PV-1 is a component of the fenestral and stomatal diaphragms in fenestrated endothelia.
نویسندگان
چکیده
PV-1 is a novel endothelial protein shown by immunocytochemical tests to be specifically associated with the stomatal diaphragms of caveolae in lung endothelium. Although the highest expression levels of both mRNA and protein are in the lung, PV-1 also has been found to be expressed in other organs. Using a specific antibody to the extracellular domain of PV-1, we have extended the survey on the presence of this protein at light and electron microscope level in several rat organs. Here we show that by immunofluorescence the antibody recognizes with high specificity the endothelium of the fenestrated peritubular capillaries of the kidney and those of the intestinal villi, pancreas, and adrenals. By immunolocalization at electron microscope level, the antibody recognizes specifically the diaphragms of the fenestrae and the stomatal diaphragms of caveolae and transendothelial channels in the endothelia of these vascular beds. No signal was detected in the continuous endothelium of the heart, skeletal muscle, intestinal muscularis, or brain capillaries or the nondiaphragmed fenestrated endothelium of kidney glomeruli. Taken together, our findings define the only antigen to be localized thus far in fenestral diaphragms. They also show that the stomatal diaphragms of caveolae and transendothelial channels and the fenestral diaphragms might be biochemically related, in addition to being morphologically similar structures.
منابع مشابه
PV1 is a key structural component for the formation of the stomatal and fenestral diaphragms.
PV1 is an endothelial-specific integral membrane glycoprotein associated with the stomatal diaphragms of caveolae, transendothelial channels, and vesiculo-vacuolar organelles and the diaphragms of endothelial fenestrae. Multiple PV1 homodimers are found within each stomatal and fenestral diaphragm. We investigated the function of PV1 within these diaphragms and their regulation and found that t...
متن کاملMultiple PV1 dimers reside in the same stomatal or fenestral diaphragm.
Several of the endothelium-specific structures that have been involved in microvascular permeability [such as caveolae, transendothelial channels (TECs), vesiculovacuolar organelles (VVOs), and fenestrae] can be provided with either a stomatal or fenestral diaphragm. In the case of fenestrae, the diaphragm has the presumed function of creating a permselective barrier for solutes from blood plas...
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The route by which water, solutes, and macromolecules traverse the endothelial cell has long been a subject of study for both physiologists and cell biologists. Recent physiologic studies describe a slit-shaped pore (5.1-5.7-nm wide) as the communicating channel, although no channel of such dimensions has been visible in electron microscopic preparations. That this channel should be found withi...
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Cationized ferritin (CF), introduced systemically in vivo or by perfusion in situ, binds preferentially to certain microdomains of the luminal plasmalemma of fenestrated capillaries (mouse pancreas and jejunum). The density and affinity of binding decrease in the following order: fenestral diaphragms greater than coated pits greater than plasmalemma proper. CF binds neither to the membrane of p...
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عنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 96 23 شماره
صفحات -
تاریخ انتشار 1999