Effects of Foam Cell Formation Induced by Mycolic Acid on the Autophagy of Macrophages

Abstract: This paper was to study the effect of foam cell formation induced by mycolic acid (MA) on the autophagy of RAW264.7 macrophages， and explore the mechanisms of MA promoting foam cell formation of macrophage. The pEGFP-LC3B plasmid encoding LC3 was constructed， then transfected into RAW264.7 cell in order to obtain the stable transfected cell line (RAW264.7/pEGFP-LC3B). The foam cell was prepared by MA inducing RAW264.7/pEGFP-LC3B. There were 3 groups in the experiment: RAW264.7 cell group， RAW264.7/ pEGFP-LC3B group and RAW264.7/pEGFP-LC3B foam cell group. RT-PCR was performed to detect the gene transcription level of Becn1 and LC3B， and the expression level of autophagy marker protein LC3B II/I of each group was assessed by Western blot. The RT-PCR results showed that the gene transcription levels of Becn1 and LC3B in RAW264.7/pEGFP-LC3B foam cell group were lower than those of the other two groups (P<0.05)， and the Western blot results showed that the ratio of LC3B II/I in RAW264.7/pEGFP-LC3B foam cell group was lower than those of the other two groups (P<0.05). Therefore， when the macrophages were induced into foam cells by MA， their autophagy level was significantly reduced. This study suggests that MA promotes foam cell formation of macrophages by inhibiting autophagy to unbalance cell’s lipid metabolism.

CSTR: 32200.14.cjcb.2015.06.0013