Parabolic flight as a space-flight analogon impacts angiogenesis and lipid metabolism

This study aimed to examine the effects of weightlessness and microgravity, induced by parabolic flight, on specific biomarkers associated with angiogenesis, lipid homeostasis, and cardiovascular diseases, including angiogenin (ANG), angiopoietin-1 (ANGPT-1), angiopoietin-like protein 4 (ANGPTL4), heat shock protein 70 (HSP70), transforming growth factor-beta (TGF-β), vascular endothelial growth factor (VEGF), and platelet-derived growth factor subunit AA (PDGF-AA).

14 healthy volunteers (mean age: 28.9 years; 6 females) participated in short-term sessions of weightlessness and microgravity using parabolic flights. Venous blood samples were collected at different time points (baseline, 1 h, and 24 h after parabolic flight) and frozen as serum samples. Initially, Proteome Profiler Angiogenesis Array was used to screen pooled serum samples of each time point for potential alterations of angiogenesis-associated proteins. Additionally, individual blood samples were analyzed using enzyme-linked immunosorbent assay (ELISA).

Proteome Arrays revealed an overall decrease of angiogenesis-associated proteins in response to parabolic flight. On the other hand, proteins associated with lipid homeostasis, such as Leptin and TIMP-4, were significantly elevated in response to parabolic flight. Individual analysis of selected proteins solely revealed a slight increase of ANGPTL4 and HSP70 levels 1 hour post-flight, although without statistical significance (p = 0.7705). Nevertheless, 24 h after parabolic flight, ANGPTL4 concentrations in serum significantly decreased compared to the preceding time point (p = 0.0020). Similarly, HSP70 was tendentially elevated 1 h after flight (p = 0.8135), though significantly declined at the end of the experiment (BL vs. 24 h: p = 0.0435; 1 h vs. 24 h: p = 0.0031). No significant differences could be observed in ANG, ANGPT1, TGF-β1, VEGF, and PDGF-AA concentrations at any time point.

The findings of this study suggest that exposure to gravitational changes, such as weightlessness and microgravity, may lead to relevant changes in angiogenesis and lipid homeostasis. The upregulation of Leptin and TIMP-4, as well as ANGPTL4 in short-term response to parabolic flight poses a risk to disturbances in lipid metabolism, potentially increasing the likelihood of cardiovascular or hepatic events. Further research is needed to better understand the impact of microgravity and weightlessness on angiogenesis and lipid metabolism to protect astronaut health during prolonged space missions.