Decreased hippocampal cholinergic neurostimulating peptide precursor protein associated with stress exposure in rat...

The stress response alters behavior, autonomic function, and secretion of multiple hormones, including corticotropin-releasing factor, adrenocorticotropin hormone, and cortisol, through the hypothalamic-pituitary-adrenal axis. Constitutive stress responses lead to a number of psychiatric disorders, including depression, posttraumatic stress disorder, Alzheimer's disease (AD), and other anxiety disorders through increased stress hormones and other unknown factors. Here, we performed a proteomic analysis of rat brain exposed to restraint stress compared with a nonstress group by using 2D-DIGE and MALDI-TOF analysis. Several proteins were identified by peptide mass fingerprint (PMF), including down-regulated hippocampal cholinergic neurostimulating peptide precursor protein (HCNP-pp). The current study demonstrates that HCNP-pp mRNA and protein expression are decreased in rat hippocampus after stress exposure. The level of HCNP-pp in H19-7, a rat hippocampal cell line, significantly decreases with dexamethasone treatment, a synthetic glucocorticoid. Thus, this finding suggests that HCNP-pp expression may decrease in response to stress exposure. Decreased HCNP-pp from stress exposure may result in lower levels of HCNP that might contribute to a loss of acetylcholine production.