Biology subjects

Zara, F.

Publications and source records attributed to Zara, F..

4 recordsLinked to original sources

bioRxiv2025

Predicting Drug Response with Multi-Task Gradient-Boosted Trees in Epilepsy

MotivationDespite the availability of numerous anti-seizure medications (ASMs), drug resistance remains a major issue for people with epilepsy. The probability of achieving seizure freedom diminishes with each unsuccessful drug trial, and the impact of genetic and clinical markers on ASM response remains unclear. To address this issue, we used state-of-the-art machine learning (ML) methods to predict the response of people with epilepsy to individual ASMs based on their clinical and genomic information. ResultsTo overcome data sparsity for less common drugs, we implement a multi-task (MT) learning approach for gradient-boosted trees (GBTs), assuming that predicting responses to different ASMs involves similar tasks. This strategy allows models for less prevalent drugs to leverage the more abundant data available for other drugs during training. The proposed model outperforms individual and combined drug-response predictions for most drugs. Our findings identify key genomic and clinical features influencing drug response, enhancing understanding of individual drug responses in people with epilepsy, and aiding clinicians in making informed treatment decisions. Availability and ImplementationDue to privacy reasons data is not publically available. The code will be made available upon acceptance under https://github.com/pfeiferAI/MT-GBT

bioinformatics↗

bioRxiv2024

A claudin5-binding peptide enhances the permeability of the blood-brain-barrier

The blood-brain barrier (BBB) is essential to maintain brain homeostasis and healthy conditions but it also prevents drugs from reaching brain cells. In the BBB, tight junctions (TJs) are multi-protein complexes located at the interface between adjacent brain endothelial cells that regulate paracellular diffusion and claudin-5 (CLDN5) is the major component of the TJ portfolio, playing a pivotal role in restricting the paracellular traffic. In view of obtaining fine control over the transport across the BBB, the use of competing peptides able to bind CLDN5 to induce transient and regulated permeabilization of the paracellular passage is emerging as a potentially translatable strategy for clinical applications. In this work, we designed and tested short peptides with improved solubility and biocompatibility using a combined approach that involved structural modeling techniques and in vitro validation, generating a robust workflow for the design, screening, and optimization of peptides for the modulation of the BBB paracellular permeability. We designed a selection of 11- to 16-mer compounds derived from the first CLDN5 extracellular domain and from the CLDN5-binding domain of Clostridium perfringens enterotoxin and determined their efficiency in enhancing BBB permeability. The computational analysis classified all tested peptides based on solubility and affinity to CLDN5, and provided atom-level details of the binding process. From our screening, we identified a novel CLDN5-derived peptide, here called f1-C5C2, which demonstrated good solubility in biological media, efficient binding to CLDN5 subunits, and capability to increase permeability at low concentrations. The peptidomimetic in silico/in vitro strategy described here can achieve a transient and reversible permeabilization of the BBB with potential applications in the pharmacological treatment of brain diseases. HIGHLIGHTSO_LIWater-soluble peptidomimetics are used to competitively bind claudin-5 tight junction proteins and increase the permeability of the blood-brain barrier; C_LIO_LITrans-endothelial electrical resistance and dissociation constant measurements demonstrate the binding affinity of the peptide f1-C5C2 for claudin-5; C_LIO_LIUnbinding free energy calculations correlated with experimental results and provided information on the protein-peptide binding interface. C_LIO_LIIncubation with the peptide f1-C5C2 allows paracellular transport of 4K, but not 70K, dextran. C_LI GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=88 SRC="FIGDIR/small/591687v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@70fe54org.highwire.dtl.DTLVardef@496a28org.highwire.dtl.DTLVardef@1d89a81org.highwire.dtl.DTLVardef@187acec_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2024

Beyond Kaftrio: mechanistic insights to maximize N1303K-CFTR rescue

IntroductionN1303K is the fourth most frequent Cystic Fibrosis (CF) causing mutation. People with CF (pwCF) clinical status can be improved by Elexacaftor(ELX)/Tezacaftor(TEZ)/Ivacaftor (ETI) combotherapy. We investigated the mechanism underlying N1303K-CFTR rescue. MethodsN1303K-CFTR expression and maturation was evaluated by Western Blot in cell lines and Human Nasal Epithelial Primary Cells (HNECs). Cell surface expression was studied by nanoluciferase complementation assay and TurboID proximity labeling. Functional rescue was tested in vitro by YFP-Based Assay and Short Circuit Current. ResultsCorrection by ELX/TEZ increases N1303K-CFTR amounts, but not its maturation in CFTR-expressing HEK and 16HBEge cell lines and in HNECs. In control conditions, N1303K-CFTR is more distributed at the cell surface and significantly more surface partners are identified in the N1303K-CFTR interactome as compared to F508del-CFTR in HEK cells. ELX/TEZ induces a global stabilization of N1303K-CFTR without favoring its plasma membrane relocation in contrast to F508del-CFTR which is redistributed to the membrane. ETI increases N1303K-CFTR activity in HNECs and can be increased by API co-potentiation with a predicted increase in Forced Expiratory Volume in 1 second (ppFEV1) by respectively 13(2)% and 18%(3). This is consistent with a gain in ppFEV1 reported in pwCF carrying the N1303K mutation and additional improvement by API in a patient. ConclusionThese results support the expansion of ETI approval to N1303K mutation but highlight different mechanisms of action than for F508del.

physiology↗

bioRxiv2017

Heterogeneous Contribution of Microdeletions in the Development of Common Generalized and Focal epilepsies

BackgroundMicrodeletions are known to confer risk to epilepsy, particularly at genomic rearrangement \"hotspot\" loci. However, deciphering their role outside hotspots and risk assessment by epilepsy sub-type has not been conducted.\n\nMethodsWe assessed the burden, frequency and genomic content of rare, large microdeletions found in a previously published cohort of 1,366 patients with Genetic Generalized Epilepsy (GGE) plus two sets of additional unpublished genome-wide microdeletions found in 281 Rolandic Epilepsy (RE) and 807 Adult Focal Epilepsy (AFE) patients, totaling 2,454 cases. These microdeletion sets were assessed in a combined analysis and in sub-type specific approaches against 6,746 ethnically matched controls.\n\nResultsWhen hotspots are considered, we detected an enrichment of microdeletions in the combined epilepsy analysis (adjusted-P= 2.00x10-7; OR = 1.89; 95%-CI: 1.51-2.35), where the implicated microdeletions overlapped with rarely deleted genes and those involved in neurodevelopmental processes. Sub-type specific analyses showed that hotspot deletions in the GGE subgroup contribute most of the signal (adjusted-P = 1.22x10-12; OR = 7.45; 95%-CI = 4.20-11.97). Outside hotspot loci, microdeletions were enriched in the GGE cohort for neurodevelopmental genes (adjusted-P = 4.78x10-3; OR = 2.30; 95%-CI = 1.42-3.70), whereas no additional signal was observed for RE and AFE. Still, gene content analysis was able to identify known (NRXN1, RBFOX1 and PCDH7) and novel (LOC102723362) candidate genes affected in more than one epilepsy sub-type but not in controls.\n\nConclusionsOur results show a heterogeneous effect of recurrent and non-recurrent microdeletions as part of the genetic architecture of GGE and a minor to negligible contribution in the etiology of RE and AFE.

genetics↗