Decoding the Amniotic Membrane Transcriptome during Equine Ascending Placentitis

The equine amniotic membrane is a critical barrier to the amniotic compartment and may contribute to surfactant synthesis. To investigate its role in ascending placentitis, we used RNA sequencing, bioinformatics, and immunohistochemistry to analyze gene expression in amniotic membranes from experimentally induced placentitis cases (n = 6) and gestationally matched controls (n = 6). We identified 288 differentially expressed genes (DEGs), with upregulation of TLR4, PTGS2, PTGES, MMP9, CASP3, SOD2, BNIP3, and HMOX1 in placentitis. Immunohistochemistry confirmed protein expression of TLR4 and PTGS2. Functional annotation revealed enrichment in toll-like receptor signaling, suggesting immune activation may impair placental function. These findings highlight the amniotic membrane's active role in immune response during placentitis. Overall design: RNAseq profiling of the aniotic membrane of mares during ascending placentitis compared to a negative control.