To study the effects of Shenqifuzheng Injection (SFI) on micro-RNAs in human dendritic cells

Method: This study used a 2-step approach. By first we were using a robust DC cell line to identify those miRNA that might be involved in DC activation; then followed by confirmation using monocyte-derived DC which was closer to real-life physiological contexts. THP-1 cell, a human monocytic leukemia cell line, has previously been shown to be useful for the in vitro study of DC. In this study, we identified a number of potential miRNA candidates in the DCs activated by SFI using MicroRNA Array of 381 known human miRNAs (Sanger miR Base, version 14). miR-22, miR-107 and miR-200a were then selected from the over 30 potential miRNA candidates with relative expression fold change >2 indentified in accordance to the computational evidences retrieved in the annotation database pipeline miR Base. These three miRNAs were further examined for any change in expression in a confirmatory study using the monocyte-derived DCs (MDDC) from peripheral blood mononuclear cells of healthy normal subjects (n=7) through the quantification by Real Time RT-PCR quantification. These results were correlated with the expression levels of HLA-DR and CD80 on the MDDCs using flow cytometry.||Results: The confirmatory results did not show any consistent up-regulation in the expressions of miR22, miR107 and miR-200a due to SFI across the seven MDDC samples. In addition, test results on MDDCs upon treatment of SFI in two different dilutions of 1/20 and 1/40 respectively for 24 hours incubation also demonstrated insignificant expression changes of HLA-DR and CD80 (p>0.05). Furthermore, the correlation of the expression three mi-RNA and the surface expression levels of HLA-DR and CD80 were not statistically significant for MDDCs with treatment of SFI diluted in 1/20 for 1 hour, SFI diluted in 1/20 for 4 hours, and SFI diluted in 1/40 for 1 hour (p>0.05).||Conclusions: Increased expression of miRNA of miR-22, miR-107 and miR-200a were found only in the cell line of THP-1, but failed to be shown consistently in the MDDCs from seven human peripheral blood samples. Thus whether these three mi-RNAs were really important epigenetic regulators during the process of SFI on DC remain unknown; and will require more future investigations by using multiple authentic DC sources.