Expression Of EIF3p170and Cycle Regulation Factors On Developmental Mouse Cardiomyocytes

Objective:To explored the expression of eIF3p170in the development of cardiac myocytes and the relationship between eIF3p170and the cell cycle regulation factors such as cell division cycle2(cdc2), CyclinDl and Cyclin B1in the development of cardiac myocytes.Methods:Fetal mouse hearts on days13,15, and18of gestation and postnatal mouse hearts on days1,2,3,5,10,20,30were employed in this research. All samples (fetal and postnatal hearts) were immediately frozen in liquid Nitrogen (N2) and stored at-80℃for further study. The expression of eIF3P170,cdc2, CyclinD1and CyclinB1mRNA were detected with Reverse transcriptase polymerase chain reaction (RT-PCR) at different time points and detected the relationship between eIF3P170and cdc2, CyclinDl and CyclinBl expression. The expression of cdc2, CyclinD1and CyclinB1protein were detected with Western-blotting at different time points. SPSS18.0statistical software was applicated for statistical data analysis, and P<0.05was considered to be statistically significant.Results:1. The expressions of eIF3P170, cdc2mRNAs were higher in the embryonic day13,15,18and postnatal days,2,3,5and the expressions of these mRNAs reached to the strongest at postnatal day5 (vs with other time points, all P<0.05). Then the expressions of the genes decreased gradually to the weakest at the postnatal day30(vs with other time points, all P<0.05). The expressions of Cyclin D1were higher in the embryonic day13,15,18and postnatal days1,2,3,5and the expressions of these mRNAs reached to the strongest at postnatal day5, but there were no significant statistically except the postnatal day30. Then the expressions of these genes decreased gradually to the weakest at the postnatal day30(vs with other time points, all P<0.05). The expressions of CyclinB1mRNA were higher in the embryonic day13,15,18and postnatal days1,2,3,5. Then the expressions of these genes decreased gradually to the weakest at the postnatal day30, but there were no significant statistically.2. The mRNA expressions of eIF3P170were correlated positively with cdc2, CyclinD1and CyclinB1mRNA expressions respectively.3. The protein expressions of cdc2were higher in the embryonic days15and18, and then decreased from postnatal day1on (P<0.05). The protein expressions of CyclinD1were higher in the embryoes and the early life after birth, then decreased on postnatal day5(P<0.05). The protein expressions of CyclinB1were lower in embryo period and early days after birth, which then expressed higher on postnatal day5(P<0.05).Conclusions:1.The mRNA expressions of eIF3P170, cdc2, CyclinD1and CyclinB1in mice hearts of the embryo and the early life after birth were high, and reached maximum at postnatal day5, then decreased gradually till postnatal day30.The protein expressions of cdc2decreased from postnatal day1on. The protein expression of CyclinD1decreased on postnatal day5, and the protein expression of CyclinB1increased on postnatal day5.2.Through the linear correlation analysis found that the mRNA expressions of eIF3P170with the mRNA expressions of cdc2, CyclinD1and CyclinB1were correlated positively.3. eIF3P170, cdc2, CyclinD1, CyclinB1may participate in cardiac myocytes withdraw the cell cycle.