title: 3D compartmented model to study the neurite-related toxicity of Aβ aggregates included in collagen gels of adaptable porosity.
abstract: Insoluble deposits of β-amyloid (Aβ) are associated to neurodegenerative pathologies, in particular Alzheimer's Disease (AD). The toxicity of synthetic amyloid-like peptides has been largely demonstrated and shown to depend upon their aggregation state. However, standard 2D cell culture conditions are not well suited to study the role of the close vicinity of Aβ aggregates and growing neurites in the degenerative process. Here, we have designed a compartmented set-up where model neural cells are differentiated on the surface of Aβ-containing collagen matrices. The average pore size can be modulated, from below 0.2μm to more than 0.5μm by simple treatment with collagenase, to respectively hamper or permit neurite outgrowth towards the depth of the matrix. Dense Aβ aggregates (Congo red and ThT-positive) were obtained inside the collagen matrix with a homogeneous distribution and dimensions similar to those observed in post-mortem brain slices from Alzheimer's patients. The aggregates are not toxic to cells when the pore size is small, in spite of relatively high concentrations of 0.05-0.62mg of peptide per gram of collagen (equivalent to 11.3-113μM). In contrast, on Aβ-containing matrices with large pores, massive neural death is observed when the cells are seeded in the same conditions. It is the first time to our knowledge that Aβ aggregates with a typical morphology of dense plaques are obtained within a porous biomimetic matrix, and are shown to be toxic only when accessible to differentiating cells.
  
  
  
  Insoluble deposits of β-amyloid (Aβ) are associated to neurodegenerative pathologies, in particular Alzheimer's Disease (AD). In this study, we have formed Aβ aggregates directly inside a biomimetic collagen matrix loaded with growth factors to induce the differentiation of PC12 or SH-SY6Y cells. For the first time, we show that when the contact between cells and Aβ aggregates is allowed by opening up the matrix porosity, the close vicinity with aggregates induces neurite dystrophy. The compartmented 3D culture model developed and used in this study is a valuable tool to study the cytotoxicity of preformed dense Aβ aggregates and proves that contact between the aggregates and neurons is required to induce neurodegenerative processes.
authors.affiliation: Ecole Pratique des Hautes Etudes, PSL Research University, 75014 Paris, France; Institut Charles Gerhardt, UMR 5253, Equipe MACS, Ecole Nationale Supérieure de Chimie, 8 rue de l'école normale, F-34296 Montpellier Cedex 5, France; INSERM 1198 - Unité mixte UM - EPHE, Université Montpellier II - Place Eugène Bataillon-CC105, 34095 Montpellier Cedex 5, France.
authors.forename: Marie-Noëlle
authors.initials: MN
authors.lastname: Labour
authors.affiliation: Ecole Pratique des Hautes Etudes, PSL Research University, 75014 Paris, France; Institut Charles Gerhardt, UMR 5253, Equipe MACS, Ecole Nationale Supérieure de Chimie, 8 rue de l'école normale, F-34296 Montpellier Cedex 5, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Vigier
authors.affiliation: Institut Charles Gerhardt, UMR 5253, Equipe MACS, Ecole Nationale Supérieure de Chimie, 8 rue de l'école normale, F-34296 Montpellier Cedex 5, France.
authors.forename: Dan
authors.initials: D
authors.lastname: Lerner
authors.affiliation: Ecole Pratique des Hautes Etudes, PSL Research University, 75014 Paris, France; INSERM 1198 - Unité mixte UM - EPHE, Université Montpellier II - Place Eugène Bataillon-CC105, 34095 Montpellier Cedex 5, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Marcilhac
authors.affiliation: Ecole Pratique des Hautes Etudes, PSL Research University, 75014 Paris, France; Institut Charles Gerhardt, UMR 5253, Equipe MACS, Ecole Nationale Supérieure de Chimie, 8 rue de l'école normale, F-34296 Montpellier Cedex 5, France. Electronic address: Emmanuel.Belamie@enscm.fr.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Belamie
mesh_terms: D000544:Alzheimer Disease; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D003094:Collagen / Q000737:chemistry*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008959:Models, Neurological; D016501:Neurites / Q000378:metabolism / Q000473:pathology; D016716:PC12 Cells; D016062:Porosity; D066329:Protein Aggregates; D051381:Rats; D017208:Rats, Wistar
chemical_list: D016229:Amyloid beta-Peptides; D066329:Protein Aggregates; D003094:Collagen
keywords: Alzheimer disease; Aβ aggregates; Collagen matrices; Compartmented culture; Neurite dystrophy