DDIAS Regulation of STAT3/CCL2 Promotes Macrophage Polarization to M1 type in Kawasaki Disease.

Objective: To investigate the molecular mechanism by which DNA damage induced apoptosis suppressor (DDIAS) regulates STAT3/CCL2 to enhance macrophage polarization to M1 type in Kawasaki disease (KD).

Methods: A KD vascular model was established by culturing human coronary artery endothelial cells (HCAECs) in vitro. Small interfering RNA of DDIAS (si-DDIAS) was transfected into the KD cell model. The human macrophage cell line THP-1 was induced into M1 macrophages using phorbol myristate acetate (PMA) and lipopolysaccharide (LPS) and co-cultured with the endothelial cells using the HCAECs medium. Western blot analysis was utilized to assess cellular DDIAS, p-STAT3, STAT3, and CCL2 protein expression. MTT was utilized to detect cell proliferation. ELISA was utilized to assess the expression levels of TNF-α, IL-4, IL-6, IL-8 and CCL2 in cell supernatants. Flow cytometry was utilized to examine cell apoptosis and the expression of M1 macrophage surface marker CD86.

Results: The expression level of DDIAS was elevated in the KD group compared to the Control group. Serum inhibition of HCAEC proliferation in the KD group was concentration-dependent and pro-inflammatory cytokines were substantially elevated, while the anti-inflammatory cytokines were substantially reduced (P<0.05). Compared to the si-NC group, cell proliferation was considerably enhanced; pro-inflammatory cytokines were substantially reduced; anti-inflammatory cytokines were substantially elevated, and the expression of p-STAT3 and CCL2 was lowered in the si-DDIAS group (P<0.05). The percentage of M1 macrophages was substantially elevated in the THP-1+LPS group compared to the THP-1 group (P<0.05). Compared to the THP-1+LPS+si-NC group, macrophage CCL2 expression was decreased in the THP-1+LPS+si-DDIAS group; the percentage of M1 macrophages was substantially lowered (P<0.05); and the levels of pro-inflammatory cytokines and CCL2 in the cell supernatant were substantially reduced. Incubation of macrophages with STAT3 agonist reversed these changes, which were exacerbated by the addition of neutralizing antibody CCL2.

Conclusions: Downregulation of DDIAS inhibits macrophage polarization toward the M1 type through inhibition of the STAT3/CCL2 signaling pathway and can ameliorate vascular injury and inflammation in KD coronary arteries.