Publications by authors named "Giuseppina D'Alessandro"

The eukaryotic replisome, which consists of the CDC45-MCM2-7-GINS (CMG) helicase, replicative polymerases, and several accessory factors, sometimes encounters proteinaceous obstacles that threaten genome integrity. These obstacles are targeted for removal or proteolysis by the E3 ubiquitin ligase TRAIP, which associates with the replisome. However, TRAIP must be carefully regulated to avoid inappropriate ubiquitylation and disassembly of the replisome.

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Introduction: Recent studies have shown that lifestyle factors, including diet and environmental stimuli, significantly alter the composition of gut microbiota and the metabolites they produce. Specifically, housing mice in an enriched environment (EE) enhances the production of short-chain fatty acids, which in part mediate the effects of EE on brain plasticity. In this study, we tested the hypothesis that the gut microbial composition of EE-exposed mice could be transplanted into mice housed in a standard environment (SE) to replicate the environmental effects on behavior, gene expression and neurogenesis.

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The use of a ketogenic diet (KD) in glioma is currently tested as an adjuvant treatment in standard chemotherapy regimens. The metabolic shift induced by the KD leads to the generation of ketone bodies that can influence glioma cells and the surrounding microenvironment, but the mechanisms have not yet been fully elucidated. Here, we investigated the potential involvement of glial cells as mediators of the KD-induced effects on tumor growth and survival rate in glioma-bearing mice.

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Background: Deciphering variants of uncertain significance (VUS) represents a major diagnostic challenge, partially due to the lack of easy-to-use and versatile cellular readouts that aid the interpretation of pathogenicity and pathophysiology. To address this challenge, we propose a high-throughput screening of cellular functionality through an imaging flow cytometry (IFC)-based platform.

Methods: Six assays to evaluate autophagic-, lysosomal-, Golgi- health, mitochondrial function, ER stress, and NF-κβ activity were developed in fibroblasts.

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Article Synopsis
  • HAP1 is a human cell line that's good for studying gene changes and mutations due to its unique genetic makeup, but it's unusually sensitive to the cancer drug camptothecin.
  • This sensitivity is linked to a problem with TDP1, an enzyme that helps fix certain DNA issues, specifically due to a mutation that disrupts its function.
  • Researchers were able to use CRISPR technology to restore TDP1 in HAP1 cells, creating new cell lines that can be used for deeper studies on how DNA repairs itself in the presence of camptothecin.
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The E3 ubiquitin ligase TRAIP associates with the replisome and helps this molecular machine deal with replication stress. Thus, TRAIP promotes DNA inter-strand crosslink repair by triggering the disassembly of CDC45-MCM2-7-GINS (CMG) helicases that have converged on these lesions. However, disassembly of single CMGs that have stalled temporarily would be deleterious, suggesting that TRAIP must be carefully regulated.

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Myeloid cells are fundamental constituents of the brain tumor microenvironment. In this chapter, we describe the state-of-the-art knowledge on the role of microglial cells in the cross-talk with the most common and aggressive brain tumor, glioblastoma. We report in vitro and in vivo studies related to glioblastoma patients and glioma models to outline the symbiotic interactions that microglia develop with tumoral cells, highlighting the heterogeneity of microglial functions in shaping the brain tumor microenvironment.

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  • Aging affects both the brain and immune system, leading to chronic inflammation in microglia, which are crucial immune cells in the brain.
  • Intranasal treatment with extracellular vesicles (EVs) from microglial-like cells improved the morphology and behavior of aged mice, reducing anxiety and enhancing spatial learning with notable differences between sexes.
  • The study highlights the potential of BV2-derived EVs to combat age-related inflammation in the brain, suggesting they could be a promising therapeutic resource for aging-related cognitive decline.
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  • Decitabine (5-aza-dC) is a nucleoside analogue used for treating certain blood cancers, but its effectiveness can vary and relapses are common.
  • Research using CRISPR/Cas9 screens identified that the loss of the enzyme DCTD makes cancer cells resistant to decitabine by reducing the production of 5-aza-dUMP, which is toxic to cells.
  • The study revealed that the protein TOPORS helps repair decitabine-induced DNA damage and may be targeted for new biomarkers to predict how patients respond to decitabine treatment.
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Gliomas are among the most fatal tumors, and the available therapeutic options are very limited. Additionally, the blood-brain barrier (BBB) prevents most drugs from entering the brain. We designed and produced a ferritin-based stimuli-sensitive nanocarrier with high biocompatibility and water solubility.

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  • Covalent DNA-protein cross-links (DPCs) are harmful lesions that stall DNA replication and need various repair mechanisms, including their impact on transcription.
  • The study reveals that DPCs hinder transcription and trigger the degradation of RNA polymerase II, with Cockayne syndrome (CS) proteins CSB and CSA helping to repair these lesions in transcribed genes.
  • CSB and CSA deficiencies result in transcriptional restart issues post-DPC induction, whereas certain nucleotide excision repair factors are not essential, indicating a specific transcription-coupled DPC repair pathway that may explain neurological symptoms in Cockayne syndrome.
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In recent years, several studies described the close relationship between the composition of gut microbiota and brain functions, highlighting the importance of gut-derived metabolites in mediating neuronal and glial cells cross-talk in physiological and pathological condition. Gut dysbiosis may affects cerebral tumors growth and progression, but the specific metabolites involved in this modulation have not been identified yet. Using a syngeneic mouse model of glioma, we have investigated the role of dysbiosis induced by the administration of non-absorbable antibiotics on mouse metabolome and on tumor microenvironment.

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Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition characterized by elusive underlying mechanisms. Recent attention has focused on the involvement of astrocytes and microglia in ASD pathology. These glial cells play pivotal roles in maintaining neuronal homeostasis, including the regulation of metabolism.

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Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with no effective therapy, causing progressive loss of motor neurons in the spinal cord, brainstem, and motor cortex. Regardless of its genetic or sporadic origin, there is currently no cure for ALS or therapy that can reverse or control its progression. In the present study, taking advantage of a human superoxide dismutase-1 mutant (hSOD1-G93A) mouse that recapitulates key pathological features of human ALS, we investigated the possible role of voltage-gated potassium channel Kv1.

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The catalytic cycle of topoisomerase 2 (TOP2) enzymes proceeds via a transient DNA double-strand break (DSB) intermediate termed the TOP2 cleavage complex (TOP2cc), in which the TOP2 protein is covalently bound to DNA. Anticancer agents such as etoposide operate by stabilizing TOP2ccs, ultimately generating genotoxic TOP2-DNA protein cross-links that require processing and repair. Here, we identify RAD54 like 2 (RAD54L2) as a factor promoting TOP2cc resolution.

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Glioblastoma multiforme (GBM) is the most common and aggressive type of malignant primary brain tumor, and it is characterized by a high recurrence incidence and poor prognosis due to the presence of a highly heterogeneous mass of stem cells with self-renewal capacity and stemness maintenance ability. In recent years, the epigenetic landscape of GBM has been explored and many epigenetic alterations have been investigated. Among the investigated epigenetic abnormalities, the bromodomain and extra-terminal domain (BET) chromatin readers have been found to be significantly overexpressed in GBM.

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Tumor associated macrophages (TAMs) are the mostprevalent cells recruited in the tumor microenvironment (TME). Once recruited, TAMs acquire a pro-tumor phenotype characterized by a typical morphology: ameboid in the tumor core and with larger soma and thick branches in the tumor periphery. Targeting TAMs by reverting them to an anti-tumor phenotype is a promising strategy for cancer immunotherapy.

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Microglial cells play pleiotropic homeostatic activities in the brain, during development and in adulthood. Microglia regulate synaptic activity and maturation, and continuously patrol brain parenchyma monitoring for and reacting to eventual alterations or damages. In the last two decades microglia were given a central role as an indicator to monitor the inflammatory state of brain parenchyma.

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Gut microorganisms and the products of their metabolism thoroughly affect host brain development, function and behavior. Since alterations of brain plasticity and cognition have been demonstrated upon motor, sensorial and social enrichment of the housing conditions, we hypothesized that gut microbiota and metabolome could be altered by environmental stimuli, providing part of the missing link among environmental signals and brain effects. In this preliminary study, metagenomic and metabolomic analyses of mice housed in different environmental conditions, standard and enriched, identify environment-specific microbial communities and metabolic profiles.

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The growing interest in the role of microglia in the progression of many neurodegenerative diseases is developing in an ever-expedited manner, in part thanks to emergent new tools for studying the morphological and functional features of the CNS. The discovery of specific biomarkers of the microglia phenotype could find application in a wide range of human diseases, and creates opportunities for the discovery and development of tailored therapeutic interventions. Among these, recent studies highlight the pivotal role of the potassium channels in regulating microglial functions in physiological and pathological conditions such as Alzheimer's Disease, Parkinson's Disease, and Amyotrophic Lateral Sclerosis.

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'Dysbiosis' of the adult gut microbiota, in response to challenges such as infection, altered diet, stress, and antibiotics treatment has been recently linked to pathological alteration of brain function and behavior. Moreover, gut microbiota composition constantly controls microglia maturation, as revealed by morphological observations and gene expression analysis. However, it is unclear whether microglia functional properties and crosstalk with neurons, known to shape and modulate synaptic development and function, are influenced by the gut microbiota.

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Glioblastoma (GBM) is the most aggressive form of glioma tumor in adult brain. Among the numerous factors responsible for GBM cell proliferation and invasion, neurotransmitters such as dopamine, serotonin and glutamate can play key roles. Studies performed in mice housed in germ-free (GF) conditions demonstrated the relevance of the gut-brain axis in a number of physiological and pathological conditions.

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Dysregulation of calcium signaling is emerging as a key feature in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD), and targeting this process may be therapeutically beneficial. Under this perspective, it is important to study proteins that regulate calcium homeostasis in the cell. Sorcin is one of the most expressed calcium-binding proteins in the human brain; its overexpression increases endoplasmic reticulum (ER) calcium concentration and decreases ER stress in the heart and in other cellular types.

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Glioma is a CNS tumor with few therapeutic options. Recently, host microbiota has been involved in the immune modulation of different tumors, but no data are available on the possible effects of the gut-immune axis on brain tumors. Here, we investigated the effect of gut microbiota alteration in a syngeneic (GL261) mouse model of glioma, treating mice with two antibiotics (ABX) and evaluating the effects on tumor growth, microbe composition, natural killer (NK) cells and microglia phenotype.

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