STARD7 DEFICIENCY MODULATES THE EXPRESSION OF EXTRACELLULAR MATRIX ASSOCIATED-PROTEINS IN HTR8/SVNEO CELLS

CAPITAL FEDERAL

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIA; 2017

StarD7 transcript encodes an intracellular lipid transport protein, a member of the START domain superfamily, which is involved in many physiological processes. It facilitates the delivery of phosphatidylcholine to the mitochondria and previous results indicated that StarD7 knockdown decreases ACBG2 multidrug transporter level, cell migration, proliferation, and phospholipid synthesis. Additionally, we reported that its suppression promotes reticulum endoplasmic stress and ROS production. Here, we examined the effect of StarD7 silencing on several extracellular matrix associated- proteins in derived-first trimester trophoblast HTR8/SVneo cells. Data from qPCR and western analysis demonstrated a decrease in Cx43 mRNA and protein levels in the HTR8/SVneo cells transfected with StarD7 siRNA compared to control siRNA. Additionally, a significant increase in the mRNA and protein levels of integrin α5 in silenced cells was determined by qRT-PCR, western blot, and immunofluorescence assays. Also, a clear increase in the transcript level of integrin β1, as well as in the mature β1 and integrin α1 proteins were detected. Furthermore, StarD7 silencing leads to an increase in β-catenin and nidogen-1 at both protein and mRNA levels, as well as in the amount of MMP9 secreted to the culture medium. Collectively, our studies indicate that StarD7 depletion causes a dysregulation in several ECM-associated proteins suggesting that beyond its role in lipid transport, StarD7 contributes to maintain cellular homeostasis.