The Influence Of FN–induced ERS On Foam Cell Formation Induced By Ox-LDL

Object: To explore the potential mechanism of fibronctin(FN) in AS. We hypothesize that FN influence the formation of foamy macrophage by inducing endoplasmic reticulum stress(ERS) in RAW264.7 cells.Methords: Utilizing Western blot to detected the expression of fibronectin and GRP78/bip in RAW264.7 incubated by ox-LDL. Examine the FN gene by RT-PCR. Examine the expression of FN and GRP78/bip after FNsiRNA and PBA used in RAW264.7 incubated by ox-LDL. ELISA analysis was performed to detect protein expression in the cell culture medium after incubated by ox-LDL. Oil-ox- LDL uptake was detected by fluorescence microscopy after transfected with FNsiRNA.Results: Western blot analysis showed that expression levels of FN and GRP78/bip were increased in Raw264.7 cells when induced by ox-LDL(P<0.05). RT-PCR suggests the expression of FN were increased(P<0.05). When adding PBA(the depressor of ERS),the increased of the GRP78/bip was inhibited and the increase of FN unchanged(P<0.05). In addition, when we knockdown the FN gene and then add the ox-LDL, the increase of FN and GRP78/bip are all inhibited. In the same time, the uptake of ox-LDL are decrease.Conclusions: Fibronectin induced endoplasmic reticulum stress on the formation of foam cells in AS.