Transcriptome modulation by hydrocortisone in severe burn shock: ancillary analysis of a prospective randomized trial

Differential benefits of steroid therapies in adults following major burn injury

BACKGROUND

Major thermal injury induces a complex pathophysiological state characterized by burn shock and hypercatabolism. Steroids are used to modulate these post-injury responses. However, the effects of steroids on acute post-burn outcomes remain unclear.

METHODS

In this study of 52 thermally injured adult patients (median total burn surface area 42%, 33 males and 19 females), the effects of corticosteroid and oxandrolone on mortality, multi-organ failure (MOF), and sepsis were assessed individually. Clinical data were collected at days 1, 3, 7, and 14 post-injury.

RESULTS

Twenty-two (42%) and 34 (65%) burns patients received corticosteroids and oxandrolone within the same cohort, respectively. Following separate analysis for each steroid, corticosteroid use was associated with increased odds of in-hospital mortality (OR 3.25, 95% CI: 1.32-8•00), MOF (OR 2.36, 95% CI: 1.00-1.55), and sepsis (OR 5.95, 95% CI: 2.53-14.00). Days alive (HR 0.32, 95% CI: 0.18-0.60) and sepsis-free days (HR 0.54, 95% CI: 0.37-0.80) were lower among corticosteroid-treated patients. Oxandrolone use was associated with reduced odds of 28-day mortality (OR 0.11, 95% CI: 0.04-0.30), in-hospital mortality (OR 0.19, 95% CI: 0.08-0.43), and sepsis (OR 0.24, 95% CI: 0.08-0.69). Days alive, at 28 days (HR 6.42, 95% CI: 2.77-14.9) and in-hospital (HR 3.30, 95% CI: 1.93-5.63), were higher among the oxandrolone-treated group. However, oxandrolone was associated with increased MOF odds (OR 7.90, 95% CI: 2.89-21.60) and reduced MOF-free days (HR 0.23, 95% CI: 0.11-0.50).

CONCLUSION

Steroid therapies following major thermal injury may significantly affect patient prognosis. Oxandrolone was associated with better outcomes except for MOF. Adverse effects of corticosteroids and oxandrolone should be considered when managing burn patients.

Gene Expression Scoring of Immune Activity Levels for Precision Use of Hydrocortisone in Vasodilatory Shock

PURPOSE

Among patients with vasodilatory shock, gene expression scores may identify different immune states. We aimed to test whether such scores are robust in identifying patients' immune state and predicting response to hydrocortisone treatment in vasodilatory shock.

MATERIALS AND METHODS

We selected genes to generate continuous scores to define previously established subclasses of sepsis. We used these scores to identify a patient's immune state. We evaluated the potential for these states to assess the differential effect of hydrocortisone in two randomized clinical trials of hydrocortisone versus placebo in vasodilatory shock.

RESULTS

We initially identified genes associated with immune-adaptive, immune-innate, immune-coagulant functions. From these genes, 15 were most relevant to generate expression scores related to each of the functions. These scores were used to identify patients as immune-adaptive prevalent (IA-P) and immune-innate prevalent (IN-P). In IA-P patients, hydrocortisone therapy increased 28-day mortality in both trials (43.3% vs 14.7%, P = 0.028) and (57.1% vs 0.0%, P = 0.99). In IN-P patients, this effect was numerically reversed.

CONCLUSIONS

Gene expression scores identified the immune state of vasodilatory shock patients, one of which (IA-P) identified those who may be harmed by hydrocortisone. Gene expression scores may help advance the field of personalized medicine.

CD14 Involvement in Third-degree Skin Burn-induced Myocardial Injury via the MAPK Signaling Pathway

This study investigated the potential genes and related pathways in burn-induced myocardial injury. Rat myocardial injury induced by third-degree burn and the histopathological structures, apoptosis, and cardiac injury markers were then identified using hematoxylin & eosin staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining, and enzyme-linked immunosorbent assay. Next, differentially expressed mRNAs were screened through next-generation sequencing (NGS), followed by functional annotation and key gene validation through quantitative reverse transcription-polymerase chain reaction. Subsequently, CD14 was screened out, and small interfering RNAs against CD14 were transfected to H9C2 cells to further verify the role of CD14 in burn-induced injury. The results showed that third-degree burn could markedly damage the structure of myocardial tissue, induce the apoptosis of myocardial cells, and increase the levels of myocardial injury-related markers, suggesting that burns could induce myocardial injury in rats. Besides, NGS data discovered that third-degree burn could result in 416 differentially upregulated mRNAs and 285 differentially downregulated mRNAs in myocardial tissue. It was also disclosed that differentially expressed mRNAs were mainly enriched in the phosphatidylinositol 3-kinase/Akt, mitogen-activated protein kinase (MAPK), and tumor necrosis factor signaling pathways. Furthermore, cell viability was significantly decreased in H9C2 cells treated with 10% rat burn serum. CD14 was significantly differentially expressed and screened out for further studies. Treatment with burn serum can significantly upregulate the phosphorylation level of extracellular signal-regulated kinase, p38, and c-Jun N-terminal kinase and the expression of cleaved caspase-3 and downregulate the expression of Bcl2 when compared with those in negative control of small interfering RNA transfected H9C2 cells, whereas interfering with CD14 expression reversed the effects of burn serum. The study demonstrated that burn serum treatment could activate the MAPK signaling pathway to promote cell apoptosis, and it can be reversed by interfering with the expression of CD14.

Comparison of machine-learning methodologies for accurate diagnosis of sepsis using microarray gene expression data

We investigate the feasibility of molecular-level sample classification of sepsis using microarray gene expression data merged by in silico meta-analysis. Publicly available data series were extracted from NCBI Gene Expression Omnibus and EMBL-EBI ArrayExpress to create a comprehensive meta-analysis microarray expression set (meta-expression set). Measurements had to be obtained via microarray-technique from whole blood samples of adult or pediatric patients with sepsis diagnosed based on international consensus definition immediately after admission to the intensive care unit. We aggregate trauma patients, systemic inflammatory response syndrome (SIRS) patients, and healthy controls in a non-septic entity. Differential expression (DE) analysis is compared with machine-learning-based solutions like decision tree (DT), random forest (RF), support vector machine (SVM), and deep-learning neural networks (DNNs). We evaluated classifier training and discrimination performance in 100 independent iterations. To test diagnostic resilience, we gradually degraded expression data in multiple levels. Clustering of expression values based on DE genes results in partial identification of sepsis samples. In contrast, RF, SVM, and DNN provide excellent diagnostic performance measured in terms of accuracy and area under the curve (>0.96 and >0.99, respectively). We prove DNNs as the most resilient methodology, virtually unaffected by targeted removal of DE genes. By surpassing most other published solutions, the presented approach substantially augments current diagnostic capability in intensive care medicine.

Identification of Key Genes Associated with Changes in the Host Response to Severe Burn Shock: A Bioinformatics Analysis with Data from the Gene Expression Omnibus (GEO) Database

Background

Patients with severe burns continue to display a high mortality rate during the initial shock period. The precise molecular mechanism underlying the change in host response during severe burn shock remains unknown. This study aimed to identify key genes leading to the change in host response during burn shock.

Methods

The GSE77791 dataset, which was utilized in a previous study that compared hydrocortisone administration to placebo (NaCl 0.9%) in the inflammatory reaction of severe burn shock, was downloaded from the Gene Expression Omnibus (GEO) database and analyzed to identify the differentially expressed genes (DEGs). Functional enrichment analyses of Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were performed. The protein–protein interaction (PPI) network of DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database and then visualized in Cytoscape. In addition, important modules in this network were selected using the Molecular Complex Detection (MCODE) algorithm, and hub genes were identified in cytoHubba, a Cytoscape plugin.

Results

A total of 1059 DEGs (508 downregulated genes and 551 upregulated genes) were identified from the dataset. The DEGs enriched in GO terms and KEGG pathways were related to immune response. The PPI network contained 439 nodes and 2430 protein pairs. Finally, important modules and hub genes were identified using the different Cytoscape plugins. The key genes in burn shock were identified as arginase 1 (ARG1), cytoskeleton-associated protein (CKAP4), complement C3a receptor (C3AR1), neutrophil elastase (ELANE), gamma-glutamyl hydrolase (GGH), orosomucoid (ORM1), and quiescin sulfhydryl (QSOX1).

Conclusion

The DEGs, functional terms and pathways, and hub genes identified in the present study can help shed light on the molecular mechanism underlying the changes in host response during burn shock and provide potential targets for early detection and treatment of burn shock.

Endogenous Retroviruses Transcriptional Modulation After Severe Infection, Trauma and Burn

Although human endogenous retroviruses (HERVs) expression is a growing subject of interest, no study focused before on specific endogenous retroviruses loci activation in severely injured patients. Yet, HERV reactivation is observed in immunity compromised settings like some cancers and auto-immune diseases. Our objective was to assess the transcriptional modulation of HERVs in burn, trauma and septic shock patients. We analyzed HERV transcriptome with microarray data from whole blood samples of a burn cohort (n = 30), a trauma cohort (n = 105) and 2 septic shock cohorts (n = 28, n = 51), and healthy volunteers (HV, n = 60). We described expression of the 337 probesets targeting HERV from U133 plus 2.0 microarray in each dataset and then we compared HERVs transcriptional modulation of patients compared to healthy volunteers. Although all 4 cohorts contained critically ill patients, the majority of the 337 HERVs was not expressed (around 74% in mean). Each cohort had differentially expressed probesets in patients compared to HV (from 19 to 46). Strikingly, 5 HERVs were in common in all types of severely injured patients, with 4 being up-modulated in patients. We highlighted co-expressed profiles between HERV and nearby CD55 and CD300LF genes as well as autonomous HERV expression. We suggest an inflammatory-specific HERV transcriptional response, and importantly, we introduce that the HERVs close to immunity-related genes might have a role on its expression.