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Gouti, M.

Publications and source records attributed to Gouti, M..

5 recordsLinked to original sources

A scalable human neuromuscular organoid platform enables lineage-specific analysis of drug responses in spinal muscular atrophy.

Scalable human models that capture interactions between distinct tissues remain limited, constraining mechanistic insight and therapeutic prediction. Here, we established a scalable, automation-compatible human neuromuscular organoid (NMO) platform that enables integrated analysis of neuronal and muscle lineages in spinal muscular atrophy (SMA). Patient-derived NMOs reproducibly self-organise into spinal cord and skeletal muscle compartments and form functional neuromuscular circuits. SMA NMOs recapitulate early disease features, including reduced survival motor neuron (SMN) protein levels and impaired neuromuscular junction (NMJ) maturation. Single-nucleus RNA sequencing identifies lineage-specific transcriptional changes across neuronal and muscle compartments preceding functional deficits. Using this platform, we compared two clinically relevant SMN2 splicing modulators and observed distinct, cell-type-dependent responses. While both compounds increased SMN levels and NMJ number, only one enhanced myofiber growth and improved contractile function. These findings highlight muscle maturation, rather than NMJ number alone, as a key determinant of functional recovery and establish NMOs as a scalable system for studying cell-type-specific therapeutic responses.

bioengineering↗

Guided maturation of human neuromuscular organoids via electrical stimulation

Organoids derived from human pluripotent stem cells (hPSCs) are emerging as powerful models for studying development and disease. Despite their physiological relevance, the predictive power of organoids remains limited by the immature state of the constituent cells, posing a major challenge for mechanistic studies of adult physiology and late-onset diseases and disorders. Here, we establish a strategy for enhancing the maturation status of human neuromuscular organoids (NMOs) through chronic Electrical Pulse Stimulation (EPS). We demonstrate that low-frequency EPS, applied early on during NMO development and maintained over several weeks, promotes structural and functional maturation of neuromuscular junctions (NMJs). Independent of stimulation waveform dynamics, EPS-trained NMOs (EPS-NMOs) displayed stronger and more frequent spontaneous contractions that persisted long after stimulation ceased. Quantitative imaging and transcriptomic analyses revealed a robust improvement in EPS-NMO skeletal muscle and neural tissue morphology, coordinated regulation of lineage-specific biomarkers, and upregulation of gene programmes associated with mature neuromuscular function. Mechanobiological measurements further demonstrated increased EPS-NMO tissue stiffness and faster relaxation dynamics, consistent with advanced excitation-contraction coupling and force generation. Collectively, these findings establish EPS as a powerful, non-invasive, and on-demand modality for driving the morphological and functional maturation of complex organoid systems.

bioengineering↗

Sox2 levels configure the WNT response of epiblast progenitors responsible for vertebrate body formation

WNT signalling has multiple roles. It maintains pluripotency of embryonic stem cells, assigns posterior identity in the epiblast and induces mesodermal tissue. We provide evidence that these distinct functions are conducted by the transcription factor SOX2, which adopts different modes of chromatin interaction and regulatory element selection depending on its level of expression. At high levels, SOX2 acts as a pioneer factor, displacing nucleosomes from regulatory elements with high affinity SOX2 binding sites and recruiting the WNT effector, TCF/{beta}-catenin, to maintain pluripotent gene expression. Reducing SOX2 levels destabilises pluripotency and reconfigures SOX2/TCF/{beta}-catenin occupancy to caudal epiblast expressed genes. These contain low-affinity SOX2 sites and are co-occupied by T/Bra and CDX. The loss of SOX2 allows WNT induced mesodermal differentiation. These findings define a role for Sox2 levels in dictating the chromatin occupancy of TCF/{beta}-catenin and reveal how context specific responses to a signal are configured by the level of a transcription factor.

developmental biology↗

Human axial progenitors generate trunk neural crest cells

The neural crest (NC) is a multipotent embryonic cell population generating distinct cell types in an axial position-dependent manner. The production of NC cells from human pluripotent stem cells (hPSCs) is a valuable approach to study human NC biology. However, the origin of human trunk NC remains undefined and therefore current in vitro differentiation strategies induce only a modest yield of trunk NC cells. Here we show that hPSC-derived axial progenitors, the posteriorly-located drivers of embryonic axis elongation, give rise to trunk NC cells and their derivatives. Moreover, we define the molecular signatures associated with the emergence of human NC cells of distinct axial identities in vitro. Collectively, our findings indicate that there are two routes toward a human post-cranial NC state: the birth of cardiac and vagal NC is facilitated by retinoic acid-induced posteriorisation of an anterior precursor whereas trunk NC arises within a pool of posterior axial progenitors.

developmental biology↗

Regionalization of the nervous system requires axial allocation prior to neural lineage commitment

SummaryNeural induction in vertebrates generates a central nervous system that extends the rostral-caudal length of the body. The prevailing view is that neural cells are initially induced with anterior (forebrain) identity, with caudalising signals then converting a proportion to posterior fates (spinal cord). To test this model, we used chromatin accessibility assays to define how cells adopt region-specific neural fates. Together with genetic and biochemical perturbations this identified a developmental time window in which genome-wide chromatin remodeling events preconfigure epiblast cells for neural induction. Contrary to the established model, this revealed that cells commit to a regional identity before acquiring neural identity. This \"primary regionalization\" allocates cells to anterior or posterior regions of the nervous system, explaining how cranial and spinal neurons are generated at appropriate axial positions. These findings prompt a revision to models of neural induction and support the proposed dual evolutionary origin of the vertebrate central nervous system.

developmental biology↗