Erythropoietin and the effect of oxygen during proliferation and differentiation of human neural progenitor cells

<p>Abstract</p> <p>Background</p> <p>Hypoxia plays a critical role in various cellular mechanisms, including proliferation and differentiation of neural stem and progenitor cells. In the present study, we explored the impact of lowered oxygen on the differentiation potential of human neural progenitor cells, and the role of erythropoietin in the differentiation process.</p> <p>Results</p> <p>In this study we demonstrate that differentiation of human fetal neural progenitor cells under hypoxic conditions results in an increased neurogenesis. In addition, expansion and proliferation under lowered oxygen conditions also increased neuronal differentiation, although proliferation rates were not altered compared to normoxic conditions. Erythropoietin partially mimicked these hypoxic effects, as shown by an increase of the metabolic activity during differentiation and protection of differentiated cells from apoptosis.</p> <p>Conclusion</p> <p>These results provide evidence that hypoxia promotes the differentiation of human fetal neural progenitor cells, and identifies the involvement of erythropoietin during differentiation as well as different cellular mechanisms underlying the induction of differentiation mediated by lowered oxygen levels.</p

Effect of 3D-scaffold formation on differentiation and survival in human neural progenitor cells

<p>Abstract</p> <p>Background</p> <p>3D-scaffolds have been shown to direct cell growth and differentiation in many different cell types, with the formation and functionalisation of the 3D-microenvironment being important in determining the fate of the embedded cells. Here we used a hydrogel-based scaffold to investigate the influences of matrix concentration and functionalisation with laminin on the formation of the scaffolds, and the effect of these scaffolds on human neural progenitor cells cultured within them.</p> <p>Methods</p> <p>In this study we used different concentrations of the hydrogel-based matrix PuraMatrix. In some experiments we functionalised the matrix with laminin I. The impact of concentration and treatment with laminin on the formation of the scaffold was examined with atomic force microscopy. Cells from a human fetal neural progenitor cell line were cultured in the different matrices, as well as in a 2D culture system, and were subsequently analysed with antibody stainings against neuronal markers. In parallel, the survival rate of the cells was determined by a live/dead assay.</p> <p>Results</p> <p>Atomic force microscopy measurements demonstrated that the matrices are formed by networks of isolated PuraMatrix fibres and aggregates of fibres. An increase of the hydrogel concentration led to a decrease in the mesh size of the scaffolds and functionalisation with laminin promoted aggregation of the fibres (bundle formation), which further reduces the density of isolated fibres. We showed that laminin-functionalisation is essential for human neural progenitor cells to build up 3D-growth patterns, and that proliferation of the cells is also affected by the concentration of matrix. In addition we found that 3D-cultures enhanced neuronal differentiation and the survival rate of the cells compared to 2D-cultures.</p> <p>Conclusions</p> <p>Taken together, we have demonstrated a direct influence of the 3D-scaffold formation on the survival and neuronal differentiation of human neural progenitor cells. These findings emphasize the importance of optimizing 3D-scaffolds protocols prior to <it>in vivo </it>engraftment of stem and progenitor cells in the context of regenerative medicine.</p

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Clinical Congenital Anophthalmos and Microphthalmos&mdash;Experiences of Patients and Their Parents after More than 10 Years of Treatment

Congenital clinical anophthalmos and blind microphthalmos describe the absence of an eye or the presence of a small eye in the orbit. Between 1999 and 2013, 97 children with anophthalmos or microphthalmos were treated with self-inflating, hydrophilic gel expanders at the Rostock Eye Clinic. More than a decade later, this study investigated the perspective of patients and parents regarding the treatment, the surgical outcome, and the emotional and social well-being of the patients. A total of 22 families with 16 patients sighted in the other eye and six patients blind in both eyes participated. Questionnaires were developed, including items on physical, emotional, social, and medical aspects. The patients felt emotionally stable and integrated into their social environment, with no major limitations reported by the majority. These statements were confirmed by most of the parents. Parents (67%) indicated that the success of the operation was already apparent after the first intervention and that the current situation did not play a role in the patients&rsquo; social environment. The study provided new insights into the therapy results, the postoperative care, and the social and emotional stability of the prosthesis-wearing patients, indicating the chosen expander methods as promising in terms of positive postoperative care

Clinical Congenital Anophthalmos and Microphthalmos—Experiences of Patients and Their Parents after More than 10 Years of Treatment

Congenital clinical anophthalmos and blind microphthalmos describe the absence of an eye or the presence of a small eye in the orbit. Between 1999 and 2013, 97 children with anophthalmos or microphthalmos were treated with self-inflating, hydrophilic gel expanders at the Rostock Eye Clinic. More than a decade later, this study investigated the perspective of patients and parents regarding the treatment, the surgical outcome, and the emotional and social well-being of the patients. A total of 22 families with 16 patients sighted in the other eye and six patients blind in both eyes participated. Questionnaires were developed, including items on physical, emotional, social, and medical aspects. The patients felt emotionally stable and integrated into their social environment, with no major limitations reported by the majority. These statements were confirmed by most of the parents. Parents (67%) indicated that the success of the operation was already apparent after the first intervention and that the current situation did not play a role in the patients’ social environment. The study provided new insights into the therapy results, the postoperative care, and the social and emotional stability of the prosthesis-wearing patients, indicating the chosen expander methods as promising in terms of positive postoperative care

Social, Educational and Medical Aspects after Cataract Surgery of Bilaterally Blind Children in Kinshasa&mdash;Perception of Parents and Children

The study investigated the influence of bilateral cataract surgery on the social and educational development of previously bilaterally blind children in Sub-Saharan Africa (SSA), where the prevalence of blindness due to cataract is higher than in high-income countries. The views of both, parents and children, were evaluated with structured interviews based on a newly developed questionnaire related to surgery, follow-up, and family life after surgery. The mean age of the children at interview was 14.4 &plusmn; 8.1 years, with 27 females and 26 males. Satisfaction with the outcome of the surgery was reported by 91% of parents. Parents would recommend surgery, because of the children being happy and able to act more independently, with personal, educational and familial factors essentially contributing to the reported satisfaction. The results also showed that 85.0% of children did not wear eyeglasses. Reasons given were mainly cost-related, but also included limited communication between families and health institutions. Providing and maintaining a high-quality and accessible pediatric cataract surgery and healthcare service for follow-up is a major requisite to reduce childhood blindness in SSA. Our study proved the necessity and effectiveness of a community-based rehabilitation program that cares about each individual child, whatever his or her social background

Ocular Morbidity—A Critical Analysis to Improve Outpatient Services in an Eye Department in a Sub-Saharan Megacity

The aim of this study was to analyse outpatient services in an ophthalmic clinic of a church-run hospital providing secondary level care in an African megacity, paying special attention to the poorest users of the services. The range of examination was reviewed from 500 patient records of all ages consecutively chosen on random days attending the outpatient department for the first time in order to optimize workflow and to analyse the offered treatment modalities. Mean age was 41.9 ± 21.9 years, and 53.6% of the patients were female. Of the patients, 74.8% presented with visual impairment. The most frequent findings were refractive errors (35.8%), presbyopia (21.2%), allergic conjunctivitis (14.0%), cataract (13.2%) and glaucoma (6.4%). Patient management consisted of optical treatment (49.6%), surgery (11.4%) and medical treatment (39.0%). These results show the importance of the demand in refractive services and the need to train specific service providers. Knowing the frequencies of common conditions enables more appropriate diagnostic and treatment strategies, e.g., the importance of refractive errors, and should lead to improvements in training, staffing, therapeutics and patient outcomes. This approach can be applied to many other outpatient services and should be evaluated in light of the city’s impoverished health outreach and educational situation

Pharmacoepidemiological assessment of adherence and influencing co-factors among primary open-angle glaucoma patients—An observational cohort study

<div><p>The goal of this study was to assess the adherence of primary open-angle glaucoma (POAG) patients to medication, and to determine co-factors influencing adherence, using a representative sample of members of the largest German public health insurer. The observational cohort study was based on a longitudinal data set from 2010–2013 and included 250,000 insured persons aged 50 and older with 10,120 diagnosed POAG patients. Uni- and multivariate analysis was performed to investigate several aspects of glaucoma, such as prevalence, adherence, and co-factors influencing adherence. The main outcome measured adherence with prescriptions filled within a year. Multivariate panel regression analysis was used to determine the co-factors influencing this adherence. Prevalence of POAG was 3.36% [CI: 3.28–3.43%], with 2.91% [CI: 2.81–3.01%] for males and 3.71% [CI: 3.61–3.81%] for females, increasing with age. The mean level of adherence in terms of prescriptions filled was 66.5% [CI: 65.50–67.60%]. The results of this analysis revealed a significant influence of age, duration of the disease, care need, distance to death, and multimorbidity as co-factors of non-adherence, whereas gender had no influence. The analysis provided detailed information about POAG health care aspects concerning prevalence and adherence. The most endangered risk groups for non-adherence were patients aged 50–59, patients older than 80 years, patients with a longer duration of POAG, patients with care needs, and patients with three or more severe diseases in addition to glaucoma. To know the predictors responsible for an increased risk to develop POAG is of importance for all persons involved in health care management. Therefore effective strategies to increase awareness of patients and medical care personnel about non-adherence and the importance of a regular and continuous medication to avoid further nerve fiber damage and possible blindness have to be developed.</p></div