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Results for “Complement C1s”

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At least 325 records · Page 18Linked to original sources
PubMed2004

Up-regulated expression of the MAT-8 gene in prostate cancer and its siRNA-mediated inhibition of expression induces a decrease in proliferation of human prostate carcinoma cells.

In order to analyze differential gene expression of putative prostate tumor markers we compared the expression levels of >400 cancer-related genes using the cDNA array technique in a set of prostate tumors and matched normal prostate tissues. Up-regulated expression of mammary tumor 8 kDa protein (MAT-8), complement component C1S (C1S), ferritin heavy chain (FTH1), peptidyl-prolyl cis-trans isomerase A (PPIA), RNA-binding protein regulatory subunit DJ-1 protein (DJ-1) and vacuolar ATP synthase subunit F (ATP6V1F) was determined in prostate carcinoma and confirmed by using quantitative real-time RT-PCR analyses. Furthermore, quantitative real time RT-PCR on intact RNAs from 11 paired laser microdissected epithelial tissue samples confirmed up-regulated MAT-8 expression in 6 out of 11 prostate tumors. To determine the function of MAT-8 in vitro, human PC-3 and LNCaP prostate carcinoma cells were transfected with small interfering double-stranded RNA (siRNA) oligonucleotides against the MAT-8 gene leading to a specific down-regulation of MAT-8 expression. In addition, suppression of MAT-8 expression caused a significant decrease in cellular proliferation of both prostate cancer cell lines, whereas invasive capacity and cellular apoptosis remained unaffected. Taken together, our results indicate that the human MAT-8 gene contains the potential to serve as a prostate cancer expression marker and that MAT-8 plays an important role in cellular growth of prostate carcinomas.

Aged↗
PubMed1992

Improved detection of homology in distantly related proteins: similarity of adducin with actin-binding proteins.

A novel and generally applicable method is described for the detection of homology in distantly related proteins using a new domain sequence database that contains over 20,000 protein sequence segments of known function. The use of the method is illustrated on distantly related domains shared by complement components C1S and C1R, calcium-dependent serine proteinase and bone morphogenetic protein 1. New homologies are shown between human adducin and the actin-binding domains of alfa-actinin and dystrophin.

Actinin↗
PubMed1990

Ca2+ binding properties and Ca2(+)-dependent interactions of the isolated NH2-terminal alpha fragments of human complement proteases C1-r and C1-s.

The NH2-terminal alpha fragments of human complement proteases C1-r and C1-s were obtained by limited proteolysis of the native proteins with trypsin, and isolated. C1-r alpha extended from residues 1 to 208 of C1-r A chain, with at least two cleavage sites within disulfide loops, after lysine 134 and arginine 202. C1-s alpha comprised residues 1-192 of the C1-s A chain, with one cleavage site within a disulfide loop, after arginine 186. C1-r alpha was monomeric either in the presence or absence of Ca2+ but formed Ca2(+)-dependent dimers with native C1-s. C1-s alpha dimerized in the presence of Ca2+ and formed Ca2(+)-dependent tetramers (C1-s alpha-C1-r-C1-r-C1-s alpha) with native C1-r. C1-r alpha and C1-s alpha associated in the presence of Ca2+ to form C1-r alpha-C1-s alpha heterodimers. Equilibrium dialysis studies indicated that each alpha region binds Ca2+ with a dissociation constant ranging from 19 microM (native proteins) to 38 microM (fragments). C1-r alpha, C1-r alpha-C1-s alpha, and the native C1-s-C1-r-C1-r-C1-s tetramer bound 0.9, 1.9, and 4.0 Ca2+ atoms/mol, respectively, whereas dimers C1-s alpha-C1-s alpha and C1-s-C1-s incorporated 2.9 and 3.0 Ca2+ atoms/mol. It is concluded that each alpha region contains one high affinity Ca2+ binding site. This 1:1 stoichiometry is maintained upon heterologous (C1-r-C1-s) interaction, whereas the homologous (C1-s-C1-s) interaction provides one additional binding site.

Amino Acid Sequence↗
PubMed1987

Interactions of plasma kallikrein and C1-s with normal and dysfunctional C1(-)-inhibitor proteins from patients with hereditary angioneurotic edema: analytic gel studies.

Purified preparations of normal C1(-)-inhibitor (C1(-)-INH) formed high mol wt complexes with plasma kallikrein that were stable during sodium dodecyl sulfate (SDS)-gel electrophoresis, but most of the dysfunctional C1(-)-INH proteins isolated from plasma of patients with type II hereditary angioneurotic edema (HANE) did not. Two of eight dysfunctional C1(-)-INH proteins were cleaved to lower mol wt forms that were not seen following the reaction of normal C1(-)-INH with equimolar amounts, or less, of plasma kallikrein. Only the higher mol wt component of normal C1(-)-INH (106,000 mol wt) appeared to form a stable complex with the plasma kallikrein, whereas both the 106,000 and 96,000 mol wt forms made stable complexes with C1-s. When a preparation of normal C1(-)-INH containing a homogeneous single band of C1(-)-INH was exposed to C1-s or kallikrein, a "doublet" form evolved in which the heaviest band was in the original position of native C1(-)-INH; C1-s cleavage provided a second band of 96,000; and cleavage by kallikrein, a second band of 94,000 mol wt. We conclude that dysfunctional C1(-)-INH proteins from plasma of persons with type II hereditary angioneurotic edema have impaired interactions with plasma kallikrein and are heterogeneous with respect to these interactions. Moreover, the requirements for the formation of stable complexes between normal C1(-)-INH and plasma kallikrein differed from those for stable complex formation with C1-s. The doublet form of C1(-)-INH, which purified preparations frequently demonstrate, may be due to prior cleavage by C1-s or kallikrein.

Angioedema↗
PubMed1984

N-Acetyl-L-tyrosine ethyl ester (ATEe) hydrolytic activities of diseased human palatine tonsils. Possible pathogenesis of recurrent acute tonsillitis.

The N-acetyl-L-tyrosine ethyl ester (ATEe)-hydrolysing activities of tonsillar extracts in cases of recurrent acute tonsillitis decreased more than those in less severe cases of chronic tonsillitis and in cases of obstructive enlargement of the palatine tonsil. Since ATEe is hydrolysed by C1-esterase, the ATEe hydrolytic activity of the tonsil might be related to the C1-activating system of the tonsil. This indicates that tonsils in which ATEe hydrolytic activities are low, repeatedly and severely, become infected, possibly due to easy invasion of micro-organisms.

Acute Disease↗
PubMed1983

[New preparation method of C1 esterase for the dosage of its plasma inhibitor].

A purification method for C1 esterase is described. The final product significantly improved the sensitivity and the specificity of the enzymatic measurement of its plasma inhibitor C1-INH or alpha 2-neuraminoglycoprotein (alpha 2-NGP) by esterolysis of a synthetic substrate N-acetyl-L-tyrosine ethyl ester (ALTEe). A comparative study was done between the chromatographed C1 esterase and the native serum euglobulins: qualitative and quantitative determination of the serum contaminants, enzymatic activity measurement of C1-INH in normal subjects and in patients suffering from hereditary angioneurotic oedema (OANH) as well as in therapeutical C1-inhibitor concentrates.

Angioedema↗
PubMed1982

[Clinical features, pathogenesis, and therapy of hereditary angioneurotic edema (author's transl)].

The hereditary angioneurotic edema is probably a more frequent disease than presumed until now. It is inherited as an autosomal dominant trait, and is due to diminished or functionally deficient C1 esterase inhibitor. Family history is negative in cases of spontaneous mutations. Two thirds of the patients are already affected in infancy with peripheral edema, facial edema, abdominal symptoms and/or edema of the glottis occuring spontaneously or secondary to trauma. Recently the prognosis has become better due to early diagnosis and the possibility of substitution therapy with C1 esterase inhibitor. A long-term prophylaxis may be achieved with synthetic androgens.

Adolescent↗
PubMed1995

Changes in the contact system during orthotopic liver transplantation with and without aprotinin.

The main cause of nonsurgical bleeding during orthotopic liver transplantation has been attributed to be hyperfibrinolysis due to high plasma levels of tissue plasminogen activator. The aim of this study was to investigate contact activation and its possible contribution to fibrinolysis during OLT with and without aprotinin. Aprotinin or placebo was given to 20 patients undergoing OLT as part of a randomized double-blind trial. Plasma samples were collected before, during, and after OLT. There were decreased preoperative levels of prekallikrein and factor XIIa (P < 0.05), with a trend for kallikrein and factor XIIa activity to increase during OLT peaking on reperfusion (P < 0.05). Kallikrein inhibition, C1 esterase inhibitor, and alpha-2-macroglobulin levels were normal before surgery, with low normal levels of antithrombin III and alpha-2-antiplasmin; these levels decreased during OLT with no specific change on reperfusion. In the aprotinin-treated group, kallikrein inhibition levels increased (P < 0.05) from preoperative mean (+/- SD) values of 101 +/- 47% to 154 +/- 42% and antiplasmin levels increased (P < 0.05) from 72 +/- 28% to 243 +/- 53% during the anhepatic phase, reflecting the effect of aprotinin. The antifibrinolytic effect of aprotinin was demonstrated by decreased levels of D-dimer on reperfusion (P < 0.05) and at the end of OLT (P < 0.001) in the aprotinin-treated group. We have shown that contact activation during OLT is minimal and that aprotinin does not alter the pattern of contact activation, but provides an antikallikrein effect.

Adult↗
PubMed1995

[Hemostasis disorders in patients with pulmonary tuberculosis].

Coagulation studies in 82 patients with pulmonary tuberculosis showed that latent intravascular coagulation occurs not only in patients with active disease, but also in those with marked residual changes. The level of Cl-esterase inactivator may serve as an indicator of the disease prognosis: if its concentration is low, the prognosis is poor. Total fibronectin was measured in 76 patients with different tuberculosis activity. The results suggest that this protein's blood levels reflect the activity of the specific process in the lungs. Normal fibronectin concentrations indicate cure of tuberculosis.

Adolescent↗