Extracellular matrix components in nasal polyposis

Lymphatic Vessels in Chronic Rhinosinusitis

Purpose

The purpose of this study was to analyze the nasal lymphatic system in order to uncover novel factors that might be involved in pathogenesis of chronic rhinosinusitis (CRS) with (CRSwNP) and without nasal polyps (CRSsNP).

Patients and Methods

Lymphatic vessels (LVs) and macrophages were localized and counted in the inferior and middle turbinate, the uncinate process and the ethmoid of CRSwNP and CRSsNP patients, the NP and the inferior turbinate of controls (n≥6 per group). Lysates of the same tissue types (n=7 per group) were analyzed for lymphatic vessel endothelial receptor 1 (LYVE-1), for matrix metalloproteinase 14 (MMP-14) and for Hyaluronic acid (HA) using ELISA. HA was localized in sections of CRSwNP NP, CRSsNP ethmoid and control inferior turbinate (n=6 per group). The results of HA levels were correlated to the number of macrophages in tissues. The nasal secretions of CRSwNP (n=28), CRSsNP (n=30), and control (n=30) patients were analyzed for LYVE-1 and HA using ELISA.

Results

The number of LVs was significantly lower in tissues of both CRS groups compared to the control. In the tissue lysates, LYVE-1 expression differed significantly between the CRSwNP tissues with a particularly high level in the NP. MMP-14 was significantly overexpressed in CRSwNP uncinate process. There were no significant differences in tissue HA expression. In the mucus LYVE-1 was significantly underexpressed in CRSsNP compared to CRSwNP and control, while HA was significantly underexpressed in both CRS groups. In the NP, HA and macrophages were accumulated particularly below the epithelium. Tissue levels of HA revealed a significant positive correlation with the number of macrophages.

Conclusion

CRS might be associated with an insufficient clearing of the nasal mucosa through the lymphatics. The accumulation of HA and macrophages might promote inflammation, fluid retention, and polyp formation. These results may provide novel CRS-associated factors.

Pericyte loss leads to microvessel remodeling and nasal polyp formation

BACKGROUND

Chronic rhinosinusitis (CRS) may be caused by increased vascular permeability and inflammatory cell leakage in the subepithelial tissue.

AIMS/OBJECTIVES

The aim of this study is to clarify the role of pericytes in tissue edema, microvessel dysfunction and vascular remodeling mechanisms in patients of CRS with nasal polyps (CRSwNP).

MATERIAL AND METHODS

A total of 63 tissue samples were collected, including 42 CRSwNP samples (22 eosinophilic CRSwNP (eCRSwNP) and 20 non-eosinophilic CRSwNP (non-eCRSwNP) samples) and 21 samples of CRS without nasal polyps (CRSsNP). The samples were stained by immunofluorescence to measure microvessel density (MVD) and microvessel pericyte coverage index (MPI).

RESULTS

We found that the albumin expression in the eCRSwNP group was significantly increased (p < .05). The MPI was significantly decreased (p <.05). There was a significant negative correlation between the MPI and the plasma albumin level (r=-0.82, p < .05). The MPI was negatively correlated with eosinophilic count (r=-0.77, p < .05). In the eCRSwNP group, the expressions of IL-4, Ang-1 and Ang-2 were increased compared with those in the control group.

CONCLUSIONS AND SIGNIFICANCE

Pericyte loss may induce microvessel dysfunction, affect the development of interstitial edema and eosinophilic exosmosis in eCRSwNP, and contribute to the formation and maintenance of nasal polyps.

Bioinspired Crowding Inhibits Explosive Ice Growth in Antifreeze Protein Solutions

Antifreeze (glyco)proteins (AF(G)Ps) are naturally evolved ice inhibitors incomparable to any man-made materials, thus, they are gaining intensive interest for cryopreservation and beyond. AF(G)Ps depress the freezing temperature (T_f) noncolligatively below the melting temperature (T_m), generating a thermal hysteresis (TH) gap, within which the ice growth is arrested. However, the ice crystals have been reported to undergo a retaliatory and explosive growth beyond the TH gap, which is lethal to living organisms. Although intensive research has been carried to inhibit such an explosive ice growth, no satisfactory strategy has been discovered until now. Here, we report that crowded solutions mimicking an extracellular matrix (ECM), in which AF(G)Ps are located, can completely inhibit the explosive ice growth. The crowded solutions are the condensates of liquid-liquid phase separation consisting of polyethylene glycol (PEG) and sodium citrate (SC), which possess a nanoscale network and strong hydrogen bond (HB) forming ability, completely different to crowded solutions made of single components, that is, PEG or SC. Due to these unique features, the dynamics of the water is significantly slowed down, and the energy needed for breaking the HB between water molecules is distinctly increased; consequently, ice growth is inhibited as the rate of water molecules joining the ice is substantially reduced. The present work not only opens a new avenue for cryopreservation, but also suggests that the ECM of cold-hardy organisms, which also exhibit great water confining properties, may have a positive effect in protecting the living organisms from freezing damage.

Hyaluronan synthases and hyaluronidases in nasal polyps

Nasal polyps (NPs) are benign lesions of nasal and paranasal sinuses mucosa affecting 1-4 % of all adults. Nasal polyposis affects the quality of patient's life as it causes nasal obstruction, postnasal drainage, purulent nasal discharge, hyposmia or anosmia, chronic sinusitis, facial pain and snoring. Without treatment, the disease can alter the craniofacial skeleton in cases of extended growth of polyps. The development of NPs is caused by the hyperplasia of nasal or paranasal sinuses mucosa, and edema of extracellular matrix. This is usually the result of high concentration of high molecular mass hyaluronan (HA) which is either overproduced or accumulated from blood supply. The size of HA presents high diversity and, especially in pathologic conditions, chains of low molecular mass can be observed. In NPs, chains of about 200 kDa have been identified and considered to be responsible for the inflammation. The purpose of the present study was the investigation, in NPs and normal nasal mucosa (NM), of the expression of the wild-type and alternatively spliced forms of hyaluronidases, their immunolocalization, and the expression of HA synthases to examine the isoform(s) responsible for the increased amounts of HA in NPs. Hyaluronidases' presence was examined on mRNA (RT-PCR analysis) and protein (immunohistochemistry) levels. Hyaluronan synthases' presence was examined on mRNA levels. Hyaluronidases were localized in the cytoplasm of epithelial and inflammatory cells, as well as in the matrix. On mRNA level, it was found that hyal-1-wt was decreased in NPs compared to NM and hyal-1-v3, -v4 and -v5 were substantially increased. Moreover, HAS2 and HAS3 were the only hyaluronan synthases detected, the expression of which was almost similar in NPs and NM. Overall, the results of the present study support that hyaluronidases are the main enzymes responsible for the decreased size of hyaluronan observed in NPs; thus they behave as inflammatory agents. Therefore, they could be a potential target for the design of a more advanced treatment for nasal polyposis.

[The functional disturbances in the vegetative nervous system associated with nasal and paranasal sinuses pathology]

The authors undertook the analysis of the literature data on the functional state of the vegetative nervous system (VNS) in the patients presenting with otorhinolaryngological pathology. These data suggest the participation of VNS in the origin and development of many ENT diseases. Moreover, they demonstrate the absence of commonly accepted approaches to the study of VNS and the assessment of clinical manifestations of vegetative dysfunction syndrome. The necessity of the further investigationsinto this problem is emphasized taking into consideration various types of vegetative constitution in the patients suffering from diseases of the upper respiratory tract.

Altered expression of tissue remodeling genes in a mouse model of acute allergic rhinitis

BACKGROUND

Osteogenesis, fibrosis, and scarring are prominent pathologic changes resulting from chronic sinonasal inflammation, and these tissue changes may increase the degree of disease symptomatology and the level of surgical difficulty. Members of the bone morphogenetic protein (BMP) and fibroblast growth factor (FGF) families of cytokines and the matrix metalloproteinase (MMP) family of endopeptidases are known to regulate tissue remodeling in other disease processes, but their role in acute and chronic sinonasal inflammation remains undefined.

METHODS

A previously described mouse model of acute allergic rhinitis secondary to Aspergillus fumigatis exposure in BALB/C mice was used. Intranasal challenge was performed 1 week following intraperitoneal sensitization with A. fumigatis extract and mice were sacrificed 6 hours (n = 8) and 24 hours (n = 8) later. Additional mice were intranasally challenged 3 times per week and sacrificed at the end of 7 days (n = 8) and 21 days (n = 8). The snouts were processed for quantitative reverse-transcription polymerase chain reaction (RT-PCR) and compared to untreated controls for messenger ribonucleic acid (mRNA) expression of BMP1, 2, 3, 4, 5, 6, 7, 8a, 8b, 9, 10, FGF1, 2, 3, 4, 5, 6, 7, 8, 10, and MMP1a, 2, 3, 7, 8, 9, 12, and 14. Additional 21-day-old mice were prepared for sinonasal histopathology. Control mice were treated with the same protocol, with intraperitoneal phosphate-buffered saline (PBS) and intranasal PBS substituted for A. fumigatis extract. Untreated mice were used for additional comparison.

RESULTS

Compared to both the PBS-treated and untreated control groups, statistically significant (p < 0.05) upregulation of MMP8 was observed in the 6-hour time point. Significant downregulation of MMP8 was observed at 1 week. Significant upregulation of FGF3 was observed at 1 week (p < 0.05). BMP3 and BMP5 were significantly downregulated in the 1-week group (p < 0.05). The mice exhibited histologic sinonasal changes consistent with allergic inflammation.

CONCLUSION

Intranasal exposure to A. fumigatis results in altered expression of several tissue remodeling cytokines at varying time points in the acute allergic rhinitis mouse model. These changes in cytokine regulation may subsequently contribute to sinonasal osteogenesis, scarring, and fibrosis as seen in chronic rhinosinusitis.

Tissue remodeling gene expression in a murine model of chronic rhinosinusitis

OBJECTIVE/HYPOTHESIS

The matrix metalloproteinase (MMP), fibroblast growth factor (FGF), and bone morphogenetic protein (BMP) families regulate tissue remodeling in many normal and pathophysiologic processes. We hypothesize that induction of chronic sinonasal inflammation will be associated with changes in regulation of these tissue remodeling cytokines.

METHODS

Balb/c mice aged 8 to 12 weeks were sensitized and treated with intranasal Aspergillus fumigatis (AF) three times per week for 1 week, 3 weeks, 2 months, and 3 months (n = 8 each time point). Sinonasal tissues were evaluated for changes in MMP, FGF, and BMP regulation using standard RT-PCR techniques. Additional snouts were processed for histology and immunohistochemistry. Untreated mouse snouts of identical age were used as controls.

RESULTS

Significant upregulation of MMP8 was observed at 2 months, and MMP1a, MMP7, MMP8, and MMP12 were all significantly upregulated at 3 months. FGF3 was significantly upregulated at 3 weeks and 3 months, and FGF5, FGF6, and FGF8 were all significantly upregulated at 3 months. BMP8b and BMP9 were significantly upregulated at 3 months. Histologic analysis revealed mucosal, stromal, and mucin gland hypertrophy, increased mucin production, and metaplasia with loss of cilia. Antibody staining was strongly positive in the AF-treated group.

CONCLUSIONS

Induction of CRS is associated with time-dependent changes in tissue remodeling cytokine expression occurring in conjuction with inflammatory tissue changes. Antibody staining for upregulated cytokines suggests local production within the sinonasal mucosa. Further study is required to better understand the association between BMP, FGF, and MMP regulation and tissue remodeling changes resulting from chronic inflammation.

Primary role of growth-related oncogene-alpha and granulocyte chemotactic protein-2 as neutrophil chemoattractants in chronic rhinosinusitis

BACKGROUND

The aetiology of chronic rhinosinusitis (CRS) remains unclear. The purpose of this study was to investigate neutrophil-attracting chemokine patterns in CRS without nasal polyposis.

METHODS

The biological activity of the chemokines was identified using a two-step high-performance liquid chromatography (HPLC) technique combined with a bioassay in extracts from 55 CRS patients, and in the turbinate mucosa (TM) of patients (N=51) undergoing septumplasty. The biologic activity of each chemokine was assessed using blocking antibodies to chemokines. Immunolocalization of detected neutrophil chemokines was performed by quantitative evaluation of immunohistochemistry. Besides, PCR analysis was performed to quantify neutrophil chemokine mRNA.

RESULTS

In CRS, the chemokines primarily detected by two-step HPLC were growth-related oncogene-alpha (GRO-alpha) and the granulocyte chemotactic protein-2 (GCP-2). Blocking of GCP-2 and GRO-alphad each resulted in chemotaxis inhibition rates of 43.3% and 35.9%, respectively, whereas anti-IL-8 and anti-ENA-78 had no effect. Both GCP-2 and GRO-alphad were generally synthesized by the surface epithelium and mucosal glands while GRO-alpha in particular was synthesized by endothelial cells, as shown by immunohistochemistry. The concentrations of the chemokines IL-8 and epithelial cell-derived neutrophil attractant-78 (ENA-78) were low in CRS and TM.

CONCLUSION

It appears that both GRO-alpha and GCP-2 contribute to neutrophil chemotaxis in CRS, whereas IL-8 and ENA-78 appear to be of secondary importance for the chemotaxis of neutrophils in this condition. The expression of chemokines in mucosal gland cells is the main phenomenon involved in constitutive neutrophil chemotaxis in the TM.