Cell cycle-dependent expression of Kv3.4 channels modulates proliferation of human uterine artery smooth muscle cells.
OBJECTIVE
Vascular smooth muscle cell (VSMC) proliferation is involved in cardiovascular pathologies associated with unwanted arterial wall remodelling. Coordinated changes in the expression of several K+ channels have been found to be important elements in the phenotypic switch of VSMCs towards proliferation. We have previously demonstrated the association of functional expression of Kv3.4 channels with proliferation of human uterine VSMCs. Here, we sought to gain deeper insight on the relationship between Kv3.4 channels and cell cycle progression in this preparation.


RESULTS
Expression and function of Kv3.4 channels along the cell cycle was explored in uterine VSMCs synchronized at different checkpoints, combining real-time PCR, western blotting, and electrophysiological techniques. Flow cytometry, Ki67 expression and BrdU incorporation techniques allowed us to explore the effects of Kv3.4 channels blockade on cell cycle distribution. We found cyclic changes in Kv3.4 and MiRP2 mRNA and protein expression along the cell cycle. Functional studies showed that Kv3.4 current amplitude and Kv3.4 channels contribution to cell excitability increased in proliferating cells. Finally, both Kv3.4 blockers and Kv3.4 knockdown with siRNA reduced the proportion of proliferating VSMCs.


CONCLUSIONS
Our data indicate that Kv3.4 channels exert a permissive role in the cell cycle progression of proliferating uterine VSMCs, as their blockade induces cell cycle arrest after G2/M phase completion. The modulation of resting membrane potential (V(M)) by Kv3.4 channels in proliferating VSMCs suggests that their role in cell cycle progression could be at least in part mediated by their contribution to the hyperpolarizing signal needed to progress through the G1 phase.
Miguel-Velado
Eduardo
E
Departamento de Bioquímica y Biología Molecular y Fisiología e Instituto de Biología y Genética Molecular , Universidad de Valladolid y CSIC, Valladolid, Spain.
Pérez-Carretero
Francisco D
FD
Colinas
Olaia
O
Cidad
Pilar
P
Heras
Magda
M
López-López
José R
JR
Pérez-García
M Teresa
MT
D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D008564:Membrane Potentials; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D010641:Phenotype; D026902:Potassium Channel Blockers / Q000494:pharmacology; D024642:Potassium Channels, Voltage-Gated / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D051670:Shaw Potassium Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D055988:Uterine Artery / Q000378:metabolism
C492015:KCNC4 protein, human; C418492:KCNE3 protein, human; D026902:Potassium Channel Blockers; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger; D051670:Shaw Potassium Channels