Category: Project

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare and progressive brain disorder that primarily affects young children. It leads to significant health problems, including an abnormally large head size, movement difficulties, seizures, and cognitive impairments. Currently, no effective treatments are available for MLC, which is caused by genetic mutations that affect a protein called MLC1.

Our research project aims to understand better the structure and function of the MLC1 protein and how its malfunction leads to MLC. We will use advanced cryo-EM imaging techniques to study the detailed structure of MLC1 and its interaction with another protein called GlialCAM. Additionally, we will develop new laboratory methods to study how MLC1 functions in transporting ions across cell membranes, which is crucial for maintaining brain health.

By examining both the normal and mutated forms of MLC1, we hope to uncover how specific genetic changes disrupt its function. This information will be critical for identifying potential targets for new treatments. Ultimately, our goal is to pave the way for developing effective therapies that can improve the quality of life for individuals affected by MLC.

Furthermore, the insights gained from this study may also enhance our understanding of other leukodystrophies, contributing to broader scientific and medical advancements in the field of brain disorders.

X-linked adrenoleukodystrophy (ALD) is a genetic disorder that affects the nervous system and adrenal glands. It is caused by mutations in the ABCD1 gene that lead to the accumulation of very long-chain fatty acids (VLCFA) in the body. These fatty acids build up in various tissues, including the adrenal glands, spinal cord, and brain, causing damage. Boys with ALD are typically healthy at birth, but about half will develop adrenal insufficiency and about a third will develop cerebral ALD (CALD) by the age of 10. In adults, both men and women can develop a condition called adrenomyeloneuropathy (AMN), which progressively affects the spinal cord.

Hematopoietic stem cell transplantation (HSCT) can halt the progression of CALD if performed early, but early diagnosis is crucial. Newborn screening (NBS) has greatly improved the care of boys with ALD by allowing early detection and intervention, which can prevent irreversible damage. In the U.S., more than 44 states have included ALD in their newborn screening programs, and other countries such as Taiwan and the Netherlands, have initiated ALD newborn screening.

Despite the success of newborn screening in identifying boys at risk for ALD, there are challenges. One important issue is the high rate of identification of variants of uncertain significance (VUS) in the ABCD1 gene. These VUS can be difficult to classify as pathogenic (ALD) or benign (no ALD), complicating diagnosis and management. This uncertainty can lead to unnecessary medical procedures and anxiety for families.

To address this, we have developed a new type of probe, called PeroxiSPY, that allows live imaging of peroxisomes (cell structures involved in fatty acid metabolism). These probes can help identify functional abnormalities in peroxisomes and are dependent on ABCD1-3 transporters. By designing ABCD1-specific PeroxiSPY probes, we aim to develop a test that can accurately measure the function of the ABCD1 protein. This would help distinguish between benign and pathogenic variants of the gene, improving the accuracy and utility of newborn screening programs for ALD.

The project aims to generate ABCD1-specific PeroxiSPY probes that will allow precise measurement of ABCD1 function using advanced microscopy techniques. This will be tested in cells derived from ALD patients and individuals with VUS in ABCD1. The availability of a rapid and sensitive assay to define whether a VUS is pathogenic (causing ALD) or benign (not causing ALD) is of paramount importance to families.

The leukodystrophy Hypomyelination with Brain stem and Spinal cord involvement and Leg spasticity, or short HBSL, is a devastating neurological condition caused by mutations of the DARS1 gene. DARS1 encodes an enzyme indispensably involved in protein synthesis in all cells and organisms. In most cases, HBSL has an early childhood onset and progressive disease course. Symptoms include motor impairments, hypomyelination, spasticity, ataxia, seizures, inability to walk unsupported, intellectual disability, and premature death. As with most leukodystrophies, no curative treatments exist. In a pioneering effort, our team at UNSW Sydney has created a set of accurate mouse disease models capturing the clinical spectrum of HBSL. We have further developed optimised viral gene therapy vectors with the ability to replace the mutated, malfunctioning DARS1 gene with a healthy and functional copy. This project brings together these two key innovative approaches to establish the effectiveness and safety of the HBSL gene therapy across the spectrum of disease severities. Our aim is to establish the proof-of-therapeutic-concept for a genetic treatment of HBSL, with the potential to halt and reverse neurological deficits arising from DARS1 deficiency. The project will further identify translation ready gene delivery vectors with the propensity for the human central nervous system to accelerate the development of an HBSL gene therapy pathway towards clinical studies. Our optimised HBSL gene therapy platform – paired with the identification of novel vectors for human gene delivery – will also advance our capabilities for the development of gene therapies for other forms of leukodystrophy, with broad extension for the treatment of genetic brain diseases in general.

Leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation (LBSL) is a rare disorder that affects the white matter in the brain and spinal cord, usually appearing in childhood or adolescence. Symptoms include loss of coordination and difficulty walking. LBSL is caused by mutations in the DARS2 gene, which produces an enzyme necessary for making mitochondrial proteins.

Most patients have two different mutations in the DARS2 gene: one common mutation that creates a shortened protein and another variable mutation that changes a single amino acid. These mutations impact the brain and spine the most, but the exact mechanisms of how they cause the disease are unknown.

To study LBSL and find potential treatments, researchers have created two mouse models that mimic the genetic traits seen in LBSL patients using CRISPR/Cas9 gene editing. These models include a DARS2 knockout and a DARS2 missense mutation. These mouse models are designed to closely resemble the genetic profile of LBSL patients, helping researchers understand the disease better. The research involves characterizing these mouse models to uncover the cellular and molecular mechanisms of the disease. This includes evaluating motor skills, examining brain and spine tissue, and analyzing gene expression and protein levels. This research is crucial for understanding LBSL and developing effective treatments to improve patients’ lives. By studying these mouse models, we hope to unravel the underlying mechanisms of LBSL and identify potential targets for future therapies.

We propose studies that will allow for new pioneering gene editing approaches for adult-onset leukoencephalopathy with axonal spheroids and pigmented glia. As orphan disease ALSP is in desperate need for treatment options. This disease strikes individuals in the prime of their life and families live with uncertainty as to the fate of their children who also carry the genetic burden. Beyond allogeneic bone marrow transplantation there are currently no treatment modalities available, and the procedure carries high mortality and complication rate. A simple gene addition approach, like viral mediated gene therapy, is also not possible due to the oncogenic potential of overexpression of CSF1R. In addition to new gene editing approaches, we also introduce a new humanized mouse model that allows us to assess engraftment of bone marrow cells. This carries wider relevance for the field of leukodystrophies.

Canavan disease (CD) is a rare neurological disease, caused by mutation(s) in the ASPA gene, which encodes ASPA enzyme. These mutation(s) cause a deficiency in enzyme activity, resulting in excessive N-acetylaspartic acid (NAA) throughout the CNS. Excess NAA results in a breakdown of the myelin and white matter in the brain. Symptoms of CD include intellectual disability, loss of motor skills, abnormal muscle tone, visual degeneration and macrocephaly, with the majority of patients succumbing to the disease during childhood. Many treatments and therapies have been explored, with gene therapy emerging as the most promising, with much of this research conducted by Prof. Gao, Prof Gessler, and researchers at the Horae Gene therapy Centre, UMASS Chan Medical School.

The project will focus on optimising the ASPA transgene, with a preliminary study completed, which has been observed to show disease rescue in the animal disease model. We aim to expand the study to identify an optimised ASPA transgene for therapeutic consideration; providing a high potency ASPA (via rAAV delivery), allowing for a vector dose reduction, improving the safety profile of the treatment, reducing potential adverse effects, reducing the cost of therapeutic production; all for a safe and efficacious Canavan gene therapy.

MLC is a very rare, incurable leukodystrophy. Patients develop progressive deterioration of motor functions leading to wheel-chair dependence, cognitive decline and seizures, and their management requires intensive parental, scholastic and social support. Since the pathological process is partially reversible, the comprehension of the molecular defects causing the disease may allow the identification of specific molecules to be targeted to correct the dysregulated processes and slow down MLC progression, thus improving disease symptoms. We here proposed to study MLC dysfunctional mechanisms and test therapeutic compounds in astrocytes differentiated from patient skin cells and in blood samples. Results obtained from these studies will allow the identification of pharmacological compounds able to correct MLC defects in patient-derived cells, providing the foundation for therapeutic strategies potentially translatable to patients.

Project financed by ELA up to: 97 000 €

Project financed by ELA up to: 100 000 €