Comprehensive Analysis of microRNAs in Human Adult Erythropoiesis.

Aneesha Nath,Janakiram Rayabaram,Anurag Dutta Chaudhury,Jyoti Singh,Karthik Chambayil,Smitha Ijee,Shaji R Velayudhan,Debanjan Roy,Yukio Nakamura,Abhirup Bagchi

doi:10.3390/cells10113018

Abstract

MicroRNAs (miRNAs) are small non-coding RNAs, which play an important role in various cellular and developmental processes. The study of miRNAs in erythropoiesis is crucial to uncover the cellular pathways that are modulated during the different stages of erythroid differentiation. Using erythroid cells derived from human CD34+ hematopoietic stem and progenitor cells (HSPCs)and small RNA sequencing, our study unravels the various miRNAs involved in critical cellular pathways in erythroid maturation. We analyzed the occupancy of erythroid transcription factors and chromatin accessibility in the promoter and enhancer regions of the differentially expressed miRNAs to integrate miRNAs in the transcriptional circuitry of erythropoiesis. Analysis of the targets of the differentially expressed miRNAs revealed novel pathways in erythroid differentiation. Finally, we described the application of Clustered regularly interspaced short palindromic repeats-Cas9 (CRISPR-Cas9) based editing of miRNAs to study their function in human erythropoiesis.

Highlights

Erythropoiesis is a dynamic multi-stage cellular process involving the differentiation of hematopoietic stem and progenitor cells (HSPCs) to form enucleated red blood cells (RBCs)
Terminal erythroid differentiation begins with proerythroblasts, which undergo sequential mitoses to form basophilic erythroblasts, polychromatophilic erythroblasts, and orthochromatophilic erythroblasts, which enucleate to become reticulocytes and eventually into mature RBCs [3,4]
In a two-phase ex-vivo erythropoiesis protocol, Phase I favors the expansion of CD34+ HSPCs, and Phase II of the culture allows the robust erythroid differentiation of HSPCs to various erythroid progenitor cells and eventually enucleated reticulocytes [8,65]

Summary

Introduction

Erythropoiesis is a dynamic multi-stage cellular process involving the differentiation of HSPCs to form enucleated red blood cells (RBCs). The earliest lineage-committed progenitors of erythropoiesis are the slowly proliferating burst forming unit-erythroid (BFU-E) cells, which differentiate to rapidly dividing colony-forming unit erythroid (CFU-E) cells that differentiate further into morphologically recognizable proerythroblasts [1,2]. Terminal erythroid differentiation begins with proerythroblasts, which undergo sequential mitoses to form basophilic erythroblasts (baso-E), polychromatophilic erythroblasts (poly-E), and orthochromatophilic erythroblasts (ortho-E), which enucleate to become reticulocytes and eventually into mature RBCs [3,4]. During this process, erythroid cells exhibit a gradual decrease in cell size, hemoglobinization, and chromatin condensation, leading to the final stages of enucleation and expulsion of other cell organelles [5]. Due to the well-orchestrated features of cellular differentiation, erythropoiesis is an important biological process for understanding the general mechanisms of gene regulation in lineage commitment and differentiation [3,4,6,7,8]

Methods

Results

Conclusion