Biology subjects

Crestani, M.

Publications and source records attributed to Crestani, M..

8 recordsLinked to original sources

bioRxiv2024

Identification of neuronatin as a SERCA2b regulin-like protein and assessment of its aggregation propensity via coarse grained simulations.

Neuronatin (NNAT) is small transmembrane protein involved in a wide range of physiological processes, such as white adipose tissue browning and neuronal plasticity, as well as pathological ones, such as Lafora disease caused by the formation of NNAT aggregates. However, its 3D structure is unknown, and its mechanism of action is still unclear. In this study the two most well-known NNAT isoforms ( and {beta}) were modelled and the interaction with the SERCA2b calcium pump was assessed using computational methods. First, molecular docking identified the same binding region as the one described for phospholamban, a thoroughly described SERCA inhibitor. Then, analyses of the flux of water molecules during molecular dynamics simulations highlighted significant similarities between the behavior of SERCA2b when in complex with phospholamban, and when in complex with either NNAT isoform. These results suggest that NNAT could be considered a "regulin-like" protein. Additional all-atom and coarse-grained simulations of multiple copies of NNAT highlighted a significant aggregation potential of both NNAT isoforms, supporting experimental data. Statement of significanceThis study presents the first structural model of neuronatin (NNAT) isoforms and {beta}. Through molecular docking and molecular dynamics simulations, we propose a NNAT interaction mechanism with the SERCA2b calcium pump similar to that of phospholamban, a known regulin and SERCA inhibitor. Our analyses also suggested a strong aggregation potential of NNAT based on all-atom and coarse-grained simulations, in line with experimental data on its involvement in Lafora disease. These insights suggest NNAT can be considered a "regulin-like" protein, advancing our understanding of its molecular function and contributing to new perspectives in targeting NNAT-related pathologies, as well as reinforcing the role of coarse-grained simulations as a valid tool to assess protein aggregation potential.

bioinformatics↗

bioRxiv2024

DUALISTIC SAHA DOSE-DEPENDENT EFFECTS ON GLIAL-INFLAMMATORY RESPONSE

Neuroinflammation comprises biochemical and cellular responses of the nervous system to injury, emerging as a central process in many neurological conditions. Although beneficial in nature, over-activation of the immune response may result in the production of neurotoxic factors that exacerbate the disease state. Due to the relevant role of histone acetylation in transcriptional regulation, inhibition of histone deacetylase (HDAC) activity plays a central role in the pathogenesis of inflammation. Here, we investigated the impact of HDACs inhibition in the regulation of the inflammatory response elicited by lipopolysaccharide (LPS) in glia cells using trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA). We observed that acute and prolonged exposure to low doses of TSA boosts the inflammatory response in glia cells. Conversely, TSA pre-treatment in cells exposed to LPS decreases inflammation. Additionally, we observed that low and high doses of SAHA exert opposite effects on LPS-induced inflammatory response. Low dose (100 nM) potentiates inflammatory response by increasing the production of pro-inflammatory cytokines tumour necrosis factor (TNF)- and interleukin (IL) - 1{beta}; and reducing the anti-inflammatory mediator IL-10. Nevertheless, 5 {micro}M SAHA reverts the pro-towards anti-inflammatory profile. To better characterize SAHA dualistic effects in glia cells, we generated comparative genome-wide gene expression data. Simultaneous exposure to 5 {micro}M SAHA and LPS (10 ng/ml) alters the expression of 1628 genes, while the combination of 100 nM SAHA and LPS regulates the expression of 97 transcripts. Both doses of SAHA differentially regulate important pathways involved in cellular function maintenance, homeostasis, and survival. Likewise, inhibition of the Janus Kinase - signal transducers and activators of the transcription (JAK/STAT) signalling pathway seems to mediate the anti-inflammatory effects of 5 {micro}M SAHA. On the other hand, 100 nM SAHA increases pro-inflammatory cytokine levels possibly via modulation of the underlined feedback mechanisms triggered by IL-10 expression regulation. Together, these results contribute to outline a comprehensive picture of the involvement of HDACs inhibitors (HDACi) in the onset or prevention of neuroinflammation, showing that their effects depend on cell types, HDACi dosage and specificity, and protocol used.

molecular biology↗

bioRxiv2024

Unraveling Glioblastoma Heterogeneity: Introducing SP2G Method for Identifying Invasive Sub-Populations

Glioblastomas exhibit remarkable heterogeneity at various levels, including motility modes and mechanoproperties that contribute to tumor resistance and recurrence. In a recent study using gridded micropatterns mimicking the brain vasculature, we linked glioblastoma cell motility modes, mechanical properties, formin content, and substrate chemistry. We now introduce SP2G (SPheroid SPreading on Grids), an analytic platform designed to identify the migratory modes of patient-derived glioblastoma cells and rapidly pinpoint the most invasive sub-populations. Tumorspheres are imaged as they spread on gridded micropatterns and analyzed by our semi-automated, open-source, Fiji macro suite that characterizes migration modes accurately. With SP2G, we could reveal intra-patient motility heterogeneity with molecular correlations to specific integrins and EMT markers. Thus, our system presents a versatile and potentially pan-cancer workflow to detect diverse invasive tumor sub-populations in patient-derived specimens and offers a valuable tool for therapeutic evaluations at the individual patient level. TeaserCracking the inter and intra-patient diversity in Glioblastoma migration profiles

biophysics↗

bioRxiv2023

SP2G: an imaging and analysis pipeline revealing the inter and intra-patient migratory diversity of glioblastoma

Glioblastomas are heterogeneous, primary brain tumors hiding several sub-populations. Patient-derived xenografts are considered gold-standards to study glioblastoma invasion. However, they present many disadvantages, including time consumption, complex standardization, high cost. To counteract these issues and rapidly identify the most invasive sub-populations, we developed an in vivo mimicry platform named SP2G (SPheroid SPreading on Grids). Live imaging of tumor-derived spheroids spreading on gridded micro patterns mimicking the brain vasculature recapitulated 3D motility features observed in brain or 3D matrices. Using patient-derived samples coupled with a semi-automated macro suite, SP2G easily characterized and sorted differences in cell migration and motility modes. Moreover, SP2G exposed the hidden intra-patient heterogeneity in cell motility that correlated molecularly to specific integrins. Thus, SP2G constitute a versatile and potentially pan-cancer workflow to identify the diverse invasive tumor sub-populations in patient-derived specimens. SP2G includes an integrative tool, available as open-source Fiji macro suite, for therapeutic evaluations at single patient level. TeaserCracking the inter and intra-patient diversity in Glioblastoma migration profiles

biophysics↗

bioRxiv2023

Mechanically induced topological transition of spectrin regulates its distribution in the mammalian cortex

The cell cortex is a dynamic assembly that ensures cell integrity during passive deformation or active response by adapting cytoskeleton topologies with poorly understood mechanisms. The spectrin meshwork ensures such adaptation in erythrocytes and neurons. Erythrocytes rely on triangular-like lattices of spectrin tetramers, which in neurons are organized in periodic arrays. We exploited Expansion Microscopy to discover that these two distinct topologies can co-exist in other mammalian cells such as fibroblasts. We show through biophysical measurements and computational modeling that spectrin provides coverage of the cortex and, with the intervention of actomyosin, erythroid-like lattices can dynamically transition into condensates resembling neuron-like periodic arrays fenced by actin stress fibers. Spectrin condensates experience lower mechanical stress and turnover despite displaying an extension close to the contour length of the tetramer. Our study sheds light on the adaptive properties of spectrin, which ensures protection of the cortex by undergoing mechanically induced topological transitions.

cell biology↗

bioRxiv2022

Emergent oscillations during cellular directional decision-making on junctions

Motile cells inside living tissues often encounter junctions, where their path branches into several alternative directions of migration. We present a theoretical model of cellular polarization for cells migrating along one-dimensional lines, arriving at a symmetric Y-junction and extending protrusions along the different paths that emanate from the junction. The model predicts the spontaneous emergence of deterministic oscillations between competing protrusions, whereby the cellular polarization and growth alternates between the competing protrusions. The oscillations are modified by cellular noise, but remain as a dominant feature which affects the time it takes the cell to migrate across the junction. These predicted oscillations in the cellular polarization during the directional decision making process at the junction are found experimentally for two different cell types, non-cancerous endothelial and cancerous glioma cells, migrating on patterned network of thin adhesive lanes with junctions.

biophysics↗

bioRxiv2022

PIP4K2B is a mechanosensor and induces heterochromatin-driven nuclear softening through UHRF1.

Phosphatidylinositol-5-phosphate (PtdIns5P)-4-kinases (PIP4Ks) are stress-regulated phosphoinositide kinases able to phosphorylate PtdIns5P to PtdIns(4, 5)P2. In cancer patients their expression is typically associated with bad prognosis. Among the three PIP4K isoforms expressed in mammalian cells, PIP4K2B is the one with more prominent nuclear localization. Here, we unveil the role for PIP4K2B as mechanosensor. PIP4K2B protein level, indeed, strongly decreases in cells growing on soft substrates. Its direct silencing or pharmacological inhibition, mimicking cell response to soft, triggers a concomitant reduction of the epigenetic regulator UHRF1 and induces changes in nuclear polarity, nuclear envelope tension and chromatin compaction. This substantial rewiring of the nucleus mechanical state drives YAP cytoplasmic retention and impairment of its activity as transcriptional regulator, finally leading to defects in cell spreading and motility. Since YAP signalling is essential for initiation and growth of human malignancies, our data suggest that potential therapeutic approaches targeting PIP4K2B could be beneficial in the control of the altered mechanical properties of cancer cells.

cell biology↗

bioRxiv2020

Adaptive mechanoproperties characterize glioblastoma fitness for invasion

Glioblastoma are heterogeneous tumors composed of highly invasive and highly proliferative clones. Heterogeneity in invasiveness could emerge from discrete biophysical properties linked to specific molecular expression. We identified clones of patient-derived glioma propagating cells that were either highly proliferative or highly invasive and compared their cellular architecture, migratory and biophysical properties. We discovered that invasiveness was linked to cellular fitness. The most invasive cells were stiffer, developed higher mechanical forces on the substrate and moved stochastically. The mechanochemical-induced expression of the formin FMN1 conferred invasive strength that was confirmed in patient samples. Moreover, FMN1 ectopic expression in less invasive clones increased fitness parameters. Mechanistically, FMN1 acts from the microtubule lattice, counteracting microtubule bundling and promoting a robust cell-body cohesion leading to highly invasive hurdling motility. One Sentence SummaryFMN1 increases cell mechanics and invasiveness.

cell biology↗