This study was aimed to set up and evaluate a quantitative method for detecting lumbrokinase level in plasma. The lumbrokinase was used to immunize rabbit and BALB/c mouse for preparation of rabbit or mouse-derived polyclonal antibodies, and then the standard curves were drawn up by detecting the lumbrokinase diluted in PBS using the double antibody sandwich ELISA. This method further was analyzed for its specificity, precision and recovery rate. This established double antibody sandwich ELISA was used to assay the lumbrokinase in human plasma, and the assayed results were assessed. The results showed that a double antibody sandwich ELISA for the detection of lumbrokinase has been established. And the standard curve fitting R value > 0.99, the precision assessment showed that the measured values of coefficient of variation (CV) in 3 batches were all < 15%; recovery assessment in 3 batches showed that all the measured recovery rates were > 80%; the quantitative low limit was assessed as 5 ng/ml (precision CV < 15%, recovery rate > 85%). It is concluded that this method is consistent with the criteria stipulated by the Pharmacopeia, which provides a reliable measurement method for quantitative detection of plasma lumbrokinase in clinical trials.
Animals ; Endopeptidases ; blood ; Enzyme-Linked Immunosorbent Assay ; methods ; Humans ; Mice ; Mice, Inbred BALB C ; Plasma ; Rabbits

OBJECTIVETo study the effect of imbalance between lysosomal enzymes and their inhibitors in blood on disturbance of the local and whole body after trauma.

METHODSThe dynamic changes of lysosomal enzymes and proteinase inhibitors were studied in 12 pigs with femoral comminuted fractures in both hind limbs caused by high velocity missiles. Four normal pigs served as controls.

RESULTSAfter injury, the activity of Cathepsin D in arterial plasma increased gradually and reached the highest level at 8 hours, acid phosphatase in serum began to increase at 12 hours and the value of serum elastase did not change significantly. The level of alpha1-antitrypsin, a proteinase inhibitor in plasma, decreased significantly in the early stage after injury [73.5%+/-6.4% and 81.0%+/-5.1% of the baseline value (1.67 micromol x ml(-1) x min(-1)+/- 0.29 micromol x ml(-1) x min(-1)) at l and 2 hours after injury, respectively, P<0.05], then increased gradually and was higher than the baseline value at 12 hours after injury.

CONCLUSIONSImbalance between lysosomal enzymes and proteinase inhibitors occurs soon after injury, which might result in continuous tissue damage and play an important role in the disturbance of general reaction after injury.

Acid Phosphatase ; blood ; Animals ; Cathepsin D ; blood ; Endopeptidases ; blood ; Female ; Lysosomes ; enzymology ; Male ; Pancreatic Elastase ; blood ; Swine ; Wounds, Gunshot ; blood ; alpha 1-Antitrypsin ; analysis

PURPOSE: Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to the low density lipoprotein receptor (LDLR) and promotes degradation of the LDLR. Inhibition of PCSK9 either by reducing its expression or by blocking its activity results in the upregulation of the LDLR and subsequently lowers the plasma concentration of LDL-cholesterol. As a modality to inhibit PCSK9 action, we searched the chemical library for small molecules that block the binding of PCSK9 to the LDLR. MATERIALS AND METHODS: We selected 100 chemicals that bind to PCSK9 where the EGF-AB fragment of the LDLR binds via in silico screening of the ChemBridge chemical library, using the computational GOLD algorithm analysis. Effects of chemicals were evaluated using the PCSK9-LDLR binding assay, immunoblot analysis, and the LDL-cholesterol uptake assay in vitro, as well as the fast performance liquid chromatography assay for plasma lipoproteins in vivo. RESULTS: A set of chemicals were found that decreased the binding of PCSK9 to the EGF-AB fragment of the LDLR in a dose-dependent manner. They also increased the amount of the LDLR significantly and subsequently increased the uptake of fluorescence-labeled LDL in HepG2 cells. Additionally, one particular molecule lowered the plasma concentration of total cholesterol and LDL-cholesterol significantly in wild-type mice, while such an effect was not observed in Pcsk9 knockout mice. CONCLUSION: Our findings strongly suggest that in silico screening of small molecules that inhibit the protein-protein interaction between PCSK9 and the LDLR is a potential modality for developing hypercholesterolemia therapeutics.
Animals ; Cholesterol/*blood ; Cholesterol, LDL/blood ; Hep G2 Cells ; Humans ; Mice ; Mice, Knockout ; Proprotein Convertases/*metabolism ; Receptors, LDL/*metabolism ; Serine Endopeptidases/*metabolism ; *Small Molecule Libraries

No abstract available.
Bacterial Proteins/blood ; Endopeptidases/blood ; Humans ; Liver Cirrhosis, Biliary/*diagnosis/drug therapy/mortality ; Liver Function Tests ; Prognosis ; Severity of Illness Index ; Survival Rate ; Ursodeoxycholic Acid/therapeutic use

OBJECTIVETo investigate the changes in serum protease and cytokine in patients with silicosis, tuberculosis, and lung cancer.

METHODSSerum samples of patients with silicosis, tuberculosis, and lung cancer were collected. The variation trends of the expression of granzyme A, cathepsin G, apolipoprotein A, and interferon-β (IFN-β) were analyzed using enzyme-linked immunosorbent assay.

RESULTSThe concentration of apolipoprotein A of the silicosis group was 200 µg/ml, significantly higher than those of the tuberculosis and lung cancer groups (P < 0.05), and the lung cancer group had a significantly higher concentration of apolipoprotein A compared with the tuberculosis group (P < 0.05). The silicosis group had significantly higher expression of cathepsin G compared with the tuberculosis and lung cancer groups (P < 0.05), and the tuberculosis group and lung cancer group showed no significant difference in the concentration of cathepsin G (P > 0.05). The tuberculosis group had a significantly higher concentration of granzyme A than the silicosis and lung cancer groups (P < 0.05), and the silicosis group and lung cancer group had similar protein concentration trends (P > 0.05). The tuberculosis group and lung cancer group had significantly higher concentration of IFN-β compared with the silicosis group (P < 0.05), and the tuberculosis group and lung cancer group showed no significant difference in IFN-β concentration (P > 0.05).

CONCLUSIONThis study may offer diagnostic markers for the clinical diagnosis of silicosis, tuberculosis, and lung cancer, and could provide a basis for the research, as well as potential molecular targets for the diagnosis and treatment of these diseases.

Biomarkers ; Cathepsin G ; metabolism ; Cytokines ; blood ; Endopeptidases ; blood ; Enzyme-Linked Immunosorbent Assay ; Granzymes ; metabolism ; Humans ; Interferon-beta ; metabolism ; Lung Neoplasms ; enzymology ; Silicosis ; enzymology ; Tuberculosis ; enzymology

OBJECTIVETo report the clinical data of a case of iron-refractory iron deficiency anemia (IRIDA), so as to improve the understanding of IRIDA.

METHODSThe IRIDA patient's hematological characteristics were summarized and analyzed. The hepcidin levels were tested by ELISA kit. The TMPRSS6 gene was amplified by PCR reaction and its mutation was analyzed by sequencing. The effect of TMPRSS6 gene mutation on TMPRSS6 protein tertiary structure was predicted by Swiss-Model.

RESULTSThe patient was characterized by typical microcytic hypochromic anemia, low transferrin saturation, more reduction of intracellular iron than exocellular iron. The plasma hepcidin level was 213.77 μg/L which was significantly higher than that of IDA patients [5.19(3.31-12.02) μg/L]. The patient also carried a homozygous missense mutation of K253E in exon 7 of TMPRSS6.

CONCLUSIONIn children and younger IDA patients with no reason for iron deficiency but unresponsiveness to routine iron treatment, the diagnosis of IRIDA needs to be considered. Serum hepcidin level and TMPRSS6 gene mutation should be detected.

Anemia, Iron-Deficiency ; blood ; genetics ; Female ; Hepcidins ; blood ; Humans ; Membrane Proteins ; genetics ; Mutation ; Protein Structure, Tertiary ; Serine Endopeptidases ; genetics ; Young Adult

OBJECTIVE: To investigate the relationship between tryptase in serum and anaphylaxis. METHODS: The concentrations of tryptase in the sera of heart blood in three persons died from anaphylaxis shock were detected by ELISA. The first sample was obtained from a man, aged 38, died of injecting Amikacin. The second sample was obtained from a man, aged 42, died of injecting Cephradine. The third sample was from a woman, aged 39, died of injecting Lincomycin. All samples were stored in -20 degrees C. RESULTS: The concentrations of tryptase in sera were 52 ng/ml, 121 ng/ml and 0.73 ng/ml. It was unknown why the concentration of tryptase in the third sample was normal. CONCLUSION In fetal anaphylaxia reaction tryptase measurement is a useful indicator, but the diagnosis is not to be based on the test alone.
Adult ; Anaphylaxis/enzymology* ; Biomarkers/blood* ; Cause of Death ; Enzyme-Linked Immunosorbent Assay ; Female ; Forensic Medicine ; Humans ; Male ; Mast Cells/enzymology* ; Postmortem Changes ; Retrospective Studies ; Serine Endopeptidases/blood* ; Tryptases

BACKGROUNDIn a previously identified locus linked to hypertension on chromosome 15q, we identified three blood pressure candidate genes: insulin-like growth factor 1 receptor gene (IGF1R), myocyte specific enhancer factor 2A gene (MEF2A), and paired basic amino acid cleaving enzyme 4 gene (PACE4). In this study, we tested their associations with hypertension using haplotype analysis.

METHODSA total of 288 unrelated individuals, including 163 high diastolic blood pressure (DBP) subjects and 125 normal DBP subjects were enrolled in this case-control study. Twenty single nucleotide polymorphisms (SNPs) in the three genes were genotyped using polymerase chain reaction followed by restriction enzyme digestion. Haplotype analysis was accomplished in the following stages: (1) pair-wise linkage disequilibrium test among SNPs on the same gene was performed to explore blocks in which recombination is very unlikely to happen; (2) Estimation-Maximization algorithm was applied to estimate haplotype frequencies in each block; (3) the chi-square test was used to examine the specific haplotype difference, and a permutation test was used to examine the overall haplotype profile difference between cases and controls in each block.

RESULTSAn estimated haplotype "CCCCG" frequency in the haplotype block on the PACE4 gene was significantly higher in high DBP cases than in controls (P < 0.01). The overall estimated haplotype profile in this block was also significantly different between the cases and the controls (P < 0.001). This association indicates.

CONCLUSIONSThis study for the first time demonstrated that PACE4 gene may play an important role in the regulation of DBP. This association indicates that variations influencing DBP resides in or near this genomic region.

Adult ; Blood Pressure ; physiology ; Case-Control Studies ; Diastole ; physiology ; Female ; Haplotypes ; Humans ; Male ; Polymorphism, Single Nucleotide ; Proprotein Convertases ; Serine Endopeptidases ; genetics

BACKGROUNDFamilial hypercholesterolemia (FH) is an autosomal disorder associated with elevated plasma low density lipoprotein (LDL) levels leading to premature coronary heart disease (CHD). As a result of long-term hyperlipemia, FH patients will present endarterium thickening and artherosclerosis. In the present study we scanned the related gene of a clinically diagnosed autosomal genetic hypercholesterolemia family for the possible mutations and established eukaryotic expression vector of mutation of proprotein convertase subtilisin/kexin type 9 (PCSK9) gene with gene recombination technique to investigate the contributions of the variation on low density lipoprotein receptor (LDL-R) metabolism and function alternation.

METHODSMutation detection was conducted for LDL-R, apolipoprotein B(100) (apoB(100)) and PCSK9 gene with nucleotide sequencing in a Chinese FH family. The full-length cDNA of wild type PCSK9 gene (WT-PCSK9) was obtained from Bel-7402. Site mutagenesis was used to establish the recombinant eukaryotic expression vector carrying pathogenic type of PCSK9 gene and the inserted fragment was sequenced. With the blank vector as control, liposome transfection method was used to transfect the Bel-7402 cells with recombinant plasmid. The expression of LDL-R mRNA was examined by RT-PCR. PCSK9 and the expression of LDL-R protein were determined by Western blotting.

RESULTSThe G-->T mutation at the 918 nucleotide of PCSK9 gene resulted in the substitution of the arginine by a serine at the codon 306 of exon 6. After sequencing, it was confirmed that the inserted fragment of established expression vector had correct size and sequence and the mutant was highly expressed in Bel-7402 cells. There was no significant variation in the levels of LDL-R mRNA. LDL-R mature protein was decreased by 57% after the cells were transfected by WT-PCSK9 plasmid. Mature LDL-R was significantly decreased by 12% after the cells were transfected by R306S mutant as evidenced by gray scale scanning, suggesting that the new mutant R306S can significantly decrease the expression of mature LDL-R protein.

CONCLUSIONSA novel missense mutation of PCSK9 gene, R306S, was found and the eukaryotic expression vectors of mutant and wild-type of PCSK9 gene were established. There was no significant variation in the levels of LDL-R mRNA. The R306S mutation could significantly lead to the decrease of LDL-R mature protein expression, which might be the pathogenic gene of the FH family.

Adolescent ; Adult ; Female ; Humans ; Hyperlipoproteinemia Type II ; genetics ; Lipids ; blood ; Male ; Mutation ; Pedigree ; Proprotein Convertase 9 ; Proprotein Convertases ; Serine Endopeptidases ; genetics

Bacteremia induced by periodontal infection is an important factor for periodontitis to threaten general health. P. gingivalis DNA/virulence factors have been found in the brain tissues from patients with Alzheimer's disease (AD). The blood-brain barrier (BBB) is essential for keeping toxic substances from entering brain tissues. However, the effect of P. gingivalis bacteremia on BBB permeability and its underlying mechanism remains unclear. In the present study, rats were injected by tail vein with P. gingivalis three times a week for eight weeks to induce bacteremia. An in vitro BBB model infected with P. gingivalis was also established. We found that the infiltration of Evans blue dye and Albumin protein deposition in the rat brain tissues were increased in the rat brain tissues with P. gingivalis bacteremia and P. gingivalis could pass through the in vitro BBB model. Caveolae were detected after P. gingivalis infection in BMECs both in vivo and in vitro. Caveolin-1 (Cav-1) expression was enhanced after P. gingivalis infection. Downregulation of Cav-1 rescued P. gingivalis-enhanced BMECs permeability. We further found P. gingivalis-gingipain could be colocalized with Cav-1 and the strong hydrogen bonding between Cav-1 and arg-specific-gingipain (RgpA) were detected. Moreover, P. gingivalis significantly inhibited the major facilitator superfamily domain containing 2a (Mfsd2a) expression. Mfsd2a overexpression reversed P. gingivalis-increased BMECs permeability and Cav-1 expression. These results revealed that Mfsd2a/Cav-1 mediated transcytosis is a key pathway governing BBB BMECs permeability induced by P. gingivalis, which may contribute to P. gingivalis/virulence factors entrance and the subsequent neurological impairments.
Animals ; Rats ; Bacteremia/metabolism* ; Blood-Brain Barrier/microbiology* ; Caveolin 1/metabolism* ; Gingipain Cysteine Endopeptidases/metabolism* ; Permeability ; Porphyromonas gingivalis/pathogenicity* ; Transcytosis ; Virulence Factors/metabolism*