Research

Development of a novel therapy for muscle weakness in patients with mtDNA deletions using autologous, boosted, mutation-free mesoangioblasts

Principal Investigators:

Dr. Bert Smeets

Institution/Division:

University of Maastricht

Direct Cost Requested:

$35,265 over 1 year

Date Awarded:

November 2020

Lay Abstract:

In SLMDS, muscle weakness is an important, progressive debilitating feature for which no effective therapy is currently available. In this project, we will develop a novel therapeutic strategy by inducing muscle regeneration through the administration of large numbers of healthy, autologous muscle stem cells, called mesoangioblasts to the patient's blood. These mesoangioblasts migrate to affected muscles, grow into healthy muscle fibers and compensate loss of muscle strength. In a preliminary study, we have demonstrated that all CPEO patients with an mtDNA deletion have exclusively mutation-free, wild-type mesoangioblasts, despite high mtDNA deletion loads in muscle, and can be directly used for treatment. In this project we will extend this to Pearson and KSS patients and test if their mesoangioblasts are similarly comparable to healthy controls. As we have established a culturing protocol for mesoangioblasts, according to Good Manufacturing Practice (GMP), we will design a Phase II clinical trial, once safety of the treatment has been established in an ongoing Phase I/II trial. To improve our therapeutic strategy, we will also boost the mitochondrial content of the mesoangioblasts in order to more effectively increase the number of wild-type mtDNA in the muscle of mtDNA mutation carriers.

A screen of FDA-approved drugs that are mitophagy modulators to identify therapies for single large-scale mtDNA deletion disorders

Principal Investigators:

Dr. Suraiya Haroon and Dr. Marni Falk

Institution/Division:

Children's Hospital of Philadelphia

Direct Cost Requested:

$97,504.96 over 2 years

Date Awarded:

December 2020

Lay Abstract:

Mitochondria are components of our cells that are so specialized to make the energy we need to live that they their own DNA in order to streamline the production of energy. The genes in the mitochondrial genome (mtDNA) code for proteins essential in energy production and thus, maintaining the integrity of the mitochondrial genome is essential for human health. It is well-documented that single large deletions in the mitochondrial genome are pathogenic and can give rise to various diseases characterized by neuromuscular dysfunction such as Pearson's Syndrome and Kearn's Sayre Syndrome. Currently there are no FDA-approved cures or treatments for mitochondrial diseases. We will address this hurdle by taking two approaches to identify therapies using the microscopic worm model C. elegans. These worms are amenable to genetic and pharmacological manipulation, cost- effective and easy to rear. Most importantly, there already exists a strain that carries a single-large mtDNA deletion and such a mutant strain does not exist for any other model organism. Using this strain, we will first exploit the mechanism of mitophagy, the process by which dysfunctional mitochondria are degraded, in order to develop therapies. There are numerous publications showing that modulating mitophagy can impact mitochondrial disease progression and we will build on this knowledge to help develop targeted therapy for large-scale single mtDNA deletion diseases. Second, we will conduct a drug screen on 2560 FDA-approved and natural compound library to identify potential therapeutics. Any therapies identified to ameliorate the mutant worms using either avenues of inquiry will be validated in human patient cell lines. As an added benefit, since most compounds in the library is already considered safe for human consumption by the FDA, if some of them are able to rescue mitochondrial disease, these compounds can become available to patients more rapidly than novel compounds untested for human use.

Towards genome-wide screens to identify new drug targets in single large-scale mtDNA deletion syndromes

Principal Investigators:

Suneet Agarwal, MD, PHD

Institution/Division:

Boston Children's Hospital/Hematology-Oncology

Direct Cost Requested:

$100,000

Date Awarded:

July 2020

Lay Abstract:

Mitochondria are structures in our cells that perform numerous critical functions, including serving as the cell's energy production source or powerhouse. Unique among other structures in the cell, mitochondria have their own genome, called mitochondrial DNA (mtDNA). In a number of rare genetic diseases, there are mutations in mtDNA, resulting in defects in mitochondrial function, failure of cells and organs, and ultimately sickness and death. There are no effective therapies for mtDNA diseases. In single large-scale mtDNA deletion (SLSMD) disorders, such as Pearson syndrome and Kearns-Sayre syndrome, large segments of mtDNA are missing in some genomes, intermingled with normal mtDNA. In some cell types, we can see a shift in the balance of mutant to normal mtDNA over time, which correlates with disease improvement. In this study we aim to understand how the proportion of mutant mtDNA versus normal mtDNA can be shifted. Specifically, our proposal aims to develop new ways to 'count' mutant mtDNA in PS patient cells reliably. Such a tool would lead us to apply thousands of different treatments to PS cells and identify which of these will eliminate mutant mtDNA. If successful, these studies are expected to lead to new treatments for PS and a range of mitochondrial disorders.

Targeting cellular pathways disrupted in Pearson marrow pancreas syndrome

Principal Investigators:

Suneet Agarwal, MD, PHD

Institution/Division:

Boston Children's Hospital/Hematology-Oncology

Direct Cost Requested:

$100,000

Date Awarded:

February 2019

Lay Abstract:

Pearson syndrome (PS) affects multiple parts of the body over the lifespan. This poses a major challenge in developing genetic and cellular treatments, in terms of delivery to all the organs and tissues. Another problem with genetic therapies is a need to customize to the specific mutations in question. To address these barriers, we aim to develop strategies that will work throughout the body in PS patients, irrespective of the mutation. We will lay the foundation for these efforts under this grant by identifying pathways in cells that are commonly disrupted due to mitochondrial DNA (mtDNA) deletions. We will use PS patient cells and newly developed technologies that will enable us to analyze the effects of mtDNA deletions on cellular functions, at a previously unobtainable resolution. We expect that these studies, if successful, will provide new targets to develop systemic treatments for PS.

Developing a gene therapy approach to treat mtDNA deletion syndromes

Principal Investigators:

Carlos Moraes

Institution/Division:

University of Miami

Direct Cost Requested:

$100,000 over 2 years

Date Awarded:

July 2018

Lay Abstract:

We propose to develop a new class of mitochondrial-targeted DNA editing enzyme to eliminate mtDNA harboring large rearrangements. This new architecture, named mitoMeganuclease will cleave the mutant mtDNA allowing the wild-type to repopulate the cells. The second aim is to produce a mouse model of mtDNA deletions. We will transfer deleted mtDNA from cultured cells into mouse ES cells and produce females harboring mtDNA deletions. We will attempt to transmit these deletions through the germline. These two aims, if successful will advance the treatment of disease caused by mtDNA deletions.

Promoting clinical development of Mitochondrial Augmentation Therapy for Pearson Syndrome Patients

Principal Investigators:

Amos Toren, Elad Jacoby, Natalie Yivgi Ohana, Noa Sher, Moriya Blumkin

Institution/Division:

Sheba Medical Center, Israel

Direct Cost Requested:

$125,000 over 1 year

Date Awarded:

July 2018

Lay Abstract:

Our research and others have shown that healthy mitochondria can enter cells with damaged mitochondria and repair their function. Our preliminary results with several Pearson Syndrome patients demonstrate that healthy mitochondria taken from mothers can enter patient-derived blood cells and reduce symptoms related to Pearson Syndrome. We wish to advance this treatment to an FDA-cleared clinical trial, by providing preclinical proof that healthy mitochondria can rescue bone marrow function in mice. We also aim to optimize the system currently used to process patient samples. Finally, we will perform various tests of patient samples to identify possible markers that may correlate with clinical efficacy. Together, the results from funding will enable commencement of a clinical trial with optimal equipment, and provide a deeper understanding of treatment efficacy.

CD34+ cells enriched with blood cells derived healthy mitochondria as a treatment for Pearson Syndrome

Principal Investigators:

Amos Toren, Natalie Yivgi Ohana, Elad Jacoby, Ann Saada

Institution/Division:

Sheba Medical Center, Israel

Direct Cost Requested:

$130,000 over 1 year

Date Awarded:

April 2017

Lay Abstract:

A collaboration between hematologists from Sheba Medical Center (Prof. Amos Toren and Dr. Elad Jacoby), mitochondria-scientist from Hadassah-Hebrew University Medical Center (Prof. Ann Saada) and a researcher from a biotechnology company in Israel (Dr. Natalie Yivgi Ohana) has created a scientific research plan to bring a novel therapeutic approach to Pearson Syndrome. The technology, developed by Minovia Therapeutics over the past 6 years, is based on transplantation of normal mitochondria in patient's stem cells. The patient's own bone-marrow cells would be carriers of normal mitochondria from a donor (without deletions) and would carry normal mitochondria to other tissues through the blood stream. The group will first conduct animal studies to show the effect of such treatment on mice harboring a mitochondrial DNA mutation and use the results to apply to the FDA for a formal clinical trial.

Treatments and models for diseases caused by mitochondrial deletions

Principal Investigators:

Michal Minczuk and Payam Gammage

Institution/Division:

University of Cambridge

Direct Cost Requested:

$100,000 over 2 years

Date Awarded:

April 2017

Lay Abstract:

Mitochondria are cellular structures that provide energy from food that cells can use. They also contain DNA, called mtDNA. Intact mtDNA is vital for healthy functioning of the cell. Genetic mutations in mtDNA, where a single DNA building block is changed, or a part of mtDNA is deleted, can lead to human diseases, often affecting brain, heart, bone marrow and muscles. There are no treatments for these diseases. Our approach to treatment of mtDNA diseases is to design proteins that can specifically eliminate only the mutated mtDNA, curing patients' cells. We have already achieved this goal using in vitro models of mtDNA disease. The essential next step in bringing these proteins to the clinic is to test them in the types of cells that are affected in patients (neurons, muscle cells or blood cells) and in a living organism (in vivo). Therefore, in the first part of the proposed research, it is our intention to generate neurons, muscle cells or blood cells from patient skin cells that lack a fragment of mtDNA, into which we will administer therapeutic proteins. We expect that our intervention will improve the function of these cells, providing important pre-clinical data on the safety and efficacy of our approach. In the second part of of our planned research, we intend to develop a DNA-editing tool enabling us to cut out mtDNA fragments at will. Such a tool could be used in the future to produce animals with deleted mtDNA that would develop disease symptoms similar to human patients. These model organisms can be used to further test our therapeutic proteins and other drugs, providing the vital pre-clinical data required to take the next steps towards the use of experimental therapeutic strategies in humans.

Mitochondrial genome editing for Pearson Marrow Pancreas Syndrome

Principal Investigator:

Suneet Agarwal, MD, PHD

Institution/Division:

Boston Children's Hospital/Hematology-Oncology

Direct Cost Requested:

$100,000

Date Awarded:

February 2016

Lay Abstract:

A number of diseases are caused by dysfunction of the mitochondria, which are organelles in our cells that supply energy and perform other vital functions. Mitochondria contain many copies of their own genetic material (mtDNA), which encodes proteins critical for energy production. In mitochondrial genetic diseases, children are born with mutations in some copies of their mtDNA, resulting in dysfunction of a variety of organs that fluctuates throughout life. For example, in the mtDNA deletion disorder Pearson marrow pancreas syndrome (PS), children are born with severe blood disease and frequently digestive disorders, hormonal disturbances, and kidney problems. If children survive, they may go on to develop heart, muscle and nervous system disease as teens or young adults. For PS and other mtDNA disorders, therapy is supportive and there are no cures. A suggestion for how to tackle PS comes from observations of changes in the mtDNA in the patients themselves. Their mitochondria contain mixtures of normal and mutant mtDNA (called heteroplasmy), and over time, the ratio of mutant to normal mtDNA fluctuates in different tissues and correlates with disease. In laboratory studies, PS patient cells that are grown in a dish also show changes in the ratio of mutant to normal mtDNA over time. If we can understand this fluctuation better, and to think of ways to push the ratio in the direction of normal mtDNA in cells, we may be able to translate these insights and create new therapies for patients with PS. In this proposal, we aim to innovate and apply novel approaches to specifically deplete mutant mtDNA in PS patient cells. Our goal for this research project is to develop the tools and knowledge needed to develop a targeted therapy for patients with PS and related mtDNA disease.