Latest knowledge about changes in the proteome in microgravity

ABSTRACT

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 (µg). Moreover, they are exposed to cosmic radiation, hypodynamia, and isolation. OMICS investigations will increase our knowledge of the underlying mechanisms of µg-induced alterations in vivo and in vitro.

Areas covered

We summarize the findings over the recent 3 years on µg-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 µg-induced antibiotic resistance of bacteria, the myocardial consequences of µg-induced calpain activation, and the role of MMP13 in osteoarthritis. All these point to the fact that µg is an extreme stressor that could not be evolutionarily addressed on Earth.

Expert opinion

In conclusion, when interpreting µg-experiments, the direct, mostly unspecific stress response, must be distinguished from specific µg-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).

KEYWORDS:

• Real microgravity
• simulated microgravity
• proteome
• plants
• rodents
• human cells
• cancer

Article highlights

• Investigations of the proteome or secretome are used in space biology in order to elucidate graviperception and gravisensitivity of microorganisms, plants, animals, and human cells.

• Knowledge about alterations of the proteome and underlying pathways is important for the development of countermeasures to protect humans in space against human diseases.

• Spaceflight and simulated microgravity induce 3D growth of human different human benign and malignant cells

• 2D adherent cells and 3D multicellular spheroids differ in protein content in microgravity.

• Space experiments advance the development of biofabrication technologies.

• Investigation of effects of space environment on organisms (microorganisms, algae, and higher plants) of future bio regenerative life support systems.

• Determination of plant defense under space conditions.

• Investigation of increase in malignancy of facultative pathogens.

• Further investigation of the human immune system under space conditions with respect to microbial infections.

• Space environment is a possible breeding platform for unique strains of plants and microorganisms.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership, or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This research was funded by the German Space Agency (DLR, Deutsches Zentrum für Luft- und Raumfahrt); BMWi projects 50WB1924 (DG) and 50WB1923 (ML and PR). SMS was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES).