Topical Sunitinib ointment alleviates Psoriasis-like inflammation by inhibiting the proliferation and apoptosis of keratinocytes.

Psoriasis is a chronic auto-immune inflammation disease with skin lesions and abnormal keratinocyte proliferation. Sunitinib, a multi-targeted tyrosine kinase inhibitor, is known to selectively inhibit several growth factor receptors, including vascular endothelial growth factor receptor, platelet-derived growth factor receptor and stem cell factor. It was reported that a patient with renal cell carcinoma (RCC) whose psoriatic lesion was resolved dramatically during treatment with Sunitinib, however, the mechanism is still unclear. We applied Sunitinib ointment to treat imiquimod-induced mouse model of psoriasis and found that Sunitinib ointment could alleviate imiquimod-induced psoriasis-like inflammation and reduce the Ki67 expression, while Sunitinib ointment couldn't reduce imiquimod-induced splenomegaly of the mouse model, then we concentrated on studying the effect of Sunitinib on the proliferation and apoptosis of keratinocytes, we cultivated HaCaT cells with epidermal growth factor (HaCaT/E cells) to represent as a state of highly proliferative psoriatic keratinocytes. We found that Sunitinib could inhibit the proliferation of Hacat/E cell in a time and concentration dependent manner by influencing the expression level of cell cycle protein D1, cycle protein E1, in addition, Sunitinib could induce the apoptosis of Hacat/E cell and up-regulate the expression of poly ADP-ribose polymerase (PARP). Sunitinib down-regulated the expression of phosphorylated signal transduction and activator of transcription 3 (p-Stat3) of Hacat/E cells significantly. We conclude that Sunitinib alleviates imiquimod-induced psoriasis-like inflammation by regulating the proliferation and apoptosis of HaCaT cells through inhibiting the expression of p-Stat3.

Kuang YH ，Lu Y ，Liu YK ，Liao LQ ，Zhou XC ，Qin QS ，Jia XK ，Wu LS ，Zhu W ，Chen X ... -  《-》

The potential of Diosgenin in treating psoriasis: Studies from HaCaT keratinocytes and imiquimod-induced murine model.

Psoriasis is a cutaneous disease mainly characterized by keratinocyte hyperproliferation, abnormal epidermal differentiation, inflammation and angiogenesis. In this study, we aimed to report the therapeutic potential of Diosgenin on psoriasis-like models and explore the underlying mechanisms. For in vitro studies, we initially evaluated the bioeffects of Diosgenin on keratinocytes by detecting the cell viability, cell cycle and apoptosis in HaCaT cells. To mimic psoriatic conditions, we established hyperproliferative model by stimulating HaCaT cells with LPS/IL-22 and inflammatory model by LPS/TNF-α stimulation. Meanwhile, differentiation in HaCaT cells and angiogenesis in HUVECs/HMEC-1 were observed. The influence of Diosgenin on above-mentioned conditions was examined. For in vivo studies, we dosed imiquimod (IMQ) -induced mice with Diosgenin and conducted hematoxylin-eosin (HE), TUNEL assay and immunohistochemistry (IHC) to evaluate histological changes, apoptosis and the status of keratinocyte proliferation, epidermal differentiation, vascularity and cutaneous inflammatory cell infiltration respectively. Results showed that Diosgenin inhibited HaCaT cell growth through cell cycle arrest and NFκB inhibition while induced apoptosis by regulating Caspase3, Bax and Bcl-2 protein expression. After Diosgenin treatment, NFκB nuclear translocation and IL-22 receptor dependent pathways were suppressed in LPS/IL-22 induced HaCaT cells respectively. Furthermore, Diosgenin downregulated proinflammatory cytokines through TLR4/Myd88 inhibition and upregulated several differentiation markers' expression in HaCaT cells. Additionally, Diosgenin inhibited vascular formation partially by reducing the VEGF-α expression in keratinocytes. In animal studies, Diosgenin attenuated psoriatic lesions on mice accordingly. This study suggests that Diosgenin might be a promising candidate for developing anti-psoriatic agents.

Wu S ，Zhao M ，Sun Y ，Xie M ，Le K ，Xu M ，Huang C ... -  《-》

Indirubin ameliorates imiquimod-induced psoriasis-like skin lesions in mice by inhibiting inflammatory responses mediated by IL-17A-producing γδ T cells.

Xie XJ ，Di TT ，Wang Y ，Wang MX ，Meng YJ ，Lin Y ，Xu XL ，Li P ，Zhao JX ... -  《-》

Genistein suppresses psoriasis-related inflammation through a STAT3-NF-κB-dependent mechanism in keratinocytes.

Psoriasis is a chronic recurrent skin inflammatory disease, and inhibition of inflammation may be an effective means of treating psoriasis. The flavonoid genistein has a clear anti-inflammatory effect. However, the anti-psoriatic effects of genistein and their underlying mechanisms remain unclear. In this study, we investigated the effects of genistein on imiquimod (IMQ)-induced psoriasis-like skin lesions in vivo and explored the mechanisms underlying those effects in vitro. It was found that genistein can significantly improve IMQ-induced pathological scores of cutaneous skin lesions in mice, reduce epidermal thickness, and inhibit the expression of inflammatory factors，including interleukin (IL)-1β, IL-6, tumour necrosis factor-alpha (TNF-α), chemokine ligand 2 (CCL2), IL-17 and IL-23. In vitro studies, genistein inhibited the proliferation of human keratinocyte HaCaT cells and inhibited the expression of inflammatory factors in a dose-dependent manner which induced by TNFα. Further researches showed that genistein could also significantly inhibit phosphorylated STAT3 (pSAT3) expression in IMQ mice dorsal skin and in TNF-α-induced HaCaT cells. The inhibitory effect of genistein on the expression of IL-6, IL-23 and TNF-α was weakened after Stat3 siRNA in HaCaT cells. Genistein could also significantly inhibit TNF-α induced the nuclear translocation of NF-κB, and inhibit the phosphorylation of I-kBα (pI-kBα). After combining with NF-κB blocker BAY 11-7082, the effect of genistein down-regulate the expression of TNF-α and VEGFA was attenuated in HaCaT cells. The results suggest that genistein may be developed for the treatment of psoriasis lesions.

Wang A ，Wei J ，Lu C ，Chen H ，Zhong X ，Lu Y ，Li L ，Huang H ，Dai Z ，Han L ... -  《-》

Inhibition of JAK1/STAT3 pathway by 2-methoxyestradiol ameliorates psoriatic features in vitro and in an imiquimod-induced psoriasis-like mouse model.

Psoriasis is characterized by hyperproliferative keratinocytes, dilated capillaries and leukocyte infiltration. 2-Methoxyestradiol (2-ME) has shown significant inhibition on proliferation, angiogenesis and inflammation. To evaluate the anti-psoriatic potential of 2-ME, psoriasis-like dermatitis was induced by topical application of imiquimod (IMQ) on the dorsal skin of C57BL/6 mice for seven consecutive days, followed by treatment of vehicle or 2-ME ointment from Day 4 on. The psoriasis area and severity index (PASI) was assessed daily. On Day 8, skin histology and spleen index were assessed. The effects of 2-ME on the proliferation, apoptosis, cell cycle, vascular endothelial growth factor A (VEGFA), and Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathways of HaCaT cells stimulated by interleukin-17 (IL-17A) were detected, together with its effect on the proliferation, tube formation and VEGF receptor expression of human umbilical vein endothelial cells (HUVECs). We found that topical 2-ME treatment significantly improved IMQ-induced psoriasis-like dermatitis and decreased the PASI scores, the activation of STAT3 in the skin (P < 0.05), and the spleen index in mice (P < 0.01). In vitro, 2-ME inhibited the proliferation of HaCaT cells by inducing apoptosis and G2/M phase arrest (P < 0.01). Moreover, 2-ME suppressed IL-17A-induced VEGFA (2.5 μM: P < 0.05; 5 μM: P < 0.01) and phosphorylation of STAT3 by blocking p-JAK1 in HaCaT cells and prevented tube formation (P < 0.01) and proliferation by targeting VEGF receptors 1 (VEGFR1) and 2 (VEGFR2) in HUVECs. We conclude that 2-ME alleviated psoriasis in vivo and in vitro by inhibiting JAK1/STAT3 pathway and was a promising therapeutic agent for psoriasis.

Tang J ，Liu C ，Liu S ，Zhou X ，Lu J ，Li M ，Zhu L ... -  《-》