�A lay of raw stem cell lines volition make it possible for researchers to explore ten different genetical disorders-including muscular dystrophy, juvenile diabetes, and Parkinson's disease-in a variety of cell and tissue types as they develop in lab cultures.
Researchers led by Howard Hughes Medical Institute investigator George Q. Daley have born-again cells from individuals with the diseases into stem cells with the same genetic errors. These newly-created stem cells will countenance researchers to reproduce human tissue formation in a Petri dish as it occurs in individuals with any of the ten diseases, a vast improvement over current technology. Like all fore cells, these disease-specific stem cells mature indefinitely, and scientists can coax them into becoming a miscellany of electric cell types.
Daley, who is at Children's Hospital Boston, worked with researchers from Harvard Medical School, Massachusetts General Hospital, and the University of Washington to create the disease-specific stem cell strains. The scientists will get the cellphone lines available to scientists worldwide through a core group facility funded by the Harvard Stem Cell Institute. Daley and his colleagues published the details of the disease-specific stem cell lines in an innovative online publication of the journal Cell on August 7, 2008.
"Researchers have long wanted to notice a mode to go a patient's disease into the screen tube, to develop cells that could be cultivated into the many tissues relevant to diseases of the blood, the brain and the heart, for example," he says. "Now, we own a way to do just that-to derive pluripotent cells from patients with disease, which means the cells crapper make whatever tissue and can grow forever. This enables us to manakin thousands of conditions using classical cell culture techniques."
Daley's team has created disease-specific shank cell lines for Duchenne muscular dystrophy; Becker muscular dystrophy; juvenile-onset (type I) diabetes; Parkinson's disease; Huntington's disease; Down's syndrome; ADA severe combined immunodeficiency (a form of the disorderliness commonly known as "boy-in-the-bubble disease"); Shwachman-Bodian-Diamond syndrome (which causes bone marrow failure and a predisposition to leukemia); Gaucher disease (an inherited metabolic disorder in which a fatty meaning accumulates in several of the body's organs); and Lesch-Nyhan syndrome (an enzyme deficiency that causes a build-up of uric acid in body fluids). Many more cell lines are possible.
For years, researchers have full-grown human cells in the laboratory in an attempt to mimic various genetical diseases, but the available techniques had significant shortcomings. Cells taken directly from affected patients typically have a limited lifespan when grown in laboratory dishes, restricting the types of studies for which they can be used. Researchers often turn to cells that hold been modified to make believe them alive in a dish forever, but fixing cells to make them immortal changes their physiology and tin can cast doubtfulness on a study's results.
Recently, Daley's lab and others suffer demonstrated that adult cells can be converted to stem cells by introducing a set of genetical "reprogramming factors." To grow the disease-specific stem cells, Daley and his colleagues mixed cells from patients with the ten disorders with benign viruses to introduce the reprogramming factors into the cells. The resulting stem cells harbored the genetic diseases of the donors.
Once the researchers detached the disease-specific stem cells, they analyzed the genes and confirmed that the stem cells had the same disease-causing defects as the original donor cells. The researchers also made sure that the stem cells were pluripotent-able to differentiate into many unlike tissue types.
Daley says that in many cases these new stem-cell cultures will mimicker human disease more reliably than beast models. Despite the immense genetic similarities between man and mice, physiological differences invariably affect the trend of disease in a mouse. In some cases, the genetic defect that produces a disorder in humans-such as Down's syndrome-does not cause the same symptoms in mice. Therefore, human cell cultures ar an essential complement to research with animal models, Daley says.
The most immediate applications programme of the disease-specific stem cells will be to reproduce human diseases in culture to explore their development in different tissues, Daley says. The technique will level enable researchers to compare how the same disease varies among people, by generating disease-specific stem cell cultures from many individuals. The cells will likewise offer a proving strand for screening drugs to treat disease.
Over the longer terminus, Daley expects the proficiency will be applied clinically. For example, it may allow scientists to develop therapies exploitation a patient's own cells--reengineering the cells to correct a disease-causing defect so re-introducing them into the body.
The Harvard Stem Cell Institute will make the stem cell lines available to the scientific community as quickly as possible, Daley says. The institute will also continue to work to mother cell lines for other diseases.
Daley and his colleagues' techniques for reprogramming adult cells are readily available so other researchers can generate their possess disease-specific stem cell lines. However, "Stem cells are quite particular," Daley cautions. "They don't grow like weeds; they're more like orchids. You really take to tend to them." Therefore, he plans to collaborate with researchers at other institutions to help produce stem cell lines for the diseases they want to study.
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