New horizons in platelet research: understanding and harnessing platelet functional diversity.

Recent years have been ripe with discoveries of non-haemostatic platelet functions. This led to the appreciation of the significant, previously unknown, role played by the platelets in various pathologies and regenerative processes. As a result, exciting opportunities for clinical applications in fields as diverse as regenerative medicine and cancer treatment are emerging. However, their realization depends on the understanding of the regulatory mechanisms governing these diverse platelet functions, so that particular platelet responses could be artificially tailored to specific clinical situations. Current understanding of the signalling pathways controlling haemostatic responses is rooted in the development of quantitative assays for measuring them and sensitive markers for their quantification. However, the existing assays and markers are not sufficiently sensitive for distinguishing between individual signalling pathways and unravelling inter-pathway connections. Moreover, entirely new approaches are needed for studying non-haemostatic platelet functions, since there are currently no assays or markers for quantifying them. We review the on-going efforts in these directions, including our own recent work on using lectins as sensitive probes for profiling platelet activation.