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Biology subjects

Garcia-Gonzalez, L.

Publications and source records attributed to Garcia-Gonzalez, L..

3 recordsLinked to original sources

Variability vs Phenotype: multimodal analysis of Dravet Syndrome Brain Organoids powered by Deep Learning

Brain organoids (BO) have risen as a reliable model for neurodelopmental disorders (ND), reproducing human brain development milestones. However, their significant intra- and inter-organoid variability compromises their use in advanced tasks such as drug testing. Overcoming experimental variability is crucial for models prone to variation, like unguided BO. BO modelling in Dravet Syndrome, a late-onset epileptic ND, represents a great challenge since BO variability accumulates with time, when phenotype shows in vitro. Leveraging deep learning, we developed ImPheNet, a predictive tool grounded in BO live imaging datasets. ImPheNet accurately classified phenotypes and assessed drug toxicity in BO derived from DS, revealing differences between genotypes and upon antiseizure drug exposure. These results are supported by transcriptomic and functional data, revealing an excitatory-inhibitory imbalance during the maturation of DS organoids. Altogether, our DL-predictive live imaging strategy, ImPheNet, emerges as a powerful tool enhancing BO research and advancing ND treatments.

developmental biology↗

The Alzheimer's disease risk factor APOE4 drives pro-inflammation in human astrocytes via HDAC-dependent repression of TAGLN3

The Apolipoprotein E4 (APOE4) is the major allelic risk factor for late-onset Alzheimers disease (AD). APOE4 associates with a pro-inflammatory phenotype increasingly considered as critical in AD initiation and progression. Yet, the mechanisms driving an APOE4-dependent neuroinflammation remain unelucidated. Leveraging patient specific human induced Pluripotent Stem Cells (iPSCs) we demonstrate inflammatory chronicity and hyperactivated responses upon cytokines in human APOE4 astrocytes via a novel mechanism. We uncovered that APOE4 represses Transgelin 3 (TAGLN3), a new interacting partner of I{kappa}B, thus increasing the NF-kB activity. The transcriptional repression of TAGLN3 was shown to result from an APOE4-dependent histone deacetylase (HDAC) activity. The functional relevance of TAGLN3 was demonstrated by the attenuation of APOE4-driven neuroinflammation after TAGLN3 supplementation. Importantly, TAGLN3 downregulation was confirmed in the brain of AD patients. Our findings highlight the APOE4-TAGLN3 axis as a new pathogenic pathway that paves the way for the development of therapeutics to prevent maladaptive inflammatory responses in APOE4 carriers, while placing TAGLN3 downregulation as a potential biomarker of AD. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=98 HEIGHT=200 SRC="FIGDIR/small/440108v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@1036557org.highwire.dtl.DTLVardef@1f245bdorg.highwire.dtl.DTLVardef@c07c4aorg.highwire.dtl.DTLVardef@1200396_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

MT5-MMP controls APP metabolism and the fate of beta-CTF/C99 and Abeta through proteolytic-dependent and -independent mechanisms relevant for Alzheimer's disease

We previously discovered the implication of membrane-type 5-matrix metalloproteinase (MT5-MMP) in Alzheimers disease AD pathogenesis. Here we shed new light on pathogenic mechanisms by which MT5-MMP controls APP processing and the fate of amyloid beta peptide (A{beta}), its precursor C99 and C83. We found in HEK carrying the APP Swedish familial mutation (HEKswe) that MT5-MMP-mediated processing of APP that releases the soluble 95 kDa form (sAPP95), was hampered by the removal of the C-terminal non-catalytic domains of MT5-MMP. Catalytically inactive MT5-MMP variants increased the levels of A{beta} and promoted APP/C99 sorting in the endo-lysosomal system. We found interaction of C99 with the C-terminal portion of MT5-MMP, the deletion of which caused a strong degradation of C99 by the proteasome, preventing A{beta} accumulation. These findings reveal novel mechanisms for MT5-MMP control of APP metabolism and C99 fate involving proteolytic and non-proteolytic actions mainly mediated by the C-terminal part of the proteinase.

neuroscience↗