ABSTRACT
Objective@#To explore the impact of arsenic on cholesterol efflux and the expression of ATP-binding cassette, sub-family A, member 1 ( ABCA1 ), ATP-binding cassette transporter G1 ( ABCG1 ), and scavenger receptor class B member I ( SRBI ) in macrophages, so as to provide the evidence for the mechanism of arsenic induced atherosclerosis.@*Methods@#The human myeloid leukemia mononuclear cells ( THP-1 ), induced by phorbol myristate acetate, and mouse primary macrophages were treated with 0, 0.625, 1.25, 2.5 and 5 μmol/L NaAsO2 for 48 hours. Then the cells treated with 2.5 μmol/L NaAsO2 were changed to arsenic free mediums for 48 hours and collected every 12 hours to analyze the time effect of arsenic. The expression levels of ABCA1, ABCG1 and SRBI were determined by quantitative polymerase chain reaction and western blotting. Cholesterol efflux rates were measured by 3H isotope tracer. @*Results@#Arsenic significantly down-regulated the expression levels of ABCA1 and ABCG1, and cholesterol efflux in a dose-dependent manner. The levels of ABCA1 mRNA decreased by 69% and 72%, the levels of ABCG1 mRNA decreased by 42% and 34%, and the rate of cholesterol efflux decreased by 55% and 59% in THP-1 and mouse primary macrophages cells treated with 5 μmol/L NaAsO2 ( all P<0.05 ). Arsenic had no significant effect on SRBI expression ( all P>0.05 ). Arsenic inhibited ABCA1 expression and cholesterol efflux in THP-1 in a time-dependent manner. Compared with cells before the exposure of arsenic, the level of ABCA1 mRNA and the rate of cholesterol efflux in THP-1 bottomed at 48 hours by 43% and 42%, and gradually recovered when arsenic was removed. @*Conclusions@#Arsenic inhibits cholesterol efflux by down-regulating the expression of ABCA1 and ABCG1 in macrophages.
ABSTRACT
@#[Abstract] Objective: To investigate the effect of histone demethylase JMJD3 (jumonji domain-containing protein 3) on the stemness of diffuse large B-cell lymphoma (DLBCL) cells. Methods: The relationship between the expression of JMJD3 and the overall survival of DLBCL patients was analyzed using the clinical data of DLBCL patients in TCGA database. The control plasmid (pCMV) and JMJD3 expression plasmid(pCMV-JMJD3)weretransfectedintoDLBCLcellsofABCandGCBsubtype via lipofectamine transfection. Then, the mRNAlevels of JMJD3,ALDH1, OCT4 and SOX2 were detected by RT-PCR and qPCR; the activity ofALDH1 enzyme was detected by Flow cytometry; the protein expressions of OCT4 and SOX2 were detected by Western blotting. Gene enrichment in DLBCL patients with high JMJD3 expression was analyzed by gene set enrichment analysis (GSEA). Results: The result of prognosis analysis showed that high expression of JMJD3 was related with poor prognosis in DLBCL patients (P<0.05); however, multivariate analysis showed that the expression of JMJD3 was not the independent factor affecting the prognosis of DLBCL patients (all P>0.05). The expression of JMJD3 was remarkably increased in DLBCL cells transfected with pCMV-JMJD3, which led to significantly increased mRNA level and enzyme activity of ALDH1 as well as up-regulated mRNA and protein expressions of OCT4 and SOX2 (P<0.05 or P<0.01). GSEA analysis showed that enrichment of Wnt/β-catenin signaling pathway related gene set was observed in DLBCL patients with high JMJD3 expression (P<0.05). Conclusion: JMJD3 promotes the stemness of DLBCL cells, which may be a potential therapeutic target for DLBCL patients.