Bodyless human tear glands grown in petri dishes in a laboratory in the Netherlands have the ability to cry – and the scientists who created them have already grafted them into the eyes of live mice.
The series of experiments, set out in a new study published online in the journal on March 16 Selstamsel, can be a major step forward in the science of treating dry eyes – a condition that affects approximately 5% of adults worldwide and can lead to blindness in severe cases.
Petri dish body parts have become more common in laboratory experiments, but they are much smaller and simpler than their natural counterparts. “Mini-brains” are, for example, smooth, pea-sized, unconscious organoids that look only loosely like the original organs, Live Science reported. According to Petri-Bannier-Hélaouët, co-author of the study and researcher at the Hubrecht Institute in Utrecht, the Netherlands, the petri dish glands were quite close to the real thing.
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Human tear glands, Bannier-Hélaouët told WordsSideKick, have two components: akin cells and flexor cells.
‘Both can make tears, but the flexor cells have an additional function: they act like a channel to bring the tears to the surface of the eye. [lab-made] organoids look like this channel, “she said. The difference is that, as in the dish there is no eye to bring the tears, the organoids look like a canal with dead ends. They are balloons. ‘
The balloons are similar to the size you would find in a human, and they are about half a millimeter wide.
The researchers divided the study into three experiments. For the first time, they grew human tear glands in petri dishes and had them torn.
The growth of the organoids was one thing, Bannier-Hélaouët said. Making them cry was another, because it’s about chemicals in the brain called neurotransmitters.
“The perfect cocktail works out [of neurotransmitters] to make the organoids cry was the most challenging part. It took me about three or four months and about seven to ten trials, “she said. What is striking is that this last cocktail contains very few ingredients. One of them is simply an antioxidant molecule. ‘
After the cocktail was perfected, the researchers noticed the glands with tears that could not go anywhere.
They then implanted some of the laboratory-made glands in the tear ducts of live mice. They found that the implanted human cells could still produce tears, but they did not release them into the tubes like normal glands. Finally, she would say, it is important to find out how the glands can normally behave in living tear ducts.
“We already have ideas on how to do that,” Bannier-Hélaouët said.
In the last part of the study, the researchers focus on the origin of a form of chronic dry eye, known as Sjögren’s syndrome, an autoimmune condition that also causes dry mouth.
In petri dishes, the researchers cultured mouse tear glands adapted with no-till technology to not express a gene known as Pax6. Researchers have already determined that people with dry eye often do not have Pax6 in their eye tissue and that the gene plays an important role in eye development. Their experiment showed that the mouse organoids altered to a lack of Pax6 produced fewer tears, reinforcing the idea that the gene was linked to the medical problem.
Originally published on Live Science.