Therapeutic effect of interleukin-10 in keloid fibroblasts by suppression of TGF-β/Smad pathway

Keloids are a skin disorder where the skin goes beyond the original border of the wound or trauma, resulting in functional and cosmetic deformities, displeasure, itching, pain, psychological stress, and patient dissatisfaction. This study aimed to explore the therapeutic effect of interleukin-10 (IL-10) on the proliferation of keloid fibroblasts.

Keloid fibroblasts were isolated, primarily cultured, and treated with IL-10 at different concentrations. Normal skin fibroblasts were used as normal control. Immunofluorescent staining was performed to identify the establishment of keloid, as well as normal skin fibroblast. Cell Counting Kit-8 (CCK-8) was carried out to monitor the proliferative variation, while Western blot was conducted to detect the expression variation of key members involved in the TGF-β/Smad signaling pathway.

Identified by the IF staining of Vimentin, a classical biomarker of fibroblast, both primary culture of keloid and normal skin fibroblasts have been established. Compared with control, the proliferation of Keloid fibroblasts was shown to be significantly suppressed on treatment with IL-10 in a time and dose-dependent manner. Expression of P-Smad2/3 and Smad4 were increasingly down-regulated, whereas Smad-7 was up-regulated with the increasing concentration of IL-10. By contrast, the variation of Smad 2/3 expressions was hardly influenced. Furthermore, the Collagen Type I and Collagen Type II were found to be markedly decreased after treatment with IL-10.

IL-10 was shown to be able to significantly inhibit the proliferation of keloid fibroblasts, which was explicitly and strongly suggestive of its potential therapeutic effect in the management of keloid.