Long noncoding RNA ZFAS1/miR-150/ROCK1 axis regulates proliferation and migration of vascular smooth muscle cells

AIM: To investigate whether long noncoding RNA ZNFX1 (zinc finger NFX1-type containing 1) antisense RNA 1 (ZFAS1) promotes the proliferation and migration of vascular smooth muscle cells (VSMCs) by regulating microRNA-150 (miR-150)/ROCK1, and the involving mechanism of atherosclerosis. METHODS: Platelet-derived growth factor-BB (PDGF-BB) was used to induce proliferation and migration of VSMCs. Real-time PCR was used to detect the content of ZFAS1 in the VSMCs. After further down-regulating the expression of ZFAS1 by siRNA, the viability of VSMCs was detected by MTT assay, and the proliferation was measured by EdU staining. The migration ability of VSMCs was detected by Transwell method. The expression levels of miR-150 and ROCK1 were detected by RT-qPCR, and the protein level of ROCK1 was determined by Western blot. Luciferase reporter assay was used to confirm that ROCK1 was the target gene of miR-150. Finally, miR-150 expression was inhibited, and the proliferation and migration ability of VSMCs and expression of ROCK1 after down-regulation of ZFAS1 expression were examined. RESULTS: PDGF-BB up-regulated the expression of ZFAS1 in the VSMCs. After down-regulating the expression of ZFAS1, the proliferation and migration abilities of VSMCs were inhibited (P<0.05), the expression level of miR-150 was increased (P<0.05), and the expression level of ROCK1 was decreased (P<0.05). The results of luciferase reporter assay showed that miR-150 directly targeted ROCK1. Inhibition of miR-150 expression attenuated the inhibition of proliferation and migration of VSMCs by ZFAS1 expression knock-down (P<0.05) and up-regulated the expression level of ROCK1 (P<0.05). CONCLUSION: ZFAS1 promotes the proliferation and migration of VSMCs induced by PDGF-BB by regulating miR-150/ROCK1.     

Long noncoding RNA MALAT1 regulates Rac1b expression and is associated with colorectal cancer metastasis

AIM: To investigate the role of MALAT1 in colorectal cancer metastasis.METHODS: The mRNA expression levels of MALAT1 and Rac1b in the tumor and adjacent normal tissues were examined by real-time PCR. MALAT1 was knocked down by siRNA in colorectal cancer cell lines. The expression of Rac1b and the epithelial-mesenchymal transition markers was examined by Western blot. Cell proliferation was determined by EdU analysis. The effects of MALAT1 on the cell migration and invasion were examined by Transwell assay. RESULTS: The expression of MALAT1 was down-regulated in colorectal cancer. Down-regulation of MALAT1 induced Rac1b overexpression, which in turn increased the expression levels of E-cadherin and β-catenin. Furthermore, down-regulation of MALAT1 promoted the cell proliferation, invasion and migration. CONCLUSION: MALAT1 is associated with metastasis of colorectal cancer through regulating the expression of Rac1b and the downstream factors.     

Effect of lncRNA FEZF1-AS1 on viability and apoptosis of LPS-induced vascular endothelial cells by regulating miR-363-3p expression

AIM To investigate the mechanism of long noncoding RNA （lncRNA） FEZF1-AS1 regulating microRNA-363-3p （miR-363-3p） on the viability and apoptosis of lipopolysaocharide （LPS）-induced vascular endothelial cells. METHODS Human umbilical vein endothelial cells （HUVECs） were cultured in vitro. pcDNA-NC, pcDNA-FEZF1-AS1, anti-miR-NC, anti-miR-363-3p, miR-NC and miR-363-3p mimics were transfected into the HUVECs and LPS stimulation was applied for 24 h. RT-qPCR was used to detect the expression of FEZF1-AS1 and miR-363-3p. The cell viability was measured by MTT assay. The apoptotic rate was analyzed by flow cytometry. The dual-luciferase reporter experiment was used to verify the targeted regulation of FEZF1-AS1 and miR-363-3p. Western blot was used to determined the expression of cyclin D1, Ki67 and cleaved caspase-3. RESULTS Compared with control group, the expression level of FEZF1-AS1 in LPS group was significantly reduced （P<0.05）, and the expression level of miR-363-3p was significantly increased （P<0.05）. Compared with pcDNA-NC+LPS group, the cell viability in pcDNA-FEZF1-AS1+LPS group was significantly increased （P<0.05）, the apoptotic rate was significantly reduced （P<0.05）, the protein levels of cyclin D1 and Ki67 were significantly increased （P<0.05）, and the protein level of cleaved caspase-3 was significantly reduced （P<0.05）. Compared with anti-miR-NC+LPS group, the cell viability in anti-miR-363-3p+LPS group was significantly increased （P<0.05）, the apoptotic rate was significantly reduced （P<0.05）, the protein levels of cyclin D1 and Ki67 were significantly increased （P<0.05）, and the protein level of cleaved caspase-3 was significantly reduced （P<0.05）. Dual-luciferase reporter experiment confirmed that FEZF1-AS1 targeted miR-363-3p. Compared with miR-NC+pcDNA-FEZF1-AS1+LPS group, the cell viability in miR-363-3p+pcDNA-FEZF1-AS1+LPS group was significantly reduced （P<0.05）, the apoptotic rate was significantly increased （P<0.05）, the protein levels of cyclin D1 and Ki67 were significantly reduced （P<0.05）, and the protein level of cleaved caspase-3 was significantly increased （P<0.05）. CONCLUSION Over-expression of FEZF1-AS1 promotes the viability and inhibits apoptosis of LPS induced vascular endothelial cells by inhibiting the expression of miR-363-3p.     

lncRNA TTN-AS1 regulates the viability and invasion of lung adenocarcinoma A549 cell via miR-519d-3p/MMP2 pathway

AIM To investigate the expression level of long noncoding RNA （lncRNA） TTN antisense RNA 1 （TTN-AS1） in lung adenocarcinoma tissues and the effects of TTN-AS1 silencing on the viability and invasion of lung adenocarcinoma A549 cells. METHODS RT-qPCR was used to detect the expression of TTN-AS1, microRNA-519d-3p （miR-519d-3p） and matrix metalloproteinase 2 （MMP2） mRNA in 32 cases of lung adenocarcinoma and adjacent normal tissues. The untransfected A549 cells were divided into blank group, si-NC group （with si-NC transfection） and si-lncRNA group （with silencing of lncRNA TTN-AS1 expression）, with n=5 in each group. The effects of TTN-AS1 silencing on the viability and invasion of A549 cells were detected by CCK8 and Transwell methods. The targeting regulatory effects of TTN-AS1 on miR-519d-3p and miR-519d-3p on MMP2 were determined by dual-luciferase reporter assay, RNA immunoprecipitation test, RT-qPCR and Western blot. RESULTS The expression level of TTN-AS1 in 32 cases of lung adenocarcinoma tissues is notably higher than that in the adjacent normal tissues （P<0.05）. Silencing of TTN-AS1 in A549 cells significantly suppressed the cell viability and invasion. TTN-AS1 negatively regulated the expression of miR-519d-3p via sponging and absorbing miR-519d-3p. MMP2 is the target gene of miR-519d-3p and can be negatively regulated by miR-519d-3p. Overexpression of MMP2 partially reversed the inhibitory effect of TTN-AS1 silencing and miR-519d-3p overexpression on the invasion of A549 cells. CONCLUSION The lncRNA TTN-AS1 is overexpressed in lung adenocarcinoma tissues, and it regulates lung adenocarcinoma A549 cell viability and invasion via miR-519d-3p/MMP2 pathway.     

Effects of kaempferol-3-O-rutinoside on proliferation,migration and TGFBR1 signaling pathway activation in vascular smooth muscle cells

AIM:To investigate the effects of kaempferol-3-O-rutinoside (KR) on the proliferation, migration of vascular smooth muscle cells (VSMC) and the activation of transforming growth factor β receptor 1 (TGFBR1) signaling pathway in the cells. METHODS:The viability of VSMC was detected by MTT assay. The proliferation of VSMC was measured by EdU staining. The migration ability of VSMC was examined by Transwell assay. The protein levels of the migration-associated proteins matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) were detected by Western blot. Molecular docking study was conducted to explore the interaction between KR and TGFBR1. The protein le-vels of the phosphorylated TGFBR1, Smad2 and Smad3 were determined by Western blot. RESULTS:KR inhibited the viability of VSMC in a dose-and time-dependent manner. KR reduced the ratio of EdU-positive cells in a dose-dependent manner. KR dose-dependently suppressed the migration ability of VSMC and decreased the protein levels of MMP2 and MMP9 (P<0.05). KR docked into TGFBR1 with the binding energy of -9.804 kcal/mol by forming hydrogen bonds with SER-280, ARG-215, ASP-290 and LYS-335 of TGBFR1. KR dose-dependently suppressed the activation of TGFBR1 and its downstream proteins Smad2 and Smad3 (P<0.05). CONCLUSION:KR inhibits the proliferation and migration of VSMC, possibly via blocking the TGFBR1 signaling pathway.     

Effects of miR-130a on viability and apoptosis of rat basilar arterial smooth muscle cells

AIM: To investigate the regulatory effects of microRNA (miR)-130a on the biological characteristics of rat basilar arterial smooth muscle cells (BASMCs) and its underlying mechanisms. METHODS: The expression of miR-130a in rat BASMCs was measured by real-time PCR. After knockdown of miR-130a with inhibitor in the BASMCs, the cell viability, cell cycle distribution and apoptosis were detected by CCK-8 assay and flow cytometry. The expression of cell cycle-and apoptosis-related molecules, such as cyclin D1, cyclin-dependent kinase 2 (CDK2), p21, Bcl-2 and cleaved caspase-3/caspase-3 at protein levels was determined by Western blot. The growth arrest-specific homeobox protein (Gax) expression at mRNA and protein levels was determined by real-time PCR and Western blot. RESULTS: AngiotensionⅡ (AngⅡ) up-regulated the expression of miR-130a and down-regulated the expression of Gax (P<0.05). Transfection with miR-130a inhibitor partly reversed the increase in AngⅡ-induced cell viability and promoted the Gax expression. Furthermore, the early cell apoptotic rate was significantly increased after down-regulation of miR-130a (P<0.05), and the protein levels of cyclin D1, CDK2, Bcl-2 and p-Rb were significantly decreased, accompanied with the up-regulation of p21 and cleaved caspase-3 (P<0.05). CONCLUSION: Down-regulation of miR-130a restrains the viability and promotes the apoptosis of BASMCs by promoting Gax expression and regulating cell cycle-and apoptosis-related molecules, suggesting that miR-130a may be a potential therapeutic target of brain vascular remodeling during hypertension.     

Effects of JAG1 gene silencing on proliferation and apoptosis of human breast cancer MDA-MB-231 cells

AIM:To investigate the effects of Jagged 1 (JAG1) gene silencing on the proliferation and apoptosis of human breast cancer MDA-MB-231 cells. METHODS:The specific recombinant vector pRS-JAG1 was transfected into MDA-MB-231 cells with lipofectamine. The protein expression of JAG1 was observed by Western blotting after transfection. MTT assay was used to detect the effect of JAG1 gene silencing on the growth of the cells. The apoptosis and cell cycle were analyzed by flow cytometry. The protein levels of cyclin D1, p21CIP1/WAF1, p27KIP1, p-Rb, Bcl-2, Bax, Bcl-xL and cleaved caspase-3 were determined by Western blotting. RESULTS:Compared with control group, the expression level of JAG1 was reduced by pRS-JAG1 transfection for 72 h (P<0.05). The growth of MDA-MB-231 cells in shJAG1 group was significantly inhibited (P<0.05). The percentages of G 0/G 1-phase cells and early apoptotic rate were obviously higher in shJAG1 group than those in control group (P<0.05). The shRNA-mediated JAG1 silencing decreased the protein levels of cyclin D1, p-Rb, Bcl-2 and Bax, and increased the protein levels of p21CIP1/WAF1, p27KIP1, Bax and cleaved caspase-3 (P<0.05). CONCLUSION:JAG1 silencing effectively inhibits the proliferation and induces the apoptosis of human breast cancer cells, suggesting that JAG1 might serve as a therapeutic target for triple-negative breast cancer.     

Chlamydia pneumoniae infection induces vascular smooth muscle cell migration through stimulating Rac1 activity via PI3K activation

AIM: To determine the role of Rac1 activation in the migration of vascular smooth muscle cells (VSMCs) induced by Chlamydia pneumoniae (C.pn) infection and to investigate the effect of phosphatidylinositol 3-kinase (PI3K) on Rac1 activation during the process. METHODS: The recombinant plasmid encoding glutathione S-transferase (GST)-p21-binding domain of p21-activated kinase 1(PBD) fusion protein was transformed into the competent bacteria to induce the expression of the fusion protein. The fusion protein was purified. GST-pull down assay was performed to evaluate the activity of Rac1 in C.pn-infected VSMCs pretreated with or without PI3K inhibitor LY294002 (25 μmol/L). Wound-healing assay and Transwell assay were performed to observe the changes of C.pn infection-induced VSMCs migration with or without pre-incubation of Rac1 inhibitor NSC23766 (50 μmol/L). RESULTS: Enough and biologically active GST-PBD fusion protein was obtained after purification. The activity of Rac1 in VSMCs infected with C.pn for 24 h increased significantly and was higher than that in control group. Rac1 activation induced by C.pn infection was inhibited by the pretreatment of VSMCs with LY294002. The migration ability of C.pn-infected VSMCs pre-incubated with NSC23766 was significantly reduced and was lower than that in C.pn infection group. CONCLUSION: C.pn infection induces the migration of VSMCs possibly through stimulating Rac1 activity via PI3K activation.     

Homocysteine activates Rho kinase signaling pathway to promote viability and migration of rat basilar arterial vascular smooth muscle cells

AIM:To investigate the regulatory effects of homocysteine (Hcy) on the viability and migration of rat basilar arterial smooth muscle cells (BASMCs) and its potential molecular mechanisms. METHODS:BASMCs were isolated, cultured in vitro and treated with Hcy at different concentrations. The cell viability was measured by CCK-8 assay, and the activation of Rho kinase pathway was measured by Western blot. The cells were treated with Hcy at fixed concentration (1 mmol/L), and ROCK inhibitor Y-27632 was also used. The cell cycle distribution was analyzed by flow cytometry. The cell migration ability was detected by wound healing assay and Transwell assay. The activation of antioxidant enzymes, including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the level of malondialdehyde (MDA) were measured for determining the status of oxidative stress.RESULTS:Hcy increased the viability of BASMCs and the protein expression of GTP-RhoA and ROCK2 in a dose-dependent manner (P<0.05). Compared with the cells treated with Hcy for 24 h, the cells treated with Hcy for 48 h had enhanced viability (P<0.05). Compared with control group, treatment with Hcy increased cell population in S phase and decreased cell population in G₀/G₁ phase, while pre-incubation with Y-27632 reversed Hcy-induced G₁/S phase transition in BASMCs (P<0.05). The cell migration rate in Hcy treatment group was remarkably higher than that in control group(P<0.05), while pre-incubation with Y-27632 reversed Hcy-induced cell migration (P<0.05). Furthermore, Hcy inhibited the activation of SOD and GSH-Px, accompanied with increased MDA level (P<0.05). Compared with Hcy treatment group, pre-incubation with Y-27632 increased the activation of SOD and GSH-Px, but decreased MDA level (P<0.05). CONCLUSION:Homocysteine induces the viability and migration of rat BASMCs, and its mechanisms may be related to activation of Rho kinase pathway.     

lncRNA-MALAT1 targets and downregulates miR-570-3p expression to promote proliferation of gastric cancer cells

AIM:To investigate whether long non-coding RNA MALAT1 (lncRNA-MALAT1) targets and down-regulates microRNA-570-3p (miR-570-3p) expression to further promote the proliferation of gastric cancer cells. METHODS:Gastric cancer cell line SGC7901 was cultured in vitro and divided into 3 groups:blank control, si-MALAT1 and si-MALAT1 NC. The si-MALAT1 and si-MALAT1 NC groups were transfected with MALAT1 siRNA and its negative control, respectively. The cell proliferation was evaluated by MTS assay. The expression of miR-570-3p was detected at different time points in the pure SGC7901 gastric cancer cell line, and the expression of lncRNA-MALAT1 and miR-570-3p in different groups was detected by RT-qPCR. The potential complementary binding sites of lncRNA-MALAT1 and miR-570-3p were predicted by RegRNA. The MALAT1 gene and its mutant fragment were cloned into luciferase reporter vector psiCHECK-2. Restriction enzyme analysis and sequencing were used to identify whether the recombinant plasmids carrying MALAT1 or MALAT1-Mut were successfully constructed. miR-570-3p mimic, miR-570-3p inhibitor, miR-570-3p mimic negative control and miR-570-3p inhibitor negative control were co-transfected into the 293T cells with the luciferase repor-ters containing MALAT1 or MALAT1-Mut. Dual-luciferase reporter assay was performed to detect luciferase activity in different groups in order to verify the relationship between lncRNA-MALAT1 and miR-570-3p. RESULTS:Compared with blank control group and si-MALAT1 NC group, the A₄₉₀ value in si-MALAT1 group was significantly decreased (P<0.01). The expression of miR-570-3p presented an obvious declining trend over time. The expression of lncRNA-MALAT1 in si-MALAT1 group was remarkably decreased, whereas the expression of miR-570-3p was obviously increased. The dual-luciferase reporter assay indicated that the MALAT1 reporter luciferase activity decreased significantly in miR-570-3p mimic group compared with mimic negative control (P<0.01), and the luciferase activity of MALAT1 reporter was obviously up-regulated in miR-570-3p inhibitor group compared with miR-570-3p mimic group (P<0.01). However, miR-570-3p mi-mic, miR-570-3p inhibitor, miR-570-3p mimic negative control and miR-570-3p inhibitor negative control showed no effect on the luciferase activity of MALAT1-Mut reporter. CONCLUSION:lncRNA-MALAT1 targets and down-regulates miR-570-3p expression to further promote the proliferation of gastric cancer cells.     

miR-556-3p regulates viability,migration and invasion of endometrial cancer cells by targeting SASH1

AIM To investigate whether microRNA-556-3p （miR-556-3p） regulates the viability, migration and invasion of endometrial cancer cells by targeting SASH1 gene. METHODS The expression of miR-556-3p, and the mRNA and protein levels of SASH1 in endometrial cancer tissues were detected by RT-qPCR and Western blot. Anti-miR-556-3p or pcDNA-SASH1 was transfected into endometrial cancer Ishikawa cells. The cell viability was detected by MTT assay, the migration and invasion abilities of the cells were detected by Transwell chamber method, and the protein expression levels of cyclin D1, p21, matrix metalloproteinase-2 （MMP-2） and MMP-9 were detected by Western blot. StarBase prediction and dual-luciferase reporter experiments were used to analyze the targeting relationship between miR-556-3p and SASH1. Anti-miR-556-3p and si-SASH1 were co-transfected into the Ishikawa cells, and their effects on cell viability, migration and invasion were examined by the methods described above. RESULTS Compared with adjacent tissues, the expression of miR-556-3p in endometrial cancer tissues was increased significantly, and the expression of SASH1 at mRNA and protein levels was decreased significantly （P<0.05）. Inhibition of miR-556-3p expression or induction of SASH1 over-expression obviously reduced the viability of Ishikawa cells, the number of migratory cells, the number of invasive cells and the protein levels of cyclin D1, MMP-2 and MMP-9, and dramatically increased the protein level of p21 （P<0.05）. miR-556-3p targeted SASH1 and negatively regulated its expression. Knock-down of SASH1 expression reversed the inhibitory effect of miR-556-3p expression inhibition on the viability, migration and invasion of Ishikawa cells. CONCLUSION Inhibition of miR-556-3p expression suppresses the viability, migration and invasion of endometrial cancer cells. The mechanism is related to the regulation of its target gene SASH1.     

Effects of miR-337 targeting p53 expression on autophagy and migration ability of colon cancer cells

AIM: To investigate the effect of microRNA-337 (miR-337) on the autophagy and migration ability of colon cancer cells, and to explore its possible mechanism involving targeting p53 expression. METHODS: The me-thod of immunohistochemistry was used to detect the protein expression of beclin-1, LC3B and p53 in colon cancer tissues. The correlations between the protein expression of beclin-1/LC3B and clinicopathological features, and the correlations between the protein expression of p53 and beclin-1/LC3B were analyzed. After knock-down of p53 expression by small interfering RNA, the formation of autophagiosomes was observed under electron microscope in colon cancer cell line HCT116, and the protein expression of beclin-1 and LC3B was determined by Western blot. The miRNAs targeting p53 were predicted and screened by bioinformatics, and their expression in HCT116 cells was verified by RT-qPCR. Luciferase reporter assay was used to detect the regulatory effect of miR-337 on p53 gene. The protein expression of p53, beclin-1 and LC3B was determined by Western blot, and the migration ability of HCT116 cells after miR-337 over-expression was detected by Transwell assay. RESULTS: The protein expression of beclin-1 and LC3B in the colon cancer tissues was decreased, which was significantly related to the occurrence, development, invasion and metastasis of colon cancer. The expression of p53 was increased in the colon cancer tissues, which was negatively correlated with the protein expression of beclin-1 and LC3B. Knock-down of p53 gene expression increased the protein expression of beclin-1 and LC3B (P<0.05). Over-expression of miR-337 down-regulated the expression of p53, up-regulated the protein expression of beclin-1 and LC3B, and decreased the migration ability of HCT116 cells (P<0.05). CONCLUSION: miR-337 promotes autophagy and inhibits migration ability of colon cancer cells, and the mechanism may be related to targeted inhibition of p53 expression.     

Effects of p21-activated protein kinase 2 down-regulation on proliferation and apoptosis of human breast cancer cells

AIM：To study the effect of p21-activated protein kinase 2 (PAK2) knockdown by RNA interference on the proliferation and apoptosis of human breast cancer cells. METHODS：The short hairpin RNA (shRNA) targeting PAK2 gene was designed and used for packing lentivirus in 293T cells.Human breast cancer MCF-7 cells were infected by the virus particles and PAK2 knockdown stable cell line was established by puromycin selection. The knockdown efficiency was assessed by Western blotting. The proliferation ability of MCF-7 cells was evaluated by CellTiter 96 AQueous and anchorage-independent growth assays. The cell apoptosis induced by staurosporine was detected by flow cytometry. RESULTS：The protein level of PAK2 was significantly suppressed after silencing of PAK2 gene in MCF-7 cells (P<0.01). Furthermore, knockdown of PAK2 caused remarkable inhibition of the cell proliferation and colony formation (P<0.01). Staurosporine induced more apoptosis in the PAK2 knockdown cells compared with the control cells (P<0.01). CONCLUSION：Knockdown of PAK2 inhibits the proliferation of MCF-7 cells and increases the sensitivity of chemotherapeutic drug-induced cell apoptosis, suggesting that PAK2 might be a new therapeutic target in breast cancer treatment.     

Effect of annexin A2 on proliferation,migration and apoptosis of human cervical cancer HeLa cells

AIM：To explore the effect of annexin A2 (ANXA2) on the proliferation, migration and apoptosis abilities of human cervical cancer HeLa cells. METHODS：Overexpression vectors and siRNA of ANXA2 were constructed, and then transfected into HeLa cells. The HeLa cells were divided into 4 groups:control group, scramble group, ANXA2 overexpression group and ANXA2-siRNA group. The expression of ANXA2 at mRNA and protein levels was examined by real-time PCR and Western blotting. MTT assay, Boyden chamber and flow cytometry were used to determine the effect of ANXA2 on the proliferation, migration and apoptosis abilities of the HeLa cells. RESULTS：The proliferation and migration of HeLa cells were obviously promoted by ANXA2 overexpression. The proliferation and migration of HeLa cells were remarkably inhibited by the transfection of ANXA2-siRNA. ANXA2 had no effect on apoptosis of HeLa cells. CONCLUSION:Silencing of ANXA2 effectively inhibits the proliferation and migration of cervical cancer cells, but has little effect on apoptosis. ANXA2 may play a pivotal role in the occurrence and development of cervical cancer, and may be used as a molecular target for the treatment of cervical cancer.     

Exposure to fine particulate matter induces vascular smooth muscle cell proliferation and migration via p38 MAPK signaling pathway

AIMTo study the effects of fine particulate matter (PM2.5) on the proliferation and migration ability of human vascular smooth muscle cells (HVSMCs). METHODSHVSMCs were divided into control group and different concentrations (6.25, 12.5 and 25 mg/L) of PM2.5 groups. HVSMCs were treated with PBS or PM2.5 accord?ing to the group setting. The proliferation was measured by CCK-8 assay and EdU staining method, while the migration ability was detected by scratch assay and Transwell assay. The phosphorylation level of p38 MAPK signaling molecules was determined by Western blot. RESULTSCompared with control group, PM2.5 exposure significantly promoted the proliferation and migration ability of HVSMCs, especially at the dose of 12.5 mg/L(P<0.01). The results of Western blot showed that exposure to PM2.5 at 12.5 mg/L up-regulated the phosphorylation level of p38 MAPK rapidly in the HVSMCs, which peaked at 20 min incubation and kept at a relative high level until 60 min incubation. Pretreatment with SB203580, a p38 MAPK specific inhibitor, blocked the proliferation and migration ability induced by PM2.5(P<0.01). CONCLUSION Exposure to PM2.5 activates HVSMCs by promoting the proliferation and migration ability, and the p38 MAPK signaling pathway may be involved in this process.     

Effects of human growth arrest-specific homeobox gene delivery on proliferation,migration and cell cycle distribution of vascular smooth muscle cells

AIM: To explore a new gene therapeutic strategy for vein graft restenosis by investigating the effects of adenovirus-mediated human growth arrest-specific homeobox (Ad5-hGax) gene delivery on the proliferation, migration and cell cycle distribution of serum-induced rabbit vascular smooth muscle cells (VSMCs). METHODS: The recombinant adenovirus vector containing hGax gene was constructed and transfected into rabbit VSMCs. The expression of hGax in VSMCs was detected by RT-PCR and immunofluorescent staining. Methyl thiazolyl tetrazolium (MTT) assay was used to assess the effect of hGax over-expression on serum-induced proliferation of VSMCs. Wound healing method was applied to examine the distance of serum-induce VSMCs migration. Flow cytometry was employed to analyze the cell cycle distribution. RESULTS: The recombinant adenovirus vector Ad5-hGax was successfully constructed. The results of RT-PCR and immunofluorescent staining revealed that the hGax -transfected cells contained a 174 bp specific fragment of hGax gene and target protein 48 h after transfection. The proliferation of serum-induced VSMCs was significantly inhibited by overexpression of hGax gene as compared with control group. The migration of serum-induced VSMCs was inhibited after hGax gene delivery. Flow cytometry showed that 72 h after serum induction, the cells in G₀/G₁ phase in Ad5-hGax group were significantly increased, whereas the cells in G₂/M+S phase were significantly decreased. CONCLUSION: Overexpression of hGax gene inhibits the proliferation and migration of serum-induced rabbit VSMCs, and arrests the cells in G₀/G₁ phase. It is likely that hGax gene is a potential target for the gene therapy of vein graft restenosis.     

Effects of sinapic acid on proliferation and apoptosis of rat vascular smooth muscle cells induced by high glucose

AIM: To investigate the effects of sinapic acid(SA) on the proliferation and apoptosis of rat vascular smooth muscle cells(VSMCs) induced by high glucose(HG). METHODS: Cultured A7r5 cells were randomly divided and treated as indicated. The cell viability was determined by MTT assay. DNA synthesis was measured by BrdU assay. Cell cycle progression and cell apoptotic rate were determined by flow cytometry analysis. The levels of reactive oxygen species(ROS) were detected by ELISA. The protein levels of cyclin D1, P21, P27, phosphorylated protein kinase C(p-PKC), p-P38 and β-actin were evaluated by Western blot. RESULTS: Compared with control group, the viability of A7r5 cells was significantly enhanced, the DNA synthesis was increased, the cell cycle progression was promoted, the levels of ROS were elevated, the cell apoptotic rate was reduced, the protein expression of P21 and P27 was decreased, and the protein levels of cyclin D1, p-PKC and p-P38 were increased in HG group(all P<0.05). These effects were reversed by SA(0.1, 1 and 10 μmol/L) treatment in a dose-dependent manner(all P<0.05). Both P38 inhibitor SB203580 and PKC inhibitor chelerythrine significantly inhibit HG-induced PKC/P38 activation and cell viability(P<0.05).CONCLUSION: SA inhibits HG-induced VSMCs proliferation and promotes cell apoptosis via reducing PKC/P38 activation.     

Effects of CARHSP1 gene expression on viability,apoptosis and immune factors of vascular endothe-lial cells induced by hypoxia in atherosclerosis

AIM: To investigate the effect of calcium-regulated heat stable protein 1 (CARHSP1) gene expression on the viability, apoptosis and expression of interleukin-6 (IL-6) and C-reactive protein (CRP) in vascular endothe-lial cells induced by hypoxia.METHODS: The protein expression of CARHSP1 was detected by Western blot in atherosclerotic plaques. Human umbilical vein endothelial cells (HUVECs) were treated with hypoxia, and the cells were divided into normal culture group, hypoxia group, hypoxia+CARHSP1-siRNA group and hypoxia+pcDNA3.1-CARHSP1 group. The viability and apoptotic rate of the HUVECs were measured by CCK-8 assay and flow cytometry, respectively. The mRNA expression of IL-6 and CRP was detected by RT-PCR. The protein levels of caspase-3, cleaved caspase-3, Bcl-2 and Bax were determined by Western blot.RESULTS: The protein expression of CARHSP1 in atherosclerotic plaques was significantly higher than that in control group (P<0.05). Hypoxia significantly increased the expression of CARHSP1. The cell viability and the protein expression of Bcl-2 were significantly lower in hypoxia group than those in normal culture group (P<0.05). The apoptotic rate and the protein levels of IL-6, CRP, cleaved caspase-3 and Bax were significantly higher than those in normal culture group (P<0.05). Compared with hypoxia group, the cell viability and protein expression of Bcl-2 were significantly increased in hypoxia+CARHSP1-siRNA group, while the apoptotic rate and the protein levels of IL-6, CRP, cleaved caspase-3 and Bax were decreased significantly (P<0.05). The cell viability and protein expression of Bcl-2 were decreased significantly in hypoxia+pcDNA3.1-CARHSP1 group, while the apoptotic rate and the protein le-vels of IL-6, CRP, cleaved caspase-3 and Bax were increased significantly (P<0.05).CONCLUSION: The expression of CARHSP1 is increased in atherosclerotic plaques, and inhibition of CARHSP1 expression improves the viability, reduces the apoptosis, and down-regulates the expression of IL-6 and CRP in the HUVECs. Over-expression of CARHSP1 exerts the opposite effect.