Erythropoietin modulates intracellular calcium in a human neuroblastoma cell line

J Physiol. 1999 Apr 15;516 ( Pt 2)(Pt 2):343-52. doi: 10.1111/j.1469-7793.1999.0343v.x.

Abstract

1. Recent investigations have shown that the glycoprotein erythropoietin (Epo) and its specific receptor (EpoR) are present in the mammalian brain including human, monkey and mouse. These findings suggest a local action of Epo in the nervous system. The aim of this study was to elucidate a possible functional interaction of Epo with neuronal cells. 2. To examine the influence of externally applied Epo on Ca2+ homeostasis the human neuroblastoma cell line SK-N-MC was chosen as a suitable in vitro model for undifferentiated neuronal cells. 3. Expression of the EpoR in SK-N-MC cells was detected by reverse transcription-PCR, Western blot and immunofluorescence analysis. 4. Patch-clamp studies of SK-N-MC cells confirmed the expression of T-type Ca2+ channels, whose peak macroscopic current was increased by the addition of recombinant human Epo (rhEpo) to the bathing medium. 5. Confocal laser scanning microscopy analysis of SK-N-MC cells confirmed a transient increase in intracellular free [Ca2+] in response to externally applied rhEpo. 6. The transient response to Epo was dependent on external Ca2+ and remained even after depletion of internal Ca2+ stores by caffeine or thapsigargin. However, after depletion the response to Epo was absent when cells were superfused with the T-type Ca2+ channel blocker flunarizine. 7. This study demonstrates that Epo can interact with neuronal cells by affecting Ca2+ homeostasis through an increase in Ca2+ influx via plasma membrane T-type voltage-dependent Ca2+ channels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Brain Neoplasms / metabolism*
  • Calcium / metabolism*
  • Calcium Channels / metabolism
  • Cell Line
  • Electrophysiology
  • Erythropoietin / pharmacology*
  • Fluorescent Antibody Technique, Direct
  • Humans
  • Microscopy, Confocal
  • Neuroblastoma / metabolism*
  • Patch-Clamp Techniques
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Recombinant Proteins
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Calcium Channels
  • RNA, Messenger
  • Recombinant Proteins
  • Erythropoietin
  • Calcium