Single-cell RNA sequencing of platelets: challenges and potential.

Platelets are small, anuclear cells crucial for hemostasis, coagulation, immune responses, and vascular diseases. While unable to produce their own RNA, platelets inherit RNA from their megakaryocyte precursors, exchange RNA with other cells, and possess all the necessary machinery for protein synthesis. However, several challenges, including their limited RNA content, high reactivity of these small cells leading to their activation, have hindered single-cell transcriptomic studies of these cells. The primary objective of this study is to perform single-cell RNA sequencing (scRNA-seq) on platelets obtained from whole blood. Peripheral whole blood from a healthy donor was obtained by venipuncture and was purified to obtain platelet-rich plasma (PRP). ScRNA-seq was performed using the 10X genomics platform on PRP for the first time. Data normalization and UMAP clustering with cluster-specific differential gene expression analysis were performed. ScRNA-seq performed on platelets identified three distinct clusters, with one enriched for platelet-specific lineage markers, such as PPBP and PF4. Mitochondrial RNA was highly expressed accounting for approx. 14% of the total RNA counts. Despite procedural challenges and technical considerations including high exhaustion potential and sensitivity to handling, small cell size and limited RNA content, this pilot study demonstrates feasibility of scRNA-seq of platelets from whole blood. This advancement paves the way for groundbreaking insights into platelet biology and more focus for clinician researchers on potential research avenues.