Alterations in Microtubules, Intermediate Filaments, and Microfilaments Induced by Microcystin-LR in Cultured Cells

Toxicologic Pathology - Tập 23 Số 3 - Trang 326-337 - 1995
Mark Wickstrom1, S A Khan2, Wanda M. Haschek3, John F. Wyman4, John Eriksson5, David J. Schaeffer2, Val R. Beasley2
1Department of Veterinary Biosciences, University of Illinois, US EPA, 8 HWM-SM, 999 18th Street, Suite 500, Denver, Colorado 80202-2466
2Department of Veterinary Biosciences, University of Illinois
3Department of Veterinary Pathobiology, University of Illinois, Urbana, Illinois 6801
4Naval Medical Research Institute/Toxicology Detachment, Wright Patterson AFB, Ohio
5Turku Center for Biotechnology, Biocity, Turku, Finland

Tóm tắt

Microcystin-LR (MCLR) is a cyanobacterial hepatotoxin that inhibits intracellular serine/threonine protein phosphatases causing disruption of actin microfilaments (MFs) and intermediate filaments (IFs) in hepatocytes. This study compared the effects of MCLR on the organization of MFs, IFs, and microtubules (MTs) in hepatocytes and nonhepatocyte cell lines and determined the sequence of toxin-induced changes in these cytoskeletal components. Rat renal epithelial cells and fibroblasts were incubated with MCLR at 100 or 200 μM for 6-18 hr. Rat hepatocytes in primary culture were exposed to the toxin at 1 or 10 μm for 2-64 min. Cells were fixed and incubated with primary antibodies against β-tubulin, actin, and vimentin or cytokeratin IFs, followed by gold-labeled secondary antibodies with silver enhancement of the gold probe. The fraction of fibroblasts and hepatocytes with altered cytoskeletal morphology was evaluated as a function of MCLR dose and exposure time to assess the sequence of changes in cytoskeletal components. Changes in fibroblasts and some hepatocytes were characterized initially by disorganization of IFs, followed rapidly by disorganization of MTs, with the progressive collapse of both cytoskeletal components around cell nuclei. Many hepatocytes exhibited MT changes prior to effects on IF structure. Alterations in MFs occurred later and included initial aggregation of actin under the plasma membrane, followed by condensation into rosette-like structures and eventual complete collapse into a dense perinuclear bundle. The similarity of effects among different cell types suggests a common mechanism of action, but the independent kinetics of IF and MT disruption in hepatocytes suggests that there may be at least 2 sites of phosphorylation that lead to cytoskeletal alterations.

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Tài liệu tham khảo

10.1016/0041-0101(93)90404-7

10.1111/j.1471-4159.1993.tb02172.x

Beasley VR, Lovell RA, Dahlem AM, Haschek WM, and Hooser SB (1991). Cyclic peptide hepatotoxins from cyanobacteria (blue-green algae). In: Handbook of Natural Toxins, Vol. 6 , RF Keeler and AT Tu (eds). Marcel Dekker, New York, pp. 459-495.

10.1111/j.1749-6632.1985.tb50401.x

10.1083/jcb.98.3.847

10.1083/jcb.114.4.735

10.1016/0898-6568(92)90052-A

10.1016/0041-0101(88)90195-X

10.1016/B978-0-08-091811-2.50017-4

10.1002/cm.970180104

10.1016/0092-8674(90)90384-Q

10.1146/annurev.bi.58.070189.002321

10.1177/104063879300500317

10.1073/pnas.89.22.11093

10.1016/0005-2736(90)90190-Y

10.1016/0014-4827(89)90039-6

10.1016/S0006-291X(05)80936-2

10.1016/0009-2797(87)90042-1

10.1016/0009-2797(92)90033-H

10.1016/0014-4827(81)90435-3

10.1016/0304-4157(88)90020-2

10.1289/ehp.9193211

Galey FD, 1987, Am. J. Vet. Res, 48, 1415

10.1002/j.1460-2075.1988.tb02778.x

10.1016/0006-8993(90)91657-3

10.1038/353445a0

10.2216/i0031-8884-32-2-79.1

10.1016/0041-0101(88)90182-1

10.1007/BF01766462

10.1177/31.7.6189883

10.1016/S0021-9258(17)45384-1

10.1177/030098588902600309

10.1177/030098589102800401

10.1016/0092-8674(81)90514-6

10.1016/0014-5793(90)80245-E

10.1016/0006-291X(90)91226-I

10.1016/0092-8674(82)90400-7

10.1007/BF01629424

10.1093/carcin/13.12.2443

10.1016/0005-2736(88)90235-0

10.1083/jcb.99.1.33s

10.1016/B978-0-12-330220-5.50019-X

10.1073/pnas.88.4.1232

10.1002/path.1711660311

10.1016/0041-0101(86)90112-1

Runnegar MT, 1993, Am. J. Physiol, 265, G224, 10.1152/ajpcell.1993.265.1.C224

10.2307/3801320

10.1016/S0091-679X(08)61797-5

10.1073/pnas.89.24.11959

10.1016/0041-0101(93)90384-U

10.1016/0006-291X(90)91977-Z

10.1016/S0021-9258(18)80157-0

10.1007/BF00501916

10.1083/jcb.97.5.1476

10.1016/S0021-9258(17)42984-X

10.1111/j.1471-4159.1988.tb03051.x

10.1016/0006-291X(91)90662-Q

Yatsunami J., 1993, Cancer Res, 53, 992

10.1007/BF01637082

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Toxicologic Pathology

Tập 23 Số 3

326-337

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