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*

OBJECTIVES: To study the effect of platelet-derived growth factor-BB (PDGF-BB) on pulmonary vascular remodeling in neonatal rats with hypoxic pulmonary hypertension (HPH). METHODS: A total of 128 neonatal rats were randomly divided into four groups: PDGF-BB+HPH, HPH, PDGF-BB+normal oxygen, and normal oxygen (n=32 each). The rats in the PDGF-BB+HPH and PDGF-BB+normal oxygen groups were given an injection of 13 μL 6×10¹⁰ PFU/mL adenovirus with PDGF-BB genevia the caudal vein. After 24 hours of adenovirus transfection, the rats in the HPH and PDGF-BB+HPH groups were used to establish a neonatal rat model of HPH. Right ventricular systolic pressure (RVSP) was measured on days 3, 7, 14, and 21 of hypoxia. Hematoxylin-eosin staining was used to observe pulmonary vascular morphological changes under an optical microscope, and vascular remodeling parameters (MA% and MT%) were also measured. Immunohistochemistry was used to measure the expression levels of PDGF-BB and proliferating cell nuclear antigen (PCNA) in lung tissue. RESULTS: The rats in the PDGF-BB+HPH and HPH groups had a significantly higher RVSP than those of the same age in the normal oxygen group at each time point (P<0.05). The rats in the PDGF-BB+HPH group showed vascular remodeling on day 3 of hypoxia, while those in the HPH showed vascular remodeling on day 7 of hypoxia. On day 3 of hypoxia, the PDGF-BB+HPH group had significantly higher MA% and MT% than the HPH, PDGF-BB+normal oxygen, and normal oxygen groups (P<0.05). On days 7, 14, and 21 of hypoxia, the PDGF-BB+HPH and HPH groups had significantly higher MA% and MT% than the PDGF-BB+normal oxygen and normal oxygen groups (P<0.05). The PDGF-BB+HPH and HPH groups had significantly higher expression levels of PDGF-BB and PCNA than the normal oxygen group at all time points (P<0.05). On days 3, 7, and 14 of hypoxia, the PDGF-BB+HPH group had significantly higher expression levels of PDGF-BB and PCNA than the HPH group (P<0.05), while the PDGF-BB+normal oxygen group had significantly higher expression levels of PDGF-BB and PCNA than the normal oxygen group (P<0.05). CONCLUSIONS Exogenous administration of PDGF-BB in neonatal rats with HPH may upregulate the expression of PCNA, promote pulmonary vascular remodeling, and increase pulmonary artery pressure.
Rats ; Animals ; Hypertension, Pulmonary ; Becaplermin ; Animals, Newborn ; Proliferating Cell Nuclear Antigen ; Vascular Remodeling ; Pulmonary Artery/metabolism* ; Hypoxia ; Oxygen ; Cell Proliferation ; Myocytes, Smooth Muscle/metabolism*

OBJECTIVE: To investigate the regulatory roles of Shexiang Baoxin Pill (SXBXW) in neointimal formation and vascular smooth muscle cells (VSMCs) invasion and apoptosis as well as the potential molecular mechanisms using cultured VSMCs model of vascular injury (platelet-derived growth factor (PDGF)-BB-stimulated) in vitro. METHODS: VSMCs were randomly assigned to 5 groups: blank, PDGF-BB (20 ng/mL+ 0.1% DMSO), SXBXW-L (PDGF-BB 20 ng/mL + SXBXW low dose 0.625 g/L), SXBXW-M (PDGF-BB 20 ng/mL + SXBXW medium dose 1.25 g/L) and SXBXW-H (PDGF-BB 20 ng/mL+ SXBXW high dose 2.5 g/L) group. Cell proliferation was assessed using cell counting kit-8 (CCK-8) assay and bromodeoxyuridine (BrdU) incorporation assay, the migration effects were detected by Transwell assay, cell apoptosis rate was measured by the Annexin V/propidium iodide (PI) apoptosis kit. The markers of contractile phenotype of VSMCs were detected with immunofluorescent staining. To validate the effects of miR-451 in regulating proliferation, migration and apoptosis treated with SXBXW, miR-451 overexpression experiments were performed, the VSMCs were exposed to PDGF-BB 20 ng/mL + 0.1% DMSO and later divided into 4 groups: mimic-NC (multiplicity of infection, MOI=50), SXBXW (1.25 g/L) + mimic-NC, mimic-miR451 (MOI=50), and SXBXW (1.25 g/L) + mimic-miR451, and alterations of proteins related to the miR-451 pathway were analyzed using Western blot. RESULTS: PDGF-BB induced VSMCs injury causes acceleration of proliferation and migration. SXBXW inhibited phenotypic switching, proliferation and migration and promoted cell apoptosis in PDGF-BB-induced VSMCs. In addition, miR-451 was shown to be down-regulated in the VSMCs following PDGF-BB stimulation. SXBXW treatment enhanced the expression of miR-451 in PDGF-BB-induced VSMCs (P<0.05). Compared with SXBXW + mimic-NC and mimic-miR451 groups, the expression of tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (Ywhaz) and p53 was further reduced in SXBXW + mimic-miR451 group, while activating transcription factor 2 (ATF2) was increased in VSMCs (P<0.05). CONCLUSION SXBXW regulated proliferation, migration and apoptosis via activation of miR-451 through ATF2, p53 and Ywhaz in PDGF-BB-stimulated VSMCs.
Apoptosis ; Becaplermin/pharmacology* ; Cell Movement ; Cell Proliferation ; Cells, Cultured ; Dimethyl Sulfoxide/pharmacology* ; Drugs, Chinese Herbal ; Humans ; Hyperplasia/metabolism* ; MicroRNAs/metabolism* ; Muscle, Smooth, Vascular ; Myocytes, Smooth Muscle ; Tumor Suppressor Protein p53/metabolism*

OBJECTIVE: To investigate the effects of Bax inhibitor 1 (BI- 1) and optic atrophy protein 1 (OPA1) on vascular calcification (VC). METHODS: Mouse models of VC were established in ApoE-deficient (ApoE^-/-) diabetic mice by high-fat diet feeding for 12 weeks followed by intraperitoneal injections with N^ε-carboxymethyl-lysine for 16 weeks. ApoE^-/- mice (control group), ApoE^-/- diabetic mice (VC group), ApoE^-/- diabetic mice with BI-1 overexpression (VC + BI-1^TG group), and ApoE^-/- diabetic mice with BI-1 overexpression and OPA1 knockout (VC+BI-1^TG+OPA1^-/- group) were obtained for examination of the degree of aortic calcification using von Kossa staining. The changes in calcium content in the aorta were analyzed using ELISA. The expressions of Runt-related transcription factor 2 (RUNX2) and bone morphogenetic protein 2 (BMP-2) were detected using immunohistochemistry, and the expression of cleaved caspase-3 was determined using Western blotting. Cultured mouse aortic smooth muscle cells were treated with 10 mmol/L β-glycerophosphate for 14 days to induce calcification, and the changes in BI-1 and OPA1 protein expressions were examined using Western blotting and cell apoptosis was detected using TUNEL staining. RESULTS: ApoE^-/- mice with VC showed significantly decreased expressions of BI-1 and OPA1 proteins in the aorta (P=0.0044) with obviously increased calcium deposition and expressions of RUNX2, BMP-2 and cleaved caspase-3 (P= 0.0041). Overexpression of BI-1 significantly promoted OPA1 protein expression and reduced calcium deposition and expressions of RUNX2, BMP-2 and cleaved caspase-3 (P=0.0006). OPA1 knockdown significantly increased calcium deposition and expressions of RUNX2, BMP-2 and cleaved caspase-3 in the aorta (P=0.0007). CONCLUSION BI-1 inhibits VC possibly by promoting the expression of OPA1, reducing calcium deposition and inhibiting osteogenic differentiation and apoptosis of the vascular smooth muscle cells.
Animals ; Apolipoproteins E/metabolism* ; Calcium/metabolism* ; Caspase 3/metabolism* ; Cells, Cultured ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Diabetes Mellitus, Experimental/pathology* ; GTP Phosphohydrolases/metabolism* ; Membrane Proteins/metabolism* ; Mice ; Mice, Knockout ; Muscle, Smooth, Vascular/pathology* ; Myocytes, Smooth Muscle/pathology* ; Optic Atrophy, Autosomal Dominant/pathology* ; Osteogenesis ; Vascular Calcification/pathology* ; bcl-2-Associated X Protein/metabolism*

This study aimed to investigate the effects of hypoxia on RhoA/Rho-kinase (ROCK) signaling pathway and autophagy in pulmonary artery smooth muscle cells (PASMCs), and to explore the underlying mechanism of Umbelliferone (Umb) in ameliorating chronic hypoxic pulmonary hypertension. PASMCs were cultured from Sprague-Dawley (SD) rats and randomly divided into control group, hypoxia group, hypoxia + Umb intervention group and normoxia + Umb intervention group. Alpha smooth muscle actin (α-SMA) and LC3 were assessed by immunofluorescence staining. Protein expression of RhoA, ROCK2, p-MYPT1, LC3-II, Beclin-1, p62, C-Caspase 3, Bax and Bcl-2 was analyzed by Western blotting. In in vivo study, SD rats were divided into control group, hypoxia group and hypoxia + Umb intervention group. Weight ratio of the right ventricle (RV)/left ventricle plus septum (LV+S) was detected, and pulmonary arterial morphological features were examined by HE staining. The results indicated that compared with the control group, the LC3-II/LC3-I ratio and expression of Beclin-1 were significantly increased, while p62 expression was significantly decreased, and the expressions of RhoA, ROCK2 and p-MYPT1 were significantly increased in PASMCs of hypoxia group (P < 0.05). The changes of LC3-II/LC3-I ratio, the expressions of Beclin-1, p62, RhoA, ROCK2 and p-MYPT1 in PASMCs were reversed by Umb treatment (P < 0.05). Consistently, the pulmonary arterial wall was thickened and the RV/(LV+S) ratio was increased in hypoxic rats, which were significantly improved by Umb treatment (P < 0.05). These results suggest that Umb can improve hypoxia-induced pulmonary hypertension by inhibiting the RhoA/ROCK signaling pathway and autophagy in PASMCs.
Animals ; Autophagy ; Beclin-1/pharmacology* ; Hypertension, Pulmonary/etiology* ; Hypoxia/complications* ; Myocytes, Smooth Muscle/metabolism* ; Pulmonary Artery ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Umbelliferones/pharmacology* ; rho-Associated Kinases/pharmacology*

OBJECTIVE: To investigate the regulatory role of miRNA-26a in vascular smooth muscle cell (VSMC) calcification by regulating connective tissue growth factor (CTGF). METHODS: Rat thoracic aorta VSMCs (A7r5 cells) with induced calcification were treated with AR234960 agonist or transfected with miR-26a mimic, or with both treatments. Alizarin red staining was used to determine calcium deposition, and phosphatase (ALP) activity in the cells was measured. The mRNA and protein expressions of miR-26a, OPG, OPN, BMP-2 and collagen Ⅱ were detected using qPCR and Western blotting. The binding of miR-26a to CTGF was verified using dual luciferase reporter gene assay. RESULTS: After induced calcification, A7r5 cells showed gradually decreased miR-26a expression (P < 0.05) and progressively increased CTGF expression (P < 0.05) with the extension of induction time. Treatment of the cells with AR234960 obviously increased calcification in the cells, while transfection with miR-26a mimic significantly reduced cell calcification. The calcifying cells showed significantly increased ALP activity and expressions of OPN, BMP-2 and collagen Ⅱ (P < 0.05) and lowered OPG expression (P < 0.05), and treatment with AR234960 did not produce obvious effects on these changes (P > 0.05). Transfection with miR-26a mimic resulted in significantly decreased ALP activity and expressions OPN, BMP-2 and collagen Ⅱ expression (P < 0.05) and increased OPG expression (P < 0.05) in the calcifying cells. These effects of miR-26a mimic was significantly attenuated by treatment of the cells with AR234960 (P < 0.05). The result of luciferase reporter gene assay confirmed the binding of miR-26a to CTGF. CONCLUSION miRNA-26a can effectively alleviate vascular calcification by lowering the level of CTGF, reducing ALP activity and the expressions of OPN, BMP-2 and collagen Ⅱ, and increasing the expression of OPG.
Animals ; Calcium/metabolism* ; Cells, Cultured ; Connective Tissue Growth Factor/pharmacology* ; MicroRNAs/metabolism* ; Muscle, Smooth, Vascular ; Myocytes, Smooth Muscle ; Phosphoric Monoester Hydrolases/pharmacology* ; RNA, Messenger/metabolism* ; Rats ; Sulfones ; Vascular Calcification

OBJECTIVE: To investigate the role of myelin and lymphocyte protein (MAL) in pulmonary hypertension (PAH). METHODS: Blood samples were collected from 50 patients with PAH (PAH group) and 50 healthy individuals for detection of plasma MAL expression using ELISA.According to the echocardiographic findings, the patients were divided into moderate/severe group (n=18) and mild group (n=32), and the correlation between MAL protein level and the severity of PAH was analyzed.In a pulmonary artery smooth muscle cell model of PAH with hypoxia-induced abnormal proliferation, the effects of mal gene knockdown and overexpression on cell growth, proliferation and starvation-induced apoptosis were observed; the changes in NK-κB signaling pathway in the transfected cells were detected to explore the molecular mechanism by which MAL regulates PAMSC proliferation and apoptosis. RESULTS: The plasma level of MAL was significantly higher in patients with PAH than in healthy individuals (P < 0.05), and the patients with moderate/severe PAH had significantly higher MAL level than those with mild PAH (P < 0.001).In PAMSCs, exposure to hypoxia significantly increased the mRNA and protein expression levels of MAL (P < 0.05), and MAL knockdown obviously inhibited hypoxia-induced proliferation and promoted starvation-induced apoptosis of the PAMSCs (P < 0.05).Knocking down mal significantly inhibited the activation of NK-κB signaling pathway that participated in regulation of PAMSC proliferation (P < 0.05). CONCLUSION The plasma level of MAL is elevated in PAH patients in positive correlation with the disease severity.MAL knockdown inhibits abnormal proliferation and promotes apoptosis of PAMSCs by targeted inhibition of the NF-κB signaling pathway to improve vascular remodeling in PAH.
Humans ; Pulmonary Artery ; Hypertension, Pulmonary ; Myelin Sheath/metabolism* ; Apoptosis ; Myocytes, Smooth Muscle ; Vascular Remodeling/genetics* ; Cell Proliferation ; Hypoxia/metabolism* ; Lymphocytes