| First Author | Schubert W | Year | 2001 |
| Journal | J Biol Chem | Volume | 276 |
| Issue | 52 | Pages | 48619-22 |
| PubMed ID | 11689550 | Mgi Jnum | J:73489 |
| Mgi Id | MGI:2155547 | Doi | 10.1074/jbc.C100613200 |
| Citation | Schubert W, et al. (2001) Caveolae-deficient Endothelial Cells Show Defects in the Uptake and Transport of Albumin in Vivo. J Biol Chem 276(52):48619-22 |
| abstractText | The role of endothelial cell caveolae in the uptake and transport of macromolecules from the blood-space to the tissue-space remains controversial. To address this issue directly, we employed caveolin-1 gene knock-out mice that lack caveolin-1 protein expression and caveolae organelles. Here, we show that endothelial cell caveolae are required for the efficient uptake and transport of a known caveolar ligand, i.e. albumin, in vivo. Caveolin-1-null mice were perfused with 5-nm gold-conjugated albumin, and its uptake was followed by transmission electron microscopy. Our results indicate that gold-conjugated albumin is not endocytosed by Cav-1-deficient lung endothelial cells and remains in the blood vessel lumen; in contrast, gold-conjugated albumin was concentrated and internalized by lung endothelial cell caveolae in wild-type mice, as expected. To quantitate this defect in uptake, we next studied the endocytosis of radioiodinated albumin using aortic ring segments from wild-type and Cav-1-null mice. Interestingly, little or no uptake of radioiodinated albumin was observed in the aortic segments from Cav-1-deficient mice, whereas aortic segments from wild-type mice showed robust uptake that was time- and temperature-dependent and competed by unlabeled albumin. We conclude that endothelial cell caveolae are required for the efficient uptake and transport of albumin from the blood to the interstitium. |
