Platelets, endothelium and shear join forces to mislead neutrophils in sepsis

Pretreatment of human cerebrovascular endothelial cells with CO-releasing molecule-3 interferes with JNK/AP-1 signaling and suppresses LPS-induced proadhesive phenotype

OBJECTIVE

Exogenously administered CO interferes with PMN recruitment to the inflamed organs. The mechanisms of CO-dependent modulation of vascular proadhesive phenotype, a key step in PMN recruitment, are unclear.

METHODS

We assessed the effects/mechanisms of CO liberated from a water-soluble CORM-3 on modulation of the proadhesive phenotype in hCMEC/D3 in an in vitro model of endotoxemia. To this end, hCMEC/D3 were stimulated with LPS (1 μg/mL) for six hours. In some experiments hCMEC/D3 were pretreated with CORM-3 (200 μmol/L) before LPS-stimulation. PMN rolling/adhesion to hCMEC/D3 were assessed under conditions of laminar shear stress (0.7 dyn/cm(2) ). In parallel, expression of adhesion molecules E-selectin, ICAM-1, and VCAM-1 (qPCR), activation of transcription factors, NF-κB and AP-1 (ELISA), and MAPK-signaling (expression/phosphorylation of p38, ERK1/2, and JNK1/2; western blot) were assessed.

RESULTS

The obtained results indicate that CORM-3 pretreatment reduces PMN rolling/adhesion to LPS-stimulated hCMEC/D3 (p < 0.05). Decreased PMN rolling/adhesion to hCMEC/D3 was associated with CORM-3-dependent inhibition of MAPK JNK1/2 activation (Tyr-phosphorylation), inhibition of transcription factor, AP-1 (c-Jun phosphorylation), and subsequent suppression of VCAM-1 expression (p < 0.05).

CONCLUSIONS

These findings indicate that CORM-3 pretreatment interferes with JNK/AP-1 signaling and suppresses LPS-induced upregulation of the proadhesive phenotype in hCMEC/D3.

Expression of inflammation-associated genes in circulating leukocytes and activity of indoleamine-2,3-dioxygenase in dairy cattle with acute puerperal metritis and bacteremia

OBJECTIVE

To investigate whether expression of genes associated with inflammation and activity of indoleamine-2,3-dioxygenase (IDO) correlated with disease status and prevalence of bacteremia in post-partum dairy cattle with and without acute puerperal metritis (APM).

PROCEDURES

Blood was collected from cattle with APM and control cattle matched by parity and days in milk. Leukocytes were isolated and expression of 6 genes was quantified. Activity of IDO was measured in serum with higher performance liquid chromatography (HPLC).

RESULTS

The relative expression of IL-1β in cattle with APM was significantly lower than that in controls. IDO activity was not significantly different between bacteremic and non-bacteremic cattle

CONCLUSIONS AND CLINICAL RELEVANCE

The expression of IL-1β was lower in cattle with APM. The lower levels of IL-1β expression in PBMCs of cattle with APM suggest impaired inflammatory responses and may contribute to the development of the disease in this population of animals.

Do aspirin and statins prevent severe sepsis?

PURPOSE OF REVIEW

Sepsis is an inflammatory condition associated with significant morbidity and mortality. Given the lack of specific therapies for the condition, prevention has garnered significant interest and increased importance. The article reviews the current literature regarding the use of aspirin and statins for the prevention of sepsis.

RECENT FINDINGS

Aspirin and statins have been integral in the prevention of atherosclerotic disease. Additionally, statins have proven beneficial in the prevention of nonatherosclerotic conditions secondary to their pleiotropic effects. In animal models, this pleiotropism modulates many inflammatory pathways of sepsis. The platelet also plays an integral role in this inflammatory cascade of sepsis. Scientific data indicates that antiplatelet therapy, including aspirin, may attenuate these undesirable effects of platelets. Finally, observational studies have shown that patients taking statins have a decreased incidence of sepsis and septic shock, and aspirin may potentiate these benefits.

SUMMARY

Sepsis is a deadly and costly condition with no available, specific treatment options. The statins and aspirin are well tolerated and widely used for prevention of cardiovascular disease. Because of their effects on the immune system and inflammatory pathways, they may present viable medical options for the prevention of sepsis.

The immunopathology of sepsis: pathogen recognition, systemic inflammation, the compensatory anti-inflammatory response, and regulatory T cells

Sepsis, the systemic inflammatory response to infection, represents the major cause of death in critically ill veterinary patients. Whereas important advances in our understanding of the pathophysiology of this syndrome have been made, much remains to be elucidated. There is general agreement on the key interaction between pathogen-associated molecular patterns and cells of the innate immune system, and the amplification of the host response generated by pro-inflammatory cytokines. More recently, the concept of immunoparalysis in sepsis has also been advanced, together with an increasing recognition of the interplay between regulatory T cells and the innate immune response. However, the heterogeneous nature of this syndrome and the difficulty of modeling it in vitro or in vivo has both frustrated the advancement of new therapies and emphasized the continuing importance of patient-based clinical research in this area of human and veterinary medicine.