Multiomics Analyses of Vesicular Transport Pathway-Specific Transcripts and Proteins in Ovine Amnion: Responses to Altered Intramembranous Transport

Amniotic fluid (AF) volume (AFV) is determined primarily by the rate of intramembranous (IM) transport of AF across the amnion. Intramembranous transport is characterized as vesicular endocytotic and transcytotic processes regulated by fetal urine-derived stimulators and AF inhibitors. Our objectives were to utilize a large-scale multiomics approach to decipher the vesicular transport pathways in the amnion and to identify potential transport regulators in AF and fetal urine. We utilized fetal sheep to experimentally induce alterations in IM transport rate and analyze the expression profiles of transcripts and proteins in amnion, AF and fetal urine. Four experimental groups were studied: control (C), urine drainage with reduced IM transport rate and AFV (UD), urine drainage and fluid replacement with decreased IM transport rate but increased AFV (UDR), and intra-amniotic fluid infusion with augmented IM transport rate and AFV (IA). Amnion and fluid samples were subjected to transcriptomics (RNA-Seq) and proteomics studies followed by bioinformatics analyses using Ingenuity Pathway Analysis software. The analyses revealed 9 functional transport pathways and a panel of differentially expressed transcripts and proteins that are known mediators of vesicular transport and energy metabolism. During UD, expressions of endocytosis and trafficking mediators were reduced as compared to controls. Under UDR, expressions of energy metabolism activators increased while trafficking mediators decreased. During IA, expressions of vesicular uptake and transcellular trafficking regulators were enhanced. Co-expression of the motor protein, cytoplasmic dynein light chain-1, in both AF and fetal urine suggest that this molecule may function as a urine-derived stimulator of IM transport. Transcriptome and proteome in amnion and fetal fluids in four experimental groups. Utilized fetal sheep to experimentally induce alterations in IM transport rate and analyze the expression profiles of transcripts and proteins in amnion, AF and fetal urine.