A newly-engineered strain of mice whose dividing cells express a fluorescent protein could open the door to new methods of regulating cell proliferation in humans. Cell proliferation plays a key role in degenerative diseases, in which specific cells do not replicate enough, and in cancers, in which cells replicate too much.
Fluorescence microscopy section of the intestine. Green/yellow areas mark sites of cell proliferation. Cell nuclei marked in blue and nuclei with DNA replication marked in red.
(Photo: Agnes Klochendler)
Cells in the human body grow and multiply during body growth or during tissue regeneration after damage. However most mature tissues require only rare cell divisions. Scientists who wish to study these rare populations of replicating cells face a serious obstacle: most current methods for labeling and identifying replicating cells involve procedures that kill the cells and destroy sensitive biological material. This limits the ability of scientists to examine important functions of these cells, for example the genes active in such cells.
To address this problem, two Hebrew University of Jerusalem researchers — Prof. Yuval Dor from the Institute for Medical Research Israel-Canada (IMRIC) and Dr. Amir Eden from the Alexander Silberman Institute of Life Sciences — together with colleagues in Denmark and the U.S., created a mouse strain in which replicating cells express a fluorescent protein which is destroyed once cell division is completed. In all tissues of these mice, replicating cells are labeled by green fluorescence, which allows identification and isolation of live, replicating cells directly from healthy or diseased tissue.
Using this system, research associate Dr. Agnes Klochendler and PhD student Noa Weinberg-Corem at the Hebrew University were able to isolate a rare population of replicating cells from the livers of mice, and study the genes that they express compared with resting liver cells. Interestingly, they found that in replicating liver cells there is a significant decrease in the expression of genes responsible for key liver functions such as fatty acid and amino acid metabolism.
The research results indicate that when differentiated cells divide, they temporarily shift to a less differentiated state. This finding is important to our understanding of the difference between the two fundamental states of differentiation and proliferation in normal cells. It is also relevant for the situation in cancer, where cells are proliferating and often less differentiated.
In the future, the researchers hope to develop methods for regulating cell proliferation. For example, isolation and study of the rare replicating cells in the pancreas could lead to development of approaches to promote the proliferation and expansion of insulin-producing cells, whose loss is the hallmark of diabetes.
This could also be useful in other areas such as cancer and regenerative biology. By distinguishing between abnormally expressed genes in tumors and the genes associated with normal cell divisions, researchers may be able to identify cancer-specific replication markers with a potential to become new drug targets. Similarly, scientists could analyze the effects of specific drugs on the biology of replicating cells, providing important clues for regenerative medicine.
The study, A Transgenic Mouse Marking Live Replicating Cells Reveals In Vivo Transcriptional Program of Proliferation, was funded by the European Union and is published in the October issue of Developmental Cell.
For information, contact:Dov Smith, Hebrew University Foreign Press Liaison
Orit Sulitzeanu | Hebrew University
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy