Biology subjects

Gianoncelli, A.

Publications and source records attributed to Gianoncelli, A..

6 recordsLinked to original sources

bioRxiv2025

Functional Impact of CYFIP2 RNA Editing on Actin Regulation, Axon Growth, and Spinogenesis

Cytoplasmic FMRP Interacting Protein 2 (CYFIP2) a component of the Wave Regulatory Complex (WRC), one of the most important players in regulating cellular actin dynamics. Interestingly, CYFIP2 transcript undergoes RNA editing, an epitranscriptomic modification catalysed by ADAR enzymes, that leads adenosine (A) to inosine (I) deamination. CYFIP2 editing in the coding sequence results in a K/E substitution at amino acid 320. The functional meaning of this regulation is still unknown. In this study, we aim at investigating the potential implication of CYFIP2 RNA editing related to actin dynamics during cell differentiation, axon development and synaptogenesis in neural cells. We have generated SH-SY5Y neuroblastoma cell lines in which CYFIP2 gene has been functionally inactivated by CRISPR-Cas9 technology. CYFIP2 KO cells showed profound actin filaments disorganisation and loss of the capability to differentiate into a neuronal-like phenotype. Overexpression of both CYFIP2 unedited (K) and edited (E) isoforms rescued normal capability. Finally, we took advantage of primary neuronal culture where endogenous CYFIP2 was knocked down by shRNA technology and CYFIP2 editing variants were overexpressed. While CYFIP2 KD cells reported a decrease in axon development and spine frequency, CYFIP2-E variants increase the number of axon branches, total axon length and dendritic spine frequency compared to either CYFIP2 KD cells or CYFIP-K variants. Overall, our work reveals for the first time a functional significance of the CYFIP2 K/E RNA editing process in regulating the spreading of neuronal axons during the initial stages of in-vitro development and the process of spinogenesis.

cell biology↗

bioRxiv2024

Novel correlative microscopy approach for nano-bio interface studies of ultrafine particle-induced lung epithelial cell damage

Correlated light and electron microscopy (CLEM) has become essential in life sciences due to advancements in imaging resolution, sensitivity, and sample preservation. In nanotoxicology-- specifically, studying the health effects of particulate matter exposure--CLEM can enable molecular-level structural as well as functional analysis of nanoparticle interactions with lung tissue, key for the understanding of modes of action. In our study, we for the first time implement an integrated high-resolution fluorescence lifetime imaging microscopy (FLIM) and hyperspectral fluorescence imaging (fHSI), scanning electron microscopy (SEM), ultra-high resolution helium ion microscopy (HIM) and synchrotron micro X-ray fluorescence (SR {micro}XRF), to characterize the nano-bio interface and to better elucidate the modes of action of lung epithelial cells response to known inflammatory titanium dioxide nanotubes (TiO2 NTs). Morpho-functional assessment uncovered several mechanisms associated with the extensive DNA, essential minerals and iron accumulation, cellular surface immobilization, and the localized formation of fibrous structures, all confirming immunomodulatory responses. These findings advance our understanding of the early cellular processes leading to inflammation development after lung epithelium exposure to these, high-aspect-ratio nanoparticles. The novel experimental approach, exploiting light, ion and electron sources, provides a robust framework for future research into nanoparticle toxicity and its impact on human health.

cell biology↗

bioRxiv2023

Advances on sparse Dynamic Scanning in Spectromicroscopy through Compressive Sensing

Scanning microscopies and spectroscopies like X-ray Fluorescence (XRF), Scanning Transmission X-ray Microscopy (STXM), and Ptychography are of very high scientific importance as they can be employed in several research fields. Methodology and technology advances aim at analysing larger samples at better resolution, improved sensitivities and higher acquisition speeds. The frontiers of those advances are on detectors, radiation sources, motors, but also on acquisition and analysis software together with general methodology improvements. Weve e recently introduced and fully implemented on a soft X-ray microscopy beamline an intelligent scanning methodology based on compressive sensing. This demonstrated sparse low energy XRF scanning of dynamically chosen regions of interest in combination with STXM. It resulted in a sparse megapixel-rage low energy XRF spectroimaging through dynamic scanning that was previously not feasible. This research has been further developed and has been applied in scientific applications in biology. The developments are mostly on the dynamic triggering decisional mechanism in order to incorporate modern Machine Learning and real-time XRF fitting but also on the suitable integration of the method in the control system making it available for other beamlines and imaging techniques. On the applications front, the method was successfully used on different samples, from lung and ovarian human tissues to plant root sections. This manuscript introduces the latest advances of the method and demonstrates applications in life and environmental sciences. Finally it highlights an auxiliary development of a mobile application that assists the selection of specific regions of interest in an easy way.

biophysics↗

bioRxiv2021

The first observation of osmotically neutral sodium accumulation in the myocardial interstitium

The aim of this study was the detection and quantification of the Na+ depositions in the extracellular matrix of myocardial tissue, which are suggested to be bound by negatively charged glycosaminoglycan (GAG) structures. The presented experimental results are based on high resolution X-ray fluorescence (XRF) spectromicroscopy technique used to perform a comparative analysis of sodium containment in intracellular and interstitial spaces of cardiac tissues taken from animals selected by low and high sodium intake rates. The experimental results obtained show that high sodium daily intake can result in a remarkable increase of sodium concentration in the myocardial interstitium.

biophysics↗

bioRxiv2020

Efficient long-range conduction in cable bacteria through nickel protein wires

Filamentous cable bacteria display unrivalled long-range electron transport, generating electrical currents over centimeter distances through a highly ordered network of fibers embedded in their cell envelope. The conductivity of these periplasmic wires is exceptionally high for a biological material, but their chemical structure and underlying electron transport mechanism remain unresolved. Here, we combine high-resolution microscopy, spectroscopy, and chemical imaging on individual cable bacterium filaments to demonstrate that the periplasmic wires consist of a conductive protein core surrounded by an insulating shell layer. The core proteins contain a sulfur-ligated nickel cofactor, and conductivity decreases when nickel is oxidized or selectively removed. The involvement of nickel as the active metal in biological conduction is remarkable, and suggests a hitherto unknown form of electron transport that enables efficient conduction in centimeter-long protein structures.

microbiology↗

bioRxiv2017

Alleviation of Al toxicity by Si is associated with the formation of Al-Si complexes in root tissues of sorghum

Silicon is reported to reduce the toxic effects of Al on root elongation but the in planta mechanism by which this occurs remains unclear. Using seedlings of soybean (Glycine max) and sorghum (Sorghum bicolor), we examined the effect of up to 2 mM Si on root elongation rate (RER) in Al-toxic nutrient solutions. Synchrotron-based low energy X-ray fluorescence (LEXRF) was then used for the in situ examination of the distribution of Al and Si within cross-sections cut from the apical tissues of sorghum roots. The addition of Si potentially increased RER in Al-toxic solutions, with RER being up to ca. 0.3 mm h-1 (14 %) higher for soybean and ca. 0.2 mm h-1 (17 %) higher for sorghum relative to solutions without added Si. This improvement in RER could not be attributed to a change in Al-chemistry of the bulk nutrient solution, nor was it due to a change in the concentration of Al within the apical (0-10 mm) root tissues. Using LEXRF to examine sorghum, it was demonstrated that in roots exposed to both Al and Si, much of the Al was co-located with Si in the mucigel and outer apoplast. These observations suggest that Si reduces the toxicity of Al in planta through formation of Al-Si complexes in mucigel and outer cellular tissues, thereby decreasing the binding of Al to the cell wall where it is known to inhibit wall loosening as required for cell elongation.

plant biology↗