Effects of polycyclic aromatic hydrocarbons and abiotic stressors on Fundulus grandis cardiac transcriptomics

Following the 2010 Deepwater Horizon oil spill, extensive research has been conducted on the toxicity of oil and polycyclic aromatic hydrocarbons (PAHs) in the aquatic environment. Many studies have identified the toxicological effects of PAHs in estuarine and marine fishes, however, only recently has work begun to identify the combinatorial effect of PAHs and abiotic environmental factors such as hypoxia, salinity, and temperature. This study aims to characterize the combined effects of abiotic stressors and PAH exposure on the cardiac transcriptomes of developing Fundulus grandis larvae. In this study, F. grandis larvae were exposed to varying environmental conditions (dissolved oxygen (DO) 2, 6 ppm; temperature 20, 30 degrees C; and salinity 3, 30 ppt) as well as to a single concentration of high energy water accommodated fraction (HEWAF) (Sigma PAHs 15 ppb). Whole larvaewere sampled for RNA and transcriptional changes were quantified using RNA-Seq followed by qPCR for a set of target genes. Analysis revealed that exposure to oil and abiotic stressors impacts signaling pathways associated with cardiovascular function. Specifically, combined exposures appear to reduce development of the systemic vasculature as well as strongly impact the cardiac musculature through cardiomyocyte proliferation resulting in inhibited cardiac function and modulated blood pressure maintenance. Results of this study provide a holistic view of impacts of PAHs and common environmental stressors on the cardiac system in early life stage estuarine species. To our knowledge, this study is one of the first to simultaneously manipulate oil exposure with abiotic factors (DO, salinity, temperature) and the first to analyze cardiac transcriptional responses under these co-exposures. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study investigates the combined effects of PAHs and abiotic stressors on the cardiac transcriptomes of developing Fundulus grandis larvae. The results show that combined exposures impact signaling pathways associated with cardiovascular function, particularly affecting cardiomyocyte proliferation and leading to inhibited cardiac function. This study provides a comprehensive view of the impacts of PAHs and common environmental stressors on the cardiac system in early life stage estuarine species.