Natural inhibitors of fibrinolysis

Aoki, Nobuo

doi:10.1016/0033-0620(79)90014-8

Cited by 55 publications

(35 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The cross-linked a2PI inhibits in situ plasmin generation on the fibrin surface by physiologically occurring fibrinassociated plasminogen activation (14,15). These properties peculiar to a2PI enable it to be a much more specific and effective inhibitor of plasmin-catalyzed fibrinolysis than any other major protease inhibitors, such as a2-macroglobulin (2,9,16,17). In individuals with a congenital deficiency of a2PI, hemostatic plugs are dissolved prematurely by physiologically occurring fibrinolytic processes before the restoration ofinjured vessels, resulting in a severe hemorrhagic tendency (18,19).…”

Section: Introductionmentioning

confidence: 99%

Organization of the human alpha 2-plasmin inhibitor gene.

Hirosawa

Nakamura

Miura

et al. 1988

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

We have isolated overlapping phage genomic clones covering an area of 26 kilobases that encodes the human alpha 2-plasmin inhibitor. The alpha 2-plasmin inhibitor gene contains 10 exons and 9 introns distributed over approximately 16 kilobases of DNA. To our knowledge, the number of introns is the highest yet reported for a member of the serine protease inhibitor (serpin) superfamily. All introns are located in the 5'-half of the corresponding mRNA. The 5'-untranslated region and the leader sequence are interrupted by 3 introns totaling approximately equal to 6 kilobases. A "TATA box" sequence is located 17 nucleotides upstream from the proposed transcription initiation site. Multiple "GC box" sequences, G + C-rich sequences, and "CCAAT box"-like sequence, the hepatitis B virus enhancer element-like sequence and the human immunodeficiency virus enhancer-like sequence appear in the 5'-flanking region. The NH2-terminal region, which implements factor XIII-catalyzed cross-linking of alpha 2-plasmin inhibitor to fibrin, is encoded by the 4th exon. The reactive site and plasminogen-binding site, both located in the COOH-terminal region, are encoded by the 10th exon. When similar amino acids of alpha 2-plasmin inhibitor and other members of the serpin gene superfamily are aligned, the position of the 7th intron of the alpha 2-plasmin inhibitor gene aligns precisely with that of the second intron of the genes for rat angiotensinogen and human alpha 1-antitrypsin genes and is misaligned by only one nucleotide with that of the third intron of antithrombin III, suggesting that the alpha 2-plasmin inhibitor gene originates from the common ancestor of these serine protease inhibitors.

show abstract

Section: Introductionmentioning

confidence: 99%

Organization of the human alpha 2-plasmin inhibitor gene.

Hirosawa

Nakamura

Miura

et al. 1988

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…On a2-Plasmin inhibitor (a2-PI, also called a2-antiplasmin and primary plasmin inhibitor)-is a glycoprotein with an apparent Mr of68,000 present in human plasma (1-3). a2-PI inhibits plasmin instantaneously by forming a stoichiometric (1: 1) complex with plasmin and appears to play a critical role in the regulation of in vivo fibrinolysis (4,5). The site of synthesis of a2-PI is not known.…”

mentioning

confidence: 99%

“…a2-PI inhibits plasmin instantaneously by forming a stoichiometric (1: 1) complex with plasmin and appears to play a critical role in the regulation of in vivo fibrinolysis (4,5). The site of synthesis of a2-PI is not known.…”

mentioning

confidence: 99%

“…Thirty microliters of concentrated medium from Hep G2 cells (G2 medium) was incubated with 10 ul, of plasmin (0.22 Ag) at room temperature for 20 min. As a control, 30 u1d of normal plasma, diluted 1:4, was mixed with 5 Al ofplasmin (0.11 ;Lg) under the same conditions. The mixtures were then analyzed by crossed immunoelectrophoresis as described above.…”

mentioning

confidence: 99%

“…The medium was collected after 5 1,206 Ci/mmol; 1 Ci = 3.7 X 1010 becquerels) in 4 ml ofmethioninefree serum-free medium. The medium was then treated with 2 mM DFP and extensively dialyzed against Barb/NaCl buffer/ 1 mM iPr2P-F and 1 mM nonradioactive methionine.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Synthesis and secretion of alpha 2-plasmin inhibitor by established human liver cell lines.

Saito¹,

Goodnough²,

Knowles³

et al. 1982

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The site of synthesis of a2-plasmin inhibitor (a2-PI), a physiologic inhibitor ofplasmin, is not known with certainty. We have studied the production and secretion of x2-PI by three established human liver cell lines derived from hepatocellular carcinoma and hepatoblastoma (Hep G2, Hep 3B, and PLC/PRF/ 5). As measured by a specific radioimmunoassay, the titer of a2-PI increased in the medium ofHep G2 and Hep 3B cells with time, but no significant amount of a2-PI was found in the medium of PLC/PRF/5. There was no evidence for a significant intracellular pool of this protein. On a2-Plasmin inhibitor (a2-PI, also called a2-antiplasmin and primary plasmin inhibitor)-is a glycoprotein with an apparent Mr of68,000 present in human plasma (1-3). a2-PI inhibits plasmin instantaneously by forming a stoichiometric (1: 1) complex with plasmin and appears to play a critical role in the regulation of in vivo fibrinolysis (4,5). The site of synthesis of a2-PI is not known.Three human cell lines have recently been established from human hepatocellular carcinoma and hepatoblastoma (6,7), and have been shown to synthesize and secrete many of the major human plasma proteins, including components of the blood coagulation-fibrinolytic system such as fibrinogen, plasminogen, and a2-macroglobulin (8). The availability of these cell lines prompted us to study the production of a2-PI by cultured cells. In this paper, we report that human liver tumor cell lines synthesize and secrete functional a2-PI that has the same antigenic determinants and Mr as plasma a2-PI. A preliminary report of this study has been presented (9, t).MATERIALS AND METHODS Materials. Plasmas from normal individuals and a patient with congenital a2-PI deficiency were prepared as described (10).Three established cell lines derived from human liver tumors, Hep G2, Hep 3B, and PLC/PRF/5, were cultured in Eagle's minimal essential medium (Flow Laboratories, McLean, VA)/10% fetal bovine serum (Reheis Chemical, Kankakee, IL)/5 mM glutamine as described (10); 1.5-13.5 X 106 cells were plated in 150-cm2 polystyrene flasks (Coming Plastics, Coming, NY) containing 30 ml of medium. Half of the medium was removed on day 9 and replaced with fresh medium. At days 3, 5, 9, 11, 13, and 15, the supernatant fluid from replicate flasks was removed, centrifuged, and frozen. The cells were harvested, and viable cells were determined by the erythrosin B dye-exclusion method. The remaining cells were washed three times in Dulbecco's modified phosphate-buffered saline, centrifuged, and frozen and thawed four times in 1 ml of distilled water. These total cell lysates were also frozen until use. Cell medium and cell lysates were immediately treated with 1 mM diisopropyl phosphorofluoridate (iPr2P-F; Calbiochem-Behring). In some experiments, medium was concentrated to 1/10th to 1/15th vol by pressure dialysis against 0.025 M sodium barbital/0. 125 M sodium chloride, pH 7.4 (Barb/ NaCl buffer).Concentrations of a2-PI in the medium and cell lysates were measured by a specific and s...

show abstract