Influence of Microgravity on Cerebrovascular Complications: Exploring Molecular Manifestation and Promising Countermeasures

Abstract

With NASA and other space agencies planning for longer-duration spaceflights, such as missions to Mars, and the rise in space tourism, it is crucial to comprehend the impact of the space environment on human health. However, there is a lack of information on how spaceflight impacts cerebrovascular health. The absence of gravitational force negatively affected various physiological functions in astronauts, especially posing risks to the cerebrovascular system. Exposure to microgravity leads to fluid changes that impact cardiac function, arterial pressure, and cerebrovascular structural changes that may be the cause of cognitive impairment. Numerous experiments have simulated microgravity to study the damage caused by prolonged spaceflight and reported similar findings. Understanding the effect of simulated microgravity on cerebrovascular structure and function has important implications for cerebrovascular health on Earth and in space. Simulated microgravity has been shown to induce endothelial dysfunction, altering nitric oxide (NO) synthesis pathways and increasing oxidative stress. Dysregulation of the Renin-Angiotensin system, NADPH oxidases, K⁺ Channels, and L-type Ca²⁺ Channels contributes to vascular dysfunction, while mitochondrial complexes expression and Ca²⁺ concentration exacerbate oxidative stress. This knowledge is essential for creating effective countermeasures to protect astronaut health during extended space missions. Therapeutic interventions targeting mitochondrial ROS and NADPH oxidases showed promise in mitigating these effects. This review article delves into the significant challenges posed by extended spaceflight, focusing on the cerebrovascular systems. It also provides a comprehensive understanding of molecular mechanisms associated with microgravity-induced cerebrovascular dysfunction and potential therapeutic interventions, paving the way for safer and more effective space travel.

Graphical Abstract