SARS-CoV-2 accessory proteins involvement in inflammatory and profibrotic processes through IL11 signaling.

SARS-CoV-2, the cause of the COVID-19 pandemic, possesses eleven accessory proteins encoded in its genome. Their roles during infection are still not completely understood. In this study, transcriptomics analysis revealed that both WNT5A and IL11 were significantly up-regulated in A549 cells expressing individual accessory proteins ORF6, ORF8, ORF9b or ORF9c from SARS-CoV-2 (Wuhan-Hu-1 isolate). IL11 is a member of the IL6 family of cytokines. IL11 signaling-related genes were also differentially expressed. Bioinformatics analysis disclosed that both WNT5A and IL11 were involved in pulmonary fibrosis idiopathic disease and functional assays confirmed their association with profibrotic cell responses. Subsequently, data comparison with lung cell lines infected with SARS-CoV-2 or lung biopsies from patients with COVID-19, evidenced altered profibrotic gene expression that matched those obtained in this study. Our results show ORF6, ORF8, ORF9b and ORF9c involvement in inflammatory and profibrotic responses. Thus, these accessory proteins could be targeted by new therapies against COVID-19 disease.

Salmonella Typhimurium induces genome-wide expression and phosphorylation changes that modulate immune response, intracellular survival and vesicle transport in infected neutrophils.

Salmonella Typhimurium is a food-borne pathogen that causes salmonellosis. When in contact with the host, neutrophils are rapidly recruited to act as first line of defense. To better understand the pathogenesis of this infection, we used an in vitro model of neutrophil infection to perform dual RNA-sequencing (both host and pathogen). In addition, and given that many pathogens interfere with kinase-mediated phosphorylation in host signaling, we performed a phosphoproteomic analysis. The immune response was overall diminished in infected neutrophils, mainly JAK/STAT and toll-like receptor signaling pathways. We found decreased expression of proinflammatory cytokine receptor genes and predicted downregulation of the mitogen-activated protein (MAPK) signaling pathway. Also, Salmonella infection inhibited interferons I and II signaling pathways by upregulation of SOCS3 and subsequent downregulation of STAT1 and STAT2. Additionally, phosphorylation of PSMC2 and PSMC4, proteasome regulatory proteins, was decreased in infected neutrophils. Cell viability and survival was increased by p53 signaling, cell cycle arrest and NFkB-proteasome pathways activation. Combined analysis of RNA-seq and phosphoproteomics also revealed inhibited vesicle transport mechanisms mediated by dynein/dynactin and exocyst complexes, involved in ER-to-Golgi transport and centripetal movement of lysosomes and endosomes. Among the overexpressed virulence genes from Salmonella we found potential effectors responsible of these dysregulations, such as spiC, sopD2, sifA or pipB2, all of them involved in intracellular replication. Our results suggest that Salmonella induces (through overexpression of virulence factors) transcriptional and phosphorylation changes that increases neutrophil survival and shuts down immune response to minimize host response, and impairing intracellular vesicle transport likely to keep nutrients for replication and Salmonella-containing vacuole formation and maintenance.

Impairment of antiviral immune response and disruption of cellular functions by SARS-CoV-2 ORF7a and ORF7b.

SARS-CoV-2, the causative agent of the present COVID-19 pandemic, possesses eleven accessory proteins encoded in its genome, and some have been implicated in facilitating infection and pathogenesis through their interaction with cellular components. Among these proteins, accessory protein ORF7a and ORF7b functions are poorly understood. In this study, A549 cells were transduced to express ORF7a and ORF7b, respectively, to explore more in depth the role of each accessory protein in the pathological manifestation leading to COVID-19. Bioinformatic analysis and integration of transcriptome results identified defined canonical pathways and functional groupings revealing that after expression of ORF7a or ORF7b, the lung cells are potentially altered to create conditions more favorable for SARS-CoV-2, by inhibiting the IFN-I response, increasing proinflammatory cytokines release, and altering cell metabolic activity and adhesion. Based on these results, it is plausible to suggest that ORF7a or ORF7b could be used as biomarkers of progression in this pandemic.

Study of microRNA expression in Salmonella Typhimurium-infected porcine ileum reveals miR-194a-5p as an important regulator of the TLR4-mediated inflammatory response.

Infection with Salmonella Typhimurium (S. Typhimurium) is a common cause of food-borne zoonosis leading to acute gastroenteritis in humans and pigs, causing economic losses to producers and farmers, and generating a food security risk. In a previous study, we demonstrated that S. Typhimurium infection produces a severe transcriptional activation of inflammatory processes in ileum. However, little is known regarding how microRNAs regulate this response during infection. Here, small RNA sequencing was used to identify 28 miRNAs differentially expressed (DE) in ileum of S. Typhimurium-infected pigs, which potentially regulate 14 target genes involved in immune system processes such as regulation of cytokine production, monocyte chemotaxis, or cellular response to interferon gamma. Using in vitro functional and gain/loss of function (mimics/CRISPR-Cas system) approaches, we show that porcine miR-194a-5p (homologous to human miR-194-5p) regulates TLR4 gene expression, an important molecule involved in pathogen virulence, recognition and activation of innate immunity in Salmonella infection.

SARS-CoV-2 Accessory Proteins in Viral Pathogenesis: Knowns and Unknowns.

There are still many unanswered questions concerning viral SARS-CoV-2 pathogenesis in COVID-19. Accessory proteins in SARS-CoV-2 consist of eleven viral proteins whose roles during infection are still not completely understood. Here, a review on the current knowledge of SARS-CoV-2 accessory proteins is summarized updating new research that could be critical in understanding SARS-CoV-2 interaction with the host. Some accessory proteins such as ORF3b, ORF6, ORF7a and ORF8 have been shown to be important IFN-I antagonists inducing an impairment in the host immune response. In addition, ORF3a is involved in apoptosis whereas others like ORF9b and ORF9c interact with cellular organelles leading to suppression of the antiviral response in infected cells. However, possible roles of ORF7b and ORF10 are still awaiting to be described. Also, ORF3d has been reassigned. Relevant information on the knowns and the unknowns in these proteins is analyzed, which could be crucial for further understanding of SARS-CoV-2 pathogenesis and to design strategies counteracting their actions evading immune responses in COVID-19.

Reprogramming of microRNA expression via E2F1 downregulation promotes Salmonella infection both in infected and bystander cells.

Cells infected with pathogens can contribute to clearing infections by releasing signals that instruct neighbouring cells to mount a pro-inflammatory cytokine response, or by other mechanisms that reduce bystander cells' susceptibility to infection. Here, we show the opposite effect: epithelial cells infected with Salmonella Typhimurium secrete host factors that facilitate the infection of bystander cells. We find that the endoplasmic reticulum stress response is activated in both infected and bystander cells, and this leads to activation of JNK pathway, downregulation of transcription factor E2F1, and consequent reprogramming of microRNA expression in a time-dependent manner. These changes are not elicited by infection with other bacterial pathogens, such as Shigella flexneri or Listeria monocytogenes. Remarkably, the protein HMGB1 present in the secretome of Salmonella-infected cells is responsible for the activation of the IRE1 branch of the endoplasmic reticulum stress response in non-infected, neighbouring cells. Furthermore, E2F1 downregulation and the associated microRNA alterations promote Salmonella replication within infected cells and prime bystander cells for more efficient infection.

The Effect of Atopic Dermatitis and Diet on the Skin Transcriptome in Staffordshire Bull Terriers.

Canine atopic dermatitis (CAD) has a hereditary basis that is modified by interactions with the environment, including diet. Differentially expressed genes in non-lesional skin, determined by RNA sequencing before and after a dietary intervention, were compared between dogs with naturally occurring CAD (n = 4) and healthy dogs (n = 4). The dogs were fed either a common commercial heat-processed high carbohydrate food (kibble diet) (n = 4), or a non-processed high fat food (raw meat-based diet) (n = 4). At the end of the diet intervention, 149 differentially expressed transcripts were found between the atopic and healthy dogs. The main canonical pathways altered by the dysregulation of these genes were angiopoietin signaling, epidermal growth factor signaling, activation of angiogenesis, and alterations in keratinocyte proliferation and lipid metabolism. On the other hand, 33 differently expressed transcripts were found between the two diet groups, of which 8 encode genes that are annotated in the current version of the dog genome: immunoglobulin heavy constant mu (IGHM), immunoglobulin lambda-like polypeptide 5 (IGLL5), B-cell antigen receptor complex-associated protein beta chain (CD79B), polymeric immunoglobulin receptor (PIGR), cystathionine ß-synthase (CBS), argininosuccinate synthase 1 (ASS1), secretory leukocyte peptidase inhibitor (SLPI), and mitochondrial ribosome recycling factor (MRRF). All genes were upregulated in the raw diet group. In conclusion the findings of this study suggest alterations in lipid and keratinocyte metabolism as well as angiogenesis in the skin of atopic dogs. Additionally, a possible enhancement of innate immunity and decrease in oxidative stress was seen in raw food fed dogs, which could have an important role in preventing hypersensitivities and disturbed immunity at young age.

The effect of a raw vs dry diet on serum biochemical, hematologic, blood iron, B12 , and folate levels in Staffordshire Bull Terriers.

BACKGROUND: To date, very few studies have compared the effects of different types of feeding practices on canine physiology, such as feeding exclusively dry, raw, or homemade foods. OBJECTIVES: We aimed to report the changes in hematologic, serum biochemical, plasma folate, B12 , and whole blood iron levels in dogs fed two different diets. METHODS: A pilot study was developed to compare the effects of a heat-processed high carbohydrate (HPHC) and nonprocessed high-fat (NPHF) diet. A total of 33 client-owned Staffordshire Bull Terriers were used; 18 had canine atopic dermatitis, seven were healthy, and eight were grouped as "borderline" dogs since they did not fulfill at least six of Favrot's criteria. The comparisons were made between the diet groups at the end visit of the diet intervention, as well as within the diet groups during the study. RESULTS: Significant differences between and within the diet groups were observed, although the majority of outcomes remained within the RIs. The median time of diet intervention was 140 days. Red blood cell counts, mean cell hemoglobin concentrations, and platelet counts were significantly higher, and mean cell hemoglobin, mean cell volume, alkaline phosphatase, inorganic phosphorus, and cholesterol were significantly lower in the dogs fed the NPHF diet compared with those fed the HPHC diet after the diet trial was completed. In addition, folate, B12 , and iron decreased significantly in the NPHF diet group. CONCLUSIONS: This pilot study indicated that diet had an impact on blood values, although most remained within RIs, pointing out the need for further studies.

Functional screenings reveal different requirements for host microRNAs in Salmonella and Shigella infection.

MicroRNAs (miRNAs) are increasingly recognized for their role in infection by bacterial pathogens, although the effect of each individual miRNA remains largely unknown. Here, we used a comparative genome-wide microscopy-based functional screening approach to identify miRNAs controlling infection by two bacterial pathogens-Salmonella enterica serovar Typhimurium and Shigella flexneri. Despite the similarities between these pathogens, we found infections to be controlled by largely non-overlapping subsets of miRNAs, seemingly reflecting different requirements prompted by their distinct intracellular lifestyles. By characterizing a small subset of miRNAs chosen among the strongest inhibitors of Shigella infection, we discovered that miR-3668, miR-4732-5p and miR-6073 exert a selective effect on Shigella infection by impairing bacterial actin-based motility by downregulating N-WASP. Additionally, by identifying let-7i-3p miRNA as a strong inhibitor of Salmonella replication and performing in-depth analysis of its mechanisms of action, we showed that this miRNA specifically inhibits Salmonella infection via modulation of endolysosomal trafficking and the vacuolar environment by targeting the host RGS2 protein. These findings illustrate two paradigms underlying miRNA-mediated regulation of bacterial infection, acting as part of the host response to infection, or as part of bacterial strategies to modulate the host environment and favour pathogenesis.

Owners' perception of acquiring infections through raw pet food: a comprehensive internet-based survey.

There has been concerns related to the risk of bacterial contamination from raw pet food to humans, but research is still scarce. The purpose of this cross-sectional study was to use a worldwide internet survey-based data to evaluate the impact of raw pet foods on human health from the owners' experience. From 16 475 households, 0.2 per cent (n=39) reported having had a transmission of pathogen from the raw pet food to a human family member during the time that raw feeding had been used in the household. Only in three of those households the same pathogen that was found in the human sample was analysed and confirmed also in the raw pet food (0.02 per cent of all data). Moreover, 0.1 per cent (n=24) reported suspecting that a disease could have been transmitted to a human from the pet food. Feeding salmon and turkey, using more than 50 per cent of the diet as raw foods and preparing the raw food in the same place and utensils as the family foods all had negative association with infections. Having 2 to 6 year-old children living in the household was associated with more infections, although adults were the most frequently infected.

Salmonella Typhimurium Infection Along the Porcine Gastrointestinal Tract and Associated Lymphoid Tissues.

Salmonella is a major foodborne pathogen and pork is one of the main sources of human salmonellosis. Understanding the pathogenesis and progression of the infection within the host is of interest to establish potential approaches to control the disease in pigs. The present study evaluates factors such as intestinal colonization, fecal shedding, and pathogen persistence by 2 studies using experimental challenge with Salmonella Typhimurium in weaned pigs and euthanasia at different time points (1, 2, and 6 and 2, 14, and 30 days postinfection [dpi], respectively). Histopathology of intestine at early time points (1 dpi and 2 dpi) showed severe damage to the epithelium together with an increase in polymorphonuclear cells and macrophages (P < .001), particularly in jejunum and ileum. Large quantities of Salmonella were detected within the contents of the ileum, cecum, and colon in early infection. Salmonella could also be observed in the medulla of tonsils and mesenteric lymph nodes. From 6 dpi onward, signs of recovery were observed, with progressive restoration of the epithelium, reduction of the inflammatory infiltrate, and elimination of Salmonella from the mucosa. Concentration of Salmonella in feces and ileum content decreased, but shedding did not cease even at 4 weeks after infection. Persistence of the bacteria in mesenteric lymph nodes was identified within the connective tissue at 14 and 30 dpi. Our results demonstrate a recovery of the disease after an initial acute phase but also show persistence within the lumen and surrounding lymphoid tissue. These findings are relevant to developing effective control strategies.

Risk-modeling of dog osteosarcoma genome scans shows individuals with Mendelian-level polygenic risk are common.

BACKGROUND: Despite the tremendous therapeutic advances that have stemmed from somatic oncogenetics, survival of some cancers has not improved in 50 years. Osteosarcoma still has a 5-year survival rate of 66%. We propose the natural canine osteosarcoma model can change that: it is extremely similar to the human condition, except for being highly heritable and having a dramatically higher incidence. Here we reanalyze published genome scans of osteosarcoma in three frequently-affected dog breeds and report entirely new understandings with immediate translational indications. RESULTS: First, meta-analysis revealed association near FGF9, which has strong biological and therapeutic relevance. Secondly, risk-modeling by multiple logistic regression shows 22 of the 34 associated loci contribute to risk and eight have large effect sizes. We validated the Greyhound stepwise model in our own, independent, case-control cohort. Lastly, we updated the gene annotation from approximately 50 genes to 175, and prioritized those using cross-species genomics data. Mostly positional evidence suggests 13 genes are likely to be associated with mapped risk (including MTMR9, EWSR1 retrogene, TANGO2 and FGF9). Previous annotation included seven of those 13 and prioritized four by pathway enrichment. Ten of our 13 priority genes are in loci that contribute to risk modeling and thus can be studied epidemiologically and translationally in pet dogs. Other new candidates include MYCN, SVIL and MIR100HG. CONCLUSIONS: Polygenic osteosarcoma-risk commonly rises to Mendelian-levels in some dog breeds. This justifies caninized animal models and targeted clinical trials in pet dogs (e.g., using CDK4/6 and FGFR1/2 inhibitors).

Early Salmonella Typhimurium infection in pigs disrupts Microbiome composition and functionality principally at the ileum mucosa.

Salmonella is a major foodborne pathogen which successfully infects animal species for human consumption such as swine. The pathogen has a battery of virulence factors which it uses to colonise and persist within the host. The host microbiota may play a role in resistance to, and may also be indirectly responsible from some of the consequences of, Salmonella infection. To investigate this, we used 16S rRNA metagenomic sequencing to determine the changes in the gut microbiota of pigs in response to infection by Salmonella Typhimurium at three locations: ileum mucosa, ileum content and faeces. Early infection (2 days post-infection) impacted on the microbiome diversity at the mucosa, reflected in a decrease in representatives of the generally regarded as desirable genera (i.e., Bifidobacterium and Lactobacillus). Severe damage in the epithelium of the ileum mucosa correlated with an increase in synergistic (with respect to Salmonella infection; Akkermansia) or opportunistically pathogenic bacteria (Citrobacter) and a depletion in anaerobic bacteria (Clostridium spp., Ruminococcus, or Dialliser). Predictive functional analysis, together with metabolomic analysis revealed changes in glucose and lipid metabolism in infected pigs. The observed changes in commensal healthy microbiota, including the growth of synergistic or potentially pathogenic bacteria and depletion of beneficial or competing bacteria, could contribute to the pathogen's ability to colonize the gut successfully. The findings from this study could be used to form the basis for further research aimed at creating intervention strategies to mitigate the effects of Salmonella infection.

Regulatory role of microRNA in mesenteric lymph nodes after Salmonella Typhimurium infection.

Salmonellosis is a gastrointestinal disease caused by non-typhoidal Salmonella serovars such as Salmonella Typhimurium. This pathology is a zoonosis, and food animals with subclinical infection constitute a vast reservoir for disease. After intestinal colonization, Salmonella Typhimurium reaches mesenteric lymph nodes (MLN), where infection is controlled avoiding systemic spread. Although the molecular basis of this infection has been extensively studied, little is known about how microRNA (miRNA) regulate the expression of proteins involved in the Salmonella-host interaction. Using small RNA-seq, we examined expression profiles of MLN 2 days after infection with Salmonella Typhimurium, and we found 110 dysregulated miRNA. Among them, we found upregulated miR-21, miR-155, miR-150, and miR-221, as well as downregulated miR-143 and miR-125, all of them previously linked to other bacterial infections. Integration with proteomic data revealed 30 miRNA potentially regulating the expression of 15 proteins involved in biological functions such as cell death and survival, inflammatory response and antigenic presentation. The inflammatory response was found increased via upregulation of miRNA such as miR-21 and miR-155. Downregulation of miR-125a/b, miR-148 and miR-1 were identified as potential regulators of MHC-class I components PSMB8, HSP90B1 and PDIA3, respectively. Furthermore, we confirmed that miR-125a is a direct target of immunoproteasome component PSMB8. Since we also found miR-130 downregulation, which is associated with upregulation of HSPA8, we suggest induction of both MHC-I and MHC-II antigen presentation pathways. In conclusion, our study identifies miRNA that could regulate critical networks for antigenic presentation, inflammatory response and cytoskeletal rearrangements.

Phenotypic and functional characterization of porcine bone marrow monocyte subsets.

Monocytes comprise several subsets with distinct phenotypes and functional capacities. Based on CD163 expression, two major monocyte subsets can be discriminated in the porcine bone marrow. The CD163+ cells expressed higher levels of SLA-DR, Siglec-1, CD11R1 and CD16 when compared to CD163- monocytes, whereas no remarkable differences were observed in the expression of other markers analyzed. Gene expression analysis showed differential expression of several chemokine receptor and TLR genes. Both subsets phagocytosed microspheres with similar efficiency. However, CD163- cells tended to produce higher levels of ROS in response to PMA, whereas CD163+ cells were more efficient in endocytosing and processing antigens (DQ-OVA). CD163- monocytes produced higher levels of TNF-α and IL-10 than CD163+ cells when stimulated with LPS or Imiquimod. Both subsets produced similar amounts of IL-8 in response to LPS; however, CD163+ cells produced more IL-8 after Imiquimod stimulation. Whether these subsets represent different developmental stages, and how are they related remain to be investigated.

Comparative Proteomics Reveals Differences in Host-Pathogen Interaction between Infectious and Commensal Relationship with Campylobacter jejuni.

Campylobacter jejuni is the leading food-borne poisoning in industrialized countries. While the bacteria causes disease in humans, it merely colonizes the gut in poultry or pigs, where seems to establish a commensal relationship. Until now, few studies have been conducted to elucidate the relationship between C. jejuni and its different hosts. In this work, a comparative proteomics approach was used to identify the underlying mechanisms involved in the divergent outcome following C. jejuni infection in human and porcine host. Human (INT-407) and porcine (IPEC-1) intestinal cell lines were infected by C. jejuni for 3 h (T3h) and 24 h (T24h). C. jejuni infection prompted an intense inflammatory response at T3h in human intestinal cells, mainly characterized by expression of proteins involved in cell spreading, cell migration and promotion of reactive oxygen species (ROS). Proteomic analysis evidenced significantly regulated biofunctions in human cells related with engulfment and endocytosis, and supported by canonical pathways associated to infection such as caveolar- and clathrin-mediated endocytosis signaling. In porcine IPEC-1 cells, inflammatory response as well as signaling pathways that control cellular functions such as cell migration, endocytosis and cell cycle progression resulted downregulated. These differences in the host response to infection were supported by the different pattern of adhesion and invasion proteins expressed by C. jejuni in human and porcine cells. No marked differences in expression of virulence factors involved in adaptive response and iron acquisition functions were observed. Therefore, the results of this study suggest that both host and pathogen factors are responsible for commensal or infectious character of C. jejuni in different hosts.

Comparative genomics of canine hemoglobin genes reveals primacy of beta subunit delta in adult carnivores.

BACKGROUND: The main function of hemoglobin (Hb) is to transport oxygen in the circulation. It is among the most highly studied proteins due to its roles in physiology and disease, and most of our understanding derives from comparative research. There is great diversity in Hb gene evolution in placental mammals, mostly in the repertoire and regulation of the ß-globin subunits. Dogs are an ideal model in which to study Hb genes because: 1) they are members of Laurasiatheria, our closest relatives outside of Euarchontoglires (including primates, rodents and rabbits), 2) dog breeds are isolated populations with their own Hb-associated genetics and diseases, and 3) their high level of health care allows for development of biomedical investigation and translation. RESULTS: We established that dogs have a complement of five α and five ß-globin genes, all of which can be detected as spliced mRNA in adults. Strikingly, HBD, the allegedly-unnecessary adult ß-globin protein in humans, is the primary adult ß-globin in dogs and other carnivores; moreover, dogs have two active copies of the HBD gene. In contrast, the dominant adult ß-globin of humans, HBB, has high sequence divergence and is expressed at markedly lower levels in dogs. We also showed that canine HBD and HBB genes are complex chimeras that resulted from multiple gene conversion events between them. Lastly, we showed that the strongest signal of evolutionary selection in a high-altitude breed, the Bernese Mountain Dog, lies in a haplotype block that spans the ß-globin locus. CONCLUSIONS: We report the first molecular genetic characterization of Hb genes in dogs. We found important distinctions between adult ß-globin expression in carnivores compared to other members of Laurasiatheria. Our findings are also likely to raise new questions about the significance of human HBD. The comparative genomics of dog hemoglobin genes sets the stage for diverse research and translation.

Transcriptional analysis of porcine intestinal mucosa infected with Salmonella Typhimurium revealed a massive inflammatory response and disruption of bile acid absorption in ileum.

Infected pork meat is an important source of non-typhoidal human salmonellosis. Understanding of molecular mechanisms involved in disease pathogenesis is important for the development of therapeutic and preventive strategies. Thus, hereby we study the transcriptional profiles along the porcine intestine during infection with Salmonella Typhimurium, as well as post-transcriptional gene modulation by microRNAs (miRNA). Sixteen piglets were orally challenged with S. Typhimurium. Samples from jejunum, ileum and colon, collected 1, 2 and 6 days post infection (dpi) were hybridized to mRNA and miRNA expression microarrays and analyzed. Jejunum showed a reduced transcriptional response indicating mild inflammation only at 2 dpi. In ileum inflammatory genes were overexpressed (e.g., IL-1B, IL-6, IL-8, IL1RAP, TNFα), indicating a strong immune response at all times of infection. Infection also down-regulated genes of the FXR pathway (e.g., NR1H4, FABP6, APOA1, SLC10A2), indicating disruption of the bile acid absorption in ileum. This result was confirmed by decreased high-density lipoprotein cholesterol in serum of infected pigs. Ileal inflammatory gene expression changes peaked at 2 dpi and tended to resolve at 6 dpi. Furthermore, miRNA analysis of ileum at 2 dpi revealed 62 miRNAs potentially regulating target genes involved in this inflammatory process (e.g., miR-374 and miR-451). In colon, genes involved in epithelial adherence, proliferation and cellular reorganization were down-regulated at 2 and 6 dpi. In summary, here we show the transcriptional changes occurring at the intestine at different time points of the infection, which are mainly related to inflammation and disruption of the bile acid metabolism.

Plasma N-terminal pro-B-type natriuretic peptide concentration in healthy retired racing Greyhounds.

BACKGROUND: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a cardiac biomarker whose plasma concentration is high in some dogs with cardiopulmonary disease. NT-proBNP is a diagnostic tool that can be used to help determine if a patient has congestive heart failure. Greyhounds have functional heart murmurs, relative cardiomegaly, and high serum cTnI concentration. OBJECTIVES: The purpose of the study was to evaluate the plasma concentration of NT-proBNP in healthy Greyhounds and compare it to non-Greyhound dogs. METHODS: We prospectively evaluated healthy client-owned dogs including retired racing Greyhounds and non-Greyhounds. Plasma was obtained and transferred into tubes containing a protease inhibitor and submitted for a specific NT-proBNP ELISA assay. RESULTS: The plasma NT-proBNP concentration in Greyhounds was significantly higher than in non-Greyhound control dogs (946 vs 632 pmol/L; P < .005); 46% of Greyhounds had NT-proBNP > 1000 pmol/L. CONCLUSIONS: Plasma NT-proBNP concentration in Greyhounds is high and should be interpreted with caution.

Epsilon aminocaproic acid for the prevention of delayed postoperative bleeding in retired racing greyhounds undergoing gonadectomy.

OBJECTIVE: To evaluate the effects of epsilon aminocaproic acid (EACA) on the prevalence of postoperative bleeding in retired racing Greyhounds (RRG), and to assess its effects on selected thrombelastography (TEG) and fibrinolysis variables. STUDY DESIGN: Double-blinded, prospective, randomized study. METHODS: 100 RRG had elective ovariohysterectomy or orchiectomy and were administered EACA or placebo for 3 days after surgery. TEG variables were analyzed preoperatively and 24, 48, and 72 hours after surgery. RESULTS: Thirty percent (15/50) of RRG in the placebo group had delayed postoperative bleeding starting 36-48 hours after surgery compared with 10% (5/50) in the EACA group (P = .012). On the TEG variables, the slopes for R and K time were significantly different between treatment groups (P <.05); the R and K time decreased over time in the EACA group after surgery whereas they increased in the placebo group. The angle, maximal amplitude (MA), and G slopes were also significantly different between treatment groups (P = .001, .001, and .006, respectively). The angle, MA, and G increased postoperatively over time in the EACA group and decreased in the placebo group. All these changes are supportive of hypercoagulability associated with EACA administration. CONCLUSION: Postoperative administration of EACA significantly decreased the prevalence of postoperative bleeding in RRG undergoing surgery by increasing the clot strength.