Cilomilast enhances osteoblast differentiation of mesenchymal stem cells and bone formation induced by bone morphogenetic protein 2.
A rapid and efficient method to stimulate bone regeneration would be useful in orthopaedic stem cell therapies. Rolipram is an inhibitor of phosphodiesterase 4 (PDE4), which mediates cyclic adenosine monophosphate (cAMP) degradation. Systemic injection of rolipram enhances osteogenesis induced by bone morphogenetic protein 2 (BMP-2) in mice. However, there is little data on the precise mechanism, by which the PDE4 inhibitor regulates osteoblast gene expression. In this study, we investigated the combined ability of BMP-2 and cilomilast, a second-generation PDE4 inhibitor, to enhance the osteoblastic differentiation of mesenchymal stem cells (MSCs). The alkaline phosphatase (ALP) activity of MSCs treated with PDE4 inhibitor (cilomilast or rolipram), BMP-2, and/or H89 was compared with the ALP activity of MSCs differentiated only by osteogenic medium (OM). Moreover, expression of Runx2, osterix, and osteocalcin was quantified using real-time polymerase chain reaction (RT-PCR). It was found that cilomilast enhances the osteoblastic differentiation of MSCs equally well as rolipram in primary cultured MSCs. Moreover, according to the H89 inhibition experiments, Smad pathway was found to be an important signal transduction pathway in mediating the osteogenic effect of BMP-2, and this effect is intensified by an increase in cAMP levels induced by PDE4 inhibitor.
Department of Biomedical Engineering, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan.
Maria Chiara
MC
Munisso
Jeong-Hun
JH
Kang
Makoto
M
Tsurufuji
Tetsuji
T
Yamaoka
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D002113:Calcification, Physiologic / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4 / Q000378:metabolism; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology*; D004347:Drug Interactions; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects; D009570:Nitriles / Q000494:pharmacology*; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D015675:Osteocalcin / Q000235:genetics; D010012:Osteogenesis / Q000187:drug effects*; D058988:Phosphodiesterase 4 Inhibitors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D051785:Smad Proteins / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D050659:Core Binding Factor Alpha 1 Subunit; D003509:Cyclohexanecarboxylic Acids; D007546:Isoquinolines; D009570:Nitriles; D058988:Phosphodiesterase 4 Inhibitors; D051785:Smad Proteins; C495181:Sp7 protein, rat; D013449:Sulfonamides; D014157:Transcription Factors; D015675:Osteocalcin; C433247:Cilomilast; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D000469:Alkaline Phosphatase; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide