| Autor: |
Elke Van Rossen, Zhenan Liu, Leo van Grunsven, Jona Van der Straeten, Daele, J., Hendrik Reynaert, Roskams, T., Timmermans, J. P., Albert Geerts |
| Přispěvatelé: |
Physiology, Cell Biology and Histology, Basic (bio-) Medical Sciences, Gastroenterology, Laboratory of Molecullar and Cellular Therapy, Liver Cell Biology |
| Jazyk: |
angličtina |
| Rok vydání: |
2007 |
| Předmět: |
|
| Zdroj: |
Vrije Universiteit Brussel |
| Popis: |
Background: Hepatic stellate cells (HSCs) are important in several (patho) physical conditions. In response to chronic injury, HSCs are activated and change from quiescent to myofibroblast-like cells with contractile properties. This makes HSCs an interesting target in the study of portal hypertension, the shift in phenotype is accompanied by a dramatic change in expression of intermediate filaments (IFs). In contrast to most differentiated cell types, HSCs express a broad, but variable spectrum of Ifs. Aim: Investigate the expression and functions of the IF protein syncoilin in HSCs. Methods: Syncoilin expression in isolated and cultured mouse HSCs was studied by quantitative reverse transcription polymerase chain reaction, Western blotting, and fluorescence immunocytochemistry (confocal microscopy). We generated different syncoilin antibodies for these purposes. The function of syncoilin in HSC contraction was studied by means of optical recording using the fluorescent calcium indicator, Fluo-4. Results: Syncoilin mRNA was present in HSCs, skeletal muscle, heart, brain, and stomach and was upregulated during HSC activation. While in quiescent HSCs no syncoilin protein could be detected, this protein was strongly upregulated during in vitro activation. We verified the cellular localization of syncoilin using immunocytochemistry. We observed filamentous staining in HSCs undergoing in vitro transdifferentiation. The syncoilin IF bundles did not colocalize with alpha smooth muscle actin or desmin filaments. To assess the function of syncoilin we performed calcium measurements in HSCs transfected with control or syncoilin siRNAs. In cells transfected with syncoilin siRNA, intracellular calcium release following stimulation with endothelin-1 was reduced. Conclusion: To our knowledge, we are the first group to demonstrate the presence of the IF protein syncoilin in mouse HSCs. This IF protein is strongly upregulated during in vitro activation. We show that syncoilin is an important player in intracellular calcium signalling. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
