Progress in genetic research on psoriatic arthritis / 中华医学遗传学杂志

Psoriatic arthritis is a form of inflammatory arthritis found among patients with psoriasis, which can lead to pain, swelling or stiffness in one or more joints and even movement disorders. Epidemiological studies have shown a higher heritability for psoriatic arthritis compared with psoriasis vulgaris. With the evolvement of DNA sequencing, many genes have been associated with psoriasis vulgaris and psoriatic arthritis, which included MHC, TNF, LCE, IL23R, IL12B, TRAF3IP2 and TNFAIP3, though some, such as MHC, IL-13 and PTPN22, have been specifically associated with psoriatic arthritis. These studies have laid a foundation for risk prediction, diagnosis and drug development for psoriatic arthritis.

Dysfunction of regulatory T cells in patients with psoriasis and related mechanisms of regulation by the STAT3 signaling pathway / 中华皮肤科杂志

Objective To evaluate the function of regulatory T (Treg)cells in peripheral blood from patients with psoriasis, and to explore the possible role of the STAT3 signaling pathway in Treg cell dysfunction. Methods Totally, 81 patients with psoriasis vulgaris, who all presented with chronic plaques and had a psoriasis area and severity index (PASI)score of 10 - 30, were enrolled into this study. Forty-six healthy blood donors served as the control group. Venous blood samples were collected from these subjects followed by isolation of Treg cells and responder T (Tresp)cells. Flow cytometry was performed to determine the proportion of Treg cells in peripheral blood as well as that of cells secreting phosphorylated-STAT3(p-STAT3), interferon γ(IFN-γ), tumor necrosis factor α(TNF-α)and interleukin 17(IL-17)in Treg cells, and quantitative real-time PCR (qRT-PCR)to measure the expression levels of IFN-γ, TNF-α and IL-17 mRNAs in Treg cells. Some Treg cells and Tresp cells were cultured in vitro alone or in combination, and flow cytometry was conducted to estimate cellular proliferative activity on day 7 after stimulation with IL-2. Some patient-derived Treg cells were classified into several groups to be cultured alone or in combination with Tresp cells with or without the presence of the STAT3 pathway inhibitor, Stattic V (10 or 50 μg/L), for 7 days. Subsequently, flow cytometry was performed to evaluate the proliferative activity of Tresp cells, and qRT-PCR to measure the expression levels of IFN-γ, TNF-α and IL-17 mRNAs in Treg cells. Results No significant differences were observed in the proportion of Treg cells in peripheral blood between the patient group and control group (6.437% ± 0.186% vs. 6.812% ± 0.241%, t = 1.224, P >0.05). Compared with control-derived Treg cells, the patient-derived Treg cells showed significantly decreased proliferative activity and inhibitory effects on Tresp cells, but increased proportion of cells secreting p-STAT3, IFN-γ, TNF-α and IL-17 (all P < 0.05). After the treatment with 50 μg/L Stattic V, a significant increase was observed in the inhibitory effect of patient-derived Treg cells on Tresp cells (inhibition rate: 61.670% ± 4.640% vs. 28.820% ± 11.490%, P < 0.05), but a significant decrease in the mRNA expressions of IFN-γ (2-△△C t: 1.654 ± 0.879 vs. 23.350 ± 6.721, P <0.05), TNF-α(0.850 ± 0.705 vs. 4.847 ± 1.525, P < 0.05)and IL-17(0.572 ± 0.135 vs. 3.095 ± 0.650, all P < 0.05)in patient-derived Treg cells compared with untreated patient-derived Treg cells. Conclusions The negative regulatory effect of Treg cells on Tresp cells is decreased in patients with psoriasis, which may be associated with abnormal activation of the STAT3 signaling pathway, and inhibition of the pathway may restore the function of Treg cells to a certain extent.

CD8α+α+ T cells in lesions and peripheral blood of patients with psoriasis / 中华皮肤科杂志

Objective To investigate the distribution and proportion of CD8α+α + T cells in lesions and peripheral blood of patients with psoriasis,and to assess their roles in the pathogenesis of psoriasis.Methods An immunofluorescence assay was performed to observe the distribution of CD8α+α+ T cells in lesions of 5 patients with progressive psoriasis vulgaris and normal skin of 5 healthy human controls.Flow cytometry was conducted to determine the proportion of CD8α+α+ T cells,and to measure the expressions of interferon (IFN)-γ and tumor necrosis factor (TNF)-α in peripheral blood from 10 patients with progressive psoriasis vulgaris and 8 healthy human controls.Statistical analysis was carried out by t test with GraphPad Prism software.Results A massive infiltrate mainly composed of CD8α+α+ T cells but not CD8α+β+ T cells was observed in the upper dermis of lesions from the 5 patients with psoriasis,while there was no infiltrate of CD8α+β+ or CD8α+α+ T cells in the normal skin of 5 healthy human controls.Flow cytometry revealed that the proportion of CD8α+α+ T cells was significantly higher in peripheral blood from 10 patients with psoriasis than in that from 8 healthy human controls (26.47％ ± 12.99％ vs.9.12％ ± 4.80％,t =3.96,P＜ 0.001).Significant differences were also noted between the psoriatic patients and healthy human controls in the percentage of cells secreting IFN-γ (47.36％ ± 19.38％ vs.13.44％ ± 9.21％,t =4.54,P ＜ 0.001) and cells secreting TNF-α (54.14％ ± 21.14％ vs.34.03％ ± 17.22％,t =2.17,P ＜ 0.05) in peripheral blood CD8α+α+ T cells.Conclusions Both the distribution and proportion of CD8α+α+ T cells are increased in lesions and peripheral blood from patients with psoriasis,suggesting that CD8α+α+ T cells may be the main subgroup of CD8+ T cells that contribute to the pathogenesis of psoriasis.

Effects of narrow-band ultraviolet B on the expression of keratin 17 in keratinocytes / 中华皮肤科杂志

Objective To investigate the effects of narrow-band ultraviolet B (NB-UVB) on the expression of keratin 17 (K17) in the human keratinocyte cell line HaCaT.Methods Cultured HaCaT cells were irradiated with different doses (0,50,100,200,400 mJ/cm2) of NB-UVB followed by additional culture for 6,12 and 24 hours respectively.To explore the mechanisms underlying the effects of NB-UVB on K17 expression,some HaCaT cells were pretreated with PD98059 (an inhibitor of mitogen-activated protein kinase kinase) followed by UVB radiation and additional culture as described above.Cell counting kit-8 (CCK 8) was used to evaluate the proliferation of,real time PCR to measure the mRNA expressions of K17 in,and Western blot to determine the protein expression of K17,Erk1/2 and phosphorylated Erk1/2 in,HaCaT ceils.Results Both the proliferation of and K17 expression in HaCaT cells were promoted by NB-UVB radiation at low doses (50,100 mJ/cm2),but inhibited by NB-UVB radiation at high doses (200,400 mJ/cm2).Significant differences were observed for the proliferative activity between HaCaT cells irradiated with NB-UVB at 100 or 400 mJ/cm2 and unirradiated HaCaT ceils at 12 and 24 hours (P ＜ 0.01 or 0.05).The phosphorylation of Erk1/2 was upregulated by NB-UVB radiation at 100 mJ/cm2,but downregulated by that at 400 mJ/cm2,and the upregulation induced by low dose NB-UVB could be suppressed by blocking the Erk 1/2 pathway.Conclusion The effects of NB-UVB radiation on K17 expression may be modulated by the Erk 1/2 pathway.

Expression of miR-486-3p in psoriatic lesions and its effect on keratin 17 expression / 中华皮肤科杂志

Objective To determine the expression of miR-486-3p in psoriatic lesions and healthy human skin and to estimate its effect on keratin 17 (K17) expression in HaCaT human keratinocytes.Methods Bioinformatics was used to predict microRNAs that may affect the expression of K17.Tissue samples were obtained from the lesions of 10 patients with psoriasis and normal skin of 10 healthy human controls.RNA was extracted from these tissue samples and reversely transcribed into cDNA with the addition of a Poly (A) tail.Then,real time quantitative PCR was performed to measure the expression of miR-486-3p.Cultured keratinocytes were transfected with miR-486-3p mimics or negative control,and Western blot was performed to determine K17 expression at 48 hours after the transfection.To evaluate the inhibitory effect of miR-486-3p on K17 expression,cultured 293T cells were transfected with the plasmid containing K17 3' untranslated region (UTR) seed sequence,three plasmids containing the complete deletion,interval mutation or double repeats of the seed sequence,or negative control plasmid.At 24 hours after the transfection,a dualluciferase reporter (DLR) assay was performed to quantify the expression of K17.Results Real time PCR showed that the expression level of miR-486-3p was significantly lower in psoriatic lesions than in the normal skin (0.211 ± 0.120vs.0.555 ± 0.425,t =2.62,v =9,P ＜ 0.05).The HaCaT cells transfected with the mimics of miR-486-3p exhibited decreased expression of K17 compared with those transfected with the negative control.DLR assay revealed that the expression level (fluorescence intensity) of K17 in the negative control group was significantly higher than that in the 293T cells transfected with the seed sequence and those with the double repeats of the seed sequence (100.00％ vs.65.31％ ± 6.32％ and 54.18％ ± 10.01％ respectively,both P ＜ 0.05),but did not differ from that in the 293T cells transfected with the complete deletion and interval mutation of the seed sequence (100.00％ vs.114.77％ ± 16.14％ and 110.21％ ± 12.99％ respectively,both P ＞ 0.05).Conclusions The expression of miR-486-3p,which may inhibit K17 expression by binding to the seed sequence of K17 3'UTR,is lower in psoriatic lesions than in normal skin.The decreased expression and inhibitory effect of miR-486-3p may be implicated in the initiation and progression of psoriasis.

Follicular helper T cells in peripheral blood of patients with pemphigus and bullous pemphigoid / 中华皮肤科杂志

Objective To explore the roles of follicular helper T cells (Tfh) in the pathogenesis of pemphigus and bullous pemphigoid (BP).Methods Venous blood was collected from 20 patients (including 10 cases of pemphigus and 10 cases of BP) and 20 age- and sex-matched normal human controls.Enzyme linked immunosorbent assay (ELISA) was performed to measure the levels of serum interleukin (IL)-21 and anti-BP180-NC16A antibody,and flow cytometry to detect the percentage of Tfh in peripheral blood mononuclear cells (PBMCs).The relationship of anti-BP180-NC16A antibody titer to Tfh and IL-21 levels was assessed by linear correlation analysis.Results The serum IL-21 level and Tfh percentage in PBMCs were significantly higher in patients with pemphigus than in the normal controls (95.33 ± 33.69 vs.54.50 ± 18.13 pg/ml,t =3.38,P＜ 0.01;12.08％ ± 4.74％ vs.6.15％ ± 1.62％,t =3.74,P ＜ 0.01),and higher in patients with BP than in the normal controls ( 106.70 ± 44.91 vs.55.37 ± 15.89 pg/ml,t =3.41,P ＜ 0.01; 11.85％ ± 3.14％ vs.6.03％ ± 1.74％,t =5.13,P ＜ 0.01 ).The titer of anti-BP180-NC 16A antibody was positively correlated with the percentage of Tfh (r =0.67,P＜ 0.05) and serum level of IL-21 (r=0.77,P＜ 0.01) in patients with BP.Conclusions There is a significant increase in the percentage of Tfh and serum level of IL-21 in patients with pemphigus and BP,hinting a certain role of Tfh and IL-21 in the pathogenesis of pemphigus and BP.