Region and Cell-Selective Induction of Zbtb16/Plzf by Multiple Stressors in the Adult Murine Hypothalamus.

Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, a neuroendocrine system that regulates responses related to feeding, reproduction, and aggression, among other homeostatic functions. Stressors significantly impact gene expression along the HPA axis and in hypothalamic nuclei that drive it, including the paraventricular nucleus (PVN). To identify genetic regulators of stress responses in the PVN, adult mice underwent 2 h of multi-modal stress before gene expression profiles were analyzed using bulk RNA sequencing. A transcription factor zinc finger and BTB domain containing 16 (Zbtb16), also known as PLZF, was identified as a stress responsive, glucocorticoid receptor (GR) target in the PVN. Zbtb16 mRNA expression was increased by two-fold in male and female mice within 2 h of restraint stress or injection of a synthetic glucocorticoid, dexamethasone (DEX). Immunohistochemistry (IHC) confirmed Zbtb16 protein expression and localization in the PVN following 20 min of restraint stress and 4 h of recovery. Cellular analyses revealed that Zbtb16 was highly expressed in CRH neurons in the PVN, neurons routinely activated post-stress as indicated by colocalization with c-FOS. Adult mice were also exposed to an immune stress by injection of tumor necrosis factor alpha (TNFα) to assess Zbtb16 regulation. Expanded analyses indicated that the cell specificity of Zbtb16 expression was region-specific, colocalizing with CRH neurons in the mid-PVN but more in astrocytes surrounding the PVN. These findings identify Zbtb16 as a glucocorticoid- and cytokine-inducible transcriptional regulator with region- and cell type-specific roles in PVN stress circuitry.