by Alessio N, Stellavato A, Squillaro T, Del Gaudio S, Di Bernardo G, Peluso G, De Rosa M, Schiraldi C, Galderisi U
Mesenchymal stem cells, a subpopulation of mesenchymal stromal cells (MSCs), are present in the stroma of several tissues. MSC cultivation for clinical treatments may greatly affect MSC properties. A primary handicap is replicative senescence that impairs MSC functions. Hyaluronan (HA) is present in the extracellular matrix that composes the stem cell niche environment and is under investigation as a key factor for stem cell growth. We evaluated the effect on MSC cultivation of HA hybrid cooperative complexes (HCC) that are obtained from high (H) and low (L) weight molecules (NAHYCO™). We compared this HCC with H-HA and L-HA. We investigated the effects of these HAs on proliferation, cell cycle, apoptosis, senescence, and differentiation following the addition of the polymer solutions in the culture media at concentrations that did not drastically modify the medium viscosity. Interestingly, 0,16% HCC significantly delayed the senescence compared with the controls. This occurred without alteration of the cell cycle, cytotoxicity, or apoptosis. HCCs also promoted adipogenic and chondrogenic differentiation. Our finding could suggest a potential functional role of HCC above the updated scientific reports of its effects and pave the way to optimization of MSC cultivation for therapeutic application.
on Journal of cellular physiology
by Alessio N, Pipino C, Mandatori D, Di Tomo P, Ferone A, Marchiso M, Melone MAB, Peluso G, Pandolfi A, Galderisi U
Mesenchymal stromal cells (MSCs) are considered to be an excellent source in regenerative medicine. They contain several cell subtypes, including multipotent stem cells. MSCs are of particular interest as they are currently being tested using cell and gene therapies for a number of human diseases. They represent a rare population in tissues; for this reason, they require, before being transplanted, an in vitro amplification. This process may induce replicative senescence, thus affecting differentiation and proliferative capacities. Increasing evidence suggests that MSCs from fetal tissues are significantly more plastic and grow faster than MSCs from bone marrow. Here, we compare amniotic fluid mesenchymal stromal cells (AF-MSCs) and bone marrow mesenchymal stromal cells (BM-MSCs) in terms of cell proliferation, surface markers, multidifferentiation potential, senescence, and DNA repair capacity. Our study shows that AF-MSCs are less prone to senescence with respect to BM-MSCs. Moreover, both cell models activate the same repair system after DNA damage, but AF-MSCs are able to return to the basal condition more efficiently with respect to BM-MSCs. Indeed, AF-MSCs are better able to cope with genotoxic stress that may occur either during in vitro cultivation or following transplantation in patients. Our findings suggest that AF-MSCs may represent a valid alternative to BM-MSCs in regenerative medicine, and, of great relevance, the investigation of the mechanisms involved in DNA repair capacity of both AF-MSCs and BM-MSCs may pave the way to their rational use in the medical field.
on Stem cells (Dayton, Ohio)
by Squillaro T, Galano G, De Rosa R, Peluso G, Galderisi U
Exposure to high levels of ionizing radiation (IR) (>0.5Gy), negatively affect health. but, less is known about the effects of low dose IR (LDIR) but recent, evidence suggests that it may have profound effects on cellular functions. We are commonly exposed to LDIR over natural background levels from numerous sources: people may be exposed to low dose IR for medical diagnosis and therapy, air travel, illegal IR waste dumpsites or by occupational exposures in the nuclear and medical sectors. Stem cells reside for long periods of time in our bodies, and this increases the possibility that they may be accumulate genotoxic damage derived from extrinsic LDIR or intrinsic sources (such as DNA replication). In this review we provide an overview of LDIR effects on biology of stem cell compartments. The principal findings and issues reported in the scientific literature are discussed in order to present the current understanding of the LDIR exposure risk, and assess whether it may impact human health. We first consider the general biological consequences of LDIR exposure. Following this, we discuss the effects of LDIR on stem cells as discovered through in vitro and in vivo studies. This article is protected by copyright. All rights reserved.
on Scientific reports
by Cuomo F, Coppola A, Botti C, Maione C, Forte A, Scisciola L, Liguori G, Caiafa I, Ursini MV, Galderisi U, Cipollaro M, Altucci L, Cobellis G
Human mesenchymal stromal/stem cells (hMSCs) emerged as a promising therapeutic tool for ischemic disorders, due to their ability to regenerate damaged tissues, promote angiogenesis and reduce inflammation, leading to encouraging, but still limited results. The outcomes in clinical trials exploring hMSC therapy are influenced by low cell retention and survival in affected tissues, partially influenced by lesion's microenvironment, where low oxygen conditions (i.e. hypoxia) and inflammation coexist. Hypoxia and inflammation are pathophysiological stresses, sharing common activators, such as hypoxia-inducible factors (HIFs) and NF-κB. HIF1α and HIF2α respond essentially to hypoxia, activating pathways involved in tissue repair. Little is known about the regulation of HIF3α. Here we investigated the role of HIF3α in vitro and in vivo. Human MSCs expressed HIF3α, differentially regulated by pro-inflammatory cytokines in an oxygen-independent manner, a novel and still uncharacterized mechanism, where NF-κB is critical for its expression. We investigated if epigenetic modifications are involved in HIF3α expression by methylation-specific PCR and histone modifications. Robust hypermethylation of histone H3 was observed across HIF3A locus driven by pro-inflammatory cytokines. Experiments in a murine model of arteriotomy highlighted the activation of Hif3α expression in infiltrated inflammatory cells, suggesting a new role for Hif3α in inflammation in vivo.
by Alessio N, Squillaro T, Özcan S, Di Bernardo G, Venditti M, Melone M, Peluso G, Galderisi U
Mesenchymal stromal cells (MSCs) are not a homogenous population but comprehend several cell types, such as stem cells, progenitor cells, fibroblasts, and other types of cells. Among these is a population of pluripotent stem cells, which represent around 1-3% of MSCs. These cells, named multilineage-differentiating stress enduring (Muse) cells, are stress-tolerant cells. Stem cells may undergo several rounds of intrinsic and extrinsic stresses due to their long life and must have a robust and effective DNA damage checkpoint and DNA repair mechanism, which, following a genotoxic episode, promote the complete recovery of cells rather than triggering senescence and/or apoptosis. We evaluated how Muse cells can cope with DNA damaging stress in comparison with MSCs. We found that Muse cells were resistant to chemical and physical genotoxic stresses better than non-Muse cells. Indeed, the level of senescence and apoptosis was lower in Muse cells. Our results proved that the DNA damage repair system (DDR) was properly activated following injury in Muse cells. While in non-Muse cells some anomalies may have occurred because, in some cases, the activation of the DDR persisted by 48 hr post damage, in others no activation took place. In Muse cells, the non-homologous end joining (NHEJ) enzymatic activity increases compared to other cells, while single-strand repair activity (NER, BER) does not. In conclusion, the high ability of Muse cells to cope with genotoxic stress is related to their quick and efficient sensing of DNA damage and activation of DNA repair systems.
on Experimental & molecular medicine
by Alessio N, Riccitiello F, Squillaro T, Capasso S, Del Gaudio S, Di Bernardo G, Cipollaro M, Melone MAB, Peluso G, Galderisi U
Several aspects of stem cell life are governed by epigenetic variations, such as DNA methylation, histone modifications, and chromatin remodeling. Epigenetic events are also connected with the impairment of stem cell functions. For example, during senescence, there are significant changes in chromatin organization that alter transcription. The MECP2 protein can bind methylated cytosines and contribute to regulating gene expression at one of the highest hierarchical levels. Researchers are particularly interested in this protein, as up to 90% of Rett syndrome patients have an MECP2 gene mutation. Nevertheless, the role of MECP2 in this disease remains poorly understood. We used a mouse model of Rett syndrome to evaluate whether residual MECP2 activity in neural stem cells (NSCs) induced the senescence phenomena that could affect stem cell function. Our study clearly demonstrated that the reduced expression of MECP2 is connected with an increase in senescence, an impairment in proliferation capacity, and an accumulation of unrepaired DNA foci. Mecp2 NSCs did not cope with genotoxic stress in the same way as the control cells did. Indeed, after treatment with different DNA-damaging agents, the NSCs from mice with mutated Mecp2 accumulated more DNA damage foci (γ-H2AX+) and were more prone to cell death than the controls. Senescence in Mecp2 NSCs decreased the number of stem cells and progenitors and gave rise to a high percentage of cells that expressed neither stem/progenitor nor differentiation markers. These cells could be senescent and dysfunctional.
on Cell death & disease
by Melone MAB, Valentino A, Margarucci S, Galderisi U, Giordano A, Peluso G
Metabolic flexibility describes the ability of cells to respond or adapt its metabolism to support and enable rapid proliferation, continuous growth, and survival in hostile conditions. This dynamic character of the cellular metabolic network appears enhanced in cancer cells, in order to increase the adaptive phenotype and to maintain both viability and uncontrolled proliferation. Cancer cells can reprogram their metabolism to satisfy the energy as well as the biosynthetic intermediate request and to preserve their integrity from the harsh and hypoxic environment. Although several studies now recognize these reprogrammed activities as hallmarks of cancer, it remains unclear which are the pathways involved in regulating metabolic plasticity. Recent findings have suggested that carnitine system (CS) could be considered as a gridlock to finely trigger the metabolic flexibility of cancer cells. Indeed, the components of this system are involved in the bi-directional transport of acyl moieties from cytosol to mitochondria and vice versa, thus playing a fundamental role in tuning the switch between the glucose and fatty acid metabolism. Therefore, the CS regulation, at both enzymatic and epigenetic levels, plays a pivotal role in tumors, suggesting new druggable pathways for prevention and treatment of human cancer.
by Valentino A, Calarco A, Di Salle A, Finicelli M, Crispi S, Calogero RA, Riccardo F, Sciarra A, Gentilucci A, Galderisi U, Margarucci S, Peluso G
Cancer cells reprogram their metabolism to maintain both viability and uncontrolled proliferation. Although an interplay between the genetic, epigenetic and metabolic rewiring in cancer is beginning to emerge, it remains unclear how this metabolic plasticity occurs. Here, we report that in prostate cancer cells (PCCs) microRNAs (miRNAs) greatly contribute to deregulation of mitochondrial fatty acid (FA) oxidation via carnitine system modulation. We provide evidence that the downregulation of hsa-miR-124-3p, hsa-miR-129-5p and hsa-miR-378 induced an increase in both expression and activity of CPT1A, CACT and CrAT in malignant prostate cells. Moreover, the analysis of human prostate cancer and prostate control specimens confirmed the aberrant expression of miR-124-3p, miR-129-5p and miR-378 in primary tumors. Forced expression of the miRNAs mentioned above affected tumorigenic properties, such as proliferation, migration and invasion, in PC3 and LNCaP cells regardless of their hormone sensitivity. CPT1A, CACT and CrAT overexpression allow PCCs to be more prone on FA utilization than normal prostate cells, also in the presence of high pyruvate concentration. Finally, the simultaneous increase of CPT1A, CACT and CrAT is fundamental for PCCs to sustain FA oxidation in the presence of heavy lipid load on prostate cancer mitochondria. Indeed, the downregulation of only one of these proteins reduces PCCs metabolic flexibility with the accumulation of FA-intermediate metabolites in the mitochondria. Together, our data implicate carnitine cycle as a primary regulator of adaptive metabolic reprogramming in PCCs and suggest new potential druggable pathways for prevention and treatment of prostate cancer.
on Neoplasia (New York, N.Y.)
by Alessio N, Capasso S, Ferone A, Di Bernardo G, Cipollaro M, Casale F, Peluso G, Giordano A, Galderisi U
Although mice models rank among the most widely used tools for understanding human genetics, biology, and diseases, differences between orthologous genes among species as close as mammals are possible, particularly in orthologous gene pairs in which one or more paralogous (i.e., duplicated) genes appear in the genomes of the species. Duplicated genes can possess overlapping functions and compensate for each other. The retinoblastoma gene family demonstrates typical composite functionality in its three member genes (i.e., RB1, RB2/P130, and P107), all of which participate in controlling the cell cycle and associated phenomena, including proliferation, quiescence, apoptosis, senescence, and cell differentiation. We analyzed the role of the retinoblastoma gene family in regulating senescence in mice and humans. Silencing experiments with each member of the gene family in mesenchymal stromal cells (MSCs) and fibroblasts from mouse and human tissues demonstrated that RB1 may be indispensable for senescence in mouse cells, but not in human ones, as an example of species specificity. Furthermore, although RB2/P130 seems to be implicated in maintaining human cell senescence, the function of RB1 within any given species might differ by cell type, as an example of cell specificity. For instance, silencing RB1 in mouse fibroblasts induced a reduced senescence not observed in mouse MSCs. Our findings could be useful as a general paradigm of cautions to take when inferring the role of human genes analyzed in animal studies and when examining the role of the retinoblastoma gene family in detail.
on Journal of cellular physiology
by Squillaro T, Schettino C, Sampaolo S, Galderisi U, Di Iorio G, Giordano A, Melone MAB
Aging is a primary risk factor for both neurodegenerative disorders (NDs) and tumors such as adult-onset brain tumors. Since NDs and tumors are severe, disabling, progressive and often incurable conditions, they represent a pressing problem in terms of human suffering and economic costs to the healthcare systems. The current challenge for physicians and researchers is to develop new therapeutic strategies in both areas to improve the patients' quality of life. In addition to genetics and environmental stressors, the increase in cellular oxidative stress as one of the potential common etiologies has been reported for both disorders. Recently, the scientific community has focused on the beneficial effects of dietary antioxidant classes, known as nutraceuticals, such as carotenoids, vitamins, and polyphenols. Among these compounds, polyphenols are considered to be one of the most bioactive agents in neurodegeneration and tumor prevention. Despite the beneficial activity of polyphenols, their poor bioavailability and inefficient delivery systems are the main factors limiting their use in medicine and functional food. The development of polymeric nanoparticle-based delivery systems able to encapsulate and preserve polyphenolic compounds may represent a promising tool to enhance their stability, solubility, and cell membrane permeation. In the present review we provide an overview of the main polyphenolic compounds used for ND and brain tumor prevention and treatment that explores their mechanisms of action, recent clinical findings and principal factors limiting their application in medicine.