Cell death in the hematopoietic system

The mammalian hematopoietic system is prodigious: billions of blood cells are generated every day to maintain the supply of oxygen to the tissues, repair damaged vasculature, and resist infection. It is becoming increasingly clear that the intrinsic apoptosis pathway, under the control of the Bcl-2 family of proteins, plays many essential roles in the development and function of hematopoietic cells of most, if not all, of the various lineages. It promotes survival, regulates key aspects of maturation and function, and ultimately triggers the timely demise of functionally expended cells. In this chapter, we review the role of the intrinsic pathway in mediating the life and death of the non-lymphoid hematopoietic lineages.