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Jumaana Syed Ali, Chennai, India  
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Raising a child with SMA

Last September, doctors diagnosed Holly with SMA, a motor neuron disease which affects the voluntary muscles.

Last September, doctors diagnosed Holly with SMA, a motor neuron disease which affects the voluntary muscles.

A Lamar couple says they knew something wasn’t right with their baby, but just assumed she was delayed in her development. They later found out their baby girl suffered from an incurable muscular disease called Spinal Muscular Atrophy or SMA.

Christie and Marty Tolson have a full-time nurse to help them with their 20-month-old daughter, Holly because she requires around-the-clock attention.

Last September, doctors diagnosed Holly with SMA, a motor neuron disease which affects the voluntary muscles. Holly can’t crawl, walk, control her head and neck or swallow.

The couple knew something wasn’t right with their daughter, early on. She wouldn’t put any weight bearing on her legs at all. We kind of just putting it off thinking she was just lazy,” Christie said.

As time went on, the Tolson’s had to confront fears. They said one of the hardest parts about dealing with Holly’s SMA was breaking the news to her 10-year-old brother, Zack. “We had to tell him that his sister may not live to see her second birthday,” said Christy, “And that she would have all these machines to help keep her healthy and lungs clear.”

Eight machines help keep Holly alive. A special vest shakes her to break up mucus in her body. She’s fed through a tube three times a day and overnight. Holly also takes medications and vitamins by way of the tube. “She has physical therapy. She has water therapy. She has speech therapy and occupational therapy,” Christie explained.

And when all the therapy is over, Holly gets to play with some of her favorite toys. Because she’s so weak, the toys require only a gentle touch to operate. Holly’s parents want others to know that if you sense something is wrong with your child, get them examined.

There is no cure for SMA, but the Tolson’s aren’t giving up. “There’s hope. There’s hope for Holly and other children with SMA,” Christy said.

One in every 6,000 to 10,000 babies is born with SMA.

SOURCE: www.carolinalive.com

Posted on October 19, 2010 at 6:47 pm by Jumaana Syed Ali · Permalink · Leave a comment
In: SMA Bravos · Tagged with: , , , , , ,

CT boy lives five years, starts school despite muscular disorder

Ethan Takacs studies in his kindergarten classroom

Ethan Takacs studies in his kindergarten classroom

FAIRFIELD, CT (CNN) – A little boy in Connecticut who wasn’t expected to live past his infancy is now happily attending kindergarten.

“Basically the doctor was telling me ways to remember him before he was already gone,” said Jason Takacs of Fairfield, CT.

Ethan Takacs, his son, has Spinal Muscular Atrophy, a rare genetic disorder that doesn’t let muscles move and causes breathing and swallowing problems. Because of the disease, he expected to live longer than 18 months, according to doctors.

Jason Takacs said doctors gave his family “very little hope.” But now he’s overjoyed his son has started school and can move a few fingers and make some small noises.

While Ethan Takacs’ family is happy about the progress, his health remains their top concern.

“I know he is going into a place he is so happy,” said Kelly Takacs, Ethan’s mother. “At the same time everybody has got their eye on the situation.”

Ethan Takacs teacher reported he’s very smart, and his family said he’s the one teaching them a thing or two about life.

SOURCE: www.walb.com

Planet Gift Baskets Partners With The Inland Empire Lemon-Aide For Life To Find A Cure For Spinal Muscular Atrophy

Spinal Muscular Atrophy can be fatal among children in the U.S.A. Fund raisers are held throughout the year to help find a cure and support families affected by the disease.

Planet Gift Baskets supports finding a cure for Spinal Muscular Atrophy by participating in the annual Lemon-Aide For Life fundraiser. Each year families from Highland, San Bernardino and surrounding Inland Empire cities gather to raise money to find a cure for the disease known as SMA that can affect children.

Spinal Muscular Atrophy is a neuromuscular disease characterized by degeneration of muscles.

A small group of parents started Families of SMA in 1984. They wanted to raise funds for SMA research to cure the disease, and support all affected families. Back then, very little was known about Spinal Muscular Atrophy. Very little research was being conducted. No one knew the cause of the disease let alone how to find a treatment and a cure. Patients and families affected by SMA were on their own and had little hope. Today, FSMA has a different story to tell. Families of SMA has created hope for our community that did not exist in 1984. Families of SMA raised and funded over $50 million for SMA research. Their support comes from generous individual donations and numerous fund raising events held by volunteer families and our Chapters.

Kim Donnelly, mother of Joseph Jean who died of SMA at eight months old, hosts the SMA lemon- aide stand every year close to the anniversary of his death. The fire department, and hundreds of local families come by and purchase lemonade and donate their time and money to help support the families who have been effected by SMA.

Not only are donations offered to find a cure for the disease, family support is also a large portion of the FSMA (families of SMA) main goals. They help families understand the disease as well as offer much needed support for caring with an infant with the diagnosis. Because SMA can be fatal, support is given through their website found at www.FSMA.com to help families cope with infant loss and grief as well as caring for a baby with the disease.

Planet Gift Baskets specializes in sympathy gifts, including infant and child loss memorial gifts. “We frequently get requests for meaningful infant sympathy loss gifts. Because SMA effects children, we felt this cause was a perfect fit for us,” states Pam Brown, owner of Planet Gifts Baskets. All fund raising for families of SMA is done by families, neighbors and friends effected by the disease through bake sales, lemonade stands and other community events. If you are interested in donating to help further research and support families effected by SMA, visit http://www.fsma.com or http://www.planetgiftbaskets.com for further information.

SOURCE: www.prweb.com

Researchers confirm prenatal heart defects in spinal muscular atrophy cases

University of Missouri professor says new concept could lead to better therapies and supportive care

COLUMBIA, Mo. ? University of Missouri researchers believe they have found a critical piece of the puzzle for the treatment of Spinal Muscular Atrophy (SMA) ? the leading genetic cause of infantile death in the world. Nearly one in 6,000 births has SMA, and it is estimated that nearly one in 30 to 40 people have the trait that leads to SMA.

In a new study in Human Molecular Genetics, Christian Lorson, professor in the Department of Veterinary Pathobiology and the Department of Molecular Microbiology and Immunology, has found prenatal cardiac defects in mice with SMA. Lorson believes this discovery has implications for eventual treatment as clinicians can no longer concentrate exclusively on the nervous system when treating SMA.

Lorson’s research team, headed by Monir Shababi, research scientist, examined two animal models of SMA and discovered that cardiac defects are found throughout SMA development and include neonatal fibrosis in the heart, ventricle malformation, thinning of the cardiac wall and slower heart rates.

“It is likely that in severe cases of SMA, the disease is not limited to motor neurons; rather, it becomes a multisystem disease, and the cardiac contribution is just one of the systems,” said Lorson, who works in the MU Bond Life Sciences Center. “These results are consistent with clinical reports of severe SMA cases that describe a number of cardiac defects. To fully address this disease, any new therapies or drugs must be effective in every tissue, not just motor neurons. The more we understand the disease, the better off we will be in terms of developing therapeutics or better supportive care. What this conservatively means for humans is that therapies have to go beyond the nervous system in the most severe and most profound cases.”

Spinal muscular atrophy is caused by loss of a gene known as SMN1. Humans have an additional gene called SMN2 which only makes a small amount of the normal SMN protein ? the protein required to prevent SMA. SMN1 and SMN2 are greater than 99 percent identical, but a small difference between the two causes the dramatic difference in the amount of functional protein produced by SMN2.

Typically, the disease moves from the outlying limbs into the trunk of the body. Most deaths are caused by respiratory failure in the lungs. Researchers have been targeting SMN2 ? what Lorson calls the “partially functioning backup copy” ? because any increase in SMN2 means better results.

“SMN2 is like a light that’s been dimmed, and we’re trying anything to get it brighter. Even turning it up a little bit would likely help dramatically,” Lorson said.

SOURCE: www.genengnews.com

Winnipeg family raising money for SMA in daughter’s memory

Georgia Lucas was just a few months old when she was diagnozed with a disease that took her life within weeks. Now, her family is hoping to raise awareness and support for others living with Spinal Muscular Atrophy.

Georgia Lucas was just a few months old when she was diagnozed with a disease that took her life within weeks. Now, her family is hoping to raise awareness and support for others living with Spinal Muscular Atrophy. Photo Credit: Global News, Winnipeg

Georgia Lucas was just five-months old when she was diagnosed with a disorder that would take her life within weeks.

“Georgia suffered from the most severe type, which means she couldn’t even sit up ever,” said Kristen McDowell Lucas, Georgia’s mother. “She was never strong enough to sit up on her own.”

The rare disorder is called Spinal Muscular Atrophy. It attacks cells in the spinal cord and Brainstem.

“We just knew that she was so sick, so ill,” said McDowell Lucas. “Her body was shutting down on her faster than I could imagine.”

After Georgia’s passing, the Lucas family decided to celebrate what would have been Georgia’s first birthday by holding a fundraising party.

“I decided I had to throw a first birthday,” said McDowell Lucas. “And I had to raise awareness about SMA in the process because it continues to be the number one genetic killer of children.”

The first ever Georgia’s Journey of Hope was a huge success with donations reaching the $10,000 mark. All proceeds went to families of Spinal Muscular Atrophy Canada.

“SMA is the closest neuromuscular disease to a cure,” said McDowell Lucas. “They think they can cure it in five to ten years if they get enough money.”

This Sunday, the Lucas family will celebrate what would have been Georgia’s second birthday. It’s a party that’s open to the public. Georgia’s mom says the fundraiser is not meant to be a sad day for the Lucas family.

“We want to celebrate her life and what she meant to us,” said McDowell Lucas. “And we will continue doing it every year until there is a cure.”

Georgia’s Journey of Hope takes place this Sunday from 12:30pm to 4:30pm at the Glenwood Community Centre. There’s tons of activities for the family, or if you can’t stick around, they’ll gladly accept any donations.

SOURCE: www.globalwinnipeg.com

MU researchers get to the ‘heart’ of SMA therapy

COLUMBIA — New developments in Spinal Muscular Atrophy research at MU are pointing toward big changes in treatment.

Spinal Muscular Atrophy is a genetic disorder that affects between 2.5 and 3.3 percent of people, according to an MU news release. According to the Spinal Muscular Atrophy Foundation, people affected by the disorder are missing a gene that produces SMN-1, a protein necessary for healthy motor neurons. Motor neurons send the signal to muscles that make them move. When there is not enough SMN-1 in the body, the neurons die, leading to loss of mobility.

Christian Lorson is a professor of veterinary pathobiology and molecular microbiology and immunology at MU. Working with a team of scientists, he has found that the disorder affects the heart and neurons separately.

Research on animals has shown that, even as embryos, mice with Spinal Muscular Atrophy can show heart defects before neuron damage, said Monir Shababi, the research scientist heading the project. This discovery shook the foundation of the treatment knowledge base.

“[Clinicians] always thought the heart failure was a consequence of neurodegeneration, which is known as the major defect in SMA patients,” Shababi said of the heart defects.

This research would suggest that heart failure is a direct result of the disorder, rather than a link in the chain of events.

“If you have a genetic defect, it’s something that happened before conception,” said Jennifer Kussmann, a genetic counselor at MU. “So we can’t go back in time and rebuild the muscle.”

However, the knowledge of a heart defect in a person with Spinal Muscular Atrophy would allow clinicians to treat defects before they become life-threatening, Shababi said.

“As soon as the patient is diagnosed with SMA, [clinicians] will look at the heart and possibly give some medication to delay the heart failure,” Shababi said. “It just creates an awareness that something is going wrong with the heart.”

This awareness could encourage a change in treatment of the disorder.

“With new, SMA-specific therapeutics on the horizon, it will be important to address the entire disease, such as motor neurons and cardiac issues,” Lorson said.

People with Spinal Muscular Atrophy also have the option of replacing that missing gene — a process that has worked with animal models. However, researchers realize the experiments are not conclusive enough to guarantee success in humans.

“Models of disease are just that – they’re models and therefore only present part of the human condition,” Lorson said. When working with Spinal Muscular Atrophy in animals, “you’re doing a new experiment, you’re not verifying the animal results,” he said.

Replacing the SMN protein like a supplement is also an option, but it’s challenging because it requires crossing the blood-brain barrier, which is the body’s natural defense of the central nervous system, Lorson said.

Lorson and his team’s discovery is not a cure, but a step toward better treatment and better quality of life for people living with the disorder, he said.

SOURCE: http://www.columbiamissourian.com

Researchers Discover Key Gene for Making Motor Neurons

Cross section of the mouse spinal cord, showing that the FoxP1 protein (red) marks the nuclei of motor neurons that innervate limb muscles.

Cross section of the mouse spinal cord, showing that the FoxP1 protein (red) marks the nuclei of motor neurons that innervate limb muscles. These neurons also express a retinoid synthetic enzyme RALDH2 (green) which is controlled by FoxP1 and directs later aspects of motor neuron development. Expression of FoxP1 in these neurons is essential for the activity of Hox proteins that control motor neuron diversity.

Simple, everyday movements require the coordination of dozens of muscles, guided by the activity of hundreds of motor neurons. Now, researchers have revealed an important step in the process that guides the early development of neurons themselves, as they establish the precise connections between the spinal cord and muscles. This knowledge will help scientists search for drugs to treat diseases that destroy motor neurons, such as amyotrophic lateral sclerosis, or Lou Gehrig’s disease.

As a vertebrate organism develops, the long, outstretched processes of motor neurons wend their way from the spinal column to wire up every muscle in the body. In mammals, many hundreds of different types of motor neurons are needed to control the variety of muscle types used to coordinate movement. The highly specialized motor neurons that innervate muscles in the arms, legs, hands, and feet are the most recent of these to evolve. As an animal develops, these neurons become increasingly specialized – first establishing themselves as motor neurons, then taking on the characteristics needed to control a limb, then preparing to target a specific muscle. Proper function depends on each of these neurons finding its way from the spinal cord to the group of muscle cells that it is equipped to control.

Now, Howard Hughes Medical Institute investigator Thomas M. Jessell, working together with Jeremy Dasen of New York University and Philip Tucker of The University of Texas at Austin, has discovered the genetic recipe for making these specialized motor neurons. The key ingredient is a gene called Foxp1, which regulates the activity of a series of crucial patterning genes of the Hox family, and thereby coordinates the identity and connectivity of motor neurons. Without FoxP1, the axons of motor neurons that extend into an animal’s limb wander aimlessly and connect to muscles at random, Jessell and Dasen have found. The paper describing these findings is published in the July 25, 2008, issue of the journal Cell.

The Hox genes are among the most highly conserved of the developmental genes and are best known for their role in controlling the overall pattern of body development. Like many developmental regulators, the proteins produced by Hox genes control the activity of a diverse assortment of target genes. In previous work, Jessell, who is at Columbia University Medical Center, and Dasen discovered that 21 of the 39 mammalian Hox genes orchestrate the program of motor neuron development and connectivity. Their new work shows that FoxP1 is an essential co-factor for the entire set of Hox proteins that generate the motor neurons that control limb movement. Intriguingly, the level of FoxP1 expressed by developing motor neurons determines the precise subtype that they will form.

“This paper makes the surprising discovery that one accessory co-factor, FoxP1, is needed for the output of each of the 21 Hox proteins that make motor neurons different,” says Jessell. “Depending on which Hox gene is turned on, FoxP1 is induced to different levels. And this difference in level programs which motor neuron subtype is generated. It is a complicated but satisfying genetic logic, one that appears to have evolved to ensure the generation of the diverse array of motor neuron subtypes needed for fine motor control of the limbs.”

To emphasize the importance of this highly-evolved class of motor neurons, Jessell points to a relatively primitive vertebrate, the eel-like jawless fish known as a lamprey. “Lampreys don’t play the violin and they don’t run – their motor programs are designed for simple swimming behaviors,” Jessell says. “The lamprey represents the most extreme example of vertebrate organisms whose lifestyle permits them to survive with a highly reduced array of motor neuron subtypes.

“At some point in evolution, vertebrates acquired the ability to generate hundreds of motor neuron subtypes, presumably to accommodate the appearance of limbs new muscle classes,” says Jessell. He and his colleagues suspect this diversity may have arisen when FoxP1 began to be expressed in the spinal cord But exactly when FoxP1 expression first appeared in the spinal cord and how its expression is linked to Hox activities remain unsolved puzzles that Jessell and Dasen are now pursuing. Together with Sten Grillner of the Karolinska Institute and Manuel Pombal of the University of Vigo in Spain, they are beginning these studies by analyzing the expression and function of the FoxP1 gene in lampreys.

Jessell, Dasen, and Tucker demonstrated the significance of FoxP1 in mice by inactivating the gene and showing that the spinal cord lacked the full repertoire of motor neurons without it. “This mutation, in effect, reverts the spinal cord to a primitive ancestral state, generating a lamprey-like spinal cord encased in a mammalian body,” Jessell says. Mice without FoxP1 die before birth because the gene is also critical for heart development, so the scientists are now analyzing genetically-modified mice in which FoxP1 is deleted selectively from motor neurons. “We anticipate that these animals will have a severe impairment in motor behavior, and studying later phases of FoxP1 function should reveal insights into the assembly of motor circuits in the spinal cord as well as the periphery” he says.

Jessell’s Columbia colleagues Hynek Wichterle and Mirza Peljto, in work supported by ProjectALS, are already using the Fox-Hox recipe in their attempts to create better ways of screening for drugs to treat Lou Gehrig’s disease and other types of motor neuron degeneration. Fine-tuning the expression of the these proteins has recently permitted Wichterle and Peltjo to convert embryonic stem cells into the highly-specialized motor neurons that innervate limb muscles.

“This is a promising screening strategy for identifying drugs that prevent or slow the degeneration of motor neurons,” says Jessell. “Hopefully, many researchers will build upon these advances in basic motor neuron biology to design better and more predictive therapeutic screens.”

Posted on August 26, 2010 at 6:15 am by Jumaana Syed Ali · Permalink · Leave a comment
In: SMA Research News · Tagged with: , , ,

New stem cell frontier: treating dying babies

The newest treatment using human embryonic stem cells targets one of the most tragic groups of patients: babies with a severe genetic disorder that kills them in their first year of life.

Hans Keirstead, a UC Irvine researcher whose treatment for acute spinal cord injuries will become the world’s first clinical trial using human embryonic stem cells, says he is nearly ready with what could become the world’s second.

“I have a really good feeling about it,” he said. “It’s going to be a heck of a trial.”

If approved by the Food and Drug Administration, the treatment could ease the suffering — and perhaps one day extend the lives — of infants with type one spinal muscular atrophy, a degenerative disorder similar to Lou Gehrig’s disease.

The infants have trouble breathing and swallowing, and cannot sit without support.

“It manifests at one to three months of age,” Keirstead said. “Most of the babies are dead in their first year. It’s the number one genetic killer of infants.”

Keirstead, who is developing the treatment and safety protocols with the California Stem Cell Inc. in Irvine, said he will apply to the FDA in the next few weeks to begin clinical trials of his treatment method.

But Keirstead said his treatment for acute spinal cord injuries, which will soon be used in Geron Corp.’s first-ever clinical trial, is simple compared to treating spinal muscular atrophy.

The treatment involves injecting motor neurons grown from stem cells into the spinal cords of infants.

The first patients to receive the motor neurons, however, will be the most severely afflicted, as is typically required by the FDA.

“These babies we’re going to put them into are dying babies,” Keristead said. “The first few patients are expected to die.”

Later groups of infants with the disorder treated with Keirstead’s method could see an easing of suffering in their short lives, and perhaps improved function of their limbs and organs.

“We expect it is going to improve the quality of the lives of patients when alive,” he said. “We don’t know that, we’re not claiming it, but we’re excited about it.”

And Keirstead said working out clinical trial procedures and methods is getting faster and cheaper.

Preparing the Geron Corp. trial took eight years and $45 million, he said. The new trial will likely cost $3 million to $5 million, and took only three years.

Keirstead sees this is a pioneering era for human embryonic stem cells, with researchers around the world staking their claims to various forms of treatment, while technology and medical techniques blossom.

Human embryonic stem cells can potentially become any type of cell in the body.

“Clearly, they have the potential to treat every disorder,” he said. “This is the beginning. We are going to look back at this as history-changing times.”

But because the stem cells are derived from human embryos they provoke controversy, even though the early-stage embryos used in the research are otherwise destined to be discarded by fertility clinics.

“This tissue would be destroyed anyway,” he said.

Stem-cell research was dealt a severe setback this week by a federal judge in Washington, D.C., who overturned the Obama administration’s expansion of the research in 2009.

The judge said the president could not override a 1996 law barring funding for such research.

It will likely mean a suspension of tens of millions of dollars in research funding for stem cells from the National Institutes of Health, though the Obama administration vowed to appeal the ruling.

The ruling will have little effect on the work of Keirstead and other researchers at UCI, whose main sources of funding are the state’s $3 billion stem-cell research initiative and private donations.

Both the Geron Corp. clinical trial and the trial Keirstead hopes to begin with the dying infants will be privately funded.

Still, the ruling is expected to have a chilling effect on stem-cell research across the nation.

SOURCE: http://www.ocregister.com

FightSMA Launches Gene Therapy Fundraising Campaign: ‘Realizing the Dream’

Fight SMA and Gwendolyn Strong Foundation partner on effort to raise money for spinal muscular atrophy gene therapy.

RICHMOND, VA – Richmond-based Fight SMA announced today a new fundraising campaign for SMA gene therapy, ‘Realizing the Dream.’ FightSMA is collaborating with the Santa Barbara, California-based Gwendolyn Strong Foundation, to form a bi-coastal partnership with a common goal: to bring spinal muscular atrophy (SMA) gene therapy to clinical trial.

“Ten years ago, it would have been unheard of to say scientists were approaching a treatment or cure for spinal muscular atrophy,” said FightSMA President Martha Slay. “Today, the dream is being realized in some of the most prestigious labs across the country. Never before has there been such promise for SMA gene therapy.”

Beginning now and for the next three years, families and groups in the SMA community will raise funds to build a safe foundation, deliver genes to an SMA model, and produce adequate vector (gene delivery) supply. These efforts will support Dr. Brian Kaspar of Nationwide Children’s Hospital and The Ohio State University and other collaborating scientists.

FightSMA, working with the Gwendolyn Strong Foundation, a funding source for critical SMA science and awareness initiatives, invites the SMA community to make a decade-old dream come true. “Our SMA gene therapy program at Nationwide Children’s Hospital and the Ohio State University continues to show great promise for treating SMA patients,” said Dr. Kaspar.

FightSMA’s objective for the balance of 2010 is to complete funding for Phase One, and for Year-One of Phase-Two of the research program.

“The first objective is to build a solid foundation of safety and to eliminate toxicity,” said Dr. Chris Lorson, FightSMA Science Director.”

Additionally, FightSMA plans to raise another $250,000 to fund the first year of Phase Two (Delivery & Efficacy). The ‘Realizing the Dream’ program will be accomplished through a series of campaigns. Completing these two Phases will bring SMA gene therapy significantly closer to clinical trial.

FightSMA has been instrumental in helping to develop a gene therapy strategy to cure spinal muscular atrophy (SMA), including oligonucleotides and gene replacement vectors. The strides that SMA researchers have made in the gene therapy arena have provided insights into a range of genetic disorders, including other neurodegenerative disease (ALS/Lou Gehrig’s disease, myotonic dystrophy, Huntington disease) and other diseases such as Duchenne muscular dystrophy.
For more information on the FightSMA – Gwendolyn Strong Foundation partnership and ‘Realizing the Dream’ campaign, visit www.fighsma.org or call 804-515-0080.

FightSMA was created to strategically accelerate the search for a treatment and cure for spinal muscular atrophy (SMA), the number-one inherited cause of infant death. The organization pursues this objective by raising awareness and funding for SMA research.

Steve Mullen
(804) 372-7677
steve@endgamepr.com

http://www.fightsma.org

SOURCE: http://news.topwirenews.com

Posted on August 22, 2010 at 10:55 am by Jumaana Syed Ali · Permalink · Leave a comment
In: SMA Fund News, USA · Tagged with: , , , , ,

CSHL researchers demonstrate efficacy of antisense therapy for spinal muscular atrophy

The devastating, currently incurable motor-neurone disease spinal muscular atrophy (SMA) might soon be treated with tiny, chemically modified pieces of RNA called antisense oligonucleotides (ASOs).

Scientists at Cold Spring Harbor Laboratory (CSHL) and California-based Isis Pharmaceuticals have succeeded in reversing symptoms of Type III SMA, a relatively mild form of the disease, in mice by introducing an ASO into their spinal cords. The ASO fixes the molecular mistake underlying SMA by redirecting a cellular editing process called alternative splicing.

‘Validating ASO efficacy in animal models is a crucial pre-clinical step before this strategy can be applied in SMA patients,’ says CSHL Professor Adrian Krainer, Ph.D. ‘We have now successfully demonstrated this therapeutic efficacy in the mouse nervous system. Although the mice only have the mild symptoms of Type III SMA, our treatment can effectively correct them.’

Based in part on the team’s findings, which appear online ahead of print on July 12th in Genes and Development, Isis selected an antisense drug candidate to move forward in development to treat SMA.

‘SMA is the leading genetic cause of infant mortality and has limited treatment options for patients. With Dr Krainer’s lab at Cold Spring Harbor Laboratory, we have made significant progress in identifying a drug development candidate and conducting early preclinical studies to access its therapeutic potential,’ said Frank Bennett, Ph.D., Senior Vice President of Research at Isis Pharmaceuticals. ‘We are committed to advancing this program toward the clinic.’

SMA is caused by insufficient levels of a protein called Survival of Motor Neurone (SMN) in the spinal cord’s motor neurones, which waste away along with the muscles that they can no longer control. The SMN1 gene, which produces the SMN protein, is missing or mutated beyond repair in SMA patients. Humans have a second SMN-producing gene called SMN2, but this gene is a poor backup, as it produces very little functional SMN protein. This deficiency stems from a mistake that occurs during splicing, a molecular editing process that kicks in after the gene’s DNA has been copied into RNA.

Normally, newly copied RNA molecules are edited, or spliced, to produce a functional blueprint for protein production. Cellular machinery that includes splicing enzymes cuts out unnecessary bits of RNA called introns and splice together the remaining essential bits called exons. In the case of the SMN2 gene, however, the splicing complex mistakenly skips an exon.

‘Coaxing a patient’s cells into efficiently including this exon, instead of skipping it, is expected to decrease the severity of SMA symptoms,’ explains Krainer. ‘Our strategy to enhance exon inclusion was to disrupt or mask ‘splicing silencers’ – regions of RNA in or around the exon that impair its recognition by the cell’s splicing machinery, and thereby promote its skipping.’

Several years ago, Krainer’s team and their collaborators at Isis designed and tested synthetic molecules, the ASOs, which can be programmed to bind to any piece of RNA according to this target RNA’s sequence of nucleotides or ‘letters’ of its genetic code. By comparing hundreds of ASOs that targeted various regions in or near the skipped exon in the SMN2 RNA, the team zeroed in on one ASO that optimally enhanced exon inclusion and production of functional SMN protein.

‘We first showed that this ASO corrected SMN2 splicing in the test tube, and in patients’ cells grown in the lab,’ says CSHL Research Investigator Yimin Hua, Ph.D., who spearheaded this work in Krainer’s lab. In 2008, the team injected these ASO molecules into the bloodstream of mice engineered to carry a human SMN2 gene that display symptoms of type III SMA. This regimen corrected SMN2 splicing in the animals’ liver and kidneys but not in spinal cord neurones – where they are most needed – because the ASOs failed to breach the blood-brain barrier and enter the spinal cord.

The collaborators have now overcome this limitation by directly delivering ASOs into the animals’ central nervous system, a common route of administration for other drugs such as chemotherapy agents. Infusing ASOs into the fluid that surrounds the brain and spinal cord resulted in a robust increase in the levels of SMN protein in individual motor neurones throughout the spinal cord of type III SMA mice.

‘This effect persisted for half a year after the treatment ended, indicating that the ASO is extremely stable,’ explains Krainer. ‘And equally importantly, none of the ASO doses tested triggered toxicity or inflammation in any of the mice tested.’

Mice with type III SMA typically develop necrosis – the death of cells and destruction of tissue – in adulthood. Although they do not display muscle weakness, these animals begin to lose their tail and ears 3-4 weeks after they are born, with complete loss occurring within a few more weeks. To test the ability of the ASOs to prevent these symptoms, which resemble clinical features observed in some infants with the more severe type I SMA, the team treated neonatal mice or 15-day-old mouse embryos with a single ASO injection.

This treatment prevented both tail and ear necrosis in the neonates and embryos, which developed into adults with normal tails and ears. The researchers suggest that supplying the therapeutic ASO to the animals’ central nervous system, which restored cellular SMN protein levels, might in turn prevent neuronal deterioration, muscle wasting, and vascular problems in the tail and ears.

SOURCE: http://www.sciencecentric.com

Posted on August 22, 2010 at 10:52 am by Jumaana Syed Ali · Permalink · Leave a comment
In: SMA Research News · Tagged with: , , , , , ,
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