College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China.
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China; Institute of Nutritional and Metabolic Disorders in Domestic Animals and Fowls, Nanjing Agricultural University, Nanjing, 210095, Jiangsu Province, China.
Chemosphere. 2018 May;199:718-727. doi: 10.1016/j.chemosphere.2018.02.009. Epub 2018 Feb 3.
The co-contamination of cereals, grains, crops, and animal feeds by mycotoxins is a universal problem. Humans and animals are exposed to several mycotoxins simultaneously as evidenced by extensive studies on this topic. Yet, most studies have addressed the effects of mycotoxins individually. Aflatoxin B1 and ochratoxin A can induce immunotoxicity. However, it remains unclear whether a combination of these mycotoxins aggravates immunotoxicity and the potential mechanism underlying this effect. In this study, we used the cell line 3D4/21, swine alveolus macrophages and innate immune cell. The results showed that the percentage of cell inhibition, annexin V/PI-positive rates, and the expression of pro-inflammatory cytokines (tumor necrosis factor alpha and interleukin-6) significantly increased and the release of lactate dehydrogenase and phagocytotic index were significantly decreased at different concentrations of aflatoxin B1 and ochratoxin A combination when compared with control. The combination of aflatoxin B1 and ochratoxin A significantly decreased the production of GSH and increased reactive oxygen species level. However, N-acetylcysteine suppressed the oxidative stress and alleviated the immunotoxicity induced by the combination. The combination of aflatoxin B1 and ochratoxin A markedly enhanced the degradation of IκBa, the phosphorylation of nuclear factor kappa B (p65), and the translocation of activated nuclear factor kappa B (NF-κB) into the nuclei as demonstrated by western blotting and confocal laser scanning microscopy. These effects could be reversed by BAY 11-7082, a specific inhibitor of NF-κB. Taken together, a combination of aflatoxin B1 and ochratoxin A could aggravate immunotoxicity by activating the NF-κB signaling pathway.
真菌毒素对谷物、粮食、农作物和动物饲料的共同污染是一个普遍存在的问题。广泛的研究表明，人类和动物同时暴露于多种真菌毒素中。然而，大多数研究都针对单一真菌毒素的影响。黄曲霉毒素 B1 和赭曲霉毒素 A 可诱导免疫毒性。然而，目前尚不清楚这些真菌毒素的组合是否会加重免疫毒性，以及这种效应的潜在机制。在这项研究中，我们使用了 3D4/21 细胞系、猪肺泡巨噬细胞和固有免疫细胞。结果表明，与对照组相比，不同浓度的黄曲霉毒素 B1 和赭曲霉毒素 A 组合可显著增加细胞抑制率、膜联蛋白 V/PI 阳性率和促炎细胞因子（肿瘤坏死因子-α和白细胞介素-6）的表达，同时显著降低乳酸脱氢酶的释放和吞噬指数。黄曲霉毒素 B1 和赭曲霉毒素 A 的组合可显著降低 GSH 的产生，增加活性氧水平。然而，N-乙酰半胱氨酸抑制氧化应激，缓解组合引起的免疫毒性。黄曲霉毒素 B1 和赭曲霉毒素 A 的组合可显著增强 IκBa 的降解、核因子 kappa B（p65）的磷酸化以及激活的核因子 kappa B（NF-κB）向核内的易位，Western blot 和共聚焦激光扫描显微镜分析结果均表明了这一点。NF-κB 的特异性抑制剂 BAY 11-7082 可逆转这些作用。综上所述，黄曲霉毒素 B1 和赭曲霉毒素 A 的组合可通过激活 NF-κB 信号通路加重免疫毒性。
