Paeoniflorin suppresses the apoptosis and inflammation of human coronary artery endothelial cells induced by oxidized low-density lipoprotein by regulating the Wnt/ß-catenin pathway.

CONTEXT: Paeoniflorin (PF) contributes to improving coronary artery disease (CAD). OBJECTIVE: This study clarified the efficiency of PF in CAD and the molecular mechanism. MATERIALS AND METHODS: Human coronary artery endothelial cells (HCAECs) were treated with oxidized low-density lipoprotein (ox-LDL; 20, 40, 80 and 160 µg/mL) and PF (0.05, 0.1 0.2 and 0.4 mM). To study cell phenotypes, HCAECs were treated with 80 µg/mL ox-LDL with or without 0.1 mM PF for 24 h, and cell viability and apoptosis were evaluated using the methyl thiazolyl tetrazolium (MTT) assay and flow cytometry, respectively. In addition, inflammatory cytokines levels were measured by enzyme-linked immunosorbent assay (ELISA). Western blot evaluated the Wnt/ß-catenin pathway-related factors. RESULTS: ox-LDL and PF (0.2 and 0.4 mM) suppressed cell viability in a dose-dependent manner. The IC50 value of PF was 722.9 nM. PF facilitated cell viability (115.76%), inhibited apoptosis (46.28%), reduced IL-6 (63.43%) and IL-8 (66.70%) levels and increased IL-10 levels (181.15%) of ox-LDL-treated HCAECs. Additionally, PF inactivated the Wnt/ß-catenin pathway, and XAV939 treatment further promoted cell viability (120.54%), suppressed apoptosis (56.92%), reduced the levels of IL-6 (76.16%) and IL-8 (86.82%) and increased the IL-10 levels (120.22%) of ox-LDL-induced HCAECs after PF treatment. Moreover, PF alleviated plaque lesions of the aorta and aorta root and serum lipid of ApoE-/- mice with a high-fat diet. DISCUSSION AND CONCLUSIONS: This study first revealed that PF inhibited ox-LDL-induced HCAECs apoptosis and inflammation via the Wnt/ß-catenin pathway and alleviated CAD, suggesting the potential of PF as a drug for CAD treatment.

Ginsenoside Rb3 reduces ox-LDL-induced injury in human aortic endothelial cells by regulating the miR-513a-5p/ZBTB20 axis.

BACKGROUND: Atherosclerosis (AS) is a common vascular disease, and its main influencing factor is endothelial damage caused by oxidized low-density lipoprotein (ox-LDL). As one of the main active ingredients of ginseng, ginsenoside Rb3 has anti-inflammatory and anti-oxidative effects. However, the role of ginsenoside Rb3 in endothelial injury induced by ox-LDL is not clear. OBJECTIVES: This study aimed to evaluate the effect and potential mechanism of ginsenoside Rb3 action on ox-LDL-treated human aortic endothelial cells (HAECs). MATERIAL AND METHODS: The HAECs treated with ox-LDL were used to establish an in vitro AS model. The viability of the HAECs was analyzed with Cell Counting Kit-8 (CCK-8). Flow cytometry was performed to assess the apoptosis. Oxidative stress, inflammation and endothelial dysfunction were evaluated using enzyme-linked immunosorbent assay (ELISA) and western blotting. The levels of miR-513a-5p were assessed using quantitative real-time polymerase chain reaction (qPCR). A dual-luciferase assay was performed to analyze the relationship between miR-513a-5p and a zinc finger and BTB domain-containing protein (ZBTB20). RESULTS: Exposure of HAECs to ox-LDL (50 µg/mL) reduced cell viability, superoxide dismutase (SOD) activity and endothelial nitric oxide synthase (eNOS) expression, while increasing the levels of malondialdehyde (MDA), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and soluble intercellular adhesion molecule-1 (sICAM-1). The pretreatment with Rb3 markedly enhanced cell viability and decreased ox-LDL-induced oxidative stress, inflammation and endothelial dysfunction in HAECs. The ox-LDL decreased the level of miR-513a-5p, which was reversed by Rb3 pretreatment. The ZBTB20 was a target of miR-513a-5p in HAECs, and ox-LDL upregulated ZBTB20 expression, which was reversed by Rb3 pretreatment. The protective effect of Rb3 on ox-LDL-induced HAECs was diminished by miR-513a-5p inhibition, which was reversed by ZBTB20 knockdown. CONCLUSIONS: Ginsenoside Rb3 reduces the effects of ox-LDL on HAECs by regulating the miR-513a-5p/ZBTB20 axis, which provides a theoretical basis for the treatment of AS.

MicroRNA miR-34a-5p inhibition restrains oxidative stress injury of macrophages by targeting MDM4.

OBJECTIVE: Atherosclerosis is a chronic cardiovascular disease associated with oxidative stress damage, which is caused by excessive oxidation of low-density lipoprotein (ox-LDL). The role of microRNA miR-34a-5p on oxidative stress in ox-LDL-treated macrophages was investigated in this study. METHODS: Flow cytometry was prepared for assessing THP1-derived macrophage apoptosis. The protein and expression levels of miR-34a-5p and MDM4 were examined by Western blot and RT-qPCR, respectively. We also measured the levels of total cholesterol (TC) and triglyceride to determine the lipid accumulation. Subsequently, the activities of superoxide dismutase, malondialdehyde, and reactive oxygen species revealed the level of oxidative stress injury after miR-34a-5p and MDM4 knockdown. RESULTS: After ox-LDL treatment, cell apoptosis of macrophages increased in a dose-dependent and time-dependent manner. With the increase of ox-LDL treatment and the prolongation of treatment time, the expression level of miR-34a-5p was upregulated. Next, interfering with miR-34a-5p inhibited lipid accumulation and oxidative stress injury in ox-LDL-stimulated macrophages. MDM4 was a target gene of miR-34a-5p and was upregulated in ox-LDL-stimulated macrophages. With the increase of ox-LDL treatment and the prolongation of treatment time, the expression level of MDM4 was downregulated. Importantly, MDM4 knockdown partially counteracted the inhibitory effect of miR-34a-5p on oxidative stress injury. CONCLUSION: MicroRNA miR-34a-5p knockdown suppressed oxidative stress injury via MDM4 in ox-LDL-treated macrophages.

Knockdown of circ_0002194 protects against oxidized low-density lipoprotein-induced cell damage via the regulation of the miR-637/PACS2 axis in human vascular endothelial cells.

OBJECTIVES: Atherosclerosis is one of the most common cardiovascular diseases. The functional roles of circular (circ) RNAs have been discovered in atherosclerosis. Our goal was to explore the regulation and mechanism of circ_0002194 in oxidized low-density lipoprotein-induced human vascular endothelial cells. METHODS: Circ_0002194, microRNA-637 (miR-637) and phosphofurin acidic cluster sorting protein 2 (PACS2) levels were determined through the reverse transcription-quantitative polymerase chain reaction. Cell viability was detected using the Cell Counting Kit-8 assay, and angiogenetic ability was analysed via the tube formation assay. Flow cytometry was used to measure cell apoptosis. Western blot was performed to examine protein expression. Oxidative stress was assessed using commercial kits. The RNA immunoprecipitation assay and dual-luciferase reporter assay were conducted for target analysis. RESULTS: Treatment with oxidized low-density lipoprotein induced the upregulation of circ_0002194 in endothelial cells. Cell viability and angiogenesis were promoted while cell apoptosis and oxidative stress were reduced by the downregulation of circ_0002194 in the cell model. Furthermore, miR-637 was identified as an miRNA target of circ_0002194, and the regulatory role of circ_0002194 was associated with the sponge effect on miR-637. Moreover, circ_0002194 could regulate PACS2 by affecting miR-637. Additionally, miR-637 suppressed endothelial cell damage by partly mediating the expression of PACS2. CONCLUSIONS: The results demonstrated that circ_0002194 facilitated endothelial cell dysfunction in atherosclerosis partly through upregulating PACS2 by targeting miR-637.

Acacia jacquemontii ethyl acetate extract reduces hyperglycemia and pro-inflammatory markers while increasing endogenous antioxidant potential in alloxan-induced diabetic rats.

Acacia jacquemontii possess has numerous traditional therapeutic uses. The rationale of this study was to investigate the role of Acacia jacquemontii ethyl acetate extract (AJEAE) in the downregulation of hyperglycemia. The current study was performed in two parts, in vitro, through characterization (high-performance liquid chromatography), estimation of total phenolic content, total flavonoid content, antioxidant (2,2-diphenyl-1-picrylhydrazylassay), and α-amylase inhibitory activities of the studied extract, and in vivo using Wistar rats in which animals were divided into five groups NC, DC, GL, AJEAE 250 mg/kg, and AJEAE 500 mg/kg. The effects of AJEAE on fasting plasma glucose, plasma insulin, HOMA-IR, oral glucose tolerance test, glycated hemoglobin (HBA1c), lipid profile, inflammatory cytokines (Interleukin-6, tumor necrosis factor-alpha), and oxidative stress markers (lipid peroxidation, nitic oxide, superoxide dismutase, catalase, glutathione peroxidase) were evaluated. Our findings confirmed the presence of quercetin, kaempferol, gallic acid, vanillic acid, syringic acid, M-coumaric acid, sinapic acid, chlorogenic acid, cinnamic acid, and ferulic acid in AJEAE. Total flavonoid and phenolic contents in AJEAE were 83.83 mg GAE/g and 77.06 mg QE/g, respectively. Significant inhibition of DPPH (69.470%/1 mg/ml) and α-amylase (71.8%/1 mg/ml) activities were exhibited by AJEAE. Alloxan-injected rats showed marked hyperglycemia and hypoinsulinemia, and increased inflammatory marker levels as compared to normal control (p < 0.001). Additionally, raised levels of triglyceride (139.7 ± 2.771), total cholesterol (198.7 ± 1.856), very low-density lipoprotein (33.43 ± 0.2728), low-density lipoprotein (155.5 ± 2.754), lipid peroxidation, and nitric oxide (p < 0.001) and decreased levels of high-density lipoprotein (17.20 ± 0.1732), superoxide dismutase, catalase, and glutathione peroxidase were observed in diabetic rats (p < 0.001). AJEAE significantly (p < 0.05) improved the aforementioned parameters and the protective efficacy was comparable to glibenclamide. Histopathological findings also evidenced the anti-hyperglycemic properties of AJEAE through regeneration of pancreatic ß cells. Conclusively, our findings demonstrated the antihyperglycemic, antihyperlipidemic, antioxidant, anti-inflammatory, and pancreatic beta ß cell regenerative properties of AJEAE against alloxan-induced diabetes.

LncRNA KCNQ1OT1 depletion inhibits the malignant development of atherosclerosis by miR-145-5p.

BACKGROUND: Atherosclerosis (AS) is a lipid-driven inflammatory disease of the arterial intima. Evidence is growing that dysregulation of lncRNAs is implicated in the pathogenesis of AS. In this research, the role of lncRNA KCNQ1OT1 in AS was investigated. METHODS: ApoE-/- mice were fed on a high fat diet to establish mouse models of AS. Macrophages (THP-1) were treated with oxidized low-density lipoprotein (ox-LDL) to establish cell models of AS. Atherosclerotic lesions of AS mice were determined by performing Oil red O staining. Lipid metabolic disorders and inflammatory were detected using specific assay kits. KCNQ1OT1 and miR-145-5p expression was measured using RT-qPCR. Levels of PPARα and CPT1 were measured using western blot. RESULTS: KCNQ1OT1 expression was upregulated and miR-145-5p was downregulated in atherosclerotic plaques of AS mice and ox-LDL-treated THP-1 cells. Lipid metabolic disorders and inflammation in vivo and in vitro were attenuated by either KCNQ1OT1 knockdown or miR-145-5p overexpression. Additionally, KCNQ1OT1 acted as a molecular sponge of miR-145-5p and downregulated miR-145-5p expression. Furthermore, silencing miR-145-5p abolished the effect of KCNQ1OT1 knockdown. CONCLUSION: Silencing KCNQ1OT1 attenuates AS progression by sponging miR-145-5p.

Overexpression of sFlt-1 represses ox-LDL-induced injury of HUVECs by activating autophagy via PI3K/AKT/mTOR pathway.

Soluble fms-like tyrosine kinase-1 (sFlt-1), a circulating antiangiogenic protein, is involved in the pathogenesis of atherosclerosis (AS), and the underlying mechanism is still unclear. Here, we attempted to investigate the mechanism of action of sFlt-1 in AS. Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low density lipoprotein (ox-LDL) to induce cell injury. ox-LDL treatment increased LC3-II/LC3-I ratio, Beclin-1 expression and GFP-LC3 puncta in HUVECs, suggesting that ox-LDL may induce autophagic flux impairment in HUVECs. ox-LDL-treated HUVECs displayed a decrease of sFlt-1 levels. Moreover, ox-LDL treatment reduced cell proliferation and elevated apoptosis in HUVECs, which was abrogated by sFlt-1 overexpression. Up-regulation of sFlt-1 repressed the activity of PI3K/AKT/mTOR signaling pathway and enhanced autophagy in HUVECs following ox-LDL treatment. Additionally, sFlt-1 overexpression-mediated increase of autophagy in ox-LDL-treated HUVECs was abolished by 3-methyladenine (autophagy inhibitor). 3-methyladenine abrogated the impact of sFlt-1 overexpression on proliferation and apoptosis in ox-LDL-treated HUVECs. This work confirmed that overexpression of sFlt-1 activated autophagy by repressing PI3K/Akt/mTOR signaling pathway, and thus alleviated ox-LDL-induced injury of HUVECs. Therefore, this study suggests that sFlt-1 may be a potential target for AS treatment.

Long Noncoding RNA MALAT1 Regulates the Progression of Atherosclerosis by miR-330-5p/NF-κB Signal Pathway.

ABSTRACT: Long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was reported to be related to atherosclerosis (AS) progression. However, the underlying mechanism of MALAT1 in AS remains unknown. Quantitative real-time polymerase chain reaction was performed to detect the expression of MALAT1 and miR-330-5p. Western blot was applied to assess the protein levels of cluster of differentiation 36, interleukin-1ß, interleukin-6 and tumor necrosis factor-α, phosphorylation of nuclear factor kappa-B inhibitor alpha and phosphorylation of p65. Flow cytometry assay, cell counting kit 8 assay, triglyceride, and total cholesterol detection assays were used to detect the apoptosis, viability, and lipid indexes of THP-1 macrophages-derived foam cells. Online database starbasev2.0 was used to predict the binding sequences between MALAT1 and miR-330-5p and it was verified by dual-luciferase reporter system and RNA immunoprecipitation assay. Besides, an AS mice model was used to evaluate the effect of MALAT1 in vivo. As a result, MALAT1 was overexpressed, whereas miR-330-5p was downregulated in THP-1 macrophages-derived foam cells. MiR-330-5p was a target of MALAT1. MALAT1 depletion inhibited cell formation, apoptosis, and inflammation in THP-1 macrophages-derived foam cells. Besides, MALAT1 overexpression promoted the inflammation in AS mice model, which promoted the pathogenesis of AS. Furthermore, miR-330-5p regulated the nuclear factor kappa light chain enhancer of activated B cells (NF-κB) pathway in THP-1 macrophages-derived foam cells. Moreover, MALAT1 regulated NF-κB signal pathway to mediate the pathogenesis of AS by sponging miR-330-5p. MALAT1 sponges miR-330-5p to activate NF-κB signal pathway in THP-1 macrophages-derived foam cells. This finding may provide a novel biomarker for AS diagnosis.

Knockdown of circ_0004104 Alleviates Oxidized Low-Density Lipoprotein-Induced Vascular Endothelial Cell Injury by Regulating miR-100/TNFAIP8 Axis.

ABSTRACT: Coronary artery disease (CAD) is a common cardiovascular disease, mainly due to vascular endothelial cell (VEC) injury caused by atherosclerosis. Circular RNA has been shown to be involved in the regulation of various diseases. However, the role and mechanism of circ_0004104 in CAD are still unclear. Oxidized low-density lipoprotein (ox-LDL) was used to construct the VEC injury model in vitro. The expression levels of circ_0004104 and miR-100 were measured by quantitative real-time polymerase chain reaction. The proliferation of VECs was determined using 3-(45)-dimethylthiahiazo (-z-y1)-35-di-phenytetrazoliumromide assay and 5-ethynyl-2'-deoxyuridine staining assay. VEC apoptosis rate was assessed using flow cytometry, and caspase-3 activity was measured using a Caspase-3 Assay Kit. The protein expression levels of Ki-67, cleaved-caspase3, and tumor necrosis factor-α-induced protein 8 (TNFAIP8) were detected by western blot analysis. Furthermore, enzyme-linked immunosorbent assay was performed to assess the concentrations of inflammatory cytokines. In addition, the relationship between miR-100 and circ_0004104 or TNFAIP8 was confirmed by dual-luciferase reporter assay and biotin-labeled RNA pull-down assay. Our results revealed that circ_0004104 was upregulated and miR-100 was downregulated in patients with CAD and ox-LDL-induced VECs. Ox-LDL could inhibit the proliferation and promote the apoptosis and inflammation of VECs to induce VEC injury. However, silenced circ_0004104 could alleviate VEC injury induced by ox-LDL. Moreover, we found that circ_0004104 could sponge miR-100 and a miR-100 inhibitor could reverse the inhibition effect of circ_0004104 knockdown on ox-LDL-induced VEC injury. In addition, TNFAIP8 was a target of miR-100, and miR-100 alleviated ox-LDL-induced VEC injury by targeting TNFAIP8. Our data suggested that circ_0004104 promoted ox-LDL-induced VEC injury by the miR-100/TNFAIP8 axis, indicating that circ_0004104 might be a potential biomarker for CAD treatment.

Circ_0010283/miR-377-3p/Cyclin D1 Axis Is Associated With Proliferation, Apoptosis, Migration, and Inflammation of Oxidized Low-density Lipoprotein-Stimulated Vascular Smooth Muscle Cells.

ABSTRACT: Circular RNAs have been reported as vital regulators and promising therapeutic targets in multiple human diseases, including atherosclerosis (AS). However, the functional roles of circ_0010283 in AS remain unclear. The real-time quantitative polymerase chain reaction was used to determine the expression levels of circ_0010283, microRNA (miR)-377-3p, and cyclin D1 (CCND1) in serum samples. The vascular smooth muscle cells (VSMCs) were treated with oxidized low-density lipoprotein (ox-LDL) to establish the in vitro cell model of AS. The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide and clonal colony-forming assays were performed to assess cell proliferation. The apoptosis was determined by flow cytometry assay. The migration of VSMCs was examined by wound healing and transwell assays. Western blot analysis was used to quantify protein expression. The association among circ_0010283, miR-377-3p, and CCND1 was confirmed by dual-luciferase reporter assay. We found that the serum level of circ_0010283 was upregulated in patients with AS and treatment with ox-LDL also increased the expression of circ_0010283 in VSMCs. Treatment with ox-LDL also increased proliferation, migration, and inflammation while inhibited apoptosis in VSMCs, which was overturned by silencing of circ_0010283. Moreover, miR-377-3p was a target of circ_0010283, and downregulation of miR-377-3p counteracted circ_0010283 silencing-induced effects on ox-LDL-stimulated VSMCs. The overexpression of miR-377-3p inhibited proliferation, migration, and inflammation while induced apoptosis of VSMCs by targeting CCND1. CCND1 was a target of miR-377-3p, and circ_0010283 acted as the miR-377-3p sponge to increase CCND1 expression. Circ_0010283 regulated proliferation, apoptosis, migration, and inflammation of ox-LDL-stimulated VSMCs through modulating miR-377-3p and CCND1.

P2X7 Receptor Antagonist Attenuates Retinal Inflammation and Neovascularization Induced by Oxidized Low-Density Lipoprotein.

Age-related macular degeneration (AMD) is a common and severe blinding disease among people worldwide. Retinal inflammation and neovascularization are two fundamental pathological processes in AMD. Recent studies showed that P2X7 receptor was closely involved in the inflammatory response. Here, we aim to investigate whether A740003, a P2X7 receptor antagonist, could prevent retinal inflammation and neovascularization induced by oxidized low-density lipoprotein (ox-LDL) and explore the underlying mechanisms. ARPE-19 cells and C57BL/6 mice were treated with ox-LDL and A740003 successively for in vitro and in vivo studies. In this research, we found that A740003 suppressed reactive oxygen species (ROS) generation and inhibited the activation of Nod-like receptor pyrin-domain protein 3 (NLRP3) inflammasome and nuclear factor-κB (NF-κB) pathway. A740003 also inhibited the generation of angiogenic factors in ARPE-19 cells and angiogenesis in mice. The inflammatory cytokines and phosphorylation of inhibitor of nuclear factor-κB alpha (IKBα) were repressed by A740003. Besides, ERG assessment showed that retinal functions were remarkably preserved in A740003-treated mice. In summary, our results revealed that the P2X7 receptor antagonist reduced retinal inflammation and neovascularization and protected retinal function. The protective effects were associated with regulation of NLRP3 inflammasome and the NF-κB pathway, as well as inhibition of angiogenic factors.

LncRNA H19 Mitigates Oxidized Low-Density Lipoprotein Induced Pyroptosis via Caspase-1 in Raw 264.7 Cells.

Atherosclerosis (AS) is mainly characterized by the activation of inflammatory cells and chronic inflammatory responses after cell injury. Pyroptosis is a form of programmed cell death (PCD) accompanied by the release of inflammatory factors. Many studies have shown that pyroptosis plays an important role in AS. Increasing evidence also indicates that long non-coding RNA H19 (lncRNA H19) involved in AS. However, whether the role of lncRNA H19 in AS is related to pyroptosis and the underlying mechanisms are largely unknown. In this study, we found that oxidized low-density lipoprotein (ox-LDL) induced pyroptosis and decreased the expression of lncRNA H19 in Raw 264.7 cells. Besides, silencing endogenous lncRNA H19 increased inflammatory responses and pyroptosis while exogenous overexpression of lncRNA H19 reversed this effect. Notably, we identified that the inhibitor of caspase-1 (XV-765) completely abrogated the silencing endogenous lncRNA H19 mediated pyroptosis. In addition, we found that lncRNA H19 inhibited ox-LDL-induced activation of nuclear factor-kappa B (NF-κB), mitochondrial dysfunction, and reduced the production of reactive oxygen species (ROS). Moreover, VX-765 impaired the silencing endogenous lncRNA H19 mediated pyroptosis. Overall, these findings indicated that lncRNA H19 may play an important role in pyroptosis and may serve as a potential therapeutic target for AS.

Circ_USP36 Silencing Attenuates Oxidized Low-Density Lipoprotein-Induced Dysfunction in Endothelial Cells in Atherosclerosis Through Mediating miR-197-3p/ROBO1 Axis.

ABSTRACT: Circular RNAs (circRNAs) are reported to play pivotal regulatory roles in atherosclerosis progression. In the present study, we explored the biological role of circRNA ubiquitin-specific peptidase 36 (circ_USP36; hsa_circ_0003204) in oxidized low-density lipoprotein (ox-LDL)-induced dysfunction of endothelial cells (ECs). RNA and protein levels were determined by reverse transcription-quantitative polymerase chain reaction and Western blot assay, respectively. Cell proliferation was analyzed by 5-ethynyl-2'-deoxyuridine assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry was conducted to analyze cell cycle progression and cell apoptosis. The release of tumor necrosis factor α in the supernatant was measured by enzyme linked immunosorbent assay. Cell death was evaluated by lactate dehydrogenase assay. Intermolecular interaction was verified by dual-luciferase reporter assay. Circ_USP36 expression was significantly up-regulated in the serum of atherosclerosis patients and ox-LDL-stimulated HUVECs than that in their corresponding controls. ox-LDL exposure inhibited the proliferation ability and cell cycle progression and triggered the apoptosis and inflammation of HUVECs, and these effects were largely overturned by the knockdown of circ_USP36. microRNA-197-3p (miR-197-3p) was a target of circ_USP36, and circ_USP36 knockdown-mediated protective role in ox-LDL-induced HUVECs was largely counteracted by the silence of miR-197-3p. miR-197-3p interacted with the 3' untranslated region of roundabout guidance receptor 1 (ROBO1). Circ_USP36 knockdown reduced ROBO1 expression partly by up-regulating miR-197-3p in HUVECs. ROBO1 overexpression reversed miR-197-3p accumulation-mediated effects in ox-LDL-induced HUVECs. In conclusion, circ_USP36 interference alleviated ox-LDL-induced dysfunction in HUVECs by targeting miR-197-3p/ROBO1 axis.

miR-100-5p in human umbilical cord mesenchymal stem cell-derived exosomes mediates eosinophilic inflammation to alleviate atherosclerosis via the FZD5/Wnt/ß-catenin pathway.

Exosomes derived from human umbilical cord mesenchymal stem cells (hUCMSC-Ex) play important roles in immune and inflammation diseases. However, the role of hUCMSC-Ex in atherosclerosis has not been elucidated. In this study, the isolated exosomes were identified by transmission electron microscopy and nanoparticle tracking analysis. Exosome marker protein levels were increased in the hUCMSC-Ex compared with those in hUCMSC suspension, indicating that exosomes were successfully isolated from hUCMSCs. Furthermore, eosinophils were treated with oxidized low-density lipoprotein (ox-LDL) to construct inflammation model and then incubated with hUCMSC-Ex derived from hUCMSCs which were transfected with miR-100-5p mimic or miR-100-5p inhibitor. We found that hUCMSC-Ex increased miR-100-5p expression, inhibited cell migration, promoted cell apoptosis, and reduced inflammatory cytokine levels in ox-LDL-treated eosinophils, and miR-100-5p overexpression in hUCMSCs enhanced these effects, while miR-100-5p inhibition reversed these effects. Moreover, frizzled 5 (FZD5) was a target gene of miR-100-5p. FZD5 overexpression reversed the inhibitory effects of hUCMSC-Ex-miR-100-5p on cell progression and inflammation in eosinophils. Additionally, hUCMSC-Ex-miR-100-5p decreased the expression of cyclin D1 and ß-catenin proteins. Wnt/ß-catenin pathway activator BML-284 effectively reversed the effects of hUCMSC-Ex-miR-100-5p on cell progression and inflammation in eosinophils. ApoE-/- mice were fed with high-fat diet to construct an atherosclerosis mice model, and hUCMSC-Ex was injected into mice. hUCMSC-Ex reduced atherosclerotic plaque area and inflammation response in atherosclerosis mice. This study demonstrates that hUCMSC-Ex-miR-100-5p inhibits cell progression and inflammatory response in eosinophils via the FZD5/Wnt/ß-catenin pathway, thereby alleviating atherosclerosis progression.

Syzygium cumini leaf extract protects macrophages against the oxidized LDL-induced toxicity: A promising atheroprotective effect.

Oxidized LDL (oxLDL) plays a pivotal role on atherosclerosis development, mainly in the formation of lipid-laden macrophage "foam cells". As a consequence, substances that can modulate LDL oxidation have a pharmacological and therapeutic relevance. Based in previous findings showing the ability of Syzigium cumini leaf extract (ScExt) in preventing LDL oxidation in vitro, this study was aimed to assess the effects of ScExt on oxLDL-mediated toxicity in murine J774 macrophages-like cells. For biochemical analyses, LDL isolated from fresh human plasma and oxidized with CuSO4 was incubated with ScExt pre-treated macrophages. Our results demonstrated that ScExt was efficient in preventing the overproduction of reactive oxygen/nitrogen species (ROS/RNS), the loss of macrophage's viability and the foam cells formation induced by oxLDL. These protective effects of ScExt make it a promising antioxidant for future trials toward atherogenesis.

G protein-coupled receptor 39 activation alleviates oxidized low-density lipoprotein-induced macrophage inflammatory response, lipid accumulation and apoptosis by inducing A20 expression.

G protein-coupled receptor 39 (GPR39) agonist weakens oxidized low-density lipoprotein (ox-LDL)-induced attachment of monocytes to vascular endothelial cells and thus alleviates atherosclerosis. This study looks at whether GPR39 protects macrophages against ox-LDL-induced inflammation and apoptosis and ameliorates lipid accumulation in atherosclerosis and investigates its mechanism. Following inducement of ox-LDL, the expression of GPR39 and tumor necrosis factor alpha-induced protein 3 (TNFAIP3, also known as A20) in Raw 264.7 cells was detected by RT-qPCR and western blotting. The viability of macrophages treated with GPR39 agonist was detected by a cell counting kit 8 kit. GPR39 and A20 expression in ox-LDL-challenged macrophages was assayed by RT-qPCR and western blot with or without GPR30 agonist. After transfection of small interfering RNA (siRNA)-A20, the expression of pro-inflammatory cytokine tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß and IL-6 and anti-inflammatory cytokine IL-10 as well as NF-κB p65 and COX2 was detected. Lipid accumulation was observed through Oil Red O Staining. Total cholesterol (TC) and free cholesterol (FC) in macrophages were detected by commercial kits. Lastly, macrophage apoptosis was observed through TUNEL, and apoptosis-related proteins were detected by western blotting . Results indicated that decreased expression of GPR39 and A20 was observed in ox-LDL-induced macrophages. GPR39 agonist significantly increased A20 expression in ox-LDL-treated macrophages. Furthermore, A20 interference reversed the inhibitory effect of GPR39 agonist on ox-LDL-induced inflammation, lipid accumulation, TC and FC overexpression as well as cell apoptosis. In conclusion, activating GPR39 alleviates ox-LDL-induced macrophage inflammation, lipid accumulation and apoptosis in an A20-dependent manner.

CircSCAP Aggravates Oxidized Low-density Lipoprotein-induced Macrophage Injury by Upregulating PDE3B by miR-221-5p in Atherosclerosis.

ABSTRACT: Atherosclerosis (AS) is a major risk factor for cardiovascular disease, in which circular RNAs play important regulatory roles. This research aimed to explore the biological role of circular RNA Sterol Regulatory Element Binding Transcription Factor Chaperone (circSCAP) (hsa_circ_0001292) in AS development. Real-time PCR or Western blot assay was conducted to analyze RNA or protein expression. Cell proliferation and apoptosis were analyzed by CCK-8 assay and flow cytometry. The levels of lipid accumulation-associated indicators and oxidative stress factors were detected using commercial kits. The levels of inflammatory cytokines were examined using enzyme-linked immunosorbent assay. Intermolecular interaction was verified by dual-luciferase reporter analysis or RNA pull-down analysis. CircSCAP and phosphodiesterase 3B (PDE3B) levels were elevated, whereas the miR-221-5p level was decreased in patients with AS and oxidized low-density lipoprotein (ox-LDL)-induced THP-1 cells. CircSCAP absence suppressed lipid deposition, inflammation, and oxidative stress in ox-LDL-induced THP-1 cells. MiR-221-5p was a target of circSCAP, and anti-miR-221-5p largely reversed si-circSCAP-induced effects in ox-LDL-induced THP-1 cells. PDE3B was a target of miR-221-5p, and PDE3B overexpression largely counteracted miR-221-5p accumulation-mediated effects in ox-LDL-induced THP-1 cells. NF-κB signaling pathway was regulated by circSCAP/miR-221-5p/PDE3B axis in ox-LDL-induced THP-1 cells. In conclusion, circSCAP facilitated lipid accumulation, inflammation, and oxidative stress in ox-LDL-induced THP-1 macrophages by regulating miR-221-5p/PDE3B axis.

Long non-coding RNA MIAT regulates ox-LDL-induced cell proliferation, migration and invasion by miR-641/STIM1 axis in human vascular smooth muscle cells.

BACKGROUND: Atherosclerosis (AS) is a primary cause of coronary heart and vascular diseases. Long non-coding RNAs (lncRNAs) are indicated to regulate AS progression. This study aimed to reveal the biological roles of lncRNA myocardial infarction associated transcript (MIAT) in oxidized low-density lipoprotein (ox-LDL)-induced human vascular smooth muscle cells (VSMCs). METHODS: The RNA levels of MIAT, microRNA-641 (miR-641) and stromal interaction molecule 1 (STIM1) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein levels were determined by western blot analysis. Cell proliferation was assessed by cell colony formation and DNA content quantitation assays. Cell migration and invasion were demonstrated by wound-healing and transwell assays. The putative binding relationships between miR-641 and MIAT or STIM1 were predicted by starbase online database, and identified by dual-luciferase reporter and RNA immunoprecipitation assays. RESULTS: MIAT and STIM1 expression were substantially upregulated, whereas miR-641 expression was downregulated in ox-LDL-induced VSMCs compared with control groups. Functionally, MIAT silencing attenuated ox-LDL-induced cell proliferation, migration and invasion in VSMCs; however, these effects were impaired by miR-641 inhibitor. STIM1 overexpression also restrained miR-641-mediated impacts on cell proliferation and metastasis under ox-LDL. Mechanistically, MIAT acted as a sponge for miR-641, and miR-641 was associated with STIM1. CONCLUSIONS: MIAT silencing hindered ox-LDL-induced cell proliferation, migration and invasion by downregulating STIM1 expression through binding to miR-641 in VSMCs. The mechanism provided us with a new target for AS therapy.

Anti-inflammatory activity of the Tongmai Yangxin pill in the treatment of coronary heart disease is associated with estrogen receptor and NF-κB signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: The Tongmai Yangxin Pill (TMYX) is a patented traditional Chinese medicine originating from two classic prescriptions, Zhigancao Decoction and Shenmai Yin, which composed of 11 Chinese medicinal herbs: Rehmannia glutinosa (Gaertn.) DC., Spatholobus suberectus Dunn, Ophiopogon japonicus (Thunb.) Ker Gawl., Glycyrrhiza uralensis Fisch., Polygonum multiflorum Thunb., Equus asinus L., Schisandra chinensis (Turcz.) Baill., Codonopsis pilosula (Franch.) Nannf., Chinemys reevesii (Gray), Ziziphus jujuba Mill. and Cinnamomum cassia (L.) J.Presl (Committee of the Pharmacopoeia of PR China, 2015). TMYX has marketed in China for the treatment of chest pain, palpitation, angina, irregular heartbeat and coronary heart disease (CHD) for several decades. Previous studies have confirmed that TMYX can treat CHD by reducing inflammation, but the underlying pharmacological mechanism remains unclear. AIM OF THE STUDY: This study aimed to declare the underlying pharmacological mechanism of anti-inflammatory activity of TMYX in the treatment of CHD via clinical trial, microarray study, bioinformatics analysis and the vitro assays. MATERIALS AND METHODS: Eight CHD patients' serum biochemical indices including coagulation function, lipid metabolism, endothelial injury, metalloprotease, adhesion molecule, inflammatory mediator and homocysteine were measured to investigate the reduction of CHD risk by TMYX oral administration (40 pills/time, 2 times/day) for eight weeks. The expression profile chips and Ingenuity Pathway Analysis (IPA) were assessed to reveal the global transcriptional response and predict related functions, diseases and canonical pathways. The in vitro anti-inflammatory actions of TMYX were evaluated using oxidized low-density lipoprotein (100 µg/mL) induced murine RAW264.7 macrophage with an ethanol extract from TMYX (EETMYX) (25-100 µg/mL). RESULTS: TMYX treatment showed reduced levels of apolipoprotein B, endothelin 1, nuclear factor κB (NF-κB) and homocysteine in CHD patients. In contrast, the treatment increased the ratio of apolipoprotein A/apolipoprotein B. EETMYX restored cell morphology and suppressed the lipid deposition of the induced foam cells. EETMYX exerted anti-inflammatory effects by raising the mRNA and protein expression of Estrogen receptor 1 (ESR1), blocking the reduction of IκBa level and the phosphorylation of IKKα/ß, IκBα and NF-κB p65, accompanied by inhibiting MCP-1, TNF-α and IL-6 production, which were consistent with bioinformatics predictions. CONCLUSION: TMYX treatment improved the biochemical indices in CHD patients. EETMYX effectively attenuated macrophage foam cell formation and exhibited anti-inflammatory activity is associated with regulating ESR1 and NF-κB signaling pathway activity.

Suppression of apoptosis in vascular endothelial cell, the promising way for natural medicines to treat atherosclerosis.

Atherosclerosis, a chronic multifactorial disease, is closely related to the development of cardiovascular diseases and is one of the predominant causes of death worldwide. Normal vascular endothelial cells play an important role in maintaining vascular homeostasis and inhibiting atherosclerosis by regulating vascular tension, preventing thrombosis and regulating inflammation. Currently, accumulating evidence has revealed that endothelial cell apoptosis is the first step of atherosclerosis. Excess apoptosis of endothelial cells induced by risk factors for atherosclerosis is a preliminary event in atherosclerosis development and might be a target for preventing and treating atherosclerosis. Interestingly, accumulating evidence shows that natural medicines have great potential to treat atherosclerosis by inhibiting endothelial cell apoptosis. Therefore, this paper reviewed current studies on the inhibitory effect of natural medicines on endothelial cell apoptosis and summarized the risk factors that may induce endothelial cell apoptosis, including oxidized low-density lipoprotein (ox-LDL), reactive oxygen species (ROS), angiotensin II (Ang II), tumor necrosis factor-α (TNF-α), homocysteine (Hcy) and lipopolysaccharide (LPS). We expect this review to highlight the importance of natural medicines, including extracts and monomers, in the treatment of atherosclerosis by inhibiting endothelial cell apoptosis and provide a foundation for the development of potential antiatherosclerotic drugs from natural medicines.