Alcohol Binge Reduces Systemic Leukocyte Activation and Pulmonary PMN Infiltration After Blunt Chest Trauma and Hemorrhagic Shock

NEW INSIGHTS INTO THE PATHOPHYSIOLOGY OF TRAUMA AND HEMORRHAGE

ABSTRACT

Circulatory shock from trauma and hemorrhage remains a clinical challenge with mortality still high within the first hours after impact. It represents a complex disease involving the impairment of a number of physiological systems and organs and the interaction of different pathological mechanisms. Multiple external and patient-specific factors may further modulate and complicate the clinical course. Recently, novel targets and models with complex multiscale interaction of data from different sources have been identified which offer new windows of opportunity. Future works needs to consider patient-specific conditions and outcomes to mount shock research onto the next higher level of precision and personalized medicine.

Fast Maturation of Splenic Dendritic Cells Upon TBI Is Associated With FLT3/FLT3L Signaling

The consequences of systemic inflammation are a significant burden after traumatic brain injury (TBI), with almost all organs affected. This response consists of inflammation and concurrent immunosuppression after injury. One of the main immune regulatory organs, the spleen, is highly interactive with the brain. Along this brain–spleen axis, both nerve fibers as well as brain-derived circulating mediators have been shown to interact directly with splenic immune cells. One of the most significant comorbidities in TBI is acute ethanol intoxication (EI), with almost 40% of patients showing a positive blood alcohol level (BAL) upon injury. EI by itself has been shown to reduce proinflammatory mediators dose-dependently and enhance anti-inflammatory mediators in the spleen. However, how the splenic immune modulatory effect reacts to EI in TBI remains unclear. Therefore, we investigated early splenic immune responses after TBI with and without EI, using gene expression screening of cytokines and chemokines and fluorescence staining of thin spleen sections to investigate cellular mechanisms in immune cells. We found a strong FLT3/FLT3L induction 3 h after TBI, which was enhanced by EI. The FLT3L induction resulted in phosphorylation of FLT3 in CD11c+ dendritic cells, which enhanced protein synthesis, maturation process, and the immunity of dendritic cells, shown by pS6, peIF2A, MHC-II, LAMP1, and CD68 by immunostaining and TNF-α expression by in-situ hybridization. In conclusion, these data indicate that TBI induces a fast maturation and immunity of dendritic cells which is associated with FLT3/FLT3L signaling and which is enhanced by EI prior to TBI.

Injury Patterns after Falling down Stairs-High Ratio of Traumatic Brain Injury under Alcohol Influence

Falling down a staircase is a common mechanism of injury in patients with severe trauma, but the effect of varying fall height according to the number of steps on injury patterns in these patients has been little studied. In this retrospective study, prospectively collected data from a Level 1 Trauma Center in Germany were analyzed regarding the injury patterns of patients admitted through the trauma room with suspicion of multiple injuries following a fall down a flight of stairs between January 2016 and December 2019. In total 118 patients were examined which where consecutively included in this study. More than 80% of patients suffered a traumatic brain injury, which increased as a function of the number of stairs fallen. Therefore, the likelihood of intracranial hemorrhage increased with higher numbers of fallen stairs. Fall-associated bony injuries were predominantly to the face, skull and the spine. In addition, there was a high coincidence of staircase falls and alcohol intake. Due to a frequent coincidence of staircase falls and alcohol, the (pre-)clinical neurological assessment is complicated. As the height of the fall increases, severe traumatic brain injury should be anticipated and diagnostics to exclude intracranial hemorrhage and spinal injuries should be performed promptly to ensure the best possible patient outcome.

Differential effect of ethanol intoxication on peripheral markers of cerebral injury in murine blunt traumatic brain injury

Background

Blood-based biomarkers have proven to be a reliable measure of the severity and outcome of traumatic brain injury (TBI) in both murine models and patients. In particular, neuron-specific enolase (NSE), neurofilament light (NFL) and S100 beta (S100B) have been investigated in the clinical setting post-injury. Ethanol intoxication (EI) remains a significant comorbidity in TBI, with 30–40% of patients having a positive blood alcohol concentration post-TBI. The effect of ethanol on blood-based biomarkers for the prognosis and diagnosis of TBI remains unclear. In this study, we investigated the effect of EI on NSE, NFL and S100B and their correlation with blood–brain barrier integrity in a murine model of TBI.

Methods

We used ultra-sensitive single-molecule array technology and enzyme-linked immunosorbent assay methods to measure NFL, NSE, S100B and claudin-5 concentrations in plasma 3 hours post-TBI.

Results

We showed that NFL, NSE and S100B were increased at 3 hours post-TBI. Interestingly, ethanol blood concentrations showed an inverse correlation with NSE but not with NFL or S100B. Claudin-5 levels were increased post-injury but no difference was detected compared to ethanol pretreatment. The increase in claudin-5 post-TBI was correlated with NFL but not with NSE or S100B.

Conclusions

Ethanol induces an effect on biomarker release in the bloodstream that is different from TBI not influenced by alcohol. This could be the basis of investigations into humans.

Acute Alcohol Intoxication Modulates Monocyte Subsets and Their Functions in a Time-Dependent Manner in Healthy Volunteers

Background

Excessive alcohol intake is associated with adverse immune response-related effects, however, acute and chronic abuse differently modulate monocyte activation. In this study, we have evaluated the phenotypic and functional changes of monocytes in acutely intoxicated healthy volunteers (HV).

Methods

Twenty-two HV consumed individually adjusted amounts of alcoholic beverages until reaching a blood alcohol level of 1‰ after 4h (T4). Peripheral blood was withdrawn before and 2h (T2), 4h (T4), 6h (T6), 24h (T24), and 48h (T48) after starting the experiment and stained for CD14, CD16 and TLR4. CD14^brightCD16^-, CD14^brightCD16⁺ and CD14^dimCD16⁺ monocyte subsets and their TLR4 expression were analyzed by flow cytometry. Inflammasome activation via caspase-1 in CD14⁺ monocytes was measured upon an ex vivo in vitro LPS stimulation. Systemic IL-1β and adhesion capacity of isolated CD14⁺ monocytes upon LPS stimulation were evaluated.

Results

The percentage of CD14⁺ monocyte did not change following alcohol intoxication, whereas CD14^brightCD16^- monocyte subset significantly increased at T2 and T24, CD14^brightCD16⁺ at T2, T4 and T6 and CD14^dimCD16⁺ at T4 and T6. The relative fraction of TLR4 expressing CD14⁺ monocytes as well as the density of TLR4 surface presentation increased at T2 and decreased at T48 significantly. TLR4⁺CD14⁺ monocytes were significantly enhanced in all subsets at T2. TLR4 expression significantly decreased in CD14^brightCD16^- at T48, in CD14^brightCD16⁺ at T24 and T48, increased in CD14^dimCD16⁺ at T2. IL-1β release upon LPS stimulation decreased at T48, correlating with TLR4 receptor expression. Alcohol downregulated inflammasome activation following ex vivo in vitro stimulation with LPS between T2 and T48 vs. T0. The adhesion capacity of CD14⁺ monocytes decreased from T2 with significance at T4, T6 and T48. Following LPS administration, a significant reduction of adhesion was observed at T4 and T6.

Conclusions

Alcohol intoxication immediately redistributes monocyte subsets toward the pro-inflammatory phenotype with their subsequent differentiation into the anti-inflammatory phenotype. This is paralleled by a significant functional depression, suggesting an alcohol-induced time-dependent hyporesponsiveness of monocytes to pathogenic triggers.

Reduced phagocytosis, ROS production and enhanced apoptosis of leukocytes upon alcohol drinking in healthy volunteers

Background

Alcohol drinking is associated with a serious risk of developing health problems as well as with a large number of traumatic injuries. Although chronic alcohol misuse is known to contribute to severe inflammatory complications, the effects of an acute alcohol misuse are still unclear. Here, the impact of acute alcohol drinking on leukocyte counts and their cellular functions were studied.

Methods

Twenty-two healthy volunteers (12 female, 10 male) received a predefined amount of a whiskey-cola mixed drink (40% v/v), at intervals of 20 min, over 4 h to achieve a blood alcohol concentration of 1‰. Blood samples were taken before drinking T₀, 2 h (T₂), 4 h (T₄), 6 h (T₆), 24 h (T₂₄) and 48 h (T₄₈) after starting drinking alcohol. Leukocytes, monocytes and granulocyte counts and their functions regarding the production of reactive oxidative species (ROS), phagocytosis and apoptosis were analyzed by flow cytometry.

Results

Total leukocyte counts significantly increased at T₂ and T₄, while granulocyte and monocyte counts decreased at T₄ and T₆ vs. T₀. Monocytes increased significantly at T₂₄ and T₄₈ vs. T₀. While the total number of ROS-producing leukocytes and notably granulocytes significantly increased, in parallel, the intracellular ROS intensity decreased at T₂ and T₆. The numbers of ROS-positive monocytes have shown a delayed modulation of ROS, with a significant reduction in the total number of ROS-producing cells at T₄₈ and a significantly reduced intracellular ROS-intensity at T₂₄. Phagocyting capacity of leukocytes significantly decreased at T₄ and T₆. In general leukocytes, and notably granulocytes demonstrated significantly increased early (T₂), while monocyte exerted significantly increased late apoptosis (T₂₄ and T₄₈).

Conclusions

Alcohol drinking immediately impacts leukocyte functions, while the impact on monocytes occurs at even later time points. Thus, even in young healthy subjects, alcohol drinking induces immunological changes that are associated with diminished functions of innate immune cells that persist for days.

Effect of gestational and lactational nonylphenol exposure on airway inflammation in ovalbumin-induced asthmatic rat pups

To investigate the effect of gestational and lactational nonylphenol (NP) exposure on airway inflammation in ovalbumin (OVA)-induced asthmatic pups. Dams were gavaged with NP at dose levels of 25 mg/kg/day (low dose), 50 mg/kg/day (middle dose), 100 mg/kg/day (high dose) and groundnut oil alone (vehicle control) respectively from gestational day 7 to postnatal day 21. The results showed that the NP content in the lung tissues of pups in the 100 mg/kg NP group was significantly higher than that of the control group (P = 0.004). In the 100 mg/kg NP group, the infiltration of lymphocytes and eosinophils with thicken smooth muscle layer and inflammatory cells in the lumen were observed in the lung tissues of pups. Osmiophilic lamellar bodies were found in the cytoplasm of type II epithelial cells; mitochondria were clearly swollen. Compared with the control group, the levels of interleukin-4 (IL-4) in BALF (P = 0.042) and ovalbumin-specific serum immunoglobulin E (OVA-sIgE) (P = 0.005) in the OVA group were significantly higher. 25 mg/kg NP-OVA co-exposure synergistically decreased nuclear factor-κB (NF-κB) mRNA expression in the lung tissues of pups; Exposure to 50 mg/kg NP combined with OVA antagonized the increased expression of high mobility group box 1 (HMGB1) mRNA in the lung tissue. The combined exposure to 50 mg/kg NP and OVA synergistically increased HMGB1 protein expression in the lung tissues. 25 mg/kg NP-OVA co-exposure antagonized the increased nuclear factor-κB (NF-κB) protein expression in the lung tissues. There was a positive correlation between NP content and HMGB1 protein expression in the lung tissue of asthmatic pups (r = 0.602, P < 0.001). In conclusion, gestational and lactational exposure to 100 mg/kg NP in maternal rats exacerbated airway inflammation in OVA-induced asthmatic pups, and there is an interactive effect between NP and OVA. When the perinatal rats were exposed to 100 mg/kg NP, the levels of HMGB1 and NF-κB in the lung tissues of OVA-induced asthmatic pups were increased.