Effects Of PKC-? On Expressions Of Artial Remodeling Proteins In HL-1 Cardiomyocytes Cultured In Hyperglycemia

Objective:To evaluate the roles of PKC-?/NF-?B pathway on atrial remodeling in HL-1 cardiomyocytes cultured in high glucose culture medium.Methods:The present study was divided into two parts.Firstly,HL-1 cardiomyocytes were extracted and cultured in 6-well culture plate.Cells were randomized into five groups: Control group,hyperglycemia group 1,hyperglycemia group 2,hypertonic group 1 and hypertonic group 2.The cells in control group were cultured with 5.5 mmol/L glucose.The cells in hyperglycemia group,hyperosnotic group were cultured with hyperglycemia(25 mmol/L and 33.3 mmol/L glucose),hypertonic(5.5 mmol/L glucose+19.5 mmol/L mannitol and 5.5 mmol/L glucose+27.5 mmol/L mannitol)respectively.After 48 hours,protein and mRNA expressions of PKC-? and downstream related factors were detected by western blot and RT-qPCR respectively.Secondly,HL-1 cardiomyocytes were extracted and cultured in 6-well culture plate.Cells were ranomized into five groups Control,Mock-control group,Mock-hyperglycemia group,siRNA-PKC?-control group,siRNA-PKC?-hyperglycemia group respectively.After 48 hours,protein and mRNA expressions of PKC-? and downstream related factors were detected by western blot and RT-qPCR respectively.Results: Firstly,the protein expressions of PKC-?,P38 MAPK,NF-?B,p-I-?B,TGF-? and TNF-? in hyperglycemia groups were significantly higher than those in control group(P < 0.05).There was no significant difference in the protein expressions of PKC-?,P38 MAPK,NF-?B,p-I-?B,TGF-? and TNF-? between hypertonic group and control group(P>0.05).TGF-? mRNA expression was higher in hyperglycemia groups than that in control group(P<0.05).There were no significant differences in the mRNA expression levels of PKC-?,P38 MAPK,NF-?B between hyperglycemia group and control group(P>0.05).Compared with control group,there was no significant difference in the protein expressions of PKC-??P38MAPK?NF-?B?TGF-? mRNA expressions in hypertonic group(P>0.05).Compared with hypertonic group,protein expressions of PKC-?,P38 MAPK,NF-?B,p-I-?B,TGF-? and TNF-? in hyperglycemia groups were significantly higher(P < 0.05).TGF-? mRNA expression was higher in hyperglycemia groups than that in hypertonic group(P<0.05).There were no significant differences in the mRNA expression levels of PKC-?,P38 MAPK,NF-?B between hyperglycemia group and hypertonic group(P>0.05).Secondly,the protein expressions of PKC-?,P38 MAPK,NF-?B,TGF-? and TGF-? mRNA in Mock-hyperglycemia group were significantly higher than those in control group(P<0.05).Compared with control group,there were no significant differences in the mRNA expression levels of PKC-?,P38 MAPK and NF-?B in Mock-hyperglycemia group(P > 0.05).Compared with Mock-hyperglycemia group,the protein expression levels of PKC-?,P38 MAPK,NF-?B,TGF-? and TGF-?,PKC-? mRNA expression in siRNA-PKC? hyperglycemia group were significantly lower(P<0.05).There was no significant difference in the mRNA expression levels of P38 MAPK,NF-?B in siRNA-PKC? hyperglycemia group(P>0.05).Conclusion: Firstly,Activation of PKC-? and up-regulation of related factors may play important roles in atrial remodeling in diabetes.Secondly,the protein expression level of PKC-? was significantly down-regulated after siRNA-PKC-? transfection,and protein expressions of NF-?B and TGF-?,P38 MAPK were down-regulated,it indicates that activation of PKC-?/NF-?B signaling pathway playing an important role in atrial remodeling in diabetes.The result may provide new thought for the upstream treatment of AF promotion by diabetes mellitus.