Cellular response to physical exercise: analysis of serum proteins modulation and expression profiles in circulating progenitor cells

Physical activity plays an important role against pathological degenerative conditions and metabolic diseases. In particular, it works as a modulator of the mutually exclusive osteogenic or adipogenic fates of mesenchymal stem cells through a direct action on differentiation-related gene expression. On the other hand, it has also been reported that oxidative stress generated by strenous physical efforts (e.g. marathon running) can affect cell functions. The purpose of this study was to investigate the effects induced by a half marathon in male amateur runners. In particular the investigation focused on: i) serum proteins modulation in response to the oxidative environment, ii) the modulation of circulating progenitor cells commitment, monitored in terms of gene expression; iii) progenitor cells proliferation and homeostasis, monitored through the expression levels of genes related to telomerase activity and autophagic induction, respectively; iv) the effects of soluble factors present in runners\u2019 sera on differentiation process in an in vitro cellular model. The shotgun proteomic approach applied to runners\u2019 sera confirmed the production of reactive oxygen species, counteracted by an increased production of detoxifying and scavenger proteins. Overall, the proteome modulation profile suggests a consequent positive effect of the trained condition. Gene expression analyses showed an upregulation of osteogenesis related genes in Circulating Progenitor cells (CPs) after training, in particular RUNX2 and BMPs. In addition, chondrogenesis related genes such as SOX9, COMP and COL2A1 were upregulated after the run. At the same time, the higher expression of BMP3 suggests a stimulation of CPs proliferation which justifies as well the increased expression of telomerase-related genes, TERT and TERF1. The enhanced expression of autophagyrelated genes (ATG3 and ULK1) correlates positively with the induction of MSCs differentition. Data based on an in vitro model (i.e. Bone Marrow-derived MSCs supplemented with pre- and post-run sera), suggest that intense physical exercise enhances BM-MSC potential for osteo-chondrogenic commitment at the expense of the mutually exclusive adipogenesis. The in vitro deposition of calcium salts demonstrates mineralization, i.e. complete maturation of osteoblasts promoted by soluble factors in runners\u2019 sera. In conclusion, changes induced by physical activity may be considered positive in terms of: i) oxidative stress management during oxigen reactive species production; ii) progenitor cells proliferation, under autophagy-mediated positive selection; iii) osteochondrogenic induction of CPs; iv) production of circulating soluble factors which support complete maturation of committed osteoblasts. All data seem to suggest that physical activity has positive effects on overall health

Clones of aging: When better fitness can be dangerous

The biological and clinical significance of aberrant clonal expansions in aged tissues is being intensely discussed. Evidence is accruing that these clones often result from the normal dynamics of cell turnover in our tissues. The aged tissue microenvironment is prone to favour the emergence of specific clones with higher fitness partly because of an overall decline in cell intrinsic regenerative potential of surrounding counterparts. Thus, expanding clones in aged tissues need not to be mechanistically associated with the development of cancer, albeit this is a possibility. We suggest that growth pattern is a critical phenotypic attribute that impacts on the fate of such clonal proliferations. The acquisition of a better proliferative fitness, coupled with a defect in tissue pattern formation, could represent a dangerous mix setting the stage for their evolution towards neoplasia

Physical Exercise Modulates miR-21-5p, miR-129-5p, miR-378-5p, and miR-188-5p Expression in Progenitor Cells Promoting Osteogenesis

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

Analyzing BioRad-Illumina Single Cell RNA-Seq data with open source tools

Single cell RNA-Seq is a powerful technique that is becoming more popular since it enables to sequence the transcriptome of each cell within a population of different cell types in a single experiment. Currently, there are a few different technologies, like BioRad-Illumina ddSeq and 10X Chromium

New Insights into the Runt Domain of RUNX2 in Melanoma Cell Proliferation and Migration

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

Physical activity modulates miRNAs levels and enhances MYOD expression in myoblasts

Stem cells functions are regulated by different factors and non-conding RNAs, such as microRNA. MiRNAsplay an important role in modulating the expression of genes involved in the commitment and differentiation of progenitor cells. MiRNAs are post transcriptional regulators which may be modulated by physical exercise. MiRNAs, by regulating different signaling pathways, play an important role in myogenesis as well as in muscle activity. MiRNAs quantification may be considered for evaluating physical performance or muscle recovery. With the aim to identify specific miRNAs potentially involved in myogenesis and modulated by physical activity, we investigated miRNAs expression following physical performance in Peripheral Blood Mononuclear Cells (PBMCs) and in sera of half marathon (HM) runnners. The effect of runners sera on Myogenesis in in vitro cellular models was also explored. Therefore, we performed Microarray Analysis and Real Time PCR assays, as well as in vitro cell cultures analysis to investigate myogenic differentiation. Our data demonstrated gender-specific expression patterns of PBMC miRNAs before physical performance. In particular, miR223-3p, miR26b-5p, miR150-5p and miR15-5p expression was higher, while miR7a-5p and miR7i-5p expression was lower in females compared to males. After HM, miR152-3p, miR143-3p, miR27a-3p levels increased while miR30b-3p decreased in both females and males: circulating miRNAs mirrored these modulations. Furthermore, we also observed that the addition of post-HM participants sera to cell cultures exerted a positive effect in stimulating myogenesis. In conclusion, our data suggest that physical activity induces the modulation of myogenesis-associated miRNAs in bothfemales and males, despite the gender-associated different expression of certain miRNAs, Noteworthy, these findings might be useful for evaluating potential targets for microRNA based-therapies in diseases affecting the myogenic stem cells population

Physical activity prevents cartilage degradation: a metabolomics study pinpoints the involvement of vitamin B6

Osteoarthritis (OA) is predominantly characterized by the progressive degradation of articular cartilage, the connective tissue produced by chondrocytes, due to an imbalance between anabolic and catabolic processes. In addition, physical activity (PA) is recognized as an important tool for counteracting OA. To evaluate PA effects on the chondrocyte lineage, we analyzed the expression of SOX9, COL2A1, and COMP in circulating progenitor cells following a half marathon (HM) performance. Therefore, we studied in-depth the involvement of metabolites affecting chondrocyte lineage, and we compared the metabolomic profile associated with PA by analyzing runners' sera before and after HM performance. Interestingly, this study highlighted that metabolites involved in vitamin B6 salvage, such as pyridoxal 5'-phosphate and pyridoxamine 5'-phosphate, were highly modulated. To evaluate the effects of vitamin B6 in cartilage cells, we treated differentiated mesenchymal stem cells and the SW1353 chondrosarcoma cell line with vitamin B6 in the presence of IL1\u3b2, the inflammatory cytokine involved in OA. Our study describes, for the first time, the modulation of the vitamin B6 salvage pathway following PA and suggests a protective role of PA in OA through modulation of this pathway

Fisetin: an integrated approach to identify a strategy promoting osteogenesis

Flavonoids may modulate the bone formation process. Among flavonoids, fisetin is known to counteract tumor growth, osteoarthritis, and rheumatoid arthritis. In addition, fisetin prevents inflammation-induced bone loss. In order to evaluate its favorable use in osteogenesis, we assayed fisetin supplementation in both in vitro and in vivo models and gathered information on nanoparticle-mediated delivery of fisetin in vitro and in a microfluidic system. Real-time RT-PCR, Western blotting, and nanoparticle synthesis were performed to evaluate the effects of fisetin in vitro, in the zebrafish model, and in ex vivo samples. Our results demonstrated that fisetin at 2.5 μM concentration promotes bone formation in vitro and mineralization in the zebrafish model. In addition, we found that fisetin stimulates osteoblast maturation in cell cultures obtained from cleidocranial dysplasia patients. Remarkably, PLGA nanoparticles increased fisetin stability and, consequently, its stimulating effects on RUNX2 and its downstream gene SP7 expression. Therefore, our findings demonstrated the positive effects of fisetin on osteogenesis and suggest that patients affected by skeletal diseases, both of genetic and metabolic origins, may actually benefit from fisetin supplementation

A potential role of RUNX2- RUNT domain in modulating the expression of genes involved in bone metastases: an in vitro study with melanoma cells

Ectopic expression of RUNX2 has been reported in several tumors. In melanoma cells, the RUNT domain of RUNX2 increases cell proliferation and migration. Due to the strong link between RUNX2 and skeletal development, we hypothesized that the RUNT domain may be involved in the modulation of mechanisms associated with melanoma bone metastasis. Therefore, we evaluated the expression of metastatic targets in wild type (WT) and RUNT KO melanoma cells by array and real-time PCR analyses. Western blot, ELISA, immunofluorescence, migration and invasion ability assays were also performed. Our findings showed that the expression levels of bone sialoprotein (BSP) and osteopontin (SPP1) genes, which are involved in malignancy-induced hypercalcemia, were reduced in RUNT KO cells. In addition, released PTHrP levels were lower in RUNT KO cells than in WT cells. The RUNT domain also contributes to increased osteotropism and bone invasion in melanoma cells. Importantly, we found that the ERK/p-ERK and AKT/p-AKT pathways are involved in RUNT-promoted bone metastases. On the basis of our findings, we concluded that the RUNX2 RUNT domain is involved in the mechanisms promoting bone metastasis of melanoma cells via complex interactions between multiple players involved in bone remodeling

Runx2 downregulation, migration and proliferation inhibition in melanoma cells treated with BEL \u3b2-trefoil

Malignant melanoma is a lethal form of skin cancer and highly metastatic tumor has a poor prognosis; BEL \u3b2-trefoil, a lectin, obtained by our group, possesses the ability to act specifically on malignant cells. Therefore, the aim of our study was to investigate the effects of BEL \u3b2-trefoil in melanoma cells in an attempt to evaluate its potential usage as anticancer agent. BEL \u3b2-trefoil was purified by chromatography and A375 and MeWo melanoma cells were treated. Viability and proliferation were evaluated as well as apoptosis, RUNX2 gene expression and migration ability. The treated tumor cells decreased viability as well as proliferative ability. Flow cytometry analysis showed a lessen effect of the treatment on apoptosis. The gene expression analysis showed a reduction of RUNX2 expression in a manner dose depend and migration ability was reduced significantly in both treated cell lines. Our findings suggest that BEL \u3b2-trefoil can be considered a useful tool against malignancy thank to its effect based on the simultaneous proliferation ability reduction as well as the inhibition of migration capacity on melanoma tumor cells