胆汁内外引流术对梗阻性黄疸大鼠肺肿瘤坏死因子α、中性粒细胞弹性蛋白酶的影响

目的研究胆汁内外引流方法对梗阻性黄疸大鼠肺肿瘤坏死因子α(TNF-α)、中性粒细胞弹性蛋白酶(NE)水平的影响。方法将64只成年SD雄性大鼠随机分为4组,分别建立梗阻性黄疸(OJ)、胆汁内引流术(ID)、胆汁外引流术(ED)及假手术(SH)4组模型。于2次术后第14天留取肺组织匀浆液标本。采用双抗体夹心酶联免疫吸附法(ELISA)检测10%肺匀浆液TNF-α水平,生化法检测10%肺匀浆液NE水平。结果成功建立了大鼠梗阻性黄疸及内外引流术模型。梗阻性黄疸时大鼠肺TNF-α、NE水平较假手术对照组明显升高(100.893 pg/mL±21.271 pg/mL vs 64.091 pg/mL±13.034 pg/mL,P<0.01;50.396μg/mL±17.388μg/mL vs 39.718μg/mL±9.625μg/mL,P<0.05)。通过胆汁内引流术解除黄疸后,大鼠肺TNF-α浓度(75.141 pg/mL±15.849 pg/mL)与梗阻性黄疸组相比下降明显(P<0.01);而通过胆汁外引流术解除黄疸后,大鼠肺TNF-α浓度仍较高(112.129 pg/mL±36.886 pg/mL),与梗阻性黄疸组相比无差异(P>0.05)。行胆汁内、外引流术后,大鼠肺NE水平均降低(39.390μg/mL±12.410μg/mL、44.790μg/mL±16.681μg/mL),但与梗阻性黄疸组相比内引流明显(P<0.05)、外引流无差异(P>0.05),且内引流恢复至正常水平,与假手术对照组相比无差异(P>0.05)。结论梗阻性黄疸可导致肺组织炎症细胞因子升高,胆汁内引流术可明显改善梗阻性黄疸时肺组织炎症细胞因子水平、甚至接近正常,而胆汁外引流术没有改善肺炎症细胞因子水平,提示术前利用胆汁内引流术解除梗阻性黄疸缓解肺部炎症反应优于外引流术。     

Age-dependent changes of K-elastin stimulated effector functions of human phagocytic cells: Relevance for atherogenesis

Effector functions of the elastin receptor on human phagocytic cells from young and older individuals were studied. In cells of young healthy subjects the elastin peptides, the agonists of receptor, stimulated both superoxide anion release from PMNs and phagocytosis of coated human red cells by monocytes. Elastin appeared to inhibit the cholesterol synthesis in monocytes, measured by the incorporation of ¹⁴C-acetate. In comparison with phagocytic cells of young (≤25 ± 6 years) subjects, PMNs of elderly donors (≥75 ±10 years) bore a similar number of binding sites for soluble elastin peptides, and the affinity of the elastin receptor was unchanged as shown by Scatchard analysis. The phagocytosis of coated human red cells stimulated by elastin peptides was also similar in the two age groups. However, several differences were found between phagocytic cells of young and elderly donors 1) PMNs of elderly released increased amounts of elastase from both resting and elastin peptide stimulated cells, and 2) monocytes of elderly showed a lack of inhibition of cholesterol synthesis by elastin peptides when maintained in cholesterol-free medium. These changes in effector functions of phagocytic cells from elderly donors might contribute to the age-dependent increase of susceptibility to the development of atherosclerotic lesions.     

重组人Elafin转染气道上皮对炎性损伤因子攻击的保护作用

目的探讨重组人Elafin对炎症损伤因子中性粒细胞弹性蛋白酶(NE)攻击气道上皮保护作用的分子机制。方法通过构建人中性粒细胞弹性蛋白酶抑制剂Elafin真核表达载体pEGFP-C1-Elafin,并将其转染入NCI-H292细胞中,再用中性粒细胞弹性蛋白酶(NE)刺激24h后,用底物法测定培养上清中NE的活性,Westernbolt检测细胞中ZO-1表达。结果转染Ela-fin NE组培养上清液中NE活性与转染空载体的细胞相比较明显降低,而细胞内ZO-1蛋白含量明显增高。结论NE是引起气道慢性炎症的终效因子,通过转染重组人Elafin可对抗NE破坏气道上皮完整性的作用,增强气道抗感染能力。     

c-src/NADPH氧化酶1/活性氧对中性粒细胞弹力蛋白酶诱导气道黏蛋白5 AC表达的影响

目的 探讨中性粒细胞弹力蛋白酶(NE)诱导气道黏液高分泌的上游信号调节机制.方法 体外培养人气道BEAS-2B上皮细胞,将细胞分为空白对照组(不加任何刺激)、NE组(NE刺激)、NE+PP2组(NE刺激合并c-src抑制剂PP2)、NE+c-src siRNA组(NE刺激合并c-src siRNA)、NE+Noxl siRNA组[NE刺激合并NADPH氧化酶1(Nox1)siRNA]、阴件siRNA对照组(加入阴性对照siRNA)及NE+阴性siRNA组(NE刺激合并阴性对照siRNA)为干预条件.检测干预前后各组细胞巾活性氧含量、NoxI蛋白含量、黏蛋白5AC的蛋白及mRNA水平.用四甲基偶氮唑盐法测定各组细胞活性;活性氧试剂盒测定活性氧相对含量;逆转录PCR法检测各组黏蛋白5AC mRNA水平;ELISA法分析细胞黏蛋白5AC的蛋白相对含量;Western blot法检测Noxl蛋白及c-src蛋白的相对含量.结果 NE组细胞中Nox1蛋白相对含量为0.88±0.12,高于空白对照组的0.32±0.09(t=9.12.P=0.003);活性氧相对含量为0.76±0.09,高于空白对照组的0.18±0.02(t=9.44,P=0.003);黏蛋白5AC蛋白相对含量为0.82±0.09,基因转录水平为0.77±0.05,均高于空白对照组(分别为0.21±0.11和0.18±0.08,t值分别为7.75和6.13,P值分别为0.004和0.006).NE+c-src siRNA组细胞的Nox1蛋白相对含最(0.39±0.08)、活性氧相对含量(0.29±0.05)均低于NE组(t值分别为5.43和5.60,均P=0.007);黏蛋白5AC蛋白相对含量(0.38±0.09)及mRNA水平(0.41±0.04)低于NE组(t值分别为5.28和4.09,P值分别为0.008和0.034).NE+PP2组活性氧相对含量为0.41±0.11,Nox1蛋白相对含量为0.44±0.05,黏蛋白5AC蛋白及mRNA水平分别为0.48±0.08和0.46±0.07,均低于NE组(均P<0.05).NE+Noxl siRNA组中活性氧相对含量(0.19±0.06)、黏蛋白5AC蛋白相对含量(0.31±0.05)及mRNA水平(0.32±0.06)也低于NE组(均P<0.05).结论 c-src/Noxl参与了NE诱导的活性氧活化,是气道上皮细胞黏蛋白5AC合成及分泌的上游信号调节因子.     

多核白细胞弹性蛋白酶对人角膜基质细胞MMP-1、MMP-3表达的影响

目的探讨多核白细胞弹性蛋白酶与白细胞介素(IL)-1α对人角膜基质细胞MMP-1、-3表达的影响。方法体外培养人角膜基质细胞,在培养液中添加或不添加多核白细胞弹性蛋白酶或IL-1α,培养5 d,通过免疫印迹分析法测定培养上清中的MMP-1、-3的表达。结果在无任何刺激下人角膜基质细胞不表达MMP-1、-3;添加IL-1α后可诱导前体MMP-1、-3表达,而添加多核白细胞弹性蛋白酶不能诱导MMP-1、-3的表达;多核白细胞弹性蛋白酶可激活在IL-1α诱导下产生的前体MMP-1、-3转化为活化形式的MMP-1、-3。结论多核白细胞弹性蛋白酶和IL-1α可协同诱导角膜基质细胞的胶原降解,诱发角膜溃疡的发生。     

Fecal pancreatic elastase: a reproducible marker for severe exocrine pancreatic insufficiency

Background In order to apply fecal pancreatic elastase for follow-up of exocrine pancreatic function in chronic pancreatitis and cystic fibrosis, we examined the sensitivity, specificity, and long-term variability of a new polyclonal antibody-based enzyme-linked immunosorbent assay (ELISA). Methods Patients with definite chronic pancreatitis (n = 23), probable or possible chronic pancreatitis (n = 14), autoimmune pancreatitis (n = 7), or acute pancreatitis (n = 11), and 51 healthy subjects and 11 healthy infants participated in this study. Pancreatic function was graded as normal (n = 3), mild (n = 18), moderate (n = 9), or severe (n = 18) exocrine insufficiency on the basis of secretin tests. Fecal pancreatic elastase was measured by a new ELISA. Results Fecal pancreatic elastase concentration in control subjects varied widely, with a median of 478 μg/g. The specificity of this test was 90.2% with a cutoff value of >200 μg/g. The sensitivities were 60.9% for detecting definite chronic pancreatitis, 76.5% for calcifying pancreatitis, 71.4% for autoimmune pancreatitis, and 7.1% for probable or possible chronic pancreatitis. The sensitivities were 16.7% for mild, 12.5% for moderate, and 72.2% for severe exocrine pancreatic insufficiency. Forty patients were reexamined after a median interval of 347 days. The fecal pancreatic elastase levels between the first and second tests were not significantly different. Two infants, 4.5 and 5 months old, had abnormally low values, but after a median of 304 days all infants showed normal levels (median, 444 μg/g). Conclusions Fecal pancreatic elastase is a reproducible marker for severe exocrine pancreatic insufficiency. This test is valuable for longitudinal follow-up of exocrine pancreatic function.     

Inhibition of neutrophil elastase prevents the development of murine dextran sulfate sodium-induced colitis

Background Neutrophil elastase (NE) is a major secretory product from activated neutrophils and a major contributor to tissue destruction. However, little is known about the pathogenic contribution of NE to ulcerative colitis (UC). This study was designed to investigate the contribution of NE by measuring NE activity in plasma and colonic mucosal tissue from UC patients and a murine acute colitis model, and to elucidate the therapeutic effect of the NE-specific inhibitor ONO-5046. Methods The NE enzyme activities in plasma and colonic mucosal tissue from UC patients were directly measured using an enzyme–substrate reaction. Acute colitis was induced in mice by administration of 1.5% dextran sulfate sodium (DSS) for 5 days. DSS-induced colitis mice were then treated with ONO-5046 (50 mg/kg body weight) intraperitoneally twice a day. Results In UC patients, the NE enzyme activity was significantly elevated in both the plasma and colonic mucosal tissue compared with healthy controls. In DSS-induced colitis mice, the NE enzyme activity increased in parallel with the disease development. ONO-5046 showed therapeutic effects in DSS-treated mice by significantly reducing weight loss and histological score. ONO-5046 suppressed the NE enzyme activities in both plasma and culture supernatant of colonic mucosa from DSS-induced colitis mice. Conclusions ONO-5046, a specific NE inhibitor, prevented the development of DSS-induced colitis in mice. NE therefore represents a promising target for the treatment of UC patients.     

Relationship of Helicobacter pylori-associated Gastritis and Polymorphonuclear Leukocyte Elastase

Abstract: Background: Much remains to be clarified about the mechanisms of Helicobacter pylori (H. pylori)-associated gastritis. We considered the possibility of neutrophil involvement and investigated the role of polymorphonuclear leukocyte elastase (PMN-E) in the etiology of H. pylori-associated gastritis. Methods: In 60 patients with gastritis, infection by H. pylori was diagnosed by a combination of the ELISA method and conventional culture method. The hexosamine contents of the mucosal tissues and plasma polymorphonucler leukocyte elastase complexes (PMN-EC) were determined. Results: PMN-EC was found to be elevated in H. pylori-positive gastritis patients, and the degree of elevation was proportionately related to the grade of gastritis inflammation. The hexosamine concentration of the gastric antral mucosa was significantly lower in H. pylori-positive patients than in the H. pylori-negative patients. The ratio of PMN-EC/gastric mucosal hexosamine concentration was significantly higher in the H. pylori-positive group than in the negative group. Conclusion: These data suggest that one of the mechanisms of the H. pylori-associated gastritis may be the infiltration of neutrophils into the gastric mucosa followed by the release of PMN-E which is responsible for the degradation of gastric mucosal proteins and resultant tissue damages.     

Double de novo mutations of ELA2 in cyclic and severe congenital neutropenia

Heterozygous mutations of ELA2, encoding the protease neutrophil elastase (NE), cause either autosomal dominant cyclic neutropenia or severe congenital neutropenia (SCN). Three hypotheses have been proposed for how allelic mutations produce these different disorders: 1) disruption of proteolytic activity; 2) mislocalization of the protein; or 3) destabilization of the protein resulting in induction of the unfolded protein response. As with other dominant diseases with reduced reproductive fitness, sporadic cases can result from new mutations not inherited from either parent. Here we report an exceptional genetic phenomenon in which both a cyclic neutropenia patient and an SCN patient each possess two new ELA2 mutations. Because of the rarity of the phenomenon, we investigated the origins of the mutations and found that both arise nonmosaically and in cis from the paternally-inherited allele. Moreover, these cases offer a unique opportunity to investigate molecular pathways distinguishing these two forms of hereditary neutropenia. We have characterized the mutants separately and in combination, with respect to their effects on proteolysis, subcellular trafficking, and induction of the unfolded protein response. Each pair of mutations acts more or less additively to produce equivalent net effects on reducing proteolytic activity and induction of the unfolded protein response, yet each has different and somewhat opposing effects on disturbing subcellular localization, thus offering support for a role for protein mistrafficking as a disease mechanism.