Figure 4 shows mRNA expression levels of IL-10, HO-1, COX-2, NF-κB, and iNOS in neutrophils of patients with SBP and noninfected AF, and of patients with SID distributed according to intracellular norfloxacin concentration after 4-hour resting culture or stimulated with LPS. As can be observed, in a nonstimulated situation, increasing intracellular amounts of norfloxacin

significantly up-regulates IL-10 and HO-1 mRNA expression, compared with patients with noninfected AF and patients with SBP. On the other hand, proinflammatory mediators are down-regulated in patients with SID as intracellular norfloxacin concentrations rise, compared with patients with noninfected AF or patients with SBP. When LPS is added to culture, proinflammatory mediators respond by increasing their gene expression levels in patients with noninfected AF to levels similar to those present in patients mTOR inhibitor with SBP. However, in the presence of norfloxacin, levels buy Palbociclib of these molecules are held to levels similar to those present in nonstimulated conditions, abrogating the effect of LPS and significantly

increasing IL-10 and HO-1 expression as intracellular norfloxacin concentrations rise. Protein expression of all studied molecules in both conditions mimic those obtained for gene expression and can be followed in the corresponding blots along Fig. 4 (data on protein band densitometry is provided in Supporting Information Fig. 1). In vitro experiments with anti–IL-10 mAb were conducted to validate the inflammation regulatory mechanism associated with norfloxacin in patients with SID (Fig. 5). After stimulation with LPS plus anti–IL-10 mAb, half of the cultured cells were directly MCE tested and the other half was washed with PBS and recultured with LPS alone. In the first set, stimulation with LPS plus anti–IL-10 mAb induced higher levels of proinflammatory mediators than LPS-stimulated cells

in all groups of patients. Especially relevant, all proinflammatory mediators were dramatically higher than in LPS-stimulated cells from patients with SID, reaching levels observed in cells from patients with noninfected AF. Besides, increasing intracellular norfloxacin concentrations did not decrease their expression levels, as happened with LPS-stimulated cells. Although anti–IL-10 did not affect IL-10 synthesis, proinflammatory control was clearly abolished, probably through an IL-10 downstream regulation of HO-1, which was severely decreased in anti–IL-10 presence. In the second set, levels of proinflammatory mediators were restored to those present in Fig. 4 and increasing amounts of norfloxacin were again associated with decreasing COX-2, iNOS, and NF-κB expression levels.