Gypenoside XVII inhibits ox-LDL-induced macrophage inflammatory responses and promotes cholesterol efflux through activating the miR-182-5p/HDAC9 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The deposition of lipids in macrophages and the subsequent formation of foam cells significantly increase the risk of developing atherosclerosis (As). Targeting ATP-binding cassette transporter A1/G1 (ABCA1/ABCG1)-mediated reverse cholesterol transport is crucial for regulating foam cell formation. Therefore, the search for natural chemical components with the ability to regulate ABCA1/G1 is a potential drug target to combat the development of atherosclerosis. Gypenoside XVII (GP-17), a gypenoside monomer extracted from gynostemma pentaphyllum, presents an efficient anti-atherosclerosis function. However, the suppressed formation mechanism of foam cells by GP-17 remains elusive.

AIM OF STUDY

To explore the protective activities of GP-17 in ox-LDL-induced THP-1 macrophage-derived foam cells through modulating the promotion of cholesterol efflux and alleviation of inflammation.

MATERIALS AND METHODS

MTT was used to detect cell viability. Bodipy493/503 and oil red O staining were performed to measure cell lipid deposition. Enzymatic assay was used to measure intracellular cholesterol measurement. Cholesterol efflux/uptake were determined by cholesterol efflux assay and Dil-ox-LDL uptake assay. Inflammatory cytokines were measured by ELISA. Bioinformatics prediction and dual luciferase reporter assay were performed to validate miR-182-5p targeting HDAC9. Relative protein levels were evaluated by immunoblotting and relative gene levels were determined by quantitative real-time PCR.

RESULTS

Our results showed that GP-17 upregulated the expression of ABCA1, ABCG1 and miR-182-5p, but reduced HDAC9 expression levels in lipid-loaded macrophages, which promoted cholesterol efflux and inhibited lipid deposition. Additionally, GP-17 promoted the M2 phenotype of the macrophage and suppressed the inflammatory response in THP-1 macrophage-derived foam cells. Overexpression of HDAC9 or suppression of miR-182-5p eliminated the effects of ABCA1/G1 expression, lipid deposition and pro-inflammatory response.

CONCLUSION

These findings suggest that GP-17 exerts a beneficial effect on macrophage lipid deposition and inflammation responses through activating the miR-182-5p/HDAC9 signaling pathway.

The Pregnancy-Associated Plasma Protein-A (PAPP-A) Story

Pregnancy-associated plasma protein-A (PAPP-A) was first identified in the early 1970s as a placental protein of unknown function, present at high concentrations in the circulation of pregnant women. In the mid-to-late 1990s, PAPP-A was discovered to be a metzincin metalloproteinase, expressed by many nonplacental cells, that regulates local insulin-like growth factor (IGF) activity through cleavage of high-affinity IGF binding proteins (IGFBPs), in particular IGFBP-4. With PAPP-A as a cell surface-associated enzyme, the reduced affinity of the cleavage fragments results in increased IGF available to bind and activate IGF receptors in the pericellular environment. This proteolytic regulation of IGF activity is important, since the IGFs promote proliferation, differentiation, migration, and survival in various normal and cancer cells. Thus, there has been a steady growth in investigation of PAPP-A structure and function outside of pregnancy. This review provides historical perspective on the discovery of PAPP-A and its structure and cellular function, highlights key studies of the first 50 years in PAPP-A research, and introduces new findings from recent years.

Longitudinal dynamics of circulating miRNAs in a swine model of familial hypercholesterolemia during early atherosclerosis

Atherosclerosis is a complex progressive disease involving intertwined biological mechanisms. We aimed to identify miRNA expression dynamics at the early stages of atherosclerosis using a large swine model (Wisconsin Miniature Swine, WMS). A total of 18 female pigs; 9 familial hypercholesterolemic (WMS-FH) and 9 normal control swine (WMS-N) were studied. miRNA sequencing was performed on plasma cell-free RNA at 3, 6, and 9 months of age. RT-qPCR validated DE miRNAs in a new cohort of animals (n = 30) with both sexes. Gene ontology and mRNA targets for DE miRNAs were identified. In vivo multimodality imaging and histopathology were performed to document the presence of atherosclerosis at termination. 20, 19, and 9 miRNAs were significantly DE between the groups at months 3, 6, and 9, respectively. Most DE miRNAs and their target genes are involved in human atherosclerosis development. Coronary atherosclerosis was documented in 7/9 WMS-FH pigs. Control animals had no lesions. miR-138, miR-152, miR-190a, and miR-196a showed a significant diagnostic power at month 3, whereas miR-486, miR-126-3p, miR-335, and miR-423-5p were of significant diagnostic power at month 9. In conclusion, specific DE miRNAs with significant discriminatory power may be promising biomarkers for the early detection of coronary atherosclerosis.

Role of miR-182 in cardiovascular and cerebrovascular diseases

The treatment of cardiovascular and cerebrovascular diseases have undergone major advances in recent decades, allowing for a more effective prevention of cardiovascular and cerebrovascular events. However, cardiac and cerebral atherothrombotic complications still account for substantial morbidity and mortality worldwide. Novel therapeutic strategies are critical to improve patient outcomes following cardiovascular diseases. miRNAs are small non-coding RNAs, that regulate gene expression. Here, we discuss the role of miR-182 in regulating myocardial proliferation, migration, hypoxia, ischemia, apoptosis and hypertrophy in atherosclerosis, CAD, MI, I/R injury, organ transplant, cardiac hypertrophy, hypertension, heart failure, congenital heart disease and cardiotoxicity. Besides, we also summarize the current progress of miR-182 therapeutics in clinical development and discuss challenges that will need to be overcome to enter the clinic for patients with cardiac disease.

Inhibition of miR-182-5p Targets FGF9 to Alleviate Osteoarthritis

Background. The pathogenesis of osteoarthritis (OA) is complex and there is no specific drug for treatment. The aim of this study was to identify the molecular targets of OA therapy, focusing on the expression and biological functions of miR-182-5p and its target genes in OA. Methods. miR-182-5p and fibroblast growth factor 9 (FGF9) were overexpressed or knocked down in IL-1β-induced chondrocytes. An OA knee model was performed by surgically destroying the medial meniscus. The gene expression of miR-182-5p and FGF9 was calculated. The protein FGF9 was tested by western blotting. Cell counting kit-8 (CCK8), plate cloning assay, and flow cytometry were conducted to evaluate cell proliferation and apoptosis. The expression of inflammatory factors, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, and interleukin (IL)-8, was evaluated using enzyme-linked immunosorbent assay (ELISA). Dual-luciferase reporter assays validated the targeting relationship between miR-182-5p and FGF9. Hematoxylin–eosin (HE) and safranin O-fast Green (S–O) staining were utilized to access cartilage damage. Ki67 expression in cartilage was detected using immunohistochemistry (IHC). TdT-mediated dUTP nick-end labeling (TUNEL) assays were used to calculate the apoptosis rate of cartilage. Results. The expression of miR-182-5p was upregulated, and FGF9 was downregulated in the IL-1β-induced chondrocytes. OA chondrocytes proliferation ability in the miR-182-5p mimics group was decreased, and the apoptosis rate and inflammatory factor were increased. Transfection with miR-182-5p inhibitor increased the proliferative ability and decreased the apoptosis rate in the IL-1β-induced chondrocytes. Transfection with miR-182-5p inhibitor reversed IL-1β-induced inflammatory factor release in chondrocytes. Targeted binding sites existed between miR-182-5p and FGF9. After overexpression of FGF9, the miR-182-5p effect on OA chondrocytes was reversed. The hyaline cartilage thickness and proteoglycan content decreased in OA rats, and this was reversed by miR-182-5p inhibitor treatment. Conclusions. miR-182-5p expression levels were increased in OA chondrocytes and regulated chondrocyte proliferation, apoptosis, and inflammation by targeting FGF9. miR-182-5p is a potential gene for OA treatment.

Circadian system microRNAs - Role in the development of cardiovascular diseases

Circadian rhythm regulates numerous physiological processes, and disruption of the circadian clock can lead to cardiovascular disease. Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Small non-coding RNAs, microRNAs (miRNAs), are involved in regulating gene expression, both those important for the cardiovascular system and key circadian clock genes. Epigenetic mechanisms based on miRNAs are essential for fine-tuning circadian physiology. Indeed, some miRNAs depend on circadian periodicity, others are under the influence of light, and still others are under the influence of core clock genes. Dysregulation of miRNAs involved in circadian rhythm modulation has been associated with inflammatory conditions of the endothelium and atherosclerosis, which can lead to coronary heart disease and myocardial infarction. Epigenetic processes are reversible through their association with environmental factors, enabling innovative preventive and therapeutic strategies for cardiovascular disease. Here, is a review of recent findings on how miRNAs modulate circadian rhythm desynchronization in cardiovascular disease. In the era of personalized medicine, the possibility of treatment with miRNA antagomirs should be time-dependent to correspond to chronotherapy and achieve the most significant efficacy.

Exosomes Promote Atherosclerosis Progression by Regulating Circ_100696/miR-503-5p/PAPPA Axis-Mediated Vascular Smooth Muscle Cells Proliferation and Migration

Circular RNAs (circRNAs) are known to play a crucial role in the progression of atherosclerosis (AS). In this study, we aim to explore the function of oxidized low-density lipoprotein (ox-LDL)-induced macrophage-derived exosomal circ_100696 in AS.THP-1 macrophages were induced by ox-LDL to mimic AS cell model. A quantitative real-time polymerase chain reaction (qRT-PCR) assay was applied to determine the expression of circ_100696, microRNA-503-5p (miR-503-5p), and pregnancy-associated plasma protein A (PAPPA). The morphology and size distribution of exosomes were examined by transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). Western blot assay was performed for protein levels. Cell proliferation was assessed using 5-ethynyl-2'-deoxyuridine (EdU) assay. Flow cytometry analysis was performed to analyze the cell cycle. Wound-healing assay and transwell assay were done to examine cell migration. RNA pull-down assay, dual-luciferase reporter assay, and RNA immunoprecipitation (RIP) assay were employed to analyze the relationship among circ_100696, miR-503-5p, and PAPPA.Circ_100696 level was increased in ox-LDL-induced THP-1 macrophages and ox-LDL-treated THP-1 macrophage-derived exosomes (OM-Exo). OM-Exo promoted the proliferation, cell cycle, and migration of vascular smooth muscle cells (VSMCs). Circ_100696 was upregulated in VSMCs cocultured with OM-Exo. Circ_100696 knockdown reversed the effects of OM-Exo on VSMC proliferation and migration. Circ_100696 was demonstrated to function as the sponge for miR-503-5p, and miR-503-5p directly targeted PAPPA. Circ_100696 overexpression facilitated VSMC proliferation and migration, with miR-503-5p upregulation or PAPPA silencing reversing these effects. Moreover, circ_100696 overexpression promoted PAPPA expression by targeting miR-503-5p.OM-Exo promoted VSMC growth and migration by regulating the circ_100696/miR-503-5p/PAPPA axis, thereby promoting AS progression.

New developments in non-exosomal and exosomal ncRNAs in coronary artery disease

Aim & methods: Non-exosomal and exosomal ncRNAs have been reported to be involved in the regulation of coronary artery disease (CAD). Therefore, to explore the biological effects of non-exosomal/exosomal ncRNAs in CAD, the authors searched for studies published in the last 3 years on these ncRNAs in CAD and summarized their functions and mechanisms. Results: The authors summarized 120 non-exosomal ncRNAs capable of regulating CAD progression. In clinical studies, 47 non-exosomal and nine exosomal ncRNAs were able to serve as biomarkers for the diagnosis of CAD. Conclusion: Non-exosomal/exosomal ncRNAs are not only able to serve as biomarkers for CAD diagnosis but can also regulate CAD progression through ceRNA mechanisms and are a potential target for early clinical intervention in CAD.

Hypoxia-induced miR-182-5p regulates vascular smooth muscle cell phenotypic switch by targeting RGS5

In response to vascular injury or alterations in the local environment, such as hypoxia and hypertension, contractile vascular smooth muscle cells (VSMCs) are able to switch to a synthetic phenotype characterized by increased extracellular matrix synthesis with decreased expression of contractile markers. miR-182-5p has recently been reported to play a regulatory role in VSMCs proliferation. However, little is known about its target genes and related pathways in VSMCs phenotypic switch. Here, we investigated the function of miR-182-5p in VSMCs phenotypic switch. The results showed that upregulation of miR-182-5p promoted the switching of VSMCs from a contractile to a synthetic phenotype under hypoxic conditions. Mechanistically, hypoxia elevated miR-182-5p, leading to a reduction in expression of contractile markers and weakened RhoA signaling. Using bioinformatics analysis, dual-luciferase reporter assays and rescue assays, we demonstrated that miR-182-5p suppressed RhoA signaling by targeting RGS5. Collectively, the results from the present study indicated that miR-182-5p/RGS5/RhoA axis regulated hypoxia-induced VSMCs phenotypic switch.

Role and mechanism of circular RNA circ_0050486 in regulating oxidized low-density lipoprotein-induced injury in endothelial cells

BACKGROUND

Dysfunction of endothelial cells in the arterial vasculature is an essential contributor to the pathogenesis of atherosclerosis. Circular RNAs (circRNAs) exert important regulatory functions in endothelial cell dysfunction. Here, we explored the precise role and mechanism of circ_0050486 in regulating endothelial cell injury induced by oxidized low-density lipoprotein (ox-LDL).

METHODS

Circ_0050486, microRNA (miR)-182-5p and myeloid differentiation primary response gene 88 (MyD88) were quantified by quantitative real-time PCR or western blot. Cell viability, proliferation and apoptosis were examined by MTS, 5-Ethynyl-2'-Deoxyuridine (EdU), and flow cytometry assays, respectively. Direct relationship between miR-182-5p and circ_0050486 or MYD88 was verified by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays.

RESULTS

Circ_0050486 was upregulated in atherosclerosis serum and ox-LDL-treated human aortic endothelial cells (HAECs). Silencing of circ_0050486 suppressed HAEC injury induced by ox-LDL. Mechanistically, circ_0050486 targeted miR-182-5p, and the effects of circ_0050486 silencing were partially due to the upregulation of miR-182-5p. MYD88 was a direct target of miR-182-5p, and miR-182-5p-mediated inhibition of MYD88 attenuated ox-LDL-evoked HAEC injury. Circ_0050486 bound to miR-182-5p to regulate MYD88 expression. Additionally, the NF-κB signaling pathway was involved in the regulation of circ_0050486/miR-182-5p/MYD88 axis in ox-LDL-treated HAECs.

CONCLUSION

Our study identifies the functional role of circ_0050486 in ox-LDL-induced endogenous cell injury and establishes a mechanism of circ_0050486 function by affecting MYD88 through competitively binding to shared miR-182-5p.

Histone Deacetylase 1 Depletion Alleviates Coronary Heart Disease Via the MicroRNA-182-Mediated Transforming Growth Factor β/Smad Signaling Pathway

ABSTRACT

Histone deacetylase (HDAC) determines the acetylation status of histones, thereby regulating gene expression. HDAC inhibitors have been demonstrated to suppress cardiomyocyte growth in vitro and in vivo. We assessed here whether HDAC1 exerts an aggravating effect on coronary heart disease (CHD). Epigenetic probe array revealed that HDAC1 was overexpressed in patients with CHD. HDAC1 was then downregulated in rat cardiomyocytes, and microRNA microarray analysis was performed to detect downstream targets of HDAC1, followed by chromatin immunoprecipitation validation. HDAC1 inhibited miR-182 expression through deacetylation. miR-182 was poorly expressed in patients with CHD. Using enzyme-linked immunosorbent assay, Reverse transcription-quantitative PCR, hematoxylin-eosin staining, terminal deoxynucleotidyl transferase (TdT)-mediated 2'-deoxyuridine 5'-triphosphate (dUTP) nick-end labeling assay, and immunohistochemistry, we observed that HDAC1 downregulation promoted cardiac function, restored lipid levels, reduced myocardial injury markers and inflammatory factors, and alleviated myocardial tissue damage and apoptosis in CHD rats. By contrast, miR-182 downregulation exacerbated injury in rats in the presence of HDAC1 knockdown. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the target genes of miR-182 were mainly enriched in the transforming growth factor (TGF)-β/Smad pathway. Western blot also validated that HDAC1/miR-182 modulated the TGF-β/Smad pathway activity. Our results demonstrated that HDAC1 repressed miR-182 and activated the TGF-β/Smad pathway to promote CHD.

ox-LDL regulates proliferation and apoptosis in VSMCs by controlling the miR-183-5p/FOXO1

BACKGROUND

microRNA-mRNA axes that are involved in oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs) proliferation/apoptosis imbalance need to be further investigated.

OBJECTIVE

To investigate the functional role of miR-183-5p/FOXO1 in VSMCs and its interaction with ox-LDL.

METHODS

RNA sequencing was used to detect transcriptome changes of VSMCs treated with ox-LDL. miR-183-5p and FOXO1 expression levels in VSMCs after ox-LDL treatment were assessed using qRT-PCR and western blotting. The regulatory effect of miR-183-5p on FOXO1 has been tried to prove using a dual-luciferase reporter assay. The functions of miR-183-5p, and FOXO1 were analyzed by CCK-8 assay and flow cytometry assay. The tissue samples or serum samples of high fat-feeding mice and carotid atherosclerosis patients were collected, and the levels of miR-183-5p/FOXO1 were analyzed.

RESULTS

RNA sequencing data showed 81 miRNAs including miR-183-5p was significantly changed after ox-LDL treatment in VSMCs. FOXO1, a miR-183-5p's potential target, was also down-regulated in ox-LDL treated cells. qRT-PCR and western blot found that expression of FOXO1 mRNA and protein significantly reduced in VSMCs treated with ox-LDL, accompanied by overexpression of miR-183-5p. miR-183-5p inhibited FOXO1 mRNA by binding to its 3' UTR. Interference miR-183-5p/FOXO1 could change proliferation/apoptosis imbalance in VSMCs under ox-LDL stimulation. Higher levels of miR-183-5p but reduced FOXO1 can be found in the thoracic aorta tissues of high fat-feeding mice. In serum samples from individuals with carotid atherosclerosis, Higher levels of miR-183-5p were observed. the miR-183-5p level was positively related to the level of serum ox-LDL in patients.

CONCLUSIONS

Aberrant expression of miR-183-5p/FOXO1 pathway mediated ox-LDL-induced proliferation/apoptosis imbalance in VSMCs. The miR-183-5p/FOXO1 axis can potentially be utilized as the target in the treatment of patients with atherosclerosis.

miR-222-5p promotes dysfunction of human vascular smooth muscle cells by targeting RB1

BACKGROUND

Coronary atherosclerosis (AS) is characterized by the formation of plaque in the vessel wall. The structural and functional changes of vascular smooth muscle cells (VSMCs) can promote plaque formation and induce plaque instability.

OBJECTIVE

To investigate the functions and mechanism of miR-222-5p in VSMCs under the treatment of oxidized low-density lipoprotein (ox-LDL).

METHODS

miR-222-5p expression in ox-LDL-treated VSMCs and the serum of Apolipoprotein E (ApoE) knockout mice was detected by reverse transcription quantitative polymerase chain reaction. The viability and migration of VSMCs were detected by Cell Counting Kit-8 and Transwell assays. Protein levels of proliferation and migration-related factors were evaluated by western blotting. Luciferase reporter assays were performed to explore the binding between miR-222-5p and retinoblastoma susceptibility protein (RB1) gene in VSMCs. ApoE-knockout mice were infected with the lentivirus inhibiting miR-222-5p expression to explore the effect of miR-222-5p on pathological changes. Hematoxylin and eosin (H&E) staining, trichrome staining, and Oil Red O staining were conducted to determine the necrotic core area and atherosclerotic lesion size in the ascending aorta of ApoE-knockout mice.

RESULTS

With the accumulation of ox-LDL concentration and treatment time, miR-222-5p expression was gradually upregulated in VSMCs. Similarly, miR-222-5p expression was increased in the serum of ApoE-knockout mice. miR-222-5p knockdown inhibited the proliferative and migratory abilities of ox-LDL-treated VSMCs, and the inhibitory effect on cellular behaviors was then significantly reversed by co-knockdown of RB1. RB1 is a downstream target gene of miR-222-5p, and miR-222-5p bound with 3'-untranslated region of RB1 in VSMCs. We further confirmed that miR-222-5p knockdown alleviated pathological changes and inhibited lipid deposition in the serum of ApoE-knockout mice in vivo.

CONCLUSION

miR-222-5p accelerates the dysfunction of VSMCs and promotes pathological changes and lipid deposition in ApoE-knockout mice by targeting RB1. The study may provide novel therapeutic targets for AS.

Relationships between Indicators of Lower Extremity Artery Disease and miRNA Expression in Peripheral Blood Mononuclear Cells

Lower extremity artery disease (LEAD) is an underdiagnosed and globally underestimated vascular disease caused by the progressive and chronic formation of atherosclerotic plaques in the arteries of the lower limbs. Much evidence indicates that the abnormal course of pathophysiological processes underlying LEAD development is associated with altered miRNA modulatory function. In the presented study, relationships between miRNA expression and clinical indicators of this disease (ABI, claudication distance, length of arterial occlusion, Rutherford category, and plaque localization) were identified. MiRNA expression profiles were obtained using next-generation sequencing in peripheral blood mononuclear cells (PBMCs) of 40 LEAD patients. Correlation analysis performed using the Spearman rank correlation test revealed miRNAs related to ABI, claudication distance, and length of arterial occlusion. In the DESeq2 analysis, five miRNAs were found to be dysregulated in patients with Rutherford category 3 compared to patients with Rutherford category 2. No miRNAs were found to be differentially expressed between patients with different plaque localizations. Functional analysis performed using the miRNet 2.0 website tool determined associations of selected miRNAs with processes underlying vascular pathology, such as vascular smooth muscle cell differentiation, endothelial cell apoptosis, response to hypoxia, inflammation, lipid metabolism, and circadian rhythm. The most enriched functional terms for genes targeted by associated miRNAs were linked to regulation of the cell cycle, regulation of the transcription process, and nuclear cellular compartment. In conclusion, dysregulations of miRNA expression in PBMCs of patients with LEAD are indicative of the disease and could potentially be used in the prediction of LEAD progression.

Pregnancy-associated plasma protein-A (PAPPA) promotes breast cancer progression

Breast cancer is the most common malignancy in females and poses a significant health threat to women. Pregnancy-associated plasma protein-A (PAPPA) is highly expressed in pregnancy-associated breast cancer (PABC) tissues. In this study, we investigated the functional role of PAPPA in regulating the malignant phenotype of breast cancer. We first examined the expression level of PAPPA in PABC tissue and breast cancer cell lines using quantitative real-time polymerase-chain reaction (qRT-PCR) and western blot. Next, the functional role of PAPPA in breast cancer cells was validated by overexpression and knockdown experiments. Cell counting kit-8 (CCK-8) proliferation assay, 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay, wound healing and transwell invasion assay were used to examine cell proliferation, migration, and invasion ability. We further identified the microRNA target regulating PAPPA and studied its functional role. Finally, we examined the impact of PAPPA on the tumorigenesis and metastasis of breast cancer in mice model. Our study revealed that PAPPA was upregulated in PABC tissues and breast cancer cells. Overexpression of PAPPA promoted cell proliferation, motility, invasion, and epithelial-mesenchymal transition (EMT). We further identified miR-497-5p as a negative regulator of PAPPA, which suppressed cell proliferation, migration, invasion, and EMT in breast cancer cells. We also validated the oncogenic role of PAPPA in the mouse xenograft model. Collectively, our study suggests that PAPPA is an oncogenic protein highly expressed in PABC tissues and promotes breast cancer progression, which could serve as a novel therapeutic target for breast cancer.

A novel circUBR4/miR-491-5p/NRP2 ceRNA network regulates oxidized low-density lipoprotein-induced proliferation and migration in vascular smooth muscle cells

ABSTRACT

Vascular smooth muscle cells (VSMCs) play critical roles in the progression of atherosclerosis. Circular RNA (circRNA) ubiquitin protein ligase E3 component n-recognin 4 (circUBR4) has been shown to regulate VSMC migration and proliferation. Here, we sought to identify the mechanism in the regulation of circUBR4. CircUBR4, microRNA (miR)-491-5p and Neuropilin-2 (NRP2) were quantified by quantitative real-time PCR (qRT-PCR) and western blot. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) and 5-Ethynyl-2'-Deoxyuridine (EDU) assays. Cell migration was examined by wound-healing and transwell invasion assays. The direct relationship between miR-491-5p and circUBR4 or NRP2 was validated by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Our data indicated that in VSMCs, ox-LDL induced circUBR4 expression. Silencing endogenous circUBR4 attenuated VSMC proliferation and migration induced by ox-LDL. Mechanistically, circUBR4 targeted miR-491-5p by pairing to miR-491-5p. Moreover, miR-491-5p was identified as a downstream mediator of circUBR4 function in ox-LDL-treated VSMCs. NRP2 was a direct target of miR-491-5p, and circUBR4 acted as a competing endogenous RNA (ceRNA) for miR-491-5p to regulate NRP2 expression. Additionally, NRP2 was a functionally downstream effector of miR-491-5p in regulating ox-LDL-evoked VSMC proliferation and migration. Our findings identify a new ceRNA network, the circUBR4/miR-491-5p/NRP2 axis, for the regulation of circUBR4 in VSMC migration and proliferation.

Downregulation of microRNA-512-3p enhances the viability and suppresses the apoptosis of vascular endothelial cells, alleviates autophagy and endoplasmic reticulum stress as well as represses atherosclerotic lesions in atherosclerosis by adjusting spliced/unspliced ratio of X-box binding protein 1 (XBP-1S/XBP-1U)

AS is an important pathological basis of cardiovascular disease. It has been reported that miRNAs are involved in almost all steps of AS, including the injury and dysfunction of endothelial cells and vascular smooth muscle cells. This work was designed to elucidate the biological functions of miR-512-3p in the pathological process of AS and probe into the underlying molecular mechanism. In the present work, ox-LDL-treated HUVECs served as the in vitro model of AS and ApoE-/- mice were nourished with a high-fat diet to establish an in vivo model of AS. Proliferation, apoptosis and migration of HUVECs were evaluated by performing CCK-8, TUNEL staining, western blot and transwell assays. Immunofluorescence examined LC3 expression and levels of autophagy-related and ER stress-related proteins were determined by western blot assay. In addition, starBase predicted the complementary binding sites of XBP-1 to miR-512-3p and luciferase reporter assay confirmed the interaction between miR-512-3p and XBP-1. Moreover, H&E staining was employed to evaluate atherosclerotic lesions in AS model mice. Results revealed that ox-LDL treatment decreased the proliferative and migrative activities and promoted the apoptosis of HUVECs as well as induced autophagy and ER stress, which were abrogated by miR-512-3p silencing. Importantly, ox-LDL treatment elevated miR-512-3p expression and XBP-1 was a direct target of miR-512-3p. Mechanistically, knockdown of miR-512-3p enhanced the viability, suppressed the apoptosis and promoted the migration of ox-LDL-treated HUVECs, alleviated atherosclerotic lesions in AS model mice as well as repressed autophagy and ER stress by targeting XBP-1 to manipulate the ratio of XBP-1S/XBP-1U.

LncRNA APOA1-AS facilitates proliferation and migration and represses apoptosis of VSMCs through TAF15-mediated SMAD3 mRNA stabilization

Coronary atherosclerosis (CAS) is a major cause of cardiovascular disease. Long non-coding RNAs (lncRNAs) have been implicated as novel biomarkers in coronary artery disease (CAD). APOA1 antisense RNA (APOA1-AS) was proven to show high expression during atherosclerotic development, but no report has uncovered the detailed mechanism of APOA1-AS in CAS. Thus, this paper aims to explore the role of APOA1-AS in CAS. Vascular smooth muscle cells (VSMCs) were treated with oxidized low-density lipoprotein (ox-LDL) to mimic atherosclerosis-like injury. Quantitative real-time PCR (RT-qPCR) and western blot analysis analyzed gene expression. Cell counting kit-8 (CCK-8), wound healing assay, and flow cytometry were implemented to assess the function of APOA1-AS in modulating pathological phenotype of VSMCs. Results demonstrated that APOA1-AS was notably up-regulated in ox-LDL treated VSMCs (ox-LDL-VSMCs). The deficiency of APOA1-AS hindered proliferation and migration and stimulated apoptosis in ox-LDL-VSMCs. Mechanistically, APOA1-AS recruited TATA-box binding protein associated factor 15 (TAF15) protein to stabilized SMAD family member 3 (SMAD3) mRNA and activate the TGF-β/SMAD3 signaling pathway. In conclusion, APOA1-AS contributed to proliferation and migration and repressed apoptosis of VSMCs through TAF15-mediated SMAD3 mRNA stabilization, indicating that APOA1-AS could be a promising target for CAS.

Neuroprotective effect of miR-204-5p downregulation against isoflurane-induced learning and memory impairment via targeting EphB2 and inhibiting neuroinflammation

BACKGROUND

Isoflurane, one of the most commonly used inhalational anesthetics, is usually used in surgery patients and often causes long-term learning and memory impairment. The aim of this study was to explore the role of microRNA-204-5p (miR-204-5p) in isoflurane-induced learning and memory impairment in rats.

METHODS

The Morris Water Maze (MWM) test was used to estimate the spatial learning and memory abilities of laboratory rats. Enzyme-linked immunosorbent assay (ELISA) was used to determine interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) concentrations in the hippocampal tissues. The expression level of miR-204-5p was determined by using quantitative reverse transcription polymerase chain reaction (qRT-PCR). The potential target genes of miR-204-5p were predicted and verified by the TargetScan and dual-luciferase reporter assay, respectively.

RESULTS

Isoflurane-induced rats showed significantly higher neurological function scores, higher escape latency and shorter time spent in the original quadrant. Isoflurane could significantly induce neuroinflammation, and the expression of miR-204-5p was increased in the hippocampal tissue of rats exposed to isoflurane. Moreover, downregulation of miR-204-5p attenuated the effect of isoflurane treatment on the escape latency and the time in the original quadrant, and inflammatory cytokines level was downregulated by inhibiting the expression of miR-204-5p. EphB2 was verified as a direct target gene of miR-204-5p.

CONCLUSION

Downregulated miR-204-5p exerts protective effects against isoflurane-induced learning and memory impairment via targeting EphB2 and inhibiting neuroinflammation. MiR-204-5p could serve as a potential therapeutic target for the lightening of cognitive dysfunction induced by isoflurane.