Contracting human muscles "in vitro"
Researchers from Duke University, working under the guidance of Associate Professor Nenad Bursac, have grown miniature human skeletal muscles in laboratory conditions that can not only contract, but also adequately respond to external stimuli, such as electrical impulses, biochemical signals and pharmacological drugs. This achievement can bring to a new level the development of drugs and the study of diseases of muscle tissue.
Micrograph of human muscle fiber bundles grown in laboratory conditions.
Coloring allows you to see the characteristic structure represented by muscle fibers
and associated proteins (red).
At the initial stage of the study, the authors took a sample of partially differentiated human cells that have already lost the properties of stem cells, but have not yet turned into muscle cells. These myogenic progenitor cells were cultured in the laboratory to increase the population by more than 1000 times. After that, they were placed in a three-dimensional frame filled with a nutrient-containing gel.
This allowed the cells to form functioning muscle bundles located parallel to each other.
Two bundles of muscle fibers grown in laboratory conditions are stretched in a rectangular frame immersed in a nutrient medium.
The set of tests carried out by the authors confirmed the similarity of the obtained cells with the muscle cells of a living organism. The cells contracted strongly in response to electrical impulses.
Moreover, they responded adequately to acetylcholine, changes in the concentration of calcium ions and other signaling mechanisms used by the nervous system to activate muscles.
Experiments with various pharmacological drugs, including clenbuterol, an over–the–counter drug for improving the physical fitness of athletes, have demonstrated the suitability of new cells for preclinical trials of new drugs.
The reactions observed in this case corresponded to what was happening in the human body. In response to the action of various drugs, dose-dependent hypertrophy or toxic myopathy, similar to those observed in clinical conditions, were manifested.
One of the goals of the authors' work is to provide patients with personalized medical care by isolating a small tissue sample, growing muscle cells in the laboratory and selecting the optimal treatment method. To achieve this goal, they have already started working together with clinicians to compare the effectiveness of drugs in the treatment of patients with reactions of cells grown in the laboratory.
They are also working on a technique for growing contracting muscle cells from induced pluripotent stem cells. This will allow us to work with patients whose diseases make it difficult to obtain biopsy material of muscle tissue, for example, those suffering from Duchenne myodystrophy.
Article by Lauran Madden et al. Bioengineered human myobundles mimic clinical responses of skeletal muscle to drugs is published in open access in the journal eLife.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Duke University:
First Contracting Human Muscle Grown in Laboratory.
14.01.2015