SirT1 brings stemness closer to cancer and aging

Sirtuin 1 acts in various cell processes, deacetylating both chromatin and non-histone proteins, and its role in cancer and aging has long been studied and debated. Here we discuss another aspect of SirT1 biology, its function as a stem cell pluripotency and differentiation regulator. We evaluate the implications of these findings in sirtuin inhibition-based cancer treatment and in the application of sirtuin activation for anti-aging therapy

The genesis of human hematopoietic stem cells

Developmental hematopoiesis consists of multiple, partially overlapping hematopoietic waves that generate the differentiated blood cells required for embryonic development while establishing a pool of undifferentiated hematopoietic stem cells (HSCs) for postnatal life. This multilayered design in which active hematopoiesis migrates through diverse extra and intraembryonic tissues has made it difficult to define a roadmap for generating HSCs vs non-self-renewing progenitors, especially in humans. Recent single-cell studies have helped in identifying the rare human HSCs at stages when functional assays are unsuitable for distinguishing them from progenitors. This approach has made it possible to track the origin of human HSCs to the unique type of arterial endothelium in the aorta-gonad-mesonephros region and document novel benchmarks for HSC migration and maturation in the conceptus. These studies have delivered new insights into the intricate process of HSC generation and provided tools to inform the in vitro efforts to replicate the physiological developmental journey from pluripotent stem cells via distinct mesodermal and endothelial intermediates to HSCs

Epigenetic regulation of developmental genes in embryonic stem cell differentation

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 26-04-201

Comunità rom nella provincia di Napoli: l’esperienza di conoscenza di una diversa realtà insediativa, la redazione delle linee-guida e la progettazione dei villaggi - Rom community in the province of Naples: the experience of knowledge of a different settlement, the drafting of guidelines and the design of villages

L’idea dell’assessorato alla Pace, all’Immigrazione ed alla Cooperazione Internazionale della Provinciale di Napoli, di sottoporre al mondo accademico il cosiddetto “problema rom”, nacque nel 2006 dalla volontà di rispondere all’ormai storica emergenza dei “campi nomadi”, legata alle condizioni di forte degrado igienico-sanitario ed infrastrutturale in cui tuttora, purtroppo, versano questi luoghi. La richiesta all’università fu quella di condurre un’analisi, coordinata dalla prof.ssa Marina Fumo, sugli insediamenti rom, spontanei e non, presenti nella provincia, per poter elaborare delle linee-guida alla realizzazione di nuove e più idonee soluzioni residenziali. In 2006 the Provincial Administration of Naples has given the start to a study on the local gipsy’s settlements. The aim was developing knowledge to face the emergencies caused by poor hygiene and lacking infrastructure in these spontaneous settlements. Coordinated by Marina Fumo the research produced guidelines to adequate residential solutions. The open- source survey was the method applied for the analysis and for draft representation, allowing the identification of identity-shaping elements, not deductible from traditional cartography

Regulation of expression of two LY-6 family genes by intron retention and transcription induced chimerism.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: Regulation of the expression of particular genes can rely on mechanisms that are different from classical transcriptional and translational control. The LY6G5B and LY6G6D genes encode LY-6 domain proteins, whose expression seems to be regulated in an original fashion, consisting of an intron retention event which generates, through an early premature stop codon, a non-coding transcript, preventing expression in most cell lines and tissues. RESULTS: The MHC LY-6 non-coding transcripts have shown to be stable and very abundant in the cell, and not subject to Nonsense Mediated Decay (NMD). This retention event appears not to be solely dependent on intron features, because in the case of LY6G5B, when the intron is inserted in the artificial context of a luciferase expression plasmid, it is fully spliced but strongly stabilises the resulting luciferase transcript. In addition, by quantitative PCR we found that the retained and spliced forms are differentially expressed in tissues indicating an active regulation of the non-coding transcript. EST database analysis revealed that these genes have an alternative expression pathway with the formation of Transcription Induced Chimeras (TIC). This data was confirmed by RT-PCR, revealing the presence of different transcripts that would encode the chimeric proteins CSNKbeta-LY6G5B and G6F-LY6G6D, in which the LY-6 domain would join to a kinase domain and an Ig-like domain, respectively. CONCLUSION: In conclusion, the LY6G5B and LY6G6D intron-retained transcripts are not subjected to NMD and are more abundant than the properly spliced forms. In addition, these genes form chimeric transcripts with their neighbouring same orientation 5' genes. Of interest is the fact that the 5' genes (CSNKbeta or G6F) undergo differential splicing only in the context of the chimera (CSNKbeta-LY6G5B or G6F-LY6G6C) and not on their own

Dual-color HIV reporters trace a population of latently infected cells and enable their purification

AbstractHIV latency constitutes the main barrier for clearing HIV infection from patients. Our inability to recognize and isolate latently infected cells hinders the study of latent HIV. We engineered two HIV-based viral reporters expressing different fluorescent markers: one HIV promoter-dependent marker for productive HIV infection, and a second marker under a constitutive promoter independent of HIV promoter activity. Infection of cells with these viruses allows the identification and separation of latently infected cells from uninfected and productively infected cells. These reporters are sufficiently sensitive and robust for high-throughput screening to identify drugs that reactivate latent HIV. These reporters can be used in primary CD4 T lymphocytes and reveal a rare population of latently infected cells responsive to physiological stimuli. In summary, our HIV-1 reporters enable visualization and purification of latent-cell populations and open up new perspectives for studies of latent HIV infection

Epigenetic repression of ROR2 has a Wnt-mediated, pro-tumourigenic role in colon cancer

9 páginas, 4 figuras.-- et al.[Background]: Wnt factors control cell differentiation through semi-independent molecular cascades known as the β-catenin-dependent (canonical) and -independent (non-canonical) Wnt signalling pathways. Genetic and epigenetic alteration of components of the canonical Wnt signalling pathway is one of the primary mechanisms underlying colon cancer. Despite increasing evidence of the role of the non-canonical pathways in tumourigenesis, however, the underlying molecular mechanisms are poorly understood. [Results]: Here we report that the receptor tyrosine kinase-like orphan receptor 2 (ROR2), a transmembrane receptor for Wnt factors that activates non-canonical pathways, is frequently repressed by aberrant promoter hypermethylation in human colon cancer cell lines and primary tumours. By restoring ROR2 activity in colon cancer cells harbouring ROR2 promoter hypermethylation, we show that the role of ROR2 in colon cancer cells is mediated, at least in part, by canonical Wnt and that its epigenetic-dependent loss can be pro-tumourigenic. [Conclusions]: Our data show the importance of epigenetic alterations of ROR2 in colon cancer, highlighting the close interconnection between canonical and non-canonical Wnt signalling pathways in this type of tumour.AM is funded by the Spanish Ministerio de Ciencia e Innovación (MICINN; SAF2007-60341, ISCIII-RETIC RD06/0020/0009), VC receives a fellowship from the Spanish FPU Research Programme, EL and CH are recipients of fellowships from the Spanish FIS Research Programme. The Instituto Universitario de Oncología is supported by Obra Social Cajastur, Spain. This work was supported by the MICINN (PI061267; PS09/02454; Ref. 200820I172).Peer reviewe

Preventing the acute skin side effects in patients treated with radiotherapy for breast cancer: the use of corneometry in order to evaluate the protective effect of moisturizing creams

BACKGROUND AND PURPOSE: The purpose of this study was to add, to the objective evaluation, an instrumental assessment of the skin damage induced by radiation therapy. MATERIALS AND METHODS: A group of 100 patients affected by breast cancer was recruited in the study over one year. Patients were divided into five groups of 20 patients. For each group it was prescribed a different topical treatment. The following products were used: Betaglucan, sodium hyaluronate (Neoviderm®), Vitis vinifera A. s-I-M.t-O.dij (Ixoderm®), Alga Atlantica plus Ethylbisiminomethylguaicolo and Manganese Cloruro (Radioskin1®) and Metal Esculetina plus Ginko Biloba and Aloe vera (Radioskin 2®); Natural triglycerides-fitosterols (Xderit®); Selectiose plus thermal water of Avene (Trixera+®). All hydrating creams were applied twice a day starting 15 days before and one month after treatment with radiations. Before and during treatment patients underwent weekly skin assessments and corneometry to evaluate the symptoms related to skin toxicity and state of hydration. Evaluation of acute cutaneous toxicity was defined according to the RTOG scale. RESULTS: All patients completed radiotherapy; 72% of patients presented a G1 cutaneous toxicity, 18% developed a G2 cutaneous toxicity, 10% developed a G3 toxicity, no one presented G4 toxicity. The corneometry study confirmed the protective role of effective creams used in radiation therapy of breast cancer and showed its usefulness to identify radiation-induced dermatitis in a very early stage. CONCLUSIONS: The preventive use of topic products reduces the incidence of skin side effects in patients treated with radiotherapy for breast cancer. An instrumental evaluation of skin hydration can help the radiation oncologist to use strategies that prevent the onset of toxicity of high degree. All moisturizing creams used in this study were equally valid in the treatment of skin damage induced by radiotherapy

Epigenetic Mechanisms Regulate MHC and Antigen Processing Molecules in Human Embryonic and Induced Pluripotent Stem Cells

Background Human embryonic stem cells (hESCs) are an attractive resource for new therapeutic approaches that involve tissue regeneration. hESCs have exhibited low immunogenicity due to low levels of Mayor Histocompatibility Complex (MHC) class-I and absence of MHC class-II expression. Nevertheless, the mechanisms regulating MHC expression in hESCs had not been explored. Methodology/Principal Findings We analyzed the expression levels of classical and non-classical MHC class-I, MHC class-II molecules, antigen-processing machinery (APM) components and NKG2D ligands (NKG2D-L) in hESCs, induced pluripotent stem cells (iPSCs) and NTera2 (NT2) teratocarcinoma cell line. Epigenetic mechanisms involved in the regulation of these genes were investigated by bisulfite sequencing and chromatin immunoprecipitation (ChIP) assays. We showed that low levels of MHC class-I molecules were associated with absent or reduced expression of the transporter associated with antigen processing 1 (TAP-1) and tapasin (TPN) components in hESCs and iPSCs, which are involved in the transport and load of peptides. Furthermore, lack of β2-microglobulin (β2m) light chain in these cells limited the expression of MHC class I trimeric molecule on the cell surface. NKG2D ligands (MICA, MICB) were observed in all pluripotent stem cells lines. Epigenetic analysis showed that H3K9me3 repressed the TPN gene in undifferentiated cells whilst HLA-B and β2m acquired the H3K4me3 modification during the differentiation to embryoid bodies (EBs). Absence of HLA-DR and HLA-G expression was regulated by DNA methylation. Conclusions/Significance Our data provide fundamental evidence for the epigenetic control of MHC in hESCs and iPSCs. Reduced MHC class I and class II expression in hESCs and iPSCs can limit their recognition by the immune response against these cells. The knowledge of these mechanisms will further allow the development of strategies to induce tolerance and improve stem cell allograft acceptance