Project description:Burn injuries are devastating traumas, often leading to life-long consequences that extend beyond the observable burn scar. Burn injury patients commonly develop chronic neurological disorders but the long-lasting impacts of burn injuries on neurons and glia in the brain is unknown. Whole transcriptome RNA-sequencing from cortical excitatory neurons, inhibitory neurons, astrocytes and microglia showed very few changes to the expression of genes with known functions five weeks following a non-severe burn injury in adult mice. However, genes related to GABA-A receptors in excitatory neurons and several cellular functions in microglia was found to be to differentially expressed in burn injured mice. These findings shed light on the long-term effect of burn injuries on the brain and may help identify potential therapeutic targets and windows to prevent neurological dysfunction in burn patients.
Project description:Severe burn injury is a one of the most devastating forms of trauma with over 1.1 million burns each year requiring medical attention in the United States. Deaths from burn injury are commonly caused by immune-related sequelae such as pneumonia, organ failure and other opportunistic bacterial infections. Though there have been numerous studies to assess the immunological dysfunction associated with burn injury, there have yet to be a predictive biomarker, that can be used to assess high risk patients and their outcomes. We hypothesized that circulating extracellular vesicles (EVs) released early after burn injury would promote activate peripheral macrophages and specific cargo could be used as a biomarker to identify at-risk patients. To test this hypothesis, we assessed the immune consequences of adoptive transfer of EVs isolated after burn injury in vitro and used unbiased proteomic on EVs from mouse models and human burn patients from the UNC Jaycee Burn Center. Findings here suggest EVs serve as mediators of immune dysfunction and potential biomarkers.
Project description:Rationale: Despite shortening vasopressor use in shock, hydrocortisone administration remains controversial, with potential harm on the immune system. Few studies assessed hydrocortisone impact on the transcriptional response in shock, and we are lacking data in burns. Objectives: To assess the hydrocortisone-induced transcriptional modulation in severe burn shock, particularly on the immune response. Methods: We collected whole blood samples (n= 117) during a randomized controlled trial assessing the efficacy of hydrocortisone administration on burn shock. Using whole genome microarrays, we first compared burn patients from the placebo group (n=15) to healthy volunteers (n=13) to describe the transcriptional modulation induced by burn shock over the first week. Then we compared burn patients randomized for either hydrocortisone administration (n=15) or placebo (n=15) to assess hydrocortisone-induced modulation. Measurements and Main Results: Study groups were similar in terms of severity and major outcomes, but shock duration (significantly reduced in the hydrocortisone group). Many genes (n=2250) were differentially expressed between burn patients and healthy volunteers, with 85% of them exhibiting a profound and persistent modulation over seven days. Interestingly, we showed that hydrocortisone enhanced the shock-associated repression of adaptive, but also innate immunity. Conclusions: We found that the initial host response to burn shock encompasses a wide and persistent modulation of gene expression, with profound modulation of pathways associated with metabolism and immunity. Importantly, hydrocortisone administration may worsen the immunosuppression associated with severe injury. These data should be taken into account in the risk ratio of hydrocortisone administration in patients with inflammatory shock.
Project description:Burn injury induces a systemic hyperinflammatory response with detrimental side effects. Studies have described the biochemical changes induced by severe burns, but the transcriptome response is not well characterized. The goal of this work is to characterize the blood transcriptome after burn injury. Burn patients presenting to a regional center between 2012-2017 were prospectively enrolled. Blood was collected on admission and at predetermined time points (hours 2, 4, 8, 12, 24). RNA was isolated and transcript levels were measured with a gene expression microarray. To identify differentially regulated genes (FDR≤0.1) by burn injury severity, patients were grouped by total body surface area (TBSA) above or below 20% and statistically enriched pathways were identified. Sixty-eight patients were analyzed, most patients were male with a median age of 41 (IQR, 30.5-58.5) years, and TBSA of 20% (11-34%). Thirty-five patients had %TBSA injury ≥20%, and this group experienced greater mortality (26% vs. 3%, p=0.008). Comparative analysis of genes from patients with </≥20% TBSA revealed 1505, 613, 380, 63, 1357, and 954 differentially expressed genes at hours 0, 2, 4, 8, 12 and 24 respectively. Pathway analysis revealed an initial upregulation in several immune/inflammatory pathways within the ≥20% TBSA groups followed by shutdown. Severe burn injury is associated with an early proinflammatory immune response followed by shutdown of these pathways. Examination of the immunoinflammatory response to burn injury through differential gene regulation and associated immune pathways by injury severity may identify mechanistic targets for future intervention.
Project description:Blister fluid (BF) is a novel and viable research matrix for burn injury study, which can reflect both systemic and local micro-environmental responses. The protein abundance in BF from different burn severities were initially observed using a 2D SDS-PAGE approach. Subsequently, a quantitative data independent acquisition (DIA) method – SWATHTM was employed to characterize the proteome of pediatric burn blister fluid. More than 600 proteins were quantitatively profiled in 87 BF samples from different pediatric burn patients.
Project description:To understand the age-dependent response to burn injury, blood samples from pediatric and adult patients were collected at different times after severe burn injury. Gene expression was measured using Affymetrix U133 Plus 2.0 arrays for both patient samples and healthy controls. Time points were binned into two groups: early stage for <11 days and middle stage for 11-49 days.
Project description:To understand the age-dependent response to burn injury, blood samples from pediatric and adult patients were collected at different times after severe burn injury. Gene expression was measured using Affymetrix U133 Plus 2.0 arrays for both patient samples and healthy controls. Time points were binned into two groups: early stage for <11 days and middle stage for 11-49 days. 114 arrays for 57 patients (2 time points per patient) and 63 arrays for 63 healthy controls.
Project description:Burn injury remains a major clinical challenge to both survival and to quality of life. Its progressive, aberrant inflammation underlies the lethal dysfunction of various organs and the pain it induces is excruciating and notoriously difficult to manage. While it is known that burn injury’s complex local and disseminating pathology is orchestrated from the burned tissue, few studies have sought to characterise the local signalling environment. An enhanced understanding of the local and acutely temporally-dynamic processes defining burn injury and its progression is required for the development of novel therapeutic interventions. Microdialysis was used as an interstitial sampling technique, conducted over three hours post-burn. Samples were analysed by metabolomics and a multiplex cytokine immunoassay. Next-Generation sequencing libraries of the burn and control microdialysis sites were prepared to measure transcriptional changes potentially underlying the interstitial profile characterising burn injury.
Project description:Tigecycline is a broad-spectrum active intravenous antibiotic that is also active against methicillin-resistant staphylococcus aureus. In Phase 3 and 4 clinical trials, increased all-cause mortality was observed in patients treated with tigecycline compared to patients in the control group. The reason for the increase is not yet clear. In this study, we found tigecycline could cause abnormal coagulation in tumor patients, especially in patients with hematological malignancies. The main manifestations were decreased fibrinogen and prolonged activated prothrombin time (APTT), thrombin time (TT) and D-dimer. In addition, functional studies have found that tigecycline could inhibit platelet adhesion and aggregation, and the patient's coagulation function could gradually recover after discontinuation. Gene sequencing results suggested that tigecycline could significantly regulate the expression of genes related to platelet function pathways, and could increase the incidence of single nucleotide polymorphisms and the number of alternative splices in CHO cells with tigecycline treatment. Abnormal platelet function and low numbers are common in patients with hematological malignancies. Our study could explain the mechanism of abnormal coagulation caused by tigecycline. At the same time, a warning should be given when doctors applied tigecycline to cure infections in tumor patients.