Effect of Danhong injection on expressions of macrophage scavenger receptor 1 and sub-family A member 1 in human U937 cells

OBJECTIVE: To study the effects of Danhong injection (DHI) on expression of the macrophage scavenger receptor 1 (MSR1) and ATP-binding cassette, sub-family A member 1 (ABCA1) genes, which encode scavenger receptor-A I (SR-AI) and ATP-binding cassette transporter 1 (ABCA1), respectively, as a potential anti-atherosclerotic mechanism. METHODS:HumanU937cellswerestimulatedbyincubation with 100 nM phorbol 12-myristate 13-acetate (PMA) for 48 h.These stimulated, monocyte-like cells were then incubated for 24 h with 50 mg/L oxidized low-density lipoprotein (ox-LDL, to induce foam cell formation), together with a liver X receptor (LXR) agonist or with different DHI concentrations. MSR1 and ABCA1 mRNA levels were measured by fluorescence-based quantitative PCR. RESULTS: Compared with control cells (which received only ox-LDL), cells treated with both ox-LDL and 10 μmol/L LXR agonist showed lower MSR1 ex-pression (but this effect was not statistically significant, P>0.05) and higher ABCA1 expression (P< 0.01). Cells that received ox-LDL and 3 mL/L DHI possessed higher MSR1 mRNA levels than the controls, whereas cells treated with ox-LDL and higher DHI concentrations (10, 30 or 60 mL/L) showed lower MSR1 expression levels (but the differences observed between DHI concentration groups were not statistically significant, P>0.05). ABCA1 expression in cells treated with ox-LDL and 3, 10 or 30 mL/L DHI was higher than in the control cells, and increased with increasing DHI concentration (P<0.05). ABCA1 expression in cells treated with ox-LDL and the highest DHI concentration tested (60 mL/L) was not significantly different from that in the controls. ABCA1 mRNA levels in cells treated with ox-LDL and DHI were similar to, or lower than, those in cells treated with ox-LDL and the LXR agonist. CONCLUSION: DHI does not affect MSR1 mRNA levels in ox-LDL-treated U937 cells. However, at certain concentrations (10 and 30 mL/L), DHI significantly increases ABCA1 mRNA levels. Therefore, the anti-atherosclerotic action of DHI might be mediated by an increased expression of ABCA1.

OBJECTIVE： To study the effects of Danhong injec- tion （DHI） on expression of the macrophage scaven- ger receptor 1 （MSR1） and ATP-binding cassette, sub-family A member 1 （ABCA1） genes, which en- code scavenger receptor-A I （SR-AI） and ATP-bind- ing cassette transporter 1 （ABCA1）, respectively, as a potential anti-atherosclerotic mechanism. METHODS： Human U937 cells were stimulated by in- cubation with 100 nM phorbo112-myristate 13-ace- tate （PMA） for 48 h.These stimulated, monocyte-like cells were then incubated for 24 h with 50 mg/L oxi- dized low-density lipoprotein （ox-LDL, to induce foam cell formation）, together with a liver X recep- tor （LXR） agonist or with different DHI concentra- tions. MSR1 and ABCA1 mRNA levels were mea- sured by fluorescence-based quantitative PCR. RESULTS： Compared with control cells （which re- ceived only ox-LDL）, cells treated with both ox-LDL and 10 IJmol/L LXR agonist showed lower MSR1 ex-pression （but this effect was not statistically signifi- cant, P〉0.05） and higher ABCA1 expression （P〈 0.01）. Cells that received ox-LDL and 3 mL/L DHI possessed higher MSR1 mRNA levels than the con- trols, whereas cells treated with ox-LDL and higher DHI concentrations （10, 30 or 60 mL/L） showed low- er MSR1 expression levels （but the differences ob- served between DHI concentration groups were not statistically significant, P〉0.05）. ABCA1 expression in cells treated with ox-LDL and 3, 10 or 30 mL/L DHI was higher than in the control cells, and increased with increasing DHI concentration （P〈0.05）. ABCA1 expression in cells treated with ox-LDL and the highest DHI concentration tested （60 mL/L） was not significantly different from that in the controls. ABCA1 mRNA levels in cells treated with ox-LDL and DHI were similar to, or lower than, those in cells treated with ox-LDL and the LXR agonist. CONCLUSION： DHI does not affect MSR1 mRNA lev- els in ox-LDL-treated U937 cells. However, at certain concentrations （10 and 30 mL/L）, DHI significantly increases ABCA1 mRNA levels. Therefore, the an- ti-atherosclerotic action of DHI might be mediated by an increased expression of ABCA1.