Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.69 (APC)
 16,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An assay was developed for the measurement of human protein C inhibitor antigen (PCI) in blood plasma and other biological fluids. Both native PCI, modified inhibitor, and complexes of inhibitor with activated protein C or plasma kallikrein could be measured with the assay. Inhibitor antigen concentrations were found to be very high in seminal plasma (greater than 200 mg/liter), more than 40 times the concentration of PCI found in blood plasma. The inhibitor in seminal plasma was unable to form complexes with activated protein C. Gel filtration and immunoblotting findings indicated that the inhibitor in seminal plasma is present in a high molecular mass complex or cleaved to its modified form. As PCI antigen was absent from seminal plasma of patients with dysfunctional seminal vesicles, the seminal vesicle glands would appear to be the major source of seminal plasma PCI, a conclusion supported by immunohistochemical demonstration of the presence of PCI epitopes in the secretory epithelium of the seminal vesicles. Specific PCI immunoreactivity was also shown to be present in the testes, the epididymis glands, and the prostate, suggesting the inhibitor to have a complex or multiple function in the male reproductive system. Conclusive evidence of a local synthesis of PCI in the four male sex glands was provided by Northern blot analysis of RNA from these organs.
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PMID:Protein C inhibitor in human body fluids. Seminal plasma is rich in inhibitor antigen deriving from cells throughout the male reproductive system. 137 13

Protein C is a vitamin K-dependent protein circulating in plasma as a zymogen to an anticoagulant serine protease. After its activation, protein C cleaves and inactivates coagulation factors Va and VIIIa. Human protein C is synthesized in liver and undergoes extensive post-translational modification during its synthesis. Recently, the protein C inhibitor was demonstrated to be synthesized in several organs of the human male reproductive tract. Moreover, vitamin K-dependent protein S, which functions as a co-factor to activated protein C, was found to be synthesized in the Leydig cells of human testis. The aim of this study was to elucidate whether the protein C gene is also expressed in the male reproductive system. Specific immunostaining of protein C was found in Leydig cells of human testis, in the excretory epithelium of epididymis, and in some epithelial glands of the prostate, whereas no immunostaining was detected in seminal vesicles. Northern blotting and non-radioactive in situ hybridization demonstrated protein C mRNA in Leydig cells, in the excretory epithelium of epididymis, and in some of the epithelial glands of the prostate. The mRNA was distributed perinuclearly and the localization was in accordance with the specific immunostaining for protein C. The epithelium of epididymis was also found to contain both protein S mRNA and immunoreactivity. The demonstration of both protein C and protein S immunoreactivities, as well as their mRNAs, in male reproductive tissues suggests as yet unknown local functions for these proteins.
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PMID:The gene encoding vitamin K-dependent anticoagulant protein C is expressed in human male reproductive tissues. 776 27

Vitamin K-dependent protein S is an anticoagulant plasma protein that functions as a co-factor to activated protein C in the degradation of coagulation factors Va and VIIIa. We investigated the tissue/cellular distribution of protein S synthesis by Northern blotting, in situ hybridization, and immunohistochemistry. Northern blotting together with in situ hybridization, using specific oligodeoxynucleotide probes, demonstrated protein S mRNA in liver, lung, testis, epididymis, ovary, uterus, and brain. In the reproductive system, protein S mRNA was present in the cytoplasm of Leydig cells, interstitial cells of the ovary, epithelial cells of the epididymis, and in the endometrium, including endometrial mucous glandular membrane in the myometrium. Bronchial epithelial cells and alveolar macrophages were positive in the respiratory system. In the central nervous system, pyramidal neurons in the cerebral cortex and in the hippocampal region, and dentate fascia neurons gave strongly positive signals. Immunohistochemistry with monoclonal antibodies yielded a staining pattern that correlated well with results of in situ hybridization. In conclusion, results from Northern blotting, in situ hybridization, and immunohistochemistry suggested that rabbit protein S is expressed in several extrahepatic tissues. The presence of protein S transcripts in these fully differentiated cells suggests a cell type-specific gene expression which may be related to local anticoagulation or to other as yet unknown protein S functions.
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PMID:The gene encoding vitamin K-dependent anticoagulant protein S is expressed in multiple rabbit organs as demonstrated by northern blotting, in situ hybridization, and immunohistochemistry. 782 69

Activated protein C (APC) acts as an anticoagulant by inhibiting coagulation factors Va and VIIIa. Although the liver appears to be the primary site of protein C (PC) synthesis, the demonstration that other components of this system are produced extrahepatically raises the possibility that PC itself is synthesized in other tissues. We therefore used quantitative reverse transcription-polymerase chain reaction, in situ hybridization, and immunohistochemistry to screen various murine tissues for PC expression. Relatively high levels of PC mRNA were detected in the kidney (35% of liver) and testis (22% of liver). PC mRNA and antigen were demonstrated in tubular epithelial cells in the renal cortex, in spermatogenic cells in the testis, and in epithelial cells in the epididymis. Low but significant levels of PC mRNA were detected in the epididymis (1.7% of the level in liver), brain (1.1% of liver), and lung (0.8% of liver). PC antigen was demonstrated in bronchial epithelial cells in the lung, in pyramidal neurons in the cerebrum, and in Purkinje cells in the cerebellum. The extrahepatic expression of PC mRNA (ie, in the kidney) was significantly decreased in mice with renal disease (eg, in MRL lpr/lpr mice with autoimmune lupus nephritis, in db/db mice with diabetic nephropathy, and in endotoxin-treated mice with acute renal injury). The decreased renal expression of PC may contribute to the increased procoagulant potential of the kidney during septic and inflammatory processes and to the progression of kidney disease associated with these conditions.
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PMID:Extrahepatic expression and regulation of protein C in the mouse. 970 14