Isolation of ckit-positive cardiosphere-forming cells from human atrial biopsy

There is increasing interest in developing cell-based therapies to regenerate functional muscle and blood vessels in infarcted dysfunctional myocardium, using stem cells resident in the adult heart. The objective of our study was to identify an easy and cost-effective method for the isolation and expansion of human adult cardiac-resident stem cells. The cells were isolated from right atrial biopsy samples obtained from patients with ischemic heart disease, who were undergoing coronary artery bypass grafting. Two different isolation methods, enzymatic and nonenzymatic, were employed. The cell yield and cluster formation were not significantly different with either of the techniques used for cell isolation. The nonenzymatic method is recommended because of its simplicity and lower cost compared to the enzymatic method

Endomyocardial fibrosis: a case for the tropical doctor

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Endomyocardial fibrosis-the possible connexion with myocardial levels of magnesium and cerium

This article does not have an abstract

Genetic and epigenetic mechanisms in the development of arteriovenous malformations in the brain

Abstract Vascular malformations are developmental congenital abnormalities of the vascular system which may involve any segment of the vascular tree such as capillaries, veins, arteries, or lymphatics. Arteriovenous malformations (AVMs) are congenital vascular lesions, initially described as “erectile tumors,” characterized by atypical aggregation of dilated arteries and veins. They may occur in any part of the body, including the brain, heart, liver, and skin. Severe clinical manifestations occur only in the brain. There is absence of normal vascular structure at the subarteriolar level and dearth of capillary bed resulting in aberrant arteriovenous shunting. The causative factor and pathogenic mechanisms of AVMs are unknown. Importantly, no marker proteins have been identified for AVM. AVM is a high flow vascular malformation and is considered to develop because of variability in the hemodynamic forces of blood flow. Altered local hemodynamics in the blood vessels can affect cellular metabolism and may trigger epigenetic factors of the endothelial cell. The genes that are recognized to be associated with AVM might be modulated by various epigenetic factors. We propose that AVMs result from a series of changes in the DNA methylation and histone modifications in the genes connected to vascular development. Aberrant epigenetic modifications in the genome of endothelial cells may drive the artery or vein to an aberrant phenotype. This review focuses on the molecular pathways of arterial and venous development and discusses the role of hemodynamic forces in the development of AVM and possible link between hemodynamic forces and epigenetic mechanisms in the pathogenesis of AVM

Correction to: Genetic and epigenetic mechanisms in the development of arteriovenous malformations in the brain

Upon publication of the original article [1] the authors noticed that the affiliation Manipal Academy of Higher Education (MAHE), Manipal, Karnataka, India was missing

A Splicing-Independent Function of RBM10 Controls Specific 3′ UTR Processing to Regulate Cardiac Hypertrophy

Summary: RNA binding motif protein 10 (RBM10) is a regulator of alternative splicing in apoptosis and inflammation. We discovered a splicing-independent function of RBM10 critical for the regulation of heart failure (HF). RBM10 is enriched in the heart and associates with Star-PAP (TUT1) to control the expression and 3′ end processing of cardiac mRNAs. The RBM10 RRM2 domain binds the Star-PAP catalytic domain, which directs Star-PAP activity toward polyadenylation. RBM10 binds the pre-mRNA UTR, assembles the Star-PAP complex, and guides this complex specifically to mRNAs encoding anti-hypertrophy regulators. Accordingly, we tested cellular hypertrophy in rat cardiomyoblasts and cardiac hypertrophy (CH) and the subsequent progression to HF in Wistar rat hearts. We demonstrated downregulation of RBM10 during CH and HF. Ectopic re-expression of RBM10 rescued cardiomyocyte hypertrophy. RBM10 depletion evoked a hypertrophic response in H9c2 cells. Our results establish an anti-hypertrophy mechanism mediated by RBM10 in the heart that is directly linked to HF. : Regulation at the mRNA 3′ UTR is a critical mechanism in the heart, but how it is accomplished during hypertrophy or heart failure is poorly understood. Mohan et al. report an anti-hypertrophy mechanism mediated by RBM10 through 3′ UTR processing of key hypertrophy factors that regulates heart failure. Keywords: 3′ end processing, Star-PAP, RBM10, gene expression, 3′ UTR, cardiac mRNA, heart failure, cardiac hypertroph

Association of monocyte chemoattractant protein-1 -2518 polymorphism with metabolic syndrome in a South Indian cohort

Background: Previous reports have indicated an association of monocyte chemoattractant protein-1 (MCP-1) with risk factors for atherosclerosis and coronary artery disease (CAD). Because some of these risk factors form components of metabolic syndrome, in the present study, we investigated the association of an important promoter region polymorphism of MCP-1, A-2518G, and its serum levels with metabolic syndrome in a South Indian cohort. Methods: The study comprised of 126 healthy subjects aged 30-59 years from South India. Subjects were classified on the basis of presence or absence of metabolic syndrome and metabolic syndrome components as per the International Diabetes Federation definition. MCP-1 genotyping was done by polymerase chain reaction restriction fragment-length polymorphism, and serum levels were estimated by enzyme-linked immunosorbent assay. Results: The MCP-1 -2518G allele frequency in the study population was 32.9% and the mean MCP-1 serum levels were 523 ± 272.3 pg/mL. Subjects with metabolic syndrome showed an increased presence of the MCP-1 -2518G allele in comparison to those without metabolic syndrome (odds ratio [OR] = 5.03, P = 0.02). The association was related to a higher proportion of this allele in subjects with increased waist circumference (OR = 3.78, P = 0.05). Conclusions: The MCP-1 -2518G allele may be contributing to atherosclerosis and CAD by conferring an increased risk to metabolic syndrome and/or obesity

Cyclophilin A Impairs Efferocytosis and Accelerates Atherosclerosis by Overexpressing CD 47 and Down-Regulating Calreticulin

Impairment of efferocytosis in apoptotic macrophages is a known determinant of the severity of atherosclerosis and the vulnerability of plaques to rupture. The precise mechanisms involved in impaired efferocytosis are unclear. Given the well-recognized role of the inflammatory cytokine cyclophilin A (Cyp A) in modulating several atherogenic mechanisms in high-glucose primed monocytes, we investigated the role of Cyp A in macrophage efferocytosis. The efficiency of efferocytosis in RAW 264.7 macrophages grown in vitro and primed with cyclophilin A was assessed using flow cytometry and confocal assays. Cholesterol content in cells was measured using cell-based cholesterol efflux assay. Proteomic analysis and bioinformatics tools were employed to decipher the link between cyclophilin A and the known ligand receptors involved in efferocytosis. Cyclophilin A was found to impair efferocytosis in apoptotic macrophages by reducing ABCA1-mediated cholesterol efflux in foam cells derived from macrophages. Cyclophilin A-primed macrophages showed an increase in expression of the don’t-eat-me signal CD 47 and a decrease in the expression of the eat-me signal, calreticulin. Phagocytosis was restored upon silencing of cyclophilin A. New Zealand white rabbits were fed a high-fat diet, and lesions in their aortae were analyzed histologically for evidence of atherosclerosis and the expression of Cyp A, CD 47 and calreticulin, the ligand receptor involved in efferocytosis. Gene and protein expressions in aortae and macrophages were analyzed by real-time PCR and Western blotting. Cyclophilin A, via its effects on the expression of CD 47 and calreticulin, impairs efferocytosis in apoptotic macrophages. Together with its impact on cholesterol efflux from macrophages, these effects can amplify other mechanisms of Cyp A in accelerating the progression of atherosclerosis

Gene expression analysis of nidus of cerebral arteriovenous malformations reveals vascular structures with deficient differentiation and maturation

<div><p>Objective</p><p>Arteriovenous malformations (AVMs) are characterised by tangles of dysplastic blood vessels which shunt blood from arteries to veins with no intervening capillary bed. It is not known at what stage of development and differentiation, AVM vessels became aberrant. To address this, we have analysed the expression of vascular differentiation, vascular maturation and brain capillary specific genes in AVM nidus.</p><p>Methodology</p><p>We performed immunohistochemistry and western blot analysis of vascular differentiation (<i>HEY2</i>, <i>DLL4</i>, <i>EFNB2</i>, and <i>COUP-TFII</i>), vascular maturation (<i>ENG</i> and <i>KLF2</i>) and brain capillary specific genes (<i>GGTP</i> and <i>GLUT1</i>) on ten surgically excised human brain AVMs and ten normal human brain tissues.</p><p>Results</p><p>Immunohistochemical analysis revealed that AVM vessels co-express both artery and vein differentiation genes. H-score analysis revealed that there is statistically significant (P < 0.0001) increase in expression of these proteins in AVM vessels compared to control vessels. These findings were further confirmed by western blot analysis and found to be statistically significant (P < 0.0001 and P < 0.001) for all proteins except Hey2. Both immunostaining and western blot analysis revealed that AVM vessels express GGTP and GLUT1, markers specific to brain capillaries. Immunofluorescent staining demonstrated that expression of KLF2, a vascular maturation marker is significantly (P <0.001) decreased in AVM vessels and was further confirmed by western blot analysis (P < 0.001). Immunohistochemical and western blot analysis demonstrated that another vascular maturation protein Endoglin had high expression in AVM vessels compared to control vessels. The results were found to be statistically significant (P < 0.0001).</p><p>Summary</p><p>Our findings suggest that vascular structures of AVMs co-express markers specific for arteries, veins and capillaries. We conclude that AVM nidus constitutes of aberrant vessels which are not terminally differentiated and inadequately matured.</p></div

Gene expression analysis of nidus of cerebral arteriovenous malformations reveals vascular structures with deficient differentiation and maturation - Fig 8

<p><b>(A) Photomicrograph of tissues stained with the antibody against KLF2 in AVM and control tissues.</b> KLF2 is not expressed in AVM nidus structures. In control vessels, KLF2 is expressed (green) in the endothelial cell lining (arrowhead) and smooth muscle cells (arrow). Magnified images are shown in a and b. Hoechst 33342 (blue) is used to counter stain nuclei. 60X magnification. <b>(B) Graphical representation of fluorescence intensity of KLF2 in AVM and control tissues.</b> KLF2 expression is significantly low in AVM nidus structures (n = 10) compared to control tissues (n = 10) (*P < 0.001).</p