GSE167568
Effect of in utero nicotine exposure and elastase instillation on transcriptomic profile at post-elastase day 21 in mice
Purpose: The goal of this study is to address if in utero and early life nicotine exposure can prime the offspring to be more succetible to develop emphysema in adulthood Methods:  A mouse model of two hits: a prenatal hit and a later insult delivered in adulthood was used in this study. In brief, Nicotine (200 mg/L) was supplied immediately after mating and administered to the females in drinking water supplemented with 2% saccharin for the whole period of gestation and until the post-natal day 16 (nicotine group). As a control, we used drinking water with 2% saccharin (control group). Pups born from nicotine-exposed or control mothers were intranasally instilled with elastase or saline at the age of 11 weeks and sacrificed at post-elastase day (ped) 21. Lungs were collected at ped21 and laser dissected to separate the emphysematous and normal-looking tissue from elastase-instilled lungs. The RNA was then extracted and submited to RNAseq analysis. We had 6 different groups: two for saline instilled animals (normal_control_saline (C-S),  normal_nicotine-saline (N-S)), and for elastase-instilled animals we had 4 groups: 2 for emphysematous regions (emphysema_ControlElastase (eC-E) and emphysema_NicotineElastase(eN-E)) and 2 for normal regions (normal_ControlElastase(nC-E) and normal_NicotineElastase(nN-E)). Results: Nicotine upregulated zero and 46 genes and downregulated 2 and 29 in saline and elastase instilled respectivelly. Elastase upregulated zero and 3 and downregulated 1 and 1 genes in controls and nicotine-pretreated samples respectively. Pathway analysis performed with differentially expressed genes due to nicotine-pretreatment in elastase instilled animals with MetaCore software (https://portal.genego.com/) (fold change of 2 or more and p<0.05) revealed downregulation of the several immune system related pathways, gamma-secretase proteolitic pathway, ubiquitin-proteasomal pathway, notch signaling pathway and others. Conclusions: Our results identify the the early nicotine exposure as an important insult that affects the proteomic signature at ped21 Overall design: Lung mRNA profiles of wild type (WT) C57BL/6J mouse lungs were generated using single-end reads with Illumina HiSeq