Septic shock in advanced age: Transcriptome analysis reveals altered molecular signatures in neutrophil granulocytes
Ontology highlight
ABSTRACT: Transcriptional profiling of granulocytes from 24 subjects was used to investigate their differences regarding sepsis and aging. Two-colour hybridization design. Aliquots of total RNA isolated from adult or elder individuals with sepsis or healthy controls were labeled with Cy3 and co-hybridized with a common reference RNA pool (Universal Human Reference RNA, Agilent, cat #740000) labeled with Cy5 . Biological replicates:6 per group. No technical replicates.
Project description:Timely and reliable distinction of non-infectious systemic inflammatory response syndrome (SIRS), common in critically ill patients, from sepsis to support adequate antimicrobial therapy safes lives but is clinically challenging. Expeditious sepsis biomarkers are thus urgently sought. Blood transcriptional profiling provides insights into sepsis pathophysiology, but variability in leukocyte subtype composition complicates profile interpretation, and reliable reference genes to normalize gene expression in sepsis are lacking. Here, we identified AKIRIN1 as a reference gene, specifically, in peripheral NK cells and granulocytes for differential gene expression analysis between patients with SIRS and septic shock on intensive care unit admission. Discovery by a two-step probabilistic selection from microarray data followed by validation through branched DNA assays in independent patients revealed several candidate reference genes in NK cells, namely, AKIRIN1, PPP6R3, TAX1BP1, and ADRBK1. For in vitro priming of NK cells, GUSB however was confirmed as reference gene of choice. Initially, no candidate genes could be validated in granulocytes, an additional rescreen of known reference genes by RT-PCR included. By serendipity, we could determine equal AKIRIN1 expression levels also in SIRS and septic shock granulocytes and no change by in vitro challenge of granulocytes with LPS. Inspection of four external neutrophil transcriptome datasets further support unchanged AKIRIN1 expression in human systemic inflammation. Invariable AKIRIN1 expression in peripheral NK cells and granulocytes needs further validation in sepsis and other infectious and inflammatory diseases. As a reference gene in these cells and conditions, AKIRIN1 may further our understanding of innate immunity and lead to new biomarkers.
Project description:Timely and reliable distinction of non-infectious systemic inflammatory response syndrome (SIRS), common in critically ill patients, from sepsis to support adequate antimicrobial therapy safes lives but is clinically challenging. Expeditious sepsis biomarkers are thus urgently sought. Blood transcriptional profiling provides insights into sepsis pathophysiology, but variability in leukocyte subtype composition complicates profile interpretation, and reliable reference genes to normalize gene expression in sepsis are lacking. Here, we identified AKIRIN1 as a reference gene, specifically, in peripheral NK cells and granulocytes for differential gene expression analysis between patients with SIRS and septic shock on intensive care unit admission. Discovery by a two-step probabilistic selection from microarray data followed by validation through branched DNA assays in independent patients revealed several candidate reference genes in NK cells, namely, AKIRIN1, PPP6R3, TAX1BP1, and ADRBK1. For in vitro priming of NK cells, GUSB however was confirmed as reference gene of choice. Initially, no candidate genes could be validated in granulocytes, an additional rescreen of known reference genes by RT-PCR included. By serendipity, we could determine equal AKIRIN1 expression levels also in SIRS and septic shock granulocytes and no change by in vitro challenge of granulocytes with LPS. Inspection of four external neutrophil transcriptome datasets further support unchanged AKIRIN1 expression in human systemic inflammation. Invariable AKIRIN1 expression in peripheral NK cells and granulocytes needs further validation in sepsis and other infectious and inflammatory diseases. As a reference gene in these cells and conditions, AKIRIN1 may further our understanding of innate immunity and lead to new biomarkers.
Project description:Sepsis is defined as a systemic inflammatory response secondary to a proven or suspected infection. Mechanisms governing this inflammatory response have been shown to be complex and dynamic, involving cross-talking among diverse signaling pathways. However, current knowledge on mechanisms underlying sepsis is far from providing a complete picture of the syndrome, justifying additional efforts that might add to this scenario. Microarray-based expression profiling is a powerful approach for the investigation of complex clinical conditions such as sepsis: the analysis of gene transcription at the genome level potentially avoids results derived from biased assumptions. In this study we investigate whole-genome gene expression profiles of mononuclear cells from survivor and non-survivor septic patients. Blood samples were collected at the time of sepsis diagnosis and seven days later, allowing us to evaluate the role of biological processes or genes possibly involved in patient recovery. Aiming to circumvent, at least partially, the heterogeneity of septic patients we included only patients admitted with sepsis caused by community-acquired pneumonia. Global gene expression profiling allowed us to characterize early sepsis, as compared to healthy individuals. Our results corroborate literature reports on inflammation response in the early stages of sepsis but highlight great heterogeneity in gene expression during sepsis progress. Additionally, global gene expression in the early stage was also able to distinguish sepsis from septic shock and correlated with patient outcome. Differences in oxidative stress seem to be associated with clinical outcome, since significant differences in the expression profile of related genes were observed between survivors and non-survivors at the time of patient enrollment (early sepsis). However, our results substantiate current knowledge supporting that sepsis syndrome development is indeed multifaceted. Although the initial infection of enrolled patients was pneumonia, seven days later gene expression profiles seemed to be characteristic of each patient, common gene expression changes distinguishing survivors from non-survivors. This result could be associated with the underlying health status of each one of them, with complications due to sepsis itself as well as with distinct timing for response to treatment. In this study we investigate whole-genome gene expression profiles of mononuclear cells from survivor (n=5) and non-survivor (n=5) septic patients, as well as from 3 healthy controls. Blood samples were collected at the time of sepsis diagnosis and seven days later, allowing us to evaluate the role of biological processes or genes possibly involved in patient recovery. Aiming to circumvent, at least partially, the heterogeneity of septic patients we included only patients admitted with sepsis caused by community-acquired pneumonia.
Project description:Septic cardiac dysfunction is a key feature of severe sepsis and septic shock, contributing to multiorgan dysfunction syndrome and death. It has been established that persistent beta adrenergic stimulation is detrimental in sepsis, and that specific beta 1 blockade mitigates excessive systemic inflammation and improves myocardial function. The aim of this study was to investigate the effects of specific beta 1 blocker esmolol on septic mouse myocardium by genomic and proteomic techniques. We also evaluated survival of septic mice and systemic inflammation under esmolol treatment. C57BL/6 mice were rendered septic by 2 models: cecal ligature and perforation (CLP) and intraperitoneal injection of lipopolysaccharides (LPS). Effects of esmolol on myocardium were assessed by microarray technique. Total RNA were isolated and purified from a 30mg sample of the heart of 6 groups of 8 animals, depending on the sepsis model and the treatment. The labeled cDNA from the treated animals were hybridized against the labeled cDNA from the untreated animals with 2 dye-swaps done for each sepsis model.
Project description:Normal children, children with SIRS, children with sepsis, and children with septic shock. Objectives: To advance our biological understanding of pediatric septic shock, we measured the genome-level expression profiles of critically ill children representing the systemic inflammatory response syndrome (SIRS), sepsis, and septic shock spectrum. Experiment Overall Design: Prospective observational study involving microarray-based bioinformatics.
Project description:Patients with severe sepsis are often associated with thrombocytopenia. This study comprehensively analyzes gene expression in platelets of patients with sepsis to explore the mechanisms by which septic patients develop thrombocytopenia.
Project description:Sepsis is a life-threatening condition caused by a dysregulated immune response to infection, leading to organ failure. Despite its significant global burden, the underlying mechanisms of immune dysfunction in sepsis remain incompletely understood. This study explores the role of DNA methylation in white blood cells in sepsis pathogenesis by assessing a prospective case-control study comparing DNA methylation profiles between patients with community-acquired sepsis and matched controls with similar infections who did not develop sepsis. Blood samples were collected within 24 hours of hospital admission, and DNA methylation was analyzed using Illumina MethylationEPIC 850 v2 arrays and bisulfite pyrosequencing. The discovery cohort (n=32) identified 4,640 differentially methylated positions (DMPs), with notable hypomethylation in immune-related genes. Functional enrichment analysis revealed significant involvement of these genes in immune processes, including neutrophil activation and monocyte differentiation. Key findings highlighted hypomethylation of SERPINA1, AZU1, MPO, and SLX4, which was validated in an independent cohort (n=28). Correlation analyses demonstrated significant associations between the methylation levels of these genes and clinical severity markers, such as SOFA score and procalcitonin levels. Notably, SLX4 hypomethylation showed the highest predictive value for poor prognosis (AUC 0.821), while SERPINA1 hypomethylation exhibited strong diagnostic potential for sepsis (AUC 0.858). Our findings suggest that DNA methylation changes, particularly in immune-related genes, could serve as valuable biomarkers for diagnosing sepsis and predicting patient outcomes. Further research is warranted to confirm their clinical utility and explore potential therapeutic targets.
Project description:PCT concentration in the bloodstream correlates well with sepsis presence and in severe cases increases up to a thousand times from the healthy physiological values in a short time. In this study, we developed a rapid technique for PCT detection by MALDI-MS, that uses in-situ enrichment directly on the specialized immuno MALDI chips that are utilized directly as MALDI plates. The method’s ability to detect PCT was confirmed by comparing the results with LC-MS bottom-up workflow.
Project description:Nowadays, sepsis and septic shock have become major public health problems, which are the main cause of death among patients admitted to the intensive care units. Notably, myocardial dysfunction during sepsis, usually called sepsis-induced myocardial depression, is common in septic shock patients whose incidence is about 70% and leads to a high mortality. However, the mechanism underlying the septic myocardial depression is still unclear. Recently, proteomics has become a powerful method for explore protein dynamics and their complex regulatory mechanism, and thus generates a profound impact on precision medicine and the clinical setting. Importantly, the expression patterns of global proteins in heart tissue between sepsis and control group remain unclear. Therefore, we performed the rat models of sepsis-induced myocardial depression and investigated global protein expression profiles in heart tissue between sepsis and control group using 4D label-free proteomic technique.