Adipose tissue protects against skin photodamage through CD151- and AdipoQ- EVs

To clarify the protective effects of subcutaneous adipose tissue (SAT) against photodamage, we utilized nude mouse skin with or without SAT. Skin and fibroblasts were treated with adipose tissue-derived extracellular vesicles (AT-EVs) or extracellular vesicles derived from adipose-derived stem cells (ADSC-EVs) to demonstrate that SAT protects the overlying skin from photodamage primarily through AT-EVs. Surprisingly, AT-EVs stimulated fibroblast proliferation more rapidly than ADSC-EVs did. The yield of AT-EVs from the same volume of AT was 200 times greater than that of ADSC-EVs. To compare the differences between AT-EVs and ADSC-EVs, we used a proximity barcoding assay (PBA) to analyze the surface proteins on individual particles of these two types of EVs. PBA analysis revealed that AT-EVs contain diverse subpopulations, with 83.42% expressing CD151, compared to only 1.98% of ADSC-EVs. Furthermore, AT-EVs are internalized more rapidly by cells than ADSC-EVs, as our study demonstrated that CD151-positive AT-EVs were endocytosed more quickly than their CD151-negative counterparts. Additionally, adiponectin in AT-EVs activated the AMPK pathway and inhibited the NF-κB pathway, enhancing fibroblast protection against photodamage. The significantly higher yield and faster acquisition of AT-EVs compared to ADSC-EVs underscore their potential for broader applications.