Effects of estrogen, raloxifene, and levormeloxifene on the expression of Rho-kinase signaling molecules in urethral smooth muscle cells.
OBJECTIVE
To investigate the effects of estrogen, raloxifene, and levormeloxifene on the expression of Rho-kinase signaling molecules in urethral smooth muscle cells (USMCs).


METHODS
USMCs were isolated from female rats. Expression of calponin and estrogen receptors α (ERα) was detected by immunofluorescence staining. Cells were treated with estrogen, raloxifene, or levormeloxifene at 0, 1, 10, and 100 nmol/L for 48 h and then processed for Western blotting with antibodies against RhoA, Rho kinase I and II (Rock-I and Rock-II), myosin light chain (MLC), phosphorylated MLC, and β-actin. Protein expression was quantitated by densitometry, followed by statistical analysis with β-actin as control.


RESULTS
USMCs expressed calponin and ERα. Treatment of USMCs with estrogen, raloxifene or levormeloxifene resulted in decreased expression of RhoA, Rock-I, Rock-II, and p-MLC in a dosage-dependent manner.


CONCLUSIONS
Estrogen, raloxifene, and levormeloxifene may affect urinary continence by inhibiting the expression of Rho-kinase signaling molecules.
Knuppe Molecular Urology Laboratory, Department of Urology, School of Medicine, University of California, San Francisco, California 94143, USA.
Nongxiu
N
Ning
Guiting
G
Lin
Tom F
TF
Lue
Ching-Shwun
CS
Lin
D000818:Animals; D002135:Calcium-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D002478:Cells, Cultured / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D047628:Estrogen Receptor alpha / Q000096:biosynthesis / Q000235:genetics; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D008840:Microfilament Proteins / Q000096:biosynthesis / Q000235:genetics; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D018994:Myosin Light Chains / Q000096:biosynthesis / Q000235:genetics; D011759:Pyrrolidines / Q000494:pharmacology* / Q000633:toxicity; D020849:Raloxifene Hydrochloride / Q000494:pharmacology* / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D014521:Urethra / Q000166:cytology / Q000187:drug effects*; D014549:Urinary Incontinence / Q000503:physiopathology; D054460:rho-Associated Kinases / Q000096:biosynthesis* / Q000235:genetics; D020742:rhoA GTP-Binding Protein / Q000096:biosynthesis / Q000235:genetics; D000096985:Calponins
D002135:Calcium-Binding Proteins; D047628:Estrogen Receptor alpha; D004967:Estrogens; D008840:Microfilament Proteins; D018994:Myosin Light Chains; D011759:Pyrrolidines; D020849:Raloxifene Hydrochloride; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein; D000096985:Calponins; C108255:levormeloxifene