Nitric oxide enhances extracellular ATP induced Ca²⁺ oscillation in HeLa cells

Arch Biochem Biophys. 2015 Jan 1:565:68-75. doi: 10.1016/j.abb.2014.11.006. Epub 2014 Nov 25.

Abstract

Calcium (Ca(2+)) oscillations play a central role in varieties of cellular processes including fertilization and immune response, but controversy over the regulation mechanisms still exists. It has been known that nitric oxide (NO) dependently regulates Ca(2+) signaling in most physiopathological processes. Previous study indicated that eNOS translocation during some pathological process influences intracellular Ca(2+) homeostasis. In this study, we investigated the role and mechanism of NO on Ca(2+) release by overexpressing eNOS in cytoplasm (Cyto-eNOS) and endoplasmic reticulum (ER-eNOS) of HeLa cells. We found that the properties of Ca(2+) release were altered by the overexpression of eNOS. The amplitude and frequency of extracellular ATP (eATP)-induced Ca(2+) oscillation were enhanced in both Cyto-eNOS and ER-eNOS cells, respectively. Especially, the enhancement of the amplitude and frequency of the Ca(2+) oscillation was much more significant in the ER-eNOS cells than that of Cyto-eNOS cells. Further study indicated that this effect was abrogated by NO inhibitor, L-NAME, suggesting it was not an artificial result induced by ER stress. Furthermore, an up-regulated phosphorylation of phospholamban (PLB) was observed and the sarco-endoplasmic reticulum Ca(2+)-ATPase (SERCA) function was activated followed by the significant increase in the ER Ca(2+) load. Taken together, we revealed a novel regulatory mechanism of Ca(2+) oscillation.

Keywords: Calcium oscillation; Nitric oxide; Phospholamban; eNOS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / genetics
  • Adenosine Triphosphate / metabolism
  • Adenosine Triphosphate / pharmacology*
  • Calcium Signaling / drug effects*
  • Calcium-Binding Proteins / genetics
  • Calcium-Binding Proteins / metabolism
  • Cytoplasm / genetics
  • Cytoplasm / metabolism*
  • Endoplasmic Reticulum / genetics
  • Endoplasmic Reticulum / metabolism
  • Enzyme Inhibitors / pharmacology
  • HeLa Cells
  • Humans
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Nitric Oxide / genetics
  • Nitric Oxide / metabolism*
  • Nitric Oxide Synthase Type III / antagonists & inhibitors
  • Nitric Oxide Synthase Type III / genetics
  • Nitric Oxide Synthase Type III / metabolism
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases / genetics
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases / metabolism

Substances

  • Calcium-Binding Proteins
  • Enzyme Inhibitors
  • phospholamban
  • Nitric Oxide
  • Adenosine Triphosphate
  • NOS3 protein, human
  • Nitric Oxide Synthase Type III
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases
  • NG-Nitroarginine Methyl Ester