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Masset, G.

Publications and source records attributed to Masset, G..

2 recordsLinked to original sources

Organoid-to-organoid transplantation and pro-neurogenic treatment promote graft integration and neuronal repair in a human ischemic model

Neuronal loss resulting from brain injury and neurodegenerative diseases currently lacks effective regenerative therapies. While neurogenic compounds and cell transplantation hold promise, clinical translation is hindered by poor graft integration and limited cell survival. Here, we developed a novel organoid-to-organoid transplantation model using human pluripotent stem cell-derived cortical organoids (hCOs) to evaluate a dual cell transplantation and pro-neurogenic strategy for brain repair. We demonstrate that pro-neurogenic treatment with ER272 stimulates early-stage hCO growth and enhances neurogenesis through a PKC- and Notch-dependent pathway. Mechanistically, ER272 upregulates genes associated with extracellular matrix, cell adhesion and growth factor signaling. Notably, combining early-stage hCO transplantation with ER272 treatment significantly enhanced graft integration and improved neuronal repair in an ischemic-like model of late-stage host hCOs. This novel human organoid-to-organoid platform offers a robust translational tool to test regenerative therapies and highlight the potential of combining cell transplantation with pro-neurogenic stimulation for the treatment of neurological conditions associated with neuronal loss.

neuroscience↗

SARS-CoV2 infection triggers reactive astrocyte states and inflammatory conditions in long-term Human Cortical Organoids

SARS-CoV2, severe acute respiratory syndrome coronavirus 2, is frequently associated with neurological manifestations. Despite the presence of mild to severe CNS-related symptoms in a cohort of patients, there is no consensus whether the virus can infect directly brain tissue or if the symptoms in patients are a consequence of peripheral infectivity of the virus. Here, we use long-term human stem cell-derived cortical organoids to assess SARS-CoV2 infectivity of brain cells and unravel the cell-type tropism and its downstream pathological effects. Our results show consistent and reproducible low levels of SARS-CoV2 infection of astrocytes, deep projection neurons, upper callosal neurons and inhibitory neurons in 6 months human cortical organoids. Interestingly, astrocytes showed the highest infection rate among all infected cell populations that led to increased presence of reactive states. Further, transcriptomic analysis revealed overall changes in expression of genes related to cell metabolism, astrocyte activation and, inflammation and further, upregulation of cell survival pathways. Thus, local and minor infectivity of SARS-CoV2 in the brain may induce widespread adverse effects and may lead to resilience of dysregulated neurons and astrocytes within an inflammatory environment.

neuroscience↗