Search

Despite advancements in critical care and resuscitation, traumatic injuries are one of the leading causes of death around the world and can bring about long-term disabilities in survivors. One of the primary causes of death for trauma patients are secondary phase complications that can develop weeks or months after the initial insult. These secondary complications typically occur due to systemic immune dysfunction that develops in response to injury which can lead to immunosuppression, coagulopathy, multiple organ failure, unregulated inflammation, and potentially sepsis in patients. Recently, extracellular vesicles (EVs) have been identified as mediators of these processes since their levels are increased in circulation after traumatic injury and they encapsulate cargo that can aggravate secondary complications. In this review, we will discuss the role of EVs in the post-trauma pathologies that arise after burn injuries, trauma to the central nervous system, and infection. Additionally, we will examine the use of EVs as biomarkers for predicting late-stage trauma outcomes and as therapeutics for reversing the pathological processes that develop post-trauma. Overall, EVs have emerged as critical mediators of trauma-associated pathology and their use as a therapeutic agent represents an exciting new field of biomedicine.

Two glycosaminoglycan (GAG) biopolymers, hyaluronic acid (HA) and chondroitin sulfate (CS), were chemically modified via carbodiimide chemistry to facilitate the loading and release of nitric oxide (NO) to develop a multi-action wound healing agent. The resulting NO-releasing GAGs released 0.2-0.9 μmol NO mg

The treatment of chronic inflammation with systemically administered anti-inflammatory treatments is associated with moderate-to-severe side effects, and the efficacy of locally administered drugs is short-lived. Here we show that inflammation can be locally suppressed by a fusion protein of the immunosuppressive enzyme indoleamine 2,3-dioxygenase 1 (IDO) and galectin-3 (Gal3). Gal3 anchors IDO to tissue, limiting the diffusion of IDO-Gal3 away from the injection site. In rodent models of endotoxin-induced inflammation, psoriasis, periodontal disease and osteoarthritis, the fusion protein remained in the inflamed tissues and joints for about 1 week after injection, and the amelioration of local inflammation, disease progression and inflammatory pain in the animals were concomitant with homoeostatic preservation of the tissues and with the absence of global immune suppression. IDO-Gal3 may serve as an immunomodulatory enzyme for the control of focal inflammation in other inflammatory conditions.

No methods exist to rapidly and accurately quantify the immune insult created by burn injuries. The development of a rapid, noninvasive clinical biomarker assay that evaluates a burn patient's underlying immune dysfunction and predicts clinical outcomes could transform burn care. We aimed to determine a set of peripheral biomarkers that correlates with clinical outcomes of burn patients.This prospective observational study enrolled two patient cohorts within a single burn center into an institutionally approved institutional review board study. Blood draws were performed48 hours after injury. Initial unbiased immune gene expression analysis compared 23 burn patients and 6 healthy controls using multiplex immune gene expression analysis of RNA from peripheral blood mononuclear cells. We then performed confirmatory outcomes analysis in 109 burn patients and 19 healthy controls using a targeted rapid quantitative polymerase chain reaction. Findings were validated and modeled associations with clinical outcomes using a regression model.A total of 149 genes with a significant difference in expression from burn patients compared with controls were identified. Pathway analysis identified pathways related to interleukin (IL)-10 and inducible nitric oxide synthase signaling to have significant z scores. quantitative polymerase chain reaction analysis of IL-10, IL-12, arginase 1 (ARG1), and inducible nitric oxide synthase demonstrated that burn injury was associated with increased expression of ARG1 and IL-10, and decreased expression of nitric oxide synthase 2 (NOS2) and IL-12. Burn severity, acute lung injury, development of infection, failure of skin autograft, and mortality significantly correlated with expression of one or more of these genes. Ratios of IL-10/IL-12, ARG1/NOS2, and (ARG1-IL-10)/(NOS2-IL-12) transcript levels further improved the correlation with outcomes. Using a multivariate regression model, adjusting for patient confounders demonstrated that (ARG1-IL-10)/(NOS2-IL-12) significantly correlated with burn severity and development of acute lung injury.We present a means to predict patient outcomes early after burn injury using peripheral blood, allowing early identification of underlying immune dysfunction.Prognostic/Epidemiological; Level II.

Cancer cells exert mastery over the local tumor-associated stroma (TAS) to configure protective immunity within the tumor microenvironment. The immunomodulatory character of pancreatic lysates of patients with cancer differs from those with pancreatitis. In this study, we evaluated the cross-talk between pancreatic cancer and its TAS in primary human cell culture models. Upon exposure of TAS to pancreatic cancer cell-conditioned media, we documented robust secretion of IL6 and IL8. This TAS response was MyD88-dependent and sufficient to directly suppress both CD4+ and CD8+ T-cell proliferation, inducing Th17 polarization at the expense of Th1. We found that patients possessed a similar shift in circulating effector memory Th17:Th1 ratios compared with healthy controls. The TAS response also directly suppressed CD8+ T-cell–mediated cytotoxicity. Overall, our results demonstrate how TAS contributes to the production of an immunosuppressive tumor microenvironment in pancreatic cancer. Cancer Res; 77(3); 672–83. ©2016 AACR.

Nicotine treatment does not lead to c-Met activation in PC cells.

Purpose: The relationship between smoking and pancreatic cancer biology, particularly in the context of the heterogeneous microenvironment, remains incompletely defined. We hypothesized that nicotine exposure would lead to the augmentation of paracrine growth factor signaling between tumor-associated stroma (TAS) and pancreatic cancer cells, ultimately resulting in accelerated tumor growth and metastasis.Experimental Design: The effect of tobacco use on overall survival was analyzed using a prospectively maintained database of surgically resected patients with pancreatic cancer. Nicotine exposure was evaluated in vitro using primary patient–derived TAS and pancreatic cancer cells independently and in coculture. Nicotine administration was then assessed in vivo using a patient-derived pancreatic cancer xenograft model.Results: Continued smoking was associated with reduced overall survival after surgical resection. In culture, nicotine-stimulated hepatocyte growth factor (HGF) secretion in primary patient-derived TAS and nicotine stimulation was required for persistent pancreatic cancer cell c-Met activation in a coculture model. c-Met activation in this manner led to the induction of inhibitor of differentiation-1 (Id1) in pancreatic cancer cells, previously established as a mediator of growth, invasion and chemoresistance. HGF-induced Id1 expression was abrogated by both epigenetic and pharmacologic c-Met inhibition. In patient-derived pancreatic cancer xenografts, nicotine treatment augmented tumor growth and metastasis; tumor lysates from nicotine-treated mice demonstrated elevated HGF expression by qRT-PCR and phospho-Met levels by ELISA. Similarly, elevated levels of phospho-Met in surgically resected pancreatic cancer specimens correlated with reduced overall survival.Conclusions: Taken together, these data demonstrate a novel, microenvironment-dependent paracrine signaling mechanism by which nicotine exposure promotes the growth and metastasis of pancreatic cancer. Clin Cancer Res; 22(7); 1787–99. ©2015 AACR.

Burn patients are subject to significant acute immune and metabolic dysfunction. Concomitant inhalation injury increases mortality by 20%. In order to identify specific immune and metabolic signaling pathways in burn (B), inhalation (I), and combined burn-inhalation (BI) injury, unbiased nanoString multiplex technology was used to investigate gene expression within peripheral blood mononuclear cells (PBMCs) from burn patients, with and without inhalation injury. PBMCs were collected from 36 injured patients and 12 healthy, non-burned controls within 72 h of injury. mRNA was isolated and hybridized with probes for 1342 genes related to general immunology and cellular metabolism. From these specific gene patterns, specific cellular perturbations and signaling pathways were inferred using robust bioinformatic tools. In both B and BI injuries, elements of mTOR, PPARγ, TLR, and NF-kB signaling pathways were significantly altered within PBMC after injury compared to PBMC from the healthy control group. Using linear regression modeling, (1) DEPTOR, LAMTOR5, PPARγ, and RPTOR significantly correlated with patient BMI; (2) RPTOR significantly correlated with patient length of stay, and (3) MRC1 significantly correlated with the eventual risk of patient mortality. Identification of mediators of this immunometabolic response that can act as biomarkers and/or therapeutic targets could ultimately aid the management of burn patients.

Evaluation of the cutting efficiency and effectiveness, surface roughness, and cleanability of a novel rotary instrument is lacking.The purpose of this in vitro study was to compare the cutting efficiency and effectiveness of a recently introduced diamond rotary instrument containing corundum microspheres with conventional instruments by evaluating the heat generated, surface roughness, and cleanability of each instrument after tooth preparations.Sound molars (n=225) were used to evaluate cutting efficiency and effectiveness by measuring the heat generated by 3 diamond dental rotary instruments: test instrument (TI), reference instrument (RI), and NTI instrument (NI). Thirty cavity preparations (27 mmThe NI instrument had the lowest mean ΔT (1.47 °C). The TI (1.77 °C) and RI (1.85 °C) groups showed statistically similar means (P.05). The TI presented the lowest surface roughness (1.68 μm), followed by the RI (1.87 μm) (P.001). The NI resulted in the highest surface roughness (2.17 μm) (P.001). The disinfection protocols used were more effective on the TI group than on the RI group regardless of organisms and time exposed to the cleaning solution (P.001).The novel diamond instrument demonstrated similar cutting efficiency and effectiveness when compared with conventional diamond instruments. However, the novel instrument produced smoother tooth preparations and was easier to clean than the conventional diamond rotary instruments.

Severe burn injury leads to a cascade of local and systemic immune responses that trigger an extreme state of immune dysfunction, leaving the patient highly susceptible to acute and chronic infection. When combined with inhalation injury, burn patients have higher mortality and a greater chance of developing secondary respiratory complications including infection. No animal model of combined burn and inhalation injury (B+I) exists that accurately mirrors the human clinical picture, nor are there any effective immunotherapies or predictive models of the risk of immune dysfunction. Our earlier work showed that the mechanistic/mammalian target of rapamycin (mTOR) pathway is activated early after burn injury, and its chemical blockade at injury reduced subsequent chronic bacterial susceptibility. It is unclear if mTOR plays a role in the exacerbated immune dysfunction seen after B+I injury. We aimed to: (1) characterize a novel murine model of B+I injury, and (2) investigate the role of mTOR in the immune response after B+I injury. Pulmonary and systemic immune responses to B+I were characterized in the absence or presence of mTOR inhibition at the time of injury. Data describe a murine model of B+I with inhalation-specific immune phenotypes and implicate mTOR in the acute immune dysfunction observed.

Implantable glucose biosensors provide real-time information about blood glucose fluctuations, but their utility and accuracy are time-limited due to the foreign body response (FBR) following their insertion beneath the skin. The slow release of nitric oxide (NO), a gasotransmitter with inflammation regulatory properties, from a sensor surface has been shown to dramatically improve sensors’ analytical biocompatibility by reducing the overall FBR response. Indeed, work in a porcine model suggests that as long as the implants (sensors) continue to release NO, even at low levels, the inflammatory cell infiltration and resulting collagen density are lessened. While these studies strongly support the benefits of NO release in mitigating the FBR, the mechanisms through which exogenous NO acts on the surrounding tissue, especially under the condition of hyperglycemia, remain vague. Such knowledge would inform strategies to refine appropriate NO dosage and release kinetics for optimal therapeutic activity. In this study, we evaluated mediator, immune cell, and mRNA expression profiles in the local tissue microenvironment surrounding implanted sensors as a function of NO release, diabetes, and implantation duration. A custom porcine wound healing-centric multiplex gene array was developed for nanoString barcoding analysis. Tissues adjacent to sensors with sustained NO release abrogated the implant-induced acute and chronic FBR through modulation of the tissue-specific immune chemokine and cytokine microenvironment, resulting in decreased cellular recruitment, proliferation, and activation at both the acute (7-d) and chronic (14-d) phases of the FBR. Further, we found that sustained NO release abrogated the implant-induced acute and chronic foreign body response through modulation of mRNA encoding for key immunological signaling molecules and pathways, including STAT1 and multiple STAT1 targets including MAPK14, IRAK4, MMP2, and CXCL10. The condition of diabetes promoted a more robust FBR to the implants, which was also controlled by sustained NO release.