Latest knowledge about changes in the proteome in microgravity.

Introduction: A long-term stay of humans in space causes health problems and changes in protists and plants. Deep space exploration will increase the time humans or rodents will spend in microgravity (µ). Moreover, they are exposed to cosmic radiation, hypodynamia, and isolation. OMICS investigations will increase our knowledge of the underlying mechanisms of µ-induced alterations and .

Areas Covered: We summarize the findings over the recent 3 years on µ-induced changes in the proteome of protists, plants, rodent, and human cells. Considering the thematic orientation of microgravity-related publications in that time frame, we focus on medicine-associated findings, such as the µ-induced antibiotic resistance of bacteria, the myocardial consequences of µ-induced calpain activation, and the role of MMP13 in osteoarthritis. All these point to the fact that µ is an extreme stressor that could not be evolutionarily addressed on Earth.

Expert Opinion: In conclusion, when interpreting µ-experiments, the direct, mostly unspecific stress response, must be distinguished from specific µ-effects. For this reason, recent studies often do not consider single protein findings but place them in the context of protein-protein interactions. This enables an estimation of functional relationships, especially if these are supported by epigenetic and transcriptional data (multi-omics).