Effects Of Different Umbilical Cord Blood Lead Levels On Telomere Length And Telomere Binding Protein (TRF1,TRF2) In Neonate

Objective To investigate the relationship among umbilical cord blood lead levels on telomere length and telomere binding protein (TRF1, TRF2) in neonate.Methods We collected84cases of umbilical cord blood from term infants whose gestation was without acute or chronic disease from Qingdao Municipal Hospital between July of2010to April of2013and the umbilical cord blood concentration was less than100μg/L.We used atomic absorption spectrometry to determine the concentration of umbilical cord blood lead and we divided the84cases into two groups according to the lead levels of umbilical cord blood at30μg/L,umbilical cord blood lead concentration less than30μg/L was very low lever group and more than30μg/L was low lover group. To extract umbilical cord blood DNA, extraction genome DNA from whole blood was used. Fluorescence quantitative PCR was used to measure the telomere length of genome DNA and ELISA to measure the concentration of telomere binding protein TRF1,TRF2. We used SPSS17.0to analyse the difference of two groups and the relationship were analyzed with Spearman correlation research.Result①The telomere length of very low lever group was0.684±0.540and low lever group was0.350±0.285. The difference between two groups was statistically significant (t=2.429, P=0.020).②RF1concentration of very low lever group was77.219±9.431(pg/ml) and low lever group was90.462±17.346(pg/ml). The difference between two groups was statistically significant(t=-3.146, P=0.003). TRF2concentration of very low lever group was220.296±57.042(pg/ml) and low lever group was180.194±28.767(pg/ml). The difference between two groups was statistically significant(t=2.782, P=0.008).③The relationship of the telomere length and umbilical cord blood lead concentrations correlated negatively(r=-0.342, P=0.027),which means that with increasing umbilical cord blood lead concentration, the telomere length of the neonate were progressive shorten. The relationship of the telomere blinding protein TRF1and umbilical cord blood lead concentrations correlated positively(r=0.482, P=0.001), however, the relationship of the telomere blinding protein TRF2and umbilical cord blood lead concentrations correlated negatively(r=-0.314, P=0.043).This means with increasing umbilical cord blood lead concentration, telomere blinding protein TRF1expression was more and TRF2was less.Conclusions The telomere length in neonate was associated with the umbilical cord blood lead levels, and with increasing umbilical cord blood lead concentration, the telomere length of neonate is progressive shorten, the expression of telomere blinding protein TRF1is increase and TRF2is decrease. Those explain that the factor of protect is reductive and harmful is incremental. The umbilical cord blood lead effect the expression of telomere blinding protein to interfere with telomere length.