title: Melanocytes--a novel tool to study mitochondrial dysfunction in Duchenne muscular dystrophy.
abstract: Dystrophin is a subsarcolemmal protein that, by linking the actin cytoskeleton to the extracellular matrix via dystroglycans, is critical for the integrity of muscle fibers. Here, we report that epidermal melanocytes, obtained from conventional skin biopsy, express dystrophin with a restricted localization to the plasma membrane facing the dermal-epidermal junction. In addition the full-length muscle isoform mDp427 was clearly detectable in melanocyte cultures as assessed by immunohistochemistry, RNA, and Western blot analysis. Melanocytes of Duchenne muscular dystrophy (DMD) patients did not express dystrophin, and the ultrastructural analysis revealed typical mitochondrial alterations similar to those occurring in myoblasts from the same patients. Mitochondria of melanocytes from DMD patients readily accumulated tetramethylrhodamine methyl ester, indicating that they are energized irrespective of the presence of dystrophin but, at variance from mitochondria of control donors, depolarized upon the addition of oligomycin, suggesting that they are affected by a latent dysfunction unmasked by inhibition of the ATP synthase. Pure melanocyte cultures can be readily obtained by conventional skin biopsies and may be a feasible and reliable tool alternative to muscle biopsy for functional studies in dystrophinopathies. The mitochondrial dysfunction occurring in DMD melanocytes could represent a promising cellular biomarker for monitoring dystrophinopathies also in response to pharmacological treatments.
authors.affiliation: Department of Medical Science, University of Ferrara, Ferrara, Italy.
authors.forename: Camilla
authors.initials: C
authors.lastname: Pellegrini
authors.forename: Alessandra
authors.initials: A
authors.lastname: Zulian
authors.forename: Francesca
authors.initials: F
authors.lastname: Gualandi
authors.forename: Elisa
authors.initials: E
authors.lastname: Manzati
authors.forename: Luciano
authors.initials: L
authors.lastname: Merlini
authors.forename: Maria E
authors.initials: ME
authors.lastname: Michelini
authors.forename: Luisa
authors.initials: L
authors.lastname: Benassi
authors.forename: Sandra
authors.initials: S
authors.lastname: Marmiroli
authors.forename: Alessandra
authors.initials: A
authors.lastname: Ferlini
authors.forename: Patrizia
authors.initials: P
authors.lastname: Sabatelli
authors.forename: Paolo
authors.initials: P
authors.lastname: Bernardi
authors.forename: Nadir M
authors.initials: NM
authors.lastname: Maraldi
mesh_terms: D001706:Biopsy; D015152:Blotting, Northern; D015153:Blotting, Western; D016022:Case-Control Studies; D002478:Cells, Cultured; D016189:Dystrophin / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000378:metabolism; D008544:Melanocytes / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D025261:Mitochondrial Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D032446:Myoblasts / Q000378:metabolism; D009840:Oligomycins / Q000494:pharmacology; D012235:Rhodamines / Q000378:metabolism; D012867:Skin / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D013997:Time Factors; D049411:Utrophin / Q000378:metabolism
chemical_list: C484258:DMD protein, human; D016189:Dystrophin; D004791:Enzyme Inhibitors; D009840:Oligomycins; D012235:Rhodamines; C483599:UTRN protein, human; D049411:Utrophin; C401833:tetramethylrhodamine methyl ester; D025261:Mitochondrial Proton-Translocating ATPases