Biology subjects

Alberti, P.

Publications and source records attributed to Alberti, P..

3 recordsLinked to original sources

bioRxiv2025

CANVAS causing AAGGG repeat expansions cause tissue-specific reduction in RFC1 expression and increase sensitivity to DNA damage

Biallelic AAGGG expansions in Replication Factor Complex Subunit 1 (RFC1) are associated with cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) and are increasingly recognised as a common cause of adult-onset ataxia and sensory neuropathy. However, the disease-causing mechanisms remain unclear. Here we leveraged in vitro assays, post-mortem brain tissue, patient-derived cell lines and a neuronal Drosophila model to demonstrate that AAGGG expansions are associated with tissue-specific reductions in the expression of RFC1 transcript, along with impaired RFC1 function and increased sensitivity to DNA damage from platinum-based drugs. CRISPR/Cas9 excision of the AAGGG repeat and flanking AluSx3 element normalized RFC1 expression in iPSC-derived neurons and rescued the DNA damage response, providing a framework for future therapeutic strategies. We also show that these biological findings are clinically relevant in heterozygous AAGGG expansion carriers, who display an increased risk and severity of neuropathy with platinum-based chemotherapy.

neuroscience↗

bioRxiv2021

Folding and Persistence Time of Intramolecular G-Quadruplexes Transiently Embedded in a DNA duplex

G-quadruplex (G4) DNA structures have emerged as important regulatory elements during DNA replication, transcription or repair. While many in-vitro studies have focused on the kinetics of G4 formation within DNA single-strands, G4 are found in-vivo in double-stranded DNA regions, where their formation is challenged by pairing between the two complementary strands. Since the energy of hybridization of Watson-Crick structures dominates the energy of G4 folding, this competition should play a critical role on the persistence of G4 in vivo. To address this issue, we designed a single molecule assay allowing measuring G4 folding and persistence while the structure is periodically challenged by the complementary strand. We quantified both the folding rate and the persistence time of biologically relevant G4 structures and showed that the dynamics of G4 formation depends strongly on the genomic location. G4 are found much more stable in promoter regions and replication origins than in telomeric regions. In addition, we characterized how G4 dynamics was affected by G4 ligands and showed that both folding rate and persistence increased. Our assay opens new perspectives for the measurement of G4 dynamics, which is critical to understand their role in genetic regulation.

biophysics↗

bioRxiv2019

Pathogenic Role of Delta 2 Tubulin in Bortezomib Induced Peripheral Neuropathy

The pathogenesis of chemotherapy induced peripheral neuropathy (CIPN) is still poorly understood. Herein, we found that the CIPN-causing drug, bortezomib (Bort), induces delta 2 tubulin (D2) while affecting MT stability and dynamics in sensory neurons, and that accumulation of D2 is a hallmark of Bort-induced peripheral neuropathy in humans. Furthermore, while induction of D2 was sufficient to cause axonopathy and inhibit mitochondria motility, reducing D2 alleviated both axonal degeneration and loss of mitochondria motility promoted by Bort. Altogether, our data demonstrate that Bort, structurally unrelated to tubulin poisons, can affect the tubulin cytoskeleton in sensory neurons in vitro, in vivo and in humans, indicating that the pathogenic mechanisms of seemingly unrelated CIPN drugs may converge on tubulin damage. They further reveal a previously unrecognized pathogenic role for D2 in bortezomib-causing CIPN through its regulation of mitochondria dynamics.

neuroscience↗