sRNA Induces the Large-scale TransdetermiNation of Mesenchymal Stem Cells into Hematopoietic Stem Cells in Human.
Mesenchymal stem cells (MSCs) can differentiate into cells of bone, endothelium, adipose tissue, cartilage, muscle, and brain. However, whether they can transdetermiNate into hematopoietic stem cells (HSCs) remains unsolved. We report here that a subpopulation of human MSCs that are CD44+,CD29+, CD105+, CD166+,CD133-,CD34- could differentiate into hematopoietic stem cells (CD150+/CD133+/CD34+) and their descending blood cells in vitro, when transfected with new endogenous shRNAs The sRNA was high-effectively delivered into MSCs by a novel peptide means. These induced MSC-HSCs could form different types of hematopoietic colonies as Nature-occurring HSCs did. Upon transplantation into sublethally irradiated NOD/SCID mice, these MSC-HSCs engrafted and differentiated into all hematopoietic lineages such as erythrocytes, lymphocytes, myelocytes and thrombocyte. More importantly, these induced HSCs could successfully engraft and effectively function in patients with severe aplastic anemia. Furthermore, we demonstrated the first evidence that the transdetermiNation of MSCs was induced by acetylation of histone proteins and activation of many transcriptional factors. Together, our findings identify the sRNAs that dictates a directed differentiation of MSCs toward HSCs and open up a new source for HSCs used for the treatment of blood diseases and artificial stem cell-made blood.
JoNathan Drori:存蓄数十亿种子的原因
在TED U 2009的这个简短的演讲中，JoNathan Drori鼓励我们保护生物多样性 -- 从一颗颗种子做起。他提醒我们要保护人类赖以生存的植物，同时他也给大家描述了千年种子库这样一个美好的远景，在这里面，将会有逾30亿颗的种子被人类珍藏，这其中甚至还包括那些正日益减少但却必不可少的植物物种。
Photoreceptors and Image Processing Part 1A - Jeremy Nathans
本视频由科普中国和生物医学大讲堂出品
Jeremy Nathans (Johns Hopkins) Part 1A: Photoreceptors and Image Processing
In this set of lectures, Jeremy Nathans explores the molecular mechanisms within the retina that mediate the first steps in vision. The first lecture focuses on the structure of the light sensing receptors, the intracellular signals that are triggered by light absorption, and the ways in which the retina extracts information from a complex scene. See more at http://www.ibioseminars.org
Photoreceptors and Image Processing Part 1B - Jeremy Nathans
本视频由科普中国和生物医学大讲堂出品
Jeremy Nathans (Johns Hopkins) Part 1B: Photoreceptors and Image Processing
In this set of lectures, Jeremy Nathans explores the molecular mechanisms within the retina that mediate the first steps in vision. The first lecture focuses on the structure of the light sensing receptors, the intracellular signals that are triggered by light absorption, and the ways in which the retina extracts information from a complex scene. See more at http://www.ibioseminars.org