On the surface of the cells sits the extracellular matrix, composed of a tangle of proteins, carbohydrates, and much more. This matrix acts as a site of signaling and cell anchoring depending on what comprises the matrix. One set of molecules comprising the extracellular matrix are the Glycosaminoglycans (GAGs). GAGs are polysaccharides, which translates to “long complex sugar” made up of repeating disaccharides that can act as perfect binding sites for both cells and signaling molecules.

The Petrey lab is especially interested in how GAGs regulate hematopoiesis, or the creation of blood cells. Within the bone marrow reside hematopoietic stem cells (HSCs) that are the precursors to blood cells. GAGs, particularly heparan sulfate, assist in the anchoring of HSCs within the marrow. This also allows for GAGs to act as scaffolds for incoming signaling molecules, such as growth factors and cytokines, to bind to for the growing HSCs. GAGs also help define the microenvironment surrounding HSCs in the bone marrow, influencing where HSCs bind in the marrow, and how they differentiate and self-renew.  

Our research wants to explore the interplay of GAGs in diseases. How does altered GAG expression or function contribute to blood diseases? How do GAGs function in leukemia, a cancer in which HSCs lose function? In which blood diseases are GAGs increased or decreased in the marrow?