Bone vasculature and bone marrow vascular niches in health and disease.
Chen J., Hendriks M., Chatzis A., Ramasamy SK., Kusumbe AP.
Bone vasculature and bone marrow vascular niches supply oxygen, nutrients and secrete angiocrine factors required for the survival, maintenance and self-renewal of stem and progenitor cells. In the skeletal system, vasculature create nurturing niches for bone and blood-forming stem cells. Blood vessels regulate hematopoiesis and drive bone formation during development, repair and regeneration. Dysfunctional vascular niches induce skeletal ageing, bone diseases and hematological disorders. Recent cellular and molecular characterization of the bone marrow microenvironment, has provided unprecedented insights into the complexity, heterogeneity and functions of the bone vasculature and vascular niches. The bone vasculature is composed of distinct vessel subtypes that differentially regulate osteogenesis, hematopoiesis, and disease conditions in bones. Further, bone marrow vascular niches supporting stem cells are often complex microenvironments involving multiple different cell populations and vessel subtypes. This review provides an overview of the emerging vascular cell heterogeneity in bone and the new roles of the bone vasculature and associated vascular niches in health and disease.