Atypical expression and distribution of embryonic stem cell marker, OCT4, in human lung adenocarcinoma

Lung cancer is one of the leading causes of cancer-related deaths in the world. Although the origin still remains to be resolved, a prevailing hypothesis implies the involvement of cancer stem cells (CSCs) responsible for tumor initiation, maintenance, and progression. Embryonic stem cell marker, OCT4, encoding the spliced variants OCT4A and OCT4B, has recently been shown to have a dual role; as a potential adult stem cell marker and as a CSC marker in germline and somatic tumors.

Embryonic exposure to corticosterone modifies the juvenile stress response, oxidative stress, and telomere length.

Early embryonic exposure to maternal glucocorticoids can broadly impact physiology and behaviour across phylogenetically diverse taxa. The transfer of maternal glucocorticoids to offspring may be an inevitable cost associated with poor environmental conditions, or serve as a maternal effect that alters offspring phenotype in preparation for a stressful environment. Regardless, maternal glucocorticoids are likely to have both costs and benefits that are paid and collected over different developmental time periods. We manipulated yolk corticosterone (cort) in domestic chickens (Gallus domesticus) to examine the potential impacts of embryonic exposure to maternal stress on the juvenile stress response and cellular ageing. Here, we report that juveniles exposed to experimentally increased cort in ovo had a protracted decline in cort during the recovery phase of the stress response. All birds, regardless of treatment group, shifted to oxidative stress during an acute stress response. In addition, embryonic exposure to cort resulted in higher levels of reactive oxygen metabolites and an over-representation of short telomeres compared with the control birds. In many species, individuals with higher levels of oxidative stress and shorter telomeres have the poorest survival prospects. Given this, long-term costs of glucocorticoid-induced phenotypes may include accelerated ageing and increased mortality.

Stress and Strain Adaptation in Load-Dependent Remodeling of the Embryonic Left Ventricle

Altered pressure in the developing left ventricle (LV) results in altered morphology and tissue material properties. Mechanical stress and strain may play a role in the regulating process. This study showed that confocal microscopy, three-dimensional reconstruction, and finite element analysis can provide a detailed model of stress and strain in the trabeculated embryonic heart. The method was used to test the hypothesis that end-diastolic strains are normalized after altered loading of the LV during the stages of trabecular compaction and chamber formation. Stage-29 chick LVs subjected to pressure overload and underload at stage 21 were reconstructed with full trabecular morphology from confocal images and analyzed with finite element techniques. Measured material properties and intraventricular pressures were specified in the models. The results show volume-weighted end-diastolic von Mises stress and strain averaging 50–82% higher in the trabecular tissue than in the compact wall. The volume-weighted-average stresses for the entire LV were 115, 64, and 147Pa in control, underloaded, and overloaded models, while strains were 11, 7, and 4%; thus, neither was normalized in a volume-weighted sense. Localized epicardial strains at mid-longitudinal level were similar among the three groups and to strains measured from high-resolution ultrasound images. Sensitivity analysis showed changes in material properties are more significant than changes in geometry in the overloaded strain adaptation, although resulting stress was similar in both types of adaptation. These results emphasize the importance of appropriate metrics and the role of trabecular tissue in evaluating the evolution of stress and strain in relation to pressure-induced adaptation.

Identification of candidate genes and physiological pathways involved in gonad deformation in whitefish (Coregonus spp.) from Lake Thun, Switzerland

In 2000, fishermen reported the appearance of deformed reproductive organs in whitefish (Coregonus spp.) from Lake Thun, Switzerland. Despite intensive investigations, the causes of these abnormalities remain unknown. Using gene expression profiling, we sought to identify candidate genes and physiological processes possibly associated with the observed gonadal deformations, in order to gain insights into potential causes. Using in situ-synthesized oligonucleotide arrays, we compared the expression levels at 21,492 unique transcript probes in liver and head kidney tissue of male whitefish with deformed and normally developed gonads, respectively. The fish had been collected on spawning sites of two genetically distinct whitefish forms of Lake Thun. We contrasted the gene expression profiles of 56 individuals, i.e., 14 individuals of each phenotype and of each population. Gene-by-gene analysis revealed weak expression differences between normal and deformed fish, and only one gene, ictacalcin, was found to be up-regulated in head kidney tissue of deformed fish from both whitefish forms, However, this difference could not be confirmed with quantitative real-time qPCR. Enrichment analysis on the level of physiological processes revealed (i) the involvement of immune response genes in both tissues, particularly those linked to complement activation in the liver, (ii) proteolysis in the liver and (iii) GTPase activity and Ras protein signal transduction in the head kidney. In comparison with current literature, this gene expression pattern signals a chronic autoimmune disease in the testes. Based on the recent observations that gonad deformations are induced through feeding of zooplankton from Lake Thun we hypothesize that a xenobiotic accumulated in whitefish via the plankton triggering autoimmunity as the likely cause of gonad deformations. We propose several experimental strategies to verify or reject this hypothesis.

Short- and long-term cultivation of embryonic and neonatal murine keratinocytes

Studies using cultured cells allow one to dissect complex cellular mechanisms in greater detail than when studying living organisms alone. However, before cultured cells can deliver meaningful results they must accurately represent the in vivo situation. Over the last three to four decades considerable effort has been devoted to the development of culture media which improve in vitro growth and modeling accuracy. In contrast to earlier large-scale, non-specific screening of factors, in recent years the development of such media has relied increasingly on a deeper understanding of the cell's biology and the selection of growth factors to specifically activate known biological processes. These new media now enable equal or better cell isolation and growth, using significantly simpler and less labor-intensive methodologies. Here we describe a simple method to isolate and cultivate epidermal keratinocytes from embryonic or neonatal skin on uncoated plastic using a medium specifically designed to retain epidermal keratinocyte progenitors in an undifferentiated state for improved isolation and proliferation and an alternative medium to support terminal differentiation.

The overexpression of homeotic complex gene Ultrabithorax in the post-embryonic neuronal lineages of the ventral nervous system in Drosophila melanogaster

This study uses a molecular technique called MARCM (Mosaic Analysis with a Repressible Cell Marker) to label neuronal lineages that overexpress the Hox gene Ultrabithorax (Ubx) in an unlabeled, wild type background. The results indicate that the overexpression of Ubx is sufficient to transform more anterior neuronal lineages to themorphology of their more posterior counterparts. The data presented here begin to elucidate the role that the Hox genes have in shaping segment-specific neural connections in the post-embryonic ventral nervous system.

Use of human embryonic stem cells and umbilical cord blood stem cells for research and therapy: a prospective survey among health care professionals and patients in Switzerland

BACKGROUND: Scientific progress in the biology of hematopoietic stem cells (HSCs) provides opportunities for advances in therapy for different diseases. While stem cell sources such as umbilical cord blood (UCB) are unproblematic, other sources such as human embryonic stem cells (hESCs) raise ethical concerns. STUDY DESIGN AND METHODS: In a prospective survey we established the ethical acceptability of collection, research, and therapy with UCB HSCs versus hESCs among health care professionals, pregnant women, patients undergoing in vitro fertilization therapy, parents, and HSC donors and recipients in Switzerland. RESULTS: There was overall agreement about an ethical justification for the collection of UCB for research and therapy in the majority of participants (82%). In contrast, research and therapy with hESCs was acceptable only by a minority (38% of all responders). The collection of hESCs solely created for HSC collection purposes met overall with the lowest approval rates. Hematologists displayed among the participants the highest acceptance rates for the use of hESCs with 55% for collection, 63% for research, and 73% for therapy. CONCLUSIONS: This is the first study assessing the perception of hESCs for research and therapy in comparison with UCB HSCs in different target groups that are exposed directly, indirectly, or not at all to stem cell-based medicine. Our study shows that the debate over the legitimacy of embryo-destructive transplantation medicine is far from over as particularly hESC research continues to present an ethical problem to an overwhelming majority among laypersons and even among health care professionals.

Expression of FGFRL1, a novel fibroblast growth factor receptor, during embryonic development

FGFRL1 is a novel member of the fibroblast growth factor receptor (FGFR) family. To investigate its expression during mammalian embryonic development, we have used the mouse system. Expression of Fgfrl1 is very low in mouse embryos of day 6 but steadily increases until birth. As demonstrated by in situ hybridization of 16-day-old embryos, the Fgfrl1 mRNA occurs in cartilaginous structures such as the primordia of bones and the permanent cartilage of the trachea, the ribs and the nose. In addition, some muscle types, including the muscles of the tongue and the diaphragm, express Fgfrl1 at relatively high level. In contrast, the heart and the skeletal muscles of the limbs, as well as many other organs (brain, lung, liver, kidney, gut) express Fgfrl1 only at basal level. It is conceivable that Fgfrl1 interacts with other Fgfrs, which are expressed in cartilage and muscle, to modulate FGF signaling.

Differential expression of IGF-I mRNA and peptide in the male and female gonad during early development of a bony fish, the tilapia Oreochromis niloticus

Insulin-like growth factor I (IGF-I) plays a key role in the complex system that regulates bony fish growth, differentiation, and reproduction. The major source of circulating IGF-I is liver, but IGF-I-producing cells also occur in other organs, including the gonads. Because no data are available on the potential production sites of IGF-I in gonad development, developmental stages of monosex breedings of male and female tilapia from 0 day postfertilization (DPF) to 90 DPF were investigated for the production sites of IGF-I at the peptide (immunohistochemistry) and mRNA (in situ hybridization) level. IGF-I mRNA first appeared in somatic cells of the male and female gonad anlage at 7 DPF followed by IGF-I peptide around 9-10 DPF. Gonad anlagen were detected from 7 DPF. Starting at 7 DPF, IGF-I peptide but no IGF-I mRNA was observed in male and female primordial germ cells (PGCs) provided that IGF-I mRNA was not under the detection level, this observation may suggest that IGF-I originates from the somatic cells and is transferred to the PGCs or is of maternal origin. While in female germ cells IGF-I mRNA and peptide appeared at 29 DPF, in male germ cells both were detected as late as at 51-53 DPF. It is assumed that the production of IGF-I in the germ cells is linked to the onset of meiosis that in tilapia ovary starts at around 28 DPF and in testes at around 52-53 DPF. In adult testis, IGF-I mRNA and peptide occurred in the majority of spermatogonia and spermatocytes as well as in Leydig cells, the latter indicating a role of IGF-I in the synthesis of male sex steroids. In adult ovary, IGF-I mRNA and IGF-I peptide were always present in small and previtellogenic oocytes but only IGF-I peptide infrequently occurred in oocytes at the later stages. IGF-I expression appeared in numerous granulosa and some theca cells of follicles at the lipid stage and persisted in follicles with mature oocytes. The results suggest a crucial role of local IGF-I in the formation, differentiation and function of tilapia gonads.

Uniform vascular-endothelial-cell-specific gene expression in both embryonic and adult transgenic mice

TIE2 is a vascular endothelial-specific receptor tyrosine kinase essential for the regulation of vascular network formation and remodeling. Previously, we have shown that the 1.2-kb 5' flanking region of the TIE2 promoter is capable of directing beta-galactosidase reporter gene expression specifically into a subset of endothelial cells (ECs) of transgenic mouse embryos. However, transgene activity was restricted to early embryonic stages and not detectable in adult mice. Herein we describe the identification and characterization of an autonomous endothelial-specific enhancer in the first intron of the mouse TIE2 gene. Furthermore, combination of the TIE2 promoter with an intron fragment containing this enhancer allows it to target reporter gene expression specifically and uniformly to virtually all vascular ECs throughout embryogenesis and adulthood. To our knowledge, this is the first time that an in vivo expression system has been assembled by which heterologous genes can be targeted exclusively to the ECs of the entire vasculature. This should be a valuable tool to address the function of genes during physiological and pathological processes of vascular ECs in vivo. Furthermore, we were able to identify a short region critical for enhancer function in vivo that contains putative binding sites for Ets-like transcription factors. This should, therefore, allow us to determine the molecular mechanisms underlying the vascular-EC-specific expression of the TIE2 gene.