red blood cells
Bone marrow transplants offer a way to cure leukemia, sickle cell disease, and a variety of other life-threatening blood disorders.There are two major problems, however: One is many patients don’t have a well-matched donor to provide the marrow needed to reconstitute their blood with healthy cells. Another is even with a well-matched donor, rejection or graft versus host disease can occur, and lifelong immunosuppression may be needed.
A much more powerful option would be to develop a means for every patient to serve as their own bone marrow donor. To address this challenge, researchers have been trying to develop reliable, lab-based methods for making the vital, blood-producing component of bone marrow: hematopoietic stem cells (HSCs).
Two new studies by NIH-funded research teams bring us closer to achieving this feat. In the first study, researchers developed a biochemical “recipe” to produce HSC-like cells from human induced pluripotent stem cells (iPSCs), which were derived from mature skin cells. In the second, researchers employed another approach to convert mature mouse endothelial cells, which line the inside of blood vessels, directly into self-renewing HSCs. When these HSCs were transplanted into mice, they fully reconstituted the animals’ blood systems with healthy red and white blood cells.
Tags: adult stem cell therapy, adult stem cells, B cells, blood, blood cells, blood disorders, blood stem cells, bone marrow transplant, bone marrow transplantation, cell reprogramming, endothelial cells, graft versus host disease, hematopoietic stem cells, HSC, HSCs, immune system, immunosuppression, induced Pluripotent Stem cells, iPS cells, iPSCs, leukemia, red blood cells, regenerative medicine, sickle cell disease, stem cells, T cells, transcription factors, white blood cells
Scientists first described the sickle-shaped red blood cells that give sickle cell disease its name more than a century ago. By the 1950s, the precise molecular and genetic underpinnings of this painful and debilitating condition had become clear, making sickle cell the first “molecular disease” ever characterized. The cause is a single letter “typo” in the gene encoding oxygen-carrying hemoglobin. Red blood cells containing the defective hemoglobin become stiff, deformed, and prone to clumping. Individuals carrying one copy of the sickle mutation have sickle trait, and are generally fine. Those with two copies have sickle cell disease and face major medical challenges. Yet, despite all this progress in scientific understanding, nearly 70 years later, we still have no safe and reliable means for a cure.
Recent advances in CRISPR/Cas9 gene-editing tools, which the blog has highlighted in the past, have renewed hope that it might be possible to cure sickle cell disease by correcting DNA typos in just the right set of cells. Now, in a study published in Science Translational Medicine, an NIH-funded research team has taken an encouraging step toward this goal . For the first time, the scientists showed that it’s possible to correct the hemoglobin mutation in blood-forming human stem cells, taken directly from donors, at a frequency that might be sufficient to help patients. In addition, their gene-edited human stem cells persisted for 16 weeks when transplanted into mice, suggesting that the treatment might also be long lasting or possibly even curative.
Tags: anemia, blood, bone marrow stem cells, Cas9, CRISPR, CRISPR/Cas9, DNA editing, gene editing, genetic blood diseases, genetic engineering, genomics, hemaglobin, hematology, hematopoietic stem cells, human stem cells, immune deficiency, molecular disease, red blood cells, RNA, sickle cell anemia, sickle cell disease, sickle cell triat, sickle mutation, translational medicine
Just as superheroes often change their forms to save the day, so it seems do red blood cells as they mobilize to heal a wound. Red blood cells usually look like oval, bi-concave discs, but NIH-funded researchers recently discovered that they are actually talented shape-shifters.
Posted In: Science