441: Differential mitochondrial DNA methylation in growth restricted placentas

lipase, or MAGL) remodel tissues. Leptin activates a key ECB-degrading enzyme called fatty acid amide-hydrolase (FAAH) in immunologic and neuronal cells. Relationships between placental ECBs, placental structure, and maternal/fetal leptin have not been reported. This study aimed : 1) to evaluate expression of placental ECBs and their relationships to placental composition and to fetal and maternal leptin status in a baboon model; 2) to sequence baboon CB1 and CB2 receptors for the first phylogenetic comparison to humans. STUDY DESIGN: Placentas from eight baboons were collected and processed as described previously (Farley et al., 2009). Placental composition was estimated using computerized stereology on electron micrographs. Immunohistochemistry employed commercial antibodies. Slides were scanned and processed as previously described (Brocato et al., 2012). RT PCR was done with a kit according to manufacturer’s instructions. Twotailed correlation was applied for statistical analysis, P value of 0.05 was used to determine significance. RESULTS: The ratio of fetal endothelium to placental tissue correlated positively with MAGL and FAAH expressions (r 0.79, p 0.05 and r 0.70, p 0.05, respectively). Protein expression of FAAH in syncytiotrophoblast correlated positively with fetal leptin concentration (r 0.98, p 0.0001, Fig. 1A). CB1 receptors were expressed in fetal endothelial cells, cytotrophoblast, and fibroblasts of villous core (Fig.1B), displaying 100% homology on the protein level with human receptor. CONCLUSION: This is the first report regarding possible regulation of placental ECBs by fetal leptin and ECBs association with fetal endothelial remodeling. Placental FAAH may be a promising target for treatment of poor fetal growth.