Basic fibroblast growth factor expression in recurrent versus non-recurrent nasal polyposis

Expression of matrix metalloproteinase 2 and 9 and tissue inhibitor of metalloproteinase 1 in nonrecurrent vs recurrent nasal polyps

BACKGROUND

Matrix metalloproteinases (MMPs) 2 and 9 are a group of Zn2+-dependent endopeptidases to remodel the extracellular matrix. The association of these 2 endopeptidases with the development of morphologic changes in nasal polyps was previously described.

OBJECTIVE

To determine whether MMP-2, MMP-9, and tissue inhibitor of MMP-1 (TIMP-1) play a role in the recurrence of nasal polyps.

METHODS

To compare MMP-2, MMP-9, and TIMP-1 expression in recurrent vs nonrecurrent polyps, nasal polyps (NPs) and recurrent nasal polyps (RNPs) were obtained from 15 NP patients with chronic rhinosinusitis (CRS) undergoing endoscopic sinus surgery (ESS) and 15 RNP patients with CRS undergoing revision ESS. Fifteen specimens of inferior turbinate mucosa from patients undergoing nasal septal surgery were used as control. Through real-time polymerase chain reaction and immunohistochemistry, MMP-2, MMP-9, and TIMP-1 expressions were measured among controls, NP patients, and RNP patients.

RESULTS

Expression of MMP-9 messenger RNA in the NP patients was significantly higher than in the controls. In addition, expression of MMP-9 messenger RNA in the RNP patents was significantly increased compared with NP patients. With immunohistochemistry, a more increased expression of MMP-9 was observed in NP patients than controls. Expression of MMP-9 in RNP patients was also significantly high compared with NP patients, particularly in stroma.

CONCLUSION

Expression of MMP-9 is increased in NP patients, and it is so more in the mucosa of RNP patients. Increased expression of MMP-9 is particularly found in the stoma of RNP patients, and it may contribute to the recurrence of NP.

Expression of transcription factors NF-kappaB and AP-1 in nasal polyposis

BACKGROUND

The treatment and prognosis of nasal polyposis (NP) may be influenced by transcription factors, but their expression is poorly understood.

OBJECTIVE

To determine the expression of transcription factors [(nuclear factor-kappaB) NF-kappaB and (activator protein) AP-1], cytokines [IL-1beta, TNF-alpha and (granulocytes and macrophage colony-stimulating factor) GM-CSF], growth factor (b-FGF), chemokine (eotaxin-2) and adhesion molecule (ICAM-1) in NP in comparison with nasal mucosa controls. Methods Cross-sectional study. Twenty biopsies of nasal polyps were compared with eight middle turbinate biopsies. p65, c-Fos, IL-1beta, TNF-alpha, ICAM-1, b-FGF, eotaxin-2 and GM-CSF were analysed through RQ-PCR, and p65 and c-Fos were also analysed through Western blotting.

RESULTS

NF-kappaB expression was increased in patients with NP when compared with control mucosa (P<0.05), whereas AP-1 expression did not differ significantly between groups. Expressions of IL-1beta, eotaxin-2 and b-FGF were also increased in patients with NP compared with controls (P<0.05).

CONCLUSIONS

The transcription factor NF-kappaB is more expressed in NP than in control mucosa. This is important in NP because NF-kappaB can induce the transcription of cytokines, chemokines and adhesion molecules, which play an important role in the inflammatory process. Moreover, transcription factors influence the response to corticosteroids, which are the basis of NP treatment. Transcription factor AP-1 does not seem to have a significant role in the pathological process.

Tissue remodelling in upper airways: where is the link with lower airway remodelling?

Tissue remodelling reported in upper airways include epithelial hyperplasia, increased matrix deposition in the nasal or paranasal lining, matrix degradation and accumulation of plasma proteins. Genetic influences, foetal exposures and early life events may contribute to structural changes such as subepithelial fibrosis from an early age. Other structural alterations are related to duration of the disease and long-term uncontrolled inflammation. Structural changes may increase alteration of the protective functions of the upper airways namely by affecting mucociliary clearance and conditioning of inspired air. The sequences of tissue changes during wound repair of upper airway mucosa after surgery are illustrative of the complexicity of tissue modelling and remodelling and could be considered as an important source of information for a better understanding of the complex relationship between inflammatory reaction, of the subsequent tissue damages and fibroblast metabolism of upper airways.