PAX4 Enhances Beta-Cell Differentiation of Human Embryonic Stem Cells

Background Human embryonic stem cells (HESC) readily differentiate into an apparently haphazard array of cell types, corresponding to all three germ layers, when their culture conditions are altered, for example by growth in suspension as aggregates known as embryoid bodies (EBs). However, this diversity of differentiation means that the efficiency of producing any one particular cell type is inevitably low. Although pancreatic differentiation has been reported from HESC, practicable applications for the use of β-cells derived from HESC to treat diabetes will only be possible once techniques are developed to promote efficient differentiation along the pancreatic lineages. Methods and Findings Here, we have tested whether the transcription factor, Pax4 can be used to drive the differentiation of HESC to a β-cell fate in vitro. We constitutively over-expressed Pax4 in HESCs by stable transfection, and used Q-PCR analysis, immunocytochemistry, ELISA, Ca2+ microfluorimetry and cell imaging to assess the role of Pax4 in the differentiation and intracellular Ca2+ homeostasis of β-cells developing in embryoid bodies produced from such HESC. Cells expressing key β-cell markers were isolated by fluorescence-activated cell sorting after staining for high zinc content using the vital dye, Newport Green. Conclusion Constitutive expression of Pax4 in HESC substantially enhances their propensity to form putative β-cells. Our findings provide a novel foundation to study the mechanism of pancreatic β-cells differentiation during early human development and to help evaluate strategies for the generation of purified β-cells for future clinical applications

Persistence of weekly alendronate: a real-world study in Croatia

Long-term treatment of osteoporosis is required for optimal efficacy, but adherence to therapy is suboptimal with daily and weekly oral bisphosphonates. The aim of this study was to assess real-world persistence (long-term adherence) with weekly alendronate. Persistence data were collected according to World Health Organization criteria for the prior month and year for 102 consecutive patients with osteoporosis at three outpatient clinics in Croatia. Persistence was assessed using medication possession ratios (MPR). Adequate persistence was defined as sufficient medication supply to ensure antifracture efficacy (MPR >or=80%). Self-reported persistence data were compared with resupply prescription data from primary care physicians (PCPs). The effect of patient age, co-therapy, co-morbidity, and time since osteoporosis was diagnosed were evaluated. A diagnosis of osteoporosis was established 3.21+/-1.83 years prior for the 96 women and six men enrolled (mean age 66.92+/-8.05 years). During the previous year, 86.3% patients reported not missing any tablets. Age correlated with the number of missed tablets, with older patients missing more tablets (p=0.038). Patients with co-therapy (p=0.042) missed more tablets. PCPs reported that 65.7% of the patients were issued prescriptions for 52 tablets. A total of 68.7% had MPR >80%. Patients with rheumatoid arthritis did not impact MPR (p=0.936). Previous fractures or number of fractures were not associated with persistence (p>0.05). In Croatia, persistence was superior with weekly-administered alendronate than has been reported elsewhere, perhaps due to socio-cultural factors. Larger, longitudinal studies are needed to confirm these results

Generation of gene-modified goats targeting MSTN and FGF5 via zygote injection of CRISPR/Cas9 system

Recent advances in the study of the CRISPR/Cas9 system have provided a precise and versatile approach for genome editing in various species. However, the applicability and efficiency of this method in large animal models, such as the goat, have not been extensively studied. Here, by co-injection of one-cell stage embryos with Cas9 mRNA and sgRNAs targeting two functional genes (MSTN and FGF5), we successfully produced gene-modified goats with either one or both genes disrupted. The targeting efficiency of MSTN and FGF5 in cultured primary fibroblasts was as high as 60%, while the efficiency of disrupting MSTN and FGF5 in 98 tested animals was 15% and 21% respectively, and 10% for double gene modifications. The on- and off-target mutations of the target genes in fibroblasts, as well as in somatic tissues and testis of founder and dead animals, were carefully analyzed. The results showed that simultaneous editing of several sites was achieved in large animals, demonstrating that the CRISPR/Cas9 system has the potential to become a robust and efficient gene engineering tool in farm animals, and therefore will be critically important and applicable for breeding