Mechanism of earthquake simulation as a prenatal stressor retarding rat offspring development and chinese medicine correcting the retardation: hormones and gene-expression alteration

Abstract

We aimed to investigate the mechanism of shaking as a prenatal stressor impacting the development of the offspring and Chinese medicines correcting the alterations. Pregnant rats were randomized into earthquake simulation group (ESG), herbal group (HG) which received herbal supplements in feed after shaking, and control group (CG). Findings revealed body weight and open field test (OFT) score of ESG offspring were statistically inferior to the CG and HG offspring. The corticosterone levels of ESG were higher than those of CG but not than HG. The dopamine level of ESG was slightly lower than that of the CG and of HG was higher than that of ESG. The 5-HT of ESG was higher than CG and HG. The growth hormone level of the ESG was significantly lower than ESG but not than CG. Gene expression profile showed 81 genes upregulated and 39 genes downregulated in ESG versus CG, and 60 genes upregulated and 28 genes downregulated in ESG versus HG. Eighty-four genes were found differentially expressed in ESG versus CG comparison and were normalized in ESG versus HG. We conclude that maternal shaking negatively affected physical and nervous system development, with specific alterations in neurohormones and gene expression. Chinese herbal medicine reduced these negative outcomes.

Figure 1

Mean plot of body weight. According to the ANOVA for Repeated Measurement, the body weight of ESG offspring were statistically all inferior to the CG offspring despite in Day 10 (P < 0.05). The body weight HG offspring were statistically superior to the ESG offspring despite in Day 5 (P < 0.05); The body weight HG in Day 15, Day 20 and Day 25 were statistically superior to the CG (P < 0.05).

Figure 2

Box plot of OFT in the comparison between CG, ESG, and HG. ESG showed less scores than CG (P < 0.05) and HG (P < 0.05).

Figure 3

ELISA outcomes of corticosterone, dopamine, 5-HT, and growth hormone. (a) ANOVA test for the corticosterone showed P = 0.027 in CG versus ESG, P = 0.491 in CG versus HG, and P = 0.111 in ESG versus HG. (b) ANOVA test for the dopamine showed P = 0.065 in CG versus ESG, P = 0.805 in CG versus HG, and P = 0.039 in ESG versus HG. (c) ANOVA test for 5-HT showed P = 0.000 in CG versus ESG, P = 0.004 in CG versus HG, and P = 0.013 in ESG versus HG. (d) ANOVA test for the growth hormone showed P = 0.135 in CG versus ESG, P = 0.034 in CG versus HG, and P = 0.001 in ESG versus HG.

Figure 4

Heat map of the differently expressed genes. R2_1_NS, R2_2_NS, and R2_3_NS refer to ESG and R4_1_NS, R4_2_NS, R4_3_NS to CG.

Figure 5

Heat map of the differently expressed genes. R2_1_NS, R2_2_NS, and R2_3_NS refer to ESG and R3_1_NS, R3_2_NS, R3_3_NS to HG.

Figure 6

RT-PCR validation of the selected four genes from gene expression profile chips, that is, Irf7, Ninj2, and Plxnc1, and Isca1. ΔΔCt < 0 indicates the target genes were hyperexpressed in ESG/HG comparing with CG while ΔΔCt > 0 indicates the target genes were hypoexpressed in ESG/HG comparing with CG. FC > 2 indicates the target genes were hyperexpressed in ESG/HG comparing with CG while FC < 0.5 indicates the target genes were hypoexpressed in ESG/HG comparing with CG.