P²ALS

The Robert Packard Center for ALS Research and Project A.L.S. have joined forces to advance ALS science and efforts toward therapy worldwide. Funded by an anonymous grant with a requirement for clear milestones and deadlines, the two "P" organizations, known as P²ALS, are pooling key researchers for the first time.

P²ALS concentrates its energy on three broad aims: 1) understand glial and motor neuron signaling 2) uncover genes that cause or increase the risk of ALS while we advance gene silencing therapy and 3) use the most advanced stem cell techniques to develop human-based models that will speed therapy. The following Packard Center researchers are now involved in P²ALS:

Bergles | Bridges | Cleveland | Gerdes | Kaspar | Maragakis | Rothstein

Dwight Bergles, PhD

Johns Hopkins School of Medicine
Developmental potential and consequences of NG2 glia proliferation in ALS

The goals of our project are to define the fate of proliferating NG2 cells in the context of motor neuron degeneration in mouse models of ALS, and see if the proliferation and likely differentiation of these glial cells accelerates ALS. As part of the P2ALS group, we will also assist in identifying glial cell types generated from iPS cells and glial restricted precursors.

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Don Cleveland, PhD & Brian Kaspar, PhD

Ludwig Institute for Cancer Research, UCSD / Research Institute at Nationwide Children’s Hospital, OSU
Targeting astrocytes as a therapy for ALS: testing the effectiveness of AAV9 as a therapeutic vector for gene delivery across the blood brain barrier

We will examine the effectiveness of gene delivery to astrocytes, via peripheral administration of adeno-associated virus (AAV9), as a potential gene therapy in ALS. AAV9-based approaches can determine if reducing mutant SOD1 within astrocytes — starting when symptoms have appeared — is effective in slowing disease progression. Last, we will test whether AAV9-mediated delivery through the blood brain barrier can effectively carry either of two growth factors (IGF-1 and VEGF) into the nervous system. IGF-1 and VEGF delivered by other routes have been reported effective in slowing disease.

If successful, these studies may prove the principle of this kind of viral delivery as a new tool for central nervous system therapy for ALS and other neurodegenerative diseases.

Specifically, the Kaspar lab will produce AAV9 vectors to express Cre recombinase, siRNA vectors against SOD1, IGF-1 and VEGF for use in ALS studies.

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John Gerdes, PhD & Richard Bridges, PhD

University of Montana
Cerebral positron emission tomography (PET) imaging agents for monitoring ALS therapy and astroglia: from chemicals to rodents to humans

The EAAT2 molecule is a cell membrane protein that removes an excess of the neurotransmitter glutamate. Abnormalities in EAAT2 quantity or in its behavior have long been tied to ALS. This could make the molecule a good indicator, or biomarker, of nervous system health. At some point, it could provide a way to measure if treatment is effective.

In our supported research, we hope to create a radioligand (tracer) molecule targeted to the EAAT2 protein. The tracer will enable us to detect the EAAT2 biomarker noninvasively within the brain and spinal cord, using positron emission tomography (PET) imaging. Our challenge comes in designing a tracer with a unique chemical structure — a molecule with a high affinity for the EAAT2 target protein, one that can penetrate the brain’s natural barriers and that reaches specific central nervous system tissues. Ultimately, data from our studies may lead to a noninvasive way to monitor ALS in the clinic.

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Nicholas Maragakis, MD

Johns Hopkins School of Medicine
Engraftment of iPS cells in vivo: biology, alteration, survival of host motor neurons

Investigator Nicholas Maragakis is undertaking studies that compare what happens to cells destined to become motor neurons when they’re inserted into spinal cords of healthy rats. The key is that these “precursor” cells are derived from healthy individuals, from those with sporadic ALS or from familial (SOD1) ALS.

He’s also investigating the fate of cells destined to become glia cells (another nervous system cell) when inserted into the spinal cords of healthy rats. These precursor cells, as well, are derived from healthy individuals, from those with sporadic ALS or from familial (SOD1) ALS.

He’s then repeating the studies, only, this time, transplanting cells into the spinal cords of rats that are SOD1 models of ALS, not only to see how the cells behave, but also to see if there’s any slowing or halting of disease.

All of the precursor cells used are products of iPS cells—the stem cells that can be formed from adult skin fibroblast cells.

This will give Maragakis information about the usefulness of transplanted cells destined to become motor neurons or glial cells. It’s possible that the added cells will be protective, that they may replace dead or dying cells or that they’ll prompt the nervous system to make its own replacement cells.

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Jeffrey Rothstein, MD, PhD

Johns Hopkins School of Medicine
Molecular/protein Pathways of glial dysfunction in ALS mutant SOD1 and TDP43 models

Studies show that abnormally operating astroglia play a significant part in diseases like ALS. Their specific cellular defects, however, are poorly understood. The Rothstein laboratory will explore the existence of a novel mechanism for neurodegeneration in ALS, namely, the possibility that in the disease, astroglia can’t carry out a usual role of releasing the critical nutrient lactate to neighboring motor neurons which need it as a source of energy.

There’s data to suggest that dysfunctioning astroglial transporter molecules (called MCTs) contribute significantly to the advance of ALS.

1. MCTs and glial biology

Our laboratory aims to investigate the normal biology of MCTs on a molecular level. We’ll test the hypothesis that glia support neurons by transporting and releasing essential lactate to them via the transporter molecules MCT1/MCT4. Further, we’ll see if dysfunction of this pathway contributes to motor neuron death in diseases like ALS.

The team will work also with the Henderson and Eggan laboratories (P2ALS collaborators) to examine the biology of MCTs using cultures of potentially abnormal cells generated from living ALS patients. Those cultures are created using the newer induced pluripotent stem cell (iPS cells) techniques. With the Bergles lab at Johns Hopkins, we’ll also compare MCT1 biology in NG2 cells, oligodendroglia and astroglia.

Finally, the lab will generate ways to screen rapidly for drugs that can inhibit or activate the MCT1 molecules — a first step in developing therapies.

2. Gliogenesis via small molecules

In a second project, our lab will test a variety of chemicals/drugs on rodent and human NG2 cells in hopes of identifying small molecules that cause these immature cells to differentiate into mature astroglia — in lab dishes or animals. These experiments take advantage of extensive earlier research, a body of preliminary data and the existence of key reagents and mouse models.

3. Genetic analysis of astroglial in vivo biology

As a third project, the Rothstein group will generate transgenic mice carrying a newly developed technology, the “astroglial BAC-TRAP reporter” that will allow us to collect translated mRNA from their living astrocytes. This is a way to tell which genes are being expressed — or not — in the animals’ cells at any age or in any specific part of the central nervous system.

The idea is to see which genes are active or repressed in astroglia during ALS or other disease conditions. And that, in turn, gives us an edge in finding ALS genes.

Our lab has already perfected a way to separate astroglia from other cells in ALS mice. We’ve generated preliminary data to compare astroglia collected from healthy spinal cords and those from healthy brains. And we’re comparing astroglia from those regions in animals with ALS.

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