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Transferring NOn autonomous cell degeneration models between EU and USA for development of effective therapies for Motor Neuron Diseases (MND)

Final Report Summary - NO-MND (Transferring NOn autonomous cell degeneration models between EU and USA for development of effective therapies for Motor Neuron Diseases (MND).)

Many human diseases, in particular neurodegenerative disorders, have been traditionally classified as “cell autonomous” pathologies, meaning that damage within a specific population of vulnerable cells (i.e. neurons) alone is sufficient to cause the disease. However, recently, the concept of non-autonomous mechanisms increasingly emerged, meaning that diseased cells, such as astrocytes, cause the pathological phenotype of other cells (motor neurons, MNs), regardless of their status.
The NO-MND project addressed different aspects of non-autonomous cell death in the pathogenesis of MN diseases (MNDs), improving the development of therapeutic strategies designed to diminish morbidity and mortality of these severe disorders. The primary objective was achieved by forming a strong research partnership and realizing staff exchange in order to reinforce a network with significant international impact. The project strengthened the cooperation between two European academic institutions from Italy and Greece, and one other organization from the USA:
This project involved academic researchers with long-standing expertise in the field of MNDs. This complementary team at the European and USA level permitted a successful execution of the project, allowing a prompt and effective translation of the results in meaningful approaches towards clinical application.
NO-MND objective. MNDs, including Amyotrophic Lateral Sclerosis (ALS) and Spinal Muscular Atrophy (SMA), are severe debilitating neurological diseases characterized by selective and progressive degeneration of MNs. Glial cells play a pivotal role in the non-autonomous loss of MNs in these diseases. The main goal of the NO-MND program was to decipher the mechanisms underlying cell death caused by non-neuronal cells as possible therapeutic targets. This was achieved via two research lines: 1) developing and studying in vitro disease platforms to elucidate cellular and molecular interactions between non-neuronal cells and MNs using cell reprogramming and differentiation methodologies; 2) assessing the possible therapeutic effect caused by the transplantation of non-neuronal cells into MND models.
Work program. NO-MND was organized in six work packages (WP). WP1 was devoted to project management and network establishment and coordination. WP2 and 3 focused on in vitro experiments employing astrocytes obtained from reprogrammed skin fibroblasts of patients with ALS (WP2) and SMA (WP3). Human MND astrocytes have been co-cultured with human pluripotent stem-cell-derived MNs, establishing a complete human co-culture system. WP4 and WP5 analyzed the transplantation of glial and neuronal restricted precursors (GRPs and NRPs) obtained from induced pluripotent stem cells (iPSCs) as a therapeutic approach for ALS (WP4) and SMA (WP5). WP6 was concerned with training, practice and dissemination activities.
Achievements. NO-MND program produced important scientific outcomes, not just in terms of knowledge transfer between the participants, through training activities and networking, but also as experimental studies. Herein we demonstrated that ALS/SMA patient iPSC-derived astrocytes modulate MN degeneration in a non-cell autonomous manner in in vitro and in vivo models.
The principal scientific achievements obtained from each of the work packages are as follows: WP1: comprehensive networking and organization of project activities; WP2: establishment of a fully humanized in vitro model of ALS by which we demonstrate that, unlike healthy astrocytes, only ALS astrocytes are capable of killing MNs in a selective way; WP3: confirmation that human SMA MNs possess a reduced rate of survival in culture, and that this can be ameliorated by up-regulating SMN protein level by oligonucleotides or small molecules. The role of astrocytes in SMA MN death was also analyzed. We determined how astrocytes induce MN death in ALS/SMA by combined proteomics and genomics approaches. We identified pivotal players driving the death phenotype that represent promising target for gene therapy. WP4-5: generation of GRPs and NRPs derived from iPSCs for cell transplantation experiments in ALS/SMA models. Transplantation with a specific sub-population of neural stem cells in ALS/SMA models have been performed in parallel. We observed a neuroprotective effect of the transplanted donor cells, which successfully prolonged the onset of disease and increased the survival of MNDs models. We pointed out that the precise selection of a specific donor cell population is critical for the engraftment and therapeutic action.
The NO-MND WPs have been executed through highly successful researcher exchanges amongst the partners. Four international symposia and numerous meetings were held. Researchers presented their results in seminars, and contributed to the writing of 25 journal papers, and more than 23 abstracts, and presentations in over 11 international conferences.
Benefits and outgrowth. Our results suggest that neuronal selective vulnerability in MNDs can be most probably caused not only by MNs, whose progressive degeneration is hallmark of MNDs, but also by the concomitant convergence of several disease-causing factors triggering damage within the vulnerable neurons and multiple surrounding cell types, in particular astrocytes. This is a significant aspect when developing treatment modalities, as they could be designed by targeting any of the mechanisms and cell subtypes implicated.
NO-MND people exchange and dissemination actions, including seminars, workshops, symposia, and collaborative writing of scientific papers and abstracts, have produced a variety of new connections and collaborations amongst researchers from the host Institutions and other scientists outside the Consortium. NO-MND knowledge transfer and networking generated several scientific publications including an article detailing the contribution of non-neuronal cells to SMA pathogenesis co-authored by all the partners. Three co-authored research papers are under submission. The participants had the opportunity to focus their research activity to gather knowledge in iPSCs and cell transplantation protocols so as to enhance the knowledge at hand pertaining to the present day technology and developing novel experiment scenarios for the effective treatment of MNDs. Bi-directional exchange of knowledge amongst EU and Third country has been instrumental in enhancing the collaboration and for the achievements of significant results in MNDs field. Overall, NO-NMD project provided substantial contributions to the understanding and to the development of meaningful therapeutic strategies for ALS and SMA patients.