Lycium barbarum polysaccharides attenuate oxidative stress injury of human endothelium-like EA.hy926 cells induced by hydrogen peroxide

AIM: To study the effect of Lycium barbarum polysaccharides (LBP) on oxidative stress injury of human endothelium-like EA.hy926 cells induced by hydrogen peroxide (H₂O₂). METHODS: The EA.hy926 cell model of oxidative stress injury was established by H₂O₂ treatment. The EA.hy926 cells were divided into 5 groups:control group, damage (H₂O₂ at 50 mmol/L) group, LBP (100 mg/L) group, anti-damage groups (LBP at 50 mg/L, 100 mg/L or 200 mg/L+50 mol/L H₂O₂), and LY294002 (20 μmol/L) group. The effect of LBP at different concentrations on the cell viability of EA.hy926 cells was measured by CCK-8 assay, and the optimum concentration of LBP was screened out. The apoptotic of EA.hy926 cells was analyzed by flow cytometry. Acridine orange/ethidium bromide (AO/EB) staining was used to observe the morphological characteristics of the apoptotic cells. The cell migration ability was detected by scratch method. The levels of nitric oxide (NO) and vascular endothelial growth factor (VEGF) in the cell culture medium were examined. The protein levels of cleaved caspase-3, Bax, Bcl-2, endothelial NO synthase (eNOS), p-eNOS and p-Akt were determined by Western blot. RESULTS: LBP at concentration of 100 mg/L significantly attenuated the injury of EA.hy926 cells induced by H₂O₂, as indicated by improved cell viability (P<0.05) and decreased apoptosis (P<0.05). Pretreatment with LBP elevated the levels of NO and VEGF (P<0.05), and promoted the migration ability of EA.hy926 cells. LBP also increased the Bcl-2/Bax ratio, down-regulated the protein level of cleaved caspase-3, and up-regulated the protein levels of eNOS and p-eNOS. The protective effect of LBP were abolished by pretreatment of the EA.hy926 cells with the inhibitor of PI3K (P<0.05). As a result, the protein level of p-Akt was down-regulated, and the level of NO was also significantly reduced. CONCLUSION: LBP has protective effect on H₂O₂ -induced EA.hy926 cells by attenuating apoptosis of the cells. The mechanism is closely related to the activation of PI3K/Akt/eNOS signaling pathway.     

Salvianolate attenuates oxidative stress injury of human endothelial EA.hy926 cells induced by hydrogen peroxide

AIM: To investigate the effect of salvianolate on oxidative damage induced by hydrogen peroxide in human endothelial EA.hy926 cells.METHODS: EA.hy926 cells were cultured in vitro and divided into the following groups:control group, damage group, and anti-damage groups (salvianolate+damage groups). The cell viability was measured by CCK-8 assay. The migration ability of the EA.hy926 cells was detected by Transwell assay. The content of nitric oxide (NO) in the culture supernatant of the EA.hy926 cells was examined. The levels of vascular endothelial growth factor (VEGF) were detected by ELISA. The apoptosis,mitochondrial membrane potential and intracellular superoxide anion content of the EA.hy926 cells were analyzed by flow cytometry. The protein levels of caspase-3, cleaved caspase-3, Bcl-2, Bax, NF-κB and p53 were determined by Western blot. RESULTS: Compared with damage group, the viability of EA.hy926 cells pretreated with salvianolate at different concentrations was significantly increased (P<0.05). The apoptotic rate was significantly decreased (P<0.05). Savianolate enhanced the migration ability of the cells. The levels of VEGF, NO and mitochondrial transmembrane potential were increased (P<0.05), and the intracellular ROS level was significantly decreased (P<0.05). The protein levels of NF-κB, p53, Bax and cleaved caspase-3 were significantly decreased, and the protein level of Bcl-2 was markedly increased(P<0.05). CONCLUSION: Savianolate reduces the damage of EA.hy926 cells by hydrogen peroxide exposure, and its mechanism may be related to the blocking of NF-κB signaling pathway.     

Inhibitory effect of catalpol on inflammation and expression of RAGE in EA.hy926 cells induced by advanced glycation end products

AIM: To investigate the inhibitory effect of catalpol on inflammation in EA.hy926 cells induced by advanced glycation end products(AGEs) and to explore its antioxidant mechanisms.METHODS: Human endothelial cell line EA.hy926 was cultured and randomly divided into control group, catalpol(0.5 mmol/L) group, AGEs group, high-dose(0.5 mmol/L) catalpol+AGEs group, middle-dose(0.25 mmol/L) catalpol+AGEs group and low-dose(0.05 mmol/L) catalpol+AGEs group. Intracellular reative oxygen species(ROS) production was detected by laser scanning confocal microscopy. The levels of monocyte chemotactic protein-1(MCP-1), tumor necrosis factor-α(TNF-α) and vascular cell adhesion molecule-1(VCAM-1) in culture supernatant were detected by commercial ELISA kits. The expression of MCP-1, TNF-α, VCAM-1 and receptor for advanced glycation end products(RAGE) in the EA.hy926 cells were detected by Western blot.RESULTS: In high-dose catalpol+AGEs and middle-dose catalpol+AGEs groups, the generation of ROS was decreased significantly. The levels of MCP-1, TNF-α and VCAM-1, and protein expression of MCP-1, TNF-α and VCAM-1 were significantly lower. The expression of RAGE protein in EA.hy926 cells were significantly inhibited(P<0.05).CONCLUSION: Catalpol effectively inhibits the AGEs-induced oxidative stress and inflammation in EA.hy926 cells, which may be associated with a decrease in the expression of RAGE.     

Expression of Smoothened and its role in endothelial cells in synovial tissues of rheumatoid arthritis

AIM: To investigate the expression of Sonic Hedgehog signaling pathway-associated factor Smoothened (Smo) and its role in endothelial cells in synovial tissue of active rheumatoid arthritis (RA). METHODS: Smo expression in synovial tissue from 4 RA patients and 4 patients with trauma or meniscal injury (without arthritis, used for control) was detected by the method of immunohistochemistry. Human umbilical vein endothelial cell line EA.hy926 was used as the model of synovial vascular endothelial cells. The expression of Smo was detected by Western blotting after TNF-α treatment. The small interfering RNA (siRNA) specifically targeting Smo gene was synthesized and transfected into EA.hy926 cells. The interference efficiency of the siRNA on the production of Smo protein was determined by Western blotting. The cells were treated with TNF-α and actinomycin D (ActD) 24 h after siRNA transfection. The cell survival rate was determined by CCK-8 assay and the apoptotic rate was examined by flow cytometry. RESULTS: Smo was highly expressed in synovial tissue from active RA patients, especially in endothelial cells as compared with control group. TNF-α significantly increased the protein expression of Smo in EA.hy926 cells. EA.hy926 cells transfected with Smo-siRNA showed a significant decrease in the cell viability with the cell survival rate of (24.30±0.45)% and the apoptotic rate of (48.00±1.96)%, as compared with those in negative control group ［(36.86±0.62）% and （31.70±0.82）%, respectively］. CONCLUSION: Smo may play a role in the regulation of apoptosis in endothelial cells in RA synovium.     

miR-126 regulates expression of vascular endothelial growth factor in EA.hy926 cells

AIM：To explore the effects of miR-126 on the expression of vascular endothelial growth factor (VEGF) in vascular endothelial cell line EA.hy926. METHODS：EA.hy926 cells were cultured in vitro and transfected with miR-126 mimics or miR-126 inhibitor by cation-mediated transfection method. The total RNA was extracted from the culture cells 36 h after transfection of miR-126 mimics or miR-126 inhibitor. The expression of VEGF at mRNA and protein levels was detected by real-time PCR and Western blotting. RESULTS：Thirty-six hours after transfection of miR-126 inhibitor at concentration of 50 nmol/L, the expression of VEGF at mRNA and protein levels increased significantly as compared with the negative control (P<001). However, transfection of miR-126 mimics at concentration of 50 nmol/L for 36 h significantly decreased the expression of VEGF at mRNA and protein levels as compared with the negative control. CONCLUSION：miR-126 inhibits the expression of VEGF. VEGF may be one of the target genes regulated by miR-126.     

AngiotensinⅡ activates autophagy pathway through elevating ROS level in vascular endothelial cells

AIM: To evaluate the effects of angiotensinⅡ (AngⅡ) on autophagy induction in vascular endothelial cells. METHODS: Human vascular endothelial EA.hy926 cells were used in the study. Intracellular reactive oxygen species (ROS) levels were detected by a microplate reader after the cells were treated with AngⅡ (10^-7 mol/L) or AngⅡ combined with antioxidant N-acetyl-L-cysteine (NAC,50 μmol/L) for 24 h. The protein levels of LC3-Ⅱ was detected by Western blotting after the cells were stimulated by different concentrations (10^-8, 10^-7, 10^-6 mol/L) of AngⅡ for 24 h or by AngⅡ (10^-7mol/L) for different time (0 h, 6 h, 12 h, 24 h, 36 h). The number of autophagosomes was evaluated by fluorescence microscopy after stained with acridine orange. Similarly, the protein level of LC3-Ⅱ and the number of autophagosomes were detected after treated with AngⅡ(10^-7mol/L), AngⅡ combined with autophagy inhibitor 3-methyladenine (3-MA) at concentration of 2 mmol/L or AngⅡ combined with NAC at concentration of 50 μmol/L. RESULTS: Intracellular ROS level and LC3-Ⅱprotein level were significantly increased (P<0.05) after the cells were treated with AngⅡ, accompanied by the significant increase in the number of autophagosomes. AngⅡ-induced autophagy (as showed both in LC3-Ⅱprotein level and autophagosomes) was dramatically down-regulated by the treatment with 3-MA or NAC in EA.hy926 cells (P<0.05). CONCLUSION: AngⅡ induces autophagy through elevating ROS levels in EA.hy926 cells.     

Injuring effect of DMSO-soluble particles from cigarette smoke on human umbilical vein endothelial cell line EA. hy 926 in vitro

AIM: To investigate the injuring effect of DMSO-soluble particles from cigarette smoke(DSP) on human umbilical vein endothelial cells. METHODS: Human umbilical vein endothelial cell line EA. hy 926 was used as target cells in the study. The growth and viability of the cells treated with various dosages (1, 2, 4 or 4 mL/L) of DSP and low dose (2 mL/L) of DSP at different time points were evaluated by MTT colorimetric assay and celllular protein assay in 96-well plates. Transmission electron microscopy study was carried out to observe the ultrastructure of human umbilical vein endothelial cells under DSP treatment.RESULTS: DSP inhibited the proliferation of human umbilical vein endothelial cell line EA. hy 926. Under DSP treatment, the reducing cellular protein and increasing cell death(mainly necrosis) were observed in time-dependent and dosage-dependent manners.CONCLUSIONS: These results indicated that the toxic effect of DSP caused functional disturbance and structural damage of human endothelial cells.     

Effect of luteolin on TGF-β1-induced epithelial-mesenchymal transition in lung cancer A549 cells

AIM:To investigate the effects of luteolin on the invasion and epithelial-mesenchymal transition (EMT) induced by transforming growth factor-β1 (TGF-β1) in lung cancer A549 cells. METHODS:The effect of luteolin at 5, 10, 20, 40, 80 and 160 μmol/L on the viability of A549 cells was measured by MTT assay. The invasion ability was analyzed by Transwell method. The morphological changes of the A549 cells were observed under microscope.The protein expression of E-cadherin and vimentin in the A549 cells were determined by Western blot. RESULTS:The viability of the A549 cells was significantly inhibited by luteolin in a dose-time dependent manner (P<0.05). The IC₅₀ of luteolin for the A549 cells (24 h) was 68.79 μmol/L, while that (48 h) was 47.86 μmol/L. TGF-β1 induced morphological alteration of the A549 cells from epithelial to mesenchymal forms. Luteolin significantly inhibited TGF-β1-induced invasion of the A549 cells (P<0.01). The protein expression of E-cadherin was significantly down-regulated and the protein expression of vimentin was significantly up-regulated in the presence of TGF-β1 at 5 μg/L (P<0.01). However, luteolin reversed TGF-β1-induced EMT, up-regulation of E-cadherin and down-regulation of vimentin (P<0.01). CONCLUSION:Lu-teolin reverses TGF-β1-induced EMT in the lung cancer A549 cells.     

DENV-2 induces apoptosis of EA.hy926 cells through mitochondrial pathway

AIM：To explore the effect of dengue virus type 2 (DENV-2) infection on the change of mitochondrial membrane potential (Δψm) in EA.hy926 cells. METHODS：The inhibitory effect of DENV-2 infection on EA.hy926 cell growth was examined by MTT assay. The changes of Δψm were analyzed by flow cytometry or observed under fluorescence microscope with JC-1 staining. The activity of caspase-9 was measured by a colorimetric kit. RESULTS：Infection of DENV-2 for 24 h, 36 h and 48 h inhibited the viability of EA.hy926 cells. After DENV-2 infection, the changes of Δψm in EA.hy926 cells were observed. Compared with the normal control cells, Δψm in DENV-2-infected EA.hy926 cells was notably decreased. The activity of caspase-9 increased at early stage after infection of DENV-2 and maintained at a high level at least to 48 h. CONCLUSION：DENV-2 infection decreases the mitochondrial membrane potential and increases the activity of caspase-9 in EA.hy926 cells in the early stage of proliferation, thus promoting the process of apoptosis.     

ZNF580 is up-regulated in S1P-induced migration and proliferation of endothelial cells

AIM: To investigate whether a novel human C2H2-type zinc finger protein ZNF580 is involved in the proliferation and migration of endothelial cells induced by sphingosine 1-phosphate (S1P). METHODS: The cDNA of EA.hy926 cells was analyzed by RT-PCR to determine the S1P receptor expression profile. The cells were incubated with S1P at different concentrations and for different time intervals. Total RNA and protein in treated EA.hy926 cells were analyzed by RT-PCR and Western blotting. SB203580, a chemical inhibitor of p38 MAPK, was used to determine whether p38 MAPK pathway had any effect on the up-regulation of ZNF580 expression by S1P. The plasmid pEGFP-ZNF580 or the synthetic ZNF580-siRNA was transfected into EA.hy926 cells with Lipofectamine 2000 for 48 h. Cell migration assay and MTT colorimetric assay were used to investigate the effects of ZNF580 on the motility and growth of endothelial cells. RESULTS: EA.hy926 endothelial cells expressed S1P1, S1P3 and S1P5 receptors. Furthermore, S1P up-regulated ZNF580 at mRNA and protein levels in a concentration- and time-dependent manner. The p38 MAPK pathway specific inhibitor SB203580 blocked the S1P-induced up-regulation of ZNF580 expression. Moreover, overexpression/silencing of ZNF580 in EA.hy926 cells led to enhancement/decrease of the migration and proliferation of the cells. CONCLUSION: S1P-induced migration and proliferation of endothelial cells are critical for angiogenesis. ZNF proteins usually play an essential role in altering gene expression and regulating the angiogenesis.     

Hydrogen sulfide inhibits doxorubicin-induced inflammation and cytotoxicity in rat cardiomyocytes by modulating activation of NF-κB pathway

AIM：To investigate whether hydrogen sulfide (H2S) attenuates doxorubicin (DOX)-induced inflammation and cytotoxicity in rat cardiomyocytes (H9c2 cells) by modulating nuclear factor κB (NF-κB) pathway. METHODS：The expression of NF-κB p65 was measured by western blotting. The secretion levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor α (TNF-α) were tested by enzyme-linked immunosorbent assay (ELISA). Cell viability was detected by Cell Counting Kit-8 (CCK-8) assay. Hoechst 33258 nuclear staining was used to detect the morphological changes and number of apoptotic cells. RESULTS：Treatment of H9c2 cells with 5 μmol/L DOX significantly up-regulated the expression level of phosphorylated NF-κB p65 (p-p65), and induced inflammation and cytotoxicity, as evidenced by increases in secretion levels of IL-1β, IL-6 and TNF-α and number of apoptotic cells as well as a decrease in cell viability. Pretreatment of H9c2 cells with 400 μmol/L NaHS (a donor of H2S) for 30 min markedly depressed the up-regulation of p-p65 expression induced by DOX. In addition, NaHS pretreatment also reduced DOX-induced inflammatory response and injury, leading to decreases in IL-1β, IL-6 and TNF-α secretion and number of apoptotic cells as well as an increase in cell viability. Similar to the effect of NaHS, pretreatment with 100 μmol/L pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB, also blocked DOX-induced cardiac inflammation and cytotoxicity. Co-administration of IL-1 receptor antagonist (IL-1Ra) and DOX reduced DOX-induced activation of NF-κB and cytotoxicity in H9c2 cells. CONCLUSION：During the DOX-induced cardiomyocyte inflammation, there is positive interaction between NF-κB pathway and IL-1β. H2S may protect cardiomyocytes against DOX-induced inflammatory response and cytotoxicity by inhibiting NF-κB pathway.     

Effect of N,N-dimethylsphingosine on the expression of adhesion molecules in human umbilical vein endothelial cell line EA.hy926

AIM: To investigate whether and how N, N-dimethylsphingosine (DMS) plays a role in modulating the adhesion of monocytes to vascular endothelial cells, and identify whether human umbilical vein endothelial cell line EA.hy926 take place of the vascular endothelial cells.METHODS: Adhesion ratio was measured by flow cytometry, and immunohistochemistry was used to detect the expression of ICAM-1 and P-selectin in HUVEC: EA.hy926 cells after the effect of DMS. RESULTS: DMS inhibited the adhesion of monocytes to HUVEC: EA.hy926 cells in a time-dependent and concentration-dependent manner by reducing the expression of ICAM-1 and P-selectin. CONCLUSIONS: DMS reduced adhesion molecule expression in vascular endothelial cells. DMS may be an important contributor to reduce adhesion ratio, suggesting that DMS plays a negative role in proinflammatory and immune functions of the modified vascular endothelial cells during atherosclerosis and restenosis.     

Effect of lipopolysaccharide on viability and secretion function of human umbilical vein endothelial cells

AIM: To observe the direct effect of lipopolysaccharide (LPS) on secretion of endothelin-1 (ET-1) and nitric oxide by human umbilical vein endothelial cell and cell viability of the secretor. METHODS: The third passage of human umbilical vein endothelial cells were incubated with different concentrations of LPS (1 g/L, 100 mg/L, 10 mg/L, 1 mg/L, 100 μg/L, 10 μg/L, 1 μg/L) for 6 hours, and the culture supernatants were collected. The concentrations of ET-1 were determined by radioimmunoassay, the concentrations of nitric oxide were determined using Greiss's method. The viabilities of cells were measured by MTT method. RESULTS: The concentration of ET-1 (pg/L) of normal control group was 251.64±10.90. The concentrations of ET-1 (pg/L) of LPS treated groups were 220.85±19.14, 278.67±15.45, 306.40±11.60, 312.87±33.50, 324.38±17.02, 291.49±14.30, 282.11±13.38, respectively (each group compared with normal control group, P<0.05 or P<0.01). The concentration of NO_x (μmol/L) of normal control group was 629.46±13.36. The concentrations of NO_x (μmol/L) of LPS treated groups were 732.58±23.21, 669.87±9.32, 661.24±16.80, 650.33±13.24, 606.59±12.94, 626.75±9.83, 627.61±5.61, respectively (each group compared with normal control group, P<0.05 or P<0.01). The viabilities of endothelial cells of LPS treated groups were 74%, 81%, 86%, 88%,91%, 93%, 93%, respectively. CONCLUSION: LPS of lower concentrations had no significantly lethal effect on human umbilical vein endothelial cells, but enhanced secretion of ET-1 and inhibited NO production. LPS in higher concentrations showed significant lethal effect on human umbilical vein endothelial cells, inhibited secretion of ET-1 and enhanced NO production.     

Pycnogenol suppresses TGF-β1-induced hepatic stellate cell activation via ERK-mediated autophagy inhibition

AIM: To explore the effect of Pycnogenol on transforming growth factor-β1 (TGF-β1)-induced hepatic stellate cell activation. METHODS: Cultured LX-2 cells were treated with 5 μg/L TGF-β1 and different concentrations (0, 10, 25 and 50 mg/L) of Pycnogenol. The viability of the LX-2 cells under the conditions with or without autophagy inhibitor 3-MA and ERK inhibitor PD98059 was determined by MTT assay. The protein levels of α-SMA, ColⅠ, TIMP-1, LC3-Ⅱ/Ⅰ, beclin 1, p-ERK1/2 and ERK1/2 were detected by Western blot. RESULTS: Compared with control group, 5 μg/L TGF-β1 treatment elevated the cell viability, and increased the protein levels of α-SMA, ColⅠ, TIMP-1, LC3-Ⅱ/Ⅰ, beclin 1, p-ERK1/2, and ERK1/2 in the LX-2 cells (P<0.05). However, these effects were reversed by Pycnogenol pretreatment in a dose-dependent manner and the inhibitory effect of 50 mg/L Pycnogenol was the most significant in the LX-2 cells (P<0.05). Furthermore, compared with TGF-β1 group, pretreatment with 50 mg/L Pycnogenol, 5 mmol/L 3-MA or 20 μmol/L PD98059 downregulated TGF-β1-induced cell viability and the protein levels of α-SMA and LC3-Ⅱ/Ⅰ in the LX-2 cells (P<0.05). CONCLUSION: Pycnogenol suppresses TGF-β1-induced hepatic stellate cell activation via p-ERK and autophagy inhibition.     

Analysis of cytokines derived from murine yolk sac endothelial cells cultured in vitro

AIM:To purify murine yolk sac endothelial cells (mYS-EC) and investigate the cytokines mRNA expression in mYS-EC. METHODS:The murine yolk sacs were digested with 0.1% collagenase, resuspended in DMEM and counted after digestion and centrifugation. The yolk sac adherent cells were cultured in DMEM containing 15% FBS with 10% mBMEC-CM or 5μg/L VEGF, ECGF and bFGF. The phagocytose function and expression of vWF were evaluated via particle phagocytosis and immunohistochemistry method. Atlas cDNA expression array was used for analysis of cytokine expression in mYS-EC. RESULTS:Colonies consisting of pure yolk sac endothelial cells were obtained in liquid culture system containing 15% FBS and 10% mBMEC-CM or 5μg/L VEGF, ECGF and bFGF. For complete purification of the endothelial cells, subsequent passage was also necessary. Cellular cord formed during passage culture. The endothelial cells were round or oval sharp in morphology, positive in phagocytosis and factor VIII related antigen (von Willebrand's Factor, vWF). The mRNA expressions of cytokines, such as TGF-β2, TNF-α, IFN-γ, FL, BMP-4, MIP-1β, BMP-2A, FLT2, endothelin 2, thymosin β10, IL-6, IL-13, IL-9, SCYA5 and ACBP were detected in mYS-ECs. CONCLUSION:mYS-EC was purified and expanded in vitro. The mRNA expression of 15 kinds of cytokines was detected in mYS-ECs by Atlas arrays.     

Plasma circulating miR-126 in patients with coronary artery heart disease and its effect on vascular endothelial cells

AIM: To investigate the role of plasma circulating miR-126 and miR-16 in the patients with coronary artery heart disease and to explore the influence of miR-126 on vascular endothelial cells. METHODS: Plasma total RNA was isolated from 52 patients with stable coronary artery disease and 52 healthy volunteers. The circulating miR-126 and miR-16 in those people were detected using specific primers. Endothelial cell line EA.hy926 was transfected with a miR -126 inhibitor, and total RNA of the cells was isolated 30 h after transfection to detect the expression level of vascular endothelial growth factor (VEGF). RESULTS: The expression of plasma circulating miR-126 was significantly decreased in the patients with coronary artery heart disease compared with healthy controls (P<0.05). No significant difference of circulating miR-16 between the patients with coronary artery heart disease and healthy controls was observed (P>0.05). The expression of VEGF in the endothelial cell line EA.hy926 transfected with miR-126 inhibitor was 2.08 times higher than that in negative control cells 30 h after transfection (P<0.05). CONCLUSION: Plasma circulating miR-126 is significantly decreased in the patients with coronary artery heart disease. Plasma circulating miR-16 in the patients with coronary artery heart disease and in the healthy controls is stable. miR-126 negatively regulates the expression of VEGF in vascular endothelial cells.     

Effects of atorvastatin on expression of PAPP-A induced by TNF-α and IL-1β in rat aortic endothelial cells

AIM: To investigate the effects of atorvastatin on the expression of pregnancy-associated plasma protein A(PAPP-A)induced by TNF-α and IL-1β in endothelial cells. METHODS: The rat aortic endothelial cells were isolated from thoracic aortas and cultured by the tissue explant method. The cells in passage 3-4 were used in the experiment and were randomly divided into 4 groups: blank control group: the cells were treated without any intervention; atorvastatin concentration groups: the cells were incubated with atorvastatin at the concentrations of 0.1, 1 and 10 μmol/L for 24 h; atorvastatin time groups: the cells were incubated with atorvastatin at the concentration of 10 μmol/L for 6 h,12 h and 24 h; atorvastatin+inflammatory factors groups: the cells were pre-incubated with 60 μg/L TNF-α or 20 μg/L IL-1β for 1 h, then different concentrations of atorvastatin (0.1, 1.0, 10 μmol/L) were added for 6 h,12 h and 24 h. MTT reduction assay was used to observe the cell proliferation. The mRNA expression of PAPP-A was detected by RT-PCR. The protein level of PAPP-A in the supernatants of cultured cells was measured by ELISA. RESULTS: Compared with blank control group, no significant change of cell proliferation was observed after the intervention of atorvastatin and TNF-α/IL-1β for 3 h, 6 h, 12 h, 24 h and 48 h, indicating that the drugs had no toxic effects on the cells. No significant difference of PAPP-A expression between atorvastatin groups and blank control groups was found. Compared with TNF-α groups and IL-1β groups, PAPP-A expressions in atorvastatin intervention groups significantly decreased. The protein level of PAPP-A was gradually decreased with the raised concentration of atorvastatin and the prolonged time in a concentration- and time-dependent manner. CONCLUSION: Atorvastatin doesn't influence the PAPP-A expression, but inhibits the expression of PAPP-A activated by inflammatory factors in a concentration- and time-dependent manner in primary cultured rat aortic endothelial cells.     

Protective effect of anti-aging Klotho protein on human umbilical vein endothelial cells treated with high glucose

AIM: To study the protective effect of anti-aging Klotho protein on human umbilical vein endothelial cells (HUVECs) treated with high glucose (HG).METHODS: HUVECs were cultured in vitro, and divided into PBS control group, 5.5 mmol/L glucose group, 33.3 mmol/L glucose group, 0.1 μmol/L Klotho+33.3 mmol/L glucose group, 1 μmol/L Klotho+33.3 mmol/L glucose group, and 10 μmol/L Klotho+33.3 mmol/L glucose group. The viability of the HUVECs was measured by MTT assay. The content of malondialdehyde (MDA), and the activities of lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione (GSH) in cell culture supernatants were observed. The production of reactive oxygen species (ROS) in HUVECs was analyzed by flow cytometry. The levels of nitric oxide (NO), endothelin (ET-1), intercellular adhesion molecule-1 (ICAM-1) in HUVEC culture medium were detected by ELISA. The protein expression of nuclear factor-kappa B (NF-κB) in the HUVECs was determined by Western blot. RESULTS: Compared with PBS control group, 33.3 mmol/L glucose significantly decreased the HUVEC viability, increased ROS, LDH and MDA levels, reduced the activities of SOD and GSH, decreased the NO secretion, and induced the ET-1 and ICAM-1 secretion and the protein expression of NF-κB in HUVECs. When HUVECs were treated with Klotho protein at different concentrations combined with 33.3 mmol/L glucose, the cell viability was increased significantly, the ROS, LDH and MDA levels were decreased significantly, the antioxidant SOD and GSH activities were significantly increased, the secretion of NO was increased, but ET-1 and ICAM-1 releases and protein expression of NF-κB were significantly reduced.CONCLUSION: Anti-aging Klotho protein promotes the viability of HUVECs treated with HG, reduces the oxidative damage and ROS production, and restores the normal secretory function of HUVECs, thus playing a protective role in vascular endothelial cells through reducing the protein expression of NF-κB.     

Nitric oxide-mediated the cardioprotection of tumor necrosis factor-alpha on cultured neonatal rat cardiomyocytes during hypoxia/reoxygenation

AIM: To investigate the role of nitric oxide synthase (NOS), soluble guanylyl cyclase (sGC) and protein kinase C (PKC) signaling in tumor necrosis factor-α (TNF-α)-induced cardioprotection against hypoxia/reoxygenation (H/R) injury. METHODS: Neonatal rat ventricular myocytes were pretreated with TNF-α or sodium nitroprusside (SNP) or L-arginine (L-Arg), respectively, for 12 h and then subjected to continuous hypoxia for 12 h, followed by reoxygenation for 6 h. The manganese superoxide dismutase (Mn-SOD) activity of the cells was measured after H/R. Myocyte injury was determined by the release of lactic dehydrogenase (LDH). RESULTS: TNF-α (10⁵ U/L) significantly increased the Mn-SOD activity and decreased release of LDH from ventricular myocytes. The cardioprotection against H/R injury was induced by the pretreatment with SNP (5 μmol/L) or L-Arg (5 mmol/L), which was blocked by ODQ (10 μmol/L), the specific sGC inhibitor, and Chel (5 μmol/L), the specific PKC inhibitor. Pretreatment with L-NAME (100 μmol/L), ODQ, Chel, antoxidant 2-MPG (400 μmol/L) or tyrosine kinase inhibitor genistein (50 μmol/L) attenuated the increased Mn-SOD activity and reduced LDH level induced by TNF-α. CONCLUSION: The results suggest that NO may play a role in TNF-α-induced cardioprotection, which is mediated by sGC and PKC.     

Angiotensin-(1-7) protects H9c2 cardiac cells against high glucose-induced injury and inflammation by inhibiting the interaction between TLR4 activation and necroptosis

AIM: To investigate whether angiotensin-(1-7)[Ang-(1-7)] protects H9c2 cardiac cells against high glucose (HG)-induced injury and inflammation by inhibiting the interaction between Toll-like receptor 4 (TLR4) activation and necroptosis. METHODS: The expression levels of receptor-interacting protein 3 (RIP3; an indicator of necroptosis) and TLR4 were determined by Western blot. Cell viability was measured by CCK-8 assay. The activity of lactate dehydrogenase (LDH) in the culture medium was measured with a commercial kit. The releases of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were measured by ELISA. The intracellular level of reactive oxygen species (ROS) was analyzed by 2', 7'-dichlorfluorescein-diacetate (DCFH-DA) stating followed by photofluorography. Mitochondrial membrane potential (MMP) was examined by rhodamine 123 staining followed by photofluorography. RESULTS: After the H9c2 cardiac cells were treated with HG (35 mmol/L glucose) for 24 h, the expression of RIP3 was obviously increased. Co-treatment of the cells with 30 μmol/L TAK-242 (an inhibitor of TLR4) attenuated the up-regulation of RIP3 induced by HG. Furthermore, the expression of TLR4 was significantly increased after the cells were exposed to HG for 24 h, and co-treatment of the cells with 100 μmol/L necrostatin-1 (Nec-1; a specific inhibitor of necroptosis) and HG for 24 h attenuated the up-regulation of TLR4 expression induced by HG. Moreover, 1 μmol/L Ang-(1-7) simultaneously blocked the up-regulation of the RIP3 and TLR4 induced by HG. On the other hand, co-treatment of the cells with 1 μmol/L Ang-(1-7), 30 μmol/L TAK-242 or 100 μmol/L Nec-1 and HG for 24 h attenuated HG-induced injuries and inflammatory response, leading to the increase in the cell viability, and the decreases in the activity of LDH, ROS generation, MMP loss as well as the releases of IL-1β and TNF-α. CONCLUSION: Ang-(1-7) protects H9c2 cardiac cells against HG-induced injury and inflammation by inhibiting the interaction between TLR4 activation and necroptosis.