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Biology subjects

Santonicola, P.

Publications and source records attributed to Santonicola, P..

4 recordsLinked to original sources

Integrated CHARGE syndrome models reveal epigenetic modulators of reproductive phenotypes

Loss-of-function variants in CHD7 cause CHARGE syndrome (CS), a rare developmental disorder showing multisystem malformations, including reproductive defects linked to gonadotropin-releasing hormone (GnRH) neuron dysfunction. CHD7 encodes a chromatin remodeler essential for early transcriptional regulation across various tissues. Currently, no pharmacological treatments exist, and approaches aimed at identifying tissue-specific CHD7 targets are also lacking, making CS treatment an unmet clinical need. To explore mechanisms relevant to CS-associated reproductive defects, we established a dual screening platform combining CRISPR-engineered Chd7-depleted mouse GnRH neurons with a Caenorhabditis elegans chd-7 mutant showing reproductive abnormalities. Transcriptomic and functional analyses of Chd7-deficient cells revealed impaired cellular processes along with dysregulation of semaphorin (Sema) genes, key regulators of GnRH neuron development. A screen of 234 epigenetic modulators in C. elegans identified compounds modifying aberrant mutant phenotype, two of which also rescued cellular defects and Sema expression in vitro. Altogether, these findings indicate that CHD7 deficiency reshapes neuroendocrine-relevant pathways and that selected compounds modulate CS-associated phenotypes across species, with SEMA signalling emerging as candidate druggable downstream pathway in CS requiring further mechanistic validation.

developmental biology↗

A Spinal Muscular Atrophy Model Reveals Both Developmental and Degenerative Neuronal Defects in C. elegans

Spinal muscular atrophy (SMA) is a neuromuscular disorder primarily caused by mutations in the Survival of Motor Neuron 1 (SMN1) gene. SMN1 is ubiquitously expressed and encodes a protein essential for the assembly of small nuclear ribonucleoproteins (snRNPs), key components of pre-mRNA splicing. Beyond this canonical role, SMN participates in several other fundamental cellular processes, including RNA transport, regulation of actin dynamics, transcription, and translation. While multiple hypotheses have been put forward to explain selective motor neuron (MN) vulnerability to SMN deficiency, the precise mechanisms involved remain incompletely understood. In this study, we used a simple and tractable C. elegans model to investigate the molecular mechanisms underlying neuronal degeneration in SMA. Silencing of the smn-1 in targeted neurons resulted in defects in the birth and development of both motor neurons and touch receptor neurons (TRNs). In TRNs SMN-1 depletion caused distinct defects in neuronal process morphology. Our results provide evidence that key aspects of SMA pathology are conserved in C. elegans, which may offer new opportunities to elucidate the molecular mechanisms underlying neuronal degeneration in SMA.

genetics↗

Microalgae as a novel biofactory for biocompatible and bioactive extracellular vesicles

Nanoalgosomes are extracellular vesicles (EVs) released by microalgal cells that can mediate intercellular and cross-kingdom communication. In the present study, starting from the optimized nanoalgosome manufacturing from cultures of marine microalgae, we evaluated their innate biological properties in preclinical models. Our investigation of nanoalgosome biocompatibility included toxicological analyses, starting from studies on the invertebrate model organism Caenorhabditis elegans, proceeding to hematological and immunological evaluations in mice and immune-compatibility ex vivo. Nanoalgosome biodistribution was evaluated in mice with accurate space-time resolution, and in C. elegans at cellular and subcellular levels. Further examination highlighted the antioxidant and anti-inflammatory bioactivities of nanoalgosomes. This holistic approach to nanoalgosome functional characterization showcases that nanoalgosomes are innate effectors and potential drug delivery system for novel cosmetic formulations and EV-based therapies.

cell biology↗

TGS1 controls snRNA 3' end processing, prevents neurodegeneration and ameliorates SMN-dependent neurological phenotypes in vivo

Trimethylguanosine synthase 1 (TGS1) is a highly conserved enzyme that converts the 5 mono-methylguanosine cap of snRNAs to a trimethylguanosine cap. Here, we show that loss of TGS1 in C. elegans, D. melanogaster and D. rerio results in neurological phenotypes similar to those caused by Survival Motor Neuron (SMN) deficiency. Importantly, expression of human TGS1 ameliorates the SMN-dependent neurological phenotypes in both flies and worms, revealing that TGS1 can partly counteract the effects of SMN deficiency. TGS1 loss in HeLa cells leads to the accumulation of immature U2 and U4atac snRNAs with long 3 tails that are often uridylated. snRNAs with defective 3 terminations also accumulate in Drosophila Tgs1 mutants. Consistent with defective snRNA maturation, TGS1 and SMN mutant cells also exhibit partially overlapping transcriptome alterations that include aberrantly spliced and readthrough transcripts. Together, these results identify a neuroprotective function for TGS1 and reinforce the view that defective snRNA maturation affects neuronal viability and function.

genetics↗