A group led by Assistant Professor Dan Ohtan Wang from Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS) in Japan successfully visualized RNA behavior and its response to drugs within the living tissue brain of live mice by labeling specific RNA molecules with fluorescent probes. Their study, published in Nucleic Acids Research , can potentially lead to faster, and more accurate screening processes for the discovery and development of new drugs.
RNA is a molecule that plays a key role within a living organism, holding information as to when, where, and how much protein must be allocated, which is also responsible for controlling the biological reactions within a living cell. RNAs behave uniquely and are distributed unequally in each cell, existing more in some areas of the cell than others depending on environmental factors and cell conditions. In some cases, these chemical changes can put the cell's health at risk due to RNA disruption. However, it is unclear as to how the distribution of RNA molecules is regulated in the cell, and what causes them to act abnormally.
By introducing a non-toxic, fluorescent probe within the brain of live mice, the team succeeded in visualizing targeted RNA in the cell nucleus. This fluorescent probe emits varying intensities of light depending on RNA concentration levels, enabling the team to effectively quantitatively analyze RNA in the living body. The imaging technique, for the first time in the world, quantitatively conveyed that the RNA behavior in live tissue differed from that of a cultured cell when a drug was administered.
Wang hopes that this new imaging technique can help reveal "the natural state of RNA," that allows us to observe the emergence and disappearance of RNA clusters in many types of species, including those that cannot be genetically engineered. "Our next goal is to investigate differences of RNA activity in a live, single cell, what regulates RNA activity, and compare healthy tissue and unhealthy tissue to elucidate gene expression mechanisms and pathologies caused by abnormal RNA activity."
An overview of the novel labeling technique in this study. Probes are introduced into the cell through the injection of fluorescent probes and the application of electric current pulses to label target RNA in live tissue. This new labeling technique allows us to observe localized RNA in the cells of live tissue. The bottom right image shows RNA behavior in the cerebellar cell nucleus existing locally in granular form.
Paper Information
[DOI] http://dx.doi.org/10.1093/nar/gkv614
[KURENAI Access URL] http://hdl.handle.net/2433/198594
Ikumi Oomoto, Asuka Suzuki-Hirano, Hiroki Umeshima, Yong-Woon Han, Hiroyuki Yanagisawa, Peter Carlton, Yoshie Harada, Mineko Kengaku, Akimitsu Okamoto, Tomomi Shimogori, and Dan Ohtan Wang
"ECHO-liveFISH: in vivo RNA labeling reveals dynamic regulation of nuclear RNA foci in living tissues"
Nucleic Acids Research , first published online: 22 June 2015
