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Real‐time monitoring of specific oxygen uptake rates of embryonic stem cells in a microfluidic cell culture device 下载免费PDF全文
Alexandre Super Nicolas Jaccard Marco Paulo Cardoso Marques Rhys Jarred Macown Lewis Donald Griffin Farlan Singh Veraitch Nicolas Szita 《Biotechnology journal》2016,11(9):1179-1189
Oxygen plays a key role in stem cell biology as a signaling molecule and as an indicator of cell energy metabolism. Quantification of cellular oxygen kinetics, i.e. the determination of specific oxygen uptake rates (sOURs), is routinely used to understand metabolic shifts. However current methods to determine sOUR in adherent cell cultures rely on cell sampling, which impacts on cellular phenotype. We present real‐time monitoring of cell growth from phase contrast microscopy images, and of respiration using optical sensors for dissolved oxygen. Time‐course data for bulk and peri‐cellular oxygen concentrations obtained for Chinese hamster ovary (CHO) and mouse embryonic stem cell (mESCs) cultures successfully demonstrated this non‐invasive and label‐free approach. Additionally, we confirmed non‐invasive detection of cellular responses to rapidly changing culture conditions by exposing the cells to mitochondrial inhibiting and uncoupling agents. For the CHO and mESCs, sOUR values between 8 and 60 amol cell?1 s?1, and 5 and 35 amol cell?1 s?1 were obtained, respectively. These values compare favorably with literature data. The capability to monitor oxygen tensions, cell growth, and sOUR, of adherent stem cell cultures, non‐invasively and in real time, will be of significant benefit for future studies in stem cell biology and stem cell‐based therapies. 相似文献
83.
Zsolt Toth Bernadett Papp Kevin Brulois Youn Jung Choi Shou-Jiang Gao Jae U. Jung 《PLoS pathogens》2016,12(9)
One of the hallmarks of the latent phase of Kaposi’s sarcoma-associated herpesvirus (KSHV) infection is the global repression of lytic viral gene expression. Following de novo KSHV infection, the establishment of latency involves the chromatinization of the incoming viral genomes and recruitment of the host Polycomb repressive complexes (PRC1 and PRC2) to the promoters of lytic genes, which is accompanied by the inhibition of lytic genes. However, the mechanism of how PRCs are recruited to the KSHV episome is still unknown. Utilizing a genetic screen of latent genes in the context of KSHV genome, we identified the latency-associated nuclear antigen (LANA) to be responsible for the genome-wide recruitment of PRCs onto the lytic promoters following infection. We found that LANA initially bound to the KSHV genome right after infection and subsequently recruited PRCs onto the viral lytic promoters, thereby repressing lytic gene expression. Furthermore, both the DNA and chromatin binding activities of LANA were required for the binding of LANA to the KSHV promoters, which was necessary for the recruitment of PRC2 to the lytic promoters during de novo KSHV infection. Consequently, the LANA-knockout KSHV could not recruit PRCs to its viral genome upon de novo infection, resulting in aberrant lytic gene expression and dysregulation of expression of host genes involved in cell cycle and proliferation pathways. In this report, we demonstrate that KSHV LANA recruits host PRCs onto the lytic promoters to suppress lytic gene expression following de novo infection. 相似文献
84.
Dorottya Pásztor Bence Lajos Kolozsvári Adrienne Csutak András Berta Ziad Hassan Bernadett Ujhelyi Péter Gogolák Mariann Fodor 《PloS one》2016,11(4)
PurposeTo compare the concentrations of 11 tear mediators in order to reveal the biochemical difference between pellucid marginal degeneration (PMD) and keratoconus (KC).MethodsWe have designed a cross-sectional study in which patients with corneal ectasia based on slit-lamp biomicroscopy and Pentacam HR (keratometry values (K1, K2, Kmax), astigmatism, minimal radius of curvature (Rmin), corneal thickness (Apex and Min), indices (surface variation, vertical asymmetry, keratoconus, central keratoconus, height asymmetry and decentration)) were enrolled. Eyes of keratoconic patients were similar to the PMD patients in age and severity (K2, Kmax and Rmin). Non-stimulated tear samples were collected from nine eyes of seven PMD patients, 55 eyes of 55 KC patients and 24 eyes of 24 healthy controls. The mediators’ (interleukin -6, -10, chemokine ligand 5, -8, -10, matrix metalloproteinase (MMP) -9, -13, tissue inhibitor of metalloproteinases (TIMP)-1, tissue plasminogen activator, plasminogen activator inhibitor, nerve growth factor) concentrations were measured using Cytometric Bead Array.ResultsMMP-9 was the only mediator which presented relevant variances between the two patient groups (p = 0.005). The ratios of MMP-9 and TIMP-1 were 2.45, 0.40 and 0.23 in PMD, KC and the controls, respectively.ConclusionAs far as we are aware, this is the first study that aims to reveal the biochemical differences between PMD and KC. Further studies of biomarkers to investigate the precise role of these mediators need to be defined, and it is important to confirm the observed changes in a larger study to gain further insights into the molecular alterations in PMD. 相似文献
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Binary mixture of Satureja hortensis and Origanum vulgare subsp. hirtum essential oils: in vivo therapeutic efficiency against Helicobacter pylori infection 下载免费PDF全文
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György B Tóthfalusi L Nagy G Pásztói M Géher P Lörinc Z Polgár A Rojkovich B Ujfalussy I Poór G Pócza P Wiener Z Misják P Koncz A Falus A Buzás EI 《Arthritis research & therapy》2008,10(5):R110-12
Introduction
Although natural autoantibodies make up the majority of circulating immunoglobulins and are also present in high numbers in therapeutically used intravenous immunoglobulin preparations, they have received little attention and their precise role remains largely unknown. An increasing awareness of the importance of posttranslational autoantigen modifications and glycobiology led us to explore carbohydrate-reactive natural autoantibodies in patients with rheumatoid arthritis. This study examined systematic antibodies reactive to glycosaminoglycans (GAGs), the carbohydrate components of proteoglycans that are released in large amounts from degrading cartilage.Methods
To measure antibodies reactive to six different types of GAGs, a specialised ELISA was used in which the carbohydrates were covalently linked to the plastic surface through a 2 nm spacer. Sera from rheumatoid arthritis patients (n = 66), umbilical cord serum samples (n = 11) and adult controls (n = 54) were studied. In order to explore cross-reactivity with microbial antigens, bacterial peptidoglycans and fungal polysaccharides were used. Sera and synovial fluid samples were also tested using a GlycoChip carbohydrate array to characterise individual carbohydrate recognition patterns. We followed a multistep statistical screening strategy for screening GAG-reactive antibodies as predictive disease markers.Results
While anti-GAG antibodies were absent in the umbilical cord sera, they were readily detectable in adult controls and were significantly elevated in patients with rheumatoid arthritis (p < 0.001). Anti-GAG antibodies showed significant cross-reactivity among different types of GAGs. They also reacted with bacterial peptidoglycans and fungal polysaccharides. Interestingly, anti-chondroitin sulphate C IgM antibody levels showed inverse correlation both with the Disease Activity Score (DAS) 28 scores and C-reactive protein (CRP) levels in rheumatoid arthritis.Conclusion
The highly abundant and cross-reactive, GAG-specific natural autoantibodies in serum may serve as novel disease-state markers in patients with rheumatoid arthritis. 相似文献87.
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Pharmacological up-regulation of heat shock proteins (hsps) rescues motoneurons from cell death in a mouse model of amyotrophic
lateral sclerosis. However, the relationship between increased hsp expression and neuronal survival is not straightforward.
Here we examined the effects of two pharmacological agents that induce the heat shock response via activation of HSF-1, on
stressed primary motoneurons in culture. Although both arimoclomol and celastrol induced the expression of Hsp70, their effects
on primary motoneurons in culture were significantly different. Whereas arimoclomol had survival-promoting effects, rescuing
motoneurons from staurosporin and H2O2 induced apoptosis, celastrol not only failed to protect stressed motoneurons from apoptosis under same experimental conditions,
but was neurotoxic and induced neuronal death. Immunostaining of celastrol-treated cultures for hsp70 and activated caspase-3
revealed that celastrol treatment activates both the heat shock response and the apoptotic cell death cascade. These results
indicate that not all agents that activate the heat shock response will necessarily be neuroprotective. 相似文献
89.
Czeglédi István Preiszner Bálint Vitál Zoltán Kern Bernadett Boross Nóra Specziár András Takács Péter Erős Tibor 《Hydrobiologia》2019,846(1):147-158
Hydrobiologia - Detailed knowledge on the habitat preference of invasive fishes and the bias of different fishing methods in determining their population dynamic parameters are essential in... 相似文献
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Gitta Szabó Bernadett Khayer Anna Rusznyák István Tátrai György Dévai Károly Márialigeti Andrea K. Borsodi 《Hydrobiologia》2011,663(1):217-232
Seasonal studies of surface sediment bacterial communities, from two basins with differing trophic states within Lake Balaton
(Hungary), were carried out using molecular (denaturing gradient gel electrophoresis, DGGE) and cultivation-based techniques.
The presence of polyphosphate accumulates was tested using Neisser staining, and phosphatase activity was investigated on
organic phosphorus (P) compound. Aerobic viable cell counts were significantly higher in the eutrophic than mesotrophic basin
in each season. The lowest viable counts were observed in the autumn and the highest in spring and summer month in both basins.
The DGGE fingerprints of the samples reflected that the composition of sediment bacterial communities in the two basins were
distinct in spring and summer, and similar in autumn, but similarly diverse in all seasons. On the basis of partial 16S rDNA
sequences, the 216 strains were affiliated with six major bacterial lineages: Firmicutes; Actinobacteria, Bacteroidetes, Alphaproteobacteria,
Betaproteobacteria, and Gammaproteobacteria. Common species characterized from both basins constituted up to 66% of all identified
phylotypes. Strains related to Bacillus sp. were dominant in all but one sample. Isolates affiliated with Aeromonas sp. prevailed in the sample taken from the mesotrophic basin in spring. The majority of the strains showed excess poly-P
accumulation. Association of Neisser staining and phosphatase activity test results suggested that excess poly-P accumulation
serves as P storage for sediment bacteria. Our study implied the importance of Firmicutes, Actinobacteria, Alphaproteobacteria,
and Aeromonas species in benthic bacterial P retention. 相似文献