Scientists hope their discovery will show French politicians the need to ensure human embryonic stem cell research.STEVE GSCHMEISSNER / SCIENCE PHOTO LIBRARYIt is known no cure for the Group of hereditary diseases as muscular dystrophy muscle wasting. This is particularly worrying because one of the most commonly specify forms - 1 myotonic - is serious, if he formerly manifest after the generations, and the acquisition of perishable additional symptoms, such as delays, spiritual development.
A group of French scientists have now for some symptoms you give 1 myotonic unravel molecular pathways, of can be responsible. You used a controversial source material: disease-specific human embryonic stem cells (hES) cell lines. They hope that their results, published online in cell Cell1 stem, today will affect a French political debate, which is in danger, to limit such work. The French Senate is addressed on the 5 April, votes in the first reading of the new legislation of the country's bio-ethics update right (see France is considering embryo research reform).
Type 1 myotonic results from a defect in a gene - Dystrophia Myotonica protein kinase (DMPK) - However, that the expression of other healthy genes relates to damage. The team of researchers led by Cécile Martinat, a geneticist at the Institute for stem cell therapy in Evry, identified two such genes that are suppressed in the disease. They showed that the oppression neurons it prevented from efficiently building connections with muscle cells.
In contrast to has not mutated in most genetic diseases, the damaged gene DMPK. Instead, reviewed by a long and unstable' triplet', interrupted his code in three of the four nucleotides that make up DNA, are repeated in more than fifty times. Of times get the string tends to be longer with each generation.
"This is an excellent example of the value of the use of hES cells and something to learn a genetic disease of the biology," says Nissim Benvenisty, a geneticist at the Hebrew University in Jerusalem. Benvenisty on a cell line disease-specific hES also has done research, to learn how the damaged gene caused the fragile-X syndrome, the most common inherited cause of developmental delay, initiated the disease2.
The French scientists of used cell lines embryos derived from two with the damaged gene DMPK. These embryos had to examine genetic diagnosis (PGD), a procedure couples at high risk of passing hereditary disease to their children during the in vitro fertilization undertaken identified. A single cell is removed from an embryo before implantation, and examines his genes; only healthy embryos are then implanted in the mother. In countries that allow such procedures, discarded embryos can be grown with disease genes in cell lines, to model the disease.
Martinet's team developed the hES cells to a group of neuron, which would connect nerves normally muscles. The group saw about the entire genome in these cells compare gene expression it with, found in healthy cells, and 15 genes with altered expression. Two of these genes was one of the family SLITRK, which on impact how neurons sprout is known.
The scientists have shown, that the day of your cycle these two genes of the neural cells to 'Neurite' sprout projections in unusually large amounts cause - but apparently little success. If she incubated the neural cells with muscle cells, the Neurites could not form their usual neuromuscular contacts, as well as in control cells Act.
If the researchers had the hES cells in classes of neural cells that do not specify muscles with nerves differentiated, you will find defects Neurite.
Scientists hope that it one day, with reprogrammed hES cells in most experiments and future therapies adult cells to replace that can distinguish any cell type, called induced pluripotent stem (iPS).
"But just iPS cells with a mutated gene DMPK can not fully impersonate the intricate triplet repeat damage that occurs 1 myotonic dystrophy, due to the complex genomic in type and epigenetic changes relating to new programming," says Marc Peschanski, Director of the Institute for stem cell therapy and author of the latest paper. "Also, iPS cells can not in any case help to understand the critical events, in very early development to the myotonic dystrophy syndrome," he adds.
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In fact, Benvenisty's team found that, in contrast to its disease-specific hES cells, iPS cells with the fragile X mutant gene put out of action, not the early developmental events to fragile X syndrome3 reproduce - she will also cause a triplet repeat errors.
Peschanski runs a large iPS cells research programme in addition to his work of hES cell. He says "We iPS cells to model certain diseases make our gold standard, if we don't have access to the relevant hES cells--remain".
Politicians who often – wrongly - insist hES cells from research is that iPS cells says Peschanski can replace for hES cells. He is frustrated that the lower House of the French Parliament this argument, called when proposing a ban of hES cell research in France. Peschanski works since then with other French scientists, the Senate, the proposal next week to convince.
Marteyn, A. et al. cell stem cells 8, 1-11 (2011).?| Article |?ChemPort |Eiges, R. et al. cell stem cells 1, 568-577 (2007).?| Article |?ISI |?ChemPort |Urbach, A., bar-Nur, O., Daley, G. f. & Benvenisty, N. cell stem cell 6, 407-411 (2010).?| Article |?ISI |?ChemPort |If you something offensive or inappropriate or that otherwise are not met our conditions or Community guidelines, select you the appropriate "this comment report" Link.Kommentare on this thread are marked according to the time of booking.There are currently no comments.
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