Neutrophil elastase:From mechanisms to therapeutic potential / 药物分析学报

Neutrophil elastase(NE),a major protease in the primary granules of neutrophils,is involved in microbicidal activity.NE is an important factor promoting inflammation,has bactericidal effects,and shortens the inflammatory process.NE also regulates tumor growth by promoting metastasis and tumor microenvironment remodeling.However,NE plays a role in killing tumors under certain conditions and promotes other diseases such as pulmonary ventilation dysfunction.Additionally,it plays a complex role in various physiological processes and mediates several diseases.Sivelestat,a specific NE inhibitor,has strong potential for clinical application,particularly in the treatment of coronavirus disease 2019(COVID-19).This review discusses the pathophysiological processes associated with NE and the potential clinical applications of sivelestat.

Research progress on the development of human neutrophil elastase inhibitors / 药学学报

Human neutrophil elastase (hNE) is a serine proteolytic enzyme mainly distributed in neutrophils. When the balance between anti-hNE protein and hNE is broken, excessive release of hNE can cause the occurrence of various diseases. Therefore, inhibition of hNE is a promising therapeutic strategy. In this paper, the structure, action mechanism, physiological function of hNE and the development of hNE inhibitors were briefly summarized, in order to provide information for the related research.

Inhibition of lead-induced hepatic inflammation by inhibiting neutrophil granule protein in mice / 中国职业医学

Objective To explore the beneficial effects and mechanisms of neutrophil elastase (NE) and myeloperoxidase (MPO) on lead-induced hepatic inflammation in mice. Methods The specific pathogen free male C57BL/6 mice were randomly divided into four groups： control group, lead-exposed group, NE inhibitor group, and MPO inhibitor group, with three mice in each group. The mice in lead-exposed group, NE inhibitor group, and MPO inhibitor group were intraperitoneally injected with a dose of 10 mg/kg body mass of lead acetate solution, while the mice of control group received an equal volume of 0.9% saline three times per week for four weeks. In the last seven days, mice in both inhibitor groups were intraperitoneally injected with a dose of 40 mg/kg NE inhibitor sivelestat sodium or MPO inhibitor 4-aminobenzoic acid hydrazide (4-ABAH) once per day. Mouse body weight and liver histopathological changes were observed. The mRNA expression of genes associated with inflammation, such as tumor necrosis factor-α (Tnfa), interleukin-1β (Il1b), interleukin-6 (Il6), and nucleotide-binding oligomerization domain-like receptor protein 3(Nlrp3), apoptosis-associated speck-like protein (Asc) and cysteinyl aspartate specific proteinase (Caspase1) in the mouse liver tissues was detected by real-time quantitative polymerase chain reaction. The protein expression of NLRP3, ASC, and CASPASE-1 was detected using Western blotting. Results The activities of mice in all four groups were generally normal, and there was no significant difference in body weight (P>0.05). The results of hematoxylin-eosin staining showed that the cell size of hepatocytes varied in the lead-exposed mice, with indistinct cell boundaries, indicating early inflammatory responses in liver tissues. After intervention with NE or MPO inhibitors, the early inflammatory responses improved in the liver tissues of the mice in both inhibitor groups, with a better improvement observed in MPO inhibitor group compared with the NE inhibitor group. The mRNA expression of Tnfa, Il1b, Il6, Nlrp3, Asc, and Caspase1, as well as the protein expression of ASC, and CASPASE-1 in the livers of mice in the lead-exposed group was higher compared with those in the control group (all P<0.05). Compared with the lead-exposed group, the relative mRNA expression of Tnfa, Il1b, Il6, Nlrp3 and Asc was decreased in the liver tissues of mice in the NE inhibitor group (all P<0.05), while the relative expression of mRNA of Tnfa, Il1b, Il6, Caspase1 and the protein expression of ASC and CASPASE-1 were decreased in the liver tissues of mice in the MPO inhibitor group (all P<0.05). Conclusion Lead induce hepatic inflammation in mice by activating NLRP3 inflammasome. The inhibition of NE or MPO improve the lead-induced hepatic inflammatory responses in mice by alleviating NLRP3 inflammasome activation.

Selective decrease in alpha1-antitrypsin levels in diabetic retinopathy: Could the levels of it be playing a role in the pathophysiology of diabetic retinopathy?

Background & objectives: Type 2 diabetes mellitus (T2DM) is known to induce inflammation and activation of neutrophils causing the release of neutrophil elastase (NE), a pro-inflammatory proteinase. The activity of NE is regulated by endogenous inhibitors alpha1-antitrypsin (?1-AT) and alpha2- macroglobulin (?2-MG). Disrupted proteolytic homeostasis in T2DM patients is one of the causes for vascular complications. This study was carried out for evaluating the levels of plasma NE, ?1-AT, ?2-MG and NE-?1-AT complex to understand their roles in the pathophysiology of diabetic nephropathy (DN) and diabetic retinopathy (DR). Methods: A total of 240 participants (Control, n=60; T2DM, n=60; DN, n=60; and DR, n=60) were recruited after recording history, clinical examination and laboratory investigations. Retinopathy was confirmed by fundoscopy and nephropathy by urinary albumin excretion and serum creatinine levels. NE was measured using STANA. ?1-AT, ?2-MG and NE-?1-AT complex were estimated by ELISA. Results: Baseline clinical and laboratory findings were confirmatory to the study groups. The mean elastase activity was higher (P<0.0005) in diabetes groups (T2DM=0.73±0.31, DN=0.87±0.35, DR=0.76±0.41) than controls (0.35±0.20). The levels of ?1-AT were lower in DR (8.77±2.85) than DN (26.26±6.16) and T2DM (41.13±14.06) when juxtaposed with controls (122.95±25.71). The approximate fold decrease of ?1-AT levels was 15 for DR and four for DN compared to controls. The levels of ?2-MG were lowered in T2DM (167.29±30.45), DN (144.66±13.72), and DR (104.67±11.47) than controls (208.87±31.16). The NE-?1-AT complex levels were: controls (215.83±13.61), T2DM (98.85±23.85), DN (129.26±20.40) and DR (153.25±17.11). Interpretation & conclusions: Homeostasis of NE, ?1-AT and ?2-MG is disrupted in T2DM, DN and DR. Strikingly reduced levels of ?1-AT observed in DR are indicative of its possible role in the pathophysiology of retinopathy and emphasizes ?1-AT as a plausible therapeutic target.

Research progress of effect of neutrophil elastase and its inhibitors in sepsis / 中华危重病急救医学

Sepsis is a clinical syndrome of life-threatening organ dysfunction caused by infection. When an infection occurs, as the first line of defense of the body's immune system, neutrophils are first recruited to the site of infection to capture and kill pathogens by releasing neutrophil elastase (NE). However, a large amount of NE release will injury the surrounding normal tissues and induce organ dysfunction or failure. NE inhibitors can inhibit NE activity and reduce inflammatory response, which may be a promising drug for the treatment of sepsis. Currently, a variety of NE inhibitors have been developed and reported, but there is no systematic overview of their characteristics, and the role and underlying mechanisms of NE and related inhibitors in sepsis have not been thoroughly discussed. This article will make a review in this regard, in order to elucidate the effect of NE and its inhibitors in sepsis.

Efficacy and safety of sivelestat in patients with acute lung injury in the intensive care unit / 中华急诊医学杂志

Objective:To explore the efficacy and safety of sivelestat, a neutrophil elastase (NE) inhibitor, in the treatment of acute lung injury (ALI) in the intensive care unit (ICU).Methods:A retrospective analysis was performed on 171 patients with ALI in the ICU of the First Affiliated Hospital of Zhengzhou University from June 2020 to June 2021, including 77 patients in the sivelestat group and 94 patients in the conventional treatment group. Acute physiology and chronic health evaluation (APACHE) Ⅱ score, Murray lung injury score, oxygenation index (PaO 2/FiO 2 ratio), inflammatory cytokines (IL-6, IL-10, TNF-α), ventilator-free days (VFD), the length of ICU stay, and the 28-day mortality were collected to assess the efficacy of sivelestat. At the same time, adverse reactions and laboratory test results within 30 days after the use of sivelestat were recorded to assess the safety. Results:Compared with conventional treatment, oxygenation index, Murray lung injury scores, IL-6, IL-10, and TNF-α were significantly improved after 7 days of sivelestat treatment. Compared with the conventional treatment group, the VFD was significantly longer ( P = 0.0119) and the length of ICU stay was significantly shorter ( P = 0.0269) in the sivelestat group. The mortality was 14.29% in the sivelestat group and 22.34% in the conventional treatment group and, with no statistically significant. In the meantime, sivelestat did not increase adverse reactions within 30 days after treatment. Conclusions:Sivelestat treatment is safe and more effective than conventional treatment for ALI patients in the ICU.

Effect of Tangnaikang on Imbalance Between NE and α1-AT in Spontaneous Type 2 Diabetic Mouse / 中国实验方剂学杂志

Objective: To observe the regulatory effect of Tangnaikang (TNK) on imbalance between neutrophil elastase (NE) and α1-antitrypsin (α1-AT) in ob/ob mice with type 2 diabetes mellitus (T2DM). Method: Thirty-two male SPF ob/ob mice were randomly divided into model group (DM, normal saline) and high-dose TNK group (TNKH, TNK solution 16.04 g·kg-1), middle-dose TNK group (TNKM, TNK solution 8.02 g·kg-1) and low-dose TNK group (TNKL, TNK solution 4.01 g·kg-1). Another 8 C57BL/6J mice were included in normal group (Con, saline). The experiment lasted for four weeks. The general state, body weight (BW) and fasting blood glucose (FBG) of the mice were recorded weekly, the oral glucose tolerance (OGTT) test was performed on the 25th day, the insulin tolerance (ITT) test was performed on the 27th day, and the area under the curve (AUC) was calculated. After the end of the experiment, serum was used to detect the level of fasting insulin (Fins), insulin resistance index (HOMA-IR), total triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), NE and α1-AT. Adipose tissue was used to detect the expressions of NE, α1-AT, phosphor-insulin receptor substrate 1 antibody (p-IRS1) and glucose transporter 4 (GLUT4) proteins. Result: Compared with the Con group, the BW of the ob/ob mice of the model group increased significantly, the glucose and lipid metabolism indexes showed diabetes, the serum and adipose tissue NE increased significantly (Pα1-AT decreased significantly (PPPogtt and AUCITT were significantly decreased (PPα1-AT increased significantly (PPConclusion: TNK can reduce the BW of ob/ob mice, improve glycolipid metabolism, increase α1-AT level, decrease NE level, and regulate IRS1-GLUT4 signaling pathway, which may be one of its mechanisms in improving IR of adipose tissue mediated by neutrophil.

Application value of neutrophil elastase and fibrinogen combined with tumor necrosis factor-α in the prognosis prediction of severe pneumonia in children / 中国中西医结合急救杂志

Objective To study the application value of neutrophil elastase (NE), fibrinogen (Fib) combined with tumor necrosis factor-α (TNF-α) in the prognosis prediction of severe pneumonia in children. Methods Eighty-two children with severe pneumonia who were admitted into the Yuhang District Maternal and Child Health Hospital of Hangzhou in Zhejiang Province from July 2016 to September 2018 were treated as a severe group, and the children with severe pneumonia were subdivided into a survival group (70 cases) and a death group (12 cases) according to the prognosis; another 90 children with common pneumonia who were treated in our hospital at the same time were selected as a general group; and 85 normal children who received physical examinations at the same time as a healthy control group. The levels of serum NE, Fib and TNF-α in the three groups were measured by enzyme-linked immunosorbent assay (ELISA), and the pneumonia severity index (PSI) was calculated in the severe group and the general group; Spearman correlation analysis was used to analyze the correlation between NE, Fib, TNF-α and PSI;the NE, Fib and TNF-α levels were evaluated to predict the prognosis of children with severe pulmonary disease;the receive operating characteristic (ROC) curve was drawn to evaluate the prognostic value of NE, Fib, TNF-α in children with severe pulmonary disease. Results The expression levels of serum NE, Fib and TNF-α in the severe group were higher than those in the general group and the healthy control group [NE (μg/L): 127.5±12.3 vs. 75.1±6.6, 24.3±5.9, Fib (g/L): 6.9±1.2 vs. 5.1±0.7, 2.8±0.8, TNF-α (μg/L): 98.3±6.9 vs. 63.1±6.8, 30.2±2.1, all P <0.05]. Serum levels of NE, Fib and TNF-α in the death group were higher than those in the survival group [NE (μg/L):141.2±14.9 vs. 80.3±7.4, Fib (g/L): 7.6±1.5 vs. 5.7±1.0, TNF-α (μg/L): 105.4±7.8 vs. 68.2±4.6, all P < 0.05]. It was shown by ROC curve analysis that NE, Fib, TNF-α have some value in predicting the prognosis of children with severe pneumonia, the area under the ROC curve (AUC) were 0.889, 0.809, 0.803, 0.961, 95% confidence internal (95%CI) were 0.817-0.968、0.706-0.909、0.702-0.891、0.908-1.000, the sensitivity were 71.2%, 62.7%, 64.9%, 92.3%, the specificity were 73.5%, 68.3%, 74.5%, 90.9%, all P = 0.000. The PSI of severe pneumonia group was significantly higher than that of the general group (97.4±12.1 vs. 76.4±9.6), the PSI of the death group was obviously higher than that of the survival group (100.8±13.1 vs. 87.3±10.5), and the differences were statistically significant (both P < 0.01). Spearman correlation analyses showed that serum NE, Fib, TNF-α and PSI were significantly positively correlated in children with severe pneumonia respectively (r = 0.767, 0.734, 0.673, all P < 0.05), and there were positive correlations between NE and Fib (r = 0.655,P = 0.000), NE and TNF-α (r = 0.530,P = 0.000), Fib and TNF-α (r = 0.522,P = 0.000). Conclusion The combined detections of NE, Fib, and TNF-α levels can help clinicians determine the changes in the condition of children with severe pneumonia and evaluate their prognoses, combined detection has high sensitivity and specificity.

Role of inositol-requiring kinase 1α/X-box binding protein 1 in airway mucus secretion induced by neutrophil elastase / 上海交通大学学报（医学版）

Objective: To explore the effect of endoplasmic reticulum stress (ERS) on neutrophil elastase (NE) induced mucin 5AC (MUC5AC) production in human airway epithelial cells. Methods: HBE16 airway epithelial cells were cultured and pretreated with reactive oxygen species (ROS) inhibitor N-acetylcysteine (NAC) or ERS inhibitor 4-phenylbutyrate (4-PBA), or transfected with small interfering RNA (siRNA) against inositolrequiring kinase 1α (IRE-1α) or X-box binding protein 1 (XBP-1), respectively before incubation with NE. NE group and blank control group were also set up. ROS production was assayed by detection kit; expression of glucose-regulated protein 78 (GRP78), phosphorylated protein kinase R-like endoplasmic reticulum kinase (pPERK), activating transcription factor 6 (ATF6), phosphorylated IRE-1α (pIRE-1α), and XBP-1 protein was detected by Western blotting; spliced XBP-1 (XBP-1s) mRNA was measured by real-time PCR; levels of MUC5AC protein in culture supernatant and cytoplasm were assayed by ELISA and immunofluorescence. Results: There was an obvious increase of ROS production with strong elevation of GRP78, ATF6, pPERK, and pIRE-1α protein in NE group cells after 24 h, compared with blank control group (P<0.05). The protein and mRNA of XBP-1s, and MUC5AC production also increased obviously (P<0.05). NAC and 4-PBA reduced ERS-related protein expression and MUC5AC production and secretion (P<0.05). Further studies showed that MUC5AC secretion was also blunted by IRE-1α siRNA or XBP-1 siRNA, accompanied with decreased expression of XBP-1s mRNA and protein (P<0.05). Conclusion: NE induces ERS by producing ROS, and increases MUC5AC protein production and secretion; IRE-1α/XBP-1 play a certain role in this process.

Pravastatin sodium inhibits the release and activity of human peripheral blood neutrophil elastase induced by lipopolysaccharide / 安徽医科大学学报

Objective To study the effects of pravastatin sodium on the release and activity of neutrophil elastase ( NE) in human neutrophile granulocyte induced by lipopolysaccharide( LPS) . Methods Human neutrophile gran-ulocyte were isolated by Ficoll density gradient centrifugation, neutrophils and intracellular azurophilic granules were identified by myeloperoxidase( MPO) staining, LPS stimulated degranulation of neutrophils. The MPO activity in the supernatant was measured by colorimetric assay to determine the appropriate stimulus time and concentration, and neutrophil was treated with pravastatin sodium after LPS stimulation. ELISA mothed was used to detect the cell culture supernatant of NE content and NE activity was detected by colorimetric method. Results The content and activity of NE in the supernatant were significantly increased after LPS stimulation. The NE in the supernatant of the cells treated with pravastatin was significantly lower( P＜0.05) . Conclusion Pravastatin sodium can reduce neutrophil degranulation induced by LPS stimulation and decrease the release and activity of NE.

Clinical Observation of Zidan Yinxie Granules Combined with Acitretin Capsule and Compound Flumetasone Ointment in the Treatment of Psoriasis Vulgaris / 中国药房

OBJECTIVE:To observe the clinical efficacy and safety of Zidan yinxie granules combined with Acitretin capsule and Compound flumetasone ointment in the treatment of psoriasis vulgaris. METHODS:A total of 97 patients with psoriasis vulgaris were divided into control group(48 cases)and observation group(49 cases)according to number random method. Control group was given Acitretin capsule 10 mg,tid,for consecutive 8 weeks,and then 10 mg,bid,for consecutive 4 weeks and Compound flumetasone ointment for external use,bid. Observation group was given Zidan yinxie granule 4 g,tid,on the basis of control group. Treatment courses of 2 groups lasted for 12 weeks. Clinical efficacy was observed in 2 groups. Psoriasis area and severity index(PASI)score,VAS score,dermatology life quality index(DLQI) score,the expression of neutrophil elastase(NE),Trappin-2 and placental calcadin(P-cad)in serum and tissue fluid of skin lesion were observed before and after treatment. Recurrence followed up for 6 months in total effective patients and the occurrence of ADR were observed. RESULTS:Two patients of observation group withdrew from the study,and 47 patients completed the study;three patients of control group withdrew from the study,and 45 patients completed the study. Total response rate of observation group was 97.87%,which was significantly higher than 84.44% of control group,with statistical significance(P<0.05). After treatment,PASI,VAS and DLQI scores,the content of NE,Trappin-2 and P-cad in serum and tissue liquid of skin lesion were significantly lower than before treatment;the observation group was significantly lower than the control group. After 6-month follow-up,recurrence rate of total effective patients in observation group(28.26%)was significantly lower than control group(47.36%),and average recurrence time of observation group [(17.91 ± 3.10)weeks]was longer than that of control group [(9.80± 3.41)weeks],with statistical significance(P<0.05). There was no statistical significance in the total incidence of ADR between 2 groups(P>0.05). CONCLUSIONS:Zidan yinxie granules combined with Acitretion capsule and compound flumetasone ointment show clinical efficacy in the treatment of psoriasis vulgaris by lowering the expression of NE, Trappin-2 and P-cad in serum and tissue liquid of skin lesion with good safety.

Content of neutrophil elastase in EPS and seminal plasma: A combined predictor in the diagnosis of type IIIA prostatitis with secondary infertility / 中华男科学杂志

Objective@#To investigate the value of the content of neutrophil elastase (NE) in the expressed prostatic secretion (EPS) and seminal plasma (SP) as a combined predictor in the diagnosis of type IIIA prostatitis with secondary infertility.@*METHODS@#This study included 62 fathers (group A) and 67 infertile men (group B), all with type IIIA prostatitis, and another 57 controls with no genitourinary tract disease (group C). We measured the NE contents in the EPS and SP, obtained the results of routine semen and EPS examinations and Chronic Prostatitis Symptom Index (CPSI), and calculated the ratio of EPS NE/SP NE by binary logistic regression analysis.@*RESULTS@#The combined predictor of type IIIA prostatitis with secondary infertility was SP NE-2 × EPS NE. Among the 129 patients with type IIIA prostatitis, the combined predictor was correlated strongly negatively with the WBC count in the EPS (r = －0.914, P 0.05). The mean values of the combined predictor in groups A, B, and C were －2 238 (95% CI: －2 595 to －2 054), －1 511 (95% CI: －1 778 to －1 307), and －148 (95% CI: －181 to －118), respectively, with statistically significant differences between the cases and controls as well as between groups A and B (P <0.01). The area under the ROC curve of the combined predictor for the diagnosis of type IIIA prostatitis with secondary infertility was 0.71 (P <0.001).@*CONCLUSIONS@#The content of neutrophil elastase in the EPS combined with that in the seminal plasma contributes to the diagnosis of type IIIA prostatitis with secondary infertility, which is superior to either the neutrophil elastase content in the EPS or that in the seminal plasma used alone.

Effects of curcumin on the lung collagen area and the expressions of TNF-α, IL-6 and NE in paraquat-poisoned rats / 中华急诊医学杂志

Objective To observe the effects of curcumin on the lung collagen area and the expression of TNF-α,IL-6 and NE in paraquat-poisoning rats at different intervals,and discuss the possible mechanism of curcumin antagonizing paraquat poisoning.Methods A total of 108 SPF Wistar rats were divided into three groups (random number):blank group (B group) for control,paraquat poisonin group (PQ group) and curcumin-treatment group (PC group).The rats of PQ group and PC group were given paraquat (50 mg/kg) by gavage,and the rats of B group were given equal volume of sterile saline solution at the same time.Thirty minutes later,the rats of PC group were given curcumin (200 mg/kg) by intraperitoneal injection,and rats of B group and PC group were given equal volume of sterile saline solution instead.At 3 d,7 d and 14 d after modeling,the distribution and pathological changes of lung tissue and collagen fiber were observed by HE and Masson staining.The concentration of tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) were detected by enzyme-immunoassay.The lung neutrophil elastase (NE)expression was observed by immuno-histochemical method.Result Compared with B group,PQ group had pulmonary alveolitis in different degrees at different intervals,and the most serious pulmonary alveolitis was observed at 7 d after modeling.Diffused pulmonary fibrosis of the lung tissue and a large area of collagen fiber deposition were observed especially at 14 d after modeling,as well as the expression of NE was observed obviously,especially at 14 d after modeling.The concentration of TNF-α,IL-6 in serum were significantly increased (P ＜ 0.05,P ＜ 0.01).Compared with PQ group,the pulmonary alveolitis and fibrosis obviously in PC group with obvious reduction in the expression of NE and significant descrease in the concentrations of TNF-o and IL-6 (P ＜ 0.05).Conclusion Inhabiting inflammatory factors to alleviate the seriousness of alveolar inflammation and pulmonary fibrosis might be one of the mechanism of treatment with curcumin for paraquat poisoning rats.

Study of antagonistic activity against M3 receptor and inhibition activity to neutrophil elastase of tropane compounds / 上海交通大学学报（医学版）

Objective · To design and synthesize five new tropane compounds, and test their antagonistic activity against M3 receptor and inhibition activity to neutrophil elastase (NE), of which the structure-activity relationship were preliminarily investigated. Methods · The five compounds, A1-A3,B1 and C1, were prepared with 3α-hydroxy-tropane (A0) as the starting material by modifying the structure in C-3α position and N atom on the tropane skeleton. The antagonistic activity of the compounds to muscarinic M3 receptors on tracheal rings of guinea pigs was evaluated by functional assays in vitro. The hydrolysis of PGlu-Pro-Val-PNA as substrate was catalyzed by NE to get colorful nitroaniline (PNA). The NE inhibition activity of the tropane compounds was obtained by determining the absorbance [(D(405 nm)] of PNA. Results · The five new tropane compounds generated strong antagonistic activity against M3 receptors. Among them, A2 had the greatest activity [antagonistic parameter pA2(M3)=9.004], and elicited obvious inhibitory effect to NE (inhibition ratio YA2=20.29%). Conclusion · Introducing strong electron-attraction group, such as sulfuryl and hydrophobic group with large volume into C-3α position on the tropane skeleton can improve the M3 receptor antagonistic activity as well as the NE inhibition activity.

Investigation to the Expression of NE and TNF-α in Serum and BALF of Rabbits with Acute Lung Injury Interposed by XueBiJing in Underwater Explosion / 现代检验医学杂志

Objective The concentration of NE and TNF-α was detected for elucidating the change of them in sera and bronchoalveolar lavage fluid (BALF) of rabbits with acute lung injury interposed by XueBiJing therapy in underwater explosion.Methods Underwater explosion decive was applied to cause acute lung injury of rabbits.The 20 rabbits were randomly divided into two groups which were injury group and XueBiJing therapy group,respectively.The concentration of NE and TNF-α in sera and BALF were detected by ELISA method in 24 hours after bursting.Results The concentration of TNF-α in sera (353.30±166.86 ng/L) of rabbits in therapy group were significantly lower than those in injury group (552.30± 169.64 ng/L;t=2.645,P =0.016).The concentration of NE in sera (63.40 ± 36.09 ng/ml) were lower than that of rabbits in injury group (97.60 ± 36.20 ng/ml;t=2.116,P=0.049).At the same time the concentration of NE in BALF (102.10± 9.50 ng/ml) of rabbits in therapy group were significantly lower than those in injury group (136.70± 13.60 ng/ml;t=6.593,P=0.000).Conclusion The expression of TNF-α in sera and NE in sera and BALF in rabbits with acute lung injury interposed by XueBiJing in underwater explosion were lower than those of injury group.

Effect of heparin pretreatment on the level of neutrophil extracellular traps of serum and lung tissue in septic mice / 中华危重病急救医学

Objective To investigate the influence of heparin pretreatment on serum and lung tissue level of neutrophil extracellular traps (NETs) in septic mice model and its molecular mechanism.Methods Ninety male C57BL/6J mice were randomly divided into control group (n = 30), lipopolysaccharides (LPS) group (n = 30, 30 mg/kg LPS in 100μL normal saline was intraperitoneally injected) and LPS+heparin group (n = 30, 8 U of heparin in 20μL normal saline was subcutaneously injected 30 minutes before the injection of LPS). Six hours later of LPS injection, blood was collected and lung tissue was harvested. Enzyme linked immunosorbent assay (ELISA) was used to assess the concentration of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and histones 2AX (H2AX), neutrophil elastase (NE), which reflected NETs concentration. PicoGreen fluorescent dyes was used to detect serum circulating free DNA (cf-DNA/NETs) concentration. The protein expression levels of H2AX and NE in lung tissue were examined by Western Blot.Results The serum concentrations of TNF-α, IL-6, H2AX, NE, cf-DNA/NETs, and the protein expression levels of H2AX and NE in lung tissue of septic mice were significantly higher than those of control group [TNF-α (ng/L): 133.0±14.1 vs. 2.7±1.0, IL-6 (ng/L): 3911.2±189.2 vs. 298.9±52.5, H2AX (ng/L): 545.5±40.0 vs. 21.9±8.3, NE (μg/L): 6.48±0.12 vs. 0.47±0.15, cf-DNA/NETs (μg/L): 846.3±137.5 vs. 152.7±36.4, H2AX protein (gray value): 1.14±0.09 vs. 0.68±0.04, NE protein (gray value): 0.56±0.03 vs. 0.32±0.04, allP 0.05).Conclusion Heparin pretreatment could significantly decrease the level of NETs in serum and lung tissue, and can be the potential mechanism of its organ protection in sepsis.

Sivelestat alleviates nonalcoholic steatohepatitis in mice through inhibiting activation of Kupffer cells / 中华肝脏病杂志

Objective@#To investigate the role of neutrophil elastase inhibitor, sivelestat, in preventing and treating nonalcoholic steatohepatitis (NASH) and its underling mechanisms.@*Methods@#A total of forty 4-week-old male C57BL/6J ApoE-/-mice were equally divided into the following four groups: standard chow (SC)+isotonic saline; SC+sivelestat; high-fat, high-cholesterol (HFHC) diet+isotonic saline; and HFHC+sivelestat. These mice were treated with above methods for 12 weeks. Blood and liver tissue samples were collected to measure biochemical parameters, hepatic steatosis and non-alcoholic fatty liver disease (NAFLD) activity score (inflammation) were evaluated by oil red O staining and HE staining, respectively. The mRNA and protein expression levels of hepatic inflammatory cytokines, CD68, and F4/80 were determined by quantitative RT-PCR and immunohistochemistry, respectively. Comparison of means between the four groups was made by one-way analysis of variance, and comparison between any two groups was made by the LSD or SNK method (for data with homogeneity of variance) or the Tamhane or Dunnett method (for data with heterogeneity of variance).@*Results@#Mice fed with an HFHC diet for 12 weeks developed typical pathological features of NASH compared with those fed with SC. Compared with mice fed with HFHC diet without sivelestat, those treated with HFHC and sivelestat exhibited the following features: (1) significantly reduced fast blood glucose, blood cholesterol, and hepatic biochemical parameters, as well as increased insulin sensitivity; (2) significantly reduced NAFLD activity score (5.71±1.11 vs 3.16±1.16, P < 0.05); (3) reduced monocyte chemoattractant protein-1 and tumor necrosis factor -α; (4) significantly reduced mRNA levels of CD68 and F4/80; and (5) reduced expression of CD68 in the liver.@*Conclusion@#Sivelestat alleviates the hepatic steatosis and inflammation of NASH in mice by inhibiting the activation of Kupffer cells.

Effects of Modified Zhisou Power on Epidermal Growth Factor Receptor and Neutrophil Elastase in Rats with Cold-Dryness Chronic Obstructive Pulmonary Disease / 中国中医药信息杂志

Objective To reveal the effects of cold-dryness and modified Zhisou Power on epidermal growth factor receptor (EGFR) and neutrophil elastase (NE) in rats with COPD. Methods COPD model was established with an elastase dose into the trachea combined with exposure to smoking for 90 d; cold-dryness COPD group was further developed by exposure to a cold, dry environment for 90 d. After 90 days, cold-dryness COPD rats was divided into cold-dryness group and Zhisou Power intervention group (treated with modified Zhisou Power for 7 days). On the 97th day, all rats were killed. Pathological changes in lungs were observed. mRNA and protein expression of EGFR were measured by RT-qPCR and Western blot, and the amount of NE in serum and BALF were examined by ELISA. Results EGFR mRNA and protein expression were significantly higher in COPD group, cold-dryness group and Zhisou Power intervention group than in control group. EGFR was significantly lower in Zhisou Power intervention group than in COPD group and cold-dryness group. NE was significantly higher in serum and BALF in COPD group, cold-dryness group and Zhisou Power intervention group than in control group. NE in BALF was significantly higher in cold-dryness group than in COPD group. NE in BALF was significantly lower in Zhisou Power intervention group than in cold-dryness group. Conclusion Modified Zhisou Power can down-regulate the expression of EGFR and the mount of NE in cold-dryness COPD rats to treat COPD.

Research Progress of Human Neutrophil Elastase Inhibitors and Their Application in Diverse Diseases / 中国药学杂志

To comprehensively understand the research status of human neutrophil elastase inhibitors (HNEI) and their clinical application prospect, the papers about novel HNEI discovered since 2011 and diseases related to human neutrophil elastase (HNE) in addition to pulmonary diseases were summarized. The results showed that a lot of highly selective and potent HNE inhibitors have been discovered since 2011. HNE participates in the development of many diseases. In addition to the infectious and inflammatory pulmonary diseases reported in the past, it is also associated with ischemia-reperfusion injury, rheumatoid arthritis, autoimmune diabetes, nephritis, cancer and other diseases. The development of novel HNEI with high potency and low toxicity has been an important direction for HNE-related diseases.

Neutrophil elastase levels in the gingival crevicular fluid following hyaluronan gel application in the treatment of chronic periodontitis: A randomized split‑mouth study.

Background: Neutrophils are the predominant leukocytes in the periodontium, which prevent infection from periodontal pathogens and subsequent tissue destruction. A potentially destructive role has been elucidated, especially due to elastase enzyme. Controlling its levels might be crucial in minimizing the tissue destruction. Hyaluronan, known to inhibit the release of this enzyme from neutrophils, might be a viable option to treat chronic periodontitis. Aims: The aim of this study is to evaluate and compare the effects of 0.2% hyaluronan gel adjunctive to scaling and root planing on the levels of elastase in gingival crevicular fluid (GCF). Settings and Design: This split‑mouth study included eighty (forty experimental and forty control) sites from twenty patients representing both sexes. Materials and Methods: GCF samples were collected from all the eighty sites; simultaneously, clinical periodontal parameters were recorded. Enzyme‑linked immunosorbent assay was used to determine the levels of elastase at baseline and 6 weeks after therapy, following mechanical debridement and subsequent subgingival placement of the experimental drug. Statistical Analysis Used: With the aid of statistical software (SPSS Version 13), Student’s t‑test and Pearson’s correlation test were performed. Results: There was a mean reduction in the elastase levels from baseline to 6 weeks after therapy in the experimental group. However, the difference between the groups was not statistically significant. Conclusions: Adjunctive use of hyaluronan following mechanical debridement resulted in comparable reduction in the elastase levels, suggesting that this substance has an inhibitory effect on elastase, and subsequent tissue destruction. Further long‑term studies are mandatory to validate the results of this study.