Résumé
AIM:To investigate the effect of gestational diabetes mellitus ( GDM) on glucose-lipid metabolism in the offspring mice and the underlying mechanisms .METHODS:Wild-type female mice were intraperitoneally injected with streptozotocin at 30 mg/kg in the second trimester of pregnancy to establish GDM model .Normal saline was used as control.F1 offspring mice were fed for 8 weeks after birth.The blood glucose and lipid levels were detected randomly .The mRNA levels of p300 and p300/CBP-associated factor ( PCAF) were detected by qPCR .The expression of peroxisome pro-liferator-activated receptor-γ( PPAR-γ) , glucose transporter typer 4 ( GLUT-4 ) and medium-chain acyl-CoA dehydroge-nase ( MCAD) at mRNA and protein levels was determined by qPCR and Western blot .ChIP-qPCR was employed to ana-lyze the binding status of p 300 with the promoter of PPAR-γand the acetylation level of histone H 3 in the promoter region of PPAR-γ.RESULTS:Blood glucose and total cholesterol levels were significant increased in the offspring mice ( P<0.05).The expression levels of p300, PPAR-γ, GLUT-4 and MCAD were decreased compared with the control group (P<0.05).Binding affinity of p300 with the promoter of PPAR-γwas reduced (P<0.05).The level of acetylated his-tone H3 in the promoter region of PPAR-γwas decreased significantly ( P<0.05) .CONCLUSION:Regulation of PPAR-γexpression by p300 may induce glucose-lipid metabolism disorder in the cardiomyocytes of GDM offspring mice .
Résumé
Aim To investigate the protective effect of Glucogon like pep tide-1 (GLP-1 )on H9C2 cardio-myocytes against AGEs-induced apoptosis and the po-tential molecular mechanisms.Methods H9 C2 car-diomyocytes cells cultured in vitro were divided into the following groups:normal control group ,1 0 0 mg · L-1 AGEs group,100 mg·L-1 AGEs+10 nmol·L-1 GLP-1 group,100 mg·L-1 AGEs+5 mmol·L-1 N-acetyl-cysteine (NAC)group.Cell viabillity rate was meas-ured by CCK-8 assay,ROS production was measured by DCFH-DA fluorescent probe;Cells in different groups were stained with Annexin V-FITC/PI and then apoptotic rate was detected by flow cytometry;Nucleus morphology was observed under fluorescence micro-scope after being incubated with Honchest 33258;Bax, Bcl-2 mRNA gene expression was measured using RT-PCR;Western blot was applied to assess the apoptotic components expression including Bax and Bcl-2.Re-sult Compared with control group,cell viability rate in AGEs group was decreased in a dose-dependent manner;cell apoptosis and ROS production in H9 C2 cells were remarkably increased in AGEs group.How-ever,compared with AGEs group,GLP-1 reduced ROS production and ameliorated cell apoptosis caused by AGEs;the expression of pro-apototic proteins Bax was decreased,the expression of anti-apoptotic proteins like Bcl-2 was increased. Conclusion GLP-1 protects H9 C2 cardiomyocytes against AGEs-induced apoptosis, which may be related to the reduction of the active oxy-gen (ROS).
Résumé
AIM:To investigate whether the opening of ATP-sensitive K+(KATP) channels protects H9c2 car-diac cells against high glucose ( HG)-induced injury and inflammation by inhibiting the Toll-like receptor 4 ( TLR4 )/nu-clear factor-κB ( NF-κB) pathway.METHODS:The protein levels of TLR4 and NF-κB p65 were determined by Western blot.The levels of interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α) were detected by ELISA.The cell viabil-ity was measured by CCK-8 assay.Mitochondrial membrane potential (MMP) was examined by rhodamine 123 (Rh 123) staining followed by photofluorography.The intracellular levels of reactive oxygen species ( ROS) were detected by 2′, 7′- dichlorfluorescein-diacetate (DCFH-DA) staining followed by photofluorography.The number of apoptotic cells was ob-served by Hoechst 33258 nuclear staining followed by photofluorography.RESULTS: After the H9c2 cardiac cells were treated with HG (35 mmol/L glucose) for 24 h, the protein levels of TLR4 and phosphorylated NF-κB p65 ( p-NF-κB p65) were significantly increased.Pretreatment of the cells with 100 μmol/L diazoxide ( DZ, a KATP channel opener) for 30 min before exposure to HG considerably blocked the up-regulation of the TLR4 and p-NF-κB protein levels induced by HG.Moreover, co-treatment of the cells with 30 μmol/L TAK-242 (an inhibitor of TLR4) obviously inhibited the HG-in-duced up-regulation of the p-NF-κB p65 protein level.On the other hand, pretreatment of the cells with 100 μmol/L DZ had a clear myocardial protection effect, which attenuated the HG-induced cytotoxicity, inflammatory response, mitochon-drial damage, oxidative stress and apoptosis, evidenced by an increase in the cell viability, and decreases in the levels of IL-1βand TNF-α, MMP loss, ROS generation and the number of apoptotic cells.Similarly, co-treatment of H9c2 cardiac cells with 30μmol/L TAK-242 or 100μmol/L PDTC ( an inhibitor of NF-κB) and HG for 24 h also obviously reduced the above injuries and inflammation induced by HG.CONCLUSION: The opening of KATP channels protects H9c2 cardiac cells against HG-induced injury and inflammation by inhibiting the TLR4/NF-κB pathway.