(HM07) Defining the Platelet Transcriptome in Dogs

Abstract: Background – Little is known regarding the platelet transcriptome in health or disease, but application of next generation RNA sequencing technologies can provide unprecedented new insights into platelet function and dysfunction.

Hypothesis/Objectives – We hypothesized that platelet transcriptome in dogs could be sequenced using single cell and bulk RNA sequencing. Platelet samples from healthy adult dogs were subjected to transcriptomic analysis with the objective to create a healthy platelet sequence database for analysis of platelets from dogs with diseases associated with high thromboembolic risk.

Animals – Blood samples were prospectively collected from 10 healthy dogs.

Methods – Platelet transcriptomes were sequenced using single cell RNA sequencing (SCS) (6/10 samples) or bulk RNA sequencing (4/10 samples). For SCS analysis, cells were prepared from blood leukocytes using a 10X Chromium instrument while bulk RNA sequence was done using purified platelets and ultra-low pass RNA sequencing. Descriptive statistics were utilized.

Results – SCS analysis identified 3 unique subpopulations of platelets, and uniquely upregulated genes were identified to differentiate platelets from other leukocytes, including genes associated with expression of integrins, cytoskeletal proteins, coiled domain proteins and carboxylase proteins. These findings indicate that platelets remain transcriptionally active in circulation and that their transcriptomic profiles can be defined using RNA sequencing technologies.

Conclusions and clinical importance – Transcriptomic profiling of platelets can be used to define healthy platelet function and to identify unique gene expression profiles associated with dysfunctional platelets in prothrombotic diseases. This information can guide targeted therapies for prevention and treatment of thrombotic diseases.