The S100B/RAGE Pathway in Amyotrophic Lateral Sclerosis-induced Astrocyte Activation and Motor Neuron Death: a Potential Target for Therapy
Project location: ITALY, Rome
Project start date: September 2016 - Project end date: February 2018
Project number: 2016-033
Beneficiary: Università Cattolica del Sacro Cuore
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting brain and spinal motor neurons, with a median survival time from 20 to 48 months from symptom onset. No cure is known for ALS, since pathophysiological mechanisms contributing to the disease onset and development are essentially unknown. Anyway, some promising clues have been open. A pathological hallmark of ALS is motor neuron death enhanced by non-neuronal cells (astrocytes, microglia) via an inflammatory response, which accelerates the disease progression. In this respect, at present the comprehension and the consequent control of the molecular mechanisms at the basis of astrocytic dysfunction in ALS are regarded to be of fundamental importance to limit neuronal injury and the progression of the disease. Astrocytes are main players in this scenario acting on motor neurons through direct and indirect mechanisms.
Most of the aberrant pathways that lead to astrocytosis highlight the critical role of dysregulated intracellular calcium levels. S100B is a Ca2+-binding protein present in astrocytes and involved in regulatory processes upon modifications of intracellular Ca2+ concentrations. Importantly, S100B can also be secreted by astrocytes at high concentrations behaving as a neuroinflammatory mediator and displaying toxicity through its binding to the receptor for advanced glycation end-products (RAGE). In astrocytes, S100B is also known to activate a RAGE-dependent autocrine loop inducing proinflammatory neurodegenerative features. Important evidence would indicate that astrocyte activation in ALS deeply involves S100B: during ALS progression S100B increases selectively in astrocytes and motoneurons of patients, and the S100B/RAGE pathway has recently been shown to be upregulated in human ALS spinal cord. In addition, in an ALS rat model S100B is augmented in 'aberrant astrocytes', characterized by an increase in neurotoxic potential.
Thus, the understanding of the role played by S100B in ALS astrocytes and in their interplay with neurons through RAGE could be useful to counteract neuroinflammation and motor neuron death in ALS. This project is aimed at studying the role of astrocytic S100B protein as an intracellular and extracellular mediator of astrocyte activation and consequent motor neuron toxicity. The working hypothesis - which is also based on preliminary data of the proposers indicating that astrocyte activation in ALS involves the overexpression and secretion of S100B and that its downregulation in ALS astrocytes decreases several proinflammatory features - is that the induction of S100B in astrocytes, its release and its autocrine/paracrine effect through RAGE could represent an hazardous mechanism that takes place during ALS, putatively representing a part of a final common pathway in the pathological process. Therefore, targeting the action of S100B at different levels (production, activity, release) might reduce the pathogenic astrocytic potential and motor neuron death, eventually ameliorating the progression of the disease: this will be the purpose of the present project.
The research will be performed at the Institute of Anatomy and Cell Biology of the Università Cattolica del Sacro Cuore (UCSC) Medical School, under the direction of Professor Fabrizio Michetti. UCSC Medical School is located in the Rome campus and works in close partnership with the University Hospital “Agostino Gemelli”, one of the largest and most important medical institutions in Italy with 70,000 discharges per year. Research Groups operating within the University retain a documented expertise in both basic and clinical research in the field of neuromuscular diseases, and, in particular, of amyotrophic lateral sclerosis (ALS), being part of large international multicenter studies. In particular, the research group coordinated by Prof Michetti has a wide and documented expertise in the study of the morphological and molecular features associated to neurodegeneration. The Institute of Anatomy and Cell Biology is fully equipped for most advanced molecular/cell biology and immunocytochemistry studies, and a fully equipped animal house is also available for the Institute.
The study will use an approach based on co-cultures of neurons and astrocytes to investigate the possible relation between secreted astrocytic S100B and its interaction with its receptor RAGE in neurons. The expression of S100B will also be experimentally inhibited in ALS astrocytes to test the possible attenuation of their detrimental potential. Finally the synthesis of S100B will be inhibited using gene modification in an animal model of ALS (SOD1G93A mice) and survival, motor performances and histopathological features will be evaluated in these animals. The Nando and Elsa Peretti Foundation has awarded a grant for this project. The research program is supposed to be performed in 2 years.
In summary, the attainment of the expected results would identify S100B as a new potential therapeutic target for the treatment of ALS: achievements obtained by this basic research project can have an immediate preclinical translational outcome as S100B and RAGE could represent the targets to test druggable inhibitors, to analyse the effects of pharmacological inhibition of the S100B pathway on ALS course. In addition, the knowledge of molecular targets downstream of S100B possibly involved in the conversion of astrocytes into a neurotoxic phenotype, could suggest new therapeutic clues to be explored in ALS. It may also be relevant, in this respect, that structure-based studies oriented to identify novel S100B inhibitors are currently under investigation. Finally, although ALS is a rare disease, it has many features that are common to other more frequent neurodegenerative syndromes such as Alzheimer’s and Parkinson’s diseases. In all these cases neuroinflammation occurs with similar mechanisms, players and outcomes. Therefore the results obtained by this study could provide beneﬁts with wide-reaching applications, elucidating mechanisms that could occur in a similar fashion in other neurodegenerative diseases.
Among the universities which award legally recognized degrees (as with Italian State Universities), the Università Cattolica del Sacro Cuore (UCSC) is the most comprehensive and complete in Italy. The network of Cultural Development Centers extends as far as the Italian islands, making the University strongly national, with the added bonus of also being recognized in the international scientific community. On the whole UCSC offers diverse and articulate study opportunities both in the humanities, as well as in the scientific fields. The extensive research program closely collaborates with 16 internal colleges, 62 departments and 93 research centers. Their common goal is the understanding and study of those topics that have proved vital to the well being of each human being: the new frontiers of economics, bioethics, environmental recuperation, developments in the judicial fields, family dynamics, major mass phenomena, the evolution of political systems, new horizons in medicine, the technological applications of physics and mathematics, and the most recent discoveries in environmental research.
The "Agostino Gemelli" UCSC Medical School was established in Rome on November 5th, 1961 under first university president Professor Francesco Vito. Also in attendance were the current and future popes - Pope Giovanni XXIII, and the Milan Archbishop, Cardinal Giovanni Battista Montini, who was subsequently elected Pope Paolo VI.
UCSC Medical School is located in the Rome campus, comprising two courses leading to a degree in Medicine and Surgery (one Italian-speaking degree and one English-speaking degree) and a degree in Dentistry. The Faculty works in close partnership with the 2,000-bed university hospital “Agostino Gemelli”, one of the largest and most important medical institutions in Italy with 70,000 discharges per year. Research Groups operating within the University retain a documented expertise in both basic and clinical research in the field of neuromuscular diseases, and, in particular, of amyotrophic lateral sclerosis (ALS), being part of large international multicenter studies. In particular, the research group coordinated by Prof Michetti, who is an internationally recognized neuroscientist, has a wide and documented expertise in the study of the morphological and molecular features associated to neurodegeneration. The Institute of Anatomy and Cell Biology is fully equipped for most advanced molecular/cell biology and immunocytochemistry studies. A fully equipped animal house is also available for the Institute.
The Principal Investigator (P.I.) of this project is Prof Fabrizio Michetti. Prof Michetti (1970 M.D.;1974 Neurologist; 1977 Psychiatrist, UCSC) is Full Professor of Anatomy since 1986, and Chairman of the Institute of Anatomy and Cell Biology, School of Medicine, UCSC, since 1999. The research group coordinated by Prof Michetti, which operates in strict collaboration with clinical neurologists at the Policlinico Universitario Agostino Gemelli, has a wide and documented expertise in the study of the morphological and molecular features associated to neurodegeneration. In particular, the research group includes Dr Nadia D'Ambrosi and Dr Camilla Bernardini, who are internationally recognized investigators mainly involved in ALS studies, with specific expertises in cell biology and molecular biology , respectively,and Dr Maria Concetta Geloso, who is an internationally recognized investigator involved in neurodegeneration studies, with a specific expertise in morphological investigations. In this respect, the establishment of a biobank for tissues from ALS patients, funded by the Associazione Italiana Sclerosi Laterale Amiotrofica (AISLA), is currently in progress, in collaboration with Dr Mario Sabatelli (Insitute of Neurology, Policlinico Universitario Agostino Gemelli) at the Institute of Anatomy and Cell Biology of the Università Cattolica del S. Cuore. Prof Michetti is also Director of PhD program in Molecular Morphology (UCSC; Università di Lecce),since 1997, and member of the academic board for the PhD program in Neuroscience, UCSC, since 1999. He is the Coordinator of the Latium Musculoskeletal Tissue Bank (since 2006). Appointed to hold a course on Neuroanatomy, Master’s degree in Bioengeneering, University Paris Descartes (since 2011). Appointed to be a Member of the Faculty of the School for Mental Health and Neuroscience -course “From Human Neuroanatomy to Psychopathology”, Maastricht University (2016). Member of the Editorial Board of Neurochemical Research (since 2015) and of the Journal of Chemical Neuroanatomy (since 2015). Member of the Council of the European Society for Neurochemistry (since 2015).2006/2010: delegate from the Italian Gouvernment in the Management Committee and Chairman of the Working Group “Neurodegenerative Processes” of the COST B 30 action “Neural Regeneration and Plasticity”. He acted and currently acts as a reviewer for international scientific journals (including Acta Neuropathologica, Clinical Chemistry) and for national and international research projects (including (Università Cattolica del S.Cuore, Italian Ministry for University, Italian Ministry for Health, Italian National Agency for the Evaluation of Universities and Research Institutions, Spanish Ministry for Health, Greek Ministry for Education, Polish-Norwegian Research Programme, Executive Agency for Higher Education of Romania, V European Framework Program-Panel Neuroscience, VI European Framework Program-Panel V European Framework Program-Panel Neuroscience, VI European Framework Program-Panel Stem Cells, VII European Framework Program-Panel Neurodegeneration-Panel Biomarkers-Panel Innovation). He is the author of 157 papers published in full in international scientific journals (including Nature, The Lancet). Personal Impact Factor:670. H index: 37 (ISI). He is the applicant of one EU/USA granted patent.
The Institute of Anatomy and Cell Biology is fully equipped for most advanced molecular/cell biology and immunocytochemistry studies. The facilities include a microarray GeneChip Affymetrix platform, a next generation Illumina sequencing apparatus, a Leica laser microdissector, a Zeiss confocal microscope, a Stereoinvestigator platform for quantitative morphology. A fully equipped animal house is also available for the Institute.