Mini kidneys on the conveyor
Researchers from the University of Washington in Seattle, working under the guidance of associate Professor Benjamin Freedman, have developed an automated system for quickly obtaining miniature models of organs from human stem cells.
The traditional way to grow cells for biomedical research is to cultivate them on flat surfaces. This two-dimensional approach is overly simplistic. In recent years, specialists have made significant progress in growing three-dimensional structures from cells, known as mini-organs or organoids. They resemble rudimentary organs and in many ways reproduce their functions. These properties make organoids an ideal object for biomedical research, but their mass production has proved to be a very difficult task.
In their study, the authors used a robotic system to automate the procedure for growing organoids from stem cells. Despite the fact that such approaches have shown quite good results in working with adult stem cells, until now specialists have not been able to automate the production of organoids from pluripotent stem cells. The attractiveness of the latter lies in their immaturity and the ability to differentiate into cells of different organs and tissues.
The process proposed by the researchers is that a robot capable of manipulating liquids places stem cells in tablets, each of which contains 384 miniature wells. After that, for 21 days, the cells form kidney organoids. At the same time, at least 10 microlunks are formed in each of them, and thousands of organoids are formed in each tablet. According to the authors, only manually preparing for an experiment of this scale would take a researcher a whole day, whereas it takes only 20 minutes for a robot to do this. In addition, the robot does not get tired and does not make mistakes. It is obvious that when it is necessary to perform repetitive manipulations of the same type, robots cope much better than humans.
Top view of a microlunar tablet containing kidney organoids created by a robot from human stem cells. Different segments of the kidneys are marked with red, green and yellow colors.
The researchers also used the latest automated technology, known as single cell RNA sequencing, to identify the various cell types that make up the organoids. The obtained results confirmed that the organoids are indeed miniature analogues of developing kidneys, but contain a certain number of cells that are not related to the kidneys, not previously described in such cultures.
According to Dr. Friedman, these data describe the nature of the organoids grown and provide a starting point from which to build upon when improving the technique. At the same time, the value of the developed high-performance platform lies in the possibility of making changes to the procedure at any stage and in many different ways, while quickly receiving information about the results to which the changes are made.
For example, researchers have managed to find a way to significantly increase the number of cells forming blood vessels in organoids, which increases their similarity to real kidneys.
In addition, the authors applied their technology to search for drugs that can influence the course of various diseases. As part of one of the experiments, they produced organoids from cells with a mutation that causes polycystic kidney disease – a hereditary disease that often leads to the development of kidney failure and occurs in the world with a frequency of 1 case per 600 people. In this disease, the renal ducts swell and form growing cysts that displace healthy tissues.
The authors affected polycystic organoids with various compounds and found that one of them, blebbistatin, causes a significant increase in the number and size of cysts. This was quite unexpected, since blebbistatin is known for its ability to block the activity of the myosin protein, which provides muscle fiber contraction. Apparently, the renal ducts expand and contract also due to myosin, whose dysfunction leads to the formation of cysts. In the future, the authors plan to study this mechanism in more detail.
Article by Stefan M. Czerniecki et al. High-Throughput Screening Enhancements Kidney Organoid Differentiation from Human Pluripotent Stem Cells and Enables Automated Multidimensional Phenotyping is published in the journal Cell Stem Cell.
Evgenia Ryabtseva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of the University of Washington Health Sciences/UW Medicine: Robots grow mini-organs from human stem cells.