UCLA Scientists Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research have made several discoveries that are critically important to understanding how blood stem cells are created and maintained — both in the body and in the laboratory.
The findings may lead to the creation of a new source of life-saving blood-forming stem cells, which could help people with a wide range of blood diseases by reducing many of the risks of bone marrow transplants. Thousands of people each year in the U.S. alone are diagnosed with diseases that could be treated with the procedure (…)
Blood-forming stem cells, or hematopoietic stem cells, are found in the bone marrow and can create any type of blood cell. The researchers pinpointed the function of a cluster of specialized genes that play a key role in creating and preserving hematopoietic stem cells and identified the process by which those genes are activated during human development and in the laboratory (…)
The UCLA research could provide a way to create patient-specific hematopoietic stem cells, which would reduce some of the challenges associated with bone marrow transplants.
“Our work focuses on finding a way to generate a supply of these life-saving hematopoietic stem cells in the lab so that they are a perfect match to the patient in need of a transplant,” said Mikkola, a professor of molecular, cell and developmental biology in the UCLA College and a member of the UCLA Jonsson Comprehensive Cancer Center.
“One big challenge is that when we try to create hematopoietic stem cells from pluripotent stem cells in the lab, they don’t acquire the same abilities of the real hematopoietic stem cells found in the body.”
Pluripotent stem cells are capable of becoming any cell type in the human body. However, some tissue-specific stem cells, such as hematopoietic stem cells, have been difficult to derive from pluripotent stem cells, creating a fundamental challenge associated with the creation of stem cell-based medical treatments.
Mikkola and the research team first tried to create hematopoietic stem cells in the lab from pluripotent stem cells. When they compared the lab-created cells to the hematopoietic stem cells found in the body, they found that an important cluster of genes, called HOXA genes, weren’t activated in the lab-created cells. They also showed that HOXA genes help hematopoietic stem cells maintain their stem cell attributes, such as the ability to generate more copies of themselves, which is a defining characteristic of any kind of stem cell.
“Without the ability to self-renew, hematopoietic stem cells cannot be used for transplantation therapies,” said Calvanese, an assistant project scientist in Mikkola’s lab. “Our findings show that the activation of HOXA genes can be used as a marker for hematopoietic stem cells that have acquired the capacity to renew themselves.” (…)