Neural differentiation of human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) can produce a valuable and robust source of human neural cell subtypes, holding great promise for the study of neurogenesis and development, and for treating neurological diseases. However, current hESCs and hiPSCs neural differentiation protocols require either animal factors or embryoid body formation, which decreases efficiency and yield, and strongly limits medical applications. Here we develop a simple, animal‐free protocol for neural conversion of both hESCs and hiPSCs in adherent culture conditions. A simple medium formula including insulin induces the direct conversion of >98% of hESCs and hiPSCs into expandable, transplantable, and functional neural progenitors with neural rosette characteristics. Further differentiation of neural progenitors into dopaminergic and spinal motoneurons as well as astrocytes and oligodendrocytes indicates that these neural progenitors retain responsiveness to instructive cues revealing the robust applicability of the protocol in the treatment of different neurodegenerative diseases. The fact that this protocol includes animal‐free medium and human extracellular matrix components avoiding embryoid bodies makes this protocol suitable for the use in clinic. Stem Cells Translational Medicine 2017;6:1217–1226

Background: Photoreceptors, light-sensing neurons in retina, are central to vision. Photoreceptor cell death (PCD) is observed in most inherited and acquired retinal dystrophies. But the underlying molecular mechanism of PCD is unclear. Photoreceptors are sturdy neurons that survive high oxidative and phototoxic stress, which are known threats to genome stability. Unexpectedly, DNA damage response in mice photoreceptors is compromised; mainly due to loss of crucial DNA repair proteins, ATM and 53BP1. We tried to understand the molecular function of ATM and 53BP1 in response to oxidative stress and how suppression of DNA repair response in mice retina affect photoreceptor cell survival. Methods: We use the state of art cell biology methods and structure-function analysis of mice retina. RNA:DNA hybrids (S9.6 antibody and Hybrid-binding domain of RNaseH1) and DNA repair foci (gH2AX and 53BP1) are quantified by confocal microscopy, in retinal sections and cultured cell lines. Oxidative stress, DNA double strand break, RNaseH1 expression and small-molecule kinase-inhibitors were used to understand the role of ATM and RNA:DNA hybrids in DNA repair. Lastly, retinal structure and function of ATM deficient mice, in Retinal degeneration 1 (Pde6brd1) background, is studied using Immunohistochemistry and Electroretinography. Results: Our work has three novel findings: firstly, both human and mice photoreceptor cells specifically accumulate RNA:DNA hybrids, a structure formed by re-hybridization of nascent RNA with template DNA during transcription. Secondly, RNA:DNA-hybrids promote ataxia-telangiectasia mutated (ATM) activation during oxidative stress and 53BP1-foci formation during downstream DNA repair process. Thirdly, loss of ATM -in murine photoreceptors- protract DNA repair but also promote their survival.  Conclusions: We propose that due to high oxidative stress and accumulation of RNA:DNA-hybrids in photoreceptors, expression of ATM is tightly regulated to prevent PCD. Inefficient regulation of ATM expression could be central to PCD and inhibition of ATM-activation could suppress PCD in retinal dystrophy patients.

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BackgroundMutations in pre-mRNA splicing factor PRPF31 can lead to retinitis pigmentosa (RP). Although the exact disease mechanism remains unknown, it has been hypothesized that haploinsufficiency might be involved in the pathophysiology of the disease.MethodsIn this study, we have analyzed a mouse model containing the p.A216P mutation in Prpf31 gene.ResultsWe found that mutant Prpf31 protein produces cytoplasmic aggregates in the retinal pigment epithelium and decreasing the protein levels of this splicing factor in the nucleus. Additionally, normal protein was recruited in insoluble aggregates when the mutant protein was overexpressed in vitro. In response to protein aggregation, Hspa4l is overexpressed. This member of the HSP70 family of chaperones might contribute to the correct folding and solubilization of the mutant protein, allowing its translocation to the nucleus.ConclusionsOur data suggests that a mechanism haploinsufficiency and dominant-negative is involved in retinal degeneration due to mutations in PRPF31. HSP70 over-expression might be a new therapeutic target for the treatment of retinal degeneration due to PRPF31 mutations.

We present the results of the clinical validity in the screening of idiopathic scoliosis with a nonharming method of back surface topography by means of structured light projection. A total of 155 patients were evaluated (mean age 13.3 years). They were divided into two groups: pathologic patients (scoliosis) and nonpathologic patients (control and asymmetries). An analytical case-control study was carried out. Our topographic method obtained 92% sensitivity and 74% specificity as a screening test in identifying patients with scoliosis (P=0.05). We could quantify the vertebral deformity of scoliosis in the three spatial planes by means of three topographic variables, Horizontal Plane Deformity Index, Posterior Trunk Symmetry Index and Columnar Profile, and to elaborate a combined screening algorithm with good reliability parameters.

To our knowledge our study suggests for the first time in the literature a positive effect of sildenafil in the immediate posttransplantation outcome of warm ischemic kidneys without secondary systemic effects.

This study shows that the synchronous mode of LVAD operation is feasible. Moreover, a delay in device contraction until the second half of the cardiac cycle optimizes ventricular unloading and may eventually improve myocardial recovery.

We present SIMHYB, a Java-based software for the simulation of mixed hybridizing populations. The software incorporates user-defined initial parameters and input files to account for the initial census size of two species in a closed population, the number of intermediate specific classes, the directional fertility among specific classes, the fitness coefficients for each specific class, the inheritance of fitness, and the degree of ageing and self-incompatibility of the individuals. All these demographic and adaptive parameters can be modified by the user to analyze their effect on the evolution of the mixed population. SIMHYB allows the traceability of each individual, whose pedigree is also recorded. For each simulated generation the software yields an output file that is easily convertible to an input for STRUCTURE, one of the most popular softwares for the Bayesian analysis of populations. Application of SIMHYB to simulate Quercus ilex and Q. suber hybridizing populations, and further analysis with STRUCTURE, reveals that advanced introgressed individuals are very often misclassified with the currently available set of nuclear microsatellite markers, so that introgression between these two species could have been underestimated in previous studies. However, we provide a simple parameter based on STRUCTURE results to identify the directionality of pollination in the progeny of a known mother tree.