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

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

Acta Pharmacologica Sinica ◽

10.1038/s41401-021-00833-y ◽

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.

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Mir10a overexpression aggravates the renal ischemia-reperfusion injury associated with a decrease in PIK3CA

10.21203/rs.2.23453/v2 ◽

2020 ◽

Author(s):

Dongsheng Xu ◽

Wenjun Li ◽

Tao Zhang ◽

Gang Wang

Keyword(s):

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Luciferase Reporter ◽

Akt Pathway ◽

Luciferase Reporter Gene ◽

Gene Assay ◽

Underlying Mechanisms ◽

Related Proteins ◽

Hypoxia Reoxygenation

Abstract Background: To investigate the effect of miR-10a on the renal tissues with ischemia-reperfusion (I/R) injury in rats and explore the underlying mechanisms of miR-10a in the HK-2 cells of hypoxia-reoxygenation. Methods: The miR-10a level was measured in renal tissues with I/R rats by RT-PCR. In order to research the role of miR-10a in the renal tissues, miR-10 agonist and miR-10a antagonist were used to treat I/R rats. The levels of serum creatinine (Scr) and blood urea nitrogen (BUN) in serum, renal histopathology, apoptosis of cells in renal tissues were analyzed, separately. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway related proteins were measured by Western blot. The HK-2 cell was cultured to study the mechanism of miR-10a in the model of hypoxia-reoxygenation. The dual luciferase reporter gene assay was used to confirm the PI3K p100 catalytic subunit α (PIK3CA) was a target gene of miR-10a. Results: After renal I/R injury in rats, the miR-10a expression was significantly increased (p<0.05). Injection of miR-10a agonist significantly aggravated the injury of renal and raised the apoptosis of cells in renal in rats with renal I/R injury (p<0.05). However, administration of miR-10a antagonist obviously improved the injury of renal, decreased the renal cells apoptosis and inhibited the PI3K/Akt pathway activity (p<0.05). In vitro experiments, the negative relation between PIK3CA and miR-10a was confirmed. Further, overexpression of miR-10a significantly decreased the proliferation of HK-2 cells, and increased the cells apoptosis via up-regulating PI3K/Akt pathway (p<0.05). Conclusion: miR-10a could aggravate the renal I/R injury associated with a decrease in PIK3CA/PI3K/Akt pathway.

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Abstract 13141: Cellular Microrna 449b Upregulation Sensitizes Ischemia/reperfusion Injury via Inhibition of Nrf-1, Increasing Ros Production and Apoptosis in the Diabetic Heart

Circulation ◽

10.1161/circ.132.suppl_3.13141 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Hang Wang ◽

Wayne Lau ◽

Erhe Gao ◽

Walter Koch ◽

Xin Ma ◽

...

Keyword(s):

Oxidative Stress ◽

Molecular Mechanisms ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Experimental Studies ◽

Diabetic Heart ◽

Luciferase Reporter ◽

Proteomics Data ◽

Luciferase Reporter Gene ◽

Gene Assay

Myocardial ischemic/reperfusion (MI/R) injury is significantly enhanced in diabetes by incompletely understood mechanisms. Recent clinical and experimental studies demonstrate that hypoadiponectinemia during diabetes enhances oxidative stress and exaggerates MI/R injury. However, molecular mechanisms responsible for hypoadiponectinemia-induced oxidative stress remain unknown. In a discovery-driven fashion, we determined the role of cardiac microRNAs in the MI/R response in adiponectin knockout (APNKO) mice. From 68 total miRNAs differentially expressed between APNKO and wild type (WT) mice, miRNA 449b was identified as the microRNA most relevant to oxidative stress and apoptosis. In cultured neonatal cardiomyocytes, miRNA 449b silencing inhibited hypoxia/reoxygenation-induced apoptosis, whereas miR-449b overexpression significantly increased oxidative stress and cardiomyocyte apoptosis. In APNKO mice, administration of anti-miR-449b decreased oxidative stress (-17.2±3.8%, p<0.05), reduced caspase-3 activity (-21.3±4.2%, p<0.05), attenuated myocardial apoptosis (-16.3±4.1%, p<0.05), and improved myocardial function (1.4±0.3 fold). To identify the downstream molecule regulated by miRNA 449b, we integrated transcriptomics and proteomics data with computational annotation data, and identified Nrf-1 as a miRNA 449b target. A luciferase reporter gene assay demonstrated that miRNA 449b inhibited Nrf-1 expression via Nrf-1 mRNA 3’UTR region binding. Finally, we demonstrated that miRNA 449b was significantly upregulated, Nrf-1 expression was significantly decreased, and the anti-oxidative molecule metallothionein (MT) was significantly inhibited in the diabetic heart subjected to MI/R. Administration of anti-miR-449b in diabetic animals upregulated Nrf-1 and MT expression, reduced oxidative stress, and improved cardiac function (P<0.01) after MI/R. Taken together, this study provides the first evidence that hypoadiponectinemia during diabetes causes cardiac miRNA-449b upregulation and subsequent downregulation of Nrf-1 and MT, thus enhancing oxidative stress and MI/R injury. MicroRNA 449b may represent a potential therapeutic target against diabetic heart disease.

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microRNA-223 promotes autophagy to aggravate lung ischemia-reperfusion injury by inhibiting the expression of transcription factor HIF2α

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00009.2020 ◽

2020 ◽

Vol 319 (1) ◽

pp. L1-L10

Author(s):

Chunlin Ye ◽

Wanghong Qi ◽

Shaohua Dai ◽

Guowen Zou ◽

Weicheng Liu ◽

...

Keyword(s):

Ischemia Reperfusion Injury ◽

Tissue Injury ◽

Cell Model ◽

Ischemia Reperfusion ◽

Pulmonary Ventilation ◽

Pulmonary Arteries ◽

Luciferase Reporter ◽

Tunel Staining ◽

Luciferase Reporter Gene ◽

Gene Assay

Lung ischemia-reperfusion (I/R) injury severely endangers human health, and recent studies have suggested that certain microRNAs (miRNAs) play important roles in this pathological phenomenon. The current study aimed to ascertain the ability of miR-223 to influence lung I/R injury by targeting hypoxia-inducible factor-2α (HIF2α). First, mouse models of lung I/R injury were established: during surgical procedures, pulmonary arteries and veins and unilateral pulmonary portal vessels were blocked and resuming bilateral pulmonary ventilation, followed by restoration of bipulmonary ventilation. In addition, a lung I/R injury cell model was constructed by exposure to hypoxic reoxygenation (H/R) in mouse pulmonary microvascular endothelial cells (PMVECs). Expression of miR-223, HIF2α, and β-catenin in tissues or cells was determined by RT-qPCR and Western blot analysis. Correlation between miR-223 and HIF2α was analyzed by dual luciferase reporter gene assay. Furthermore, lung tissue injury and mouse PMVEC apoptosis was evaluated by hematoxylin and eosin (H&E), TUNEL staining, and flow cytometry. Autophagosomes in cells were detected by light chain 3 immunofluorescence assay. miR-223 was expressed at a high level while HIF2α/β-catenin was downregulated in tissues and cells with lung I/R injury. Furthermore, miR-223 targeted and repressed HIF2α expression to downregulate β-catenin expression. The miR-223/HIF2α/β-catenin axis aggravated H/R injury in mouse PMVECs and lung I/R injury in mice by enhancing autophagy. Taken together, miR-223 inhibits HIF2α to repress β-catenin, thus contributing to autophagy to complicate lung I/R injury. These findings provide a promising therapeutic target for treating lung I/R injury.

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

Journal of Experimental Medicine ◽

10.1084/jem.20192230 ◽

2020 ◽

Vol 217 (11) ◽

Cited By ~ 1

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.

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The Long Noncoding RNA-H19 Mediates the Progression of Fibrosis from Acute Kidney Injury to Chronic Kidney Disease by Regulating the miR-196a/Wnt/β-Catenin Signaling

Nephron ◽

10.1159/000518756 ◽

2021 ◽

pp. 1-11

Author(s):

Xiangnan Dong ◽

Rui Cao ◽

Qiang Li ◽

Lianghong Yin

Keyword(s):

Chronic Kidney Disease ◽

Acute Kidney Injury ◽

Kidney Disease ◽

Noncoding Rna ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Collagen I ◽

Luciferase Reporter ◽

Kidney Fibrosis

Introduction: Long noncoding RNAs (lncRNAs) have been reported to be involved in the occurrence and development of various diseases. This study was to investigate the role of lncRNA-H19 in the transition from acute kidney injury (AKI) to chronic kidney disease (CKD) and its underlying mechanism. Methods: Bilateral renal pedicle ischemia-reperfusion injury (IRI) was used to establish the IRI-AKI model in C57BL/6 mice. The expression levels of lncRNA-H19, miR-196a-5p, α-SMA, collagen I, Wnt1, and β-catenin in mouse kidney tissues and fibroblasts were determined by quantitative real-time PCR and Western blotting. The degree of renal fibrosis was evaluated by hematoxylin and eosin staining. The interaction between lncRNA-H19 and miR-196a-5p was verified by bioinformatics analysis and luciferase reporter assay. Immunohistochemistry and immunofluorescence were used to evaluate the expression of α-SMA and collagen I in kidney tissues and fibroblasts of mice. Results: lncRNA-H19 is upregulated, and miR-196a-5p is downregulated in kidney tissues of IRI mice. Moreover, miR-196a-5p is a direct target of lncRNA-H19. lncRNA-H19 overexpression promotes kidney fibrosis and activates fibroblasts during AKI-CKD development, while miR-196a-5p overexpression reversed these effects in vitro. Furthermore, lncRNA-H19 overexpression significantly upregulates Wnt1 and β-catenin expression in kidney tissues and fibroblasts of IRI mice, while miR-196a-5p overexpression downregulates Wnt1 and β-catenin expression in kidney tissues and fibroblasts of IRI mice. Conclusion: lncRNA-H19 induces kidney fibrosis during AKI-CKD by regulating the miR-196a-5p/Wnt/β-catenin signaling pathway.

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

Biomolecules ◽

10.3390/biom9090404 ◽

2019 ◽

Vol 9 (9) ◽

pp. 404 ◽

Cited By ~ 2

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.

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

Clinical Science ◽

10.1042/cs20180758 ◽

2018 ◽

Vol 132 (19) ◽

pp. 2121-2133 ◽

Cited By ~ 4

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.

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Renal-Protective Effects and Potential Mechanisms of Traditional Chinese Medicine after Ischemia-Reperfusion Injury

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2021/5579327 ◽

2021 ◽

Vol 2021 ◽

pp. 1-6

Author(s):

Demin Liu ◽

Songling Tang ◽

Lu Gan ◽

Wei Cui

Keyword(s):

Chinese Medicine ◽

Traditional Chinese Medicine ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Mitochondrial Fission ◽

Hypovolemic Shock ◽

Kidney Injury ◽

Protective Effects ◽

Underlying Mechanisms ◽

Anti Inflammation

Renal ischemia-reperfusion (I/R) injury mainly causes acute kidney injury (AKI) after renal transplantation, trauma, sepsis, and hypovolemic shock. Patients with renal I/R injury are frequently associated with a poor prognosis. Traditional Chinese medicine (TCM) has been used for the prevention and treatment of various diseases in China and other Asian countries for centuries. Many studies have shown the protective effect of TCM on renal I/R injury, due to its diverse bioactive components. The potential mechanisms of TCMs on renal I/R injury include anti-inflammation, antioxidative effect, anti-cell death, downregulation of adhesion molecule expression, regulation of energy metabolism by restoring Na+-K+-ATPase activity, and mitochondrial fission. This review summarizes the major developments in the effects and underlying mechanisms of TCMs on the renal I/R injury.

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