Changes in hippocampal inflammatory-related and redox enzyme genes in response to sub-acute restraint stress: Additional dataset

This data article presents complementary results pertaining to the research article entitled “Sub-acute restraint stress progressively increases oxidative/nitrosative stress and inflammatory markers while transiently upregulating antioxidant gene expression in the rat hippocampus” (Chen et al., 2018). The present article provides additional gene expression data of selected neuroinflammatory markers and regulatory enzymes involved in oxidation-reduction reactions. Male Wistar rats aged 7–8 weeks were exposed to control, 1, 2, or 3 episodes of 6-h restraint stress in the light cycle after which the whole brain was quickly removed and the hippocampus excised for relative gene expression analysis. Specifically, mRNA levels of inflammatory regulators including allograft inflammatory factor 1, class II major histocompatibility complex, integrin alpha M, interferon gamma, and prostaglandin-endoperoxide synthase 2 were analyzed by real-time PCR. The gene expression of redox regulatory enzymes including glutathione peroxidase 1, glutathione peroxidase 4, superoxide dismutase 1, superoxide dismutase 2, myeloperoxidase, and NADPH oxidase subunit P47phox were also determined. These data provide useful insights in the molecular basis of inflammatory and redox regulation in the hippocampus following a short term to repeated psychological challenge in rats.

Male Wistar rats were randomly allocated into treatment groups of no stress (unstressed), acute (1 Day, single time of 6 h) and repeated (2 and 3 Days, 6 h/day) from 9.00 to 15.00 h using adjustable wire mesh restrainers. At the end of each treatment, whole brain was rapidly removed, and the hippocampus was cryo-dissected for relative gene expression analyses.

Experimental features
Total RNA was extracted from each isolated hippocampal tissue, reversed transcribed to cDNA, and the relative expression of targeted genes was determined by real-time PCR.

Data source location
School of Biomedical Sciences, The University of Queensland, Brisbane, Australia Data accessibility The data are available within this article.

Value of the data
Allograft inflammatory factor 1 and integrin alpha M mRNA expression data can be used to demonstrate the regulatory hierarchy of microglial activation markers at the transcriptional level in the hippocampus following repeated stress.
MHC class II transactivator, interferon gamma, and myeloperoxidase mRNA expression data can be used to indicate stress induces microglial activation.
These data provide evidence for temporal dynamics of neuroinflammatory and antioxidant regulation following stress.

Experimental animals
The University of Queensland Animal Ethics Committee approved all experimental procedures under approval number SBS/456/14/URG. Individually housed male Wistar rats (Rattus norvegicus) aged 7-8 weeks were sourced from The University of Queensland Biological Resources and maintained within the Australian Institute of Biotechnology and Nanotechnology animal facility. Rats were housed under standard laboratory conditions (22 7 2°C; 55 7 5% humidity) with a 12:12 h lightdark cycle (lights on at 07.00 h) and ad libitum access to standard rat chow and water. Prior to experimentation, rats were habituated to human handling for 10 min per day over six days and on each experimental day were transported to an experimental room within the same animal facility for acclimation one hour prior to any experimental procedures.

Experimental protocol
Treatment groups consisted of unstressed, acute (1 Day, single time of 6 h) and repeated (2 and 3 Days, 6 h/day) restraint from 9.00 to 15.00 h (n ¼ 8 per group) using restrainers described previously from our laboratory [2]. Control animals were deprived of food and water for the 6-h experimental period. Rats were subsequently overdosed with Pentobarbital Sodium (intraperitoneal injection: Lethabarb, 100 mg/kg, Virbac, Peakhurst, Australia) and the brain was quickly removed and snap-frozen for storage at À 80°C. The hippocampus was isolated from brains sectioned on a cryostat and stored at À 80°C for relative gene expression analyses.

Statistical analysis
Data were analyzed using statistical software GraphPad Prism (Version 7.04, GraphPad Software Inc., San Diego, CA, USA). Data were first analyzed for normality using the Brown-Forsythe test. Oneway ANOVA with Fisher's least significant difference test were used to compare normally distributed data. A non-parametric Kruskal-Wallis ANOVA with Dunn's test was used for data with significantly different standard deviations. All comparisons were made against the unstressed group of animals. Results were expressed as mean 7 standard error of the mean ( 7 SEM) and p-values less than 0.05 were considered statistically significant.