Nox4 and Oxidative Stress Mediate TGF-β1 Induced Human Kidney Proximal Cell Apoptosis in Ischemic Reperfusion Injury.
1Internal Medicine, Konyang University, Deajeon, Republic of Korea
2Pharmacology, Konyang University, Daejeon, Republic of Korea
Meeting: 2017 American Transplant Congress
Abstract number: A162
Keywords: Ischemia, NADPH oxidase, Reactive oxygen species, Transforming growth factor-beta (TGF-b)
Session Information
Session Name: Poster Session A: Ischemic Injury and Organ Preservation Session I
Session Type: Poster Session
Date: Saturday, April 29, 2017
Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Hall D1
Aims
Ischemia/reperfusion injury, resulting from hypoxic damage within a graft, is the leading cause of cell death and graft rejection. In this study, we investigated whether Nox4 have a great role in ischemic injury in a cellular model in which experimental hypoxia was induced using CoCl2
Main methods
The ischemic injury induced in HK-2 cells by CoCl2 was validated by reduced cell viability at different times and doses. Reverse transcription polymerase chain reaction for Nox4 and TGF-β1 was performed. Western blotting for Nox4 and Smad pathway were done. ROS production was detected using a DHE stain and Amplex red assay. HK-2 cells were transfected with siNox4 and pretreated with GKT137831(most specific Nox1/4 inhibitor). ELISA has been used to measure TGF-β1 levels. The effect of treatment with TGF-β1 type 1 tyrosine kinase inhibitor SB431542 on Nox4 expression was observed.
Results
Expression of Nox4 in HK-2 cells significantly increased by hypoxic stimulation. TGF-β1 was secreted endogenously by hypoxic HK-2 cells. SB4315432 significantly inhibited Nox4 expression in HK-2 cells via Smad2/3 dependent cell signaling pathway. Silencing of Nox4 recued production of reactive oxygen species (ROS), downregulation of proinflammatory markers and reduced caspase 3/7 activity in hypoxic HK-2 cells. Pretreatment of GKT137831 replicated theses results.
Conclusions
Hypoxia induces HK-2 cell apoptosis through the signaling pathway involving Nox4 dependent ROS generation and TGF-β1 via Smad pathway. Therapies targeting Nox4 may be effective against ischemia induced graft kidney injury.
CITATION INFORMATION: Yoon S.-H, Cho S, Kim D.-I, Yoon S.-R, Hwang W.-M, Yu S.-L, Kang J. Nox4 and Oxidative Stress Mediate TGF-β1 Induced Human Kidney Proximal Cell Apoptosis in Ischemic Reperfusion Injury. Am J Transplant. 2017;17 (suppl 3).
To cite this abstract in AMA style:
Yoon S-H, Cho S, Kim D-I, Yoon S-R, Hwang W-M, Yu S-L, Kang J. Nox4 and Oxidative Stress Mediate TGF-β1 Induced Human Kidney Proximal Cell Apoptosis in Ischemic Reperfusion Injury. [abstract]. Am J Transplant. 2017; 17 (suppl 3). https://atcmeetingabstracts.com/abstract/nox4-and-oxidative-stress-mediate-tgf-1-induced-human-kidney-proximal-cell-apoptosis-in-ischemic-reperfusion-injury/. Accessed May 27, 2025.« Back to 2017 American Transplant Congress