Single-cell transcriptomic comparison of young and aged dermal macrophages

Previously, in a meta-analysis of public single-cell transcriptomes profiling various healthy and disease tissues, we demonstrated that macrophage heterogeneity in skin, as well as in other mouse tissues, could be described into 5 distinct identities (S1-5) with a defined transcriptomic fingerprint, regardless of tissue origins. We established a general identity scheme for tissue macrophages, MIKA (Macrophage Identity Kinetics Archive) as an alternative to the conventional M1/M2 scheme which shows limitations in annotating in vivo tissue macrophages. (PMID: 39720957) MIKA was recently updated to finetune identity definition, and to include more tissues and pathophysiological conditions. (PMID: 41342690) Under the current MIKA framework, tissue macrophages are classified to 6 core identities (S1-S6, common to various tissues) and/or tissue-specific macrophages. This dataset is a part of the raw data sources of the latest version of MIKA profiling single-cell transcriptomes of F4/80+MHCII-hi macrophages FACS-isolated from dorsal skin of young (9 week-old) and old (108 week-old) C57BL/6 male mice. Overall design: Dorsal skins were dissected from male mice of indicated ages, pooled and digested for single cell isolation. Male mice were analysed to avoid drastic menopausal endocrine changes. Macrophages were sorted as F4/80+MHCII-hi cells by BD FACSAria III and transcriptomes were analysed by single-cell RNA-seq.