Exposure to microgravity affects human physiology in various ways, and astronauts frequently report skin-related problems. Skin rash and irritation are frequent complaints during space missions, and skin thinning has also been reported after returning to Earth. However, spaceflight missions for studying the physiological changes in microgravity are impractical. Thus, we used a previously developed 3D clinostat to simulate a microgravity environment and investigate whether physiological changes of the skin can be reproduced in a 3D in vitro setting. Our results showed that under time-averaged simulated microgravity (taSMG), the thickness of the endothelial cell arrangement increased by up to 59.75%, indicating skin irritation due to vasodilation, and that the diameter of keratinocytes and fibroblast co-cultured spheroids decreased by 6.66%, representing skin thinning. The α1 chain of type I collagen was upregulated, while the connective tissue growth factor was downregulated under taSMG. Cytokeratin-10 expression was significantly increased in the taSMG environment. The clinostat-based 3D culture system can reproduce physiological changes in the skin similar to those under microgravity, providing insight for understanding the effects of microgravity on human health before space exploration.

暴露于微重力以各种方式影响人体生理机能，宇航员经常报告与皮肤相关的问题。皮疹和刺激是太空任务期间常见的抱怨，返回地球后也有皮肤变薄的报道。然而，研究微重力生理变化的航天任务是不切实际的。因此，我们使用先前开发的 3D 恒压仪来模拟微重力环境，并研究皮肤的生理变化是否可以在 3D 体外环境中重现。我们的结果表明，在时间平均模拟微重力（taSMG）下，内皮细胞排列的厚度增加了 59.75%，表明血管舒张导致皮肤刺激，角质形成细胞和成纤维细胞共培养球体的直径减少了 6.66 %, 代表皮肤变薄。I型胶原的α1链被上调，而在taSMG下结缔组织生长因子被下调。Cytokeratin-10 表达在 taSMG 环境中显着增加。基于clinostat的3D培养系统可以再现类似于微重力下皮肤的生理变化，为在太空探索之前了解微重力对人类健康的影响提供见解。