title: Hyperbaric oxygen preconditioning inhibits skin flap apoptosis in a rat ischemia-reperfusion model.
abstract: BACKGROUND
  Hyperbaric oxygen (HBO) improves skin flap function and inhibits partial necrosis induced by ischemia-reperfusion (I/R) injury. Our study aimed to evaluate the mechanism underlying HBO regulation of the antiapoptosis factors associated with I/R injury of skin flaps.
  
  
  METHODS
  The rats were divided into sham surgery, I/R, and HBO groups. Rats from the HBO group received HBO preconditioning followed by I/R surgery. Blood perfusion of the skin flaps was measured with laser Doppler flowmeters. Tissue morphology and apoptosis were subsequently assessed based on hematoxylin-eosinhe and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining. Protein expression of phosphorylated apoptosis signal-regulating kinase 1 (pASK-1), phosphorylated c-Jun N-terminal kinase (pJNK), B-cell lymphoma-2 (Bcl-2), and Bcl2-associated X protein (Bax) was examined by immunodetection, and Bcl-2 messenger RNA expression was detected by quantitative polymerase chain reaction. In addition, caspase-3 activity was also measured.
  
  
  RESULTS
  The result of microcirculation analysis showed that the survival and blood perfusion rates significantly increased in the skin flap after HBO exposure. Terminal deoxynucleotidyl transferase dUTP nick-end labeling staining revealed that cell apoptosis was significantly attenuated in the HBO group. Furthermore, HBO preconditioning increased the expression of Bcl-2 and inhibited pASK-1, pJNK, and Bax expression as determined by both immunohistochemistry and Western blot. Caspase-3 activity and the Bax/Bcl-2 ratio declined in the HBO group.
  
  
  CONCLUSIONS
  HBO preconditioning effectively ameliorates I/R injury by regulating the apoptosis signal-regulating kinase 1 and/or c-Jun N-terminal kinase pathway and anti- and proapoptosis factors.
authors.affiliation: Department of Plastic Surgery, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Yi-Ding
authors.initials: YD
authors.lastname: Xiao
authors.affiliation: College of Life Sciences and Bioengineering, Beijing University of Technology, Beijing, China.
authors.forename: Yun-Qi
authors.initials: YQ
authors.lastname: Liu
authors.affiliation: College of Life Sciences and Bioengineering, Beijing University of Technology, Beijing, China.
authors.forename: Jia-La
authors.initials: JL
authors.lastname: Li
authors.affiliation: College of Life Sciences and Bioengineering, Beijing University of Technology, Beijing, China. Electronic address: xmma@bjut.edu.cn.
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Ma
authors.affiliation: Department of Plastic Surgery, Peking Union Medical College Hospital, Beijing, China. Electronic address: wybenz@sina.com.
authors.forename: You-Bin
authors.initials: YB
authors.lastname: Wang
authors.affiliation: College of Life Sciences and Bioengineering, Beijing University of Technology, Beijing, China.
authors.forename: Yi-Fang
authors.initials: YF
authors.lastname: Liu
authors.affiliation: Department of Plastic Surgery, Peking Union Medical College Hospital, Beijing, China.
authors.forename: Ming-Zi
authors.initials: MZ
authors.lastname: Zhang
authors.affiliation: College of Life Sciences and Bioengineering, Beijing University of Technology, Beijing, China.
authors.forename: Peng-Xiang
authors.initials: PX
authors.lastname: Zhao
authors.affiliation: College of Life Sciences and Bioengineering, Beijing University of Technology, Beijing, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Xie
authors.affiliation: College of Life Sciences and Bioengineering, Beijing University of Technology, Beijing, China.
authors.forename: Zi-Xuan
authors.initials: ZX
authors.lastname: Deng
mesh_terms: D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D004195:Disease Models, Animal; D006931:Hyperbaric Oxygenation; D019194:Ischemic Preconditioning / Q000379:methods*; D048848:MAP Kinase Kinase Kinase 5 / Q000378:metabolism; D008297:Male; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D012867:Skin / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D048848:MAP Kinase Kinase Kinase 5; C505410:Casp3 protein, rat; D053148:Caspase 3
keywords: Apoptosis; Hyperbaric oxygen; Ischemia–reperfusion; Skin flaps