Ozone and procaine increase secretion of platelet-derived factors in platelet-rich plasma.

Platelet-rich plasma (PRP) is gaining more and more attention in regenerative medicine as an innovative and efficient therapeutic approach. The regenerative properties of PRP rely on the numerous bioactive molecules released by the platelets: growth factors are involved in proliferation and differentiation of endothelial cells and fibroblasts, angiogenesis and extracellular matrix formation, while cytokines are mainly involved in immune cell recruitment and inflammation modulation. Attempts are ongoing to improve the therapeutic potential of PRP by combining it with agents able to promote regenerative processes. Two interesting candidates are ozone, administered at low doses as gaseous oxygen-ozone mixtures, and procaine. In the present study, we investigated the effects induced on platelets by the in vitro treatment of PRP with ozone or procaine, or both. We combined transmission electron microscopy to obtain information on platelet modifications and bioanalytical assays to quantify the secreted factors. The results demonstrate that, although platelets were already activated by the procedure to prepare PRP, both ozone and procaine induced differential morpho-functional modifications in platelets resulting in an increased release of factors. In detail, ozone induced an increase in surface protrusions and open canalicular system dilation suggestive of a marked α-granule release, while procaine caused a decrease in surface protrusions and open canalicular system dilation but a remarkable increase in microvesicle release suggestive of high secretory activity. Consistently, nine of the thirteen platelet-derived factors analysed in the PRP serum significantly increased after treatment with ozone and/or procaine. Therefore, ozone and procaine proved to have a remarkable stimulating potential without causing any damage to platelets, probably because they act through physiological, although different, secretory pathways.

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.

Ozone Activates the Nrf2 Pathway and Improves Preservation of Explanted Adipose Tissue In Vitro.

In clinical practice, administration of low ozone (O3) dosages is a complementary therapy for many diseases, due to the capability of O3 to elicit an antioxidant response through the Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2)-dependent pathway. Nrf2 is also involved in the adipogenic differentiation of mesenchymal stem cells, and low O3 concentrations have been shown to stimulate lipid accumulation in human adipose-derived adult stem cells in vitro. Thus, O3 treatment is a promising procedure to improve the survival of explanted adipose tissue, whose reabsorption after fat grafting is a major problem in regenerative medicine. In this context, we carried out a pilot study to explore the potential of mild O3 treatment in preserving explanted murine adipose tissue in vitro. Scanning and transmission electron microscopy, Western blot, real-time polymerase chain reaction and nuclear magnetic resonance spectroscopy were used. Exposure to low O3 concentrations down in the degradation of the explanted adipose tissue and induced a concomitant increase in the protein abundance of Nrf2 and in the expression of its target gene Hmox1. These findings provide a promising background for further studies aimed at the clinical application of O3 as an adjuvant treatment to improve fat engraftment.

Ozone at low concentrations does not affect motility and proliferation of cancer cells in vitro.

Exposure to low ozone concentrations is used in medicine as an adjuvant/complementary treatment for a variety of diseases. The therapeutic potential of low ozone concentrations relies on their capability to increase the nuclear translocation of the Nuclear factor erythroid 2-related factor 2 (Nrf2), thus inducing the transcription of Antioxidant Response Elements (ARE)-driven genes and, through a cascade of events, a general cytoprotective response. However, based on the controversial role of Nrf2 in cancer initiation, progression and resistance to therapies, possible negative effects of ozone therapy may be hypothesised in oncological patients. With the aim to elucidate the possible changes in morphology, migration capability and proliferation of cancer cells following mild ozone exposure, we performed wound healing experiments in vitro on HeLa cells treated with low ozone concentrations currently used in the clinical practice. By combining a multimodal microscopy approach (light and fluorescence microscopy, scanning electron microscopy, atomic force microscopy) with morphometric analyses, we demonstrated that, under our experimental conditions, exposure to low ozone concentrations does not alter cytomorphology, motility and proliferation features, thus supporting the notion that ozone therapy should not positively affect tumour cell growth and metastasis.

The Role of Nrf2 in the Antioxidant Cellular Response to Medical Ozone Exposure.

Ozone (O3) is a natural, highly unstable atmospheric gas that rapidly decomposes to oxygen. Although not being a radical molecule, O3 is a very strong oxidant and therefore it is potentially toxic for living organisms. However, scientific evidence proved that the effects of O3 exposure are dose-dependent: high dosages stimulate severe oxidative stress resulting in inflammatory response and tissue injury, whereas low O3 concentrations induce a moderate oxidative eustress activating antioxidant pathways. These properties make O3 a powerful medical tool, which can be used as either a disinfectant or an adjuvant agent in the therapy of numerous diseases. In this paper, the cellular mechanisms involved in the antioxidant response to O3 exposure will be reviewed with special reference to the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) and its role in the efficacy of ozone therapy.

Ozone Treatment of Grapes During Withering for Amarone Wine: A Multimodal Imaging and Spectroscopic Analysis.

The production of Amarone wine is governed by a disciplinary guideline to preserve its typical features; however, postharvest infections by the fungus Botrytis cinerea (B. cinerea) not only represent a phytosanitary problem but also cause a significant loss of product. In this study, we tested a treatment with mild ozoniztion on grapes for Amarone wine production during withering in the fruttaio (the environment imposed by the disciplinary guideline) and evaluated the impact on berry features by a multimodal imaging approach. The results indicate that short and repeated treatments with low O3 concentrations speed up the naturally occurring berry withering, probably inducing a reorganization of the epicuticular wax layer, and inhibit the development of B. cinerea, blocking the fungus in an intermediate vegetative stage. This pilot study will pave the way to long-term research on Amarone wine obtained from O3-treated grapes.

Low ozone concentrations promote adipogenesis in human adipose-derived adult stem cells.

Ozone is a strong oxidant, highly unstable atmospheric gas. Its medical use at low concentrations has been progressively increasing as an alternative/adjuvant treatment for several diseases. In this study, we investigated the effects of mild ozonisation on human adipose-derived adult stem (hADAS) cells i.e., mesenchymal stem cells occurring in the stromal-vascular fraction of the fat tissue and involved in the tissue regeneration processes. hADAS cells were induced to differentiate into the adipoblastic lineage, and the effect of low ozone concentrations on the adipogenic process was studied by combining histochemical, morphometric and ultrastructural analyses. Our results demonstrate that ozone treatment promotes lipid accumulation in hADAS without inducing deleterious effects, thus paving the way to future studies aimed at elucidating the effect of mild ozonisation on adipose tissue for tissue regeneration and engineering.

Mild ozonisation activates antioxidant cell response by the Keap1/Nrf2 dependent pathway.

Treatment with low-dose ozone is successfully exploited as an adjuvant therapy in the treatment of several disorders. Although the list of medical applications of ozone therapy is increasing, molecular mechanisms underlying its beneficial effects are still partially known. Clinical and experimental evidence suggests that the therapeutic effects of ozone treatment may rely on its capability to mount a beneficial antioxidant response through activation of the nuclear factor erythroid-derived-like 2 (Nrf2) pathway. However, a conclusive mechanistic demonstration is still lacking. Here, we bridge this gap of knowledge by providing evidence that treatment with a low concentration of ozone in cultured cells promotes nuclear translocation of Nrf2 at the chromatin sites of active transcription and increases the expression of antioxidant response element (ARE)-driven genes. Importantly, we show that ozone-induced ARE activation can be reverted by the ectopic expression of the Nrf2 specific inhibitor Kelch-like ECH associated protein (Keap1), thus proving the role of the Nrf2 pathway in the antioxidant response induced by mild ozonisation.