A purified extract from Clematis mandshurica prevents staurosporin-induced downregulation of 14-3-3 and subsequent apoptosis on rat chondrocytes.
OBJECTIVE
To dissect the mechanism of the protection of staurosporin-induced apoptosis on rat chondrocytes by a purified extract from Clematis mandshurica.


METHODS
Primary cultured rat articular chondrocytes as well as RCJ3.1C.18 cells were incubated with 1 microM staurosporin and 300 microg/ml purified extract from Clematis mandshurica. Western blot assay, silencing 14-3-3 gene and immunoprecipitation were conducted.


RESULTS
Clematis mandshurica prevented staurosporin-induced downregulation of several antiapoptotic bcl-2 family proteins Bcl-xL and Bcl-2, and staurosporin-induced upregulation of an apoptotic bcl-2 family protein Bax. Clematis mandshurica also prevented staurosporin-induced downregulation of a premitochondrial antiapoptotic protein 14-3-3. It is noticeable that siRNA to 14-3-3 abolished the prevention of caspase-3 activation by Clematis mandshurica. Furthermore viability assay corroborated that silencing of 14-3-3 gene abolished this apoptosis protection efficacy by Clematis mandshurica. Immunoprecipitation assay elucidated that Clematis mandshurica prevented the staurosporin-induced reduction of the interactions between 14-3-3 with phospho-ser112-Bad and Bcl-xL to phospho-ser155-Bad.


CONCLUSIONS
Clematis mandshurica prevents staurosporin-induced apoptosis of rat chondrocytes via 14-3-3.
Lee
Sung Won
SW
Department of Rheumatology, Dong-A University College of Medicine and Medical Science Research Center, 3-1 Dongdaesin-Dong, Seo-Gu, Busan, South Korea.
Choi
Sun Mee
SM
Chang
Yun Suk
YS
Kim
Kyung Taek
KT
Kim
Tae Hyun
TH
Park
Hwan Tae
HT
Park
Bong Soo
BS
Sohn
You Jeong
YJ
Park
Soo Kyung
SK
Cho
Su Hyun
SH
Chung
Won Tae
WT
Yoo
Young Hyun
YH
D048948:14-3-3 Proteins / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002358:Cartilage, Articular / Q000166:cytology; D018929:Cell Culture Techniques; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects*; D039324:Clematis / Q000737:chemistry*; D015536:Down-Regulation / Q000187:drug effects; D005270:Femur Head / Q000166:cytology; D006811:Humerus / Q000166:cytology; D010936:Plant Extracts / Q000302:isolation & purification* / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019311:Staurosporine / Q000494:pharmacology
D048948:14-3-3 Proteins; D010936:Plant Extracts; D019311:Staurosporine