Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, USA; Department of Environmental Sciences, University of California, Riverside, CA 92521, USA.
Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA.
Comp Biochem Physiol C Toxicol Pharmacol. 2019 Jun;220:31-35. doi: 10.1016/j.cbpc.2019.03.001. Epub 2019 Mar 6.
During the spring and summer of 2010, the Deepwater Horizon (DWH) oil well released over three million barrels of crude oil into the Gulf of Mexico. As the oil dispersed it contaminated ecosystems that support numerous Gulf species including mahi-mahi (Coryphaena hippurus). The timing of the spill, and location of the surface slick, coincided with the spawning of many species in the region, raising concerns over embryonic and larval exposure. Numerous abnormalities due to crude oil exposure have been documented in fish early life stages, including cardiotoxicity; however, knowledge of the molecular mechanisms that cause these phenotypes is still limited. Several transcriptomic studies have presented cholesterol biosynthesis as one of the top enriched pathways following PAH exposure. In this study we exposed mahi-mahi embryos to DWH oil collected from the surface slick. At exposures ranging from ∑PAH 1.69 μg/L to ∑PAH 5.99 μg/L, the resulting larvae demonstrated significant increases in farnesyl-diphosphate farnesyltransferase 1 (fdft1) and an upward trend in 3-Hydroxy-3-Methylglutaryl-CoA Reductase (hmgcr) expression, genes that encode key enzymes in the cholesterol biosynthetic pathway. In addition to the increased expression of genes in cholesterol biosynthetic pathway, a significant decrease in total cholesterol was observed in larval homogenates, at ∑PAH 8.3 μg/L. These data confirm earlier transcriptomic studies and show that oil may diminish cholesterol and adversely impact numerous cellular functions due to altered membrane stability.
在 2010 年春夏两季，深水地平线（DWH）油井向墨西哥湾泄漏了超过三百万桶原油。随着石油的扩散，它污染了支持许多墨西哥湾物种的生态系统，包括鲯鳅（Coryphaena hippurus）。泄漏的时间和浮油的位置正好与该地区许多物种的产卵期相吻合，这引发了人们对胚胎和幼虫暴露的担忧。由于原油暴露，鱼类早期生活阶段出现了许多异常，包括心脏毒性；然而，导致这些表型的分子机制的知识仍然有限。几项转录组学研究表明，在多环芳烃暴露后，胆固醇生物合成是最丰富的途径之一。在这项研究中，我们将鲯鳅胚胎暴露于从浮油中采集的 DWH 油中。在∑PAH 1.69μg/L 至∑PAH 5.99μg/L 的暴露范围内，结果表明幼虫的法呢基二磷酸法尼基转移酶 1（fdft1）显著增加，3-羟基-3-甲基戊二酰辅酶 A 还原酶（hmgcr）的表达呈上升趋势，这些基因编码胆固醇生物合成途径中的关键酶。除了胆固醇生物合成途径中基因表达增加外，在∑PAH 8.3μg/L 时，幼虫匀浆中的总胆固醇也显著下降。这些数据证实了早期的转录组学研究，并表明由于膜稳定性的改变，油可能会减少胆固醇并对许多细胞功能产生不利影响。
