The role of matrix metalloproteinases in recurrent tonsillitis

The immunomodulatory role of matrix metalloproteinases in colitis-associated cancer

Matrix metalloproteinases (MMPs) are an important class of enzymes in the body that function through the extracellular matrix (ECM). They are involved in diverse pathophysiological processes, such as tumor invasion and metastasis, cardiovascular diseases, arthritis, periodontal disease, osteogenesis imperfecta, and diseases of the central nervous system. MMPs participate in the occurrence and development of numerous cancers and are closely related to immunity. In the present study, we review the immunomodulatory role of MMPs in colitis-associated cancer (CAC) and discuss relevant clinical applications. We analyze more than 300 pharmacological studies retrieved from PubMed and the Web of Science, related to MMPs, cancer, colitis, CAC, and immunomodulation. Key MMPs that interfere with pathological processes in CAC such as MMP-2, MMP-3, MMP-7, MMP-9, MMP-10, MMP-12, and MMP-13, as well as their corresponding mechanisms are elaborated. MMPs are involved in cell proliferation, cell differentiation, angiogenesis, ECM remodeling, and the inflammatory response in CAC. They also affect the immune system by modulating differentiation and immune activity of immune cells, recruitment of macrophages, and recruitment of neutrophils. Herein we describe the immunomodulatory role of MMPs in CAC to facilitate treatment of this special type of colon cancer, which is preceded by detectable inflammatory bowel disease in clinical populations.

Selected cytokines in hypertrophic adenoids in children suffering from otitis media with effusion

OBJECTIVES

The aim of the current study was to assess the levels of MMP-8, MMP-9 and TIMP-1 in the group of children with adenoids who suffered from exudative otitis media.

METHODS

The study included 20 patients (10 females and 10 males) with adenoid hypertrophy coexisting with otitis media with effusion. The reference group included 24 patients (10 females and 14 males) with adenoid hypertrophy without otitis media. The levels of MMP-8, MMP-9 and TIMP-1 were determined in supernatants obtained from phytohemagglutinin (PHA)-stimulated cell cultures of the tonsils, using commercial enzyme-linked immunosorbent assay kits (R@D Systems, USA).

RESULTS

The median MMP-8, MMP-9 and TIMP-1 concentrations (220.8 ng/mL, 311.1 ng/mL, 53.5 ng/mL, respectively) in the study group were significantly higher (p = 0.000, p = 0.000, p = 0.048, respectively) than those in the reference group (93.5 ng/mL, 112.5 ng/mL, 36.95 ng/mL, respectively). ROC analysis revealed that the area under a curve (AUC) for both metalloproteinases MMP-8 and MMP-9 was 1 with a diagnostic sensitivity of 100% and diagnostic specificity of 95.8%, as compared to 0.690 for TIMP-1. Significant differences were found between the AUC for MMP-8 and TIMP-1 and MMP-9 and TIMP-1 (p < 0.001 for both comparisons).

CONCLUSIONS

The changes in the concentrations of MMP-8, MMP-9 and TIMP-1 may indicate an increased remodeling of the extracellular matrix in children with adenoid hypertrophy and otitis media with effusion. The findings can have clinical as well as diagnostic utility. Determination of MMP-8 and MMP-9 may help qualify a child for adenoidectomy and differentiate pediatric patients affected by adenoid hypertrophy with and without otitis media.

Biochemical and Biological Attributes of Matrix Metalloproteinases

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that are involved in the degradation of various proteins in the extracellular matrix (ECM). Typically, MMPs have a propeptide sequence, a catalytic metalloproteinase domain with catalytic zinc, a hinge region or linker peptide, and a hemopexin domain. MMPs are commonly classified on the basis of their substrates and the organization of their structural domains into collagenases, gelatinases, stromelysins, matrilysins, membrane-type (MT)-MMPs, and other MMPs. MMPs are secreted by many cells including fibroblasts, vascular smooth muscle (VSM), and leukocytes. MMPs are regulated at the level of mRNA expression and by activation of their latent zymogen form. MMPs are often secreted as inactive pro-MMP form which is cleaved to the active form by various proteinases including other MMPs. MMPs cause degradation of ECM proteins such as collagen and elastin, but could influence endothelial cell function as well as VSM cell migration, proliferation, Ca²⁺ signaling, and contraction. MMPs play a role in tissue remodeling during various physiological processes such as angiogenesis, embryogenesis, morphogenesis, and wound repair, as well as in pathological conditions such as myocardial infarction, fibrotic disorders, osteoarthritis, and cancer. Increases in specific MMPs could play a role in arterial remodeling, aneurysm formation, venous dilation, and lower extremity venous disorders. MMPs also play a major role in leukocyte infiltration and tissue inflammation. MMPs have been detected in cancer, and elevated MMP levels have been associated with tumor progression and invasiveness. MMPs can be regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs), and the MMP/TIMP ratio often determines the extent of ECM protein degradation and tissue remodeling. MMPs have been proposed as biomarkers for numerous pathological conditions and are being examined as potential therapeutic targets in various cardiovascular and musculoskeletal disorders as well as cancer.

Evaluation of iron and zinc levels in recurrent tonsillitis and tonsillar hypertrophy

OBJECTIVES

The aim of this study is to look into the roles of iron and zinc metals in etiopathogenesis of recurrent tonsillitis and tonsillar hypertrophy by evaluating the levels of iron and zinc elements in the palatine tonsillar tissue.

METHODS

In total, 40 patients who underwent a tonsillectomy to treat recurrent tonsillitis and tonsillar hypertrophy were included in the study. Patients were classified into two groups, recurrent tonsillitis and tonsillar hypertrophy, determined by the results of clinical and histopathological examination. The levels of iron and zinc elements were determined for each tonsillar tissue sample.

RESULTS

There was a significant difference in the iron and zinc concentrations (p<0.001) between the tonsillar hypertrophy and recurrent tonsillitis groups. The levels of iron and zinc were significantly lower in the recurrent tonsillitis group.

CONCLUSIONS

This study suggests that low tissue concentrations of iron and zinc may lead to recurrent tonsillitis.

The TIMP-1 expression in germinal centers of hypertrophied adenoids in children

OBJECTIVES

The main aim of this study was to evaluate TIMP-1 expression in germinal centers of hypertrophied adenoids in children on the assumption that it can be treated as a marker of adenoidal tissue function.

PATIENTS AND METHODS

The study involved 54 children undergoing adenoidectomy; divided into three age groups: aged up to 5 years (8 children), 5-10 years (31 children) and over 10 years (15 children). The analyzed material was adenoids removed on the ground of hypertrophy, which caused obstructive symptoms and/or otitis media with effusion onset. Immunohistochemical analyses were carried out using monoclonal mouse antibody (Ab) (Novocastra) directed against human TIMP-1 protein. The presence of TIMP-1 positive lymphocytes within germinal centers and TIMP-1 immunostaining were scored.

RESULTS

The immunohistochemical staining showed the TIMP-1 positive lymphocytes mainly within the mantle zone. There was no statistically significant difference between the mean age of children for TIMP-1 immunoreaction levels. We have not found statistical correlation between the TIMP-1 staining and the clinical status of patients.

CONCLUSION

It is difficult to interpret our results. Our findings did not demonstrate changes in TIMP-1 expression according to age. This may indicate that the processes of hyperplasia, hypertrophy and atrophy of adenoid are not influenced by age and support our thesis that adenoid involution is rather the effect of changes in the number of lymphoid follicles that changes in them. However there is a need for further observational studies of TIMPs and MMPs in adenoid tissue.

Activity of soluble aminopeptidase A and dipeptidyl peptidase IV and membrane-bound aminopeptidase B and pyroglutamyl peptidase I in adenoid hyperplasia, tonsillar hyperplasia and chronic tonsillitis

OBJECTIVE

To analyze soluble and membrane-bound peptidase activities in the tonsils and adenoids removed from patients with adenoid hyperplasia, tonsillar hyperplasia and chronic tonsillitis.

METHODS

A total of 48 tissue samples from patients undergoing adenoidectomy and tonsillectomy for adenoid hyperplasia, tonsillar hyperplasia or chronic tonsillitis were analyzed. The catalytic activity of a pool of peptidases in the soluble (dipeptidyl peptidase IV, aminopeptidase A, aminopeptidase N and cystinyl aminopeptidase) and membrane-bound (prolyl endopeptidase, aspartyl aminopeptidase, aminopeptidase B and pyroglutamyl peptidase I) fractions was measured fluorometrically.

RESULTS

The activity of membrane-bound aminopeptidase B was higher in cases of chronic tonsillitis and adenoid hyperplasia than in tonsillar hyperplasia, p=0.004. Soluble dipeptidyl peptidase IV and membrane-bound pyroglutamyl peptidase I were found to be more active in tissues from male chronic tonsillitis tissues, p<0.05, while membrane-bound aminopeptidase B activity was higher in tissues of females with tonsillar hyperplasia, p<0.001. In the case of chronic tonsillitis, soluble aminopeptidase A was found to have a higher level of activity in tissues from children than those from adults, p=0.005.

CONCLUSIONS

Our results suggest a potential role of soluble aminopeptidase A, soluble dipeptidyl peptidase IV, membrane-bound aminopeptidase B and membrane-bound pyroglutamyl peptidase I in the pathobiology of adenoid hyperplasia, tonsillar hyperplasia and chronic tonsillitis that is differently regulated as a function of gender. These finfings may modify in the future the clinical approach to these diseases.

Altered dipeptidyl peptidase IV and prolyl endopeptidase activities in chronic tonsillitis, tonsillar hyperplasia and adenoid hyperplasia

OBJECTIVE

To analyse peptidase activities in the removed tonsils and adenoids from patients with chronic tonsillitis, tonsillar hyperplasia and adenoid hyperplasia.

METHODS

We have analyzed 48 tissue samples from patients undergoing tonsillectomy and adenoidectomy for chronic tonsillitis, tonsillar hyperplasia or adenoid hyperplasia. Tonsillectomy and adenoidectomy samples were collected and frozen for later enzyme analysis. The catalytic activity of a pool of peptidases (dipeptidyl peptidase IV, prolyl endopeptidase, aminopeptidase A, aminopeptidase N, aspartyl aminopeptidase, aminopeptidase B, neutral endopeptidase, pyroglutamyl peptidase I, puromycin-sensitive aminopeptidase and cystinyl aminopeptidase) was measured fluorometrically.

RESULTS

The activity of prolyl endopeptidase was higher in tonsillar hyperplasia and adenoid hyperplasia than in chronic tonsillitis. On the contrary, dipeptidyl peptidase IV activity was higher in chronic tonsillitis than in hypertrophic tissues. When data were stratified by age and gender, dipeptidyl peptidase IV was also found to be more active in adult and male chronic tonsillitis tissues. Inversely, dipeptidyl peptidase IV activity was higher in tissues of females with tonsillar hyperplasia.

CONCLUSIONS

These data indicate the involvement of dipeptidyl peptidase IV and prolyl endopeptidase in the mechanisms underlying chronic tonsillitis, tonsillar hyperplasia and adenoid hyperplasia.