Spatial expression of two anti-inflammatory mediators, annexin 1 and galectin-1, in nasal polyposis

Preterm Lung Exhibits Distinct Spatiotemporal Proteome Expression at Initiation of Lung Injury

The development of regional lung injury in the preterm lung is not well understood. This study aimed to characterize time-dependent and regionally specific injury patterns associated with early ventilation of the preterm lung using a mass spectrometry-based proteomic approach. Preterm lambs delivered at 124-127 days gestation received 15 or 90 minutes of mechanical ventilation (positive end-expiratory pressure = 8 cm H₂O, Vt = 6-8 ml/kg) and were compared with unventilated control lambs. At study completion, lung tissue was taken from standardized nondependent and dependent regions, and assessed for lung injury via histology, quantitative PCR, and proteomic analysis using Orbitrap-mass spectrometry. Ingenuity pathway analysis software was used to identify temporal and region-specific enrichments in pathways and functions. Apoptotic cell numbers were ninefold higher in nondependent lung at 15 and 90 minutes compared with controls, whereas proliferative cells were increased fourfold in the dependent lung at 90 minutes. The relative gene expression of lung injury markers was increased at 90 minutes in nondependent lung and unchanged in gravity-dependent lung. Within the proteome, the number of differentially expressed proteins was fourfold higher in the nondependent lung than the dependent lung. The number of differential proteins increased over time in both lung regions. A total of 95% of enriched canonical pathways and 94% of enriched cellular and molecular functions were identified only in nondependent lung tissue from the 90-minute ventilation group. In conclusion, complex injury pathways are initiated within the preterm lung after 15 minutes of ventilation and amplified by continuing ventilation. Injury development is region specific, with greater alterations within the proteome of nondependent lung.

Galectin-1: A Jack-of-All-Trades in the Resolution of Acute and Chronic Inflammation

Regulatory signals provide negative input to immunological networks promoting resolution of acute and chronic inflammation. Galectin-1 (Gal-1), a member of a family of evolutionarily conserved glycan-binding proteins, displays broad anti-inflammatory and proresolving activities by targeting multiple immune cell types. Within the innate immune compartment, Gal-1 acts as a resolution-associated molecular pattern by counteracting the synthesis of proinflammatory cytokines, inhibiting neutrophil trafficking, targeting eosinophil migration and survival, and suppressing mast cell degranulation. Likewise, this lectin controls T cell and B cell compartments by modulating receptor clustering and signaling, thus serving as a negative-regulatory checkpoint that reprograms cellular activation, differentiation, and survival. In this review, we discuss the central role of Gal-1 in regulatory programs operating during acute inflammation, autoimmune diseases, allergic inflammation, pregnancy, cancer, and infection. Therapeutic strategies aimed at targeting Gal-1-glycan interactions will contribute to overcome cancer immunosuppression and reinforce antimicrobial immunity, whereas stimulation of Gal-1-driven immunoregulatory circuits will help to mitigate exuberant inflammation.

Divergent Annexin A1 expression in periphery and gut is associated with systemic immune activation and impaired gut immune response during SIV infection

HIV-1 disease progression is paradoxically characterized by systemic chronic immune activation and gut mucosal immune dysfunction, which is not fully defined. Annexin A1 (ANXA1), an inflammation modulator, is a potential link between systemic inflammation and gut immune dysfunction during the simian immunodeficiency virus (SIV) infection. Gene expression of ANXA1 and cytokines were assessed in therapy-naïve rhesus macaques during early and chronic stages of SIV infection and compared with SIV-negative controls. ANXA1 expression was suppressed in the gut but systemically increased during early infection. Conversely, ANXA1 expression increased in both compartments during chronic infection. ANXA1 expression in peripheral blood was positively correlated with HLA-DR+CD4+ and CD8+ T-cell frequencies, and negatively associated with the expression of pro-inflammatory cytokines and CCR5. In contrast, the gut mucosa presented an anergic cytokine profile in relation to ANXA1 expression. In vitro stimulations with ANXA1 peptide resulted in decreased inflammatory response in PBMC but increased activation of gut lymphocytes. Our findings suggest that ANXA1 signaling is dysfunctional in SIV infection, and may contribute to chronic inflammation in periphery and with immune dysfunction in the gut mucosa. Thus, ANXA1 signaling may be a novel therapeutic target for the resolution of immune dysfunction in HIV infection.

Host and Toxoplasma gondii genetic and non-genetic factors influencing the development of ocular toxoplasmosis: A systematic review

Toxoplasmosis is a cosmopolitan infection caused by the apicomplexan parasite Toxoplasma gondii. This infectious disease is widely distributed across the world where cats play an important role in its spread. The symptomatology caused by this parasite is diverse but the ocular affectation emerges as the most important clinical phenotype. Therefore, we conducted a systematic review of the current knowledge of ocular toxoplasmosis from the genetic diversity of the pathogen towards the treatment available for this infection. This review represents an update to the scientific community regarding the genetic diversity of the parasite, the genetic factors of the host, the molecular pathogenesis and its association with disease, the available diagnostic tools and the available treatment of patients undergoing ocular toxoplamosis. This review will be an update for the scientific community in order to encourage researchers to deploy cutting-edge investigation across this field.

Ac2-26 Mimetic Peptide of Annexin A1 Inhibits Local and Systemic Inflammatory Processes Induced by Bothrops moojeni Venom and the Lys-49 Phospholipase A2 in a Rat Model

Annexin A1 (AnxA1) is an endogenous glucocorticoid regulated protein that modulates anti-inflammatory process and its therapeutic potential has recently been recognized in a range of systemic inflammatory disorders. The effect of the N-terminal peptide Ac2-26 of AnxA1 on the toxic activities of Bothrops moojeni crude venom (CV) and its myotoxin II (MjTX-II) were evaluated using a peritonitis rat model. Peritonitis was induced by the intraperitoneal injection of either CV or MjTX-II, a Lys-49 phospholipase A2. Fifteen minutes after the injection, the rats were treated with either Ac2-26 or PBS. Four hours later, the CV and MjTX-II-induced peritonitis were characterized by neutrophilia (in the peritoneal exudate, blood and mesentery) and increased number of mesenteric degranulated mast cells and macrophages. At 24 hours post-injection, the local inflammatory response was attenuated in the CV-induced peritonitis while the MjTX-II group exhibited neutrophilia (peritoneal exudates and blood). Ac2-26 treatment prevented the influx of neutrophils in MjTX-II-induced peritonitis and diminished the proportion of mesenteric degranulated mast cells and macrophages in CV-induced peritonitis. Additionally, CV and MjTX-II promoted increased levels of IL-1β and IL-6 in the peritoneal exudates which were significantly reduced after Ac2-26 treatment. At 4 and 24 hours, the endogenous expression of AnxA1 was upregulated in the mesenteric neutrophils (CV and MjTX-II groups) and mast cells (CV group). In the kidneys, CV and MjTX-II administrations were associated with an increased number of macrophages and morphological alterations in the juxtamedullary nephrons in proximal and distal tubules. Ac2-26 promoted significant recovery of the juxtamedullary structures, decreased the number of macrophages and diminished the AnxA1 in epithelial cells from distal tubules and renal capsules. Our results show that Ac2-26 treatment significantly attenuates local and systemic inflammatory processes and indicate this peptide as a potential target for the development of new therapeutic strategies for the snakebite envenomation treatment.

Inflammation and cancer: role of annexin A1 and FPR2/ALX in proliferation and metastasis in human laryngeal squamous cell carcinoma

The anti-inflammatory protein annexin A1 (ANXA1) has been associated with cancer progression and metastasis, suggesting its role in regulating tumor cell proliferation. We investigated the mechanism of ANXA1 interaction with formylated peptide receptor 2 (FPR2/ALX) in control, peritumoral and tumor larynx tissue samples from 20 patients, to quantitate the neutrophils and mast cells, and to evaluate the protein expression and co-localization of ANXA1/FPR2 in these inflammatory cells and laryngeal squamous cells by immunocytochemistry. In addition, we performed in vitro experiments to further investigate the functional role of ANXA1/FPR2 in the proliferation and metastasis of Hep-2 cells, a cell line from larynx epidermoid carcinoma, after treatment with ANXA1_2–26 (annexin A1 N-terminal-derived peptide), Boc2 (antagonist of FPR) and/or dexamethasone. Under these treatments, the level of Hep-2 cell proliferation, pro-inflammatory cytokines, ANXA1/FPR2 co-localization, and the prostaglandin signalling were analyzed using ELISA, immunocytochemistry and real-time PCR. An influx of neutrophils and degranulated mast cells was detected in tumor samples. In these inflammatory cells of peritumoral and tumor samples, ANXA1/FPR2 expression was markedly exacerbated, however, in laryngeal carcinoma cells, this expression was down-regulated. ANXA1_2–26 treatment reduced the proliferation of the Hep-2 cells, an effect that was blocked by Boc2, and up-regulated ANXA1/FPR2 expression. ANXA1_2–26 treatment also reduced the levels of pro-inflammatory cytokines and affected the expression of metalloproteinases and EP receptors, which are involved in the prostaglandin signalling. Overall, this study identified potential roles for the molecular mechanism of the ANXA1/FPR2 interaction in laryngeal cancer, including its relationship with the prostaglandin pathway, providing promising starting points for future research. ANXA1 may contribute to the regulation of tumor growth and metastasis through paracrine mechanisms that are mediated by FPR2/ALX. These data may lead to new biological targets for therapeutic intervention in human laryngeal cancer.

Galectin fingerprinting in naso-sinusal diseases

Galectins, a family of endogenous lectins, are multifunctional effectors that act at various sites and can be used in immunohistochemical localization studies of diseased states. Since they form a potentially cooperative and antagonistic network, we tested the hypothesis that histopathological fingerprinting of galectins could refine the molecular understanding of naso-sinusal pathologies. Using non-cross-reactive antibodies against galectin-1, -3, -4, -7, -8 and -9, we characterized the galectin profiles in chronic rhinosinusitis, nasal polyposis, inverted papillomas and squamous cell carcinomas. The expression, signal location and quantitative parameters describing the percentage of positive cells and labeling intensity were assessed for various cases. We discovered that inverted papillomas showed a distinct galectin immunohistochemical profile. Indeed, epithelial overexpression of galectin-3 (P=0.0002), galectin-4 (P<10⁻⁶), galectin-7 (P<10⁻⁶) and galectin-9 (P<10⁻⁶) was observed in inverted papillomas compared to non-malignant diseases. Regarding carcinomas, we observed increased expression of galectin-9 (P<10⁻⁶) in epithelial cells compared to non-tumor pathologies. Our results suggest that galectin-3, -4, -7 and -9 could be involved in the biology of inverted papillomas. In addition, we observed that the expression of galectin in naso-sinusal diseases seems to be affected by tumor progression and not inflammatory or allergic phenomena.

Expression of annexin-A1 and galectin-1 anti-inflammatory proteins and mRNA in chronic gastritis and gastric cancer

Objective. The anti-inflammatory proteins annexin-A1 and galectin-1 have been associated with tumor progression. This scenario prompted us to investigate the relationship between the gene and protein expression of annexin-A1 (ANXA1/AnxA1) and galectin-1 (LGALS1/Gal-1) in an inflammatory gastric lesion as chronic gastritis (CG) and gastric adenocarcinoma (GA) and its association with H. pylori infection. Methods. We analyzed 40 samples of CG, 20 of GA, and 10 of normal mucosa (C) by the quantitative real-time PCR (qPCR) technique and the immunohistochemistry assay. Results. High ANXA1 mRNA expression levels were observed in 90% (36/40) of CG cases (mean relative quantification RQ = 4.26  ±  2.03) and in 80% (16/20) of GA cases (mean RQ = 4.38  ±  4.77). However, LGALS1 mRNA levels were high (mean RQ = 2.44  ±  3.26) in 60% (12/20) of the GA cases, while low expression was found in CG (mean RQ = 0.43 ± 3.13; P < 0.01). Normal mucosa showed modest immunoreactivity in stroma but not in epithelium, while stroma and epithelium displayed an intense immunostaining in CG and GA for both proteins. Conclusion. These results have provided evidence that galectin-1 and mainly annexin-A1 are overexpressed in both gastritis and gastric cancer, suggesting a strong association of these proteins with chronic gastric inflammation and carcinogenesis.

Chronic rhinosinusitis with nasal polyps: a proteomic analysis

OBJECTIVES

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a severe subtype of chronic rhinosinusitis that can affect patients despite medical and surgical interventions. The purpose of this study was to utilize the techniques of proteomics to investigate differences in protein abundance within the sinonasal mucosa of patients with CRSwNP compared to healthy controls.

METHODS

In a case-control study at a tertiary-care academic medical center, sinonasal mucosa was harvested from 3 patients with CRSwNP and 3 control patients undergoing transsphenoidal excision of pituitary tumors. Two-dimensional gel electrophoresis was used to identify proteins with elevated or reduced abundance in CRSwNP patients compared to controls. The proteins showing the greatest abundance differences were characterized by mass spectrometry.

RESULTS

More than 300 differentially abundant proteins (p < or = 0.05) were identified. Many of these protein species were involved in the host inflammatory response. Proteins up-regulated in CRSwNP patients included eosinophil lysophospholipase by a ratio (R) of 18.13, RHO-GDP dissociation inhibitor 2 (R = 2.80), and apolipoprotein A-1 (R = 1.73). Down-regulated proteins in CRSwNP patients included catalase (R = -5.87), annexin A1 (R = -6.27), and keratin II-8 (R = -6.73). A detailed analysis of additional protein species is outlined.

CONCLUSIONS

The proteomic approach allows detection of significant differences in protein abundance in CRSwNP and provides unique insight into the pathophysiology of this common disease.

Exploiting the Annexin A1 pathway for the development of novel anti-inflammatory therapeutics

The appreciation that the inflammatory reaction does not 'spontaneously' finish, but rather that inflammatory resolution is an active phenomenon brought about by endogenous anti-inflammatory agonists opens multiple opportunities for a reassessment of the complexity of inflammation and its main mediators. This review dwells on one of these pathways, the one centred around the glucocorticoid-regulated protein Annexin A1 and its G protein-coupled receptor. In recent years, much of the knowledge detailing the processes by which Annexin A1 expresses its anti-inflammatory role on innate immunity has been produced. Moreover, the generation of the Annexin A1 null mouse colony has provided important proof-of-concept experiments demonstrating the inhibitory properties of this mediator in the context of inflammatory and/or tissue-injury models. Therefore, Annexin A1 acts as a pivotal homeostatic mediator, where if absent, inflammation would overshoot and be prolonged. This new understanding scientific information could guide us onto the exploitation of the biological properties of Annexin A1 and its receptor to instigate novel drug discovery programmes for anti-inflammatory therapeutics. This line of research relies on the assumption that anti-inflammatory drugs designed upon endogenous anti-inflammatory mediators would be burdened by a lower degree of secondary effects as these agonists would be mimicking specific pathways activated in our body for safe disposal of inflammation. We believe that the next few years will produce examples of such new drugs and the validity of this speculation could then be assessed.

Expression of annexin A1 mRNA in peripheral blood from oral squamous cell carcinoma patients

Several studies have been suggesting annexin A1 protein as an active player in tumorigenesis of many organs. Nevertheless, its tumor biomarker role has been mainly studied in tissues by immunohistochemistry or cell culture. Hence, in this investigation, the peripheral blood from 27 oral squamous cell carcinoma (OSCC) patients and 25 negative control individuals were examined by quantitative real-time PCR. Down-regulated ANXA1 expression at mRNA level was observed in OSCC samples (p=0.026). Significantly diminished mRNA levels correlated to age, sex and the anatomical site of the tumor lesion were observed. Moreover, the ROC curve analysis revealed the performance of ANXA1 expression as a suitable biomarker for patients with oral cavity cancer, especially those with 60years of age or older and/or women. For the first time, ANXA1 mRNA is revealed as blood-based biomarker, and its adoption for complementary non-invasive diagnosis of OSCC is suggested. These results suggest that, beyond the anti-inflammatory function, annexin A1 may also play a tumor suppressor role in peripheral blood cells, such as leukocytes.