Effect Of The Activation Of TOLL-like Receptor7(TLR7) On The Proliferation And Differentiation Of HaCaT Cells

Object To explore the impact of the activation of TOLL-Like Receptor7(TLR7) on theproliferation and differentiation of HaCaT cells，and then uncover the mechanism.Method HaCaT cells were cultured and treated with various concentration of theligands of TLR7namely Gardiquimod for different time. MTT and FACS methodswere used to analyze the the activation of TOLL-Like Receptor7(TLR7) on theproliferation of HaCaT cells.Though treated with various concentration of the ligandsof TLR7namely Gardiquimod for different time,the makers (the layer of granuleKeratin1, the layer of basis Keratin5and the layer of thorn Involucrin) of HaCaT cellsdifferentiation induced by the certain concentration of CaCl2were detected byReal-time PCR and Western-Blot, and by this we explore the impact of the activationof TOLL-Like Receptor7TLR7on the differentiation of HaCaT cells induced by CaCl2.Furthernore, we analyzed signaling pathways (PI3K-AKT and RAS-MAPK) actiativedin HaCaT cells by Western-Blot. Before an hour HaCaT cells were treated with theligand of TLR7namely Gardiquimod we used the s, ecific inhibitors(PD98059andLY2940002) selectively inhibit ERK1/2and AKT phosphorylation to reveal therelationship between the affect of TLR7on the proliferation and differentiation, andthese relative signaling pathways.Results The results of MTT and FACS highlighted that the ligands of TLR7Gardiquimod promotes the proliferation of HaCaT cells at a dose-dependent andtime-dependent ways. However, the ligands of TLR7Gardiquimod inhibited themakers (K1, INV and K5) expression of HaCaT cells differentiation induced by CaCl2 at mRNA and protein levels. Mechanistic studies show that the ligands of TLR7Gardiquimod increased the phosphorylation of ERK1/2and AKT, and the specificinhibitors of the phosphorylation of ERK1/2(PD98059) or AKT (LY2940002) couldantagonize the effect of the ligands of TLR7Gardiquimod on the proliferation anddifferentiation of HaCaT cells.Conclusion The ligands of TLR7Gardiquimod patially depend on the PI3K-AKT andRAS-MAPK signaling pathways to regulate the proliferation and differentiation inHaCaT cells.