Since in vitro methods (2D and 3D) used for the preclinical testing of candidate anti-aging compounds mimic the complexity of human skin aging unsatisfactorily, we wished to develop an ex vivo assay for interrogating key aging-read outs in healthy human skin. Healthy, full-thickness skin biopsies (2 males, 4x females; 22 - 77 years) were organ-cultured in serum-free, supplemented medium for 3 days in the presence/absence of recognized anti-aging compounds (tretinoin (5µM), resveratrol (10µM), or caffeine (200µM), and key skin aging biomarkers were analyzed by quantitative (immuno-)histomorphometry and/or qRT-PCR. After only 3 days ex vivo, vehicle-treated human skin underwent striking intrinsic aging-associated changes: in the epidermis, keratinocyte proliferation (Ki-67), sirtuin-1, MTCO1 and collagen 17A protein expression as well as mitochondrial complex II/IV activity were all significantly reduced. In the dermis, collagen III protein and hyaluronic acid content declined significantly. In contrast, aging-associated DNA damage (p-H2A.X), increased in epidermal keratinocytes, and whole skin extracts showed up-regulated mRNA levels of metalloproteinases (MMP-1, 2, 3 and 9), senescence-associated secretory phenotype cytokines (IL6, IL8), and of both CXCL10 and cyclin-dependent kinase inhibitor 1A (CDKN1). The known senolytics, tretinoin, resveratrol, and caffeine, all markedly reduced p-H2A.X accumulation, increased epidermal collagen17A and dermal collagen III deposition, and reduced MMP2 protein expression. Caffeine also prevented the upregulation of CXCL10, IL6, IL8, MMP2 and CDKN1 transcription ex vivo. Here, we show here that organ culture rapidly and robustly induces a spontaneous aging/senescence program in healthy human skin, which can be quantitatively assessed and manipulated with senolytics. Thus, this simple, but clinically relevant ex vivo model provides an excellent new assay system for pre-

ESDR581 - Spontaneous, Intrinsic Aging in Organ-Cultured Human Skin as Novel Ex Vivo Assay to Test Candidate Anti-Aging Actives

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.