Novel microRNA correlations in the severely injured

Extracellular RNA Sensing Mediates Inflammation and Organ Injury in a Murine Model of Polytrauma

Severe traumatic injury leads to marked systemic inflammation and multiorgan injury. Endogenous drivers such as extracellular nucleic acid may play a role in mediating innate immune response and the downstream pathogenesis. Here, we explored the role of plasma extracellular RNA (exRNA) and its sensing mechanism in inflammation and organ injury in a murine model of polytrauma. We found that severe polytrauma-bone fracture, muscle crush injury, and bowel ischemia-induced a marked increase in plasma exRNA, systemic inflammation, and multiorgan injury in mice. Plasma RNA profiling with RNA sequencing in mice and humans revealed a dominant presence of miRNAs and marked differential expression of numerous miRNAs after severe trauma. Plasma exRNA isolated from trauma mice induced a dose-dependent cytokine production in macrophages, which was almost abolished in TLR7-deficient cells but unchanged in TLR3-deficient cells. Moreover, RNase or specific miRNA inhibitors against the selected proinflammatory miRNAs (i.e., miR-7a-5p, miR-142, let-7j, miR-802, and miR-146a-5p) abolished or attenuated trauma plasma exRNA-induced cytokine production, respectively. Bioinformatic analyses of a group of miRNAs based on cytokine readouts revealed that high uridine abundance (>40%) is a reliable predictor in miRNA mimic-induced cytokine and complement production. Finally, compared with the wild-type, TLR7-knockout mice had attenuated plasma cytokine storm and reduced lung and hepatic injury after polytrauma. These data suggest that endogenous plasma exRNA of severely injured mice and ex-miRNAs with high uridine abundance prove to be highly proinflammatory. TLR7 sensing of plasma exRNA and ex-miRNAs activates innate immune responses and plays a role in inflammation and organ injury after trauma.

Biomarkers of endothelial cell dysfunction persist beyond resuscitation in patients with hemorrhagic shock

BACKGROUND

It has been shown that microRNA-19b (miR-19b) binds to and degrades syndecan-1 after hemorrhagic shock (HS) and contributes to endothelial dysfunction in vitro and in vivo. The objective of the current study was to assess longitudinal changes in miR-19b and syndecan-1 in HS patients.

METHODS

Blood samples from HS patients (blood pressure <90 mm Hg and ≥2 U blood) were collected upon admission, completion of hemostasis, and after 24 hours for miR-19b (quantitative reverse transcription PCR) and syndecan-1 (enzyme-linked immunosorbent assay) and compared with controls and minimally injured (Injury Severity Score, ≤9). Inflammatory cytokines were measured (Luminex [Thermo Fisher, Waltham, MA]). Correlations between syndecan-1, miR-19b, inflammatory markers, and patient outcomes were performed. Logistic regression models were developed for outcomes.

RESULTS

Thirty-four HS patients were studied: age, 46 (19-89) years; male, 82%; penetrating, 35%; Injury Severity Score, 24 ± 10; and blood products at 24 hours, 21 ± 19 U. MicroRNA-19b was increased upon arrival and further increased over time: 4.6 → 6.7 → 24.1-fold change compared with 0.1 and 1.2 for minimally injured patients and controls, respectively. Syndecan-1 was increased to 42.6 → 50 → 51.5 ng/mL over time compared with 14.7 and 23.5 for minimally injured and controls, respectively. Values for both biomarkers remained significantly increased through 24 hours and were associated with a persistent increase in inflammatory cytokines. Admission syndecan-1 significantly predicted mortality, coagulopathy, and massive transfusion.

CONCLUSION

We have shown for the first time that miR-19b and syndecan-1 were biomarkers for endothelial dysfunction independent of resuscitation. MicroRNA-19b did not demonstrate a strong correlation with syndecan-1 nor outcomes. Admission syndecan-1, however, remains a strong prognostic marker, but its elevation over time suggests a versatile role following HS that requires further investigation.

LEVEL OF EVIDENCE

Prognostic/Epidemiological; Level II.

The Network of miRNA-mRNA Interactions in Circulating T Cells of Patients Following Major Trauma - A Pilot Study

Purpose

Following major trauma, genes involved in adaptive immunity are downregulated, which accompanies the upregulation of genes involved in systemic inflammatory responses. This study investigated microRNA (miRNA)-mRNA interactome dysregulation in circulating T cells of patients with major trauma.

Patients and Methods

This study included adult trauma patients who had an injury severity score ≥16 and required ventilator support for more than 48 h in the intensive care unit. Next-generation sequencing was used to profile the miRNAs and mRNAs expressed in CD3+ T cells isolated from patient blood samples collected during the injury and recovery stages.

Results

In the 26 studied patients, 9 miRNAs (hsa-miR-16-2-3p, hsa-miR-16-5p, hsa-miR-185-5p, hsa-miR-192-5p, hsa-miR-197-3p, hsa-miR-23a-3p, hsa-miR-26b-5p, hsa-miR-223-3p, and hsa-miR-485-5p) were significantly upregulated, while 58 mRNAs were significantly downregulated in T cells following major trauma. A network consisting of 8 miRNAs and 22 mRNAs interactions was revealed by miRWalk, with three miRNAs (hsa-miR-185-5p, hsa-miR-197-3p, and hsa-miR-485-5p) acting as hub genes that regulate the network. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis suggested that “chemokine signaling pathway” was the predominant pathway.

Conclusion

The study revealed a miRNA-mRNA interactome consisting of 8 miRNAs and 22 mRNAs that are predominantly involved in chemokine signaling in circulating T cells of patients following major trauma.

Exosomes Derived From Heat Stroke Cases Carry miRNAs Associated With Inflammation and Coagulation Cascade

The pathological mechanism underlying heat stroke (HS) is associated with the dysbalanced inflammation and coagulation cascade. Cell-derived circulating extracellular vesicles (EVs), as a novel pathway mediating intercellular communication, are associated with the immune response and inflammation in critical inflammatory syndromes, such as sepsis. Although these vesicles contain genetic material correlated with their biological function, their molecular cargo during HS remains unknown. In this study, we evaluate the presence of microRNAs (miRNAs) and messenger RNAs (mRNAs) associated with inflammatory responses and coagulation cascade in exosomes of patients with HS. Blood samples were collected from three patients with HS at the time of admission to the intensive care unit; three healthy volunteers were selected as control. Exosomes were isolated using ultracentrifugation, and their miRNA content was profiled using next-generation sequencing; mRNA content was evaluated using qPCR array. Compared with those from healthy volunteers, exosomes from patients with HS showed substantial changes in the expression of 202 exosomal miRNAs (154 upregulated and 48 downregulated miRNAs). The most upregulated miRNAs included miR-511-3p, miR-122-5p, miR-155-3p, miR-1290, and let7-5p, whereas the most downregulated ones included miR-150-3p, 146a-5p, and 151a-3p. Gene ontology enrichment of the miRNAs of patients with HS compared with control subjects were associated mostly with inflammatory response, including T cell activation, B cell receptor signaling, dendritic cell chemotaxis and leukocyte migration, and platelet activation and blood coagulation. The identified miRNAs were primarily enriched to the signal transduction pathways namely, T cell receptor signaling, Ras signaling, chemokine signaling, platelet activation, and leukocyte transendothelial migration, all of which are associated with inflammation and hemostasis. Multiple targeted mRNAs associated with the inflammatory response, blood coagulation, and platelet activation were further verified in serum exosomes. Exosomes from patients with HS convey miRNAs and mRNAs associated with pathogenic pathways, including inflammatory response and coagulation cascade. Exosomes may represent a novel mechanism for intercellular communication during HS.

miR-19b targets pulmonary endothelial syndecan-1 following hemorrhagic shock

Hemorrhagic shock results in systemic injury to the endothelium contributing to post-shock morbidity and mortality. The mechanism involves syndecan-1, the backbone of the endothelial glycocalyx. We have shown in a rodent model that lung syndecan-1 mRNA is reduced following hemorrhage, whereas the molecular mechanism underlying the mRNA reduction is not clear. In this study, we present evidence that miR-19b targets syndecan-1 mRNA to downregulate its expression. Our results demonstrate that miR-19b was increased in hemorrhagic shock patients and in-vitro specifically bound to syndecan-1 mRNA and caused its degradation. Further, hypoxia/reoxygenation (H/R), our in vitro hemorrhage model, increased miR-19b expression in human lung microvascular endothelial cells, leading to a decrease in syndecan-1 mRNA and protein. H/R insult and miR-19b mimic overexpression comparably exaggerated permeability and enhanced endothelial barrier breakdown. The detrimental role of miR-19b in inducing endothelial dysfunction was confirmed in vivo. Lungs from mice undergoing hemorrhagic shock exhibited a significant increase in miR-19b and a concomitant decrease in syndecan-1 mRNA. Pretreatment with miR-19b oligo inhibitor significantly decreased lung injury, inflammation, and permeability and improved hemodynamics. These findings suggest that inhibition of miR-19b may be a putative therapeutic avenue for mitigating post shock pulmonary endothelial dysfunction in hemorrhage shock.

Circulating miRNAs Associated With ER Stress and Organ Damage in a Preclinical Model of Trauma Hemorrhagic Shock

Circulating microRNAs (miRNA) alterations have been reported in severe trauma patients but the pathophysiological relevance of these changes is still unclear. miRNAs are critical biologic regulators of pathological events such as hypoxia and inflammation, which are known to induce endoplasmic reticulum (ER) stress. ER stress is emerging as an important process contributing to the development of single and/or multiple organ dysfunction after trauma hemorrhagic shock (THS) accompanied by impaired tissue microcirculation and inflammation. Here, we aim to bring new insights into the involvement of miRNAs associated with ER stress in THS. THS was induced in rats by a median laparotomy and blood withdrawal until mean arterial pressure (MAP) dropped to 30-35 mmHg followed by a restrictive (40 min) and full reperfusion (60 min) with Ringer's solution. Tunicamycin was used to induce ER stress. Blood samples were collected 24 h after THS for the determination of pathological changes in the blood (PCB) and circulating miRNAs. Plasma levels of circulating miRNAs were compared between THS, tunicamycin, and sham groups and correlated to biomarkers of PCB. MiRNA profile of THS animals showed that 40 out of 91 (44%) miRNAs were significantly upregulated compared to sham (p < 0.01). The data showed a very strong correlation between liver injury and miR−122-5p (r = 0.91, p < 0.00001). MiR-638, miR−135a-5p, miR−135b-5p, miR-668-3p, miR-204-5p, miR−146a-5p, miR−200a-3p, miR−17-5p, miR−30a-5p, and miR−214-3p were found positively correlated with lactate (r > 0.7, p < 0.05), and negatively with base excess (r ≤ 0.8, p < 0.05) and bicarbonate (r ≤ 0.8, p < 0.05), which are clinical parameters that reflected the shock severity. Tunicamycin significantly modified the microRNA profile of the animals, 33 out of 91 miRNAs were found differentially expressed. In addition, principal component analysis revealed that THS and tunicamycin induced similar changes in plasma miRNA patterns. Strikingly, the data showed that 15 (25.9%) miRNAs were regulated by both THS and tunicamycin (p < 0.01). This included miR−122-5p, a liver-specific microRNA, but also miR−17-5p and miR-125b-5p which are miRNAs remarkably involved in unfolded protein response (UPR)-mediating pro-survival signaling (IRE1α). Since miRNAs associated with ER stress are clearly correlated with THS, our data strongly suggest that interaction between miRNAs and ER stress is an important pathologic event occurring during THS. Overall, we consider that the miRNA profile developed in this study can provide a rationale for the development of bench-to-bedside strategies that target miRNAs in critical care diseases or be used as biomarkers in the prognosis of trauma patients.

Temporal expression of circulating miRNA after severe injury

BACKGROUND

Severe injury can lead to immune dysfunction and predispose patients to infection and death. Micro-RNAs regulate gene expression and may act as biomarkers for susceptibility to infection. The aim of this study was to examine the temporal and differential expression of previously identified dysregulated micro-RNAs in patients with severe injury.

METHODS

Fourteen severely injured patients requiring transfusion were enrolled prospectively in this study approved by our institutional review board. Inclusion criteria consisted of adult patients deemed clinically to be in hemorrhagic shock necessitating transfusion in the acute phase of their injury care. Peripheral blood samples were obtained after admission to the surgical intensive care unit and again at 6, 12, 24, and 48 hours after admission. The samples obtained at arrival to the intensive care unit and 24 and 48 hours later were analyzed in this data set. Fourteen healthy volunteers served as controls. The 10 dysregulated micro-RNAs identified in a prior study at the 12-hour time point and important genes in innate immunity were measured using quantitative reverse transcription-polymerase chain reaction.

RESULTS

The participants were 21-77 years old (median, 42), 78% were male, and their Injury Severity Score ranged from 11 to 43 (median, 27); 11 had blunt and 3 had penetrating injuries. Three were intubated and 5 had received blood products before arrival at the hospital. Base deficit on hospital admission was 3-20 (median, 9). All patients required blood transfusion secondary to blood loss sustained during injury. Eleven of the 14 patients went directly to the operating room from the emergency department for control of the source of hemorrhage. Survival to discharge was 93%. Seven patients developed infection. Compared with healthy controls, miR-106a was downregulated at all time points compared with controls (P < .05). miR-618 was upregulated in initial blood draws (P < .05) and at 24 and 48 hours (P < .06). Tumor necrosis factor α and human leukocyte antigen-DR (HLA-DR) were downregulated, and interleukin-10 and PD-L1 were upregulated (P < .05). In patients who developed infection, miR-106a levels appeared more downregulated than those who did not develop infection.

CONCLUSION

miR-106a was downregulated in trauma patients after major injury for up to 48 hours after intensive care unit admission. Tumor necrosis factor α and interleukin-10 are targeted by miR-106a, which are regulators of the immune response. Manipulation of micro-RNA expression may be a therapeutic target for immune dysfunction.

Exosomes from patients with septic shock convey miRNAs related to inflammation and cell cycle regulation: new signaling pathways in sepsis?

Background

Exosomes isolated from plasma of patients with sepsis may induce vascular apoptosis and myocardial dysfunction by mechanisms related to inflammation and oxidative stress. Despite previous studies demonstrating that these vesicles contain genetic material related to cellular communication, their molecular cargo during sepsis is relatively unknown. In this study, we evaluated the presence of microRNAs (miRNAs) and messenger RNAs (mRNAs) related to inflammatory response and redox metabolism in exosomes of patients with septic shock.

Methods

Blood samples were collected from 24 patients with septic shock at ICU admission and after 7 days of treatment. Twelve healthy volunteers were used as control subjects. Exosomes were isolated by ultracentrifugation, and their miRNA and mRNA content was evaluated by qRT-PCR array.

Results

As compared with healthy volunteers, exosomes from patients with sepsis had significant changes in 65 exosomal miRNAs. Twenty-eight miRNAs were differentially expressed, both at enrollment and after 7 days, with similar kinetics (18 miRNAs upregulated and 10 downregulated). At enrollment, 35 differentially expressed miRNAs clustered patients with sepsis according to survival. The pathways enriched by the miRNAs of patients with sepsis compared with control subjects were related mostly to inflammatory response. The comparison of miRNAs from patients with sepsis according to hospital survival demonstrated pathways related mostly to cell cycle regulation. At enrollment, sepsis was associated with significant increases in the expression of mRNAs related to redox metabolism (myeloperoxidase, 64-fold; PRDX3, 2.6-fold; SOD2, 2.2-fold) and redox-responsive genes (FOXM1, 21-fold; SELS, 16-fold; GLRX2, 3.4-fold). The expression of myeloperoxidase mRNA remained elevated after 7 days (65-fold).

Conclusions

Exosomes from patients with septic shock convey miRNAs and mRNAs related to pathogenic pathways, including inflammatory response, oxidative stress, and cell cycle regulation. Exosomes may represent a novel mechanism for intercellular communication during sepsis.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2003-3) contains supplementary material, which is available to authorized users.

Use of Circulating and Cellular miRNAs Expression in Forensic Sciences

The current practice in the field of forensic medicine imposes the use of modern investigation techniques. The complexity of laboratory investigation methods needed for a final result of the investigation in forensic medicine needed new biomarkers of higher specificity and selectivity. Such biomarkers are the microRNAs (miRNAs), short, non-coding RNAs composed of 19–24 nucleotides. Their characteristics, such as high stability, selectivity, and specificity for biological fluids, differ from tissue to tissue and for certain pathologies, turning them into the ideal candidate for laboratory techniques used in forensic medicine. In this paper, we wish to highlight the biochemical properties and the usefulness of miRNAs in forensic medicine.

Overexpression of miR-24 Is Involved in the Formation of Hypocoagulation State after Severe Trauma by Inhibiting the Synthesis of Coagulation Factor X

BACKGROUND

Dysregulation of microRNAs may contribute to the progression of trauma-induced coagulopathy (TIC). We aimed to explore the biological function that miRNA-24-3p (miR-24) might have in coagulation factor deficiency after major trauma and TIC.

METHODS

15 healthy volunteers and 36 severe trauma patients (Injury Severity Score ≥ 16 were enrolled. TIC was determined as the initial international normalized ratio >1.5. The miR-24 expression and concentrations of factor X (FX) and factor XII in plasma were measured. In vitro study was conducted on L02 cell line.

RESULTS

The plasma miR-24 expression was significantly elevated by 3.17-fold (P = 0.043) in major trauma patients and reduced after 3 days (P < 0.01). The expression level was significantly higher in TIC than in non-TIC patients (P = 0.040). Multivariate analysis showed that the higher miR-24 expression was associated with TIC. The plasma concentration of FX in TIC patients was significantly lower than in the non-TIC ones (P = 0.030) and controls (P < 0.01). A negative correlation was observed between miR-24 and FX. miR-24 transduction significantly reduced the FX level in the supernatant of L02 cells (P = 0.030).

CONCLUSIONS

miR-24 was overexpressed in major trauma and TIC patients. The negative correlation of miR-24 with FX suggested the possibility that miR-24 might inhibit the synthesis of FX during TIC.

Past, Present, and Future of Augmentation of Monocyte Function in the Surgical Patient

BACKGROUND

Patients who survive the early phases of major sepsis and trauma can have greater susceptibility to nosocomial infection later. One cause may be impaired monocyte function, which can leave the patient at risk of overwhelming sepsis and multi-organ dysfunction. Efforts to target this immune defect have been fraught with challenges, with many questions unanswered. We summarized the past and current and likely future therapeutic approaches to augmentation of monocyte function in the surgical patient.

METHODS

A literature search was conducted using PubMed to determine the evidence to date for immunoadjuvant therapy specifically for monocyte impairment. The search terms were "monocyte," "immunoparalysis," "tolerance," and "deactivation" cross-referenced with "trauma," "major surgery," and "sepsis." We supplemented our search with "interferon-γ," "granulocyte colony-stimulating factor" (G-CSF), and "granulocyte-macrophage colony-stimulating factor" (GM-CSF), known agents used for this purpose. We limited our findings to clinical trials in human beings. Relevant currently registered trials relating to impaired monocyte function also were included.

RESULTS

Interferon-γ appears to be the most commonly studied therapeutic agent to augment monocyte function, followed in decreasing order by GM-CSF and G-CSF. Studies were heterogeneous, generally under-powered, and enrolled few target patients with documented monocyte impairment. Finally, current studies are focusing on personalized therapy in order to treat those with monocyte impairment, with attention to programmed cell death protein 1 (PD-1) and programmed cell death ligand (PD-L1) as both markers and therapeutic targets.

CONCLUSION

Early studies have been promising in identifying patients who are likely to benefit from monocyte augmentation; i.e., those with low HLA-DR or ex-vivo tumor necrosis factor (TNF)-α production. The surgeon remains incompletely equipped to enhance monocyte function consistently and specifically in order to reduce the mortality rate. Although there is little evidence to support the routine use of any of these immunotherapies, the issues of patient selection, timing of administration, and treatment duration have hampered any true answers to this important clinical problem. The challenge remains in identifying the right patients, at the right time, to receive the right therapy.

Epigenetic regulatory pathways involving microRNAs may modulate the host immune response following major trauma

BACKGROUND

Posttraumatic nosocomial pneumonia is a common complication resulting in significant morbidity. Trauma-induced immunocompromise is associated with an enhanced susceptibility to pneumonia. In this study, we explore the hypothesis that posttranscriptional epigenetic regulation of gene expression may be an important factor in determining this immune phenotype. We describe the pattern of production of microRNAss (miRs) and their association with nosocomial pneumonia following severe trauma.

METHODS

A convenience sample of 30 ventilated polytrauma patients (

UKCRN ID

5637) and 16 healthy controls were recruited. Messenger RNA and protein levels of key cytokines were quantified within 2 hours of the injury and at 24 hours. Three miRs per cytokine were then selected based on miRBase target prediction scores and quantified using polymerase chain reaction. Nosocomial pneumonia was defined using the Centers for Disease Control and Prevention definitions.

RESULTS

Median Injury Severity Score (ISS) was 29, and 47% of the patients developed nosocomial pneumonia. miR-125a and miR-202 decreased by 34% and 77%, respectively, immediately following injury, whereas their target, IL-10, increased messenger RNA levels 3-fold and protein levels 180-fold. Tumor necrosis factor α (TNF-α) and IL-12 gene expression decreased by 68% and 43%, respectively, following injury, and this was mirrored by a 10-fold increase in miR-181, an miR predicted to target TNF-α transcripts. Lower levels of miR-125a and miR-374b were associated with the later acquisition of hospital-acquired pneumonia.

CONCLUSION

Alteration in the expression of miRs with highly predicted complementarity to IL-10 and TNF-α may be an important mechanism regulating the posttraumatic immunosuppressive phenotype in intensive care unit patients.

LEVEL OF EVIDENCE

Retrospective observational study, level III.

Direct Peritoneal Resuscitation Alters Hepatic miRNA Expression after Hemorrhagic Shock

BACKGROUND

MicroRNAs (miRNAs) are small segments of noncoding RNA that regulate gene expression and protein function, and therefore are key regulators of cellular processes including those of the inflammatory cascade after hemorrhagic shock (HS). We have previously shown that direct peritoneal resuscitation (DPR), as an adjunct to traditional IV fluid resuscitation, improves visceral blood flow and reduces pro-inflammatory cytokines released during HS. The effects of DPR on hepatic miRNA (miR) expression patterns after resuscitated HS are not known.

STUDY DESIGN

Male Sprague-Dawley rats were divided into 3 groups: sham (no HS); conventional resuscitation (CR; HS, then resuscitated with shed blood and 2 volumes of saline); and DPR (CR plus 30 mL peritoneal dialysis solution). Animals were sacrificed at 4 hours, and miRNAs were measured using reverse transcription polymerase chain reaction.

RESULTS

Use of DPR downregulated 68 of 92 hepatic miRNAs compared with only 2 of 92 upregulated when compared with CR alone, p < 0.01). Specifically, miR-9-5p, miR-122-5p, and miR-146, which regulate NFκB, were downregulated 4.1-, 3.4-, and 0.86-fold, respectively; miR-29a and miR-126 were upregulated 0.88- and 3.7-fold when DPR was compared with CR.

CONCLUSIONS

Adding DPR downregulated most hepatic miRNAs compared with CR alone. Some miRNAs were affected more significantly, suggesting that although this clinical intervention causes a near-global downregulation of hepatic miRNA, it still targets specific inflammatory pathways. Use of DPR for resuscitation of patients in HS may reduce hepatic inflammation to improve patient outcomes after hemorrhage.