Translate this page to:
Portuguese
In JoVE (1)
Other Publications (3)
Automatic Translation
This translation into Portuguese was automatically generated.
English Version | Other Languages
Articles by Brigitte Lahni in JoVE
JoVE General
Chip baseado em Cultura de Células tridimensional em perfundidos Micro-biorreatores
Institute for Biological Interfaces, Forschungszentrum Karlsruhe
Descrevemos uma plataforma baseada em chip para o cultivo tridimensional de células em micro-biorreatores. Um chip pode abrigar até 10 milhões. células que podem ser cultivadas sob condições estritamente definidas em relação ao fluxo de fluidos, etc tensão de oxigênio em um circuito de circulação estéril, fechado.
Other articles by Brigitte Lahni on PubMed
Expression of the Cochaperone HspBP1 is Not Coordinately Regulated with Hsp70 Expression
Intracellular levels of the heat stress protein Hsp70 are elevated following exposure to elevated temperature. The cochaperone HspBP1 is an intracellular protein that is known to bind to and regulate Hsp70 activity. The purpose of this study was to determine if HspBP1 levels changed when Hsp70 levels were altered. Heat stress resulted in an increase in Hsp70 levels but no change in HspBP1 levels. Treatment of cells with the apoptosis inducing drug camptothecin lowered Hsp70 levels but again had no effect on HspBP1 levels. Cells treated with camptothecin plus heat stress did not exhibit an increase in Hsp70 levels. Over-expression in cells stably transfected with HspBP1 cDNA resulted in a 290% increase in HspBP1 levels without a similar change in Hsp70 levels. These results demonstrate that Hsp70 and HspBP1 are not coordinately regulated but provide evidence that an increase in the ratio of HspBP1 to Hsp70 correlates with apoptosis, in a similar way to reducing the amount of Hsp70.
Expression of HSP72 After ELF-EMF Exposure in Three Cell Lines
It has been reported that magnetic fields with flux densities ranging from microT to mT are able to induce heat shock factor, HSP72 mRNA or heat shock proteins in various cells. In this study we investigated changes in the HSP72 mRNA transcription level in three cell lines (HL-60, H9c2, and Girardi heart cells) and in the intracellular HSP72 protein content in two cell lines (HL-60 and Girardi heart cells) after treatment schemes using electromagnetic fields with a flux density of 2 microT to 4 mT, a frequency of 50 Hz and exposure times from 15 to 30 min. None of the treatments or modalities showed any significant effect on the HSP72 protein level, although HSP72 mRNA could be induced, at least to some extent, with one of the parameter combinations in all cell lines tested. Obviously, HSP72 mRNA transcription and translation are not necessarily coupled in certain cells. This leads to the conclusion that electromagnetic field effects on HSP72 mRNA levels are not indicative for downstream effects unless increased mRNA levels can be correlated with increased HSP72 protein levels as well.
A Chip-based Platform for the in Vitro Generation of Tissues in Three-dimensional Organization
We describe a multi-purpose platform for the three-dimensional cultivation of tissues. The device is composed of polymer chips featuring a microstructured area of 1-2 cm(2). The chip is constructed either as a grid of micro-containers measuring 120-300 x 300 x 300 microm (h x l x w), or as an array of round recesses (300 microm diameter, 300 microm deep). The micro-containers may be separately equipped with addressable 3D-micro-electrodes, which allow for electrical stimulation of excitable cells and on-site measurements of electrochemically accessible parameters. The system is applicable for the cultivation of high cell densities of up to 8 x 10(6) cells and, because of the rectangular grid layout, allows the automated microscopical analysis of cultivated cells. More than 1000 micro-containers enable the parallel analysis of different parameters under superfusion/perfusion conditions. Using different polymer chips in combination with various types of bioreactors we demonstrated the principal suitability of the chip-based bioreactor for tissue culture applications. Primary and established cell lines have been successfully cultivated and analysed for functional properties. When cells were cultured in non-perfused chips, over time a considerable degree of apoptosis could be observed indicating the need for an active perfusion. The system presented here has also been applied for the differentiation analysis of pluripotent embryonic stem cells and may be suitable for the analysis of the stem cell niche.
