MiRNAs regulate the expression of sterol‐O acyltransferase 1 through inhibiting the 3′UTR of TGFβ receptor type 1 during embryonic development

Abstract

Nutrients are utilized and re‐constructed by endodermal epithelial cells (EECs) of yolk sac membrane (YSM) in avian species during embryonic development. Sterol‐O acyltransferase 1 (SOAT1) is the key enzyme to convert cholesterol to cholesteryl ester, and for packaging into very‐low‐density lipoproteins for further delivering to growing embryos. During embryonic development, the quick absorption of yolk is matched with the significant changes of SOAT1 mRNA and enzymatic activity. MicroRNAs (miRNAs), groups of highly conserved small non‐coding RNA molecules, are usually ~23 nucleotides across species, serving classical biofunctions as mRNA‐targeting cleavage, translation repression and mRNA deadenylation. miRNAs have been identified to regulate angiogenesis, invasion and metabolism during mammalian development. However, the involvement and importance of miRNAs in lipid utilization during avian embryogenesis remains unclear.Using a RNA sequencing technique, we found many miRNAs expressed during quail embryonic development. We confirmed the expression pattern with real time PCR and several miRNAs (gga‐miR‐181a‐5p, gga‐miR‐133a‐5p, and gga‐miR‐429‐3p) were selected because they are candidates targeting to the receptor (TGFβ receptor type 1, TGFBR1) that regulates the expression of SOAT1. Similar to SOAT1 mRNA concentration, the gga‐miR‐181a‐5p expressions were gradually elevated during development, but gga‐miR‐429‐3p were presented in the opposite direction. Moreover, transfection with gga‐miR‐181a‐5p, gga‐133a‐5p, or gga‐429‐3p inhibited TGFBR1 and SOAT1 mRNA expressions in EECs. The 3′ untranslated region (3′UTR) of TGFBR1 is speculated to be one of the targets of miRNAs (gga‐miR‐181a‐5p, gga‐miR‐133a‐5p, and gga‐miR‐429‐3p).Taken together, miRNAs expression during embryonic development can regulate SOAT1 expression through inhibiting the 3′UTR of TGFBR1. This is indicative of possible regulation of avian yolk lipid utilization and modification of hatchability by modifying miRNA expression.Support or Funding InformationMinistry of Science and Technology, Taiwan (ROC)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.