Publications by authors named "Valentina Melzi"

Brain organoids, three-dimensional cell structures derived from pluripotent stem cells, closely mimic key aspects of the human brain in vitro, providing a powerful tool for studying neurodevelopment and disease. The neuroectodermal induction protocol employed for brain organoid generation primarily gives rise to the neural cellular component but lacks the vital vascular system, which is crucial for the brain functions by regulating differentiation, migration, and circuit formation, as well as delivering oxygen and nutrients. Many neurological diseases are caused by dysfunctions of cerebral microcirculation, making vascularization of human brain organoids an important tool for pathogenetic and translational research.

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Mitofusin-2 (MFN2) is an outer mitochondrial membrane protein essential for mitochondrial networking in most cells. Autosomal dominant mutations in the MFN2 gene cause Charcot-Marie-Tooth type 2A disease (CMT2A), a severe and disabling sensory-motor neuropathy that impacts the entire nervous system. Here, we propose a novel therapeutic strategy tailored to correcting the root genetic defect of CMT2A.

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Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder and the most common motor neuron disease. ALS shows substantial clinical and molecular heterogeneity. In vitro and in vivo models coupled with multiomic techniques have provided important contributions to unraveling the pathomechanisms underlying ALS.

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Background: Allgrove disease is a rare genetic syndrome characterized by adrenal insufficiency, alacrimia, achalasia and complex neurological involvement. Allgrove disease is due to recessive mutations in the AAAS gene, which encodes for the nucleoporin Aladin, implicated in the nucleocytoplasmic transport. The adrenal insufficiency has been suggested to rely on adrenal gland-ACTH resistance.

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Congenital Central Hypoventilation Syndrome (CCHS) is a rare disorder of the autonomic nervous system (ANS), characterized by inadequate control of autonomic ventilation and global autonomic dysfunction. Heterozygous polyalanine repeat expansion mutations in exon 3 of the transcription factor Paired-like homeobox 2B (PHOX2B) gene occur in 90% of CCHS cases. In this study, we describe the generation and characterization of two human induced pluripotent stem cell (hiPSC) lines from female CCHS patients carrying a heterozygous + 5 alanine expansion mutation.

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Motor neuron diseases (MNDs) are a group of fatal, neurodegenerative disorders with different etiology, clinical course and presentation, caused by the loss of upper and lower motor neurons (MNs). MNs are highly specialized cells equipped with long, axonal processes; axonal defects are some of the main players underlying the pathogenesis of these disorders. Microtubules are key components of the neuronal cytoskeleton characterized by dynamic instability, switching between rapid polymerization and shrinkage.

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Article Synopsis
  • Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disease mainly affecting motor neurons, with only 10% of cases being inherited.
  • The study analyzed microRNA (miRNA) expression in motor neurons and exosomes from both familial ALS patients and healthy controls, revealing specific miRNAs (miR-34a, miR-335, and miR-625-3p) that were dysregulated and linked to the disease's progression.
  • Additionally, significant changes in the levels of miR-34a-3p and miR-625-3p were found in the cerebrospinal fluid of patients, suggesting that examining miRNA across different biological samples could enhance our understanding of ALS and support
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Spinal muscular atrophy is a motor neuron disorder caused by mutations in SMN1. The reasons for the selective vulnerability of motor neurons linked to SMN (encoded by SMN1) reduction remain unclear. Therefore, we performed deep RNA sequencing on human spinal muscular atrophy motor neurons to detect specific altered gene splicing/expression and to identify the presence of a common sequence motif in these genes.

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Amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder that is characterized by a progressive degeneration of motor neurons (MNs). The pathomechanism underlying the disease is largely unknown, even though increasing evidence suggests that RNA metabolism, including microRNAs (miRNAs) may play an important role. In this study, human ALS induced pluripotent stem cells were differentiated into MN progenitors and their miRNA expression profiles were compared to those of healthy control cells.

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Riboflavin is essential in numerous cellular oxidation/reduction reactions but is not synthesized by mammalian cells. Riboflavin absorption occurs through the human riboflavin transporters RFVT1 and RFVT3 in the intestine and RFVT2 in the brain. Mutations in these genes are causative for the Brown-Vialetto-Van Laere (BVVL), childhood-onset syndrome characterized by a variety of cranial nerve palsies as well as by spinal cord motor neuron (MN) degeneration.

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COQ2 mutations have been implicated in the etiology of multiple system atrophy (MSA) in Japan. However, several genetic screenings have not confirmed the role of its variants in the disease. We performed COQ2 sequence analysis in 87 probable MSA.

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