Usher Syndrome Blog and News
The latest USH blog posts and various news items impacting the Usher syndrome community. Join our mailing list.
Cedars-Sinai, a non-profit healthcare organization based in Los Angeles, has received authorization from the FDA to launch a 16-person, Phase 1/2a clinical trial of human neural progenitor cells—stem cells that have almost developed into neural cells—for patients with retinitis pigmentosa (RP). The trial will be launched after investigators receive the final institutional review of the study protocol. The trial is being funded by a $10.5 million grant from the California Institute for Regenerative Medicine. The initial study was conducted by Dr. Shaomei Wang, MD, PhD, a professor of Biomedical Sciences and a research scientist in the Eye Program at the Board of Governors Regenerative Medicine Institute. He showed that human neural progenitor cells have the potential to treat RP. The clinical trial will be directed by Dr. Clive Svendsen, PhD, professor of Biomedical Sciences and Medicine and director the Cedars-Sinai Board of Governors Regenerative Medicine Institute. Dr. David Lao, MD, from Retina-Vitreous Associates Medical Group in Beverly Hill, will be responsible for the subretinal injection of the cells into patients. The ultimate goal of this therapy is to restore the vision by replacing the defective photoreceptors.
What this means for Usher syndrome: This means that more potential stem-cell based treatments are becoming available to treat Usher patients. Since photoreceptors are the main cell group affected in Usher syndrome, the possibility of successfully replacing them with healthy cells give hope to patients that are losing their sight. Still we need to be careful and wait for the results of this new clinical trial.
This study used the highly sensitive RNAscope in situ hybridization assay and single-cell RNA-sequencing techniques to investigate the distribution of Clrn1 and CLRN1 in mouse and human retina respectively. The pattern of Clrn1 mRNA cellular expression is similar in both mouse and adult human retina, with CLRN1 transcription being localized in Müller glia and photoreceptors. The study generated a novel knock-in mouse with a hemagglutinin (HA) epitope-tagged CLRN1 and showed that CLRN1 is expressed continuously at the protein level in the retina. Following enzymatic de-glycosylation and immunoblotting analysis, scientists detected a single CLRN1-specific protein band in homogenates of mouse and human retina, consistent in size with the main CLRN1 isoform. Taken together, their results implicate Müller glia in USH3 pathology, for future mechanistic and therapeutic studies to prevent vision loss in this disease.
What this means for Usher syndrome: As shown in previous studies of the USH1C protein in zebrafish, Müller glia, in addition to photoreceptors, may be involved in Usher syndrome.
Pamela Aasen, the proud parent of Ethan & Gavin who have Usher syndrome type 1b, reflects on her family's journey to overcome the challenges of Usher syndrome.
Megan Lengel, a recent college graduate and young adult with Usher syndrome, has offered to share with us her valuable experience attending college while dealing with Usher syndrome.
Usher Kids UK brings together families of children with Usher syndrome in the United Kingdom. Learn more about our USH Partner.
Hear See Hope has been funding Usher syndrome research for 15 years. Learn more about our USH Partner.
Usher 1F Collaborative's mission is to fund medical research to find a cure for the vision loss of Usher Syndrome type 1F. Learn more about our USH Partner.
Wake Forest Institute for Regenerative Medicine (WFIRM) scientists have fine-tuned their delivery system to send a DNA editing tool to alter DNA sequences and modify gene function. With this new method, researchers can package together the Cas9 protein and guide RNA for the CRISPR mediated gene editing. Previously, the two components—Cas9 protein and guide RNA—had to be delivered separately which was not as efficient. The new system offers the delivery efficiency of conventional lentiviral vectors that enable transient Cas9 expression. Transient Cas9 expression means a decrease chance of having unwanted effects when using this therapy.
What this means for Usher syndrome: For Usher patients, improving the efficacy of CRISPR technology means that they will be able to receive a more efficient treatment with very low side-effects.
Ava's Voice empowers youth with Usher syndrome. Learn more about our USH Partner.
Case Western Reserve University (CWRU) and Boston-based genetic medicine company Akouos have entered into an exclusive licensing agreement to develop a patented gene therapy that could potentially treat hearing loss associated with a type of Usher syndrome. It may be able to stop the progression of hearing loss and prevent deafness in people with USH3A. The hearing loss is “sensorineural,” meaning it is caused by abnormalities of the inner ear, while the vision is due to the degeneration of the retina at the back of the eye. The technology has allowed researchers to develop a more precise animal model of the hearing loss associated with Usher syndrome type 3A, and the potential for the technology to deliver the preservation of hearing and quality of life for children and adults diagnosed with the genetic disorder.
What this means for Usher syndrome: The development of a more precise animal model for USH3A will exponentially expedite the identification of novel and more efficient therapies to slow or complete stop the progression of this disease.
As part of the Human Cell Atlas Project, Australian scientists created the world’s most detailed gene map of the human retina. Dr. Wong says, “By creating a genetic map of the human retina, we can understand the factors that enable cells to keep functioning and contribute to healthy vision.” The map provides a detailed gene profile of individual retinal cell types that will help us study how those genes impact different kinds of cells. Scientists can have a clear benchmark to assess the quality of the cells derived from stem cells to determine whether they have the correct genetic code which will enable them to function.
What this means for Usher syndrome: By having this atlas of healthy cells and their interconnections, researchers will be able to predict the effect of different drugs to treat eye diseases, including Usher syndrome.
The birth control pill has been found to contain a compound which gives long-term protection against two degenerative eye diseases – glaucoma and retinitis pigmentosa (RP), according to recent research from University College Cork (UCC) scientists in Ireland. The eye protective compound was discovered during a search through all the compounds approved by the FDA for treatment of people with eye diseases. The UCC scientists have found that norgestrel in animal models can provide protection against some common degenerative diseases of the eye.
What this means for Usher syndrome: Based on this study, norgestrel therapy will be a good alternative approach for the prevention of photoreceptor cell death in Usher patients.
Researchers in Germany have recently developed a “retina-on-a-chip” which combines living human cells with an artificial tissue-like system. The scientists describe their work as “merging organoid and organ-on-a-chip technology to generate complex multi-layer tissue models in a human Retina-on-a-Chip platform.” Ophthalmologic drugs largely rely on animal models, which often do not provide results that are translatable to human patients. In this study, researchers present the retina-on-a-chip (RoC), a novel microphysiological model of the human retina integrating more than seven different essential retinal cell-types derived from human induced pluripotent stem cells (hiPSCs).
What this means for Usher syndrome: this model can be used to test hundreds of drugs for harmful effects on the “human” retina very quickly and enables scientists to take stem cells from a specific patient and study both the disease and potential treatment in the individual’s own cells.
CRISPR (clustered regularly interspaced palindromic repeats) is a cutting-edge genetic editing technique that enables the targeting and editing of specific sequences in the human DNA. CRISPR is known to result in unwanted gene edits that can occur when working with embryos. However, if the edits are done on adult humans and children, no transference occurs, and any potential damage remains to one individual. Allergan and Editas Medicine EDIT, a pharmaceutical company in Cambridge, Massachusetts, has announced in July they are ready to enroll subjects into its first of its kind CRISPR-based therapy trials, a development that would involve gene editing inside the human body. A propriety EDIT-101 injection is administrated into the eye to deliver “gene-altering machinery” directly to the photoreceptor cells. Once injected, EDIT-101 cuts out the mutated DNA, including CEP290 gene responsible for progressive photoreceptor-cell loss, which leads to an inherited type of blindness, Leber congenital amaurosis 10. The goal is for this cut to be repair by the DNA-repairing process that will lead to the expression of the normal protein.
What this means for Usher syndrome: potential treatments for vision loss are being discovered every day. In this case, the use of CRISPR technology will help to replace and repair mutations present in the Usher proteins and thus, help to restore vision as well as hearing.
In a new study of patients with Retinitis Pigmentosa, the Keck School of Medicine of USC researchers have found that adapted augmented reality (AR) glasses can improve patients’ mobility by 50% and grasp performance by 70%. Utilizing a different approach by employing assistive technology to enhance natural senses, the team adapted AR glasses that project bright colors onto patients’ retinas, corresponding to nearby obstacles.
What this means for Usher syndrome: we can improve the quality of life for patients with low vision due to retinitis pigmentosa through the use of augmented reality technology.
Drug repurposing is a new and attractive aspect of therapy development that could offer low-cost and accelerated establishment of new treatment options. The enzyme poly-ADP-ribose-polymerase (PARP) has important roles for many forms of DNA repair and it also participates in transcription, chromatin remodeling and cell death signaling. Currently, some PARP inhibitors are approved for cancer therapy, by means of canceling DNA repair processes and cell division.
Excessive PARP activity is also involved in neurodegenerative diseases including the currently untreatable and blinding retinitis pigmentosa group of inherited retinal photoreceptor degenerations. Hence, repurposing of known PARP inhibitors for patients with non-oncological diseases might provide a facilitated route for a novel retinitis pigmentosa therapy.
What this means for Usher syndrome: PARP inhibitors are approved for their use in cancer therapy, suggesting they can be repurposed to treat retinitis pigmentosa at a very low cost and shorter waiting times compared to novel drugs.
Researchers from Sun Yat-sen University are attempting to test the efficacy and safety of oral minocycline for the treatment of retinitis pigmentosa (RP). Minocycline, a second generation, semi-synthetic tetracycline antibiotic, a highly lipophilic molecule and can easily pass through the blood-brain barrier. Several clinical trials and animal experiments have reported that minocycline exert anti-apoptotic, anti-inflammatory and antioxidant effects in treating neurodegenerative diseases. They have proposed to test the effect and safety of oral minocycline for RP.
What this means for Usher syndrome: If clinical trials are successful, Usher patients will have the possibility to be included in this non-invasive therapy to prevent photoreceptor cell death.
To develop biological approaches to restore vision, scientists developed a method of transplanting stem cell-derived retinal tissue into the retina of an animal model, a cat. Human embryonic stem cells were successfully grafted into the retina of cats. The researchers observed strong infiltration of immune cells into the graft and surrounding tissue in the cats treated with prednisolone alone. The cats treated with prednisolone plus cyclosporine A showed better survival and low immune response to the grafts. This work demonstrates the feasibility of engrafting human embryonic stem cell-derived retinal tissue into the retina of large-eye animal models. Transplanting retinal tissue in degenerating cat retina will enable rapid development of preclinical work focused on vision restoration.
What this means for Usher syndrome: This procedure may provide a platform for testing stem cell-based therapies to treat Usher syndrome patients.
A major cause of human blindness is the death of rod photoreceptors. As rods degenerate, synaptic structures between rod and rod bipolar cells disappear and the rod bipolar cells extend their dendrites and occasionally make aberrant contacts. Such changes are broadly observed in blinding disorders caused by photoreceptor cell death and are thought to occur in response to deafferentation. How the remodeled retinal circuit affects visual processing following rod rescue is not known. To address this question, we generated male and female transgenic mice wherein a disrupted cGMP-gated channel (CNG) gene can be repaired at the endogenous locus and at different stages of degeneration by tamoxifen-inducible cre-mediated recombination. In normal rods, light-induced closure of CNG channels leads to hyperpolarization of the cell, reducing neurotransmitter release at the synapse. Similarly, rods lacking CNG channels exhibit a resting membrane potential that was ~10 mV hyperpolarized compared to WT rods, indicating diminished glutamate release. Retinas from these mice undergo stereotypic retinal remodeling as a consequence of rod malfunction and degeneration. Upon tamoxifen-induced expression of CNG channels, rods recovered their structure and exhibited normal light responses. Moreover, we show that the adult mouse retina displays a surprising degree of plasticity upon activation of rod input. Wayward bipolar cell dendrites establish contact with rods to support normal synaptic transmission, which is propagated to the retinal ganglion cells. These findings demonstrate remarkable plasticity extending beyond the developmental period and support efforts to repair or replace defective rods in patients blinded by rod degeneration.
What this means for Usher syndrome: If the same plasticity exists in the human retina, and the communications between bipolar cells and rods can be reestablished, this will suggest that future research can be directed toward the search for new therapies that will increase or accelerate these communications. Within that scenario, Usher patients will benefit in the future since they will be able preserve and restore some of their retinal activity.
Scientists from Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland and Scuola Superiore Sant’ Anna in Italy are developing a technology, OpticSELINE, for the blind that stimulates the optic nerve. The idea is to produce phosphenes, the sensation of seeing light in the form of seeing white patterns, without seeing light directly. Unfortunately, only a few hundred patients qualify for the current retinal implants on the market for clinical reasons. The intraneural electrode is a potential solution to this exclusion, since the optic nerve and the pathway to the brain are often intact. Intraneural electrodes contain an array of 12 electrodes and are more stable and less likely to move around once they are implanted. To understand the effectiveness of the electrodes, scientists delivered electric current to the optic nerve through OpticSELINE and measured the brain’s activity . The stimulation showed each electrode induces a special pattern of cortical activation, suggesting that intraneural stimulation of the optic nerve is selective and informative.
What this means for Usher syndrome: newer technologies such as the OpticSELINE are being developed as potential solutions to help the blind see. It might take some time and several clinical trials to fine-tune those stimulated cortical patterns but as they are now those visual signals generated by the OpticSELINE will be able to provide visual aid in the near future.
The conference transcript and presentation slides from the annual Usher Syndrome (USH) Connections Conference are now available! Check out the transcript and slides to learn how important the USH Trust Registry is to treatment development, how a drug treatment entering clinical trial could help people with Usher syndrome, and more.
The identification of the causes and understandings of the functions of many inherited retinal diseases (IRDs) has led to the development of exciting new gene/disease specific treatment opportunities. There are numerous treatments available that are aimed at a level of not just targeting specific genes but also certain mutations. Therefore, gene/disease specific treatments rely on persistent target cells and sufficient visual function to work effectively. However, many patients are outside of this window of opportunity and must rely on other approaches.
What this means for Usher syndrome: there are many different treatment and therapy options that are in development for retinitis pigmentosa.
Ophthalmology researchers at the University of Louisville have discovered the loss of vision in retinitis pigmentosa is the result of a disruption in the flow of glucose to the rods and cones. Metabolic changes result in the reduced availability of glucose in the cells; thus, starving the photoreceptors of necessary nutrients. Douglas C. Dean PhD stated, “Attacking glucose utilization is a major strategy in fighting lung cancer. This unexpected connection in retinal and lung cancer metabolism has led us to link these seemingly unrelated systems to search for common drugs that target both lung cancer and retinal degeneration."
What this means for Usher syndrome: This connection between lung cancer and retinal degeneration will help us find potential drugs to treat both diseases.
Researchers at Children’s Hospital of Philadelphia (CHOP) reported a more sensitive method for capturing the footprint of AAV vectors — the range of sites where the vectors transfer new genetic material. AAV vectors are bioengineered tools that use a harmless virus to transport modified genetic material safely into tissues and cells. To use these vectors safely and effectively, researchers must have a complete picture of where in the body the virus delivers the gene. Current methods to define gene transfer rely on fluorescent reporter genes that glow under a microscope, highlighting cells that take up and express the delivered genetic material. Unfortunately, these methods reveal only cells with stable, high levels of cargo. This new technology provides a better and more sensitive method for researchers to detect where the gene is expressed, even if it is expressed at low levels or for only a short time. To address this gap, Beverly L. Davidson, PhD and her laboratory developed a new AAV screening technique that uses sensitive editing-reporter transgenic mice that are marked even with a short burst of expression.
What this means for Usher syndrome: This new method will help to improve the safety of AAV-gene editing approaches because it better defines sites where the vector expresses the modified gene. AAV-gene editing might be developed into a treatment for Usher syndrome.
Scientists from Okayama University have developed a film coupled with photoelectric dye that generates electric signals in response to light. When the device was placed on an instrument that measures electric potential, the film generated waves of electric signals after being exposed to a flashing light. Researchers have highlighted that the device may function as a “novel type of retinal prosthesis.”
What this means for Usher syndrome: This device might be developed into an implant treatment for vision loss in Usher syndrome.