Evolving concepts on the microenvironmental niche for hematopoietic stem cells.

PURPOSE OF REVIEW: The hematopoietic stem cell niche is critical for the maintenance and proliferation of hematopoietic stem cells and, as such, is not only essential for steady-state hematopoiesis but may also be relevant to hematologic disease. The present review discusses recent advances in the understanding of interactions within the niche, its potential role in disease pathogenesis and models of its use as a therapeutic target. RECENT
FINDINGS: Recent studies have continued to provide important insights into the cellular and molecular components constituting the hematopoietic stem cell niche. Niche interactions have been shown to be involved in the pathogenesis of hematologic disease in animal models. Molecular components of the niche involved in these interactions have been identified, and proof of principle that their manipulation can result in therapeutic benefit is available. Finally, pharmacologic manipulation of the niche is now being tested in stem cell-based therapies.
SUMMARY: Increasing insights into the molecular architecture of the hematopoietic stem cell niche have led to the exploitation of the niche as a target in stem cell therapies and offer the prospect of niche-targeted therapy as a new treatment modality in hematologic disease.