Morpho-functional alterations in testicular and nervous cells submitted to modelled microgravity

Area of Science:

• Cell biology
• Gravitational biology
• Space medicine

Background:

• Life on Earth evolved under gravity, but spaceflight introduces microgravity.
• Cellular-level studies on microgravity effects are limited.
• Earth-based simulations using Random Positioning Machines (RPMs) help study microgravity impacts.

Purpose of the Study:

• To investigate the effects of simulated microgravity on various cell types.
• To understand cellular adaptation mechanisms to altered gravity.
• To explore potential physiological adaptations in astronauts.

Main Methods:

• Utilized a 3D Random Positioning Machine (RPM) to simulate microgravity.
• Observed cellular changes in lymphocytes, astrocytes, neurons, and testicular cells.
• Analyzed cytoskeleton organization, cell division, mitochondria, apoptosis, protein expression, and enzyme activity.

Main Results:

• Short-term microgravity disrupted cytoskeleton, impaired cell division, damaged mitochondria, and increased apoptosis.
• Transmembrane transport proteins and steroid dehydrogenases were affected.
• After 20 hours, cells recovered, organized cytoskeleton, normalized mitosis, and returned to baseline apoptosis levels by producing heat shock proteins.

Conclusions:

• Simulated low gravity causes transient cellular alterations.
• Cultured cells demonstrate adaptability to gravity vector changes.
• Cellular recovery mechanisms, like heat shock protein synthesis, enable adaptation to microgravity, potentially explaining astronaut adaptation.