Expression of USP15, TßR-I and Smad7 in psoriasis.

The deubiquitinating enzyme ubiquitin specific peptidase 15 (USP15) is regarded as a regulator of TGFß signaling pathway. This process depends on Smad7, the inhibitory factor of the TGFß signal, and type I TGFß receptor (TßR-I), one of the receptors of TGFß. The expression level of USP15 seems to play vital roles in the pathogenesis of many neoplasms, but so far there has been no report about USP15 in psoriasis. In this study, immunohistochemical staining of USP15, TßR-I and Smad7 was performed in 30 paraffin-embedded psoriasis specimens and 10 normal specimens to investigate the expression of USP15, TßR-I and Smad7 in psoriasis and to explore the relevance among them. And USP15 small interfering RNA (USP15 siRNA) was used to transfect Hacat cells to detect the mRNA expression of TßR-I and Smad7. Of 30 cases of psoriasis in active stage, 28, 24 and 26 cases were positive for USP15, TßR-I and Smad7 staining, respectively. The positive rates of USP15 and Smad7 were significantly higher in psoriasis specimens than in normal skin specimens (44.1%±26.0% vs. 6.1%±6.6%, 47.2%±27.1% vs. 6.6%±7.1%), and positive rate of TßR-I (20.3%±22.2%) in psoriasis was lower than that in normal skin specimens (46.7%±18.2%). There was a significant positive correlation between USP15 and Smad7 expression, and significant negative correlations between USP15 and TßR-expression, an I d between TßR- and Smad7 expression I in psoriasis. After transfection of USP15 siRNA in Hacat cells, the expression of TßR-mRNA was up I -regulated and that of Smad7 was down-regulated. It is concluded that USP15 may play a role in the pathogenesis of psoriasis through regulating the TßR-I/Smad7 pathway and there may be other cell signaling pathways interacting with USP15 to take part in the development of psoriasis.

IL-36 cytokine expression and its relationship with p38 MAPK and NF-κB pathways in psoriasis vulgaris skin lesions.

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 nuclear factor-kappa B (NF-κB) pathways in psoriasis vulgaris skin lesions. The expression levels of IL-36α, IL-36ß, IL-36Γ, phosphorylated p38 MAPK, and NF-κBp65 were detected in the skin tissues of 38 psoriasis patients and 17 healthy control subjects by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting. The cytokine expression levels were compared between the psoriasis group and the control group. A correlation analysis between cytokine proteins was performed in the psoriasis group. Results showed that the expression levels of IL-36a, IL-36ß, IL-36Γ, phosphorylated p38 MAPK and NF-κBp65 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-κBp65 expression (P<0.05). A significant positive correlation was also found between the phosphorylated p38 MAPK and NF-κBp65 expression (P<0.01). It was concluded that the increased IL-36 expression is correlated with p38 MAPK and NF-κB pathways in psoriasis vulgaris skin lesions. All the three factors may be jointly involved in the pathogenesis and local inflammatory response of psoriasis.

Nerve growth factor, brain-derived neurotrophic factor and their high-affinity receptors are overexpressed in extramammary Paget's disease.

BACKGROUND: Neurotrophin (NT) systems appear to play important roles in the pathogenesis of several tumors, but their expression in extramammary Paget's disease (EPD) has not been investigated. METHODS: Thirty-four paraffin-embedded EPD specimens (32 primary EPD and 2 metastatic to lymph nodes) were subject to immunohistochemical staining for nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), NT3, NT4, their high-affinity receptors (TrkA, TrkB and TrkC) and the common low-affinity receptor, p75 NT receptor (p75). RESULTS: All 34 EPD specimens, including 2 metastatic to lymph nodes, showed cytoplasmic overexpression of NGF, BDNF, TrkA and TrkB. The expression (% positive cells) of NGF, BDNF, NT3, NT4, TrkA and TrkB (81.6 ± 14.9, 86.0 ± 10.4, 89.6 ± 14.9, 87.8 ± 17.9, 83 ± 14.4 and 86.2 ± 11.7%) in EPD was significantly higher than in normal skin (21.6 ± 6.5, 27.6 ± 4.5, 19.7 ± 10.1, 8.2 ± 10.0, 25.0 ± 5.3 and 25.4 ± 6.4%), and the expression of these factors in invasive EPD was significantly higher than in noninvasive EPD. Interestingly, Paget cells were negative for p75 and TrkC in all the 34 EPD specimens. CONCLUSIONS: These results suggest that overexpression of NGF, BDNF and their high-affinity receptors (TrkA and TrkB) might play a role in the pathogenesis of EPD.

Association of down-regulation of CD109 expression with up-expression of Smad7 in pathogenesis of psoriasis.

Transforming growth factor (TGF)-ß signaling plays an important role in the pathogenesis of psoriasis. CD109, a novel TGF-ß co-receptor, which inhibits TGF-ß signaling by enhancing Smad7-dependent degradation of TGF-ß type I receptor (TGF-ß RI), is abnormally expressed in psoriasis. To date, the expression of Smad7 and the correlation between CD109 and Smad7 expression in psoriasis have not been fully elucidated. This study was designed to investigate the expression and the correlation of CD109 and TGF-ß signaling associated proteins in psoriasis and their roles in the pathogenesis of psoriasis. Thirty-two psoriasis specimens were subjected to immunohistochemical staining for CD109, Smad7, TGF-ß RI and Ki67. Ten normal skin (NS) specimens served as controls. The positive expression rate (% positive cells) of Smad7 and Ki67 in psoriasis was significantly higher than in NS (62.6%±19.9% vs. 17.2%±4.4%, and 50.7%±14.3% vs. 19.5%±3.2%, respectively, P<0.001), and the expression levels of CD109 and TGF-ß RI were reduced significantly in psoriasis as compared with NS (8.1%±6.7% vs. 35.8%±6.7% and 27.3%±3.4% vs. 3.0%±3.4%, respectively, P<0.001). There were significantly negative correlations between CD109 and Smad7 (r=-0.831, P<0.01). These findings indicated that CD109 might play a certain role in the pathogenesis of psoriasis. Lower expression of CD109 and TGF-ß RI was highly correlated with higher expression of Smad7 and Ki67, suggesting that CD109 may induce the pathogenesis of psoriasis through Smad7-mediated degradation of TGF-ß RI, and lead to the termination of TGF-ß signaling.