Lin Wang, Liao Ling, Ling Ling, Zou Wansheng, Shi Pengling, Wang Suqin, Yang Pinhong, Yang Jifeng
College of Life and Environmental Sciences, Hunan University of Arts and Science, Changde, 415000, China; Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, 650500, China; Hunan Provincial Key Laboratory for Molecular Immunity Technology of Aquatic Animal Diseases, Changde, 415000, China.
College of Life and Environmental Sciences, Hunan University of Arts and Science, Changde, 415000, China.
Fish Shellfish Immunol. 2025 Jul;162:110370. doi: 10.1016/j.fsi.2025.110370. Epub 2025 Apr 25.
Microcystin-LR (MC-LR), a toxin produced by cyanobacterial blooms, poses a significant threat to aquatic animals and humans. Biochar (BC), known for its high adsorption capacity, is increasingly being utilized to remove hazardous pollutants from aquatic environment. In the present study, we conducted a full factorial experiment to investigate the potential immunotoxicity in male zebrafish (Danio rerio) exposed to environmentally relevant levels of MC-LR (0, 1, 5, 25 μg/L) and rice straw-derived BC (0, 100 μg/L) for 30 d. The findings revealed that subchronic MC-LR exposure caused concentration-dependent splenic histopathological injuries, characterized by an augmentation of melano-macrophage centers, edematous mitochondria, and vacuolation. While the presence of BC mitigated the inflammatory response and mitochondrial damage in the combined groups. Furthermore, in contrast to the group solely exposed to 25 μg/L MC-LR, decreased levels of interleukin 1β (IL1β), tumor necrosis factor α (TNFα), and interleukin 6 (IL6) as well as significant downregulation of inflammation and immune-related genes (tlr4a, myd88, p38a, tnfα) were noticed in the corresponding co-exposure group, which confirmed that BC can reduce MC-LR-induced inflammatory response. Concurrently, a significant increase in complement C3 (C3) content, along with higher splenic c3b expression levels, was observed in the MC-LR-co-BC group in relative to the group exposed solely to MC-LR, suggesting that BC alleviated MC-LR-induced innate immune inhibition. Our results also demonstrated that BC can decrease MC-LR contents in both water and spleen, thereby alleviating MC-LR-induced inflammation and innate immune inhibition via the MyD88-dependent toll-like receptor (TLR/MyD88) signaling pathway in male zebrafish. Our results underscore the potential of BC to mitigate the deleterious impacts of MC-LR on aquatic organisms in blooms-contaminated water.
微囊藻毒素-LR（MC-LR）是一种由蓝藻水华产生的毒素，对水生动物和人类构成重大威胁。生物炭（BC）以其高吸附能力而闻名，越来越多地被用于从水生环境中去除有害污染物。在本研究中，我们进行了一项全因子实验，以调查暴露于环境相关水平的MC-LR（0、1、5、25μg/L）和稻草衍生的BC（0、100μg/L）30天的雄性斑马鱼（Danio rerio）的潜在免疫毒性。研究结果表明，亚慢性MC-LR暴露导致浓度依赖性的脾脏组织病理学损伤，其特征为黑素巨噬细胞中心增加、线粒体水肿和空泡化。而BC的存在减轻了联合组中的炎症反应和线粒体损伤。此外，与仅暴露于25μg/L MC-LR的组相比，相应的共暴露组中白细胞介素1β（IL1β）、肿瘤坏死因子α（TNFα）和白细胞介素6（IL6）水平降低，以及炎症和免疫相关基因（tlr4a、myd88、p38a、TNFα）的显著下调，这证实了BC可以减少MC-LR诱导的炎症反应。同时，相对于仅暴露于MC-LR的组，在MC-LR与BC共暴露组中观察到补体C3（C3）含量显著增加，以及脾脏c3b表达水平更高，表明BC减轻了MC-LR诱导的先天免疫抑制。我们的结果还表明，BC可以降低水和脾脏中的MC-LR含量，从而通过雄性斑马鱼中依赖MyD88的Toll样受体（TLR/MyD88）信号通路减轻MC-LR诱导的炎症和先天免疫抑制。我们的结果强调了BC减轻MC-LR对水华污染水中水生生物有害影响的潜力。
