Paterno, R. | Search bioRxiv

bioRxiv2024

Host brain environmental influences on transplanted medial ganglionic eminence progenitors

Interneuron progenitor transplantation can ameliorate disease symptoms in a variety of neurological disorders. This strategy is based on transplantation of embryonic medial ganglionic eminence (MGE) progenitors. Elucidating host brain environment influences on interneuron progenitors as they integrate is critical to optimizing this strategy across different disease states. Here, we systematically evaluated age and brain region influences on survival, migration and differentiation of transplant-derived cells. We find that early postnatal MGE transplantation yields superior survival and more extensive migratory capabilities compared to juvenile or adult. MGE progenitors migrate more widely in cortex compared to hippocampus. Maturation to interneuron subtypes is regulated by age and brain region. MGE progenitors transplanted into dentate gyrus sub-region of early postnatal hippocampus can differentiate into astrocytes. Our results suggest that host brain environment critically regulates survival, spatial distribution and maturation of MGE-derived interneurons following transplantation. These findings inform and enable optimal conditions for interneuron transplant therapies.

neuroscience↗

bioRxiv2023

Spontaneous Mutation in 2310061I04Rik Results in Reduced Expression of Mitochondrial Genes and Impaired Brain Myelination

Here, we describe a spontaneous mouse mutant with a deletion in a predicted gene 2310061I04Rik (Rik) of unknown function located on chromosome 17. A 59 base pair long deletion occurred in the first intron of the Rik gene and disrupted its expression. Riknull mice were born healthy and appeared anatomically normal up to two weeks of age. After that, these mice showed inhibited growth, ataxic gait, and died shortly after postnatal day 24 (P24). Transcriptome analysis at P14 and P23 revealed significantly reduced expression of mitochondrial genes in Riknull brains compared to wild type controls including mt-Nd4, mt-Cytb, mt-Nd2, mt-Co1, mt-Atp6, and others. Similarly, genes specific for myelinating oligodendrocytes also showed reduced expression in P23 Riknull brains compared to controls. Histological examination of anterior thalamic nuclei demonstrated decreased myelination of anteroventral nuclei but not of anterodorsal nuclei in P23 Riknull mice. Myelination of the anterior commissure was also impaired and displayed extensive vacuolation. Consistent with these findings, immunohistochemistry showed reduced expression of Opalin, a glycoprotein expressed in differentiated oligodendrocytes. Taken together, these results suggest that RIK is important for oligodendrocyte maturation, and myelination in the developing brain.

neuroscience↗