Simulated microgravity attenuates skin wound healing by inhibiting dermal fibroblast migration via F‐actin/YAP signaling pathway

Abstract

Skin and its cell components continuously subject to extrinsic and intrinsic mechanical forces and are mechanical sensitive. Disturbed mechanical homeostasis may lead to changes in skin functions. Gravity is the integral mechanical force on the earth, however, how gravity contributes to the maintenance of skin function and how microgravity in space affects the wound healing are poorly understood. Here, using microgravity analogs, we show that simulated microgravity (SMG) inhibits the healing of cutaneous wound and the accumulation of dermal fibroblasts in the wound bed. In vitro, SMG inhibits the migration of human foreskin fibroblast cells (HFF‐1), and decreases the F‐actin polymerization and YAP (yes‐associated protein) activity. The SMG‐inhibited migration can be recovered by activating YAP or F‐actin polymerization using lysophosphatidic acid (LPA) or jasplakinolide (Jasp), suggesting the involvement of F‐actin/YAP signaling pathway in this process. In SMG rats, LPA treatment improves the cutaneous healing with increased dermal fibroblasts in the wound bed. Together, our results demonstrate that SMG attenuates the cutaneous wound healing by inhibiting dermal fibroblast migration, and propose the crucial role of F‐actin/YAP mechano‐transduction in the maintenance of skin homeostasis under normal gravity, and YAP as a possible therapeutic target for the skin care of astronauts in space.

Morphological Changes of 3T3 Cells under Simulated Microgravity

“…Yang and colleagues (2016) showed that SMG could alter the circadian rhythm of 3T3 cells by influencing the mRNA expression of circadian genes and induce a change in Per1 and Per2 expression [19]. Fibroblasts exhibit high sensitivity to SMG, which validates the possible significance of the TGF-β1/Smad3 signaling pathway in regulating wound healing [20]. A recent study revealed that changes in fibroblast structures and delayed cell migration were the main effects of altered gravity, contributing to alterations in the fibroblasts' function related to wound healing [21].…”

Omics Studies of Tumor Cells under Microgravity Conditions

“…So far, multiple changes occurring in tissues and on the cellular level have been reported [30,31]. Human cell cultures of benign and malignant cells exposed to real microgravity (r-µg, also called weightlessness) in space showed several morphological and molecular changes [32][33][34][35][36][37][38][39][40][41]. Low differentiated FTC-133 follicular thyroid cancer cells studied in space for 10 days (d) during the Shenzhou-8 space mission showed changes in growth behavior and exhibited two different phenotypes after spaceflight.…”