miR-150 in Early B cell Development

Define B cells at early stage: miR-150 in B cell progenitors

Our previous publication demonstrated that miR-150 is a key regulator for B cell development. Premature expression of miR-150 in hematopoietic stem cells (HSC) blocks early B cell differentiation from the pre-B cell stage, leading to severe B cell deficiency in the circulation(9). Our recent preliminary results suggested that elevated miR-150 levels in hematopoietic stem cells did not significantly affect immunoglobulin rearrangement but instead, down-regulated multiple components in pre-B cell receptor (pre-BCR) complex assembly and signaling. In addition, we identified several genes that are crucial for early B cell formation and are also predicted miR-150 targets. Therefore, we hypothesize that miR-150 is a key regulator of early B cell lineage determination and differentiation. When prematurely expressed in HSCs or early B cell progenitors, it represses genes required for early B cell lineage determination.