Biology subjects

Mouilleau, V.

Publications and source records attributed to Mouilleau, V..

3 recordsLinked to original sources

bioRxiv2025

Scalable Human Cellular Models of Parkinson Disease Reveal A Druggable Link Between the Angiotensin Receptor 1 and Alpha-Synuclein Pathology

BackgroundParkinsons disease (PD) involves progressive loss of midbrain dopaminergic (mDA) neurons in the substantia nigra. No disease-modifying treatments exist, only symptomatic relief. Our lab reported an unbiased screen in larval zebrafish identifying renin-angiotensin-aldosterone system (RAAS) inhibitors, including clinically used AGTR1 inhibitors for hypertension, as potent neuroprotective agents. This study aims to investigate the effects of AGTR1 inhibition on human mDA neuron survival using inducible neurodegenerative 2D and 3D models for human mDA neuron degeneration. MethodsWe report a scalable high-content platform, using CRISPR-engineered human induced pluripotent stem cell (hiPSC)-derived mDA neurons expressing a tyrosine hydroxylase (TH) fluorescent reporter, allowing to track mDA neuron survival live "in a dish". We developed chemically inducible neurodegenerative 2D and 3D models for human mDA neuron degeneration, allowing to recapitulate PD pathology in human cells in vitro. ResultsOur model establishes scalable human cellular models of PD well-suited for therapeutic discovery. Using 2D and 3D mono and co-cultures, this study demonstrates that inhibition of AGTR1, via chemical or genetic means, protects against chemically induced mDA neuron degeneration. Transcriptomic analyses show AGTR1 inhibition lowers synuclein transcription, by reducing SNCA and SNCB gene expression. In 3D neuron-glia assembloids, AGTR1 inhibition protects against the accumulation of phosphorylated form of -synuclein (p129-Syn), key PD pathological marker. ConclusionsWe highlight AGTR1 as a key regulator of -synuclein transcription and aggregation in human mDA neurons, and AGTR1 inhibition as pro-survival in human iPSC-derived models. These findings position inhibition of AGTR1 as a promising therapeutic strategy for PD neuroprotection.

neuroscience↗

bioRxiv2024

PCM1 conveys centrosome asymmetry to polarized endosome dynamics in regulating daughter cell fate

Vertebrate radial glia progenitors (RGPs), the principal neural stem cells, balance self-renewal and differentiation through asymmetric cell division (ACD), during which unequal inheritance of centrosomes is observed. Mechanistically, how centrosome asymmetry leads to distinct daughter cell fate remains largely unknown. Here we find that the centrosome protein Pericentriolar Material 1 (Pcm1), asymmetrically distributed at the centrosomes, regulates polarized endosome dynamics and RGP fate. In vivo time-lapse imaging and nanoscale-resolution expansion microscopy of zebrafish embryonic RGPs detect Pcm1 on Notch ligand-containing endosomes, in a complex with the polarity regulator Par-3 and dynein motor. Loss of pcm1 disrupts endosome dynamics, with clonal analysis uncovering increased neuronal production at the expense of progenitors. Pcm1 facilitates an exchange of Rab5b (early) for Rab11a (recycling) endosome markers and promotes the formation of Par-3 and dynein macromolecular complexes on recycling endosomes. Finally, in human-induced pluripotent stem cell-derived brain organoids, PCM1 shows asymmetry and co-localization with PARD3 and RAB11A in mitotic neural progenitors. Our data reveal a new mechanism by which centrosome asymmetry is conveyed by Pcm1 to polarize endosome dynamics and Notch signaling in regulating ACD and progenitor fate.

cell biology↗

bioRxiv2020

Dynamic extrinsic pacing of the HOX clock in human axial progenitors controls motor neuron subtype specification

SUMMARYRostro-caudal patterning of vertebrates depends on the temporally progressive activation of HOX genes within axial stem cells that fuel axial embryo elongation. Whether HOX genes sequential activation, the “HOX clock”, is paced by intrinsic chromatin-based timing mechanisms or by temporal changes in extrinsic cues remains unclear. Here, we studied HOX clock pacing in human pluripotent stem cells differentiating into spinal cord motor neuron subtypes which are progenies of axial progenitors. We show that the progressive activation of caudal HOX genes in axial progenitors is controlled by a dynamic increase in FGF signaling. Blocking FGF pathway stalled induction of HOX genes, while precocious increase in FGF alone, or with GDF11 ligand, accelerated the HOX clock. Cells differentiated under accelerated HOX induction generated appropriate posterior motor neuron subtypes found along the human embryonic spinal cord. The HOX clock is thus dynamically paced by exposure parameters to secreted cues. Its manipulation by extrinsic factors alleviates temporal requirements to provide unprecedented synchronized access to human cells of multiple, defined, rostro-caudal identities for basic and translational applications.View Full Text

developmental biology↗