BACKGROUND: The main cause of restenosis after percutaneous transluminal angioplasty (PTA) is the excessive proliferation and migration of vascular smooth muscle cells (VSMCs). Lin28a has been reported to play critical regulatory roles in this process. However, whether CCAAT/enhancer-binding proteins β (C/EBPβ) binds to the Lin28a promoter and drives the progression of restenosis has not been clarified. Therefore, in the present study, we aim to clarify the role of C/EBPβ-Lin28a axis in restenosis. METHODS: Restenosis and atherosclerosis rat models of type 2 diabetes ( n   =  20, for each group) were established by subjecting to PTA. Subsequently, the difference in DNA methylation status and expression of C/EBPβ between the two groups were assessed. EdU, Transwell, and rescue assays were performed to assess the effect of C/EBPβ on the proliferation and migration of VSMCs. DNA methylation status was further assessed using Methyltarget sequencing. The interaction between Lin28a and ten-eleven translocation 1 (TET1) was analysed using co-immunoprecipitation (Co-IP) assay. Student's t -test and one-way analysis of variance were used for statistical analysis. RESULTS: C/EBPβ expression was upregulated and accompanied by hypomethylation of its promoter in restenosis when compared with atherosclerosis. In vitroC/EBPβ overexpression facilitated the proliferation and migration of VSMCs and was associated with increased Lin28a expression. Conversely, C/EBPβ knockdown resulted in the opposite effects. Chromatin immunoprecipitation assays further demonstrated that C/EBPβ could directly bind to Lin28a promoter. Increased C/EBPβ expression and enhanced proliferation and migration of VSMCs were observed after decitabine treatment. Further, mechanical stretch promoted C/EBPβ and Lin28a expression accompanied by C/EBPβ hypomethylation. Additionally, Lin28a overexpression reduced C/EBPβ methylation via recruiting TET1 and enhanced C/EBPβ-mediated proliferation and migration of VSMCs. The opposite was noted in Lin28a knockdown cells. CONCLUSION Our findings suggest that the C/EBPβ-Lin28a axis is a driver of restenosis progression, and presents a promising therapeutic target for restenosis.
Animals ; Cell Proliferation/genetics* ; Cell Movement/genetics* ; Muscle, Smooth, Vascular/metabolism* ; Rats ; DNA Methylation/physiology* ; CCAAT-Enhancer-Binding Protein-beta/genetics* ; Male ; Myocytes, Smooth Muscle/cytology* ; Rats, Sprague-Dawley ; RNA-Binding Proteins/genetics* ; Cells, Cultured ; Coronary Restenosis/metabolism*

Objective To explore the role and mechanism of mammalian target of rapamycin (mTOR) in oxidized low-density lipoprotein (oxLDL)-induced ferroptosis in vascular smooth muscle cells (VSMCs). Methods A model of oxLDL-induced VSMC ferroptosis was established. VSMCs were co-treated with either the mTOR inhibitor rapamycin or the autophagy inducer carbonyl cyanide m-chlorophenylhydrazone (CCCP), followed by detection of autophagy and ferroptosis-related indexes. Quantitative real-time PCR and Western blot were used respectively to analyze the expression of mTOR, glutathione peroxidase 4 (GPX4), sequestosome 1 (p62), and microtubule-associated protein 1 light chain 3 (LC3). Flow cytometry was employed to assess VSMC death. C11 BODIPY fluorescent staining was used to measure cellular lipid peroxidation levels. Colorimetric assays were performed to determine the contents of malondialdehyde (MDA), ferrous ion (Fe²⁺) and glutathione (GSH). Results oxLDL significantly upregulated mTOR expression in VSMCs, while increasing p62 expression and reducing LC3 expression, thereby suppressing VSMC autophagy. Compared with oxLDL treatment alone, rapamycin co-treatment reversed oxLDL-induced VSMC ferroptosis, as characterized by reduced VSMC death, increased GPX4 expression and GSH contents, along with decreased MDA content, Fe²⁺ content and lipid peroxidation levels. Similarly, CCCP co-treatment activated autophagy characterized by reduced p62 expression and elevated LC3 expression, which subsequently alleviated oxLDL-induced ferroptosis, showing reduced VSMC death, increased GPX4 expressions and GSH contents, and decreased MDA content, Fe²⁺ content and lipid peroxidation levels. Moreover, mTOR inhibition by rapamycin significantly reversed the oxLDL-induced upregulation of p62 and downregulation of LC3. Conclusion mTOR may promote oxLDL-induced VSMC ferroptosis by suppressing autophagy.
Ferroptosis/drug effects* ; Lipoproteins, LDL/metabolism* ; TOR Serine-Threonine Kinases/physiology* ; Autophagy/drug effects* ; Muscle, Smooth, Vascular/metabolism* ; Animals ; Rats ; Myocytes, Smooth Muscle/cytology* ; Cells, Cultured ; Lipid Peroxidation/drug effects* ; Sequestosome-1 Protein/genetics* ; Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism* ; Microtubule-Associated Proteins/genetics* ; Sirolimus/pharmacology*

OBJECTIVES: To investigate the synergistic mechanism of the traditional Chinese medicine Rosa laevigata Michx. (RLM) for treatment of pulmonary arterial hypertension (PAH). METHODS: Network pharmacological analysis was carried out to screen the active ingredients of RLM and PAH disease targets and construct the "component-target-disease" interaction network, followed by gene enrichment analysis and molecular docking studies. In the cell experiments, primary cultures of rat pulmonary arterial smooth muscle cells were exposed to hypoxia for 24 h and treated with solvent or 100, 200 and 300 mg/mL RLM, and the changes in cell proliferation were detected using Western blotting for PCNA and immunofluorescence staining. In the animal experiment, male SD rats were randomized into 5 control group, monocrotaline (MCT) solvent group, and MCT with RLM (100, 200 and 300 mg/mL) treatment groups. HE staining and immunofluorescence staining were used to observe histopathological changes in the pulmonary blood vessels of the rats. RESULTS: Seven core active ingredients (including β-sitosterol and kaempferol) in RLM and 39 key disease targets were identified, and molecular docking showed that SRC was a high-affinity target. KEGG enrichment analysis showed that the differential genes were significantly enriched in calcium signaling and PI3K-AKT pathways. In rat pulmonary arterial smooth muscle cells, hypoxic exposure significantly up-regulated cellular expression of PCNA and phosphorylation levels of Src and AKT1, which were obviously lowered by RLM treatment. In RLM-treated rat models, the mean pulmonary artery pressure and right ventricular hypertrophy index (Fulton index) were significantly reduced, the tricuspid annular plane systolic excursion (TAPSE) was improved, and pulmonary vascular wall thickening and fibrosis were obviously ameliorated. CONCLUSIONS RLM inhibits pulmonary arterial smooth muscle cell proliferation in rat models of hypertension possibly by regulating the Src-AKT1 axis, suggesting the potential of RLM as a new natural drug for treatment of pulmonary hypertension.
Animals ; Cell Proliferation/drug effects* ; Proto-Oncogene Proteins c-akt/metabolism* ; Rats, Sprague-Dawley ; Pulmonary Artery/cytology* ; Male ; Rats ; Myocytes, Smooth Muscle/cytology* ; Hypertension, Pulmonary/pathology* ; Drugs, Chinese Herbal/pharmacology* ; Signal Transduction/drug effects* ; Muscle, Smooth, Vascular/cytology* ; src-Family Kinases/metabolism* ; Cells, Cultured

OBJECTIVES: To investigate the mechanism of DDX17 for regulating proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) during the development of pulmonary hypertension (PH). METHODS: In murine PASMCs cultured under normoxic or hypoxic conditions, the effects of transfection with si-Ddx17 and insulin treatment, alone or in combination, on cell proliferation and migration were evaluated using Ki-67 immunofluorescence staining, scratch assay and Transwell assay. Western Blotting was performed to detect the changes in protein expression levels of DDX17, 4EBP1, S6, p-4EBP1, and p-S6. In a mouse model of PH induced by intraperitoneal injection of monocrotaline (MCT), the changes in pulmonary vasculature were examined using HE staining following tail vein injection of AD-Ddx17i. RESULTS: The PASMCs in hypoxic culture exhibited significantly enhanced cell proliferation and migration and protein expressions of p-4EBP1 and p-S6, and these changes were obviously reversed by transfection with si-Ddx17. Treatment with insulin significantly attenuated the effect of si-Ddx17 against hypoxic exposure-induced changes in PASMCs. In the mouse model of MCT-induced PH, transfection with AD-Ddx17i obviously alleviated pulmonary vascular stenosis and intimal hyperplasia. CONCLUSIONS The expression of DDX17 is elevated in hypoxia-induced PASMCs and PH mice, and silencing DDX17 significantly inhibits PASMC proliferation and migration in vitro and pulmonary vascular remodeling in PH mice by reducing mTORC1 activity.
Animals ; Cell Proliferation ; Cell Movement ; DEAD-box RNA Helicases/metabolism* ; Myocytes, Smooth Muscle/metabolism* ; Mice ; Pulmonary Artery/cytology* ; Hypertension, Pulmonary/metabolism* ; Mechanistic Target of Rapamycin Complex 1 ; Cells, Cultured ; Muscle, Smooth, Vascular/cytology*

Renin-angiotensin system (RAS) is involved in the regulation of vascular smooth muscle cell (VSMC) tension. Angiotensin II (Ang II) as the main effector molecule of RAS can increase the intracellular Ca concentration and cause VSMCs contraction by activating angiotensin II type 1 receptor (AT1R). The large-conductance Ca- and voltage-activated potassium (BK) channel is an essential potassium channel in VSMCs, playing an important role in maintaining membrane potential and intracellular potassium-calcium balance. The BK channel in VSMCs mainly consists of α and β1 subunits. Functional BKα subunits contain voltage-sensors and Ca binding sites. Hence, increase in the membrane potential or intracellular Ca concentration can trigger the opening of the BK channel by mediating transient K outward current in a negative regulatory manner. However, increasing evidence has shown that although Ang II can raise the intracellular Ca concentration, it also inhibits the expression and function of the BK channel by activating the PKC pathway, internalizing AT1R-BKα heterodimer, or dissociating α and β1 subunits. Under some specific conditions, Ang II can also activate the BK channel, but the underlying mechanism remains unknown. In this review, we summarize the potential mechanisms underlying the inhibitory or activating effect of Ang II on the BK channel, hoping that it could provide a theoretical basis for improving intracellular ion imbalance.
Angiotensin II ; physiology ; Calcium ; physiology ; Humans ; Large-Conductance Calcium-Activated Potassium Channels ; physiology ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; physiology ; Renin-Angiotensin System

Vascular smooth muscle cells (VSMC) are the main cellular component of vessel wall. The changes of VSMC functions including phenotypic transformation and apoptosis play a critical role in the pathogenesis of intracranial aneurysm (IA). Autophagy can participate in the regulation of vascular function by regulating cell function. In the initial stage of IA, the activation of autophagy can accelerate the phenotypic transformation of VSMC and inhibit VSMC apoptosis. With the progress of IA, the relationship between autophagy and apoptosis changes from antagonism to synergy or promotion, and a large number of apoptotic VSMC lead to the rupture of IA. In this review, we describe the role of autophagy regulating the function of VSMC in the occurrence, development and rupture of IA, for further understanding the pathogenesis of IA and finding molecular targets to prevent the formation and rupture of IA.
Autophagy ; Humans ; Intracranial Aneurysm ; pathology ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology

OBJECTIVE: To investigate the effect of rosuvastatin on homocysteine (Hcy) induced mousevascular smooth muscle cells(VSMCs) dedifferentiation and endoplasmic reticulum stress(ERS). METHODS: VSMCs were co-cultured with Hcy and different concentration of rosuvastatin (0.1, 1.0 and 10 μmol/L). Cytoskeleton remodeling, VSMCs phenotype markers (smooth muscle actin-α, calponin and osteopontin) and ERS marker mRNAs (Herpud1, XBP1s and GRP78) were detected at predicted time. Tunicamycin was used to induce, respectively 4-phenylbutyrate(4-PBA) inhibition, ERS in VSMCs and cellular migration, proliferation and expression of phenotype proteins were analyzed. Mammalian target of rapamycin(mTOR)-P70S6 kinase (P70S6K) signaling agonist phosphatidic acid and inhibitor rapamycin were used in Rsv treated VSMCs. And then mTOR signaling and ERS associated mRNAs were detected. RESULTS: Compared with Hcy group, Hcy+ Rsv group (1.0 and 10 μmol/L) showed enhanced α-SMA and calponin expression (<0.01), suppressed ERS mRNA levels (<0.01) and promoted polarity of cytoskeleton. Compared with Hcy group, Hcy+Rsv group and Hcy+4-PBA group showed suppressed proliferation, migration and enhanced contractile protein expression (<0.01); while tunicamycin could reverse the effect of Rsv on Hcy treated cells. Furthermore, alleviated mTOR-P70S6K phosphorylation and ERS (<0.01)were observed in Hcy+Rsv group and Hcy+rapamycin group, compared with Hcy group; while phosphatidic acid inhibited the effect of Rsv on mTOR signaling activation and ERS mRNA levels (<0.01). CONCLUSIONS Rosuvastatin could inhibit Hcy induced VSMCs dedifferentiation suppressing ERS, which might be regulated by mTOR-P70S6K signaling.
Actins ; metabolism ; Animals ; Calcium-Binding Proteins ; metabolism ; Cell Dedifferentiation ; drug effects ; Cells, Cultured ; Endoplasmic Reticulum Stress ; drug effects ; Heat-Shock Proteins ; metabolism ; Homocysteine ; Membrane Proteins ; metabolism ; Mice ; Microfilament Proteins ; metabolism ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; drug effects ; Ribosomal Protein S6 Kinases, 70-kDa ; metabolism ; Rosuvastatin Calcium ; pharmacology ; TOR Serine-Threonine Kinases ; metabolism ; X-Box Binding Protein 1 ; metabolism

Autophagy plays a crucial role in maintaining normal structure and vascular function in vivo. When stress-relevant stimuli are involved, the increases of autophagy can protect vascular smooth muscle cells, promote cell survival, and phenotype transformation, as well as reduce calcification. On the contrary, the decrease of autophagy can accelerate cell senescence, resulting in structural changes and dysfunction of vasomotor and vasodilation. However, excessive activation of autophagy can induce the damage of the healthy protein and essential organelles, and even lead to autophagic cell death, accelerating the progression of vascular disease. Thus, the precise targeting of autophagy opens a novel way for treatment of vascular diseases.
Autophagy ; physiology ; Cell Survival ; Cellular Senescence ; Disease Progression ; Humans ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; physiology ; Vascular Diseases ; pathology ; therapy

The present study was to investigate the role of TRPC6 in pulmonary artery smooth muscle cells (PASMCs) proliferation and apoptosis under hypoxia and hypercapnia. PASMCs were isolated from chloral hydrate-anesthetized male Sprague-Dawley (SD) rats. Cellular purity was assessed by immunofluorescence staining for smooth muscle α-actin under fluorescence microscopy. Passage 4-6 PASMCs were starved for 24 h in serum-free DMEM and divided into 5 groups randomly: normoxia, hypoxia and hypercapnia, DMSO, TRPC6 inhibitor SKF-96365 and TRPC6 activator OAG groups. The normoxic group was incubated under normoxia (5% CO, 21% O, 37 °C) for 24 h, and the others were incubated with corresponding drugs under hypoxic and hypercapnic (6% CO, 5% O, 37 °C) atmosphere for 24 h. TRPC6 mRNA was detected by reverse transcription-PCR. TRPC6 protein was detected by Western blotting. The proliferation of PASMCs was performed by CCK-8 kit. Apoptosis of the PASMCs was detected using TUNEL assay. The [Ca]in the PASMCs was measured using Fura 2-AM fluorescence. The results showed that the expressions of TRPC6 mRNA and protein, and [Ca]were upregulated under hypoxic and hypercapnic conditions. Hypoxia and hypercapnia promoted cellular proliferation and inhibited apoptosis in the PASMCs. OAG enhanced the above-mentioned effects of hypoxia and hypercapnia, whereas SKF-96365 reversed these effects. These results suggest that TRPC6 may play a role in PASMCs proliferation and apoptosis under hypoxia and hypercapnia by regulating [Ca].
Actins ; Animals ; Apoptosis ; Calcium ; metabolism ; Cell Hypoxia ; Cell Proliferation ; Cells, Cultured ; Hypercapnia ; physiopathology ; Imidazoles ; Male ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; metabolism ; Pulmonary Artery ; cytology ; Rats ; Rats, Sprague-Dawley ; TRPC Cation Channels ; metabolism

PURPOSE: MicroRNAs are small non-coding RNAs that play important roles in vascular smooth muscle cell (VSMC) function. This study investigated the role of miR-379 on proliferation, invasion, and migration of VSMCs and explored underlying mechanisms thereof. MATERIALS AND METHODS: MicroRNA, mRNA, and protein levels were determined by quantitative real-time PCR and western blot. The proliferative, invasive, and migratory abilities of VSMCs were measured by CCK-8, invasion, and wound healing assay, respectively. Luciferase reporter assay was used to confirm the target of miR-379. RESULTS: Platelet-derived growth factor-bb was found to promote cell proliferation and suppress miR-379 expression in VSMCs. Functional assays demonstrated that miR-379 inhibited cell proliferation, cell invasion, and migration. Flow cytometry results further showed that miR-379 induced apoptosis in VSMCs. TargetScan analysis and luciferase report assay confirmed that insulin-like growth factor-1 (IGF-1) 3'UTR is a direct target of miR-379, and mRNA and protein levels of miR-379 and IGF-1 were inversely correlated. Rescue experiments showed that enforced expression of IGF-1 sufficiently overcomes the inhibitory effect of miR-379 on cell proliferation, invasion, and migration in VSMCs. CONCLUSION: Our results suggest that miR-379 plays an important role in regulating VSMCs proliferation, invasion, and migration by targeting IGF-1.
Apoptosis ; Cell Movement/*physiology ; Cell Proliferation/*physiology ; Humans ; Insulin ; Insulin-Like Growth Factor I/*physiology ; MicroRNAs/*physiology ; Muscle, Smooth, Vascular/*cytology ; Proto-Oncogene Proteins c-sis/*physiology ; RNA, Messenger/metabolism ; Real-Time Polymerase Chain Reaction ; Sincalide/physiology ; Wound Healing/physiology