title: Effect of roscovitine on intracellular calcium dynamics: differential enantioselective responses.
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.
authors.affiliation: Department of Biosciences, Biotechnologies and Biopharmaceutics and ∥Centre of Excellence Genomic and Proteomics GEBCA, University of Bari , Italy.
authors.forename: Grazia
authors.initials: G
authors.lastname: Tamma
authors.forename: Marianna
authors.initials: M
authors.lastname: Ranieri
authors.forename: Annarita
authors.initials: A
authors.lastname: Di Mise
authors.forename: Alessia
authors.initials: A
authors.lastname: Spirlì
authors.forename: Annamaria
authors.initials: A
authors.lastname: Russo
authors.forename: Maria
authors.initials: M
authors.lastname: Svelto
authors.forename: Giovanna
authors.initials: G
authors.lastname: Valenti
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D002460:Cell Line; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004285:Dogs; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D061985:Madin Darby Canine Kidney Cells; D011687:Purines / Q000494:pharmacology*; D000077546:Roscovitine; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism
chemical_list: D007211:Indoles; D011687:Purines; D000077546:Roscovitine; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D002118:Calcium; C000543:cyclopiazonic acid