Effects Of Halometasone And Calcipotriol On Cell Proliferation,Expression Of Glucocorticoid Receptorα And Vitamin D Receptor In Human Keratinocyte HaCaT Cell Line

BackgroundPsoriasis is a common,chronic,inflammatory skin disease characterized by erythematous,scaly plaques on the extensor surfaces of the body and scalp.Excessive proliferation and abnormal differentiation of keratinocytes are the primary pathological manifestations.Topical treatments are first-line therapies for the majority of patients.Most commonly prescribed are topical glucocorticoids and vitamin D3 analogs.Glucocorticoids work by binding to the glucocorticoid receptor(GR)and vitamin D3 analogs work by binding to the vitamin D receptor(VDR).Domestic and international clinical observations showed that glucocorticoids combined vitamin D3 analogs were more effective than using any one of two drugs for the treatment of psoriasis.Previous research showed that dexamethasone could up-regulated the expression of VDR in squamous cell carcinoma cells.The phenomenon revealed that glucocorticoids had potential effects on the expression of VDR.GRα and VDR are belonged to nuclear hormone receptor superfamily and There may be interactive correlation between GRα and VDR.When glucocorticoids combined vitamin D3 analogs were used to treat psoriasis,whether glucocorticoids had effects on the therapeutic efficacy of vitamin D3 analogs and whether vitamin D3 analogs had effects on the therapeutic efficacy of glucocorticoids.It forces us to focus on the effects of halometasone which is one of the representative topical glucocorticoids and calcipotriol which is one of the representative vitamin D3 analogs on the expression of glucocorticoid receptor α and vitamin D receptor in human keratinocyte HaCaT cell line.ObjectiveTo investigate the effects of halometasone and calcipotriol on the cell proliferation and the expression of GRα and VDR in human keratinocytes,and to observe mutual potential effects of glucocorticoid and vitamin D3 analog on therapeutic efficacy,for further insights into the mechanism of glucocorticoid combined vitamin D3 analog for the treatment of psoriasis.The purpose of this study is to provide experimental and theoretical basis in clinical treatment.Methods1.HaCaT cells were treated by halometasone or calcipotriol alone or in combination with different concentrations and for various durations.The cell proliferation was observed by CCK8 assay.2.HaCaT cells were treated by halometasone with different concentrations and for various durations.Quantitative Real-time PCR and Western blotting were used to detect the expression level of GRα and VDR mRNA and protein.3.HaCaT cells were treated by calcipotriol with different concentrations and for various durations.Quantitative Real-time PCR and Western blotting were used to detect the expression level of GRα and VDR mRNA and protein.Results1.CCK8 assay showed that halometasone and calcipotriol could significantly inhibited the cell proliferation in a dose-dependent manner.The effects were most obvious with treatment for 24 h.Halometasone also significantly enhanced the inhibitory effects of calcipotriol on keratinocyte proliferation.2.Halometasone could up-regulated the expression of GRα at the level of mRNA and protein in a dose-dependent manner for 24 h,but it had no effects on the expression of GRα at the level of mRNA and could down-regulated the expression of GRα at the level of protein for 48 h.Halometasone could up-regulated the expression of VDR at the level of mRNA and protein in a dose-dependent manner at any time.3.Calcipotriol could up-regulated the expression of VDR at the level of mRNA and protein in a dose-dependent manner at any time.Calcipotriol could up-regulated the expression of GRα at the level of mRNA and protein in a dose-dependent manner for 24 h,but it had no effects on the expression of GRα at the level of mRNA and protein for 48 h.Conclusion1.Halometasone could enhance the inhibitory effects of calcipotriol on keratinocyte proliferation.Halometasone combination of calcipotriol inhibited proliferation of synergy to keratinocyte.2.Halometasone down-regulated the expression of GRα at the level of protein for 48 h,which revealed that receptors were down-regulated depending on ligands.It might partly explain the resistance to topical glucocorticoid therapy.3.The up-regulation on the expression of VDR in keratinocytes by halometasone revealed that halometasone might enhance the reactivity of topical vitamin D3 analog on keratinocytes.It may partly explain the phenomenon that halometasone could enhance the therapeutic efficacy of topical vitamin D3 analogs in the treatment of psoriasis.4.Calcipotriol up-regulated the expression of VDR keratinocytes and the receptor was not down-regulated depending on ligand.It could enhance therapeutic efficacy of topical vitamin D3 analogs in clinical.5.Calcipotriol could up-regulated the expression of GRα for 24 h,but it had no effects on the expression of GRα for 48 h.It revealed that the effect of calcipotriol on the expression of glucocorticoid receptor α in keratinocyte was limited by time.