Topical tofacitinib treatment alleviated LL37-induced rosacea-like phenotype
To explore the therapeutic effect of topical tofacitinib treatment on rosacea, we established an LL37-induced rosacea-like mouse model. Twelve hours after the final treatment, no obvious inflammatory erythema was observed in the PBS group. In contrast, mice in the LL37 group exhibited distinct and sharply defined inflammatory erythema on the dorsal skin, indicating successful modeling. The inflammatory erythema on the dorsal skin of mice was significantly alleviated in the LL37+TOFA and LL37+TAA groups compared to the LL37 group (Fig 1a, b). The area of redness was significantly decreased (P<0.05 for both) (Fig 1c). The redness score was significantly lower in the LL37+TOFA group compared to the LL37 group (P<0.001 for both) (Fig 1d, e).
Topical tofacitinib treatment improved inflammatory infiltration in LL37-induced rosacea-like mouse.
The results of HE staining on skin lesion specimens showed that the skin tissue of mice in the PBS group and the PBS+TOFA group exhibited a normal structure in all layers without evident inflammatory infiltration. In contrast, the skin tissue of mice in the LL37 group exhibited thickening, with a significant infiltration of inflammatory cells into the dermis. Compared to the LL37 group, the severity of inflammation was notably reduced in the LL37+TOFA group and the LL37+TAA group, with a significant decrease in the number of infiltrating inflammatory cells in the dermis (P<0.001 for both) (Fig 2a, e). The toluidine blue staining of skin lesion sections revealed that in the PBS group and the PBS+TOFA group, occasional mast cells were observed in the dermal layer. However, in the LL37 group, there was a significant increase in the number of mast cells infiltrating into the dermal layer. Compared to the LL37 group, both the LL37+TOFA group and the LL37+TAA group exhibited a significant reduction of mast cell infiltration in the dermal layer (P<0.001 for both) (Fig 2b, f). The improvement in inflammatory infiltration and the reduction in mast cell infiltration in the skin lesions of the LL37+TOFA group and the LL37+TAA group were similar. Meanwhile, compared to the LL37 group, the number of infiltrating CD4+ T cells in the dermis of skin lesions was significantly reduced in the LL37+TOFA and the LL37+TAA groups (P<0.01, P<0.001 , respectively) (Fig 2c, g).
Images of H&E (a) and Toluidine blue (b) stained skin sections (200× and 400×). Images of skin sections stained with CD4 (c) and CD34 (d) immunohistochemistry (200× and 400×). (e) Quantitative analysis of the number of dermal infiltrating cells per HPF. Quantitative analysis of the number of dermal infiltrating mast cells (f), CD4+T cells (g), and CD34+ capillaries (h) per HPF. (each group n=6, data is presented as mean ± SD, *P<0.05, **P<0.01, ***P<0.001)
Topical tofacitinib treatment improved cutaneous angiogenesis in LL37-induced rosacea-like mouse.
CD34 is a specific antibody for vascular endothelial cells. Through immunohistochemical staining, we observed a significant increase in capillary proliferation in the dermis of mice in the LL37 group. However, in the LL37+TOFA group and LL37+TAA group, the number of capillaries in the dermal layer of skin lesions was significantly reduced (P<0.001 for both) (Fig 2d, h).
Topical tofacitinib treatment inhibiting LL-37-induced activation of JAK/STAT pathway in mouse.
We detected the relative mRNA expression levels of 7 STATs by RT-qPCR. The results showed that, compared to the PBS group, the mRNA relative expression levels of STAT1, STAT2, STAT3, STAT4, and STAT5a were significantly increased in the skin lesions of mice in the LL37 group (P<0.001, P<0.01, P<0.05, P<0.001, P<0.05, respectively) (Fig 3). After treatment with 2% tofacitinib emulsion, compared to the LL37 group, the mRNA relative expression levels of STAT1, STAT4, and STAT5a were significantly decreased in the skin lesions of mice in the LL37+TOFA group (P<0.05, P<0.001, P<0.05, respectively) (Fig 3a, d and e).
Oral tofacitinib treatment alleviated clinical symptoms of ETR patients.
Three ETR patients received oral tofacitinib treatment at a dose of 5 mg per administration, twice daily, for a total duration of 4 weeks. After 4 weeks of treatment, the erythema and papules on the patients' cheeks demonstrated significant improvement compared to their pre-treatment condition (Fig 4a). The patients' CEA, PSA, and GFSS scores all demonstrated significant reductions (all P<0.05) (Fig 4b, c and d).