Signal transduction pathways (MAPKs, NF-κB, and C/EBP) regulating COX-2 expression in nasal fibroblasts from asthma patients with aspirin intolerance. PLoS One. 2012;7:e51281. [PMID: 23240010 PMCID: PMC3519844 DOI: 10.1371/journal.pone.0051281]

Chronic Rhinosinusitis with Nasal Polyps and Asthma

Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) characterized by a type 2 immune signature often have severe and recurrent disease. Lower airway conditions such as asthma are common comorbidities and share similar pathophysiology. CRSwNP with asthma is characterized by tissue eosinophilia and high local IgE levels. Clinically, CRSwNP with comorbid asthma is associated with more severe sinonasal symptoms and worse quality of life, and it is more difficult to treat both medically and surgically. Asthma in the presence of nasal polyposis is also more difficult to control, being more exacerbation prone, with increased airway obstruction and more extensive eosinophilic inflammation. Aspirin/nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (AERD) is a recognized phenotype of CRSwNP with comorbid asthma. Patients with CRSwNP with comorbid AERD are among those with the most severe and difficult-to-treat disease, and tend to have severe NP. The shared pathophysiology of the upper and lower airways has important implications for both the diagnosis and management of respiratory comorbidities. However, in clinical practice, the nose and lungs are often treated as separate entities. The underlying systemic inflammatory link between CRSwNP and asthma provides a compelling rationale for systemic treatment with novel biologics targeting shared underlying type 2 inflammatory pathways.

Defective Induction of COX-2 Expression by Psoriatic Fibroblasts Promotes Pro-inflammatory Activation of Macrophages

Fibroblasts play an important role as members of the innate immune system through the secretion of COX-2-derived inflammatory mediators such as prostaglandin E₂ (PGE₂). However, it has been described that dermal fibroblasts behave like mesenchymal stem cells reducing lymphocyte recruitment and dendritic cell activation through PGE₂ release. As the role of fibroblasts in psoriasis remains poorly characterized, in the present study we have evaluated the possible influence of PGE₂ derived from dermal fibroblasts as modulator of the immune response in psoriatic skin. Our results indicate that under inflammatory conditions, psoriatic fibroblasts showed defective induction of COX-2, which resulted in diminished production of PGE₂, in contrast to healthy fibroblasts. This phenotype correlated with deficient c-Jun N-terminal kinase (JNK) activation, in accordance with the hypothesis that alterations in members of the JNK pathway are associated with psoriasis. Furthermore, conditioned medium from psoriatic fibroblasts promoted the polarization of monocytic cells toward a pro-inflammatory profile, effect that was mimicked in healthy fibroblasts after pre-incubation with indomethacin. These results are consistent with a prominent role of dermal fibroblasts in the regulation of inflammatory response through the participation of COX-derived metabolites. This resolutive behavior seems to be defective in psoriatic fibroblasts, offering a possible explanation for the chronification of the disease and for the exacerbation triggered by nonsteroidal anti-inflammatory drugs (NSAIDS) such as indomethacin.

Clinical efficacy of recombinant human latrophilin 3 antibody in the treatment of pediatric asthma

Pediatric asthma is a chronic pulmonary inflammatory disease featuring hypersecretion of mucus and inflammation in the airway, resulting in dysfunction of the airway smooth muscle. Previous evidence demonstrated that latrophilins, a novel family of receptors, present a beneficial effect on airway smooth muscle cells. In the present study, the therapeutic effects of recombinant human latrophilin 3 (rhLPHN3) antibody (Ab) in patients with pediatric asthma were investigated, and the molecular mechanism underlying the function of LPHN3 in the treatment of asthma in clinical practice was examined. A total of 342 pediatric asthma cases were recruited and randomly divided into three groups, receiving treatment with rhLPHN3 Ab (n=134), salbutamol (n=108) or montelukast (n=100) by nasal aerosolization. Each group received the respective clinically tested dose for 16 weeks. Inflammatory factors interleukin (IL)-10, IL-17, IL-4, matrix metallopeptidase-9 (MMP-9), interferon-γ (IFN-γ) and transforming growth factor-β (TGF-β) levels in peripheral blood mononuclear cells were analyzed prior to and post treatment. The clinical outcomes revealed that pathological alterations were significantly improved following treatment with rhLPHN3 Ab for patients with pediatric asthma when compared with those receiving salbutamol and montelukast. It was also observed that rhLPHN3 Ab downregulated the plasma concentration levels of IL-10, IL-17, IL-4 and MMP-9, and upregulated IFN-γ and TGF-β levels in the three groups. In addition, clinical data demonstrated that rhLPHN3 Ab significantly promoted E-selectin and mucin 5AC expression, as well as improved the activation of nuclear factor (NF)-κB p65 DNA binding activity and the phosphorylation levels of protein kinase A. Furthermore, rhLPHN3 Ab markedly improved adhesion and proliferation of airway smooth muscle cells, which led to promotion of the contraction of these cells. In conclusion, these clinical data suggest that rhLPHN3 Ab serves an important role in the inhibition of inflammatory mediators through downregulation of NF-κB signaling pathway, which contributes to airway remodeling and bronchodilation in patients with pediatric asthma.

Release of cyclooxygenase-2 and lipoxin A4 from blood leukocytes in aspirin-exacerbated respiratory disease

BACKGROUND

The release of cyclooxygenase-2 (COX-2) and lipoxin A4 (LXA4) from blood mononuclear cells in patients with aspirin-exacerbated respiratory disease (AERD) is only partially understood.

OBJECTIVE

To investigate the presence of COX-2 and LXA4 in peripheral blood mononuclear cells (PBMC) derived from patients with AERD and with nasal polyps (NP) (designated as the AERD-NP group), patients with NP without AERD (the NP group), and healthy controls without sinus disease (the control group).

METHODS

Blood was taken from 14 patients in the AERD-NP group, 6 patients in the NP group, and 8 healthy subjects in the control group. After culturing of human PBMC, the presence of COX-2 protein and LXA4 (ELISA) was detected in the supernatant, and the results were compared among the groups.

RESULTS

COX-2 and LXA4 were detectable after culturing of PBMC in all patients in the AERD-NP and NP groups and in the control subjects. COX-2 was highest in the patients in the AERD-NP group, but the difference was not significant compared with patients with non-AERD polyp and with the control subjects. LXA4 was also highest in the AERD-NP group, but the difference was also not significant compared with the patients who were non-AERD polyp and the control subjects.

CONCLUSION

Neither the release of COX-2 or LXA4 was different between the patients with AERD and with NPs, the patients without AERD and with NPs, and the healthy control group. The release of these proteins in AERD needs further investigation.

Acacia ferruginea inhibits inflammation by regulating inflammatory iNOS and COX-2

Inflammation is a local defensive reaction of a host to cellular injury or infection. Prolonged inflammation can contribute to pathogenesis of many disorders. Identification of naturally occurring phytoconstituents that can suppress inflammatory mediators can lead to the discovery of anti-inflammatory therapeutics. Acacia ferruginea is used traditionally to treat numerous ailments including hemorrhage, irritable bowel syndrome and leprosy. The present study evaluated the anti-inflammatory activity of A. ferruginea extract against acute (carrageenan) and chronic (formaldehyde) inflammation in Balb/c mice. Pre-treatment with A. ferruginea extract (10 mg/kg BW) for 5 consecutive days via intraperitonial (IP) administration significantly inhibited subsequent induction of paw edema in both models; the effects were comparable to that of the standard drug indomethacin. The results also showed the A. ferruginea extract significantly inhibited nitric oxide (NO) synthesis and iNOS expression (as measured in serum), diminished inflammation in - and neutrophil infiltration to - the paw tissues and led to a reduction in the number of COX-2(+) immunoreative cells (as evidenced by histologic and immunohistochemical analyses) in the paws relative to those in paws of mice that received the irritants only. Further, in vitro studies showed the extract could significantly scavenge free radicals generated as in DPPH and NO radical generating assays. Taken together, the results showed that A. ferruginea extract imparted potent anti-oxidant and -inflammatory effects, in part by maintaining oxidative homeostasis, inhibiting NO synthesis and suppressing iNOS and COX-2 expression and so could potentially be exploited as a potential plant-based medication against inflammatory disorders.

Targeting TLR4/MAPKs signaling pathway: A better option for therapeutic inhibition of atherosclerosis

Cardiovascular diseases, especially atherosclerosis, found to be the dreadful diseases worldwide. There are diverse pathways associated with the progression of atherosclerosis. One of the important signaling pathways to target atherosclerotic plaque rupture is toll-like receptor 4 (TLR4) Pathway. Several studies are available for illustrating the role of TLR4 in health and diseases. Different types of immune cell are activated in atherosclerosis but primary cells that are activated by the TLR4 signaling are macrophages and endothelial cells. Mechanisms by which macrophages uptake lipids are diverse and it is very important to target signaling pathway responsible for controlling foam cell formation. The process of macrophages transformed foam cell formation is the critical event in progression of atherosclerotic lesion and TLR4 found to have actively participate in the event through mitogen activated protein kinases (MAPKs) activation. The activation of MAPKs signaling pathway leads to the accumulation of cholesterol in the macrophages and also contribute to the dissociation of IκB and the nuclear translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 subunit, thereby activating key inflammatory cascade activation by MAPKs/NF-κB signaling pathway to induce toxicity by activating different inflammatory parameters. Hence, the review focussed on exploring the role of TLR4/MAPKs signaling pathway for the therapeutic inhibition of atherosclerosis.

Sphingolipids and antimicrobial peptides: function and roles in atopic dermatitis

Inflammatory skin diseases such as atopic dermatitis (AD) and rosacea were complicated by barrier abrogation and deficiency in innate immunity. The first defender of epidermal innate immune response is the antimicrobial peptides (AMPs) that exhibit a broad-spectrum antimicrobial activity against multiple pathogens, including Gram-positive and Gram-negative bacteria, viruses, and fungi. The deficiency of these AMPs in the skin of AD fails to protect our body against virulent pathogen infections. In contrast to AD where there is a suppression of AMPs, rosacea is characterized by overexpression of cathelicidin antimicrobial peptide (CAMP), the products of which result in chronic epidermal inflammation. In this regard, AMP generation that is controlled by a key ceramide metabolite S1P-dependent mechanism could be considered as alternate therapeutic approaches to treat these skin disorders, i.e., Increased S1P levels strongly stimulated the CAMP expression which elevated the antimicrobial activity against multiple pathogens resulting the improved AD patient skin.

Low prostaglandin E2 and cyclooxygenase expression in nasal mucosa fibroblasts of aspirin-intolerant asthmatics

BACKGROUND AND OBJECTIVE

Anomalies in the regulation of cyclooxygenase (COX)-1 and -2 have been described in nasal polyps of aspirin-induced asthma (AIA). Whether these anomalies are specific to nasal polyps or affect all the nasal mucosa (NM) of upper airways is still unclear. The objective of this study was to compare the COX pathway in NM of AIA patients with the NM of control subjects.

METHODS

Fibroblasts were isolated from NM of five AIA patients (AIA-NM) and five control subjects (control-NM). Cells were treated with 10 ng/mL interleukin (IL)-1β for up to 72 h. Prostaglandin E2 (PGE2 ) production was measured by enzyme-linked immunosorbent assay (ELISA), expression of COX-1 protein by Western blot and COX-2 protein by ELISA, Western blot and immunofluorescence techniques.

RESULTS

IL-1β increased PGE2 production and COX-1 protein expression in control-NM fibroblasts, but no changes were found in AIA-NM. IL-1β provoked a significant time-dependent increase in COX-2 protein expression in control-NM fibroblasts but had a very mild effect on COX-2 protein expression in AIA-NM.

CONCLUSIONS

Our data suggest that abnormalities in the COX pathway are not a phenomenon exclusive to nasal-polyp mucosa as they are also present in all the NM of AIA patients. These anomalies may be involved in the pathogenesis of airway inflammation and non-steroidal anti-inflammatory drug intolerance in asthma patients with chronic rhinosinusitis and nasal polyposis.