Platelets from 13-lined ground squirrels are resistant to cold storage lesions

Area of Science:

• Comparative physiology
• Hematology
• Mammalian hibernation

Background:

• Hibernation involves decreased heart rate and blood flow, increasing clot risk.
• Mammalian platelets face cold storage lesions and rapid clearance, limiting human platelet transfusion shelf life to 7 days.
• Ground squirrels sequester platelets in the liver during torpor, releasing them upon arousal.

Purpose of the Study:

• To investigate the resistance of ground squirrel platelets to cold storage lesions compared to human platelets.
• To elucidate potential mechanisms underlying platelet cold adaptation in hibernating mammals.

Main Methods:

• Human and ground squirrel platelets were stored at room temperature or 4°C.
• Analysis included phosphatidylserine exposure, caspase activation, and sialic acid residue cleavage.
• Phagocytosis assays using HepG2 cells were performed post-storage.

Main Results:

• Human platelets stored at 4°C showed increased phosphatidylserine exposure, caspase activation, and desialylation.
• Cold-stored human platelets were readily phagocytosed by HepG2 cells.
• Ground squirrel platelets exhibited minimal cold storage lesions, with low phagocytosis rates even after cold exposure.

Conclusions:

• Ground squirrel platelets demonstrate remarkable resistance to cold storage lesions compared to human platelets.
• This resistance suggests a natural adaptation in hibernating species for maintaining platelet function during torpor.
• Findings may inform strategies for improving human platelet storage and transfusion viability.