NBIA NEWS & INFORMATION

BPAN researcher develops stem cell model, awaits funding for planned drug screening

September 2023

By Patricia Wood 

Dr. Paul Lockhart of Murdoch Children's Research Institute of Melbourne, Austrailia, establishes "brain cell" model for BPAN research.

Dr. Paul Lockhart of Murdoch Children’s Research Institute in Melbourne, Australia, says that while his BPAN research established an important ‘brain cell’ model using stem cells from affected BPAN individuals, his next step — to screen drugs for treatment — awaits sufficient funding to proceed.

Lockhart received $60,561 in February 2020 from the 2019 Million Dollar Bike Ride grant
program that our families supported. He planned to do the drug screening after his initial findings, but the pandemic led to staffing shortages and much higher drug screening costs than anticipated. As a result, he returned $25,814 in unspent funds this spring. That money was added to this year’s funds raised for the University of Pennsylvania sponsored bike ride and will now help fund two $60,000 BPAN research grants in the current grant call underway. 

Lockhart says the model he developed with stem cells from BPAN individuals will be used to
screen 3,000 compounds approved by the Food and Drug Administration in the search for a
BPAN treatment. The screening process will require multi-year funding to identify drugs capable
of restoring the normal cell functioning called autophagy, which is the removal and recycling of
damaged cells.

Lockhart’s project was titled “Development of novel human stem cell models of BPAN for disease modeling and drug screening” and was part of a larger project that was the first research into BPAN undertaken in Australia. It was made possible in 2019 with an anonymous $200,000 donation in honor of Angus Hunter, who has BPAN. The Hunters live in Melbourne and are active in raising awareness and funds for BPAN research.

Lockhart’s team used skin cells from six affected children. These samples were converted into induced pluripotent stem cells (iPSCs), which can then be converted into almost any type of human cell.

The team also did gene editing to generate an identical matching (isogenic) iPSC that corrected the genetic change causing BPAN. The researchers converted these matched pairs into brain cells in a lab dish and analyzed them to determine what effect the genetic change was having on cell structure and function. These biochemical studies investigated how well the autophagy pathway operated in the mutant cells.

A talk on this work given at our 2021 family conference BPAN research update session can be viewed here starting at the 3:25 minute mark.

Lockhart, who spoke at our 2021 family conference about this work, said that
a method from the iPSC was developed for successfully generating neurons
and also glia that essentially work normally. This demonstrated that there was
no significant impact of the genetic change on the ability of cells to survive,
convert to different types of brain cells and form the linkages between cells
that are critical for brain function.

Furthermore, analysis of the autophagy pathway demonstrated that this was
not functioning properly in affected cells compared to the controls. This finding
confirmed that the iPSC model could replicate what has been observed in other
cell and animal models, demonstrating its utility as a preclinical model to
understand the effect of BPAN on brain function. Although Lockhart was not
able to complete additional studies, his group demonstrated that rapamycin, an
FDA approved drug, could increase autophagy activity in the model.

This ‘brain cell’ preclinical model of BPAN is important, Lockhart said, because
it “means we can generate the brain cell types that are specifically affected in 
individuals with BPAN. This includes cortical neurons, important for cognitive function, and dopaminergic neurons, which are important for movement.”

Lockhart plans to publish his results and will undertake drug screening when funding allows.

2022 Million Dollar Bike Ride results in $69,775 for BPAN research

April 2023

Professor Betrand Mollereau of ENS-Lyon in France, was the 2022 MDBR research grant recipient.

Thanks to fundraising efforts by BPAN families and a matching grant from the University of Pennsylvania’s Orphan Disease Center, new BPAN research is now underway to better understand what causes the disease.

Professor Bertrand Mollereau of Ecole Normale Supérieure de Lyon, (ENS-Lyon) in France, received $69,775 as the 2022 BPAN research grant recipient from this annual in-person and virtual bike-riding event.

Mollereau and his co-investigators on the project at ENS-Lyon, Dr. Ludivine Walker and Marion Celle, will spend a year studying autophagy. Autophagy is the cell’s housekeeping and recycling process in which a cell breaks down old, damaged or abnormal parts and reuses some of them to keep the body functioning smoothly. Sometimes, however, the process doesn’t work the way it should.

Defective autophagy has been observed in several BPAN cellular and animal models. Some scientists think insufficient autophagy could be responsible for neurodegeneration in BPAN patients. Hence, a research priority is identifying novel therapeutics that restore the cleaning-and-recycling system.

Collaborating with Mollereau’s lab on the project is Dr. Apostolos Papandreou of University College London. He and colleagues at the Kurian/Ketteler laboratories at UCL have identified small molecule compounds that correct autophagy in certain types of stem cells taken from BPAN patients known as cultured induced pluripotent stem cells (IPSC).

An important step in selecting the best compounds is to show how well they work in an animal model of the disease. For this purpose, Mollereau and co-investigators have developed an animal fly model of BPAN that exhibits hallmarks of the disease, such as an autophagy defect, iron accumulation, neurodegeneration and a movement disorder.

For his part of the project, Papandreou will continue characterizing compounds in IPSC. These cells have unique properties of self-renewal and can be made into many other types of cells. Mollereau and co-investigators will select the best molecule compounds that restore autophagy to these stem cells to see if they can rescue the cellular and movement defects in BPAN flies.

The resulting compounds will then be tested in a larger animal, with a goal of creating a clinical trial to see if one or more of these compounds might benefit BPAN individuals.

Mollereau’s project is titled “Establishing autophagy inducers as novel therapies in cellular and animal models of Beta-propeller Protein-Associated Neurodegeneration (BPAN).”

Two MPAN grants worth $140,000 awarded to further disease insights

 December 2022

The NBIA Disorders Association, along with three sister organizations in Europe, have awarded two MPAN grants that will forward research priorities set during a workshop on Mitochondrial Membrane Protein-Associated Neurodegeneration.

Dr. Lena F. Burbulla of the Ludwig-Maximilian University in Munich, Germany, and Dr. Rajnish Bharadwaj of the University of Rochester Medical Center, Rochester, New Jersey, each received one-year research grants of $70,000 to study MPAN.

The funding was made possible through an international collaboration that also included the Associazione Italiana Sindromi Neurodegenerative da Accumulo di Ferro (AISNAF) in Italy, Hoffnungsbaum e.V. in Germany and Stichting Ijzersterk in The Netherlands.

In a 2021 workshop led by Dr. Francesca Sofia, founder and chief executive of Science Compass in Milan, Italy, researchers collaborated to collect data as well as assess strengths, challenges, and trends in MPAN research to establish a set of scientific priorities. For details, see page 8 of our December 2021 Newsletter.

Dr. Lena Burbulla of Ludwig-Maximilian University in Munich, Germany, receives a $70,000 research grant to study MPAN in December.

Burbulla’s research involves human disease modelling by creating patient-derived cells to discover new underlying mechanisms driving pathology in MPAN. To do so her lab uses induced pluripotent stem cells (iPSCs) generated from skin cells from people affected with MPAN. Burbulla’s team will utilize these stem cells – that theoretically can be turned into any type of cell in the body – to generate dopaminergic nerve cells that are known to be affected in MPAN patient brains. Dopaminergic nerve cells produce the neurotransmitter dopamine, a chemical messenger involved in regulating body movements, memory, motivation, attention, learning and more.

Mutations in one specific gene, C19orf12, are the only known cause of MPAN. The function of the resulting protein C19orf12 remains largely unknown. Disease modelling approaches will help the researchers examine, in a patient-specific model, the C19orf12 protein function and, most importantly, how brain cells are impacted when this protein is impaired or lost. Burbulla and her team will investigate the effect of loss of C19orf12 function in mitochondrial health in these patient nerve cells. The mitochondria are the “powerhouses of the cell” producing about 90% of the energy cells need to survive. When mitochondria are damaged, disastrous consequences for the cell can occur, along with a toxic series of events that culminate in nerve cell death. Given that the C19orf12 protein is known to associate with mitochondria, its loss of function may affect mitochondria and have wide-ranging impacts on cell health and resilience.

The stem cell model will enable the researchers to compare the MPAN cells to healthy cells and better understand the protein’s role. They will also look beyond mitochondria for disease-associated pathology, probing for possible alterations in the processing of the neurotransmitter dopamine in these nerve cells, as well as a protein called alpha-synuclein, known to pathologically accumulate in MPAN patient brains.

Alpha-synuclein is found on the ends of nerve cells in the synaptic terminals — the area between neurons where the neurotransmitters are released to relay messages throughout the body. Abnormally shaped or overly abundant alpha-synuclein leads to aggregation, or clustering, of the proteins and inhibits normal neuron function.

Dr. Rajnish Bharadwaj of the University of Rochester Medical Center, in Rochester, New Jersey, receives a $70,000 grant to research MPAN in December.

Baharadwaj’s research will focus on better understanding the proteins produced by the C19orf12 gene. His team will use fruit fly models that have been genetically engineered to lack the CG3740 and CG11671 genes, which correspond to the C19orf12 gene in humans.

Previous studies from other groups and his ongoing work have shown that the model flies have shorter life spans, deficits in movement and loss of neurons in the brain and retina. This suggests that the fruit flies will be a promising model to study NBIA.

The team’s studies also suggest the C19orf12 is a membrane contact site protein that may be involved in communication between organelles, specialized subunits within the cell, such as the endoplasmic reticulum and lipid droplets (fats). The endoplasmic reticulum’s role in the cell is to produce proteins, and it’s involved in the production and storage of lipids.

The team’s goal is to study how the C19orf12 protein is involved in lipid metabolism and mitochondrial function. Lipid metabolism is the process of production and degradation of lipids, or fats, in cells. The researchers want to uncover this role in the brain and other organs. Both lipid metabolism and mitochondrial function are implicated in other forms of NBIA as well.

Overall, the creation and study of these disease models and subsequent research will advance the understanding of MPAN and pave the way for developing treatments.