LPS-induced gene expression of inflammation-related genes in neutrophils from familial Mediterranean fever patients

Abstract

BackgroundAutoinflammatory disorders, such as Familial Mediterranean fever (FMF), characterized by abnormally increased inflammation, and mediated predominantly by the cells of innate immune system. FMF characterized by the episodes of self-resolving severe inflammation, with fever and serositis. The major cell type found in FMF inflammatory exudates are neutrophils. It is not known whether bacterial lipopolysaccharide (LPS) could influence neutrophil activation in FMF. We examined in vitro effect of LPS (10 ng/ml) exposure on expression of 13 selected genes in FMF and control neutrophils using quantitative real-time RT-PCR. ResultsLPS exposure induced basal expression of TLR4 (4.4-fold increase, p < 0.05), IL-1β (9-fold, p < 0.01), IL-8 (13-fold, p=0.06), TNFAIP6 (11-fold, p < 0.05) genes in FMF neutrophils, and of TLR4 (17.6-fold, p < 0.001), IL-1β (25-fold, p < 0.001), IL-8 (36-fold, p < 0.001), TNFAIP6 (61-fold, p < 0.001) in healthy neutrophils. ConclusionsOur findings indicate that gene expression in LPS-exposed FMF and control neutrophils is characterized by a number of shared alterations. In spite of pre-activated state of FMF neutrophils, LPS exposure further enhanced expression of the investigated genes. The ability of FMF neutrophils to enhance LPS-induced inflammatory reaction was however attenuated compared to healthy neutrophils. In conclusion, our data indicate that FMF neutrophils may display features of LPS tolerance, and this speculation should be explored further.

Gene–Dose Effect of MEFV Gain-of-Function Mutations Determines ex vivo Neutrophil Activation in Familial Mediterranean Fever

“…This indicates that therapeutically applied colchicine does not control the ex vivo analyzed spontaneous activation of neutrophils irrespective of the clinical phenotype. These observations are supported by a previous work demonstrating increased transcription of selected genes by short-time-cultured neutrophils derived from colchicine-treated FMF patients (8).…”

“…Neutrophils are the main tissueinfiltrating cells during FMF attacks and therefore the most likely responsible for a large proportion of the observed inflammatory symptoms (7). RNA analysis of isolated shorttime cultured neutrophils from patients with FMF revealed an altered spontaneous gene expression profile, for example, caspase-1, c-FOS, TLR2, and MMP9, when compared to control neutrophils (8).…”

Update on Pyrin Functions and Mechanisms of Familial Mediterranean Fever

“…Thus, the routine experimental procedures involving external mechanical forces applied to cells may lead to the generation of danger signals that are sensed by the pyrin inflammasome. Recent investigations showing the pyrin inflammasome activation in response to actin modifications ( Xu et al, 2014 ; Kim et al, 2015 ), together with our results suggesting the excessive activation of neutrophils from FMF patients in ex vivo experiments ( Manukyan et al, 2013a , b ), warrants further studies of pyrin-cytoskeleton interactions, especially in the case of FMF.…”

“…It was shown that Rho activation is sufficient to promote migration of monocytes across endothelial cells ( Honing et al, 2004 ). In our experiments, we have observed a phenomenon of heightened sensitivity of neutrophils from FMF patients toward in vitro conditions in the inductor-free media ( Manukyan et al, 2013a , b ). This suggests that the host-derived stress signals could be responsible for the activation of these cells.…”

The Presentation, Assessment, Pathogenesis, and Treatment of Calcinosis in Juvenile Dermatomyositis

“…Hydroxyapatite crystals invoke an inflammatory response in joints and soft tissue, making colchicine a consideration when trying to treat calcinosis, particularly in light of its inhibition of IL-1β and the inflammasome [83]. Taborn et.…”