Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01034 (cystatin C)
 3,397 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunohistochemical analysis of brains of patients with Alzheimer disease (AD) revealed that the cysteine proteinase inhibitor cystatin C colocalizes with amyloid beta-protein (Abeta) in parenchymal and vascular amyloid deposits. No evidence of cerebral hemorrhage was observed in any of the brains studied. Immunoelectron microscopy demonstrated dual staining of amyloid fibrils with anti-Abeta and anti-cystatin C antibodies. Cystatin C immunoreactivity was also observed in amyloid deposits in the brain of transgenic mice overexpressing human beta amyloid precursor protein. Massive deposition of the variant cystatin C in the cerebral vessels of patients with the Icelandic form of hereditary cerebral hemorrhage with amyloidosis is thought to be responsible for the pathological processes leading to stroke. Anti-cystatin C antibodies strongly labeled pyramidal neurons within cortical layers most prone to amyloid deposition in the brains of AD patients. Immunohistochemistry with antibodies against the carboxyl-terminus of Abeta(x-42) showed intracellular immunoreactivity in the same neuronal subpopulation. It remains to be established whether the association of cystatin C to Abeta plays a primary role in amyloidogenesis of AD or is a late event in which the protein is bound to the previously formed Abeta amyloid fibrils.
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PMID:Codeposition of cystatin C with amyloid-beta protein in the brain of Alzheimer disease patients. 1120 79

Persistent nociceptive input increases neuronal excitability and induces a program of gene expression in the dorsal spinal cord. The alteration in gene expression commences with phosphorylation and induction of immediate early genes and proceeds to target genes. Only a few target genes have been identified as yet. The present report uses a polymerase chain reaction-based subtraction cloning procedure to obtain an "anatomically focused" complementary DNA library enriched in transcripts related to sensory spinal cord (rat dorsal horn minus ventral horn). A subset of clones from this library (n=158) was screened to verify dorsal horn enrichment and to identify those regulated by carrageenan-induced peripheral inflammation. Molecular classes which displayed enriched expression included a proto-oncogene not previously associated with sensory processes, two regulators of the Rho/Rac pathway which controls cell shape, and three genes involved in cytoskeletal regulation and scaffolding. Additional transcripts coded for proteins involved in intercellular communication or intracellular function. Within the set of 158 transcripts, one known and two unknown genes were induced by persistent noxious input. The known gene codes for the secreted cysteine proteinase inhibitor, cystatin C, suggesting that modulation of extracellular proteolytic activity occurs. Since it is secreted, cystatin C may also provide a cerebrospinal fluid bio-marker for persistent pain states. Using a combined anatomical and functional approach, we have extended the molecular repertoire of genes expressed and induced in second-order neurons or supporting glial cells in several new directions, with particular emphasis on regulation of cell morphology and plasma membrane dynamics. Some of these proteins reveal new pathways for information signaling in the sensory half of the spinal cord and require further research to understand their role in the adult spinal cord. The induced genes may provide new molecular targets for therapeutic development and provide new probes for investigating the dynamic state of cellular activity that occurs during persistent pain states.
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PMID:Spinal cord genes enriched in rat dorsal horn and induced by noxious stimulation identified by subtraction cloning and differential hybridization. 1124 63

The concentration of cystatin C, a cysteine proteinase inhibitor, was measured during the treatment of murine LS lymphosarcoma with cyclophosphamide and HA-1 murine hepatoma with the antitumor drug Ukrain. It was shown that concentrations of cystatin C were very low in both the tumor tissues studied (HA-1 hepatoma cells and LS lymphosarcoma); increased cystatin C concentrations were found only in Ukrain-treated murine hepatoma, suggesting the mechanism of antitumor effect of this drug. Cyclophosphamide treatment in LS lymphosarcoma did not influence the concentration of cystatin C in tumor cells. At the same time, a marked increase in cathepsin B and cathepsin L activity in LS lymphosarcoma was found, indicating the involvement of apoptosis in the mechanism of antitumor action of cyclophosphamide. While the DNA from untreated LS lymphosarcoma was very homogenous and its molecular weight was high, the DNA from tumors of treated mice broke down, giving rise to the ladder figure characteristically produced by cells dying from apoptosis. Evidence was obtained that cyclophosphamide-induced tumor regression was effected by apoptosis.
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PMID:Cystatin C in LS lymphosarcoma and HA-1 hepatoma treated with Ukrain and cyclophosphamide and involvement of apoptosis. 1134 40

Cystatin C is the best known extracellular endogenous cysteine proteinase inhibitor and has been studied as a possible index of tumor growth and as a marker of the effectiveness of antitumor therapy. The aim of this study was to evaluate cystatin C concentrations in murine tumor tissues (compared with other organs not directly involved with tumor development, such as the liver and spleen) during treatment with several antitumor drugs (Ukrain and/or cyclophosphane). Cystatin C concentrations in murine tissues and biological fluids was determined by enzyme-linked immunosorbent (ELISA) assay. The cystatin C ELISA test is a sandwich immunoassay, which uses immobilized rabbit antihuman cystatin C Pab and mouse antihuman cystatin C Mab-HRP (monoclonal antibodies, conjugated with horseradish peroxidase). We observed decreased serum cystatin C concentrations compared with controls in all nontreated tumor models: HA-1 hepatoma (solid and ascitic forms), lung adenocarcinoma (solid and ascitic forms) and LS lymphosarcoma. In the ascitic fluid of mice with HA-1 hepatoma the cystatin C concentration was much lower than in the serum of the same mice (about 20-fold lower). In the HA-1 model of hepatoma cells cystatin C concentration decreased about 2-3-fold compared with the control (intact liver) and Ukrain significantly increased the cystatin C concentration. Cyclophosphane treatment of LS lymphosarcoma significantly increased the cystatin C concentration in serum. Cyclophosphane treatment (50 mg/kg, single injection) increased cystatin C by up to 8-fold more in tumor issue. Ukrain treatment of LS lymphosarcoma was also followed by increased levels of cystatin C in tumor tissue (4-fold); cyclophosphane plus Ukrain had a similar positive effect. In the group with LS lymphosarcoma Ukrain or cyclophosphane plus Ukrain treatment induced a significant increase in cystatin C concentration in liver. Liver cystatin C concentration decreased in the HA-1 hepatoma group and treatment with Ukrain or carboxymethylated beta-1, 3-glucan (CMG) increased this index in both groups. Spleen cystatin C concentrations decreased about 5-fold in LS lymphosarcoma compared with controls and combined treatment with cyclophosphane plus Ukrain restored the index to the normal value. We can conclude that both murine tumors studied were characterized by low cystatin C concentrations in tumor tissues and decreased cystatin C concentrations (to a lesser degree) were also observed in liver and spleen as a result of the "toxic" effect of tumor bearing. Effective treatment in all cases (especially with Ukrain or a combination of cyclophosphane plus Ukrain) induced a significant increase in cystatin C. Obviously, the decrease in cystatin C concentration predominantly in tumor tissue was connected with tumor development and restoration of cystatin C level may be used as a marker of efficacy of antitumor therapy.
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PMID:Cysteine proteinase inhibitor level in tumor and normal tissues in control and cured mice. 1134 42

We compared the distribution of a cysteine proteinase inhibitor, cystatin C, with that of cathepsin K in osteoclasts of the mouse tibia by immunolight and immunoelectron microscopy. Light microscopically, strong immunoreactivity for cystatin C was found extracellularly along the resorption lacuna and intracellularly in the organelles of osteoclasts. In serial sections, various patterns of cystatin C and cathepsin K localization were seen, specifically: (1) some resorption lacuna were positive for both cystatin C and cathepsin K; (2) others were positive for either cystatin C or cathepsin K, but not both; and (3) some lacuna were negative for both. In osteoclasts, the localization of cystatin C was similar to that of cathepsin K. Furthermore, cystatin C immunoreactivity was detected in preosteoclasts and osteoblasts, whereas cathepsin K was seen only in preosteoclasts. Electron microscopically, cystatin C immunoreactive products were found in the rough endoplasmic reticulum (ER), Golgi apparatus, vesicles, granules, and vacuoles of osteoclasts. These cystatin C-positive vesicles had fused or were in the process of fusion with the ampullar vacuoles (extracellular spaces) containing cystatin C-positive, fragmented, fibril-like structures. The extracellular cystatin C was deposited on and between the cytoplasmic processes of ruffled borders, and on and between type I collagen fibrils. In the basolateral region of osteoclasts, cystatin C-positive vesicles and granules also fused with vacuoles that contained cystatin C-positive or negative fibril-like structures. These results indicate that osteoclasts not only synthesize and secrete cathepsin K from the ruffled border into the bone resorption lacunae, but also a cysteine proteinase inhibitor, cystatin C. Therefore, it is suggested that cystatin C regulates the degradation of bone matrix by cathepsin K, both extracellularly and intracellularly.
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PMID:Comparison in localization between cystatin C and cathepsin K in osteoclasts and other cells in mouse tibia epiphysis by immunolight and immunoelectron microscopy. 1147 90

Evidence was recently reported that the cysteine proteinase inhibitor, cystatin C, is highly expressed by cultured human retinal pigment epithelial (RPE) cells. As a step towards understanding possible functions of this protein associated with the RPE, the localization, targetting and trafficking of cystatin C were investigated. Constructs encoding an enhanced variant of green fluorescent protein (EGFP) fused to precursor cystatin C and to mature cystatin C were made and transfected into cultured human RPE cells. Expression of fusion proteins was monitored in vivo by fluorescence confocal microscopy. In cells transfected with precursor cystatin C-EGFP, fluorescence was initially targetted to the perinuclear zone, co-localizing with the Golgi apparatus. Transfected cells were observed at intervals over a period of up to 3 weeks, during which time fluorescent vesicles developed peripherally and basally while fluorescence continued to be detected in the Golgi region. Immunochemical analysis of cell lysates confirmed the expression of a fusion protein recognized by antibodies to both cystatin C and EGFP. Cells transfected with the construct lacking the leader peptide of precursor cystatin C presented a diffuse and weak fluorescence. Together, these results imply a leader sequence-dependent processing of cystatin C through the secretory pathway of RPE cells. This was confirmed by the detection, by Western blotting, of the chimaeric protein alongside endogenous cystatin C in the medium of transfected RPE cells.
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PMID:Precursor cystatin C in cultured retinal pigment epithelium cells: evidence for processing through the secretory pathway. 1168 90

Cystatin C is a new endogenous marker of renal function whose serum concentration correlates better with glomerular filtration rate than creatinine. Cystatin C has been suggested to be a marker of renal function). Cystatin C is a cysteine proteinase inhibitor. It is produced at a constant rate in all investigated nucleated cells, its gene is a housekeeping type. Cystatin C is freely filtered in the renal glomeruli and reabsorbed and catabolised in the proximal tubules. Reference intervals have been determined for cystatin C in adults and in children older than one year without gender differences. Several studies including adults and children with different renal diseases with various kidney function have suggested serum cystatin C to be a better marker of GFR than serum creatinine. Fully automated assays using particle-enhanced turbidimetry (PETIA) or particle-enhanced nephelometry (PENIA) are available and the assays are precise, rapid and usable in clinical routine practice.
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PMID:[Diagnostic usefulness of cystatin C measurement]. 1181 47

Cystatin C, a major extracellular cysteine proteinase inhibitor, is deposited as amyloid in brain haemorrhage patients with hereditary cystatin C amyloid angiopathy (HCCAA). A disease-causing mutation on the genetic level results in the substitution Leu68-->Gln (L68Q) in cystatin C, which causes protein instability. Besides carrying the L68Q substitution, cystatin C in amyloid deposits isolated from patients is N-terminally truncated by 10 amino acids. To elucidate the role of the N-terminal truncation for protein stability and aggregation properties, (delta1-10,L68Q)-cystatin C was produced in an Escherichia coli expression system and characterised. Unlike wild-type cystatin C, this variant rapidly dimerised under physiological conditions. Two unfolding intermediates of (delta1-10,L68Q)-cystatin C were identified, under the same pH and ionic strength conditions as required to form intermediates of full-length L68Q cystatin C. No evidence was found that the N-terminal truncation per se alters protein stability and leads to higher forms of aggregation. Monomeric as well as dimeric L68Q cystatin C incubated with neutrophil elastase was truncated as in HCCAA patients' amyloid. A protein variant with a thrombin cleavage site placed in front of residue Gly11 in L68Q cystatin C was constructed and used to confirm that the N-terminal segment is similarly accessible to proteinases in the monomeric and dimeric states of L68Q cystatin C. Thus, the N-terminal segment of L68Q cystatin C is exposed to proteolytic attack and does not seem to be involved in intramolecular contacts leading to dimerisation or higher-order aggregation. We conclude that the N-terminal truncation likely is an event secondary to amyloid formation, and of no relevance for the development of HCCAA.
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PMID:Physico-chemical properties of the N-terminally truncated L68Q cystatin C found in amyloid deposits of brain haemorrhage patients. 1193 68

Intact peritoneal macrophages in vitro secreted the cysteine proteinase inhibitor cystatin C. Polysaccharides stimulated cystatin C secretion: lipopolysaccharide < carboxymethylated beta-D-glucan < sulfoethylated beta-D-glucan. Human plasma low-density- (LDL) and high-density lipoproteins (HDL) are still more potent inducers of cystatin C secretion by macrophages. Peritoneal macrophages from mice with experimental HA-1 hepatoma compared to those from intact mice secreted more cystatin C with maximum polysaccharide-stimulated secretion after 30 min of incubation. LDL and HDL induced cystatin C secretion by tumor macrophages also.
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PMID:Effect of polysaccharides and human plasma lipoproteins on the secretion of cystatin C by peritoneal macrophages from normal and tumor bearing mice. 1506 96

Neuroglobin (Ngb) is a newly discovered globin that is expressed in vertebrate brain. It has been reported that Ngb levels increase in neurons in response to oxygen deprivation, and that Ngb protects neurons from hypoxia. However, the mechanism of this neuroprotection remains unclear. In the present study, we identified human cystatin C, a cysteine proteinase inhibitor, as an Ngb-binding protein by using a yeast two-hybrid system. Surface plasmon resonance experiments verified that Ngb binds to cystatin C dimers, not to the monomers. Because both intracellular cystatin C and the amyloidogenic variant of cystatin C form dimers, Ngb may modulate the intracellular transport (or secretion) of cystatin C to protect against neuronal death under conditions of oxidative stress and/or it may have a role in the development of neurodegenerative diseases.
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PMID:Association of human neuroglobin with cystatin C, a cysteine proteinase inhibitor. 1512 77


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