Ethanol toxicity affects olfactory receptor genes in forebrain of fetal mice

Investigating the effects of chronic perinatal alcohol and combined nicotine and alcohol exposure on dopaminergic and non-dopaminergic neurons in the VTA

The ventral tegmental area (VTA) is the origin of dopaminergic neurons and the dopamine (DA) reward pathway. This pathway has been widely studied in addiction and drug reinforcement studies and is believed to be the central processing component of the reward circuit. In this study, we used a well-established rat model to expose mother dams to alcohol, nicotine-alcohol, and saline perinatally. DA and non-DA neurons collected from the VTA of the rat pups were used to study expression profiles of miRNAs and mRNAs. miRNA pathway interactions, putative miRNA-mRNA target pairs, and downstream modulated biological pathways were analyzed. In the DA neurons, 4607 genes were differentially upregulated and 4682 were differentially downregulated following nicotine-alcohol exposure. However, in the non-DA neurons, only 543 genes were differentially upregulated and 506 were differentially downregulated. Cell proliferation, differentiation, and survival pathways were enriched after the treatments. Specifically, in the PI3K/AKT signaling pathway, there were 41 miRNAs and 136 mRNAs differentially expressed in the DA neurons while only 16 miRNAs and 20 mRNAs were differentially expressed in the non-DA neurons after the nicotine-alcohol exposure. These results depicted that chronic nicotine and alcohol exposures during pregnancy differentially affect both miRNA and gene expression profiles more in DA than the non-DA neurons in the VTA. Understanding how the expression signatures representing specific neuronal subpopulations become enriched in the VTA after addictive substance administration helps us to identify how neuronal functions may be altered in the brain.

Toxicogenomic analysis of the pulmonary toxic effects of hexanal in F344 rat

Hexanal is a major component of indoor air pollutants and is a kind of aldehydes; it has adverse effects on human health. We performed an in vivo inhalation study and transcriptomic analysis to determine the mode of toxic actions in response to hexanal. Fischer 344 rats of both sexes were exposed by inhalation to hexanal aerosol for 4 h day^-1 , 5 days week^-1 for 4 weeks at 0, 600, 1000, and 1500 ppm. Throughout our microarray-based genome-wide expression analysis, we identified 56 differentially expressed genes in three doses of hexanal; among these genes, 11 genes showed dose-dependent expression patterns (10 downregulated and 1 upregulated, 1.5-fold, p < 0.05). Through a comparative toxicogenomics database (CTD) analysis of 11 genes, we determined that five genes (CCL12, DDIT4, KLF2, CEBPD, and ADH6) are linked to diverse disease categories such as cancer, respiratory tract disease, and immune system disease. These diseases were previously known for being induced by volatile organic compounds (VOCs). Our data demonstrated that the hexanal-induced dose-dependent altered genes could be valuable quantitative biomarkers to predict hexanal exposure and to perform relative risk assessments, including pulmonary toxicity. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 382-396, 2017.

Expression profiling of microRNAs in lipopolysaccharide-induced acute lung injury after hypothermia treatment

We investigated the expression profiles of miRNAs in acute lung injury (ALI) rats after hypothermia treatment. ALI rats were induced with lipopolysaccharide (LPS) and maintained with hypothermia (HT) or normothermia (NT) for 6 hours. HT attenuated inflammatory cell infiltration in the lung and improved biochemical indicators of multi-organ dysfunction. Nineteen miRNAs were significantly differentially expressed in the HT group compared with the NT group. miR-142, miR-98, miR-541, miR-503, miR-653, miR- 223, miR-323 and miR-196b exhibited opposite patterns of expression between the two groups. These dysregulated miRNAs were mainly involved in the immune and inflammatory response on functional annotation analyses. This study shows that HT has lung protective effects and influences expression profiles of miRNAs in ALI. And dysregulated miRNAs after HT modulate the immune and inflammation in ALI. These results suggest that dysregulated miRNAs play a role in the mechanism of the lung protective effects of HT in ALI.