miR-34a-5p inhibits the erythroid differentiation of K562 cells / 基础医学与临床

Objective To study the effects of microRNA-34a-5p on erythroid differentiation of K562 cells.Methods K562 cells were transfected with the microRNA-34a-5p mimics and antisense inhibitors specifically targeting mi-croRNA-34a-5p, respectively.The effects of over-expression or knocking-down of microRNA-34a-5p were exam-ined by Quantitative RT-PCR.Flow cytometry was performed to detect specific surface marker of erythroid cells . The benzidine staining assay was used to access the differentiation of K 562 cells.Western blot was performed to de-tect miRNA targets.Results microRNA-34a-5p was down-regulated at the early stage of K562 erythroid differenti-ation.Over-expression of microRNA-34a-5p in K562 cells attenuates erythroid differentiation , in contrast, inhibi-tion of microRNA-34a-5p accelerates erythroid pheotypes in K562 cells.c-MYB was found to be the direct target of microRNA-34 a-5 p in erythroid cells .Conclusions microRNA-34 a-5 p regulates early erythroid differentiation of K562 cells via repressing c-MYB.

ZNF330 promotes erythroid differentiation / 基础医学与临床

Objective To explore the effects of ZNF330 on erythroid differentiation of K562 cells and underlying mechanism .Methods Realtime PCR was performed to detect the expression of ZNF 330 in K562 cells induced by hemin .After CD34 +cells being infected by the recombination lentivirus ZNF 330-RNAi, Realtime PCR was applied to detect the expression of CD235a and γ-globin.The luciferase report assay was performed to examine if ZNF 330 could act as a trans-acting factor in 293T/17 cells.Co-Immunoprecipitation (Co-IP) was applied in 293T/17 cells to detect the interaction between ZNF 330 and ZNF408 which was involved in mRNA degradation .Results The ex-pression of ZNF330 was up-regulated after hemin treatment .The expression of CD235a andγ-globin decreased after inhibition expression of ZNF 330 had no effect on report gene .Co-Ip in two ways confirmed the direct binding be-tween ZNF330 and ZNF408 .Conclusions ZNF330 can promote erythroid differentiation , and a possible mecha-nism is that ZNF330 inhibits the function of ZNF 408 , a factor that is involved in mRNA degradation , through the interaction between the two proteins .

MiR-24 improves beta-like globin gene expression through targeting Sp1 / 生物工程学报

We studied the function and mechanism of miR-24 in regulating beta-like globin gene expression. We first detected the expression of miR-24 during erythroid differentiation and also detected the globin gene expression in miR-24 overexpressing K562 cells through q-PCR. Dual-luciferase reporter assay and Western blotting were used to identify target genes of miR-24. "Rescue experiment" was further used to investigate the regulation of miR-24 on globin gene expression whether depending on targeting Sp1 or not. We found that miR-24 increased during hemin-induced K562 cells and EPO-induced HPCs (hematopoietic progenitor cells) erythroid differentiation. Overexpression of miR-24 in K562 cells promoted the epsilon- and gamma-globin gene expression during hemin-induced erythroid differentiation through targeting the negative globin regulator Sp1. These results suggested that miR-24 can improve the expression of beta-like globin gene through targeting Sp1.

Relationship between apolipoprotein E ε4,ε2 alleles and intrauterine growth / 中华神经科杂志

Objective To investigate the relationship between apolipoprotein E (ApoE) ε4,ε2 alleles and intrauterine growth.Methods ApoE genotypes of 1418 people born in Peking Union Medical College Hospital were analyzed,allele frequencies were calculated and their parameters at birth were collected.To compare ApoE ε4,ε2 alleles with parameters at birth through single factor analysis and Logistic regression analysis.Results The alleLic frequencies of e2,83 and 84 were 8.11%,83.39% and 8.50% in the group.The results of single factor analysis showed that there was significant difference between the distribution of ponderal index (PI) in the ApoE ε2 allele group(χ2=4.87 ,P=0.027).While there was no significant difference between the distribution of head circumference at birth,placental weight and gestational age in the ApoE ε2 allele group.ApoE ε2 allele showed negative correlation with small PI in the logistic regression analysis(χ2=5.077 ,P=0.024),after adjusted for gender,age,head circumference at birth,placental weight,gestational age,parity and maternal age at delivery.No association between ApoE ε4 allele and parameters at birth was found.Conclusions ApoE ε2 allele may have protective effect on PI.No association was found between ApoE ε4 allele and intrauterine growth.