mRNA and microRNA Profiles in the Amygdala Are Relevant to Susceptibility and Resilience to Psychological Stress Induced in Mice

Severe or prolonged stress increases the risk for developing psychopathological disorders. An individual's perception of stress exposure varies greatly, as do its consequences. Numerous individuals demonstrate resilience to psychological stress. The mRNA and microRNA profiles of stress susceptibility and resilience to induced psychological stress in the amygdala remain to be elucidated. In this work, psychological stress was induced in an observer mouse by witnessing a similar individual under attack by an aggressor. After 5 days of psychological stress, the degree of fear memory and anxiety in mice was measured by a social interaction test and elevated plus-maze (EPM) test. mRNA and microRNA profiles were quantified by high-throughput sequencing in amygdala tissue harvested from Control, Susceptible and Resilient mice. In the amygdala of Susceptible versus Resilient mice, the upregulation of peptide, thyrotropin-releasing hormone, ECM receptors, glutamatergic synapse, cytokine-cytokine receptor interaction, long-term depression, PI3K-Akt, oxytocin, GnRH, HIF-1, estrogen, and calcium signaling pathways may be related to psychological stress-induced susceptibility, and their downregulation may be related to resilience. The downregulation of adrenergic synapse, adherens junction, Wnt, sphingolipid, B cell receptor, cAMP, Rap1, and Toll-like receptor signaling pathways may be related to psychological stress-induced susceptibility, and the upregulation may be related to resilience. Results by sequencing of mRNA and microRNA profiles are consistent, in which some are validated by qRT-PCR and dual-luciferase reporter assay. Susceptibility and resilience induced by psychological stresses are caused by the imbalanced regulation of different synapses and signaling pathways in the amygdala.