Characteristics of Neonatal Sepsis and Predictive Values of Polyfunctional Assessment of Umbilical Cord Neutrophils Based on Single Cell Proteomic Secretion.

The early diagnosis of neonatal sepsis is crucial as it remains a prevalent cause of neonatal mortality. In this study, we conducted an analysis on the clinical data and detection indicators of 22 cases with sepsis and 62 cases without sepsis among neonates. Our findings indicate that the clinical signs observed in neonates with sepsis lack specificity. In addition, the commonly used clinical inflammatory indicators (such as leukocyte count, neutrophil-to-lymphocyte ratio [NLR], C-reactive protein [CRP], procalcitonin) exhibit limited sensitivity and specificity. Furthermore, the current clinical measures lack the assessment of inflammatory factors. Therefore, in order to enhance the accuracy of early sepsis diagnosis in neonates, we have employed a novel microfluidic-based single-cell technology platform for the analysis of 32 cytokines secreted by neutrophils at the individual cell level under various toxin stimulation conditions. We have further investigated and compared the disparities in single-cell protein secretomics between umbilical cord blood neutrophils and healthy adult peripheral neutrophils within an in vitro sepsis model. Our findings indicate that in a resting state UCB neutrophils exhibited lower polyfunctionality compared with healthy adult blood neutrophils, and notable variations in cytokine secretion profiles were detected between the two groups. However, the polyfunctionality of UCB neutrophils significantly increased and surpassed that of healthy adult neutrophils when exposed to alpha-hemolysin or lipopolysaccharide. UCB neutrophils secreted a wide range of chemokines and inflammatory factors, among which GM-CSF and IL-18 were the most significant. Furthermore, we initially categorized the functional subgroups of neutrophils by considering the secretion of five primary cytokines by neutrophils (GM-CSF, IL-18, IL-8, MIP-1ß, and MIF). The current study, for the first time, examined in detail the heterogeneity of protein secretion and the functional diversity of UCB neutrophils stimulated by different antigens. Moreover, new insight into neonatal sepsis, early diagnosis, and wider clinical applications of UCB neutrophils are provided by these data.

A Collaborative Approach for Metal Pollution Assessment in Production System of Plastic-Shed Vegetables Near Industrial Areas.

A collaborative assessment approach, including impact index of comprehensive quality (IICQ), food pollution index (FPI), and single factor pollution index (PI), was used to simultaneously select priority metal pollutants and assess metal contamination status in the plastic-shed soil (PSS)-vegetable system of the industrial towns situated in the Yangtze River Delta, China. Overall, significant Cr increment as well as Cd and Cu pollution in PSS existed, which was related to anthropogenic activities, especially industrial wastewater irrigation. The evaluation using PI and FPI demonstrated that priority metal pollutants were Cu and Cd in PSS while Cr and Cd in vegetables. Additionally, the estimation using IICQ method revealed that 23.3% and 13.3% of the sampling sites were sub-moderately and heavily contaminated by metals, respectively. These sites especially with heavy pollution need priority pollution management. These data will be beneficial to metal pollution control in PSS-vegetable system around industrial areas.

Engineered nanovesicles from activated neutrophils with enriched bactericidal proteins have molecular debridement ability and promote infectious wound healing.

Background: Bacterial infections pose a considerable threat to skin wounds, particularly in the case of challenging-to-treat diabetic wounds. Systemic antibiotics often struggle to penetrate deep wound tissues and topically applied antibiotics may lead to sensitization, necessitating the development of novel approaches for effectively treating germs in deep wound tissues. Neutrophils, the predominant immune cells in the bloodstream, rapidly release an abundance of molecules via degranulation upon activation, which possess the ability to directly eliminate pathogens. This study was designed to develop novel neutrophil cell engineered nanovesicles (NVs) with high production and explore their bactericidal properties and application in promoting infectious wound healing. Methods: Neutrophils were isolated from peripheral blood and activated in vitro via phorbol myristate acetate (PMA) stimulation. Engineered NVs were prepared by sequentially extruding activated neutrophils followed by ultracentrifugation and were compared with neutrophil-derived exosomes in terms of morphology, size distribution and protein contents. The bactericidal effect of NVs in vitro was evaluated using the spread plate technique, LIVE/DEAD backlight bacteria assay and observation of bacterial morphology. The therapeutic effects of NVs in vivo were evaluated using wound contraction area measurements, histopathological examinations, assessments of inflammatory factors and immunochemical staining. Results: Activated neutrophils stimulated with PMA in vitro promptly release a substantial amount of bactericidal proteins. NVs are similar to exosomes in terms of morphology and particle size, but they exhibit a significantly higher enrichment of bactericidal proteins. In vitro, NVs demonstrated a significant bactericidal effect, presumably mediated by the enrichment of bactericidal proteins such as lysozyme. These NVs significantly accelerated wound healing, leading to a marked reduction in bacterial load, downregulation of inflammatory factors and enhanced collagen deposition in a full-thickness infectious skin defect model. Conclusions: We developed engineered NVs derived from activated neutrophils to serve as a novel debridement method targeting bacteria in deep tissues, ultimately promoting infectious wound healing.

Construction and multicohort validation of a colon cancer prognostic risk score system based on big data of neutrophil-associated differentially expressed genes.

Objective: To investigate the role of neutrophils in colon cancer progression. Methods: Genetic data from 1,273 patients with colon cancer were procured from public databases and categorized based on genes linked to neutrophils through an unsupervised clustering approach. Through univariate Cox regression analysis, differentially expressed genes (DEGs) influencing overall survival (OS) were identified, forming the basis for establishing a prognostic risk score (PRS) system specific to colon cancer. Additionally, the correlation between PRS and patient prognosis, immune cell infiltration, and intratumoral gene mutations were analyzed. Validation of PRS as an indicator for "pan-tumor" immunotherapy was conducted using four distinct immunotherapy cohorts. Results: The research identified two distinct subtypes of colon cancer, namely Cluster A and B, with patients in Cluster B demonstrating remarkably superior prognoses over those in Cluster A. A total of 17 genes affecting OS were screened based on 109 DEGs between the two cluster for constructing the PRS system. Notably, individuals classified under the high-PRS group (PRShigh) exhibited poorer prognoses, significantly linked with immune cell infiltration, an immunosuppressive tumor microenvironment, and increased genomic mutations. Remarkably, analysis of immunotherapy cohorts indicated that patients with PRShigh exhibited enhanced clinical responses, a higher rate of progression-free events, and improved overall survival post-immunotherapy. The PRS system, developed based on tumor typing utilizing neutrophil-associated genes, exhibited a strong correlation with prognostic elements in colon cancer and emerged as a vital predictor of "pan-tumor" immunotherapy efficacy. Conclusions: PRS serves as a prognostic model for patients with colon cancer and holds the potential to act as a "pan-tumor" universal marker for assessing immunotherapy efficacy across different tumor types. The study findings lay a foundation for novel antitumor strategies centered on neutrophil-focused approaches.

Fractionation of metals in soil for strawberry cultivation: Effect on metal migration in food chain and application in risk assessment.

Although trace metals in strawberry production system have attracted growing attention, little is known about metal fractionation in soil for strawberry cultivation. We hypothesized that the metal fractions in soil influenced by strawberry production had significant effect on food chain transport of metals and their risk in soil. Here, samples of strawberries and soil were gathered in the Yangtze River Delta, China to verify the hypothesis. Results showed that the acid-soluble Cr, Cd, and Ni in soil for strawberry cultivation were 21.5%-88.3% higher than those in open field soil, which enhanced uptake and bioaccessible levels of these metals in strawberries. Overall, the ecological, mobility, and health risks of Pb, Zn, Ni, and Cu in soil were at a low level. However, the ecological risk of bioavailable Cd, mobility risk of Cd, and cancer risk of bioavailable Cr in over 70% of the soil samples were at moderate, high, and acceptable levels, respectively. Since the increased acid-soluble Cr and Ni in soil were related to soil acidification induced by strawberry production, nitrogen fertilizer application should be optimized to prevent soil acidification and reduce transfer of Cr and Ni. Additionally, as Cd and organic matter accumulated in soil, the acid-soluble Cd and the ecological and mobility risks of Cd in soil were enhanced. To decrease transfer and risk of Cd in soil, organic fertilizer application should be optimized to mitigate Cd accumulation, alter organic matter composition, and subsequently promote the transformation of bioavailable Cd into residual Cd in soil.

Investigation of Allogeneic Neutrophil Transfusion in Improving Survival Rates of Severe Infection Mice.

The management of granulocytopenia-associated infections is challenging, and a high mortality rate is associated with traditional supportive therapies. Neutrophils-the primary defenders of the human immune system-have potent bactericidal capabilities. Here, we investigated the dynamic in vivo distribution of neutrophil transfusion and their impact on the treatment outcome of severe granulocytopenic infections. We transfused 89Zr-labeled neutrophils in the C57BL/6 mice and observed the dynamic neutrophil distribution in mice for 24 h using the micro-positron emission tomography (Micro-PET) technique. The labeled neutrophils were predominantly retained in the lungs and spleen up to 4 h after injection and then redistributed to other organs, such as the spleen, liver, and bone marrow. Neutrophil transfusion did not elicit marked inflammatory responses or organ damage in healthy host mice. Notably, allogeneic neutrophils showed rapid chemotaxis to the infected area of the host within 1 h. Tail vein infusion of approximately 107 neutrophils substantially bolstered host immunity, ameliorated the inflammatory state, and increased survival rates in neutrophil-depleted and infected mice. Overall, massive allogeneic neutrophil transfusion had a therapeutic effect in severe infections and can have extensive applications in the future.

DNase aggravates intestinal microvascular injury in IBD patients by releasing NET-related proteins.

Neutrophils accumulate in the inflammatory mucosa of patients with inflammatory bowel disease (IBD), and excessive release of NETs (neutrophil extracellular traps may be one of the important factors that cause IBD progression. However, the specific mechanism underlying vascular injury caused by NETs remains unclear. Immunofluorescence, ELISA, and flow cytometry were used in this study to detect the expression of NETs and DNase in the tissue and peripheral blood samples of patients with IBD. DSS mouse model was used to detect colon injury and vascular permeability. We found that NETs and DNase levels increased in the colon of patients with IBD. We found an increase in the activity of NET-related MPO released by DNase. DNase released NET-related proteins and damaged vascular endothelial cells in vitro. In DSS mouse model, the synchronous increase of DNase and NETs in the colon leads to an increase in vascular injury markers (CD44, sTM). DNase aggravated colon injury and increased vascular permeability in vivo, which was inhibited by gentamicin sulfate (GS). GS does not reduce the expression of DNase, but rather reduces the release of NET-related proteins to protect vascular endothelium by inhibiting DNase activity. MPO and histones synergistically damaged the vascular endothelium, and vascular injury can be improved by their active inhibitors. We further found that H2 O2 is an important substrate for MPO induced vascular damage. In conclusion, in IBD, DNase, and NET levels increased synchronously in the lesion area and released NET-related proteins to damage the vascular endothelium. Therefore, targeting DNase may be beneficial for the treatment of IBD.