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Updated: Jul 20, 2026
A Method for Labeling Vasculature in Embryonic Mice
Published on: October 7, 2011
PV-1 labels trans-cellular openings in mouse endothelial cells and is negatively regulated by VEGF
Robert Hnasko1, John Mark Carter, Freddy Medina
1United States Department of Agriculture, Agricultural Research Service-Pacific West Area, Western Region Research Center, Foodborne Contaminants Research Unit, Albany, California, USA.
Abstract:
The PV-1 protein is endogenously expressed from a single mRNA in the mouse pancreatic MS-1 endothelial cell line as a 60-kDa N-glycosylated and 50-kDa non-glycosylated protein that form DTT sensitive oligomers. In the absence of cell permeabilization, PV-1 antibodies label transcellular openings of variable size, many that penetrate through the cytosol with circular openings on the free and attached surface of the plasma membrane. Intracellular PV-1 is localized in perinuclear aggregates that can extend as a fibrous network through the cytosol and often surround the nuclear compartment. In some cells, PV-1 is organized as a large unipolar spindle-like structure that is often associated with severe deformation of the nucleus. The VEGF-R2 inhibitor SU5614 increased the PV-1 protein levels in a dose-dependent manner and inhibited MS-1 cell growth, without inducing apoptosis. This report provides compelling evidence for a functional role of PV-1 in the formation of large transendothelial channels and modulation of nuclear shape. Moreover, these data suggest the PV-1 protein is negatively regulated by VEGF.
Insights
The PV-1 protein plays a key role in forming transendothelial channels and altering nuclear shape in MS-1 cells. Vascular endothelial growth factor (VEGF) appears to negatively regulate PV-1 protein levels.
Area of Science:
- Endothelial cell biology
- Protein biochemistry
- Molecular cell biology
Background:
- The PV-1 protein is endogenously expressed in mouse pancreatic MS-1 endothelial cells.
- PV-1 exists as N-glycosylated (60-kDa) and non-glycosylated (50-kDa) forms, forming DTT-sensitive oligomers.
- Antibodies against PV-1 label transcellular openings and intracellular aggregates in non-permeabilized cells.
Purpose of the Study:
- To investigate the functional role of PV-1 in endothelial cell structure and regulation.
- To explore the relationship between PV-1, transendothelial channels, nuclear shape, and VEGF signaling.
Main Methods:
- Immunofluorescence labeling of PV-1 in MS-1 cells.
- Analysis of PV-1 protein expression and oligomerization.
- Treatment with VEGF-R2 inhibitor SU5614 to assess effects on PV-1 levels and cell growth.
- Microscopy to observe cellular and nuclear morphology.
Main Results:
- PV-1 antibodies revealed transcellular openings and intracellular fibrous networks, sometimes deforming the nucleus.
- SU5614 treatment increased PV-1 protein levels and inhibited MS-1 cell growth without inducing apoptosis.
- PV-1 protein levels were found to be negatively regulated by VEGF.
Conclusions:
- PV-1 is functionally involved in the formation of transendothelial channels and modulation of nuclear shape.
- VEGF negatively regulates PV-1 protein expression, suggesting a role in endothelial barrier function and cell morphology.
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