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Biology subjects

Kozhevnikova, E. N.

Publications and source records attributed to Kozhevnikova, E. N..

2 recordsLinked to original sources

Morphofunctional Characterization of Colonic Organoids from Muc2-/- Mice

Inflammatory bowel diseases (IBD) remain a serious challenge in gastroenterology, and disruption of the mucus barrier integrity plays a key role in their pathogenesis. The Muc2 protein is the main structural component of the protective mucus layer in the colon, and mice with a knockout of the Muc2 gene (Muc2-/-) serve as a classic model for studying IBD. In the present work, three-dimensional cultured organoids derived from the colonic crypts of Muc2-/- mice and their wild-type littermates (Muc2/) were used for a comparative analysis of their morphofunctional characteristics. Using morphometric analysis and flow cytometry to identify the Lgr5 stem cell population, we demonstrated that organoids obtained from Muc2-/- animals are characterized by a smaller size, absence of crypt-like structures, increased proliferative activity, and a reduced proportion of stem cells compared to organoids derived from wild-type littermates. The obtained data indicate that Muc2 deficiency and the associated intestinal inflammation affect epithelial architecture and stem cell balance outside the inflammatory environment in vitro. Thus, 3D colonic organoids derived from Muc2 knockout mice represent a promising tool for studying IBD and testing novel therapeutic strategies.

cell biology↗

Hao-Fountain syndrome protein USP7 controls neuronal differentiation via BCOR-ncPRC1.1

Pathogenic variants in the ubiquitin-specific protease 7 (USP7) gene cause a neurodevelopmental disorder called Hao-Fountain syndrome. However, which of USP7s pleiotropic functions are relevant for neurodevelopment remains unclear. Here, we present a combination of quantitative proteomics, transcriptomics and epigenomics to define the USP7 regulatory circuitry during neuronal differentiation. USP7 activity is required for the transcriptional programs that direct both differentiation of embryonic stem cells into neural stem cells, and the neuronal differentiation of SH-SY5Y neuroblastoma cells. USP7 controls the dosage of the Polycomb H2AK119ub1 ubiquitin ligase complexes ncPRC1.1 and ncPRC1.6. Loss-of-function experiments revealed that BCOR-ncPRC1.1, but not ncPRC1.6, is a key effector of USP7 during neuronal differentiation. Indeed, BCOR-ncPRC1.1 mediates a major portion of USP7-dependent gene regulation during this process. Besides providing a detailed map of the USP7 regulome during neurodifferentiation, our results suggest that USP7 and ncPRC1.1-associated neurodevelopmental disorders involve dysregulation of a shared epigenetic network.

molecular biology↗