Nat Microbiol: scientists identify the function of new microRNAs in the process of pathogenic bacteria infection

January 12, 2020 / BIOON/ --MicroRNAs are small RNA molecules that do not encode proteins, but they play a variety of important roles, such as acting as regulators of gene expression Therefore, microRNAs have become the focus of scientists' attention Although they have thousands of different sequences, in most cases, each microRNA plays a role for scientists But it's unknown Photo source: Ryan Jeffs / Wikipedia recently published in the international journal Nature Microbiology In the previous research report, researchers from the University of Cordoba and other institutions revealed the special functions of specific microRNAs in the process of Salmonella typhimurium and Shigella flexneri infection These bacteria are two similar bacteria, which can cause infection when people eat contaminated water or food These are two intracellular pathogens, which can invade healthy cells and cause similar disease symptoms Although they have many similarities, the results show that the infection induced by these two bacteria may be controlled by two different microRNAs with completely opposite functions In this study, the researchers studied more than 1400 different microRNAs to confirm the role of these two kinds of bacteria in the cell In Shigella, for example, once the host cell is infected, a kind of microRNA will activate the responsible bacteria The regenerated genes began to express, a mechanism by which pathogens began to attack host cells in order to reproduce This was not only confirmed in the laboratory, but also in the intestinal mucosa of pigs The results reveal how microRNAs work in a completely different way, which has not been described before In the infection of Shigella, for example, some small molecules are inherited Substances play a special role in the immune response of the body to pathogens, while in infections such as Salmonella, bacteria will develop some special strategies to facilitate their own reproduction According to researcher Juan Jose Garrido, we need to understand the specific mechanism of action of each pathogen, so as to develop different targeted therapies; if we don't know the mechanism of action of microRNA regulation, we may blindly develop therapies, and as a result, we will randomly use various antibiotics to enhance bacteria In the laboratory alone, researchers have Salmonella strains that are resistant to 14 different antibiotics Based on this, it is expected to clarify the pathogenesis of each pathogen or help researchers develop new and efficient antimicrobial therapy Original sources: Aguilar, C., Cruz, A.R., Rodrigues ropes, I et al Functional screens require different requirements for host microRNAs in Salmonella and Shigella infection NAT Microbiol 5, 192 – 205 (2020) doi: 10.1038/s41564-019-0614-3