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Frankfurt am Main, Germany

Seeger T.,Institute for Cardiovascular Regeneration
European journal of heart failure | Year: 2013

Ageing of the immune system, immunosenescence, is characterized by impaired lymphopoiesis, especially B-lymphocyte maturation, and is a hallmark of chronic heart failure (CHF). MicroRNAs (miRNAs) are non-coding, small RNAs, which post-transcriptionally control gene expression of multiple target genes. The miR-181 family is known to control haematopoietic lineage differentiation. Here, we study the role of the miR-181 family in immunosenescence and CHF. We conducted a clinical study analysing peripheral blood (PB) for miRNA expression and leucocyte distribution of young healthy controls (25 ± 4 years; n = 30), aged healthy controls (64 ± 5 years; n = 13), and age-matched CHF patients (64 ± 11years; n = 18). The expression of miR-181 family members was reduced, whereas miR-34a was increased in PB of aged individuals. In particular, miR-181c was further reduced in age-matched CHF patients. In PB, we observed reduced numbers of lymphocytes, in particular cytotoxic T cells and B cells, with rising age, and the expression of miR-181 correlated with the number of B cells. Notably, in CHF patients, ischaemic heart failure was associated with a further reduction of total B cells as well as their subpopulations, such as memory B cells, compared with age-matched healthy volunteers. Ageing- and CHF-associated changes in PB leucocyte subsets are paralleled by alterations in the expression of miRNAs involved in lymphopoiesis, which might play an important role in the age-related and CHF-mediated dysregulation of immune functions resulting in immunosenescence. Furthermore, miR-181c may serve as a marker for reduced immune functions in CHF patients.

Fischer A.,Goethe University Frankfurt | Fischer A.,Institute for Cardiovascular Regeneration | Roxe T.,Goethe University Frankfurt | Roxe T.,Institute for Cardiovascular Regeneration | And 10 more authors.
Circulation: Heart Failure | Year: 2012

Background-Chronic heart failure (CHF) is associated with a 4-fold increased risk for osteoporotic fractures. Therefore, we sought to identify the pathophysiological link between chronic heart failure and catabolic bone remodeling. Methods and Results-In a total cohort of 153 subjects (123 patients with CHF, 30 patients with coronary artery disease and preserved cardiac function) as well as mice with heart failure, bone marrow (BM) plasma levels of the catabolic receptor activator of NF-?B ligand (RANKL), and its antagonist, osteoprotegerin were measured. The osteoclast inducing activity of BM plasma was tested in cell culture. BM plasma levels of RANKL and of the ratio RANKL/osteoprotegerin were significantly elevated in patients with CHF. On multivariate regression analysis, parameters of severity and duration of heart failure were independent determinants of elevated BM plasma RANKL levels. BM plasma levels of RANKL were directly correlated with the systemic marker of bone turnover C-telopeptide of type 1 collagen (r=0.6; P<0.001). Alterations in BM plasma levels of RANKL/osteoprotegerin were confirmed in a mouse model of postinfarction heart failure. Stimulation of human mesenchymal cells with BM plasma obtained from CHF patients increased the formation of osteoclasts, and this effect was blocked by the RANKL inhibition. Conclusions-CHF is associated with a profound and selective elevation of the bone resorption stimulating RANKL within the BM microenvironment. These data for the first time disclose a direct pathophysiological pathway linking CHF with catabolic bone remodeling associated with an increased osteoporotic fracture risk. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifiers: NCT 00289822, NCT 00284713, NCT 00326989, NCT 00962364. © 2012 American Heart Association, Inc.

Urbich C.,Institute for Cardiovascular Regeneration | De Souza A.I.,St Georges, University of London | Rossig L.,Institute for Cardiovascular Regeneration | Yin X.,Kings College London | And 8 more authors.
Journal of Molecular and Cellular Cardiology | Year: 2011

Early pro-angiogenic cells (EPCs) have been shown to be involved in neovascularization, angiogenesis and re-endothelialization and cathepsin L inhibition blunted their pro-angiogenic effect. In the present study, we have analysed and mapped the proteome and secretome of human EPCs, utilizing a combination of difference in-gel electrophoresis (DIGE) and shotgun proteomics. A population of 206 protein spots were analysed, with 171 being identified in the cellular proteome of EPCs. 82 proteins were identified in their conditioned medium, including the alternative macrophage markers C-C motif chemokine 18 (CCL18) and the hemoglobin scavenger receptor CD163 as well as platelet factor 4 (CXCL4) and platelet basic protein (CXCL7) with "platelet alpha granule" being returned as the top category according to the Gene Ontology Annotation. Apart from cathepsin L, the cathepsin L inhibitor also attenuated the release of a wide range of other cathepsins and lysosomal proteins such as legumain, but stimulated the secretion of members of the S100 protein family. The data presented here are the most comprehensive characterization of protein expression and secretion in human EPCs to date and highlight the potential importance of cysteine proteases in the processing of platelet factors for their pro-angiogenic potential. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited". © 2010 Elsevier Ltd.

Seeger T.,Institute for Cardiovascular Regeneration | Seeger T.,Goethe University Frankfurt | Xu Q.-F.,Institute for Cardiovascular Regeneration | Muhly-Reinholz M.,Institute for Cardiovascular Regeneration | And 4 more authors.
Journal of Molecular and Cellular Cardiology | Year: 2016

Heart failure due to myocardial infarction is a major cause of mortality. The microRNA (miR) family let-7 is expressed during embryonic development and is up-regulated in differentiated cells. The aim of this study was to study the role of let-7 after acute myocardial infarction (AMI). We designed an antimiR to inhibit the highest expressed members of the let-7 family, let-7 a, b and c. Administration at day 0 and day 2 after AMI resulted in sustained knockdown of let-7 after 28 days. Let-7 inhibition prevented deterioration of cardiac functions compared to control treatment which was especially due to improvements in the infarcted, apical cardiac segments. We observed higher contents of fibrosis in the border zone as well as increased numbers of cells positive for TCF21, which is also expressed in epicardial cells. Markers were augmented after let-7 inhibition and let-7 blocked EMT in epicardial cells in vitro. Lineage tracing in TCF21iCre/+:R26RtdT mice showed abundant tomato positive cells in the infarct and border zone. In conclusion, let-7 inhibition resulted in functional benefits due to an increase in recruitment of epicardial cells and EMT. © 2016.

Fadini G.P.,University of Padua | Fadini G.P.,Venetian Institute of Molecular Medicine | Albiero M.,University of Padua | Albiero M.,Venetian Institute of Molecular Medicine | And 27 more authors.
Circulation Research | Year: 2011

Rationale: Acquisition of a procalcific phenotype by resident or circulating cells is important for calcification of atherosclerotic plaques, which is common in diabetes. Objective: We aim to identify and characterize circulating calcifying cells, and to delineate a pathophysiological role for these cells in type 2 diabetes. Methods and Results: We demonstrate for the first time that a distinct subpopulation of circulating cells expressing osteocalcin and bone alkaline phosphatase (OC+BAP+) has procalcific activity in vitro and in vivo. The study of naïve patients with chronic myeloid leukemia indicated that OC+BAP+ cells have a myeloid origin. Myeloid calcifying OC+BAP+ cells (MCCs) could be differentiated from peripheral blood mononuclear cells, and generation of MCCs was closely associated with expression of the osteogenic transcription factor Runx2. In gender-mismatched bone marrow-transplanted humans, circulating MCCs had a much longer half-life compared with OC -BAP- cells, suggesting they belong to a stable cell repertoire. The percentage of MCCs was higher in peripheral blood and bone marrow of type 2 diabetic patients compared with controls but was lowered toward normal levels by optimization of glycemic control. Furthermore, diabetic carotid endoarterectomy specimens showed higher degree of calcification and amounts of cells expressing OC and BAP in the α-smooth muscle actin-negative areas surrounding calcified nodules, where CD68+ macrophages colocalize. High glucose increased calcification by MCCs in vitro, and hypoxia may regulate MCC generation in vitro and in vivo. Conclusions: These data identify a novel type of blood-derived procalcific cells potentially involved in atherosclerotic calcification of diabetic patients. © 2011 American Heart Association, Inc.

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