Phospholipase C-β1 and β4 contribute to non-genetic cell-to-cell variability in histamine-induced calcium signals in HeLa cells

PLoS One. 2014 Jan 27;9(1):e86410. doi: 10.1371/journal.pone.0086410. eCollection 2014.

Abstract

A uniform extracellular stimulus triggers cell-specific patterns of Ca(2+) signals, even in genetically identical cell populations. However, the underlying mechanism that generates the cell-to-cell variability remains unknown. We monitored cytosolic inositol 1,4,5-trisphosphate (IP3) concentration changes using a fluorescent IP3 sensor in single HeLa cells showing different patterns of histamine-induced Ca(2+) oscillations in terms of the time constant of Ca(2+) spike amplitude decay and the Ca(2+) oscillation frequency. HeLa cells stimulated with histamine exhibited a considerable variation in the temporal pattern of Ca(2+) signals and we found that there were cell-specific IP3 dynamics depending on the patterns of Ca(2+) signals. RT-PCR and western blot analyses showed that phospholipase C (PLC)-β1, -β3, -β4, -γ1, -δ3 and -ε were expressed at relatively high levels in HeLa cells. Small interfering RNA-mediated silencing of PLC isozymes revealed that PLC-β1 and PLC-β4 were specifically involved in the histamine-induced IP3 increases in HeLa cells. Modulation of IP3 dynamics by knockdown or overexpression of the isozymes PLC-β1 and PLC-β4 resulted in specific changes in the characteristics of Ca(2+) oscillations, such as the time constant of the temporal changes in the Ca(2+) spike amplitude and the Ca(2+) oscillation frequency, within the range of the cell-to-cell variability found in wild-type cell populations. These findings indicate that the heterogeneity in the process of IP3 production, rather than IP3-induced Ca(2+) release, can cause cell-to-cell variability in the patterns of Ca(2+) signals and that PLC-β1 and PLC-β4 contribute to generate cell-specific Ca(2+) signals evoked by G protein-coupled receptor stimulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Calcium Signaling / drug effects
  • Calcium Signaling / physiology*
  • Cytosol / metabolism
  • DNA Primers / genetics
  • HeLa Cells
  • Histamine / metabolism*
  • Histamine / pharmacology
  • Humans
  • Inositol 1,4,5-Trisphosphate / metabolism
  • Isoenzymes / metabolism
  • Phospholipase C beta / metabolism*
  • RNA Interference
  • RNA, Small Interfering / genetics
  • Receptors, G-Protein-Coupled / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • DNA Primers
  • Isoenzymes
  • RNA, Small Interfering
  • Receptors, G-Protein-Coupled
  • Histamine
  • Inositol 1,4,5-Trisphosphate
  • Phospholipase C beta

Grants and funding

This work was supported by grants from the Ministry of Education, Culture, Sports, Science and Technology of Japan to T. Matsu-ura (22770227), T. Michikawa (20370054), and K. Mikoshiba (2022007). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.