Key Laboratory for Sustainable Utilization of Marine Fisheries Resources, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, PR China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, PR China.
Key Laboratory for Sustainable Utilization of Marine Fisheries Resources, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, PR China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, PR China; Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang, PR China.
Environ Pollut. 2021 Jan 15;269:116112. doi: 10.1016/j.envpol.2020.116112. Epub 2020 Nov 22.
Nuclear factor-erythroid 2-related factor-2 (Nrf2) is an important modulator of cellular responses against Cd in mammalian cells. However, whether such modulation is conserved in Marsupenaeus japonicas remains unknown.In our study, the shrimps were injected with dsRNA targeting Nrf2 at 4 μg g body weight (b.w.) or sulforaphane (SFN) at 5 μg g b.w., and then were exposed to 40 mg L CdCl for 48 h. After Nrf2 knockdown, the Cd content increased, but decreased in the SFN group. This suggested that Nrf2 could promote Cd excretion. A terminal deoxynulceotidyl transferase nick-end-labeling (TUNEL) assay revealed that the Nrf2 knockdown increased the number of apoptotic cells in M. japonicas, while SFN decreased the number of apoptotic cells. After Nrf2 knockdown, the total antioxidant capacity (T-AOC), superoxide dismutase (Sod) activity, and related gene expression decreased significantly, while the malondialdehyde (MDA) content increased remarkably. By contrast, SFN injection alleviated the oxidative stress, as evidenced by increased T-AOC, Sod activity, sod mRNA expression and a reduced MDA content. Similarly, detoxification related enzyme activities (ethoxyresorufin O-deethylase and glutathione-S-transferase (GST)) and their corresponding gene expressions (cyp3a (cytochrome P450 family 3 subfamily A) and gst) were suppressed in the ds-Nrf2 injection group, while they were elevated in the SFN group. In addition, ds-Nrf2 activated mitochondrial apoptotic pathway, as evidenced the mRNA and protein levels of caspase-3, Bcl2 associated X protein (Bax), and p53, while SFN treatment suppressed them. These results displayed that in M. japonicus Cd-induced cellular oxidative damage probably acts via the Nrf2 pathway.
核因子红细胞 2 相关因子 2（Nrf2）是哺乳动物细胞中细胞对 Cd 反应的重要调节剂。然而，这种调节在日本沼虾中是否保守尚不清楚。在本研究中，虾被注射 4μg/g 体重（b.w.）的 Nrf2 双链 RNA（dsRNA）或 5μg/g b.w.的萝卜硫素（SFN），然后暴露于 40mg/L 的 CdCl 48h。Nrf2 敲低后，Cd 含量增加，而 SFN 组则减少。这表明 Nrf2 可以促进 Cd 排泄。末端脱氧核苷酸转移酶介导的缺口末端标记（TUNEL）检测表明，Nrf2 敲低增加了日本沼虾凋亡细胞的数量，而 SFN 则减少了凋亡细胞的数量。Nrf2 敲低后，总抗氧化能力（T-AOC）、超氧化物歧化酶（Sod）活性和相关基因表达显著降低，而丙二醛（MDA）含量显著增加。相反，SFN 注射减轻了氧化应激，表现为 T-AOC、Sod 活性、 sod mRNA 表达增加和 MDA 含量降低。同样，解毒相关酶活性（乙氧基异吩恶唑 O-脱乙基酶和谷胱甘肽-S-转移酶（GST））及其相应的基因表达（cyp3a（细胞色素 P450 家族 3 亚家族 A）和 gst）在 ds-Nrf2 注射组中受到抑制，而在 SFN 组中则升高。此外，ds-Nrf2 激活了线粒体凋亡途径，表现为 caspase-3、Bcl2 相关 X 蛋白（Bax）和 p53 的 mRNA 和蛋白水平升高，而 SFN 处理则抑制了它们。这些结果表明，在日本沼虾中，Cd 诱导的细胞氧化损伤可能通过 Nrf2 途径发挥作用。
