Mechanism of reduction of protection induced by hypoxic postconditioning in diabetic myocardiocytes subjected to hypoxia-reoxygenation: the relationship with DJ-1 expression
10.3760/cma.j.issn.0254-1416.2016.04.030
- VernacularTitle:缺氧后处理对糖尿病性心肌细胞缺氧复氧时保护作用削弱的机制:与DJ-1表达的关系
- Author:
Bin ZHOU
;
Zhongyuan XIA
;
Bo ZHAO
;
Qian SUN
;
Rui XUE
;
Min LIU
- Publication Type:Journal Article
- Keywords:
Anoxia;
Ischemic postconditioning;
Diabetes mellitus;
Myocytes,cardiac;
Reperfusion injury;
Intracellular signaling petides and proteins
- From:
Chinese Journal of Anesthesiology
2016;36(4):495-497
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the mechanism of reduction of protection induced by hypoxic postconditioning (HPO) in diabetic myocardiocytes subjected to hypoxia-reoxygenation (H/R),and the relationship with DJ-1 expression.Methods H9c2 cells cultured in normal culture atmosphere were randomly divided into 6 groups (n=36 each) using a random number table:control group (group C),group H/R,group HPO,plasmid carrying DJ-1 gene transfection group (group D),plasmid carrying DJ-1 gene transfection + H/R group (group DH),and plasmid carrying DJ-1 gene transfection + H/R + HPO group (group DHH).H/R was induced by 4 h of hypoxia followed by 2 h of reoxygenation.H9c2 cells were cultured in high glucose culture medium (30 mmol/L) for 48 h in C,H/R and HPO groups.H/R model was established in H/R and HPO groups.HPO was induced by 3 cycles of 5 min reoxygenation and 5 min hypoxia before the onset of reoxygenation in group HPO.In D,DH and DHH groups,the plasmid carrying DJ-1 gene (pEX-2-EGFP-DJ-1) was transfected into the cells,and then the cells were cultured in high glucose culture medium and subjected to H/R and HPO,respectively.At 2 h of reoxygenation,the cell survival rate was measured using the cell counting kit-8 assay,and the level of lactate dehydrogenase (LDH) in the supernatant was detected by enzyme-linked immunosorbent assay,the autophagosomes were examined with a transmission electron microscope,and the expression of DJ-1 and p62 and ratio of microtubule-associated protein 1 light chain 3 Ⅱ / Ⅰ (LC3 Ⅱ / Ⅰ) in cells were detected by Western blot.Results Compared with group C,the cell survival rate and DJ-1 expression were significantly decreased,and the LDH activity was significantly increased in H/R and HPO groups (P＜0.01).There was no significant difference in the parameters mentioned above between H/R and HPO groups (P＞0.05).Compared with group D,the cell survival rate was significantly decreased,and the LDH activity was significantly increased in group DH (P＜0.01).Compared with group DH,the cell survival rate,the number of autophagosomes and LC3 Ⅱ / Ⅰ ratio were significantly increased,and the LDH activity and p62 expression were significantly decreased in group DHH (P＜0.01).There was no significant difference in the parameters mentioned above between H/R and DH groups (P＞0.05).Conclusion The mechanism of reduction of protection induced by HPO in diabetic myocardiocytes subjected to H/R is related to high glucose-induced inhibition of DJ-1 expression and decrease in autophagy.
