Several studies have revealed the unknown new function of macrophages!

June 11, 2019 news / BIOON / - this issue brings you the latest research progress on macrophages, and leads you to learn about the new functions, features and applications of macrophages found in recent studies 【1】 Cancer Res: scholars from Tongji Medical College found that macrophages secrete exosomes to promote the metastasis and invasion of colorectal cancer doi: 10.1158/0008-5472.can-18-0014 clinical and experimental evidence showed that tumor-related macrophages can promote the occurrence and progress of cancer, but so far, how macrophages regulate the metastasis of colorectal cancer has not been fully revealed Recently, Wang Guihua and others from Tongji Medical College of Huazhong University of science and technology found that M2 type macrophages can communicate with colorectal cancer cells by secreting exosomes to affect the migration and invasion of cancer cells The relevant research results were published in the international academic journal Cancer Research In this study, the researchers first found that the migration and invasion of colorectal cancer cells regulated by M2 macrophages depended on exosomes secreted by M2 macrophages Further analysis showed that the macrophage derived exosomes contained high levels of mir-21-5p and mir-155-5p, and the migration and invasion of colorectal cancer cells mediated by macrophage derived exosomes depended on these two miRNAs Later, the researchers studied the mechanism They found that macrophages transferred mir-21-5p and mir-155-5p into colorectal cancer cells through exosomes, and then the two molecules combined with BRG1 coding sequence to down regulate the expression level of BRG1 Previous studies have confirmed that BRG1 is the key molecule to promote colorectal cancer metastasis, and this molecule will The expression was down regulated In summary, these results suggest that M2 macrophages induce colorectal cancer cells to migrate and invade during the malignant progression of cancer, and respond to tumor microenvironment by influencing BRG1 expression The dynamic dialogue between colorectal cancer cells and M2 macrophages provides a new possibility for the treatment of metastatic colorectal cancer 【2】 Nature: Pan Weijun, research group of Chinese Academy of Sciences, reveals the homing mechanism of a kind of macrophage guided hematopoietic stem cells doi: 10.1038/s41586-018-0709-7 in a new study, Wei Jun, researcher of Shanghai Institute of nutrition and health, Chinese Academy of Sciences Pan) and his team used advanced real-time imaging and a cell labeling system to conduct high-resolution analysis on the homing of hematopoietic stem cells in the hematopoietic tissues of zebrafish tail (equivalent to the embryonic liver of mammals), and revealed the role of vascular structure in regulating the homing of hematopoietic stem cells to the niche microenvironment The results were published in the journal Nature Photo source: nature pan Weijun's team identified a niche cell population called VCAM-1 + macrophages patrolling the inner surface of venous plexus, interacting with hematopoietic stem cells in a way dependent on itga4, and guiding hematopoietic stem cells to nest in the niche microenvironment These cells, called usher cells, together with the capillaries and venous plexus of the caudal vein, determine the homing hotspots of hematopoietic stem cells in the niche microenvironment What's more, these leading cells patrol around the homing hot spot area Once they are found, they will be guided to a specific vascular structure, so as to realize homing of hematopoietic stem cells to the niche microenvironment In summary, this study provides new insights into the homing mechanism of hematopoietic stem cells and reveals that the patrolling VCAM-1 + macrophage population plays an important role in homing hematopoietic stem cells 【3】 Science: reveal the mechanism of macrophage self sacrifice to protect us from bacterial invasion doi: 10.1126/science.aau2818 as winter approaches, the immune system is working overtime Gastroenteritis can turn the strongest into a bedridden convalescent The virus is spreading in kindergartens This year's flu is in full swing Knowing that a group of specialized immune cells - macrophages - are willing to burst themselves to tell other cells about this danger can be a little comforting But flu is a strange thing The same bacteria and viruses don't attack everyone at the same intensity Some people are really sick, others are not Why is that? What happens to the body when viruses and bacteria invade the body? Scientists are interested in this problem One of them is Professor EGIL lien of the center for molecular inflammation research, Norwegian University of science and technology He is one of Norway's leading experts on how bacteria attack humans Lien, Dr Pontus? Rning and other researchers have made new discoveries about what happens when bacteria such as Yersinia and Salmonella are at their peak of activity This information is important not only because Yersinia still exists and antibiotic resistance is a growing problem, but also because this new knowledge may be used to study other diseases This knowledge may also be used to develop more effective drugs The results were published in the journal Science The researchers report that macrophages actually burst themselves, releasing proteins that are resistant to invading bacteria and their damage This self burst also reminds other immune cells that macrophages sacrifice themselves to let other cells know what's going on This process is called apoptosis Specifically, macrophages form pores on their surfaces This causes water to flow into the cell, causing it to expand until it bursts When they burst, they also release substances that inhibit the growth of invading bacteria and alert other cells It's very effective, isn't it? The tricky Yersinia knows all this and tries to camouflage itself and secrete antidotes The researchers found that the human body knows that Yersinia camouflages itself They explained that macrophages activate a standby mechanism in a way that was not previously understood 【4】 Science: lipid containing exosomes released by fat cells can regulate macrophage doi: 10.1126/science.aaw6765 - in a new study on mice, researchers from Columbia University and Rutgers University in the United States found that fat tissue released a lipid filled particle, which plays a role in immune function and metabolism The results were published in the journal Science In previous studies, Ferrante laboratory has found that in addition to fat cells, fat tissue also contains many immune cells, including a large number of macrophages In other tissues, macrophages devour and destroy pathogens "For a long time, we have been trying to understand the role of these immune cells in adipose tissue," Ferrante said "A few years ago, his team found that macrophages found in adipose tissue absorb and" digest "large amounts of lipids He and others think the lipids come from degradation products of triglycerides In the current new study, the researchers found that fat cells not only release the fatty acids in triglycerides, they also release intact triglycerides packaged in small particles These lipid filled particles called adipocyte exosomes (adexo) are absorbed by macrophages in adipose tissue Macrophages rapidly degrade triglycerides in adexo and release fatty acids Ferrante speculates that the released fatty acids are absorbed by fat cells in the lipid cycle, thus providing new lipids for fat cells "There is a similar mechanism in bone: osteoclasts - another type of macrophage - degrade bone into calcium and phosphate, which are used to make new bones," Ferrante said This cycle is essential for bone health Now we want to know if a similar cycle exists in fat tissue to keep it healthy "In addition, the researchers found that adexo seems to control the development of immune cells Scientists do not have a clear understanding of how macrophages produce tissue-specific functions However, Ferrante and his team have found that adexo may play a central role in "educating" immune cells, inducing bone marrow cells to develop into macrophages, which are then digested and recycled with guidance 【5】 Nat commun: tumor cells recruit and change macrophage DOI through miRNAs https://doi.org/10.1038/s41467-019-08989-2 the interaction between tumor cells and immune cells will change the phenotype of immune cells, and microRNAs (Mirs) are the key bridge in this process But researchers don't know how Mirs transmit and affect target cells, especially tumor associated macrophages (TAMs) Photo source: nature communications researchers from Goethe University and other institutions in Frankfurt recently found that breast cancer cells express mir-375 highly, which can release these Mirs in a non exocrine form during apoptosis Through deep sequencing of these mirome, the researchers found that these mirome enhanced the uptake of mir-375 by TAMs, which was mediated by CD36 When ingested by macrophages, these mir-375 will directly target tns3 and Pxn, thus enhancing the ability of macrophages to migrate and infiltrate into tumor cells or tumors in mice In tumor cells, mir-375 can regulate the expression of CCL2 to further increase the recruitment of macrophages This study provides evidence for the transport of Mir from tumor cells to TAMs At the same time, it is found that mir-375 is a key regulator of macrophage infiltration in tumor tissue, which can promote the formation of tumor microenvironment 【6】 Nat Biotechnology: a major breakthrough! Reprogramming macrophages as sensors to detect cancer and other diseases! DOI https://doi.org/10.1038/s41587-019-0064-8 endogenous biomarkers are still indicators of early diagnosis of many diseases, but many of them lack the sensitivity and specificity to effectively guide disease control, which makes early diagnosis of diseases, monitoring and treatment of disease progress become a problem In order to solve this problem, researchers from Stanford University School of Medicine recently developed a cell-based in vivo biosensor under the leadership of Professor Sanjiv s Gambhir from the Department of bioengineering, Department of Radiology and Department of molecular imaging, which can realize the early diagnosis of tumor with high sensitivity The researchers engineered macrophages to combine the expression of luciferase with the activation of arginase-1 promoter, so that these macrophages can sense the M2 tumor related metabolic spectrum to produce luciferase After the cells were constructed successfully, the researchers infused these cells back into the mice model of colorectal cancer and breast cancer, and found that these macrophages can migrate to the tumor site, activate the expression of arginase-1, which allows the researchers to diagnose the tumor by bioluminescence imaging and detecting the content of luciferase in the blood Photo source: Nature Biotechnology researchers found that by detecting luciferase in the blood, the macrophage sensor can detect 25% in the presence of inflammation