Role of mitochondrial respiratory chain complex III in high glucose peritoneal dialysate-induced hyperpermeability of HPMCs.
BACKGROUND
High-glucose-based peritoneal dialysis solution (PDS) is considered to be one of the primary causes for the increase of ionic permeability in peritoneum as detected by transmesothelial electrical resistance (TER) measurements and claudin-1 expression. However, the mechanism is not clear. The aim of this study is to test the hypothesis that high-glucose PDS induces hyperpermeability in human peritoneal mesothelial cell (HPMC) monolayer by mitochondrial respiratory chain complex III pathway.


METHODS
HPMCs were cultured in a 1 : 1 mix of Dulbecco's modified Eagle's medium (DMEM) and PDS containing 1.5% and 4.25% glucose for 24 h. A 1 : 1 mixture of 160 mg/L glutathione and 4.25% glucose PDS was also added as an antioxidant group. TER measurement and immunostaining and western blot analysis of claudin-1 expression were examined for detection of permeability damage in HPMCs. MitoSOX™ Red staining and respiratory chain complexes' activities were determined for detection of mitochondrial reactive oxygen species (ROS) production and mitochondrial complexes' activities.


RESULTS
TER decreased in a time- and concentration-dependent manner after culture with high-glucose PDS for 24 h. Claudin-1 was also downregulated. Complex III activity was inhibited accompanied by increasing mitochondrial ROS generation. These changes were partially prevented by glutathione.


CONCLUSIONS
These findings demonstrate that mitochondrial respiratory complex III pathway has crucial importance in maintaining permeability of HPMCs, which might reveal a valuable target for novel therapies to fight hyperpermeability of peritoneum during the prolonged PD treatment.
Zhu
Xuejing
X
Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, Hunan, PR China.
Ling
Guanghui
G
Xiao
Li
L
Liu
Yinhong
Y
Duan
Shaobin
S
Peng
Youming
Y
Kanwar
Yashpal S
YS
Sun
Lin
L
Liu
Fuyou
F
D002460:Cell Line; D062445:Claudin-1; D017097:Electric Impedance; D014450:Electron Transport Complex III / Q000378:metabolism*; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005947:Glucose / Q000009:adverse effects*; D005978:Glutathione / Q000494:pharmacology; D015312:Hemodialysis Solutions / Q000009:adverse effects*; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D010530:Peritoneal Dialysis; D010537:Peritoneum / Q000187:drug effects* / Q000378:metabolism; D010539:Permeability / Q000187:drug effects
C568108:CLDN1 protein, human; D062445:Claudin-1; D015312:Hemodialysis Solutions; D008565:Membrane Proteins; D014450:Electron Transport Complex III; D005978:Glutathione; D005947:Glucose