Vascular Surgery Patients with Elevated Neutrophil Lymphocyte Ratios Have Downregulated Neutrophil Complement RNA Expression
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ABSTRACT: Elevated NLR (neutrophil-lymphocyte ratio) in elective vascular surgery (EVS) patients is associated with increased mortality independent of perioperative surgical outcome. To understand why high NLR is associated with higher mortality, we investigated neutrophil and lymphocyte transcriptome expression in patients undergoing EVS.
Project description:This study evaluated the impact of a preoperative carbohydrate oral drink on the postoperative Neutrophil / Lymphocyte Ratio (NLR) and the incidence of postoperative complications after elective open colon surgery compared to the conventional preoperative fasting protocol. Hypothesis was: preoperative carbohydrate loading reduces postoperative NLR value and reduces the incidence and severity of postoperative complications in colorectal surgery.
Project description:During systemic inflammation, different neutrophil subsets are mobilized to the blood circulation. These neutrophil subsets can be distinguished from normal circulating neutrophils (CD16bright/CD62Lbright) based on either an immature CD16dim/CD62Lbright or a CD16bright/CD62Ldim phenotype. Interestingly, the latter neutrophil subset is known to suppress lymphocyte proliferation ex vivo, but the underlying mechanism is largely unknown. We performed transcriptome analysis on the different neutrophil subsets to identify changes that are relevant for their functions. Neutrophil subsets were isolated by FACS sorting from the blood of healthy volunteers who were administered a single dose of lipopolysaccharide (LPS). The transcriptome was determined by microarray. The mobilized neutrophil subsets were characterized by specific transcriptome profiles reflecting their phase in neutrophil lifespan. Interestingly, the CD16bright/CD62Ldim suppressive neutrophils showed an interferon-induced transcriptome profile. This was confirmed by stimulation of peripheral neutrophils with IFNgamma. These cells acquired the capacity to suppress lymphocyte proliferation through the expression of programmed death ligand 1 (PD-L1). These data demonstrate that the suppressive phenotype of the neutrophil subset is induced by IFNgamma. Specific stimulation of neutrophils might have a pivotal role in regulating lymphocyte-mediated inflammation and autoimmune disease. After LPS infusion, blood was taken at t=0 and t=4 hours. Neutrophils were FACS sorted based on CD16 and CD62L expression. Gene expression of neutrophil subsets was assessed relative to t=0 as control.
Project description:Elevated neutrophil-to-lymphocyte ratio (NLR) in patients who undergo elective vascular surgery (EVS) have increased mortality independent of perioperative surgical outcome. To understand why high NLR is associated with higher mortality, we investigated neutrophil and lymphocyte transcriptome expression in patients undergoing EVS. Blood samples were collected from patients undergoing EVS and healthy donors for NLR calculation. RNA samples were isolated from patients' neutrophils and lymphocytes and divided into NLR_Low (<3) and NLR_High (≥3) groups (n = 6 each). Paired samples with the highest RNA integrity number (mean = 9.8 ± 0.4) were sequenced and analyzed for differential expression. Normalized data were inputted for downstream analysis using iPathwayGuide (AdvaitaBio) and gene set enrichment analysis using GenePattern and MSigDB (Broad Institute). There was no clinical difference between the patient groups with regard to clinical diagnosis, age, sex, history of hypertension, lipid abnormalities, diabetes mellitus, smoking, or statin use. The mean NLR was 4.37 ± 0.27 SEM in the NLR_High and 1.88 ± 0.16 for the NLR_Low groups. Significantly differentially expressed gene sets identified in the RNA sequence data were enriched highly (P = 1E-24) in the humoral immunity and complement systems. Neutrophils from NLR_High patients downregulated complement genes (C1QA, C1QB, C1QC, C1S, C2, CR2, C3AR1, C3, C8G, and C9 and complement regulatory genes CD59, SERPING1, C4BPA, CFH, and CFI). Downregulation of gene expressions of humoral immunity and complement within the neutrophils are associated with elevated NLR. It remains to be determined whether and how these changes contribute to increased late mortality previously observed in patients undergoing EVS.
Project description:During systemic inflammation, different neutrophil subsets are mobilized to the blood circulation. These neutrophil subsets can be distinguished from normal circulating neutrophils (CD16bright/CD62Lbright) based on either an immature CD16dim/CD62Lbright or a CD16bright/CD62Ldim phenotype. Interestingly, the latter neutrophil subset is known to suppress lymphocyte proliferation ex vivo, but the underlying mechanism is largely unknown. We performed transcriptome analysis on the different neutrophil subsets to identify changes that are relevant for their functions. Neutrophil subsets were isolated by FACS sorting from the blood of healthy volunteers who were administered a single dose of lipopolysaccharide (LPS). The transcriptome was determined by microarray. The mobilized neutrophil subsets were characterized by specific transcriptome profiles reflecting their phase in neutrophil lifespan. Interestingly, the CD16bright/CD62Ldim suppressive neutrophils showed an interferon-induced transcriptome profile. This was confirmed by stimulation of peripheral neutrophils with IFNgamma. These cells acquired the capacity to suppress lymphocyte proliferation through the expression of programmed death ligand 1 (PD-L1). These data demonstrate that the suppressive phenotype of the neutrophil subset is induced by IFNgamma. Specific stimulation of neutrophils might have a pivotal role in regulating lymphocyte-mediated inflammation and autoimmune disease.
Project description:Colorectal cancer (CRC) is the second leading cause of cancer-related death in the Western world. Overall survival (OS) remains poor, with 50% estimated 5-year survival. In Italy, current estimates indicate that in 2020 a number of 43.700 patients have been affected by colorectal cancer, with an increasing of diagnosed cases in both men and women. It is clear that it is worthwhile to investigate the evaluation of colorectal cancer which could reflect a different spread of screening programs or be the effect of different timing in the start of the programs themselves. To improve the overall survival of colorectal cancer patients, robust biomarkers for screening and predicting disease recurrence could help identify high-risk patients, facilitate a close patient follow-up, and decide appropriate treatment regimens during the postoperative care. Colonoscopy remains the most efficient method for detecting CRC, yet its general application in the setting of screening is limited due to the uncomfortable experience and the high costs. accumulating studies have revealed the potential of systemic inflammatory markers such as C-reactive protein (CRP), albumin, neutrophils, platelets, and lymphocytes, and also biomarker combination ratios [(eg, CRP-albumin ratio (CAR), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR)] as prognostic biomarkers in different cancers, including CRC. Chronic inflammation affects all stages of tumor development. Several studies have shown that various preoperative markers reflecting systemic inflammatory response, including NLR and CRP ratio, offer predictive potential for postoperative morbidity and mortality in CRC patients. However, several issues require addressing prior to the adoption of these inflammatory markers in the clinical practice for CRC patients undergoing surgery: a) the combination of inflammatory factors that might be best in predicting oncological outcomes in colorectal cancer patients remains unclear; b) previous studies for systemic inflammatory markers have mainly interrogated their prognostic potential for oncological outcomes but have not laid emphasis for evaluating their predictive value for postoperative complications; c) there is a lack of consensus on the cut-off thresholds used for each marker for determining mortality risk resulting from surgical and oncological outcomes.
Project description:Sterile tissue injury after stroke causes lymphocyte contraction in lymphoid tissues and may decrease circulating IgA-levels. Intestinal Peyer’s patches (PP) harbor large numbers of IgA+ B cell precursors and plasma cells. Whether and how tissue injury triggers PP-B cell death, thereby mediating IgA-loss, is unknown. We found decreased circulating IgA levels in stroke and myocardial infarction patients. Experimental stroke and myocardial infarction in mice phenocopied the human situation. Decreased plasma and fecal IgA were accompanied by rapid and macroscopic shrinkage of PP caused by substantial losses of PP-resident IgA+ precursors and plasma cells in mice. Tissue injury induced neutrophil activation endowed with the release of toxic neutrophil extracellular traps (NETs). Antibody-mediated or genetically- induced neutrophil loss, digestion of NETs, or inhibition of their release by the Gasdermin D blockade completely prevented lymphocyte loss and PP shrinkage. We also identified NETs in the plasma of stroke and myocardial infarction patients. Hence, tissue injury induces systemic NET-release, which might be targeted to maintain immune homeostasis at mucosal barriers.
Project description:Neutrophil extracellular vesicles (EVs) are known to play a protective role in arthritic joints by suppressing inflammation and cartilage degeneration. In the current study, we investigated the functional characteristics of EVs derived from stimulated neutrophils and their protective effects in cartilage repair in vitro. We first optimized the stimulation conditions of neutrophils that led to production of EVs with chondroprotective function. To understand this protective mechanism, EVs from TGF-β-stimulated neutrophils were added to stimulated chondrocytes with IL-1β, and their responses were examined by bulk-RNA analysis.
Project description:Neutrophil extracellular vesicles (EVs) are known to play a protective role in arthritic joints by suppressing inflammation and cartilage degeneration. In the current study, we investigated the functional characteristics of EVs derived from stimulated neutrophils and their protective effects in cartilage repair in vitro. We first optimized the stimulation conditions of neutrophils that led to production of EVs with chondroprotective function. To understand this protective mechanism, EVs from TGF-β-stimulated neutrophils were added to stimulated chondrocytes with IL-1β, and their responses were examined by bulk-RNA analysis.