Store-operated Ca2+ Channels Are Involved In Erythropoiesis

Abstract

Erythropoiesis is the process which produces red blood cells from erythropoietic stem cells. Ca2+ is a fundamental second messenger which regulates dynamic cellular processes, such as, cell differentiation, proliferation, cytoskeletal rearrangement, and cell cycle. Ca2+ signaling is also known to involve in erythropoiesis. However, underlying mechanisms and specific function of Ca2+ channels in erythropoiesis remain elusive. Here, we identified the effects of Store-Operated Ca2+ channels (SOCs) inhibitors in erythroid lineage determination and proliferation of CD34+ hematopoietic stem cells (HSCs) with colony-forming unit (CFU) assay. SOCs inhibitors reduced the proportion of erythroid lineage and proliferation rate. Next, we demonstrated that the mRNA expression level of SOCs modulators, STIM1 and STIM2, increased during erythropoiesis. Besides, we observed two different patterns of cytosolic Ca2+ fluctuation in the maturation stage of RBC formation by doing Fluo-4 Ca2+ imaging. In conclusion, this study suggests a novel role of SOCs during erythropoiesis, red blood cell formation.