How liver tissue regenerates

The liver is uniquely able to regenerate after tissue damage or partial removal. A specialized cell type, known as liver sinusoidal endothelial cells, has been thought to promote this regeneration, but Laurie DeLeve and her colleagues at the University of Southern California suspected that stem cells and progenitor cells might also be responsible. Using rats, they identified the presence of stem and progenitor cells that give rise to liver sinusoidal endothelial cells in the liver and bone marrow. Next, the team found that the bone marrow-derived cells were not required for liver cell proliferation when there was no damage. But, following surgical removal of a portion of the rat liver, an infusion of bone marrow-derived progenitor cells was required for liver regeneration. These results improve our understanding of how liver tissue regenerate and shed light on liver complications in patients with suppressed bone marrow tissue.