School of law / College of Fishery, Henan Normal University, Xinxiang, Henan, 453007, China.
State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, China.
Fish Physiol Biochem. 2022 Feb;48(1):117-131. doi: 10.1007/s10695-021-01041-5. Epub 2022 Jan 10.
The heavy metal cadmium (Cd) is an environmental pollutant that poses serious health hazards. Due to the increasing contamination of aquatic systems with Cd, the increased accumulation of Cd in fish has become a food safety and public health concern. Heme oxygenase (HO) is an important antioxidant enzyme that plays a key role in defending the body against oxidative damage, but little research has been done in common carp. In this study, 6 HO genes were identified in the common carp genome database. Comparative genomics analysis showed considerable expansion of the HO genes and verified the four-round whole genome duplication (WGD) event in common carp. Phylogenetic analysis revealed that all HO genes of common carp were clustered into orthologous groups, indicating high conservation during evolution. In addition, the tissue distribution results showed that most HO genes had extensive tissue distribution and showed tissue-specific expression patterns. Exposure to 0.5 mg/L Cd significantly reduced the expression of TGF-β and IL-10 in common carp, which may indicate that Cd exposure can destroy the physical barrier function of the intestine, inhibit intestinal immune defense and induce intestinal inflammation. To find a suitable concentration of Bacillus coagulans that could activate HO-1 genes and the immunity of the organism, we investigated the changes in HO-1 gene expression levels in the intestinal tract of common carp under Cd stress at 30 days and 60 days by adding different concentrations of B. coagulans to the feed. Compared with the Cd stress group without supplementation, the expression levels of the HO-1 gene in the gut of three different concentrations of B. coagulans were almost increased. And B. coagulans with L2 concentrations had better activation effect on the HO-1 gene. Similarly, compared to the Cd stressed group, adding B. coagulans to the diet can almost cause the early upregulation of IL-10 and TGF-β genes. Therefore, the addition of appropriate concentrations of B. coagulans may be a good way to activate HO-1, IL-10, and TGF-β genes, reduce oxidative damage, and encourage the immune.
重金属镉（Cd）是一种环境污染物，对健康构成严重威胁。由于水生系统中 Cd 的污染不断增加，鱼类中 Cd 的积累增加已成为食品安全和公共卫生关注的问题。血红素加氧酶（HO）是一种重要的抗氧化酶，在抵御身体氧化损伤方面起着关键作用，但在鲤鱼中研究甚少。在本研究中，在鲤鱼基因组数据库中鉴定了 6 种 HO 基因。比较基因组学分析表明，HO 基因得到了极大的扩展，并证实了鲤鱼经历了四轮全基因组复制（WGD）事件。系统发育分析表明，鲤鱼的所有 HO 基因都聚类为同源基因，表明在进化过程中具有高度保守性。此外，组织分布结果表明，大多数 HO 基因具有广泛的组织分布，并表现出组织特异性表达模式。暴露于 0.5mg/L Cd 显著降低了 TGF-β和 IL-10 在鲤鱼中的表达，这可能表明 Cd 暴露会破坏肠道的物理屏障功能，抑制肠道免疫防御并诱导肠道炎症。为了找到一种合适的凝结芽孢杆菌浓度，可以激活 HO-1 基因和机体的免疫力，我们在饲料中添加不同浓度的凝结芽孢杆菌，研究了在 30 天和 60 天 Cd 胁迫下鲤鱼肠道中 HO-1 基因表达水平的变化。与未补充的 Cd 应激组相比，三种不同浓度凝结芽孢杆菌在肠道中的 HO-1 基因表达水平几乎都增加了。并且 L2 浓度的凝结芽孢杆菌对 HO-1 基因具有更好的激活作用。同样，与 Cd 应激组相比，在饮食中添加凝结芽孢杆菌几乎可以使早期的 IL-10 和 TGF-β基因上调。因此，添加适量的凝结芽孢杆菌可能是激活 HO-1、IL-10 和 TGF-β 基因、减少氧化损伤和增强免疫力的好方法。
