Summary
Microtubules (MT) occur in the keratinocytes as 20 nm broad tubular structures with an electron-lucent core surrounded by an electron-dense wall. The number and the length of the MT increased to the upper epidermal layers.
In the normal keratinocytes the MT were relatively short (maximal length 2.2 μm) and slightly tortuous. Their outline was tenuous and irregular. Sometimes the MT were interrupted indicating a high fragility. In the upper layers of the psoriatic epidermis the MT reached a maximal length of 3.1 μm, showing a greater elongation than in the normal epidermis. The MT were straight and distinctly limited, most likely resulting from a higher grade of stabilization or polymerisation.
By their interaction with the tonofilaments the MT may contribute to the stability of the cell shape, delaying the flattening of the psoriatic keratinocytes in the upper epidermal layers. Nowhere did the MT make direct contact with the cell membrane. At some places they did gain access to the cell membrane by short microfilaments.
Zusammenfassung
Mikrotubuli (MT) kommen in den Keratinocyten als 20 nm breite tubuläre Strukturen vor, deren helles Zentrum von einem elektronendichten Wall umgeben ist. Anzahl und Länge der MT nimmt zu den oberen Epidermisschichten hin zu.
In den Keratocyten der gesunden Epidermis sind die MT verhältnismäßig kurz (maximal 2,2μm) und zeigen einen leicht wellenförmigen Verlauf. Ihre Begrenzung ist unscharf und unregelmäßig. Stellenweise beobachtet man Unterbrechungen der MT, so daß insgesamt die normalen Keratinocyten relativ fragile MT zu besitzen scheinen. Demgegenüber sind die MT in den psoriatischen Keratinocyten länger. Sie erreichen in den oberen Epidermisschichten eine Länge von 3,1 μm. Sie sind gerade und deutlich begrenzt. Offenbar weisen die MT in den Keratinocyten der psoriatischen Haut eine höhere Festigkeit bzw. einen höheren Polymerisationsgrad auf.
Die MT überkreuzen die Tonofilamentbündel in der Zellperipherie. Dadurch könnten sie die Zellform stabilisieren und in der psoriatischen Epidermis die Abflachung der Zellen in den oberen Zellagen verzögern. Ein direkter Kontakt der MT zur äußeren Zellmembran wurde nicht beobachtet. Nur selten verbinden kurze Mikrofilamente die MT mit der Zellmembran.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Amos, L. A.: Tubulin assembly. Nature 270, 98–99 (1977)
Anton-Lamprecht, I.: Intracelluläre Geißeln in Epidermiszellen menschlicher Haut. Arch. Dermatol. Forsch. 243, 199–208 (1972)
Bhattacharryya, B., Wolff, J.: Polymerisation of membrane tubulin. Nature 264, 576–577 (1976)
Branson, R. J.: Orthogonal arrays of microtubules in flattening cells of the epidermis. Anat. Rec. 160, 109–122 (1965)
Brinkley, B. R., Fuller, G. M., Highfield, D. P.: Cytoplasmic microtubules in normal and transformed cells in culture: Analysis by tubulin antibody immunofluorescence. Proc. Natl. Acad. Sci. U.S.A. 72, 4981–4985 (1975)
Bryan, J.: A quantitative analysis of microtubule elongation. J. Cell. Biol. 71, 749–767 (1976)
De Mey, J., Hoebeke, J., De Brabander, M., Geuens, G., Joniau, M.: Immunoperoxidase visualisation of microtubules and microtubular protein. Nature 264, 273–275 (1976)
Frankel, F. R.: Organization and energy-dependent growth of microtubules in cells. Proc. Natl. Acad. Sci. U.S.A. 73, 2798–2802 (1976)
Lancet: Malfunctioning microtubules, pp. 697–698 (1978)
Loor, F.: Cell surface design. Nature 264, 272–273 (1976)
Mahrle, G.: Demonstration of giant and anular nexus in the psoriatic epidermis. Arch. Dermatol. Res. 261, 181–188 (1978)
McGuire, J., Lazarides, E., Di Pasquale, A.: Actin is present in mammalian keratocytes. In: Biochemistry of cutaneous epidermal differentiation. Seiji, M., Bernstein, J. A. (eds.), pp. 69–80. Baltimore-London-Tokyo: University Park Press 1977
Nicolson, G. L.: Transmembrane control of the receptors on normal and tumor cells. I. Cytoplasmic influence over cell surface components. Biochim. Biophysiol. Acta 457, 57–108 (1976)
Olmsted, J. B., Borisy, G.: Microtubules. Ann. Rev. Biochem. 42, 507–540 (1973)
Poste, G., Papahadjopoulos, D., Nicolson, G. L.: Local anesthetic affect transmembrane cytoskeletal control of mobility and distribution of cell surface receptors. Proc. Natl. Acad. Sci. U.S.A. 72, 4430–4434 (1975)
Rupec, M.: Die Microtubuli der Keratocyten normaler menschlicher Epidermis. Arch. Dermatol. Forsch. 249, 235–246 (1974)
Szekeres, L.: Strukturelle Varianten der intracellulären Geißeln und Centriolen in Naevus-Zellen. Z. Hautkr. 50, 461–466 (1975)
Tucker, J. B.: Shape and pattern specification during microtubule bundle assembly. Nature 266, 22–26 (1977)
Voorhees, J. J., Marcelo, C.: Molecular mechanisms and the cyclic nucleotide cascade in psoriasis. In: Psoriasis, Proceedings of the Second International Symposium, Stanford 1976. Farber, E. M., Cox, A. J., Jacobs, P. H., Nall, M. L. (eds.), pp. 91–99. New York: Yorke Medical Books 1977
Wanger, L., Sundqvist, K.-G.: Membrane-associated actin in psoriatic epidermis. Acta Dermatol. Venerol. (Stockh.) 58, 79–82 (1978)
Weber, K., Birring, T., Osborn, M.: Specific visualization of tubulin containing structures in tissue culture cells by immunofluorescence. Exp. Cell. Res. 95, 111–120 (1975)
Author information
Authors and Affiliations
Additional information
Dedicated to Prof. Dr. G. Stüttgen on his 60th birthday
Supported by the Deutsche Forschungsgemeinschaft Grant no. Ma 674/1
Rights and permissions
About this article
Cite this article
Mahrle, G. Increased elongated and stabilized microtubules in psoriatic keratinocytes. Arch Dermatol Res 264, 307–318 (1979). https://doi.org/10.1007/BF00412658
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00412658