Effects of umbilical cord blood monocytes transplantation in neonatal rats with hypoxic-ischemic brain damage on rat astrocyte proliferation and its correlation with bone morphogenetic protein 4 / 中华实用儿科临床杂志

ABSTRACT

Objective To investigate the effect of umbilical cord blood monocytes(UCBMC) transplantation in neonatal rats with hypoxic-ischemic brain damage (HIBD) on rat astrocyte proliferation and its correlation with bone morphogenetic protein(BMP) 4.Methods Forty 7-day-old SD rats with the random number table,were divided into normal control(CON) group,hypoxic-ischemic(HI) group,normal(N) + UCBMC group,HI + UCBMC group,10 rats in each group.HIBD model was prepared according to the Rice method.Twenty-four hours after hypoxia,the UCBMC group and HI + UCBMC group were injected with 3 × 106 UCBMC via the lateral ventricle.Seven days after transplantation,changes in the number of neurons were observed by Nissl staining;the expression of glial fibrillary acidic protein (GFAP) was observed by Western blot;the astrocyte proliferation was observed by proliferating cell nuclear antigen (PCNA)/GFAP,BMP4/GFAP immunofluorescence double staining,and their correlation was analyzed.Results Nissl staining showed that the neurons at cerebral cortex and hippocamp were irregularly arranged and decreased in the HI group,and the number of Nissl-stained cells were significantly less than that in the CON group(tcortex =26.54,thippocamp =32.26,all P ＜0.05) ;but the Nissl-stained cells were well arranged in the HI + UCBMC group and more Nissl-stained cells were observed as compared with the HI group (tcortex =10.18,thippocamp =12.56,all P ＜ 0.05) ; Western blot showed that the expression of GFAP in the HI group was significantly higher than that in CON group(t =5.50,P ＜ 0.05) ;but the expression of GFAP in the HI + UCBMC group was significantly lower than that in the HI group (t =3.04,P ＜ 0.05) ; immunofluorescence double staining showed that there were more PCNA + GFAP + cells in the HI group compared with the CON group(t =10.39,P ＜ 0.05),but fewer PCNA + GFAP + cells were observed in the HI + UCBMC group than those in the HI group(t =3.72,P ＜ 0.05).And there were more BMP4 + cells in the HI group compared with the CON group (t =5.52,P ＜ 0.05),but fewer BMP4 + cells were observed in the HI + UCBMC group than those in the HI group(t =2.33,P ＜0.05).The fluorescence intensity of GFAP were correlated with that of BMP4 in HI + UCBMC group (r =0.84,P ＜ 0.05).Conclusions UCBMC transplantation can decrease the proliferation of the astrocytes,thus promote brain damage repair and its mechanism might be collected with the decreased expression of BMP4.