1. Rab11a Is Essential for Lamellar Body Biogenesis in the Human Epidermis
- Author
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Elise Gaspard, Sophie Allart, Michel Simon, Corinne Leprince, Guy Serre, Marie Reynier, Alain Moga, Dominique Goudounèche, Unité différenciation épidermique et auto-immunité rhumatoïde (UDEAR), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National de la Santé et de la Recherche Médicale (INSERM), SYNELVIA, Centre de Microscopie Électronique Appliquée à la Biologie (CMEAB), Hôpital de Rangueil, CHU Toulouse [Toulouse]-CHU Toulouse [Toulouse]-Toulouse Réseau Imagerie-Genotoul ( TRI-Genotoul), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Toulouse Réseau Imagerie-Genotoul ( TRI-Genotoul), and CARBILLET, Véronique
- Subjects
Keratinocytes ,0301 basic medicine ,MESH: Organelle Biogenesis ,Dermatology ,MESH: Homeostasis / genetics ,MESH: Keratinocytes / cytology ,Lamellar granule ,Biology ,Biochemistry ,Sampling Studies ,Tissue Culture Techniques ,03 medical and health sciences ,0302 clinical medicine ,MESH: Sampling Studies ,MESH: rab GTP-Binding Proteins / genetics ,[SDV.MHEP.MI]Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,medicine ,Stratum corneum ,Homeostasis ,Humans ,MESH: Gene Silencing ,Lamellar structure ,MESH: Tissue Culture Techniques ,Gene Silencing ,Molecular Biology ,Cells, Cultured ,Transepidermal water loss ,MESH: Humans ,Organelle Biogenesis ,Corneocyte ,integumentary system ,Cell Biology ,MESH: Epidermis / metabolism ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,rab GTP-Binding Proteins ,030220 oncology & carcinogenesis ,[SDV.MHEP.MI] Life Sciences [q-bio]/Human health and pathology/Infectious diseases ,Organelle biogenesis ,Epidermis ,Biogenesis ,MESH: Cells, Cultured - Abstract
International audience; Most of the skin barrier function is attributable to the outermost layer of the epidermis, the stratum corneum, which is composed of flattened, anucleated cells called corneocytes surrounded by a lipid-enriched lamellar matrix. The composition of the stratum corneum is directly dependent on the underlying granular keratinocytes, which are the last living cells in the stratified epidermis. Many components present in the intercorneocyte matrix are delivered by the underlying granular keratinocytes through a secretion process dependent on lysosome-related organelles called lamellar bodies. Because of the importance of lamellar bodies in the maintenance of the epidermal barrier, the mechanisms regulating their biogenesis must be better understood. In this study, we show that the Rab11a GTPase is highly expressed in terminally differentiated keratinocytes, where it is partly associated with lamellar bodies. Rab11a silencing in three-dimensional in vitro reconstructed human epidermis induces a barrier defect, a decrease in the amount of lipid found in the stratum corneum, a reduction in lamellar body density and secretion areas in granular keratinocytes, and the mis-sorting of lamellar body cargoes being driven to the lysosomal degradation pathway. Our results highlight the importance of Rab11a-dependent regulation of lamellar body biogenesis in keratinocytes and consequently on epidermal barrier homeostasis.
- Published
- 2016