Giulia Abate

Enhanced Sensing of Interleukin 8 by Stripping Voltammetry: Carbon Nanotubes versus Fullerene

The ability to detect protein biomarkers at a sub-nanomolar level represents a pervasive challeng... more The ability to detect protein biomarkers at a sub-nanomolar level represents a pervasive challenge in order to bring a significant improvement in early diagnosis or progression of pato-physiological processes. To this aim, Screen Printed Electrochemical Sensors have been acquiring a predominant importance. The possibility to use them with different measurement techniques, and to customize their surface to improve the performance represent really attractive features. In this work, performances of two different carbon nanostructures in combination with Stripping Voltammetry were evaluated as tools to improve the detection of Interleukin 8, a cytokine that has pivotal roles in various inflammatory processes and considered as a universal biomarker. Commercially-available Carbon sensors were modified using Carbon Nanotubes and Spherical Fullerene through drop casting technique. Interleukin 8 was quantified using an indirect techniques based on silver stripping catalyzed using Alkaline Ph...

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Unfolded P53 as a novel lead biomarker for Alzheimer’s disease diagnosis

Alzheimer's & Dementia, 2020

Blood‐based biomarkers represent a promising choice for early Alzheimer’s disease (AD) diagnosis ... more

Study of a low-cost sensitive point-of-care testing system using screen printed biosensors for early biomarkers detection related to Alzheimer disease

Among neurodegenerative diseases, Alzheimer Disease (AD) represents one of the most serious patho... more Among neurodegenerative diseases, Alzheimer Disease (AD) represents one of the most serious pathology, for which an early diagnosis is still missing. A peculiar expression of an altered conformational isoform of p53 protein was reported to be a biomarker able to distinguish AD subjects from healthy population, quantifiable using a blood-based enzyme-linked immunosorbent assay (ELISA). In order to overcome ELISA limitations related to reliability and to improve sensitivity, this study aimed to realize a low cost highly sensitive portable point-of-care (PoC) testing system based on screen printed electrochemical sensors (SPES). The development of the platform specifically included both the design of the sensing probe and of the electronic circuit devoted to the conditioning and acquisition of the transduced electric signal. In particular, silver, carbon and silver-silver chloride were selected respectively to realize conductive tracks, working and counter electrodes, reference electro...

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Spectrophotometer measurements to characterize conformational state of the proteins: p53 analysis

2018 IEEE International Symposium on Medical Measurements and Applications (MeMeA), 2018

The development of sensing techniques for the analysis of protein samples represents an area of g... more The development of sensing techniques for the analysis of protein samples represents an area of great interest for biotechnology, pharmacology and diagnostics. Traditional biochemical assays available present limitations in term time and cost efficiency. On the contrary, optical based techniques, such as spectrophotometry, might offer the interesting possibility of a non-invasive and continuous monitoring. The present work proposes a spectrophotometer-based method of identifying different conformational states of p53, a redox sensitive protein involved in several pathophysiological processes. Samples containing three different structural states of p53 (Wild type p53, Denatured p53 and Oxidized p53) has been investigated using spectrophotometer in a measuring wavelength range from 185nm to 1400nm, in order to detect the differences in light absorption. The unfolding state of p53 redox products has been further studied performing a label-based silver stripping voltammetry. Results fro...

From blood-based redox profile to the validation of a lead biomarker for the timely diagnosis of Alzheimer’s disease

Acta Neurobiologiae Experimentalis, 2017

Discovery of Simple Blood-Based Test to Predict Early Onset of Alzheimer’s Using Standard Clinical Mass Spectrometry Platforms

a Diadem srl, Brescia, Italy b I.S.B. Ion Source & Biotechnologies srl, Biotechnology, Bresso, It... more a Diadem srl, Brescia, Italy b I.S.B. Ion Source & Biotechnologies srl, Biotechnology, Bresso, Italy c The Florey Institute of Neuroscience and Mental Health, Parkville, Australia d The Australian e-Health Research Centre, CSIRO, Herston, Australia e Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy f Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy

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Pharmacological profile of γ-oryzanol: Its antioxidant mechanisms and its effects in age-related diseases

Aging

Abstract γ-Oryzanol is the most potent natural antioxidant in rice (Oryza sativa L.), and its pha... more Abstract γ-Oryzanol is the most potent natural antioxidant in rice (Oryza sativa L.), and its pharmacological profile has been intensively investigated. A growing body of evidence demonstrated that γ-oryzanol exerts its antioxidant activity at least through three mechanisms: (1) acting as a free radical scavenger, (2) boosting endogenous antioxidant enzyme activities, and (3) modulating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. In fact, its beneficial health effects have been demonstrated in a series of pathological conditions where oxidative stress is a main feature, such as hyperlipidemia, hyperglycemia, inflammation, and cognitive impairment. Additionally, different pharmacokinetic studies of γ-oryzanol have illustrated that it is absorbed in the intact form via the intestine into the blood circulation in a dose-dependent manner and highly distributed throughout the body, particularly in the brain. Its safety with no observed adverse effect makes γ-oryzanol as a natural dietary supplement for humans, and it is approved in Japan as a prescription medicine.

Impact of COVID-19 on Alzheimer’s Disease Risk: Viewpoint for Research Action

Healthcare

In the middle of the coronavirus disease 19 (COVID-19) outbreak, the main efforts of the scientif... more In the middle of the coronavirus disease 19 (COVID-19) outbreak, the main efforts of the scientific community are rightly all focused on identifying efficient pharmacological treatments to cure the acute severe symptoms and developing a reliable vaccine. On the other hand, we cannot exclude that, in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) positive subjects, the virus infection could have long-term consequences, leading to chronic medical conditions such as dementia and neurodegenerative disease. Considering the age of SARS-CoV-2 infected subjects, the neuroinvasive potential might lead/contribute to the development of neurodegenerative diseases. Here, we analyzed a possible link between SARS-CoV-2 infection and Alzheimer’s disease risk, hypothesizing possible mechanisms at the base of disease development. This reflection raises the need to start to experimentally investigating today the mechanistic link between Alzheimer’s disease (AD) and COVID-19 to be ready t...

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Post-translational Modifications of the p53 Protein and the Impact in Alzheimer’s Disease: A Review of the Literature

Our understanding of Alzheimer’s disease (AD) pathogenesis has developed with several hypotheses ... more Our understanding of Alzheimer’s disease (AD) pathogenesis has developed with several hypotheses over the last 40 years, including the Amyloid and Tau hypotheses, respectively. More recently, the p53 protein, well-known as ‘the guardian of the genome,’ has gained attention for its role in the early evolution of AD. This is due to p53’s central role in the control of oxidative stress and potential involvement in both Amyloid and Tau pathways. p53 is commonly regulated by post-translational modifications (PTMs), which affect its conformation, increasing its capacity to adopt multiple structural and functional states, including those that can influence several processes in AD. The following review will explore the impact of p53 post-translational modifications (PTMs) on its function and consequential involvement in AD pathogenesis.

Phytochemical Analysis and Anti-Inflammatory Activity of Different Ethanolic Phyto-Extracts of Artemisia annua L

Biomolecules

Artemisia annua L. (AA) has shown for many centuries important therapeutic virtues associated wit... more Artemisia annua L. (AA) has shown for many centuries important therapeutic virtues associated with the presence of artemisinin (ART). The aim of this study was to identify and quantify ART and other secondary metabolites in ethanolic extracts of AA and evaluate the biological activity in the presence of an inflammatory stimulus. In this work, after the extraction of the aerial parts of AA with different concentrations of ethanol, ART was quantified by HPLC and HPLC-MS. In addition, anthocyanins, flavanols, flavanones, flavonols, lignans, low-molecular-weight phenolics, phenolic acids, stilbenes, and terpenes were identified and semi-quantitatively determined by UHPLC-QTOF-MS untargeted metabolomics. Finally, the viability of human neuroblastoma cells (SH-SY5Y) was evaluated in the presence of the different ethanolic extracts and in the presence of lipopolysaccharide (LPS). The results show that ART is more concentrated in AA samples extracted with 90% ethanol. Regarding the other me...

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Variation in Phytochemical, Antioxidant and Volatile Composition of Pomelo Fruit (Citrus grandis (L.) Osbeck) during Seasonal Growth and Development

Plants

Citrus fruits exhibit a high level of different phytoconstituents, of which the changes in the di... more Citrus fruits exhibit a high level of different phytoconstituents, of which the changes in the different parts of the fruit during ripening have not been thoroughly studied yet. Thus, in this study, we have investigated how different parts of pomelo fruit (Citrus grandis L.) are modified throughout the development of two consecutive growing seasons. In detail, the main phytochemical compounds, such as total phenolic content, total flavonoid content, antioxidant capacity, DPPH free radical scavenging activity, Ferric reducing antioxidant power (FRAP), and naringin and tannin content, were analyzed. A systematic metabolism of these compounds was found during the development of the fruit, but some pomelo tissues showed a fluctuating trend, suggesting a dependence on the different growing season. Focusing on the tissue distribution of these compounds, the fruit membrane contained the highest level of total phenolic and flavonoid content; fruit flavedo displayed the highest antioxidant c...

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A Conformation Variant of p53 Combined with Machine Learning Identifies Alzheimer Disease in Preclinical and Prodromal Stages

Journal of Personalized Medicine

Early diagnosis of Alzheimer’s disease (AD) is a crucial starting point in disease management. Bl... more Early diagnosis of Alzheimer’s disease (AD) is a crucial starting point in disease management. Blood-based biomarkers could represent a considerable advantage in providing AD-risk information in primary care settings. Here, we report new data for a relatively unknown blood-based biomarker that holds promise for AD diagnosis. We evaluate a p53-misfolding conformation recognized by the antibody 2D3A8, also named Unfolded p53 (U-p532D3A8+), in 375 plasma samples derived from InveCe.Ab and PharmaCog/E-ADNI longitudinal studies. A machine learning approach is used to combine U-p532D3A8+ plasma levels with Mini-Mental State Examination (MMSE) and apolipoprotein E epsilon-4 (APOEε4) and is able to predict AD likelihood risk in InveCe.Ab with an overall 86.67% agreement with clinical diagnosis. These algorithms also accurately classify (AUC = 0.92) Aβ+—amnestic Mild Cognitive Impairment (aMCI) patients who will develop AD in PharmaCog/E-ADNI, where subjects were stratified according to Cere...

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The pleiotropic role of p53 in functional/dysfunctional neurons: focus on pathogenesis and diagnosis of Alzheimer’s disease

Alzheimer's Research & Therapy

Background Understanding the earliest pathophysiological changes of Alzheimer’s disease (AD) may ... more Background Understanding the earliest pathophysiological changes of Alzheimer’s disease (AD) may aid in the search for timely diagnostic biomarkers and effective disease-modifying therapies. The p53 protein is mostly known for its role in tumor suppression. However, emerging evidence supports that dysregulated p53 activity may contribute to various peripheral and brain alterations during the earliest stages of AD. This review describes the mechanisms through which p53 dysregulation may exacerbate AD pathology and how this could be used as a potential peripheral biomarker for early detection of the disease. Main body p53, known as the guardian of the genome, may underlie various compensation or defense mechanisms that prevent neurons from degeneration. These mechanisms include maintenance of redox homeostasis, regulation of inflammation, control of synaptic function, reduction of amyloid β peptides, and inhibition of neuronal cell cycle re-entry. Thereby, dysregulation of p53-depende...

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Electrochemical detection of different p53 conformations by using nanostructured surfaces

Scientific Reports

Protein electrochemistry represents a powerful technique for investigating the function and struc... more Protein electrochemistry represents a powerful technique for investigating the function and structure of proteins. Currently available biochemical assays provide limited information related to the conformational state of proteins and high costs. This work provides novel insights into the electrochemical investigation of the metalloprotein p53 and its redox products using label-free direct electrochemistry and label-based antibody-specific approaches. First, the redox activities of different p53 redox products were qualitatively investigated on carbon-based electrodes. Then, focusing on the open p53 isoform (denatured p53), a quantitative analysis was performed, comparing the performances of different bulk and nanostructured materials (carbon and platinum). Overall, four different p53 products could be successfully discriminated, from wild type to denatured. Label-free analysis suggested a single electron exchange with electron transfer rate constants on the order of 1 s−1. Label-bas...

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γ-Oryzanol Improves Cognitive Function and Modulates Hippocampal Proteome in Mice

Nutrients

Rice (Oryza sativa L.) is the richest source of γ-oryzanol, a compound endowed with antioxidant a... more Rice (Oryza sativa L.) is the richest source of γ-oryzanol, a compound endowed with antioxidant and anti-inflammatory properties. γ-Oryzanol has been demonstrated to cross the blood-brain barrier in intact form and exert beneficial effects on brain function. This study aimed to clarify the effects of γ-oryzanol in the hippocampus in terms of cognitive function and protein expression. Adult mice were administered with γ-oryzanol 100 mg/kg or vehicle (control) once a day for 21 consecutive days following which cognitive behavior and hippocampal proteome were investigated. Cognitive tests using novel object recognition and Y-maze showed that long-term consumption of γ-oryzanol improves cognitive function in mice. To investigate the hippocampal proteome modulated by γ-oryzanol, 2D-difference gel electrophoresis (2D-DIGE) was performed. Interestingly, we found that γ-oryzanol modulates quantitative changes of proteins involved in synaptic plasticity and neuronal trafficking, neuroprotect...

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A telescope GWAS analysis strategy, based on SNPs-genes-pathways ensamble and on multivariate algorithms, to characterize late onset Alzheimer’s disease

Scientific Reports

Genome–wide association studies (GWAS) have revealed a plethora of putative susceptibility genes ... more Genome–wide association studies (GWAS) have revealed a plethora of putative susceptibility genes for Alzheimer’s disease (AD), with the sole exception of APOE gene unequivocally validated in independent study. Considering that the etiology of complex diseases like AD could depend on functional multiple genes interaction network, here we proposed an alternative GWAS analysis strategy based on (i) multivariate methods and on a (ii) telescope approach, in order to guarantee the identification of correlated variables, and reveal their connections at three biological connected levels. Specifically as multivariate methods, we employed two machine learning algorithms and a genetic association test and we considered SNPs, Genes and Pathways features in the analysis of two public GWAS dataset (ADNI-1 and ADNI-2). For each dataset and for each feature we addressed two binary classifications tasks: cases vs. controls and the low vs. high risk of developing AD considering the allelic status of ...

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A Novel Technique to Characterize Conformational State of the Proteins: p53 Analysis

Sensors, 2019

γ-Oryzanol Improves Cognitive Function and Modulates Hippocampal Proteome in Mice

Nutrients, Mar 31, 2019

Rice (Oryza sativa L.) is the richest source of γ-oryzanol, a compound endowed with antioxidant a... more Rice (Oryza sativa L.) is the richest source of γ-oryzanol, a compound endowed with antioxidant and anti-inflammatory properties. γ-Oryzanol has been demonstrated to cross the blood-brain barrier in intact form and exert beneficial effects on brain function. This study aimed to clarify the effects of γ-oryzanol in the hippocampus in terms of cognitive function and protein expression. Adult mice were administered with γ-oryzanol 100 mg/kg or vehicle (control) once a day for 21 consecutive days following which cognitive behavior and hippocampal proteome were investigated. Cognitive tests using novel object recognition and Y-maze showed that long-term consumption of γ-oryzanol improves cognitive function in mice. To investigate the hippocampal proteome modulated by γ-oryzanol, 2D-difference gel electrophoresis (2D-DIGE) was performed. Interestingly, we found that γ-oryzanol modulates quantitative changes of proteins involved in synaptic plasticity and neuronal trafficking, neuroprotection and antioxidant activity, and mitochondria and energy metabolism. These findings suggested γ-oryzanol as a natural compound able to maintain and reinforce brain function. Although more intensive studies are needed, we propose γ-oryzanol as a putative dietary phytochemical for preserving brain reserve, the ability to tolerate age-related changes, thereby preventing clinical symptoms or signs of neurodegenerative diseases.

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From Blood-Based Redox Profile to the Identification of a Lead Biomarker for the Timely Diagnosis of Alzheimer’s Disease

Alzheimer's & Dementia

Nailfold capillary feature Category Multivariable* odds ratio (95% confidence interval) Unadjuste... more Nailfold capillary feature Category Multivariable* odds ratio (95% confidence interval) Unadjusted P value FDRAdjusted P value Mean tortuosity scorey 0 to <1 1.0 (ref) 1 to <2 3.4 (1.0, 12.2) .060 .083 2 14.1 (3.1, 63.9) .0006 .0036 Number of hemorrhages per 100 capillaries 0 to <1 1.0 (ref) 1 to <2 8.4 (1.9, 36.6) .0045 .014 2 4.4 (1.3, 14.9) .019 .037 Number of avascular zones 100 microns per 100 capillaries 0 to <1 1.0 (ref) 1 to <2 2.3 (0.6, 8.7) .23 .23 22 2.9 (0.9, 9.0) .069 .083

Electrochemical detection of different p53 conformations by using nanostructured surfaces

Scientific Reports volume 9, Article number: 17347 (2019), 2019

Protein electrochemistry represents a powerful technique for investigating the function and struc... more Protein electrochemistry represents a powerful technique for investigating the function and structure of proteins. Currently available biochemical assays provide limited information related to the conformational state of proteins and high costs. This work provides novel insights into the electrochemical investigation of the metalloprotein p53 and its redox products using label-free direct electrochemistry and label-based antibody-specific approaches. First, the redox activities of different p53 redox products were qualitatively investigated on carbon-based electrodes. Then, focusing on the open p53 isoform (denatured p53), a quantitative analysis was performed, comparing the performances of different bulk and nanostructured materials (carbon and platinum). Overall, four different p53 products could be successfully discriminated, from wild type to denatured. Label-free analysis suggested a single electron exchange with electron transfer rate constants on the order of 1 s−1. Label-bas...

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