Atherosclerosis (AS) is a prevalent clinical vascular condition and serves as a pivotal pathological foundation for cardiovascular diseases. Understanding the pathogenesis of AS has significant clinical and societal implications, aiding in the development of targeted drugs. Neutrophils, the most abundant leukocytes in circulation, assume a central role during inflammatory responses and closely interact with AS, which is a chronic inflammatory vascular disease. Neutrophil extracellular traps (NETs) are substantial reticular formations discharged by neutrophils that serve as an immune defense mechanism. These structures play a crucial role in inducing dysfunction of the vascular barrier following endothelial cell injury. Components released by NETs pose a threat to the integrity of vascular endothelium, which is essential as it acts as the primary barrier to maintain vascular wall integrity. Endothelial damage constitutes the initial stage in the onset of AS. Recent investigations have explored the intricate involvement of NETs in AS progression. The underlying structures of NETs and their active ingredients, including histone, myeloperoxidase (MPO), cathepsin G, neutrophil elastase (NE), matrix metalloproteinases (MMPs), antimicrobial peptide LL-37, alpha-defensin 1-3, and high mobility group protein B1 have diverse and complex effects on AS through various mechanisms. This review aims to comprehensively examine the interplay between NETs and AS while providing insights into their mechanistic underpinnings of NETs in this condition. By shedding light on this intricate relationship, this exploration paves the way for future investigations into NETs while guiding clinical translation efforts and charting new paths for therapeutic interventions.
Extracellular Traps/physiology* ; Humans ; Atherosclerosis/immunology* ; Neutrophils/physiology* ; Leukocyte Elastase/metabolism* ; Peroxidase/physiology* ; Matrix Metalloproteinases/physiology* ; Cathepsin G/metabolism* ; Cathelicidins ; HMGB1 Protein/physiology* ; Histones ; Animals ; Endothelium, Vascular

OBJECTIVETo investigate the changes in serum protease and cytokine in patients with silicosis, tuberculosis, and lung cancer.

METHODSSerum samples of patients with silicosis, tuberculosis, and lung cancer were collected. The variation trends of the expression of granzyme A, cathepsin G, apolipoprotein A, and interferon-β (IFN-β) were analyzed using enzyme-linked immunosorbent assay.

RESULTSThe concentration of apolipoprotein A of the silicosis group was 200 µg/ml, significantly higher than those of the tuberculosis and lung cancer groups (P < 0.05), and the lung cancer group had a significantly higher concentration of apolipoprotein A compared with the tuberculosis group (P < 0.05). The silicosis group had significantly higher expression of cathepsin G compared with the tuberculosis and lung cancer groups (P < 0.05), and the tuberculosis group and lung cancer group showed no significant difference in the concentration of cathepsin G (P > 0.05). The tuberculosis group had a significantly higher concentration of granzyme A than the silicosis and lung cancer groups (P < 0.05), and the silicosis group and lung cancer group had similar protein concentration trends (P > 0.05). The tuberculosis group and lung cancer group had significantly higher concentration of IFN-β compared with the silicosis group (P < 0.05), and the tuberculosis group and lung cancer group showed no significant difference in IFN-β concentration (P > 0.05).

CONCLUSIONThis study may offer diagnostic markers for the clinical diagnosis of silicosis, tuberculosis, and lung cancer, and could provide a basis for the research, as well as potential molecular targets for the diagnosis and treatment of these diseases.

Biomarkers ; Cathepsin G ; metabolism ; Cytokines ; blood ; Endopeptidases ; blood ; Enzyme-Linked Immunosorbent Assay ; Granzymes ; metabolism ; Humans ; Interferon-beta ; metabolism ; Lung Neoplasms ; enzymology ; Silicosis ; enzymology ; Tuberculosis ; enzymology

Because of the complexity of the cathepsin B-like (CBL) family, an information on the biological and biochemical characteristics of individual CBL genes is lacking. In this study, we investigated the degradative effects of the recombinant HC58 protein isolated from Haemonchus contortus parasites on protein substrates over a broad pH range in vitro. This protein, which hydrolyzed the synthetic peptide substrates Z-FR-AMC and Z-RR-AMC, had characteristics of the cysteine protease class of proteins. In the acidic pH range, the isolated protein actively degraded hemoglobin (Hb), the heavy chain of goat immunoglobulin G, and azocasein. By contrast, it degraded fibrinogen in the alkaline pH range. These activities were strongly inhibited in the presence of the cysteine protease inhibitor E-64. While the protein digested Hb, it did not induce the agglutination of erythrocytes from its natural host. These results suggest that the HC58 protein may play a role in the nutrition of this parasite.
Animals ; Caseins/metabolism ; Cathepsin B/antagonists&inhibitors/*genetics/isolation & purification/*metabolism ; Cysteine Proteinase Inhibitors/pharmacology ; DNA, Complementary/genetics ; Goat Diseases/*parasitology ; Goats ; Haemonchiasis/parasitology/*veterinary ; Haemonchus/*enzymology/genetics/isolation & purification ; Hemagglutination Tests/veterinary ; Hemoglobins/metabolism ; Hydrogen-Ion Concentration ; Immunoglobulin G/metabolism ; Leucine/analogs & derivatives/pharmacology ; RNA, Helminth/chemistry/genetics ; Recombinant Proteins/genetics/metabolism ; Reverse Transcriptase Polymerase Chain Reaction/veterinary

BACKGROUNDPrevious studies have indicated that thrombin (TM) may play a major role in brain edema after intracerebral hemorrhages (ICHs). However, the mechanism of TM-induced brain edema is poorly understood. In this study, we explored the effect of TM on the permeability of the blood brain barrier (BBB) and investigated its possible mechanism, aiming at providing a potential target for brain edema therapy after ICHs.

METHODSTM or TM + cathepsin G (CATG) was stereotaxically injected into the right caudate nucleus of Sprague-Dawley rats in vivo. BBB permeability was measured by Evans-Blue extravasation. Brain water content was determined by the dry-wet weight method. Brain microvascular endothelial cells were then cultured in vitro. After TM or TM + CATG was added to the endothelial cell medium, changes in the morphology of cells were dynamically observed by phase-contrast light microscopy, and the expression of matrix metalloproteinase-2 (MMP-2) protein was measured by immunohistochemical method.

RESULTSBBB permeability increased at 6 hours after a TM injection into the ipsilateral caudate nucleus (P < 0.05), peaked between 24 hours (P < 0.01) and 48 hours (P < 0.05) after the injection, and then declined. Brain water content changed in parallel with the changes in BBB permeability. However, at all time points, BBB permeability and brain water content after a TM + CATG injection were not significantly different from the respective parameters in the control group (P > 0.05). TM induced endothelial cell contraction in vitro in a time-dependent manner and enhanced the expression of MMP-2 protein. After incubation with TM + CATG, cell morphology and MMP-2 expression did not change significantly as compared to the control group (P > 0.05).

CONCLUSIONSIncreased BBB permeability may be one of the mechanisms behind TM-induced cerebral edema. TM induces endothelial cell contraction and promotes MMP-2 expression by activating protease activated receptor-1 (PAR-1), possibly leading to the opening of the BBB.

Animals ; Blood-Brain Barrier ; drug effects ; Body Water ; metabolism ; Brain Edema ; etiology ; Cathepsin G ; Cathepsins ; pharmacology ; Cerebral Hemorrhage ; complications ; Matrix Metalloproteinase 2 ; analysis ; Permeability ; Rats ; Rats, Sprague-Dawley ; Receptor, PAR-1 ; physiology ; Serine Endopeptidases ; Thrombin ; toxicity