Early Low-Grade Inflammation Induced by High-Salt Diet in Sprague Dawley Rats Involves Th17/Treg Axis Dysregulation, Vascular Wall Remodeling, and a Shift in the Fatty Acid Profile.

BACKGROUND/AIMS: Unrestricted increased table salt (NaCl) intake is associated with oxidative stress and inflammation, leading to endothelial dysfunction and atherosclerosis. However, data on salt-induced immunomodulatory effects in the earliest phase of salt loading are scarce. METHODS: In the present study, an animal model of short-term salt loading was employed, including male Sprague Dawley rats consuming a high-salt diet (HSD; 4% NaCl) or standard laboratory chow (low-salt; LSD; 0.4% NaCl) during a 7-day period. The contribution of angiotensin II (ANGII) suppression was tested by adding a group of rats on a high-salt diet receiving ANGII infusions. Samples of peripheral blood/mesenteric lymph node leukocytes, brain blood vessels, and serum samples were processed for flow cytometry, quantitative real-time PCR, total proteome analysis, and multiplex immunoassay. RESULTS: Data analysis revealed the up-regulation of Il 6 gene in the microcirculation of high-salt-fed rats, accompanied by an increased serum level of TNF-alpha cytokine. The high-salt diet resulted in increased proportion of serum mono-unsaturated fatty acids and saturated fatty acids, reduced levels of linoleic (C18:2 ω-6) and α-linolenic (C18:3 ω-3) acid, and increased levels of palmitoleic acid (C16:1 ω-7). The high-salt diet had distinct, lymphoid compartment-specific effects on leukocyte subpopulations, which could be attributed to the increased expression of salt-sensitive SGK-1 kinase. Complete proteome analysis revealed high-salt-diet-induced vascular tissue remodeling and perturbations in energy metabolism. Interestingly, many of the observed effects were reversed by ANGII supplementation. CONCLUSION: Low-grade systemic inflammation induced by a HSD could be related to suppressed ANGII levels. The effects of HSD involved changes in Th17 and Treg cell distribution, vascular wall remodeling, and a shift in lipid and arachidonic acid metabolism.

Multi Platforms Strategies and Metabolomics Approaches for the Investigation of Comprehensive Metabolite Profile in Dogs with Babesia canis Infection.

Canine babesiosis is an important tick-borne disease worldwide, caused by parasites of the Babesia genus. Although the disease process primarily affects erythrocytes, it may also have multisystemic consequences. The goal of this study was to explore and characterize the serum metabolome, by identifying potential metabolites and metabolic pathways in dogs naturally infected with Babesia canis using liquid and gas chromatography coupled to mass spectrometry. The study included 12 dogs naturally infected with B. canis and 12 healthy dogs. By combining three different analytical platforms using untargeted and targeted approaches, 295 metabolites were detected. The untargeted ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) metabolomics approach identified 64 metabolites, the targeted UHPLC-MS/MS metabolomics approach identified 205 metabolites, and the GC-MS metabolomics approach identified 26 metabolites. Biological functions of differentially abundant metabolites indicate the involvement of various pathways in canine babesiosis including the following: glutathione metabolism; alanine, aspartate, and glutamate metabolism; glyoxylate and dicarboxylate metabolism; cysteine and methionine metabolism; and phenylalanine, tyrosine, and tryptophan biosynthesis. This study confirmed that host-pathogen interactions could be studied by metabolomics to assess chemical changes in the host, such that the differences in serum metabolome between dogs with B. canis infection and healthy dogs can be detected with liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) methods. Our study provides novel insight into pathophysiological mechanisms of B. canis infection.

Multi-Omics Approach to Elucidate Cerebrospinal Fluid Changes in Dogs with Intervertebral Disc Herniation.

Herniation of the intervertebral disc (IVDH) is the most common cause of neurological and intervertebral disc degeneration-related diseases. Since the disc starts to degenerate before it can be observed by currently available diagnostic methods, there is an urgent need for novel diagnostic approaches. To identify molecular networks and pathways which may play important roles in intervertebral disc herniation, as well as to reveal the potential features which could be useful for monitoring disease progression and prognosis, multi-omics profiling, including high-resolution liquid chromatography-mass spectrometry (LC-MS)-based metabolomics and tandem mass tag (TMT)-based proteomics was performed. Cerebrospinal fluid of nine dogs with IVDH and six healthy controls were used for the analyses, and an additional five IVDH samples were used for proteomic data validation. Furthermore, multi-omics data were integrated to decipher a complex interaction between individual omics layers, leading to an improved prediction model. Together with metabolic pathways related to amino acids and lipid metabolism and coagulation cascades, our integromics prediction model identified the key features in IVDH, namely the proteins follistatin Like 1 (FSTL1), secretogranin V (SCG5), nucleobindin 1 (NUCB1), calcitonin re-ceptor-stimulating peptide 2 precursor (CRSP2) and the metabolites N-acetyl-D-glucosamine and adenine, involved in neuropathic pain, myelination, and neurotransmission and inflammatory response, respectively. Their clinical application is to be further investigated. The utilization of a novel integrative interdisciplinary approach may provide new opportunities to apply innovative diagnostic and monitoring methods as well as improve treatment strategies and personalized care for patients with degenerative spinal disorders.

N-glycome of the Lysosomal Glycocalyx is Altered in Niemann-Pick Type C Disease (NPC) Model Cells.

Increasing evidence implicates lysosomal dysfunction in the pathogenesis of neurodegenerative diseases, including the rare inherited lysosomal storage disorders (LSDs) and the most common neurodegenerative diseases, such as Alzheimer's and Parkinson's disease (AD and PD). Although the triggers of the lysosomal impairment may involve the accumulated macromolecules or dysfunction of the lysosomal enzymes, the role of the lysosomal glycocalyx in the lysosomal (dys)function has not been studied. The goal of this work was to analyze whether there are changes in the lysosomal glycocalyx in a cellular model of a LSD Niemann-Pick type C disease (NPC). Using the ferrofluid nanoparticles we isolated lysosomal organelles from NPC1-null and CHOwt cells. The magnetically isolated lysosomal fractions were enriched with the lysosomal marker protein LAMP1 and showed the key features of NPC disease: 3-fold higher cholesterol content and 4-5 fold enlarged size of the particles compared with the lysosomal fractions of wt cells. These lysosomal fractions were further processed to isolate lysosomal membrane proteins using Triton X-114 and their N-glycome was analyzed by HILIC-UPLC. N-glycans presented in each chromatographic peak were elucidated using MALDI-TOF/TOF-MS. We detected changes in the N-glycosylation pattern of the lysosomal glycocalyx of NPC1-null versus wt cells which involved high-mannose and sialylated N-glycans. To the best of our knowledge this study is the first to report N-glycome profiling of the lysosomal glycocalyx in NPC disease cellular model and the first to report the specific changes in the lysosomal glycocalyx in NPC1-null cells. We speculate that changes in the lysosomal glycocalyx may contribute to lysosomal (dys)function. Further glycome profiling of the lysosomal glycocalyx in other LSDs as well as the most common neurodegenerative diseases, such as AD and PD, is necessary to better understand the role of the lysosomal glycocalyx and to reveal its potential contribution in lysosomal dysfunction leading to neurodegeneration.

Plasma proteomic profiling and pathway analysis of normal and overconditioned dairy cows during the transition from late pregnancy to early lactation.

This study applied a quantitative proteomics approach along with bioinformatics analyses to investigate changes in the plasma proteome of normal and overconditioned dairy cows during the transition period. Fifteen weeks before their anticipated calving date, 38 multiparous Holstein cows were selected based on their current and previous body condition scores (BCS) and allocated to either a high or a normal BCS group (19 cows each). They received different diets until dry-off to reach targeted differences in BCS and back fat thickness (BFT) until dry-off. At dry-off, normal BCS cows had a BCS <3.5 (minimum, 2.75) and BFT <1.2 cm (minimum, 0.58), and the high BCS cows had a BCS >3.75 (maximum, 4.50) and BFT >1.4 cm (maximum, 2.90). The proteomics study used a subset of 5 animals from each group. These cows were selected based on their circulating concentrations of fatty acids (FA) on d 14 postpartum and ß-hydroxybutyrate (BHB) on d 21 postpartum, representing the greater or the lower extreme values within their BCS group, respectively. The high BCS subset (HE-HBCS) had 4.50 < BCS > 3.75, FA = 1.17 ± 0.46 mmol/L, and BHB = 2.15 ± 0.42 mmol/L (means ± SD), and the low BCS subset (LE-NBCS) had 3.50 < BCS > 2.75, FA = 0.51 ± 0.28 mmol/L, and BHB = 0.84 ± 0.17 mmol/L. Plasma samples from d -49, +7, and +21 relative to parturition were used for proteome profiling by applying the quantitative tandem mass tags (TMT) approach. Nondepleted plasma samples were subjected to reduction and digestion and then labeled with TMT 10plex reagents. High-resolution liquid chromatography-tandem mass spectrometry analysis of TMT-labeled peptides was carried out, and the acquired spectra were analyzed for protein identification and quantification. In total, 254 quantifiable proteins (criteria: 2 unique peptides and 5% false discovery rate) were identified in the plasma samples. From these, 24 differentially abundant proteins (14 more abundant, 10 less abundant) were observed in the LE-NBCS cows compared with the HE-HBCS cows during the transition period. Plasma α-2-macroglobulins were more abundant in HE-HBCS versus LE-NBCS cows at d +7 and +21. Gene Ontology enrichment analyses of differentially abundant proteins revealed that the acute inflammatory response, regulation of complement activation, protein activation cascade, and regulation of humoral immune response were the most enriched terms in the LE-NBCS group compared with the HE-HBCS group. In addition, we identified 24 differentially abundant proteins (16 in the LE-NBCS group, and 8 in the HE-HBCS group) during the transition period. The complement components C1q and C5 were less abundant, while C3 and C3d were more abundant in LE-NBCS compared with HE-HBCS cows. Overall, overconditioning around calving was associated with alterations in protein pathways related to acute inflammatory response and regulation of complement and coagulation cascades in transition cows.

Effect of Tff3 Deficiency and ER Stress in the Liver.

Endoplasmic reticulum (ER) stress, a cellular condition caused by the accumulation of unfolded proteins inside the ER, has been recognized as a major pathological mechanism in a variety of conditions, including cancer, metabolic and neurodegenerative diseases. Trefoil factor family (TFFs) peptides are present in different epithelial organs, blood supply, neural tissues, as well as in the liver, and their deficiency has been linked to the ER function. Complete ablation of Tff3 expression is observed in steatosis, and as the most prominent change in the early phase of diabetes in multigenic mouse models of diabesity. To elucidate the role of Tff3 deficiency on different pathologically relevant pathways, we have developed a new congenic mouse model Tff3-/-/C57BL6/N from a mixed background strain (C57BL6/N /SV129) by using a speed congenics approach. Acute ER stress was evoked by tunicamycin treatment, and mice were sacrificed after 24 h. Afterwards the effect of Tff3 deficiency was evaluated with regard to the expression of relevant oxidative and ER stress genes, relevant proinflammatory cytokines/chemokines, and the global protein content. The most dramatic change was noticed at the level of inflammation-related genes, while markers for unfolded protein response were not significantly affected. Ultrastructural analysis confirmed that the size of lipid vacuoles was affected as well. Since the liver acts as an important metabolic and immunological organ, the influence of Tff3 deficiency and physiological function possibly reflects on the whole organism.

Impact of High Salt Diet on Cerebral Vascular Function and Stroke in Tff3-/-/C57BL/6N Knockout and WT (C57BL/6N) Control Mice.

High salt (HS) dietary intake leads to impaired vascular endothelium-dependent responses to various physiological stimuli, some of which are mediated by arachidonic acid (AA) metabolites. Transgenic Tff3-/- gene knockout mice (Tff3-/-/C57BL/6N) have changes in lipid metabolism which may affect vascular function and outcomes of stroke. We aimed to study the effects of one week of HS diet (4% NaCl) on vascular function and stroke induced by transient occlusion of middle cerebral artery in Tff3-/- and wild type (WT/C57BL/6N) mice. Flow-induced dilation (FID) of carotid artery was reduced in WT-HS mice, but not affected in Tff3-/--HS mice. Nitric oxide (NO) mediated FID. NO production was decreased with HS diet. On the contrary, acetylcholine-induced dilation was significantly decreased in Tff3-/- mice on both diets and WT-HS mice. HS intake and Tff3 gene depletion affected the structural components of the vessels. Proteomic analysis revealed a significant effect of Tff3 gene deficiency on HS diet-induced changes in neuronal structural proteins and acute innate immune response proteins' expression and Tff3 depletion, but HS diet did not increase the stroke volume, which is related to proteome modification and upregulation of genes involved mainly in cellular antioxidative defense. In conclusion, Tff3 depletion seems to partially impair vascular function and worsen the outcomes of stroke, which is moderately affected by HS diet.

Proteomics in Veterinary Medicine and Animal Science: Neglected Scientific Opportunities with Immediate Impact.

Animal/veterinary proteomics is an evolving field which holds a great promise not only for fundamental and applied discoveries regarding biology and pathology of domestic species, but can also be implemented in comparative applications of human diseases research. Experimental proteomics in domestic animals have advantages over use of rodents, such as multiple sampling in time series and availability of biological samples in sufficient volume for multiple analyses, such that both experimental and natural disease processes can be investigated. While there are certain technical limitations in the expansion of the field, they can currently be circumvented and in the future mastered with a greater participation of proteomic experts, which will in turn drive the accessibility of species-specific reagents, data volume expansion in bioinformatic databases, and increased funding. This Viewpoint highlights some comparative proteomics studies addressing important issues and encourages readers to expand their horizons of domestic animal proteomics research. It will hopefully inspire new fruitful collaborations between veterinary and animal scientists and proteomic specialists for research in these areas that can have immediate and direct impact on health, society, and the economy.

Biomarker and proteome analysis of milk from dairy cows with clinical mastitis: Determining the effect of different bacterial pathogens on the response to infection.

Antimicrobial usage (AMU) could be reduced by differentiating the causative bacteria in cases of clinical mastitis (CM) as either Gram-positive or Gram-negative bacteria or identifying whether the case is culture-negative (no growth, NG) mastitis. Immunoassays for biomarker analysis and a Tandem Mass Tag (TMT) proteomic investigation were employed to identify differences between samples of milk from cows with CM caused by different bacteria. A total of 94 milk samples were collected from cows diagnosed with CM across seven farms in Scotland, categorized by severity as mild (score 1), moderate (score 2), or severe (score 3). Bovine haptoglobin (Hp), milk amyloid A (MAA), C-reactive protein (CRP), lactoferrin (LF), α-lactalbumin (LA) and cathelicidin (CATHL) were significantly higher in milk from cows with CM, regardless of culture results, than in milk from healthy cows (all P-values <0.001). Milk cathelicidin (CATHL) was evaluated using a novel ELISA technique that utilises an antibody to a peptide sequence of SSEANLYRLLELD (aa49-61) common to CATHL 1-7 isoforms. A classification tree was fitted on the six biomarkers to predict Gram-positive bacteria within mastitis severity scores 1 or 2, revealing that compared to the rest of the samples, Gram-positive samples were associated with CRP < 9.5 µg/ml and LF ≥ 325 µg/ml and MAA < 16 µg/ml. Sensitivity of the tree model was 64%, the specificity was 91%, and the overall misclassification rate was 18%. The area under the ROC curve for this tree model was 0.836 (95% bootstrap confidence interval: 0.742; 0.917). TMT proteomic analysis revealed little difference between the groups in protein abundance when the three groups (Gram-positive, Gram-negative and no growth) were compared, however when each group was compared against the entirety of the remaining samples, 28 differentially abundant protein were identified including ß-lactoglobulin and ribonuclease. Whilst further research is required to draw together and refine a suitable biomarker panel and diagnostic algorithm for differentiating Gram- positive/negative and NG CM, these results have highlighted a potential panel and diagnostic decision tree. Host-derived milk biomarkers offer significant potential to refine and reduce AMU and circumvent the many challenges associated with microbiological culture, both within the lab and on the farm, while providing the added benefit of reducing turnaround time from 14 to 16 h of microbiological culture to just 15 min with a lateral flow device (LFD).

Comparison between enhanced MALDI in-source decay by ammonium persulfate and N- or C-terminal derivatization methods for detailed peptide structure determination.

Amino acid sequencing and more detailed structure elucidation analysis of peptides and small proteins is a very difficult task even if state-of-the-art mass spectrometry (MS) is employed. To make this task easier, chemical derivatization methods of the N terminus with 4-sulfophenyl-isothiocyanate (SPITC) or the C terminus with 2-methoxy-4,5-dihydro-1H-imidazole (Lys-tag) can enhance peptide fragmentation or fragment ionizability, via proton mobility/localization mechanisms making tandem MS (MS(2)) spectra more informative and less demanding for structural interpretation. Observed disadvantages related to both derivatization methods are sample- and time-consuming procedures and the increased number of reaction byproducts. A novel, sulfate radical in-source formation method of matrix-assisted laser desorption ionization (MALDI) MS based on chemically enhanced in-source decay (ISD) can be accomplished by simple addition of ammonium persulfate (APS) in the matrix solution. This method enables effective decomposition of peptide ions already in the first stage of MS analysis where a large number of fragment ions are produced. The resultant MALDI-ISD mass spectra (MS after APS → MALDI-ISD MS) are almost equivalent to conventional, collision-induced dissociation (CID) MS(2) spectra. These fragment ions are further subjected to the second stage of the MS, and consequently, MS(3) spectra are produced, which makes the sequence analysis more informative and complete (CID MS(2) is thus equivalent to CID MS(3)). Multiply stage MS after APS addition showed enhanced sensitivity, resolution, and mass accuracy compared to peptide derivatization (SPITC and Lys-tag) or conventional MS and MS(2) analyses and offered more detailed insight into peptide structure.

Antitumor mechanisms of amino Acid hydroxyurea derivatives in the metastatic colon cancer model.

The paper presents a detailed study of the biological effects of two amino acid hydroxyurea derivatives that showed selective antiproliferative effects in vitro on the growth of human tumor cell line SW620. Tested compounds induced cell cycle perturbations and apoptosis. Proteins were identified by proteomics analyses using two-dimensional gel electrophoresis coupled to mass spectrometry, which provided a complete insight into the most probable mechanism of action on the protein level. Molecular targets for tested compounds were analyzed by cheminformatics tools. Zinc-dependent histone deacetylases were identified as potential targets responsible for the observed antiproliferative effect.

Data Independent Acquisition Reveals In-Depth Serum Proteome Changes in Canine Leishmaniosis.

Comprehensive profiling of serum proteome provides valuable clues of health status and pathophysiological processes, making it the main strategy in biomarker discovery. However, the high dynamic range significantly decreases the number of detectable proteins, obstructing the insights into the underlying biological processes. To circumvent various serum enrichment methods, obtain high-quality proteome wide information using the next-generation proteomic, and study host response in canine leishmaniosis, we applied data-independent acquisition mass spectrometry (DIA-MS) for deep proteomic profiling of clinical samples. The non-depleted serum samples of healthy and naturally Leishmania-infected dogs were analyzed using the label-free 60-min gradient sequential window acquisition of all theoretical mass spectra (SWATH-MS) method. As a result, we identified 554 proteins, 140 of which differed significantly in abundance. Those were included in lipid metabolism, hematological abnormalities, immune response, and oxidative stress, providing valuable information about the complex molecular basis of the clinical and pathological landscape in canine leishmaniosis. Our results show that DIA-MS is a method of choice for understanding complex pathophysiological processes in serum and serum biomarker development.

Serum and urine profiling by high-throughput TMT-based proteomics for the investigation of renal dysfunction in canine babesiosis.

Canine babesiosis is a tick-borne disease caused by Babesia canis, with acute kidney injury as one of the common complications. In the study 8 healthy control dogs and 22 dogs with naturally occurring babesiosis were enrolled, with the aim to analyse differences in serum and urinary proteomes between healthy dogs and dogs with different degree of renal dysfunction in babesiosis using a label-based high-throughput quantitative proteomic approach. In serum, 58 proteins were found differentially abundant between healthy controls and groups of dogs with different degrees of renal dysfunction in babesiosis, while in urine there were 259 differentially abundant proteins. In addition, altered biological pathways were detected in the diseased dogs using bioinformatics tools and validation of several candidate biomarkers was performed. SIGNIFICANCE: The main aim of this comprehensive study was to perform analyses of serum and urinary proteomes of dogs with renal dysfunction in babesiosis compared to healthy dogs using, for the first time, a high-throughput proteomic method and functional enrichment analyses. Serum and urine samples of the same dogs were investigated in order to gain a more complete picture of pathologic changes taking place in renal dysfunction in babesiosis. We highlighted two putative biomarkers validated herein which could be of importance for early diagnosis of renal dysfunction in canine babesiosis, as they are easily accessible from urine and their concentration rises before the appearance of azotaemia: urinary neutrophil gelatinase-associated lipocalin (NGAL) and urinary liver-type fatty acid-binding protein (L-FABP).

Effect of dietary Spirulina (Arthrospira platensis) on the intestinal function of post-weaned piglet: An approach combining proteomics, metabolomics and histological studies.

The effect of dietary Spirulina (Arthrospira platensis) and CAZyme supplementation was assessed on the gut of weaned piglets, using an integrated NMR-metabolomics approach combined with Tandem Mass Tag labelled proteomics. Thirty weaned male piglets were assigned to one of the three following diets (n = 10): cereal and soybean meal basal diet (Control), basal diet with 10% Spirulina inclusion (SP) and SP diet supplemented with 0.01% lysozyme (SP + L). The experiment lasted 4 weeks and, upon slaughter, small intestine samples were collected for histological, metabolomic and proteomic analysis. No significant differences were found for the histology and metabolomics analysis between the three experimental groups. Lactate, glutamate, glycine and myo-inositol were the most abundant metabolites. Proteomics results showed 1502 proteins identified in the intestine tissue. A total of 23, 78, 27 differentially abundant proteins were detected respectively for the SP vs. Control, SP + L vs. Control and SP + L vs. SP comparisons. The incorporation of Spirulina and supplementation of lysozyme in the piglet's diets is associated to intestinal proteomic changes. These include increased protein synthesis and abundance of contractile apparatus proteins, related with increased nutrient availability, which has beneficial (increased glucose uptake) and detrimental (increased digesta viscosity) metabolic effects. SIGNIFICANCE: The use of conventional feedstuffs becomes increasingly prohibitive due to its environmental toll. To increase the sustainability of the livestock sector, novel feedstuffs such as microalgae need to be considered. However, its recalcitrant cell wall has antinutritional effects that can inhibit high dietary inclusion levels. The supplementation with CAZymes is a possible solution to this issue. The small intestine is a central piece in monogastric digestion and of particular importance for the weaned piglet. Studying the effect of dietary Spirulina and CAZyme supplementation on its histomorphology, metabolome and proteome allows studying relevant physiological adaptations to these diets.

Faecal proteomics in the identification of biomarkers to differentiate canine chronic enteropathies.

Canine chronic enteropathy (CCE) is a collective term used to describe a group of idiopathic enteropathies of dogs that result in a variety of clinical manifestations of intestinal dysfunction. Clinical stratification into food-responsive enteropathy (FRE) or non-food responsive chronic inflammatory enteropathy (CIE), is made retrospectively based on response to treatments. Faecal extracts from those with a FRE (n = 5) and those with non-food responsive chronic inflammatory enteropathies (CIE) (n = 6) were compared to a healthy control group (n = 14) by applying TMT-based quantitative proteomic approach. Many of the proteins with significant differential abundance between groups were pancreatic or intestinal enzymes with pancreatitis-associated protein (identified as REG3α) and pancreatic M14 metallocarboxypeptidase proteins carboxypeptidase A1 and B identified as being of significantly increased abundance in the CCE group. The reactome analysis revealed the recycling of bile acids and salts and their metabolism to be present in the FRE group, suggesting a possible dysbiotic aetiology. Several acute phase proteins were significantly more abundant in the CCE group with the significant increase in haptoglobin in the CIE group especially notable. Further research of these proteins is needed to fully assess their clinical utility as faecal biomarkers for differentiating CCE cases. SIGNIFICANCE: The identification and characterisation of biomarkers that differentiate FRE from other forms of CIE would prove invaluable in streamlining clinical decision-making and would avoid costly and invasive investigations and delays in implementing effective treatment. Many of the proteins described here, as canine faecal proteins for the first time, have been highlighted in previous human and murine inflammatory bowl disease (IBD) studies initiating a new chapter in canine faecal biomarker research, where early and non-invasive biomarkers for early clinical stratification of CCE cases are needed. Pancreatitis-associated protein, pancreatic M14 metallocarboxypeptidase along with carboxypeptidase A1 and B are identified as being of significantly increased abundance in the CCE groups. Several acute phase proteins, were significantly more abundant in the CCE group notably haptoglobin in dogs with inflammatory enteropathy. The recognition of altered bile acid metabolism in the reactome analysis in the FRE group is significant in CCE which is a complex condition incorporating of immunological, dysbiotic and faecal bile acid dysmetabolism. Both proteomics and immunoassays will enable the characterisation of faecal APPs as well as other inflammatory and immune mediators, and the utilisation of assays, validated for use in analysis of faeces of veterinary species will enable clinical utilisation of faecal matrix to be fully realised.

Evaluation of Changes in Metabolites of Saliva in Canine Obesity Using a Targeted Metabolomic Approach.

Obesity is a common problem in pet dogs, affecting half of the general population in some countries. Excess body weight causes several disorders and has a negative impact on dogs' quality of life. The use of metabolomics allows the identification of metabolite traces from the metabolic pathways involved in pathological processes. This study aimed to evaluate salivary metabolite variations in dogs with obesity. The salivary samples of 19 dogs were analyzed using a targeted metabolomic approach, through which 234 metabolites were quantified. Of these, multivariate analysis identified 27 different metabolites altered in dogs with obesity compared with control dogs. These metabolites were mainly classified as amino acids, glycerides, sphingolipids, glycerophospholipids, and acylcarnitines. Some of the changes in these metabolites reflect the insulin resistance status related to obesity in dogs. Overall, it can be concluded that the salivary metabolome of obese dogs reflects the metabolic changes occurring in obesity and could be a source of potential biomarkers for this complex condition.

Changes in salivary proteins can reflect beneficial physiological effects of ejaculation in the dog.

The objective of this study was to study the changes in salivary proteins that occur in the dog after the ejaculation process. Saliva samples from eight dogs before and after induced ejaculation were analyzed by proteomic using Tandem Mass Tag (TMT) labeling and LC-MS/MS analysis. A total of 33 salivary proteins showed significant changes after the ejaculation process. The up-regulated proteins that showed changes of higher magnitude were mucin-7 (MUC-7), peroxiredoxin-4 (PRDX4) and galectin-3 (LEGALS3) whereas proteins such as alpha-1-acid glycoprotein (A1G1) and alpha-1B-glycoprotein (A1BG) were the most down-regulated. MUC-7 and PRDX4 expression in saliva after ejaculation could be associated with the protective "environment" created by the organism to exert pr 3o-fertility activities and antioxidants benefits in spermatozoa. Also LEGALS3 increment could be associated with an improvement of wellbeing and could contribute to a positive global effect in the body. Down-regulations of A1G1 and A1GB proteins found in saliva after ejaculation could be associated with a reduction in systemic inflammation. Overall it can be concluded that, changes in proteins in saliva that are produced after ejaculation can reflect a state of increase immune defenses, improvement of antioxidant status and low inflammation.

Untargeted metabolomic profiling of serum in dogs with hypothyroidism.

Hypothyroidism is one of the most commonly diagnosed endocrine disease in dogs. The clinical signs are caused by a deficiency of the active thyroid hormones triiodothyronine (T3) and thyroxine (T4) and have a negative impact on dog's quality of life. We hypothesized that serum metabolic profile varies between healthy dogs and dogs with hypothyroidism. Twenty serum samples from dogs with hypothyroidism and 20 from healthy dogs were used for untargeted metabolomics analysis performed by LC/MS analysis. Fifteen metabolites showed significant changes between hypothyroid and healthy dogs, being the pentose phosphate pathway (PPP), aminoacyl-tRNA biosynthesis and pyrimidine metabolism the principal pathways altered in hypothyroidism. Specifically, metabolites such as D-gluconic acid and L-Isoleucine may potentially act as biomarkers of disease.

Tandem Mass Tag (TMT) Proteomic Analysis of Saliva in Horses with Acute Abdominal Disease.

The aim of this study was to investigate the changes in the salivary proteome in horses with acute abdominal disease (AAD) using a tandem mass tags (TMT)-based proteomic approach. The saliva samples from eight horses with AAD were compared with six healthy horses in the proteomic study. Additionally, saliva samples from eight horses with AAD and eight controls were used to validate lactoferrin (LF) in saliva. The TMT analysis quantified 118 proteins. Of these, 17 differed significantly between horses with AAD and the healthy controls, 11 being downregulated and 6 upregulated. Our results showed the downregulation of gamma-enteric smooth muscle actin (ACTA2), latherin isoform X1, and LF. These proteins could be closely related to an impaired primary immune defense and antimicrobial capacity in the mucosa. In addition, there was an upregulation of mucin 19 (MUC19) and the serine protease inhibitor Kazal-type 5 (SPINK5) associated with a protective effect during inflammation. The proteins identified in our study could have the potential to be novel biomarkers for diagnosis or monitoring the physiopathology of the disease, especially LF, which decreased in the saliva of horses with AAD and was successfully measured using a commercially available immunoassay.

Metabolic profiling of serum from dogs with pituitary-dependent hyperadrenocorticism.

Hyperadrenocorticism (HAC) is one of the most common endocrine diseases in dogs characterized by excessive cortisol production caused by an adrenocorticotropic hormone (ACTH)-secreting tumor, namely pituitary-dependent HAC (PDH) or cortisol-secreting adrenal tumor. Metabolomics presents the ability to identify small molecule metabolites. Thus, the use of metabolomics techniques in canine PDH can provide information about the pathophysiology and metabolic changes in this disease. This study aimed to identify and compare differences in serum metabolites between dogs with PDH and healthy dogs. The metabolomic profile of 20 dogs diagnosed with PDH was compared with 20 healthy dogs using liquid chromatography/mass spectrometry (LC/MS), and metabolite discrimination was performed using partial least squares-discriminant analysis (PLS-DA), the variable important in projection (VIP) and fold changes (FC) group-wise comparisons. The hypergeometric test identified the significantly altered pathways. A total of 21 metabolites were found to be significantly different between the two groups. The major alterations were found in arachidonic and decanoic acid, and phospholipids related to phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylinositol (PI). These metabolites are related to insulin resistance and other complications (i.e. hypertension). Our results indicate that PDH produces changes in serum metabolites of dogs, and the knowledge of these changes can aid to better understanding of pathophysiological processes involved and contribute to potentially detect new biomarkers for this disease.