Effect of acute and chronic social stress on hippocampal transcriptome in mice

We investigated gene expression in mice subjected to acute and chronic social stress of different duration. Microarray data showed that chronic stress affected genes involved in function of vascular system (Alas2, Hbb-b1, Hba-a2, Hba-a1), injury response (Vwf, Mgp, Cfh, Fbln5, Col3a1, Ctgf) and inflammation (Isg20, Ctla2a, Ctla2b,Lcn2, Lrg1, Rsad2,S100a8, S100a9). Review of the literature revealed that the most frequently regulated genes (up or down) were Igfbp2, Igf2, Prlr, App, Cdh1, Col1A1, Clic6, Enpp2, Sostdc1,Itgb6, Mef2c, Spp1, and Zeb2. Obtained results suggest that stress may affect brain functions through the stress-induced dysfunction of the vascular system. Some of the key genes revealed by the review of published data participate both in the response to injury and in the mechanism of learning and memory. These genes may constitute a link between stress and stress-induced memory impairments. An important issue raised by our work is also the risk of tissue contamination with choroid plexus. Such contamination would result in consistent up- or down-regulation of genes, such as Ttr, Igf2, Igfbp2, Prlr, Enpp2, Sostdc1, 1500015O10RIK (Ecrg4), Kl, Clic6, Kcne2, F5, Slc4a5, and Aqp1. This is analysis of 24 hippocampal RNA samples. Each sample consisted of equal amounts of total RNA from 3 mice subjected to the same experimental condition. Comparisons: acute stress vs. acute control (unstressed), stress-8 days vs. control-8 days, stress-13 days vs. control-13 days, stress-13 days+5 days of rest vs. control-13 days+5 days of rest. 3 biological replicates in each comparison. Dye swap (technical replicate) was included for each biological replicate.