title: Cytoskeleton Aberrations in Alkaptonuric Chondrocytes.
abstract: Alkaptonuria (AKU) is an ultra-rare autosomal genetic disorder caused by a defect in the activity of the enzyme homogentisate 1,2-dioxygenase (HGD) that leads to the accumulation of homogentisic acid (HGA) and its oxidized product, benzoquinone acetic acid (BQA), in the connective tissues causing a pigmentation called "ochronosis." The consequent progressive formation of ochronotic aggregates generate a severe condition of oxidative stress and inflammation in all the affected areas. Experimental evidences have also proved the presence of serum amyloid A (SAA) in several AKU tissues and it allowed classifying AKU as a secondary amyloidosis. Although AKU is a multisystemic disease, the most affected system is the osteoarticular one and articular cartilage is the most damaged tissue. In this work, we have analyzed for the first time the cytoskeleton of AKU chondrocytes by means of immunofluorescence staining. We have shown the presence of SAA within AKU chondrocytes and finally we have demonstrated the co-localization of SAA with three cytoskeletal proteins: actin, vimentin, and β-tubulin. Furthermore, in order to observe the ultrastructural features of AKU chondrocytes we have performed TEM analysis, focusing on the Golgi apparatus structure and, to demonstrate that pigmented areas in AKU cartilage are correspondent to areas of oxidation, 4-HNE presence has been evaluated by means of immunofluorescence. J. Cell. Physiol. 232: 1728-1738, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Siena, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Geminiani
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Siena, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Gambassi
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Siena, Italy.
authors.forename: Lia
authors.initials: L
authors.lastname: Millucci
authors.affiliation: Dipartimento di Scienze della Vita, Università degli Studi di Siena, Siena, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Lupetti
authors.affiliation: Dipartimento di Medicina Molecolare e dello Sviluppo, Università degli Studi di Siena, Siena, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Collodel
authors.affiliation: Dipartimento di Medicina Molecolare e dello Sviluppo, Università degli Studi di Siena, Siena, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Mazzi
authors.affiliation: Dipartimento di Scienze Mediche, Chirurgiche e Neuroscienze, Università degli Studi di Siena, Siena, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Frediani
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Siena, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Braconi
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Siena, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Marzocchi
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Siena, Italy.
authors.forename: Marcella
authors.initials: M
authors.lastname: Laschi
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Siena, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Bernardini
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Siena, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Santucci
mesh_terms: D000199:Actins / Q000378:metabolism; D000328:Adult; D000368:Aged; D000447:Aldehydes / Q000378:metabolism; D000474:Alkaptonuria / Q000473:pathology*; D015415:Biomarkers / Q000378:metabolism; D002358:Cartilage, Articular / Q000378:metabolism; D016022:Case-Control Studies; D019902:Chondrocytes / Q000378:metabolism* / Q000648:ultrastructure; D003599:Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D005455:Fluorescent Antibody Technique; D006056:Golgi Apparatus / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D010860:Pigments, Biological / Q000378:metabolism; D000685:Serum Amyloid A Protein / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism; D014746:Vimentin / Q000378:metabolism
chemical_list: D000199:Actins; D000447:Aldehydes; D015415:Biomarkers; D010860:Pigments, Biological; D000685:Serum Amyloid A Protein; D014404:Tubulin; D014746:Vimentin; C027576:4-hydroxy-2-nonenal