Spatial and Temporal Profiles for Anti-Inflammatory Gene Expression in Leukocytes during a Resolving Model of Peritonitis

Abstract

The recent appreciation of the role played by endogenous counterregulatory mechanisms in controlling the outcome of the host inflammatory response requires specific analysis of their spatial and temporal profiles. In this study, we have focused on the glucocorticoid-regulated anti-inflammatory mediator annexin 1. Induction of peritonitis in wild-type mice rapidly (4 h) produced the expected signs of inflammation, including marked activation of resident cells (e.g., mast cells), migration of blood-borne leukocytes, mirrored by blood neutrophilia. These changes subsided after 48–96 h. In annexin 1null mice, the peritonitis response was exaggerated (∼40% at 4 h), with increased granulocyte migration and cytokine production. In blood leukocytes, annexin 1 gene expression was activated at 4, but not 24, h postzymosan, whereas protein levels were increased at both time points. Locally, endothelial and mast cell annexin 1 gene expression was not detectable in basal conditions, whereas it was switched on during the inflammatory response. The significance of annexin 1 system plasticity in the anti-inflammatory properties of dexamethasone was assessed. Clear induction of annexin 1 gene in response to dexamethasone treatment was evident in the circulating and migrated leukocytes, and in connective tissue mast cells; this was associated with the steroid failure to inhibit leukocyte trafficking, cytokine synthesis, and mast cell degranulation in the annexin 1null mouse. In conclusion, understanding how inflammation is brought under control will help clarify the complex interplay between pro- and anti-inflammatory pathways operating during the host response to injury and infection.

The Role and Effects of Glucocorticoid-Induced Leucine Zipper in the Context of Inflammation Resolution

“…In a self-resolving model of zymosaninduced peritonitis, AnxA1-deficient mice resolved inflammation similarly to WT mice, despite greater numbers of neutrophils and increased amounts of the chemokines KC and IL-1b at early time points (50). Additionally, AnxA1 KO mice showed defective GC suppression of inflammation in carrageenan-induced edema, zymosan-induced peritonitis, and Ag-induced arthritis, when GC was administered previously to the inflammatory stimulus (18,32).…”

Anti-inflammatory functions of glucocorticoid-induced genes

“…Inflammatory responses of an AnxA1 null mouse strain were exaggerated (Chatterjee et al, 2005;Hannon et al, 2003;Warne et al, 2006;Yang et al, 2004), and cells derived from these mice overexpressed COX-2, IL-1β and -6 in response to pro-inflammatory stimuli (Croxtall et al, 2003;Damazo et al, 2006;Hannon et al, 2003;Yang et al, 2006;Yona et al, 2004;Yona et al, 2005), suggesting that AnxA1 is an endogenous inhibitor of inflammatory responses . It should be noted here that cells lacking AnxA1 also showed differences of morphology (Croxtall et al, 2003) and phagocytic properties , which might be indicative of altered membrane physiology.…”

Analysis of clinical data and T helper 1/T helper 2 responses in patients with different clinical forms of leprosy

“…Sections for immunohistochemistry were prepared on slides with biological adhesive (BIOBOND; British Biocell International, Cardiff, UK) and subsequently incubated with the following reagents at room temperature, as described previously 25 : a) incubated in a water bath at 100°C in 0.21% sodium citrate solution for 30 min; b) blocked with 3% hydrogen peroxide in 70% methanol for 1h; c) permeabilized by incubation with 0.4% Tween 20 in phosphate buffered saline (PBS) for 15 min; d) blocked with 5% bovine serum albumin (BSA), diluted in PBS for 1h; e) incubated with the primary antibodies: rabbit anti-CD4 (ABCAM, USA) (1:100 in 1% BSA), mouse anti-CC-chemikine receptor 5 (CCR5) (ABCAM, USA) (1:100 in 1% BSA), for the detection of membrane markers for Th1, and anti-CCR4 mouse (ABCAM, USA) (1:100 in 1% BSA), for the detection of membrane marker for Th2. Slides were incubated with the antibody solution for 18h at 4°C in a moist chamber.…”