The topical application of lactic acid bacteria (LAB) is recognized as a useful approach to improve skin health. This work aims to characterize by a multidisciplinary approach, the wound healing, anti-inflammatory, anti-pathogens and proteomic effects of six LAB lysates, belonging to the genus Lactobacillus. Our results demonstrated that the lysates of tested LAB stimulated the proliferation of keratinocytes, and that L. plantarum SGL 07 and L. salivarius SGL 19 accelerated the re-epithelization by inducing keratinocyte migration. The bacterial lysates also reduced the secretion of specific pro-inflammatory mediators from keratinocytes. Furthermore, viable L. salivarius SGL 19 and L. fermentum SGL 10 had anti-pathogenic effects against S. aureus and S. pyogenes, while L. brevis SGL 12 and L. paracasei SGL 04 inhibited S. aureus and S. pyogenes, respectively. The tested lactobacilli lysates also induced specific proteome modulation of the exposed keratinocytes, involving dysregulation of proteins (such as interleukin enhancer-binding factor 2 and ATP-dependent RNA helicase) and pathways (such as cytokine, NF-kB, Hedgehog, and RUNX signaling) associated with their specific wound healing and anti-inflammatory effects. This study indicates the different potential of selected lactobacilli, suggesting that they may be successfully used in the future together with conventional therapies to bring relief from skin disorders. Abbreviations LAB Lactic acid bacteria TNF-α Tumor necrosis factor-alpha IFN-γ Interferon-gamma PBS Phosphate buffered saline DMEM Dulbecco's modified Eagle's medium MCP-1 Monocyte chemoattractant protein-1 RANTES Regulated on activation, normal T cell expressed and secreted LC-MS/MS Liquid chromatography-tandem mass spectrometry SWATH Sequential window acquisition of all theoretical mass spectra The skin, considered the largest organ of the body, is involved in a variety of functions and acts primarily as a protective barrier preventing the entry of potential pathogens. In particular, skin homeostasis is regulated by microorganisms, the so called skin microbiota, which act on keratinocytes and on their cytokine release, ensuring

Physical exercise is known to promote beneficial effects on overall health, counteracting risks related to degenerative diseases. MicroRNAs (miRNAs), short non-coding RNAs affecting the expression of a cell’s transcriptome, can be modulated by different stimuli. Yet, the molecular effects on osteogenic differentiation triggered by miRNAs upon physical exercise are not completely understood. In this study, we recruited 20 male amateur runners participating in a half marathon. Runners’ sera, collected before (PRE RUN) and after (POST RUN) the run, were added to cultured human mesenchymal stromal cells. We then investigated their effects on the modulation of selected miRNAs and the consequential effects on osteogenic differentiation. Our results showed an increased expression of miRNAs promoting osteogenic differentiation (miR-21-5p, miR-129-5p, and miR-378-5p) and a reduced expression of miRNAs involved in the adipogenic differentiation of progenitor cells (miR-188-5p). In addition, we observed the downregulation of PTEN and SMAD7 expression along with increased AKT/pAKT and SMAD4 protein levels in MSCs treated with POST RUN sera. The consequent upregulation of RUNX2 expression was also proven, highlighting the molecular mechanisms by which miR-21-5p promotes osteogenic differentiation. In conclusion, our work proposes novel data, which demonstrate how miRNAs may regulate the osteogenic commitment of progenitor cells in response to physical exercise.

Lack of physical exercise is considered an important risk factor for chronic diseases. On the contrary, physical exercise reduces the morbidity rates of obesity, diabetes, bone disease, and hypertension. In order to gain novel molecular and cellular clues, we analyzed the effects of physical exercise on differentiation of mesenchymal circulating progenitor cells (M-CPCs) obtained from runners. We also investigated autophagy and telomerase-related gene expression to evaluate the involvement of specific cellular functions in the differentiation process. We performed cellular and molecular analyses in M-CPCs, obtained by a depletion method, of 22 subjects before (PRE RUN) and after (POST RUN) a half marathon performance. In order to prove our findings, we performed also in vitro analyses by testing the effects of runners' sera on a human bone marrow-derived mesenchymal stem (hBM-MSC) cell line. PCR array analyses of PRE RUN versus POST RUN M-CPC total RNAs put in evidence several genes which appeared to be modulated by physical activity. Our results showed that physical exercise promotes differentiation. Osteogenesis-related genes as RUNX2, MSX1, and SPP1 appeared to be upregulated after the run; data showed also increased levels of BMP2 and BMP6 expressions. SOX9, COL2A1, and COMP gene enhanced expression suggested the induction of chondrocytic differentiation as well. The expression of telomerase-associated genes and of two autophagy-related genes, ATG3 and ULK1, was also affected and correlated positively with MSC differentiation. These data highlight an attractive cellular scenario, outlining the role of autophagic response to physical exercise and suggesting new insights into the benefits of physical exercise in counteracting chronic degenerative conditions.

The mortality rate for malignant melanoma (MM) is very high, since it is highly invasive and resistant to chemotherapeutic treatments. The modulation of some transcription factors affects cellular processes in MM. In particular, a higher expression of the osteogenic master gene RUNX2 has been reported in melanoma cells, compared to normal melanocytes. By analyzing public databases for recurrent RUNX2 genetic and epigenetic modifications in melanoma, we found that the most common RUNX2 genetic alteration that exists in transcription upregulation is, followed by genomic amplification, nucleotide substitution and multiple changes. Additionally, altered RUNX2 is involved in unchecked pathways promoting tumor progression, Epithelial Mesenchymal Transition (EMT), and metastasis. In order to investigate further the role of RUNX2 in melanoma development and to identify a therapeutic target, we applied the CRISPR/Cas9 technique to explore the role of the RUNT domain of RUNX2 in a melanoma cell line. RUNT-deleted cells showed reduced proliferation, increased apoptosis, and reduced EMT features, suggesting the involvement of the RUNT domain in different pathways. In addition, del-RUNT cells showed a downregulation of genes involved in migration ability. In an in vivo zebrafish model, we observed that wild-type melanoma cells migrated in 81% of transplanted fishes, while del-RUNT cells migrated in 58%. All these findings strongly suggest the involvement of the RUNT domain in melanoma metastasis and cell migration and indicate RUNX2 as a prospective target in MM therapy.

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