Using human retinal organoids to discover mechanisms and therapies for CRB1 retinopathy

Awardee: Brian Ballios

Institution: University Health Network

Grant Amount: $66,991

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

Mutations in the CRB1 gene cause early cellular disorganization of the retina and loss of the light-sensitive photoreceptors in the eye, leading to irreversible blindness in children and adolescents. No treatments exist for these diseases. Structural differences between rodent and human retinal tissue preclude the use of animal models to uncover new therapies. Our work uses human CRB1 patient-derived stem cells to generate retinal “mini-organs in a dish” (organoids) to model CRB1 disease in the lab. Retinal organoids exhibit the same structure and major cell types found in the human retina; our CRB1 retinal organoids have the exact genetic makeup as the patient they were derived from. Comparisons of early retinal development in our CRB1 organoids with those derived from a healthy donor have shown defects in cell birth and proliferation. We aim to characterize how these early abnormalities affect the mature structure and organization of the retina in older organoids. We will analyse gene expression differences between healthy and CRB1-diseased organoids to uncover mechanisms and pathways involved in causing the disease state. These will serve as targets for testing new therapies for CRB1 disease using drugs known to modulate those pathways, and observe whether we can reverse early developmental defects.

Deciphering perturbations of primary cilia in Okur-Chung neurodevelopmental disorder

Awardee: Abdelhalim Loukil

Institution: Sanford Research Institute

Grant Amount: $60,013

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

The proposed project aims to investigate how mutations in the Csnk2a1 gene contribute to a rare genetic disorder called OCNDS, which causes speech difficulties, motor impairments, and cognitive issues. We will look at how these mutations affect the function of primary cilia, which are tiny hair-like structures in cells that play an important role in cell communication and brain development. By studying both mouse models and patient cells, we will identify the specific molecular changes in cilia caused by the gene mutation and their effects on brain development. This proposal will help us better understand how ciliary malfunction contributes to developmental difficulties in OCNDS. Additionally, we hope to uncover novel therapeutic targets by identifying the molecular pathways affected by the mutation. Our ultimate goal is to provide insights that could lead to potential treatments for the neurological challenges seen in OCNDS.

In Vivo, Non-Viral Base Editing To Correct AT Variants In Brain, Blood, Lung, and Liver

Awardee: Xizhen Lian

Institution: Johns Hopkins University

Grant Amount: $41,740

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

Ataxia telangiectasia (A-T) is a multi-organ disorder caused by recessive mutations in the ATM gene, which encodes a master regulator of the DNA damage response and impacts redox balance, angiogenesis, and glucose metabolism. In this project we will explore a base editing strategy to correct a pathogenic ATM mutation to initiate the PIs' efforts towards precision gene therapy for treating A-T. Specifically, the PIs have access to ATM patient cells harboring the R2598X mutation, and this variant is amenable to base correction. Employing lipid nanoparticles, the most clinically advanced nonviral gene delivery technology, the PIs will demonstrate in vivo base editor delivery into hematopoietic stem cells, lung and liver to potentially alleviate A-T-related morbidity and mortality. Overall, results obtained with the support of this project will set the stage for future A-T gene therapy studies including the optimization of prime editing strategies to correct ATM and expanding delivery to the central nervous system.

Investigating Excitation/Inhibition Balance in Cortical-Thalamic Circuitry in CDKL5 Deficiency Disorder Using Human-Derived Assembloids

Awardee: Francesca Puppo

Institution: University of California, San Diego

Grant Amount: $61,007

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

This project focuses on CDKL5 Deficiency Disorder (CDD), a severe neurodevelopmental condition that causes drug-resistant epilepsy. In CDD, the balance between brain signals that excite and inhibit activity (called the excitation/inhibition or E/I balance) is disrupted, potentially leading to seizures. Cortical-thalamic projections have been implicated with the generation of seizures. However, traditional mouse models have not been able to effectively model the seizure phenotype in CDKL5 deficiency and study the complex interactions between thalamus and cortex. To address this, we will use advanced human-derived models called corticothalamic (CTh) assembloids, which combine brain-like structures (organoids) from patients with CDKL5 mutations. These models allow us to recreate the brain circuits involved in seizures and study how their development is altered. By using cutting-edge technologies such as high-density multi-electrode arrays, calcium imaging, and optogenetics, we can precisely investigate how disruptions in the E/I balance contribute to hyperexcitability in these circuits. Our research aims to identify the key mechanisms behind seizure generation in CDD, paving the way for potential therapies. This study directly supports ongoing efforts to improve CDD disease models and uncover new targets for treatment.

Epilepsy linked toTBC1D24 Loss: pH-Targeted Pharmacological and Nanotechnological Interventions

Awardee: Caterina Michetti

Institution: University of Genoa

Grant Amount: $62,937

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

This project aims to exploit a new preclinical mouse model (Tbc1d24-cKO) to study early-onset epilepsy caused by TBC1D24 loss. Using this model, we will test two innovative treatment strategies targeting the root causes of hyperexcitability in neurons. The first approach involves a small molecule that enhances lysosomal acidification by stimulating the v-ATPase enzyme, restoring pH balance in neuronal cells and potentially reducing neuronal hyperactivity. The second approach involves a novel nanomachine called pHIL, which is designed to selectively inhibit overactive neurons in response to pH shifts that occur during seizures. By activating a light-sensitive protein under acidic conditions, pHIL can reduce excitability without affecting healthy neurons. This research is particularly relevant to early-onset epilepsy linked to TBC1D24 pathogenic variants, a condition with no effective treatments. Our Tbc1d24-cKO mouse model allows us to test these therapies in vivo, offering a unique opportunity to explore the underlying mechanisms of epileptogenesis and to identify robust therapeutic strategies. The proposed strategies target different aspects of the pH imbalance associated with TBC1D24 loss, and testing both approaches improves the likelihood of finding an effective treatment for early-onset epilepsy.

An iPSC-based Platform for Characterization of Neuronal Circuit Dysfunction in RASopathies

Awardee: Sattar Khoshkhoo

Institution: Brigham and Women's Hospital

Grant Amount: $58,222

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

RASopathies are a group of genetic disorders that affect multiple body systems and are often linked to neurocognitive issues like learning disabilities, autism, and epilepsy. These conditions arise due to overactive Ras-MAPK signaling, which plays a crucial role in brain development and function. However, the specific effects of Ras-MAPK overactivation on brain circuits are not well understood. This project aims to use patient-derived stem cells to model RASopathies and investigate how abnormal signaling impacts brain cell communication. Moreover, by testing drugs that inhibit the Ras-MAPK pathway, this proposal will evaluate the feasibility of using Ras-MAPK inhibitors as a therapeutic strategy to restore normal brain activity in affected individuals. This research platform will also enable future drug discovery for rare genetic diseases that affect brain circuits.

Investigating SETBP1 pathogenic variants in lung malformation and function using human induced pluripotent stem cell-derived organoids

Awardee: Amy Wong

Institution: Toronto Hospital for Sick Children

Grant Amount: $70,000.00

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

Schinzel-Giedon Syndrome (SGS) is an ultra-rare, life-limiting multisystem disorder caused by mutations in the SETBP1 gene that results in abnormal accumulation of the protein. At the genetic level, SETBP1 helps regulate the expression of genes that drives developmental processes. Therefore disruption in how this protein functions can impact a wide spectrum of developmental programs leading to abnormalities including broad neurodevelopmental impairments, gastrointestinal complications and structural malformations in multiple organs, with no cure. Lung malformations and increased risk of respiratory infections is a clinical feature in some SGS patients, the mechanism of how SETBP1 impacts how the lung cells form and function is unknown. Here, we will create lung organoids (mini lungs in a dish) from stem cells harbouring SETBP1 pathogenic mutations to better understand how the protein impacts the formation of the airway cells and function of the airways including response to respiratory virus infections.

A novel RNA therapeutic for the treatment of CTNNB1 syndrome

Awardee: Jeff Coller

Institution: Johns Hopkins University

Grant Amount: $63,312

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

B-catenin is a protein that is important for proper function and communication between cells of an organism. Involved in cancer, it has also more recently been implicated in neurodevelopmental disorders, including autism. Children with mutations that decrease the levels and thereby affect the function of B-catenin show intellectual disability, microcephaly and developmental delays. We have developed an RNA technology that can enhance the expression of a given protein by increasing its messenger RNA’s potency, by tethering a polyadenosine tail to the transcript via an antisense oligonucleotide. Preliminary results show that this strategy can increase the levels of B-catenin in human neurons, suggesting it could treat patients with different mutations that lead to insufficient B-catenin levels.

A comprehensive functional analysis of Dup15q ‎genes: phenotypic effects and treatment ‎following restoration‎

Awardee: Alon Zaslaver

Institution: The Hebrew University

Grant Amount: $47,038

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

Dup15q syndrome is genetically inherited and is caused due to an extra copy of a piece of ‎chromosome ‎‎15. As a results, the genes located on that chromosome region are expressed at ‎higher levels. However, ‎it is less clear which genes contribute to the various observed deficits. ‎Moreover, unless genetically tested during pregnancy, children with Dup15q are typically ‎‎diagnosed only at the age of ~2 years old. Thus, new therapeutic approaches need to focus on ‎‎improving and restoring functional deficits after most embryonic neurodevelopmental processes ‎are complete.‎ To address all these needs, we will use the powerful genetic model system (C. elegans worms). ‎Specifically, we ‎carefully designed an experimental genetic system which allows mild and fine ‎upregulation of individual and combinations of Dup15q genes during neurodevelopment, and ‎restoration of the elevated expression to normal ‎levels at the adult stage of the animal. To ‎analyze neurodevelopmental deficits, we will ‎use state-of-the-art experimental techniques ‎including functional imaging of neural activity and behavioral ‎assays.‎ These efforts will reveal the individual and sets of genes that lead to neurodevelopmental ‎phenotypes, and most importantly, whether restoration of gene expression to normal levels,‎ can improve these phenotypic deficits. Such findings may pave the way to novel interventions ‎and ‎therapeutic approaches.‎

Molecular and Functional Mechanisms Underlying Cortical Activity in CACNA1A Epilepsy

Awardee: Fikri Birey

Institution: Emory University

Grant Amount: $57,450

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

This proposal focuses on studying genetic mutations in the CACNA1A gene, which are known to cause a severe neurodevelopmental condition chiefly characterized by epilepsy and cerebellar ataxia. Our team will implement 3D models of human cortical development, namely forebrain assembloids, derived from induced pluripotent stem cells carrying two types of mutations: loss-of-function (LOF) and gain-of-function (GOF). These models will help to better understand how different brain cell types, specifically glutamatergic (excitatory) and GABAergic (inhibitory) neurons, are impacted by these mutations. The study has three main objectives: first, to identify gene expression changes in neurons affected by the mutations; second, to examine how neuronal functions, such as signaling, are altered; and third, to test the effectiveness of a potential therapy known as antisense oligonucleotides (ASOs) in correcting the effects of GOF mutations. This work addresses critical gaps in our understanding by using human-specific models, offering more relevant insights than animal studies, and potentially leading to new treatments for disorders linked to CACNA1A mutations.

Exploring Chromosomal Instability and Cellular Phenotypes in Ring Chromosome 14 Syndrome

Awardee: Matthew Tegtmeyer

Institution: Purdue University

Grant Amount: $60,840.00

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

We will explore whether various culture maintenance conditions can promote the stability of ring 14 in patient reprogrammed iPSCs.

Characterization of seizures in a new mouse model of KCNT1 G288S

Awardee: Jill Silverman

Institution: UC Davis

Grant Amount: $68,667

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

KCNT1-related epilepsy is an autosomal dominant NDD, resulting from de novo pathogenic variants in the sodium activated potassium channel, and are associated with Epilepsy of Infancy with Migrating Focal Seizures (EIMFS), and Autosomal Dominant Nocturnal Frontal Lobe Epilepsy (ADNFLE), characterized by clusters of nocturnal motor seizures. Few animal models exist that carry any of the 64 known human variants described, to date. To that end, we will focus our proposed studies on a novel mouse model of the human gene variant G288S (corresponding to mouse Kcnt1 G269S), a mutation located within the sequence coding for the channel pore. This mouse model has substantial translational potential because we will investigate the impact of early life seizure on occurrence, recurrence, and severity of seizure phenotypes across the lifespan to aged adults, and severity and neuro and respiratory physiological phenotypes.

Molecular Pathogenesis and Epigenetic Rescue of Novel Human Models of ZC4H2-associated rare disorders.

Awardee: Julian Halmai

Institution: UC Davis

Grant Amount: $54,187

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

The main objectives of this project are to establish human models of three unique loss of function ZARD variants within control sex-matched IMR90 NSC, using gene editing and to characterize the cellular and molecular phenotypes associated with ZARD pathology, with interest in understanding the link between ZC4H2 loss of function and BMP-Smad signaling pathway dysregulation. This proposal, if successful with shed light onto ZARD related pathology and the potential targets for therapeutic intervention.

CROSS-TISSUE ULTRASTRUCTURAL IMAGING FOR DISCOVERING FIBROTIC DETERMINANTS AND ACTIONABLE TARGETS IN DC/TBD

Awardee: Alfredo Rodríguez

Institution: National Autonomous University of Mexico (UNAM)

Grant Amount: $62,158

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

Fibrosis of the lung and liver are threatening complications for patients with DC/TBD, however the composition of the fibrotic niche and potential targets for treating and preventing it are virtually unknown. In this proposal we have assembled an international team from Mexico (UNAM) and the USA (Mayo Clinic) that will examine the composition of the fibrotic niche. Using high precision microscopy, we will generate multidimensional images of primary fibrotic lung and liver from patients with DC/TBD and using computational tools we will reconstruct the fibrotic niche in these tissues, importantly without tissue dissociation and maintaining its architecture. We will use markers for detecting multiple cell types, including pro-fibrotic immune cells, followed by state-of-the-art spatial transcriptomics using Xenium technology. Our combined approach will provide an unprecedented single cell resolution of the DC/TBD critical fibrotic tissues and will help us propose actionable targets for preventing and treating fibrosis.

Charting WDR45-dependent genes for neurodegeneration at a single-cell resolution

Awardee: Young Ah Seo

Institution: Regents of the University of Michigan

Grant Amount: $75,815.00

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

BPAN (β-propeller protein-associated neurodegeneration) is a rare neurodegenerative disorder caused by mutations in the WDR45 gene, often leading to progressive brain damage and abnormal iron buildup in the brain. Unfortunately, no cure exists for BPAN, and current treatments only manage symptoms. Our research focuses on uncovering the underlying causes of neurodegeneration in BPAN. Using a mouse model where the WDR45 gene has been deleted, we will employ single-cell RNA sequencing (scRNA-seq) to analyze changes in gene expression at the individual cell level. This will help us identify the specific brain cells and molecular pathways most affected by WDR45 loss. By mapping these pathways, we aim to pinpoint new targets for potential therapies that could prevent or slow down the progression of BPAN. This project could pave the way for developing treatments that address the root causes of BPAN, benefiting patients with this rare condition.

Short-interfering RNA to reduce heparan sulfate in Sanfilippo B syndrome

Awardee: Patricia Dickson

Institution: Washington University in St. Louis

Grant Amount: $60,000

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

This is a proposal to use ribonucleic acid (RNA) interference to reduce the production of heparan sulfate in the brain for Sanfilippo syndrome. Substrate reduction therapy aims to reduce the amount of substrate, or material, that cannot be broken down by the body. In Sanfilippo, the substrate is heparan sulfate. Heparan sulfate is made by dedicated proteins that help assemble the molecule (biosynthesis). We aim to inhibit three genes that are involved in heparan sulfate production (Exostosin1 (EXT 1), Exostosin 2 (EXT2), and N-Deacetylase And N-Sulfotransferase 2 (NDST2)). Our initial tests show that we can turn down the production of these genes and that doing so reduces the amount of heparan sulfate in the brain. Here, we propose to determine the most effective combination of RNA to reduce heparan sulfate in the brains of mice with Sanfilippo B syndrome. We then plan to study the effects of substrate reduction therapy using this RNA approach on behavior, pathology, and heparan sulfate levels long term. If successful, this approach could be applied to all Sanfilippo types and to other mucopolysaccharidoses (MPS) in which heparan sulfate accumulates in excess.

Does Treatment with Diazoxide or a novel form of Diazoxide Choline elevate the plasma glucose levels in GLUT1 Deficiency Syndrome thus potentially increasing glucose transport the blood brain barrier?

Awardee: Paul Thornton

Institution: Cook Children's Medical Center

Grant Amount: $60,367

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

We propose to study currently available Diazoxide and a novel drug, Diazoxide Choline which is a more palatable tablet formulation, to see if we can elevate the plasma glucose safely and effectively in children and adults with Glut 1 Deficiency Syndrome. We aim to 1) determine if Diazoxide and Diazoxide Choline increase plasma glucose levels measured by continuous glucose monitoring; 2) compare effects of equivalent doses of Diazoxide and Diazoxide Choline on CGM measured glucose; and 3) evaluate safety and tolerability of both forms of Diazoxide.

Selective HDAC6 inhibitors as a novel treatment for CNS pathology in MPS-I

Awardee: Nicolina Cristina Sorrentino

Institution: University of Naples " Federico II"

Grant Amount: $60,378.00

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

The Mucopolysaccharidoses (MPS) are a group of inherited disorders caused by mutations in genes affecting systemic organs with severe involvement of brain and retina tissues. Since the symptoms occur during the first years of life, an early therapeutic intervention to treat the systemic problems is essential. Recently, scientists discovered that MPS is linked to other serious brain diseases like Alzheimer's and Parkinson's. MPS type I represents the most severe MPS caused by the deficiency of Iduronidase (IDUA) protein, responsible for breaking down substances, like glycosaminoglycans (GAG), leading to systemic and cerebral symptoms. The treatment of brain pathology represents the primary goal in developing any therapeutic approach for MPS-I. Along with glycosaminoglycan accumulation that represent the primary storage, another important player of MPS disorder is represented by the block of the cellular 'garbage disposal' process, called autophagy, which cause the accumulation of secondary toxic materials and strongly influence the neuropathology progression. Current therapeutic strategies are based on the restoration of only the functional IDUA protein, which is not sufficient for removing all the secondary storage present in the cells of MPS-I patients. In this light, a new treatment stimulating autophagy and tackling accumulation of toxic materials might restore CNS and retinal health in MPS-I. For this reason, we propose a new pharmacological approach aimed at reactivating the autophagy mechanism, removing storage toxic material, promoting neuroprotection in brain and retina of MPS-I. Advanced pharmacology and cellular biology techniques will be employed to develop selective compounds in order to target and treat MPS-I brain cells. Additionally, biochemical, molecular and immunofluorescence analyses will be performed on MPS-I cell lines in order to validate the effectiveness of the therapy in restoring neuronal function and reducing the accumulation of toxic materials.

Targeting GNAS-Driven Pathway for Precision Therapy of Fibrous Dysplasia

Awardee: J. Silvio Gutkind

Institution: University of California, San Diego

Grant Amount: $80,468.00

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

Fibrous dysplasia (FD) is a rare bone disorder where normal bone is replaced with fibrous tissue, leading to deformities, fractures, and chronic pain. FD is caused by mutations in the GNAS gene, which results in the continuous activation of a signaling pathway that disrupts normal bone formation. This mutation typically occurs early in development and affects not only the skeleton but also other tissues, such as the skin and endocrine organs. Currently, there are no targeted treatments available for FD, and existing therapies are primarily focused on managing symptoms rather than addressing the underlying cause of the disease. Our research aims to better understand how FD develops by studying the stem cells that give rise to the disease and how the GNAS mutation alters their normal function. We will use advanced techniques to investigate these cells at a single-cell level, allowing us to identify the specific molecular changes that drive the progression of FD. In addition, we are exploring new therapeutic strategies by targeting key components of the GNAS signaling pathway. Specifically, we are focusing on inhibiting the PKA catalytic subunit, which is a crucial downstream player in the pathway affected by the GNAS mutation. We believe that blocking this molecule will help restore the balance of bone formation and potentially reverse the progression of FD. By combining our understanding of FD development with new therapeutic approaches, we aim to open the door to more effective treatments for patients with this debilitating condition. Our ultimate goal is to develop targeted therapies that can halt or reverse the progression of FD, improving the life expectancy and quality of life for those affected by the disease.

Elucidating a link between microfractures and fibrous dysplasia bone pain in mice

Awardee: Ariane Zamarioli

Institution: Ribeirao Preto Medical School

Grant Amount: $40,234.00

Funding Period: February 1, 2025 - January 31, 2026

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Summary:

FD/MAS are severe congenital disorders that result in significant bone pain, skeletal deformities, and endocrine dysfunction. Bone pain is one of the most difficult symptoms to manage in FD/MAS patients. Currently, a variety of pharmacotherapies, including bisphosphonates, are used to alleviate skeletal disease activity and bone pain. However, the mechanisms behind bone pain in FD/MAS remain unclear. Microfractures are suspected to be a contributing factor. This proposal seeks to explore the relationship between FD-related bone pain and microfractures using an established FD animal model.