Hibernating bears offer clues to preventing thrombosis in humans

Study uncovers key protein as protective factor against blood clots

Hibernating brown bears have provided an insight into thrombosis prevention during extended immobilisation. PA

A recent study involving hibernating brown bears has revealed a factor that safeguards them from thrombosis during six months of immobilisation.

The study, which also looked at people who can't move for long periods, found that having lower levels of a specific protein called HSP47 in blood cells helps protect against blood clotting.

This discovery, backed by research in pigs and mice, shows the protection is found in many different mammals and could help create new blood clot prevention treatments.

Venous thromboembolism (VTE), a cardiovascular condition in which blood clots form in veins, can cause death or severe disability.

Individuals who experience short-term immobility due to illness or injury face an increased risk of VTE, while those with chronic paralysis from spinal cord injuries do not.

Hibernating brown bears, despite being immobile for months at a time, also do not show an increased risk of thrombosis during hibernation.

These observations suggest a molecular mechanism that defends against the condition during extended immobilisation periods in both species.

To investigate this protection, researchers led by Manuela Thienel analysed blood samples from hibernating brown bears and chronically immobilised humans.

By using a technique called mass spectrometry-based proteomics, the researchers discovered that blood cells from hibernating bears have a unique pattern that helps prevent blood clotting.

This pattern is marked by lower levels of a protein called HSP47 and fewer signs of inflammation.

This pattern was also observed in immobilised humans, with additional support from pig and mouse studies.

To further examine the effect of immobilisation, the researchers subjected healthy individuals to bed rest, noting a significant reduction in HSP47 after 27 days.

The results suggest that the reduction in HSP47 during long-term immobilisation offers protection from thrombosis.