Space travel does not significantly impact cardiac sarcomere function but does induce immune-related proteomic...

Area of Science:

• Space medicine
• Cardiovascular physiology
• Skeletal muscle research

Background:

• Space exploration poses risks to human physiology, including microgravity and radiation.
• The effects of spaceflight on cardiac muscle contractility are not fully understood.
• Previous research indicates microgravity impacts skeletal muscle, but cardiac muscle effects require further investigation.

Purpose of the Study:

• To investigate the impact of spaceflight on the myocardial contractile function of cardiomyocytes.
• To characterize the mechanical properties of the sarcomere after ~38.5 days in space.
• To identify proteomic changes in cardiomyocytes due to space travel.

Main Methods:

• Experiments utilized skinned cardiomyocytes from mice that traveled to the International Space Station and age-matched ground controls.
• Functional experiments assessed sarcomere force-generating capacity, calcium sensitivity, and cooperativity.
• Mass spectrometry (MS) and gene ontology analysis were performed to evaluate proteomic and pathway changes.

Main Results:

• Spaceflight for ~38.5 days did not alter sarcomere force-generating capacity (Tmax), calcium sensitivity (EC50), or cooperativity.
• Passive force and cross-sectional area (CSA) remained consistent between spaceflight and ground control groups.
• MS analysis revealed immune-related proteomic changes in the spaceflight group, while pathways associated with sarcomere contractility were unchanged.

Conclusions:

• Approximately 38.5 days of space travel does not significantly affect the intrinsic contractile state of murine cardiomyocytes.
• Spaceflight appears to induce immune-related proteomic alterations in cardiomyocytes.
• Further research is needed to understand the long-term implications of these immune changes for cardiovascular health during space missions.