Month: July 2020

Further, a significant enrichment of regulated genes involved in transcription regulator activity and response to hypoxia was observed. The regulation of genes involved in these processes is suggested to lead to adaptive changes, which allow the cell to gain more energy and lead to the delivery of oxygen. Interestingly, we could not identify an accumulation of hypoxia-regulated genes involved in inflammation, although hypoxia in adipose tissue is suggested to lead to a chronic inflammatory state. Of note, white adipose tissue consists of different cell types, such as preadipocytes, macrophages, endothelial cells, fibroblasts and leukocytes, which all contribute to the production and release of cytokines. It is also suggested, that the response to hypoxia differs depending on the cell type and the tissue environment. Therefore, the contribution of adipocytes to the total amount of secreted factors from adipose tissue in vivo which lead to a chronic inflammation is not fully understood. From the large number of hypoxia-regulated transcripts, nine genes were found to be differentially expressed after all time periods of hypoxia investigated in our microarray study. Our findings in SGBS adipocytes are consistent with Niraparib previous reports observed in other cell types. As the SGBS cells, used for this study have been proven in several human adipocyte biology studies to have characteristics very similar to adipocytes we consider our findings also relevant for adipocytes in general. VEGF is essential for the development of the vascular system and promotes angiogenesis and also ADM has been shown to induce angiogenesis. Both, the growth of adipose tissue and hypoxic conditions require the development of the vascular network. Concentrations of serum VEGF have been described to positively correlate with body mass index and body weight reduction led to a decrease in VEGF circulating levels. This angiogenic factor has also been suggested to be involved in the development of the comorbidities associated with obesity. Furthermore, plasma concentration of the antiadipogenic factor ADM increases with obesity, the incidence of type 2 diabetes, cardiovascular diseases and inflammation. The expression of ADM and DDIT4 in adipocytes, which is induced in response to different situations of cellular stress is in addition to hypoxia also regulated by insulin and in terms of DDIT4, whose overexpression may participate to the development of insulin resistance, depends on the transcription factor HIF-1. Further, also KDM3A has been described as a regulator of genes involved in energy expenditure and fat storage. Therefore, these identified genes may play a crucial role in the regulation of obesity and the metabolic syndrome. The remaining hypoxia-regulated genes that were identified are involved in different cellular functions: protein-protein interaction and signalling, glycolysis, glucogen accumulation which is suggested as metabolic longterm adaption to hypoxia, and regulation of transcription. The function of WD-repeat proteins differs from signal transduction, regulation of transcription, and apoptosis, but the function of WDR73 still remains unknown.

Vertebrate Hb is a tetramer composed of two a- and two b-chains. Mb is a monomer that is mainly located in the cytoplasm of the myocytes in heart or skeletal muscles. Mb stores O2, facilitates O2 diffusion to the mitochondria, and may also be involved in the decomposition of NO. Within the past ten years, sequencing of CPI-613 expressed sequence tags and whole genomes revealed the presence of additional globin types in vertebrates, such as neuroglobin and cytoglobin. Ngb resides in the central and peripheral nervous system of vertebrates. The exact function of Ngb is still uncertain, but there is evidence that it has a protective role related to the oxidative metabolism. Cygb is expressed in fibroblast-related cell types and distinct neurons. Cygb is possibly involved in collagen synthesis or O2 supply to distinct enzymes. Deoxygenated Hb and Mb display a socalled pentacoordinated heme, while Ngb and Cygb are hexacoordinated. Ngb and Cygb are widespread among vertebrates and occur in fishes, amphibians, reptiles, birds and mammals. Other globins appear to be restricted to certain vertebrate classes. In birds, an eye-specific globin has been identified, while globin Y is expressed in various tissues of Xenopus. GbX has only been identified in “lower” vertebrates, i.e. fishes and amphibians, but appears to have been lost in Amniota. Although the GbX sequence is highly conserved among fishes and amphibians, it displays only limited similarities to any other globin. In phylogenetic analyses GbX joins a clade consisting of Ngb, invertebrate nerve globins and the Hbs of the tunicate Ciona intestinalis. GbX is widely expressed in goldfish tissues but displays a more restricted localization in brain and eye of Xenopus. Hypoxia decreases the levels of GbX mRNA in adult zebrafish. Due to unique N- and C-terminal extensions, the GbX sequence is longer than that of a typical globin and spans,200 amino acids. Our results indicate that GbX is anchored in the cell-membrane by dual N-terminal acylation. While membrane-bound globins have previously been identified in some bacteria and the green shore crab, GbX is the first such globin-type discovered in vertebrates. In order to gain further insight into possible functional role of GbX, we also investigated heme coordination and reactivity towards O2 and the ability to form disulfide bonds. Our data provide evidence for a novel globin function in vertebrates that is associated with its membrane localization and unlikely to be involved O2 transport and storage. In previous studies using goldfish, a broad expression pattern of GbX in various non-neuronal tissues was observed. By contrast, GbX was preferentially expressed in the brain and eye of the clawed frog X. laevis. We identified high amounts of GbX mRNA in eyes and brain, which is consistent with the detection of GbX protein in selected brain and eye areas of D. rerio. We therefore conclude that the localization of GbX is likely conserved in fishes and amphibians. Whether the divergent pattern in goldfish is a unique feature of that species remains to be demonstrated.

Similar results have been reported related to viral infectivity and these same physico-chemical characteristics using field water samples. In addition, biotic components including WZ8040 distributor aquatic invertebrates and microorganisms have recently been proposed as potential factors affecting virus removal or accumulation in the environment. Finally, viral persistence in aquatic habitats has been demonstrated to be a determinant for IA virus transmission dynamics in wild duck populations. Several studies have attempted to isolate or detect IA viruses from surface water in habitats utilized by waterfowl. In these studies, virus subtypes detected in local aquatic habitats reflected the current subtype diversity circulating in waterfowl populations. Considering that water-borne transmission drives IA virus dynamics in wild birds, one could expect that a strong selective pressure may exist for IA virus maintenance in aquatic habitats. To date, environmental persistence and replication in the natural host have not been documented for water-isolated viruses, limiting our understanding of viral fitness in ducks and aquatic habitats. In this study, we performed the complete genome sequencing and estimated the persistence in water and replication in duck of two IA viruses isolated from surface lake water in Minnesota, USA. In particular, we investigated: the relative abundance of the two subtypes in viruses isolated in wild duck populations during three consecutive seasons, at the same sampling site; the genetic relatedness of these environmental isolates to IA recovered from wild ducks in Minnesota and North America; the persistence of the two viruses in water under different laboratory-conditions ; and the ability of these isolates to replicate in experimentally infected Mallards. We discuss the significance of the results regarding the role of water-borne transmission in IA virus ecology and epidemiology in wild duck populations. Both the H3N8 and H4N6 subtypes that were isolated from surface lake water have been commonly detected in North American waterfowl. At our study sites, the prevalence of these subtypes was relatively low in wild duck populations during the years of detection; however, the limited number of viruses recovered during 2006 provided limited information on virus subtypes circulating in local duck populations during that year. Interestingly, both the H3 and H4 virus subtypes were the most prevalent the year following their isolation in lake water. Although circumstantial, this pattern is consistent with a possible inter-annual environmental persistence. Phylogenetic analyses suggested that both isolates were reassortants related to viruses circulating in wild ducks in Minnesota at the time of sampling. In addition, we provide evidence that surface glycoproteins were highly similar to others identified in viruses circulating in North American ducks both before and after their detection in Minnesota. Based on phylogenetic analyses, no similar viral strain were however identified the years following their isolation in lake water, in Minnesota. This result suggests that, for the two water isolates, local persistence in aquatic habitats over winter was unlikely.

While blastomeres of the Wortmannin 8-cell stage embryo and the cells of the ICM show some biological similarities, including a non-polarized phenotype and pluripotent potential, they also exhibit significant differences. Indeed, microarray analysis of gene expression during six developmental stages of human preimplantation embryos showed a group of 2299 probe sets differentially expressed in blastocyst stage compared to 8-cell stage embryos. The majority of these genes were involved in lipid and fatty acid metabolism. In addition, a group of 1715 probe sets involved in the regulation of transcription and nucleic acid metabolism were down-regulated in blastocysts compared to 8 cell stage embryos. Furthermore, the DNA of the blastomeres of the 8 cell stage embryos is completely demethylated as a result of reprogramming and activation of embryonic genome whereas the methylation marks are already re-established in the cells of the ICM. In addition, blastomeres of the 8-cell stage embryo exhibit lower telomerase activity and shorter average telomere length than cells in the ICM. During the derivation process, hESC acquire a polarized phenotype, a characteristic not present in the pluripotent mouse ESC. Indeed, they appear closer to mouse stem cells derived from primitive ectoderm than those from the inner cell mass. Similarly, the active molecular signaling pathways in hESC resemble those of mouse epiblast stem cells derived from postimplantation embryo. This indicates that hESC derived from the ICM acquire characteristics typical of more advanced stages of development. Hence, we investigated whether human stem cell lines derived from late totipotent blastomeres of the cleavage stage embryo develop a more “primitive” phenotype than ICM-derived lines by profiling their respective gene expression, molecular regulation and signaling pathways. In this study, we examined whether the inherent differences in the developmental stage of the starting embryonic cell population are maintained in the derived hESC lines by evaluating the stemness, differentiation capacity and gene expression profiles of blastomere- and ICM-derived hESC lines. In this study we have investigated whether differentiation status of source cells within preimplantation embryo affects phenotype and transcriptional profile of derived hESC lines. One of potential hurdles in performing such an analysis is the presence of differences between hESC cell lines that are not related to the developmental stage of the cells of origin. These differences may arise during cell line derivation and expansion as a result of in vitro selection of specific phenotypic and molecular traits/characteristics. Another potential contributing factor to hESC line heterogeneity is diverse genetic makeup of the embryos due to outbred nature of human embryos. Consequently, despite the expression of a common pluripotent phenotype, hESC lines derived from single stage embryos, namely the ICM of the blastocyst, have been reported to show significant variations in both their molecular profiles and differentiation capacity. To minimize the effect of these factors on our investigation, we used for this study multiple hESC lines with different genetic backgrounds.

Exposure to DEPs is an environmental and occupational health concern, and epidemiological, clinical and toxicological data indicate that exposure to DEPs induces both hypersensitive disease and cancer. Considering the fact that hypersensitive disease and cancer involve different immune responses, we investigated the relationship between the physicochemical properties of DEPs and the biological responses induced by DEP exposure. DEPs are composed of a carbonaceous core with adsorbed organic compounds, sulfates, and trace elements. Soluble organic compounds, including PAHs, can represent up to 60% of the mass of the particle. The main targets of DEPs introduced into the body via the bronchial tubes are immune cells in the BAL fluid and airway epithelial cells. The human epithelium contains several types of polarized cells with specific functions. The permeability of a molecule depends mainly on its electric charge of the molecule and to a lesser extent on its molar mass. Therefore, neutrally charged, small particles may pass the cell membrane more easily than charged, large ones. The total cells in BAL fluid increased at all times tested, indicating that DEPs did not induce apoptosis or necrosis. The rapid increase in the burden of hypersensitive disease has undeniably occurred in parallel with rapid industrialization and urbanization in many parts of the world. Several studies have shown that DEPs act as adjuvants to CYT387 allergens and hence increase the sensitization response. Furthermore, Ma and Ma reported that the organic component of DEPs may skew the immunity toward a Th2 response, whereas the particulate component of DEPs may stimulate both the Th1 and Th2 responses. In this study, DEP exposure was found to cause an obvious increase in the TNF-a levels in the BAL fluid to 4.1-fold that in the control, with a marked increase in CD8+ T-cell distribution on day 1 after treatment, but induced B-cell dominance with rapid recovery of the ratio of CD4+/CD8+ T cells on day 7. In addition, on day 7, the concentrations of IL-1, IL-6, and IL-5 in the blood were 4.1-, 12.8-, and 5.2-fold that in the control, respectively, whereas the IL-12 concentration in the BAL fluid increased to 10.4-fold that in the control. Considering the fact that the cellular response in the blood stream was caused by exposure to DEPs engulfed by immune cells, we suggest that the changes observed from day 1, i.e., Th1-type inflammatory response and CD8+ T-cell dominance, may have been effected by the surface charge and surface chemicals, and those from day 7, i.e., Th2-type inflammatory response, may be attributed to the release of the soluble chemical components of DEPs engulfed into immune cells. Our suggestions are supported by the rapid decrease in the levels of IL-12 and the rapid increase in the levels of IL-10 and IL-17 in the BAL fluid after complete phagocytosis of DEPs by immune cells in the BAL fluid on day 28. However, there is a possibility that other cells in the lung including epithelial cells will also release some cytokines and measurement in BAL fluid cannot differentiate them from immune cells.