Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists identify fundamental brain defect, probable drug target in fragile X syndrome

18.09.2007
Scientists have discovered how the gene mutation responsible for fragile X syndrome--the most common inherited form of mental retardation--alters the way brain cells communicate. In neurons cultured from laboratory rats, the scientists also were able to reverse the effects of the mutation using a drug targeted to the specific site in an upstream pathway of the defect. The finding could lead to the development of human therapies for this previously untreatable condition.

The research was led by Stephen T. Warren, PhD, Timmie professor and chair of human genetics in Emory University School of Medicine, and Gary J. Bassell, PhD, Emory professor of cell biology. It will be reported in the Proceedings of the National Academy of Sciences (PNAS) the week of Sept. 17. Lead author is Emory genetics postdoctoral fellow Mika Nakamoto.

"We have now explained the fundamental defect in the brain in fragile X syndrome and, most importantly, found that we can correct this problem in the laboratory," says Dr. Warren. "This is quite exciting, progressing from the identification of the gene in 1991 to now believing we will be able to treat a previously untreatable condition. Our next steps will be to continue screening and identifying the best drugs to try and correct the deficiencies that result from fragile X syndrome."

Fragile X syndrome is caused by a mutation in the FMR1 gene on the X chromosome. A region of the mutated FMR1 gene repeats a trinucleotide sequence of DNA bases--CGG--between 200 and 1,000 times, rather than the normal 6 to 55 repeats in normal individuals. The abnormal trinucleotide repeats cause the absence of the FMR protein normally produced by the gene.

... more about:
»AMPAR »Drug »FMRP »Syndrome »Target »discovered »mGluR5 »receptor

Dr. Warren and his colleagues led an international team that discovered the FMR1 gene in 1991. They later characterized the FMR protein (FMRP) and developed diagnostic tests for fragile X syndrome. Ever since, their research has focused on identifying the specific consequences of FMRP deficiency in the brain and finding targets for drug therapy.

Previously, Dr. Warren, working with scientists at Brown University, discovered that the absence of FMRP in the mouse model of fragile X syndrome leads to an abnormality in synaptic strength, or the degree by which neurons communicate, that suggested an abnormality of AMPAR receptors on the surface of neurons. These receptors are necessary for neurons to connect with each other at synapses, allowing the communication that leads to learning and memory. Drs. Warren and Bassell discovered that in fragile X syndrome, AMPAR receptors move in and out of the surface neuronal cells more frequently and destabilize the synaptic connections. The Emory scientists and others believe this is the ultimate defect in fragile X syndrome.

Using cultured neurons in the laboratory, manipulated to model fragile X syndrome, the Emory scientists were able to target the mGluR5 receptor with an mGluR5 antagonist--MPEP. Since the mGluR5 receptor is upstream of FMRP and has an opposing influence over the neuron, tempering mGluR5 stimulation should normalize the consequence of the loss of FMRP. Indeed, the Emory scientists found the targeted MPEP therapy rescued the abnormal AMPAR receptor movement on the surface of the FMRP-deficient neurons.

"By adding a drug that antagonizes the mGluR5 receptor and signal, we were able to normalize the AMPAR receptor trafficking, and presumably allow the neurons to make appropriate synaptic connections," Dr. Warren says. "This gives us great hope that we will be able to develop treatments for patients with fragile X syndrome."

Holly Korschun | EurekAlert!
Further information:
http://www.emory.edu

Further reports about: AMPAR Drug FMRP Syndrome Target discovered mGluR5 receptor

More articles from Life Sciences:

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

nachricht The Nagoya Protocol Creates Disadvantages for Many Countries when Applied to Microorganisms
05.12.2016 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

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...

Im Focus: Quantum Particles Form Droplets

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...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

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,...

Im Focus: Molecules change shape when wet

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>