Collagen fiber and cellular dynamics of axolotl skin with aging

As skin ages, its structure and function undergo significant transformations driven by complex cellular and molecular processes. In this study, we explore these changes using the axolotl, an amphibian model known for its transparent skin, allowing detailed observation of both epidermal and dermal layers. We found that axolotl skin, composed of an epidermis and a collagen-rich dermis with three distinct layers (stratum baladachinum, spongiosum, and compactum), shows clear age-related alterations. These changes include reduced fibroblast numbers, altered lattice-patterned cell morphology, disruption of the lattice patterned collagen fiber pattern, thickening the stratum spongiosum, and thinning of the stratum compactum. Notably, fibroblasts, which play a crucial role in collagen braiding, displayed diminished functionality in older axolotls. This study highlights how aging affects both the structural integrity of dermal collagen and cellular dynamics. Given the similarity between axolotl and mammalian skin, these findings may provide valuable insights into the mechanisms of skin aging and potential avenues for anti-aging therapies. This research offers a foundation for future studies aimed at understanding skin aging and regeneration.