Effect of fluid shear force on the expression of glucose-regulated protein 78 and C/EBP homologous proteins in human umbilical vein endothelial cells
Objective To explore the effect of fluid shear stress on the expression of glucose regulatory protein 78(GRP78)and C/EBP homologous protein(CHOP)in human umbilical vein endothelial cells(HUVECs).Methods HUVECs were used as experimental cells,and a fluid dynamics simulation experimental system was designed and constructed.Different fluid shear stresses were applied to the experimental cells by controlling the flow rate of the perfusion fluid in the experimental system.According to the fluid shear stress experienced by the experimental cells in the experimental system,they were divided into low shear stress group(group A;0.4Pa),medium shear stress group(group B;0.8 Pa)and high shear stress group(group C;1.2 Pa).Each group of HUVECs consisted of 3 cell slides,and each slide was repeatedly circulated through the perfusion solution of the experimental system for 12 h.Western blotting was used to detect the levels of GRP78 and CHOP proteins,and real-time quantitative reverse transcription polymerase chain reaction was used to determine the levels of GRP78 and CHOP and their messenger RNA(mRNA)in each group.GraphPad Prism 8.0 software was used to statistically analyze the data.Results(1)The relative expression levels of GRP78 protein in groups A,B and C were 1.33±0.46,0.93±0.34,0.64±0.30,respectively,the difference among groups was statistically significant(F=36.17,P<0.05).The relative expression level of GRP78 protein in group A was higher than that in group B and group C(both P<0.01),and the relative expression level of GRP78 protein in group B was higher than that in group C(P=0.0013).The relative expression levels of CHOP protein in the three groups were 1.29±0.38 in group A,0.90±0.34 in group B,and 0.59±0.29 in group C,the difference among groups was statistically significant(F=41.27,P<0.05).The relative expression level of CHOP protein in group A was higher than that in group B and group C(both P<0.01),and the relative expression level of CHOP protein in group B was higher than that in group C(P=0.0 004).(2)The relative expression levels of GRP78 mRNA in groups A,B,and C were 18.3±3.4,11.3±1.8,5.4±2.2,respectively,the difference among groups was statistically significant(F=189.20,P<0.05).The relative expression level of GRP78 mRNA in group A was higher than that in group B and group C(both P<0.01),and the relative expression level of GRP78 mRNA in group B was higher than that in group C(P<0.01).The relative expression levels of CHOP mRNA in the three groups were 20.4±3.8 in group A,14.2±2.1 in group B,and 7.8±1.3 in group C,the difference among groups was statistically significant(F=171.80,P<0.05).The relative expression level of CHOP mRNA in group A was higher than that in group B and group C(both P<0.01),and the relative expression level of CHOP mRNA in group B was higher than that in group C(P<0.01).Conclusion Low fluid shear stress may increase the protein and mRNA expression levels of GRP78 and CHOP in HUVECs.
HemodynamicsHuman umbilical vein endothelial cellsEndoplasmic reticulum stressFluid shear forceGlucose-regulated protein 78C/EBP homologous protein