Transforming growth factor (TGF)-β type I receptor kinase (ALK5) inhibitor alleviates profibrotic TGF-β1 responses in fibroblasts derived from Peyronie's plaque.
BACKGROUND
Transforming growth factor-β1 (TGF-β1) has been identified as an important fibrogenic cytokine associated with Peyronie's disease (PD).


OBJECTIVE
The aim of this study was to study the differential expression of the TGF-β1 and Smad transcription factors in plaque tissue from PD patients and to determine the antifibrotic effect of SKI2162 (SK Chemicals, Seoul, South Korea), a novel small-molecule inhibitor of activin receptor-like kinase 5 (ALK5), a type I receptor of TGF-β, in primary fibroblasts derived from human PD plaque.


METHODS
Plaque tissue was isolated from five PD patients, and tunica albuginea tissue was obtained from four control patients. Plaque tissues from a patient with PD were used for primary fibroblast culture. Fibroblasts were pretreated with SKI2162 (10 µM) and then stimulated with TGF-β1 (10ng/mL).


METHODS
The plaque or tunica albuginea tissue was stained with Masson's trichrome or antibody to TGF-β1, phospho-Smad2 (P-Smad2), and P-Smad3. Protein was extracted from treated fibroblasts for Western blotting, and the membranes were probed with antibody to P-Smad2/Smad2, P-Smad3/Smad3, plasminogen activator inhibitor-1, fibronectin, collagen I, and collagen IV. We also determined the inhibitory effect of SKI2162 on TGF-β1-induced nuclear translocation of Smad2/3 in fibroblasts.


RESULTS
The plaque tissue from PD patients showed higher TGF-β1, P-Smad2, and P-Smad3 immunoreactivity than did the tunica albuginea tissue from control patients. SKI2162 not only blocked TGF-β1-induced phosphorylation and nuclear translocation of Smad2 and Smad3, but also inhibited the production of extracellular matrix markers in fibroblasts derived from human PD plaque.


CONCLUSIONS
In light of the pivotal role of TGF-β and Smads in the pathogenesis of PD, pharmacologic inhibition of ALK5 may represent a novel targeted approach to treating PD.
Laboratory of Regenerative Sexual Medicine and Department of Urology, Inha University School of Medicine, Incheon, South Korea.
Shuguang
S
Piao
Min Ji
MJ
Choi
Munkhbayar
M
Tumurbaatar
Woo Jean
WJ
Kim
Hai-Rong
HR
Jin
Sun Hwa
SH
Shin
Buyankhuu
B
Tuvshintur
Guo Nan
GN
Yin
Jae Sook
JS
Song
Mi-Hye
MH
Kwon
Sang-Jin
SJ
Lee
Jee-Young
JY
Han
Seong-Jin
SJ
Kim
Ji-Kan
JK
Ryu
Jun-Kyu
JK
Suh
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000328:Adult; D000368:Aged; D015153:Blotting, Western; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010411:Penile Induration / Q000188:drug therapy* / Q000378:metabolism; D010413:Penis / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors*; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000037:antagonists & inhibitors*; D051899:Smad2 Protein / Q000378:metabolism; D051900:Smad3 Protein / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000037:antagonists & inhibitors* / Q000378:metabolism
D018125:Receptors, Transforming Growth Factor beta; C497782:SMAD2 protein, human; C497790:SMAD3 protein, human; D051899:Smad2 Protein; D051900:Smad3 Protein; D053773:Transforming Growth Factor beta1; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625841:TGFBR1 protein, human