Skin undergoes constant self-renewal, and its functional decline is a visible consequence of aging. Understanding human skin aging requires in-depth knowledge of the molecular and functional properties of various skin cell types. We performed single-cell RNA sequencing of human eyelid skin from healthy individuals across different ages and identified eleven canonical cell types, as well as six subpopulations of basal cells. Further analysis revealed progressive accumulation of photoaging-related changes and increased chronic inflammation with age. Transcriptional factors involved in the developmental process underwent early-onset decline during aging. Furthermore, inhibition of key transcription factors HES1 in fibroblasts and KLF6 in keratinocytes not only compromised cell proliferation, but also increased inflammation and cellular senescence during aging. Lastly, we found that genetic activation of HES1 or pharmacological treatment with quercetin alleviated cellular senescence of dermal fibroblasts. These findings provide a single-cell molecular framework of human skin aging, providing a rich resource for developing therapeutic strategies against aging-related skin disorders.

皮肤不断自我更新，其功能衰退是老化的明显后果。了解人类皮肤老化需要深入了解各种皮肤细胞类型的分子和功能特性。我们对来自不同年龄的健康个体的人眼睑皮肤进行了单细胞 RNA 测序，并确定了 11 种典型细胞类型以及 6 种基底细胞亚群。进一步的分析显示，随着年龄的增长，光老化相关变化的逐渐积累和慢性炎症的增加。参与发育过程的转录因子在衰老过程中经历了早发性下降。此外，抑制成纤维细胞中的关键转录因子HES1和KLF6角质形成细胞中的 α 不仅会损害细胞增殖，还会增加衰老过程中的炎症和细胞衰老。最后，我们发现HES1 的基因激活或槲皮素的药物治疗减轻了真皮成纤维细胞的细胞衰老。这些发现提供了人类皮肤衰老的单细胞分子框架，为开发针对衰老相关皮肤疾病的治疗策略提供了丰富的资源。