Expression Of Secretory Leukoprotease Inhibitor Research Articles

Black Lentil Water Extract Inhibited Inflammatory Cytokines in a Colitis-Associated Colon Carcinogenesis Model

Abstract Objectives The objective was to compare the impact of black lentil water extract (BL) and delphinidin 3-O-(2-O-β-d-glucopyranosyl-α-l-arabinopyranoside) (D3G)-rich lentil extract on tumor development and inflammation in an azoxymethane (AOM)/dextran sodium sulfate (DSS) model. Methods C57BL/6 mice were randomly separated into four groups: healthy control (n = 6), AOM/DSS control (n = 14), AOM/DSS + BL (600 mg/kg body weight, n = 12), and AOM/DSS + D3G (41 mg/kg body weight, equivalent to D3G concentration in BL, n = 12). Mice were given treatments for 11 weeks using a voluntary oral jelly administration. Fecal samples were collected three times: after one week of treatments prior to the first AOM injection, after the first (of three) DSS cycle, and at the time of euthanasia. Secretory leukoprotease inhibitor (SLPI) expression was evaluated by qPCR, calprotectin by ELISA and fecal metabolite profiles by Agilent GC-MS system. Results AOM/DSS + BL presented a lower (p < 0.05) disease activity index, throughout and at the end (2.4) compared to AOM/DSS control (6.3). AOM/DSS + BL mice had an average of 7.8 neoplasms/mouse vs. 12.8 for the AOM/DSS (p < 0.05). Pro-inflammatory cytokines were downregulated in the colon mucosa in AOM/DSS + BL and AOM/DSS + D3G: interleukin 1β (−77.5%, −70.7%), interleukin 6 (−44.4%, −44.9%), respectively, compared to the AOM/DSS control. In non-polyp tissue, SLPI expression was higher compared to the healthy (1.0) and AOM/DSS control (5.0), AOM/DSS + BL (14.6) and AOM/DSS + D3G (10.3) groups. In polyp tissue, SLPI expression was highest in the AOM/DSS + BL group (24.3) versus the AOM/DSS control (9.3) and AOM/DSS + D3G (10.0). At the time of euthanasia, fecal calprotectin concentration was low for the healthy control (1.6 µg/g), AOM/DSS + BL (1.8 µg/g), and AOM/DSS + D3G (2.4 µg/g), but increased dramatically for the AOM/DSS control (4.1 µg/g) (p < 0.05). Gallic and protocatechuic acids and epicatechin were found in feces; the concentration of amino acids such as alanine, isoleucine, and leucine was lower, and unsaturated fatty acids were higher for AOM/DSS + BL and AOM/DSS + D3G versus the AOM/DSS control. Conclusions BL and D3G-rich extracts showed anti-inflammatory effects and modified fecal metabolites while BL additionally prevented growth of neoplasia. Funding Sources US Department of Agriculture Hatch 1,014,457.

Regulation and activity of secretory leukoprotease inhibitor (SLPI) is altered in smokers

A hallmark of cigarette smoking is a shift in the protease/antiprotease balance, in favor of protease activity. However, it has recently been shown that smokers have increased expression of a key antiprotease, secretory leukoprotease inhibitor (SLPI), yet the mechanisms involved in SLPI transcriptional regulation and functional activity of SLPI remain unclear. We examined SLPI mRNA and protein secretion in differentiated nasal epithelial cells (NECs) and nasal lavage fluid (NLF) from nonsmokers and smokers and demonstrated that SLPI expression is increased in NECs and NLF from smokers. Transcriptional regulation of SLPI expression was confirmed using SLPI promoter reporter assays followed by chromatin immunoprecipitation. The role of STAT1 in regulating SLPI expression was further elucidated using WT and stat1(-/-) mice. Our data demonstrate that STAT1 regulates SLPI transcription in epithelial cells and slpi protein in the lungs of mice. Additionally, we reveal that NECs from smokers have increased STAT1 mRNA/protein expression. Finally, we demonstrate that SLPI contained in the nasal mucosa of smokers is proteolytically cleaved but retains functional activity against neutrophil elastase. These results demonstrate that smoking enhances expression of SLPI in NECs in vitro and in vivo, and that this response is regulated by STAT1. In addition, despite posttranslational cleavage of SLPI, antiprotease activity against neutrophil elastase is enhanced in smokers. Together, our findings show that SLPI regulation and activity is altered in the nasal mucosa of smokers, which could have broad implications in the context of respiratory inflammation and infection.

152 Estrogen-regulated MicroRNAs control the expression of secretory leukoprotease inhibitor in monocytes

Apoptosis is a physiological process essential for homeostasis of epithelial organisation and function. CF lung disease is characterised by chronic infection and inflammation and previous work suggests that apoptosis is dysfunctional in the CF airways with conflicting results. In addition, controversy exists regarding how CFTR misfolding contributes to apoptosis. In this study, we evaluated the relationship between CFTR mutation and apoptosis in DF508-CFTR CF airway epithelial cells. Basal activity of the executioner caspase, caspase-3, was significantly increased in CF tracheal and bronchial epithelial cell lines and primary bronchial epithelial cells compared to non-CF controls. In addition, activity of the upstream initiator caspase, caspase-8, was significantly increased in CF epithelial cells compared to controls, suggesting involvement of extrinsic apoptosis signalling, which is mediated by the activation of death receptors, such as Fas (CD95). Increased levels of Fas were observed in CF epithelial cells, and neutralization of Fas significantly inhibited caspase-3 activity in CF epithelial cells compared to untreated cells. Furthermore, activation of Fas significantly increased caspase-3 activity and apoptosis in CF epithelial cells compared to control cells. Overall, these results suggest that CF airway epithelial cells are more sensitive to apoptosis via increased levels of Fas and subsequent activation of the Fas death receptor pathway.

Update in Cystic Fibrosis 2010

Update in Cystic Fibrosis 2010

Secretory leukoprotease inhibitor inhibits cell growth through apoptotic pathway on ovarian cancer

In light of the poor prognosis for ovarian cancer, research continues for innovative and efficacious treatment modalities. It is now widely accepted that new approaches for the treatment of ovarian cancers are pivotal in further improving prognosis of this disease. Secretory leukoprotease inhibitor (SLPI) is an 11.7-kDa non-glycosylated, serine protease inhibitor that has a broad inhibitory spectrum against serine protease. SLPI showed potential therapeutic inhibitory effects mediated by tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), TNF-alpha, death receptor (DR)-4, DR-5 and TNF receptor (TNFR)-I expression which lead to an activation of apoptosis pathway through Caspase-2, Caspase-8 and Caspase-9. We examined whether levels of SLPI protein expression correlated with clinicopathological characteristics in 58 ovarian cancer samples, and investigated the role of SLPI and its biological functions. SLPI expression showed a significant correlation between low expression of SLPI and amount of ascites (p=0.021), lymph node metastasis (p=0.011). We propose that SLPI could be considered a therapeutic target for the treatment of ovarian cancer.

Secretory Leukoprotease Inhibitor in Mucosal Lymph Node Dendritic Cells Regulates the Threshold for Mucosal Tolerance

The notion that the mucosal immune system maintains a tolerogenic response to harmless Ags while continually being challenged with microbial products seems an enigma. The aim of this study was to unravel mechanisms that are involved in regulating the development of tolerance under constant microbial pressure. The tolerogenic response to Ags administered via the nasal mucosa is dependent on the organized lymphoid tissue of the cervical lymph nodes (LN). We show that cervical LN differentially express secretory leukoprotease inhibitor (SLPI) compared with peripheral LN. SLPI was expressed by dendritic cells (DCs) and because SLPI is known to suppress LPS responsiveness, it was hypothesized that its expression in mucosal DCs may be required to regulate cellular activation to microbial products. Indeed, compared with wild-type controls, bone marrow-derived DCs from SLPI(-/-) mice released more inflammatory cytokines and enhanced T cell proliferation after stimulation with low dose LPS. This increased sensitivity to LPS was accompanied by increased NF-kappaB p65 activation in SLPI(-/-) DCs. In vivo, nasal application of OVA with LPS to SLPI(-/-) mice resulted in enhanced DC activation in the cervical LN reflected by increased costimulatory molecule expression and release of inflammatory cytokines. This led to failure to maintain tolerance to nasal OVA application in the presence of low doses of LPS. We propose that expression of SLPI functions as a rheostat by controlling the level of bacterial stimuli that induce mucosal DC activation. As such, it regulates the quality of the ensuing Ag-specific immune response in the mucosa draining LN.

Nrf2‐deficient mice are highly susceptible to cigarette smoke‐induced emphysema

Inflammation, protease/anti-protease imbalance and oxidative stress play important roles in the pathogenesis of emphysema. Nrf2 counteracts oxidative tissue damage and inflammation through transcriptional activation via the anti-oxidant responsive element (ARE). To clarify the protective role of Nrf2 in the development of emphysema, the susceptibility of Nrf2-knockout mice to cigarette smoke (CS)-induced emphysema was examined. In Nrf2-knockout mice, emphysema was first observed at 8 weeks and exacerbated by 16 weeks following CS-exposure, whereas no pathological abnormalities were observed in wild-type mice. Neutrophilic lung inflammation and permeability lung damage were significantly enhanced in Nrf2-knockout mice 8 weeks after CS-exposure. Importantly, neutrophil elastase activity in bronchoalveolar lavage fluids was markedly higher in Nrf2-knockout mice preceding the pronounced neutrophil accumulation. The expression of secretory leukoprotease inhibitor, a potent inhibitor of neutrophil elastase, was inducible in wild-type, but not in Nrf2-knockout mice. This protease/anti-protease imbalance, together with the lack of inducible expression of ARE-regulated anti-oxidant/anti-inflammatory genes, may explain the predisposition of Nrf2-knockout mice to neutrophilic inflammation. Indeed, specific activators of Nrf2 induced the expression of the SLPI gene in macrophages. These results indicate that Nrf2 protects against the development of emphysema by regulating not only the oxidant/anti-oxidant balance, but also inflammation and the protease/anti-protease balance.

Characterization of the ovine ortholog of secretory leukoprotease inhibitor

There is great interest in the use of the sheep as a model for the investigation of inflammation in the lung. The serine antiproteases secretory leukoprotease inhibitor (SLPI) and elafin are important "alarm antiproteases" in the lung and have potentially important roles in the innate immune response. SLPI was first characterized in man and subsequently in murine, porcine, and rat tissues. Here we present the first data concerning the gene and cDNA sequence encoding for the ovine ortholog of SLPI, a protein of 132 amino acids with 66% sequence identity at the amino acid level with human SLPI. A 24-amino-acid signal sequence signifies that, like the other mammalian orthologs, ovine SLPI is a secreted protein. Tissue distribution of expression is demonstrated by reverse transcription polymerase chain reaction (RT-PCR) and shows features similar to SLPI expression in other mammals, specifically at mucosal surfaces such as the upper respiratory and intestinal tracts, and also the skin, liver, and kidney. This distribution lends credence to SLPI having important roles in innate immunity. We have also cloned the ovine SLPI cDNA into an expression vector and expressed the ovine SLPI protein in vitro. This has enabled us to demonstrate that ovine SLPI is correctly processed (Western blot analysis and SELDI-TOF mass spectrometry analysis) and has biological antihuman neutrophil elastase activity. In summary, the ovine ortholog of SLPI shows similarities to other members of the SLPI family and has all the features of a modulator of innate immunity.

Transforming growth factor-beta1 is a potent inhibitor of secretory leukoprotease inhibitor expression in a bronchial epithelial cell line. Munich Lung Transplant Group.

Obliterative bronchiolitis (OB) is the major long-term complication following lung and heart-lung transplantation. In bronchoalveolar lavage fluid samples obtained from patients suffering from OB, a marked increase in the number of neutrophils and elevated expression of transforming growth factor (TGF)-beta1 had been found. The goal of the study was to evaluate whether TGF-beta1 is capable of interfering with the expression of the secretory leukoprotease inhibitor (SLPI), the dominating defence of the conducting airways against neutrophil elastase (NE). The authors analysed the effects of TGF-beta1 on gene expression and protein release of SLPI by cultured human bronchial epithelial (BEAS-2B) cells. SLPI protein levels in the supernatants were quantified with a specific enzyme-linked immunosorbent assay; SLPI messenger ribonucleic acid (mRNA) levels were measured by reverse transcriptase polymerase chain reaction. Incubation with TGF-beta1 induced a marked decrease in SLPI protein levels (1 ng x mL(-1) TGF-beta1: stimulation index (SI; protein: relation to SLPI protein release of resting cells)=0.56; 10 ng x mL(-1) TGF-beta1: SI=0.48; 50 ng x mL(-1) TGF-beta1: SI=0.37, p<0.01 each) and mRNA expression (1 ng x mL(-1) TGF-beta1: SI (SI mRNA: relation to SLPI mRNA expression of resting cells)=0.46; 10 ng x mL(-1) TGF-beta1: SI=0.31; 50 ng x mL(-1) TGF-beta1: SI=0.18, p<0.01 each) in a dose dependent fashion. Simultaneous incubation of BEAS-2B cells with TGF-beta1 and NE also caused a significant reduction in SLPI synthesis (10 ng x mL(-1) TGF-beta1 + 7.5 U x mL(-1) NE: mRNA SI=0.61, p<0.05; protein SI=0.65, p<0.05; 50 ng x mL(-1) TGF-beta1 + 7.5 U x mL(-1) NE: mRNASI=0.52, p<0.05; protein SI=0.58, p<0.05; 10 ng x mL(-1) TGF-beta1: mRNA SI=0.33, p<0.01; protein SI=0.38, p<0.01). In conclusion, the data suggest that the coincidence of neutrophilia and upregulation of transforming growth factor-beta1 in obliterative bronchiolitis may lead to uninhibited neutrophil elastase activity by downregulation of secretory leukoprotease inhibitor, with the consequence of ongoing injury to the epithelium.

気道の防御機構 気管支腺の役割

Bronchial glands are abundant in human airways, playing a central role in airway secretion and the secretion of mucin, electrolytes and various defensive substances. Both mucin and electrolyte secretions from the bronchial glands maintain an effective mucociliary transport in the airways. Various defensive substances from the bronchial glands include lactoferrin, lysozyme, secretory IgA, secretory leukoprotease inhibitor (SLPI) and surfactant protein A (SP-A). Here, we focused on SLPI and SP-A secretion from human bronchial glands. First, we examined the secretory response and gene expression of SLPI in isolated human glands in response to human neutrophil elastase (HNE). The results indicate that, in human bronchial glands, HNE at low concentrations stimulates SLPI production and secretion, whereas HNE at high concentrations does not. Next, we examined SP-A secretion and gene expression in human bronchial glands. The findings indicate that human bronchial gland cells can transcribe the SP-A2 gene and produce SP-A in a manner different from alveoli, thus playing a role in airway defense mechanisms.