Human severe sepsis cytokine mixture increases β2-integrin-dependent polymorphonuclear leukocyte adhesion to cerebral microvascular endothelial cells in vitro

Abstract

IntroductionSepsis-associated encephalopathy (SAE) is a state of acute brain dysfunction in response to a systemic infection. We propose that systemic inflammation during sepsis causes increased adhesion of leukocytes to the brain microvasculature, resulting in blood-brain barrier dysfunction. Thus, our objectives were to measure inflammatory analytes in plasma of severe sepsis patients to create an experimental cytokine mixture (CM), and to use this CM to investigate the activation and interactions of polymorphonuclear leukocytes (PMN) and human cerebrovascular endothelial cells (hCMEC/D3) in vitro.MethodsThe concentrations of 41 inflammatory analytes were quantified in plasma obtained from 20 severe sepsis patients and 20 age- and sex-matched healthy controls employing an antibody microarray. Two CMs were prepared to mimic severe sepsis (SSCM) and control (CCM), and these CMs were then used for PMN and hCMEC/D3 stimulation in vitro. PMN adhesion to hCMEC/D3 was assessed under conditions of flow (shear stress 0.7 dyn/cm2).ResultsEight inflammatory analytes elevated in plasma obtained from severe sepsis patients were used to prepare SSCM and CCM. Stimulation of PMN with SSCM led to a marked increase in PMN adhesion to hCMEC/D3, as compared to CCM. PMN adhesion was abolished with neutralizing antibodies to either β2 (CD18), αL/β2 (CD11α/CD18; LFA-1) or αM/β2 (CD11β/CD18; Mac-1) integrins. In addition, immune-neutralization of the endothelial (hCMEC/D3) cell adhesion molecule, ICAM-1 (CD54) also suppressed PMN adhesion.ConclusionsHuman SSCM up-regulates PMN pro-adhesive phenotype and promotes PMN adhesion to cerebrovascular endothelial cells through a β2-integrin-ICAM-1-dependent mechanism. PMN adhesion to the brain microvasculature may contribute to SAE.

Polystyrene-Divinylbenzene-Based Adsorbents Reduce Endothelial Activation and Monocyte Adhesion Under Septic Conditions in a Pore Size-Dependent Manner

“…G-CSF is the principal granulopoietic growth factor regulating the maturation of neutrophil precursors and has been found to increase the sensitivity to LPS by upregulation of lipopolysaccharide binding protein. Our results are in line with recent data reporting a 25-fold increase of MCP-1 and a 32-fold increase of G-CSF in plasma of severe sepsis patients [ 30 ].…”

Regulation of Sirtuin 3-Mediated Deacetylation of Cyclophilin D Attenuated Cognitive Dysfunction Induced by Sepsis-Associated Encephalopathy in Mice

“…Elevated levels of cytokines, such as IL-1β, TNF-α, and IL-6, have been observed in the brain parenchyma and cerebrospinal fluid after sepsis (Jeremias et al 2015 ; Takahashi et al 2014 ). The neuropathology in SAE is quite similar to that in patients with severe sepsis in terms of elevated levels of proinflammatory cytokines in the brain (Blom et al 2015 ). Sepsis-induced alterations in mitochondrial damage were associated with SIRT3 downregulation.…”

Inactivation of the tyrosine phosphatase SHP-2 drives vascular dysfunction in Sepsis

“…During systemic infection the endothelium is exposed to a complex composition of inflammatory factors contributing to the induction of adhesion molecules and disease progression [4,38]. To study if endothelial SHP-2 activity is affected by the inflammatory conditions in sepsis, we first performed experiments in mice suffering from polymicrobial sepsis induced by peritoneal contamination and infection (PCI) [34].…”