[Role of Omi/HtrA2 in renal tubular cells apoptosis induced by post asphyxial serum of neonate].
OBJECTIVE
To investigate the mechanism of inducing apoptosis of Omi/HtrA2 in renal tubular cells with post asphyxial serum of neonate.


METHODS
Human renal proximal tubular cell line HK-2 cell was used as target cell. They were divided into three groups: control group, asphyxia group and Ucf-101 (Omi/HtrA2 special inhibitor) treated group. The challenge concentration of serum obtained from neonates 24 hours after asphyxia was 20%, and the treatment concentration of Ucf-101 was 10 mumol/L. The Omi/HtrA2 translocation in renal tubular cells was observed with confocal microscopy, and the rate of apoptosis was detected with flow cytometer.


RESULTS
It was found that Omi/HtrA2 was translocated into cytoplasm in asphyxia group, and the rate of Omi/HtrA2 translocation in HK-2 cells of asphyxia group was significantly increased [(28.1+/-3.6)% vs. (9.4+/-2.1)%, P<0.01]. Compared with the control group, after being treated with post asphyxial serum, the rate of apoptosis of HK-2 cells in asphyxia group was significantly increased [(36.3+/-4.4)% vs.(12.4+/-2.9)%, P<0.01]. Compared with asphyxia group, the rate of apoptosis in HK-2 cells in Ucf-101 treated group was significantly decreased [(27.0+/-3.9)% vs.(36.3+/-4.4)%, P<0.01].


CONCLUSIONS
These experimental data demonstrates that post asphyxial serum of neonate can induce apoptosis of HK-2 cells, and translocation of Omi/HtrA2 from mitochondria into cytoplasm may play an important role in its intracellular signal transduction mechanism in induction of apoptosis.
Zhang
Yong
Y
Department of Newborn Medicine, Affiliated Hospital of Luzhou Medical College, Luzhou 646000, Sichuan, China.
Dong
Wen-bin
WB
Li
Qing-ping
QP
Deng
Cun-liang
CL
Xiong
Tao
T
Lei
Xiao-ping
XP
Guo
Lin
L
D017209:Apoptosis; D001238:Asphyxia Neonatorum; D002460:Cell Line; D003593:Cytoplasm / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D000074923:High-Temperature Requirement A Serine Peptidase 2; D006801:Humans; D007231:Infant, Newborn; D007687:Kidney Tubules, Proximal / Q000166:cytology*; D008928:Mitochondria / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D021381:Protein Transport; D011744:Pyrimidinones / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000378:metabolism / Q000502:physiology*; D044967:Serum; D015398:Signal Transduction; D013871:Thiones / Q000494:pharmacology
D024101:Mitochondrial Proteins; D011744:Pyrimidinones; D013871:Thiones; C501517:UCF 101; D012697:Serine Endopeptidases; C000615914:HTRA2 protein, human; D000074923:High-Temperature Requirement A Serine Peptidase 2