Oxidized Low-Density Lipoprotein Induces WNT5A Signaling Activation in THP-1 Derived Macrophages and a Human Aortic Vascular Smooth Muscle Cell Line

Abstract

The pathogenesis of atherosclerosis is complex, evolves, and involves many cell types. Macrophages and vascular smooth muscle cells (VSMCs) are critically involved in atherosclerosis development and progression. Several studies have shown that WNT5A protein is abundantly expressed in human atherosclerotic lesions; however, the mechanism and role of WNT signaling pathway activation is not clearly known. Using THP-1 derived macrophages, and human aortic VSMC cells, we evaluated in vitro how oxidized low-density lipoprotein (oxLDL) and WNT5A signaling interact in these two cell lines. We used western blot, scratch assay, metabolic proliferation assay, as well as immunostaining to analyze the effect of Wnt signaling activation. The results demonstrated that oxLDL, as well as WNT5A (control), induced Disheveled-2 (DVL2) activation and Kif26b degradation, indicating activation of non-canonical Wnt signaling. We found that oxLDL and WNT5A induced FZD5-ROR2 co-localization at the cellular membrane in vitro in THP-1 derived macrophages. Box5 (FZD5 receptor antagonist) inhibited oxLDL-induced DVL2/JNK activation secondary to newly secreted WNT protein from THP-1 derived macrophages. We found that WNT3A (canonical Wnt) and WNT5A showed different roles in this VSMC cell line. These findings indicate that WNT5A is upregulated by oxLDL, promotes foam cell formation, and affects VSMC phenotype and migration in these two cell lines. Also, in these cell lines FZD5 signaling seems to be necessary for lipid accumulation and, through this mechanism, WNT5A could modulate foam cell formation. Thus, our results suggest that WNT5A may contribute to the pathogenesis of vascular disease through modulating macrophage and VSMC behavior.

DOCK9 antisense RNA2 interacts with LIN28B to stabilize Wnt5a and boosts proliferation and migration of oxidized low densitylipoprotein-induced vascular smooth muscle cells

“…Overexpression of Wnt5a promoted the proliferation and migration of ox-LDL-induced VSMCs, suggest that Wnt5a might promote the progression of atherosclerosis. Interestingly, Ackers et al [ 24 ] found that Wnt5a might promote differentiation of the human VSMCs into foam cells, indirectly aggravating atherosclerosis, in line with the findings in this study. Of note, the expression of Wnt5a was decreased when DOCK9-AS2 or LIN28B was silenced, indicating a potential regulatory role of DOCK9-AS2/LIN28B on Wnt5a.…”

Wnt5a/Ror2 promotes vascular smooth muscle cells proliferation via activating PKC

“…Our previous study has illustrated that the combination of Wnt5a and Ror2 together suppresses the expression of adenosine triphosphate-binding cassette transporter A1 (ABCA1) promotes cholesterol accumulation and secretion of pro-inflammatory cytokines and nuclear translocation of NF-κB in VSMCs, and ultimately leads to atherosclerosis [16]. OxLDL increased Wnt5a expression, induced foam cell formation, and affected the migration and phenotype of VSMCs [27]. In the present study, our results demonstrated that Wnt5a could significantly promote VSMCs proliferation, while knockdown of Wnt5a reversed the VSMCs proliferation.…”

Inhibition of microRNA-494-3p activates Wnt signaling and reduces proinflammatory macrophage polarization in atherosclerosis

“… 34 , 35 , 36 , 37 The Wnt signaling pathway in macrophages has been described to be important for phagocytosis, clearance of LDLs, and foam cell formation, and thus may have a role in limiting cholesterol accumulation in atherosclerosis. 36 , 38 , 39 , 40 WNT5A and LRP6 are both Wnt components that play a role in cholesterol metabolism, 39 , 40 and both are putative targets of miR-494-3p. WNT5A expression levels did not respond to 3GA-494 treatment ( Figure S2 ), but expression of LRP6 was significantly decreased in 3GA-494-treated M2 macrophages.…”