Biology subjects

Benchoua, A.

Publications and source records attributed to Benchoua, A..

5 recordsLinked to original sources

bioRxiv2026

Cortical organoids from congenital DM1 PSCs reveal MBNL-dependent corticogenesis defects and enable preclinical testing of therapeutic compounds

Myotonic dystrophy type 1 (DM1) is caused by an expansion of a CTG repeat in the 3' untranslated region of the DMPK gene, leading to accumulation of toxic CUG-repeat RNAs, sequestration of MBNL proteins and widespread splicing dysregulation. Congenital DM1 (CDM), the most severe form of the disease, is associated with profound muscular and neurodevelopmental defects, yet the mechanisms underlying early human brain involvement remain poorly understood. Here, we generated cortical organoids from patient-derived pluripotent stem cells carrying >1000 CTG repeats, an expansion typically associated with CDM, to model early human neurodevelopment. DM1 molecular and cellular hallmarks were detected at early developmental stages, including nuclear DMPK RNA foci in neural progenitor cells and reduced proliferative capacity. As organoids matured, CDM cultures displayed altered cortical composition, with reduced CTIP2 and SATB2 neuronal populations and increased NFIA/GFAP glial cells. In parallel, 120-day-old organoids recapitulated splicing abnormalities previously identified in DM1 patient brain tissue. To assess the contribution of MBNL dysfunction, we analyzed cortical organoids derived from MBNL2 and MBNL1/2/3 knockout induced pluripotent stem cells, which reproduced key neurodevelopmental phenotypes observed in CDM organoids, supporting a central role for MBNL loss of function in impaired corticogenesis. Finally, we evaluated the translational relevance of this model using tideglusib and erythromycin, two compounds currently under clinical evaluation in DM1 patients. Both treatments reduced DMPK RNA foci and restored proliferation defects in SOX2 neural progenitors. Together, these findings establish cortical organoids as a robust human model of CDM-associated neurodevelopmental defects, uncover MBNL-dependent mechanisms underlying early corticogenesis impairment and demonstrate the utility of this platform for translational therapeutic discovery in DM1.

pathology↗

bioRxiv2024

Advanced human cerebral organoids as a model for investigating glioma stem cell interactions with microglia and vascular cells and response to radiotherapy

The recent development of human brain organoids from induced pluripotent stem cells (IPSCs) enables the modeling of brain biology and pathophysiology, such as gliomas. However, most models lack vascular and/or immune systems, both of which play essential roles in maintaining brain health and in pathophysiological mechanisms. We have established a new method for generating vascularized complex cerebral organoids (CCOs) containing microglial cells (brain-resident macrophages) by incorporating bipotent hematopoietic/endothelial progenitors derived from the same IPSC lines during the early stages of development. This approach led to the formation of extensive vascular-like structures with blood-brain barrier characteristics, which were perfused upon transplantation into immunodeficient mice. Additionally, microglial cells exhibiting typical phenotypes and functionalities also developed within the CCOs. By coculturing CCOs with glioma stem cells, we demonstrated that this model effectively recapitulates the tumor niche of glioblastoma, showing vascular co-option, reprogramming of microglia into tumor-associated macrophages, and recurrence after radiotherapy. In conclusion, our vascularized and immunocompetent CCO model will be invaluable for understanding human brain development, exploring how this process is disrupted in diseases like gliomas, and discovering new therapeutic strategies.

cancer biology↗

bioRxiv2023

Pharmacological modulation of developmental and synaptic phenotypes in human SHANK3 deficient stem cell-derived neuronal models

One sentence summaryThis study describes the use of SHANK3 deficient stem cell-derived neuronal models to screen and characterize small molecules that partially rescued developmental and synaptic defects related to Phelan-McDermid syndrome (PMDS). Phelan-McDermid syndrome (PMDS) arises from mutations in the terminal region of chromosome 22q13, impacting the SHANK3 gene. The resulting deficiency of the postsynaptic density scaffolding protein SHANK3 is associated with autism spectrum disorder (ASD). We examined 12 different PMDS patient and CRISPR-engineered stem cell-derived neuronal models and controls and found that reduced expression of SHANK3 leads to neuronal hyperdifferentiation, increased synapse formation, and decreased neuronal activity. We performed automated imaging-based screening of 7,120 target-annotated small molecules and identified three compounds that rescued SHANK3-dependent neuronal hyperdifferentiation. One compound, Benproperine, rescued the decreased colocalization of Actin Related Protein 2/3 Complex Subunit 2 (ARPC2) with {beta}-actin and rescued increased synapse formation in SHANK3 deficient neurons when administered early during differentiation. Neuronal activity was only mildly affected, highlighting Benproperines effects as a neurodevelopmental modulator. This study demonstrates that small molecular compounds that reverse developmental phenotypes can be identified in human neuronal PMDS models.

neuroscience↗

bioRxiv2021

Human Cytomegalovirus modifies placental small extracellular vesicle secretion and composition towards a proviral phenotype to enhance infection of fetal recipient cells

Although placental small extracellular vesicles (sEVs) are extensively studied in the context of pregnancy, little is known about their role during human cytomegalovirus (hCMV) congenital infection, especially at the beginning of pregnancy. In this study, we examined the consequences of hCMV infection on sEVs production, composition and function using an immortalized human cytotrophoblast cell line derived from first trimester placenta. By combining complementary approaches of biochemistry, electron microscopy and quantitative proteomic analysis, we showed that hCMV infection increases the yield of sEVs produced by cytotrophoblasts and modifies their protein content towards a proviral phenotype. We further demonstrate that sEVs secreted by hCMV-infected cytotrophoblasts potentiate infection in naive recipient cells of fetal origin, including human neural stem cells. Importantly, these functional consequences are also observed with sEVs prepared from either an ex vivo model of infected histocultures from early placenta or from the amniotic fluid of patients naturally infected by hCMV at the beginning of pregnancy. Based on these findings, we propose that placental sEVs could be key actors favoring viral dissemination to the fetal brain during hCMV congenital infection. Significance StatementHuman cytomegalovirus (hCMV) infection is a major issue during pregnancy, affecting 1% of births in western countries. Despite extensive research, the pathophysiology of this congenital infection remains unclear. Recently, increasing evidence point to the key role of placental small extracellular vesicles (sEVs) in materno-fetal communication during pregnancy. Here, we examined the impact of hCMV infection on the protein composition and function of placental sEVs. We observe that hCMV infection leads to major changes in placental sEV protein content. Functional studies show the ability of sEVs produced by placental infected cells to facilitate further infection of naive recipient fetal cells, notably human neural stem cells. Our study demonstrates that placental sEVs are key players of hCMV pathophysiology during congenital infection.

cell biology↗

bioRxiv2019

Pathological modeling of TBEV infection reveals differential innate immune responses in human neurons and astrocytes that correlate with their susceptibility to infection.

Tick-borne encephalitis virus (TBEV) is a member of the Flaviviridae family, Flavivirus genus, which includes several important human pathogens. It is responsible for neurological symptoms that may cause permanent disability or death, and, from a medical point of view, is the major arbovirus in Central/Northern Europe and North-eastern Asia. TBEV tropism is critical for neuropathogenesis, yet, little is known about the molecular mechanisms that govern the susceptibility of human brain cells to the virus. In this study, we sought to establish and characterize a new in vitro model of TBEV infection in the human brain and to decipher cell type-specific innate immunity and its relation to TBEV tropism and neuropathogenesis. We showed that infection of neuronal/glial cultures derived from human fetal neural progenitor cells (hNPCs) mimicked three major hallmarks of TBEV infection in the human brain, namely, preferential neuronal tropism, neuronal death and astrogliosis. We also showed that these cells had conserved their capacity to build an antiviral response against TBEV. TBEV-infected neuronal/glial cells, therefore, represented a highly relevant pathological model. By enriching the cultures in either human neurons or astrocytes, we further demonstrated qualitative and quantitative differential innate immune responses in the two cell types that correlated with their particular susceptibility to TBEV. Our results thus reveal that cell type-specific innate immunity is likely to contribute to shaping TBEV tropism for human brain cells. They offer a new in vitro model to further study TBEV-induced neuropathogenesis and improve our understanding of the mechanisms by which neurotropic viruses target and damage human brain cells.\n\nAuthor summaryTick-borne encephalitis virus (TBEV), a neurotropic Flavivirus that is responsible for encephalitis in humans, is of growing concern in Europe. Indeed, over the last two decades the number of reported cases has continuously increased and the virus has spread into new geographical areas. Whereas it is well established that neurons are the main target of TBEV in the human brain, the mechanisms that underlie this preferential tropism have not yet been elucidated. Here, we used neuronal/glial cells derived from human fetal neural progenitors to establish and characterize a new in vitro pathological model that mimics major hallmarks of TBEV infection in vivo; namely, neuronal tropism, neuronal death and astrogliosis. Using this highly relevant model, we showed that human neurons and astrocytes were both capable of developing an innate immune response against TBEV, but with dissimilar magnitudes that correlated with differential susceptibility to TBEV. Our results thus revealed that TBEV tropism for subsets of human brain cells is likely to depend on cell-type specific innate immunity. This improves our understanding of the mechanisms by which neurotropic viruses target and damage human brain cells and may help guide development of future therapies.

microbiology↗