StarD7 knockdown leads to α5β1 integrin upregulation and Golgi fragmentation in HTR8/SVneo cells

CÓRDOBA

Congreso; REUNIÓN SAIB 2016; 2016

StarD7 belongs to START domain protein family, which is involved in lipid transport, metabolism and signaling. Preliminary results indicate that StarD7 silencing induces a decrease in HTR8/SVneo cell migration measured by wound healing assay. To address the mechanism implicated in this process the levels of α5 and β1 integrin subunits, p-FAK as well as β-catenin proteins were measured in HTR8/SVneo transfected with StarD7 siRNA for 72 h. Surprisingly, a significant increase in the mRNA and protein levels of α5 integrin in silenced cells was determined by qRT-PCR, western blot, and immunofluorescence assays. Also, a clear increase in the transcript level of β1 integrin, as well as in the β1 mature protein was detected. In addition, StarD7 silencing leads to an increase in p-FAK and β-catenin protein levels, whereas a decrease in the level of MMP9 secreted to the culture medium was established in StarD7 siRNA cells. Since it is widely accepted that Golgi apparatus regulates directional cell migration we analyzed its integrity. Immunofluorescence assay using anti-GM130 revealed that StarD7 knockdown induced Golgi apparatus fragmentation. In summary, our results suggest that StarD7 depletion causes a dysregulation in several molecules as well as in Golgi apparatus, which are involved in maintaining cellular migration.