Abstract
Cleft palate (CP), a congenital defect in the oral and maxillofacial regions, is difficult to detect prenatally. This study investigated the correlation between differentially expressed proteins in serum and CP induced by all-trans retinoic acid (atRA) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in mice. We studied 80 mice in the following groups: male mice (male; n = 6), nonpregnant female control mice (NP-CRL; n = 6), healthy pregnant controls (P-CRL; Con; n = 24), pregnant mice with CP induced by atRA (n = 24), or pregnant mice with CP induced by TCDD (TCDD; n = 20). Pregnant mice were given with atRA (100 mg/kg) or TCDD (40 μg/kg), or corn oil by oral gavage at E10.5. The serum samples were collected and eight proteins-including interleukin (IL)-12p40, IL-12p70, receptor for advanced glycation end products (RAGE), interferon (IFN)-γ, IFN-β, IL-10, leukemia inhibitory factor (LIF), and epiregulin-were detected by enzyme-linked immunosorbent assay. Placental tissues were immunostained for IL-12p40 and RAGE from stages E13.5 to E16.5. In P-CRL mice, serum IL-12p40 was significantly increased at E13.5 and declined over E14.5-E16.5. P-CRL had lower IFN-γ levels at E13.5 compared with NP-CRL. The CP groups showed lower concentrations of IL-12p40 at E13.5-E14.5 and clearly higher concentrations of soluble RAGE (sRAGE) at E13.5 when compared with P-CRL. IL-12p40 immunostaining clearly decreased in placental tissue sections obtained from E13.5 to E14.5 in both CP groups. These findings suggest that reduced levels of IL-12p40 and increased levels of sRAGE in serum may be correlated with chemically induced CP in mice, but further studies would be required to establish this.