Already at the current level of development of medicine, wewe can grow many tissues for transplantation. But the problem is that this applies for the most part only to fairly “simply” arranged tissues such as skin, bones or muscles. And the more complex the device has tissue, the more difficult it is to create it “in vitro”. Perhaps, the nerve tissue of the brain, spinal cord, and retina is in first place in the complexity of growing. And precisely the way to create the latter was recently found by experts from Johns Hopkins University (USA).
The main problem when creating any typestissue in the laboratory is to elucidate trigger factors and conditions leading to the differentiation of progenitor cells. After all, getting stem cells is not a particular problem. Retinal cells, as you know, are divided into 2 types, responsible for daytime and twilight vision - sticks and cones. Moreover, cells that recognize colors are divided into 3 subspecies: S-type cells capture the blue-violet part of the spectrum, M-type cells - green-yellow, and L-type cells - red (by the way, it is a defect in those other cells is responsible for the development of various forms of color blindness). And all these cells develop from one population. And scientists have discovered what exactly affects their development.
In studies of vertebrates andIt has been revealed in humans that the thyroid hormones of the thyroid gland and, in particular, triiodothyronine, play an important role in the processes of retinal cell formation. The addition of triiodothyronine to the culture medium with table cells under certain conditions triggers the cell specialization process. Moreover, an excess of the hormone blocks the maturation of S-type cells and the development of M and L cells, and a lack of triiodothyronine, on the contrary, provokes inhibition of the development of M and L cells by S-type cell formation.
The development of various cell lines depending on the level of thyroid hormone concentration
This process is quite laborious, butthe researchers were able to grow a functioning retinal organoid that responds to light, and even released a short demo clip, available below. According to the authors, their search can become not only the key to creating an artificial retina, but also to the treatment of color blindness and other visual impairment.
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