Effect of roscovitine on intracellular calcium dynamics: differential enantioselective responses

Mol Pharm. 2013 Dec 2;10(12):4620-8. doi: 10.1021/mp400430t. Epub 2013 Oct 29.

Abstract

Cyclin-dependent kinases (CDKs) inhibitors have emerged as interesting therapeutic candidates. Of these, (S)-roscovitine has been proposed as potential neuroprotective molecule for stroke while (R)-roscovitine is currently entering phase II clinical trials against cancers and phase I clinical tests against glomerulonephritis. In addition, (R)-roscovitine has been suggested as potential antihypertensive and anti-inflammatory drug. Dysfunction of intracellular calcium balance is a common denominator of these diseases, and the two roscovitine enantiomers (S and R) are known to modulate calcium voltage channel activity differentially. Here, we provide a detailed description of short- and long-term responses of roscovitine on intracellular calcium handling in renal epithelial cells. Short-term exposure to (S)-roscovitine induced a cytosolic calcium peak, which was abolished after stores depletion with cyclopiazonic acid (CPA). Instead, (R)-roscovitine caused a calcium peak followed by a small calcium plateau. Cytosolic calcium response was prevented after stores depletion. Bafilomycin, a selective vacuolar H(+)-ATPase inhibitor, abolished the small calcium plateau. Long-term exposure to (R)-roscovitine significantly reduced the basal calcium level compared to control and (S)-roscovitine treated cells. However, both enantiomers increased calcium accumulation in the endoplasmic reticulum (ER). Consistently, cells treated with (R)-roscovitine showed a significant increase in SERCA activity, whereas (S)-roscovitine incubation resulted in a reduced PMCA expression. We also found a tonic decreased ability to release calcium from the ER, likely via IP3 signaling, under treatment with (S)- or (R)-roscovitine. Together our data revealed that (S)-roscovitine and (R)-roscovitine exert distinct enantiospecific effects on intracellular calcium signaling in renal epithelial cells. This distinct pharmacological profile can be relevant for roscovitine clinical use.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Calcium Signaling / drug effects*
  • Cell Line
  • Cytosol / drug effects
  • Cytosol / metabolism
  • Dogs
  • Endoplasmic Reticulum / drug effects
  • Endoplasmic Reticulum / metabolism
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Indoles / pharmacology
  • Kidney / drug effects
  • Kidney / metabolism
  • Madin Darby Canine Kidney Cells
  • Purines / pharmacology*
  • Roscovitine
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases / metabolism

Substances

  • Indoles
  • Purines
  • Roscovitine
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases
  • Calcium
  • cyclopiazonic acid