Abstract 494: P21 Plays a Protective Role Against Renal Ischemia Reperfusion Injury and is an Essential Factor for Ischemic Preconditioning

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Satoshi Nishioka ◽  
Daisuke Nakano ◽  
Kento Kitada ◽  
Hiroyuki Ohosaki ◽  
Tadashi Sofue ◽  
...  
Keyword(s):  
Ischemic Preconditioning ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Protective Role ◽  
Renal Ischemia ◽  
Histological Changes ◽  
Sham Surgery ◽  
Life Threatening

Background: We previously reported that various pathological conditions including high blood pressure increase p21 expression in the kidney; however, the functional importance of renal p21 up-regulation has not been clarified yet. In the present study, we evaluated the role of p21 in acute kidney injury, a life-threatening disease that can occur independently of the pathological background of patients (whether renal p21 is up-regulated or not). Methods and Results: The mice lacking functional p21 (p21-KO, n=9) and its wild-type control (WT, n=7) underwent a 45-min renal ischemia followed by a 24-h reperfusion (I/R). I/R significantly increased both mRNA expression and nuclear immunoreactivity of p21 in the kidney of WT compared with sham surgery (p21/β-actin, 1.28±0.23 vs. 0.57±0.15, respectively, P<0.05). I/R injury analyzed by blood urea nitrogen (BUN) and kidney histological changes were exacerbated in p21-KO mice (BUN: WT; 103.8±4.6 mg/dL, p21-KO; 127.7±5.2 mg/dL, P<0.05). The results suggest that p21 plays a protective role against I/R injury. Therefore, we next examined whether p21 is also associated with the protective effect of ischemic preconditioning (IPC), which is an established method of attenuating the I/R injury. IPC (4 sets of a 5-min ischemia and a 5-min reperfusion) clearly improved the I/R injury in WT (BUN: sham; 87.7±22.0 mg/dL, IPC; 39.0±2.3 mg/dL, n=3 and n=7, respectively, P<0.05), whereas there was no difference in the I/R injury in p21-KO mice (BUN: sham; 136.5±13.6 mg/dL, IPC; 127.9±6.9 mg/dL, n=5 and n=8, respectively). IPC increased the renal expression of p21 prior to I/R compared with sham surgery (p21/β-actin: 1.07±0.08 vs. 0.26±0.05 fold, respectively, P<0.05). Conclusion: Renal p21 plays a protective role against I/R injury and is necessary for the beneficial effect of renal IPC.

scholarly journals Protective role of extracellular superoxide dismutase in renal ischemia/reperfusion injury

2010 ◽  
Vol 78 (4) ◽  
pp. 374-381 ◽  
Author(s):  
Markus P. Schneider ◽  
Jennifer C. Sullivan ◽  
Paul F. Wach ◽  
Erika I. Boesen ◽  
Tatsuo Yamamoto ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Protective Role ◽  
Renal Ischemia ◽  
Extracellular Superoxide Dismutase ◽  
Renal Ischemia Reperfusion Injury

Loss of clusterin expression worsens renal ischemia-reperfusion injury

2010 ◽  
Vol 298 (3) ◽  
pp. F568-F578 ◽  
Author(s):  
Wenjun Zhou ◽  
Qiunong Guan ◽  
Chris C. H. Kwan ◽  
Huifang Chen ◽  
Martin E. Gleave ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Clinical Care ◽  
Kidney Injury ◽  
Protective Role ◽  
Experimental Models ◽  
Novel Therapy ◽  
Clusterin Expression

Prevention of ischemia-reperfusion injury (IRI) is a challenge in clinical care of the patients with kidney transplants or acute kidney injury, and understanding of the intrinsic mechanisms of resistance to injury in the kidney will lead to a novel therapy. Clusterin, a secreted glycoprotein, is an antiapoptotic protein in cancer cells. Our study is to investigate the role of clusterin in renal IRI. Renal IRI in mice was induced by clamping renal vein and artery for 45 or 50 min at 32°C. Apoptosis of renal tubular epithelial cells (TECs) was determined by FACS analysis. Clusterin expression was examined by Western blot or immunohistochemistry. Here, we showed that clusterin protein was induced in TECs following IRI, and more tubules expressed clusterin in the kidneys following ischemia at higher temperatures. In human proximal TEC HKC-8 cultures, clusterin was upregulated by removal of serum and growth factors in medium and was downregulated by TNF-α-IFN-γ mixture. The levels of clusterin were positively correlated with cell survival in these conditions. Knockdown or knockout of clusterin expression enhanced the sensitivity of TECs to apoptosis. In experimental models of renal IRI, deficiency in clusterin expression worsened the injury, as indicated by a significant increase in renal tissue damage with higher levels of serum creatinine and blood urea nitrogen and by a poorer recovery from the injury in clusterin-deficient mice compared with wild-type mice. Our data indicate that the reduction of inducible expression of clusterin results in an increase in TEC apoptosis in the cultures and renders mice susceptibility to IRI, implying a protective role of clusterin in kidney injury.

scholarly journals c-MYC-induced long noncoding RNA MEG3 aggravates kidney ischemia–reperfusion injury through activating mitophagy by upregulation of RTKN to trigger the Wnt/β-catenin pathway

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Dajun Liu ◽  
Ying Liu ◽  
Xiaotong Zheng ◽  
Naiquan Liu
Keyword(s):  
Reperfusion Injury ◽  
Noncoding Rna ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
In Vitro Models ◽  
Downstream Effector ◽  
Life Threatening

AbstractIschemia–reperfusion injury (IRI)-induced acute kidney injury (AKI) is a life-threatening disease. The activation of mitophagy was previously identified to play an important role in IRI. Maternally expressed 3 (MEG3) can promote cerebral IRI and hepatic IRI. The present study was designed to study the role of MEG3 in renal IRI. Renal IRI mice models were established, and HK-2 cells were used to construct the in vitro models of IRI. Hematoxylin–eosin staining assay was applied to reveal IRI-triggered tubular injury. MitoTracker Green FM staining and an ALP kit were employed for detection of mitophagy. TdT-mediated dUTP-biotin nick-end labeling assay was used to reveal cell apoptosis. The results showed that renal cortex of IRI mice contained higher expression of MEG3 than that of sham mice. MEG3 expression was also elevated in HK-2 cells following IRI, suggesting that MEG3 might participate in the development of IRI. Moreover, downregulation of MEG3 inhibited the apoptosis of HK-2 cells after IRI. Mitophagy was activated by IRI, and the inhibition of MEG3 can restore mitophagy activity in IRI-treated HK-2 cells. Mechanistically, we found that MEG3 can bind with miR-145-5p in IRI-treated cells. In addition, rhotekin (RTKN) was verified to serve as a target of miR-145-5p. MEG3 upregulated RTKN expression by binding with miR-145-5p. Further, MEG3 activated the Wnt/β-catenin pathway by upregulation of RTKN. The downstream effector of Wnt/β-catenin pathway, c-MYC, served as the transcription factor to activate MEG3. In conclusion, the positive feedback loop of MEG3/miR-145-5p/RTKN/Wnt/β-catenin/c-MYC promotes renal IRI by activating mitophagy and inducing apoptosis, which might offer a new insight into the therapeutic methods for renal IRI in the future.

scholarly journals Ischemic Preconditioning Promotes Autophagy and Alleviates Renal Ischemia/Reperfusion Injury

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Ying Xie ◽  
Jing Xiao ◽  
Chensheng Fu ◽  
Zhenxing Zhang ◽  
Zhibin Ye ◽  
...  
Keyword(s):  
Ischemic Preconditioning ◽  
Caspase 3 ◽  
Cell Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Renal Ischemia ◽  
Beclin 1 ◽  
Autophagic Flux ◽  
Dependent Manner

Autophagy is important for cellular survival during renal ischemia/reperfusion (I/R) injury. Ischemic preconditioning (IPC) has a strong renoprotective effect during renal I/R. Our study here aimed to explore the effect of IPC on autophagy during renal I/R injury. Rats were subjected to unilateral renal ischemia with or without prior IPC. Hypoxia/reoxygenation (H/R) injury was induced in HK-2 cells with or without prior hypoxic preconditioning (HPC). Autophagy and apoptosis were detected after reperfusion or reoxygenation for different time. The results showed that the levels of LC3II, Beclin-1, SQSTM1/p62, and cleaved caspase-3 were altered in a time-dependent manner during renal I/R. IPC further induced autophagy as indicated by increased levels of LC3II and Beclin-1, decreased level of SQSTM1/p62, and accumulation of autophagosomes compared to I/R groups at corresponding reperfusion time. In addition, IPC reduced the expression of cleaved caspase-3 and alleviated renal cell injury, as evaluated by the levels of serum creatinine (Scr), neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) in renal tissues. In conclusion, autophagy and apoptosis are dynamically altered during renal I/R. IPC protects against renal I/R injury and upregulates autophagic flux, thus increasing the possibility for a novel therapy to alleviate I/R-induced acute kidney injury (AKI).

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