Magdalena Garncarz

Plasma miRNAs as potential biomarkers of chronic degenerative valvular disease in Dachshunds

BackgroundEndocardiosis is the most common heart disease in Dachshunds and is therefore an important cause of cardiac morbidity and death. In recent years we have observed an increasing interest in the development of new genetic and genomic markers of heart disease. The discovery of miRNAs circulating in biofluids such as plasma or serum aroused researchers’ interest in using them as potential biomarkers. In the present study we analysed the expression of 9 miRNAs described in literature as being involved in cardiovascular pathology in the plasma of dogs suffering from endocardiosis.ResultsExpression analysis using the Real-time PCR method revealed that two out of nine miRNAs were significantly downregulated: the expression of miR-30b differed between ACVIM stage B and stage A (control) dogs; the expression of mi-133b differed ACVIM stage C and stage A dogs. 5 miRNAs (miR-125, miR-126, miR-21, miR-29b and miR-30b) showed a trend of downregulation in the ACVIM C group. Levels of miR-423 were the same in healthy and diseased dogs. Expression of miR-208a and 208b was not detected.ConclusionsmiR-30b could be a potential biomarker of ACVIM stage B heart failure in Dachshunds with endocardiosis and miR-133b could be a potential biomarker of ACVIM stage C. The lack of expression or lack of significant changes in expression in 7 miRNAs which are potential biomarkers of heart diseases in humans proves that findings from human medicine are not always directly reflected in veterinary medicine.

A retrospective study of clinical signs and epidemiology of chronic valve disease in a group of 207 Dachshunds in Poland

BackgroundChronic mitral valve disease is frequently seen in the Dachshund. Dachshunds (n=207) made up 11.73% of the dogs admitted to the Cardiology Service at the Small Animal Clinic, Warsaw University of Life Sciences, Poland (first visits only).ResultsOf these, 35 dogs had no clinically detectable heart disease while 172 had chronic valve disease with the mitral valve affected most often (130 dogs), both mitral and tricuspid valves infrequently (39 dogs) and rarely the tricuspid valve (3 dogs). Males were affected more frequently than females and the average age of dogs with chronic valve disease was 11.9 years for females and 11.3 years for males. A majority of the diseased Dachshunds were classified as ISACHC 2 (79), followed by ISACHC 1 (60). Most frequent clinical signs noted by owners included coughing, exercise intolerance, dyspnea and tachypnea. Heart murmurs were generally louder with increased disease severity; however there were 20 dogs in the ISACHC 1 group with no audible heart murmurs. The most frequent electrocardiographic abnormalities included an increased P wave and QRS complex duration, increased R wave amplitude and tachycardia. With increased disease severity, echocardiography revealed an increase in heart size. A higher ISACHC class was related to increased heart size (based on echocardiography) and increased percentage of patients exhibiting enlargement of both left atrium and left ventricle (based on radiography).ConclusionsThe Dachshund is often affected by chronic mitral valvular disease with a late onset of associated clinical signs and few cardiac complications.

The transcriptomic profile of peripheral blood nuclear cells in dogs with heart failure

BackgroundIn recent years advances have been made in the investigative methods of molecular background of canine heart disease. Studies have been conducted to identify specific genes which, when pathologically expressed, could lead to the dysfunction of the canine heart or are correlated with heart failure. For this purpose genome wide microarray experiments on tissues from failing hearts have been performed. In the presented study a whole genome microarray analysis was used for the first time to describe the transcription profile of peripheral blood nuclear cells in dogs with heart failure. Dogs with recognized heart disease were classified according the ISACHC (International Small Animal Cardiac Health Council) classification scheme as class 1 (asymptomatic) - 13 dogs, class 2 (mild to moderate heart failure) - 13 dogs and class 3 (severe heart failure) - 12 dogs. The control group consisted of 14 healthy dogs. The clinical picture of the animals included: animal history, clinical examination, echocardiographic examination and where applicable electrocardiographic and radiographic examinations.ResultsIn the present study we identified four sets of differentially expressed genes, namely heart-failure-specific genes and ISACHC1-specific genes, ISACHC2-sepcific genes and ISACHC-3 specific genes. The most important set consisted of genes differentially expressed in all dogs with heart failure, despite the ISACHC stage. We identified 71 heart-failure-specific genes which were involved in two statistically significant receptor signalling pathways, namely angiotensinR - > CREB/ELK-SRF/TP53 signalling and ephrinR - > actin signalling. The number of ISACHC1-specific genes was 83; ISACHC2-specific genes - 1247 and ISACHC3-specific - 200.ConclusionsThe transcriptomic profile of peripheral blood nuclear cells in dogs with heart failure seems to reflect the presence of clinical signs of the disease in patients based on the observation that the largest number of differentially expressed genes was identified in ISACHC 2 group of patients. This group consists of dogs just starting to show clinical signs of heart failure. A set of genes was also found to have changed expression in all dogs with heart failure, despite the stage of the disease.

Genomic and genetic aspects of heart failure in dogs - a review.

The most common causes of heart failure in dogs are valvular disease, predominantly endocardiosis, and myocardial disease, predominantly dilated cardiomyopathy. They are related to changes in the expression of several genes in the heart muscle and in peripheral blood nuclear cells which could be considered as prognostic or diagnostic markers of heart disease in dogs. Since many human genetic markers of heart failure have turned out to be useless in dogs, the screening for genomic markers of canine heart failure could give more insight into the molecular pathology of these diseases and aid the development of new treatment strategies.

Correlation between peripheral blood cell transcriptomic profile and clinical parameters of chronic mitral valve disease in Dachshunds

Studies identifying specific pathologically expressed genes have been performed on diseased myocardial tissue samples, however less invasive studies on gene expression of peripheral blood mononucleated cells give promising results. This study assessed transcriptomic data that may be used to evaluate Dachshunds with chronic mitral valve disease. Dachshunds with different stages of heart disease were compared to a control, healthy group. Microarray data analysis revealed clusters of patients with similar expression profiles. The clusters were compared to the clinical classification scheme. Unsupervised classification of the studied groups showed three clusters. Clinical and laboratory parameters of patients from the cluster 1 were in accordance with those found in patients without heart disease. Data obtained from patients from the cluster 3 were typical of advanced heart failure patients. Comparison of the cluster 1 and 3 groups revealed 1133 differentially expressed probes, 7 significantly regulated process pathways and 2 significantly regulated Ariadne Metabolic Pathways. This study may serve as a guideline for directing future research on gene expression in chronic mitral valve disease.

Comparison of oscillometric, Doppler and invasive blood pressure measurement in anesthetized goats

Arterial blood pressure (BP) can be measured directly using an invasive intra-arterial method. This method is considered a gold standard, however it is potentially hazardous and requires expensive equipment and professional skills. Therefore, two non-invasive methods–Doppler ultrasonic sphygmomanometry and oscillometry–have been introduced in veterinary medicine. Their accuracy has so far been reliably evaluated in various animal species, however only one study included a small group of goats. Therefore, we carried out a large-scale study which aimed to evaluate agreement between the two non-invasive methods and invasive intra-arterial BP measurement in anesthetized goats at various age. The study included 122 goats of two Polish local breeds (Polish White Improved and Polish Fawn Improved): 67 adult females, 35 adult males, and 20 two-month-old female kids. Goats were anesthetized with the intravenous mixture of xylazine and ketamine. BP was measured simultaneously with the three methods in each goat with 7 measurements on average taken. The study showed that according to the criteria of the American College of Veterinary Internal Medicine (ACVIM) oscillometric method yielded BP measurements sufficiently consistent with invasive intra-arterial method in anesthetized adult goats– 95% of oscillometric BP measurements were expected to differ from invasive BP measurements by at most ±20–25 mmHg. The agreement was worse in goat kids–oscillometry significantly overestimated invasive BP measurements, which resulted in highly asymmetrical 95% limits of agreement. Doppler systolic BP very poorly conformed to invasive systolic BP both in adult goats and in kids and all the ACVIM criteria were violated. Concluding, oscillometry, but not Doppler ultrasonic sphygmomanometry, may be regarded as an alternative to invasive BP measurement in large-scale scientific studies involving adult goats, however, individual oscillometric BP measurements should be treated with caution as estimated 95% limits of agreement were wide.

Mitral regurgitation in Dachshund dogs without heart murmurs

Abstract Introduction: Older small breed dogs are considered at risk for heart failure secondary to chronic mitral valve disease. However, few data are available on the onset of this disease in such dogs. This study was performed to determine if auscultation alone can be used to eliminate clinically relevant mitral valve regurgitation seen in echocardiography in Dachshund dogs. Material and Methods: Clinical and echocardiographic data were obtained from 107 dogs without heart murmurs. Results: The study revealed that 63.6% of the dogs had mitral regurgitation. Numbers increased with age and a larger percentage of male Dachshunds were affected than female Dachshunds. Mitral valve prolapse and thickening were mild, and the regurgitant area inextensive in most dogs. Conclusions: The study shows that mitral valve regurgitation is prevalent (63.6%) in Dachshunds without heart murmurs. Typical lesions often become apparent during echocardiographic examinations in dogs under 5 years of age.

ProANP as a screening biomarker for hypertrophic cardiomyopathy in Maine coon cats

The aim of this study was to determine if atrial natriuretic peptide can be used as an early screening tool for hypertrophic cardiomyopathy in Maine coon cats. ANIMALS The study was performed in 43 Maine coon cats of both sexes, aged 11 to 92 months. Clinical and echocardiographic examinations were done and proANP serum concentrations were measured every three months over a period of one year (each cat had a total of five examinations). Cats were divided into 3 groups based on echocardiographic results: group 1 - healthy cats, group 2 - cats with unequivocal hypertrophic cardiomyopathy results, group 3 - cats with HCM. The study showed that the concentration of atrial natriuretic peptide correlates with the severity of HCM. A significant increase in serum concentration of this peptide was observed in cats from group 3, but it did not differ significantly between cats from group 2 and the healthy animals (p>0.05). A correlation was also found between proANP and age of the cats (p<0.01, r=0.5578) as well as between the ejection fraction (p=0.0285, r=0.5305) and end-systolic left ventricular diameter (p=0.05, r=0.48) in the affected animals. Atrial natriuretic peptide may be used to help in the diagnosis of advanced stages of HCM in Maine coon cats. Cats with high levels of proANP should be assigned to echocardiographic studies to confirm the disease.

Transcriptomic profiling of peripheral blood nucleated cells in dogs with and without clinical signs of chronic mitral valve disease

Abstract The aim of the study was to demonstrate differences in the gene expression of signalling pathways between healthy dogs and dogs with chronic mitral valve disease in different heart failure groups. Blood samples were collected from 49 dogs of various breeds between 1.4 and 15.2 years of age. Isolated RNA samples were analysed for quality and integrity and the gene expression profile was determined. The study demonstrated that nucleated cells from peripheral blood can be used to assess the status of heart failure in dogs. Furthermore, significant differences in the expression of the genes were noticed between healthy dogs and dogs with clinical signs of chronic mitral valve disease. This is a preliminary non-invasive study showing the feasibility of genetic testing from peripheral blood nucleated cells, which at the same time has made it possible to set the future directions of genetic studies in clinical cases of canine chronic mitral valve disease.

Lead II Electrocardiography in Standing and Right Lateral Recumbency in Dogs with Normal Echocardiographic Heart Chamber Values

Abstract The electrocardiographic (ECG) exam has been routinely used in veterinary cardiology with reference values available for the right lateral recumbent position. Many situations require the exam to be performed in the standing position. The study presents that the quality of the ECG recording is comparable for the standing and right lateral recumbent positions, as well as significant differences of the P, S and T waves recorded in two positions.