Circ_0004872 promotes platelet-derived growth factor-BB-induced proliferation, migration and dedifferentiation in HA-VSMCs via miR-513a-5p/TXNIP axis.

The proliferation, migration and dedifferentiation of vascular smooth muscle cells (VSMCs) exert crucial roles in atherosclerosis (AS) progression. The aim of our study was to explore the influences of circular RNA 0004872 (circ_0004872) in platelet-derived growth factor-BB (PDGF-BB)-induced AS cell model and investigate the underlying mechanisms. Real-time quantitative polymerase chain reaction (RT-qPCR) was implemented for the expression detection of circ_0004872, mitogen-activated protein kinase 1 (MAPK1) messenger RNA (mRNA), microRNA-513a-5p (miR-513a-5p) and thioredoxin interacting protein (TXNIP). Cell proliferation was analyzed via Cell Counting Kit 8 (CCK8) assay. Cell migration was assessed via wound healing assay and transwell migration assay. Western blot assay was used to measure the expression of alpha smooth muscle actin (α-SMA), osteopontin (OPN), calponin and TXNIP. Dual-luciferase reporter assay and RNA-pull down assay were used for confirmation of interaction between miR-513a-5p and circ_0004872 or TXNIP. Circ_0004872 expression was elevated in PDGF-BB-induced human aortic vascular smooth muscle cells (HA-VSMCs) and carotid plaque tissues. Circ_0004872 silencing alleviated PDGF-BB-induced proliferation, migration and dedifferentiation in HA-VSMCs. MiR-513a-5p bound to circ_0004872, and circ_0004872 knockdown-induced effects in PDGF-BB-treated HA-VSMCs were largely attenuated by the silencing of miR-513a-5p. MiR-513a-5p bound to the 3' untranslated region (3'UTR) of TXNIP, and miR-513a-5p overexpression-mediated effects were counteracted by the transfection of pcDNA-TXNIP in PDGF-BB-induced HA-VSMCs. TXNIP was modulated by circ_0004872/miR-513a-5p signaling cascade in HA-VSMCs. Circ_0004872 accelerated PDGF-BB-induced proliferation, migration and dedifferentiation in HA-VSMCs through enhancing TXNIP level via sponging miR-513a-5p.

Fan K ，Ruan X ，Wang L ，Lu W ，Shi Q ，Xu Y ... -  《-》

Hsa_circ_0032389 Enhances Proliferation and Migration in PDGF-BB-Induced Human Aortic Vascular Smooth Muscle Cells.

Circular RNA (circRNAs) has been confirmed to participate in atherosclerosis (AS) progression. However, the role and mechanism of hsa_circ_0032389 in AS process still need to be further revealed. This study evaluates the role and mechanism of hsa_circ_0032389 in AS process. Platelet-derived growth factor-BB (PDGF-BB) was used to induce human aortic vascular smooth muscle cells (HA-VSMCs). The expression levels of hsa_circ_0032389, microRNA (miR)-513a-5p, and fibroblast growth factor receptor substrate 2 (FRS2) were examined by quantitative real-time PCR. Cell proliferation and migration were analyzed using cell counting kit 8 assay, flow cytometry, EdU assay, transwell assay, and wound healing assay. Protein expression was assessed using western blot analysis. Dual-luciferase reporter and RIP assays were used to confirm RNA interaction. Hsa_circ_0032389 was overexpressed in PDGF-BB-induced HA-VSMCs, and its downregulation inhibited HA-VSMC viability, cell cycle, EdU positive cell rate, migratory cell number, and wound closure rate under PDGF-BB treatment. The luciferase activity of hsa_circ_0032389wt could be reduced by miR-513a-5p mimic, and both hsa_circ_0032389 and miR-513a-5p were enriched in anti-Ago2, confirming that miR-513a-5p could be sponged by hsa_circ_0032389. MiR-513a-5p inhibitor reversed the effect of hsa_circ_0032389 knockdown on PDGF-BB-induced HA-VSMC viability, cell cycle, EdU positive cell rate, migratory cell number, and wound closure rate. Moreover, the luciferase activity of FRS2wt was reduced by miR-513a-5p mimic, and both FRS2 and miR-513a-5p were enriched in anti-Ago2, verifying that FRS2 was targeted by miR-513a-5p. MiR-513a-5p suppressed PDGF-BB-induced HA-VSMC viability, cell cycle, EdU positive cell rate, migratory cell number, and wound closure rate by targeting FRS2. Our results indicated that hsa_circ_0032389 enhanced PDGF-BB-induced HA-VSMC proliferation and migration via regulating miR-513a-5p/FRS2 axis.

Qian H ，Ma S ，Zhou Q ，Lei C ... -  《-》

Circ_CHFR Promotes Platelet-Derived Growth Factor-BB-Induced Proliferation, Invasion, and Migration in Vascular Smooth Muscle Cells via the miR-149-5p/NRP2 Axis.

Circular RNA checkpoint with forkhead and ring finger domains (circ_CHFR) were reported to regulate vascular smooth muscle cell (VSMC) dysfunction during atherosclerosis (AS). However, the molecule mechanism of circ_CHFR in AS remains largely unclear. Human VSMCs (HVSMCs) were exposed to platelet-derived growth factor-BB (PDGF-BB) in vitro. Levels of circ_CHFR, microRNA (miR)-149-5p, and neuropilin 2 (NRP2) were determined using quantitative real-time polymerase chain reaction and western blot. Cell proliferation, migration, and invasion were analyzed using cell counting kit-8, colony formation, flow cytometry, wound healing, and transwell assays. The binding interaction between miR-149-5p and circ_CHFR or NRP2 was investigated using the dual-luciferase reporter and RNA immunoprecipitation assays. Circ_CHFR was elevated in PDGF-BB-induced HVSMCs in a dose-independent manner. Silencing of circ_CHFR reversed PDGF-BB-evoked promotion of cell proliferation, migration and invasion, as well as suppression of cell apoptosis in HVSMCs. Mechanistically, circ_CHFR directly bound to miR-149-5p, and miR-149-5p inhibition attenuated the effects of circ_CHFR knockdown on PDGF-BB-induced HVSMCs. Besides, NRP2 was confirmed to be a target of miR-149-5p, and circ_CHFR could regulate NRP2 expression through sponging miR-149-5p. Moreover, miR-149-5p overexpression abolished PDGF-BB-triggered enhancement of cell proliferation, migration, and invasion by targeting NRP2. Circ_CHFR promoted the proliferation, invasion, and migration of PDGF-BB-induced HVSMCs through miR-149-5p/NRP2 axis, providing a new insight into the pathogenesis of AS and a potential therapeutic target for AS treatment.

Wang M ，Li C ，Cai T ，Zhang A ，Cao J ，Xin H ... -  《-》

Hsa_circ_0031891 targets miR-579-3p to enhance HMGB1 expression and regulate PDGF-BB-induced human aortic vascular smooth muscle cell proliferation, migration, and dedifferentiation.

Atherosclerosis (AS) is an underlying cause of the majority of coronary artery disease (CAD), in which proliferation, migration, and dedifferentiation of vascular smooth muscle cells (VSMCs) exert vital roles. It has been reported that circular RNAs (circRNAs) are associated with the VSMCs function. Here, we undertook to explore the biological function and mechanism of hsa_circ_0031891 in a platelet-derived growth factor-BB (PDGF-BB)-induced AS cell model. Hsa_circ_0031891 and microRNA-579-3p (miR-579-3p) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation and migration were detected using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), wound healing, and transwell assay. Protein levels of alpha-smooth muscle actin (α-SMA), smooth muscle protein 22-α (SM22-α), Osteopontin, and High mobility group box-1 (HMGB1) were determined using western blot assay. After predicting via a variety of bioinformatics software, the binding between miR-579-3p and hsa_circ_0031891 or HMGB1 was validated using dual-luciferase reporter and RNA pull-down assays. Increased hsa_circ_0031891 and HMGB1 and reduced miR-579-3p were found in CAD patients and PDGF-BB-induced human aortic vascular smooth muscle cells (HA-VSMCs). Moreover, hsa_circ_0031891 deficiency relieved PDGF-BB-mediated HA-VSMC proliferation, migration, and dedifferentiation. Mechanically, hsa_circ_0031891 modulated HMGB1 expression via sponging miR-579-3p. Hsa_circ_0031891 boosted PDGF-BB-induced proliferation, migration, and dedifferentiation partly by regulating the miR-579-3p/HMGB1 axis, hinting at a feasible therapeutic strategy for AS.

Wang L ，Li H ，Zheng Z ，Li Y ... -  《-》

Circ_0002984 Enhances Growth, Invasion, and Migration in PDGF-bb-Induced Vascular Smooth Muscle Cells Through miR-379-5p/FRS2 Axis.

The accumulation of vascular smooth muscle cells (VSMCs) is considered to play important roles in atherosclerosis (AS) development and progression. Circ_0002984 was found to be increased in oxidized low-density lipoprotein (ox-LDL) human VSMCs (HVSMCs). However, the function and mechanism of circ_0002984 in VSMC dysfunction remain unknown. In this study, the expression of circ_0002984, microRNA (miR)-379-5p, and fibroblast growth factor receptor substrate 2 (FRS2) was detected using quantitative real-time polymerase chain reaction and western blot. Cell proliferation, cell cycle, migration, and invasion were detected using Cell Counting Kit-8, flow cytometry, and transwell assays. The binding interaction between miR-379-5p and circ_0002984 or FRS2 was confirmed by the dual-luciferase reporter assay. Collectively, this study found that circ_0002984 was elevated in platelet-derived growth factor type bb (PDGF-bb)-induced HVSMCs. Circ_0002984 knockdown abrogated PDGF-bb-induced proliferation, migration, and invasion in HVSMCs. Mechanistically, circ_0002984 was confirmed to target miR-379-5p, and miR-379-5p upregulation reversed the protective effects of circ_0002984 knockdown on PDGF-bb-induced HVSMCs. Besides, when FRS2 was a target of miR-379-5p, miR-379-5p restoration abolished PDGF-bb-evoked HVSMC dysfunction, which was attenuated by the overexpression of FRS2. Moreover, circ_0002984 could regulate FRS2 expression through sponging miR-379-5p in HVSMCs. Collectively, these results demonstrated that circ_0002984 promoted PDGF-bb-induced VSMC proliferation, migration, and invasion through the regulation of miR-379-5p/FRS2 axis, suggesting a new insight into the pathogenesis of AS and the potential application of circ_0002984 in AS treatment.

Zheng X ，Liu J ，Gong X ，Zhang X ，Ma S ... -  《-》