Evaluation of MMP-12 expression in chronic rhinosinusitis with nasal polyposis.

BACKGROUND: The purpose of this study was to evaluate the expression of MMP-12 in patients with chronic rhinosinusitis with polyps (CRSwNP). METHODOLOGY: Tissue samples from 37 patients with CRSwNP undergoing functional endoscopic sinus surgery and healthy mucosa specimens from 12 healthy controls were obtained intraoperatively. The mRNA and protein expression levels of MMP-12 were quantified by real-time polymerase chain reaction and Western blotting, respectively. RESULTS: mRNA levels of MMP-12 were significantly elevated in the CRSwNP tissue samples compared to those in control ones. The protein levels of MMP-12 showed a trend of increasing but with no statistical significance. CONCLUSIONS: Elevation of MMP-12 in patients with CRSwNP suggests its potential implication in the pathogenesis of the disease. The difference in the expression profile observed between mRNA and protein levels could be due to post-translational gene expression regulation. Our findings provide evidence that MMP-12 along with other MMPs may serve as a biomarker and therapeutic target in the management of the disease.

Matrix metalloproteinases and chronic rhinosinusitis with nasal polyposis. Unravelling a puzzle through a systematic review.

BACKGROUND: The expression of metalloproteinases (MMPs) in chronic rhinosinusitis with nasal polyposis (CRSwNP) was reviewed in order to investigate their possible use as therapeutical targets and/or biomarkers. METHODOLOGY: The differences between CRSwNP and normal controls or CRS without NP, as well as the effects of various treatments on MMPs, tissue inhibitors of MMPs (TIMPs) and MMP/TIMP ratios were considered as primary outcomes. Additional factors reported to affect MMP expression levels were noted as secondary outcomes. Data regarding inflammatory subtypes, patients’ clinical characteristics, controls, laboratory method(s) and origin of samples were also pooled. Studies on 10 or fewer patients or on specimens other than nasal and serum were excluded. RESULTS: Forty-three studies were included. Tissue sample origin, allergic rhinitis, smoking, infection, medication intake and primary or recurrent disease should be considered as confounding factors for MMP levels. MMP-1 and -7 were consistently found to be significantly higher in CRSwNP patients than controls. CRSwNP endotypes with distinctly different inflammation patterns seem to present similar MMP-related remodelling patterns. CONCLUSIONS: The existing literature has revealed several population and methodology related confounding factors and remains inconclusive regarding the roles of MMPs in CRSwNP pathophysiology and their possible clinical usefulness as biomarkers and therapeutical targets.

Histological and biochemical evidence related to the collagen quality in torn rotator cuff tendons.

This study investigates the histological background of torn rotator cuff tendons, evaluates the stability of newly synthesized collagen by measuring the hydro-xyproline content and attempts to correlate these findings with the clinical outcome after reconstruction of the rotator cuff. Sixty-one patients underwent reconstruction for a -rotator cuff tear. They were evaluated preoperatively with the Constant-Murley score, MRI and ultrasound. Biopsy samples were taken from chronic rotator cuff tears and histological analysis was performed. Hydroxyprolin presence was evaluated in various -tissues. Mean follow-up was 46 months. Histological analysis revealed collagen fragmentation and thinning (90.2% of patients), myxoid degeneration (88%), hyaline degeneration (50.8%), chondroid metaplasia (44.3%), calcification (24.7%), fatty infiltration (20.4%) and vascular proliferation (62.3%). Hydroxyproline was under-represented in newly synthesized collagen in 57% of patients. In the majority of the patients with a low hydroxyproline/collagen ratio the histological findings were abnormal. None of the findings was related to the clinical outcome with a statistical significance. Histological and biochemical findings reflected the poor quality of the tendon. The good clinical outcome did not depend on the histological or biochemical findings but rather on the meticulous surgical reconstruction and physical therapy.