Penn researchers report that gene therapy awakens the brain despite blindness from birthJune 26, 2007Philadelphia -- Researchers at the University of Pennsylvania have demonstrated that gene therapy used to restore retinal activity to the blind also restores function to the brain's visual center, a critical component of seeing. The multi-institutional study led by Geoffrey K. Aguirre, assistant professor of neurology in Penn's School of Medicine, shows that gene therapy can improve retinal, visual-pathway and visual-cortex responses in animals born blind and has the potential to do the same in humans. "The retina of the eye captures light, but the brain is where vision is experienced," Aguirre said. "The traditional view is that blindness in infancy permanently alters the structure and function of the brain, leaving it unable to process visual information if sight is restored. We've now challenged that view." The results support the potential for human benefit from retinal therapies aimed at restoring vision to those with genetic retinal disease. Researchers used functional MRI to measure brain activity in blind dogs born with a mutation in gene RPE65, an essential molecule in the retinoid-visual cycle. The same mutation causes a blindness in humans called Leber congenital amaurosis, or LCA. It is the first human eye-retinal disorder slated for gene therapy. Gene therapy, performed by introducing a working copy of RPE65 into the retina, restored eye function in canines. Yet, it was previously unclear if the brain could "receive" the restored sight. The team found that gene therapy to the eye dramatically increased responses to light within the visual cortex of the canine brain. The recovery of visual brain function occurred in a canine that had been blind for the first four years of its life, and recovery was found to persist in another dog for at least two-and-a-half years after therapy, suggesting a level of permanence to the treatment. Penn scientists then studied the structure and function of the visual brain of human patients with the same form of blindness. Young adults with blindness from RPE65 mutation had intact visual brain pathways with nearly normal structure. The Penn team also found that, while the visual cortex of these patients with LCA did not respond to dim lights, the brain's reaction to brighter lights was comparable to that of individuals with normal sight. "It seems these patients have the necessary brain pathways ready to go if their eyes start working again," Aguirre said. The results of the current study are critical to these human clinical trials, led at Penn's Scheie Eye Institute by Samuel G. Jacobson, professor of ophthalmology, and Artur V. Cideciyan, research associate professor of ophthalmology. "Existence of functional potential both in the eye and brain are prerequisites for successful gene therapy in all forms of LCA," Cideciyan said. "In the RPE65 form of the disease, we now have evidence for both, and treatment at the retinal level has the hope of recovery of useful vision in patients." University of Pennsylvania |
|||||||||||||||||||||
| Related Gene Therapy Current Events and Gene Therapy News Articles Research reveals lipids' unexpected role in triggering death of brain cells The lipid that accumulates in brain cells of individuals with an inherited enzyme disorder also drives the cell death that is a hallmark of the disease, according to new research led by St. Jude Children's Research Hospital investigators. No-entry zones for AIDS virus The AIDS virus inserts its genetic material into the genome of the infected cell. Scientists of the German Cancer Research Center have now shown for the first time that the virus almost entirely spares particular sites in the human genetic material in this process. This finding may be useful for developing new, specific AIDS drugs. Cornell researchers identify a weak link in cancer cell armor The seeming invincibility of cancerous tumors may be crumbling, thanks to a promising new gene therapy that eliminates the ability of certain cells to repair themselves. Treatment to improve degenerating muscle gains strength A study appearing in Science Translational Medicine puts scientists one step closer to clinical trials to test a gene delivery strategy to improve muscle mass and function in patients with certain degenerative muscle disorders. Iowa State University researcher discovers key to vital DNA, protein interaction A researcher at Iowa State University has discovered how a group of proteins from plant pathogenic bacteria interact with DNA in the plant cell, opening up the possibility for what the scientist calls a "cascade of advances." Scientists successfully reprogram blood cells Researchers have transplanted genetically modified hematopoietic stem cells into mice so that their developing red blood cells produce a critical lysosomal enzyme -preventing or reducing organ and central nervous system damage from the often-fatal genetic disorder Hurler's syndrome. Immune therapy can protect against or treat later lymphoma Specially developed immune system cells that target the common Epstein-Barr virus can protect immune-suppressed bone marrow transplant recipients against lymph system disease and cancers that arise from the viral infection. Caltech researchers show efficacy of gene therapy in mouse models of Huntington's disease Researchers at the California Institute of Technology (Caltech) have shown that a highly specific intrabody (an antibody fragment that works against a target inside a cell) is capable of stalling the development of Huntington's disease in a variety of mouse models. Immunotherapy demonstrates long-term success in treating lymphoma Targeted immunotherapy has been an attractive new therapeutic area for a number of cancers because it has the potential to destroy tumor cells without damaging surrounding normal tissue. New study results demonstrate high success rates using specialized white blood cells to prevent or treat lymphoma associated with the Epstein-Barr virus (EBV-lymphoma) in patients who have received a hematopoietic stem cell transplant (HSCT). Toward bold new anti-cancer medicines Bold new strategies in the battle against cancer may turn forms of the disease that presently are incurable into manageable conditions that can be controlled for long periods of time. More Gene Therapy Current Events and Gene Therapy News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||