Transcriptomic Analysis of Mineralized Adipose-Derived Stem Cell Tissues for Calcific Valve Disease Modelling.

Calcific aortic valve disease (CAVD) is characterized by the fibrosis and mineralization of the aortic valve, which leads to aortic stenosis and heart failure. At the cellular level, this is due to the osteoblastic-like differentiation of valve interstitial cells (VICs), resulting in the calcification of the tissue. Unfortunately, human VICs are not readily available to study CAVD pathogenesis and the implicated mechanisms in vitro; however, adipose-derived stromal/stem cells (ASCs), carrying the patient's specific genomic features, have emerged as a promising cell source to model cardiovascular diseases due to their multipotent nature, availability, and patient-specific characteristics. In this study, we describe a comprehensive transcriptomic analysis of tissue-engineered, scaffold-free, ASC-embedded mineralized tissue sheets using bulk RNA sequencing. Bioinformatic and gene set enrichment analyses revealed the up-regulation of genes associated with the organization of the extracellular matrix (ECM), suggesting that the ECM could play a vital role in the enhanced mineralization observed in these tissue-engineered ASC-embedded sheets. Upon comparison with publicly available gene expression datasets from CAVD patients, striking similarities emerged regarding cardiovascular diseases and ECM functions, suggesting a potential link between ECM gene expression and CAVDs pathogenesis. A matrisome-related sub-analysis revealed the ECM microenvironment promotes the transcriptional activation of the master gene runt-related transcription factor 2 (RUNX2), which is essential in CAVD development. Tissue-engineered ASC-embedded sheets with enhanced mineralization could be a valuable tool for research and a promising avenue for the identification of more effective aortic valve replacement therapies.

Analysis of the Columellar-Labial Angle in Perioral Aging.

BACKGROUND: The young face presents a convex and rounded aspect; with aging, this changes to a more concave and flattened aspect, with the angles of the face undergoing changes through soft tissue repositioning and bone remodeling. The columellar-labial angle is one of the features that change. OBJECTIVES: The objective of the present study was to analyze the columellar-labial angle at different stages of adult life and assess its contribution to facial changes during aging. METHODS: We analyzed a database (December 2017-March 2018) of 722 female patients, aged 21 to 88 years, and obtained anthropometric measurements of the columellar-labial angle with a Canfield Vectra 3D image analysis system. Our database originates from a private clinic where all patients were registered and photographed. RESULTS: Our analysis showed a decrease in the columellar-labial angle, mainly observed from patients aged 60 years and older. This decrease can be explained by the absorption of body structures that occurs during aging. CONCLUSIONS: The columellar-labial angle decreases with age, and this finding may provide a better understanding of the transformation that occurs with aging. Obtaining a clearer view of the changes that occur in the face will improve treatments for facial rejuvenation, either conservative or surgical, and provide a basis for future studies and knowledge expansion.

Erosive Pustular Dermatosis of the Scalp: Why Do We Miss It?

Erosive pustular dermatosis of the scalp (EPDS) is an uncommon disease and primarily affects older men who have photo-damaged bald scalp, as was confirmed by our case series. EPDS is probably an overlooked disease, whose diagnosis is often missed because of a higher incidence of other cutaneous diseases affecting the same area and usually secondary to chronic actinic damage, such as actinic keratosis, basal cell carcinoma, and squamous cell carcinoma. For the first time, we report a case series of misdiagnosed EPDS with the aim of understanding why a diagnosis of EPDS was initially missed and try to give some tips to avoid future diagnostic delay.

Global Mapping of Open Chromatin Regulatory Elements by Formaldehyde-Assisted Isolation of Regulatory Elements Followed by Sequencing (FAIRE-seq).

Genetic information is organized in a complex structure composed of DNA and proteins together designated chromatin. Chromatin plays a dynamic role in transcriptional processes in that alteration of the interaction between its components results in the deregulation of cellular transcriptional program. Modification of epigenetic marks, variation in the precise positioning of nucleosomes, and consequent mobilization of nucleosomes regulate the access of various transcriptional factors to its underlying DNA template. Nucleosome-depleted regions, also designated open chromatin domains, are associated with active DNA regulatory elements, including promoters, enhancers, silencers, and insulators. Here, we describe the protocol of a rapid and simple technique entitled FAIRE (formaldehyde-assisted isolation of regulatory elements). Combined with high-throughput sequencing (FAIRE-seq), this procedure allows isolation of nucleosome-free regions and their mapping along the genome, thereby providing a global view of cell-specific regulatory elements.

The transcriptional co-repressor TLE3 suppresses basal signaling on a subset of estrogen receptor α target genes.

Chromatin constitutes a repressive barrier to the process of ligand-dependent transcriptional activity of nuclear receptors. Nucleosomes prevent the binding of estrogen receptor α (ERα) in absence of ligand and thus represent an important level of transcriptional regulation. Here, we show that in breast cancer MCF-7 cells, TLE3, a co-repressor of the Groucho/Grg/TLE family, interacts with FoxA1 and is detected at regulatory elements of ERα target genes in absence of estrogen. As a result, the chromatin is maintained in a basal state of acetylation, thus preventing ligand-independent activation of transcription. In absence of TLE3, the basal expression of ERα target genes induced by E2 is increased. At the TFF1 gene, the recruitment of TLE3 to the chromatin is FoxA1-dependent and prevents ERα and RNA polymerase II recruitment to TFF1 gene regulatory elements. Moreover, the interaction of TLE3 with HDAC2 results in the maintenance of acetylation at a basal level. We also provide evidence that TLE3 is recruited at several other regulatory elements of ERα target genes and is probably an important co-regulator of the E2 signaling pathway. In sum, our results describe a mechanism by which TLE3 affects ligand dependency in ERα-regulated gene expression via its binding restricting function and its role in gene regulation by histone acetylation.

LRH-1 governs vital transcriptional programs in endocrine-sensitive and -resistant breast cancer cells.

Tumor characteristics are decisive in the determination of treatment strategy for patients with breast cancer. Patients with estrogen receptor α (ERα)-positive breast cancer can benefit from long-term hormonal treatment. Nonetheless, the majority of patients will develop resistance to these therapies. Here, we investigated the role of the nuclear receptor liver receptor homolog-1 (LRH-1, NR5A2) in antiestrogen-sensitive and -resistant breast cancer cells. We identified genome-wide LRH-1-binding sites using ChIP-seq (chromatin immunoprecipitation sequencing), uncovering preferential binding to regions distal to transcriptional start sites. We further characterized these LRH-1-binding sites by integrating overlapping layers of specific chromatin marks, revealing that many LRH-1-binding sites are active and could be involved in long-range enhancer-promoter looping. Combined with transcriptome analysis of LRH-1-depleted cells, these results show that LRH-1 regulates specific subsets of genes involved in cell proliferation in antiestrogen-sensitive and antiestrogen-resistant breast cancer cells. Furthermore, the LRH-1 transcriptional program is highly associated with a signature of poor outcome and high-grade breast cancer tumors in vivo. Herein, we report the genome-wide location and molecular function of LRH-1 in breast cancer cells and reveal its therapeutic potential for the treatment of breast cancers, notably for tumors resistant to treatments currently used in therapies.

Endocrine resistance in breast cancer: from cellular signaling pathways to epigenetic mechanisms.

Although multiple cellular mechanisms have been proposed to explain endocrine resistance in breast cancer, the genomics events promoting the dysregulation of gene expression pattern are not clearly understood. Because chromatin plays a dynamic role in the estrogen receptor α (ERα) transcriptional program, we herein review signaling pathways implicated in endocrine resistance and try to merge them with recent epigenetic studies.

ERRs and cancers: effects on metabolism and on proliferation and migration capacities.

ERRs are orphan members of the nuclear receptor superfamily which, at least for ERRα and ERRγ display important roles in the control of various metabolic processes. On other hand, correlations have been found between the expression of ERRα and γ and diverse parameters of tumor progression in human cancers. Whereas it is tempting to speculate that ERR receptors act in tumors through the regulation of metabolism, recent data have suggested that they also may directly regulate tumor proliferation and progression independently of their effects on metabolism. The two aspects of tumoral functions of ERR receptors are the purpose of the present review.

H3K27 demethylation by JMJD3 at a poised enhancer of anti-apoptotic gene BCL2 determines ERα ligand dependency.

Chromatin represents a repressive barrier to the process of ligand-dependent transcriptional activity of nuclear receptors. Here, we show that H3K27 methylation imposes ligand-dependent regulation of the oestrogen receptor α (ERα)-dependent apoptotic response via Bcl-2 in breast cancer cells. The activation of BCL2 transcription is dependent on the simultaneous inactivation of the H3K27 methyltransferase, EZH2, and the demethylation of H3K27 at a poised enhancer by the ERα-dependent recruitment of JMJD3 in hormone-dependent breast cancer cells. We also provide evidence that this pathway is modified in cells resistant to anti-oestrogen (AE), which constitutively express BCL2. We show that the lack of H3K27 methylation at BCL2 regulatory elements due to the inactivation of EZH2 by the HER2 pathway leads to this constitutive activation of BCL2 in these AE-resistant cells. Our results describe a mechanism in which the epigenetic state of chromatin affects ligand dependency during ERα-regulated gene expression.

Modulating estrogen receptor-related receptor-alpha activity inhibits cell proliferation.

High expression of the estrogen receptor-related receptor (ERR)-alpha in human tumors is correlated to a poor prognosis, suggesting an involvement of the receptor in cell proliferation. In this study, we show that a synthetic compound (XCT790) that modulates the activity of ERRalpha reduces the proliferation of various cell lines and blocks the G(1)/S transition of the cell cycle in an ERRalpha-dependent manner. XCT790 induces, in a p53-independent manner, the expression of the cell cycle inhibitor p21(waf/cip)(1) at the protein, mRNA, and promoter level, leading to an accumulation of hypophosphorylated Rb. Finally, XCT790 reduces cell tumorigenicity in Nude mice.