cGMP-enhancing- and alpha1A/alpha1D-adrenoceptor blockade-derived inhibition of Rho-kinase by KMUP-1 provides optimal prostate relaxation and epithelial cell anti-proliferation efficacy.
BACKGROUND
Soluble guanylyl cyclase (sGC)/cyclic guanosine monophosphate (cGMP)/protein kinase G (PKG) and Rho kinase (ROCK2) pathways are important in the regulation of prostate smooth muscle tone. This study is aimed to examine the relaxation activities of a sGC activator and PDE5A/ROCK2 inhibitor KMUP-1 in rat prostate and associated anti-proliferation activity in human prostatic epithelial cells.


METHODS
The action characteristics of KMUP-1 were identified by isometric tension measurement, receptor binding assay, Western blotting and radioimmunoassay in rat prostate. Anti-proliferation activity of KMUP-1 in human prostatic epithelial PZ-HPV-7 cells was identified using flow cytometry and real time QRT-PCR.


RESULTS
KMUP-1 inhibited phenylephrine-induced contractility in a concentration-dependent manner. KMUP-1 possessed potent alpha(1A/)alpha(1D)-adrenoceptor binding inhibition activity, increased cAMP/cGMP levels and increased the expression of sGC, PKG, and PKA protein in rat prostate. Moreover, KMUP-1 inhibited phenylephrine-induced ROCK2 expression. KMUP-1 inhibited cell growth, arrested the cell cycle at G(0)/G(1) phase and increased the expression of p21 in PZ-HPV-7 cells.


CONCLUSIONS
These results broaden our knowledge of sGC/cGMP/PKG and ROCK2 regulation on the relaxation and proliferation of prostate, which may help in the design of benign prostate hyperplasia (BPH) therapies that target these signaling pathways. KMUP-1 possesses the potential benefit in the treatment of BPH by its alpha(1A/)alpha(1D)-adrenoceptor blockade, sGC activation, inhibition of PDE5A and ROCK2 and p21 protein enhancement, leading to attenuation of the smooth muscle tone and the proliferation of epithelial PZ-HPV-7 cells. The synergistic contribution of these pathways by KMUP-1 may benefit BPH patients with lower urinary tract symptoms.
Liu
Chi-Ming
CM
Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Lo
Yi-Ching
YC
Wu
Bin-Nan
BN
Wu
Wen-Jeng
WJ
Chou
Yii-Her
YH
Huang
Chun-Hsiung
CH
An
Li-Mei
LM
Chen
Ing-Jun
IJ
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D004357:Drug Synergism; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D010879:Piperazines / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology*; D011467:Prostate / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011687:Purines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism; D000068677:Sildenafil Citrate; D013449:Sulfonamides / Q000494:pharmacology; D013450:Sulfones / Q000494:pharmacology; D000077409:Tamsulosin; D014970:Xanthines / Q000494:pharmacology*; D054460:rho-Associated Kinases
D000317:Adrenergic alpha-Antagonists; D047908:Intracellular Signaling Peptides and Proteins; D010879:Piperazines; D010880:Piperidines; D011687:Purines; D011942:Receptors, Adrenergic, alpha; D013449:Sulfonamides; D013450:Sulfones; D014970:Xanthines; C439304:KMUP 1; D000068677:Sildenafil Citrate; D000242:Cyclic AMP; D017346:Protein Serine-Threonine Kinases; C515852:ROCK2 protein, human; D054460:rho-Associated Kinases; D017869:Cyclic GMP-Dependent Protein Kinases; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517381:PDE5A protein, human; C517384:Pde5a protein, rat; D000077409:Tamsulosin; D006152:Cyclic GMP