Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Carnegie Mellon scientists develop tool that uses MRI to visualize gene expression in living animals

21.03.2005


In a first, Carnegie Mellon University scientists have "programmed" cells to make their own contrast agents, enabling unprecedented high-resolution, deep-tissue imaging of gene expression. The results, appearing in the April issue of Nature Medicine, hold considerable promise for conducting preclinical studies in the emerging field of molecular therapeutics and for monitoring the delivery of therapeutic genes in patients.

"For 20 years it has been the chemist’s job to develop agents that can be used to enhance MRI contrast," said Eric Ahrens, assistant professor of biological sciences in the Mellon College of Science at Carnegie Mellon. "Now, with our approach, we have put this job into the hands of the molecular biologist. Using off-the-shelf molecular biology tools we can now enable living cells to change their MRI contrast via genetic instructions."

"The new imaging method is a platform technology that can be adapted for many tissue types and for a range of preclinical uses in conjunction with emerging molecular therapeutic strategies," Ahrens said.



Ahrens’ new approach uses magnetic resonance imaging (MRI) to monitor gene expression in real-time. Because MRI images deep tissues non-invasively and at high resolution, investigators don’t need to sacrifice animals and perform laborious and costly analysis.

To trigger living cells into producing their own contrast agent, Ahrens gave them a gene that produces a form of ferritin, a protein that normally stores iron in a non-toxic form. This metalloprotein acts like a nano-magnet and a potent MRI "reporter."

A typical MRI scan detects and analyzes signals given off by hydrogen protons in water molecules after they are exposed to a magnetic field and radiofrequency pulses. These signals are then converted into an image. Ahrens’ new MRI reporter alters the magnetic field in its proximity, causing nearby protons to give off a distinctly different signal. The resulting image reveals dark areas that indicate the presence of the MRI reporter.

"Our technology is adaptable to monitor gene expression in many tissue types. You could link this MRI reporter gene to any other gene of interest, including therapeutic genes for diseases like cancer and arthritis, to detect where and when they are being expressed," Ahrens said.

Existing methods used to image gene expression have limitations, according to Ahrens. Some methods cannot be used in living subjects, fail to image cells deep inside the body or don’t provide high-resolution images. Other approaches using MRI are not practical for a wide range of applications.

Ahrens and his colleagues constructed a gene carrier, or vector, that contained a gene for the MRI reporter. They used a widely studied vector called a replication-defective adenovirus that readily enters cells but doesn’t reproduce itself. Ahrens injected the vector carrying the MRI reporter gene into brains of living mice and imaged the MRI reporter expression periodically for over a month in the same cohort of animals. The research showed no overt toxicity in the mouse brain from the MRI reporter.

Lauren Ward | EurekAlert!
Further information:
http://www.cmu.edu

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

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...

Im Focus: Tracing down linear ubiquitination

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...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

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...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>