Jiangsu Institute of Marine Resources, Lianyungang 222005, China; Jiangsu Key Laboratory of Marine Bioresources and Environment, Huaihai Institute of Technology, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Lianyungang 222005, China.
Jiangsu Key Laboratory of Marine Bioresources and Environment, Huaihai Institute of Technology, China.
Aquat Toxicol. 2019 May;210:98-105. doi: 10.1016/j.aquatox.2019.02.013. Epub 2019 Feb 27.
In order to understand the mechanisms of the toxicity of lead (Pb) on invertebrates, the immunotoxic effects of Pb in the marine crab, Charybdis japonica, were evaluated in the present study. The crabs were exposed to 0.066, 0.132, 1.318, 2.636, 6.590, and 13.181 μM of lead acetate and a control over 30 days, and the hemolymph was sampled terminally for testing the immunity-related indices, including total hemocyte count (THC), hemocyanin content, the activities of the phenoloxidase (PO) and lysozyme (LSZ). In addition, tissue samples were collected from the hepatopancreas, gill, muscle and ovary after 30 days of exposure for detecting the Pb accumulation in the major organs. The gene expression profiles of metallothionein (MT) and heat shock protein 70 (HSP70) in the hepatopancreas of C. japonica upon exposure to lead acetate over 96 h were also analyzed. The results showed a decline in the majority of the immunity-related parameters after an initial rise, and their levels were significantly lower in the treatment groups compared with those in the control, except in the group exposed to 0.066 μM of lead acetate for 30 days. Furthermore, a significant negative correlation was observed between the lead acetate concentration and the hemocyanin content, the activities of PO and LSZ (P<0.01). The expression levels of MT and HSP70 genes were rapidly induced, reaching a peak level after 12 and 24 h of exposure, respectively, and remained at a significantly higher level than the control after 96 h of exposure. It was also observed that the distribution pattern of Pb in the tissues of exposed crabs was in the order of gill > hepatopancreas > ovary and muscle, and exhibited a concentration-dependent response. Taken together, the results revealed that Pb exposure induced the immunosuppression of C. japonica and resulted in bioaccumulation, which could subsequently increase the disease susceptibility and threaten the food safety.
为了了解铅（Pb）对无脊椎动物毒性的作用机制，本研究评估了 Pb 对海洋螃蟹 Charybdis japonica 的免疫毒性作用。螃蟹暴露于 0.066、0.132、1.318、2.636、6.590 和 13.181 μM 的醋酸铅溶液和对照组中 30 天，在末期取样血淋巴以测试与免疫相关的指标，包括总血细胞计数（THC）、血蓝蛋白含量、酚氧化酶（PO）和溶菌酶（LSZ）的活性。此外，在暴露 30 天后从肝胰腺、鳃、肌肉和卵巢采集组织样本，以检测主要器官中的 Pb 积累。还分析了暴露于醋酸铅 96 小时后，C. japonica 肝胰腺中金属硫蛋白（MT）和热休克蛋白 70（HSP70）的基因表达谱。结果表明，大多数免疫相关参数在最初升高后下降，与对照组相比，处理组的水平显著降低，除了暴露于 0.066 μM 醋酸铅的组 30 天。此外，Pb 醋酸盐浓度与血蓝蛋白含量、PO 和 LSZ 的活性呈显著负相关（P<0.01）。MT 和 HSP70 基因的表达水平迅速诱导，暴露 12 和 24 小时后分别达到峰值水平，暴露 96 小时后仍保持显著高于对照组的水平。还观察到暴露螃蟹组织中 Pb 的分布模式为鳃>肝胰腺>卵巢和肌肉，并表现出浓度依赖性反应。综上所述，结果表明 Pb 暴露诱导了 C. japonica 的免疫抑制，并导致生物累积，随后可能会增加疾病易感性并威胁食品安全。
