Author Correction: Pro-inflammatory cytokines activate hypoxia-inducible factor 3α via epigenetic changes in mesenchymal stromal/stem cells.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Risk Stratification in Bicuspid Aortic Valve Aortopathy: Emerging Evidence and Future Perspectives.

The current management of aortic dilatation associated with congenital bicuspid aortic valve (bicuspid aortic valve aortopathy) is based on dimensional parameters (diameter of the aneurysm, growth of the diameter over time) and few other criteria. The disease is however heterogeneous in terms of natural and clinical history and risk of acute complications, ie aortic dissection. Dimensional criteria are now admitted to have limited value as predictors of such complications.

Is there a role for autophagy in ascending aortopathy associated with tricuspid or bicuspid aortic valve?

Autophagy is a conserved process by which cytoplasmatic elements are sequestered in vesicles and degraded after their fusion with lysosomes, thus recycling the precursor molecules. The autophagy-mediated removal of redundant/harmful/damaged organelles and biomolecules plays not only a replenishing function, but protects against stressful conditions through an adaptive mechanism. Autophagy, known to play a role in several pathological conditions, is now gaining increasing attention also in the perspective of the identification of the pathogenetic mechanisms at the basis of ascending thoracic aortic aneurysm (TAA), a localized or diffused dilatation of the aorta with an abnormal widening greater than 50 percent of the vessel's normal diameter.

Locally different proteome in aortas from patients with stenotic tricuspid and bicuspid aortic valves†.

Objectives: We aimed to compare the intracellular proteome of ascending aortas from patients with stenotic bicuspid (BAV) and tricuspid aortic valves (TAV) to identify BAV-specific pathogenetic mechanisms of aortopathy and to verify the previously reported asymmetric expression of BAV aortopathy [concentrated at the convexity (CVX)] in its 'ascending phenotype' form.

Methods: Samples were collected from the CVX and concavity sides of non-aneurysmal ascending aortas in 26 TAV and 26 BAV patients undergoing stenotic aortic valve replacement. Aortic lysates were subjected to cellular protein enrichment by subfractionation, and to proteome comparison by 2-dimensional fluorescence difference in-gel electrophoresis.

Ascending aortas from heart donors and CABG patients are not equivalent as control in aortopathy studies.

Objectives: A careful selection of reference samples in studies on the pathogenesis of thoracic ascending aorta (TAA) dilation is crucial for reliability, consistency and reproducibility of experimental results. Several studies include control TAA samples from heart donors. Others include samples harvested during coronary artery bypass graft (CABG) procedures or a mix of samples from heart donors and CABG patients.

Pro-inflammatory cytokines activate hypoxia-inducible factor 3α via epigenetic changes in mesenchymal stromal/stem cells.

Human mesenchymal stromal/stem cells (hMSCs) emerged as a promising therapeutic tool for ischemic disorders, due to their ability to regenerate damaged tissues, promote angiogenesis and reduce inflammation, leading to encouraging, but still limited results. The outcomes in clinical trials exploring hMSC therapy are influenced by low cell retention and survival in affected tissues, partially influenced by lesion's microenvironment, where low oxygen conditions (i.e.

Neural stem cells from a mouse model of Rett syndrome are prone to senescence, show reduced capacity to cope with genotoxic stress, and are impaired in the differentiation process.

Several aspects of stem cell life are governed by epigenetic variations, such as DNA methylation, histone modifications, and chromatin remodeling. Epigenetic events are also connected with the impairment of stem cell functions. For example, during senescence, there are significant changes in chromatin organization that alter transcription.

Polyamine concentration is increased in thoracic ascending aorta of patients with bicuspid aortic valve.

Polyamines are cationic molecules synthesized via a highly regulated pathway, obtained from the diet or produced by the gut microbiota. They are involved in general molecular and cellular phenomena that play a role also in vascular disease. Bicuspid aortic valve (BAV) is a congenital malformation associated to a greater risk of thoracic ascending aorta (TAA) aneurysm, whose pathogenesis is not yet well understood.

Misidentified Human Gene Functions with Mouse Models: The Case of the Retinoblastoma Gene Family in Senescence.

Although mice models rank among the most widely used tools for understanding human genetics, biology, and diseases, differences between orthologous genes among species as close as mammals are possible, particularly in orthologous gene pairs in which one or more paralogous (i.e., duplicated) genes appear in the genomes of the species.

A Possible Early Biomarker for Bicuspid Aortopathy: Circulating Transforming Growth Factor β-1 to Soluble Endoglin Ratio.

Rationale: The pathogenesis of bicuspid aortic valve (BAV)-associated aortopathy is poorly understood, and no prognostic biomarker is currently available.

Objective: We aimed to identify putative circulating biomarkers pathogenetically and prognostically linked to bicuspid aortopathy.

Methods And Results: By reverse transcription polymerase chain reaction, we evaluated gene expression variations (versus normal aorta) of transforming growth factor-β1 (TGF-β1), connective tissue growth factor, matrix metalloproteinase-2 (MMP-2), MMP-14, endoglin (ENG), and superoxide dismutase 3 in ascending aorta samples from 50 tricuspid and 70 patients with BAV undergoing surgery for aortic stenosis (aorta diameter ≤45 mm: BAV or >45 mm: BAV).

Patients with bicuspid and tricuspid aortic valve exhibit distinct regional microrna signatures in mildly dilated ascending aorta.

MicroRNAs are able to modulate gene expression in a range of diseases. We focused on microRNAs as potential contributors to the pathogenesis of ascending aorta (AA) dilatation in patients with stenotic tricuspid (TAV) or bicuspid aortic valve (BAV). Aortic specimens were collected from the 'concavity' and the 'convexity' of mildly dilated AAs and of normal AAs from heart transplant donors.

Impact of lysosomal storage disorders on biology of mesenchymal stem cells: Evidences from in vitro silencing of glucocerebrosidase (GBA) and alpha-galactosidase A (GLA) enzymes.

Lysosomal storage disorders (LDS) comprise a group of rare multisystemic diseases resulting from inherited gene mutations that impair lysosomal homeostasis. The most common LSDs, Gaucher disease (GD), and Fabry disease (FD) are caused by deficiencies in the lysosomal glucocerebrosidase (GBA) and alpha-galactosidase A (GLA) enzymes, respectively. Given the systemic nature of enzyme deficiency, we hypothesized that the stem cell compartment of GD and FD patients might be also affected.

Epigenetic regulation of TGF-β1 signalling in dilative aortopathy of the thoracic ascending aorta.

The term 'epigenetics' refers to heritable, reversible DNA or histone modifications that affect gene expression without modifying the DNA sequence. Epigenetic modulation of gene expression also includes the RNA interference mechanism. Epigenetic regulation of gene expression is fundamental during development and throughout life, also playing a central role in disease progression.

Mesenchymal stromal cells having inactivated RB1 survive following low irradiation and accumulate damaged DNA: Hints for side effects following radiotherapy.

Following radiotherapy, bone sarcomas account for a significant percentage of recurring tumors. This risk is further increased in patients with hereditary retinoblastoma that undergo radiotherapy. We analyzed the effect of low and medium dose radiation on mesenchymal stromal cells (MSCs) with inactivated RB1 gene to gain insights on the molecular mechanisms that can induce second malignant neoplasm in cancer survivors.

Changes in autophagy, proteasome activity and metabolism to determine a specific signature for acute and chronic senescent mesenchymal stromal cells.

A sharp definition of what a senescent cell is still lacking since we do not have in depth understanding of mechanisms that induce cellular senescence. In addition, senescent cells are heterogeneous, in that not all of them express the same genes and present the same phenotype. To further clarify the classification of senescent cells, hints may be derived by the study of cellular metabolism, autophagy and proteasome activity.

De-regulated expression of the BRG1 chromatin remodeling factor in bone marrow mesenchymal stromal cells induces senescence associated with the silencing of NANOG and changes in the levels of chromatin proteins.

Stem cells have a peculiar chromatin architecture that contributes to their unique properties, including uncommitted status, multi/pluripotency and self-renewal. We analyzed the effect of the de-regulation of the SWI/SNF chromatin remodeling complex in mesenchymal stromal cells (MSC) through the silencing and up-regulation of BRG1, which is the ATPase subunit of the complex. The altered expression of BRG1 promoted the senescence of MSC with suppression of the NANOG transcription, which is part of the transcriptional circuitry governing stem cell functions.

Low dose radiation induced senescence of human mesenchymal stromal cells and impaired the autophagy process.

Low doses of radiation may have profound effects on cellular function. Individuals may be exposed to low doses of radiation either intentionally for medical purposes or accidentally, such as those exposed to radiological terrorism or those who live near illegal radioactive waste dumpsites.We studied the effects of low dose radiation on human bone marrow mesenchymal stromal cells (MSC), which contain a subpopulation of stem cells able to differentiate in bone, cartilage, and fat; support hematopoiesis; and contribute to body's homeostasis.

Novel potential targets for prevention of arterial restenosis: insights from the pre-clinical research.

Restenosis is the pathophysiological process occurring in 10-15% of patients submitted to revascularization procedures of coronary, carotid and peripheral arteries. It can be considered as an excessive healing reaction of the vascular wall subjected to arterial/venous bypass graft interposition, endarterectomy or angioplasty. The advent of bare metal stents, drug-eluting stents and of the more recent drug-eluting balloons, have significantly reduced, but not eliminated, the incidence of restenosis, which remains a clinically relevant problem.

Sera of overweight people promote in vitro adipocyte differentiation of bone marrow stromal cells.

Introduction: Overweight status should not be considered merely an aesthetic concern; rather, it can incur health risks since it may trigger a cascade of events that produce further fat tissue through altered levels of circulating signaling molecules.

Methods: We decided to investigate the influence of overweight individuals' sera on in vitro MSC proliferation and differentiation.

Results: We observed that in vitro incubation of bone marrow stromal cells with the sera of overweight individuals promotes the adipogenic differentiation of MSCs while partially impairing proper osteogenesis.

Silencing of RB1 and RB2/P130 during adipogenesis of bone marrow stromal cells results in dysregulated differentiation.

Bone marrow adipose tissue (BMAT) is different from fat found elsewhere in the body, and only recently have some of its functions been investigated. BMAT may regulate bone marrow stem cell niche and plays a role in energy storage and thermogenesis. BMAT may be involved also in obesity and osteoporosis onset.

Preamplification procedure for the analysis of ancient DNA samples.

In ancient DNA studies the low amount of endogenous DNA represents a limiting factor that often hampers the result achievement. In this study we extracted the DNA from nine human skeletal remains of different ages found in the Byzantine cemetery of Abdera Halkidiki and in the medieval cemetery of St. Spiridion in Rhodes (Greece).

Genetic, epigenetic and stem cell alterations in endometriosis: new insights and potential therapeutic perspectives.

Human endometrium is a highly dynamic tissue, undergoing periodic growth and regression at each menstrual cycle. Endometriosis is a frequent chronic pathological status characterized by endometrial tissue with an ectopic localization, causing pelvic pain and infertility and a variable clinical presentation. In addition, there is well-established evidence that, although endometriosis is considered benign, it is associated with an increased risk of malignant transformation in approximately 1.

Local inhibition of ornithine decarboxylase reduces vascular stenosis in a murine model of carotid injury.

Objectives: Polyamines are organic polycations playing an essential role in cell proliferation and differentiation, as well as in cell contractility, migration and apoptosis. These processes are known to contribute to restenosis, a pathophysiological process often occurring in patients submitted to revascularization procedures. We aimed to test the effect of α-difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase, on vascular cell pathophysiology in vitro and in a rat model of carotid arteriotomy-induced (re)stenosis.

Silencing of RB1 but not of RB2/P130 induces cellular senescence and impairs the differentiation potential of human mesenchymal stem cells.

Stem cell senescence is considered deleterious because it may impair tissue renewal and function. On the other hand, senescence may arrest the uncontrolled growth of transformed stem cells and protect organisms from cancer. This double function of senescence is strictly linked to the activity of genes that the control cell cycle such as the retinoblastoma proteins RB1, RB2/P130, and P107.