Tiziana Squillaro

Biological Scientist, PhD

Name Tiziana
Surname Squillaro
Institution Università degli Studi della Campania Luigi Vanvitelli
E-Mail tiziana.squillaro@unicampania.it
Address Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, 2nd Division of Neurology, Center for Rare Diseases, University of Campania "Luigi Vanvitelli", Napoli, Italy
Tiziana Squillaro

Member PUBLICATIONS

  • In Reply.

    Publication Date: 01/11/2018 on Stem cells (Dayton, Ohio)
    by Squillaro T, Finicelli M, Peluso G, Galderisi U
    DOI: 10.1002/stem.2900
  • Metabolic syndrome, Mediterranean diet, and polyphenols: Evidence and perspectives.

    Publication Date: 14/10/2018 on Journal of cellular physiology
    by Finicelli M, Squillaro T, Di Cristo F, Di Salle A, Melone MAB, Galderisi U, Peluso G
    DOI: 10.1002/jcp.27506

    Metabolic syndrome (MetS) is defined as the co-occurrence of metabolic risk factors that includes insulin resistance, hyperinsulinemia, impaired glucose tolerance, type 2 diabetes mellitus, dyslipidemia, and visceral obesity. The clinical significance of MetS consists of identifying a subgroup of patients sharing a common physiopathological state predisposing to chronic diseases. Clinical and scientific studies pinpoint lifestyle modification as an effective strategy aiming to reduce several features accountable for the risk of MetS onset. Among the healthy dietary patterns, the Mediterranean diet (MedDiet) emerges in terms of beneficial properties associated with longevity. Current evidence highlights the protective effect exerted by MedDiet on the different components of MetS. Interestingly, the effect exerted by polyphenols contained within the representative MedDiet components (i.e., olive oil, red wine, and nuts) seems to be accountable for the beneficial properties associated to this dietary pattern. In this review, we aim to summarize the principal evidence regarding the effectiveness of MedDiet-polyphenols in preventing or delaying the physiopathological components accountable for MetS onset. These findings may provide useful insights concerning the health properties of MedDiet-polyphenols as well as the novel targets destined to a tailored approach to MetS.

  • Hybrid complexes of high and low molecular weight hyaluronan delay in vitro replicative senescence of mesenchymal stromal cells: a pilot study for future therapeutic application.

    Publication Date: 12/07/2018 on Aging
    by Alessio N, Stellavato A, Squillaro T, Del Gaudio S, Di Bernardo G, Peluso G, De Rosa M, Schiraldi C, Galderisi U
    DOI: 10.18632/aging.101493

    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.

  • Nano-delivery systems for encapsulation of dietary polyphenols: an experimental approach for neurodegenerative diseases and brain tumors.

    Publication Date: 24/05/2018 on Biochemical pharmacology
    by Squillaro T, Cimini A, Peluso G, Giordano A, Melone M
    DOI: 10.1016/j.bcp.2018.05.016

    Neurodegenerative diseases (NDs) and brain tumors are severe, disabling, and incurable disorders that represent a critical problem regarding human suffering and the economic burden on the healthcare system. Because of the lack of effective therapies to treat NDs and brain tumors, the challenge for physicians is to discover new drugs to improve their patients' quality of life. In addition to risk factors such as genetics and environmental influences, increased cellular oxidative stress has been reported as one of the potential common etiologies in both disorders. Given their antioxidant and anti-inflammatory potential, dietary polyphenols are considered to be one of the most bioactive natural agents in chronic disease prevention and treatment. Despite the protective activity of polyphenols, their inefficient delivery systems and poor bioavailability strongly limit their use in medicine and functional food. A potential solution lies in polymeric nanoparticle-based polyphenol delivery systems that are able to enhance their absorption across the gastrointestinal tract, improve their bioavailability, and transport them to target organs. In the present manuscript, we provide an overview of the primary polyphenols used for ND and brain tumor prevention and treatment by focusing on recent findings, the principal factors limiting their application in clinical practice, and a promising delivery strategy to improve their bioavailability.

  • The Effect of Low-Dose Ionizing Radiation on Stem Cell Biology: A Contribution to Radiation Risk.

    Publication Date: 17/04/2018 on Stem cells (Dayton, Ohio)
    by Squillaro T, Galano G, De Rosa R, Peluso G, Galderisi U
    DOI: 10.1002/stem.2836

    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.

  • Stress and stem cells: adult Muse cells tolerate extensive genotoxic stimuli better than mesenchymal stromal cells.

    Publication Date: 10/04/2018 on Oncotarget
    by Alessio N, Squillaro T, Özcan S, Di Bernardo G, Venditti M, Melone M, Peluso G, Galderisi U
    DOI: 10.18632/oncotarget.25039

    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.

  • Neural stem cells from a mouse model of Rett syndrome are prone to senescence, show reduced capacity to cope with genotoxic stress, and are impaired in the differentiation process.

    Publication Date: 22/03/2018 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
    DOI: 10.1038/s12276-017-0005-x

    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.

  • Huntingtin protein: A new option for fixing the Huntington's disease countdown clock.

    Publication Date: 08/03/2018 on Neuropharmacology
    by Caterino M, Squillaro T, Montesarchio D, Giordano A, Giancola C, Melone MAB
    DOI: 10.1016/j.neuropharm.2018.03.009

    Huntington's disease is a dreadful, incurable disorder. It springs from the autosomal dominant mutation in the first exon of the HTT gene, which encodes for the huntingtin protein (HTT) and results in progressive neurodegeneration. Thus far, all the attempted approaches to tackle the mutant HTT-induced toxicity causing this disease have failed. The mutant protein comes with the aberrantly expanded poly-glutamine tract. It is primarily to blame for the build-up of β-amyloid-like HTT aggregates, deleterious once broadened beyond the critical ∼35-37 repeats threshold. Recent experimental findings have provided valuable information on the molecular basis underlying this HTT-driven neurodegeneration. These findings indicate that the poly-glutamine siding regions and many post-translation modifications either abet or counter the poly-glutamine tract. This review provides an overall, up-to-date insight into HTT biophysics and structural biology, particularly discussing novel pharmacological options to specifically target the mutated protein and thus inhibit its functions and toxicity.

  • Stem Cells and DNA Repair Capacity: Muse Stem Cells Are Among the Best Performers.

    Publication Date: 01/01/2018 on Advances in experimental medicine and biology
    by Squillaro T, Alessio N, Di Bernardo G, Özcan S, Peluso G, Galderisi U
    DOI: 10.1007/978-4-431-56847-6_5

    Stem cells persist for long periods in the body and experience many intrinsic and extrinsic stresses. For this reason, they present a powerful and effective DNA repair system in order to properly fix DNA damage and avoid the onset of a degenerative process, such as neoplastic transformation or aging. In this chapter, we compare the DNA repair ability of pluripotent stem cells (ESCs, iPSCs, and Muse cells) and other adult stem cells. We also describe personal investigations showing a robust and effective capacity of Muse cells in sensing and repairing DNA following chemical and physical stress. Muse cells can repair DNA through base and nucleotide excision repair mechanisms, BER and NER, respectively. Furthermore, they present a pronounced capacity in repairing double-strand breaks by the nonhomologous end joining (NHEJ) process. The studies addressing the role of DNA damage repair in the biology of stem cells are of paramount importance for comprehension of their functions and, also, for setting up effective and safe stem cell-based therapy.

  • Localization of neuroglobin in the brain of R6/2 mouse model of Huntington's disease.

    Publication Date: 03/11/2017 on Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology
    by Cardinale A, Fusco FR, Paldino E, Giampà C, Marino M, Nuzzo MT, D'Angelo V, Laurenti D, Straccia G, Fasano D, Sarnataro D, Squillaro T, Paladino S, Melone MAB
    DOI: 10.1007/s10072-017-3168-2

    Neuroglobin (Ngb) is expressed in the central and peripheral nervous system, cerebrospinal fluid, retina, and endocrine tissues where it is involved in binding O2 and other gasotransmitters. Several studies have highlighted its endogenous neuroprotective function. Huntington's disease (HD), a dominant hereditary disease, is characterized by the gradual loss of neurons in discrete areas of the central nervous system. We analyzed the expression of Ngb in the brain tissue of a mouse model of HD, in order to define the role of Ngb with respect to individual cell type vulnerability in HD and to gender and age of mice. Our results showed different expressions of Ngb among neurons of a specific region and between different brain regions. We evidenced a decreased intensity of Ngb at 13 weeks of age, compared to 7 weeks of age. The double immunofluorescence and fluorescence resonance energy transfer (FRET) experiments showed that the co-localization between Ngb and huntingtin at the subcellular level was not close enough to account for a direct interaction. We also observed a different expression of Ngb in the striatum, depending on the sex and age of animals. These findings provide the first experimental evidence for an adaptive response of Ngb in HD, suggesting that Ngb may exert neuroprotective effects in HD beyond its role in reducing sensitivity to oxidative stress.