Role of mitochondria in the maintenance of platelet function during in vitro storage

Abstract

Platelets undergo structural and biochemical alterations during in vitro storage and these are collectively called platelet storage lesions (PSL). The mitochondrion is an important cell organelle involved not only in energy production but also in the regulation of cellular functions and viability. This implies that some platelet functions may be regulated by mitochondria; hence, preservation of mitochondrial functions may be important for the maintenance of platelet quality in stored platelet concentrates (PCs). This work describes the effects of various compounds on mitochondrial functions important for the maintenance of platelet quality in in vitro stored PCs. PCs were stored at 22 °C with gentle agitation in the presence or absence of 2,4-dinitrophenol, antimycin A, acetyl-l-carnitine and ascorbic acid. The effects of these products on platelet quality were assessed by analysing glucose and lactate concentrations, pH of the storage medium, shape of the platelets, mitochondrial membrane potential and depolarisation, surface expression of CD62P and collagen-induced platelet aggregation. 2,4-Dinitrophenol and antimycin A increased PSL levels, whereas acetyl-l-carnitine reduced the level of changes in pH and mitochondrial depolarisation. Ascorbic acid in the storage medium resulted in improved levels of collagen-induced platelet aggregation. However, none of the examined reagents suppressed CD62P expression in platelets. These results suggest that preservation of mitochondrial function is fundamental, but not fully sufficient, for the maintenance of platelet in vitro quality during storage. Further research is necessary to develop methods for preserving both mitochondrial and platelet functions in in vitro stored PCs.