Molecular and Genetic Laboratory, College of Life Science, Henan Normal University, 46# East of Construction Road, Xinxiang, 453007, Henan, China.
Molecular and Genetic Laboratory, College of Life Science, Henan Normal University, 46# East of Construction Road, Xinxiang, 453007, Henan, China.
Aquat Toxicol. 2023 May;258:106483. doi: 10.1016/j.aquatox.2023.106483. Epub 2023 Mar 11.
The negative consequences of microplastics pollution on the health of aquatic species have garnered extensive attention. However, the mechanisms through which microplastics may cause harm in the reproductive processes of fish remain unknown. For this study, Cyprinus carpio var. was subjected to four treatments with various concentrations of PVC microplastics for 60 days, through food rationed diets (no plastic control, 10%, 20% and 30%). The gonadosomatic indices, gonad and brain histologies, sex hormone levels, and transcriptional and translational genes in the hypothalamic-pituitary-gonadal (HPG) axes of both sexes were observed. According to the results, the gonadosomatic indices were significantly decreased, gonadal development was delayed, and the level of estradiol (E2) in the females was significantly elevated. In addition, the expression levels of genes associated with the HPG axis in the brains and gonads (gnrh, gtha1, fshβ, cyp19b, erα, vtg1, dmrt1, sox9b, and cyp19a) and the transcription levels of apoptosis-related genes in the brains and gonads (caspase3, bax, and bcl-2) exhibited significant changes. Further investigation revealed that the translation levels of genes linked to sex differentiation and sex steroid hormone (cyp19b and dmrt1) were significantly altered. These findings indicated that PVC likely microplastics may have a negative impact on the reproductive system of Cyprinus carpio var. by inhibiting gonadal development, affecting the gonad and brain structures, and altering the levels of steroid hormones and the expression of HPG axis-related genes. This work provides new insights into the toxicity of microplastics in aquatic organisms by revealing that PVC microplastics are a potential threat against the reproduction of fish populations.
微塑料污染对水生物种健康的负面影响已引起广泛关注。然而，微塑料在鱼类生殖过程中产生危害的机制尚不清楚。在这项研究中，鲫鱼被分为四组，分别投喂不同浓度 PVC 微塑料的食物（无塑料对照、10%、20%和 30%），持续 60 天。观察了雌雄两性的性腺指数、性腺和脑组织学、性激素水平以及下丘脑-垂体-性腺（HPG）轴的转录和翻译基因。结果表明，性腺指数显著下降，性腺发育迟缓，雌性雌激素（E2）水平显著升高。此外，大脑和性腺中与 HPG 轴相关的基因（gnrh、gtha1、fshβ、cyp19b、erα、vtg1、dmrt1、sox9b 和 cyp19a）以及大脑和性腺中与细胞凋亡相关的基因（caspase3、bax 和 bcl-2）的表达水平均发生显著变化。进一步研究表明，与性别分化和性类固醇激素（cyp19b 和 dmrt1）相关的基因的翻译水平也发生了显著改变。这些发现表明，PVC 微塑料可能通过抑制性腺发育、影响性腺和脑组织结构以及改变类固醇激素水平和 HPG 轴相关基因的表达，对鲫鱼的生殖系统产生负面影响。这项工作通过揭示 PVC 微塑料是鱼类种群繁殖的潜在威胁，为水生生物中微塑料的毒性提供了新的见解。
