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Urpi, A.

Publications and source records attributed to Urpi, A..

3 recordsLinked to original sources

MET inhibition exploits conserved regulatory dependencies in malignant rhabdoid tumors

Malignant rhabdoid tumors (MRTs) are lethal, yet genomically simple childhood cancers characterised by universal SWI/SNF dysregulation. Despite this shared molecular framework, the regulatory programs sustaining MRTs and how they wire actionable dependencies, remain poorly defined. Here, we integrated single-cell multi-omic profiling and spatial transcriptomics across anatomically and molecularly diverse MRTs, generating a comprehensive multimodal MRT dataset at single-cell resolution. We leveraged this resource to identify candidate tumor-specific dependencies, which were subsequently functionally validated in vitro and in vivo in matched patient-derived models. We found that distinct malignant subpopulations are spatially patterned in complex environmentally shaped topologies, consistent with reciprocal interactions with stromal and immune compartments contributing to intratumoral transcriptional diversity. We identified recurrent transcriptional metaprograms conserved across patients and molecular subtypes, including a previously undescribed shared core rhabdoid program, as well as a metaprogram characterized by extracellular matrix interactions, and preferentially localized in tumor-stroma intermixed neighborhoods, supporting identification of niche conditioning cues. Mechanistically, we identified regulatory wiring driving these metaprograms, with the core shared rhabdoid programme coordinated by a circuit centred on TCF12, ZNF148 and CHD2. Guided by target nominations from our integrated analyses, we performed a curated drug screen using patient-derived MRT models and validated HGF/MET signaling as a selective vulnerability in extrarenal rhabdoid tumors. Pharmacologic MET inhibition was cytotoxic in sensitive models and induced a complete response in vivo using a clinically approved compound. Importantly, MET expression in primary tumors correlated with response, supporting biomarker-guided patient stratification for immediate clinical translation. Collectively, our findings define the molecular architecture of MRTs, reveal conserved regulatory programs beyond anatomical and molecular subtypes, and highlight a targetable signaling axis with immediate translational potential, establishing a framework for precision therapy in this lethal pediatric malignancy.

cancer biology↗

Maltodextrin administration ameliorates brain pathology in a mouse model of mitochondrial disease

Mitochondrial dysfunction lead to a wide group of progressive and fatal pathologies known as mitochondrial diseases (MD). One of the most common pediatric representation of MD is Leigh Syndrome, affecting 1/40.000 births. LS is characterized by neurodegeneration in specific brain areas, such as brainstem and basal ganglia, and by respiratory and motor alterations. However, the results obtained from clinical trials based on antioxidant therapies are controversial. Thus, the development novel antioxidant strategy is required to improve the efficacy of current palliative treatments. In this regard, Ndufs4KO mouse model is a suitable model to test new drugs in the field of MD and LS. Therefore, we set to assess the therapeutic potential of oral administration of Micrococcus luteus, a high-antioxidant content microorganism. Incidentally, we identified that while M. luteus administration did not possess any beneficial actions, the cryopreservant maltodextrin (MDX), included in the preparation, ameliorated the phenotype of Ndufs4KO mice. Our results show that MDX treatment at a concentration of 30 g/L increased lifespan and reduced microglial reaction compared to vehicle-treated Ndufs4KO mice. However, no improvement in locomotion nor respiratory function was observed in MDX-treated mice compared to vehicle-treated Ndufs4KO mice. Metataxonomic characterization of intestinal microbiome identified differential profiles in Ndufs4KO mice at the genus level. Furthermore, MDX treatment increased the variability of the abundance of Akkermansia sp. Thus, this work paves the way for further studies to confirm the therapeutic potential of MDX in mitochondrial disease.

neuroscience↗

Vestibular CCK neurons drive motion-induced malaise

Travel can induce motion sickness (MS) in susceptible individuals. MS is an evolutionary conserved mechanism caused by mismatches between motion-related sensory information and past visual and motion memory, triggering a malaise accompanied by hypolocomotion, hypothermia, hypophagia and nausea. Vestibular nuclei (VN) are critical for the processing of movement input from the inner ear. Motion-induced activation of VN neurons recapitulates MS-related signs. However, the genetic identity of VN neurons mediating MS- related autonomic and aversive responses remains unknown. Here, we identify a central role of cholecystokinin (CCK)-expressing VN neurons in motion-induced malaise. Moreover, we show that CCK VN inputs onto the parabrachial nucleus activate Calca- expressing neurons and are sufficient to establish avoidance to novel food, which is prevented by CCK-A receptor antagonism. These observations provide greater insight into the neurobiological regulation of MS by identifying the neural substrates of MS and providing potential targets for treatment. SIGNIFICANCE STATEMENTWe live in an age where travel is paramount. However, one of the most disabling conditions inherent to traveling is motion sickness (MS). While studies have underscored the role of the vestibular system in the development of MS, the neuronal populations involved in motion-induced malaise remain largely unknown. Here, we describe the vestibular pathways eliciting MS responses, and identify a key role for cholecystokinin (CCK)-expressing vestibular neurons. We reveal that a vestibulo-parabrachial (PBN) CCKergic projection is sufficient to induce conditioned taste aversion, likely through the activation of calcitonin gene-related peptide-expressing PBN neurons. Finally, we underscore the role of CCK-A receptor signaling as a novel druggable target to treat MS, providing novel insight on the neurobiological substrates of MS.

neuroscience↗