Roles of store-operated Ca²⁺channels in regulating cell cycling and migration of human cardiac c-kit⁺progenitor cells

Abstract

Cardiac c-kit(+) progenitor cells are important for maintaining cardiac homeostasis and can potentially contribute to myocardial repair. However, cellular physiology of human cardiac c-kit(+) progenitor cells is not well understood. The present study investigates the functional store-operated Ca(2+) entry (SOCE) channels and the potential role in regulating cell cycling and migration using confocal microscopy, RT-PCR, Western blot, coimmunoprecipitation, cell proliferation, and migration assays. We found that SOCE channels mediated Ca(2+) influx, and TRPC1, STIM1, and Orai1 were involved in the formation of SOCE channels in human cardiac c-kit(+) progenitor cells. Silencing TRPC1, STIM1, or Orai1 with the corresponding siRNA significantly reduced the Ca(2+) signaling through SOCE channels, decreased cell proliferation and migration, and reduced expression of cyclin D1, cyclin E, and/or p-Akt. Our results demonstrate the novel information that Ca(2+) signaling through SOCE channels regulates cell cycling and migration via activating cyclin D1, cyclin E, and/or p-Akt in human cardiac c-kit(+) cells.

TRPC1/TRPC3 channels mediate lysophosphatidylcholine-induced apoptosis in cultured human coronary artery smooth muscles cells

“…The cell viability was determined with MTT assay as described previously [51, 52]. Briefly, human coronary artery SMCs were seeded in 96-well plates (Thermo Fisher Scientific, MA, USA) for 24 h and incubated with medium containing 5% FBS and different concentrations of lypoPC or equal volume of vehicle (ethanol, Sigma-Aldrich) for different period of time.…”

Bradykinin‐mediated Ca2+ signalling regulates cell growth and mobility in human cardiac c‐Kit+ progenitor cells

“…Our recent study demonstrated that TRPC1, Orai1 and STIM1 are components of SOCE channel complex in human cardiac c‐Kit + progenitor cells 13. If bradykinin‐induced Ca 2+ influx is mediated solely by TRPC1 channel, the effect would not be affected in cells with silenced Orai1 or STIM1.…”

“…We have recently demonstrated that SOCE channel participates in regulating cell growth and migration,13 and bradykinin promotes cell cycling progression and mobility in cultured human cardiac c‐Kit + progenitor cells 10. To investigate whether the stimulation of cell cycling progression and mobility by bradykinin is related to Ca 2+ signalling.…”

“…Gene silencing was conducted with small interfering RNA (siRNA) technique as described previously 11, 13. Briefly, human cardiac c‐Kit + progenitor cells were seeded in six‐well plates or 96‐well plates at a confluence of 60%‐80% overnight.…”

“…Reverse transcription‐polymerase chain reaction was employed to determine mRNA expression in cells with silenced IP3Rs, TRPC channels or SOCE channels for siRNA efficacy as described previously 10, 13. Briefly, total RNA was extracted from human cardiac c‐Kit + progenitor cells transfected with corresponding siRNA for 48 hours using TRIzol reagent.…”