Maria Paola Bertuccio

Toxicological assessment of multi-walled carbon nanotubes on A549 human lung epithelial cells

An in vitro model resembling the respiratory epithelium was used to investigate the biological response to laboratory-made pristine and functionalised multi-walled carbon nanotubes (pMWCNT and MWCNT-COOH). Cell uptake was analysed by MWCNT-COOH, FITC labelled and the effect of internalisation was evaluated on the endocytic apparatus, mitochondrial compartment and DNA integrity. In the dose range 12.5-100μgml(-1), cytotoxicity and ROS generation were assayed, evaluating the role of iron (the catalyst used in MWCNTs synthesis). We observed a correlation between MWCNTs uptake and lysosomal dysfunction and an inverse relationship between these two parameters and cell viability (P<0.01). In particular, pristine-MWCNT caused a time- and dose-dependent ROS increase and higher levels of lipid hydroperoxides compared to the controls. Mitochondrial impairment was observed. Conversely to the functionalised MWCNT, higher micronuclei (MNi) frequency was detected in mono- and binucleate pMWCNT-treated cells, underlining an aneugenic effect due to mechanical damage. Based on the physical and chemical features of MWCNTs, several toxicological pathways could be activated in respiratory epithelium upon their inhalation. The biological impacts of nano-needles were imputable to their efficient and very fast uptake and to the resulting mechanical damages in cell compartments. Lysosomal dysfunction was able to trigger further toxic effects.

Mitochondrial-Mediated Apoptosis Pathway in Alveolar Epithelial Cells Exposed to the Metals in Combustion-Generated Particulate Matter

Previously a significant mitochondrial impairment was identified in alveolar epithelial cells exposed to metals adsorbed to combustion-generated particulate matter (PM). Due to the critical role of mitochondria in apoptosis, the aim of this study was to investigate the pro-apoptotic potential of metals present in oil fly ash (OFA). A549 cells were exposed to water-soluble components of an OFA sample, containing vanadium [V(IV)], iron [Fe(III)], and nickel [Ni(II)] (68.8, 110.4, and 18 μM, respectively). Experiments were also performed using individual metal solutions. Apoptosis was detected and the mitochondrial role was assessed by a caspase-9 inhibitor (Z-LEHD-FMK). To determine whether the presence of impaired mitochondria in unexposed daughter cells increased apoptosis, an in vitro model was developed that allowed determination of effects until the third cell generation. To specifically examine the toxicity of vanadium (V), that characterize the airborne pollutant examined in this study, p53involvement and metabolic impairment through changes in HIF-1α and Glut-1 expression were determined. OFA and individual metal solutions produced significant apoptosis in the progeny of exposed cells, triggering the intrinsic apoptosis pathway. In apoptosis induced by poorly genotoxic metal V, p53 did not play a significant role. However, V exposure increased nuclear translocation of HIF-1α and expression of the Glut-1 receptor, indicating metabolic impairment due to metal-induced mitochondrial dysfunction. Overall, these results improve our knowledge of the pathogenic role that airborne metals and in particular V exerted in respiratory epithelium.

Higher levels of oxidative DNA damage in cervical cells are correlated with the grade of dysplasia and HPV infection

The Human papillomavirus is responsible for the most common sexually transmitted infection and is also known to be an oncogenic virus that is associated with cervical, anogenital, and head‐neck cancers. The present study aims to assess whether oxidative DNA damage is correlated with the grade of HPV‐related lesions. Moreover, we evaluated clinical data and unhealthy lifestyles to verify their possible influence on the genesis of oxidative DNA damage in cervical cells. We quantified the amount of 8‐Oxo‐2′‐deoxyguanosine in DNA as a biomarker of oxidative damage in women with and without HPV infection. We also correlated oxidative damage with different stages of cervical lesions and available clinical data (e.g., HPV genotypes). To identify HPV infections, in which proteins with a transforming potential are produced, we performed a qualitative detection of HPV E6/E7 mRNA. Our results showed greater oxidative damage in HPV‐related dysplastic cervical lesions compared to samples with normal cytology, especially in women with high‐grade squamous intraepithelial lesions. The latter showed a closed link with high‐risk HPV genotypes. Reactive oxygen species can induce DNA double‐strand breaks in both the host DNA and in the circular viral episome; this could facilitate the integration of the virus, promoting HPV carcinogenesis. Therefore, in HPV‐infected women, it could be useful to reduce additional resources of reactive oxygen/nitrogen species (RONS) with a healthy lifestyle. J. Med. Virol. 88:336–344, 2016.

Mitochondrial dysfunction by pro-oxidant vanadium: Ex vivo assessment of individual susceptibility

The aim was to assess the individual susceptibility to mitochondrial impairment induced by ex vivo exposure to vanadium, an airborne pro-oxidant pollutant. In lymphocyte cultures V(IV)-treated of forty-five healthy subjects, we evaluated the mitochondrial transmembrane potential (Δψm) and the H2O2 in comparison to background values. As variables, we included both lifestyle factors and genetic polymorphisms (GSTM1 and GSTT1 variants, and C677T and A1298C variants of methylenetetrahydrofolate reductase MTHFR). H2O2 mitochondrial content increased significantly (P<0.05) after metal exposure while, in comparison to basal Δψm, both depolarisation and hyperpolarisation were recorded. This underlined the mitochondrial dysfunction vanadium-induced that worsens the redox imbalance by endogenous ROS overproduction. Only age was found to contribute significantly to the high inter-individual variability, as assessed by multivariate analysis. In older subjects, the H2O2/Δψm values underline the organelle impairment and, under V-exposure, Δψm values were inversely related to age (R=-0.591; P=0.012).

Intracellular accumulation of cell cycle regulatory proteins and nucleolin re-localization are associated with pre-lethal ultrastructural lesions in circulating T lymphocytes: The HIV-induced cell cycle dysregulation revisited

The HIV-induced demise of CD4-T cells is thought to be a result of the execution of genetically programmed cell death that occurs in lymphoid tissue, where many resident T cells are chronically hyperactivated. Since HIV-induced alterations of cell cycle control has been often indicated as prominent mechanism of immune hyper activation and cause of apoptotic death, the signal pathway involved in cell cycle dysregulation of T lymphocytes from HIV infected patients was extensively studied. Here, we also demonstrate that circulating T lymphocytes leave lymphoid tissues with diffused regressive lesions (vacuolization, blebbing, nuclear evanescence and organelle swelling). Equally diffused are biochemical anomalies that accompany the overall disarrangement of cell structure, particularly the fragmentation and diffusion into the cytoplasm of C23/nucleolin, the intracellular accumulation of short lived regulatory proteins and the decrease in expression of membrane proteins. All this is something more than a cell cycle-related remodelling of cell morphology and biochemical mechanisms, and rather recalls a necrotic/oncotic cell damage. Since these changes are associated with adaptive mechanisms to hypoxia, we give evidence for alteration of cell cycle control developing in conditions of scarce energy supply.

In vitro assessment of the indirect antioxidant activity of Sulforaphane in redox imbalance vanadium-induced

Abstract Owing to sulforaphane presence, a dietary consumption of Brassicaceae prevents chronic diseases. This hormetic compound induces adaptive stress response at subtoxic doses, while doses that exceed the cellular defence are toxic. In HepG2, Caco-2 and Vero cells, we investigated the sulforaphane (SFN) (5 μM) role in counteracting redox imbalance induced by VOSO4 [V(IV)]. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test showed a dose-dependent viability reduction (r < −0.95; p < 0.01) (range 5–80 μM). At 5 μM, SFN enhancement of mitochondrial activity was confirmed by Δψm (p < 0.05) both in basal condition and in redox-stressed cells. Intracellular ROS, DNA and lysosomal oxidative damages underlined the indirect antioxidant SFN activity, confirmed by the increase of GSH. The SFN empowering effects on mitochondrial function were imputable to the presence of mitochondrial proteins among the Nrf2-responsive phase II proteins. Considering the link between oxidative stress and chronic diseases, a long-term dietary intake of Brassicaceae could be strongly advisable.

In vitro assessment of neurotoxicity and neuroinflammation of homemade MWCNTs

Multi walled carbon nanotubes (MWCNTs) activate pathways involved in cytotoxicity, genotoxicity and inflammation. Inhaled MWCNTs are translocated to extra pulmonary organs and their hydrophobicity allows them to cross the blood-brain barrier (BBB). Further exposure of central nervous system (CNS) occurs via olfactory neurons. Using differentiated SH-SY5Y, we studied the neurotoxicity and neuroinflammation of pristine and functionalised MWCNTs. ROS overproduction was dose- and time-dependent (P<0.01) and was related to mitochondrial impairment, DNA damage and decreased viability (P<0.05). Transcript levels of TNFα, IL-1β and IL-6 increased, as confirmed by an ELISA test. Raman spectra were acquired to assess MWCNT-cells interactions. The almost superimposable pro-oxidant activity of both CNTs could be imputable to excessive lengths with regard to the pristine MWCNTs and to the eroded surface, causing increased reactivity, with regard to functionalised MWCNTs. Considering the ease with which lightweight MWCNTs aerosolize and the increased production, the results underlined the potential onset of neurodegenerative diseases, due to unintentional MWCNT exposure.

HIV genomic mutations causing resistance to antiretroviral drugs in seropositive Sicilians.

Through the use of highly active antiretroviral therapy a significant reduction occurred in mortality and morbidity caused by Human Immunodeficiency Virus. The use of antiretroviral drugs resulted in the emergence of resistant viral strains due to mutations that cause a selective advantage to the virus. The aim of our study is to monitor the HIV-1 infection in Sicilians patients evaluating the presence of mutations that make the virus resistant to the therapy. The QIAGEN QIAamp Viral RNA Mini Kit was used to extract HIV-1 viral RNA from 300 patients while the TRUGENE HIV-1 Genotyping Kit and the OpenGene DNA Sequencing System determined viral mutations in the RNA samples. The analysis showed that from 300 subjects, 116 developed Antiretroviral Drug Resistance. The percentage of patients with resistance to nucleoside reverse transcriptase inhibitor (NRTI), non nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitor was 26%, 23% and 20%, respectively. Comparison between drug resistances and mutations showed that 134 individuals had mutations in genes codifying for reverse transcriptase but a little more than 50% were associated with resistance to reverse transcriptase inhibitors, in particular 78 and 68 subjects developed drug resistances to NRTI and NNRTI classes respectively. Subjects that showed mutations in genes codifying for protease were 216 but only 59 of these were associated with resistance to protease inhibitors. Our findings emphasize the importance of continued resistance surveillance. Monitoring of transmitted resistance continues to be needed among treatment-exposed patients because of the benefit it provides for the development of drugs effective against the most frequently found drug-resistant viruses.

Nucleolin relocalization associated with pre-lethal alterations of T cell morphology: redefining cell death in HIV infection

Results Here we demonstrate that circulating T lymphocytes, both CD4+ and CD8+, leave lymphoid tissues with diffused regressive lesions such as vacuolization, blebbing, nuclear evanescence and organelle swelling. Equally diffused are biochemical anomalies that accompany the overall disarrangement of cell structure, namely (i) fragmentation and diffusion into the cytoplasm of C23/ nucleolin, the principal structural protein of the nucleus (ii) an accumulation of short lived regulatory proteins (p16, p21 and p53), likely due to the progressive extinction of the ATP ub proteasome system and (iii) a decreased expression of membrane proteins.