A lone genetic mutation can cause a life-changing disorder with effects on multiple body systems. Lysosomal storage diseases, for example, of which there are dozens, arise due to single mutations that affect production of critical enzymes required to metabolize large molecules in cells. These disorders affect multiple organs including, notably, the brain, causing intellectual disability of varying degrees.Gene therapy holds promise to address these conditions, but the brains own protective mechanism the blood-brain barrier has been a formidable challenge for researchers working to develop one.
In a new study published in the journal Brain, a team led by John H. Wolfe, a researcher with Penns School of Veterinary Medicine and Perelman School of Medicine and the Childrens Hospital of Philadelphia, successfully applied a gene therapy platform to completely correct brain defects in a large animal model of a human genetic disease.
This is the first example of a large-brain mammal with a bona fide human genetic disease that has intellectual disability as part of the human syndrome where weve been able to correct the biochemistry and pathologic lesions in the whole brain, says Wolfe.
Wolfe has worked on models of human genetic diseases that impact the brain for many years. With gene therapy, a delivery vehicle typically a viral vector is used to provide the normal version of a mutated gene to correct a condition. Wolfe and other scientists working in this area have made steady progress to treat neurogenetic diseases in rodents. However, applying the same treatment to the much larger brain of higher mammals has only been able to produce partial corrections.
Theres been a lot of excitement for the last 10 years or so that specific vectors can be injected into the blood and enter the brain, says Wolfe. They do cross the blood-brain barrier. One such treatment with restricted distribution has been effective in treating a disease that primarily affects the spinal cord.
And while scientists have shown these therapies can reverse the pathology throughout the brains of mice, its been hard to judge what effect it would have in patients, as the rodent brains have a much smaller cerebral cortex than larger mammals, like humans.
In the current study, the team used an animal model with a brain more similar to humans, cats, to assess the effectiveness of a gene-correcting therapy for one type of lysosomal storage disease: a condition called alpha-mannosidosis, which naturally occurs in cats and results from a mutated copy of the alpha-mannosidase gene.
Having refined the gene delivery technique during many years of work, the researchers selected a specific vector that they showed, in mice, was capable of crossing the blood-brain barrier to reach sites throughout the brain.
They next delivered the vector, containing a reporter gene, to normal cats. Several weeks later, they were able to find evidence that the corrected gene had distributed to various parts of the brain, including the cerebral cortex, hippocampus, and mid-brain.
Finally the research team assessed the therapy in cats with alpha-mannosidosis, using either a low or high dose of the vector. They injected the therapy into the carotid artery, so that it would go directly to the brain before traveling to other parts of the body. Compared to untreated cats, treated animals had a significant delayed onset of certain neurological symptoms and a longer lifespan; those that received the higher dose of the vector delivered through the carotid artery lived the longest.
Its a big advance, says Wolfe. Nobody has been able to treat the whole brain of a large-brained animal before. Were hopeful that this will translate into clinical use in humans.
Wolfe cautions, however, the findings dont amount to a cure.
These were significant improvements, but they were only just improvements on a serious condition, Wolfe says. The cats werent cured, and we dont know what impact this has on mental ability. However, since the pathology is found throughout the brain, it is thought that complete correction will be necessary.
As alpha-mannosidosis is a childhood-onset disease with no cure, however, any improvements that lessen the severity of symptoms are welcome. The approach the researchers developed may potentially be employed to treat many other diseases that affect the whole central nervous system.
In future work, Wolfe and his collaborators hope to refine their methods to achieve the same outcomes with a lower dose, making an effective treatment safer as well as more affordable. And they will continue to work to understand the details of why their treatment works, including precisely how the vector travels through the brain, a line of investigation that could shed light on additional strategies to address these serious disorders.
This article has been republished from the following materials. Note: material may have been edited for length and content. For further information, please contact the cited source.
Link:
Gene Therapy Beats the Blood-Brain Barrier To Cure Cat Disease - Technology Networks
- About the Gene Therapy Review - November 8th, 2009 [November 8th, 2009]
- Contribute an Article - November 8th, 2009 [November 8th, 2009]
- EBSCO Publishing Deal - November 8th, 2009 [November 8th, 2009]
- Advertising Opportunities - November 8th, 2009 [November 8th, 2009]
- Instructions for Authors - November 8th, 2009 [November 8th, 2009]
- Isis Collaboration With Ortho-McNeil Inc for Metabolic Diseases - November 8th, 2009 [November 8th, 2009]
- Dystrophin Gene Transfer safe in Duchenne muscular dystrophy - November 8th, 2009 [November 8th, 2009]
- Researchers Identify Gene for Rare Form of Spinal Muscular Atrophy - November 8th, 2009 [November 8th, 2009]
- Fatal brain cancer tamed by New gene therapy - November 8th, 2009 [November 8th, 2009]
- Gene therapy effective in fighting obesity in mice - November 8th, 2009 [November 8th, 2009]
- Genzyme gene therapy for people with peripheral artery disease failed in a clinical trial to help them regain some mobility - November 8th, 2009 [November 8th, 2009]
- Gene Therapy May Stall Inherited Emphysema - December 31st, 2009 [December 31st, 2009]
- Gene Therapy and Stem Cells Save Limb - December 31st, 2009 [December 31st, 2009]
- TNVitamins.com – $10 Off Of $50 order - May 7th, 2011 [May 7th, 2011]
- 15% Off Any PetAlive Order - May 7th, 2011 [May 7th, 2011]
- At PetAlive – $10 off order of $50 or more - May 7th, 2011 [May 7th, 2011]
- Native Remedies coupon – 5% Off Any Order - May 7th, 2011 [May 7th, 2011]
- Native Remedies – Save $5 coupon - May 7th, 2011 [May 7th, 2011]
- Welcome to the Gene Therapy Review - May 15th, 2011 [May 15th, 2011]
- Editorial Board - May 15th, 2011 [May 15th, 2011]
- Gene Therapy Job Board - May 15th, 2011 [May 15th, 2011]
- Corporate Membership - May 22nd, 2011 [May 22nd, 2011]
- Native Remedies coupon – 25% Off Any Order - May 29th, 2011 [May 29th, 2011]
- What is Gene Therapy? - June 19th, 2011 [June 19th, 2011]
- Research and Markets: Recent Advances in Cancer Research and Therapy - Increased Research on one of the Major Causes ... - April 25th, 2012 [April 25th, 2012]
- Gene Therapy part 2 - Video - April 30th, 2012 [April 30th, 2012]
- Gene therapy reverses Parkinson's symptoms: study - Video - April 30th, 2012 [April 30th, 2012]
- CBS This Morning - Gene therapy reverses Parkinson's symptoms: study - Video - April 30th, 2012 [April 30th, 2012]
- Engineering adenoviruses for gene therapy - Video - April 30th, 2012 [April 30th, 2012]
- What is Gene Therapy (The General Explains) - Video - April 30th, 2012 [April 30th, 2012]
- What is Gene Therapy - Animation - Video - April 30th, 2012 [April 30th, 2012]
- Microbiology Gene Therapy - Video - April 30th, 2012 [April 30th, 2012]
- Gene Therapy in Detail - Video - April 30th, 2012 [April 30th, 2012]
- Breakthrough in Haemophilia treatment - Video - April 30th, 2012 [April 30th, 2012]
- Virology Seminar - Gene Therapy - April 30th, 2012 [April 30th, 2012]
- Gene Therapy Video - Video - April 30th, 2012 [April 30th, 2012]
- Study: Gene Therapy for HIV Safe, But Effectiveness Still Unclear - May 4th, 2012 [May 4th, 2012]
- Gene Therapy Safe in Decade-Long HIV Study That May Widen Use - May 4th, 2012 [May 4th, 2012]
- Gene therapy for HIV safe, but effectiveness still unclear - May 4th, 2012 [May 4th, 2012]
- A Step Forward For Gene Therapy To Treat HIV - May 4th, 2012 [May 4th, 2012]
- A Media Event on Clinical Developments in Gene and Cell Therapy - May 4th, 2012 [May 4th, 2012]
- Families of SMA Awards New Funding to Advance a CNS Delivered Gene Therapy for Spinal Muscular Atrophy - May 4th, 2012 [May 4th, 2012]
- AIDS gene therapy safe -- is it a "cure"? - May 4th, 2012 [May 4th, 2012]
- Generational Achievements in Gene and Cell Therapy Honored at ASGCT 15th Annual Meeting - May 5th, 2012 [May 5th, 2012]
- Lewis speaks on gene therapy at Lexington Community Education event - May 7th, 2012 [May 7th, 2012]
- Penn researchers report a gene-therapy success - May 10th, 2012 [May 10th, 2012]
- Gene therapy for hearing loss: Potential and limitations - May 13th, 2012 [May 13th, 2012]
- Gene therapy extends mouse lifespan by 24 pc - May 16th, 2012 [May 16th, 2012]
- Gene therapy dramatically extends mouse lifespan - May 16th, 2012 [May 16th, 2012]
- Gene therapy may extend life: Study - May 16th, 2012 [May 16th, 2012]
- First gene therapy successful against aging-associated decline: Mouse lifespan extended up to 24% with a single ... - May 16th, 2012 [May 16th, 2012]
- Gene Therapy Extends Mouse Lifespan - May 16th, 2012 [May 16th, 2012]
- Gene Therapy for Brain Disease - May 17th, 2012 [May 17th, 2012]
- Children with rare, incurable brain disease improve after gene therapy - May 17th, 2012 [May 17th, 2012]
- FIRST Anti-Aging Gene Therapy (Brainstorm Ep72) - Video - May 23rd, 2012 [May 23rd, 2012]
- Gene therapy can correct forms of severe combined immunodeficiency - May 25th, 2012 [May 25th, 2012]
- RetroSense Therapeutics Completes pre-IND Meeting for RST-001 - May 25th, 2012 [May 25th, 2012]
- Gene therapy can correct forms of severe combined immunodeficiency, study suggests - May 26th, 2012 [May 26th, 2012]
- Alliance for Cancer Gene Therapy celebrates 10 years - May 29th, 2012 [May 29th, 2012]
- Research on gene therapy by Prasad Eye - June 1st, 2012 [June 1st, 2012]
- Baxter Announces Collaboration with Chatham Therapeutics for Factor IX Hemophilia B Gene Therapy Treatment - June 5th, 2012 [June 5th, 2012]
- Transgenomic Launches Breakthrough Blood-Based Cancer Gene Testing Technology at 2012 ASCO Annual Meeting - June 5th, 2012 [June 5th, 2012]
- Baxter Inks Deal with Chatham - June 6th, 2012 [June 6th, 2012]
- PIK3CA Gene Patent for Predicting Response to Targeted Therapy Issued – Exclusively Licensed to Transgenomic - June 11th, 2012 [June 11th, 2012]
- SalutarisMD Announces Positive Case Report of a New Investigational Wet AMD Therapy at ARVO - June 15th, 2012 [June 15th, 2012]
- Research and Markets: Gene Therapy - Global Strategic Business Report - 2012 - June 15th, 2012 [June 15th, 2012]
- New York Law Firm’s MesotheliomaHelp.net Site Publishes Interview with Gene Therapy Author - June 17th, 2012 [June 17th, 2012]
- uniQure Extends Collaboration with Protein Sciences Corporation on Use of its expresSF+® Cell Line for Gene Therapy - June 19th, 2012 [June 19th, 2012]
- Anti-cocaine vaccine described in Human Gene Therapy Journal - June 19th, 2012 [June 19th, 2012]
- bluebird bio Receives U.S. and European Orphan Drug Designation for Novel Gene Therapy to Treat Adrenoleukodystrophy - June 19th, 2012 [June 19th, 2012]
- Close to a cure: Greater Hartford takes on rare Jewish genetic disease - June 19th, 2012 [June 19th, 2012]
- Gene Therapy Helps Treat Children with Rare Brain Disorder - June 20th, 2012 [June 20th, 2012]
- Gold nanoparticles capable of 'unzipping' DNA - June 21st, 2012 [June 21st, 2012]
- ‘Gene-silencing’ drug can halt and reverse deadly brain disorder - June 21st, 2012 [June 21st, 2012]
- uniQure Collaborates with UCSF on GDNF Gene Therapy in Parkinson's Disease - June 22nd, 2012 [June 22nd, 2012]
- Gene-silencing method offers possible therapy for Huntington's disease - June 22nd, 2012 [June 22nd, 2012]
- Gene mutations cause massive brain asymmetry - June 24th, 2012 [June 24th, 2012]
- Research and Markets: Translational Regenerative Medicine - Oncology, CNS and Cardiovascular-Rich Pipeline Features ... - June 25th, 2012 [June 25th, 2012]
- Stress Blocks Gene That Guards Brain Against Depression - June 26th, 2012 [June 26th, 2012]
- Targeted gene therapy enhances treatment for Pompe disease - June 26th, 2012 [June 26th, 2012]