title: The nanomechanical role of melanin granules in the retinal pigment epithelium.
abstract: Nanomechanical properties of cells and tissues, in particular their elasticity, play an important role in different physiological and pathological processes. Recently, we have demonstrated that melanin granules dramatically modify nanomechanical properties of melanoma cells making them very stiff and, as a result, less aggressive. Although the mechanical effect of melanin granules was demonstrated in pathological cells, it was never studied in the case of normal cells. In this work, we analyzed the impact of melanin granules on nanomechanical properties of primary retinal pigment epithelium tissue fragments isolated from porcine eyes. The obtained results clearly show that melanin granules are responsible for the exceptional nanomechanical properties of the tissue. Our findings suggest that melanin granules in the retinal pigment epithelium may play an important role in sustaining the stiffness of this single cell layer, which functions as a natural mechanical barrier separating the retina from the choroid.
authors.affiliation: Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Poland; Laboratory of Imaging and Atomic Force Spectroscopy, Malopolska Centre of Biotechnology, Jagiellonian University, Poland. Electronic address: michal.sarna@uj.edu.pl.
authors.forename: Michal
authors.initials: M
authors.lastname: Sarna
authors.affiliation: Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Olchawa
authors.affiliation: Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Zadlo
authors.affiliation: Department of Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Poland.
authors.forename: Dawid
authors.initials: D
authors.lastname: Wnuk
authors.affiliation: Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Poland.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Sarna
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004548:Elasticity; D008543:Melanins / Q000032:analysis*; D020460:Melanosomes / Q000737:chemistry / Q000648:ultrastructure*; D018625:Microscopy, Atomic Force; D055213:Retinal Pigment Epithelium / Q000737:chemistry / Q000648:ultrastructure*; D013552:Swine
chemical_list: D008543:Melanins
keywords: Atomic force microscopy; Blood-retinal barrier; Elasticity; Melanin granules; Nanomechanical properties; Retinal pigment epithelium