Abstract: Objective To prepare an atherosclerosis(As)model employing an oxidised low-density lipoprotein(ox-LDL)-induced mouse macrophage cell line, so as to see whether microRNA-1270(miRNA-1270)interfered with macrophage inflammation and lipid metabolism via the angiopoietin-like protein 7(ANGPTL7)/p38 pathway. Methods Mouse mononuclear macrophages(RAW264.7)were cultured and ox-LDL was added to construct macrophage models. According to the different intervention conditions, the groups were as follows: blank group, ox-LDL group, ANGPTL7 group, p38 protein inhibition group, p65 protein inhibition group, miR-1270 mimic group, miR-1270 mimic negative control group, miR-1270 inhibitor group, and miR-1270 inhibitor negative control group. The mRNA expression level was detected by real-time quantitative PCR, the protein expression level was detected by Western bloting, and the lipid accumulation was detected by oil red staining. Results The number of macrophages containing red fat particles was increased in ox-LDL-exposed macrophages, with high expressions of ANGPTL7, p38, and IL-6, and low expression of IL-10, and a positive correlation between ANGPTL7 and p38 and lipid accumulation(P<0.01). Compared with the ANGPTL7 group, there was no significant difference in the relative expression of ANGPTL7 and p38 proteins in the p38 protein inhibition group, a decrease in the relative expression of IL-6 protein, an increase in the relative expression of IL-10 protein, and a decrease in the number of red adipose microparticle-containing macrophages(P<0.01). Compared with the ANGPTL7 group, there was no statistically significant difference in the expression of the indicators in the p65 protein inhibition group, and there was no statistically significant difference in the number of macrophages containing red fat particles(P>0.05). Compared with the blank group, the relative expression of miR-1270 gene was decreased and the relative expression of ANGPTL7 gene and protein was increased in the ox-LDL group, and miR-1270 was negatively correlated with the relative expressions of ANGPTL7 gene(r2=0.665 7, P<0.01). Compared with the ox-LDL group, the miR-1270 mimic group had increased relative expression of the miR-1270 gene, decreased relative expression of the ANGPTL7 gene and protein, decreased relative expression of the p38 and IL-6 proteins, increased relative expression of the IL-10 protein, and decreased number of red adipose microparticle-containing macrophages(P<0.01). The miR-1270 inhibitor group had a decrease in the relative expression of the miR-1270 gene, an increase in the relative expression of the ANGPTL7 gene and protein, an increase in the relative expressions of the p38 and IL-6 proteins, a decrease in the relative expression of the IL-10 protein, and an increase in the number of macrophages containing red adipose microparticles(P<0.01). Compared with the ox-LDL group, there was no significant difference in the expression of the indicators in the negative control group, and there was no statistically significant difference in the number of macrophages containing red fat particles(P>0.05). Conclusion In the ox-LDL-exposed macrophage model, ANGPTL7 promotes inflammation and lipid accumulation in macrophages via the p38 pathway, which is a new mechanism to promote the development of atherosclerosis. miR-1270, as a protective factor, can target and inhibit the transcriptional expression of the ANGPTL7 gene, reduce macrophage inflammation and lipid accumulation via the p38 pathway, and reversibly control the development of atherosclerosis, and is a potential early screening target for atherosclerosis. It is a potential target for early screening of atherosclerosis.

Key words: Gene epigenetics, Atherosclerosis, microRNA-1270, Angiopoietin-like protein 7, p38 protein, Inflammatory response, Lpid accumulation