Benvitimod inhibits MCM6-meditated proliferation of keratinocytes by regulating the JAK/STAT3 pathway

Formulation and Evaluation of Different Nanogels of Tapinarof for Treatment of Psoriasis

Psoriasis is an immune-mediated skin condition. There are many therapeutic options for its treatment; however, none of them is completely effective. Tapinarof is a promising new active substance; it was recently approved by the FDA for the treatment of psoriasis. The aim of our study was to prepare topical nanoformulations of the active substance to improve its bioavailability and therapeutic effect. The biocompatibility investigation of the formulations was carried out by MTT assay, and the size distribution of the preparations was investigated by DLS. In parallel, the rheological properties and the texture were examined, and the in vitro release of tapinarof was assessed by the Franz diffusion method. An in vitro wound healing assay was also carried out to study the drug's properties. Our results show that the preparations were safe on HaCaT cells. The particle size of the formulations was proven to be in the nanoscale range. In the in vitro release studies, nanogel II. showed greater release of the active substance. According to the wound healing assay, incorporation of the drug into nanoformulations increases the antiproliferative and antimigration activity of the drug. Overall, nanoformulations of tapinarof were successfully prepared, and our results suggest that they can be a useful addition to the current therapeutic practice of psoriasis.

Tetrastigma hemsleyanum polysaccharides alleviate imiquimod-induced psoriasis-like skin lesions in mice by modulating the JAK/STAT3 signaling pathway

BACKGROUND

The pathogenesis of psoriasis involves the interaction between keratinocytes and immune cells, leading to immune imbalance. While most current clinical treatment regimens offer rapid symptom relief, they often come with significant side effects. Tetrastigma hemsleyanum polysaccharides (THP), which are naturally nontoxic, possess remarkable immunomodulatory and anti-inflammatory properties.

METHODS

In this study, we utilized an imiquimod (IMQ)-induced psoriasis mouse model and a LPS/IL-6-stimulated HaCaT model. The potential and mechanism of action of THP in psoriasis treatment were assessed through methods including Psoriasis Area Severity Index (PASI) scoring, histopathology, flow cytometry, immunoblotting, and reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Percutaneous administration of THP significantly alleviated symptoms and manifestations in IMQ-induced psoriatic mice, including improvements in psoriatic skin appearance (erythema, folds, scales), histopathological changes, decreased PASI scores, and spleen index. Additionally, THP suppressed abnormal proliferation of Th17 cells and excessive proliferation and inflammation of keratinocytes. Furthermore, THP exhibited the ability to regulate the JAK/STAT3 signaling pathway.

CONCLUSION

Findings from in vivo and in vitro studies suggest that THP can inhibit abnormal cell proliferation and excessive inflammation in lesional skin, balance Th17 immune cells, and disrupt the interaction between keratinocytes and Th17 cells. This mechanism of action may involve the modulation of the JAK/STAT3 signaling pathway, offering potential implications for psoriasis treatment.

The Role of Aryl Hydrocarbon Receptor in the Pathogenesis and Treatment of Psoriasis

The pathogenesis of psoriasis is complex. Aryl hydrocarbon receptor (AhR) is a transcription factor that can be bound and activated by structurally diverse ligands and plays an important role in a range of biological processes and in the pathogenesis of different diseases. Recently, the role of AhR in psoriasis has attracted attention. AhR has toxicological functions and physiological functions. The overexpression and activation of AhR induced by the environmental pollutant and exogenous AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can drive the development of psoriasis. This TCDD-mediated toxicological response disrupts the physiological functions of AhR resulting in skin barrier disorders and the release of inflammatory cytokines, 2 of the pivotal factors of psoriasis. In addition, highly upregulated kynureninase in psoriasis decreases endogenous AhR agonists, thereby weakening the physiological functions of AhR. Activating AhR physiological signalling should be useful in the treatment of psoriasis. Studies have demonstrated that physiological activation of AhR can dampen the severity of psoriasis. The oldest and effective treatment for psoriasis coal tar works by activating AhR, and both new anti-psoriasis drugs tapinarof and benvitimod are formulations of AhR agonist, supporting that activation of AhR can be used as a new strategy for the treatment of psoriasis. Preclinical and preliminary clinical studies have revealed the anti-psoriasis effects of a number of AhR agonists, providing potential candidates for the development of new drugs for the treatment of psoriasis.

The role of aryl hydrocarbon receptor in vitiligo: a review

Vitiligo is an acquired autoimmune dermatosis characterized by patchy skin depigmentation, causing significant psychological distress to the patients. Genetic susceptibility, environmental triggers, oxidative stress, and autoimmunity contribute to melanocyte destruction in vitiligo. Due to the diversity and complexity of pathogenesis, the combination of inhibiting melanocyte destruction and stimulating melanogenesis gives the best results in treating vitiligo. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that can regulate the expression of various downstream genes and play roles in cell differentiation, immune response, and physiological homeostasis maintenance. Recent studies suggested that AhR signaling pathway was downregulated in vitiligo. Activation of AhR pathway helps to activate antioxidant pathways, inhibit abnormal immunity response, and upregulate the melanogenesis gene, thereby protecting melanocytes from oxidative stress damage, controlling disease progression, and promoting lesion repigmentation. Here, we review the relevant literature and summarize the possible roles of the AhR signaling pathway in vitiligo pathogenesis and treatment, to further understand the links between the AhR and vitiligo, and provide new potential therapeutic strategies.

Therapeutic effectiveness of upadacitinib on individual types of rash in Japanese patients with moderate-to-severe atopic dermatitis

Atopic dermatitis (AD) is a chronic eczematous disease with various types of rash, erythema, edema/papulation, excoriation, or lichenification. Janus kinase 1 inhibitor upadacitinib is effective for moderate-to-severe AD. We aimed to investigate the therapeutic effects of upadacitinib on each rash type in AD patients in real-world clinical practice. Seventy-two Japanese patients with moderate-to-severe AD were treated with oral upadacitinib 15 mg/day plus topical corticosteroids. The Eczema Area and Severity Index (EASI) scores for erythema, edema/papulation, excoriation, or lichenification on the whole body or on head and neck, upper limbs, lower limbs, or trunk were assessed at weeks 0, 4, and 12 of treatment. The proportions of patients who achieved resolution or at least 75% reduction of EASI from baseline (EASI 75) for individual rash types were calculated at weeks 4 and 12 on the whole body or each anatomical site. The resolution rates for excoriation, erythema, edema/papulation, or lichenification on the whole body were 38.3%, 23.7%, 21.7%, and 8.3% at week 4 and 18.3%, 18.6%, 11.6%, and 13.3% at week 12, respectively. The EASI scores for all rash types significantly decreased at weeks 4 and 12 compared to week 0. The achievement rates of EASI 75 for excoriation, erythema, edema/papulation, or lichenification on the whole body were 67.2%, 66.7%, 49.2%, and 37.7% at week 4 and 57.3%, 65%, 41%, and 41% at week 12, respectively. The achievement rate of EASI 75 for erythema on head and neck at week 4 (45.3%) was lower than that on upper limbs (71%) and on lower limbs (70.8%), and that on head and neck at week 12 (42.2%) was lower than that on lower limbs (69.2%). These results indicate that upadacitinib is effective for all AD rash types, especially for excoriation and erythema, while head-and-neck erythema might be less responsive to upadacitinib.

Curcumin Alleviates Epidermal Psoriasis-Like Dermatitis and IL-6/STAT3 Pathway of Mice

Background

To further investigate why curcumin (CUR) can attenuate psoriasis-like dermatitis of mice.

Methods and Results

Sixteen mice were randomized into four groups. The control group used carrier cream, and the model and the CUR group were applied with topical 5% imiquimod in the naked mice skin once a day for 6 days (62.5 mg/day/mice). Meanwhile, the control and model mice were given the same dose of saline by oral means, while mice in the CUR groups received oral drug doses of 50 and 100 mg/kg once a day for 6 days, respectively. CUR could largely improve imiquimod-induced lesions of mice. By using the ELISA and qPCR, we found that the protein and mRNA levels of epidermal TNF-α and IL-6 were inhibited by CUR. The phosphorylation levels of STAT3 and its downstream associated protein levels (eg, Cyclin D1, Bcl-2 and Pim1) in skin tissues of different groups were also inhibited by CUR. Furthermore, the results of immunohistochemistry also showed the repressed effect of CUR for the expression of TNF-α, IL-6 and p-STAT3 in psoriasis-like lesions of mice.

Conclusion

CUR can effectively ameliorate the featured lesions of psoriasis mice, which may be closely associated with the involvement of IL-6/STAT3 signaling.

Curcumin alleviates imiquimod-induced psoriasis-like inflammation and regulates gut microbiota of mice

BACKGROUND

As a polyphenolic compound originated from the food spice turmeric, curcumin (CUR) has various pharmacological effects, such as anti-inflammatory, antioxidation, antiproliferative, and antiangiogenic activities. Psoriasis is centered on the overproduction of Th1- and Th2-related cytokines (e.g., interleukin [IL]-23, IL-17, TNF-α, IL-22), which is involved in the occurrence and development of its pathogenesis. However, whether CUR is involved in the treatment of psoriasis and its specific mechanisms are not fully understood.

METHODS

In this study, we detected the therapeutic effect of CUR (100 mg/kg/day) on IMQ-induced dermatitis in mice, analyzed by PASI scores, ELISA, HE staining, immunofluorescence. Moreover, we further confirmed the alteration in the relative abundance of the gut microbiota through 16sRNA to explore whether CUR could regulate the gut microbiota of IMQ-induced mice.

RESULT

Through intragastric administration, CUR can alleviate psoriasis-like lesions of mice by decreasing PASI scores, reducing the level of IL-6, IL-17A, IL-22, IL-23, TNF-α, and TGF-β1, promoting the expression of IL-10. Moreover, 16sRNA sequencing revealed that CUR could regulate the alteration in the abundance alteration of gut microbiota related to inflammation, such as Alistipes, Mucispirillum, and Rikenella at genus level. The correlation analysis further confirmed the close association between important microflora and psoriasis-like inflammation indicators.

CONCLUSIONS

CUR exerts the effect of alleviating dermatitis of psoriatic mice by regulating Th-17 related inflammatory factors. Moreover, the changes in gut microbiota via CUR may be another factor of relieving IMQ-induced lesions in mice. Therefore, CUR may be a highly promising candidate for the treatment of psoriasis.