Changes of platelet morphology, ultrastructure and function in patients with acute ischemic stroke based on super-resolution microscopy

Platelets are important in acute ischemic stroke (AIS) thrombosis. The observation and evaluation of platelet ultrastructure and efficacy of antiplatelet drug in AIS patients is difficult due to microscopic limitations and sensitivity of platelet. The new super-resolution microscope (SIM) can accurately, quickly analyze the platelet ultrastructure and antiplatelet drug in AIS patients. We applied SIM to observe the morphology and ultrastructure of platelets with AIS patients in different state. SIM images were analyzed to specify the dense granules and α granules change of platelets in AIS patients. Testing platelet factor 4 (PF4) to reflect platelet releasing function. We observed that platelet activation in AIS patients was greater after stimulation, with α granule showing a pattern of parenchymatous masses. SIM images analyzing showed diameter of platelets, average size of granules, area% of granules per field and mean area of granules per platelet in AIS patient were lower than healthy people. Platelet releasing function was suppressed at rest stage and more efficacy release after stimulation. 2MeSamp inhibited parenchymatous masses of α granules and reduced PF4 release of platelets after stimulation. According to the results, the structure and function of platelets in AIS patients are indeed altered. Additionally, SIM could be used as a new method to indicates the onset of AIS and assess antiplatelet drugs. ### Competing Interest Statement The authors have declared no competing interest. * ADP : adenosine diphosphate AIS : acute ischemic stroke β-TG : β-thromboglobulin CVD : cerebrovascular disease COX-1 : cyclooxygenase-1 EH : elder healthy people (>60 years old) PF4 : platelet factor 4 SIM : super-resolution microscope TH : thrombin TIA : transient ischemic attacks vwf : von willebrand factor YH : young healthy people (18~60 years old) 2MeSAMP : 2-methyl-thioadenosine-monophosphate, in vivo form of p2y12 receptor antagonist.