Publications by authors named "Simone Pelassa"

Objectives: The objectives of this study were to characterize some phenotypic and functional aspects of fibroblast-like synoviocytes isolated from the Synovial Fluid (SF-FLSs) of patients affected by Juvenile Idiopathic Arthritis (JIA) with active disease and to compare SF-FLS characteristics with those reported in the literature for FLSs of the SM (Synovial Membrane) in adult rheumatic patients.

Methods: FLSs were isolated from the SF of JIA patients with active disease by therapeutic arthrocentesis. SF-FLS surface marker expression was assessed by cytofluorimetry; proinflammatory cytokine and MMP gene expression was investigated by quantitative RT-PCR (qRT-PCR); and chondrogenic properties were evaluated by staining with Alcian-Blue.

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  • * Scientists are studying tiny molecules called microRNAs (miRNAs) to see if they can help with diagnosing and treating JIA.
  • * The review looks at how miRNAs could be used to understand the disease better and improve treatments by examining samples from JIA patients.
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Introduction: New early low-invasive biomarkers are demanded for the management of Oligoarticular Juvenile Idiopathic Arthritis (OJIA), the most common chronic pediatric rheumatic disease in Western countries and a leading cause of disability. A deeper understanding of the molecular basis of OJIA pathophysiology is essential for identifying new biomarkers for earlier disease diagnosis and patient stratification and to guide targeted therapeutic intervention. Proteomic profiling of extracellular vesicles (EVs) released in biological fluids has recently emerged as a minimally invasive approach to elucidate adult arthritis pathogenic mechanisms and identify new biomarkers.

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  • Human-induced pluripotent stem cells (hiPSCs) are valuable for modeling neurological diseases but traditional methods using animal-derived substances present challenges for clinical applications.
  • This study focuses on optimizing a feeder-free protocol to generate functional glutamatergic neurons from hiPSCs, using neurotrophins and a Geltrex-coated substrate for improved differentiation.
  • Results confirmed the effectiveness of this new approach through various analyses, demonstrating that the hiPSC-derived neurons exhibit essential features of mature neurons, which could enhance future drug discovery efforts.
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Background: Roles of astrocytes in the modulatory effects of oxytocin (OT) in central nervous system are increasingly considered. Nevertheless, OT effects on gliotransmitter release have been neglected.

Methods: In purified astrocyte processes from adult rat striatum, we assessed OT receptor (OTR) and adenosine A2A receptor expression by confocal analysis.

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Background: In the brain, polyamines are mainly synthesized in neurons, but preferentially accumulated in astrocytes, and are proposed to be involved in neurodegenerative/neuroinflammatory disorders and neuron injury. A transgenic mouse overexpressing spermine oxidase (SMOX, which specifically oxidizes spermine) in the neocortex neurons (Dach-SMOX mouse) was proved to be a model of increased susceptibility to excitotoxic injury.

Methods: To investigate possible alterations in synapse functioning in Dach-SMOX mouse, both cerebrocortical nerve terminals (synaptosomes) and astrocytic processes (gliosomes) were analysed by assessing polyamine levels, ezrin and vimentin content, glutamate AMPA receptor activation, calcium influx, and catalase activity.

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Preclinical studies highlighted that compounds targeting cannabinoid receptors could be useful for developing novel therapies against neurodegenerative disorders. However, the chronic use of orthosteric agonists alone has several disadvantages, limiting their usefulness as clinically relevant drugs. Positive allosteric modulators might represent a promising approach to achieve the potential therapeutic benefits of orthosteric agonists of cannabinoid receptors through increasing their activity and limiting their adverse effects.

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It is widely recognized that extracellular vesicles subserve non-classical signal transmission in the central nervous system. Here we assess if the astrocyte processes, that are recognized to play crucial roles in intercellular communication at the synapses and in neuron-astrocyte networks, could convey messages through extracellular vesicles. Our findings indicate, for the first time that freshly isolated astrocyte processes prepared from adult rat cerebral cortex, can indeed participate to signal transmission in central nervous system by releasing exosomes that by volume transmission might target near or long-distance sites.

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  • The study shows that A2A and D2 receptors are found together on astrocytes in the striatum of adult rats and can interact to regulate glutamate release.
  • Researchers provided evidence that this interaction occurs through the formation of A2A-D2 heteromers, which is a specific pairing of these two receptors at the cell membrane.
  • These findings are important for understanding Parkinson's disease, as they highlight how the interaction between A2A and D2 receptors in astrocytes could influence the disease's development by affecting glutamatergic transmission.
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The interaction between adenosine A2A and dopamine D2 receptors in striatal neurons is a well-established phenomenon and has opened up new perspectives on the molecular mechanisms involved in Parkinson's disease. However, it has barely been investigated in astrocytes. Here, we show by immunofluorescence that both A2A and D2 receptors are expressed in adult rat striatal astrocytes in situ, and investigate on presence, function, and interactions of the receptors in the astrocyte processes-acutely prepared from the adult rat striatum-and on the effects of homocysteine on the A2A-D2 receptor-receptor interaction.

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Macrophages (Mf) are a heterogeneous population of tissue-resident professional phagocytes and a major component of the leukocyte infiltrate at sites of inflammation, infection, and tumor growth. They can undergo diverse forms of activation in response to environmental factors, polarizing into specialized functional subsets. A common hallmark of the pathologic environment is represented by hypoxia.

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Background: More than fifty percent of neuroblastoma (NB) patients with adverse prognosis do not benefit from treatment making the identification of new potential targets mandatory. Hypoxia is a condition of low oxygen tension, occurring in poorly vascularized tissues, which activates specific genes and contributes to the acquisition of the tumor aggressive phenotype. We defined a gene expression signature (NB-hypo), which measures the hypoxic status of the neuroblastoma tumor.

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Unlabelled: Langerhans cells (LCs) are a specialized dendritic cell subset that resides in the epidermis and mucosal epithelia and is critical for the orchestration of skin immunity. Recent evidence suggest that LCs are involved in aberrant wound healing and in the development of hypertrophic scars and chronic wounds, which are characterized by a hypoxic environment. Understanding LCs biology under hypoxia may, thus, lead to the identification of novel pathogenetic mechanisms of wound repair disorders and open new therapeutic opportunities to improve wound healing.

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