scholarly journals miR-204 regulates epithelial-mesenchymal transition by targeting SP1 in the tubular epithelial cells after acute kidney injury induced by ischemia-reperfusion

2016 ◽  
Vol 37 (2) ◽  
pp. 1148-1158 ◽  
Author(s):  
Shun-Jie Chen ◽  
Ping Wu ◽  
Li-Jing Sun ◽  
Bo Zhou ◽  
Wei Niu ◽  
...  
2020 ◽  
Vol 134 (21) ◽  
pp. 2873-2891
Author(s):  
Sarah W.Y. Lok ◽  
Wai Han Yiu ◽  
Hongyu Li ◽  
Rui Xue ◽  
Yixin Zou ◽  
...  

Abstract Protease-activated receptor (PAR)-1 has emerged as a key profibrotic player in various organs including kidney. PAR-1 activation leads to deposition of extracellular matrix (ECM) proteins in the tubulointerstitium and induction of epithelial–mesenchymal transition (EMT) during renal fibrosis. We tested the anti-fibrotic potential of vorapaxar, a clinically approved PAR-1 antagonist for cardiovascular protection, in an experimental kidney fibrosis model of unilateral ureteral obstruction (UUO) and an AKI-to-chronic kidney disease (CKD) transition model of unilateral ischemia–reperfusion injury (UIRI), and dissected the underlying renoprotective mechanisms using rat tubular epithelial cells. PAR-1 is activated mostly in the renal tubules in both the UUO and UIRI models of renal fibrosis. Vorapaxar significantly reduced kidney injury and ameliorated morphologic changes in both models. Amelioration of kidney fibrosis was evident from down-regulation of fibronectin (Fn), collagen and α-smooth muscle actin (αSMA) in the injured kidney. Mechanistically, inhibition of PAR-1 inhibited MAPK ERK1/2 and transforming growth factor-β (TGF-β)-mediated Smad signaling, and suppressed oxidative stress, overexpression of pro-inflammatory cytokines and macrophage infiltration into the kidney. These beneficial effects were recapitulated in cultured tubular epithelial cells in which vorapaxar ameliorated thrombin- and hypoxia-induced TGF-β expression and ECM accumulation. In addition, vorapaxar mitigated capillary loss and the expression of adhesion molecules on the vascular endothelium during AKI-to-CKD transition. The PAR-1 antagonist vorapaxar protects against kidney fibrosis during UUO and UIRI. Its efficacy in human CKD in addition to CV protection warrants further investigation.


Biology ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 48 ◽  
Author(s):  
Theodoros Eleftheriadis ◽  
Georgios Pissas ◽  
Georgia Antoniadi ◽  
Vassilios Liakopoulos ◽  
Ioannis Stefanidis

Ischemia–reperfusion injury contributes to the pathogenesis of many diseases, with acute kidney injury included. Hibernating mammals survive prolonged bouts of deep torpor with a dramatic drop in blood pressure, heart, and breathing rates, interspersed with short periods of arousal and, consequently, ischemia–reperfusion injury. Clarifying the differences under warm anoxia or reoxygenation between human cells and cells from a native hibernator may reveal interventions for rendering human cells resistant to ischemia–reperfusion injury. Human and hamster renal proximal tubular epithelial cells (RPTECs) were cultured under warm anoxia or reoxygenation. Mouse RPTECs were used as a phylogenetic control for hamster cells. Cell death was assessed by both cell imaging and lactate dehydrogenase (LDH) release assay, apoptosis by cleaved caspase-3, autophagy by microtubule-associated protein 1-light chain 3 B II (LC3B-II) to LC3B-I ratio, necroptosis by phosphorylated mixed-lineage kinase domain-like pseudokinase, reactive oxygen species (ROS) fluorometrically, and lipid peroxidation, the end-point of ferroptosis, by malondialdehyde. Human cells died after short periods of warm anoxia or reoxygenation, whereas hamster cells were extremely resistant. In human cells, apoptosis contributed to cell death under both anoxia and reoxygenation. Although under reoxygenation, ROS increased in both human and hamster RPTECs, lipid peroxidation-induced cell death was detected only in human cells. Autophagy was observed only in human cells under both conditions. Necroptosis was not detected in any of the evaluated cells. Clarifying the ways that are responsible for hamster RPTECs escaping from apoptosis and lipid peroxidation-induced cell death may reveal interventions for preventing ischemia–reperfusion-induced acute kidney injury in humans.


2020 ◽  
Vol 134 (13) ◽  
pp. 1593-1612
Author(s):  
Chia-Lin Wu ◽  
Chia-Chu Chang ◽  
Tao-Hsiang Yang ◽  
Alexander Charng-Dar Tsai ◽  
Jui-Lin Wang ◽  
...  

Abstract Transcriptional co-activator with PDZ-binding motif (TAZ) is a key downstream effector of the Hippo tumor-suppressor pathway. The functions of TAZ in the kidney, especially in tubular epithelial cells, are not well-known. To elucidate the adaptive expression, protective effects on kidney injury, and signaling pathways of TAZ in response to acute kidney injury (AKI), we used in vitro (hypoxia-treated human renal proximal tubular epithelial cells [RPTECs]) and in vivo (mouse ischemia–reperfusion injury [IRI]) models of ischemic AKI. After ischemic AKI, TAZ was up-regulated in RPTECs and the renal cortex or tubules. Up-regulation of TAZ in RPTECs subjected to hypoxia was controlled by IκB kinase (IKK)/nuclear factor κ-light-chain-enhancer of activated B cell (NF-κB) signaling. TAZ overexpression attenuated hypoxic and oxidative injury, inhibited apoptosis and activation of p38 and c-Jun N-terminal kinase (JNK) proteins, and promoted wound healing in an RPTEC monolayer. However, TAZ knockdown aggravated hypoxic injury, apoptosis, and activation of p38 and JNK signaling, delayed wound closure of an RPTEC monolayer, and promoted G0/G1 phase cell-cycle arrest. Chloroquine and verteporfin treatment produced similar results to TAZ overexpression and knockdown in RPTECs, respectively. Compared with vehicle-treated mice, chloroquine treatment increased TAZ in the renal cortex and tubules, improved renal function, and attenuated tubular injury and tubular apoptosis after renal IRI, whereas TAZ siRNA and verteporfin decreased TAZ in the renal cortex and tubules, deteriorated renal failure and tubular injury, and aggravated tubular apoptosis. Our findings indicate the renoprotective role of tubular TAZ in ischemic AKI. Drugs augmenting (e.g., chloroquine) or suppressing (e.g., verteporfin) TAZ in the kidney might be beneficial or deleterious to patients with AKI.


2020 ◽  
Vol 39 (12) ◽  
pp. 1628-1638 ◽  
Author(s):  
J-Y Zhao ◽  
X-L Wang ◽  
Y-C Yang ◽  
B Zhang ◽  
Y-B Wu

Acute kidney injury (AKI) is an independent risk factor for chronic kidney disease (CKD). However, the role and mechanism of microRNA (miRNA, miR) in AKI-CKD transition are elusive. In this study, a murine model of renal ischemia/reperfusion was established to investigate the repairing effect and mechanism of miR-101a-3p on renal injury. The pathological damage of renal tissue was observed by hematoxylin and eosin and Masson staining. The levels of miR-101, profibrotic cytokines, and epithelial–mesenchymal transition (EMT) markers were analyzed using Western blotting, real-time polymerase chain reaction, and/or immunofluorescence. MiR-101 overexpression caused the downregulation of α-smooth muscle actin, collagen-1, and vimentin, as well as upregulation of E-cadherin, thereby alleviating the degree of renal tissue damage. MiR-101 overexpression mitigated hypoxic HK-2 cell damage. Collagen, type X, alpha 1 and transforming growth factor β receptor 1 levels were downregulated in hypoxic cells transfected with miR-101 mimic. Our study indicates that miR-101 is an anti-EMT miRNA, which provides a novel therapeutic strategy for AKI-CKD transition.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Lin Wang ◽  
Yan Xu

Abstract Background and Aims Renal ischemia/reperfusion (I/R) is the main cause for acute kidney injury, Nicotiflorin can ameliorate ischemia/reperfusion injury in other organs, just like in cerebral ischemic damage. Therefore, this article intends to explore whether Nicotiflorin has protective effects on renal tubular epithelial cell after ischemia-reperfusion. On the one hand, We use C57 mice to establish the Nicotiflorin group, DMSO group, AKI group, sham group and control group to investigate whether Nicotiflorin can ameliorate ischemia-reperfusion injury of kidney. In other hand, we use CCK8 to explore the optimal concentration of Nicotiflorin in renal tubular epithelial cells and find optimal hypoxia oxygenation time, in order to analysis the influence of Nicotiflorin. The results indicate that Nicotiflorin can alleviate ischemia-reperfusion injury by reducing apoptosis of renal tubular epithelial cells. Method In this study, we investigated the protective mechanism of Nicotiflorin on ischemic acute kidney injury by analyzing gene chip in patients with acute kidney injury and proving in vitro and in vivo experiments. The main methods are as follows: (1) Multiple nucleus ischemia-reperfusion model transcriptase data were selected from the NCBI GEO Datasets database and analyzed to screen out related proteins that may be involved in ischemia-reperfusion kidney injury; (2) The tertiary structure of Nicotiflorin and related proteins was obtained from the SWISS-MODEL database and the PubChem compound database. The molecular docking between protein and Nicotiflorin was performed using Autodock software, and the binding energy between Nicotiflorin and the selected protein was analyzed to determine Nicotiflorin binds to each other; (3) We set different groups, such as control group, sham group, AKI group, Nicotiflorin group and DMSO group in animals. The blood function was used to detect renal injury related function indicators 24 hours after modeling. Renal tissue samples were collected for real-time fluorescent RT-PCR, Western blotting and histopathological analysis; (4)Renal tubular epithelial cells were treated with different concentrations of Nicotiflorin, CCK8 was screened for the most appropriate concentration, and the hypoxic and reoxygenated cells were intervened at the concentration to explore the interaction between Nicotiflorin and the docking protein, and to observe the protective mechanism of Nicotiflorin on the kidney Results Conclusion Nicotiflorin binds to ATF3 and promotes the expression of Cyr61 through protein interactions to improve renal ischemia-reperfusion injury.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Line Stattau Bisgaard ◽  
Pernille M Christensen ◽  
Ernst-Martin Füchtbauer ◽  
Lars Bo Nielsen ◽  
Christina Christoffersen

Abstract Background and Aims Acute kidney injury is a severe disease with detrimental outcomes. The underlying ethiology is still elusive and besides dialysis, treatment options are poor. Apolipoprotein M (apoM) is mainly expressed in liver and in proximal tubular epithelial cells in the kidney. In plasma, apoM associates with HDL particles via a retained signal peptide. ApoM is a carrier of sphingosine-1-phosphate (S1P), a small bioactive lipid involved in e.g. angiogenesis, lymphocyte trafficking, and vascular barrier function. Recently, it was shown that apoM/S1P protects against development of liver and lung fibrosis. In urine, apoM is normally undetectable in both wild type mice and healthy humans. However, lack of megalin receptors in proximal tubuli induces loss of apoM into the urine. The biological function of kidney-derived apoM is unknown, but it has been hypothesized that apoM might be secreted to the pre-urine to sequester molecules, such as S1P, from secretion. The aim of this study was to unravel the role of apoM in kidney biology and in acute kidney injury. Method A novel kidney specific human apoM transgenic mouse (RPTEC-hapoMTG), was generated by expressing human apoM under the control of the proximal tubular epithelial cell specific Sglt2 promoter. The effect of kidney specific apoM overexpression on acute kidney injury was accessed by inducing either cisplatin or ischemia/reperfusion injury. Further, a stable cell line of HK-2 cells overexpressing hapoM (HK-2hapoM-TG) was generated and the cells were cultured on transwells to assess the secretion of apoM to respectively the apical and basolateral site. Results hapoM was present in plasma from RPTEC-hapoMTG mice (mean 0.18 μM), indicating that kidney-derived apoM can be secreted to plasma. When assessing the secretion of hapoM from proximal tubular epithelial cells in vitro, studies support that apoM can be secreted to both the apical (urine) and basolateral (blood) compartment. No differences in kidney injury markers (plasma urea and creatinine) between RPTEC-hapoMTG and wild type (WT) mice subjected to cisplatin injections, or in kidney injury score determined by histological evaluation was found. Similar, we could not detect any histological difference between RPTEC-hapoMTG and WT mice after ischemia/reperfusion injury, and overexpression of hapoM did not affect kidney gene expression of inflammatory markers (i.e. IL6, MCP-1) compared to WT mice. Conclusion Our study suggests that apoM can be secreted to both the apical and basolateral compartment, supporting a role for apoM in sequestering molecules from secretion in urine. Transgenic overexpression of apoM in proximal tubular epithelial cells of mice did not protect against acute kidney injury.


2015 ◽  
Vol 42 (2) ◽  
pp. 168-175 ◽  
Author(s):  
Xiu-Juan Liu ◽  
Quan Hong ◽  
Zhen Wang ◽  
Yan-Yan Yu ◽  
Xin Zou ◽  
...  

Background: Acute kidney injury (AKI) is traditionally described as a condition leading to rapid damage to kidney function, eventually becoming a significant healthcare concern with a high mortality rate. Autophagy deficiency in the tubular epithelial cells is the main cause of AKI; however, the underlying molecular mechanism remains to be defined. MicroRNAs (miRNAs) are related to autophagy in many diseases. This study was aimed at investigating the relationship between miRNA expression and autophagic activity in the pathogenesis of AKI. Methods: A mouse model of AKI was produced by ischemia reperfusion (I/R). The expressions of microRNA-34a (miR-34a) and the autophagy-related protein LC3 II/I and p62 were determined in renal tissues and the tubular epithelial cells (RTECs). Moreover, the autophagic activity was investigated after miR-34a overexpression and inhibition. Additionally, the effect of miR-34a on its target gene in regulating autophagic activity in RTECs was also investigated. Results: I/R suppressed the autophagic activity and increased the expression of miR-34a in renal tissues. The in vitro data showed that the upregulation of miR-34a suppressed, whereas the inhibition of miR-34a promoted, autophagy in RTECs. Moreover, miR-34a could directly bind to Atg4B 3′-untranslated region. In addition, the knockdown of Atg4B expression inhibited the autophagic activity in RTECs. Conclusion: This study indicated that miR-34a might regulate the autophagic activity and can cause injury in I/R RTECs via targeting Atg4B.


2014 ◽  
Vol 306 (5) ◽  
pp. F496-F504 ◽  
Author(s):  
Tatiana Novitskaya ◽  
Lee McDermott ◽  
Ke Xin Zhang ◽  
Takuto Chiba ◽  
Paisit Paueksakon ◽  
...  

Phenylthiobutanoic acids (PTBAs) are a new class of histone deacetylase (HDAC) inhibitors that accelerate recovery and reduce postinjury fibrosis after ischemia-reperfusion-induced acute kidney injury. However, unlike the more common scenario in which patients present with protracted and less clearly defined onset of renal injury, this model of acute kidney injury gives rise to a clearly defined injury that begins to resolve over a short period of time. In these studies, we show for the first time that treatment with the PTBA analog methyl-4-(phenylthio)butanoate (M4PTB) accelerates recovery and reduces postinjury fibrosis in a progressive model of acute kidney injury and renal fibrosis that occurs after aristolochic acid injection in mice. These effects are apparent when M4PTB treatment is delayed 4 days after the initiating injury and are associated with increased proliferation and decreased G2/M arrest of regenerating renal tubular epithelial cells. In addition, there is reduced peritubular macrophage infiltration and decreased expression of the macrophage chemokines CX3Cl1 and CCL2. Since macrophage infiltration plays a role in promoting kidney injury, and since renal tubular epithelial cells show defective repair and a marked increase in maladaptive G2/M arrest after aristolochic acid injury, these findings suggest M4PTB may be particularly beneficial in reducing injury and enhancing intrinsic cellular repair even when administered days after aristolochic acid ingestion.


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