Strain specific response of mice to IMQ-induced psoriasis

Extracts from Seseli mairei Wolff attenuate imiquimod-induced psoriasis-like inflammation by inhibiting Th17 cells

Objective

Seseli mairei Wolff extracts (SMWE) are widely used to treat psoriasis as a Chinese medicine, but their effect and mechanism are unclear. This study verified the effect of SMWE on psoriasis by regulating Th17 cells.

Methods

HaCaT cells were treated with IL-17A in vitro to evaluate the effect of SMWE on psoriasis. In vivo, the mice psoriasis model was established using imiquimod (IMQ, 62.5 mg/d), and intragastrically treated with the different drugs for six days. The severity of skin inflammation was evaluated with Psoriasis Area and Severity Index (PASI) scores and pathology. The levels of inflammation cytokines were assessed with immunofluorescence, immunochemistry, ELISA, and real-time PCR. The number of Th17 cells was determined with flows.

Results

SMWE inhibited the proliferation of HaCaT cells and reduced the IL-17A-induced IL-6 production in vitro. In vivo, SMWE deduced the levels of IL-1β, IL-6, IL-8, IL-17A, IL-17F, IL-22, IL-23, and TNF-α, while increasing the level of IL-10 compared to the model group. SMWE also inhibited the levels of NF-κB, JAK2, and STAT3 proteins, while declining the expressions of Gr-1, and MPO. Interestingly, SMWE significantly decreased the number of Th17 cells.

Conclusion

SMWE inhibited the proliferation of HaCaT cells and attenuated the development of psoriasis lesions by inhibiting Th17 cells to regulate the levels of inflammation cytokines.

Evidence on the therapeutic role of thiolutin in imiquimod-induced psoriasis-like skin inflammation in mice

INTRODUCTION

A recent study confirmed that thiolutin (THL), as a potent inflammasome inhibitor, plays a promising therapeutic role in multiple inflammatory disease models. However, the effect of THL on psoriasis has not been reported so far.

METHODS

A psoriasiform dermatitis model was prepared by applying 5% imiquimod (IMQ) cream on mice. A total of 36 mice were randomly divided into six groups: control, model, model + THL-L/M/H (THL, 1/2.5/5 mg/kg/day), model + methotrexate (1 mg/kg/day). Psoriasis area and severity index (PASI) scores were observed and calculated. The histological changes in skin, liver, and kidney tissues were observed by hematoxylin and eosin staining. Alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, and blood creatinine were measured by automatic biochemistry analyzer. The size of the spleens was determined, and the proportion of Foxp3 + CD4+ regulatory T (Treg) cells in the spleens was tested by flow cytometry. The proinflammatory factors and nucleotide oligomerization domain nucleotide oligomerization domain (NOD)-like receptor protein 3 (NLRP3) inflammasome protein levels were examined by reverse transcription-quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, Western blotting, and immunohistochemistry, respectively.

RESULTS

THL administration preeminently reduced the thickness, scaling, and erythema of the skin lesions, alleviated IMQ-induced psoriasiform lesions in mice, reduced the PASI score, and ameliorated histopathological changes in mouse skin. The spleen index was decreased by almost half and the proportion of Foxp3 + CD4+ Treg cells was increased after intervention by THL. THL intervention did not affect liver and kidney function, but decreased the expression levels of proinflammatory factors and NLRP3 inflammasome in the skin of psoriatic mice.

CONCLUSIONS

THL may alleviate IMQ-induced psoriasis-like manifestations in mice by inhibiting NLRP3 inflammasome.

Kaempferol modulates IFN-γ induced JAK-STAT signaling pathway and ameliorates imiquimod-induced psoriasis-like skin lesions

Immune-mediated inflammation contributes to the development of psoriasis. However, long-term treatment with global immunosuppressive agents may cause a variety of side effects including recurrent infections. Kaempferol (KP), a natural flavonol, present in various plants is proposed to be useful for the treatment of psoriasis patients. Nevertheless, an explicit understanding of KP induced mechanisms is a prerequisite for its use in clinics. Therefore, we investigated the therapeutic effects and potential mode of action of KP using IFN-γ induced HaCaT cells and imiquimod-induced psoriasis-like skin lesions in mice. In this study, we found KP reduced intracellular ROS production, inhibited rhIFN-γ-induced IFN-γR1 expression, and up-regulated SOCS1 levels in HaCaT cells. In addition, KP inhibited rhIFN-γ-induced phosphorylation of JAK-STAT signaling molecules in HaCaT cells. Most importantly, KP alleviated imiquimod-induced psoriasis-like skin lesions in mice, histopathology and proportion of DCs in the skin. Besides, it reduced the population of γδT17 cells in the lymph nodes of the psoriatic mice and also decreased the gene expression of many proinflammatory cytokines, including interleukin IL-23, IL-17A, TNF-α, IL-6, and IL-1β in addition to down-regulation of the proinflammatory JAK-STAT signaling pathway. Thus, KP modulated IFN-γ induced JAK-STAT signaling pathway by inducing IFN-γR1 expression and up-regulating SOCS1 expression. In addition, KP also ameliorated imiquimod-induced psoriasis by reducing the dendritic cell numbers, and γδT17 cell population, along with down- modulation of the JAK-STAT pathway.

Efficacy and safety of curcumin in psoriasis: preclinical and clinical evidence and possible mechanisms

Background: Psoriasis is a chronic and immune-mediated inflammatory skin disease. Many studies have shown that curcumin (CUR) has strong anti-inflammatory effects and can improve psoriasis; however, its efficacy and safety have not been confirmed, and the specific mechanism remains to be elucidated.

Objective: To evaluate the efficacy, safety, and possible mechanisms of CUR in the treatment of psoriasis.

Methods: The Cochrane Library, Embase, PubMed, Web of Science, China National Knowledge Infrastructure, Wanfang, and VIP (China Science and Technology Journal Database) were systematically searched for clinical trials and preclinical studies on the use of CUR in psoriasis treatment. All databases were searched from inception to January 2022. The meta-analysis was performed using RevMan 5.3 software.

Results: Our meta-analysis included 26 studies, comprising seven clinical randomized controlled trials and 19 preclinical studies. A meta-analysis of clinical trials showed that both CUR monotherapy and combination therapy improved Psoriasis Area and Severity Index (PASI) scores in patients compared to controls (standard mean difference [std.MD]: −0.83%; 95% confidence interval [CI]: −1.53 to 0.14; p = 0.02). In preclinical studies, CUR showed better performance in improving the phenotype of psoriatic dermatitis mice compared to controls, including total PASI score (std.MD: 6.50%; 95% CI: 10.10 to −2.90; p = 0.0004); ear thickness (p = 0.01); and the expression of inflammatory cytokines such as interleukin (IL)-17, tumor necrosis factor (TNF)-α, IL-17F, and IL-22 (p < 0.05). In cell studies, CUR inhibited cell proliferation (p = 0.04) and the cell cycle (p = 0.03) and downregulated the inflammatory cytokines IL-6 and IL-8 (p < 0.05).

Conclusions: CUR has excellent efficacy and broad potential to treat psoriasis in multiple ways. Its use also plays a crucial role in improving the psoriasis phenotype and reducing the inflammatory microenvironment. In conclusion, our findings suggest that CUR alone or in combination with other conventional treatments can effectively treat psoriasis.

Mouse Models of Psoriasis: A Comprehensive Review

The use of preclinical animal models of psoriasis has significantly increased over the last three decades, with each model having unique strengths and limitations. Some models translate better to human disease, and many have provided unique insight into psoriasis disease pathogenesis. In this comprehensive review, we present a comparative description and discussion of genetic mouse models, xenograft approaches, and elicited methods using cytokine injections into and topical imiquimod onto mice. We provide an inclusive list of genetically modified animals that have had imiquimod applied to or cytokines injected into their skin and describe the outcomes of these manipulations. This review will provide a valuable resource for those interested in working with psoriasis animal models.