Researchers at the University of Nebraska Medical Center on Tuesday announced a significant step in adult stem cell research that could take science closer to cures for glaucoma and age-related macular degeneration. A team led by Iqbal Ahmad, professor of ophthalmology and visual sciences, used adult stem cells from the cornea, the clear window at the front of the eye, and reprogrammed them to act like cells in a developing babys retina. The retina, located at the back of the eye, transforms light into neural signals thatcan be interpreted by the brain, an essential part of vision. Ahmad said the teams work built off that of Drs. John B. Gurdon and Shinya Yamanaka, who won this years Nobel Prize in science after they genetically altered adult stem cells to mimic embryonic stem cells. Before the pair's discovery, scientists believed embryonic cells, which have far greater potential to develop into different types of cells, could come only from embryos. In that early breakthrough, researchers directly manipulated gene expression inside cells to cause them to reset themselves to a more primitive state. The real advance of Ahmads team came in causing adult stem cells to change by placing them in a chemical … Continue reading →

Jan. 22, 2013 Human life is dependent on the constant growth of plants, and it is the job of stem cells to see to it that this occurs. They are found at the tips of the shoots and roots, the so-called meristems. Stem cells can transform themselves into other types of cells and develop new organs, such as leaves, fruits, and twigs, throughout the entire lifespan of the plant. However, in order for the plant to continue growing and developing organs, several cells at the tips of the shoots and roots have to remain stem cells. In order to ensure that this is the case, the cells need signals to help them identify their position in the plant and trigger the appropriate developmental program. A team led by Prof. Dr. Thomas Laux from the Institute of Biology III of the University of Freiburg has succeeded in confirming that plants need a micro-RNA at the tip of their shoots to prevent all of the stem cells from transforming themselves into other cell types. The Freiburg researchers used thale cress as a model organism for their studies. Their findings have now been published in the journal Developmental Cell. Micro-RNAs are very small … Continue reading →

Jan. 22, 2013 The research group of Luciano Di Croce, from the Center for Genomic Regulation (CRG) in Barcelona (Spain), has discovered that RYBP and CBX7, two proteins essential for gene regulation, are at the heart of the most critical decision faced by embryonic stem cells: what type of cells to become. These findings, published in the last issue of Cell Reports, shed light on the molecular mechanisms involved in stem cell biology and might have important therapeutic implications. Stem cells are the precursors of our tissue and organs. Using them could be highly promising for regenerative medicine, yet little is known about the mechanisms that regulated the potential of stem cells to give rise to the different cell types within organisms. The Polycomb repressive complex 1 (PRC1) is an epigenetic regulator essential for stem cell function and cancer progression. It has only recently become clear that PRC1 comes in different flavors, depending on which specific proteins are incorporated into it (such as either CBX7 or RYBP). However, whether or not these PRC1 subtypes carry out different biological functions was unclear. This work, headed by Lluis Morey in the Di Croce group, has taken an important step in clarifying this … Continue reading →