sphingosine-1-phosphate and Alcoholic-Intoxication

Acute ethanol intoxication increases the risk of sepsis and aggravates the symptoms of sepsis and lung injury. Therefore, this study aimed to explore whether sphingosine kinase 1 (SphK1)/sphingosine-1-phosphate (S1P)/S1P receptor 1 (S1PR1) signaling pathway functions in lung injury caused by acute ethanol intoxication-enhanced sepsis, as well as its underlying mechanism. The acute ethanol intoxication model was simulated by intraperitoneally administering mice with 32% ethanol solution, and cecal ligation and puncture (CLP) was used to construct the sepsis model. The lung tissue damage was observed by hematoxylin-eosin (H&E) staining, and the wet-to-dry (W/D) ratio was used to evaluate the degree of pulmonary edema. Inflammatory cell counting and protein concentration in bronchoalveolar lavage fluid (BALF) were, respectively, detected by hemocytometer and bicinchoninic acid (BCA) method. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and IL-18 in BALF were detected by their commercial enzyme-linked immunosorbent assay (ELISA) kits. The myeloperoxidase (MPO) activity and expression of apoptosis-related proteins and SphK1/S1P/S1PR1 pathway-related proteins were, respectively, analyzed by MPO ELISA kit and Western blot analysis. The cell apoptosis in lung tissues was observed by TUNEL assay. Acute ethanol intoxication (EtOH) decreased the survival rate of mice and exacerbated the lung injury caused by sepsis through increasing pulmonary vascular permeability, neutrophil infiltration, release of inflammatory factors, and cell apoptosis. In addition, EtOH could activate the SphK1/S1P/S1PR1 pathway in CLP mice. However, PF-543, as a specific inhibitor of SphK1, could partially reverse the deleterious effects on lung injury of CLP mice. PF-543 alleviated lung injury caused by sepsis in acute ethanol intoxication rats by suppressing the SphK1/S1P/S1PR1 signaling pathway.

Topics: Alcoholic Intoxication; Animals; Apoptosis; Cytokines; Disease Models, Animal; Enzyme Inhibitors; Inflammation Mediators; Lung; Lung Injury; Lysophospholipids; Male; Methanol; Mice, Inbred C57BL; Neutrophil Infiltration; Oxidative Stress; Phosphotransferases (Alcohol Group Acceptor); Pneumonia; Pulmonary Edema; Pyrrolidines; Sepsis; Signal Transduction; Sphingosine; Sphingosine-1-Phosphate Receptors; Sulfones

Fluid resuscitation following hemorrhagic shock is often problematic, with development of prolonged hypotension and edema. In addition, many trauma patients are also intoxicated, which generally worsens outcomes. We directly investigated how alcohol intoxication impacts hemorrhagic shock and resuscitation-induced microvascular leakage using a rat model with intravital microscopic imaging. We also tested the hypothesis that an endothelial barrier-protective bioactive lipid, sphingosine-1-phosphate (S1P), could ameliorate the microvascular leakage following alcohol intoxication plus hemorrhagic shock and resuscitation. Our results show that alcohol intoxication exacerbated hemorrhagic shock and resuscitation-induced hypotension and microvascular leakage. We next found that S1P effectively could reverse alcohol-induced endothelial barrier dysfunction using both cultured endothelial cell monolayer and in vivo models. Lastly, we observed that S1P administration ameliorated hypotension and microvascular leakage following combined alcohol intoxication and hemorrhagic shock, in a dose-related manner. These findings suggest the viability of using agonists that can improve microvascular barrier function to ameliorate trauma-induced hypotension, offering a novel therapeutic opportunity for potentially improving clinical outcomes in patients with multi-hit injuries.

Topics: Alcoholic Intoxication; Animals; Capillary Permeability; Dose-Response Relationship, Drug; Endothelium, Vascular; Humans; Hypotension; Lysophospholipids; Male; Rats; Resuscitation; Shock, Hemorrhagic; Sphingosine