Search Results (71)

Colorectal cancer (CRC) therapy faces challenges due to limited drug penetration across the blood–tumor barrier. Neutrophils, with their natural ability to migrate to inflamed and tumor sites, offer a promising cell-mediated delivery strategy. This study developed albumin nanoparticles loaded with 6-shogaol (NPs/6-shogaol) and utilized activated neutrophils as carriers to transport the nanoparticles across vascular barriers for colon cancer therapy. The physicochemical properties, biocompatibility, and targeting efficiency of the NPs were evaluated in vitro and in vivo. The formulated NPs/6-shogaol exhibited favorable physicochemical properties, including a uniform nano-scale size (~150 nm), negative zeta potential, and high drug loading efficiency. In both subcutaneous and orthotopic colon cancer models, neutrophil-mediated delivery significantly enhanced tumor accumulation of 6-shogaol, inhibited tumor growth, and induced apoptosis by suppressing neutrophil elastase (NE) expression. Notably, no significant systemic toxicity was observed. This neutrophil-hitchhiking albumin nanoplatform provides a targeted and biocompatible strategy for effective colon cancer therapy. Full article

Psoriasis is a common inflammatory skin disease with chronic manifestation in which the role of neutrophil extracellular traps (NETs) and alarmins are increasingly recognized as contributors to systemic and cutaneous inflammation. However, the interaction between alarmins and NET-driven immune responses remains poorly defined. The main aim of this study is to define the role of target alarmins (i.e., IL-33 and TSLP) in NETs induction and its subsequent impact on oxidative stress and inflammation in the peripheral blood. In the present study, we recruited active psoriasis patients (n = 56) and control (n = 56) subjects. The frequency of circulating neutrophils, the levels of NET-associated markers (MPO (myeloperoxidase)–DNA complex, CitH3 (citrullinated histone H3), PAD4 (peptidyl arginine deiminase4), NADPH oxidase, and NE (neutrophil elastase)), and alarmin transcripts (IL (interleukin)-33, TSLP (thymic stromal lymphopoietin), S100A7, S100B, HSP (heat shock protein) 60/70 were quantified using flow cytometry, ELISA (Enzyme-linked immunosorbent assay), and qPCR (quantitative polymerase chain reaction), respectively, in each group. The NET formation potential of isolated neutrophils was assessed in the presence or absence of rhIL-33 and rhTSLP by immunocytofluorescence. The effect of rhIL-33- and rhTSLP-primed NETs in augmenting oxidative stress and inflammation was evaluated on peripheral blood mononuclear cells (PBMCs) by ELISA. Significantly higher circulating neutrophils (p < 0.001) and levels of NET-associated markers (i.e., MPO–DNA complex, CitH3, PAD4, NADPH oxidase, and NE) were observed in active psoriasis patients compared to controls. Lesional skin exhibited strong expression of MPO (p < 0.001) compared to normal skin. The alarmins, IL-33 and TSLP, were markedly upregulated in the blood and skin (p < 0.05). The rhIL-33 and rhTSLP treated neutrophils demonstrated enhanced NETosis in patients (p < 0.001). Increased expression of inflammatory cytokines and oxidative stress markers were reported in PBMCs when incubated with rhIL-33- and rhTSLP-primed NETs. Taken together, our investigation demonstrated the novel mechanism wherein the alarmins IL-33 and TSLP exacerbate NET formation that may drive enhanced inflammation and oxidative stress in psoriasis. Full article

Cardiovascular diseases (CVDs) are increasingly being defined not only in terms of metabolic or purely vascular disorders, but also as complex immunometabolic disorders. One of the most groundbreaking discoveries in recent years is the role of neutrophil extracellular networks (NETs/NENs) as a key link between chronic vascular wall inflammation and thrombotic processes. In this article, we present a synthetic overview of the latest data on the biology of NETs/NENs and their impact on the development of atherosclerosis, endothelial dysfunction, and the mechanisms of immunothrombosis. We highlight how these structures contribute to the weakening of atherosclerotic plaque stability, impaired endothelial barrier integrity, platelet activation, and the initiation of the coagulation cascade. We also discuss the modulating role of classic risk factors such as hypertension, dyslipidemia, and exposure to tobacco smoke, which may increase the formation or hinder the elimination of NETs/NENs. We also focus on the practical application of this knowledge: we present biomarkers associated with the presence of NETs/NENs (cfDNA, MPO–DNA complexes, CitH3, NE), which may be useful in diagnostics and risk stratification, and we discuss innovative therapeutic strategies. In addition to classic methods for indirectly inhibiting NET/NEN formation (antiplatelet, anti-inflammatory, and immunometabolic agents), we present experimental approaches aimed at their neutralization and removal (e.g., DNase I, elastase, and myeloperoxidase inhibitors). We pay particular attention to the context of cardiac and cardiac surgical procedures (Percutaneous Coronary Intervention-PCI, coronary artery bypass grafting-CABG), where rapid NET/NEN bursts can increase the risk of acute thrombotic complications. The overall evidence indicates that NETs/NENs represent an innovative and promising research and therapeutic target, allowing us to view cardiovascular diseases in a new light—as a dynamic interaction of inflammatory, atherosclerotic, and thrombotic processes. This opens up new possibilities in diagnostics, combination treatment and personalisation of therapy, although further research and standardization of detection methods remain necessary. Full article

Cancer remains a major global health challenge requiring the development of diagnostic and therapeutic strategies. Liquid biopsy is considered a promising minimally invasive tool for cancer screening, prognosis and treatment monitoring. Recent studies suggest that neutrophil extracellular traps (NETs) may also be potential liquid biopsy markers. NETs are web-like chromatin structures released by neutrophils in response to various stimuli to trap and neutralize pathogens. However, excessive or dysregulated NET formation has been implicated in tumor progression and metastasis. Elevated levels of NETs have been observed in patients with various types of cancer and correlate with disease stage and prognosis. The presence of NET markers such as citrullinated histone H3 (H3Cit), neutrophil elastase (NE) and myeloperoxidase (MPO) has been associated with higher tumor burden and poorer clinical outcomes. Several studies have shown a positive correlation between NET markers and circulating free DNA (cfDNA) levels, suggesting that NETs may increase the sensitivity of liquid biopsy in detecting and monitoring cancer progression. This review examines the role of NETs in the tumor microenvironment, their contribution to cancer progression and metastasis, and their potential use in liquid biopsy and cancer therapy. Full article

Background: Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD), is a chronic inflammatory disorder driven by a complex interplay of immune and proteolytic mechanisms. Neutrophil elastase (NE), released at sites of inflammation, plays a central role by promoting inflammation, degrading the extracellular matrix (ECM), and disturbing intestinal barrier integrity via NF-κB activation and E-cadherin degradation. Elafin, an endogenous NE inhibitor, mitigates proteolytic damage, reinforces the intestinal barrier, and exerts anti-inflammatory effects by suppressing NF-κB and reducing pro-inflammatory cytokines. Since the NE/elafin balance is critical in IBD, assessing their ratio may provide a more precise measure of proteolytic dysregulation. This study aimed to evaluate the diagnostic and prognostic utility of urinary NE, elafin, and their ratio in IBD patients. Methods: Urinary concentrations of NE and elafin were measured by immunoassay in 88 subjects including ulcerative colitis and Crohn’s disease patients and healthy individuals. The diagnostic accuracy of these biomarkers was assessed using receiver operating characteristic (ROC) curve analysis. Results: Urinary NE levels were significantly elevated in both UC and CD patients compared to controls, with a 17-fold increase in the UC patients and a 28-fold increase in the CD patients (p < 0.0001). Elafin levels were also increased in IBD patients. The NE/elafin ratio was significantly increased in both disease groups, with a 4.5-fold increase in the UC and 5.6-fold increase in the CD patients compared to healthy controls. The ROC curve analysis demonstrated that the NE/elafin ratio is the most effective biomarker for distinguishing CD patients from healthy individuals (AUC = 0.896), with a high sensitivity (92.9%) and specificity (69.7%), making it a strong diagnostic tool. NE also showed an excellent diagnostic performance both in CD (AUC = 0.842) and UC (AUC = 0.880). The elafin urinary profile had a high diagnostic value, with a better accuracy in the UC patients (AUC = 0.772) than the CD patients (AUC = 0.674), though it was inferior to NE and NE/elafin. Conclusions: Our findings indicate that urinary NE, elafin, the and NE/elafin ratio have significant diagnostic value in differentiating IBD patients from healthy controls. The NE/elafin ratio and NE proved to be the most reliable urinary biomarkers in both CD and UC diagnosis, with a high predictive value and strong discriminatory power. Full article

Cystic fibrosis (CF) is characterized by chronic respiratory infections and excessive inflammation, driven by both host- and pathogen-derived proteases. The dysregulated activity of proteolytic enzymes such as neutrophil elastase (NE), cathepsin G, and matrix metalloproteases (MMPs) degrades lung tissue, exacerbates airway remodeling, and perpetuates inflammatory cycles. Concurrently, bacterial proteases from pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus contribute to immune evasion and tissue destruction, compounding disease severity. Despite advances in antimicrobial and anti-inflammatory therapies, protease-driven lung damage remains a critical challenge. This review examines the dual role of host and bacterial proteases in CF pathophysiology, highlighting emerging protease-targeted therapies aimed at mitigating lung damage and inflammation. Strategies explored include the inhibition of NE, MMPs, and bacterial proteases, with a focus on innovative therapeutic approaches such as dual-function inhibitors, biologics, and advanced drug delivery systems. By restoring the protease–antiprotease balance, these interventions offer the potential to improve clinical outcomes and quality of life for CF patients. Full article

Neutrophil elastase (NE) has been reported to be a pro-inflammatory stimulus for macrophages. The aim of the present study was to determine the impact of NE exposure on the human macrophage proteome and evaluate its impact on pro-inflammatory signals. Human blood monocytes from healthy volunteers were differentiated to macrophages and then exposed to either 500 nM of NE or control vehicle for 2 h in triplicate. Label-free quantitative proteomics analysis identified 41 differentially expressed proteins in the NE versus control vehicle datasets. A total of 26 proteins were downregulated and of those, 21 were cell surface proteins. Importantly, four of the cell surface proteins were proteoglycans: neuropilin 1 (NRP1), syndecan 2 (SDC2), glypican 4 (GPC4), and CD99 antigen-like protein 2 (CD99L2) along with neuropilin 2 (NRP2), CD99 antigen (CD99), and endoglin (ENG) which are known interactors. Additional NE-targeted proteins related to macrophage function were also measured including CD40, CD48, SPINT1, ST14, and MSR1. Collectively, this study provides a comprehensive unbiased view of selective NE-targeted cell surface proteins in chronically inflamed lungs. Full article

Elevated protease activity is a hallmark of non-healing chronic wounds. Though multiple biomaterials exist that are successful in treating wounds, their roles in modulating the enzymatic environment of the wound are only beginning to be elucidated. Because keratin has long been known to be resistant to degradation by most enzymes, we studied a keratin biomaterial, the human keratin matrix (HKM), in the presence of enzymes identified to contribute to wound chronicity: neutrophil-derived elastase (NE), matrix metalloproteinase 1 (MMP-1), and MMP-9. Upon finding the suppression of MMP-9 activity in the presence of HKM without reducing enzyme protein levels, we further studied the ability of HKM to bind metal ions in the wound and showed the reduction of Zn²⁺ ion concentration in the presence of HKM. Finally, because of the enzyme resistance of keratin and the suppression of wound enzymes, we demonstrated that HKM was durable in the wound environment, and did not degrade in wound healing efficacy when left in place for two weeks compared to one week in a diabetic mouse model of wound non-healing. In this way, we show HKM is a unique and effective biomaterial for the treatment of chronic wounds through the modulation of wound MMP activity. Full article

Our study examined how different titanium alloy Ti6Al4V (Ti64) and zirconia (ZrO₂) surfaces, ranging from rough to very smooth, affect the expression of elastase (NE), matrix metalloproteinase (MMP)-8, MMP-9, and extracellular traps (NETs) by neutrophils. Discs of Ti64 and ZrO₂, 10 mm in diameter and 1.5 mm thick, were created using diamond-impregnated polishing burs and paste to produce rough (Ra > 3 µm), smooth (Ra ≥ 1 to 1.5 µm), and very smooth (Ra < 0.1 µm) surfaces. Neutrophils from Wistar rats were cultured on these surfaces, and the culture supernatants were then examined for NE, MMP-8, and MMP-9 using ELISA. At the same time, NET formation was demonstrated immunohistochemically by staining neutrophils with CD16b and DNA with DAPI. Overall, the expressions of NE and MMP-8 were significantly higher from neutrophil culture on Ti64 and ZrO₂ rough surfaces compared to the very smooth surface (R > S > VS) after 2 h and 4 h of culture. The expression of MMP-9 also increased with culture time; however, no significant surface effects on expression were observed. Similarly, rough Ti64 and ZrO₂ surfaces (R & S) also showed significantly larger NET formation compared to the very smooth surface (VS) after 4 h and 8 h cultures. Our findings suggest that increasing surface roughness on Ti64 and ZrO₂ triggers higher NE, MMP-8, and NET formation secretion. Full article

Enhancing or protecting sperm motility has always been a pivotal approach to improving the ewe pregnancy rate. Sperm motility is highly susceptible to the immune status of the reproductive tract. Neutrophil extracellular traps (NETs) have been demonstrated to capture sperm and impair its motility in human, swine, and goat species. Quercetin is a flavonoid derived from Cuscuta Chinensis Lam., which can protect sperm from oxidative damage. In this study, we investigated whether inflammation decreases sperm motility and tried to clarify the potential protective mechanism of quercetin on goat sperm motility. Sperm-triggered NETs were analyzed by immunofluorescence analysis. Sperm acrosome integrity was detected by using giemsa staining. Quercetin exhibited no cytotoxicity towards sperm and PMNs within the concentration range of 20–80 μM. PMNs impaired both the survival rate and rapid linear motility of sperm, while quercetin significantly enhanced these parameters. PMNs captured sperm through NETs composed of DNA, citrullinated histone 3 (citH3), and neutrophil elastase (NE); however, quercetin effectively inhibited the release of sperm-stimulated NETs. The stimulation of PMNs with sperm resulted in a significant increase in levels of ROS and MDA, which decreased by quercetin. Moreover, PMNs caused integrity violation to both the plasma membrane and acrosome in sperm; this effect was significantly alleviated by quercetin. In conclusion, quercetin effectively ameliorated PMN-reduced sperm motility through the inhibition of NETs and oxidative stress, and preserving sperm plasma membrane and acrosome integrity, thereby providing preliminary insights into the underlying mechanisms and theoretical support for the development of potential sperm protectors. Full article

Despite numerous studies conducted by various research teams, predicting long-term outcomes (known as Post-COVID-19 Syndrome, PCS) that may result from Coronavirus Disease 2019 (COVID-19) remains challenging. PCS affects over a million people, primarily those with comorbid conditions. Therefore, it is crucial to undertake research aimed at developing a predictive model for early diagnosis of PCS, which in turn would enable faster preventive actions. The aim of this study was to assess the value of measuring and attempt a quantitative evaluation using Enzyme-Linked Immunosorbent Assay (ELISA) tests of three non-serum proteins, whose presence in the blood during COVID-19 was associated with severe disease progression: neutrophil elastase (NE), calcium-binding protein S100B, and neuron-specific enolase (NSE). The concentrations of these proteins were measured in blood serum samples collected before the COVID-19 pandemic from (1) patients with type 2 diabetes (T2DM); (2) advanced stage diabetic nephropathy (NfT2DM); (3) a healthy group; and in blood serum samples collected two years after recovering from COVID-19 from patients with (4) T2DM and (5) NfT2DM. It was found that elevated levels of NE and NSE were significantly more common (p < 0.05) in patients with NfT2DM after recovering from COVID-19 compared to the other groups, while elevated levels of S100B were significantly more frequently observed in patients with T2DM after recovering from COVID-19 (p < 0.05). Demonstrating differences in the prevalence of NE, NSE, and S100B in individuals who recovered from COVID-19 with T2DM and NfT2DM makes these proteins important components of the developing predictive model for early detection of PCS. To our knowledge, this is the first study showing the significance of NE, NSE, and S100B in PCS in the context of T2DM and NfT2DM. Full article

The measurement of cytokines in induced sputum and nasal lavage (NL) samples has been performed for years in people with cystic fibrosis (CF). The aim of this study was to directly compare sputum and NL samples and interpret results based on disease severity in patients who were categorized as having mild or severe lung disease. The categorization was based primarily on structural abnormalities detected on lung computed tomography and secondarily on lung function. The serum inflammatory markers neutrophil elastase (NE), IL-1β, 2, 6, 8, 10 and 17a were measured in each sputum and NL sample. Thirty-two sample pairs from 29 patients were included in this study (13 mild, 19 severe). In the patients classified as severe, many systemic inflammatory markers as well as sputum cytokines were significantly higher compared to those in the mild patients. However, all the markers measured in the NL were higher in the mild patients (p =< 0.05 for NE, IL-6 and IL-8). In addition, many cytokines in the NL correlated negatively with those in the sputum samples. Major differences in the cytokine levels were shown although the samples were obtained at the same time in the same patient. Advanced structural lung disease was closely related to systemic and lower airway inflammation, whereas preserved lung function was associated with higher levels in the NL. We hypothesize that the main part of the immune response takes place in the nasal mucosa in patients with minor pulmonary changes. Our results suggest that inflammation must be interpreted individually depending on the compartment in which it is measured. Further research is needed to accurately understand inflammatory markers measured in NL. Full article

Psoriasis is an inflammatory skin disease with various symptoms of differing severities and with the reported prominent involvement of neutrophil extracellular traps (NETs). The excitation of neutrophils, e.g., by interleukin 8 (IL-8) or lipopolysaccharide (LPS), leads to the citrullination of histones and the release of protein–DNA complexes into the extracellular space, where they are digested by DNases. Our aim was to explore data on the levels of protein-complexed DNAs neutrophil elastase–DNA (NE-DNA) and myeloperoxidase–DNA (MPO-DNA), citrullinated histones (citH2, citH3, citH4), and NET-degrading enzyme DNase I in the serum of psoriatic patients with varying severities of clinical symptoms assessed with the Psoriasis Area Severity Index (PASI), Body Surface Area (BSA), and Dermatology Life Quality Index (DLQI) scores. The levels of factors were detected in 52 patients with psoriasis and 22 healthy volunteers by the enzyme-linked immunosorbent assay (ELISA). The results showed the elevated levels of NE-DNA, MPO-DNA, citH3, and DNase I in the patients with psoriasis compared to healthy volunteers (p < 0.05). Additionally, changes were noticed in the levels of NE-DNA, citH3, and DNase I, depending on the severity of symptoms (p < 0.05). In mild psoriasis (PASI < 10, BSA < 10, DLQI < 10), the suppressing activity of the enzyme caused the impaired ability to remove the physiological level of NETs, whereas in moderate to severe psoriasis (PASI ≥ 10, BSA ≥ 10, DLQI ≥ 10), the enhanced activity of DNase I failed to remove NETs due to the observed overexpression. It may, thus, be concluded that the mechanism of action of NETs, which play an undeniable role in psoriatic diseases, seem to follow two different paths depending on the severity of disease, which may be crucial in selecting potential anti-NET treatment methods. Full article

The collaboration between cellular proteases and host cells is pivotal in mounting an effective innate immune defense. Of particular interest is the synergistic interaction between cathepsin G (CatG) and neutrophil elastase (NE), which are proteases secreted by activated neutrophils, and the human alveolar basal epithelial cell line (A549) and the human lung epithelial-like cell line (H1299), because of the potential implications for viral infection. Our study aimed to investigate the binding capacity of CatG and NE on the surface of A549 and H1299 cells through preincubation with purified CatG and NE; thereby, the proteolytic activity could be detected using activity-based probes. Both CatG and NE were capable of binding to the cell surface and exhibited proteolytic activity, leading to increased cell surface levels of MHC I molecules, which is crucial for displaying the endogenous antigenic repertoire. In addition, CatG cleaved the S2′ site of the SARS-CoV-2 spike protein at two specific sites (₈₁₅RS₈₁₆ and ₈₁₇FI₈₁₈) as well as NE (₈₁₃SK₈₁₄ and ₈₁₈IE₈₁₉), which potentially leads to the destruction of the fusion peptide. Additionally, furin required the presence of Ca²⁺ ions for the distinct cleavage site necessary to generate the fusion peptide. Overall, the findings suggest that CatG and NE can fortify target cells against viral entry, underscoring the potential significance of cell surface proteases in protecting against viral invasion. Full article

There is a complex interplay between viral infection and host innate immune response regarding disease severity and outcomes. Neutrophil hyperactivation, including excessive release of neutrophil extracellular traps (NETs), is linked to exacerbated disease in acute COVID-19, notably in hospitalized patients. Delineating protective versus detrimental neutrophil responses is essential to developing targeted COVID-19 therapies and relies on high-quality translational animal models. In this study, we utilize a previously established feline model for COVID-19 to investigate neutrophil dysfunction in which experimentally infected cats develop clinical disease that mimics acute COVID-19. Specific pathogen-free cats were inoculated with SARS-CoV-2 (B.1.617.2; Delta variant) (n = 24) or vehicle (n = 6). Plasma, bronchoalveolar lavage fluid, and lung tissues were collected at various time points over 12 days post-inoculation. Systematic and temporal evaluation of the kinetics of neutrophil activation was conducted by measuring markers of activation including myeloperoxidase (MPO), neutrophil elastase (NE), and citrullinated histone H3 (citH3) in SARS-CoV-2-infected cats at 4 and 12 days post-inoculation (dpi) and compared to vehicle-inoculated controls. Cytokine profiling supported elevated innate inflammatory responses with specific upregulation of neutrophil activation and NET formation-related markers, namely IL-8, IL-18, CXCL1, and SDF-1, in infected cats. An increase in MPO-DNA complexes and cell-free dsDNA in infected cats compared to vehicle-inoculated was noted and supported by histopathologic severity in respiratory tissues. Immunofluorescence analyses further supported correlation of NET markers with tissue damage, especially 4 dpi. Differential gene expression analyses indicated an upregulation of genes associated with innate immune and neutrophil activation pathways. Transcripts involved in activation and NETosis pathways were upregulated by 4 dpi and downregulated by 12 dpi, suggesting peak activation of neutrophils and NET-associated markers in the early acute stages of infection. Correlation analyses conducted between NET-specific markers and clinical scores as well as histopathologic scores support association between neutrophil activation and disease severity during SARS-CoV-2 infection in this model. Overall, this study emphasizes the effect of neutrophil activation and NET release in SARS-CoV-2 infection in a feline model, prompting further investigation into therapeutic strategies aimed at mitigating excessive innate inflammatory responses in COVID-19. Full article