study in mice brains exhibited BBB permeability changes. (E) Assessment of mice's motor and neurological performance using the mNSS. anasia to assess BBB permeability. TTC staining of brain tissue after euthanasia to pinpoint the site of brain damage. Results Evans blue dye leakage was observed in the brain tissues of the group with high AC3RL expression, indicating that the BBB permeability has expanded. The mNSS method revealed a significant rise in mice with high levels of AC3RL expression, which suggested a decline in motor and nervous function. Conclusions Whether endogenous or exogenous, increased expression of AC3RL leads to more severe cerebral ischemic injury and motor dysfunction, which we believe may be due to increased BBB permeability caused by AC3RL. Therefore, AC3RL can be used as a disease predictor in the future, reducing AC3RL will be the main indicator for reducing severe brain injury.Figure 1.Figure 2.

LONG-TERM COVID-19 EFFECT TO ENDOTHELIAL DAMAGE TROUGH EXTRINSIC APOPTOSIS LED TO CARDIOVASCULAR DISEASE PROGRESSION: AN UPDATE REVIEW

COVID-19 can involve persistence, sequelae, and other medical complications that last weeks to months after initial recovery; these prolonged symptoms called as long-term covid-19 effect. Symptoms, signs, or abnormal clinical parameters persisting two or more weeks after COVID-19 onset that do not return to a healthy baseline can potentially be long-term effects of the disease. SARS-CoV-2 affects the cardiovascular system and causes conditions such as myocarditis, arrhythmias, and myocardial injury. Vascular damage from COVID-19 has been affected directly by the SARS-CoV-2 virus infection and indirectly by systemic inflammatory cytokine storm. This damage can be long-lasting and lead to various cardiovascular complications. Fas ligand (FasL)-Fas complex is a death factor that induces cell apoptosis. Fas and FasL have been detected in the endothelial wall, and it has been proposed that Fas-mediated apoptosis has a role in physiological and pathological cell turnover in the endothelial wall. High concentrations of inflammatory cytokines, such as cytokines storm induced by SARS-CoV-2 infection, are thought to increase the expression of FasL, which leads to an increase in the regulation of extrinsic apoptosis in endothelial cells leading to endothelial damage. This article summarises the current understanding of the long-term covid-19 effect on endothelial damage through extrinsic apoptosis Fas-FasL complex.

Abstract 16942: Organized Thrombus (OTh) Formation Mediated by Disturbed Flow-Induced Endothelial Senescence-Associated Stemness (SAS)

Atherosclerotic and high-risk plaques are predominantly localized to vessel wall regions with non-laminar disturbed blood flow (d-flow), leading to the principle that d-flow-, but not laminar flow (l-flow)-driven endothelial cells (EC) dysfunction plays a role in this process. LATS1/2 and YAP are components of the Hippo signaling pathway that are involved in cellular responses to l-flow. The l-flow-mediated inhibition of LATS1/2 activity triggers YAP activation and maintains vascular structure. However, the role of Hippo signaling under d-flow remains unclear. Although both l- and d-flow increased YAP activity, only d-flow decreased LATS1/2 expression. Since the effects of l- and d-flow on EC differ, we studied the role of EC LATS1/2 using EC-specific Lats1 and 2 knock-out (EKO) mice. Within 14 days after inducing Lats1/2 deletion in tamoxifen-inducible Lats1 homo / Lats2 homo EKO mice, all the mice (27/27) died of severe systemic edema, accompanied by increased EC apoptosis and vascular permeability. We generated Lats1 he t / Lats2 homo -EKO mice ( Lats1 het /2 homo -EKO) and induced hypercholesteremia with AAV8-PCSK9 injections and a high-fat diet (HFD). After HFD, we detected plaque erosion-like plaque lesions at the d-flow areas, which revealed strongly fibrin/fibrinogen-positive organized thrombus (OTh) formation without sizeable necrotic cores. In Lats1 het /2 homo -EKO, we found significant increases in 1) EC proliferation, 2) EC apoptosis with senescent phenotype, 3) tissue factor (TF) expression, and 4) inflammation. Therefore, the phenotype observed in Lats1 het /2 homo -EKO represents a unique senescence-associated stemness (SAS) phenotype, which allows EC to escape senescence-induced cell cycle arrest. The EC proliferation induced by depletion of LATS1/2 was YAP-dependent. In contrast, EC senescence induced by CD38-mediated NAD + depletion was YAP-independent. These findings indicate that downregulating LATS1/2 expression-induced SAS leads to OTh via both YAP-dependent and independent mechanisms. OTh plays a key role in human atherosclerosis but is rarely observed in the mouse atherosclerosis model. Lats1 het /2 homo -EKO can provide a valuable platform for studying the mechanism and unique role of EC SAS-induced OTh formation.

Abstract 17196: Genetic and Acquired DHCR7 Deficiency Upregulates 7β-hydroxycholesterol to Drive Endothelial Apoptosis and Pulmonary Hypertension

Introduction: Pulmonary hypertension (PH) is a fatal disease without a cure, in which endothelial dysfunction drives pathologic remodeling of the pulmonary vasculature. Individuals with Smith-Lemli-Opitz syndrome (SLOS) develop PH, but the underlying mechanisms remain undefined. SLOS is an autosomal recessive disorder of cholesterol synthesis, resulting from loss-of-function mutations in 7-dehydrocholesterol reductase (DHCR7)-the terminal enzyme in the de novo synthesis of cholesterol- that leads to accumulation of 7-dehydrocholesterol (7-DHC) and cytotoxic oxysterol species. The role of DHCR7 in PH, however, is unknown. Hypothesis: Elevated cytotoxic oxysterols resulting from genetic or acquired DHCR7 deficiency promotes endothelial dysfunction and the development of PH. Methods & Results: DHCR7 mRNA and protein expression was decreased in pulmonary artery endothelial cells (ECs) in cellular (P=0.0089), rodent, and human PH models, mirroring DHCR7 reduction in SLOS. Both genetic loss of DHCR7 and hypoxia promoted a global shutdown of de novo cholesterol synthesis, resulting in an accumulation of cholesterol intermediates and increased derivative oxysterols. Specifically, 7β-hydroxycholesterol (7β-HC) was elevated in DHCR7-deficient ECs (P<0.0001), and 7β-HC drove endothelial apoptosis (P<0.0001) via downregulation of insulin-like growth factor 1 (IGF1) in ECs (fold change=0.101 ± 0.034, FDR=6.65E-11). Conversely, overexpression of DHCR7 upregulated IGF1 expression (P<0.0007), and IGF1 delivery reversed apoptosis (P<0.0001). Correspondingly, ECs derived from SLOS patient stem cells with DHCR7 mutations (p.T93M/c.964-1G>C) exhibited IGF1-dependent apoptosis. Finally, EC-specific DHCR7 deletion in chronically hypoxic mice induced more severe PH in vivo (right ventricular systolic pressure 36.4 mmHg vs. 30.8 mmHg, P<0.0130). Conclusions: Resulting either from hypoxic or genetic causes, DHCR7 deficiency promoted EC apoptosis and PH via 7β-HC accumulation and subsequent IGF1 downregulation. Our work is the first to define an oxysterol-dependent mechanism underlying the link between genetic and acquired DHCR7 deficiency and PH.

Abstract 13859: The Omics Signature of Human Pericardial Fluid Exosomes Reveals the Therapeutic Potential of APAF-1 Inhibition in Ischemic Heart Disease

Background: The human pericardial fluid (PF) contains heart-derived small extracellular vesicles (sEVs) able to induce vascular responses via microRNA (miR) transfer. People with diabetes (DM) are particularly at risk of severe ischemic heart disease (IHD) and might require personalized therapeutic treatment. Hypothesis: The PF-sEVs molecular profiling supports the identification of clinical-relevant therapeutic targets. Aims: 1) To characterize PF-sEVs of IHD patients with/out type-2 DM (T2DM) in comparison to controls; 2) to validate the emerging therapeutic target candidates. Methods: PF samples (n=12/group) were collected during cardiac surgeries, namely CABG (for IHD with/out DM groups) and mitral valve repair (non-IHD, non-DM control group). sEVs were prepared (SEC), quality controlled (Nanosight and Exoview) and submitted to untargeted proteomics and microRNA array (Exiqon) or validation experiments. miRNA-target prediction methods and integration of proteomics and transcriptomics via networks identified differentially expressed pathogenic proteins and their putative endogenous miRNA regulators. The emerging dysregulated miRNA/protein axis was investigated in vitro and in mice with myocardial infarction (MI) and with/out diet-induced T2DM. Results: the PF-EVs of IHD patients with DM showed increased APAF-1 and reduced let-7b-5p, a miR which we have demonstrated to repress APAF-1 by direct 3’-UTR-binding. Exposure of endothelial cells (ECs) to DM and IHD-mimicking culture conditions increases APAF-1 level, triggering apoptosis and reducing angiogenesis. The phenotype of ECs kept under disease-mimicking conditions was rescued by APAF-1 silencing (siRNAs) and by supplementation with either healthy PF-EV or LNPs carrying let-7b-5p as sole miR cargo. The synthetic APAF-1 inhibitor ZYZ-488 improved post-MI cardiac function (Vevo3100 echocardiography), increased capillary density and reduced EC apoptosis in the peri-infarct area of diabetic and non-diabetic mice of both sexes. Conclusions: PF-EVs represent a novel and privileged source for the discovery of clinical-relevant therapeutic targets. APAF-1 inhibition holds value for post-ischemic cardiac protection and repair, including in diabetic people.

Effect of serum from patients with ST-segment elevation myocardial infarction on endothelial cells

Introduction and objectives Clinical and experimental studies have shown that, in patients with reperfused ST-segment elevation myocardial infarction (STEMI), abnormalities in the endothelial monolayer are initiated during ischemia but rapidly intensify upon restoration of blood perfusion to the ischemic area. We aimed to evaluate the effect of serum isolated after revascularization from STEMI patients on the degree of endothelial permeability in vitro, by promoting endothelial cell apoptosis and necrosis in vitro. We also investigated the association between the percentage of serum-induced endothelial cell apoptosis or necrosis in vitro and the extent of cardiovascular magnetic resonance (CMR)-derived parameters of reperfusion injury (edema, hemorrhage, and microvascular obstruction).Methods Human coronary artery endothelial cells were incubated with serum isolated 24 hours after revascularization from 43 STEMI patients who underwent CMR and 14 control participants. We assessed the effect of STEMI serum on activation of apoptosis and necrosis, as well as on the permeability and structure of the endothelial monolayer.Results Serum from STEMI patients increased apoptosis (P < .01) and necrosis (P < .05) in human coronary artery endothelial cells and caused increased permeability of the endothelial monolayer in vitro (P < .01), due to enlarged intercellular spaces (P < .05 vs control in all cases). Higher serum-induced necrosis was associated with greater endothelial permeability in vitro (P < .05) and with more extensive CMR-derived indices of reperfusion injury and infarct size.Conclusions Postreperfusion serum activates necrosis and apoptosis in endothelial cells and increases the degree of endothelial permeability in vitro. The more potent the necrosis-triggering effect of serum, the more deleterious the consequences in terms of the resulting cardiac structure.

Toxic effects of bisphenol S on mice heart and human umbilical cord endothelial cells

Bisphenol S (BPS) exerts toxic effects on hippocampal HT22 cells, endocrine secretion, and reproductive capacity. However, whether BPS exerts toxic effects on the heart requires further investigation. Therefore, we investigated the effects of BPS on mouse heart tissues and predicted possible underlying molecular mechanisms of action. Our study showed that BPS induced apoptosis, increased oxidative stress response. Using electron microscopy, we found that BPS disrupted sarcomere arrangement in myocardial cells and caused reduction in the number of plasmalemmal vesicles in endothelial cells in the mouse heart tissues. Also, BPS increased expression levels of P-NF-κB in mouse heart tissues. Furthermore, we found that BPS induced reactive oxygen species (ROS) generation, NF-κB activation, promoted apoptosis, elevated expression of BAX and Caspase 3, and decreased expression of Bcl-2 in H9c2 cells and HUVECs. However, after the addition of n-acetylcysteine or pyrrolidinedithiocarbamate, ROS generation, NF-κB activation, apoptosis, and expression of BAX and Caspase 3 were reduced, whereas expression of Bcl-2 was elevated. Our results demonstrated that BPS induced apoptosis of myocardial and endothelial cells through oxidative stress by activation of NF-κB signaling pathway.

Sirtuin1 Mediates the Protective Effects of Echinacoside against Sepsis-Induced Acute Lung Injury via Regulating the NOX4-Nrf2 Axis.

Currently, the treatment for sepsis-induced acute lung injury mainly involves mechanical ventilation with limited use of drugs, highlighting the urgent need for new therapeutic options. As a pivotal aspect of acute lung injury, the pathologic activation and apoptosis of endothelial cells related to oxidative stress play a crucial role in disease progression, with NOX4 and Nrf2 being important targets in regulating ROS production and clearance. Echinacoside, extracted from the traditional Chinese herbal plant Cistanche deserticola, possesses diverse biological activities. However, its role in sepsis-induced acute lung injury remains unexplored. Moreover, although some studies have demonstrated the regulation of NOX4 expression by SIRT1, the specific mechanisms are yet to be elucidated. Therefore, this study aimed to investigate the effects of echinacoside on sepsis-induced acute lung injury and oxidative stress in mice and to explore the intricate regulatory mechanism of SIRT1 on NOX4. We found that echinacoside inhibited sepsis-induced acute lung injury and oxidative stress while preserving endothelial function. In vitro experiments demonstrated that echinacoside activated SIRT1 and promoted its expression. The activated SIRT1 was competitively bound to p22 phox, inhibiting the activation of NOX4 and facilitating the ubiquitination and degradation of NOX4. Additionally, SIRT1 deacetylated Nrf2, promoting the downstream expression of antioxidant enzymes, thus enhancing the NOX4-Nrf2 axis and mitigating oxidative stress-induced endothelial cell pathologic activation and mitochondrial pathway apoptosis. The SIRT1-mediated anti-inflammatory and antioxidant effects of echinacoside were validated in vivo. Consequently, the SIRT1-regulated NOX4-Nrf2 axis may represent a crucial target for echinacoside in the treatment of sepsis-induced acute lung injury.

Novel Targets Regulating the Role of Endothelial Cells and Angiogenesis after Infarction: A RNA Sequencing Analysis.

Endothelial cells (ECs) are a key target for cardioprotection due to their role in preserving cardiac microvasculature and homeostasis after myocardial infarction (MI). Our goal is to identify the genes involved in post-MI EC proliferation, EC apoptosis, and angiogenesis regulation via RNA-sequencing transcriptomic datasets. Using eight studies from the Gene Expression Omnibus, RNA-sequencing data from 92 mice submitted to different times of coronary ischemia or sham were chosen. Functional enrichment analysis was performed based on gene ontology biological processes (BPs). Apoptosis-related BPs are activated up to day 3 after ischemia onset, whereas endothelial proliferation occurs from day 3 onwards, including an overrepresentation of up to 37 genes. Endothelial apoptosis post-MI is triggered via both the extrinsic and intrinsic signaling pathways, as reflected by the overrepresentation of 13 and 2 specific genes, respectively. BPs implicated in new vessel formation are upregulated soon after ischemia onset, whilst the mechanisms aiming at angiogenesis repression can be detected at day 3. Overall, 51 pro-angiogenic and 29 anti-angiogenic factors displayed altered transcriptomic expression post-MI. This is the first study using RNA sequencing datasets to evaluate the genes participating in post-MI endothelium physiology and angiogenesis regulation. These novel data could lay the groundwork to advance understanding of the implication of ECs after MI.

CREB1 Silencing Protects Against Inflammatory Response in Rats with Deep Vein Thrombosis Through Reducing RPL9 Expression and Blocking NF-κB Signaling.

Apoptosis and inflammation of vascular endothelial cells (VECs) are the most important causes of deep vein thrombosis (DVT). cAMP response element binding protein 1 (CREB1) encodes a transcription factor that binds as a homodimer to the cAMP-responsive element and can promote inflammation. CREB1 is found to be upregulated in the plasma of patients with venous thromboembolism. However, the biological functions of CREB1 in DVT remain unknown. We evaluated the effect of CREB1 in a rat model of inferior vena cava (IVA) stenosis-induced DVT. IVC stenosis resulted in stable thrombus, inflammatory response and CREB1 upregulation, whereas CREB1 knockdown inhibited thrombus and inflammation in DVT rats. In vitro analysis showed that CREB1 knockdown inhibited VEC apoptosis. Mechanistically, CREB1 knockdown reduced Ribosomal protein L9 (RPL9) expression and blocked the NF-κB pathway. Therefore, CREB1 may become a potential therapeutic target of DVT prevention.

The Association among Urinary Lead and Cadmium, Serum Adiponectin, and Serum Apoptotic Microparticles in a Young Taiwanese Population.

Previous studies reported that lead (Pb) and cadmium (Cd) exposure are linked to changes in serum adiponectin; an adipokine that promotes glycolysis and inhibits gluconeogenesis to regulate glucose metabolism. However, no study has ever explored the relationship between exposure to these two heavy metals and adiponectin in adolescents and young adults. Additionally, the role of adiponectin in the relationship between Pb and Cd exposure and vascular endothelial cell apoptosis has never been investigated. In this study, 724 Taiwanese participants, aged 12 to 30 years, were enrolled to investigate the association among urinary lead and cadmium, serum adiponectin, and apoptotic microparticles (CD31+/CD42a-, CD31+/CD42a+, and CD14). The results of the current study revealed a statistically significant inverse association between urine Pb and Cd levels and adiponectin levels, as well as a positive association with apoptotic microparticles (CD31+/CD42a-, CD31+/CD42a+, and CD14). Adiponectin was also inversely correlated with CD31+/CD42a- and CD31+/CD42a+. Moreover, when subjects with both Pb and Cd levels above the 50th percentile were compared to those below it, the former group exhibited the lowest average adiponectin value. Additionally, a more pronounced positive association between heavy metals and apoptotic microparticles (CD31+/CD42a- and CD31+/CD42a+) was observed when adiponectin levels were lower. Furthermore, an interaction between adiponectin and heavy metals was identified in the relationship between these metals and CD31+/CD42a-. In conclusion, these findings suggest that Pb and Cd exposure may have an adverse effect on adiponectin, and it may play a role in the link between heavy metal exposure and the dysfunction of vascular endothelial cells. Future studies are needed to establish whether a causal relationship exists.

Human ApoE2 protects mice against Plasmodium berghei ANKA experimental cerebral malaria.

Cerebral malaria (CM) is the deadliest complication of malaria infection with an estimated 15%-25% mortality. Even with timely and effective treatment with antimalarial drugs such as quinine and artemisinin derivatives, survivors of CM may suffer long-term cognitive and neurological impairment. Here, we show that human apolipoprotein E variant 2 (hApoE2) protects mice from experimental CM (ECM) via suppression of CD8+ T cell activation and infiltration to the brain, enhanced cholesterol metabolism, and increased IFN-γ production, leading to reduced endothelial cell apoptosis, BBB disruption, and ECM symptoms. Our results suggest that hApoE can be an important factor for risk assessment and treatment of CM in humans.

Epidermal Stem Cell Derived Exosomes Alleviate Excessive Autophagy Induced Endothelial Cell Apoptosis by Delivering miR200b-3p to Diabetic Wounds

The dysfunction of endothelial cells caused by hyperglycemia is observed as a decrease in neovascularization in diabetic wound healing. Studies have found that epidermal stem cells (EpiSCs) can promote the angiogenesis of full-thickness wounds. To further explain the therapeutic effect of EpiSCs, EpiSC-derived exosomes (EpiSC-EXOs) are considered the main substance contributing to stem cell effectivity. In our study, EpiSCs and EpiSC-EXOs were supplied to the dorsal wounds of db/db mice. Results showed that EpiSCs could colonize in the wound area and both EpiSCs and EpiSC-EXOs could accelerate diabetic wound healing by promoting angiogenesis. Invitro, persistent high glucose led to the malfunction and apoptosis of endothelial cells. The apoptosis induced by high glucose is due to excessive autophagy and was alleviated by EpiSC-EXOs. RNA sequencing of EpiSC-EXOs showed that miR200b-3p was enriched in EpiSC-EXOs and alleviated the apoptosis of endothelial cells. Synapse defective rho GTPase homolog 1 was identified the target of miR200b-3p and affected the phosphorylation of ERK to regulate intracellular autophagy and apoptosis. Furthermore, animal experiments validated the angiogenic effect of miR200b-3p. Collectively, our results verified the effect of EpiSC-EXOs on apoptosis caused by hyperglycemia in endothelial cells through the miR200b-3p/synapse defective rho GTPase homolog 1 /RAS/ERK/autophagy pathway, providing a theoretical basis for EpiSC in treating diabetic wounds.

MiR-23a-3p alleviates cigarette smoke extract-induced pulmonary vascular endothelial cell apoptosis by targeting DNAJB1 in emphysema.

Cigarette smoke (CS) is an important risk factor for chronic obstructive pulmonary disease, including emphysema. MicroRNAs (miRNAs) are important regulators of emphysema progression. However, miR-23a-3p role in emphysema is unclear. CS exposure was used to construct emphysema mice models, and cigarette smoke extract (CSE)-induced pulmonary vascular endothelial cells (PMVECs) were used to mimic emphysema cell models. Mouse lung tissue was stained by immunohistochemical staining, hematoxylin and eosin staining, and TUNEL staining. MiR-23a-3p and DnaJ homolog subfamily B member 1 (DNAJB1) levels were tested using quantitative real-time PCR. DNAJB1 and apoptosis-related markers' protein levels were examined via western blot analysis. Cell viability and apoptosis were analyzed by MTT assay and flow cytometry. The interaction between miR-23a-3p and DNAJB1 was evaluated by dual-luciferase reporter assay and RIP assay. MiR-23a-3p was downregulated, and DNAJB1 was upregulated in CS-induced emphysema mice models and CSE-induced PMVECs. MiR-23a-3p overexpression promoted viability and repressed apoptosis in CSE-induced PMVECs. MiR-23a-3p targeted DNAJB1 and negatively regulated DNAJB1 expression. Moreover, DNAJB1 knockdown repressed CSE-induced PMVECs apoptosis, and miR-23a-3p inhibitor reversed this effect. Additionally, miR-23a-3p alleviated lung tissue injury and improved emphysema in mice by reducing DNAJB1 expression. MiR-23a-3p alleviated emphysema progression, which could inhibit CSE-induced PMVECs apoptosis by targeting DNAJB1.

MiR-216a reduces apoptosis of pulmonary microvascular endothelial cells in COPD by targeting DNMT1.

Abnormal apoptosis of pulmonary microvascular endothelial cells (PMVECs) participates in the pathogenesis of COPD. Studies have shown that microRNAs (miRNAs) contribute to the pathogenesis of pulmonary diseases by regulating cell apoptosis. The present study aimed to investigate the effects of miR-216a in cigarette smoke extract (CSE)-induced apoptosis of PMVECs in COPD and explore the potential mechanisms. The emphysema model mice were treated with CSE and CS exposure. The expression of miR-216a and DNA methyltransferase 1 (DNMT1) was assessed in emphysema mice and COPD patients. The miR-216a mimic and Lenti-DNMT1 were transfected into PMVECs to identify the underlying mechanisms. The expression levels of miR-216a and DNMT1 were detected by real-time quantitative polymerase chain reaction (RT-qPCR) or Western blot. Moreover, cell apoptosis was examined by flow cytometry assays. The results show that the expression of miR-216a was decreased, whereas the expression of DNMT1 was increased in the lung tissue of emphysema mice and COPD patients. In addition, the expression of miR-216a was significantly reduced in CSE-treated PMVECs, and the overexpression of miR-216a attenuated CSE-induced PMVEC apoptosis. Furthermore, the expression of DNMT1 was increased in the CSE-induced PMVECs and then was reduced after the overexpression of miR-216a in the CSE-stimulated PMVECs. Luciferase reporter assays confirmed the target reaction between miR-216a and DNMT1. Also, the overexpression of DNMT1 was able to reverse the anti-apoptotic effect of miR-216a in CSE-induced PMVECs. The results indicate that miR-216a may play a crucial role in CSE-induced apoptosis by directly regulating its target gene DNMT1 in COPD. It provides insights into the function of MiR-216a/DNMT1 as a potential molecule in COPD.

EZH2 Promotes Corneal Endothelial Cell Apoptosis by Mediating H3K27me3 and Inhibiting HO-1 Transcription

Purpose This paper aims to explore the molecular mechanism of Enhancer of Zeste Homolog 2 (EZH2)-mediated H3K27me3 in human corneal endothelial cells (HCEC) apoptosis by inhibiting Heme oxygenase-1 (HO-1) transcription to provide a potential target for the treatment of corneal apoptosis. Methods HCECs were cultured in vitro and transfected with si-EZH2, pcDNA3.1-EZH2, pcDNA3.1-HO-1, GSK-J4 (an effective H3K27me3 demethylase inhibitor), and corresponding controls. Western Blot assay was used to detect the levels of EZH2, HO-1, H3K27me3, and apoptosis-related proteins (Bcl-2, Bax, and Cleaved-caspase-3) in HCECs; CCK-8 assay was conducted to detect cell viability and flow cytometry to analyze the apoptosis. HO-1 mRNA levels were detected by RT-qPCR and changes in H3K27me3 levels on the HO-1 promoter were detected by chromatin immunoprecipitation. Results HCECs transfected with si-EZH2 showed significantly lower EZH2 mRNA and protein levels, higher HCEC viability, lower apoptosis rates, higher antiapoptotic protein Bcl-2 expression, lower proapoptotic protein (Bax and Cleaved-caspase-3) levels, and significantly higher HO-1 expression. HCECs transfected with pcDNA3.1-EZH2 showed the opposite results. EZH2 repressed HO-1 transcription by mediating H3K27me3. H3K27me27 was enriched in the HO-1 promoter and overexpression of EZH2 increased H3K27me27 levels. Promotion of H3K27me3 partially reversed the mitigating effect of si-EZH2 on HCEC apoptosis. Overexpression of HO-1 partially reversed the apoptosis-promoting effects of EZH2 and H3K27me3 on HCECs. Conclusions EZH2 promotes HCE cell apoptosis by mediating H3K27me3 to inhibit HO-1 transcription.

Exosome-derived circ_0001785 delays atherogenesis through the ceRNA network mechanism of miR-513a-5p/TGFBR3

PurposeEndothelial cell dysfunction is a major cause of early atherosclerosis. Although the role of extracellular vesicles in stabilizing atherosclerotic plaques is well established, the effect of circulating exosomes on plaque formation is still unknown. Here, we explored the effect of exosomes on atherosclerosis based on the function that exosomes can act on intercellular communication.Patients and methodsWe extracted serum exosomes from the blood of CHD patients (CHD-Exo) and healthy individuals (Con-Exo). The obtained exosomes were co-cultured with human umbilical vein endothelial cells (HUVECs) in vitro. In addition, we determined that circ_0001785 functions as a competing endogenous RNA (ceRNAs) in coronary artery disease by dual luciferase reporter gene analysis. The protective effect of circ_0001785 against endothelial cell injury was also verified using over-expression lentiviral transfection functional assays. In vivo experiments, we injected over-expressed circ_0001785 lentivirus into the tail vein of mice to observe its therapeutic effect on a mouse model of atherosclerosis.ResultsThe vitro co-cultured results showed that the amount of plasma-derived exosomes have an increase in patients with coronary artery disease, and the inflammation and apoptosis of endothelial cells were exacerbated. Over-expression of circ_0001785 reduced endothelial cell injury through the ceRNA network pathway of miR-513a-5p/TGFBR3. Quantitative reverse transcription-polymerase chain reaction identified that the expressed amount of circ_0001785 was reduced in the circulating peripheral blood of CHD patients and increased within human and mouse atherosclerotic plaque tissue. The results of in vivo experiments showed that circ_0001785 reduced aortic endothelial cell injury and the formation of intraplaque neo-vascularization, and enhanced left ventricular diastolic function, thereby delaying the development of atherosclerosis in mice.ConclusionOur results demonstrated a new biomarker, exosome-derived circ_0001785, for atherogenesis, which can reduce endothelial cell injury and thus delay atherogenesis through the miR-513a-5p/TGFBR3 ceRNA network mechanism, providing an exosome-based intervention strategy for atherosclerosis.

Danlou Tablet Protects Against Myocardial Infarction Through Promoting eNOS-Dependent Endothelial Protection and Angiogenesis.

Myocardial infarction (MI) is one of the leading causes of death worldwide. Danlou tablet (Dan) is an effective traditional Chinese medicine for cardiac protection, although the underlying mechanism was not fully understood. In this study, we used a murine MI model and demonstrated that Dan administration effectively attenuated myocardial apoptosis, cardiac remodeling, and heart failure post MI. Dan increased CD31-positive capillaries in MI hearts, and reduced the apoptosis and oxidative stress in human umbilical vein endothelial cells after oxygen-glucose deprivation stress, simultaneously with the activated HIF-1α/VEGFA/eNOS signaling. Moreover, inhibition of eNOS by L-NAME attenuated Dan-induced protection against MI, and abolished its effect in promoting angiogenesis and reducing endothelial apoptosis and oxidative stress. Collectively, Dan is beneficial to promote eNOS-dependent endothelial protection and angiogenesis thus protecting against MI. A deep understanding of Dan-induced protection might help promote clinical usage of Dan in MI treatment.

Retraction: Carbon monoxide inhibits Fas activating antibody-induced apoptosis in endothelial cells.

[This corrects the article DOI: 10.1186/2045-9912-1-8].