Liopxin A4（LXA4） is considered to be a crucial modulator in the inflammatory responses. In the present study, we aimed to study the effect of LXA4 on the inflammatory cytokines production induced by lipopolysaccharide（LPS） and the possible mechanism in normal human epidermal keratinocytes（NHEKs）. NHEKs were isolated and cultured. The expression of toll-like receptor 4（TLR4）, LXA4 receptor（ALXR） and aryl hydrocarbon receptor（Ah R） in NHEKs was detected by reverse transcription polymerase chain reaction（RT-PCR）. The m RNA and protein levels of tumor necrosis factor-alpha（TNF-α） and interleukin-1β（IL-1β） were determined in NHEKs stimulated by LPS（10 μg/m L） with or without preincubation with LXA4（100 nmol/L） for 30 min by real-time quantitative PCR（real-time q PCR） and enzyme-linked immunosorbent assay（ELISA）, respectively. The expression levels of tumor necrosis factor receptor-associated factor 6（TRAF6） and suppressors of cytokine signaling 2（SOCS2） m RNAs and proteins, and nuclear translocation of NF-k B-p65 were measured by real-time q PCR and Western blotting, respectively. The results showed that NHEKs expressed TLR4, ALXR and Ah R. LXA4 significantly inhibited the m RNA and protein expression levels of TNF-α, IL-1β and TRAF6 induced by LPS in NHEKs, and LXA4 obviously increased the expression of SOCS2 at m RNA and protein levels. The nuclear NF-k B-p65 protein expression induced by LPS was inhibited after preincubation with LXA4 in NHEKs. It was concluded that LXA4 inhibits the LPS-induced production of TNF-α and IL-1β in NHEKs by up-regulating SOCS2 and down-regulating TRAF6.
Summary： This study examined the correlation of the expression of interleukin-36 （IL-36）, a novel member of interleukin-1 （IL-1） family, with p38 mitogen-activated protein kinase （p38 MAPK） and nu clear factor-kappa B （NF-kB） pathways in psoriasis vulgaris skin lesions. The expression levels of IL-36a, IL-3613, IL-367, phosphorylated p38 MAPK, and NF-id3p65 were detected in the skin tissues of 38 psoriasis patients and 17 healthy control subjects by real-time quantitative reverse transcription po lymerase chain reaction （qRT-PCR） and Western blotting. The cytokine expression levels were com pared between the psoriasis group and the control group. A correlation analysis between cytokine pro teins was performed in the psoriasis group. Results showed that the expression levels of IL-36a, IL-3613, IL-36y, phosphorylated p38 MAPK and NF-rh3p65 in the psoriasis group were Significantly higher than those in the control group （P〈0.001）. In the psoriasis group, the IL-36 cytokine expression was positively correlated with phosphorylated p38 MAPK and NF-kBp65 expression （P〈0.05）. A significant positive correlation was also found between the phosphorylated p38 MAPK and NF-v,.Bp65 expression （P〈0.01）. It was concluded that the increased IL-36 expression is correlated with p38 MAPK and NF-kB pathways in psoriasis vulgaris skin lesions. All the three factors may be jointly involved in the pathogenesis and local inflammatory response of psoriasis.
As one of the most serious types of psoriasis, pathogenesis of erythrodermic psoriasis（EP） is unclear so far. In this study, we aimed to detect the levels of Th1/Th2 cytokine-associated transcription factors and T-lymphocyte clone in peripheral blood mononuclear cells（PBMCs） derived from EP patients, and gene expression level of T-bet/GATA-3 in skin lesion. The potential role of Th1/Th2 reaction pattern played in the pathogenesis of EP was also discussed. Serum levels of IFN-γ, IL-2, IL-4 and IL-10 were quantified by ELISA among 16 EP patients, 20 psoriasis vulgaris（PV） patients and 15 healthy controls. The expression levels of T-bet/GATA-3 in the skin lesion and PBMCs were examined by real-time qPCR. The ratio of Th1/Th2 was measured by flow cytometry. The levels of IFN-γ, IL-2, IL-4 and IL-10 were higher in EP patients than in the healthy controls. The levels of IL-4 and IL-10 were 69.44±11.45 and 12.62±4.57 pg/mL, respectively, in EP patients, significantly higher than those in PV patients and healthy controls（P〈0.05）. Flow cytometry revealed the levels of both Th1 and Th2 in PBMCs from EP patients were higher than those in healthy controls, and the Th1/Th2 ratio was dramatically lower than in PV patients（P〈0.01）. The ratios of IFN-γ/IL-4 and T-bet/GATA-3 in EP patients were both less than 1.0, suggesting a reversal when compared with the other two groups. Our study indicated that the EP patients exerted a Th1/Th2 bidirectional response pattern, and the balance of Th cell subsets inclines to Th2, which might be one of the important mechanisms of EP pathogenesis.
