Heart failure (HF) is a leading cause of death worldwide and research focused on human cardiac tissue provides insights into underlying disease mechanisms. In this study, we performed transcriptome analyses on cardiac tissue from 21 South Asian (SA) HF patients and compared them with 21 controls without HF. The aim was to i) probe dysregulated genes and pathways in HF and ii) identify a core HF gene signature conserved across etiologies and ethnicities. Gene set enrichment analyses on dysregulated genes (DGs) showed positive enrichment of Gene Ontology terms for ECM remodelling, immune signalling and negative enrichment of terms like cardiac conduction, muscle contraction reflecting altered molecular signalling and cellular cross-talk in failing hearts. The immune cell signatures among the DGs suggest changes in immune milieu which correlates with altered immune signalling pathways. Although poor concordance in DGs across studies on HF transcriptome is well documented, evidence on stratification potential of select DGs is still preliminary. Using an independent component analysis and a machine learning based workflow, we identified gene signatures from two cohorts (SA, GSE116250) independently. We refined these into a core signature after cross validating their stratification potential and by removing the genes with low potential. The core signature effectively separated HF from control samples in SA, GSE116250 and other cohorts potentially reflecting central elements underlying end stage HF. In summary, the transcriptome analyses from SA HF cohort highlights the pathways reflecting HF pathophysiology and reiterates conserved themes across public HF cohorts.

well as in those with advanced fibrosis compared to those with stages £2 (263±20 vs. 200±7 ng/ml, p<0.001).However, VCAM-1 only showed a significant difference between advanced fibrosis and stages £2 (986±54 vs. 836±23 ng/ml, p=0.008), but not when NASH was compared to NAFL.More interestingly, as can be observed in Figure 1, increasing ICAM-1 levels were significantly associated with worsening of each of the histological parameters assessed in NASH.This robust association was not observed when the same analysis was repeated for VCAM-1.Conclusions Plasma ICAM-1 was strongly associated with histological severity of liver disease in NAFLD.This finding suggests that endothelial cell activation may play an important role in the development and progression of liver disease in NAFLD.Future in vitro studies will need to address the pathophysiologic role of this association.In the meantime, this molecule should be taken into account when developing potential noninvasive biomarkers for NASH and/or advanced fibrosis.

Apelin, the endogenous ligand for the APJ receptor, has generated interest due to its beneficial effects on the cardiovascular system. Synthesized as a 77 amino acid preproprotein, apelin is post-translationally cleaved to a series of shorter peptides. Though (Pyr)1apelin-13 represents the major circulating form in plasma, it is highly susceptible to proteolytic degradation and has an extremely short half-life, making it challenging to quantify. Literature reports of apelin levels in rodents have historically been determined with commercial ELISA kits which suffer from a lack of selectivity, recognizing a range of active and inactive isoforms of apelin peptide. (Pyr)1apelin-13 has demonstrated beneficial hemodynamic effects in humans, and we wished to evaluate if similar effects could be measured in pre-clinical models. Despite development of a highly selective LC/MS/MS method, in rodent studies where (Pyr)1apelin-13 was administered exogenously the peptide was not detectable until a detailed stabilization protocol was implemented during blood collection. Further, the inherent high clearance of (Pyr)1apelin-13 required an extended release delivery system to enable chronic dosing. The ability to deliver sustained doses and stabilize (Pyr)1apelin-13 in plasma allowed us to demonstrate for the first time the link between systemic concentration of apelin and its pharmacological effects in animal models.

BACKGROUND:P2Y(6), a purinergic receptor for UDP, is enriched in atherosclerotic lesions and is implicated in pro-inflammatory responses of key vascular cell types and macrophages. Evidence for its involvement in atherogenesis, however, has been lacking. Here we use cell-based studies and three murine models of atherogenesis to evaluate the impact of P2Y(6) deficiency on atherosclerosis.METHODOLOGY/PRINCIPAL FINDINGS:Cell-based studies in 1321N1 astrocytoma cells, which lack functional P2Y(6) receptors, showed that exogenous expression of P2Y(6) induces a robust, receptor- and agonist-dependent secretion of inflammatory mediators IL-8, IL-6, MCP-1 and GRO1. P2Y(6)-mediated inflammatory responses were also observed, albeit to a lesser extent, in macrophages endogenously expressing P2Y(6) and in acute peritonitis models of inflammation. To evaluate the role of P2Y(6) in atherosclerotic lesion development, we used P2Y(6)-deficient mice in three mouse models of atherosclerosis. A 43% reduction in aortic arch plaque was observed in high fat-fed LDLR knockout mice lacking P2Y(6) receptors in bone marrow-derived cells. In contrast, no effect on lesion development was observed in fat-fed whole body P2Y(6)xLDLR double knockout mice. Interestingly, in a model of enhanced vascular inflammation using angiotensin II, P2Y(6) deficiency enhanced formation of aneurysms and exhibited a trend towards increased atherosclerosis in the aorta of LDLR knockout mice.CONCLUSIONS:P2Y(6) receptor augments pro-inflammatory responses in macrophages and exhibits a pro-atherogenic role in hematopoietic cells. However, the overall impact of whole body P2Y(6) deficiency on atherosclerosis appears to be modest and could reflect additional roles of P2Y(6) in vascular disease pathophysiologies, such as aneurysm formation.

BACKGROUND:Chronic glucocorticoid excess has been linked to increased atherosclerosis and general cardiovascular risk in humans. The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) increases active glucocorticoid levels within tissues by catalyzing the conversion of cortisone to cortisol. Pharmacological inhibition of 11βHSD1 has been shown to reduce atherosclerosis in murine models. However, the cellular and molecular details for this effect have not been elucidated.METHODOLOGY/PRINCIPAL FINDINGS:To examine the role of 11βHSD1 in atherogenesis, 11βHSD1 knockout mice were created on the pro-atherogenic apoE⁻/⁻ background. Following 14 weeks of Western diet, aortic cholesterol levels were reduced 50% in 11βHSD1⁻/⁻/apoE⁻/⁻ mice vs. 11βHSD1⁺/⁺/apoE⁻/⁻ mice without changes in plasma cholesterol. Aortic 7-ketocholesterol content was reduced 40% in 11βHSD1⁻/⁻/apoE⁻/⁻ mice vs. control. In the aortic root, plaque size, necrotic core area and macrophage content were reduced ∼30% in 11βHSD1⁻/⁻/apoE⁻/⁻mice. Bone marrow transplantation from 11βHSD1⁻/⁻/apoE⁻/⁻ mice into apoE⁻/⁻ recipients reduced plaque area 39-46% in the thoracic aorta. In vivo foam cell formation was evaluated in thioglycollate-elicited peritoneal macrophages from 11βHSD1⁺/⁺/apoE⁻/⁻ and 11βHSD1⁻/⁻/apoE⁻/⁻ mice fed a Western diet for ∼5 weeks. Foam cell cholesterol levels were reduced 48% in 11βHSD1⁻/⁻/apoE⁻/⁻ mice vs. control. Microarray profiling of peritoneal macrophages revealed differential expression of genes involved in inflammation, stress response and energy metabolism. Several toll-like receptors (TLRs) were downregulated in 11βHSD1⁻/⁻/apoE⁻/⁻ mice including TLR 1, 3 and 4. Cytokine release from 11βHSD1⁻/⁻/apoE⁻/⁻-derived peritoneal foam cells was attenuated following challenge with oxidized LDL.CONCLUSIONS:These findings suggest that 11βHSD1 inhibition may have the potential to limit plaque development at the vessel wall and regulate foam cell formation independent of changes in plasma lipids. The diminished cytokine response to oxidized LDL stimulation is consistent with the reduction in TLR expression and suggests involvement of 11βHSD1 in modulating binding of pro-atherogenic TLR ligands.