title: A purified extract from Clematis mandshurica prevents staurosporin-induced downregulation of 14-3-3 and subsequent apoptosis on rat chondrocytes.
abstract: 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.
authors.affiliation: Department of Rheumatology, Dong-A University College of Medicine and Medical Science Research Center, 3-1 Dongdaesin-Dong, Seo-Gu, Busan, South Korea.
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Sun Mee
authors.initials: SM
authors.lastname: Choi
authors.forename: Yun Suk
authors.initials: YS
authors.lastname: Chang
authors.forename: Kyung Taek
authors.initials: KT
authors.lastname: Kim
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
authors.forename: Hwan Tae
authors.initials: HT
authors.lastname: Park
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Park
authors.forename: You Jeong
authors.initials: YJ
authors.lastname: Sohn
authors.forename: Soo Kyung
authors.initials: SK
authors.lastname: Park
authors.forename: Su Hyun
authors.initials: SH
authors.lastname: Cho
authors.forename: Won Tae
authors.initials: WT
authors.lastname: Chung
authors.forename: Young Hyun
authors.initials: YH
authors.lastname: Yoo
mesh_terms: 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
chemical_list: D048948:14-3-3 Proteins; D010936:Plant Extracts; D019311:Staurosporine