Acute loss of renal function attenuates slow leukocyte rolling and transmigration by interfering with intracellular signaling

Abstract

Acute kidney injury (AKI) is a common clinical problem in critically ill patients and increases in-hospital mortality. Acute loss of renal function (ALRF) reduces leukocyte recruitment into inflamed tissue, but the underlying molecular mechanisms remain unknown. In this study, we investigated the effects of ALRF on the different steps of the leukocyte recruitment cascade by using intravital microscopy, flow chamber experiments, and biochemistry assays. ALRF abolished selectin-induced slow leukocyte rolling on E-selectin/ICAM-1 and P-selectin/ICAM-1 and also reduced transmigration without affecting chemokine-induced arrest. A reduced phosphorylation of spleen tyrosine kinase (Syk), Akt, phospholipase C (PLC) γ2, and p38 MAPK, but not altered expression levels of adhesion molecules on the surface of neutrophils, was responsible for the abolished selectin-mediated slow leukocyte rolling. The results observed in the murine system could be reproduced in flow chamber experiments with human blood. Samples from critically ill patients with sepsis-induced AKI showed a significantly higher rolling velocity on E-selectin/ICAM-1 and P-selectin/ICAM-1 compared to patients with sepsis alone or to healthy volunteers. In conclusion, these data suggest that ALRF inhibits selectin-mediated slow leukocyte rolling by reducing phosphorylation of Syk, Akt, PLCγ2, and p38 MAPK and transmigration.

FGF23 signaling impairs neutrophil recruitment and host defense during CKD

“…Blood-perfused flowchamber assays with human whole blood were performed as described previously (24,31). Glass capillaries were coated with E-selectin (3.5 μg/ml), P-selectin (20 μg/ml), E-selectin/ICAM-1 (3.5/3.5 μg/ml), or P-selectin/ICAM-1 (20/5 μg/ml) for 2 hours.…”

“…Interstitial leukocyte infiltration into the kidney itself may be initially increased during CKD, and CKD patients often present with progressive atherosclerotic diseases caused by a proinflammatory milieu, which may link these observations (2). However, it has also been shown that initial priming of neutrophils during CKD leads to unresponsiveness of neutrophils to further stimuli, accompanied by impaired migratory behavior and severely compromised phagocytic capacity, which contributes to vulnerability to exogenous pathogens (e.g., bacteria and fungi) and renders CKD patients prone to recurrent infections (29)(30)(31). This is in line with our findings that demonstrate decreased neutrophil recruitment and severely impaired host defense under inflammatory conditions in the murine system, as well as distinct impairments in several steps of the leukocyte recruitment cascade in samples from patients with CKD.…”

Lidocaine Reduces Neutrophil Recruitment by Abolishing Chemokine-Induced Arrest and Transendothelial Migration in Septic Patients

“…To investigate the effect of lidocaine on selectin-mediated slow neutrophil rolling, we used a previously published flow chamber system (15,23). The flow chamber system has the advantage that neutrophil rolling behavior can be investigated in whole blood without isolating neutrophils.…”

“…To investigate selectin-mediated slow neutrophil rolling, we used a wholeblood perfused human flow chamber system, as described previously (15,23). Briefly, glass capillaries were coated with E-selectin (3.5 mg/ml; R&D Systems, Minneapolis, MN), P-selectin (20 mg/ml; R&D Systems), E-selectin/ICAM-1 (3.5/3.5 mg/ml; R&D Systems), or P-selectin/ICAM-1 (20/5 mg/ml; R&D Systems) for 2 h. Chambers were blocked with 1% casein (Fisher Scientific, Waltham, MA) for 1 h and afterwards perfused with heparinized whole-blood samples at a constant shear stress of 5-6 dynes/cm 2 .…”

Normal mesenteric lymph ameliorates acute kidney injury following lipopolysaccharide challenge in mice

“…[7][8][9] However, whether the effect of NML on LPSinduced AKI is related to MAPK signaling molecules remains unknown. It has been shown that increased expression of LPS-binding protein (LBP) and activation of cluster of differentiation 14 (CD14), a LPS receptor can enhance the sensitization of inflammatory cells to the endotoxin or LPS that links the inflammatory response to organ injuries.…”