Seminari del DSF 2021-2022

Diet and its role in hippocampal neuroplasticity

27 October 2021 Fausto Chiazza (UNIUPO - DSF)

A lifestyle characterised by a balanced diet is essential for the homeostasis of the body and even more relevant for the central nervous system (CNS), directly influencing cognitive and emotional functions especially at particularly vulnerable ages such as adolescence. In the CNS, memory and mood are mainly regulated by the hippocampus: here occurs a neuroplasticity process known as "postnatal hippocampal neurogenesis" (hNG) which allows new neurons to form and integrate into hippocampal circuits. Numerous studies have shown that reductions in cognitive performance and the development of depression can be a consequence of a dysfunction in hNG. Much evidence also suggests that excessive food consumption can affect hNG even before significant body weight gain and therefore regardless of the development of overt metabolic diseases such as obesity and diabetes. In this project, the effects of a short intake of a high-calorie diet on hippocampal neuroplasticity and in particular on an important population of immature neurons (doublecortin +) in adolescent or adult mice were analyzed.

*Project funded by Local Research Call

3 November 2021 Federica Grosso (Azienda Ospedaliera SS Antonio e Biagio e Cesare Arrigo)

Mesothelioma, despite being a rare tumour, is the most frequent primary tumour of the pleura: about 2000 new cases occur every year in Italy. The pathogenesis is linked to exposure to asbestos and the mortality prediction models indicate that the peak will last at least until 2025 and will subsequently witness a slow decrease.

Recently, immunotherapy has shown a significant prognostic impact after almost two decades in which there was no improvement and is about to become a new therapeutic standard.

However, many other questions still remain open about the biology of this tumour: several new approaches are being evaluated to arrive at the definition of more personalized approaches, even if the road to this is still long.

17 november 2021 Zhou Wang (Aston University- Birmingham)

Transglutaminase 2 (TG2) is a multifunctional enzyme involved in various physiological and pathological processes. Physiologically, TG2 plays an important role in wound healing and angiogenesis via mediating cell adhesion, migration and survival and in matrix deposition and assembly. Pathologically, TG2 has been shown to be involved in cancer progression, fibrosis and neurodegenerative diseases. Research in our group has focused on understanding the role of TG2 in these processes in particular its role in fibrosis, cancer progression and pathological angiogenesis. Importantly, we have been working on developing therapeutic agents that specifically target TG2, such as small molecule inhibitors, for the treatment of these different human diseases, such as cardiac fibrosis, lung fibrosis, cystic fibrosis and colorectal cancer. In this seminar, I will present a summary of the recent research progress in the TG2 research field and recent updates on the research in our group.

1 December 2021 Elena Petricci (UNISI-DBCF)

With more than 50 Antibody Drug Conjugates (ADCs) in clinical trials for cancer treatment, the ADC approach opens a new era of chemotherapy. ADCs activity is strictly related to the chemical properties of both linker and payload, while the conjugation methodologies impact their homogeneity. Here we report our experience in the development of novel ADCs that can deliver to human tumours Hystone DeACetylase (HDAC) inhibitors and other payloads (i.e., Smo inhibitors) with low cytotoxicity. Different payloads were prepared using both cleavable and non-cleavable linkers and conjugated to Cetuximab and Trastuzumab resulting in ADCs exhibiting unmodified ability to recognize EGFR and efficient internalization into tumour cells. Animal models of human solid tumours showed high anti-tumour efficacy of the conjugates without the toxicity of traditional ADCs charged with highly potent cytotoxic drugs. These new bioconjugates proved to be suitable for targeted epigenetic modulation possibly extending the ADC strategy to therapeutic applications beyond cancer.

15 December 2021 Marco Ferrero (UNIUPO-DSF)

The Ultra-Fast Silicon Detectors (UFSDs) are innovative solid state detectors initially developed for high energy physics applications, now gaining interest in medicine. The elements sensitive to ionizing radiation are thin silicon layers with internal gain, able to generate large and fast signals. The time of arrival of a particle can be measured with a precision of tens of picoseconds. Thanks to their performance, UFSDs are currently being considered for ion beam characterization and monitoring in radiobiological and clinical irradiations. They can overcome the limits of the currently used ionization chambers. Recent developments in two therapy applications will be discussed: (i) counting the particles delivered at high rate (100 MHz) to a patient in a therapeutic beam; (ii) measuring the beam particle energy using the time-of-flight method.

12 January 2022  Daniele Passarella (UNIMI- Department of Chemistry)

The structural diversity, the peculiar reactivity and the singular biological activities make natural products an immense treasure that has always characterized life on earth, stimulating the interest of science aimed at identifying their biogenesis, the mechanisms of action and their possible applications, including which stands out for the defense of human health. In our research group, natural products are used as "building blocks", as "leads" to obtain analogues or as "targets" to study new synthetic ways. 4 different projects will then be presented to exemplify these 3 different ways of using natural compounds with applications aimed at two major problems such as cancer and neurodegeneration. The 4 different projects will involve withaferin A, maytansine, cannabidiol and epothilones as main actors.

19 January 2022 David Jeruzalmi (City University of New York)

Dedicated loader proteins play essential roles in bacterial DNA replication by opening ring-shaped DnaB-family helicases and chaperoning ssDNA into a central motor chamber as a prelude to DNA unwinding. Although unrelated in sequence, the E. coli DnaC and bacteriophage λ P loaders feature a similar overall architecture: a globular domain linked to an extended lasso/grappling hook element, located at their amino and carboxy termini, respectively. Both loaders remodel a closed DnaB ring into nearly identical right-handed open conformations. The sole element shared by the loaders is a single alpha helix, which binds to the same site on the helicase. Physical features of the loaders establish that DnaC and λ P evolved independently to converge, through molecular mimicry, on a common helicase opening mechanism.

9 February 2022 Heather Bondi (UNIUPO-DSF)

For a long time, the neuron was considered the fundamental unit of the central nervous system (CNS), confining the other cells to a marginal role. However, recent scientific evidence has shown that other neural populations also play key roles in brain function, thus surpassing the neurocentric view of the brain. Astrocytes, for example, in addition to providing trophic and metabolic support to neurons, participate in the regulation of neurotransmitter homeostasis, regulate the blood brain barrier and are actively involved in the processes of brain plasticity. Astrocytes are extremely plastic, capable of reshaping their shape, modifying gene expression and adapting their functions as a result of endogenous and exogenous stimuli. Through a morphometric approach, we studied the structural remodelling of astrocytes in response to aging and to an environmental stimulus, chronic stress, observing specific changes in astrocytic complexity, especially at the level of the brain areas most involved in neurodegenerative and neuropsychiatric diseases. The regulation of astroglial plasticity, therefore, opens up the possibility of identifying new therapeutic approaches for the treatment of CNS pathologies.

23 February 2022 Elia Bari (UNIUPO-DSF)

All eukaryotic cells have a more or less pronounced secretory activity and their secretion, also called secretome, is made up of soluble factors of various kinds and a corpuscle component consisting of micro / nanostructured extracellular vesicles.

In recent years, the secretome has aroused great interest from the scientific community for its potential use both in the diagnostic field, as a marker of cells with specific functions, and in the therapeutic field. In particular, the use of mesenchymal stem cell (MSC) secretome has been proposed to replace mother cells in regenerative medicine, or its vesicular component can be used as a drug delivery system. However, to successfully translate MSC secretome research to the clinic, it needs to be converted into a quality, safe and effective medicinal product. The seminar will then describe the "pharmaceuticalization" of the MSC secretome into a stable and standardized lyophilized powder, called lyosecretome. Some of the potential therapeutic applications of lyosecretoma will be discussed, in particular in the field of pulmonary pathologies, wound healing and bone regeneration, as well as in veterinary therapy of musculoskeletal pathologies, and, finally, in the conveyance and directing of active ingredients or nanoparticles to target cells / tissues.

9 March 2022 Tracey Pirali  (UNIUPO-DSF)

Deuterium incorporation is definitely entering the medicinal chemist’s toolbox. Despite being the smallest structural change that can be made in a molecule, precision deuteration might afford great advantages in many respects and lead to superior therapeutics.
By relying on the so-called Deuterium Kinetic Isotope Effect (DKIE), H-D isosterism slows down oxidative metabolism when including a rate-limiting C-H cleavage step and is perfectly suited to those soft spots in the molecule that do not tolerate changes in terms of steric hindrance or electronic properties. Deuterium incorporation might eventually lead to longer half-life, higher exposure, and in turn lower and/or less frequent dosage. Yet, the potential advantages of deuterium incorporation go beyond the simple amelioration of the pharmacokinetic profile: to name a few, H-D isosterism might reduce toxicity, minimize drug-drug interactions and interpatient variability, be responsible for biological activity, and stabilize otherwise unstable chiral centres. As a consequence, deutetrabenazine was approved in 2017 and at least other 15 deuterated candidates have entered clinical trials so far. Most of them are the result of a deuterium switching approach i.e., incorporation of deuterium in marketed drugs. While deuterium switching seems to be near to an ending, mainly due to intellectual property concerns, deuterium is becoming increasingly used since the early stages of drug discovery, as exemplified by deucravacitinib. In this seminar, case studies that exemplify the power of deuterium in medicinal chemistry will be provided, together with an analysis of the potential pitfalls that might be encountered when dealing with this isotope in drug R&D.

23 March 2022 Concettina La Motta (UNIPI)
AMP-activated protein kinase (APMK) is a serine/threonine kinase commonly acknowledged as a master regulator of intracellular energy homeostasis. It promotes energy conservation in response to environmental stimuli by both inhibiting anabolic processes and stimulating catabolic pathways. In addition, it is increasingly clear that AMPK contributes also to the modulation of immune/inflammatory cell functions such as cytokine production, chemotaxis, cytotoxicity, apoptosis and proliferation. Indeed, a reduced AMPK expression and/or activity plays a key role in the pathophysiology of immune-mediated inflammatory disorders characterized by abnormal immune cell functions, such as psoriasis, inflammatory bowel diseases, rheumatoid arthritis, atherosclerosis and some neurodegenerative diseases. Therefore, AMPK can be considered a relevant molecular target for this kind of pathologies and the obtainment of effective AMPK activators a promising approach for their treatment. In this regards, we developed a novel class of AMPK activators as a useful tool to manage inflammatory bowel diseases.

6 April 2022 Francesco Moccia (UNIPV)

It has long been known that an increase in endothelial Ca2+ concentration is crucial to finely regulate sprouting angiogenesis, and recent evidence confirmed that intracellular Ca2+ signalling drive the angiogenic behaviour also in circulating endothelial progenitor cells (EPCs). During this talk, I will describe how storeoperated Ca2+ entry can be activated by multiple pro-angiogenic cues to induce EPC proliferation, migration and tube formation, whereas endogenous TRPV1 can be stimulate by geneless optical excitation of organic semiconductors. I will conclude by describing how SOCE can be engaged by TRPV1-mediated Ca2+ entry and how this signalling cascade has the potential to promote therapeutic neovascularization in cardiovascular disorders.

20 April 2022  Mattia Mori (Università di Siena)

G-quadruplexes (G4s) are non-canonical four-stranded structural motifs of nucleic acids formed by guanine-rich sequences, which play a wide range of biological functions in human and non-human genomes. Human G4s are related to genetic disorders, hereditary diseases and cancers, and are considered as profitable targets for pharmacological intervention. Natural compounds are appealing candidates for targeting G4s due to their high structural diversity of their scaffolds. In the search for novel G4s-targeting chemotypes, we screened in silico an in-house library of plant-derived natural products. By combining molecular docking with G4-CPG experimental screening assay, we identified five hit binders of telomeric and oncogenic G4s, i.e., Bulbocapnine, Chelidonine, Ibogaine, Rotenone and Vomicine. Biophysical studies unambiguously demonstrated the selective interaction of these compounds with G4s compared to duplex DNA. The rationale behind the G4 selective recognition was suggested by molecular dynamics simulations. Chelidonine and Rotenone emerged as the most active compounds of this series against cancer cells.

27 April 2022 Mara Zilocchi (University of Regina - Canada)

Bipolar Disorder (BD) type I is a complex, highly heritable mood disorder characterized by alternating episodes of mania and depression, affecting millions globally. Although the etiology of this disorder is still poorly understood, a confluence of evidence suggests mitochondrial (mt) dysfunctions and glutamatergic alterations contribute to BD susceptibility due to decreased electron transport chain (ETC) activity and increased glutamate/glutamine ratio levels in the brain cortex of BD subjects. In this research project, we elucidated the mt dysfunctions characterizing BD patients through whole exome sequencing and biochemical fractionation coupled with mass spectrometry. After dissecting the mt protein interaction of BD vs healthy subjects, we found C6orf47, an uncharacterized protein, forming complexes with members of the ETC and glutamate metabolism in healthy subjects, while BD patients were characterized by the loss of these protein interactions. By applying targeted approaches in iPSC-derived neural progenitor cells and cortical neurons, we found C6orf47 playing a fundamental role in OXPHOS and glutamate metabolism regulation.

4 May 2022 Andrea Marcantoni (UNITO)

Synaptic dysfunction is one of the earliest hallmarks of Alzheimer’s Disease (AD). It is known that the oligomeric form of amyloid beta protein Abeta42 contributes to the development of synaptic abnormalities and cognitive impairments associated with AD. We have already reported that Abeta42 increases intracellular calcium concentration released through calcium-permeable ryanodine receptors (RyRs) and opposite effects have been described on AMPA and NMDA-dependent glutamatergic synapses. In particular, we have observed that, while the former is inhibited, the latter is potentiated. To date, there is an impressive lack of information on how Abeta42 affects the elementary parameters regulating inhibitory GABAergic synaptic function. Here the potentiating effects of Abeta42 on GABAergic synapses are examined. We further tested whether ryanodine receptors (RyRs) contributed to exacerbate the synaptic impairments observed by stabilizing the interaction between RyRs and the accessory protein calstabin. We observed that the RyRs-calstabin interaction stabilizer S107 restored the GABAergic synaptic parameters. In conclusion, our findings clarify the mechanisms of potentiation of GABAergic synapses induced by Abeta42 and suggest that RyRs are involved in the control of synaptic activity during the early stages of AD onset. Their stabilization rather than inhibition could represent a new therapeutical approach for AD treatment

18 May 2022 Gian Cesare Tron (UNIUPO-DSF) 

This seminar is divided in two parts. In the first one, the most relevant isocyanide-based multicomponent reactions recently discovered in my lab will be discussed (e.g., chloroximes-isocyanides, TosMic-aryl azides). In that period, we only considered isocyanides as reactive functional groups pivotal for the success in multicomponent transformations. However, after synthesizing and using dozens of isocyanides, we began to ponder their potential use as innovative pharmacophoric groups in medicinal chemistry. The second part of this presentation is focused on this neglected aspect of isocyanides, focusing on their metabolism and applications in med chem.

25 May 2022  Loris Rizzello (UNIMI)

Mononuclear phagocytes such as monocytes, tissue-specific macrophages, and dendritic cells are primary actors in both innate and adaptive immunity. These professional phagocytes can be parasitized by intracellular bacteria, turning them from housekeepers to hiding places and favoring chronic and/or disseminated infection. One of the most infamous is the bacteria that cause tuberculosis (TB), which is the most pandemic and one of the deadliest diseases, with one-third of the world’s population infected and an average of 1.8 million deaths/year worldwide. Here we demonstrate the effective targeting and intracellular delivery of antibiotics to infected macrophages both in vitro and in vivo, using pH-sensitive nanoscopic polymersomes made of PMPC–PDPA block copolymer. Polymersomes showed the ability to significantly enhance the efficacy of the antibiotics killing Mycobacterium bovis, Mycobacterium tuberculosis, and another established intracellular pathogen, Staphylococcus aureus. Moreover, they demonstrated to easily access TB-like granuloma tissues—one of the harshest environments to penetrate—in zebrafish models. We thus successfully exploited this targeting for the effective eradication of several intracellular bacteria. Moving on from the standard antibiotic-based therapy, we are also taking inspiration from the solutions provided by Nature and exploited the bacterial-restricted lytic properties of bacteriophages to develop an effective nanomedicinebased therapy. All known phages, with no exceptions detected so far, own a very specific set of lytic proteins, namely the endolysin (or lysin). They are highly efficient enzymes binding a very specific substrate, able to swindle cell wall integrity, and, finally, induce the death of the bacteria. Interestingly, mycobacteriophages encode for a second lysin, known as endolysin B (LysB). Contrary to other endolysin, LysB not only bears in its N-terminal the domain responsible for the binding to its target but also recognizes a different substrate represented by the outer layer (i.e., mycolic acids) of the waxy mycobacterial cell wall. This prompted us to hypothesize that the binding properties of lysins, such as LysB, might represent a high-affinity and specific tool that we can exploit to develop a selective antimycobacterial therapy. Therefore, we undertook a comprehensive study aiming to identify the minimal aminoacidic consensus sequence required for LysB binding to the mycomembrane, to create a precise targeting tool against intracellular bacteria. We believe this new bacteriophages-inspired therapy, coupled with the unique tools of by nanoparticles delivery, will provide an unprecedent therapeutic approach to Mtb infection and treatment, while also avoiding the rise in antimicrobial resistance.

8 June 2022 Letizia Zullo (Italian Institute of Technology, Genoa)

Cephalopods are highly evolved and diverse mollusks. Their nervous system is certainly the most advanced among invertebrates, and its complexity correlates well with their sophisticated behaviours and learning abilities. Their brain acquired during evolution a high level of centralization and system integration that in several aspects reached vertebrate standards. As an example, a large body of evidence supports the existence of shared forms of learning and memory, movement dynamic principles, and even of convergent neural genomic events between cephalopods and vertebrates. Cephalopod research is fast accelerating as based on the recent research advancements, the two main gaps in genomic and breeding, hindering the use of cephalopods on a global scale, have been eventually closed. Here I will present the current knowledge on the organization of the octopus brain and of the so-called “peripheral brains” of the arms, where most of the animals' neurons are distributed. I will discuss their involvement in learning processes, motion generation and complex behaviours and introduce the exciting idea that their brain to body dynamical interaction underlies the development of a new type of ‘embodied’ intelligence. Octopuses' combination of smarts and striking difference from humans could allow inferring the rules governing complex brain function and prompt the emergence of a new animal model that might change our perspective in studying brain and animal intelligence.

22 June 2022 Valentina Carabelli (UNITO)

Micrographitized-diamond MEA prototypes (μ-D-MEAs) have been used so far as amperometric sensors to detect catecholamine release from chromaffin cells or adrenal gland slices. Here we aim to show that μ-D-MEAs monitor multisite quantal exocytotic events and action potential firing from neuronal networks. To detect the activity of cultured midbrain dopaminergic neurons, μ-D-MEAs have been used either in the amperometric or in the potentiometric configuration. In the amperometric configuration, μ-D-MEAs could resolve both spontaneous and stimulated quantal dopamine release from different exocytotic sites. When used as potentiometric multiarrays, μ-D-MEAs detected the spontaneous firing activity of midbrain neurons and uncovered different effects exerted by L-DOPA on the action potential generation. Additionally, in a set of preliminary trials, μ-D-MEAs have been used to perform the simultaneous detection of quantal dopamine release and action potential firing.
Overall, these data demonstrate that μ-D-MEAs represent a reliable tool for real-time and multiparametric detection of neuronal networks activity.