Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UMMS researchers isolate gene mutations in patients with inherited amyotrophic lateral sclerosis

16.07.2012
Disruption of cytoskeleton pathways contribute to ALS pathogenesis

A new genetic mutation that causes familial amyotrophic lateral sclerosis (ALS), a fatal neurological disorder also known as Lou Gehrig's Disease, has been identified by a team of scientists led by researchers at the University of Massachusetts Medical School (UMMS).

Mutations to the profilin (PFN1) gene, which is essential to the growth and development of nerve cell axons, is estimated to account for one to two percent of inherited ALS cases. The finding, described today in the online edition of Nature, points to defects in a neuron's cytoskeleton structure as a potential common feature among diverse ALS genes.

"This discovery identifies what may possibly be a common biological mechanism involved across familial ALS cases regardless of genetics," said John Landers, PhD, associate professor of neurology and senior author of the study. "We know of at least three other ALS genes, in addition to PFN1, that adversely impact axon growth. If indeed, this is part of the disease's mechanism, then it might also be a potential target for therapeutics."

Robert Brown, MD, DPhil, a co-author on the study and chair of neurology at UMass Medical School, said "Dr. Landers has done great work in defining this new pathway for motor neuron death. We are delighted to have identified the defects in families from the U.S., Israel and France that we have been investigating for several years. Our finding is particularly exciting because it may provide new insights into ALS treatment targets."

ALS is a progressive, neurodegenerative disorder affecting the motor neurons in the central nervous system. As motor neurons die, the brain's ability to send signals to the body's muscles is compromised. This leads to loss of voluntary muscle movement, paralysis and eventually respiratory failure. The cause of most cases of ALS is not known. Approximately 10 percent of cases are inherited. Though investigators at UMass Medical School and elsewhere have identified several genes shown to cause inherited or familial ALS, almost 50 percent of these cases have an unknown genetic cause.

The current Nature study details the discovery of the PFN1 gene mutation among two large ALS families. Both families were negative for known ALS-causing mutations and displayed familial relationships that suggested a dominant inheritance mode for the disease. For each family, two affected members with maximum genetic distance were selected for deep DNA sequencing. To identify an ALS-causing mutation, genetic variations between the family members were identified and screened against known databases of human genetic variation, such as the 1000 Genomes Project. This narrowed down the resulting number of candidate, ALS-causing mutations to two within the first family and three within the second. Interestingly, both families contained different mutations within the same gene – PFN1, the likely causative mutation. With additional screening, the team documented that in a total of 274 families sequenced, seven contained a mutation to the PFN1 gene, establishing it as a likely cause for ALS.

While it is not certain how the PFN1 mutation causes ALS, the cellular functions it controls within the motor neurons are responsible for regulation of a number of activities, including the growth and development of the axon, the slender projection through which neurons transmit electrical impulses to neighboring cells, such as muscle. When introduced into motor neuron cells, normal PFN1 protein was found diffused throughout the cytoplasm. Conversely, the mutant PFN1 observed in ALS patients was found to collect in dense aggregates, keeping it from functioning properly. Motor neurons producing mutated PFN1 showed markedly shorter axon outgrowth.

"The discovery that mutant PFN1 interferes with axon outgrowth was very exciting to us," said Claudia Fallini, PhD, a postdoctoral researcher at Emory University School of Medicine who collaborated with the UMass Medical School authors to investigate PFN1's functions in cultured motor neurons. "It suggests that alterations in actin dynamics may be an important mechanism at the basis of motor neuron degeneration."

"In healthy neurons, PFN1 acts almost like a railroad tie for fibrous filaments called actin, which make up the axon" said Landers. "PFN1 helps bind these filaments to each other, promoting outgrowth of the axon. Without properly functioning PFN1 these filaments can't come together. Here we show that mutant PFN1 may contribute to ALS pathogeneses by accumulating in these aggregates and altering the actin dynamics in a way that inhibits axon outgrowth."

Drs. Landers and Brown are members of the Neurotherapeutics Institute at the University of Massachusetts Medical School.

Grant support for this project was provided by the NIH/NINDS 1R01NS065847 JEL, 1R01NS050557 RHB, RC2-NS070-342 RHB, Project ALS and P2ALS, the Angel Fund for ALS Research, the Muscular Dystrophy Association MDA173851 WR and AriSLA co-financed with support of 5x1000 Healthcare research of the Ministry of Health EXOMEFALS NT, CG, VS, JEL. Support was also provided by an SMA Europe fellowship to CF.

About the University of Massachusetts Medical School

The University of Massachusetts Medical School has built a reputation as a world-class research institution, consistently producing noteworthy advances in clinical and basic research. The Medical School attracts more than $270 million in research funding annually, 80 percent of which comes from federal funding sources. The work of UMMS researcher Craig Mello, PhD, an investigator of the prestigious Howard Hughes Medical Institute (HHMI), and his colleague Andrew Fire, PhD, then of the Carnegie Institution of Washington, toward the discovery of RNA interference was awarded the 2006 Nobel Prize in Physiology or Medicine and has spawned a new and promising field of research, the global impact of which may prove astounding. UMMS is the academic partner of UMass Memorial Health Care, the largest health care provider in Central Massachusetts.

Jim Fessenden | EurekAlert!
Further information:
http://www.umassmed.edu

More articles from Life Sciences:

nachricht Selectively Reactivating Nerve Cells to Retrieve a Memory
01.06.2020 | Universität Heidelberg

nachricht CeMM study reveals how a master regulator of gene transcription operates
01.06.2020 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

Black nitrogen: Bayreuth researchers discover new high-pressure material and solve a puzzle of the periodic table

29.05.2020 | Materials Sciences

Argonne researchers create active material out of microscopic spinning particles

29.05.2020 | Materials Sciences

Smart windows that self-illuminate on rainy days

29.05.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>