PDF(Pubmed)
Abstract：
In addition to circulating haemocytes, the immune system of the solitary ascidian Ciona robusta relies on two organs, the pharynx and the gut, and encompasses a wide array of immune and stress-related genes. How the pharynx and the gut of C. robusta react and adapt to environmental stress was assessed upon short or long exposure to hypoxia/starvation in the absence or in the presence of polystyrene nanoplastics. We show that the immune response to stress is very different between the two organs, suggesting an organ-specific immune adaptation to the environmental changes. Notably, the presence of nanoplastics appears to alter the gene modulation induced by hypoxia/starvation in both organs, resulting in a partial increase in gene up-regulation in the pharynx and a less evident response to stress in the gut. We have also assessed whether the hypoxia/starvation stress could induce innate memory, measured as gene expression in response to a subsequent challenge with the bacterial agent LPS. Exposure to stress one week before challenge induced a substantial change in the response to LPS, with a general decrease of gene expression in the pharynx and a strong increase in the gut. Co-exposure with nanoplastics only partially modulated the stress-induced memory response to LPS, without substantially changing the stress-dependent gene expression profile in either organ. Overall, the presence of nanoplastics in the marine environment seems able to decrease the immune response of C. robusta to stressful conditions, hypothetically implying a reduced capacity to adapt to environmental changes, but only partially affects the stress-dependent induction of innate memory and subsequent responses to infectious challenges.
摘要：
除了循环血细胞,孤独的海鞘Cionarobusta的免疫系统依赖于两个器官，咽部和肠道,并包含一系列与免疫和压力相关的基因。在不存在或存在聚苯乙烯纳米塑料的情况下，在短期或长期暴露于缺氧/饥饿时，评估了C.robusta的咽部和肠道如何反应和适应环境胁迫。我们表明，两个器官对压力的免疫反应非常不同，表明对环境变化的器官特异性免疫适应。值得注意的是,纳米塑料的存在似乎改变了两个器官中缺氧/饥饿诱导的基因调节，导致咽部基因上调部分增加，而肠道对压力的反应不那么明显。我们还评估了缺氧/饥饿应激是否可以诱导先天记忆，测量为响应于随后用细菌剂LPS攻击的基因表达。在攻击前一周暴露于压力诱导对LPS的反应发生实质性变化，随着咽部基因表达的普遍减少和肠道的强烈增加。与纳米塑料的共同暴露仅部分调节了应激诱导的对LPS的记忆反应，而不会显著改变任一器官的应激依赖性基因表达谱。总的来说,海洋环境中纳米塑料的存在似乎能够降低C.robusta对压力条件的免疫反应，假设意味着适应环境变化的能力下降，但仅部分影响先天记忆的压力依赖性诱导以及随后对感染性挑战的反应。
