title: In situ visualization of intracellular morphology of epidermal cells using stimulated Raman scattering microscopy.
abstract: Visualization of epidermal cells is important because the differentiation patterns of keratinocytes (KCs) are considered to be related to the functions and condition of skin. Optical microscopy has been widely used to investigate epidermal cells, but its applicability is still limited because of the need for sample fixation and staining. Here, we report our staining-free observation of epidermal cells in both tissue and culture by stimulated Raman scattering (SRS) microscopy that provides molecular vibrational contrast. SRS allowed us to observe a variety of cellular morphologies in skin tissue, including ladder-like structures in the spinous layer, enucleation of KCs in the granular layer, and three-dimensional cell column structures in the stratum corneum. We noticed that some cells in the spinous layer had a brighter signal in the cytoplasm than KCs. To examine the relevance of the observation of epidermal layers, we also observed cultured epidermal cells, including KCs at various differentiation stages, melanocytes, and Langerhans cell-like cells. Their SRS images also demonstrated various morphologies, suggesting that the morphological differences observed in tissue corresponded to the cell lineage. These results indicate the possible application of SRS microscopy to dermatological investigation of cell lineages and types in the epidermis by cellular-level analysis.
authors: Shiseido Global Innovation Center, 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama, Kanagawa 224-0025, Japan.
authors: Mariko
authors: M
authors: Egawa
authors: The University of Tokyo, Department of Electrical Engineering and Information Systems, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors: Kyoya
authors: K
authors: Tokunaga
authors: Shiseido Global Innovation Center, 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama, Kanagawa 224-0025, Japan.
authors: Junichi
authors: J
authors: Hosoi
authors: Shiseido Global Innovation Center, 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama, Kanagawa 224-0025, Japan.
authors: Shinya
authors: S
authors: Iwanaga
authors: The University of Tokyo, Department of Electrical Engineering and Information Systems, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors: Yasuyuki
authors: Y
authors: Ozeki
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D048430:Cell Shape; D002478:Cells, Cultured; D003584:Cytological Techniques / Q000379:methods*; D000078404:Epidermal Cells; D005260:Female; D006801:Humans; D015603:Keratinocytes / Q000166:cytology; D007801:Langerhans Cells / Q000166:cytology; D008544:Melanocytes / Q000166:cytology; D000073758:Nonlinear Optical Microscopy; D013059:Spectrum Analysis, Raman; D013552:Swine