Alzheimer's in vitro
Alzheimer's syndrome can be recreated on a laboratory table
Kirill Stasevich, Compulenta
Scientists have obtained neurons with Alzheimer's syndrome from skin cells of people suffering from this disease.
There are about 30 million people with Alzheimer's syndrome in the world. At the same time, those patients who have symptoms are amenable to a more or less reliable assessment. But the disease can develop for years before it takes visible forms. The appearance of characteristic neuropsychiatric signs usually indicates that the disease has entered full force. The latent course of the initial stages complicates both diagnosis and treatment.
The study of the disease is based on the material obtained from the deceased, in the course of indirect analyses and experiments on animals. Until now, it has not been possible to see how the disease develops directly in a living human nerve cell. And here the scientists were helped by stem cells – or rather, their kind, which is called induced pluripotent stem cells. In an article published in the journal Nature (Israel et al., Probing sporadic and familial Alzheimer's disease using induced pluripotent stem cells), researchers from the University of California at San Diego (USA) report that they managed to grow "Alzheimer's" neurons using fibroblasts of patients with Alzheimer's syndrome. The technique of induced stem cells makes it possible to obtain such cells from any specialized tissue. The researchers took skin fibroblasts from four patients and two more people with normal senile dementia, turned them into a kind of embryonic stem cells, and then launched their development into nerve cells.
Alzheimer's disease can occur both due to hereditary mutations transmitted from generation to generation, and due to a combination of genetic and environmental factors. In the second case, it appears as if from scratch, the external environment affects the molecular genetic mechanisms of the cell. In the experiment, there were both options. And in the case of inherited disease, signs of pathology were observed in neurons derived from artificial stem cells – increased production of beta-amyloid and tau protein.
These proteins are a hallmark of Alzheimer's syndrome: forming deposits of improperly folded protein molecules, they cause poisoning and death of nerve cells. Hereditary mutations persist in all cells of the body, and when fibroblasts turned into neurons, they just woke up. As for the "acquired" disease, the level of beta-amyloid and tau protein was increased only in one case out of two. The cells taken from the second patient with non-hereditary Alzheimer's disease were not too different from the cells obtained from patients with normal dementia. Larry Goldstein, head of research, believes that sometimes external factors play too big a role to be recreated in cell culture. In addition, other cells of the nervous system may also participate in the development of the disease in such cases.
In fact, this is not the first study on modeling Alzheimer's disease on the laboratory table. Last year, a similar experiment was conducted by another group of scientists – however, it used a different method of reprogramming cells. However, the previous results were questioned: skeptics believed that Alzheimer's disease could be caused by molecular genetic manipulation - which means it does not correspond to the real state of things in the nervous system. Now the result has been confirmed using another method, which allows us to conclude that induced stem cells are suitable for the study of Alzheimer's disease. With their help, scientists can actually observe what happens in reality during the development of the disease, without worrying about methodological artifacts. Theoretically, with the help of this method, it is possible not only to develop treatment regimens, but also to detect the disease at its earliest stages, years before the first visible symptoms appear.
Prepared based on the materials of the University of California, San Diego:
Researchers Induce Alzheimer’s Neurons From Pluripotent Stem CellsPortal "Eternal youth" http://vechnayamolodost.ru