At the molecular level, it has been widely assumed that, in single-celled organisms, each cell perceives its environment -- and responds to stress conditions -- individually, each on its own to protect itself. Likewise, it had been thought that cells in multicellular organisms respond the same way, but a new study by scientists at Northwestern University reports otherwise.
The Northwestern researchers demonstrated something very unexpected in their studies of the worm C. elegans: Authority is taken away from individual cells and given to two specialized neurons to sense temperature stress and organize an integrated molecular response for the entire organism.
The study, with results that show a possible parallel with the orchestrated “fight or flight response,” will be published in the May 9 issue of the journal Science.
“This was surprising -- that two neurons control the response of the 957 other cells in C. elegans,” said Richard I. Morimoto, Bill and Gayle Cook Professor of Biochemistry, Molecular Biology and Cell Biology in Northwestern’s Weinberg College of Arts and Sciences. He led the research team.
“It is well established that single cells respond to physiological stress on their own, cell by cell. Now we’ve shown this is not the case when individual cells become organized to form a multicellular organism. Now it is all for one -- an integrated system where the cells and tissues only respond to stress when the neuronal signal says to respond as an organism.”
The findings have implications for new ways of thinking about diseases that affect the stress pathways, says Morimoto. Neurons that sense the environment govern such important pathways as stress response and molecular chaperones, which play a significant role in aging and neurodegenerative diseases.
In their experiments, the researchers genetically blocked the two thermosensory neurons (known as AFDs) and their ability to sense temperature and discovered there was no response to stress in any cell in the organism without them. (C. elegans is a transparent roundworm whose genome, or complete genetic sequence, is known and is a favorite organism of biologists.)
“This shows, for the first time, that the molecular response to physiological stress is organized by specific neurons and suggests similarities to the neurohormonal response to stress,” said Morimoto, who was the first to clone a human heat shock gene in 1985. “The two neurons control how all the other cells in the animal sense and respond to physiological stress.”
The team also checked the “machinery” of the 957 other cells (those that are not thermosensory neurons) in the mutant animals and determined that the individual cells could sense an increase in temperature. But, because the thermosensory neurons were not working properly and sending signals, the cells did not initiate a heat shock response. No signal, no response.
The researchers proposed a model whereby this loss of cell autonomy serves to integrate behavioral, metabolic and stress-related responses to establish an organismal response to environmental change.
The researchers would predict, considering the study’s results, that other organisms including humans might have similar classes of neurons that organize and orchestrate a response to stress -- a central neuronal control switch for regulating temperature and the expression of genes that protect the health of proteins.
Megan Fellman | EurekAlert!
Unique genome architectures after fertilisation in single-cell embryos
30.03.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering