How does the human body control blood sugar balance? An international team, including the Dresden Center for Regenerative Therapy at Dresden University of Technology in Germany, has taken another step towards solving the mystery. They found a special group of "first response" cells in the pancreas that are crucial for triggering blood glucose responses. The relevant paper was published in the latest issue of the journal Science Advances. The human body needs to maintain an appropriate level of blood sugar. For example, when blood sugar in patients with diabetes rises, beta cells in the pancreas can restore blood sugar balance by releasing insulin. High or low blood sugar levels can pose a danger. Understanding how beta cells work and coordinate the response to elevated blood sugar will help to develop better treatments for diabetes. In order to study the working principle of the pancreas, researchers turned their focus to zebrafish. The working principle of the pancreas in this tropical fish is similar to that of humans. In addition, the transparent nature of zebrafish allows researchers to observe in real-time the functioning of the pancreas inside the fish. Research has found that a small portion of beta cells are more sensitive to blood glucose levels than other beta cells, and their response to glucose is faster, hence they are called "first response" cells. They act as the 'leader' and initiate the response to glucose first, followed closely by the other 'follower' cells. To verify whether followers require a leader to respond to glucose, researchers applied optogenetic technology to zebrafish. This technology can turn on or off single cells through a beam of light. The results showed that turning off the "first response" cells would decrease the response of the following cells to blood glucose. At the same time, when the "first response" cells are selectively activated, the response of the following cells will be enhanced. Researchers compared the gene expression of beta cells that are highly sensitive to glucose with beta cells that are less sensitive. They found that "first reaction" cells are involved in the production of vitamin B6. When researchers inhibited the production of vitamin B6 in the pancreas of zebrafish and mice, the ability of beta cells in both species to respond to high blood sugar significantly decreased. This indicates that vitamin B6 plays an evolutionarily conserved role in its response to glucose. The 'first response' cells may produce vitamin B6 and provide it to other beta cells to regulate their activity. Many studies have shown that low levels of vitamin B6 are associated with an increase in the incidence rate of metabolic diseases and type 2 diabetes. Understanding how vitamin B6 regulates β cells in the pancreas may provide a new perspective for the pathological study of diabetes and ultimately help to find new treatments. (New Society)