Haematopoietic stem cells niches: interrelations between structure and function.

A highly specialized, anatomically-defined tissue microenvironment localized in bone-marrow is considered as haematopoietic stem cell (HSC) niche where several groups of cells and extracellular matrix elements interact with HSCs to promote/inhibit their self renewal, differentiation and migration all of which are precisely regulated by several molecular mechanisms. In this brief review, recent progress has been documented with special emphasis on the structural-functional relationship between HSCs and surrounding cells. Some of the signalling pathways that play major roles in self-renewing and differentiation were highlighted in parallel to the current progress in HSC niches that are also considered as the critical new targets for the treatment of certain diseases.