Reinforcement of STAT3 activity reprogrammes human embryonic stem cells to naive-like pluripotency.

Leukemia inhibitory factor (LIF)/STAT3 signalling is a hallmark of naive pluripotency in rodent pluripotent stem cells (PSCs), whereas fibroblast growth factor (FGF)-2 and activin/nodal signalling is required to sustain self-renewal of human PSCs in a condition referred to as the primed state. It is unknown why LIF/STAT3 signalling alone fails to sustain pluripotency in human PSCs. Here we show that the forced expression of the hormone-dependent STAT3-ER (ER, ligand-binding domain of the human oestrogen receptor) in combination with 2i/LIF and tamoxifen allows human PSCs to escape from the primed state and enter a state characterized by the activation of STAT3 target genes and long-term self-renewal in FGF2- and feeder-free conditions.

Insulin like growth factor binding protein 7 (IGFBP7) expression is linked to poor prognosis but may protect from bone disease in multiple myeloma.

Background: Insulin like growth factor binding protein 7 (IGFBP7) is a secreted protein binding insulin like growth factor 1 (IGF-1), insulin, vascular endothelial growth factor A (VEGFA), and activin A. It antagonizes bone morphogenetic proteins and is involved in the tumour propagation of solid as well as haematological malignancies. Its role in multiple myeloma (MM) is not defined so far.

Parkin maintains mitochondrial levels of the protective Parkinson's disease-related enzyme 17-β hydroxysteroid dehydrogenase type 10.

Mutations of the PARK2 and PINK1 genes, encoding the cytosolic E3 ubiquitin-protein ligase Parkin and the mitochondrial serine/threonine kinase PINK1, respectively, cause autosomal recessive early-onset Parkinson's disease (PD). Parkin and PINK1 cooperate in a biochemical mitochondrial quality control pathway regulating mitochondrial morphology, dynamics and clearance. This study identifies the multifunctional PD-related mitochondrial matrix enzyme 17-β hydroxysteroid dehydrogenase type 10 (HSD17B10) as a new Parkin substrate.

Cell-free DNA in human follicular fluid as a biomarker of embryo quality.

Study Question: Could cell-free DNA (cfDNA) quantification in individual human follicular fluid (FF) samples become a new non-invasive predictive biomarker for in vitro fertilization (IVF) outcomes?

Summary Answer: CfDNA level in human follicular fluid samples was significantly correlated with embryo quality and could be used as an innovative non-invasive biomarker to improve IVF outcomes.

What Is Known Already: CfDNA fragments, resulting from apoptotic or necrotic events, are present in the bloodstream and their quantification is already used as a biomarker for gynaecological and pregnancy disorders. Follicular fluid is important for oocyte development and contains plasma components and factors secreted by granulosa cells during folliculogenesis.

Cell-free nucleic acids as non-invasive biomarkers of gynecological cancers, ovarian, endometrial and obstetric disorders and fetal aneuploidy.

Background: Proper folliculogenesis is fundamental to obtain a competent oocyte that, once fertilized, can support the acquisition of embryo developmental competence and pregnancy. MicroRNAs (miRNAs) are crucial regulators of folliculogenesis, which are expressed in the cumulus-oocyte complex and in granulosa cells and some can also be found in the bloodstream. These circulating miRNAs are intensively studied and used as diagnostic/prognostic markers of many diseases, including gynecological and pregnancy disorders.

Acute nutrient regulation of the mitochondrial glutathione redox state in pancreatic β-cells.

The glucose stimulation of insulin secretion by pancreatic β-cells depends on increased production of metabolic coupling factors, among which changes in NADPH and ROS (reactive oxygen species) may alter the glutathione redox state (EGSH) and signal through changes in thiol oxidation. However, whether nutrients affect EGSH in β-cell subcellular compartments is unknown. Using redox-sensitive GFP2 fused to glutaredoxin 1 and its mitochondria-targeted form, we studied the acute nutrient regulation of EGSH in the cytosol/nucleus or the mitochondrial matrix of rat islet cells.

Proteasome dysfunction mediates high glucose-induced apoptosis in rodent beta cells and human islets.

The ubiquitin/proteasome system (UPS), a major cellular protein degradation machinery, plays key roles in the regulation of many cell functions. Glucotoxicity mediated by chronic hyperglycaemia is detrimental to the function and survival of pancreatic beta cells. The aim of our study was to determine whether proteasome dysfunction could be involved in beta cell apoptosis in glucotoxic conditions, and to evaluate whether such a dysfunction might be pharmacologically corrected.

Proof of concept for AAV2/5-mediated gene therapy in iPSC-derived retinal pigment epithelium of a choroideremia patient.

Inherited retinal dystrophies (IRDs) comprise a large group of genetically and clinically heterogeneous diseases that lead to progressive vision loss, for which a paucity of disease-mimicking animal models renders preclinical studies difficult. We sought to develop pertinent human cellular IRD models, beginning with choroideremia, caused by mutations in the CHM gene encoding Rab escort protein 1 (REP1). We reprogrammed REP1-deficient fibroblasts from a CHM (-/y) patient into induced pluripotent stem cells (iPSCs), which we differentiated into retinal pigment epithelium (RPE).

Combining DGE and RNA-sequencing data to identify new polyA+ non-coding transcripts in the human genome.

Recent sequencing technologies that allow massive parallel production of short reads are the method of choice for transcriptome analysis. Particularly, digital gene expression (DGE) technologies produce a large dynamic range of expression data by generating short tag signatures for each cell transcript. These tags can be mapped back to a reference genome to identify new transcribed regions that can be further covered by RNA-sequencing (RNA-Seq) reads.

Side scatter intensity is highly heterogeneous in undifferentiated pluripotent stem cells and predicts clonogenic self-renewal.

In culture, human pluripotent stem cells (PSCs) are phenotypically (for instance, the SSEA3 expression level) and functionally (capacity to survive after single-cell dissociation) heterogeneous. We report here that the side scatter (SSC) signal measured by flow cytometry, a variable correlated with membrane irregularity and cell granularity, is very high in PSCs, even higher than in blood polymorphonuclear cells, and markedly heterogeneous. Moreover, SSC intensity rapidly and strongly decreases upon PSC differentiation into any of the three germ layers.

"Flagellated" cancer cells propel anti-tumor immunity.

The use of innate immune receptor agonists in cancer therapies has suffered from many drawbacks. Our recent observations suggest that some of these hurdles can be overcome by introducing flagellin into tumor cells to promote tumor antigen presentation by dendritic cells (DCs) and simultaneously trigger two types of pattern recognition receptors (PRRs).

Efficient transduction of healthy and malignant plasma cells by lentiviral vectors pseudotyped with measles virus glycoproteins.

A lot of genes deregulated in malignant plasma cells (PCs) involved in multiple myeloma have been reported these last years. The expression of some of these genes is associated with poor survival. A critical step is to elucidate the biological mechanisms triggered by these gene products.

Brief report: benchmarking human pluripotent stem cell markers during differentiation into the three germ layers unveils a striking heterogeneity: all markers are not equal.

Pluripotent stem cells (PSC) are functionally characterized by their capacity to differentiate into all the cell types from the three germ layers. A wide range of markers, the expression of which is associated with pluripotency, has been used as surrogate evidence of PSC pluripotency, but their respective relevance is poorly documented. Here, we compared by polychromatic flow cytometry the kinetics of loss of expression of eight widely used pluripotency markers (SSEA3, SSEA4, TRA-1-60, TRA-1-81, CD24, OCT4, NANOG, and alkaline phosphatase [AP]) at days 0, 5, 7, and 9 after induction of PSC differentiation into cells representative of the three germ layers.

Expression map of the human exome in CD34+ cells and blood cells: increased alternative splicing in cell motility and immune response genes.

Background: Hematopoietic cells are endowed with very specific biological functions, including cell motility and immune response. These specific functions are dramatically altered during hematopoietic cell differentiation, whereby undifferentiated hematopoietic stem and progenitor cells (HSPC) residing in bone marrow differentiate into platelets, red blood cells and immune cells that exit into the blood stream and eventually move into lymphoid organs or inflamed tissues. The contribution of alternative splicing (AS) to these functions has long been minimized due to incomplete knowledge on AS events in hematopoietic cells.

[Human embryonic stem cells: from the human embryo transgressed to the regenerative medicine of tomorrow].

Human embryonic stem cells (hESC) are derived from the inner cell mass (ICM) of the human blastocyst at day 5 or 6 of the early embryo development. These cells display two cardinal features: they are able to differentiate into cell types from many if not all human tissue (pluripotency) and they proliferate strongly and indefinitely without senescence in vitro. Therefore, hESC are a source of choice for stem cells for regenerative medicine and are a reference model to study the biology of pluripotency.

A gene expression signature shared by human mature oocytes and embryonic stem cells.

Background: The first week of human pre-embryo development is characterized by the induction of totipotency and then pluripotency. The understanding of this delicate process will have far reaching implication for in vitro fertilization and regenerative medicine. Human mature MII oocytes and embryonic stem (ES) cells are both able to achieve the feat of cell reprogramming towards pluripotency, either by somatic cell nuclear transfer or by cell fusion, respectively.

Peptide nucleic acids (PNAs) as diagnostic devices for genetic and cytogenetic analysis.

The peptide nucleic acids (PNAs) constitute a remarkable new class of synthetic nucleic acids analogs, based on peptide-like backbone. This structure gives to PNAs the capacity to hybridize with high affinity and specificity to complementary RNA and DNA sequences, and a great resistance to nucleases and proteinases. Originally conceived as ligands for the study of double stranded DNA, the unique physico-chemical properties of PNAs have led to the development of a large variety of research and diagnostic assays in the field of genetics, including genome mapping and mutation detection.