Mitochondrial Features of Mouse Myoblasts Are Finely Tuned by Low Doses of Ozone: The Evidence In Vitro.

The mild oxidative stress induced by low doses of gaseous ozone (O3) activates the antioxidant cell response through the nuclear factor erythroid 2-related factor 2 (Nrf2), thus inducing beneficial effects without cell damage. Mitochondria are sensitive to mild oxidative stress and represent a susceptible O3 target. In this in vitro study, we investigated the mitochondrial response to low O3 doses in the immortalized, non-tumoral muscle C2C12 cells; a multimodal approach including fluorescence microscopy, transmission electron microscopy and biochemistry was used. Results demonstrated that mitochondrial features are finely tuned by low O3 doses. The O3 concentration of 10 µg maintained normal levels of mitochondria-associated Nrf2, promoted the mitochondrial increase of size and cristae extension, reduced cellular reactive oxygen species (ROS) and prevented cell death. Conversely, in 20 µg O3-treated cells, where the association of Nrf2 with the mitochondria drastically dropped, mitochondria underwent more significant swelling, and ROS and cell death increased. This study, therefore, adds original evidence for the involvement of Nrf2 in the dose-dependent response to low O3 concentrations not only as an Antioxidant Response Elements (ARE) gene activator but also as a regulatory/protective factor of mitochondrial function.

Ozone at low concentration modulates microglial activity in vitro: A multimodal microscopy and biomolecular study.

Oxygen-ozone (O2 -O3 ) therapy is an adjuvant/complementary treatment based on the activation of antioxidant and cytoprotective pathways driven by the nuclear factor erythroid 2-related factor 2 (Nrf2). Many drugs, including dimethyl fumarate (DMF), that are used to reduce inflammation in oxidative-stress-related neurodegenerative diseases, act through the Nrf2-pathway. The scope of the present investigation was to get a deeper insight into the mechanisms responsible for the beneficial result of O2 -O3 treatment in some neurodegenerative diseases. To do this, we used an integrated approach of multimodal microscopy (bright-field and fluorescence microscopy, transmission and scanning electron microscopy) and biomolecular techniques to investigate the effects of the low O3 concentrations currently used in clinical practice in lipopolysaccharide (LPS)-activated microglial cells human microglial clone 3 (HMC3) and in DMF-treated LPS-activated (LPS + DMF) HMC3 cells. The results at light and electron microscopy showed that LPS-activation induced morphological modifications of HMC3 cells from elongated/branched to larger roundish shape, cytoplasmic accumulation of lipid droplets, decreased electron density of the cytoplasm and mitochondria, decreased amount of Nrf2 and increased migration rate, while biomolecular data demonstrated that Heme oxygenase 1 gene expression and the secretion of the pro-inflammatory cytokines, Interleukin-6, and tumor necrosis factor-α augmented. O3 treatment did not affect cell viability, proliferation, and morphological features of both LPS-activated and LPS + DMF cells, whereas the cell motility and the secretion of pro-inflammatory cytokines were significantly decreased. This evidence suggests that modulation of microglia activity may contribute to the beneficial effects of the O2 -O3 therapy in patients with neurodegenerative disorders characterized by chronic inflammation. HIGHLIGHTS: Low-dose ozone (O3 ) does not damage activated microglial cells in vitro Low-dose O3 decreases cell motility and pro-inflammatory cytokine secretion in activated microglial cells in vitro Low-dose O3 potentiates the effect of an anti-inflammatory drug on activated microglial cells.

Low Ozone Concentrations Differentially Affect the Structural and Functional Features of Non-Activated and Activated Fibroblasts In Vitro.

Oxygen-ozone (O2-O3) therapy is increasingly applied as a complementary/adjuvant treatment for several diseases; however, the biological mechanisms accounting for the efficacy of low O3 concentrations need further investigations to understand the possibly multiple effects on the different cell types. In this work, we focused our attention on fibroblasts as ubiquitous connective cells playing roles in the body architecture, in the homeostasis of tissue-resident cells, and in many physiological and pathological processes. Using an established human fibroblast cell line as an in vitro model, we adopted a multimodal approach to explore a panel of cell structural and functional features, combining light and electron microscopy, Western blot analysis, real-time quantitative polymerase chain reaction, and multiplex assays for cytokines. The administration of O2-O3 gas mixtures induced multiple effects on fibroblasts, depending on their activation state: in non-activated fibroblasts, O3 stimulated proliferation, formation of cell surface protrusions, antioxidant response, and IL-6 and TGF-ß1 secretion, while in LPS-activated fibroblasts, O3 stimulated only antioxidant response and cytokines secretion. Therefore, the low O3 concentrations used in this study induced activation-like responses in non-activated fibroblasts, whereas in already activated fibroblasts, the cell protective capability was potentiated.

Breast screening with ultrasound in women with mammography-negative dense breasts: evidence on incremental cancer detection and false positives, and associated cost.

BACKGROUND: We evaluated the contribution of ultrasound (US) in detecting breast cancer in women with dense breasts and negative mammograms. METHODS: 9157 (35.8%) of 25,572 self-referring women during 2000-2007 had BI-RADS D3-4 negative mammograms - all were screened with bilateral US. RESULTS: US detected 37 cancers - incremental cancer detection rate (ICDR) was 0.40% (95% CI: 0.39-0.41%); ICDR was 0.33% in women <50 and 0.51% in those 50 years and older. US detected a larger proportion of cancers below age 50 compared to older women. US-only detected cancers had a more favourable stage (pTis-pT1a-pT1b: 64.8% versus 35.5%, p=0.001; pN1: 13.5% versus 31.3%, p=0.047) than cancers detected on mammography. US caused additional investigations in 4.9% of women and benign surgical biopsies in 0.9%. Cost per US-screened woman, and per US-detected cancer ranged between euro59-62 and euro14,618-15,234, respectively. CONCLUSION: US detects early-stage cancers in women with mammography-negative dense breasts, with higher contribution in women younger than 50 years.