Endothelial-mesenchymal transition (EndMT) and endothelial cell apoptosis have been documented to have a role in atherosclerosis (AS) progression. To deepen knowledge in this aspect, our study investigated the effect of LIM homeobox 2 (LHX2) and adhesion-regulating molecule 1 (ADRM1) on EndMT and endothelial cell apoptosis in the oxidized low-density lipoprotein (ox-LDL) -stimulated AS cell model.Ox-LDL was utilized to treat human umbilical vein endothelial cells (HUVECs) for constructing an AS model in vitro, followed by measurement of LHX2 and ADRM1 expressions. Afterward, gain- and loss-of-function assays were performed in HUVECs, followed by detection of cell viability, invasion, migration, and apoptosis and the expression of inflammatory factors [tumor necrosis factor (TNF) -α, interleukin (IL) -1β, and IL-6], EndMT-related proteins [CD31, vascular epithelium (VE) -cadherin, vimentin, α-smooth muscle actin (SMA), Snai1, Snai2, and Twist1], and the apoptotic protein cleaved caspase-3. Interactions between LHX2 and ADRM1 were analyzed with dual-luciferase reporter gene and chromatin immunoprecipitation assays.High levels of LHX2 and ADRM1 were observed in ox-LDL-induced HUVECs. In ox-LDL-treated HUVECs, LHX2, or ADRM1 knockdown promoted CD31 and VE-cadherin levels, viability, invasion, and migration and reduced apoptosis and the expressions of TNF-α, IL-1β, IL-6, vimentin, α-SMA, Snai1, Snai2, Twist1, and cleaved caspase-3. Mechanistically, LHX2 bound to the ADRM1 promoter to promote ADRM1 transcription. Overexpression of ADRM1 annulled the aforementioned effects of LHX2 knockdown on ox-LDL-induced HUVECs.LHX2 facilitates the pathological progression of ox-LDL-stimulated AS cell models by increasing ADRM1 transcription.

Clinically, arterial injuries are always accompanied with perivascular tissue damage, which may contribute to high failure rate of vein grafts due to intimal hyperplasia and acute thrombosis. In this study, a \"perivascular tissue (PVT) deprivation\" animal model is constructed to mimic clinical scenarios and identify the contribution of arterial PVT to the success of vein grafts. Proteomics analysis suggests that depriving PVT may exacerbate reactive oxygen species (ROS)-induced endothelial apoptosis by up-regulating inflammation response and oxidative stress. Locally administering metformin on vein grafts through 3D-printed external stent (PGS-PCL) shows antioxidative and anti-inflammatory properties to protect cells from ROS invasion, thereafter decreasing acute thrombosis. Moreover, metformin induce rapid regeneration of perivascular adipose tissue in recipient regions, which improves patency by inhibiting intimal hyperplasia. Proteomics, western blot, and in vitro blocking tests reveal that metformin resists endothelial apoptosis through AMPK/mTOR and NFκB signaling pathways. To conclude, PVT deprivation exacerbates inflammatory response and oxidative stress in vein grafts bridging arterial circulation. Metformin-loaded stent ameliorates \"PVT damage\" related vein graft failure, and enhances patency of through resisting endothelial apoptosis and regenerating arterial PVAT, offering a promising avenue to improve the success of vein grafts in clinic.

Methylglyoxal (MGO), a cytotoxic metabolite of glycolysis, can cause endothelial cells impairment, which is tightly associated with diabetic vascular complication. Umbelliferone, a derivative of coumarin, participates in various pharmacological activities. This study aimed to determine the effectiveness of umbelliferone in MGO-induced apoptosis and oxidative stress in endothelial cells. In this study, it has been indicated that umbelliferone inhibited MGO-induced human umbilical vein endothelial cells (HUVECs) cytotoxicity, apoptosis, Bax/Bcl-2 protein ratio, the activity of cleaved-caspase-3, and mitochondrial membrane potential loss. Furthermore, we found that umbelliferone inhibited MGO-induced activation of mitogen-activated protein kinases and nuclear factor-κB signaling pathways in HUVECs. In addition, umbelliferone could suppress oxidative stress, as evidenced by decrease of reactive oxygen species and malondialdehyde (MDA) generation, and increase of superoxide dismutase and glutathione peroxidase contents. Moreover, we found that umbelliferone can activate Nrf2/HO-1 signaling. Importantly, silencing of Nrf2 signaling clearly eliminated the anti-oxidative stress of umbelliferone, whereas umbelliferone pretreatment had no effect on Nrf2 overexpressing HUVECs. Altogether, this study suggested that umbelliferone pretreatment has a protective effect on MGO-induced endothelial cell dysfunction through inhibiting apoptosis and oxidative stress.

Vitexin, a polyphenolic flavonoid, has been reported to be traditionally applied in the treatment of diabetes, cancer and cardiovascular diseases.
UNASSIGNED: The aim of this study was to investigate the anti-apoptosis and anti-oxidation effect and the potential mechanism of vitexin on high glucose-induced HUVECs.
UNASSIGNED: A high dose of glucose was added to HUVECs to establish an in vitro model. The cell viability was detected by CCK8 and flow cytometry assays. 2,7-dichlorodihydrofluorescein diacetate, colorimetry, and enzyme-linked immunosorbent assay were performed to detect oxidative stress. Besides, top flash and western blotting were employed to evaluate the effect of vitexin on Wnt/β-catenin. Furthermore, a Wnt/β-catenin inhibitor (KYA1797K) was used to confirm whether Wnt/β-catenin is involved in the protection of vitexin. At the same time, RT-PCR and western blot were performed to determine the effect of vitexin on Nrf2, while immunofluorescence assays were employed for the assessment of Nrf2 localisation. Then, in order to validate that Nrf2 plays an important role in the anti-oxidant effect of vitexin, methods were utilised to silence Nrf2 gene.
UNASSIGNED: Herein, vitexin inhibited the proliferation and apoptosis of HG-mediated HUVECs. Mechanically, vitexin disrupted Wnt/β-catenin signalling pathway, thus resulting in the decrease of apoptosis in HG-induced HUVECs. A Wnt/β-catenin inhibitor (KYA1797K), was used for reverse verification. In the meantime, vitexin administration decreased reactive oxygen species (ROS) production and malondialdehyde (MDA) content and increased superoxide dismutase (SOD) activity in HG-induced HUVECs. Further investigations have revealed vitexin activated Nrf2 in HUVEC under high glucose, which was involved in its anti-oxidant effects.
UNASSIGNED: Our investigation demonstrated that vitexin protected HUVECs from high glucose-induced injury via up-regulation of Wnt/β-catenin and Nrf2 signalling pathway. These results suggested that vitexin might serve as a potential drug for atherosclerosis and cardiovascular complications of diabetes.

Endothelial cell apoptosis is an important pathophysiology in many cardiovascular diseases. The gasotransmitter nitric oxide (NO) is known to regulate cell survival and apoptosis. However, the mechanism underlying the effect of NO remains unclear. In this research, by targeting cytosolic copper/zinc superoxide dismutase (SOD1) monomerization, we aimed to explore how NO inhibited endothelial cell apoptosis. We showed that treatment with the NO synthase (NOS) inhibitor nomega-nitro-l-arginine methyl ester hydrochloride (L-NAME) significantly decreased the endogenous NO content of endothelial cells, facilitated the formation of SOD1 monomers, inhibited dismutase activity, and promoted reactive oxygen species (ROS) accumulation in human umbilical vein endothelial cells (HUVECs); by contrast, supplementation with the NO donor sodium nitroprusside (SNP) upregulated NO content, prevented the formation of SOD1 monomers, enhanced dismutase activity, and reduced ROS accumulation in L-NAME-treated HUVECs. Mechanistically, tris(2-carboxyethyl) phosphine hydrochloride (TCEP), a specific reducer of cysteine thiol, increased SOD1 monomer formation, thus preventing the NO-induced increase in dismutase activity and the decrease in ROS. Furthermore, SNP inhibited HUVEC apoptosis caused by the decrease in endogenous NO, whereas TCEP abolished this protective effect of SNP. In summary, our data reveal that NO protects endothelial cells against apoptosis by inhibiting cysteine-dependent SOD1 monomerization to enhance SOD1 activity and inhibit oxidative stress.

Long non-coding RNAs (lncRNAs) are the novel class of transcripts involved in transcriptional, post-transcriptional, translational, and post-translational regulation of physiology and the pathology of diseases. Studies have evidenced that the impairment of endothelium is a critical event in the pathogenesis of atherosclerosis and its complications. Endothelial dysfunction is characterized by an imbalance in vasodilation and vasoconstriction, oxidative stress, proinflammatory factors, and nitric oxide bioavailability. Disruption of the endothelial barrier permeability, the first step in developing atherosclerotic lesions is a consequence of endothelial dysfunction. Though several factors interfere with the normal functioning of the endothelium, intrinsic epigenetic mechanisms governing endothelial function are regulated by lncRNAs and perturbations contribute to the pathogenesis of the disease. This review comprehensively addresses the biogenesis of lncRNA and molecular mechanisms underlying and regulation in endothelial function. An insight correlating lncRNAs and endothelial dysfunction-associated diseases can positively impact the development of novel biomarkers and therapeutic targets in endothelial dysfunction-associated diseases and treatment strategies.

Tumor-associated angiogenesis is a key target for anti-cancer therapy. The imbalance between pro-angiogenic and anti-angiogenic signals elicited by tumor cells or tumor microenvironment always results in activating \"angiogenic switch\". Tumor angiogenesis functions in multi-aspects of tumor biology, including endothelial cell apoptosis, tumor metastasis, and cancer stem cell proliferation. Numerous studies have indicated the important roles of inexpensive and less toxic natural products in targeting tumor angiogenesis-associated cytokines and apoptotic signaling pathways. Our current knowledge of tumor angiogenesis is based mainly on experiments performed on cells and animals, so we summarized the well-established models for angiogenesis both in vitro and in vivo. In this review, we classified and summarized the anti-angiogenic natural agents (Polyphenols, Polysaccharides, Alkaloids, Terpenoids, Saponins) in targeting various tumor types according to their chemical structures at present, and discussed the mechanistic principles of these natural products on regulating angiogenesis-associated cytokines and apoptotic signaling pathways. This review is to help understanding the recent progress of natural product research for drug development on anti-tumor angiogenesis.

Background We have previously reported important strain differences in response to SU5416 (SU, a vascular endothelial growth factor receptor 2 inhibitor) in rats and have identified a specific colony of Sprague-Dawley rats that are hyperresponsive (SDHR) to SU alone and develop severe pulmonary arterial hypertension (PAH) with a single injection of SU, even in the absence of hypoxia. Interestingly, SDHR rats exhibit incomplete penetrance of the severe PAH phenotype with an \"all-or-none\" response to SU alone, which provides a unique opportunity to assess the influence of female sex and sex hormones on susceptibility to PAH after endothelial injury in a genetically prone model. Methods and Results SDHR rats were injected with SU (20 mg/kg SC) and, in the absence of hypoxia, 72% of male but only 27% of female rats developed severe PAH at 7 weeks, which was associated with persistent endothelial cell apoptosis. This sex difference in susceptibility for severe PAH was abolished by ovariectomy. Estradiol replacement, beginning 2 days before SU (prevention), inhibited lung endothelial cell apoptosis and completely abrogated severe PAH phenotype in both male and ovariectomized female rats, while progesterone was only protective in ovariectomized female rats. In contrast, delayed treatment of SDHR rats with established PAH with estradiol or progesterone (initiated at 4 weeks post-SU) failed to reduce lung endothelial cell apoptosis or improve PAH phenotype. Conclusions Female sex hormones markedly reduced susceptibility for the severe PAH phenotype in response to SU alone in a hyperresponsive rat strain by abolishing SU-induced endothelial cell apoptosis, but did not reverse severe PAH in established disease.

Atherosclerosis causes stroke and coronary heart disease and is associated with a high mortality rate worldwide. However, the pathogenesis of atherosclerosis remains unclear. Endothelial cell apoptosis is one of the early changes observed in atherosclerosis. Previous studies have found that microRNA (miR)-616-3p may be involved in the development of atherosclerosis, but the specific mechanism is not clear. The present study aimed to investigate whether miR-616-3p is involved in endothelial cell apoptosis and its underlying mechanism. The present study demonstrated that compared with normal HUVECs, HUVECs treated with oxidized low-density lipoprotein expressed higher miR-616-3p and lower X-linked inhibitor of apoptosis protein (XIAP) levels. In the present study, HUVECs were transfected with miR-616-3p mimic and Cell Counting Kit-8 (CCK-8), flow cytometry and TUNEL staining assays demonstrated that compared with miR-616-3p mimic control, the miR-616-3p mimic promoted HUVEC apoptosis. In addition, using StarBase 3.0 for bioinformatics analysis it was predicted that miR-616-3p may bind to the 3\'untranslated region (UTR) of XIAP mRNA. The present study performed the CCK-8, flow cytometry, TUNEL staining and dual-luciferase reporter assays and demonstrated that miR-616-3p binds to the 3\'UTR of the XIAP mRNA and inhibits its expression and that this further promotes apoptosis in HUVECs. In addition, western blotting demonstrated that compared with miR-616-3p mimic control, the miR-616-3p mimic increases the level of cleaved caspase-3 in HUVECs. In summary, the present study demonstrated that miR-616-3p can directly inhibit the expression of XIAP mRNA by targeting its 3\'UTR which promoted apoptosis in HUVECs. miR-616-3p and XIAP may be used as therapeutic targets of atherosclerosis in the future.

We intended to characterize functional relevance of microRNA (miR)-224-3p in endothelial cell (EC) apoptosis and reactive oxygen species (ROS) accumulation in atherosclerosis, considering also the integral involvement of histone deacetylase 1 (HDAC1)-mediated hypoxia-inducible factor-1α (HIF1α) deacetylation. The binding affinity between miR-224-3p and Fos-like antigen 2 (FOSL2) was predicted and validated. Furthermore, we manipulated miR-224-3p, FOSL2, HDAC1, and HIF1α expression in oxidized low-density lipoprotein (ox-LDL)-induced ECs, aiming to clarify their effects on cell activities, inflammation, and ROS level. Additionally, we examined the impact of miR-224-3p on aortic atherosclerotic plaque and lesions in a high-fat-diet-induced atherosclerosis model in ApoE-/- mice. Clinical atherosclerotic samples and ox-LDL-induced human aortic ECs (HAECs) exhibited low HDAC1/miR-224-3p expression and high HIF1α/FOSL2 expression. miR-224-3p repressed EC cell apoptosis, inflammatory responses, and intracellular ROS levels through targeting FOSL2. HIF1α reduced miR-224-3p expression to accelerate EC apoptosis and ROS accumulation. Moreover, HDAC1 inhibited HIF1α expression by deacetylation, which in turn enhanced miR-224-3p expression to attenuate EC apoptosis and ROS accumulation. miR-224-3p overexpression reduced atherosclerotic lesions in vivo. In summary, HDAC1 overexpression may enhance the anti-atherosclerotic and endothelial-protective effects of miR-224-3p-mediated inhibition of FOSL2 by deacetylating HIF1α, underscoring a novel therapeutic insight against experimental atherosclerosis.