共查询到20条相似文献,搜索用时 15 毫秒
1.
Yonnie Wu Richard C Laughlin David C Henry Darryl E Krueger JoAn S Hudson Cheng-Yi Kuan Jian He Jason Reppert Jeffrey P Tomkins 《BMC cell biology》2007,8(1):36
Background
Tubular shaped mammalian cells in response to dehydration have not been previously reported. This may be due to the invisibility of these cells in aqueous solution, and because sugars and salts added to the cell culture for manipulation of the osmotic conditions inhibit transformation of normal cells into tubular shaped structures. 相似文献2.
Background
Environmental pH stress constitutes a limiting factor for S. meliloti survival and development. The response to acidic pH stress in S. meliloti is versatile and characterized by the differential expression of genes associated with various cellular functions. The purpose of this study was to gain detailed insight into the participation of sigma factors in the complex stress response system of S. meliloti 1021 using pH stress as an effector. 相似文献3.
Eric J Anderson Thomas D Falls Adam M Sorkin Melissa L Knothe Tate 《Biomedical engineering online》2006,5(1):27-14
Background
In vitro mechanotransduction studies are designed to elucidate cell behavior in response to a well-defined mechanical signal that is imparted to cultured cells, e.g. through fluid flow. Typically, flow rates are calculated based on a parallel plate flow assumption, to achieve a targeted cellular shear stress. This study evaluates the performance of specific flow/perfusion chambers in imparting the targeted stress at the cellular level. 相似文献4.
Background
Bacterial infection of the urinary tract is a common clinical problem with E. coli being the most common urinary pathogen. Bacterial uptake into epithelial cells is increasingly recognised as an important feature of infection. Bacterial virulence factors, especially fimbrial adhesins, have been conclusively shown to promote host cell invasion. Our recent study reported that C3 opsonisation markedly increases the ability of E. coli strain J96 to internalise into human proximal tubular epithelial cells via CD46, a complement regulatory protein expressed on host cell membrane. In this study, we further assessed whether C3-dependent internalisation by human tubular epithelial cells is a general feature of uropathogenic E. coli and investigated features of the bacterial phenotype that may account for any heterogeneity. 相似文献5.
Vilma A Sardão Paulo J Oliveira Jon Holy Catarina R Oliveira Kendall B Wallace 《BMC cell biology》2007,8(1):11
Background
When exposed to oxidative conditions, cells suffer not only biochemical alterations, but also morphologic changes. Oxidative stress is a condition induced by some pro-oxidant compounds, such as by tert-butylhydroperoxide (tBHP) and can also be induced in vivo by ischemia/reperfusion conditions, which is very common in cardiac tissue. The cell line H9c2 has been used as an in vitro cellular model for both skeletal and cardiac muscle. Understanding how these cells respond to oxidative agents may furnish novel insights into how cardiac and skeletal tissues respond to oxidative stress conditions. The objective of this work was to characterize, through vital imaging, morphological alterations and the appearance of apoptotic hallmarks, with a special focus on mitochondrial changes, upon exposure of H9c2 cells to tBHP. 相似文献6.
Background
When photosynthetic organisms are exposed to harsh environmental conditions such as high light intensities or cold stress, the production of reactive oxygen species like singlet oxygen is stimulated in the chloroplast. In Chlamydomonas reinhardtii singlet oxygen was shown to act as a specific signal inducing the expression of the nuclear glutathione peroxidase gene GPXH/GPX5 during high light stress, but little is known about the cellular mechanisms involved in this response. To investigate components affecting singlet oxygen signaling in C. reinhardtii, a mutant screen was performed. 相似文献7.
Michela Flego Alessandro Ascione Silvia Zamboni Maria L Dupuis Valentina Imperiale Maurizio Cianfriglia 《BMC biotechnology》2007,7(1):38
Background
A hallmark of prion disease is the transformation of normal cellular prion protein (PrPc) into an infectious disease-associated isoform, (PrPsc). Anti-prion protein monoclonal antibodies are invaluable for structure-function studies of PrP molecules. Furthermore recent in vitro and in vivo studies indicate that anti-PrP monoclonal antibodies can prevent the incorporation of PrPc into propagating prions. 相似文献8.
Liran I Shlush Shalev Itzkovitz Ariel Cohen Aviad Rutenberg Ron Berkovitz Shiran Yehezkel Hofit Shahar Sara Selig Karl Skorecki 《BMC cell biology》2011,12(1):16
Background
Cellular senescence plays important roles in the aging process of complex organisms, in tumor suppression and in response to stress. Several markers can be used to identify senescent cells, of which the most widely used is the senescence-associated β-galactosidase (SABG) activity. The main advantage of SABG activity over other markers is the simplicity of the detection assay and the capacity to identify in situ a senescent cell in a heterogeneous cell population. Several approaches have been introduced to render the SABG assay quantitative. However none of these approaches to date has proven particularly amenable to quantitative analysis of SABG activity in situ. Furthermore the role of cellular senescence (CS) in vivo remains unclear mainly due to the ambiguity of current cellular markers in identifying CS of individual cells in tissues. 相似文献9.
10.
N. Nayan A.S.M. Sonnenberg W.H. Hendriks J.W. Cone 《Journal of applied microbiology》2018,125(2):468-479
Aim
In this study, the biological variation for improvement of the nutritive value of wheat straw by 12 Ceriporiopsis subvermispora, 10 Pleurotus eryngii and 10 Lentinula edodes strains was assessed. Screening of the best performing strains within each species was made based on the in vitro degradability of fungal‐treated wheat straw.Methods and Results
Wheat straw was inoculated with each strain for 7 weeks of solid state fermentation. Weekly samples were evaluated for in vitro gas production (IVGP) in buffered rumen fluid for 72 h. Out of the 32 fungal strains studied, 17 strains showed a significantly higher (P < 0·05) IVGP compared to the control after 7 weeks (227·7 ml g?1 OM). The three best Ceriporiopsis subvermispora strains showed a mean IVGP of 297·0 ml g?1 OM, while the three best P. eryngii and L. edodes strains showed a mean IVGP of 257·8 and 291·5 ml g?1 OM, respectively.Conclusion
Ceriporiopsis subvermispora strains show an overall high potential to improve the ruminal degradability of wheat straw, followed by L. edodes and P. eryngii strains.Significance and Impact of the Study
Large variation exists within and among different fungal species in the valorization of wheat straw, which offers opportunities to improve the fungal genotype by breeding. 相似文献11.
Bin Rui Tie Shen Hong Zhou Jianping Liu Jiusheng Chen Xiaosong Pan Haiyan Liu Jihui Wu Haoran Zheng Yunyu Shi 《BMC systems biology》2010,4(1):122
Background
The cellular responses of bacteria to superoxide stress can be used to model adaptation to severe environmental changes. Superoxide stress promotes the excessive production of reactive oxygen species (ROS) that have detrimental effects on cell metabolic and other physiological activities. To antagonize such effects, the cell needs to regulate a range of metabolic reactions in a coordinated way, so that coherent metabolic responses are generated by the cellular metabolic reaction network as a whole. In the present study, we have used a quantitative metabolic flux analysis approach, together with measurement of gene expression and activity of key enzymes, to investigate changes in central carbon metabolism that occur in Escherichia coli in response to paraquat-induced superoxide stress. The cellular regulatory mechanisms involved in the observed global flux changes are discussed. 相似文献12.
Background
Green algae of the family Volvocaceae are a model lineage for studying the molecular evolution of multicellularity and cellular differentiation. The volvocine alga Gonium is intermediate in organizational complexity between its unicellular relative, Chlamydomonas, and its multicellular relatives with differentiated cell types, such as Volvox. Gonium pectorale consists of ~16 biflagellate cells arranged in a flat plate. The detailed molecular analysis of any species necessitates its accessibility to genetic manipulation, but, in volvocine algae, transformation procedures have so far only been established for Chlamydomonas reinhardtii and Volvox carteri. 相似文献13.
Background
Proline (Pro) accumulation is a widespread response of prokaryotic and eukaryotic cells subjected to osmotic stress or dehydration. When the cells are released from stress, Pro is degraded to glutamate by Pro-dehydrogenase (ProDH) and Pyrroline-5-carboxylate dehydrogenase (P5CDH), which are both mitochondrial enzymes in eukaryotes. While P5CDH is a single copy gene in Arabidopsis, two ProDH genes have been identified in the genome. Until now, only ProDH1 (At3g30775) had been functionally characterised. 相似文献14.
Background
Streptomyces coelicolor is a bacterium with a vast repertoire of metabolic functions and complex systems of cellular development. Its genome sequence is rich in genes that encode regulatory proteins to control these processes in response to its changing environment. We wished to apply a recently published bioinformatic method for identifying novel regulatory sequence signals to gain new insights into regulation in S. coelicolor. 相似文献15.
Tanja Pintsch Michel Satre Gérard Klein Jean-Baptiste Martin Stephan C Schuster 《BMC cell biology》2001,2(1):9-15
Background
Dictyostelium cells exhibit an unusual response to hyperosmolarity that is distinct from the response in other organisms investigated: instead of accumulating compatible osmolytes as it has been described for a wide range of organisms, Dictyostelium cells rearrange their cytoskeleton and thereby build up a rigid network which is believed to constitute the major osmoprotective mechanism in this organism. To gain more insight into the osmoregulation of this amoeba, we investigated physiological processes affected under hyperosmotic conditions in Dictyostelium. 相似文献16.
Background
Folate is essential for cellular proliferation and tissue regeneration. As mammalian cells cannot synthesize folates de novo, tightly regulated cellular uptake processes have evolved to sustain sufficient levels of intracellular tetrahydrofolate cofactors to support biosynthesis of purines, pyrimidines, and some amino acids (serine, methionine). Though reduced-folate carrier (RFC) is one of the major proteins mediating folate transport, knowledge of the developmental expression of RFC is lacking. We utilized in situ hybridization and immunolocalization to determine the developmental distribution of RFC message and protein, respectively. 相似文献17.
Krzysztof Wanic Bozena Krolewski Wenjun Ju Grzegorz Placha Monika A. Niewczas William Walker James H. Warram Matthias Kretzler Andrzej S. Krolewski 《PloS one》2013,8(3)
Background
In patients with Type 1 Diabetes (T1D) who develop microalbuminuria, progressive decline in glomerular filtration rate (GFR) may be initiated by leakage into the urine of toxic proteins (txUPs). This study tested this hypothesis.Methods
After archiving baseline urine, we followed T1D patients with microalbuminuria for 8–12 years to distinguish those in whom GFR declined (Decliners) and those in whom it remained stable (Non-decliners). Human proximal tubular cells (HK-2 cells) were grown in serum-free medium enriched with pooled urines from Decliners or Non-decliners. We determined genome-wide expression profiles in extracted mRNA.Results
The two pooled urines induced differential expression of 312 genes. In terms of gene ontology, molecular functions of the 119 up-regulated genes were enriched for protein binding and peptidase inhibitor activities. Their biologic processes were enriched for defense response, responses to other organisms, regulation of cellular processes, or response to stress or stimulus, and programmed cell death. The 195 down-regulated genes were disproportionately represented in molecular functions of cation binding, hydrolase activity, and DNA binding. They were disproportionately represented in biological processes for regulation of metabolic processes, nucleic acid metabolic processes, cellular response to stress and macromolecule biosynthesis. The set of up-regulated genes in HK-2 cells overlaps significantly with sets of over-expressed genes in tubular and interstitial compartments of kidney biopsies from patients with advanced DN (33 genes in one study and 25 in the other compared with 10.3 expected by chance, p<10−9 and p<10−4, respectively). The overlap included genes encoding chemokines and cytokines. Overlap of down-regulated genes was no more than expected by chance.Conclusions
Molecular processes in tubules and interstitium seen in advanced diabetic nephropathy can be induced in vitro by exposure to urine from patients with minimal microalbuminuria who subsequently developed progressive renal function decline, presumably due to putative txUPs. 相似文献18.
Azusa Kodama Hiroshi Watanabe Ryota Tanaka Masumi Kondo Victor Tuan Giam Chuang Qiong Wu Masayuki Endo Yu Ishima Masafumi Fukagawa Masaki Otagiri Toru Maruyama 《Biochimica et Biophysica Acta (BBA)/General Subjects》2014
Background
A strategy for preventing cisplatin nephrotoxicity due to enhanced oxidative stress and inflammatory response is highly desirable. Thioredoxin-1 (Trx), an endogenous redox-active protein, has a short retention time in the blood. A long acting form of Trx, human serum albumin-Trx (HSA-Trx), was produced by recombinant HSA fusion and its effectiveness in preventing cisplatin nephrotoxicity was examined.Methods
HSA-Trx was prepared in Pichia expression system. Cisplatin-induced nephropathy mouse model was established by a single administration of cisplatin.Results
Compared to saline, Trx or N-acetylcysteine, an intravenous administration of HSA-Trx attenuated the cisplatin-induced elevation in serum creatinine, blood urea nitrogen and urinary N-acetyl-β-d-glucosaminidase along with the decrease in creatinine clearance. HSA-Trx caused a substantial reduction in the histological features of renal tubular injuries and the apoptosis-positive tubular cells. Changes in superoxide, 8-OHdG, glutathione and nitrotyrosine levels indicated that HSA-Trx significantly suppressed renal oxidative stress. HSA-Trx also suppressed the elevation of TNF-α, IL-1β and IL-6. Administered fluorescein isothiocyanate-labeled HSA-Trx was found partially localized in the proximal tubular cells whereas majority remained in the blood circulation. Specific cellular uptake and the scavenging of intracellular reactive oxygen species by HSA-Trx were observed in HK-2 cells.Conclusion
HSA-Trx could be a novel and effective approach for preventing cisplatin nephrotoxicity due to its prolonged anti-oxidative and anti-inflammatory action not only in extracellular compartment but also inside the proximal tubular cell.General significance
We report the renoprotective effect of HSA-Trx against cisplatin nephrotoxicity. This work would enhance developing therapeutics against acute kidney injuries including cisplatin nephrotoxicity. 相似文献19.
20.
Célia Ferreira Sónia Silva Fábio Faria-Oliveira Eva Pinho Mariana Henriques Cândida Lucas 《BMC microbiology》2010,10(1):238