No description available.

Androgen receptor (AR) is a member of the steroid hormone receptor family of molecules, and expansion of a CAG repeat encoding polyglutamine (poly-Q) in AR gene are associated with a progressive neuromuscular disease known as spinal bulbar muscular atrophy (SBMA) or Kennedy disease. The hallmark of SBMA diseases is formation of juxtanuclear AR inclusions that have been termed ¡¥AR aggregates¡¦.Previous studies showed that transgenic mice overexpressing wild-type AR exclusively in the skeletal muscle fibers display similar abnormalities to those observed in models of SBMA disease. To elucidate the mechanisms underlying toxicity conferred by wild-type protein aggregation within normal cells, a mouse embryonic stem cell (ESC) model with non-genetic modified settings in AR overexpression was used to display the common features of polyglutamine disease in this experiment. It was found that wild-type AR proteins are highly expressed and form nuclear aggregate inclusions in response to androgen treatment in ES cells, the formation of AR aggregates inhibit the differentiation of embryonic bodys and enhanced caspase-3 activity in androgens -induced apoptosis. In addition, it was also investigated that relation between chaperones¡BAR and the endoplasmic reticulum (ER) stress-induced pathways in ES cells in this study, and it was found that chaperones could colocalize with AR aggregates, these findings may help us to better understand the roles of the chaperones on AR aggregates.

No description available.

Stem cells have the ability to reproduce themselves for a long period and differentiate into specific morphological and functional cells. The stem cells are an important material in the developmental biology, genomics, and transgenic methods, as well as in potential clinical applications, gene therapy and tissue engineering. The pluripotent stem cells will be a valuable source in numerous functional degenerated pathologies. Therefore, the objective of this research program was to establish transgenic porcine embryonic stem (pES) cell lines which can express green fluorescent protein (GFP) report gene stably for tracking after transplantation. We also developed a directed differentiation of pES into neural lineages and applied in rat Parkinson¡¦s disease model. Although the establishment of pluripotent ES cell lines from domestic species is much more difficult than that in murine species, our results had successfully isolated and established pES cell lines from pre-implantation blastocysts. Furthermore, we established the novel GFP-expressing pES cell lines (pES/GFP+), which were obtained by electroporation- mediated transfection with exogenous GFP gene. These pES/GFP+ cells exhibited pluripotent markers including Oct-4, AP, SSEA-4, TRA-1-60, and TRA-1-81 as that of human ES cells. The strategy of directed neural differentiation was to culture pES with neurogenic stimulators such as retinoic acid (RA), sonic hedgehog (SHH), and fibroblast growth factor (FGF). Upon directed differentiation toward neural differentiation, these pES-derived cells exhibited typical neuronal morphology and expressed neural lineage-specific markers such as nestin, NFL, MAP2, GFAP, A2B5, TH, ChAT, and GABA. These results showed the pES cells had the potential to differentiate into neural lineages. When pES/GFP+ cells were transplanted into the SD rat¡¦s brain, and their survival and development was determined by the non-invasive In Vivo Imaging System (IVIS 50), and the invasive fibered confocal Cellvizio® Imaging System (Cellvizio®). The results showed that fluorescent signals from pES/GFP+ cells on the injection site of SD rats¡¦ brain could be detected through the experimental period of 3 months. The level of fluorescent signals detected in treatment groups was two folds above that of the control group. Besides, the functional behavior recovery analysis by amphetamine-induced rotation test indicated the PD rat grafted with pES/GFP+ cells and their derived neural progenitors showed no significant recovery of rotation rate in these two treatments because a progressively increased relative rotation through 3 months duration. However, the relative rotation of PD rats grafted with the pES/GFP+-derived mature neurons, showed a stably decrease relative rotation and resulted in a functional recovery from Parkinsonian behavioral defects. Following 3 months completion of behavioral analyses, PD rats were sacrificed for immunohistochemical analysis. In the section of injected site without tumorgenesis and showed the survival and dopaminergic differentiation of grafted pES/GFP+ derived cells when stained with anti-TH and anti-DA. To our knowledge, there have been no reports of establishing GFP-expressing pES cell lines. These novel pES/GFP+ cell lines established in this study might serve as a non-rodent model and could benefit to the studies involving ES cell transplantation, cell replacement therapy, tissue regeneration, and actual approach for pre-clinical research due to their traceable capacity.

No description available.

Univ., Diss.--Göteborg, 2005. / Literaturverz. S. [289] - 313.

Thesis (Ph. D.)--Cornell University, January, 2007. / Vita. Includes bibliographical references (leaves 107-130).

Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Biomedical Engineering." Includes bibliographical references (p. 53-55).

Embryonic stem (ES) cells provide a potentially unlimited cell source for cellular therapies; however, reliable methods must be developed to provide clinically-relevant numbers of homogeneous therapeutic cell populations. Dynamic cultures may encourage ES cell differentiation and amenable to large-scale cell production. Our goal was to optimize dynamic culture parameters (bioreactor type, speed, cell seeding density, conditioned medium, and hypoxia) to maximize the generation of hematopoietic stem and progenitor cells (HSPCs) from ES cells and also to investigate the ability of dynamic culture-derived HSPCs to generate terminally differentiated hematopoietic cells. Our results indicate that varying cell seeding density and speed in two different bioreactors significantly affects embryoid body formation and ES cell differentiation efficiency into progenitor cells. In general, increased cell seeding density generated higher percentages of HSPCs in both bioreactors. In addition, rotary (Synthecon) bioreactors produced more sca-1⁺ progenitors, and spinner flasks generated more c-kit⁺ progenitors, demonstrating their unique differentiation profiles. cDNA microarray analysis of genes involved in pluripotency, germ layer formation, and hematopoietic differentiation showed that unique gene expression profiles were observed in the two bioreactors with the expression of specific hematopoietic genes more up regulated in the Synthecon cultures compared to spinner flasks. Combining bioreactor cultures with directed differentiation strategies via conditioned medium and hypoxic culture may further encourage hematopoietic differentiation. Dynamically cultured ES cell-derived hematopoietic stem and progenitor cells were further differentiated into a phenotype typical of dendritic cells which had the ability to process antigen. Additionally, microarray analysis of isolated ES cell-derived HSPCs demonstrated differences in the gene expression from native HSCs isolated from the fetal liver or bone marrow of mice. Insight gained from this work should be continued by comparing the differentiation efficiency of HSPCs derived in dynamic and traditional static culture methods into functional, terminally differentiated hematopoietic cells to generate clinically-relevant numbers of transplantable, therapeutic cells. / text

published_or_final_version / Obstetrics and Gynaecology / Master / Master of Philosophy