MicroRNA-21 may be involved in the therapeutic effects of Galla chinensis ointment on keloid

OBJECTIVE: Galla chinensis ointment can inhibit the proliferation of keloid fibroblasts and decrease keloid formation. We investigated whether Galla chinensis ointment inhibits keloid fibroblast proliferation through expression of microRNA-21, phosphorylated (p)-phosphatidylinositol 3-kinase (p-PI3K), chromosome 10 neutropenic protein phosphatase (PTEN), protein kinase B (p-Akt), and mammalian target of rapamycin (p-mTOR). METHODS: A keloid mouse model and human keloid-derived fibroblasts were developed and treated with Galla chinensis. Immunohistochemistry, western blot, and reverse transcription-PCR were used to detect miR-21, PI3K, PTEN, Akt, and mTOR in keloid tissues. RESULTS: p-Akt and p-mTOR were highly expressed in the control group, PTEN was highly expressed in the treatment group, and p-PI3K was highly expressed in keloid tissue in both groups. Galla chinensis reduced miR-21 expression and increased PTEN mRNA expression in keloid fibroblasts compared with the control group, resulting in increased PTEN protein and decreased p-Akt and p-mTOR protein. Galla chinensis had no effect on p-PI3K. CONCLUSION: Galla chinensis might inhibit proliferation of keloid fibroblasts by upregulating PTEN, thus inhibiting expression of miR-21 and downregulating p-Akt and p-mTOR expression. These results confirm the effect of Galla chinensis ointment on fibroblasts and suggest that it could be used to manage keloids clinically.