Real-time cellular impedance measurements detect Ca(2+) channel-dependent oscillations of morphology in human H295R adrenoma cells.
Endocrine cells, such as H295R have been widely used to study secretion of steroid and other hormones. Exocytosis-dependent hormone release is accompanied by an increase in plasma membrane surface area and a decrease in vesicle content. Recovery of vesicles and decrease in plasma membrane area is achieved by endocytotic processes. These changes in the extent of the surface area lead to morphological changes which can be determined by label-free real-time impedance measurements. Exo- and endocytosis have been described to be triggered by activation of L-type Ca(2+) channels. The present study demonstrates that activation of L-type calcium channels induces prolonged oscillating changes in cellular impedance. The data support the hypothesis that a tight regulation of the intracellular Ca(2+) concentration is a prerequisite for the observed cellular impedance oscillations. Furthermore evidence is presented for a mechanism in which the oscillations depend on a Ca(2+)-triggered calmodulin-dependent cascade involving myosin light chain kinase, nonmuscle myosin II and ultimately actin polymerization, a known determinant for cell shape changes and exocytosis in secretory cells. The described assay provides a method to determine continuously prolonged changes in cellular morphology such as exo/endocytosis cycles. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.
Metabolic Diseases, F. Hoffmann-La Roche Ltd., Pharma Research and Early Development, Basel, Switzerland.
Athanasios
A
Denelavas
Franziska
F
Weibel
Michael
M
Prummer
Alexander
A
Imbach
Roger G
RG
Clerc
Christian M
CM
Apfel
Cornelia
C
Hertel
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000302:Adrenal Cortex / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D000804:Angiotensin II / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D020746:Calcium Channels, L-Type; D002147:Calmodulin / Q000378:metabolism; D002460:Cell Line; D048430:Cell Shape / Q000187:drug effects; D017097:Electric Impedance; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D006801:Humans; D021621:Imaging, Three-Dimensional; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000378:metabolism; D019284:Thapsigargin / Q000494:pharmacology; D013997:Time Factors
D020746:Calcium Channels, L-Type; D002147:Calmodulin; D006576:Heterocyclic Compounds, 4 or More Rings; D034741:RNA, Small Interfering; D000804:Angiotensin II; C472645:blebbistatin; D010042:Ouabain; D019284:Thapsigargin; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D002118:Calcium