scholarly journals NFAT inhibitor 11R-VIVIT ameliorates mouse renal fibrosis after ischemia-reperfusion-induced acute kidney injury

2021 ◽  
Author(s):  
Zhi-yong Xie ◽  
Wei Dong ◽  
Li Zhang ◽  
Meng-jie Wang ◽  
Zhen-meng Xiao ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Renal Fibrosis ◽  
Nuclear Translocation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Ckd Progression ◽  
Renal Tubulointerstitial Fibrosis ◽  
Underlying Mechanisms

AbstractAcute kidney injury (AKI) with maladaptive tubular repair leads to renal fibrosis and progresses to chronic kidney disease (CKD). At present, there is no curative drug to interrupt AKI-to-CKD progression. The nuclear factor of the activated T cell (NFAT) family was initially identified as a transcription factor expressed in most immune cells and involved in the transcription of cytokine genes and other genes critical for the immune response. NFAT2 is also expressed in renal tubular epithelial cells (RTECs) and podocytes and plays an important regulatory role in the kidney. In this study, we investigated the renoprotective effect of 11R-VIVIT, a peptide inhibitor of NFAT, on renal fibrosis in the AKI-to-CKD transition and the underlying mechanisms. We first examined human renal biopsy tissues and found that the expression of NFAT2 was significantly increased in RTECs in patients with severe renal fibrosis. We then established a mouse model of AKI-to-CKD transition using bilateral ischemia-reperfusion injury (Bi-IRI). The mice were treated with 11R-VIVIT (5 mg/kg, i.p.) on Days 1, 3, 10, 17 and 24 after Bi-IRI. We showed that the expression of NFAT2 was markedly increased in RTECs in the AKI-to-CKD transition. 11R-VIVIT administration significantly inhibited the nuclear translocation of NFAT2 in RTECs, decreased the levels of serum creatinine and blood urea nitrogen, and attenuated renal tubulointerstitial fibrosis but had no toxic side effects on the heart and liver. In addition, we showed that 11R-VIVIT administration alleviated RTEC apoptosis after Bi-IRI. Consistently, preapplication of 11R-VIVIT (100 nM) and transfection with NFAT2-targeted siRNA markedly suppressed TGFβ-induced HK-2 cell apoptosis in vitro. In conclusion, 11R-VIVIT administration inhibits IRI-induced NFAT2 activation and prevents AKI-to-CKD progression. Inhibiting NFAT2 may be a promising new therapeutic strategy for preventing renal fibrosis after IR-AKI.

scholarly journals Huaier Extract Attenuates Acute Kidney Injury to Chronic Kidney Disease Transition by Inhibiting Endoplasmic Reticulum Stress and Apoptosis via miR-1271 Upregulation

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Jing-Ying Zhao ◽  
Yu-Bin Wu
Keyword(s):  
Chronic Kidney Disease ◽  
Acute Kidney Injury ◽  
Endoplasmic Reticulum ◽  
Kidney Disease ◽  
Endoplasmic Reticulum Stress ◽  
Molecular Mechanisms ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury

Endoplasmic reticulum stress (ERS) is strongly associated with acute kidney injury (AKI) to chronic kidney disease (CKD) transition. Huaier extract (HE) protects against kidney injury; albeit, the underlying mechanism is unknown. We hypothesized that HE reduces kidney injury by inhibiting ERS. In this study, using an AKI-CKD mouse model of ischemia-reperfusion injury (IRI), we evaluated the effect of HE on AKI-CKD transition. We also explored the underlying molecular mechanisms in this animal model and in the HK-2 human kidney cell line. The results showed that HE treatment improved the renal function, demonstrated by a significant decrease in serum creatinine levels after IRI. HE appreciably reduced the degree of kidney injury and fibrosis and restored the expression of the microRNA miR-1271 after IRI. Furthermore, HE reduced the expression of ERS markers glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) and inhibited apoptosis in the IRI group. This in vivo effect was supported by in vitro results in which HE inhibited apoptosis and decreased the expression of CHOP and GRP78 induced by ERS. We demonstrated that CHOP is a target of miR-1271. In conclusion, HE reduces kidney injury, probably by inhibiting apoptosis and decreasing the expression of GRP78 and CHOP via miR-1271 upregulation.

scholarly journals C-type lectin Mincle mediates cell death–triggered inflammation in acute kidney injury

2020 ◽  
Vol 217 (11) ◽  
Author(s):  
Miyako Tanaka ◽  
Marie Saka-Tanaka ◽  
Kozue Ochi ◽  
Kumiko Fujieda ◽  
Yuki Sugiura ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Cell Death ◽  
Free Cholesterol ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Sterile Inflammation ◽  
Renal Tubular Cell ◽  
Renal Tubules ◽  
Underlying Mechanisms

Accumulating evidence indicates that cell death triggers sterile inflammation and that impaired clearance of dead cells causes nonresolving inflammation; however, the underlying mechanisms are still unclear. Here, we show that macrophage-inducible C-type lectin (Mincle) senses renal tubular cell death to induce sustained inflammation after acute kidney injury in mice. Mincle-deficient mice were protected against tissue damage and subsequent atrophy of the kidney after ischemia–reperfusion injury. Using lipophilic extract from the injured kidney, we identified β-glucosylceramide as an endogenous Mincle ligand. Notably, free cholesterol markedly enhanced the agonistic effect of β-glucosylceramide on Mincle. Moreover, β-glucosylceramide and free cholesterol accumulated in dead renal tubules in proximity to Mincle-expressing macrophages, where Mincle was supposed to inhibit clearance of dead cells and increase proinflammatory cytokine production. This study demonstrates that β-glucosylceramide in combination with free cholesterol acts on Mincle as an endogenous ligand to induce cell death–triggered, sustained inflammation after acute kidney injury.

scholarly journals Hydroxychloroquine Inhibits Macrophage Activation and Attenuates Renal Fibrosis After Ischemia-Reperfusion Injury

2021 ◽  
Vol 12 ◽  
Author(s):  
Haofeng Zheng ◽  
Yannan Zhang ◽  
Jiannan He ◽  
Zhe Yang ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Renal Fibrosis ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Tubulointerstitial Fibrosis ◽  
Health Concern ◽  
Dependent Manner ◽  
Renal Tubulointerstitial Fibrosis

Chronic kidney disease (CKD), which is associated with high morbidity, remains a worldwide health concern, while effective therapies remain limited. Hydroxychloroquine (HCQ), which mainly targets toll-like receptor-7 (TLR-7) and TLR-9, is associated with a lower risk of incident CKD. Taking into account that TLR-9 is involved in the development of renal fibrosis and serves as a potential therapy target for CKD, we investigated whether HCQ could attenuate CKD via TLR-9 signal pathway. The effects of HCQ on renal tubulointerstitial fibrosis were further explored using a mouse model of renal tubulointerstitial fibrosis after ischemia/reperfusion injury. Bone marrow-derived macrophages were isolated to explore the effects of HCQ in vitro. Judicious use of HCQ efficiently inhibited the activation of macrophages and MAPK signaling pathways, thereby attenuating renal fibrosis in vivo. In an in vitro model, results showed that HCQ promoted apoptosis of macrophages and inhibited activation of macrophages, especially M2 macrophages, in a dose-dependent manner. Because TLR-7 is not involved in the development of CKD post-injury, a TLR-9 knockout mouse was used to explore the mechanisms of HCQ. The effects of HCQ on renal fibrosis and macrophages decreased after depletion of TLR-9 in vivo and in vitro. Taken together, this study indicated that proper use of HCQ could be a new strategy for anti-fibrotic therapy and that TLR-9 could be a potential therapeutic target for CKD following acute kidney injury.

scholarly journals NLRP2 is highly expressed and promotes apoptosis in a mouse model of kidney ischemia/reperfusion injury

2019 ◽  
Vol 17 ◽  
pp. 205873921985980 ◽  
Author(s):  
Xueyuan Yu ◽  
Xiumei Zhang ◽  
Zhao Hu
Keyword(s):  
Acute Kidney Injury ◽  
Mouse Model ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Quantitative Polymerase Chain Reaction ◽  
Kidney Injury ◽  
Kidney Ischemia

The aim of this study was to investigate the role of nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 2 (NLRP2) in kidney ischemia/reperfusion injury. A mouse model of acute kidney ischemia/reperfusion injury was established to conduct in vivo experiments. Oxygen–glucose deprivation (OGD) and cobalt chloride treatment of the HK-2 and glomerular endothelial cell (GENC) kidney cell lines were performed for the in vitro study. Reverse transcription–quantitative polymerase chain reaction, western blotting, and immunohistochemical staining were used to analyze NLRP2 expression levels. Knockdown of NLRP2 in cells was also performed, and cell apoptosis was detected using flow cytometry. NLRP2 was expressed in normal kidney tissues; however, its expression was significantly increased in the acute kidney injury model and in OGD-treated cells. Conversely, knockdown of NLRP2 reduced apoptosis of cells. These results suggested that NLRP2 was involved in kidney damage and may be an important target for treatment of acute kidney injury.

Sestrin-2 and BNIP3 regulate autophagy and mitophagy in renal tubular cells in acute kidney injury

2013 ◽  
Vol 305 (4) ◽  
pp. F495-F509 ◽  
Author(s):  
Masayuki Ishihara ◽  
Madoka Urushido ◽  
Kazu Hamada ◽  
Tatsuki Matsumoto ◽  
Yoshiko Shimamura ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Acute Kidney Injury ◽  
Light Chain ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Renal Tubules ◽  
Dependent Manner ◽  
Renal Tubular

Autophagy is a cellular recycling process induced in response to many types of stress. However, little is known of the signaling pathways that regulate autophagy during acute kidney injury (AKI). Bcl-2/adenovirus E1B 19 kDa-interacting protein (BNIP)3 and sestrin-2 are the target proteins of hypoxia-inducible factor (HIF)-1α and p53, respectively. The aim of this study was to investigate the roles of BNIP3 and sestrin-2 in oxidative stress-induced autophagy during AKI. We used rat ischemia-reperfusion injury and cultured renal tubular (NRK-52E) cells as in vivo and in vitro models of AKI, respectively. Renal ischemia-reperfusion injury upregulated the expression of BNIP3 and sestrin-2 in the proximal tubules, as measured by immunohistochemical staining and Western blot analysis. In vitro, NRK-52E cells exposed to hypoxia showed increased expression of BNIP3 mRNA and protein in a HIF-1α-dependent manner. In contrast, sestrin-2 mRNA and protein expression were upregulated in a p53-dependent manner after exposure to oxidative stress (exogenous H2O2). NRK-52E cells stably transfected with a fusion protein between green fluorescent protein and light chain 3 were used to investigate autophagy. Overexpression of BNIP3 or sestrin-2 in these cells induced light chain 3 expression and formation of autophagosomes. Interestingly, BNIP3-induced autophagosomes were mainly localized to the mitochondria, suggesting that this protein selectively induces mitophagy. These observations demonstrate that autophagy is induced in renal tubules by at least two independent pathways involving p53-sestrin-2 and HIF-1α-BNIP3, which may be activated by different types of stress to protect the renal tubules during AKI.

scholarly journals Mechanisms of Fasting-Mediated Protection against Renal Injury and Fibrosis Development after Ischemic Acute Kidney Injury

Biomolecules ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 404 ◽  
Author(s):  
Pedro Rojas-Morales ◽  
Edilia Tapia ◽  
Juan Carlos León-Contreras ◽  
Susana González-Reyes ◽  
Angélica Saraí Jiménez-Osorio ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Reperfusion Injury ◽  
Renal Fibrosis ◽  
Ischemia Reperfusion Injury ◽  
Rat Kidney ◽  
Ischemia Reperfusion ◽  
Chronic Phase ◽  
Kidney Injury ◽  
Redox Status ◽  
Extracellular Signal

Ischemia-reperfusion injury of the kidney may lead to renal fibrosis through a combination of several mechanisms. We recently demonstrated that fasting protects the rat kidney against oxidative stress and mitochondrial dysfunction in early acute kidney injury, and also against fibrosis development. Here we show that preoperative fasting preserves redox status and mitochondrial homeostasis at the chronic phase of damage after severe ischemia. Also, the protective effect of fasting coincides with the suppression of inflammation and endoplasmic reticulum stress, as well as the down-regulation of the mechanistic target of rapamycin (mTOR) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathways in the fibrotic kidney. Our results demonstrate that fasting targets multiple pathophysiological mechanisms to prevent renal fibrosis and damage that results after renal ischemia-reperfusion injury.

scholarly journals RTA-408 Protects Kidney from Ischemia-Reperfusion Injury in Mice via Activating Nrf2 and Downstream GSH Biosynthesis Gene

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Peng Han ◽  
Zhiqiang Qin ◽  
Jingyuan Tang ◽  
Zhen Xu ◽  
Ran Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Renal Function ◽  
Reperfusion Injury ◽  
Nuclear Translocation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Ros Production ◽  
Antioxidant Genes

Acute kidney injury (AKI) induced by ischemia-reperfusion is a critical conundrum in many clinical settings. Here, this study aimed to determine whether and how RTA-408, a novel oleanane triterpenoid, could confer protection against renal ischemia-reperfusion injury (IRI) in male mice. Mice treated with RTA-408 undergoing unilateral ischemia followed by contralateral nephrectomy had improved renal function and histological outcome, as well as decreased apoptosis, ROS production, and oxidative injury marker compared with vehicle-treated mice. Also, we had found that RTA-408 could strengthen the total antioxidant capacity by increasing Nrf2 nuclear translocation and subsequently increased Nrf2 downstream GSH-related antioxidant gene expression and activity. In vitro study demonstrated that GSH biosynthesis enzyme GCLc could be an important target of RTA-408. Furthermore, Nrf2-deficient mice treated with RTA-408 had no significant improvement in renal function, histology, ROS production, and GSH-related gene expression. Thus, by upregulating Nrf2 and its downstream antioxidant genes, RTA-408 presents a novel and potential approach to renal IRI prevention and therapy.

Urinary angiotensinogen predicts progressive chronic kidney disease after an episode of experimental acute kidney injury

2018 ◽  
Vol 132 (19) ◽  
pp. 2121-2133 ◽  
Author(s):  
Shuang Cui ◽  
Liling Wu ◽  
Xiaodan Feng ◽  
Huanjuan Su ◽  
Zhanmei Zhou ◽  
...  
Keyword(s):  
Renal Fibrosis ◽  
Structural Changes ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Renin Angiotensin System ◽  
Operating Characteristics ◽  
Ckd Progression ◽  
Urinary Angiotensinogen ◽  
Structural Recovery

One of the major obstacles to prevent AKI-CKD transition is the lack of effective methods to follow and predict the ongoing kidney injury after an AKI episode. In the present study, we test the utility of urinary angiotensinogen (UAGT) for dynamically evaluating renal structural changes and predicting AKI-CKD progression by using both mild and severe bilateral renal ischemia/reperfusion injury mice. UAGT returns to pre-ischemic levels 14 days after mild AKI followed by kidney architecture restoration, whereas sustained increase in UAGT accompanies by ongoing renal fibrosis after severe AKI. UAGT at day 14–42 correlates with renal fibrosis 84 days after AKI. For predicting fibrosis at day 84, the area under receiver operating characteristics curve of UAGT at day 14 is 0.81. Persistent elevation in UAGT correlates with sustained activation of intrarenal renin–angiotensin system (RAS) during AKI-CKD transition. Abrogating RAS activation post AKI markedly reduced renal fibrosis, with early RAS intervention (from 14 days after IRI) more beneficial than late intervention (from 42 days after IRI) in alleviating fibrosis. Importantly, UAGT decreases after RAS intervention, and its level at day 14–28 correlates with the extent of renal fibrosis at day 42 post RAS blockade. A pilot study conducted in patients with acute tubular necrosis finds that compared with those recovered, patients with AKI-CKD progression exhibits elevated UAGT during the 3-month follow-up after biopsy. Our study suggests that UAGT enables the dynamical monitoring of renal structural recovery after an AKI episode and may serve as an early predictor for AKI-CKD progression and treatment response.

scholarly journals Exogenous Wnt1 Prevents Acute Kidney Injury and Its Subsequent Progression to Chronic Kidney Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Xue Hong ◽  
Yanni Zhou ◽  
Dedong Wang ◽  
Fuping Lyu ◽  
Tianjun Guan ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Acute Kidney Injury ◽  
Kidney Disease ◽  
Inflammatory Responses ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Blood Biochemical

Studies suggest that Wnt/β-catenin agonists are beneficial in the treatment of acute kidney injury (AKI); however, it remains elusive about its role in the prevention of AKI and its progression to chronic kidney disease (CKD). In this study, renal Wnt/β-catenin signaling was either activated by overexpression of exogenous Wnt1 or inhibited by administration with ICG-001, a small molecule inhibitor of β-catenin signaling, before mice were subjected to ischemia/reperfusion injury (IRI) to induce AKI and subsequent CKD. Our results showed that in vivo expression of exogenous Wnt1 before IR protected mice against AKI, and impeded the progression of AKI to CKD in mice, as evidenced by both blood biochemical and kidney histological analyses. In contrast, pre-treatment of ICG-001 before IR had no effect on renal Wnt/β-catenin signaling or the progression of AKI to CKD. Mechanistically, in vivo expression of exogenous Wnt1 before IR suppressed the expression of proapoptotic proteins in AKI mice, and reduced inflammatory responses in both AKI and CKD mice. Additionally, exogenous Wnt1 inhibited apoptosis of tubular cells induced by hypoxia-reoxygenation (H/R) treatment in vitro. To conclude, the present study provides evidences to support the preventive effect of Wnt/β-catenin activation on IR-related AKI and its subsequent progression to CKD.

scholarly journals Combined melatonin and poricoic acid A inhibits renal fibrosis through modulating the interaction of Smad3 and β-catenin pathway in AKI-to-CKD continuum

2019 ◽  
Vol 10 ◽  
pp. 204062231986911 ◽  
Author(s):  
Dan-Qian Chen ◽  
Gang Cao ◽  
Hui Zhao ◽  
Lin Chen ◽  
Tian Yang ◽  
...  
Keyword(s):  
Renal Fibrosis ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Combined Therapy ◽  
Kidney Injury ◽  
Luciferase Reporter ◽  
Inhibitory Effects ◽  
Luciferase Reporter Gene ◽  
Smad3 Phosphorylation ◽  
Underlying Mechanisms

Background: Acute kidney injury (AKI) is one of the major risk factors for progression to chronic kidney disease (CKD) and renal fibrosis. However, effective therapies remain poorly understood. Here, we examined the renoprotective effects of melatonin and poricoic acid A (PAA) isolated from the surface layer of Poria cocos, and investigated the effects of combined therapy on the interaction of TGF-β/Smad and Wnt/β-catenin in a rat model of renal ischemia-reperfusion injury (IRI) and hypoxia/reoxygenation (H/R) or TGF-β1-induced HK-2 cells. Methods: Western blot and immunohistochemical staining were used to examine protein expression, while qRT-PCR was used to examine mRNA expression. Coimmunoprecipitation, chromatin immunoprecipitation, RNA interference, and luciferase reporter gene analysis were employed to explore the mechanisms of PAA and melatonin’s renoprotective effects. Results: PAA and combined therapy exhibited renoprotective and antifibrotic effects, but the underlying mechanisms were different during AKI-to-CKD continuum. Melatonin suppressed Smad-dependent and Smad-independent pathways, while PAA selectively inhibited Smad3 phosphorylation through distrupting the interactions of Smad3 with TGFβRI and SARA. Further studies demonstrated that the inhibitory effects of melatonin and PAA were partially depended on Smad3, especially PAA. Melatonin and PAA also inhibited the Wnt/β-catenin pathway and its profibrotic downstream targets, and PAA performed better. We further determined that IRI induced a nuclear Smad3/β-catenin complex, while melatonin and PAA disturbed the interaction of Smad3 and β-catenin, and supplementing with PAA could enhance the inhibitory effects of melatonin on the TGF-β/Smad and Wnt/β-catenin pathways. Conclusions: Combined melatonin and PAA provides a promising therapeutic strategy to treat renal fibrosis during the AKI-to-CKD continuum.

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