Methods for preventing, ameliorating, or reducing dermatological signs of aging are provided which employ active agents that suppress or down-regulate microRNA expression in dermal fibroblast, resulting in enhanced production of collagen, elastin and/or fibrillin in the skin. Also provided are methods for screening for activity against specific microRNAs and the methods of using active agents identified by the screening protocol in the treatment of skin.本發明提供一種防止、改善或減少皮膚老化跡象之方法,該方法採用抑制或下調微型RNA在皮膚纖維母細胞中之表現之活性劑,增強皮膚中產生膠原蛋白、彈性蛋白及/或原纖維蛋白。亦提供一種篩選可對抗特定微型RNA之活性之方法,及採用該篩選方法所確認之活性劑於治療皮膚中之方法。