Background and Aim: Hypertrophic cardiomyopathy (HCM) is a common heart problem that affects many cats. Although cats with HCM are symptomatic, some die suddenly or develop congestive heart failure. Therefore, this study aimed to estimate the prevalence of myosin-binding protein C3 (MYBPC3), A31P, and A74T polymorphisms in Maine Coon cats to assess risk factors for diagnosing HCM in cats. Materials and Methods: Forty-nine Maine Coon cats of at least 10 months of age were enrolled in this study. First, clinical parameters, such as heart rate, systolic blood pressure, and echocardiography, were evaluated. Then, polymerase chain reaction, followed by DNA sequencing, was conducted using specific primers for amino acid substitutions caused by genetic variants of MYBPC3-A31P and -A74T polymorphisms. Results: Investigations showed that the prevalence of MYBPC3-A31P and -A74T mutations in this study was 16.33% and 24.45%, respectively. Moreover, HCM in cats with MYBPC3-A31P and A74T mutations increased with age, body weight, high heart rate, and prolonged isovolumic relaxation time. Conclusion: Therefore, we propose that Maine Coon cats develop HCM due to multiple genetic factors and underlying clinical characteristics in individual cats. Furthermore, relaxation time assessments can be a sensitive technique for HCM screening during its preclinical phase and can help identify the risk of developing HCM. However, further studies are warranted to evaluate the effect of MYBPC3 mutations on the phenotypic expression of HCM.

This study aimed to identify the potential peptide candidates and expected proteins associated with MYBPC3-A74T gene mutations in Bengal cats and determine if peptidome profiles differ between healthy controls and cats with MYBPC3-A74T gene mutations. All animals were evaluated using echocardiography. DNA was isolated and followed by the screening test of MYBPC3 gene mutation. The MALDI-TOF mass spectrometry was conducted for analyzing the targeted peptide and protein patterns. The expected protein candidates were searched for within the NCBI database. Our results demonstrated that the MYBPC3-A74T gene mutation was dominant in Bengal cats but not in domestic shorthair cats. Correlations between baseline characteristics and echocardiographic parameters were discovered in Bengal cats. Mass spectrometry profiles of the candidate proteins were suspected to accompany the cat with the MYBPC3-A74T gene mutation, involving integral protein–membrane, organization of nucleus, DNA replication, and ATP-binding protein. Therefore, MYBPC3-A74T gene mutations occur frequently in Bengal cat populations. The high incidence of homozygotes for the mutation supports the causal nature of the MYBPC3-A74T mutation. In addition, peptidomics analysis was established for the first time under this condition to promise a complementary technique for the future clinical diagnosis of the MYBPC3-A74T mutation associated with physiological variables and cardiac morphology in cats.

Background and Aim: Cardiac biomarkers, such as serum galectin-3 (Gal-3) and titin levels, may be related to cats with sarcomeric gene mutations. This study evaluated cardiac biomarkers and echocardiographic parameters in cats with or without myosin-binding protein C3 (MYBPC3) gene mutations. Materials and Methods: Forty-two healthy cats without cardiac symptoms, including Bengal, Maine Coon, Scottish fold, and Ragdoll cats, were enrolled in this study. Cats were categorized into three groups: Homozygous wild type (n = 17), homozygous MYBPC3 gene mutation (n = 14), and heterozygous MYBPC3 gene mutation (n = 11). All recruited cats underwent echocardiography, and blood samples were collected for DNA extraction. DNA sequencing for MYBPC3 gene mutations at A31P and A74T loci was first examined by Sanger sequencing. The biomarkers of cardiac fibrosis (Gal-3) and myocardial stiffness (titin) were measured by enzyme-linked immunosorbent assay. Results: Gal-3 levels >250 pg/mL were associated with echocardiographic parameters. However, Gal-3 levels were not significantly different between cats with MYBPC3 gene mutations and those in the wild-type group. Titin was associated with the left ventricular (LV) thickness and systolic function (r = 0.405, p = 0.013). Qualitative measurement of titin antibodies showed that the highest percentage of these antibodies was found in homozygous wild-type cats. No correlation was found between titin levels and MYBPC3 gene mutations. Weight was positively associated with interventricular septum (r = 0.312, p = 0.056) and LV wall thickness (LVPW) (r = 0.219, p = 0.187). However, they were not associated with Gal-3 levels. Conclusion: LVPW was correlated with weight in cats with sarcomeric gene mutations. Serum titin may be an underlying factor for cardiac hypertrophy in cats. Keywords: cardiac biomarker, cat, hypertrophic cardiomyopathy, myosin-binding protein C3.

Purpose: The potential cardio-protective property of germinated brown rice (GBR) has been revealed by ameliorating risk factors related to cardiovascular diseases. This study hypothesized that the combination of GBR and cardioplegic solution could protect the cardiomyocytes exposed to simulated ischemic reperfusion injury in vitro study and preserve cardiac function during cardiopulmonary bypass surgery in animal models. Methods: Primary porcine cardiomyocytes were isolated and experimented cell viability against simulated ischemic reperfusion injury. In a cardiac surgical animal model, six pigs were randomly assigned to receive the two types of cardioplegic solution: i) St. Thomas cardioplegic solution (20 cc/kg); and ii) St. Thomas cardioplegic solution plus GBR (1 mg/kg). During open-heart surgery, the aorta was cross-clamped for 20 minutes, followed by reperfusion for 1 hour. Cardiopulmonary bypass parameters were recorded until the end of the procedure. Furthermore, hemodynamic parameters and arterial blood gas characteristics of animals among groups were monitored at different time points, including baseline before cardiopulmonary bypass (T1), during cardiopulmonary bypass (T2), during aortic clamp on (T3), and aortic clamp off (T4). Results: Primarily, GBR cotreatment with cardioplegic solution essentially resulted in the improvement of cell viability in primary porcine cardiomyocytes against simulated ischemic reperfusion induction. The findings from cardiac surgery demonstrated that mean arterial pressure and heart rate are constantly stable in cardioplegic solution combined with the GBR group, while the trend of potassium and lactase concentration was decreased in the animals receiving GBR group. Consistently, all parameters from arterial blood gas showed better outcomes in animals receiving GBR; however, there were no statistically significant differences between groups, except hepatic enzymes. Conclusion: Therefore, GBR might exert cardio-protective effects against ischemic reperfusion injury in the porcine cardiac surgery model due to anti-inflammatory response. These protective actions of GBR may explain the benefits gained from applying GBR products as a possible therapeutic supplement on cardiac diseases.