The closer people are, the more opportunities there are to exchange ideas and information. And the distance between cells is close, there will be “chemical reactions”. A new study by MIT and Boston Children’s Hospital found that physically squeezing cells and their contents can make cells grow and divide faster than normal. This research has opened up new ideas for organoid culture and regenerative medicine organ transplantation. Related papers were recently published online in the journal Cell Stem Cell.
Although squeezing an organism to grow it sounds counterintuitive, the research team explained that the effect of squeezing is to “twist out” the water in the cells, so that proteins and other cellular components are also packed more closely together. At the same time, proteins can accumulate along specific signaling pathways to help cells maintain a stem cell state, so cells can grow and divide quickly.
Ming Guo (transliteration), associate professor of mechanical engineering at MIT, and his colleagues cultivated human colon organoids in a petri dish and “squeezed” the organoids by injecting polymer into the petri dish. The injection of polymer increases the osmotic pressure around each organoid, forcing the water in the cells to flow out. Researchers have observed that the specific proteins involved in activating the Wnt pathway are tightly packed and are more likely to activate the signaling pathway and its genes that regulate growth.
The results of the study showed that the squeezed organoids grew larger and faster than the unsqueezed organoids, and there were more stem cells on their surface. This proves that squeezing does affect the growth of organoids, and the behavior of cells may change depending on how much water they contain.
Guo Ming said that simply squeezing the cells to promote their “stem cellization” can guide the cells to quickly cultivate organoids, such as artificial intestines and colons. This not only provides us with research on organ function and testing of candidate drugs for various diseases. The approach can also be applied to organ transplantation in regenerative medicine.
In the future, researchers will continue to explore cell “squeezing” as a way to accelerate the growth of organoids. They may also use these artificial organs to test new personalized medicines.
The relatively mild winds in Malaysian Borneo can explain why the island has the world’s highest tropical forest-including the tallest trees known in the tropics, such as the 100-meter-high giant tree called Menara in the picture.
Last year, an international research team introduced Menara, a yellow eucalyptus tree growing in the research area of Borneo. In a recent study published in “Tropical Biology”, Tobias Jackson of the University of Oxford in the United Kingdom led a team of scientists in the same field, using laser scanning to create 3D models of dozens of trees in the plot, and measuring Their height.
The researchers also placed strain gauges on the tree trunks to assess how much they bend in the wind and simulate the pressure they can withstand. The results show that in tropical forests, the strongest wind limits the growth of trees. Scientists have found that strong winds limit the height of tropical forests, but gentle winds on the island make trees grow very high.
Jackson said that large conifers in temperate forests, such as California coastal redwoods, can grow taller than Menara, but they may be restricted by factors other than wind speed because their trunks are much thicker.