title: Synchrotron x-ray microdiffraction reveals intrinsic structural features of amyloid deposits in situ.
abstract: Amyloidoses are increasingly recognized as a major public health concern in Western countries. All amyloidoses share common morphological, structural, and tinctorial properties. These consist of staining by specific dyes, a fibrillar aspect in electron microscopy and a typical cross-β folding in x-ray diffraction patterns. Most studies that aim at deciphering the amyloid structure rely on fibers generated in vitro or extracted from tissues using protocols that may modify their intrinsic structure. Therefore, the fine details of the in situ architecture of the deposits remain unknown. Here, we present to our knowledge the first data obtained on ex vivo human renal tissue sections using x-ray microdiffraction. The typical cross-β features from fixed paraffin-embedded samples are similar to those formed in vitro or extracted from tissues. Moreover, the fiber orientation maps obtained across glomerular sections reveal an intrinsic texture that is correlated with the glomerulus morphology. These results are of the highest importance to understanding the formation of amyloid deposits and are thus expected to trigger new incentives for tissue investigation. Moreover, the access to intrinsic structural parameters such as fiber size and orientation using synchrotron x-ray microdiffraction, could provide valuable information concerning in situ mechanisms and deposit formation with potential benefits for diagnostic and therapeutic purposes.
authors.affiliation: Laboratoire de Physique des solides, Centre Universitaire de Paris Sud, Orsay, France. fatma.briki@u-psud.fr
authors.forename: Fatma
authors.initials: F
authors.lastname: Briki
authors.forename: Jérôme
authors.initials: J
authors.lastname: Vérine
authors.forename: Jean
authors.initials: J
authors.lastname: Doucet
authors.forename: Philippe
authors.initials: P
authors.lastname: Bénas
authors.forename: Barbara
authors.initials: B
authors.lastname: Fayard
authors.forename: Marc
authors.initials: M
authors.lastname: Delpech
authors.forename: Gilles
authors.initials: G
authors.lastname: Grateau
authors.forename: Madeleine
authors.initials: M
authors.lastname: Riès-Kautt
mesh_terms: D000682:Amyloid / Q000737:chemistry*; D000686:Amyloidosis / Q000378:metabolism / Q000473:pathology; D016880:Anisotropy; D006801:Humans; D007678:Kidney Glomerulus / Q000378:metabolism / Q000473:pathology; D017356:Synchrotrons; D014961:X-Ray Diffraction
chemical_list: D000682:Amyloid