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*

The purpose of this study is to construct a muscle-specific synthetic promoter library, screen out muscle-specific promoters with high activity, analyze the relationship between element composition and activity of highly active promoters, and provide a theoretical basis for artificial synthesis of promoters. In this study, 19 promoter fragments derived from muscle-specific elements, conserved elements, and viral regulatory sequences were selected and randomLy connected to construct a muscle-specific synthetic promoter library. The luciferase plasmids pCMV-Luc and pSPs-Luc were constructed and transfected into the myoblast cell line C2C12. The activities of the synthesized promoters were evaluated by the luciferase activity assay. Two non-muscle-derived cell lines HeLa and 3T3 were used to verify the muscle specificity of the highly active promoters. The sequences of promoters with high activity, good muscle specificity, and correct sequences were analyzed to explore the relationship between the element composition and activity of promoters. We successfully constructed a muscle-specific promoter library and screened out 321 effective synthetic promoter plasmids. Among them, the activity of SP-301 promoter was 5.63 times that of CMV. The 15 promoters with high activity were muscle-specific. In the promoters with high activity and correct sequences, there was a relationship between their element composition and activity. Muscle-specific elements accounted for a high proportion in the promoters, while they had weak correlations with the promoter activity, being tissue-specific determinants. Viral elements accounted for no less than 20% in highly active promoters, which may be the key elements for the promoter activity. The content of conserved elements was proportional to the promoter activity. This study lays a theoretical foundation for the synthesis of tissue-specific efficient promoters and provides a new idea for the construction and application of in-situ gene delivery systems.
Promoter Regions, Genetic ; Humans ; Animals ; Mice ; Gene Library ; Cell Line ; Transfection ; HeLa Cells ; Luciferases/metabolism* ; Muscle, Skeletal/metabolism* ; Plasmids/genetics* ; Myoblasts/cytology*

Prostaglandin (PG) E plays critical roles during pregnancy and parturition. Emerging evidence indicates that human labour is an inflammatory event. We sought to investigate the effect of PGE on the output of proinflammatory cytokines in cultured human uterine smooth muscle cells (HUSMCs) from term pregnant women and elucidate the role of subtypes of PGE receptors (EP, EP, EP and EP). After drug treatment and/or transfection of each receptor siRNA, the concentrations of inflammatory secreting factors in HUSMCs culture medium were detected by the corresponding ELISA kits. The results showed that, PGE increased interleukin 6 (IL-6) and tumor necrosis factor alpha (TNFα) output, decreased chemokine (c-x-c motif) ligand 8 (CXCL8) output in a dose-dependent manner, but had no effect on IL-1β and chemokine (c-c motif) ligand 2 (CCL-2) secretion of HUSMCs. EP/EP agonist 17-phenyl-trinor-PGE stimulated IL-6 and TNFα whilst suppressing IL-1β and CXCL8 output. The effects of 17-phenyl-trinor-PGE on IL-1β and CXCL8 secretion were remained whereas its effect on IL-6 and TNFα output did not occur in the cells with EP knockdown. The stimulatory effects of 17-phenyl-trinor-PGE on IL-6 and TNFα were remained whereas the inhibitory effects of 17-phenyl-trinor-PGE on IL-1β secretion was blocked in the cells with EP knockdown. Either of EP and EP agonists stimulated IL-1β and TNFα output, which was reversed by EP and EP siRNA, respectively. The inhibitors of phospholipase C (PLC) and protein kinase C (PKC) blocked EP/EP modulation of TNFα and CXCL8 output. PI3K inhibitor LY294002 and P38 inhibitor SB202190 blocked 17-phenyl-trinor-PGE-induced IL-1β and IL-6 output, respectively. The inhibitors of adenylyl cyclase and PKA prevented EP and EP stimulation of IL-1β and TNFα output, whereas PLC and PKC inhibitors blocked EP- and EP-induced TNFα output but not IL-1β output. Our data suggest that PGE receptors exhibit different effects on the output of various cytokines in myometrium, which can subtly modulate the inflammatory microenvironment in myometrium during pregnancy.
Cells, Cultured ; Chromones ; pharmacology ; Cytokines ; metabolism ; Female ; Humans ; Imidazoles ; pharmacology ; Inflammation ; Morpholines ; pharmacology ; Myocytes, Smooth Muscle ; cytology ; Myometrium ; cytology ; Phosphatidylinositol 3-Kinases ; Pregnancy ; Pyridines ; pharmacology ; Receptors, Prostaglandin E ; physiology

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

We examined the effect of a combination of astaxanthin (AX) supplementation, repeated heat stress, and intermittent reloading (IR) on satellite cells in unloaded rat soleus muscles. Forty-nine male Wistar rats (8-week-old) were divided into control, hind-limb unweighting (HU), IR during HU, IR with AX supplementation, IR with repeated heat stress (41.0-41.5 °C for 30 min), and IR with AX supplementation and repeated heat stress groups. After the experimental period, the antigravitational soleus muscle was analyzed using an immunohistochemical technique. Our results revealed that the combination of dietary AX supplementation and heat stress resulted in protection against disuse muscle atrophy in the soleus muscle. This protective effect may be partially due to a higher satellite cell number in the atrophied soleus muscle in the IR/AX/heat stress group compared with the numbers found in the other groups. We concluded that the combination treatment with dietary AX supplementation and repeated heat stress attenuates soleus muscle atrophy, in part by increasing the number of satellite cells.
Animals ; Body Weight ; Dietary Supplements ; Fibrinolytic Agents/pharmacology* ; Heat-Shock Response ; Hindlimb ; Hot Temperature ; Immunohistochemistry ; Male ; Muscle, Skeletal ; Muscular Atrophy/drug therapy* ; Oxidative Stress ; Rats ; Rats, Wistar ; Satellite Cells, Skeletal Muscle/cytology* ; Xanthophylls/pharmacology*

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

OBJECTIVETo observe the effect of Pinggan Qianyang Recipe (PQR) on inhibiting angiotensin II (Ang II) induced proliferation and migration of vascular smooth muscle cells (VSMCs) and changes of DNA methylation.

METHODSVSMCs were cultured using tissue explant method, and PQR containing serum was prepared. Primarily cultured VSMCs were divided into four groups, the normal group, the model group, the folate group (folic acid intervention) , and the PQR group. The proliferation and migration of VSMCs was duplicated by Ang II. After 24-h Ang II induced culture, 40 microg/mL folic acid was added to the folate group for 48 h, while 5% PQR containing serum was added to the PQR group for 48 h. The cell growth curve of VSMCs was drawn by using Cell Counting Kit (CCK-8). The proliferative activity of VSMC was determined by MTT assay. The migration of VSMCs was measured by Millicell chamber. The general level of cytosine methylation in cell nucleus was detected via 5-mC antibodies immunofluorescence, and mRNA expression levels of DNA methyltransferase 1 (DNMT1) were measured by Real-time q-polymerase chain reaction (q-PCR).

RESULTSVSMCs were promoted by Ang II at 10(-6) mol/L for 24 h. Compared with the normal group, the proliferative activity and migration quantity of VSMCs obviously increased, and DNA methylation level obviously decreased (P < 0.05, P < 0.01). Compared with the model group, the cell growth, proliferative activity and migration quantity of VSMCs obviously decreased and the general DNA methylation level increased in the folate group and the PQR group (P < 0.05, P < 0.01). Compared with the normal group, the mRNA expression of DNMT1 decreased in the model group (P < 0.01). Compared with the model group, mRNA expression of DNMT1 in Ang II induced VSMCs was obviously enhanced in the folate group and the PQR group (P < 0.01).

CONCLUSIONSPQR could inhibit Ang II induced proliferation and migration of VSMCs, and cause high genomic DNA methylation level. Changes of DNA methylation might be associated with DNMT1 expression.

Angiotensin II ; pharmacology ; Cell Movement ; Cell Proliferation ; Cells, Cultured ; DNA (Cytosine-5-)-Methyltransferase 1 ; DNA (Cytosine-5-)-Methyltransferases ; metabolism ; DNA Methylation ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; drug effects