« Nucleu » : PN 19.29.02.01

The effect of the intestinal microbiota products and of the functional amyloid proteins on the pathological aggregation of proteins and on the propagation of pathology after a prion model in neurodegeneration models

Contracte nr. 1N/2019

Funder: Ministry of Education and Research

Duration: 2019-2022

Within the “Nucleu” Program: Systemic approaches in identifying and / or validating molecular targets for therapeutic strategies in pathologies with major health impact – SISPATH;
Objective 2. Experimental and functional models for systemic approaches in pathologies with major health implications

Project manager: Prof. Dr. Bogdan O. Popescu

Brief presentation of the project.

Neurodegenerative diseases are currently a major health issue and a priority research topic worldwide. Thus, neurodegenerative diseases are common in the adult population over 65 years, are responsible for irreversible progressive disability, have a significant negative socio-economic burden. So far there is no approved therapeutic intervention or with definite positive results to stop or slow down the evolution of these diseases, but only symptomatic therapies, with net but often modest benefits. The results of recent clinical and experimental studies indicate the existence of possible causal links between different particularities of the composition of the intestinal microbiota and neurodegenerative diseases, especially in Parkinson’s disease. The substrate of these causal bonds is mediated both by certain microbiota products (e.g. functional amyloid proteins, biosurfactants, endotoxins) and by endogenous proteins whose expression can be modulated / induced by the microbiota (e.g. calprotectin is an inflammatory marker, but also a potential amyloidogenic protein). Also, host-microbial dysfunction (dysbiosis with inflammatory bowel reaction) could produce neuronal changes favorable to neurodegeneration (e.g. secondary to alteration of the intestinal barrier and / or blood-brain barrier and / or by disruption of the microbial-intestine-brain-microbial network, oxidative stress, mitochondrial dysfunction, etc.). All these aspects have not been investigated so far in detail and represent a research topic of interest.
Project aim: characterization of the effect of bacterial functional amyloid proteins and other amyloidogenic products of the intestinal microbiota on protein pathological aggregation and on the propagation of pathology according to a prion model in neurodegeneration models, in order to identify new biomarkers and molecular targets to develop prophylactic strategies and  personalized therapies in sporadic Parkinson’s disease and other neurodegenerative diseases, thus helping to improve the approach on pathologies with a major impact on health.

Project objectives:
1. Development and improvement of the protocol for a standardized testing / immuno-dosage  of bacterial amyloidogenic products of interest.

2. Evaluation of the association between the fecal level of the bacterial amyloidogenic products of interest, the level of fecal calprotectin and the Parkinson’s disease in the incipient motor phase – case-control analytical observational study.
3. Confirmation of the results regarding the association between the fecal level of the bacterial amyloidogenic products, the level of calprotectin and the Parkinson’s disease, respectively the testing of the possible associations with other neurodegenerative proteinopathies.
4. Characterization of the effects of amyloidogenic products of the intestinal microbiota associated with Parkinson’s disease in the early motor phase and calprotectin on the aggregation and internalization / propagation of alpha-synuclein, in vitro, on cell lines, in the presence and absence of rotenone.
5. Evaluation of the effect of amyloidogenic products of the intestinal microbiota associated with Parkinson’s disease, calprotectin and short-chain fatty acids on clinical manifestations, intestinal pathology and brain pathology in vivo, on murine models of Parkinson’s disease, in conditions of wild intestinal microbiota, using protocols based on the results of in vitro studies.
6. Evaluation of the effect of amyloidogenic products of the intestinal microbiota associated with Parkinson’s disease, calprotectin and short-chain fatty acids on clinical manifestations, intestinal pathology and cerebral pathology on murine models of Parkinson’s disease, in conditions of controlled intestinal microbiota, using protocols based on previous results.
7. Evaluation of the effect of amyloidogenic products of the intestinal microbiota (selected accordingly with previous results), calprotectin and short-chain fatty acids on cell lines and murine models for other neurodegenerative diseases involving defective folding and pathological aggregation of proteins.
8. Development of an etiopathogenic model regarding the involvement of bacterial amyloid proteins, other amyloidogenic products of the intestinal microbiota and calprotectin in Parkinson’s disease, with extrapolation to Alzheimer’s disease and other neurodegenerative proteinopathies.

Estimated results:
1. fecal biomarkers for early motor stage of Parkinson’s disease – may be microbiota biomarkers, simple or composite, or mixed biomarkers, host-microbiota.

2. fecal biomarkers for early motor stage of Parkinson’s disease confirmed on another patients group and with known specificity in relation to other neurodegenerative diseases.
3. optimized experimental paradigm for evaluating the effects of intestinal microbiota products and other molecules on the aggregation, internalization and propagation of alpha-synuclein under different environmental conditions.
4. intermediate etiopathogenic model for Parkinson’s / Alzheimer’s disease on the causal relationship between exposure to bacterial amyloidogenic products, pathological aggregation of alpha-synuclein and prion-like spread of pathology from gut to brain.
5. optimized murine model for the study of the intestinal microbiota in Parkinson’s disease.
6. comprehensive etiopathogenic model regarding the involvement of bacterial functional amyloid proteins and other amyloidogenic products of the intestinal microbiota on the pathological aggregation of proteins and on the prion-like propagation model of pathology in Parkinson’s disease, extrapolated to Alzheimer’s disease and other neurodegenerative protein diseases
7. list of new potential molecular targets for personalized prophylactic therapeutic interventions / strategies, or for stopping / slowing down the evolution of neurodegenerative diseases, identified within the project.

Project deliverables

Communications at scientific meetings

  • B.O. PopescuBacteriile și neurodegenerarea (Bacteria and neurodegeneration) – Conferința Națională Alzheimer 2019, București, România, februarie 2019, oral presentation.
  • B. Popescu – Gastrointestinal dysmotility is the major cause of motor fluctuations in PD (host of the debate) – The 13th World Congress on Controversies in Neurology (CONy), Madrid, Spania, aprilie 2019 – oral presentation.
  • B. Popescu – Are microbiota reasonable targets in the therapy of neurodegenerative diseases? – YES – The 13th World Congress on Controversies in Neurology (CONy), Madrid, Spania, aprilie 2019 – oral presentation.
  • Laura Dumitrescu, Daciana Marta, Emilia Manole, Adela Danau, Antonia Lefter, Laura Cristina Ceafalan, Mihaela Gherghiceanu, Bogdan Ovidiu Popescu – Intestinal barrier integrity, bacterial endotoxin exposure and inflammation markers in Parkinson’s disease. Annual Scientific Meeting of Victor Babes Institute; The 12th National Pathology Symposium, November 21-23, 2019, Bucharest, Romania – oral presentation

Publicatii

– Octavian Ioghen, Emilia Manole, Mihaela Gherghiceanu, Bogdan O. Popescu, Laura Cristina Ceafalan, Non-Myelinating Schwann cells in health and disease. In Schwann Cells, Ed. Emeritus Prof. Stavros Baloyannis, 2020, IntechOpen, ISBN: ISBN 978-1-83962-929-7

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