Specific Neutrophil Elastase Inhibitor Research Articles

Sivelestat (Neutrophil Elastase Inhibitor) as an Anti-inflammatory and Anti-viral Agent: An In Silico Study.

Background Sivelestat is a potent and specific neutrophil elastase inhibitor. It is clinically used in treating lung injury and respiratory distress syndrome. This engaged us to undertake the present study in which sivelestat was studied as an anti-inflammatory and anti-viral agent. Methodology The docking study of sivelestat on matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), chikungunya virus nonstructural protein-2 (CVnsP2) protease, and influenza A (H1N9) virus neuraminidase was assessed using the Chemistry at Harvard Macromolecular Mechanics (CHARMM) Dock (CDOCK) method. Furthermore, molecular physicochemical; bioactivity; absorption, distribution, metabolism, and excretion (ADME); toxicity; and Search Tool for Interacting Chemicals (STITCH) analyses were performed by using the Molinspiration (Molinspiration Cheminformatics, Slovensky Grob, Slovak Republic), SwissADME SwissADME (Swiss Institute of Bioinformatics, Quartier Sorge - Bâtiment Amphipôle, Switzerland), pkCSM (University of Melbourne, Melbourne, Australia), and STITCH-free online tools. Results The molecular physicochemical assessment of the ligand (sivelestat) showed no (zero) violation and agreed with the thumb rule of five, otherwise known as Lipinski's rule of five. ADME prediction of the ligand (sivelestat) is shown to possess a low gastrointestinal absorption (GIA) property. Similarly, toxicity analysis of the ligand (sivelestat) is predicted to have a hepatotoxicity effect. STITCH analysis reveals that the ligand (sivelestat) has exhibited interactions with the three human proteins. Conclusions The present molecular docking studies showed that the ligand (sivelestat) has successfully docked with all four enzymes of interest. Hence, the current finding has provided a good understanding of sivelestat as an effective suppressor activity against all four enzymes: MMP-2, MMP-9, CVnsP2 protease, and influenza neuraminidase.

Neutrophil Elastase Remodels Mammary Tumors to Facilitate Lung Metastasis.

Metastatic disease remains the leading cause of death due to cancer, yet the mechanism(s) of metastasis and its timely detection remain to be elucidated. Neutrophil elastase (NE), a serine protease secreted by neutrophils, is a crucial mediator of chronic inflammation and tumor progression. In this study, we used the PyMT model (NE+/+ and NE-/-) of breast cancer to interrogate the tumor-intrinsic and -extrinsic mechanisms by which NE can promote metastasis. Our results showed that genetic ablation of NE significantly reduced lung metastasis and improved metastasis-free survival. RNA-sequencing analysis of primary tumors indicated differential regulation of tumor-intrinsic actin cytoskeleton signaling pathways by NE. These NE-regulated pathways are critical for cell-to-cell contact and motility and consistent with the delay in metastasis in NE-/- mice. To evaluate whether pharmacologic inhibition of NE inhibited pulmonary metastasis and phenotypically mimicked PyMT NE-/- mice, we utilized AZD9668, a clinically available and specific NE inhibitor. We found AZD9668 treated PyMT-NE+/+ mice showed significantly reduced lung metastases, improved recurrence-free, metastasis-free and overall survival, and their tumors showed similar molecular alterations as those observed in PyMT-NE-/- tumors. Finally, we identified a NE-specific signature that predicts recurrence and metastasis in patients with breast cancer. Collectively, our studies suggest that genetic ablation and pharmacologic inhibition of NE reduces metastasis and extends survival of mouse models of breast cancer, providing rationale to examine NE inhibitors as a treatment strategy for the clinical management of patients with metastatic breast cancer.

Nanoparticle-inhibited neutrophil elastase prevents neutrophil extracellular trap and alleviates rheumatoid arthritis in C57BL/6 mice

Rheumatoid arthritis (RA) is characterized by inflammation outbreak and joint destruction. As the main culprit of RA, neutrophils firstly migrated to inflamed joints and aggravate inflammatory reaction by release excess neutrophil extracellular traps (NETs). However, it remains unsatisfactory efficiency to prevent NETs formation. Emerging evidence indicated that inhibition of neutrophil elastase (NE) could prevent NETs production. Here, we established a method in which sivelestat (ST, a low molecular specific inhibitor of NE)–conjugated bovine serum albumin nanoparticles (BTST NPs) could specifically target inflamed neutrophils for delivery of ST, which could selectively inhibit NE and prevent NETs production. Moreover, BTST NPs were also loaded with dexamethasone palmitate (DP), a classic glucocorticoid drug for RA, to deliver DP to the inflammatory site to achieve synergistically treatment of RA. It was identified that activated neutrophil could selectively internalize DP/BTST NPs. The release of ST and DP were depending on ROS environments in neutrophils at inflamed joints, subsequently could hinder NETs generation. In collagen-induced arthritis (CIA) models, DP/BTST NPs significantly improved targeting effect, alleviated RA symptoms, and enhanced prominent biological safety. We pioneer proved that this novel ST-conjugated BSA NPs holds a promising approach to improve treatment of RA and various NET-mediated inflammatory diseases.

Essential Involvement of Neutrophil Elastase in Acute Acetaminophen Hepatotoxicity Using BALB/c Mice.

Intense neutrophil infiltration into the liver is a characteristic of acetaminophen-induced acute liver injury. Neutrophil elastase is released by neutrophils during inflammation. To elucidate the involvement of neutrophil elastase in acetaminophen-induced liver injury, we investigated the efficacy of a potent and specific neutrophil elastase inhibitor, sivelestat, in mice with acetaminophen-induced acute liver injury. Intraperitoneal administration of 750 mg/kg of acetaminophen caused severe liver damage, such as elevated serum transaminase levels, centrilobular hepatic necrosis, and neutrophil infiltration, with approximately 50% mortality in BALB/c mice within 48 h of administration. However, in mice treated with sivelestat 30 min after the acetaminophen challenge, all mice survived, with reduced serum transaminase elevation and diminished hepatic necrosis. In addition, mice treated with sivelestat had reduced NOS-II expression and hepatic neutrophil infiltration after the acetaminophen challenge. Furthermore, treatment with sivelestat at 3 h after the acetaminophen challenge significantly improved survival. These findings indicate a new clinical application for sivelestat in the treatment of acetaminophen-induced liver failure through mechanisms involving the regulation of neutrophil migration and NO production.

Endoplasmic Reticulum Stress is Involved in the Protective Effect of Sivelestat Sodium Hydrate (ONO-5046) in Spinal Cord Ischemia-Reperfusion Injury.

Postoperative complications of thoracoabdominal aortic aneurysm include paraplegia due to impaired blood flow in the spinal cord. Sivelestat sodium hydrate (ONO-5046), a specific neutrophil elastase inhibitor, can prevent neuropathy after ischemia-reperfusion of the spinal cord; however, the underlying mechanism remains unclear. Here, we examined whether ONO-5046 elicits its protective effects in spinal cord ischemia by affecting endoplasmic reticulum (ER) stress. Forty-five male Japanese white rabbits (weight 2.5-3.0 kg) were assigned to three groups: a sham control group (n = 5), and two other groups (n = 20, respectively; n = 5 each time point) that were subjected to spinal cord ischemia-reperfusion for 15 min and administered saline or ONO-5046 intravenously. From 8 h to 7 d after resumption of blood flow, a neurological evaluation, histological evaluation of the spinal cord, and immunohistochemical evaluation based on the expression of GRP78 and caspase12 were performed. Rabbits treated with ONO-5046 had fewer functional deficits and more surviving motor neurons after ischemia than did rabbits in the saline and control groups. In rabbits treated with ONO-5046, histological findings of the spinal cord showed a high number of viable motor nerves, whereas induction of GRP78, an ER stress response-related protein, was prolonged. Furthermore, caspase12 expression was activated by excessive ER stress and was downregulated in rabbits treated with ONO-5046, as compared with that in rabbits administered saline. ONO-5046 exerts a protective effect on the spinal cord by relieving ER stress during spinal cord ischemia.

Probiotic Escherichia coli Nissle 1917 Expressing Elafin Protects Against Inflammation and Restores the Gut Microbiota.

Intestinal mucosal inflammation and epithelial barrier dysfunction have been implicated as pathological factors in inflammatory bowel disease (IBD). An emerging area of IBD research focuses on probiotics. The probiotic Escherichia coli Nissle 1917 (EcN) is an excellent choice for engineering therapeutic microbes. Elafin is an endogenous specific inhibitor of neutrophil elastase (NE) and proteinase 3, and we previously found Elafin can effectively suppress the development of colitis. Here, we genetically engineered EcN to deliver Elafin (EcN-Elafin) directly to the colonic mucosa and explored the protective effects of EcN-Elafin against colitis in mice. EcN-Elafin significantly alleviated dextran sodium sulfate (DSS) induced colitis. Compared with wild-type EcN, oral administration of EcN-Elafin displayed better effects on loss of weight, colon length shortening, elevated expression of myeloperoxidase (MPO), and proinflammatory cytokines and chemokine in colonic tissues. In addition, EcN-Elafin restored the expression and distribution of tight junction protein ZO-1 in colonic tissues back to normal. In a damaged colonic epithelial model utilizing Caco-2 cells stimulated with TNF-α, EcN-Elafin efficiently downregulated the activation level of NF-κB signaling. EcN-Elafin was also found to have restored the dysbiosis in gut caused by DSS administration. Moreover, EcN-Elafin significantly enhanced the concentrations of butyrate and valerate in the gut lumen. Thus, our findings demonstrated that EcN-Elafin enhanced the colonic epithelial barrier, promoted the resolution of inflammation, modulated the gut microbiota, and elevated concentrations of short-chain fatty acids (SCFAs) in the gut. EcN-Elafin may be a potential therapeutic method for IBD.

Neutrophil Elastase Facilitates Cancer Cell Motility via Induction of Akt Signaling Pathway

Cancer cells create a microenvironment favoring growth of the primary tumor and cancer dissemination. We and others have demonstrated that immune cells recruited to a primary tumor actively contribute to pro‐tumorigenic and pro‐metastatic conditions. Neutrophils, one of the first inflammatory leukocytes infiltrating a developing tumor, facilitate intratumoral angiogenesis and tumor cell dissemination via newly formed blood vessels. Upon arrival to the site of primary tumor, the recruited neutrophils release their potent enzymes, including neutrophil MMP‐9, a structurally unique metalloproteinase strongly inducing angiogenesis. Herein, we demonstrate that a neutrophil‐derived serine protease, neutrophil elastase (NE), enhances cancer cell motility, which is essential for efficient cancer cell dissemination from primary tumors to secondary sites. We have shown that the treatment of tumor cells with purified NE significantly increased their migration in a chemotactic Transwell assay. Our data show significant (by 2‐fold) increase in migration rates of NE‐treated over non‐treated control for both epidermoid HEp3 and prostate PC3 carcinoma cells. We found no direct effect of NE treatment on cell proliferation, thus excluding cell division from the causes of NE‐mediated increase in rates of cell migration. However, we found that NE treatment induced activation of Akt, a protein kinase that regulates many important cell functions. We have demonstrated that NE‐mediated activation of Akt was sensitive to the specific NE inhibitor, α1PI, implicating the catalytic activity of NE in the enhancement of cell migration. Furthermore, NE‐induced cell migration was completely abrogated if tumor cells were pre‐treated with inhibitors of Akt signaling, Dasatinib and Wortmannin, before NE treatment. Together, our findings indicate that neutrophil‐specific protease, NE, is a potent inducer of tumor cell migration, and that Akt‐activation signaling constitutes an essential mechanism for NE‐enhancing effects on tumor cell migration.

Sivelestat sodium hydrate improves post-traumatic knee osteoarthritis through nuclear factor-κB in a rat model.

As a specific inhibitor of neutrophil elastase, sivelestat sodium hydrate has primarily been used in the treatment of acute lung injury caused by various factors since its approval in 2002. Sivelestat sodium hydrate also improves post-traumatic knee osteoarthritis (KOA), although its underlying mechanisms of action have yet to be elucidated. The aim of the current study was to determine if sivelestat sodium hydrate improves post-traumatic KOA through nuclear factor (NF)-κB in a rat model. Treatment with sivelestat sodium hydrate significantly inhibited the induction of structural changes and significantly increased the vertical episode count and ipsilateral static weight bearing of the joint in KOA rats (all P<0.01). Sivelestat sodium hydrate significantly inhibited tumor necrosis factor-α and interleukin-6 production, serum nitrite levels, inducible nitric oxide synthase protein expression and high mobility group box 1 (HMGB1) secretion in KOA rats compared with the model group (all P<0.01). Sivelestat sodium hydrate also significantly suppressed p50/p65 DNA binding activity and NF-κB and phosphorylated inhibitor of κB protein expression in the joints of KOA rats compared with the model group (all P<0.01). These results suggest that sivelestat sodium hydrate improves post-traumatic KOA through HMGB1 and NF-κB in rats.

TLR9 activation impairs phagocytosis-induced neutrophil apoptosis and prolongs E. coli-induced acute lung injury

Abstract Neutrophil dysfunction, resulting in delayed apoptosis and inefficient bacterial clearance, is a characteristic feature of severe pathologies, including sepsis and cystic fibrosis. Human neutrophils detect and respond to bacterial DNA (CpG DNA) through TLR9. We investigated the impact of CpG DNA on phagocytosis, phagocytosis-induced neutrophil apoptosis and clearance of E coli. Culture of human neutrophils with CpG DNA (0.1–3.2 μg/ml) resulted in decreased phagocytosis of opsonized E. coli or yeast. CpG DNA upregulated C3R (CD11b) expression, downregulated C5aR (CD88) expression and induced release of neutrophil elastase. C5aR cleavage was prevented by a specific neutrophil elastase inhibitor and the broad-spectrum serine protease inhibitor PMSF. Consistently, CpG DNA reduced phagocytosis-induced NADPH oxidase-mediated activation of caspase8 and caspase-3. These actions of CpG DNA were blocked by the telomere-derived TLR9 inhibitory oligonucleotide 5′-TTT AGG GTT AGG GTT AGG G-3′. In mice, CpG DNA impaired pulmonary clearance of E coli, suppressed neutrophil apoptosis and delayed resolution of lung injury evoked by intratracheal instillation of live E. coli. Genetic deletion of TLR9 rendered mice unresponsive to CpG DNA. These results identify a novel mechanism, neutrophil elastase-mediated inactivation of C5aR-mediated phagocytosis, by which CpG DNA could contribute to neutrophil dysfunction and prolongation of tissue injury. Our findings also suggest a therapeutic potential for TLR9 antagonists or neutrophil elastase inhibitors for enhancing clearance of bacterial infections in an environment where bacterial DNA is abundantly present.

Local inhibition of elastase reduces EMILIN1 cleavage reactivating lymphatic vessel function in a mouse lymphoedema model.

Lymphatic vasculature critically depends on the connections of lymphatic endothelial cells with the extracellular matrix (ECM), which are mediated by anchoring filaments (AFs). The ECM protein EMILIN1 is a component of AFs and is involved in the regulation of lymphatic vessel functions: accordingly, Emilin1−/− mice display lymphatic vascular morphological alterations, leading to functional defects such as mild lymphoedema, lymph leakage and compromised lymph drainage. In the present study, using a mouse post-surgical tail lymphoedema model, we show that the acute phase of acquired lymphoedema correlates with EMILIN1 degradation due to neutrophil elastase (NE) released by infiltrating neutrophils. As a consequence, the intercellular junctions of lymphatic endothelial cells are weakened and drainage to regional lymph nodes is severely affected. The local administration of sivelestat, a specific NE inhibitor, prevents EMILIN1 degradation and reduces lymphoedema, restoring a normal lymphatic functionality. The finding that, in human secondary lymphoedema samples, we also detected cleaved EMILIN1 with the typical bands of an NE-dependent pattern of fragmentation establishes a rationale for a powerful strategy that targets NE inhibition. In conclusion, the attempts to block EMILIN1 degradation locally represent the basis for a novel ‘ECM’ pharmacological approach to assessing new lymphoedema treatments.

Neutrophil elastase and its therapeutic effect on leukemia cells.

Neutrophil elastase (NE) is an early myeloid-specific serine protease, which is predominantly produced by promyelocytes. A previous study demonstrated that NE has an important role in the development of acute promyelocytic leukemia (APL). The process of APL was shown to be accelerated in animals that expressed abundant NE, whereas NE-deficient mice were protected from APL development; thus suggesting an important role for NE in the development of APL. The present study aimed to investigate the effects and possible mechanisms of NE. Up- and downregulation of NE in various leukemia cell lines was conducted in order to explore its significance in the occurrence and procession of leukemia, with the aim of identifying novel targeted therapeutic drugs for the treatment of leukemia. NE was overexpressed in cells following infection with an adenovirus, and Cell Counting kit-8 and flow cytometry results demonstrated that cell proliferation was promoted, and cell apoptosis was inhibited, as compared with the untreated cells. NE was downregulated in the cells by both RNA interference and treatment with GW311616A, a specific inhibitor of NE, following which cell growth was shown to be inhibited and apoptosis was induced. These results suggested that NE may promote the development of APL, therefore, NE may be a therapeutic target and its inhibitor GW311616A may be a potential therapeutic drug for leukemia. Furthermore, the apoptosis-associated protein B-cell lymphoma 2 (Bcl-2)-associated X protein was significantly increased, whereas Bcl-2 was markedly decreased in the cells with downregulated NE. Further experiments revealed that the probable apoptosis-associated signaling pathway was the phosphoinositide 3-kinase/AKT pathway. The present study is the first, to the best of our knowledge, to demonstrate that GW311616A, a specific NE inhibitor, may act as a potential targeted drug for leukemia, which may have a profound impact on the future of leukemia-targeted therapy.

Combined effects of sivelestat and resveratrol on severe acute pancreatitis-associated lung injury in rats

ABSTRACTDespite extensive research and clinical efforts made in the management of acute pancre­atitis during the past few decades, to date no effective cure is available and the mortality from severe acute pancre­atitis remains high. Given that lung is the primary cause of early death in acute pancreatitis patients, novel therapeutic approaches aiming to prevent lung injury have become a subject of intensive investigation. In a previous study, we demonstrated that sivelestat, a specific inhibitor of neutrophil elastase, is effective in protecting against lung failure in rats with taurocholate-induced acute pancreatitis. As part of the analyses extended from that study, the present study aimed to evaluate the role of sivelestat and/or resveratrol in the protection against acute pancreatitis-associated lung injury. The extended analyses demonstrated the following: (1) sodium taurocholate induced apparent lung injury and dysfunction manifested by histological anomalies, including vacuolization and apoptosis of the cells in the lung, as well as biochemical aberrations in the blood (an increase in amylase concentration and a decrease in partial arterial oxygen pressure) and increases in activities of reactive oxygen species, interleukin 6, myeloperoxidase, neutrophil elastase, lung edema, bronchotracho alveolar lavage protein concentration, and bronchotracho alveolar lavage cell infiltration in the lung; and (2) in lung tissues, either sivelestat or resveratrol treatment effectively attenuated the taurocholate-induced abnormalities in all parameters analyzed except for serum amylase concentration. In addition, combined treatment with both sivelestat and resveratrol demonstrated additive protective effects on pancreatitis-associated lung injury compared with single treatment.

Improving effect of Sivelestat on lipopolysaccharide‐induced lung injury in rats

Sepsis causes neutrophil sequestration in the lung, which leads to acute lung injury (ALI). Neutrophil elastase (NE) is thought to play an important role in the pathogenesis of ALI. This study investigated whether Sivelestat, a specific NE inhibitor, can attenuate ALI induced by lipopolysaccharide (LPS). In vivo, 30 male Wistar rats were divided into three groups (n=10 each groups) on the basis of the reagent used, which were subjected to LPS injection with or without Sivelestat treatments to induce ALI model. Lung injury was assessed by pulmonary histology, lung wet-weight to dry-weight (W/D) ratio, immunohistochemical analysis of intercellular adhesion molecule-1 (ICAM-1), the number of myeloperoxidase (MPO)-positive cells, and gene expression of ICAM-1. In vitro, pulmonary microvascular endothelial cells (PMVECs) were stimulated with LPS in the presence and absence of Sivelestat; nuclear factor-κB (NF-κB) p65 was measured by immunocytochemistry staining and Western blotting. Infusion of LPS induced lung injury, in vivo, as demonstrated by pulmonary edema with infiltration of neutrophils, the increase in lung W/D ratio, the number of MPO-positive cells and enhanced expression of ICAM-1 and ICAM-1 gene. In vitro, the significant increased release of NF-κB p65 and its subsequent translocation into the nucleus in PMVECs. In contrast, Sivelestat treatment significantly ameliorated the LPS-induced lung injury, as judged by the marked improvement in all these indices. These results indicated that inhibition of NE attenuated LPS-induced lung injury through an inhibition of the inflammatory signaling pathway, besides the direct inhibitory effect on NE.

Sivelestat Sodium Hydrate Inhibits Neutrophil Migration to the Vessel Wall and Suppresses Hepatic Ischemia–Reperfusion Injury

Sivelestat sodium hydrate (sivelestat) is a specific neutrophil elastase inhibitor that is effective in treating acute lung injury associated with systemic inflammatory response syndrome. As such, it may be useful in treating hepatic ischemia-reperfusion injury (IRI), a condition in which neutrophils transmigrate into the interstitium, leading to release of neutrophil elastase from neutrophils and consequent damage to the affected tissue, particularly in cases of hepatic failure after liver transplantation or massive liver resection. The purpose of this study was to examine whether treatment with sivelestat inhibits neutrophil adhesion and migration to the vessel wall and suppresses hepatic IRI. Whether and, if so, the extent to which sivelestat suppresses the adhesion and migration of neutrophils and reduces liver damage in hepatic IRI was examined in a human umbilical vein endothelial cell (HUVEC) model and a rat hepatic IRI model. In the HUVEC model, the extent of the adhesion and migration of neutrophils stimulated by platelet-activating factor were found to be dose-dependently inhibited by sivelestat treatment (p < 0.05). In the rat model, serum liver enzyme levels were significantly lower at 12 h after reperfusion, and the number of neutrophils that had migrated to extravascular sites was significantly less in the treatment group compared to the control group (p < 0.05). Sivelestat inhibits the adhesion and migration of neutrophils to vascular endothelium in hepatic IRI, thereby suppressing liver injury.

Activity of neutrophil elastase reflects the progression of acute pancreatitis

Objective. Neutrophil elastase (NE) concentration is associated with progression of acute pancreatitis (AP), but measuring total NE concentration includes biologically inactive NE. This study aims to investigate the relationship between NE activity and the aetiology and severity of AP and associated organ failure. Methods. Seventy-five patients admitted to our surgery department with a first episode of AP during 2004–2005 were age- and sex-matched to 20 healthy volunteers (controls). NE activity was assessed using venous blood samples obtained on patient admission and after 1, 2 and 14 days. One sample was also taken from each control. ANOVA was used for statistical comparison between groups. Results. Baseline NE activity (geometric mean; 95% confidence intervals) differed between patients (58.6 nM of substrate 7-amino-4-methylcoumarin [AMC]/hour; 48.52–70.72) and controls (31.5 nM AMC/hour; 25.5–39.0) (p = 0.0003), and did not correlate with time between symptom onset and admission. Patients with alcohol-induced AP demonstrated higher mean activity (59.1 nM AMC/h; 44.7–78.2) than those with gallstone-induced AP (41.7 nM AMC/h; 33.9–51.4) (p = 0.0496). NE activity was higher overall in patients with predicted severe AP (60.9 nM AMC/h; 48.0–77.2) than in those with predicted mild AP (42.1 nM AMC/h; 34.9–50.8) (p = 0.027). Patients with respiratory failure had higher NE activity (82.5 nM AMC/h; 57.5–118.4) than those without (43.9 nM AMC/h; 37.6–51.3) (p = 0.0024). Conclusions. NE activity was associated with predicted severity of AP and AP-associated respiratory failure. Specific NE inhibitors may have therapeutic potential in acute pancreatitis.

Protective Effects of Sivelestat in a Caerulein-Induced Rat Acute Pancreatitis Model

In the present study, we investigated the protective effects of sivelestat on acute pancreatitis (AP) in a rat model. Sivelestat is a specific neutrophil elastase inhibitor, which has been developed in Japan in 1991. Varying doses of sivelestat in normal saline were infused continuously in sivelestat-treated groups through osmotic pumps. Blood and pancreas samples were collected for serological and histopathological studies, and ten rats in each group were taken for survival observation. Increasing doses of sivelestat inhibits the expression of lipase, amylase, corticosterone, IL-1β, TNF-α, and nuclear factor-κB. Furthermore, sivelestat reduces the inflammatory cells infiltration, histological damage, and mortality rate. Meanwhile, the total antioxidant power and serum level of IL-4 in high-dose sivelestat-treated groups were increased. Our findings suggest that the increasing doses of sivelestat protect against caerulein-induced AP in rats, and this protection is possibly associated with the anti-inflammatory ability of sivelestat.

Renoprotective activity of sivelestat in severe acute pancreatitis in rats

Acute pancreatitis, affecting 382,014 individuals annually in China, is life-threatening in its severe form. Since acute pancreatitis-associated morbidity or mortality is attributable mainly to functional failure of the vital organs, significant research efforts have focused on the identification of novel agents with potential organ-protective properties in the hope of developing approaches to improve the outcome of acute pancreatitis. In a previous study, we demonstrated that sivelestat, a specific inhibitor of neutrophil elastase (NE), is effective in protecting against lung failure in rats with taurocholate-induced acute pancreatitis. As part of the analyses extended from that study, the present study aimed to evaluate the role of sivelestat in the protection against acute pancreatitis-associated renal injury. Renal histopathology and major renal function parameters were analyzed in renal tissue and blood specimens collected from rats with acute pancreatitis induced by the surgical administration of sodium taurocholate in the presence or absence of sivelestat treatment and in sham-operated control rats at various time-points. The extended analyses demonstrated that: i) sodium taurocholate induced apparent renal injury and dysfunction manifested by histological anomalies, including vacuolization and apoptosis of the cells of the tubular epithelial lining in the kidney, as well as biochemical aberrations in the blood (increases in levels of blood urea nitrogen, creatinine and tumor necrosis factor-α) and renal tissue (robust increases in NE activity and induced neutrophil chemoattractant-1 levels); and ii) sivelestat treatment effectively attenuated all taurocholate-induced histological anomalies and biochemical aberrations. These observations strongly suggest that the NE inhibitor, sivelestat, is effective in protecting against acute pancreatitis-associated renal injury.

Neutrophil elastase inhibitor improves survival rate after ischemia reperfusion injury caused by supravisceral aortic clamping in rats

BackgroundSivelestat sodium hydrate is a specific neutrophil elastase inhibitor effective in acute lung injury (ALI) associated with systemic inflammatory response syndrome. Bowel ischemia reperfusion injury (IRI) induced by supravisceral aortic clamping is associated with an excessive systemic inflammatory response, resulting in remote organ damage, including ALI. In this study, we investigated whether sivelestat can attenuate neutrophil sequestration in the lung, alleviate ALI, and improve survival in a rat bowel IRI model. MethodsAdult male Sprague-Dawley rats underwent bowel IRI induced by supravisceral aortic clamping and were randomly assigned to receive sivelestat or saline (control) and monitored for survival. We randomly assigned other rats to undergo laparotomy alone (sham operation), IRI alone, or IRI and sivelestat treatment. We evaluated blood samples for organ function, cytokine levels, and neutrophil elastase activity after reperfusion. Organs were analyzed histologically. We also determined lung injury in another set of rats. ResultsBowel IRI induced a significant increase in serum variables indicative of organ function, cytokine concentrations, neutrophil elastase activity, and lung permeability and edema, which reflected the presence of both systemic inflammatory response syndrome and compensatory anti-inflammatory response syndrome. Treatment with sivelestat significantly improved survival rate, lung permeability and edema, and significantly decreased levels of creatinine, interleukin 6, interleukin 10, and neutrophil elastase activity. Histological studies showed that sivelestat-treated rats had less bowel IRI-induced damage to lung and liver tissue than controls. ConclusionIn a rat model, administration of sivelestat attenuated the effects of bowel IRI induced by supravisceral aortic clamping, and improved the survival rate.

Administration of a specific inhibitor of neutrophil elastase attenuates pulmonary fibrosis after acute lung injury in mice

ABSTRACTExcess production of neutrophil elastase contributes to the pathogenesis of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). However, the role of neutrophil elastase in the repair process following ALI/ARDS is not well understood. The objective of this study was to evaluate the effect of neutrophil elastase on the process of tissue repair after acute lung injury in mice. C57BL/6 mice were exposed to sublethal irradiation followed by intranasal instillation of lipopolysaccharide (LPS) to generate a model of impaired lung repair. The authors assessed the histopathology, lung mechanics, and total lung collagen content 7 days after irradiation and/or LPS-induced injury with daily administration of a neutrophil elastase inhibitor. The number of inflammatory cells in the bronchoalveolar lavage fluid (BALF) was also evaluated. In addition, the concentration of activated transforming growth factor (TGF)-β1 in the BALF and the expression of phospho-SMAD2/3 were investigated. Irradiated and LPS-treated mice developed pulmonary fibrosis after injury. The neutrophil elastase inhibitor significantly decreased the collagen deposition in lung parenchyma and improved the static lung compliance of injured lungs. Administration of the neutrophil elastase inhibitor also decreased the accumulation of neutrophils in the BALF, TGF-β1 activation, and expression of phospho-SMAD2/3. The authors conclude that inhibiting neutrophil elastase protects against the development of lung fibrosis after acute injury. In addition, these data suggest that this neutrophil elastase inhibitor has therapeutic potential for the fibroproliferative phase of ALI/ARDS.

Early Administration of Sivelestat, the Neutrophil Elastase Inhibitor, in Adults for Acute Lung Injury Following Gastric Aspiration

Gastric aspiration is the major cause of acute lung injury (ALI) and acute respiratory distress syndrome. Aspiration-induced ALI is believed to be, at least in part, facilitated by neutrophil-derived mediators and toxic molecules. We conducted a prospective cohort study based on the hypothesis that sivelestat, a specific neutrophil elastase inhibitor, is effective for treating ALI following gastric aspiration. Forty-four ALI patients who showed evidence of aspiration were observed within 12 h before intensive care unit admission and who had been mechanically ventilated within 12 h after admission were included in this study. Lung injury score (LIS) and PAO2/FiO2 (P/F) ratio on day 7 were defined as the primary outcomes of the study. Twenty-three patients were assigned to the sivelestat group and 21 to the control group. In univariate analyses, the proportions of patients with LIS lower than 1.0 on day 7 and a P/F greater than 300 on day 7 were significantly higher in the sivelestat group than in the control group (60.9% vs. 26.3%, P = 0.03; 87.0% vs. 36.8%, P = 0.001). In the logistic regression model, the use of sivelestat was an independent predictor for LIS lower than 1.0 on day 7 (relative risk, 7.4; 95% confidence interval [CI], 1.51-36.48) and for a P/F ratio higher than 300 on day 7 (relative risk, 18.5; 95% CI, 2.72-126.46). In the Cox proportional hazards model, the use of sivelestat was associated with a lower cumulative proportion of patients who received mechanical ventilation during the initial 14 days (hazard ratio, 2.6; 95% CI, 1.17-5.55).