Effects of umbilical cord blood mononuclear cells transplantation via lateral ventricle on the neural apoptosis and the expression of Bax and Bcl-2 proteins in neonatal rats with hypoxic-ischemic brain damage

Objective To explore the effects of umbilical cord blood mononuclear cells (UCBMC) transplantation on the neuronal apoptosis and the expression of Bcl-2 and Bax proteins in neonatal rats with hypoxic-ischemic brain damage (HIBD). Methods Seven-day-old Sprague-Dawley neonatal rats were randomly divided into normal control (N)+normal saline (NS), HIBD + NS, N+UCBMC, and HIBD + UCBMC groups. HIBD model was prepared using the classical Rice-Vannucci method. Twenty-four hours after HIBD, UCBMC were transplanted in the N+UCBMC and HIBD+UCBMC groups. Seven days after transplantation, NeuN/Cleaved-Caspase-3 double immunofluorescence staining and TUNEL methods were used to observe neural apoptosis in the cortex. The expression levels of Bax and Bcl- 2 proteins were examined by Western blot analysis. Results There were more NeuN+ cleaved Caspase-3+DAPI+ and TUNEL+DAPI+ cells in the HIBD+NS group compared with the N+NS and N+UCBMC groups (P<0.01). There were less NeuN+ cleaved Caspase-3+DAPI+ and TUNEL+DAPI+ cells in the HIBD+UCBMC group compared with the HIBD + NS group (P<0.01). The concentration of Bax protein was higher and that of Bcl-2 proteins was lower in the HIBD+NS group compared with the N+NS and N+UCBMC groups (P<0.01). The concentration of Bax protein in HIBD+UCBMC group was lower than that in the HIBD+NS group (P<0.01). The concentration of Bcl-2 protein was higher compared with the HIBD+NS, N+NS and N+UCBMC groups (P<0.05). Conclusions UCBMC transplantation via lateral ventricle can upregulate the expression of Bcl-2 protein and down-regulate the expression of Bax protein, thus alleviating brain neural apoptosis in neonatal rats with HIBD.