Skin Physiology in Microgravity: A 3-Month Stay Aboard ISS Induces Dermal Atrophy and Affects Cutaneous Muscle and Hair Follicles Cycling in Mice

The study investigated the effects of a 3-month stay aboard the ISS on mouse skin physiology, revealing significant dermal atrophy with a 15% reduction in dermal thickness and increased procollagen synthesis by 42%. Hair follicle cycling was disrupted, with more follicles in the anagen phase in space mice compared to ground controls. Additionally, 434 genes were significantly modulated, many related to striated muscle homeostasis. These findings suggested that prolonged space exposure could induce skin atrophy, disrupt hair follicle cycles, and alter the transcriptomic profile of cutaneous muscles, highlighting potential health impacts for astronauts during extended space missions.