Synthetic Strategy and Evaluation of the Benzyloxy Benzylamide Derivatives as Thymic Stromal Lymphopoietin Modulators for the Treatment of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease driven by immune dysregulation, in which thymic stromal lymphopoietin (TSLP) plays a critical role by triggering type 2 inflammation and exacerbating disease progression. In this study, a screening of our in-house library for inhibition of CCL17 mRNA expression led to identification of hit compound 6a. Based on this scaffold, benzyloxy benzylamide derivatives were systematically designed and synthesized, followed by the evaluation of their anti-inflammatory potential. Among them, compound 14o exhibited the most potent inhibition of CCL17 and IL-1B mRNA expression in HaCaT keratinocytes, along with favorable drug-like properties. 14o interfered with TSLP receptor dimerization and suppressed the TSLP-induced signal transducer and activator of transcription 5 phosphorylation. Furthermore, 14o significantly attenuated TSLP-induced calcium influx and effectively alleviated pruritus and AD-like symptoms in a house dust mite (HDM)-induced AD mouse model. Collectively, these findings highlight 14o as a promising topical therapeutic candidate targeting TSLP signaling for the treatment of AD.特应性皮炎（Atopic Dermatitis, AD）是一种由免疫失调驱动的慢性炎症性皮肤病，其中胸腺基质淋巴细胞生成素（Thymic Stromal Lymphopoietin, TSLP）通过触发2型炎症反应并加重疾病进展发挥关键作用。本研究通过筛选内部自有文库以评估其对趋化因子C-C基序配体17（CCL17）mRNA表达的抑制活性，最终筛选得到命中化合物6a。基于该母核骨架，研究人员系统性设计并合成了一系列苄氧基苯甲酰胺衍生物，随后对其抗炎潜能进行了评价。其中，化合物14o在HaCaT角质形成细胞中对CCL17及白细胞介素1β（IL-1B）mRNA的表达展现出最强的抑制作用，同时具备优良的类药性质。14o可干扰TSLP受体二聚化，并抑制TSLP诱导的信号转导与转录激活因子5（Signal Transducer and Activator of Transcription 5, STAT5）磷酸化。此外，14o可显著减弱TSLP诱导的钙内流，并在屋尘螨（House Dust Mite, HDM）诱导的AD小鼠模型中有效缓解瘙痒及AD样症状。综上，上述研究结果表明14o是一种极具开发前景的靶向TSLP信号通路的外用治疗候选药物，可用于AD的治疗。