PFOA对斑马鱼胚胎发育、行为和DNA损伤的毒性研究

全氟辛酸(PFOA)是一种分布广泛的环境持久性有机污染物,在野生动物与人体内普遍被检出。目前PFOA发育毒性的特点和机制尚未阐明,已有的研究显示,PFOA毒性与受试物种及性别密切相关。因此,利用不同物种进行PFOA毒性研究对阐明其毒性机制十分重要。本研究选用了斑马鱼这种理想的脊椎动物模型,考察了PFOA暴露对其胚胎发育的自主运动、心跳、行为、细胞凋亡和DNA损伤的影响。研究发现,始于6hpf的PFOA暴露会导致斑马鱼胚胎自主运动异常,心率降低,且具有一定的剂量依赖性;6～24hpf的高浓度的PFOA暴露(>414.0mg·L-1)会导致胚胎发生显著的细胞凋亡,凋亡主要出现在眼部、头部、心脏和尾部。较高浓度的PFOA暴露(165.6mg·L-1)会使仔鱼的光刺激应激行为模式发生变化。此外,PFOA暴露会致使斑马鱼发生DNA损伤,且损伤程度随PFOA浓度的升高而加重,表明PFOA具有一定的基因毒性。上述结果表明,PFOA对斑马鱼胚胎具有发育毒性,具体表现为自主运动异常,心率降低和行为反应能力变弱,同时伴随畸形、细胞凋亡和DNA损伤。

PFOA-Induced Developmental Toxicity, Behavior Change and DNA Damage in Zebrafish Embryos

Perfluorooctanoic acid (PFOA) is an environmentally widespread and persistent chemical, which has been detected in various wildlife species and humans. The developmental toxicity of PFOA has not been well understood, and PFOA toxicity is shown to be species- and sex-dependent. Therefore, it is important to conduct studies on multiple species to better elucidate the mechanisms of PFOA-induced toxicity. Zebrafish, a well-established vertebrate model, was selected, and the impact of PFOA exposure on spontaneous movement, heart rate, swimming behavior, malformation, cellular apoptosis and DNA damage of zebrafish embryos was determined using various experimental approaches in this study. Results showed that exposure to PFOA from 6 hpf led to altered spontaneous movement and decreased heart rate in zebrafish with a dose-dependent manner. Cellular death was induced by high-concentration PFOA exposure (>414.0 mg·L^-1) from 6 to 24 hpf, as apoptotic cells were detected in the eye, head, heart and tail regions. The light stimulation test indicated that behavioral responses of zebrafish larvae were altered by PFOA exposure at 165.6 mg·L^-1, but not at lower concentrations. Meanwhile, DNA damage was detected in zebrafish embryos following exposure to PFOA with a dose-dependent manner, suggesting a genotoxic effect of PFOA. In conclusion, it is demonstrated that PFOA-induced developmental toxicity in zebrafish embryos was characterized by altered spontaneous movements and behavioral responses, reduced heart rates, occurrence of malformations as well as increased cellular death and DNA damage.