Immunobiology for Aquaculture group, Department of Cell Biology and Histology. Faculty of Biology, Campus Regional de Excelencia Internacional 'Campus Mare Nostrum', University of Murcia, Murcia, Spain.
Department of Human Pathology in Adult and Developmental Age 'Gaetano Barresi', Section of Pathology, University of Messina, Messina, Italy.
J Fish Dis. 2022 Jan;45(1):19-33. doi: 10.1111/jfd.13528. Epub 2021 Sep 22.
To date, the mechanisms of inflammation have been poorly studied in fish of commercial interest, due to the lack of development of appropriate experimental models. The current study evaluated a local inflammation triggered by a polymeric carrageenin mixture (a mucopolysaccharide derived from the red seaweed Chondrus crispus) in the skin of gilthead seabream (Sparus aurata). Fish were injected subcutaneously with phosphate-buffered saline (as control) or λ/κ-carrageenin (1%), and skin samples from the injection sites were collected 1.5, 3 and 6 hr post-injection, processed for inclusion in paraplast and stained with haematoxylin-eosin, Alcian blue or periodic acid-Schiff. Furthermore, immunohistochemistry and expression analyses of several cells' markers and proinflammatory genes were also analysed in samples of the injected sites. Microscopic results indicated an increased number of skin mucus-secreting cells and acidophilic granulocytes in the skin of fish studied at 1.5 hr and 3 hr post-injection with carrageenin, respectively, with respect to the data obtained in control fish. Otherwise, both the gene expression of the non-specific cytotoxic cell marker (granzyme B, grb) and the proinflammatory cytokine (interleukin-1β, il-1β) were up-regulated at 1.5 hr in the skin of fish injected with carrageenin compared with the control fish, whilst the gene expression of acidophilic granulocyte markers (NADPH oxidase subunit Phox22 and Phox40, phox22 and phox40) was up-regulated at 3 and 6 hr in the carrageenin group, compared with the control group. In addition, the gene expression of myeloperoxidase (mpo) was also up-regulated at 6 hr in the skin of fish injected with carrageenin in comparison with control samples. The present results indicate the chronological participation of two important immune cells involved in the resolution of the inflammation in the skin of gilthead seabream.
迄今为止，由于缺乏合适的实验模型，商业鱼类的炎症机制研究还很不完善。本研究评估了聚合角叉菜胶混合物（一种源自红海藻角叉菜的粘多糖）在金头鲷（Sparus aurata）皮肤中引发的局部炎症。鱼被皮下注射磷酸盐缓冲盐水（作为对照）或 λ/κ-角叉菜胶（1%），并在注射后 1.5、3 和 6 小时从注射部位采集皮肤样本，进行石蜡包埋处理，并进行苏木精-伊红、阿尔辛蓝或过碘酸希夫染色。此外，还对注射部位样本中的几种细胞标志物和促炎基因的免疫组织化学和表达分析进行了分析。显微镜结果表明，与对照组相比，在注射角叉菜胶后 1.5 小时和 3 小时，研究鱼的皮肤中分泌皮肤黏液的细胞和嗜酸性粒细胞的数量增加。相反，与对照组相比，在注射角叉菜胶后 1.5 小时，非特异性细胞毒性细胞标志物（颗粒酶 B，grb）和促炎细胞因子（白细胞介素-1β，il-1β）的基因表达均上调，而嗜酸性粒细胞标志物（NADPH 氧化酶亚基 Phox22 和 Phox40、phox22 和 phox40）的基因表达在 3 小时和 6 小时上调在角叉菜胶组中，与对照组相比。此外，与对照组相比，在注射角叉菜胶后 6 小时，鱼皮肤中的髓过氧化物酶（mpo）基因表达也上调。本研究结果表明，在金头鲷皮肤炎症的消退过程中，两种重要的免疫细胞按时间顺序参与其中。
