Characterization of calcium signals in human embryonic stem cells and in their differentiated offspring by a stably integrated calcium indicator protein

Ágota Apáti, Katalin Pászty, Luca Hegedus, Orsolya Kolacsek, Tamás I. Orbán, Zsuzsa Erdei, Kornélia Szebényi, Adrienn Péntek, Ágnes Enyedi, Balázs Sarkadi

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19 Citations (Scopus)

Abstract

Intracellular calcium signaling pathways play a major role in cellular responses such as proliferation, differentiation and apoptosis. Human embryonic stem cells (hESC) provide new possibilities to explore the development and differentiation of various cell types of the human body. Intracellular calcium responses to various ligands and the calcium signaling pathways, however, have not been thoroughly studied in embryonic stem cells and in their differentiated progenies. In our previous work we demonstrated that the use of the fluorescent calcium indicator Fluo-4 with confocal microscopy allows sensitive and reliable measurements of calcium modulation in human embryonic stem cells and stem-cell derived cardiomyocytes. Here we developed a human embryonic stem cell line stably expressing a genetically encoded Ca2+ indicator (GCaMP2) using a transposon-based gene delivery system. We found that the differentiation properties were fully preserved in the GCaMP2-expressing hESC lines and Ca imaging could be performed without the need of toxic dye-loading of the cells. In undifferentiated hES cells the calcium signals induced by various ligands, ATP, LPA, trypsin or angiotensin II were comparable to those in Fluo-4 loaded cells. In accordance with previous findings, no calcium signal was evoked by thrombin, histamine or GABA. Cardiomyocyte colonies differentiated from hES-GCaMP2 cells could be recognized by spontaneous contractions and Ca2+ oscillations. GCaMP2-expressing neural cells were identified based on their morphological and immuno-staining properties and Ca signals were characterized on those cells. Characteristics of both the spontaneous and ligand-induced Ca2+ signals, as well as their pharmacological modification could be successfully examined in these model cells by fluorescence imaging.

Original languageEnglish
Pages (from-to)752-759
Number of pages8
JournalCellular Signalling
Volume25
Issue number4
DOIs
Publication statusPublished - Apr 1 2013

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Keywords

  • Calcium signaling
  • Fluorescent calcium indicators
  • Genetically encoded calcium indicators
  • Human embryonic stem cell

ASJC Scopus subject areas

  • Cell Biology

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