Study On The Anti - Inflammatory Mechanism Of Exenatide In High Glucose - Induced Cardiomyocytes

Objectives:To imitate the injury induced by sustained high glucose,we use the high glucose culture the primary cardiomyocytes, Giving exendin-4 treatment to observe the influence of inflammatory markers of myocardial cells, and p-p38 MAPK and NF-κB and SIRT1 protein expression.Methods :1.Cultured cardiomyocytes were rando mly divided into 5 groups: 1) normal group:cardiomyocytes were cultured in DMEM containing 5.5mmol/L glucose;2)high glucose group: cardiomyocytes were cultured in DMEM containing 30mmol/ L Gluco-se; 3) low dose group: cardiomyocytes were c ultured in DMEM containing 30 mmol /L glucose and 10nmol/L exendin-4;4) high dose group: cardiomyocytes were culture d in DMEM containing 30mmol/L glucose and 20nmol/L exendin-4; 5) The control group:cardiomyocytes were cultured in DMEM containing 5.5m mol/L D-glucose and 24.5mmol/L D-Mannitol. After additional 24 hours culture, cells and medium were co-llected for further assays;2.The content of Inflammation factors in culture medium w-ere detected by ELISA kit.The protein expressions of p-p38 MAP K was measured by Western Blot.Myocardial cell nucleoprotein was extracted by N uclear and C ytoplasmi-c Protein Extraction K it,then,the cell nucleoprotein expressions of p65 was measured by Western Blot.RT-PCR was for the expression of SIRT1 m RNA.Results:1.The content of inflammatory cytokines IL-6 and TNF-α:Results show that compared with normal control group, the content of high glucose group of inflammati-on factor of IL-6, TNF-α were significantly increased(p<0.01,p<0.01). This suggests that high glucose can cause myocardial cell inflammatory damage. With exendin-4 tre-atment(low dose group and high dose group), inflammatory factors of IL-6(p<0.05, p<0.05),TNF-α(p<0.05,p<0.01) levels are significantly lower suggesting that exendin-4 treatment can significantly reduce inflammatory injury of cells;2.The activity of tran-scription factors the NF-κB:Results show that compared with normal group, high glu-cose group of myocardial cell nuclei p65 protein expression is significantly increased(p<0.01), while giving exendin-4(low dose and high dose) myocardial cell nucleus p65 protein expression is significantly reduced(p<0.05). Results suggesst that giving the exendin-4 significantly reverse the increased of expression of nucleus p65 caused by high glucose;3. p38 MAPK activation:Results show that compared with normal gro-up, p-p38 MAPK protein expression of the high glucose group increase significantly(p<0.01), and treated with exendin-4(low dose group and high dose group)p-p38 MAP K elevated protein expression is improved obviously(p<0.05, p< 0.05);4.the expressi-on of SIRT1:Compared with normal group, the expression of SIRT1 proteins and m R NA decrease(p<0.05)in high glucose group, and treated with exendin-4, both SIRT1 proteins(p<0.05,p<0.01) and m RNA(p<0.05,p<0.05) are increased obviously compar-ed with high glucose group.Conclusions:1. The cultivation of myocardial cells in high glucose can induce cell da mage, along with the production of inflammatory cytokines, the NF-κB activity, p-p38 MAPK protein expression increased,and the expression of SIRT1 decreased;2.The tre-tment of exendin-4 to high glucose culture of rat myocardial cells can re lieve inflam-matory cell damage, transcription factor NF-κB activity is alleviated and the expressi-on of p-p38 MAPK is decreased. Exendin-4 can inhibit p-p38 MAPK protein expressi-on and the NF-κB activity, increase the expression of SIRT1.