ASH Clinical News February 2015 | Page 22

Literature Scan New and noteworthy research from the medical literature landscape A Zebrafish and Enhanced Imaging Captures How Blood Stem Cells Take Root A research team from Boston Children Hospital’s Stem Cell Research Program has provided the first direct glimpse into how blood stem cells take root in the body to generate blood – with the help of a seethrough zebrafish and direct visualization. The dynamic imaging system offers several clues for improving bone-marrow transplants in patients with cancer, severe immune deficiencies, and blood disorders, and for helping those transplants thrive. “Our direct visualization gives us a series of steps to target, and in theory we can look for drugs that affect every step of that process,” said senior investigator, Leonard Zon, MD, director of the Stem Cell Research Program and professor of stem cell and regenerative biology at Harvard Medical School. Using time-lapse imaging of naturally transparent zebrafish embryos and “tagging” the stem cells green, researchers were able to reveal how stem cells find the “niche” where they begin to create blood in the body’s circulation. On arrival in its niche, the newborn blood stem cell attaches itself to the blood vessel wall where chemical signals prompt it to squeeze itself through the wall and into a space just outside the blood vessel. A still from the animation, illustrating the process of “endothelial cuddling.