Effect of lipopolysaccharide on glucocorticoid receptor function in control nasal mucosa fibroblasts and in fibroblasts from patients with chronic rhinosinusitis with nasal polyps and asthma.

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory disease of the upper airways frequently associated with asthma. Bacterial infection is a feature of CRSwNP that can aggravate the disease and the response to glucocorticoid treatment.

Objective: We examined whether the bacterial product lipopolysaccharide (LPS) reduces glucocorticoid receptor (GR) function in control nasal mucosa (NM) fibroblasts and in nasal polyp (NP) fibroblasts from patients with CRSwNP and asthma.

Proteasome inhibition reduces proliferation, collagen expression, and inflammatory cytokine production in nasal mucosa and polyp fibroblasts.

Proteasome inhibitors, used in cancer treatment for their proapoptotic effects, have anti-inflammatory and antifibrotic effects on animal models of various inflammatory and fibrotic diseases. Their effects in cells from patients affected by either inflammatory or fibrotic diseases have been poorly investigated. Nasal polyposis is a chronic inflammatory disease of the sinus mucosa characterized by tissue inflammation and remodeling.

Impact of cell culture methods on the outcomes of the in vitro inflammatory response in nasal polyps.

Background: In vitro culture of nasal polyp cells is frequently used in the investigation of inflammatory mechanisms and effect of treatments in nasal polyposis. Research outcomes may, however, be influenced by the culture methodology used.

Methods: Nasal polyp and nasal mucosa in vitro fibroblast cultures were pre-treated with foetal bovine serum (FBS)-free culture medium or medium supplemented with either FBS or charcoal-stripped (cs) FBS.

Nuclear translocation of the glucocorticoid receptor in fibroblasts of asthmatic patients with nasal polyposis insensitive to glucocorticoid treatment.

Background: Nasal polyposis (NP) is treated with topical glucocorticoids (GC). Some patients require endoscopic nasal surgery because GC treatment is ineffective. To exert its function, the GC needs to bind with the GC receptor (GR) and the GC-GR complex moves to the cell nucleus.

Lower sensitivity of nasal polyp fibroblasts to glucocorticoid anti-proliferative effects.

Background: Treatment with glucocorticoids (GCs) is the cornerstone of nasal polyp (NP) therapy, but some patients respond poorly to them. Fibroblasts are involved in both inflammation and remodelling of NP. We aimed to evaluate whether NP fibroblasts are less sensitive to GCs' anti-proliferative and anti-inflammatory effects, compared to nasal mucosa (NM) fibroblasts.