Polystyrene microplastics enhance the microcystin-LR-induced gonadal damage and reproductive endocrine disruption in zebrafish.
Wang Lin, Huimin Luo, Jingyi Wu, Xiangli Liu, Beibei Cao, Yuqing Liu, Pinhong Yang, Jifeng Yang
Author Information
Wang Lin: 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 Engineering Research Center of Aquatic Organism Resources and Environmental Ecology, Changde 415000, China.
Huimin Luo: College of Life and Environmental Sciences, Hunan University of Arts and Science, Changde 415000, China.
Jingyi Wu: College of Life and Environmental Sciences, Hunan University of Arts and Science, Changde 415000, China.
Xiangli Liu: College of Life and Environmental Sciences, Hunan University of Arts and Science, Changde 415000, China.
Beibei Cao: College of Life and Environmental Sciences, Hunan University of Arts and Science, Changde 415000, China.
Yuqing Liu: Department of Gastroenterology, The First People's Hospital of Changde City, Changde 415000, China.
Pinhong Yang: College of Life and Environmental Sciences, Hunan University of Arts and Science, Changde 415000, China; Hunan Engineering Research Center of Aquatic Organism Resources and Environmental Ecology, Changde 415000, China. Electronic address: yph588@163.com.
Jifeng Yang: College of Chemistry and Materials Engineering, Hunan University of Arts and Science, Changde 415000, China. Electronic address: clark_yang@yeah.net.
The coexistence of eutrophication and plastic pollution in the aquatic environment is becoming a realistic water pollution problem worldwide. To investigate the microcystin-LR (MC-LR) bioavailability and the underlying reproductive interferences in the presence of polystyrene microplastic (PSMPs), zebrafish (Danio rerio) were exposed to individual MC-LR (0, 1, 5, and 25 μg/L) and combined MC-LR + PSMPs (100 μg/L) for 60 d. Our results showed that the existence of PSMPs increased the accumulation of MC-LR in zebrafish gonads compared to the MC-LR-only group. In the MC-LR-only exposure group, seminiferous epithelium deterioration and widened intercellular spaces were observed in the testis, and basal membrane disintegration and zona pellucida invagination were noticed in the ovary. Moreover, the existence of PSMPs exacerbated these injuries. The results of sex hormone levels showed that PSMPs enhanced MC-LR-induced reproductive toxicity, which is tightly related to the abnormal increase of 17β-estradiol (E2) and testosterone (T) levels. The changes of gnrh2, gnrh3, cyp19a1b, cyp11a, and lhr mRNA levels in the HPG axis further proved that MC-LR combined with PSMPs aggravated reproductive dysfunction. Our results revealed that PSMPs could increase the MC-LR bioaccumulation by serving as a carrier and exaggerate the MC-LR-induced gonadal damage and reproductive endocrine disruption in zebrafish.
