Hepatic and hematopoietic niches

The hepatic and hematopoietic niches are specialized cellular and extracellular microenvironments that govern the behavior of stem and progenitor cells. The hematopoietic niche, predominantly found in the bone marrow of adults and the liver during embryonic development, provides essential cues for hematopoietic stem cell (HSC) maintenance, quiescence, and lineage commitment (Morrison & Scadden, 2014). The hepatic niche comprises a complex interplay of hepatocytes, hepatic stellate cells, Kupffer cells, and sinusoidal endothelial cells that maintain liver homeostasis and facilitate regeneration after injury (Gao et al., 2022). These niches play critical roles in diseases such as leukemia, where the "malignant niche" protects cancer cells from therapy, and liver cirrhosis, where the niche environment is remodeled by fibrosis (Liesveld et al., 2008). While not a single molecular target, components within these niches, such as the CXCR4/CXCL12 signaling axis, are frequently targeted by drugs like plerixafor to mobilize stem cells into the circulation. Understanding the spatial and molecular architecture of these niches is vital for developing therapies that can either restore normal tissue function or disrupt the protective environment of tumors.

Other names

Liver microenvironmentHematopoietic stem cell nicheBone marrow nicheFetal liver hematopoietic niche

Modulation of the microenvironment through the inhibition of cell-adhesion molecules or chemokine receptors to mobilize stem cells or disrupt the protective tumor niche (Liesveld et al., 2008).