017 - Arrest in Neural Progenitor Maturation Mediates Neurodevelopmental Disorders from Intrauterine Growth Restriction and Gene Inactivation

Publication Number: 17.3707

Christiana Santiago, UCLA Mattel Childrens Hospital, Los Angeles, CA, United States; Bo-Chul Shin, UCLA, Los Angeles, CA, United States; Shubhamoy Ghosh, University of California, Los Angeles David Geffen School of Medicine, Los Angeles, CA, United States; Tomoko Daida, University of California, Los Angeles David Geffen School of Medicine, Los Angeles, CA, United States; Yasemin Ozay, UCLA Mattel Childrens Hospital, Los Angeles, CA, United States; Devaskar Sherin, UCLA, Los Angeles, CA, United States

Background: Maternal malnutrition, a global health problem, causes intrauterine growth restriction (IUGR) with long-term cognitive effects on the offspring. These maternal dietary influences create a “second hit” alongside certain genetic disorders that serve as the “primary hit,” affecting neuropsychiatric outcomes. We studied a neuronal GLUT3 mutation linked to seizures and microcephaly, examining the effects of prenatal maternal calorie restriction (50% [MoMCR] vs. 0% [CON]) in this “two-hit model” on embryonic neurodevelopment.

Objective: Our objective was to test if 50% prenatal caloric restriction affects neurodevelopment in a neural-specific GLUT3 frame shift mutation, emphasizing the "second hit" from caloric restriction.

Design/Methods: We studied wild type (wt) MoMCR (n=12) mice against controls (n=12), as well as GLUT3 homozygous null mice (Emx1-glut3(-/-), n=12) versus floxed glut3(+/+) (n=12), both linked to anxiety/ADHD in the adult offspring (Tomi et al., 2012; Shin et al., 2021). We performed single nucleus (Sn)-RNA sequencing using 10X genomics, followed by computational analysis (FDR=5%) and cell annotation of embryonic day 19 (E19) cerebral cortices, alongside immunohistochemistry (IHC) and Western blot (WB) analyses. Statistical analysis included ANOVA with post-hoc Tukey’s test for more than two groups, or Student’s t-test for two-group comparisons (P < 0.05).

Results: At E19 (term ~E21), body and brain weights were similar across sexes, so data were combined. MoMCR reduced body and brain weights by ~50% compared to CON (both p< 0.0001). Litter sizes were unaffected. Emx1-glut3(-/-) mice showed similar reductions to that of MoMCR (both p< 0.0001). SnRNA-seq analysis revealed increased neural progenitors and immature neurons in MoMCR versus CON, but decreased radial glial cells, oligodendrocyte precursors, and mature neurons. E19 Emx1-glut3(-/-) mice showed increases in astrocytes, oligodendrocytic precursors, and migrating interneurons. WB analysis showed no significant changes. IHC indicated reduced Sox2+ neural stem cells, Ki67+ proliferative cells, and GLUT3 positive neural cells in both E19 MoMCR and Emx1-glut3(-/-) mice compared to their respective controls.

Conclusion(s): MoMCR reduces body and brain weights at E19 in wt and Emx1-glut3(-/-) genotypes. Both genotypes impaired maturation of neural stem cells, reduced mature neurons, and increased astrocytes, oligodendrocytes, and interneurons. Ongoing studies are exploring embryonic cortical composition under "double hit" conditions involving MoMCR in the Emx1-glut3(-/-) genotype. Supported by NICHD HD81206.