Impact of STAT/SOCS mRNA expression levels after major injury

Identification of Immune-Related Genes Concurrently Involved in Critical Illnesses Across Different Etiologies: A Data-Driven Analysis

Severe trauma and sepsis can lead to multiple organ dysfunction syndrome, which is a leading cause of death in intensive care units with mortality rates in excess of 50%. In addition to infection, the degree of immuno-inflammatory response also influences the outcome. The genomic changes observed after a variety of pathophysiological insults, such as trauma, sepsis, burns are similar, and consist of innate immune activation and adaptive immunity suppression. However, the characteristics of the shared mechanisms of aforementioned critical illnesses and the clinical relevance remain less explored. In the present study, we performed a data analysis to identify functional genes concurrently involved in critical illnesses across differing etiologies (trauma and sepsis derived from community-acquired pneumonia/abdominal source) and explored the shared signaling pathways these common genes involved in to gain insight into the underlying molecular mechanisms. A number of immune-related biological functions were found to be dysregulated in both trauma and sepsis in the present study, so we continued to identify immune-related common genes, profiled the immune cell proportion, and explored the relationships between them. The diagnostic and prognostic value of the immune-related common genes was also evaluated to address their potential clinical utilization as novel biomarkers. Notably, we identified a list of 14 immune-related genes concurrently dysregulated in trauma and sepsis showing favorable diagnostic value, among which S100P can predict prognosis of sepsis patients. Moreover, a spectrum of immune cell subsets including naïve B cells, CD8+ T cells, CD4+ memory resting T cells, activated NK cells, resting dendritic cells, plasma cells, Tregs, macrophages M0 and macrophages M1 was found to be concurrently dysregulated in both trauma and sepsis, and a close relation between above identified immune-related genes and immune cell subsets was observed. Our data-driven findings lay a foundation for future research to elucidate the pathophysiology regarding the aspect of inflammatory and immune response in critical illnesses, and suggest future studies focus on interpreting the function roles of the identified immune-related genes, as well as the reactive immune cell subsets.

Neutrophil extracellular traps contribute to immune dysregulation in bullous pemphigoid via inducing B-cell differentiation and antibody production

Bullous pemphigoid (BP), an autoimmune skin disease, is characterized by autoantibodies against hemidesmosomal proteins in the skin and mucous membranes. Neutrophils infiltrate BP skin lesions, however, their role in immune dysregulation remains unclear. We investigated whether BP involves aberrant neutrophil extracellular traps (NETs) formation in skin lesions and circulation; and examined the triggers and deleterious immuno-inflammatory consequences. In the present study, we found that circulating NET-related biomarker levels increased in serum and blister fluid of BP patients and significantly correlated with disease severity. Additionally, circulating neutrophils from BP patients displayed enhanced spontaneous NETs formation than healthy controls. In vitro, BP180-NC16A immune complexes-induced NETosis in neutrophils from BP patients, which was abrogated by Fcγ receptor and/or NADPH pathway blockade. Furthermore, the elevated levels of NETs from BP patients boosted autoantibody production by inducing B-cell differentiation into plasma cells, mediated by MAPK P38 cascade activation. Together, our findings provide strong evidence that NETs are involved in a pathogenic loop, causing excessive differentiation of B cells and promotion of autoantibody production. Hence, targeting aberrant neutrophil responses will provide novel potential targets for the treatment of BP.

Genetic contribution of suppressor of cytokine signalling polymorphisms to the susceptibility to infection after traumatic injury

Suppressor of cytokine signalling (SOCS) proteins are crucial negative regulators in many signalling pathways and are implicated in the pathogenesis of infectious diseases. The purpose of this study was to uncover possible associations of common polymorphisms within SOCS genes with infectious outcomes after traumatic injury. A total of 1087 trauma patients (Chongqing cohort 806 and Yunnan cohort 281) were recruited and followed-up for the development of infectious outcomes, such as sepsis and multiple organ dysfunction syndrome (MODS). Twelve selected single nucleotide polymorphisms (SNPs) were screened by pyrosequencing to determine their genotypes and associations with infectious complications. Among the 12 selected SNPs, only the cytokine-inducible Src homology (SH2) domain protein (CISH) promoter rs414171 polymorphism was found consistently to be associated statistically with the incidence of sepsis and MOD score in the two cohorts, despite analysing the SNPs independently or in combination. Further, patients with a T allele had significantly lower CISH expression and lower production of tumour necrosis factor (TNF)-α, but higher production of interleukin (IL)-10. Luciferase assay confirmed that the A→T variant in the rs414171 polymorphism inhibited the transcriptional activities of the CISH gene significantly. The CISH rs414171 polymorphism is associated significantly with susceptibility to sepsis and MODS in traumatic patients, which might prove to be a novel biomarker for indicating risk of infectious outcomes in critically injured patients.

Interleukin-6 and interleukin-10 plasma levels and mRNA expression in polytrauma patients

PURPOSE

Host response to polytrauma occasionally has unpredictable outcomes. Immune response is a major factor influencing patient's outcome. This study evaluated the interaction of two main cytokines in immune response after major trauma, specifically interleukin-6 (IL-6) and interleukin-10 (IL-10). Plasma level of these cytokines is determined by mRNA expression of these cytokines genes which may decide the outcome of polytrauma patients.

METHODS

This prospective multicenter trial held at four trauma centers enrolled 54 polytrauma patients [Injury Severity Score (ISS) ≥ 16]. Plasma levels and mRNA expression of IL-6 and IL-10 were measured for 5 days after trauma. Clinical evaluation was conducted to observe whether patients endured multiple organ dysfunction syndrome (MODS) and death. MODS evaluation was performed using sequential organ failure assessment (SOFA). Trauma load which in this study is represented with ISS, plasma level, expression of cytokine genes and patient's outcome were examined with correlation test and statistical analysis.

RESULTS

The elevated IL-6/IL-10 ratio indicated increased activity of systemic inflammation response, especially pro-inflammation response which bears higher probability of progressing to MODS and death. The decline of IL-6/IL-10 ratio with heavy trauma load (ISS > 30) showed that compensatory anti-inflammation response syndrome (CARS) state was more dominant than systemic inflammatory response syndrome (SIRS), indicating that malfunction and failure of immune system eventually lead to MODS and deaths. The statistical significance in plasma level of cytokines was found in the outcome group which was defined as bearing a low trauma load but mortality.

CONCLUSION

The pattern of cytokine levels in inflammation response has great impact on the outcome of polytrauma patients. Further study at the genetic level is needed to investigate inflammation process which may influence patient's outcome.