Although the transcription factor GATA-3 is known to regulate T cell development and function, its role in hematopoiesis has remained uncertain. A recent study published in Nature Immunology by McEwen Centre Researcher Dr. Norman Iscove provides new evidence that GATA-3 plays a role in regulating the function of certain hematopoetic stem cell populations.

Hematopoietic stem cells are categorized into two distinct classes based on their biology and phenotype. Long-term multi-potent hematopoietic stem cells (LT-HSCs) can sustain myeloid, erythroid and lymphoid populations due to their continued ability to self-renew. Intermediate-term HSCs (IT-HSCs) can only sustain myeloid and erythroid populations for about 12 weeks before cell numbers begin to diminish.

Dr. Iscove and his team were able to demonstrate that GATA-3 is present in LT-HSCs and not IT-HSCs, and that it remains inactive when cells are in a quiescent state. Interestingly, when LT-HSCs are signalled to proliferate, GATA-3 is activated—a process that is associated with a reduced capacity of stem cells to sustain hematopoietic populations long-term. By deleting GATA-3, the researchers were able to enhance the ability of LT-HSCs to self-renew without affecting proliferation.

These findings implicate GATA-3 as a key controller of HSC self-renewal and may have important implications for research and therapeutic applications that require the expansion of HSCs.

GATA-3 regulates the self-renewal of long-term hematopoietic stem cells. Frelin C, Herrington R, Janmohamed S, Barbara M, Tran G, Paige CJ, Benveniste P, Zúñiga-Pflücker JC, Souabni A, Busslinger M, Iscove NN. Nature Immunology. August 25 2012. [Pubmed abstract]

This work was funded by grants from the McEwen Centre for Regenerative Medicine, the Terry Fox Foundation, the Canadian Cancer Society Research Institute, the Canadian Institutes of Health Research, the Princess Margaret Cancer Foundation, The Campbell Family Institute for Cancer Research, the Stem Cell Network and the Ontario Ministry of Health and Long-Term Care.

Research on brain development has been limited by a lack of experimental models which accurately recapitulate the complexities of the human brain. A recent advancement led by Dr. Juergen Knoblich, at the Institute of Molecular Biotechnology of the Austrian Academy of Science, may have eliminated this roadblock by establishing a novel three-dimensional culture system capable of producing distinct, though interdependent, brain tissues.

This novel culture system will provide stem cell researchers with unprecedented opportunities to model brain disease and will open new lines of research in regenerative medicine. To learn more about this exciting advancement, click here.

The first Stem Cell Rounds of the season was held on September 11th, and featured a talk by McEwen Centre Researcher Dr. Norman Iscove titled “Probing stem cell biology cell by cell: where it matters, where it’s just stamp collecting”. The seminar provided new insight on the importance of linking data derived from single cell studies such as mRNA or protein expression to cell function. You can watch a podcast of the event by clicking here.

McEwen Centre Researchers Drs. Andras Nagy and John Dick have been awarded funding as part of a new initiative that aims to strengthen research collaborations between Japan and Canada. This joint program, launched by the Canadian Institutes of Health Research and the Japan Science and Technology Agency, is designed to position Canada and Japan as leaders in the field of epigenetics and health research. As part of this initiative, Dr. Dick will work with Dr. Hiromitsu Nakauchi (University of Tokyo) to improve methods for engineering stem cells while Dr. Nagy will collaborate with Dr. Yasuhiro Yamada (Kyoto University) to study cellular reprogramming.

This year's Till & McCulloch meetings, which aim to bring together researchers, clinicians and bioengineers from all areas of stem cell research, will be held in Banff, Alberta on October 23-25, 2013. Speakers at the conference will include Drs. Gordon Keller, Andras Nagy and Freda Miller. For detailed conference information, click here.