No abstract

In the last two decades, the use of ozone (O) as a complementary medical approach has progressively been increasing; however, its application is still limited due to the numerous doubts about its possible toxicity, despite the low concentrations used in therapy. For an appropriate and safe clinical application of a potentially toxic agent such as O, it is crucial to elucidate the cellular response to its administration. Molecular analyses and transmission electron microscopy were here combined to investigate in vitro the effects of O administration on transcriptional activity and nuclear domains organization of cultured SH-SY5Y neuronal cells; low O concentrations were used as those currently administered in clinical practice. Mild ozonisation did not affect cell proliferation or death, while molecular analyses showed an O-induced modulation of some genes involved in the cell response to stress (HMOX1, ERCC4, CDKN1A) and in the transcription machinery (CTDSP1). Ultrastructural cytochemistry after experiments of bromouridine incorporation consistently demonstrated an increased transcriptional rate at both the nucleoplasmic (mRNA) and the nucleolar (rRNA) level. No ultrastructural alteration of nuclear domains was observed. Our molecular, ultrastructural and cytochemical data demonstrate that a mild toxic stimulus such as mild ozonisation stimulate cell protective pathways and nuclear transcription, without altering cell viability. This could possibly account for the positive effects observed in ozone-treated patients.

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.

No abstract

Dysregulated immunity and widespread metabolic dysfunctions are the most relevant hallmarks of the passing time over the adult life and their combination at midlife is strongly related to increased vulnerability to diseases. However, their causal connection remains largely unclear. Combining multi-omics and functional analyses on adipose derived stromal cells established from young (1 month) and midlife (12 months) mice we show that the increase of Interferon Regulatory Factor 7 (IRF7) over the adult life drives major metabolic changes, which includes impaired mitochondrial function, altered amino acid biogenesis and reduced expression of genes involved in branched chain amino acid (BCAA) degradation. Our results draw a new paradigm of aging as the 'sterile' activation of a cell-autonomous pathway of self-defense and identify a crucial mediator of this pathway, IRF7, as driver of metabolic dysfunction with age.