Inhibitory Effect of HCPT on Expression of HIF-1α and Downstream Genes in Hypoxic Human Cervical SiHa Cancer Cells

The hypoxic model to simulate hypoxic microenvironment in solid tumors was established and the effect of hydrocamptothecin （HCPT） on the hypoxia-induced over-expression of HIF-1α and VEGF genes was explored. Human cervical cancer SiHa cells were cultured in vitro under hypoxic conditions （37℃, 5% CO2, 1%O2） and treated with different concentrations of HCPT for 24 h. The mRNA and protein expression levels of HIF-1α, VEGF and Glutl in SiHa cells were detected by semi-quantitative RT-PCR and Western blot respectively. Normoxic control groups were exposed to normoxic conditions for 24 h. Under normoxic conditions, HCPT had no obvious effects on the HIF-1α and VEGF gene expression. Hypoxia induced the up-regulation of HIF-1α protein and downstream VEGF gene, and HCPT showed a dose-dependently inhibitory effect on the hypoxia-induced over-expression of HIF-1α protein and VEGF gene expression in SiHa cells, whereas HCPT had no significant effect on the HIF-1α mRNA expression. No difference in HCPT cytotoxic- ity was observed between hypoxic groups and normoxic control groups. It was suggested that HCPT could inhibite the expression of HIF-1α protein and downstream VEGF gene in hypoxic SiHa cells in a dose-dependent manner, and the inhibitory effect was not related with HCPT cytotoxicity.     

Effects of glucose and insulin on the H9c2 （2-1） cell proliferation may be mediated through regulating glucose transporter 4 expression

Background The change of glucose transporter 4 （GLUT4） expression could influence glucose uptake in the myocardial cells and then effect myocardial metabolism, which maybe one of the factor for the diabetes cardiovascular disease. This study aimed to explore the influence of glucose and insulin at different concentrations on H9c2 （2-1） cell proliferation and its GLUT4 expression in vitro, and evaluate the correlation between myocardial cells proliferation and GLUT4 expression. This might be helpful for understanding the relationship between glucose metabolism and cardiovascular disease. Methods According to glucose concentrations in culture medium, cultured H9c2 rat myocardial cells were divided into five groups： control group （NC, glucose concentration 5.0 mmol/L）, low glucose group （LG, glucose concentration 0.1 mmol/L）, high glucose group 1 （HG1, glucose concentration 10 mmol/L）, high glucose group 2 （HG2, glucose concentration 15 mmol/L）, high glucose group 3 （HG3, glucose concentration 20 mmol/L）. Then according to different insulin concentrations in culture medium, each group was further divided into two subgroups： normal insulin subgroup （INSc, insulin concentration 3.8 mU/L）, high insulin subgroup （INSh, insulin concentration 7.6 mU/L）. H9c2 （2-1） cells were cultured for 1, 2, 3 days, the proliferation of cells were assayed by cell counting Kit-8 assay, the expressions of GLUT4 mRNA and protein were detected with RT-PCR and Western Blotting technique, and the relation between myocardial cells proliferation and GLUT4 expression was evaluated.     

Metformin inhibits nuclear factor-κB activation and inflammatory cytokines expression induced by high glucose via adenosine monophosphate-activated protein kinase activation in rat glomerular mesangial cells in vitro

Background The renoprotective mechanisms of adenosine monophosphate （AMP）-activated protein kinase （AMPK） agonist-metformin have not been stated clearly.We hypothesized that metformin may ameliorate inflammation via AMPK interaction with critical inflammatory cytokines The aim of this study was to observe the effects of metformin on expression of nuclear factor-κB （NF-κB）,monocyte chemoattractant protein-1 （MCP-1）,intercellular adhesion molecule-1 （ICAM-1） and transforming growth factor-beta 1 （TGF-β1） induced by high glucose （HG） in cultured rat glomerular mesangial cells （MCs）.Methods MCs were cultured in the medium with normal concentration glucose （group NG,5.6 mmol/L）,high concentration glucose （group HG,25 mmol/L） and different concentrations of metformin （group M1,M2,M3）.After 48-hour exposure,the supernatants and MCs were collected.The expression of NF-κB,MCP-1,ICAM-1,and TGF-β1 mRNA was analyzed by real time polymerase chain reaction.Westem blotting was used to detect the expression of AMPK,phospho-Thr-172 AMPK （p-AMPK）,NF-κB p65,MCP-1,ICAM-1,and TGF-β1 protein.Results After stimulated by HG,the expression of NF-κB,MCP-1,ICAM-1,TGF-β1 mRNA and protein of MCs in group HG increased significantly compared with group NG （P ＜0.05）.Both genes and protein expression of NF-κB,MCP-1,ICAM-1,TGF-β1 of MCs induced by high glucose were markedly reduced after metformin treatment in a dose-dependent manner （P ＜0.05）.The expression of p-AMPK increased with the rising of metformin concentration,presenting the opposite trend,while the level of total-AMPK protein was unchanged with exposure to HG or metformin.Conlusion Metformin can suppress the expression of NF-κB,MCP-1,ICAM-1 and TGF-β1 of glomerular MCs induced by high glucose via AMPK activation,which may partlv contribute to its reno-protection.     

Hypoxia-Inducible Factor-lalpha Suppressing Apoptosis and Increasing Tolerance of Lung Cancer Cells to Chemotherapy

In order to construct plasmid of hypoxia-inducible factor-lalpha （HIF-1α）, and transfect into human lung cancer cells A549, the change in sensitivity of lung cancer cells A549 to chemotherapy was observed. HIF-1α mRNA structure region was amplified by RT-PCR and inserted into plasmid pcDNA3. The expression plasmid pcDNA3/HIF-1α was transfected into A549 with LipofectAMINE^TM2000. The expression of HIF-1α protein was detected by Western blot. After A549 cells were transfected with HIF-1α prior to addition of 5-Fu, the growth activity was measured by growth curve, apoptosis was detected by flow cytometry at 48 h, and the levels of caspase3 and MDR-1 were determined by Western blot. The results showed that the constructed expression plasmid was analyzed with restriction enzymes and gel electrophoresis. Two DNA lanes at 2.55 kb and 5.4 kb respectively were found, which were consistent with that expected. The growth rate in 5-Fu group was significantly inhibited, and the apoptosis index and caspase3 activity were increased significantly as compared with control group. After HIF-1α being transfected into A549, the activity of MDR-1 was increased and the effect of 5-Fu was weakened. In conclusion, HIF-1α can promote chemoresistance by increasing the activation of MDR1 and suppressing apoptosis during lung cancer cells A549 in- duced with 5-Fu.     

Effects of TNF-α and curcumin on the expression of VEGF in Raji and U937 cells and on angiogenesis in ECV304 cells

Background To better understand the possibilities of antiangiogenic tumor therapy and to assess possible side effects, we investigated the effect of tumour necrosis factor （TNF）-α and curcumin on the expression of vascular endothelial growth factor （VEGF） in U937 and Raji cell lines and their effect on angiogenesis in a human umbilical vein endothelial cell （HUVECs）-derived cell line （ECV304）, and also the relationship between Notchl and VEGF. The aim of this study was to elucidate potential mechanisms controlling tumor neovascularization. Methods VEGF secreted by U937 and Raji cell lines was determined by ELISA. Angiogenesis was tested by network formation of endothelial cells on Matrigel. Levels of VEGF mRNA in U937 and Raji cells and Notchl mRNA levels in EV304 cells were determined by RT-PCR. Results Secretion of VEGF by U937 and Raji cells was increased by TNF-α treatment and suppressed by curcumin （P 〈 0. 01 ）. The mRNA expression of VEGF165 and VEGF121 （containing 165 and 121 amino acid residues, respectively） were detected in any fractions. TNF-α augmented the expression of VEGF165 and VEGF121 mRNA and curcumin reduced the expression （P 〈0. 01 ）. No networks or cords formed in control and curcumin groups. There was tube formation on matrigel in the supernatants of the Raji culture group and the supernatants groups treated by VEGF group and TNF-α in Raji cell. Notch1 mRNA was detected but there was no significant change in the VEGF group compared with control （P 〉 0. 05）. Conclusions Expressions of VEGF mRNA in U937 and Raji cells were increased by TNF-α and suppressed by curcumin. VEGF and TNF-α can induce angiogenesis, and curcumin can inhibit angiogenesis in ECV304 cells.     

The Expression of Hypoxia Inducible Factor 1-alpha in Lung Cancer and Its Correlation with P53 and VEGF

To investigate the expression of hypoxia inducible factor 1-alpha (HIF-1α) and its corre-lation with P53 and vascular endothelial growth factor (VEGF), immunohistochemical technique was employed to detect the protein expressions of HIF-1α, P53 and VEGF in specimens from 57 pa-tients with lung cancer. The results indicated that the total positive proportion of HIF-1α expres-sion was 63% and the HIF-1α expression was more frequent in bronchiole-alveolar carcinoma (86%) than in other lung cancer. There was a strong association of HIF-1α with VEGF and P53 pro-tein expressions. It is concluded that HIF-1α overexpression is a common event in lung cancer,which may be related to the up-regulation of the angiogenic factor VEGF and oncogene mutant P53 protein.     

筋脉通胶囊血清有效成分可预防大鼠高血糖浓度引起的施万细胞凋亡

Objective: To evaluate the effect of serum containing Jinmaitong Capsule (筋脉通胶囊, JMT) on apoptosis of Schwann cells (SCs) that are cultured in high glucose at the cellular and molecular levels. Methods: SCs were cultured in Dulbecco''s modi?ed Eagle''s medium (control group), high glucose (50 mmol/L) medium supplemented with 20% rat serum (HG group), and 50 mmol/L glucose medium supplemented with serum containing JMT (JMT group). SC apoptosis was detected using a terminal deoxynucleotidyl transferase dUTP nick end labeling kit. The expression of Bcl-2 and the caspase-3 p20 subunit in SCs were detected by real-time fluorogenic quantitative polymerase chain reaction and confocal laser scanning microscopy, respectively. Results: No apoptosis was detected in SCs that were cultured in the control group. The percentage of apoptosis of SCs cultured in the HG group was much higher than that in the control group. The apoptosis of SCs in the JMT group was lower than that in the HG group. Fluorescence intensity of Bcl-2 and the expression of Bcl-2 mRNA in SCs that were cultured in the HG group were much lower than those in the control group and much higher than those in the JMT group (P<0.01). The fluorescence intensity of caspase-3 p20 and the expression of caspase-3 p20 mRNA in SCs that were cultured in the HG group were much higher than those in the control group (P<0.01), and they were remarkably lower in the JMT group (P<0.01). Conclusions: JMT effectively prevents SC apoptosis that is induced by high glucose. This effect may be because of increased expression of Bcl-2 mRNA and protein and decreased expression of caspase-3 p20 mRNA and protein.     

Effect of Dexamethasone and Aquaporin-1 Antisense Oligonucleotides on the Aquaporin-1 Expression in Cultured Human Trabecular Meshwork Cells

The changes in the expression of aquaporin-1 （AQP1） mRNA and protein in cultured human trabecular meshwork （HTM） cells treated with dexamethasone and transfected with antisense oligonucleotides （AS-ODN） were studied, and the implication of AQP1 regulation in corticosteroid-glaucoma and the possibility of AS-ODN inhibiting the AQP1 expression were evaluated. The cultured HTM cells in vitro were treated with different concentrations of dexamethasone and transfected with oligonucleotides for 5 days respectively. Then, total RNA and protein of HTM cells were extracted. The changes of AQP1 mRNA and protein were demonstrated qualitatively and quantitatively by RT-PCR and Western blot. Band intensities were detected by imaging analysis. There was a parallel relationship between the results of RT-PCR and those of Western blot. The expression levels of AQP1 mRNA and protein in dexamethasone-treated groups were increased initially and decreased later as dexamethasone concentration was stepped up. In the 0.04 μg/mL and 0.4 μg/mL groups, the levels of AQP1 were higher than in control group （0 μg/mL）. In the 4 μg/ mL and 40 μg/mL groups, the AQP1 expression levels were lower than in control group. AS-ODN could down-regulate the expression of AQP1 mRNA and protein in a dose-dependent manner. At 5 μg/mL, down-regulation efficiency reached the maximum. There was no statistically significant difference in the expression of AQP1 mRNA and protein between all sense oligonucleotides groups and control group. It was suggested that dexamethasone may induce the changes of the AQP1 expression in HTM cells to be involved in the occurrence of corticosteroid-glaucoma. AS-ODN can down-regulate the AQP1 expression in HTM cells to some extent.     

Effects of transfection of ICAP-1α and its mutants on adhesion and migration of 2H-11 cells

This study examined the effect of integrin cytoplasmic domain-associated protein 1α (ICAP-1α) and its mutatants T38A and I138A on the adhesion, migration and tube formation of 2H-11 cells.rAAV-ICAP-1α, rAAV-T38A and rAAV-I138A were constructed.After infection, the expression of ICAP-1α and p-ERK1/2, p-c-Jun protein was measured by Western blotting.Adhesion ability was evaluated by using MTT.Cell migration was determined by using Boyden chamber method.Tube formation test was conducted on Matrigel.The results showed that in ICAP-1α, T38A and I138A groups, ICAP-1α protein expression was increased.In T38A and I138A groups, phospho-ERK1/2, phospho-c-Jun protein expressions were significantly increased as compared with the control group and the GFP group.ICAP-1α group protein expression was obviously decreased when compared with the control group and the GFP group.Cell adhesion ratio was 0.1429±0.0080 in control group, 0.1434±0.0077 in GFP group and the ratio in T38A and I138A groups increased to 0.3210±0.0082 and 0.3250±0.0079, respectively.In ICAP-1α group, the ratio was decreased to 0.1005±0.0073.In T38A and I138A groups, the number of migrating 2H-11 cells was increased to 31.45±3.20 and 33.10±5.40 against 18.51±2.80 in control group and 20.47±3.12 in GFP group.In ICAP-1α group, the number was decreased to 12.06±1.72.The number of tube-like structures was increased to 20.41±2.54 in T38A and to 22.26±3.07 in I138A groups as compared to those of control group 12.45±1.84 and GFP group 13.63±2.71.In ICAP-1α group, the number of tube-like structures was decreased to 8.32±1.24.It was suggested that rAAV-T38A and rAAV-I138A transfection can substantially increase 2H-11 cell adhesion, migration and angiogenisis, while rAAV-ICAP-1α can greatly inhibit the effect.These effects might be correlated with ERK1/2 and c-Jun protein phosphorylation.     

Effect of taurine on GFAP and TauT expressions in rat retinal Müller cells in high glucose culture

Objective： To detect the expression of glial fibrillary acid protein （GFAP） and taurine transporter （TauT） in the retinal Müller cells in high glucose culture with taurine and to explore the influence of glucose on the taurine transporting, and the possible protective effects of taurine on MUller cells in early diabetic retinopathy. Methods： The Müller cells from the rat retina were cultured in high glucose, and GFAP and Taut expressions were detected in the cells treated with different doses of taurine by immuocytochemical fluorescein staining and Western blotting. Results： High glucose enhanced the expression of GFAP and decreased the expression of TauT in Müller cells. Taurine decreased the up-regulation of GFAP in the cells which was induced by high glucose; 0. 1-10 mmol/L taurine increased the expression of TauT in Müller cells. Conclusion： Taurine can inhibit the changes in Müller cell resulted from high glucose.     

Effect of taurine on GFAP and TauT expressions in rat retinal Müller cells in high glucose culture

Objective： To detect the expression of glial fibrillary acid protein （GFAP） and taurine transporter （TauT） in the retinal Müller cells in high glucose culture with taurine and to explore the influence of glucose on the taurine transporting, and the possible protective effects of taurine on MUller cells in early diabetic retinopathy. Methods： The Müller cells from the rat retina were cultured in high glucose, and GFAP and Taut expressions were detected in the cells treated with different doses of taurine by immuocytochemical fluorescein staining and Western blotting. Results： High glucose enhanced the expression of GFAP and decreased the expression of TauT in Müller cells. Taurine decreased the up-regulation of GFAP in the cells which was induced by high glucose; 0. 1-10 mmol/L taurine increased the expression of TauT in Müller cells. Conclusion： Taurine can inhibit the changes in Müller cell resulted from high glucose.     

Expression of Toll-like receptor 4 in neonatal cord blood mononuclear cells in patients with preeclampsia

The expression of Toll-like receptor 4 (TLR4) in neonatal cord blood mononuclear cells (MNCs) and serum TNF-α were investigated in order to explore the roles of TLR4 in the pathogenesis of preeclampsia.The study enrolled 27 patients suffering from preeclampsia (experimental group) and 21 normal pregnancy patients (control group).After MNCs were separated, the expression of TLR4 mRNA and protein was detected by using real-time quantitative PCR and Western blotting respectively, and the expression of TNF-α by using ELISA.The results showed the TLR4 mRNA level in cord blood MNCs (2-CT:0.07±0.17), TLR4 protein expression level (absorbance ratio:0.81%±0.15%) and TNF-α level (9.5±1.73 pg/mL) were all increased in experimental group as compared with control group with the differences being statistically significant (P<0.05).There was a positive correlation between the expression of TLR4 mRNA and TNF-α in both experimental group and control group (r=0.54 and 0.53, respectively, P<0.05).It was concluded that TLR4 expression in the experimental group of cord blood MNCs was increased and there was a positive correlation between the expression of TLR4 mRNA and TNF-α in both groups.TLR4-mediated release of inflammatory cytokines may be one of the important reasons leading to preeclampsia.     

Effect of NADPH oxidase inhibitor apocynin on the expression of hypoxia-induced factor-1α and endothelin-1 in rat carotid body exposed to chronic intermittent hypoxia

The effects of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor apocynin on the enhanced hypoxia induced factor-1α (HIF-1α) and endothelin-1 (ET-1) expression,elevated systolic blood pressure under chronic intermittent hypoxia (CIH) condition and its action mechanism were investigated.Thirty healthy 8-week old Sprague-Dawley (SD) male rats were randomly divided into three groups (n=10 each): sham group,CIH group,and apocynin-treated CIH group.Tail artery systolic blood pressure was measured by tail-cuff method.Real-time fluorescence quantitative polymerase chain reaction (PCR) was used to detect the mRNA expression of HIF-1α and ET-1 in the carotid body,and the HIF-1α protein expression was examined by using Western blotting.The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were determined by using colorimetric method.In addition,the plasma ET-1 and HIF-1α levels were measured by using enzyme-linked immunosorbent assay.It was found that CIH exposure was associated with increased MDA levels,and apocynin-treated CIH animals showed reduction in MDA levels.Apocynin treatment prevented CIH-induced hypertension as well as CIH-induced decrease in SOD.The increases of HIF-1α and ET-1 mRNA along with HIF-1α protein expression in the carotid body,and elevated circulating HIF-1α and ET-1 levels were observed in CIH-exposed animals.Treatment with apocynin significantly decreased the ET-1 mRNA,HIF-1α protein expression and circulating HIF-1α level in CIH-exposed animals,and there was no statistically significant difference in the HIF-1α mRNA expression between CIH group and apocynin-treated group.These results indicated that apocynin alleviated CIH-induced hypertension by inhibiting NADPH oxidase,further leading to the reduced vasoconstrictor ET-1 level and oxidative stress.HIF-1α/ET-1 system signal pathway may interact with CIH-induced NADPH oxidase-dependent oxidative stress.Inhibition of NADPH oxidase activity may hopefully serve as a useful strategy for prevention and treatment of obstructive sleep apnea hypopnea syndrome-induced hypertension.