Journal Article

Pharmacological inhibition of demethylzeylasteral on JAK-STAT signaling ameliorates vitiligo

Kang, Pan, Li, Shuli, Yi, Xiuli, Zhang, Weigang, Li, Chunying, Guo, Sen, Gao, Tianwen, Cui, Tingting, Guo, Weinan, Chang, Yuqian, Du, Pengran

2023

Overview

Background The activation of CD8 + T cells and their trafficking to the skin through JAK-STAT signaling play a central role in the development of vitiligo. Thus, targeting this key disease pathway with innovative drugs is an effective strategy for treating vitiligo. Natural products isolated from medicinal herbs are a useful source of novel therapeutics. Demethylzeylasteral (T-96), extracted from Tripterygium wilfordii Hook F, possesses immunosuppressive and anti-inflammatory properties. Methods The efficacy of T-96 was tested in our mouse model of vitiligo, and the numbers of CD8 + T cells infiltration and melanocytes remaining in the epidermis were quantified using whole-mount tail staining. Immune regulation of T-96 in CD8 + T cells was evaluated using flow cytometry. Pull-down assay, mass spectrum analysis, molecular docking, knockdown and overexpression approaches were utilized to identify the target proteins of T-96 in CD8 + T cells and keratinocytes. Results Here, we found that T-96 reduced CD8 + T cell infiltration in the epidermis using whole-mount tail staining and alleviated the extent of depigmentation to a comparable degree of tofacitinib (Tofa) in our vitiligo mouse model. In vitro, T-96 decreased the proliferation, CD69 membrane expression, and IFN-γ, granzyme B, (GzmB), and perforin (PRF) levels in CD8 + T cells isolated from patients with vitiligo. Pull-down assays combined with mass spectrum analysis and molecular docking showed that T-96 interacted with JAK3 in CD8 + T cell lysates. Furthermore, T-96 reduced JAK3 and STAT5 phosphorylation following IL-2 treatment. T-96 could not further reduce IFN-γ, GzmB and PRF expression following JAK3 knockdown or inhibit increased immune effectors expression upon JAK3 overexpression. Additionally, T-96 interacted with JAK2 in IFN-γ-stimulated keratinocytes, inhibiting the activation of JAK2, decreasing the total and phosphorylated protein levels of STAT1, and reducing the production and secretion of CXCL9 and CXCL10. T-96 did not significantly inhibit STAT1 and CXCL9/10 expression following JAK2 knockdown, nor did it suppress upregulated STAT1-CXCL9/10 signaling upon JAK2 overexpression. Finally, T-96 reduced the membrane expression of CXCR3, and the culture supernatants pretreated with T-96 under IFN-γ stressed keratinocytes markedly blocked the migration of CXCR3 + CD8 + T cells, similarly to Tofa in vitro. Conclusion Our findings demonstrated that T-96 might have positive therapeutic responses to vitiligo by pharmacologically inhibiting the effector functions and skin trafficking of CD8 + T cells through JAK-STAT signaling.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Analysis / Biomedical and Life Sciences / Biomedicine / CD69 antigen / CD8 antigen / CD8+ T cell / Cell activation / Cell culture / Chemokines / CXCL10 protein / CXCR3 protein / Cytotoxicity / Demethylzeylasteral / Disease Biomarkers / Dosage and administration / Drug development / Drug therapy / Epidermis / Flow cytometry / Granzyme B / Hair / Health aspects / Homeopathy / Immunoregulation / Immunosuppressive agents / Infiltration / Inflammation / Interleukin 2 / JAK / Janus kinase 2 / Keratinocytes / Laboratory animals / Lymphocytes / Lymphocytes T / Lysates / Materia medica and therapeutics / Medicinal plants / Medicine, Botanic / Medicine, Herbal / Medicine/Public Health / Melanocytes / Melanoma / Perforin / Proteins / RNA polymerase / Scientific equipment and supplies industry / Skin / STAT / T cells / Therapeutics / Tofacitinib / Tumors / Vitiligo / γ-Interferon