title: Intracellular calcium dynamics dependent on defined microtopographical features of titanium.
abstract: Detailed insights into the complex cellular behavior at the biomaterial interface are crucial for the improvement of implant surfaces with respect to their acceptance and integration. The cells perceive microtopographical features and, in consequence, rearrange their adhesion structures like the actin cytoskeleton and adaptor proteins. But little is known about whether these altered cellular phenotypes have consequences for intracellular calcium signaling and its dynamics. To elucidate if an artificial, geometrical microtopography influences calcium ion (Ca(2+)) mobilization in osteoblasts, human MG-63 cells were stained with the calcium dye Fluo 3-acetoxymethyl ester and set on defined silicon-titanium (Ti) arrays with regular pillar structures (P5, 5 × 5 × 5 μm) and compared with planar Ti. To induce an immediate calcium signal, cells were stimulated with adenosine 5'-triphosphate (ATP). Interestingly, osteoblasts on micropillars expressing a shortened actin cytoskeleton were hampered in their calcium mobilization potential in signal height as well duration. Even the basal level of the intracellular Ca(2+) concentration was reduced, which was accompanied by a disturbed fibronectin synthesis. The expression of the voltage-sensitive calcium channels Cav1.2, Cav1.3 (L-type) and Cav3.1, Cav3.2, Cav3.3 (T-type) as well as the signaling proteins phospho-AKT and phospho-GSK3α/β remained unaffected on pillars. The topography-dependent calcium dynamics observed here provide new insights into how topographical cues alter cell functions - via the intracellular Ca(2+) signaling.
authors: Dept. of Cell Biology, University Medical Center Rostock, D-18057 Rostock, Germany.
authors: Susanne
authors: S
authors: Staehlke
authors: Institute of Electronic Appliances and Circuits, Interface Research Group, University of Rostock, D-18059 Rostock, Germany.
authors: Andreas
authors: A
authors: Koertge
authors: Dept. of Cell Biology, University Medical Center Rostock, D-18057 Rostock, Germany. Electronic address: barbara.nebe@med.uni-rostock.de.
authors: Barbara
authors: B
authors: Nebe
mesh_terms: D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D002460:Cell Line; D003720:Densitometry; D005353:Fibronectins / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism*; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010641:Phenotype; D010766:Phosphorylation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology*; D014867:Water / Q000737:chemistry
chemical_list: D015220:Calcium Channels; D005353:Fibronectins; D014867:Water; D014025:Titanium; D002118:Calcium
keywords: Actin; Calcium; Cell signaling; Image analysis; Microstructure; Osteoblast