Urinary Leukotriene E4 Concentrations as a Potential Marker of Inflammation in Dogs with Inflammatory Bowel Disease

Comparison of the Microbiome-Metabolome Response to Copper Sulfate and Copper Glycinate in Growing Pigs

This study aims to compare the fecal microbiome-metabolome response to copper sulfate (CuSO₄) and copper glycinate (Cu-Gly) in pigs. Twelve Meishan gilts were allocated into the CuSO₄ group and the Cu-Gly group (fed on a basal diet supplemented with 60 mg/kg copper from CuSO₄ or Cu-Gly) paired in litter and body weight. After a two-week feeding trial, the Cu-Gly group had a higher copper digestibility, blood hemoglobin, and platelet volume and higher levels of plasma iron and insulin-like growth factor-1 than the CuSO₄ group. The Cu-Gly treatment increased the abundance of the Lachnospiraceae family and the genera Lachnospiraceae XPB1014, Corprococcus_3, Anaerorhabdus_furcosa_group, Lachnospiraceae_FCS020_group, and Lachnospiraceae_NK4B4_group and decreased the abundance of the Synergistetes phylum and Peptostreptococcaceae family compared to the CuSO₄ treatment. Moreover, the Cu-Gly group had a lower concentration of 20-Oxo-leukotriene E4 and higher concentrations of butyric acid, pentanoic acid, isopentanoic acid, coumarin, and Nb-p-Coumaroyl-tryptamine than the CuSO₄ group. The abundance of Synergistetes was positively correlated with the fecal copper content and negatively correlated with the fecal butyric acid content. The abundance of the Lachnospiraceae_XPB1014_group genus was positively correlated with the plasma iron level and fecal contents of coumarin and butyric acid. In conclusion, Cu-Gly and CuSO₄ could differentially affect fecal microbiota and metabolites, which partially contributes to the intestinal health of pigs in different manners.

The profile of urinary lipid metabolites in healthy dogs

Polyunsaturated fatty acids, including arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), are converted to hundreds of lipid mediators by cyclooxygenases (COX), lipoxygenases (LOX), and cytochrome P450 (CYP), or through non-enzymatic processes, and they reflect inflammatory states of the body. We comprehensively analyzed lipid metabolites in dog urine using a liquid chromatograph-mass spectrometry (LC-MS/MS) to describe their metabolic characteristics. We detected 31 AA-derived metabolites, four EPA-derived metabolites, and a DHA-derived metabolite in all urine samples. Among AA-derived metabolites, 15, 5, 3, and 8 were generated by COX, LOX, CYP, and non-enzymatic oxidation respectively. This study will be the first step to use profiles of urinary lipid metabolites for better understanding and diagnosis of canine diseases.

Comprehensive profiling of lipid metabolites in urine of canine patients with liver mass

Fatty acids are an essential component of mammalian bodies. They go through different metabolic pathways depending on physiological states and inflammatory stimuli. In this study, we conducted a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based comprehensive analysis of lipid metabolites in urine of canine patients with liver mass. There were significant differences in quantity of some lipid metabolites that may be closely associated with the disease and/or general inflammatory responses, including increased metabolites of prostaglandin E₂ and/or PGF_2α. We demonstrated that our approach of profiling lipid metabolites in the urine is useful in gaining insights into the disease. These findings may also have an application as a screening test or a diagnosis tool for canine liver mass.

What are the potential biomarkers that should be considered in diagnosing and managing canine chronic inflammatory enteropathies?

Chronic inflammatory enteropathies in dogs are characterized by persistent or recurrent gastrointestinal signs that last for more than 3 weeks. Despite unclear etiopathogenesis, it is considered that a genetic predisposition associated with environmental factors, such as dietary antigens and intestinal microbiota, might induce an abnormal immune response in the host. The diagnosis of this condition requires full investigation in order to exclude all other possible causes. Currently, the observation of clinical signs associated with histopathologic evaluation and systematic therapeutic trials is the gold standard for the diagnosis of chronic enteropathies. Furthermore, diagnosis, monitoring the disease progression, and treatment response evaluation can be exhausting, since this whole process is time-consuming, costly, and partially invasive. Therefore, biomarkers appear as non-invasive tools, which can be useful in evaluating gastrointestinal function, identifying the presence of the disease and assessing its natural progression, monitoring gastrointestinal inflammation, predicting response to treatment, and clinical outcomes. Over the past decade, several studies were conducted in order to explore the clinical utility of biomarkers. Thus, the aim of this dissertation is to provide an overview of the biomarkers considered relevant in the diagnosis and management of dogs with chronic inflammatory enteropathies. The biomarkers addressed in this study may be serological, present in urine and feces, or even tissue-derived. This study argues that biomarkers, in particular calprotectin and calgranulin C, have great potential to be used in clinical practice in the diagnosis and management of affected dogs. However, a single biomarker cannot assuredly predict disease severity, progression, response to treatment, and clinical outcomes. Therefore, in order to achieve greater accuracy, it would be beneficial if these tools are used in conjunction with contemporary ones. Future research is needed with the aim to better determine the usefulness of these tools in chronic inflammatory enteropathies in dogs.

The profile of urinary lipid metabolites in cats

Polyunsaturated fatty acids including arachidonic acid (AA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are converted to lipid mediators by oxidation. Unlike other mammals, cats cannot synthesize AA. Since their lipid metabolic features remain unknown, we qualitatively analyzed 118 types of urinary lipid metabolites in healthy neutered cats. Using LC-MS, we found 26 lipid metabolites in urines of all individuals. In detail, 20 AA-, 5 EPA- and 1 DHA-derived lipid mediators were detected. Focusing on oxidative pathway, 17 cyclooxygenase-metabolites and 5 metabolites produced by non-enzymatic pathway were detected. Of interest, few lipoxygenase- or cytochrome P450-metabolites were excreted. Thus, AA-derived cyclooxygenase-metabolites mainly composed the urinary lipid metabolites in cats.

Association of 5'UTR polymorphism of secretory phospholipase A2 group IIA (PLA2G2A) gene with prostate cancer metastasis

Phospholipase A2 (PLA2) enzymes are small lipolytic hydrolases that can regulate immune responses through generation of Arachidonic Acid (AA), a precursor molecule of lipid mediators like prostaglandins, leukotrienes and thromboxanes. One of the family members of PLA2, secretory Phospholipase A2 Group IIA (PLA2G2A), was associated with different types of malignancies including prostate cancer. Elevated serum levels of PLA2G2A was found in prostate cancer (PCa) patients and associated with increased tumor grade in literature. 5'UTR regions have regulatory role in protein expression by controlling the accessibility of factors necessary for the translation initiation. Single nucleotide polymorphisms at 5'UTR regions have the potential to affect mRNA translation efficiency resulting in altered protein levels depending on structure and nucleotide content. Given that the 5'UTR polymorphism in PLA2G2A gene (rs11573156) is associated with increased serum levels of PLA2G2A, the association of this 5'UTR polymorphism with PCa susceptibility and metastasis was investigated in this study. Total of 261 PCa patients and 128 control individuals were genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Individuals with heterozygous CG genotype was found to have significantly reduced risk of PCa metastasis with an Odds Ratio (OR) of 0.405 (p = 0.028, 95%CI = 0.181-0.906), compared to the carriers of homozygous CC genotype (p > 0.05) suggesting an anti-metastatic effect for the G allele. No association was found between PCa susceptibility and Gleason score (p > 0.05) in Turkish population.

Cyclooxygenase-2 and 5-lipoxygenase in dogs with chronic enteropathies

Background

Cyclooxygenase‐2 (COX‐2) is a key enzyme in the synthesis of pro‐inflammatory prostaglandins and 5‐lipoxygenase (5‐LO) is the major source of leukotrienes. Their role in IBD has been demonstrated in humans and animal models, but not in dogs with chronic enteropathies (CCE).

Hypothesis

COX‐2 and 5‐LO are upregulated in dogs with CCE.

Animals

Fifteen healthy control dogs (HCD), 10 dogs with inflammatory bowel disease (IBD), and 15 dogs with food‐responsive diarrhea (FRD).

Methods

Prospective study. mRNA expression of COX‐2, 5‐LO, IL‐1b, IL‐4, IL‐6, TNF, IL‐10 and TFG‐β was evaluated by quantitative real‐time RT‐PCR in duodenal and colonic biopsies before and after treatment.

Results

COX‐2 expression in the colon was significantly higher in IBD and FRD before and after treatment (all P < .01). IL‐1b was higher in FRD in the duodenum after treatment (P = .021). TGF‐β expression was significantly higher in the duodenum of HCD compared to FRD/IBD before treatment (both P < .001) and IBD after treatment (P = .012). There were no significant differences among groups and within groups before and after treatment for IL‐4, IL‐6, TNF, and IL‐10. There was a significant correlation between COX‐2 and IL‐1b in duodenum and colon before treatment in FRD and IBD, whereas 5‐LO correlated better with IL‐6 and TNF. IL‐10 and TGF‐β usually were correlated.

Conclusions and Clinical Importance

COX‐2 is upregulated in IBD and FRD, whereas IL‐1b and TGF‐β seem to be important pro‐ and anti‐inflammatory cytokines, respectively. The use of dual COX/5‐LO inhibitors could be an interesting alternative in the treatment of CCE.

Biomarkers in canine inflammatory bowel disease diagnostics

Canine inflammatory bowel disease (IBD) is a heterogeneous group of chronic gastrointestinal disorders. The etiology, similar to human IBD, remains unknown. Canine IBD is diagnosed by exclusion, which is a long, time and money-consuming process due to the need of elimination of other diseases presenting with similar symptoms. Therefore, a search for a specific and sensitive marker is needed to overcome these difficulties. The article is divided into 3 sections presenting up-to-date information about laboratory markers, immunohistochemical markers and changes in the neurochemical coding of the enteric nervous system, concentrating on their usefulness and future applications. Data concerning laboratory and immunohistochemical markers is based mainly on canine IBD, while the neuroimmunohistochemistry section presents knowledge from human IBD due to the lack of such studies in veterinary medicine.