OxLDL/β2GPⅠ/β2GPⅠ-Ab complex in regulating the phenotypic transformation of A7r5 and the expression of lipid transporters / 临床检验杂志

ABSTRACT

Objective@#To investigate the effects of oxidized low-density lipoprotein/β2 glycoproteinⅠ/β2 glycoproteinⅠantibody (oxLDL/β2GPⅠ/β2GPⅠ-Ab) complex on the phenotypic transformation and lipid transpoters on the surface of rat thoracic aorta smooth muscle cell line (A7r5), and their correlation with toll-like receptor 4 (TLR4) signaling pathway. @*Methods@#A7r5 cells were stimulated by oxLDL, oxLDL/β2GPⅠ complex, oxLDL/β2GPⅠ-Ab complex, β2GPⅠ/β2GPⅠ-Ab complex and oxLDL/β2GPⅠ/β2GPⅠ-Ab complex respectively, and then total RNA and protein were collected. The expressions of α-smooth muscle actin (α-SMA), macrophage surface marker CD68, galectin-3 (LGALS3), scavenger receptor class B member 3 (CD36) and ATP-binding cassette transporter A1/G1 (ABCA1/ABCG1) were detected by real-time quantitative PCR (RT-qPCR), western blot and immunofluorescence (IF) respectively. The roles of TLR4 and its downstream signaling molecules in the phenotypic transformation and expression changes of lipid transporters of A7r5 cells induced by oxLDL/β2GPⅠ/β2GPⅠ-Ab complex were investigated by the pretreatment of TLR4 blocker TAK-242 (5 μmol/L) or c-Jun N-terminal kinases 1/2 (JNK 1/2) blocker SP600125 (90 nmol/L). @*Results@#The oxLDL/β2GPⅠ/β2GPⅠ-Ab complex significantly increased the levels of CD68 and LGALS3, and decreased the level of α-SMA, while TAK-242 could reverse this phenomenon. The oxLDL/β2GPⅠ/β2GPⅠ-Ab complex could promote the expression of CD36 and inhibit the expression of ABCA1/ABCG1, while TAK-242 and SP600125 could reverse this process. @*Conclusion@#The oxLDL/β2GPⅠ/β2GPⅠ-Ab complex promotes the phenotypic transformation of A7r5 cells to macrophage-like cells, regulates the expression of lipid transport-related molecules and enhances the ability of lipids transport into cells. TLR4 and JNK1/2 are closely related to this process.