title: [Role of hydrogen gas in regulating of poly (ADP-ribose) polymerase-1 dependent cell death in rat Schwann cells].
abstract: OBJECTIVE
  To investigate the protective effects and underlying molecular mechanisms of hydrogen (H2) on high glucose-induced poly (ADP-ribose) polymerase-1 (PARP-1) dependent cell death (PARthanatos) in primary rat Schwann cells.
  
  
  METHODS
  Cultured primary rat Schwann cells were randomly divided into five groups: blank control group (C group), H2 control group (H2 group), high osmotic control group (M group), high glucose treatment group (HG group), and H2 treatment group (HG+H2 group). The cells in H2 group and HG+H2 group were cultured with saturated hydrogen-rich medium containing 0.6 mmol/L of H2, and those in three control groups were cultured with low sugar DMEM medium containing 5.6 mmol/L of sugar, and the cells in HG and HG+H2 groups were given 44.4 mmol/L of glucose in addition (the medium containing 50 mmol/L of glucose), the cells in C group and H2 group were given the same volume of normal saline, and the cells in M group were given the same volume of mannitol. Cytotoxicity was evaluated using lactate dehydrogenase (LDH) release rate assays after treatment for 48 hours in each group. The contents of peroxynitrite (ONOO(-)) and 8-hydroxy-2-deoxyguanosine (8-OHdG) reflecting oxidative stress injury and DNA damage were detected by enzyme linked immunosorbent assay (ELISA). Poly (ADP-ribose) (PAR) protein expression was analyzed by Western Blot, and immunofluorescence staining was used to determine the nuclear translocation of the apoptosis-inducing factor (AIF).
  
  
  RESULTS
  The cytotoxicity in HG and HG+H2 groups was significantly increased as compared with that of C group [LDH release rate: (61.40±2.89)%, (42.80±2.32)% vs. (9.92±0.38)%, both P < 0.01], the levels of ONOO(-) and 8-OHdG were markedly elevated [ONOO(-) (ng/L): 853.58±51.00, 553.11±38.66 vs. 113.56±14.22; 8-OHdG (ng/L): 1?177.37±60.97, 732.06±54.29 vs. 419.67±28.77, all P < 0.01], and the PAR protein expression was up-regulated (A value: 0.603±0.028, 0.441±0.010 vs. 0.324±0.021, both P < 0.01). The cytotoxicity, the levels of ONOO(-) and 8-OHdG, and PAR expression in HG+H2 group were significantly lower than those of the HG group (all P < 0.01). There were no significant differences in above parameters between H2 group as well as M group and C group. It was shown by immunofluorescence that AIF was expressed in the cytoplasm in C group, H2 group and M group, AIF was expressed in the whole cell in HG group, and the expression in the nucleus was particularly increased. A small amount of AIF expression was found in the nucleus of HG+H2 group, which indicated that high glucose could promote the AIF nuclear translocation, and that hydrogen-rich medium could prevent the process of translocation.
  
  
  CONCLUSIONS
  High glucose levels could enhance DNA damage that enhance PARthanatos in primary rat Schwann cells. However, H2 can not only reduce DNA damage of injured cells, but also inhibit the special death process, reduce the cell toxicity, all of which have protective effects.
authors.affiliation: Department of Anesthesiology, General Hospital of Tianjin Medical University, Tianjin Institute of Anesthesiology, Tianjin 300052, China (Yu Y, Jiao Y, Ma XY, Yang T, Xie KL, Yu YH); Department of Anesthesiology, the Second Hospital of Tianjin Medical University, Tianjin 300211, China (Li B). Corresponding author: Yu Yonghao, Email: yuyonghao@126.com.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.forename: Yang
authors.initials: Y
authors.lastname: Jiao
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Xiaoye
authors.initials: X
authors.lastname: Ma
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.forename: Keliang
authors.initials: K
authors.lastname: Xie
authors.forename: Yonghao
authors.initials: Y
authors.lastname: Yu
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D051033:Apoptosis Inducing Factor / Q000378:metabolism; D016923:Cell Death; D002478:Cells, Cultured; D003470:Culture Media / Q000737:chemistry; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005947:Glucose / Q000009:adverse effects; D006859:Hydrogen / Q000737:chemistry*; D018384:Oxidative Stress; D030421:Peroxynitrous Acid / Q000378:metabolism; D000071137:Poly (ADP-Ribose) Polymerase-1 / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D012583:Schwann Cells / Q000166:cytology / Q000187:drug effects*
chemical_list: C494831:Aifm1 protein, rat; D051033:Apoptosis Inducing Factor; D003470:Culture Media; D030421:Peroxynitrous Acid; D006859:Hydrogen; D000080242:8-Hydroxy-2'-Deoxyguanosine; C499322:Parp1 protein, rat; D000071137:Poly (ADP-Ribose) Polymerase-1; D003849:Deoxyguanosine; D005947:Glucose