A Proteomic Approach to Elucidate the Changes in Saliva and Serum Proteins of Pigs with Septic and Non-Septic Inflammation

Abstract

Sepsis is a systemic inflammatory response triggered by an infectious agent and is recognized by the World Health Organization as a global concern, since it is one of the major causes of severe illness in humans and animals. The study of the changes that can occur in saliva and serum in sepsis can contribute to a better understanding of the pathophysiological mechanisms involved in the process and also to discover potential biomarkers that can help in its diagnosis and monitoring. The objective of this study was to characterize the changes that occur in the salivary and serum proteome of pigs with experimentally-induced sepsis. The study included five pigs with sepsis induced by LPS administration and five pigs with non-septic inflammation induced by turpentine for comparative purposes. In saliva, there were eighteen salivary proteins differentially expressed in the sepsis condition and nine in non-septic inflammation. Among these, significant increments in aldolase A and serpin B12 only occurred in the sepsis model. Changes in aldolase A were validated in a larger population of pigs with sepsis due to Streptococcus suis infection. In serum, there were 30 proteins differentially expressed in sepsis group and 26 proteins in the non-septic group, and most of the proteins that changed in both groups were related to non-specific inflammation. In the saliva of the septic animals there were some specific pathways activated, such as the organonitrogen compound metabolic process and lipid transport, whereas, in the serum, one of the main activated pathways was the regulation of protein secretion. Overall, saliva and serum showed different proteome variations in response to septic inflammation and could provide complementary information about the pathophysiological mechanisms occurring in this condition. Additionally, salivary aldolase A could be a potential biomarker of sepsis in pigs that should be confirmed in a larger population.

Changes in the Saliva Proteome of Pigs with Diarrhoea Caused by Escherichia coli

“…Overall, in our report, we found changes in proteins in saliva related to inflammation and the immune system, as have been described in saliva in pigs with sepsis experimentally induced by LPS administration and other infectious diseases such as S. suis infection [ 3 , 4 ].…”

“…It has been observed that saliva can show proteomic changes in sepsis experimentally induced by lipopolysaccharide (LPS) administration in pigs [ 3 ]. Aldolase A and serpin 12 were proteins in saliva that were significantly upregulated in sepsis.…”

Changes in Biomarkers of Redox Status in Saliva of Pigs after an Experimental Sepsis Induction

“…To the best of our knowledge, this is the first study that describes changes in biomarkers of redox status in pigs with sepsis. The pigs in our study showed, after LPS administration, increased body temperature as well as increased white blood cell count and C-reactive protein ( Table S2 ), and the presence of symptoms, such as depression, lethargy, and increased respiratory rate; which proved the validity of LPS administration as a model for sepsis in pigs, as has been previously described [ 21 , 25 ].…”

“…The following supporting information can be downloaded at: https:// www.mdpi.com/article/10.3390/antiox11071380/s1, Table S1: Description of the basis and reagents of each assay performed in the study; Table S2: Rectal temperature, white blood cell count (WBC), and C-reactive protein (CRP) of each animal included in the study before and 3 and 24 h after injection of lipopolysaccharide (LPS), turpentine (TURP), and saline (control group). Data of LPS and TURP groups were previously described [25]; Spreadsheet S1: Raw data.…”

Changes in Calprotectin (S100A8-A9) and Aldolase in the Saliva of Horses with Equine Gastric Ulcer Syndrome

“…Currently, there are commercially available assays that allow the measurement of CALP [ 17 ] and aldolase [ 18 ], having the advantages associated with automation, such as higher precision and faster sample processing. The hypotheses of this work are that CALP and aldolase can be measured in the saliva of horses with commercially available assays and, furthermore, that these assays can detect the changes in these analytes that occur in horses with EGUS.…”