Metabolic Response in Endothelial Cells to Catecholamine Stimulation Associated with Increased Vascular Permeability

Blood failure: traumatic hemorrhage and the interconnections between oxygen debt, endotheliopathy, and coagulopathy

This review explores the concept of "blood failure" in traumatic injury, which arises from the interplay of oxygen debt, the endotheliopathy of trauma (EoT), and acute traumatic coagulopathy (ATC). Traumatic hemorrhage leads to the accumulation of oxygen debt, which can further exacerbate hemorrhage by triggering a cascade of events when severe. Such events include EoT, characterized by endothelial glycocalyx damage, and ATC, involving platelet dysfunction, fibrinogen depletion, and dysregulated fibrinolysis. To manage blood failure effectively, a multifaceted approach is crucial. Damage control resuscitation strategies such as use of permissive hypotension, early hemorrhage control, and aggressive transfusion of blood products including whole blood aim to minimize oxygen debt and promote its repayment while addressing endothelial damage and coagulation. Transfusions of red blood cells, plasma, and platelets, as well as the use of tranexamic acid, play key roles in hemostasis and countering ATC. Whole blood, whether fresh or cold-stored, is emerging as a promising option to address multiple needs in traumatic hemorrhage. This review underscores the intricate relationships between oxygen debt, EoT, and ATC and highlights the importance of comprehensive, integrated strategies in the management of traumatic hemorrhage to prevent blood failure. A multidisciplinary approach is essential to address these interconnected factors effectively and to improve patient outcomes.

Endothelial Cell Dysfunction and Increased Cardiovascular Risk in Patients With Chronic Kidney Disease

The endothelium is considered to be the gatekeeper of the vessel wall, maintaining and regulating vascular integrity. In patients with chronic kidney disease, protective endothelial cell functions are impaired due to the proinflammatory, prothrombotic and uremic environment caused by the decline in kidney function, adding to the increase in cardiovascular complications in this vulnerable patient population. In this review, we discuss endothelial cell functioning in healthy conditions and the contribution of endothelial cell dysfunction to cardiovascular disease. Further, we summarize the phenotypic changes of the endothelium in chronic kidney disease patients and the relation of endothelial cell dysfunction to cardiovascular risk in chronic kidney disease. We also review the mechanisms that underlie endothelial changes in chronic kidney disease and consider potential pharmacological interventions that can ameliorate endothelial health.

Effect of albumin solutions on endothelial oxidant injury: A microfluidic study

BACKGROUND

Studies have suggested a beneficial effect of early plasma-based resuscitation in patients following trauma-hemorrhagic shock. The underlying mechanism(s) are unknown but may be owing to protective effects of plasma components on the endothelium and its glycocalyx layer. Albumin, the major protein in plasma, influences vascular integrity and has antioxidant properties in vivo. Sphingosine 1-phosphate is a bioactive sphingolipid with diverse signaling functions, which include endothelial barrier protection in part owing to preservation of the glycocalyx. Sphingosine 1-phosphate is bound mainly to albumin and high-density lipids in the plasma. Debate continues about the beneficial effect of albumin solutions in shock resuscitation. Pharmacologic preparations may modify constituents of albumin solutions for clinical use. We examined the relative effects of sphingosine 1-phosphate concentrations in albumin solutions on the endothelial-glycocalyx barrier in an in vitro microfluidic platform.

METHODS

Endothelial cell monolayers were established in microfluidic perfusion devices and exposed to control or biomimetic shock conditions followed by 5% plasma or different albumin solutions ± exogenous sphingosine 1-phosphate perfusion. Biomarkers of endothelial and glycocalyx activation, damage, and oxidant injury were then determined.

RESULTS

Endothelial cell and glycocalyx barriers were damaged after biomimetic shock conditions. Plasma and sphingosine 1-phosphate loaded albumin solutions protected against barrier injury. Modest protective effects were noted with albumin alone; the efficacy varied with sphingosine 1-phosphate content of the albumin solution.

CONCLUSION

The protective effect of albumin on the endothelia-glycocalyx barrier against oxidant injury was dependent on its sphingosine 1-phosphate concentration. Our data may help explain the discrepancies regarding the effectiveness of albumin solutions in shock resuscitation.

Co-culturing fungus Penicillium citrinum and strain Citrobacter freundii improved nitrate removal and carbon utilization by promoting glyceride metabolism

Exploring the interaction between denitrifying microbial species is significant for improving denitrification performance. In this study, the effects of co-culturing fungus Penicillium citrinum and strain Citrobacter freundii on denitrification were investigated. Results showed that the maximum nitrate removal and carbon utilization in co-culture were 68.0 and 14.1 mg·L^-1·d^-1, respectively. The total adenosine triphosphatase activity was increased to 9.87 U‧mg^-1 protein in co-culture, and nicotinamide adenine dinucleotide production was 1.7-2.3 times that of monoculture, attributing to increased carbon utilization. Further metabolomics and membrane permeability assay revealed that co-culture increased the metabolism of glycerides, thereby enhancing the membrane permeability of strain Citrobacter freundii and promoting the transmembrane transport of nitrate and glucose, which boosted nitrate reductase activity and nicotinamide adenine dinucleotide production in turn. In summary, co-culturing promoted carbon utilization and enhanced substrate removal efficiency through the metabolism of glycerides, which provided a strategy to enhance denitrification performance in wastewater treatment.