Fig. 7: Function of ERBB4 overexpression in keratinocytes.

A Expression levels of ERBB4 in HaCaT cells transfected with ERBB4-overexpression vector (ERBB4^OV) or indicated control (CTL). Cells were collected 2 days after transfection and mRNA levels were analyzed using qRT-PCR. GAPDH was used as the internal control. Each bar represents mean ± SEM (n = 3). ^***P < 0.001, compared with the indicated controls. B Representative blots showing protein levels of ERBB4 in HaCaT cells transfected with ERBB4^OV or CTL. Protein levels were detected by western blotting. GAPDH was used as a protein loading control. C Relative proliferation rate of HaCaT cells transfected with ERBB4^OV or CTL. Cell proliferation was analyzed using MTT assay. Each bar represents mean ± SEM (n = 3). ^**P < 0.01, compared with the indicated controls. D The mRNA levels of psoriasis-related genes and inflammatory genes in HaCaT cells transfected with ERBB4^OV or CTL in the presence or absence of M5 treatment. Cells were harvested 2 days after transfection and mRNA levels were analyzed using qRT-PCR. GAPDH was used as the internal control. Each bar represents mean ± SEM (n = 3). ^**P < 0.01, ^*P < 0.05, ^###P < 0.001, ^##P < 0.01, ^#P < 0.05, compared with the indicated controls. E Representative blots showing the levels of phospho-STAT3 (Tyr705), phospho-STAT3 (Ser727), phospho-NF-κB p65 (Ser311), and IL-1β in the HaCaT cells transfected with ERBB4^OV or CTL in the presence or absence of M5 treatment. Protein levels were detected by western blotting. GAPDH was used as a protein loading control.