Stop your crying – because scientists can do it for you. Using stem cells, Dutch researchers have grown miniature human tear glands capable of “crying”.
Initially, when scientists were looking to develop this technology, their first call port was the inner lining of the gut, as it changes itself every five days. They took a small piece of intestinal tissue filled with stem cells and fed proteins called growth factors to stimulate cell growth, expecting stem cells to proliferate faster.
“But to our surprise, stem cells have created a mini-organ … it’s tiny, but it contains all the different cells in the gut that you need to digest food,” said Hans Clevers, group leader at the study Hubrecht Institute. Was. At the Princess Maxima Center for Developmental Biology and Stem Cell Research and Pediatric Oncology.
That was back in 2009. Since then, researchers have created mini versions – called organoids – of the liver, pancreas, bladder and more. They went from mammals to reptiles to successfully growing snake venom glands. Last year, Clevers ’PhD students chose to work on human tear glands.
After successfully creating tear glands for the first mice, they progressed to human tissues. A small portion of suspended, donated human tissue was given a cocktail of growth factors in a prison. About a week later, the researchers cut it into small pieces and fed it something more to make some small-glands. “They looked like tiny balloons,” Clevers said.
Tear glands are useful to their human host in many ways. They produce a thin layer of fluid that lubricates the cornea, lubricates the surface of the eye, protects it from inflammation and infection, and provides nutrients. The glands are also responsible for producing tears, due to physical stimulation, say someone hangs a nail in your eye, or emotional anger, for example, a car that drives over your pet cat. In both cases the brain instructs the tear glands to cry.
“The chemical message that comes from neurons is adrenaline for your lacrimal glands. So, to really show that we have tear glands functional, we needed to show that they will respond to adrenaline, ”Clevers said.
While the mini-organs were given a constant supply of growth factor cocktails, they did not produce much tear fluid when it came to adrenaline. But once they were cut from the juice, the cells stopped dividing and were allowed to freeze and mature – adrenaline quickly produces tears, he explained.
The small balloon-like glands swelled quickly because there was no tube to escape the fluid. Clevers added that, eventually, they dropped a little liquid carb in the form of drops, either crashing or crashing themselves.
The model has some limitations. The duplicate cell – the researchers captured a cell – is made up of tear glands, but the glands also contain other cells. In addition, these organoids are not part of the human body – in which the tear glands can be wrapped by muscles and blood vessels – so there are limitations in their functioning, he warned.
“She is a recluse. But the essence of the tear gland is captured: that is, the formation of tears and then the adrenaline-induced production of tear drops. “
This model could be used by researchers globally to identify new drugs for patients who do not produce enough tears and to study how lacrimal cancer forms and how it can be treated. Finally, this type of organoid may also be transplantable in patients with non-functioning tear glands, the authors have suggested in the Cell Stem Cell Journal.
Meanwhile, researchers at Clevers’ Lab have already set their sights on their next project: Crocodile Tears.
“We want to develop crocodile tear glands,” Clevers said. “Crocodiles don’t cry because they are sad or something; They are just trying to get rid of the salt. So scientifically studying how this actually works, it’s really interesting how they use their tear glands as kidneys.
