| First Author | Runembert I | Year | 2002 |
| Journal | J Cell Sci | Volume | 115 |
| Issue | Pt 4 | Pages | 713-24 |
| PubMed ID | 11865027 | Mgi Jnum | J:120477 |
| Mgi Id | MGI:3706629 | Doi | 10.1242/jcs.115.4.713 |
| Citation | Runembert I, et al. (2002) Vimentin affects localization and activity of sodium-glucose cotransporter SGLT1 in membrane rafts. J Cell Sci 115(Pt 4):713-24 |
| abstractText | It has been reported that vimentin, a cytoskeleton filament that is expressed only in mesenchymal cells after birth, is re-expressed in epithelial cells in vivo under pathological conditions and in vitro in primary culture. Whether vimentin re-expression is only a marker of cellular dedifferentiation or is instrumental in the maintenance of cell structure and/or function is a matter of debate. To address this issue, we used renal proximal tubular cells in primary culture from vimentin-null mice (Vim(-/-)) and from wild-type littermates (Vim(+/+)). The absence of vimentin did not affect cell morphology, proliferation and activity of hydrolases, but dramatically decreased Na-glucose cotransport activity. This phenotype was associated with a specific reduction of SGLT1 protein in the detergent-resistant membrane microdomains (DRM). In Vim(+/+) cells, disruption of these microdomains by methyl-beta-cyclodextrin decreased SGLT1 protein abundance in DRM, a change that was paralleled by a decrease of Na-glucose transport activity. Importantly, we showed that vimentin is located to DRM, but it disappeared after methyl-beta-cyclodextrin treatment. In Vim(-/-) cells, supplementation of cholesterol with cholesterol-methyl-beta-cyclodextrin complexes completely restored Na-glucose transport activity. Interestingly, neither cholesterol content nor cholesterol metabolism changed in Vim(-/-) cells. Our results are consistent with the view that re-expression of vimentin in epithelial cells could be instrumental to maintain the physical state of rafts and, thus, the function of DRM-associated proteins. |
