Ultrastructural visualization of the Mesenchymal-to-Epithelial Transition during reprogramming of human fibroblasts to induced pluripotent stem cells

The Mesenchymal-to-Epithelial Transition (MET) has been recognized as a crucial step for successful reprogramming of fibroblasts to induced pluripotent stem cells (iPSCs). Thus, it has been demonstrated, that the efficiency of reprogramming can be enhanced by promoting an epithelial expression program in cells, with a concomitant repression of key mesenchymal genes. However, a detailed characterization of the epithelial transition associated with the acquisition of a pluripotent phenotype is still lacking to this date. Here, we integrate a panel of morphological approaches with gene expression analyses to visualize the dynamics of episomal reprogramming of human fibroblasts to iPSCs. We provide the first ultrastructural analysis of human fibroblasts at various stages of episomal iPSC reprogramming, as well as the first real-time live cell visualization of a MET occurring during reprogramming. The results indicate that the MET manifests itself approximately 6–12 days after electroporation, in synchrony with the upregulation of early pluripotency markers, and resembles a reversal of the Epithelial-to-Mesenchymal Transition (EMT) which takes place during mammalian gastrulation

Maximal accelerations for twelve weeks elicit improvement in a single out of a collection of cycling performance indicators in trained cyclists

INTRODUCTION: Cycling is a time-consuming sport. Cyclists, as many other athletes, therefore, focus on training effectively. The hypothesis was tested that twelve weeks of supplementary maximal acceleration training caused more favourable changes in cycling performance indicators as compared to changes measured in comparable control cyclists. METHODS: Trained cyclists (n = 24) participated. A control group and a group performing maximal acceleration training, as a supplement to their usual training, were formed. The maximal acceleration training consisted of series of ten repetitions of outdoor brief maximal accelerations, which were initiated from low speed and performed in a large gear ratio. The cyclists in the control group performed their usual training. Performance indicators, in form of peak power output in a 7-s maximal isokinetic sprint test, maximal aerobic power output in a graded test, and submaximal power output at a predetermined blood lactate concentration of 2.5 mmol L(−1) in a graded test were measured before and after the intervention. RESULTS: Peak power output in the sprint test was increased (4.1% from before to after the intervention) to a larger extent (p = 0.045) in the cyclists who had performed the maximal acceleration training than in the control cyclists (−2.8%). Changes in maximal aerobic power output and in submaximal power output at a blood lactate concentration of 2.5 mmol L(−1) were not significantly different between the groups (p > 0.351). DISCUSSION: The results indicated that the applied supplementary maximal acceleration training caused modest favourable changes of performance indicators, as compared to the changes measured in a group of comparable control cyclists

Ultrastructural myocardial changes in seven cats with spontaneous hypertrophic cardiomyopathy

AbstractObjectivesHypertrophic cardiomyopathy (HCM) is the most common heart disease in cats and shares clinical and pathological characteristics with human HCM. Little is known about the pathogenic mechanisms underlying development of spontaneous feline HCM.AnimalsThe study population consisted of seven cats diagnosed with HCM and eight age-matched cats with no evidence of cardiac disease.MethodsFresh myocardial biopsies taken from the middle of the left ventricular posterior free wall were obtained and examined with transmission electron microscopy.ResultsElectron microscopic examination showed ultrastructural aberrations of the myocardial cytoarchitecture and of the interstitium in the seven cats with HCM. In the most severely affected cats the myofibrils were disorganized and subsarcolemmal mitochondria were depleted. In control cats, contraction band artifacts were commonly seen.ConclusionsIn this preliminary study we show that ultrastructural changes of the myocardium in seven cats with HCM involve the cytoskeleton and mitochondria. We suggest that our findings are important for future research aiming at elucidating the pathogenic mechanisms underlying the phenotypic expression of feline HCM.The results of this study prompt for a larger scale study, including quantitative measurements of mitochondrial distribution and cytoskeletal derangements in feline HCM

Study of Paclitaxel-Treated HeLa Cells by Differential Electrical Impedance Flow Cytometry

This work describes the electrical investigation of paclitaxel-treated HeLa cells using a custom-made microfluidic biosensor for whole cell analysis in continuous flow. We apply the method of differential electrical impedance spectroscopy to treated HeLa cells in order to elucidate the changes in electrical properties compared with non-treated cells. We found that our microfluidic system was able to distinguish between treated and non-treated cells. Furthermore, we utilize a model for electrical impedance spectroscopy in order to perform a theoretical study to clarify our results. This study focuses on investigating the changes in the electrical properties of the cell membrane caused by the effect of paclitaxel. We observe good agreement between the model and the obtained results. This establishes the proof-of-concept for the application in cell drug therapy

Induced pluripotent stem cells derived from Alzheimer's disease patients:the promise, the hope and the path ahead

The future hope of generated induced pluripotent stem cells (iPS cells) from Alzheimer’s disease patients is multifold. Firstly, they may help to uncover novel mechanisms of the disease, which could lead to the development of new and unprecedented drugs for patients and secondly, they could also be directly used for screening and testing of potential new compounds for drug discovery. In addition, in the case of familial known mutations, these cells could be targeted by use of advanced gene-editing techniques to correct the mutation and be used for future cell transplantation therapies. This review summarizes the work so far in regards to production and characterization of iPS cell lines from both sporadic and familial Alzheimer’s patients and from other iPS cell lines that may help to model the disease. It provides a detailed comparison between published reports and states the present hurdles we face with this new technology. The promise of new gene-editing techniques and accelerated aging models also aim to move this field further by providing better control cell lines for comparisons and potentially better phenotypes, respectively