ABSTRACT
Objective To detect the expression of the transcription factor CCAAT/enhancer-binding protein alpha (C/EBP-α) in the epidermis of psoriasis vulgaris lesions,and to investigate its correlation with abnormal keratinocyte proliferation and disease severity.Methods Biopsy specimens were obtained from the lesions of 30 patients with psoriasis vulgaris and normal skin of 30 healthy human controls.A two-step immunohistochemical procedure was performed to detect the expressions of C/EBP-αt and Ki-67 in these specimens,and Western blot to quantify the expression of C/EBP-α.The proliferation index of keratinocytes was calculated according to the expression intensity of Ki-67.Statistical analysis was carried out by using the SPSS 17.0 software,and Pearson correlation analysis was conducted to assess the relationship of C/EBP-α expression level with proliferation index of keratinocytes and psoriasis area and severity index (PASI) score.Results C/EBP-α was predominantly expressed in the cytoplasm of keratinocytes,while Ki-67 in the nuclei of keratinocytes.Compared with the normal skin,the psoriatic lesions showed a significantly lower expression of Ki-67 (t =7.82,P ＜ 0.05),but higher proliferation index of keratinocytes (t =4.54,P ＜ 0.05).The expression level of C/EBP-α was negatively correlated with the proliferation index of keratinocytes and PASI score in the patients (both P ＜ 0.05).Western blot also showed an obvious decrease in the expression of C/EBP-α in psoriatic lesions.Conclusions The expression of C/EBP-α is decreased in lesions of psoriasis vulgaris,which might be involved in the pathogenesis of psoriasis vulgaris.
ABSTRACT
Objective To investigate the effect of 1, 25-dihydroxy-vitamin D3 (1, 25 (OH)2D3) on adipocyte differen-tiation and the underlying mechanism. Methods The mesenchymal stem cell line C3H10T1/2 was randomly divided into 6 groups including control group, differentiation group and 4 different doses of 1, 25(OH)2D3 groups. The control group was treated with vehicle. The differentiation group was supplemented with adipocyte differentiation reagent. And the 1,25(OH)2D3 groups were treated with adipocyte differentiation reagents and 10-9, 10-8, 10-7 and 10-6 mol/L of 25(OH)2D3. After culturing for 5 days, the cells were stained with oil red O, and the expression levels of adipocyte-specific transcription factors and Wnt/β-catenin signaling pathway related genes were examined by RT-PCR or Western blot methods. Results 1,25(OH)2D3 sig-nificantly reduced the number of differentiated adipocytes and blocked the mRNA levels of adipocyte specific transcription factor PPARγ(peroxisome proliferator-activated receptor gamma), C/EBPα(CCAAT enhancer binding proteinα) and adipo-cyte characterization factor aP2 (fatty acid binding protein 4). These were paralleled by the decreased mRNA expression of Wnt/β-catenin signaling pathway inhibitor sFRP1 (Secreted frizzled-related protein 1) and the increased level ofβ-catenin protein. Conclusion 1, 25(OH)2D3 inhibits adipocyte differentiation, which may be related to the activation of Wnt/β-catenin signaling.