神经干细胞 z-bo 2020-09-29 366

　　In a new study, researchers from the German Cancer Research Center (DKFZ) and the Heidelberg Institute of Stem Cell Technology Experimental Medicine (HI-STEM) will directly reprogram human blood cells into previously unknown neural stem cells for the first time. These induced stem cells are similar to stem cells formed during early embryonic development of the central nervous system. They can be modified and reproduced indefinitely in the laboratory and are candidates for the development of regenerative therapy. Pluripotent embryonic stem cells can proliferate indefinitely and produce all possible cell types. In 2006, Japanese scientist Shinya Yamanaka realized that such pluripotent stem cells can also be reprogrammed from mature somatic cells in the laboratory. The four genetic factors are sufficient to make mature somatic cells reverse the normal development process and produce so-called induced pluripotent stem cells (ips cells) with the same characteristics as embryonic stem cells.

　　Yamanaka's discovery won the 2012 Nobel Prize in Medicine. "This is a major advancement in stem cell research. Because Germany does not produce human embryonic stem cells, it is particularly suitable for German research. The basic research and development of stem cells is for patients. Its goal is to cure diseased tissues, despite regenerative therapy It has great potential, but this type of reprogramming also has problems. For example, pluripotent stem cells can form germ cell tumors called malformations.

　　Trumpp’s team successfully brought mature people into the body for the first time. These cells were reprogrammed into some types of induced neural stem cells, which can proliferate almost indefinitely. This is called sensory neural plate boundary stem cells (iNBSC). "Like Yamanaka, we use four genetic factors, but we use four different genetic factors for reprogramming. Our genetic factors allow the development of the nervous system to be reprogrammed. We believe this is possible."

　　In the past, other research groups have also reprogrammed connective tissue cells into mature or neural progenitor cells. However, these artificially generated nerve cells usually cannot proliferate and cannot be used for therapeutic purposes. In answering this question, Trump explained: "Generally speaking, this is a heterogeneous mixture of different cell types, which may not exist in the body under physiological conditions."

　　Through a collaborative study with Frank Edenhofer, a stem cell researcher at the University of Innsbruck, Austria, Trumpp and his team collaborated with DKFZ neuroscientist Hannah Monyer and Heidelberg University Hospital to combine the tissue cells of skin, pancreas and peripheral blood cells connect them. Successfully reprogrammed into induced neural stem cells. Till said: "The source of these cells does not affect the nature of the stem cells produced." In particular, the possibility of obtaining neural stem cells from the patient's blood without invasive intervention is one of the possibilities for developing future treatments. . A decisive advantage. It is worth noting that these reprogrammed cells are a homogenous cell type, similar to the stem cells that exist during the embryonic development of the nervous system. Till said: "During the development of the early embryonic brain, the corresponding stem cells exist in mice, and probably in humans. This study describes a new type of neural stem cells in mammalian embryos."

　　These iNBSCs have broad development potential. iNBSC has proliferation and pluripotency, and can develop in two directions. On the other hand, they are located in the central nervous system. You can choose the developmental pathway to produce mature nerve cells and glial cells, and they can also develop into neural printing cells, such as surrounding sensitive neurons, skull cartilage cells or bone cells. Produce multiple cell types.

　　Therefore, iNBSC provides an ideal basis for generating many different cell types for individual patients. Tier said: "These cells are donors and have the same genetic material. They will be recognized by the immune system and will not suffer from immune rejection." As these researchers have confirmed in experiments, CRISPR/Cas9 gene scissors can be used for modification. iNBSC and repair genetic defects. Trump said: "Therefore, it is very important for basic research, the exploration of new active substances and the development of regenerative therapies (such as patients with neurological diseases), but more research is needed before it can be applied to patients ."