Concurrent Collection of Fetal Murine Brain and Serum to Assess Effects of Maternal Diet on Nutrition and Neurodevelopment in Neurofibromatosis Type 1.

Maternal diet-induced obesity has been demonstrated to alter neurodevelopment in offspring, which may lead to reduced cognitive capacity, hyperactivity, and impairments in social behavior. Patients with the clinically heterogeneous genetic disorder Neurofibromatosis Type 1 (NF1) may present with similar deficits, but it is currently unclear whether environmental factors such as maternal diet influence the development of these phenotypes, and if so, the mechanism by which such an effect would occur. To enable evaluation of how maternal obesogenic diet exposure affects systemic factors relevant to neurodevelopment in NF1, we have developed a method to simultaneously collect non-hemolyzed serum and whole or regionally micro-dissected brains from fetal offspring of murine dams fed a control diet versus a high-fat, high-sucrose diet. Brains were processed for cryosectioning or flash frozen to use for subsequent RNA or protein isolation; the quality of the collected tissue was verified by immunostaining. The quality of the serum was verified by analyzing macronutrient profiles. Using this technique, we have identified that maternal obesogenic diet increases fetal serum cholesterol similarly between WT and Nf1-heterozygous pups.

Neurotrophin signaling is a central mechanism of salivary dysfunction after irradiation that disrupts myoepithelial cells.

The mechanisms that prevent regeneration of irradiated (IR) salivary glands remain elusive. Bulk RNAseq of IR versus non-IR human salivary glands showed that neurotrophin signaling is highly disrupted post-radiation. Neurotrophin receptors (NTRs) were significantly upregulated in myoepithelial cells (MECs) post-IR, and single cell RNAseq revealed that MECs pericytes, and duct cells are the main sources of neurotrophin ligands. Using two ex vivo models, we show that nerve growth factor (NGF) induces expression of MEC genes during development, and upregulation of NTRs in adult MECs is associated with stress-induced plasticity and morphological abnormalities in IR human glands. As MECs are epithelial progenitors after gland damage and are required for proper acinar cell contraction and secretion, we propose that MEC-specific upregulation of NTRs post-IR disrupts MEC differentiation and potentially impedes the ability of the gland to regenerate.