Angelw Chem: new chemical probes help to see brain immune cells

May 4, 2019 news / Bio Valley bio on / - researchers in South Korea and Singapore have developed a chemical probe for the first time, which can conduct real-time imaging of an immune cell called microglia in the brain of living animals The discovery was led by the Institute of basic science (IBS) of the University of science and technology of Pohang, South Korea, the Singapore Alliance for biological imaging (SBIC) and the Singapore immune network (sign) of the Singapore Institute of science, technology and Research (a * star); in addition, the Duke University of Singapore - the Duke NUS medical school in Singapore Key imaging studies have been carried out to help scientists understand the development of brain diseases, such as stroke, autism, Alzheimer's disease and Parkinson's disease Photo source: http://cn.bing.com microglia is the main immune cell in the brain Although microglia were discovered a century ago, it is only recently that researchers have found that they play an important role in the development of various nervous system diseases These findings are due to advances in the technology of isolating these cells, as well as transgenic small animal systems that express fluorescent proteins in small glial cell lineages, which enable optical microscopy to image in real time However, it is extremely difficult to study microglia of human and primates Being able to study microglia independently of other cells in the brain is essential for understanding brain development and disease Although researchers have developed some biochemical markers and molecular imaging tools to study these specialized cells, there is no way to observe microglia at the cell level in the living brain, which is more relevant to clinical practice The new study is a collaboration of two laboratories: Professor young Tae Chang, deputy director of IBS (who also works for a * star's SBIC) and assistant professor hyunsoo Shawn JE, Duke NUS The researchers screened fluorescent markers for microglia from a potential probe library Subsequently, researchers conducted a large number of in vitro and in vivo studies to prove that one of the probes, cdr20, can indeed label microglia in living cells The researchers used immunofluorescence to detect the selective staining of microglia Then, the researchers used knockout cell lines to identify enzymes that "turn on" probe fluorescence in microglia Professor Chang explained: "through in-depth study of structure activity relationship, we have developed a high-performance fluorescent chemical probe cdr20, which can observe microglia in vivo and in vitro Using genomic crispr-cas9 knockout screening, we found that ugt1a7c is a functional target protein of cdr20, which can activate the fluorescent signal of cdr20 in microglia by enzymatic glucuronization Our probe can also label microglia from human and primate, so it will be very useful for studying microglia function in higher mammals " The authors say they will continue to improve the functionality and usage of cdr20 In addition, Chang lab is screening new molecules that only label activated microglia, which scientists suspect play an important role in neuroinflammation of neurodegenerative diseases Reference: Kim B et al Visualizing microglia with a fluorescence turn on ugt1a7c substrate Angewandte chemistry.doi: https://doi.org/10.1002/anie.201903058