Regulation of the cytoskeleton and the adhesiveness of intestinal epithelial cells by leukotriene D4
Author
Summary, in English
Leukotrienes belong to a family of biologically active conjugated trienes that are formed from arachidonic acid via the 5-lipoxygenase pathway and are important mediators of inflammatory reactions. The CysLT1 receptor that specifically serves as receptor for leukotriene D4 (LTD4) has been identified as a G-protein coupled receptor.
Cell-cell and cell-matrix complexes of epithelial cells are interconnected through cytoskeletal filaments and proteins, and they influence the activities and outcome of various cellular processes. This thesis is focused primarily on the effect that LTD4 has on reorganisation of the actin cytoskeleton and on cell-cell and cell-matrix adhesion properties. We found that LTD4 caused dramatic changes in the actin cytoskeleton in intestinal epithelial cells, and an important factor in this context was the impact of this leukotriene on the actin-binding protein vinculin, which included inducing translocation of vinculin from a cell-cell to a cell-matrix complex.
In general, cell adhesion favours cell survival signalling, and integrins are the main receptors responsible for mediating the attachment of different types of cells to matrix proteins. We have unequivocally established that direct signalling occurs between the LTD4 receptor and the collagen integrins in two different cell lines respectively derived from human colon carcinoma and intestinal epithelial cells. Increased adhesion of the cancer cells depended on activation of cyclooxygenase-2, an enzyme that is involved in progression of colon cancers, whereas adhesion of the intestinal epithelial cells was augmented by LTD4-induced translocation of protein kinase C to areas where integrins bind to matrix proteins (focal adhesions). In conclusion, inflammatory mediators such as LTD4 can affect cell survival through their impact on specific integrins.
Cell-cell and cell-matrix complexes of epithelial cells are interconnected through cytoskeletal filaments and proteins, and they influence the activities and outcome of various cellular processes. This thesis is focused primarily on the effect that LTD4 has on reorganisation of the actin cytoskeleton and on cell-cell and cell-matrix adhesion properties. We found that LTD4 caused dramatic changes in the actin cytoskeleton in intestinal epithelial cells, and an important factor in this context was the impact of this leukotriene on the actin-binding protein vinculin, which included inducing translocation of vinculin from a cell-cell to a cell-matrix complex.
In general, cell adhesion favours cell survival signalling, and integrins are the main receptors responsible for mediating the attachment of different types of cells to matrix proteins. We have unequivocally established that direct signalling occurs between the LTD4 receptor and the collagen integrins in two different cell lines respectively derived from human colon carcinoma and intestinal epithelial cells. Increased adhesion of the cancer cells depended on activation of cyclooxygenase-2, an enzyme that is involved in progression of colon cancers, whereas adhesion of the intestinal epithelial cells was augmented by LTD4-induced translocation of protein kinase C to areas where integrins bind to matrix proteins (focal adhesions). In conclusion, inflammatory mediators such as LTD4 can affect cell survival through their impact on specific integrins.
Department/s
Publishing year
2002
Language
English
Document type
Dissertation
Publisher
Anita Sjölander, Depatment of Laboratory Medicine, Division of Experimental Pathology, Malmö University Hospital, Malmö, Sweden,
Topic
- Cancer and Oncology
Keywords
- oncology
- Cytology
- patologisk anatomi
- Patologi (allmän)
- pathological anatomy
- General pathology
- PKC
- vinculin
- actin filament
- focal adhesion
- LTD4
- integrin
- cancerology
- Cytologi
- onkologi
- cancer
- Biochemistry
- Metabolism
- Biokemi
- metabolism
Status
Published
Supervisor
- [unknown] [unknown]
ISBN/ISSN/Other
- ISBN: 91-628-5242-6
Defence date
24 May 2002
Defence time
10:15
Defence place
"Lilla Aulan", Medicinsk Forskningscentrum, Malmö University Hospital
Opponent
- Staffan Johansson (Prof)