title: Kamolonol suppresses angiotensin II-induced stress fiber formation and cellular hypertrophy through inhibition of Rho-associated kinase 2 activity.
abstract: Kamolonol (7-[[(1R,2R,4R,4aS,5R,8aS)-4-hydroxy-1,2,4a,5-tetramethyl-6-oxo-3,4,5,7,8,8a-hexahydro-2H-naphthalen-1-yl]methoxy]chromen-2-one) is a sesquiterpene coumarin and an active component of gum extracts from Ferulaassafoetida. The aim of this study was to investigate the anti-fibrotic and anti-cellular hypertrophic effects of kamolonol, and further to explore its possible mechanism. Kamolonol (3-30μM) significantly inhibited stress fiber formation induced by angiotensin II (Ang II) in rat heart-derived H9c2 cells. Furthermore, kamolonol (3-30μM) showed a potent inhibitory effect on Ang II-induced cellular hypertrophy in H9c2 cells. Next, a Rho-associated kinase (ROCK) activity was measured because actin stress fiber formation and/or cellular hypertrophy are usually induced by the activation of ROCK. Rho-associated kinase 2 (ROCK2) studies using a time-resolved fluorescence resonance energy transfer (TR-FRET) showed that kamolonol possesses a potent ROCK2 inhibitory activity with IC50 values of 2.27μM, and has an ATP-competitive inhibitory mode. In validation study, pretreatment of kamolonol (3-30μM) for 2h decreased the Ang II-induced phosphorylation of myosin phosphatase 1 (MYPT1) and myosin light chain 2 (MLC2). Taken together, these results indicate that kamolonol suppresses Ang II-induced stress fiber formation and cellular hypertrophy, and propose that one mechanism underlying these anti-fibrotic and anti-cellular hypertrophic effects involves inhibition of the ROCK-MLC pathway.
authors.affiliation: Research Center for Drug Discovery Technology, Korea Research Institute of Chemical Technology, Daejeon 305-343, Republic of Korea.
authors.forename: Mun Sun
authors.initials: MS
authors.lastname: Kim
authors.forename: Kwang-Seok
authors.initials: KS
authors.lastname: Oh
authors.forename: Jeong Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Shi Yong
authors.initials: SY
authors.lastname: Ryu
authors.forename: Jihye
authors.initials: J
authors.lastname: Mun
authors.forename: Byung Ho
authors.initials: BH
authors.lastname: Lee
mesh_terms: D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D003374:Coumarins / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D006984:Hypertrophy; D020128:Inhibitory Concentration 50; D010766:Phosphorylation; D051381:Rats; D012717:Sesquiterpenes / Q000494:pharmacology*; D022502:Stress Fibers / Q000378:metabolism*; D054460:rho-Associated Kinases / Q000378:metabolism*
chemical_list: C584449:7-((4-hydroxy-1,2,4a,5-tetramethyl-6-oxo-3,4,5,7,8,8a-hexahydro-2H-naphthalen-1-yl)methoxy)chromen-2-one; D003374:Coumarins; D012717:Sesquiterpenes; D000804:Angiotensin II; C515852:ROCK2 protein, human; C580818:ROCK2 protein, rat; D054460:rho-Associated Kinases
keywords: Actin stress fiber; Ang II; Angiotensin II; Cellular hypertrophy; DMEM; Dulbecco’s modified Eagle’s medium; IMAP; Kamolonol; MLC; MYPT; ROCK; Rho-associated kinase; TR-FRET; angiotensin II; immobilized metal affinity for phosphochemicals; myosin light chain; myosin phosphatase; time-resolved fluorescence resonance energy transfer