Neutrophil Elastase Increases Vascular Permeability and Leukocyte Transmigration in Cultured Endothelial Cells and Obese Mice

Potential utilization of ferulic acid and its derivatives in the management of metabolic diseases and disorders: An insight into mechanisms

Metabolic diseases are abnormal conditions that impair the normal metabolic process, which involves converting food into energy at a cellular level, and cause difficulties like obesity and diabetes. The study aimed to investigate how ferulic acid (FA) and its derivatives could prevent different metabolic diseases and disorders and to understand the specific molecular mechanisms responsible for their therapeutic effects. Information regarding FA associations with metabolic diseases and disorders was compiled from different scientific search engines, including Science Direct, Wiley Online, PubMed, Scopus, Web of Science, Springer Link, and Google Scholar. This review revealed that FA exerts protective effects against metabolic diseases such as diabetes, diabetic retinopathy, neuropathy, nephropathy, cardiomyopathy, obesity, and diabetic hypertension, with beneficial effects on pancreatic cancer. Findings also indicated that FA improves insulin secretion by increasing Ca2+ influx through the L-type Ca2+ channel, thus aiding in diabetes management. Furthermore, FA regulates the activity of inflammatory cytokines (TNF-α, IL-18, and IL-1β) and antioxidant enzymes (CAT, SOD, and GSH-Px) and reduces oxidative stress and inflammation, which are common features of metabolic diseases. FA also affects various signaling pathways, including the MAPK/NF-κB pathways, which play an important role in the progression of diabetic neuropathy and other metabolic disorders. Additionally, FA regulates apoptosis markers (Bcl-2, Bax, and caspase-3) and exerts its protective effects on cellular destruction. In conclusion, FA and its derivatives may act as potential medications for the management of metabolic diseases.

Adipocyte-targeted celastrol delivery via biguanide-modified micelles improves treatment of obesity in DIO mice

Obesity has emerged as a significant global health burden, exacerbated by serious side effects associated with existing anti-obesity medications. Celastrol (CLT) holds promise for weight loss but encounters challenges related to poor solubility and systemic toxicity. Here, we present chondroitin sulfate (CS)-derived micelles engineered for adipocyte-specific targeting, aiming to enhance the therapeutic potential of CLT while minimizing its systemic toxicity. To further enhance adipocyte affinity, we introduced a biguanide moiety into a micellar vehicle. CS is sequentially modified with hydrophilic metformin and hydrophobic 4-aminophenylboronic acid pinacol ester (PBE), resulting in the self-assembly of CLT-encapsulated micelles (MET-CS-PBE@CLT). This innovative design imparts amphiphilicity via the PBE moieties while ensuring the outward exposure of hydrophilic metformin moieties, facilitating active interactions with adipocytes. In vitro studies confirmed the enhanced uptake of MET-CS-PBE@CLT micelles by adipocytes, while in vivo studies demonstrated increased distribution within adipose tissues. In a diet-induced obese mouse model, MET-CS-PBE@CLT exhibited remarkable efficacy in weight loss without affecting food intake. This pioneering strategy offers a promising, low-risk, and highly effective solution to address the global obesity epidemic.

Ascorbic acid as serine protease inhibitor in lung cancer cell line and human serum albumin

Serine proteases (SPs) are distributed among all living cells accounting for almost one-third of all proteases. Dysregulation of SPs during inflammation and/or infection can result in devastating consequences, such as skin and lung inflammation, neuroinflammation, arthritis, as well as metastasis of cancerous cells. Such activities are tightly regulated by various inhibitors known as serine protease inhibitors (SERPIN). The thermodynamic investigations previously revealed that L-ascorbic acid binds to trypsin more firmly than pepsin and the binding force of L-ascorbic acid is driven by hydrogen bonds and van der Waals forces. However, the physiochemical effects of such interaction on trypsin and/or pepsin have not yet been reported. Ascorbic acid, also known as vitamin C, is one of the essential nutrients and most common food supplements, fortificants, and preservatives. The aim of this study was to explore the inhibitory effects of ascorbic acid on serine proteases at various concentrations on the in-vitro digestion and/or hydrolysis of intercellular matrix of cell monolayer and human serum albumin (HSA). The inhibitory effects of ascorbic on trypsin are investigated by qualitative and quantitative analysis using SDS-PAGE imaging and NIH densitometric software. Upon the addition of ascorbic acid in both indicator systems, the detachment and/or dissociation of cell monolayer and the digestion of HSA were inhibited in the presence of EDTA-Trypsin. The inhibitory effect of ascorbic acid on the digestion of intercellular matrix and/or hydrolysis of HSA showed a dose-dependent trend until it reached the maximum extent of inhibition. At an equal concentration (2.5mg/mL) ascorbic acid and EDTA-Trypsin exhibited the most potent inhibitory effect on the in vitro digestion of protein either in the form of intercellular matrix in cell monolayer and/or HSA respectively. Overall, our results based on two indicator systems strongly indicate that ascorbic acid may function as a serine protease inhibitor (SERPIN) beyond other important functions.

The association between the neutrophil-to-lymphocyte ratio and type 2 diabetes mellitus: a cross-sectional study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a prevalent chronic disease often accompanied by low-grade inflammation. Recently, the neutrophil-to-lymphocyte ratio (NLR) has garnered researchers' interest as an emerging inflammation biomarker. This study aimed to comprehensively explore the relationship between NLR and T2DM using the National Health and Nutrition Examination Survey (NHANES) database.

METHOD

We employed a cross-sectional study design to analyze data from five NHANES cycles from 2007 to 2016, excluding individuals with incomplete data. This study utilized a weighted logistic regression model, subgroup analyses, and restricted cubic spline (RCS) analysis to assess the potential relationship between NLR and T2DM.

RESULTS

A total of 9903 participants were eligible for the analysis, of which 1280 were diagnosed with T2DM. The T2DM group exhibited significantly higher NLR levels than the non-T2DM group. After adjusting for potential confounders, elevated NLR levels were associated with an increased risk of developing T2DM, indicated by an odds ratio (OR) of 1.14, 95% CI: (1.05,1.24), P = 0.003. The results of the subgroup analyses revealed a significant interaction effect between NLR and T2DM concerning race and hypertension (P for interaction < 0.05). In contrast, no significant interactions were found for age, sex, education level, body mass index (BMI), smoking status, recreational activities, and alcohol drinker (P for interaction > 0.05). RCS analysis showed a significant non-linear relationship between NLR and T2DM, with an inflection point at 2.27 (all P for non-linearity < 0.05).

CONCLUSION

Our study indicates that an elevated neutrophil-to-lymphocyte ratio is associated with a higher risk of T2DM.

Effect of Trehalose Disaccharide on Activation of Microglia and Indices of Systemic Inflammation in an Experimental Model of Alzheimer's Disease

In an experimental model of Alzheimer's disease in mice, oral administration of trehalose disaccharide reduces neuroinflammation assessed by the expression level of microglia activation marker Iba1 and affects the neutrophil degranulation activity. A potential anti-inflammatory effect of 4% trehalose solution associated with a decrease in the activity of leukocyte elastase in plasma was revealed.

Metabolic Syndrome and Cardiac Vessel Remodeling Associated with Vessel Rarefaction: A Possible Underlying Mechanism May Result from a Poor Angiogenic Response to Altered VEGF Signaling Pathways

BACKGROUND

Elevated mortality rates in patients with metabolic syndrome (MetS) are partly due to adverse remodeling of multiple organs, which may lead to cardiovascular disease, nonalcoholic fatty liver disease, kidney failure, or other conditions. MetS symptoms, such as obesity, hypertension, hyperglycemia, dyslipidemia, associated with insulin and leptin resistance, are recognized as major cardiovascular risk factors that adversely affect the heart.

SUMMARY

Pathological cardiac remodeling is accompanied by endothelial cell dysfunction which may result in diminished coronary flow, dysregulated oxygen demand/supply balance, as well as vessel rarefaction. The reduced number of vessels and delayed or inhibited formation of collaterals after myocardial infarction in MetS heart may be due to unfavorable changes in endothelial cell metabolism but also to altered expression of vascular endothelial growth factor molecules, their receptors, and changes in signal transduction from the cell membrane, which severely affect angiogenesis.

KEY MESSAGES

Given the established role of cardiac vessel endothelial cells in maintaining tissue homeostasis, defining the molecular background underlying vessel dysfunction associated with impaired angiogenesis is of great importance for future therapeutic purposes. Therefore, the aim of this paper was to present current information regarding vascular endothelial growth factor signaling in the myocardium of MetS individuals.

Stomatin promotes neutrophil degranulation and vascular leakage in the early stage after severe burn via enhancement of the intracellular binding of neutrophil primary granules to F-actin

BACKGROUND

The pathophysiology of severe burn injuries in the early stages involves complex emergency responses, inflammatory reactions, immune system activation, and a significant increase in vascular permeability. Neutrophils, crucial innate immune cells, undergo rapid mobilization and intricate pathophysiological changes during this period. However, the dynamic alterations and detailed mechanisms governing their biological behavior remain unclear. Stomatin protein, an essential component of the cell membrane, stabilizes and regulates the membrane and participates in cell signal transduction. Additionally, it exhibits elevated expression in various inflammatory diseases. While Stomatin expression has been observed in the cell and granule membranes of neutrophils, its potential involvement in post-activation functional regulation requires further investigation.

METHODS

Neutrophils were isolated from human peripheral blood, mouse peripheral blood, and mouse bone marrow using the magnetic bead separation method. Flow cytometry was used to assess neutrophil membrane surface markers, ROS levels, and phagocytic activity. The expression of the Stomatin gene and protein was examined using quantitative real-time polymerase chain reaction and western blotting methods, respectively. Furthermore, the enzyme-linked immunosorbent assay was used to evaluate the expression of neutrophil-derived inflammatory mediators (myeloperoxidase (MPO), neutrophil elastase (NE), and matrix metalloproteinase 9 (MMP9)) in the plasma. Images and videos of vascular leakage in mice were captured using in vivo laser confocal imaging technology, whereas in vitro confocal microscopy was used to study the localization and levels of the cytoskeleton, CD63, and Stomatin protein in neutrophils.

RESULTS

This study made the following key findings: (1) Early after severe burn, neutrophil dysfunction is present in the peripheral blood characterized by significant bone marrow mobilization, excessive degranulation, and impaired release and chemotaxis of inflammatory mediators (MPO, NE, and MMP9). (2) After burn injury, expression of both the stomatin gene and protein in neutrophils was upregulated. (3) Knockout (KO) of the stomatin gene in mice partially inhibited neutrophil excessive degranulation, potentially achieved via reduced production of primary granules and weakened binding of primary granules to the cell skeleton protein F-actin. (4) In severely burned mice, injury led to notable early-stage vascular leakage and lung damage, whereas Stomatin gene KO significantly ameliorated lung injury and vascular leakage.

CONCLUSIONS

Stomatin promotes neutrophil degranulation in the early stage of severe burn injury via increasing the production of primary granules and enhancing their binding to the cell skeleton protein F-actin in neutrophils. Consequently, this excessive degranulation results in aggravated vascular leakage and lung injury.

Effect of Neurotropic and Immunotropic Drugs on Leukocyte Elastase Activity In Vitro

Leukocyte elastase is a marker of inflammation. Previously, a relationship was found between the severity of mental disorders in patients and elastase-like activity of blood plasma. The effect of various neurotropic drugs on leukocyte elastase activity was analyzed in an in vitro experiment. We revealed an inhibitory effect of the benzodiazepine tranquilizers diazepam and bromodihydrochlorophenylbenzodiazepine and immunomodulators aminodihydrophthalazinedione and diclofenac on the plasma elastase-like activity of healthy donors and pure human neutrophil elastase. The antipsychotics chlorpromazine and alimemazine, as well as the nootropic vinpocetine increased elastase-like activity in a dose-dependent manner. The activating effect of chlorpromazine and vinpocetine, but not alimemazine, was reproduced in neutrophil elastase. We hypothesized that these drugs can affect the development of inflammatory reactions in the complex therapy of mental disorders.

Resolving neutrophils due to TRAM deletion renders protection against experimental sepsis

OBJECTIVE

Proper inflammation resolution is crucial to prevent runaway inflammation during sepsis and reduce sepsis-related mortality/morbidity. Previous studies suggest that deleting TRAM, a key TLR4 signaling adaptor, can reprogram the first inflammatory responder cell-neutrophil from an inflammatory state to a resolving state. In this study, we aim to examine the therapeutic potential of TRAM-deficient neutrophils in vivo with recipient mice undergoing experimental sepsis.

MATERIAL AND METHODS

Wild-type or Tram-/- mice were intraperitoneally injected with cecal slurry to induce either severe or mild sepsis. Phenotypic examinations of sepsis and neutrophil characteristics were examined in vivo and ex vivo. The propagations of resolution from donor neutrophils to recipient cells such as monocytes, T cells, and endothelial cells were examined through co-culture assays in vitro. The efficacies of Tram-/- neutrophils in reducing inflammation were studied by transfusing either wild-type or Tram-/- neutrophils into septic recipient mice.

RESULTS

Tram-/- septic mice had improved survival and attenuated injuries within the lung and kidney tissues as compared to wild-type septic mice. Wild-type septic mice transfused with Tram-/- resolving neutrophils exhibited reduced multi-organ damages and improved cellular homeostasis. In vitro co-culture studies revealed that donor Tram-/- neutrophils can effectively propagate cellular homeostasis to co-cultured neighboring monocytes, neutrophils, T cells as well as endothelial cells.

CONCLUSIONS

Neutrophils with TRAM deletion render effective reprogramming into a resolving state beneficial for ameliorating experimental sepsis, with therapeutic potential in propagating cellular and tissue homeostasis as well as treating sepsis.

Zonulin as a Potential Therapeutic Target in Microbiota-Gut-Brain Axis Disorders: Encouraging Results and Emerging Questions

The relationship between dysbiosis and central nervous diseases has been proved in the last 10 years. Microbial alterations cause increased intestinal permeability, and the penetration of bacterial fragment and toxins induces local and systemic inflammatory processes, affecting distant organs, including the brain. Therefore, the integrity of the intestinal epithelial barrier plays a central role in the microbiota-gut-brain axis. In this review, we discuss recent findings on zonulin, an important tight junction regulator of intestinal epithelial cells, which is assumed to play a key role in maintaining of the blood-brain barrier function. In addition to focusing on the effect of microbiome on intestinal zonulin release, we also summarize potential pharmaceutical approaches to modulate zonulin-associated pathways with larazotide acetate and other zonulin receptor agonists or antagonists. The present review also addresses the emerging issues, including the use of misleading nomenclature or the unsolved questions about the exact protein sequence of zonulin.

Sivelestat improves clinical outcomes and decreases ventilator-associated lung injury in children with acute respiratory distress syndrome: a retrospective cohort study

BACKGROUND

Sivelestat, a neutrophil elastase inhibitor, is a selective and targeted therapy for acute respiratory distress syndrome (ARDS) in adults; and it is also reported to apply to children with ARDS. However, there is little evidence of its efficacy in children.

METHODS

This study recruited 212 patients ranging in age from 28 days to 18 years old, and who met the diagnostic criteria for pediatric ARDS (PARDS) while hospitalized in the Intensive Care Department of the Affiliated Children's Hospital of Xi'an Jiaotong University. A total of 125 patients (case group) received sivelestat treatment, and 87 were assigned to the control group. There were no significant differences in gender (P=0.445) or age (P=0.521). Control group data were collected from the Electronic Case Information System for pediatric patients diagnosed with ARDS between March 2017 to January 2020. Data for the case group were collected from the Electronic Case Information System between February 2020 to February 2022. Demographic data, clinically relevant indicators, respiratory parameters were recorded. The 28-day mortality was the primary endpoint; the Kaplan-Meier and log-rank tests were used to evaluate cumulative survival rate.

RESULTS

For general demographic and clinical characteristics, no significant differences were observed between the two groups. Compared to the control group, the case group displayed significant improvements in PaO₂/FiO₂ at 48 h (141±45 vs. 115±21, P<0.001) and 72 h (169±61 vs. 139±40, P<0.001) post-admission, and plateau pressure was lower than that in the control group at 24 h (24±3 vs. 28±7, P<0.001), 48 h (21±4 vs. 26±7, P<0.001), and 72 h (20±2 vs. 25±6, P<0.001) post-admission. Interleukin-8 levels were lower in the case group at 48 and 72 h post-admission. Overall, 28-day mortality was 25.47% (54/212). Twenty-five children died in the sivelestat group, 29 children died in the control group. Survival analysis revealed that cumulative survival in the case group was higher than that in the control group (P=0.028).

CONCLUSIONS

ARDS is expected to have high morbidity and mortality in critical care medicine, and precise targeted drugs are lacking. Our study showed that sivelestat improved prognosis and reduces mortality in children with ARDS.

The Related Metabolic Diseases and Treatments of Obesity

Obesity is a chronic disease characterized by the abnormal or excessive accumulation of body fat, affecting more than 1 billion people worldwide. Obesity is commonly associated with other metabolic disorders, such as type 2 diabetes, non-alcoholic fatty liver disease, cardiovascular diseases, chronic kidney disease, and cancers. Factors such as a sedentary lifestyle, overnutrition, socioeconomic status, and other environmental and genetic conditions can cause obesity. Many molecules and signaling pathways are involved in the pathogenesis of obesity, such as nuclear factor (NF)-κB, Toll-like receptors (TLRs), adhesion molecules, G protein-coupled receptors (GPCRs), programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1), and sirtuin 1 (SIRT1). Commonly used strategies of obesity management and treatment include exercise and dietary change or restriction for the early stage of obesity, bariatric surgery for server obesity, and Food and Drug Administration (FDA)-approved medicines such as semaglutide and liraglutide that can be used as monotherapy or as a synergistic treatment. In addition, psychological management, especially for patients with obesity and distress, is a good option. Gut microbiota plays an important role in obesity and its comorbidities, and gut microbial reprogramming by fecal microbiota transplantation (FMT), probiotics, prebiotics, or synbiotics shows promising potential in obesity and metabolic syndrome. Many clinical trials are ongoing to evaluate the therapeutic effects of different treatments. Currently, prevention and early treatment of obesity are the best options to prevent its progression to many comorbidities.