With significant attention paid to the field of tissue-specific stem cells, the identification of stem cell-specific markers and stem cell niche is of considerable importance. Recently, we showed that high expression of integrin β3 is an attribute of both rabbit corneal epithelial stem cells and mouse hematopoietic stem cells (HSCs). Additionally, we mainly utilized HSCs to elucidate the relationship between tissue-specific stem cells and integrin β3, and demonstrated that the expression of integrin β3 (CD61) is correlated with properties of HSCs. Moreover, our results strongly indicate that the integrin β3 subunit on HSCs is associated with integrin α3v (CD51), but not integrin αIIb (CD41). These results suggest that integrin β3 subunit is available as a common surface marker of tissue-specific stem cells. In addition, induction of integrin β3 signaling on HSCs contributes to the maintenance of HSC activity during ex vivo culture, which is dependent on the presence of thrombopoietin (TPO). Thus, our finding demonstrates that integrin β3 is essential for cytokine-dependent maintenance of stem cell activity. Thus, we believe that the further study for integrin β3 on tissue-specific stem cells provides a breakthrough that permits further characterization of the stem cell niche.
