All-Trans Retinoic Acid Enhances Bacterial Flagellin-Stimulated Proinflammatory Responses in Human Monocyte THP-1 Cells by Upregulating CD14

Figure 3

ATRA enhances the expression and secretion of proinflammatory cytokines in THP-1 cells upon flagellin challenge. (a) THP-1 cells were treated with 1 μM ATRA or DMSO for 24 h and then stimulated with flagellin from S. typhimurium for 4 h mRNA expression levels of IL-1β and TNF-α were measured by RT-qPCR. Bar graphs indicate relative mRNA expression ± SD. (b) THP-1 cells were treated with 1 μM ATRA or DMSO for 24 h and then stimulated with flagellin from S. typhimurium for 24 h; the cell culture supernatant was collected and subjected to ELISA to determine TNF-α and IL-1β production. Bar graphs indicate secreted cytokine amount ± SD. Statistical significance was assessed by Student’s t test using SPSS. vs. DMSO-treated groups.

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