Deciphering the splicing order of COL6A1-3 pre-mRNAs to improve the prognosis and treatment of collagen VI-related muscular dystrophies

Awardee: Karine Choquet

Institution: Université de Sherbrooke

Grant Amount: $46,611

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

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Summary:

Collagen VI-related muscular dystrophies (COL6-RD) are a rare type of childhood-onset muscle disease. Symptoms include muscle weakness and breathing difficulties. There is currently no cure for COL6-RD, which are caused by spelling errors in the genes COL6A1, COL6A2 and COL6A3. These errors are also present in the COL6 premature (pre) messenger RNAs (mRNA), which must undergo a process called splicing to become the mature mRNAs that are used to produce collagen proteins. Some of the spelling errors that cause COL6-RD lead to defects in splicing. Depending on the type of splicing defect, the disease symptoms can be milder or more severe. The type of splicing defect can also determine which type of treatment could be beneficial. However, predicting the type of splicing defect can be challenging. COL6 pre-mRNAs are very long, but splicing has only been studied for one short section of a pre-mRNA at a time. Our project will use new technology that allows to read much longer sections of COL6 pre-mRNAs. We will investigate the order in which splicing happens in the COL6 pre-mRNAs, and how this influences the type of splicing defect caused by genetic spelling errors. We will also study how communication between different parts of a pre-mRNA that are located far away from one another affects the efficiency of treatments that aim to correct COL6 splicing defects. This project will improve our understanding of how splicing goes wrong in COL6-RD and could lead to improved treatment options for some of the spelling errors that cause COL6-RD.

Novel insights into cellular interaction in collagen VI muscular dystrophy

Awardee: Malte Tiburcy

Institution: University Medical Center Göttingen

Grant Amount: $46,611

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

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Summary:

Our research focusses on building healthy and diseased human muscle from pluripotent stem cells in the dish. By applying pluripotent stem cells with patient-specific mutations, we can measure the muscle function of individual patients in the lab. Collagen VI-related dystrophy is of particular interest to us because it is not a disease of muscle cells themselves. Instead, it affects the glue that connects all cells in the muscle. How the failing glue changes the cell behavior is not clear. We would like to use our models to better understand how the glue affects cellular interaction to cause muscle dysfunction. Ultimately, we aim to find new ways of preventing the muscle weakness in collagen VI dystrophy.

Developing peptide-conjugated antisense oligonucleotide therapy for COL6-related congenital muscular dystrophy

Awardee: Haiyan Zhou

Institution: University College London

Grant Amount: $70,133.00

Funding Period: February 1, 2024 - January 31, 2025

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Summary:

Collagen VI-related congenital muscular dystrophies (COL6-CMDs) are one of the most common types of CMDs. There is no curative treatment available. In the last few years, we have provided strong proof-of-concept evidence that experimental oligonucleotide therapy is a promising approach for the treatment of this fatal neuromuscular condition. My group has tested antisense oligonucleotide (ASO) therapeutic strategies in skin cells cultured from COL6-CMD patients and have already identified the lead ASO compounds able to correct the common disease mutations. However, for ASOs to work efficiently in humans, it is essential they target the skeletal muscle interstitial fibroblasts (MIFs), the major cell population producing collagen VI protein in muscle. So far, MIFs targeting has proved to be challenging to the field and has clearly obstructed the therapeutic development in COL6-CMDs. My group has recently identified a series of short protein fragments (peptides) that specifically bind to a cell surface receptor of MIFs, while also promoting the cellular internalization that will be needed when an oligonucleotide is attached to the peptide. Crucially, our data also demonstrated that some of these peptides efficiently target fibroblasts in a preferential manner, an important finding to avoid the accumulation of oligonucleotides in unwanted cell types. Here we propose a project aiming to further develop this exciting approach by using optimized MIF targeting peptides as a strategy to enhance the uptake of therapeutic ASOs to MIFs specifically, with an ultimate aim of developing a new therapy for COL6-CMD. The experiment plan includes: 1) To optimize the peptide sequences by testing alternative amino acids to improve the binding affinity, increase internalization and endosomal escape and reduce any potential cytotoxicity. 2) To validate the conjugates, for exon-skipping strategy in targeting MIFs, using cultured patients’ fibroblasts. 3) To generate a pilot in vivo biodistribution profile of pep-ASO conjugates, in wild-type mice. By the end of this project, we expect to identify the optimal peptide-ASO conjugates ready for further in vivo validation in the available humanized mouse model of COL6-CMD and to promote the future clinical translation of ASO therapy in COL6-CMD.

ADAR mediated RNA editing for treatment of collagen VI related muscular dystrophy

Awardee: Russell Butterfield

Institution: University of Utah

Grant Amount: $70,133.00

Funding Period: February 1, 2024 - January 31, 2025

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Summary:

The collagen VI related muscular dystrophies (COL6-RD) are inherited disorders of muscle characterized by progressive weakness and a combination of distal joint laxity and proximal joint contractures. Missense mutations substitute the glycine residues in the conserved Gly-x-y repeat of the triple helical (TH) domain are the most common mutation in COL6-RD patients. This mutation allows incorporation of abnormal chains into secreted tetramers resulting in a dominant negative effect. Currently, there are no treatment for these disorders and the dominant negative mutations pose significant challenges for developing novel treatments since simple gene-replacement will not be effective to counter the dominant-negative mechanism. In this study, we propose to apply an in-situ RNA editing strategy by recruiting adenosine deaminase acting on RNA (ADAR) with guide RNA to simultaneously correct multiple G-to-A dominant negative mutations in COL6-RD patient-derived fibroblasts. We hypothesize this strategy will significantly decrease the mutant alleles’ presence at mRNA level and result in decreased intracellular retention and increased deposition of collagen VI matrix.

The TGFβ pathway as a therapeutic target for collagen VI-related muscular dystrophy

Awardee: Payam Mohassel

Institution: Johns Hopkins University

Grant Amount: $113,008.00

Funding Period: February 1, 2023 - January 31, 2024

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Summary:

Mutations in collagen VI cause a spectrum of muscle disease ranging from severe Ullrich congenital muscular dystrophy to the milder Bethlem myopathy. Collagen VI is an integral component of the extracellular matrix. When collagen VI is not functioning properly due to mutations, skeletal muscle will develop weakness, atrophy, degeneration, and fibrosis. We have recently identified alterations in regulation of the TGFβ pathway in human muscle biopsy samples of patients with COL6-related dystrophies (COL6-RD). We have also found a similar alteration of this pathway in a new mouse model of the disease, Col6a2 knockout mice. The overall goal of this project is to help identify novel therapeutic targets in COL6-RD that engage the TGFβ pathway and to test them in the mouse model. We trust that these studies will increase our understanding of this pathway in COL6-RD and pave the way for future studies of therapeutics that target this pathway.

DYSTRO-SMARTY: A novel nanotechnology platform for delivery of nucleic acids to treat Collagen VI-related Congenital Muscular Dystrophy

Awardee: Cecilia Jimenez-Mallebrera

Institution: Hospital Sant Joan de Deu

Grant Amount: $48,876

Funding Period: February 1, 2022 - January 31, 2023

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Summary:

Nucleic-Acid based therapies are being developed at a fast pace with 11 currently approved products and many more in the pipeline. However, delivering therapeutic amounts of these nucleic acids to the target tissue remains the major hurdle, particularly for muscle diseases. Here we propose to apply a validated nanotechnology platform, SMARTY, based on non-liposomal lipid-based nanovesicles, called Quatsomes, to deliver nucleic acids to treat COL6-related Congenital Muscular Dystrophy (COL6-CMD). These nucleic acids are antisense oligonucleotides (ASO) that we have designed and tested to correct a common mutation in collagen VI genes. ASO will be conjugated to the Quatsomes and their physico-chemical properties, distribution and integrity inside the cell as well as their specificity and efficacy to correct collagen VI mutations will be systematically investigated in cells from COL6-CMD patients. The Quatsomes platform (patent WO/2020/229469), developed by our collaborators (at VHIR and ICMAB-CSIC), has already been exploited for other applications for effective intracellular delivery of nucleic acids. Moreover, Quatsomes will be produced by a GMP compliant manufacturing process. This will facilitate the future translation and approval of this potential therapy by regulatory agencies bringing COL6-RD closer to Clinical Trial Readiness.

Studying in-situ, in-vivo, and in-silico the pleiotropic action of collagen-VI to identify potential late-onset risks in COL6-CMD patients

Awardee: Jeanette Erdmann

Institution: Universität zu Lübeck

Grant Amount: $48,876

Funding Period: February 1, 2022 - January 31, 2023

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Summary:

Due to better healthcare, COL6-CMD patients have a significantly longer life expectancy today than a few decades ago. For future health management of these patients early recognition of potential late-onset disease risks such as aneurysms, cardiovascular, and intestinal diseases can be vital. We will make use of col6a2 KO zebrafish (by morpholino antisense oligonucleotides) to comprehensively study the pleiotropic action of collagen-VI. Moreover, we will leverage human genetic data from UK biobank to identify by phenome-wide association study associations between genetic variants in COL6A2 gene and potential disease risks. Both strategies may help us to identify potential late-onset risks in COL6-CMD patients.

Targeting muscle stem cells for the treatment of Collagen VI muscular dystrophies

Awardee: Nicholas Dumont

Institution: CHU Sainte-Justine research center (University of Montreal)

Award Amount: $42,406

Funding Period: February 1, 2021 - January 31, 2022

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Summary:

Mutations in one of the genes encoding for Collagen VI cause Ullrich muscular dystrophy (severe form) or Bethlem myopathy (milder form). These rare genetic diseases are characterized by progressive muscle weakness and degeneration, which can lead to functional incapacities such as impaired or delayed walking. The effect of collagen VI deficiency on muscle degeneration has been characterized; however, its impact on muscle stem cells, the engine of muscle repair, is unknown. Therefore, the overall goal of this project is to investigate if the myogenesis capacity (formation of new muscle tissue) of muscle stem cells is affected by the lack of collagen VI. We will collect samples from patients affected by collagen-VI muscular dystrophies to study muscle stem cell defects in vitro. Moreover, we will use a 3D muscle-in-a-dish system to screen for therapeutic drugs that enhance the myogenesis capacity of muscle stem cells. Overall, this project will provide a better comprehension of this rare muscular disease, and it will open the way to new therapeutic avenues.

Novel tools for drug repurposing in COL6 myopathies: accelerating the route towards therapy.

Awardee: Paolo Bonaldo

Institution: University of Padova, Department of Molecular Medicine

Award Amount: $42,406

Funding Period: February 1, 2021 - January 31, 2022

Generation and Characterization of a Collagen VI Muscular Dystrophy Zebrafish Model for Drug Screening

Awardee: Robert Bryson-Richardson

Institution: Monash University

Award Amount: $91,176

Could exon skipping strategies be used as a treatment for recessive Ullrich Congenital Muscular Dystrophy?

Awardee: May Aung-Htut

Institution: Murdoch University

Award Amount: $50,699

Funding Period: February 1, 2019 - January 31, 2020

A novel RNA-based CRISPR strategy for treating congenital muscular dystrophy

Awardee: Jamie Fitzgerald

Institution: Henry Ford Health System

Award Amount: $50,699

Funding Period: February 1, 2019 - January 31, 2020

CRISPR/Cas9 nuclease design to target allele-specific Collagen VI mutations in patients' fibroblasts

Awardee: Alessandra Recchia

Institution: University of Modena and Reggio Emilia

Award Amount: $41,831

Funding Period: January 1, 2018 - December 31, 2018

Rescue of cardiac nicotinamide adenine dinucleotide (NAD+) content improves cardiac function in dilated cardiomyopathy in CMD caused by lamin A/C gene

Awardee: Antoine Muchir

Institution: Center of Research in Myology UPMC

Award Amount: $47,000

Funding Period: January 1, 2017 - December 31, 2017

Galectin-1 protein therapy for the treatment for Laminin alpha2 related Congenital Muscular Dystrophy

Awardee: Pam Van Ry

Institution: University of Nevada School of Medicine

Award Amount: $35,000

Funding Period: January 1, 2015 - December 31, 2015