Protease nexin-1. Localization in the human brain suggests a protective role against extravasated serine proteases.
Protease nexin-1 (PN-1) is a potent thrombin inhibitor that is identical to the glia-derived neurite-promoting factor or glia-derived nexin. Here we report immunocytochemical studies of adult human cerebral cortex that revealed the presence of strong immunoreactivity for PN-1 in capillaries and in the smooth muscle cells of arteries and arterioles. Expression of PN-1 was also abundant in astroglial processes in the parenchyma and in perivascular astroglial endfeet of human cerebral cortex. In situ hybridization with an 35S-labeled RNA antisense probe for PN-1 resulted in significant labeling of astrocytes and blood vessels. Because thrombin is known to cause retraction of neurites and modification of astrocytic morphology at low concentrations, PN-1 around blood vessels may play a major protective role against extravasation of thrombin and possibly other serine protease into the human brain.
Choi
B H
BH
Department of Pathology, University of California, Irvine 92717.
Suzuki
M
M
Kim
T
T
Wagner
S L
SL
Cunningham
D D
DD
D000544:Alzheimer Disease / Q000201:enzymology*; D016564:Amyloid beta-Protein Precursor; D000911:Antibodies, Monoclonal / Q000737:chemistry; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000032:analysis* / Q000276:immunology / Q000502:physiology; D002540:Cerebral Cortex / Q000098:blood supply / Q000201:enzymology*; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D006801:Humans; D015151:Immunoblotting; D007136:Immunoglobulins / Q000737:chemistry; D015336:Molecular Probe Techniques; D009131:Muscle, Smooth, Vascular / Q000201:enzymology; D058255:Protease Nexins; D016372:RNA, Antisense; D011956:Receptors, Cell Surface; D012697:Serine Endopeptidases / Q000032:analysis* / Q000378:metabolism; D058258:Serpin E2
D016564:Amyloid beta-Protein Precursor; D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D005904:Glial Fibrillary Acidic Protein; D007136:Immunoglobulins; D058255:Protease Nexins; D016372:RNA, Antisense; D011956:Receptors, Cell Surface; C545486:SERPINE2 protein, human; D058258:Serpin E2; D012697:Serine Endopeptidases