Reversible Pathology of Sanfilippo Syndrome
Women’s and Children’s Hospital Adelaide
Dr. Kim Hemsley email@example.com
Professor John Hopwood
Grant Amount 2012 – $145,000 AUD grant
Team Sanfilippo Foundation (USA)
Stop Sanfilippo (Spain)
Little Maciek & Great Wizards (Poland)
The Sanfilippo Foundation for Children (USA)
Led by the Team Sanfilippo Foundation, a group of worldwide charities has announced a $145,000 AUD grant to Dr Kim Hemsley and Professor John Hopwood in Adelaide, Australia to study the fundamental disease processes involved in the pathology of MPS III Sanfilippo Syndrome. This effort will use the latest science to study the real-time progression of the disease in a mouse model, enabling an understanding of what goes wrong and why. The hope is that this new understanding will lead to more effective treatments and a better understanding of what, if any, of the damage might be reversed.
While this study will focus on Sanfilippo Syndrome, the findings of the study could benefit those suffering from similar lysosomal storage disorders with similar pathways such as Hunter Syndrome, Hurler Syndrome and Tay-Sachs.
Lysosomal Enhancement Therapy Sanfilippo A,B,C,D and many lysosomal diseases
Texas Children’s Hospital
Marco Sardiello, Ph.D.
Grant 2011: $150,000 (Funded in collaboration with Sanfilippo Foundation Switzerland)
This project is based on our recent discovery of a gene network that controls cellular clearance by regulating lysosomal biogenesis and function (Sardiello et al. Science 2009). Lysosomes are ubiquitous intracellular organelles dedicated to the degradation and recycling of the byproducts of cellular metabolism. We have discovered that human cells have a genetic program that controls the activity of lysosomes through the modulation of master gene TFEB, which encodes a transcription factor that directly binds to promoters of lysosomal genes and coordinately activates their transcription. By acting on TFEB, we can induce the cell to make more lysosomes, hence increasing its degradation capacity.
Sanfilippo syndrome and other neurodegenerative diseases are caused by the intracellular accumulation of undegraded, toxic molecules. We postulate that the increase of cellular degradation capacity as a result of the activation of lysosomal master gene TFEB will result in the clearing of toxic molecules. Preliminary data obtained in cells from other neurodegenerative diseases (Batten disease, Huntington’s disease) showed that the enhancement of lysosomal function via TFEB over expression results in the efficient clearance of the toxic molecules that accumulate in these diseases (lipofuscins and mutated huntingtin, respectively). Moreover, cell lines stably over expressing TFEB showed enhanced ability to degrade glycosaminoglycans (Sardiello et al. 2009), the substrate that accumulates in Sanfilippo syndrome. Therefore, this clearing effect appears to be independent from the biochemical nature of accumulated substances and from the specific site of their accumulation (lysosome for glycosaminoglycans and lipofuscins, cytoplasmic for expanded hungtintin protein). This is likely due to the fact that the lysosome is implicated in autophagy, which clears portions of the cytoplasm, and TFEB is also able to promote autophagy by activating the transcription of several autophagy genes.
Dr. Sardiello discovered an already FDA approved molecule that is shown to activate TFEB. Currently this molecule is being tested on Batten mice. A colony of Sanfilippo mice are being prepared for testing this compound. Mouse study will take approximately six months to complete.
Our grant is specifically to test the FDA approved compound on Sanfilippo B mice with comparison of oral dosing, IV dosing and intrathecal administration.
Gene Therapy Sanfilippo B
Nationwide Children’s Hospital, Columbus, Ohio
Dr. Haiyan Fu
Grant 2011: $125,000
Dr. Fu has developed an efficient gene therapy procedure to treat MPSIIIB. We have made an AAV9 vector that has the ability to cross the blood-brain-barrier. This AAV9 vector carries the gene for NAGLU, the enzyme missing in MPSIIIB patients. By a singly intravenous injection of this AAV9-NAGLU vector, we were able to restore the NAGLU enzyme activity and correct the lysosomal storage pathology throughout the brain, spinal cord and multiple somatic tissues in adult MPSIIIB mice. Most importantly, the AAV9-vector-treated mice showed significant behavioral improvement and survived to a normal lifespan. In addition, this approach is minimally invasive and the IV injection itself has minimal risk to patients. With the generous support from the Sanfilippo families and friends through Ben’s Dream – The Sanfilippo Research Foundation, the experiments of this project are still ongoing.
We believe that we are in a very good position to move our AAV9-gene-therapy approach to clinical trial. We have established a strong team with the goal of obtaining the approval from the FDA for a Phase I/II clinical trial in patients with MPS IIIB. Led by Dr. Kevin Flanigan, MD and professor of neurology, we have submitted a Pre-pre-IND package to the FDA and have a pre-pre-IND meeting scheduled with the FDA. This Pre-pre-IND interaction is for us to get advices from the FDA on specific requirements for the Pre-IND toxicology/safety testing of our approach in animals. This Pre-IND toxicology testing is absolutely required for obtaining the FDA approval for our planned MPS IIIB gene therapy clinical trial.
Additional plans and efforts have been made to prepare for moving this MPS IIIB gene therapy to a clinical trial. 1) We have submitted a translational grant application to the NIH. 2) We are planning to establish a MPS III patient registry. 3) Establish and validate the stable high yield vector producing cell line. 4) Produce clinical grade AAV9 vectors needed for the planned clinical trial, and this is required by the FDA when submitting the IND (Investigational New Drug) application. 5). Testing our AAV9-NAGLU vector in large animals considering the clinical relevance to humans.
Our added support to our work involved in establishing a high yield AAV9-hNAGLU vector production system to enable Good Manufacturing processes for clinical trial
Gene Therapy Sanfilippo A
Nationwide Children’s Hospital, Columbus, Ohio
Dr. Doug McCarty
Grant 2011: $125,000
Because all four forms of MPS III share similar disease properties, we believe that the gene therapy approach similar to that we developed for MPS IIIB may also be feasible for other forms of MPS involving a secreted enzyme. We have therefore expanded our gene therapy program to develop efficient AAV9 vector for the treatment of MPS IIIA. This project is led by Dr. Doug McCarty and has been supported by a research grant from the Sanfilippo Children’s Research Foundation (Canada) and Team Sanfilippo Foundation.
To date, we have made multiple AAV vectors carrying the gene for human SGSH, theenzyme missing in patients with MPS IIIA. We tested these vectors in human MPS IIIA cell cultures. The preliminary data showed that these AAV-SGSH-treated MPS IIIA cells produced and secreted SGSH enzyme. In addition, we treated the MPS IIIB cells with the secreted SGSH and saw significant reduction of GAG in these cells.
We are also in the process to establish the MPS IIIA mouse colony (with the help from Dr. Steve Walkley). The MPS IIIB mice will be used to test the AAV9-SGSH vectors and select the optimal vector for potential future clinical application in MPS IIIA patients. The goal of this project is to develop a systemic AAV9-SGSH gene therapy approach for the treatment of MPS IIIA in patients.
Our grant will support the construct/test the AAV9-SGSH vectors, to develop high yield AAV9-SGSH vector producing plasmid, and to initiate the development of vector producing cell line inconsideration of potential clinical application.
Lysosomal Enhancement and Regulation
Telethon Institute of Genetics and Medicine, Naples, Italy
Andrea Ballabio firstname.lastname@example.org
Grant 2011: $75,000 USD (Funded in collaboration with Stop Sanfilippo Foundation)
“Using a systems-biology approach, Prof Ballabio’s research group recently discovered a gene regulatory network (CLEAR: Coordinated Lysosomal Enhancement And Regulation) that controls lysosomal biogenesis and function (Sardiello et al., 2009). The bHLH-leucine zipper transcription factor TFEB acts as a master gene of the CLEAR network, and it binds to CLEAR target sites in the promoter of lysosomal genes and positively regulates their expression. TFEB overexpression induces lysosomal biogenesis and increases the ability of the cell to degrade complex molecules, such as GAGs. The therapeutic potential of this discovery was revealed by enhanced clearance of mutated huntingtin in a cellular model of Huntington’s disease (Sardiello et al., 2009) following TFEB overexpression, and by rescue of cell death in a mouse model of PD(Dehay et al., 2010). More recent studies performed in Prof. Ballabio’s laboratory have shown that TFEB directly regulates autophagy and that its activity is controlled by ERK2-mediated phosphorylation at a specific serine residue (Settembre et al., 2011; Cuervo, 2011; David, 2011). The group has also demonstrated that TFEB regulates lysosomal exocytosis by activation of its target gene Mucolipin 1, a Ca2+ channel located in the lysosome membrane. TFEB-mediated lysosomal exocytosis promoted cellular clearance in several murine models of LSDs, both in cell culture and in vivo (Medina et al, Developmental Cell, in press). In addition, Prof Ballabio’s group has recently identified two drugs that activate TFEB. These findings provide the research community with novel and innovative tools and strategies to promote cellular clearance. The use of transcriptional activation of lysosomal biogenesis, autophagy and lysosomal exocytosis as a tool to promote cellular clearance is a completely new concept.”
- High content screening of FDA-approved drugs (i.e. The Prestwick Chemical Library), and FDA-approved kinase inhibitors (target-focus library) using a high content assay. Evaluation of hits (EC50
- Testing any active compounds identified in Milestone 1 in a cell-based system derived from at least 2 fibroblast cell lines obtained from patients with Sanfilippo Syndrome (MPSIIIA and MPSIIIB).
Substrate Optimization Therapy Sanfilippo A,B,C and MPSI and II
Grant 2010: $50,000
Zacharon is developing a novel small molecule therapy which selectively modulates the biosynthesis of the GAGs which accumulate in patients with MPS I, II, and III A,B and C. Due to this selective modification, the deficient enzyme is no longer required for GAG degradation thus reducing lysosomal accumulation. Zacharon has completed important preclinical development activities including the demonstration of proof of concept using MPS animal models including reduction in GAG accumulation in the brain. In March of 2011, Zacharon formed a partnership with Pfizer Inc.’s Orphan and Genetic Disease Unit to complete preclinical development and successfully advance this program through clinical trials and subsequent commercialization. The successful completion of these activities is designed to enable the first small molecule therapy capable of addressing neurological decline and other needs of patients with MPS I, II, and III A,B and C.
Our grant was specifically used to increase the number of medicinal chemists working on developing analogs of the initial molecule. This allowed Zacharon to develop and more potent drug with better drug characteristics.