© F e r r a t a S t o r t i F o u n d a t i o nclassification. 22 In this study, a new serum miRNAs expression profile, potent enough to distinguish newly diagnosed MM and MGUS patients from healthy controls, was created based on TaqMan Low Density Arrays (TLDA). This profile was validated by quantitative realtime PCR (qPCR) on a larger cohort of newly diagnosed and relapsed MM as well as MGUS patients. Moreover, miRNAs levels were correlated with clinical, biochemical and cytogenetic characteristics and survival data. Methods Patients and healthy donorsPeripheral blood (PB) serum samples from 103 newly diagnosed MM patients, 18 MM patients in relapse, 57 MGUS and 30 healthy donors (HD) from the Faculty Hospital Brno, Czech Republic, were obtained for this study. PB serum samples were collected as follows: centrifugation 3500 rpm/15 min/20°C. Samples were frozen as 0.5 mL aliquots, stored at -80°C and thawed only once. For 70 MM and 36 MGUS samples, BMPCs were obtained for routine interphase fluorescence in situ hybridization analysis (I-FISH), as described previously. 23 Patients' and donors' characteristics are described in Table 1 and in the Online Supplementary Table S1. For 6 newly diagnosed MM patients, BMPCs and exosomal and non-exosomal fraction from PB serum were collected. All patients signed an informed consent form approved by the hospital ethical committee before enrollment into this study. MiRNA extractionTotal RNA enriched for miRNAs was extracted from all serum samples using miRNeasy Kit (Qiagen) modified for circulating miRNAs according to the manufacturer's instructions. MiRNA/RNA quantity was assessed on a NanoDrop ND-1000 Spectrophotometer (Thermo Scientific) as measurement of each sample 2 times with mean SD=0.292 ng/μL. All samples fit into the Nanodrop ND-1000 validated measuring range. Exosomes precipitationExosomes were collected using ExoQuick Exosome Precipitation Solution (System Biosciences). Serum samples were centrifuged for 3500 rpm/10 min/4°C, 250 μL of serum was combined with 63 μL of ExoQuick, incubated for 30 min/4°C and centrifuged for 2 min/13000 rpm. Exosomal and non-exosomal fraction was used for miRNA/RNA extraction, as described above. TaqMan Low Density ArraysMegaplex profiling using human TaqMan Low Density miRNA Arrays A+B, v3.0 (TLDA) (Life Technologies) was performed to evaluate the expression of 667 miRNA (see Online Supplementary Methods). QPCR was performed on the ABI7900HT system; raw data were analyzed using SDS software v.2.3, RQ Manager v1.2.1 (Life Technologies). Candidate miRNA confirmation by qPCR and quantification of miRNAIndividual TaqMan miRNA assays for 6 miRNA (hsa-miR-222-002276, hsa-miR-744-002324, hsa-miR-130a-000454, hsa-miR34a-000426, hsa-let-7e-002406, hsa-let-7d-002283, Life Technologies) were used for qPCR on a 7500 Real-Time PCR System. QPCR and reverse transcription was performed following the manufacturer´s recommendations (see Online Supplementary Methods). Absolute quantification to determine the copy number of each miRNA per 1...

Induced pluripotent stem (iPS) cells can be derived from a wide range of somatic cells via overexpression of a set of specific genes. With respect to their properties, iPS cells closely resemble embryonic stem cells. Because of their main property, pluripotency, iPS cells have excellent prospects for use in substitutive cell therapy; however, the methods of directed differentiation of iPS cells have not been yet sufficiently elaborated. In this work, we derived human iPS cells from fetal neural stem (FNS) cells by transfection with a polycistronic plasmid vector carrying the mouse Oct4, Sox2, Klf4, and c-Myc genes or a plasmid expressing the human OCT4 gene. We have shown that human FNS cells can be effectively reprogrammed despite a low transfection level (10%-15%) and that the use of 2-propylvaleric (valproic) acid and BIX-01294 increases the yield of iPS cell clones to ∼7-fold. Further, transient expression of OCT4 alone is sufficient for reprogramming. The iPS cells obtained express all the major markers of embryonic stem cells and are able to differentiate in vitro into ectodermal, mesodermal, and endodermal derivatives. In addition, we have found that the human iPS cells derived from FNS cells can be successfully subjected to in vitro directed chondrogenic differentiation to form functional cartilaginous tissue.

During early development in female mammals, one of the two X chromosomes recruits a variety of protein complexes that establish repressive chromatin modifications and thus becomes transcriptionally silenced. This process is termed X chromosome inactivation (XCI). Imprinted XCI of the paternal X chromosome occurs in the extraembryonic lineages of some eutherian species (e.g., rodents). In the cells of the embryo proper, the choice of the X chromosome for XCI is random. In this study we compared the distribution of some histone modifications on metaphase spreads from extraembryonic endoderm and fibroblast cell lines in vole Microtus rossiaemeridionalis, which are examples of imprinted and random XCI, respectively. The X chromosome of M. rossiaemeridionalis bears a large constitutive heterochromatic block enriched with repeated DNA, making this species a useful model for studying chromatin structure. In vole fibroblasts and the majority of extraembryonic endoderm cells, the silencing of the inactive X chromosome appears to involve two types of facultative heterochromatin. The first is defined by H3K27 trimethylation and H2A ubiquitylation and colocalizes with previously described Xist RNA banding, whereas the second is associated with H3K9 trimethylation and the heterochromatic protein HP1. The block of constitutive heterochromatin on the M. rossiaemeridionalis X chromosome has the same pattern of chromatin modifications as the second type of facultative heterochromatin. The distribution of histone modifications, HP1 protein, and Xist RNA on vole inactive X chromosome is the same during both the imprinted and the random XCI.

I Kr -rapid delayed rectifying potassium current; I Ks -slow delayed rectifying potassium current; I K1 -inward rectifying potassium current; iPSC -induced pluripotent stem cell; hERG -human ether-a-go-go-related gene; FPD -field potential duration; NRVM -neonatal rat ventricular myocyte; CV -conduction velocity; MCRmaximum capture rate; TdP -Torsade de Pointes