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Background: Heart failure is a hallmark of severe hypertrophic cardiomyopathy and dilated cardiomyopathy (DCM). Several mutations in the β-MYH7 gene lead to hypertrophic cardiomyopathy. Recently, causative mutations in the β-MYH7 gene have also been detected in DCM from different populations. Methods: Here, we sequenced the β-MYH7 gene in 137 Indian DCM patients and 167 ethnically matched healthy controls to detect the frequency of mutations and their association. Results: Our study revealed 27 variations, of which 7 mutations (8.0%) were detected exclusively in Indian DCM patients for the first time. These included 4 missense mutations—Arg723His, Phe510Leu, His358Leu, and Ser384Tyr (2.9%); a frameshift mutation—Asn676_T-del (1.5%); and 2 splice-site mutations (IVS17+2T) T>G and (IVS19-1G) G>A (3.6%). Remarkably, all 4 missense mutations altered evolutionarily conserved amino acids. All 4 missense mutations were predicted to be pathogenic by 2 bioinformatics tools—polymorphism phenotyping v2 (PolyPhen-2) and sorting intolerant from tolerant (SIFT). In addition, the 4 homology models of β-MYH7—p.Leu358, p.Tyr384, p.Leu510, and p.His723—displayed root-mean-square deviations of ∼2.55 Å, ∼1.24 Å, ∼3.36 Å, and ∼3.86 Å, respectively. Conclusions: In the present study, we detected numerous novel, unique, and rare mutations in the β-MYH7 gene exclusively in Indian DCM patients (8.0%). Here, we demonstrated how each mutant (missense) uniquely disrupts a critical network of non-bonding interactions at the mutation site (molecular level) and may contribute to development of dilated cardiomyopathy (DCM). Therefore, our findings may provide insight into the understanding of the molecular bases of disease and into diagnosis along with promoting novel therapeutic strategies (through personalized medicine). Résumé: Introduction: L’insuffisance cardiaque est une caractéristique de la cardiomyopathie hypertrophique grave et de la cardiomyopathie dilatée (CMD). Plusieurs mutations dans le gène β-MYH7 conduisent à la cardiomyopathie hypertrophique. Récemment, les mutations causales dans le gène β-MYH7 ont également été détectées au sein de différentes populations atteintes de CMD. Méthodes: Ici, nous avons séquencé le gène β-MYH7 de 137 patients indiens atteints de CMD et de 167 témoins sains appariés selon l’origine ethnique pour détecter la fréquence des mutations et leur association. Résultats: L’étude nous a permis de révéler 27 variations, dont sept mutations (8,0 %) étaient exclusivement détectées chez les patients indiens atteints de CMD pour la première fois. Parmi ces mutations, nous avons observé quatre mutations faux-sens—Arg723His, Phe510Leu, His358Leu et Ser384Tyr (2,9 %), une mutation par déphasage—Asn676_T-del (1,5 %) et deux mutations des sites d’épissage (IVS17+2T) T>G et (IVS19-1G) G>A (3,6 %). Étonnamment, les quatre mutations faux-sens changeaient les acides aminés évolutivement conservés. Selon deux outils bioinformatiques—PolyPhen-2 (de l’anglais, polymorphism phenotyping v2) et SIFT (de l’anglais, sorting intolerant from tolerant), les quatre mutations faux-sens devaient être pathogènes. De plus, les quatre modélisations de β-MYH7 par homologie—p.Leu358, p.Tyr384, p.Leu510 et p.His723—affichaient de façon respective des écarts quadratiques moyens de ∼2,55 Å, ∼1,24 Å, ∼3,36 Å et ∼3,86 Å. Conclusions: Dans la présente étude, nous avons détecté de nombreuses nouvelles mutations, uniques et rares, dans le gène β-MYH7, exclusivement chez les patients indiens atteints de CMD (8,0 %). Ici, nous avons démontré comment chaque mutant (faux-sens) perturbe de manière unique un réseau essentiel d’interactions non liantes au site de mutation (moléculaire) et peut contribuer à la survenue de la CMD. Par conséquent, les conclusions de notre étude peuvent donner un aperçu des bases moléculaires de la maladie et du diagnostic tout en favorisant la promotion de nouvelles stratégies thérapeutiques (par la médecine personnalisée).

BackgroundHypertrophic cardiomyopathy (HCM) is a genetic heart muscle disease with preserved or increased ejection fraction in the absence of secondary causes. Mutations in the sarcomeric protein-encoding genes predominantly cause HCM. However, relatively little is known about the genetic impact of signalling proteins on HCM.Methods and resultsHere, using exome and targeted sequencing methods, we analysed two independent cohorts comprising 401 Indian patients with HCM and 3521 Indian controls. We identified novel variants in ribosomal protein S6 kinase beta-1 (RPS6KB1 or S6K1) gene in two unrelated Indian families as a potential candidate gene for HCM. The two unrelated HCM families had the same heterozygous missense S6K1 variant (p.G47W). In a replication association study, we identified two S6K1 heterozygotes variants (p.Q49K and p.Y62H) in the UK Biobank cardiomyopathy cohort (n=190) compared with matched controls (n=16 479). These variants are neither detected in region-specific controls nor in the human population genome data. Additionally, we observed an S6K1 variant (p.P445S) in an Arab patient with HCM. Functional consequences were evaluated using representative S6K1 mutated proteins compared with wild type in cellular models. The mutated proteins activated the S6K1 and hyperphosphorylated the rpS6 and ERK1/2 signalling cascades, suggesting a gain-of-function effect.ConclusionsOur study demonstrates for the first time that the variants in the S6K1 gene are associated with HCM, and early detection of the S6K1 variant carriers can help to identify family members at risk and subsequent preventive measures. Further screening in patients with HCM with different ethnic populations will establish the specificity and frequency of S6K1 gene variants.

Background: Rheumatic heart disease (RHD) results from group A beta-hemolytic streptococcal pharyngeal infection is an autoimmune sequela of acute or recurrent episodes of acute rheumatic fever (ARF). This study is focused on identifying heart tissue-specific proteins implicated in the secondary immunopathogenesis of RHD. Methods: Sera from 49 RHD patients and 32 controls were probed in 2DE to study the differential expression of proteins. After 2DE, the spots were analyzed and identified using ESI-MS. A total of 1082 protein spots were detected in RHD patients and controls. Results: Two protein spots were significantly down-regulated (p≤0.01) and 34 protein spots were significantly up-regulated (p≤0.01) compared to controls. The differentially expressed protein spots were trypsin-digested and identified as hyaluronan-mediated motility receptor (RHAMM), troponin 1, janus kinase and microtubule interacting protein 1 (Jakmip 1), nuclear ubiquitous casein and cyclin-dependent kinase substrate 1, basal body-orientation factor 1 and muscle-related coiled-coil protein. A positive correlation was established with the up-regulated and down-regulated expression of these proteins suggests them as potential biomarker for RHD. Conclusion: This study highlights rheumatic mitral stenosis and regurgitation, an active inflammatory process and provides novel information about the proteins thereby elaborates the knowledge of physiology and etiology of this disease.

Dilated cardiomyopathy (DCM) is a highly heterogeneous trait with sarcomeric gene mutations predominating. The cause of a substantial percentage of DCMs remains unknown, and no gene-specific therapy is available. On the basis of resequencing of 513 DCM cases and 1,150 matched controls from various cohorts of distinct ancestry, we discovered rare, functional RAF1 mutations in 3 of the cohorts (South Indian, North Indian and Japanese). The prevalence of RAF1 mutations was ~9% in childhood-onset DCM cases in these three cohorts. Biochemical studies showed that DCM-associated RAF1 mutants had altered kinase activity, resulting in largely unaltered ERK activation but in AKT that was hyperactivated in a BRAF-dependent manner. Constitutive expression of these mutants in zebrafish embryos resulted in a heart failure phenotype with AKT hyperactivation that was rescued by treatment with rapamycin. These findings provide new mechanistic insights and potential therapeutic targets for RAF1-associated DCM and further expand the clinical spectrum of RAF1-related human disorders.

Endothelium forms an innermost lining of blood vessel and it regulates the vascular tone and permeability. A healthy vascular endothelium is antiatherogenic in nature because of its properties such as inhibition of platelet aggregation, adhesion cascades, smooth muscle cell proliferation and leukocyte adhesion. Vascular endothelial dysfunction (VED) is associated with reduced synthesis and release of nitric oxide, proinflammatory and prothrombotic properties followed by diminished vasodilation. VED has been implicated in the pathogenesis of artherosclerosis, hypertension, myocardial infarction, heart failure, renal failure and stroke. Various pharmacological interventions such as angiotensin converting enzyme (ACE) inhibitors, statins, insulin sensitizers, L-arginine as well as agents that target endothelial nitric oxide synthase (eNOS) ``coupling'' such as folates or tetrahydrobiopterin (BH4) have been noted to improve the function of vascular endothelium. In this review, we discussed various recently developed pharmacological interventions to improve the function of endothelium. Moreover, the novel targets sites involved in the pathogenesis of vascular endothelial dysfunction have been delineated.

Adiponectin, an adipocyte-derived cytokine, is known to influence cardiac remodeling and to suppress pathological cardiac growth and diabetes-induced disorders. Disruption of adiponectin or its receptor AdipoR1 has significant effects on cardiomyocyte hypertrophy and myocardial metabolism signal transduction. We recently identified a novel mutation in the AdipoR1 gene among 126 hypertrophic cardiomyopathy patients, including two family members with diabetes. Our screening identified a G>A transition at 146th position that replaced the amino acid valine (GUG) into methionine (AUG) (V146M). The consequences of this mutation on cardiac function and metabolism are not known. Here, using adenoviral gene delivery system, we found that Ad.V146M increased cell size, protein synthesis, induced expression of hypertrophic gene markers and increased serine phosphorylation of insulin receptor substrate 1 (IRS1) compared to control Ad.βGal or wild type AdipoR1 (Ad.AR1) in cultured cardiomyocytes. We also discovered that p38 and mTOR were activated by AdipoR1 mutant, but not wild-type. Pharmacological inhibition of p38 (SB203580) and mTOR (rapamycin) reversed the Ad.V146M-induced hypertrophic responses. Adiponectin is also known to promote the uptake and oxidation of fatty acid and glucose through AR1 in cultured myocytes. Recent studies suggest that p38 acts as an essential mediator in regulating adiponectin-induced glucose uptake and fatty acid oxidation in C2C12 myocytes, and the serine phosphorylation of IRS1 at S636/639 is known to be mediated by mTOR pathway. AdipoR1 mutant significantly deceased glucose uptake, facilitated palmitate uptake and repressed insulin responses. Interestingly, inhibition of p38 and mTOR pathways significantly attenuated the effects of Ad.V146M on the expression of genes involved in lipid oxidation (peroxisome proliferator-activated receptor α, PPARα; carnitine palmitoyltransferase 1, CPT1) or glucose utilization (phosphofructokinase, muscle, PFK-M), respectively. Intriguingly, these findings were confirmed in vivo in cardiac-specific transgenic mice overexpressing AdipoR1 mutant. Taken together, these results suggest that a mutation in the AdipoR1 may contribute to the development of cardiomyopathy via alterations in mTOR/p38 pathways and cardiac metabolism.

This study investigated the possible role of the cardiac isoform of alpha 2-macroglobulin (CA2M) as an early diagnostic marker for HIV-associated cardiovascular manifestations. A total of 349 samples were analysed by Western blot and quantified by sandwich enzyme-linked immunosorbent assay. The levels of CA2M present in sera of HIV-associated cardiac diseases were significantly higher than those of HIV without cardiac involvement and healthy sera. CA2M may act as a novel diagnostic marker to identify cardiac manifestations in HIV/AIDS patients.

BACKGROUND Earlier we showed cardiac isoform of alpha-2 macroglobulin (CA2M) to be an early marker of cardiac hypertrophy. DESIGN In this study, we tried to explore the possibility of using this protein as a marker for diagnosis of cardiac diseases. METHODS A total of 593 samples were analyzed for the presence of CA2M using sandwich enzyme-linked immunosorbent assay. RESULTS Samples include various cardiac diseases (230), non-cardiac ailments (263) and controls (100). CONCLUSION Levels of CA2M in cardiac diseases were significantly higher than other sample groups but moderately elevated in leprosy. This protein could be considered for diagnosis of cardiac diseases as a serum marker.

We have isolated a Staphylococcus arlettae strain, strain CVD059, from the blood of a rheumatic mitral stenosis patient. Here, we report the genome sequence and potential virulence factors of this clinical isolate. The draft genome of S. arlettae CVD059 is 2,565,675 bp long with a G+C content of 33.5%.

Myelodysplastic syndromes (MDS) are a heterogenous group of haematopoietic stem cell disorders that are multifactorial in their aetiology. Unique genetic alterations in combinations or in isolation account for a small fraction of MDS suggesting the epigenetic hypermethylation as a possible leading cause for MDS and its transformation to acute myelocytic leukaemia (AML). Therefore, in this study, promoter hypermethylation status of key cell cycle regulators was assessed as markers in MDS patients and association of hypermethylation with clinical progression of disease was also studied.Promoter hypermethylation analysis of five tumour associated genes namely p16, p15, MGMT, hMLH1 and E-cadherin were done for 41 MDS patient samples with its various subtype. The hypermethylation analysis was done by using semi-nested multiplex PCR.Eighty per cent of (33/41) of the MDS samples were found to be methylated in any one of the four genes (p16, p15, MGMT and E-cadherin). The p15 methylation was found to be the most frequent 61 per cent (25/41), E-cadherin was methylated in 39 per cent (16/41) and p16 in 37 per cent (15/41) of the cases. MGMT gene showed a low 5 per cent (2/41) methylation whereas hMLH1 gene was not methylated in any one of the samples analysed.Differential rate of methylation of the four genes (p16, p15, MGMT and E-cadherin) was observed in MDS samples. All the samples analysed showed the absence of a methylator phenotype in MDS. The methylation frequency of all these genes increased with the clinical severity of the MDS subtypes. Therefore, hypermethylation may be used as a diagnostic and prognostic tool in ascertaining the clinical severity of MDS.