Immunohistochemical profile of CD markers in experimental neural tube defect.

Neural tube defects (NTDs) are the second most common birth defects worldwide. Stem cells play a critical role in the mechanisms underlying NTDs. We established an experimental NTD model in rats using retinoic acid (RA). We used mesenchymal and hemopoietic stem cell markers to determine their distribution in the mesenchyme in and around the neuroepithelium during the embryonic and fetal periods in both cranial and caudal regions. Adult female rats were given RA on days 5 and 10 of gestation and olive oil was administered to the control group. On days 10.5 and 15.5, embryos in the experimental and control groups were removed from the uterus. Embryos were embedded in paraffin and serial sections of the cranial and caudal neural tube were examined. We found severe cranial and caudal defects including axial rotation in the experimental groups using histochemistry. We used CD44, CD56, CD73, CD90, CD105, CD271 antibodies as mesenchymal stem cell markers and CD14, CD45 as hemopoietic stem cell markers. More CD44, CD56, CD90, CD105 and CD14 were detected during the embryonic period than the fetal period. CD73 was more frequent during the fetal period, whereas CD271 and CD45 were not significantly different. When CD44, CD56, CD73, CD90, CD105, CD271 immunostaining was found, NTDs were decreased early and increased later. We found no significant difference between CD14 and CD45. Formation of NTDs was due to deterioration of the of the neuroepithelial and surrounding stem cells. One reason for the formation of NTDs is that stem cells may develop defective cell-cell or cell-matrix interactions.