Hyperglycemia has been identified as one of the important factors involved in the microvascular complications of diabetes, and has been related to increased cardiovascular mortality. Endothelial damage and dysfunction result from diabetes; therefore, the aim of this study was to determine the response of endothelial cells to stressful stimuli, modelled in normal and high glucose concentrations in vitro. Eahy 926 endothelial cells were cultured in 5 mmol/L or 30 mmol/L glucose conditions for a 24 hour period and oxidative stress was induced by exposure to hydrogen peroxide (H2O2) or tumour necrosis factor- α (TNF- α ), following which the protective effect of the glucocorticoid dexamethasone was assessed. Apoptosis, necrosis and cell viability were determined using an ELISA for DNA fragmentation, an enzymatic lactate dehydrogenase assay and an MTT assay, respectively. High glucose significantly increased the susceptibility of Eahy 926 cells to apoptosis in the presence of 500 μmol/L H2O2, above that induced in normal glucose (P<0.02). A reduction of H2O2- and TNF- α -induced apoptosis occurred in both high and low glucose after treatment with dexametha-sone (P<0.05). Conclusion high glucose is effective in significantly augmenting stress caused by H2O2, but not in causing stress alone. These findings suggest a mechanism by which short term hyperglycemia may facilitate and augment endothelial damage.

Archives ; China ; Humans ; Occupational Health ; Residence Characteristics

Humans ; Occupational Diseases ; epidemiology ; prevention & control ; Occupational Health Services

Archives ; Humans ; Occupational Health

Objective To study the protective effect of fluvastatin,one of the HMG-CoA reductase inhibitors (statins),against oxygen radical-induced oxidative damages in human aortic endothelial cell,and the role of Bcl-2 in this protection.Methods Human aortic endothelial cells with or without Bcl-2 siRNA transfection were subjected to 1-100 nM of fluvastatin and 100 la hydrogen peroxide for 24 hours.Bcl-2 mRNA and protein expression were measured by Taqman quantitative PCR and Western blotting.Cell apoptosis was measured by normal and fluorescent microscopy and Cell Death Detection ELISA.Results In the Bcl-2-expressed cells,fluvastatin significantly reversed hydrogen peroxide-induced microscopic apoptosis and apoptotic DNA fragmentation,which were accompanied by a markedly upregulation of Bcl-2 expression by fluvastatin.However,the endothelial protection by fluvastatin was completely lost in Bcl-2 siRNA transfected cells.Conclusion Fluvastatin protects human endothelial cells against oxygen radical-induced cell apoptosis in vitro,and this protection seemed to be mediated in a Bcl-2 dependent pathway.(J Geriatr Cardil 12008;5:33-38)

Objective The aim of this study was to determine if isoflavone genistien has protective effects against high glucose-induced cell apoptosis in human aortic endlthelial cells,and investigate the possible mechanism for this protection.Methods Human aortic endothelial cells subjected to normal (5mmol/L) or high glucose (25mmol/L) were treated with genistein at 0,50,100nmol/L.Parallel experiments were performed with 100nM 17b-estradiol,and also in the presence and absence of the pure anti-estrogen ICI-182,780 (100nmol/L).The effects on cell apoptotic DNA fragmentation were determined using cell death ELISA,and the effects on cellular proliferation were determined using tritiated thymidine incorporation assay.Estrogen receptor expression was detected by Taqman quantitative PCR.Results Genistein at 100nmol/L significantly reduced high glucose-induced DNA fragmentation,and reversed cell DNA synthesis inhibition (P＜0.001) after 24 hours' incubation.The effect of genistein was completely blocked by ICI-182,780administration.Estrogen receptor beta,but not alpha was found to be expressed in these cells.Conclusion Isoflavone genistein shows protection against high glucose-induced cell damage through estrogen receptor beta,reducing apoptotic DNA damage and protecting from the inhibition of cell proliferation.

Objective: To explore the role of cytosine-phosphate-guanine oligodeoxynucleotide(CpG ODN)in enhan- cing the radiosensitivity to X-ray in mouse with Lewis lung cancer.Methods: The tumor-bearing mouse model was in- duced by injevting Lewis lung cancer cells into the right infra-axillary dermis.Thirty-two C57BL/6J mice were evenly ran- domized into 4 groups.Group A: the control group;Group B: the X-Ray radiation group;Group C: the CpG group; Group D: the CpG plus X-Ray radiation group.Group B was treated with X-Ray radiation only(3 Gy/F,on day 1,3,5, 8,10,and 12;the total dose was 18 Gy);group C was administered with CpG ODN 0.05 mg on day 1,3,5,8,10, and 12;group D was administered with CpG ODN 6h before X-ray radiation.The tumor growth and tumor growth delay (TGD)were observed in all groups.Meanwhile,the pathological change of the tumor tissue was observed with H-E staining method and the apoptosis of tumor cells were examined with the method of TUNEL.Results: The Lewis hmg cancer-bearing model was successfolly established in mice.The tumor volumes of the treatment groups were smaller than that in lhe control group(P

Objective To study the relationship between the intervals of Mitomycin C treatment and cytotoxicity, apoptosis and drug resistance for bladder cancer cells.Methods The bladder transitional cell cancer line BIU-87 was treated for two hours every time for five times with intervals of 24, 48, 72 and 96 hours respectively.Cytotoxicity was measured by MTT.p53,bcl-2,Bax and p170 expression were analyzed by Western blot.Results The IC_(50)(?g/ml)were 4.41,0.71,2.83,4.51and 6.16 with treatment intervals of 24, 48, 72 and 96 hours respectively, p53 and bcl-2 were significantly down-regulated and bcl-2/Bax was re- duced at 24 hour treatment interval but not changed at 48,72 and 96 hour intervals,p170 was not detected at 24 hour treatment interval but increasingly expressed at 48,72 and 96 hours intervals.Conclusion The in- terval of Mitomycin C treatment is closely related with cytotoxieity and apoptosis and drug resistance of blad- der cancer cells.The intervals of intravesical instillations may play an important role in the effect of chemotherapy.

Objective To study the mechanism of RING finger protein 34 ( RNF34 ) involved in innate immunity . Methods Recombinant PCR was used and transient expression of the plasmid was achieved in HEK 293T cells.The cells were stimulated with Sendai virus ( SeV) or N-RIG-Ⅰfor the indicated time while luciferase activity was observed using the dual-luciferase reporter assay kit .Results We constructed the plasmid pcDNA 3-Flag-RNF34 and its three mutations .The study found that when stimulated by SeV , RNF34 could inhibit the activity of NF-κB and IFN-βmore significantly than RNF34-ΔFYVE, RNF34-ΔCID and RNF34-ΔRING.We also found that RNF 34 and its three mutants had similar inhibitory effect when the activation of NF-κB and IFN-βwas stimulated by the N-RIG-Ⅰ.Conclusion RNF34 negatively regulates innate immunity by acting on the RIG-Ⅰ-MAVS signaling pathway .

Objective To investigate the role of toll-like receptor 4 (TLR4) of endothelium or bone marrow derived cells in the acute lung injury (ALI) induced by lipopolyscccharide (LPS) in mice with reciprocal bone marrow transplantation. Method Chimeric mice were produced by reciprocal bone marrow transplantation between TLR4mut/mut and TLR4+/+ mice and divided into 4 groups: WT/WT (recipient/donor),WT/Mutant, Mutant/WT and Mutant/Mutant group. Six to eight weeks following transplantation, LPS was injected inot mice's tail vein in order to produce ALI model,and mice were sacrificed five hours later on.Samples of lung tissues were taken for the following analysis of wet/dry weight (W/D), lung permeabifity index (LPI), myeloperoxidase (MPO),levels of cytokines (TNF-α, IL-1β) and adhesion molecules (ICAM-1). Results Lung injury in the Mutant/Mutant mice was the mildest in the 4 groups. And lung injury in WT/Mutant mice was more serious than that in Mutant/WT mice. levels of MPO and ICAM-1 in WT/Mutant mice were much higher than those of Mutant/WT. In addition,the expression of ICAM-1 in WT/Mutant mice is comarable to that in WT/WT mice. Mutant/WT mice expressed higher levels of TNF-α and IL-1β than WT/Mutant mice. Conclusions Endothelial cell derived TLR4 plays ker-nel role in ALI induced by LPS via lung PMN recruitment,although bone marrow cells derived TLR4 are more im-portant for the release of cytokines.