The objectives of this proposal are: 1) to analyze mechanisms involved in transport of plasma macromolecules across microvascular endothelium ii) to define the physicochemical basis of the dependence of the permselectivity of the endothelial barrier on albumin interaction with the glycocalyx and iii) delineate the pathologic molecular mechanism(s) for increased solute transvascular exchange with diabetes. Specifically, the project will center on the interaction of albumin and glycoalbumin with the endothelium both in vivo and in vitro under normal and diabetic conditions. The work in vitro will involve growth in culture of endothelial cells isolated from various vascular beds (hearts, retina, brain, lung, fat pad, and aorta). These cell monolayers will be used to assess the binding of albumin and glycoalbumin. In order to define at the molecular level now albumin (A) and glycoalbumin(GA) interact with the endothelium in vitro and in situ/vivo, we will i) quantitate the transport rate of A and Ga across the endothelium of various microvascular beds; ii) determine the location and transendothelial transport pathway of A and GA using immunocytochemical techniques: iii) identify and characterize endothelial plasmalemmal proteins, especially those proteins that are preferentially glycated with hyperglycemia or involved in the binding of GA and A to the endothelium. We believe these approaches represent a unique system to study at the cellular and molecular level albumin-endothelium interactions under normal and pathologic conditions. Although much more work is necessary to understand more clearly microvascular transport phenomena, this project in basic microvascular research has been extended to include aspects of pathological change in the endothelial barrier and transvascular exchange with diabetes. It is clear that structural and functional alterations of capiliaries are involved in the development of serious sequelae of diabetes including diabetic retinopathy, nephropathy and polyneuropathy. There is increasing evidence that poor metabolic control and the resultant hyperglycemia plays an important role in the development of diabetic microangiopathy. This project proposes to examine the effects of hyperglycemia on the molecular mechanisms of tissue-blood transport of macromolecules. The effects of glycation of albumin and endothelial plasmalemmal surface protein on transendothelial transport will be examined.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
1R29HL043278-01
Application #
3472782
Study Section
Cardiovascular and Pulmonary Research B Study Section (CVB)
Project Start
1989-08-01
Project End
1990-02-28
Budget Start
1989-08-01
Budget End
1990-02-28
Support Year
1
Fiscal Year
1989
Total Cost
Indirect Cost
Name
Yale University
Department
Type
Schools of Medicine
DUNS #
082359691
City
New Haven
State
CT
Country
United States
Zip Code
06520
McIntosh, D P; Schnitzer, J E (1999) Caveolae require intact VAMP for targeted transport in vascular endothelium. Am J Physiol 277:H2222-32
Lee, S W; Reimer, C L; Oh, P et al. (1998) Tumor cell growth inhibition by caveolin re-expression in human breast cancer cells. Oncogene 16:1391-7
Bickel, P E; Scherer, P E; Schnitzer, J E et al. (1997) Flotillin and epidermal surface antigen define a new family of caveolae-associated integral membrane proteins. J Biol Chem 272:13793-802
Schnitzer, J E; Oh, P; McIntosh, D P (1996) Role of GTP hydrolysis in fission of caveolae directly from plasma membranes. Science 274:239-42
Garcia-Cardena, G; Oh, P; Liu, J et al. (1996) Targeting of nitric oxide synthase to endothelial cell caveolae via palmitoylation: implications for nitric oxide signaling. Proc Natl Acad Sci U S A 93:6448-53
Schnitzer, J E; Oh, P (1996) Aquaporin-1 in plasma membrane and caveolae provides mercury-sensitive water channels across lung endothelium. Am J Physiol 270:H416-22
Schnitzer, J E; Oh, P; Jacobson, B S et al. (1995) Caveolae from luminal plasmalemma of rat lung endothelium: microdomains enriched in caveolin, Ca(2+)-ATPase, and inositol trisphosphate receptor. Proc Natl Acad Sci U S A 92:1759-63
Schnitzer, J E; McIntosh, D P; Dvorak, A M et al. (1995) Separation of caveolae from associated microdomains of GPI-anchored proteins. Science 269:1435-9
Schnitzer, J E; Liu, J; Oh, P (1995) Endothelial caveolae have the molecular transport machinery for vesicle budding, docking, and fusion including VAMP, NSF, SNAP, annexins, and GTPases. J Biol Chem 270:14399-404
Schnitzer, J E; Allard, J; Oh, P (1995) NEM inhibits transcytosis, endocytosis, and capillary permeability: implication of caveolae fusion in endothelia. Am J Physiol 268:H48-55

Showing the most recent 10 out of 24 publications