GSE108378
Exploring transcriptomic landscapes in red cell populations, in their extracellular vesicles and on single cell level
Circulating human red blood cells (RBCs) consist of mature erythrocytes, and immature reticulocytes. As being anucleated cells, RBCs lack typical, abundant transcriptomes but are known to contain low amounts of diverse long transcripts and microRNAs. The exact role and importance of these RNAs is, however, lacking. To study this further, we have explored the RNA content of RBCs as well as extracellular vesicles of RBCs using next-generation sequencing (NGS). Furthermore, to understand the dynamics of the RBC transcriptome, we performed single cell RNA sequencing on RBCs both from fresh blood and blood unit. Analysis of the single cell transcriptomes revealed that while the majority of the cells don't have detectable RNA, the remaining, approximately 10% of the cells fall into three sub-populations based on their RNA content. Overall decrease in the RNA quantity over the populations is observed. Qualitative changes include the differences in the hemoglobin (Hb) content of the cells, and the changes in the expression of ribosomal and mitochondrial genes. A previously unknown transcript of a long non-coding RNA, MALAT1 (Metastasis Associated Lung Adenocarcinoma Transcript 1) is the most enriched marker gene for one subpopulation of RBCs, suggesting a role for MALAT1 in reticulocyte maturation. Enriched pathways in RBC transcriptome, such as autophagy, reflect the processes required for reticulocyte maturation to erythrocytes. RBC transcriptome is transferred to extracellular vesicles (EVs), suggesting the vesiculation as the mechanism to remove the cellular contents at the final stages of erythrocyte maturation. Overall design: RNAseq on 4 red blood cell samples and their extracellular vesicles.