Inhibition of miR-155 Attenuates CD14+ Monocyte-Mediated Inflammatory Response and Oxidative Stress in Psoriasis Through TLR4/MyD88/NF-κB Signaling Pathway

Purpose: Previous studies showed the link of CD14(+) monocytes to inflammation and oxidation in psoriasis. In the present study, we investigated the regulatory role of miR-155 in CD14(+) monocyte function in psoriasis. Materials and Methods: CD14(+) monocytes were isolated from peripheral blood by magnetic bead separation method and its function was assessed following silence of miR-155 by lentivirus transfection with or without inhibition of TLR4 pathway. CCK8 and EdU were used to assess the proliferation of CD14+ monocytes. Expression levels of SOCS1, TLR4 and MyD88 proteins were determined by Western blotting, while expression levels of IL-6, TNF-alpha, ROS, MDA and T-AOC were measured by ELISA kit. The expression levels of mRNA for miR-155, NF-Kappa l3 and its subunit NF-Kappa l3-p65 were assessed by q-PCR. Results: The results showed that compared with normal control CD14+ monocytes, the expression levels of miR-155, NF-Kappa l3 and NF Kappa l3-p65, TLR4, MyD88 and IL-6, TNF-alpha were increased, while expression levels of SOCS1 were decreased in CD14(+) monocytes from psoriatic patients. Enhanced cell proliferation and oxidation were also observed in CD14(+) monocytes from psoriatic patients. Inhibition of miR-155 partially corrected the abnormalities of cell proliferation and expression levels of biomarkers mentioned above in CD14(+) monocytes from psoriatic patients. Inhibitions of both TLR4 pathway and miR-155 further corrected abnormalities of proliferation and the above biomarkers in CD14(+) monocytes from psoriatic patients. Conclusion: These results suggest that increased expression levels of miR-155 contribute to CD14(+) monocyte-mediated inflammation and oxidation in psoriasis via TLR4 pathway.

Automated summary

The study found that in psoriatic patients, the expression levels of miR-155, NF-Kappa l3, NF-Kappa l3-p65, TLR4, MyD88, IL-6, and TNF-α were elevated in CD14(+) monocytes, while SOCS1 expression was decreased. Enhanced proliferation and oxidation were also observed in these monocytes. Inhibition of miR-155 and TLR4 pathway partially corrected these abnormalities.