Macrophage metalloelastase (MMP-12) deficiency does not alter bleomycin-induced pulmonary fibrosis in mice

BACKGROUND: Pulmonary fibrosis is characterized by excessive deposition of extracellular matrix in the interstitium resulting in respiratory failure. The role of remodeling mediators such as metalloproteinases (MMPs) and their inhibitors (TIMPs) in the fibrogenic process remains misunderstood. In particular, macrophage metalloelastase, also identified as MMP-12, is known to be involved in remodeling processes under pathological conditions. However, MMP-12 involvement in pulmonary fibrosis is unknown. Here we investigated fibrotic response to bleomycin in MMP-12 deficient mice. MATERIALS AND METHODS: C57BL/6 mice, Balb/c mice and MMP-12 -/- mice with a C57BL/6 background received 0.3 mg bleomycin by intranasal administration. 14 days after, mice were anesthetized and underwent either bronchoalveolear lavage (BAL) or lung removal. Collagen deposition in lung tissue was determined by Sircol™ collagen assay, MMP activity in BAL fluid was analyzed by zymography, and other mediators were quantified in BAL fluid by ELISA. Real time PCR was performed to assess gene expression in lung removed one or 14 days after bleomycin administration. Student t test or Mann & Whitney tests were used when appropriate for statistical analysis. RESULTS: The development of pulmonary fibrosis in "fibrosis prone" (C57BL/6) mice was associated with prominent MMP-12 expression in lung, whereas MMP-12 expression was weak in lung tissue of "fibrosis resistant" (Balb/c) mice. MMP-12 mRNA was not detected in MMP-12 -/- mice, in conformity with their genotype. Bleomycin elicited macrophage accumulation in BAL of MMP-12 -/- and wild type (WT) mice, and MMP-12 deficiency had no significant effect on BAL cells composition. Collagen content of lung was increased similarly in MMP-12 -/- and WT mice 14 days after bleomycin administration. Bleomycin elicit a raise of TGF-β protein, MMP-2 and TIMP-1 protein and mRNA in BAL fluids and lung respectively, and no significant difference was observed between MMP-12 -/- and WT mice considering those parameters. CONCLUSION: The present study shows that MMP-12 deficiency has no significant effect on bleomycin-induced fibrosis

The absence of reactive oxygen species production protects mice against bleomycin-induced pulmonary fibrosis

BACKGROUND: Reactive oxygen species and tissue remodeling regulators, such as metalloproteinases (MMPs) and their inhibitors (TIMPs), are thought to be involved in the development of pulmonary fibrosis. We investigated these factors in the fibrotic response to bleomycin of p47(phox )-/- (KO) mice, deficient for ROS production through the NADPH-oxidase pathway. METHODS: Mice are administered by intranasal instillation of 0.1 mg bleomycin. Either 24 h or 14 days after, mice were anesthetized and underwent either bronchoalveolar lavage (BAL) or lung removal. RESULTS: BAL cells from bleomycin treated WT mice showed enhanced ROS production after PMA stimulation, whereas no change was observed with BAL cells from p47(phox )-/- mice. At day 1, the bleomycin-induced acute inflammatory response (increased neutrophil count and MMP-9 activity in the BAL fluid) was strikingly greater in KO than wild-type (WT) mice, while IL-6 levels increased significantly more in the latter. Hydroxyproline assays in the lung tissue 14 days after bleomycin administration revealed the absence of collagen deposition in the lungs of the KO mice, which had significantly lower hydroxyproline levels than the WT mice. The MMP-9/TIMP-1 ratio did not change at day 1 after bleomycin administration in WT mice, but increased significantly in the KO mice. By day 14, the ratio fell significantly from baseline in both strains, but more in the WT than KO strains. CONCLUSIONS: These results suggest that NADPH-oxidase-derived ROS are essential to the development of pulmonary fibrosis. The absence of collagen deposition in KO mice seems to be associated with an elevated MMP-9/TIMP-1 ratio in the lungs. This finding highlights the importance of metalloproteinases and protease/anti-protease imbalances in pulmonary fibrosis

Implication de la métalloélastase du macrophage ou MMP-12 dans les processus inflammatoires du système respiratoire

RENNES1-BU Santé (352382103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Feasibility and efficacy of a supervised home-based physical exercise program for metastatic cancer patients receiving oral targeted therapy: study protocol for the phase II/III - UNICANCER SdS 01 QUALIOR trial

International audienceBackground: Currently, oral targeted therapies are known to be effective and are frequently used to treat metastatic cancer patients, but fatigue is a frequently reported early side effect of these treatments. This fatigue may impact the patient’s treatment adherence and result in a negative impact on quality of life. Physical exercise significantly improved the general well-being and quality of life of advanced cancer patients. However, there is no specific physical activity program adapted for patients with advanced disease. Methods QUALIOR is a two-part, randomized, open-label, and multicenter with two arms phase II/III trial. Patients (phase II: n = 120; phase III: n = 312) with metastatic cancer (breast cancer, kidney cancer, lung cancer, and other cancers [including but not limited to colon cancer, melanoma, sarcoma, or hepatocarcinoma]) treated with a first- or second-line oral targeted therapy without chemotherapy will be included. Patients will be randomized (2:1) to a 3-month supervised home-based standardized physical activity program or to a recommended adapted physical activity (via a booklet). The primary objective of the phase II is to evaluate the feasibility of the supervised program. The primary objective of the phase III is the evaluation of the benefit of the supervised home-based program compare to the recommended program in terms of fatigue and quality of life at 3 months. The secondary objectives aim to evaluate the impact of the supervised program on fatigue over time, pain, physical capacities, psychosocial and cognitive functions, general quality of life, frequency of dose reduction and patients’ adherence to the targeted therapy, overall survival, and progression-free survival. This study will also evaluate the medico-economic impact of supervised program compared to the recommended adapted physical activity program. Discussion The aim of this study is to evaluate home-based physical exercise program for metastatic cancer patients treated with oral targeted therapies to help patients to cope with fatigue and improve quality of life. Trial registration This trial was registered in ClinicalTrials.gov since May 2017 ( NCT03169075 )