BUSCADOR RECOLECTA

The association between stress and immune response activations in different diseases has been analyzed in this paper based on salivary analytics. Moreover, a first attempt to discriminate between diseases was performed by machine learning. The salivary analytics consisted of the measurement of physical (cortisol) and psychological stress (salivary alpha-amylase) indicators, innate (acute phase proteins: C-reactive protein and haptoglobin), and adaptive immune (adenosine deaminase, Cu and Zn) markers and oxidative stress parameters (antioxidant capacity and oxidative status). A total of 107 commercial growing pigs in the field were divided into six groups according to the signs of disease after proper veterinary clinical examination, specifically, healthy pigs, pigs with rectal prolapse, tail-biting, diarrhea, lameness or dyspnea. Associations between stress and immune markers were observed with different intensities. The higher associations (r = 0.61) were observed between oxidative stress markers and adaptive immune markers. On the other hand, moderate associations (r = 0.31-0.48) between physical and psychological stress markers with both innate and adaptive immune markers were observed. All pathological conditions showed statistically significant differences in at least 4 out of the 11 salivary markers studied, with no individual marker dysregulated in all the diseases. Moreover, each disease condition showed differences in the degree of activation of the systems analyzed which could be used to create different salivary profiles. A total of two dimensions were selected according to the machine learning analysis to explain the 48,3% of the variance of our data. Lameness and prolapse were the two pathological conditions most distant from the healthy condition followed by dyspnea. Tail biting and diarrhea were also far from the other diseases but nearer healthy animals. There is still room for improvements, but these preliminary results showed a great power for disease detection and characterization using salivary biomarkers profiling in the near future.

The role of hepcidins, antimicrobial peptides involved in iron metabolism, immunity, and inflammation is studied. First, gilthead seabream (Sparus aurata L.) head-kidney leucocytes (HKLs) were incubated with λ-carrageenin to study the expression of hepcidin and iron metabolism-related genes. The expression of most of the genes studied was up-regulated, whereas the ferroportin gene (slc40a) was down-regulated in HKLs incubated with λ-carrageenin. In the second part of the study, seabream specimens were injected with λ-carrageenin or buffer (control). The expression of the same genes was evaluated in the head kidney, liver, and skin at different time points after injection. The expression of Hamp1m, ferritin b and ferroportin genes (hamp1, fthb, and slc40a) was up-regulated in the head kidney of fish from the λ-carrageenin group, while the expression of Hamp2C and Hamp2E genes (hamp2.3 and hamp2.7) was down-regulated. In the liver, the expression of hamp1, ferritin a (ftha), slc40a, Hamp2J and Hamp2D (hamp2.5/6) genes was down-regulated in the λ-carrageenin group. In the skin, the expression of hamp1 and (Hamp2A Hamp2C) hamp2.1/3/4 genes was up-regulated in the λ-carrageenin group. A bioinformatic analysis was performed to predict the presence of transcription factor binding sites in the promoter region of hepcidins. Structural and physicochemical variations were found in the different mature hepcidin peptides. This study sheds light on the poorly understood roles of hepcidins in fish. The results provide insight into the regulatory mechanisms of inflammation in fish and could contribute to the development of new strategies for treat inflammation in farm animals.