Kidney Organoids as a Novel Platform to Evaluate Lipopolysaccharide-Induced Oxidative Stress and Apoptosis in Acute Kidney Injury

Sepsis-associated acute kidney injury (SA-AKI) is a life-threatening syndrome. Lipopolysaccharide (LPS) is a widely used inducer for modeling SA-AKI both in vivo and in vitro. However, due to the innate complexity of the kidney architecture, the mechanisms underlying the pathogenesis of SA-AKI, as well as those involved in LPS-induced kidney injury remain to be clarified. Kidney organoids derived from human pluripotent stem cells (hPSCs) act as a model of multiple types of kidney cells in vitro and eliminate potential confounders in vivo. In the current study, we established LPS-induced kidney injury models both in vivo and in human kidney organoids. Kidney function, pathological changes, and markers of oxidative stress were evaluated with/without the presence of methylprednisolone (MP) treatment both in vivo and in vitro. The extent of LPS-induced oxidative stress and apoptosis in kidney organoids was further investigated in vitro. LPS-induced acute kidney injury in mice, together with pathological changes and increased oxidative stress, as well as enhanced apoptosis in kidney cells were evaluated. These phenomena were ameliorated by MP treatment. Experiments in kidney organoids showed that the LPS-induced apoptotic effects occurred mainly in podocytes and proximal tubular cells. Our experiments demonstrated the efficacy of using kidney organoids as a solid platform to study LPS-induced kidney injury. LPS induced oxidative stress as well as apoptosis in kidney cells independently of changes in perfusion or immune cell infiltration. MP treatment partially alleviated LPS-induced injury by reducing kidney cell oxidative stress and apoptosis.

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The Inhibitory Impact of Schisandrin Against LPS-Induced Acute Kidney Injury in Vitro and in Vivo

10.21203/rs.3.rs-935326/v1 ◽

2021 ◽

Author(s):

Weifeng Li ◽

Qiuxia Huang ◽

Jinjin Yu ◽

Jiabao Yu ◽

Yajie Yang ◽

...

Keyword(s):

Oxidative Stress ◽

Acute Kidney Injury ◽

Kidney Tissue ◽

Kidney Injury ◽

Immunohistochemical Analysis ◽

Inflammatory Factors ◽

Raw264.7 Macrophages ◽

Bioactive Component

Abstract Schisandrin (Sch) is a main bioactive component of Schisandra sphenanthera Rehd.et Wils. It has been reported that Sch could regulate inflammatory disease. This study evaluated the anti-inflammatory and anti-oxidant effects effect of Sch on lipopolysaccharide (LPS)-induced macrophages activation and acute kidney injury mice. Male Kunming mice were intraperitoneally injected with LPS (15 mg/kg) after administration of Sch (12.5, 25, 50 mg/kg) seven days for developing acute kidney injury vivo model. RAW264.7 macrophages were pretreatment Sch (10, 20, 40 µM) and administrated LPS (1 µg/ml) to create an in vitro injury model. ELISA results found that Sch administration reduced the production of inflammatory factors induced by LPS in kidney tissues and RAW264.7 macrophages. It has been observed that Sch alleviated oxidative stress by reducing the levels of reactive oxygen species, myeloperoxidase and malondialdehyde, and increasing the activity of superoxide dismutase and glutathione peroxidase. Hematoxylin-eosin staining data suggested that Sch administration significantly reduced inflammatory cell infiltration and the kidney tissue damage induced by LPS. The blood urea nitrogen and creatinine levels were also reduced by Sch treatment. In addition, Western blot and immunohistochemical analysis showed that Sch up-regulated the expression of Nrf2 and HO-1, and decreased the expression of p-p38, p-JNK, p-ERK1/2, p-IκBα, p-NF-κBp65 and TLR4. The current research showed that Sch reduced LPS-induced acute kidney injury by inhibiting inflammation and oxidative stress, and provided insights into potential ways to treat AKI.

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Melatonin Alleviates Contrast-Induced Acute Kidney Injury by Activation of Sirt3

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/6668887 ◽

2021 ◽

Vol 2021 ◽

pp. 1-21

Author(s):

Chunmei Zhang ◽

Mengying Suo ◽

Lingxin Liu ◽

Yan Qi ◽

Chen Zhang ◽

...

Keyword(s):

Oxidative Stress ◽

Acute Kidney Injury ◽

Transforming Growth Factor ◽

Kidney Injury ◽

Transforming Growth Factor Β ◽

Activity Levels ◽

Protective Effects ◽

Melatonin Treatment

Oxidative stress and apoptosis play a vital role in the pathogenesis of contrast-induced acute kidney injury (CI-AKI). The purpose of our study was to investigate the protective effects and mechanisms of melatonin against CI-AKI in a CI-AKI mouse model and NRK-52E cells. We established the CI-AKI model in mice, and the animals were pretreated with melatonin (20 mg/kg). Our results demonstrated that melatonin treatment exerted a renoprotective effect by decreasing the level of serum creatinine (SCr) and blood urea nitrogen (BUN), lessening the histological changes of renal tubular injuries, and reducing the expression of neutrophil gelatinase-associated lipid (NGAL), a marker of kidney injury. We also found that pretreatment with melatonin remarkably increased the expression of Sirt3 and decreased the ac-SOD2 K68 level. Consequently, melatonin treatment significantly decreased the oxidative stress by reducing the Nox4, ROS, and malondialdehyde (MDA) content and by increasing the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity levels. The antiapoptotic effect of melatonin on CI-AKI was revealed by decreasing the ratio of Bax/Bcl2 and the cleaved caspase3 level and by reducing the number of apoptosis-positive tubular cells. In addition, melatonin treatment remarkably reduced the inflammatory cytokines of interleukin-1β (IL-1β), tumor necrosis factor α (TNFα), and transforming growth factor β (TGFβ) in vivo and in vitro. Sirt3 deletion and specific Sirt3 siRNA abolished the above renoprotective effects of melatonin in mice with iohexol-induced acute kidney injury and in NRK-52E cells. Thus, our results demonstrated that melatonin exhibited the renoprotective effects of antioxidative stress, antiapoptosis, and anti-inflammation by the activation of Sirt3 in the CI-AKI model in vivo and in vitro. Melatonin may be a potential drug to ameliorate CI-AKI in clinical practice.

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Silencing Long Non-coding RNA Kcnq1ot1 Limits Acute Kidney Injury by Promoting miR-204-5p and Blocking the Activation of NLRP3 Inflammasome

Frontiers in Physiology ◽

10.3389/fphys.2021.721524 ◽

2021 ◽

Vol 12 ◽

Author(s):

JunTao Wang ◽

Peng Jiao ◽

XiaoYing Wei ◽

Yun Zhou

Keyword(s):

Cell Proliferation ◽

Acute Kidney Injury ◽

Nlrp3 Inflammasome ◽

Kidney Injury ◽

Human Kidney ◽

Inflammasome Activation ◽

Nlrp3 Inflammasome Activation ◽

Apoptosis And Inflammation

Acute kidney injury (AKI) is a critical clinical disease characterized by an acute decrease in renal function. Long non-coding RNAs (LncRNAs) are important in AKI. This study aimed to explore the mechanism of lncRNA Kcnq1ot1 in AKI by sponging microRNA (miR)-204-5p as a competitive endogenous RNA (ceRNA). AKI mouse model and hypoxia/reoxygenation (H/R) model of human kidney (HK) cells were established. Kcnq1ot1 expression, cell proliferation, and apoptosis were measured. Binding relations among Kcnq1ot1, miR-204-5p, and NLRP3 were verified. Pathological changes and cell apoptosis were detected. The results showed that Kcnq1ot1 was highly expressed in the AKI model in vivo and in vitro. Kcnq1ot1 knockdown promoted cell proliferation and prevented apoptosis and inflammation. Furthermore, Kcnq1ot1 inhibited miR-204-5p expression by competitively binding to miR-204-5p in HK-2 cells. miR-204-5p targeted NLRP3 and NLRP3 overexpression averted the inhibiting effect of miR-204-5p on apoptosis and inflammation in HK-2 cells in vitro. Kcnq1ot1 knockdown in vivo promoted miR-204-5p expression, inhibited NLRP3 inflammasome activation, reduced levels of SCr, BUN, and KIM-1, and thus alleviated AKI and reduced apoptosis. In summary, silencing lncRNA Kcnq1ot1 inhibited AKI by promoting miR-204-5p and inhibiting NLRP3 inflammasome activation.

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Inhibition of gap junction composed of Cx43 prevents against acute kidney injury following liver transplantation

Cell Death and Disease ◽

10.1038/s41419-019-1998-y ◽

2019 ◽

Vol 10 (10) ◽

Cited By ~ 3

Author(s):

Dongdong Yuan ◽

Xiaoyun Li ◽

Chenfang Luo ◽

Xianlong Li ◽

Nan Cheng ◽

...

Keyword(s):

Oxidative Stress ◽

Liver Transplantation ◽

Acute Kidney Injury ◽

Kidney Injury ◽

Protective Effects ◽

Sprague Dawley ◽

Organ Protection ◽

Cx43 Expression

Abstract Postoperative acute kidney injury (AKI) is a severe complication after liver transplantation (LT). Its deterioration and magnification lead to the increase in mortality. Connexin43 (Cx43) mediates direct transmission of intracellular signals between neighboring cells, always considered to be the potent biological basis of organ damage deterioration and magnification. Thus, we explored the effects of Cx43 on AKI following LT and its related possible mechanism. In this study, alternations of Cx43 expression were observed in 82 patients, receiving the first-time orthotopic LT. We built autologous orthotopic liver transplantation (AOLT) models with Sprague–Dawley (SD) rats in vivo, and hypoxia-reoxygenation (H/R) or lipopolysaccharide (LPS) pretreatment models with kidney tubular epithelial cells (NRK-52E) in vitro, both of which were the most important independent risk factors of AKI following LT. Then, different methods were used to alter the function of Cx43 channels to determine its protective effects on AKI. The results indicated that patients with AKI suffering from longer time of tracheal intubation or intensive care unit stay, importantly, had significantly lower survival rate at postoperative 30 days and 3 years. In rat AOLT models, as Cx43 was inhibited with heptanol, postoperative AKI was attenuated significantly. In vitro experiments, downregulation of Cx43 with selective inhibitors, or siRNA protected against post-hypoxic NRK-52E cell injuries caused by H/R and/or LPS, while upregulation of Cx43 exacerbated the above-mentioned cell injuries. Of note, alternation of Cx43 function regulated the content of reactive oxygen species (ROS), which not only mediated oxidative stress and inflammation reactions effectively, but also regulated necroptosis. Therefore, we concluded that Cx43 inhibition protected against AKI following LT through attenuating ROS transmission between the neighboring cells. ROS alternation depressed oxidative stress and inflammation reaction, which ultimately reduced necroptosis. This might offer new insights for targeted intervention for organ protection in LT, or even in other major surgeries.

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Curcumin-Loaded Nanoparticles Protect Against Rhabdomyolysis-Induced Acute Kidney Injury

Cellular Physiology and Biochemistry ◽

10.1159/000484233 ◽

2017 ◽

Vol 43 (5) ◽

pp. 2143-2154 ◽

Cited By ~ 16

Author(s):

Xiaoling Chen ◽

Jian Sun ◽

Hailun Li ◽

Hongwu Wang ◽

Yongtao Lin ◽

...

Keyword(s):

Oxidative Stress ◽

Acute Kidney Injury ◽

Treatment Efficacy ◽

Kidney Injury ◽

In Vivo Studies ◽

Renal Tubules ◽

Drug Release Profile ◽

Renal Tubular

Background/Aims: Rhabdomyolysis (RM) is a potentially life-threatening condition that results from the breakdown of muscle and consequent release of toxic compounds into circulation. The most common and severe complication of RM is acute kidney injury (AKI). This study aimed to evaluate the efficacy and mechanisms of action of curcumin-loaded nanoparticles (Cur-NP) for treatment of RM-induced AKI. Methods: Curcumin-NP was synthesized using the nanocarrier distearoylphosphatidylethanolamine-polyethylene glycol (DSPE-PEG) to achieve a prolonged and constant drug release profile compared with the curcumin-free group. The anti-AKI effects of Curcumin-NP were examined both in vitro (myoglobin-treated renal tubular epithelial HK-2 cells) and in vivo (glycerol-induced AKI model). Results: Our results indicated that Curcumin-NP reversed oxidative stress, growth inhibition and cell apoptosis accompanied with down-regulation of apoptotic markers Caspase-3 and GRP-78 in vitro. In vivo studies revealed enhanced AKI treatment efficacy with Curcumin-NP as characterized by reduced serum creatine phosphokinase (CPK), creatinine (Cr) and urea and less severe histological damage in renal tubules. In addition, kidney tissues from Curcumin-NP-treated AKI rats exhibited reduced oxidative stress, apoptosis, and cleaved Capase-3 and GRP-78 expression. Conclusion: Our results suggest that nanoparticle-loaded curcumin enhances treatment efficacy for RM-induced AKI both in vitro and in vivo.

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Interleukin-1β Activates a MYC-Dependent Metabolic Switch in Kidney Stromal Cells Necessary for Progressive Tubulointerstitial Fibrosis

Journal of the American Society of Nephrology ◽

10.1681/asn.2017121283 ◽

2018 ◽

Vol 29 (6) ◽

pp. 1690-1705 ◽

Cited By ~ 45

Author(s):

Dario R. Lemos ◽

Michael McMurdo ◽

Gamze Karaca ◽

Julia Wilflingseder ◽

Irina A. Leaf ◽

...

Keyword(s):

Stromal Cells ◽

Target Genes ◽

Kidney Injury ◽

Human Kidney ◽

Metabolic Switch ◽

Metabolic Derangement ◽

Sequestosome 1 ◽

Kidney Organoids

Background Kidney injury is characterized by persisting inflammation and fibrosis, yet mechanisms by which inflammatory signals drive fibrogenesis remain poorly defined.Methods RNA sequencing of fibrotic kidneys from patients with CKD identified a metabolic gene signature comprising loss of mitochondrial and oxidative phosphorylation gene expression with a concomitant increase in regulators and enzymes of glycolysis under the control of PGC1α and MYC transcription factors, respectively. We modeled this metabolic switch in vivo, in experimental murine models of kidney injury, and in vitro in human kidney stromal cells (SCs) and human kidney organoids.Results In mice, MYC and the target genes thereof became activated in resident SCs early after kidney injury, suggesting that acute innate immune signals regulate this transcriptional switch. In vitro, stimulation of purified human kidney SCs and human kidney organoids with IL-1β recapitulated the molecular events observed in vivo, inducing functional metabolic derangement characterized by increased MYC-dependent glycolysis, the latter proving necessary to drive proliferation and matrix production. MYC interacted directly with sequestosome 1/p62, which is involved in proteasomal degradation, and modulation of p62 expression caused inverse effects on MYC expression. IL-1β stimulated autophagy flux, causing degradation of p62 and accumulation of MYC. Inhibition of the IL-1R signal transducer kinase IRAK4 in vivo or inhibition of MYC in vivo as well as in human kidney organoids in vitro abrogated fibrosis and reduced tubular injury.Conclusions Our findings define a connection between IL-1β and metabolic switch in fibrosis initiation and progression and highlight IL-1β and MYC as potential therapeutic targets in tubulointerstitial diseases.

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Modeling acute kidney injury in kidney organoids with cisplatin

10.1101/2019.12.22.886572 ◽

2019 ◽

Author(s):

Jenny L. M. Digby ◽

Aneta Przepiorski ◽

Alan J. Davidson ◽

Veronika Sander

Keyword(s):

Dna Damage ◽

Acute Kidney Injury ◽

Proximal Tubule ◽

Kidney Injury ◽

Induced Pluripotent Stem Cell ◽

Human Kidney ◽

Distal Tubule ◽

Dependent Manner ◽

Kidney Organoids

ABSTRACTAcute kidney injury (AKI) remains a major global healthcare problem and there is a need to develop human-based models to study AKI in vitro. Towards this goal, we have characterized induced pluripotent stem cell-derived human kidney organoids and their response to cisplatin, a chemotherapeutic drug that induces AKI and preferentially damages the proximal tubule. We found that a single treatment with 50 µM cisplatin induces HAVCR1 and CXCL8 expression, DNA damage (γH2AX) and cell death in the organoids in a dose-dependent manner but greatly impairs organoid viability. DNA damage was not specific to the proximal tubule but also affected the distal tubule and interstitial populations. This lack of specificity correlated with low expression of the proximal tubule-specific SLC22A2/OCT2 transporter for cisplatin. To improve viability, we developed a repeated low-dose regimen of 4x 5 µM cisplatin over 7 days and found this causing less toxicity while still inducing a robust AKI response that included secretion of known AKI biomarkers and inflammatory cytokines. This work validates the use of human kidney organoids to model aspects of AKI in vitro, with the potential to identify new AKI biomarkers and develop better therapies.

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miR-141 mediates recovery from acute kidney injury

Scientific Reports ◽

10.1038/s41598-021-94984-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lucy J. Newbury ◽

Kate Simpson ◽

Usman Khalid ◽

Imogen John ◽

Lluís Bailach de Rivera ◽

...

Keyword(s):

Oxidative Stress ◽

Acute Kidney Injury ◽

Cell Viability ◽

Messenger Rna ◽

Tyrosine Phosphatase ◽

Kidney Injury ◽

Clinical Problem ◽

Proximal Tubular

AbstractAcute kidney injury (AKI) is a global clinical problem characterised by a sudden decline in renal function and mortality as high as 60%. Current AKI biomarkers have limited ability to classify disease progression and identify underlying pathological mechanisms. Here we hypothesised that alterations in urinary microRNA profiles could predict AKI recovery/nonrecovery after 90 days, and that injury-specific changes would signify microRNA mediators of AKI pathology. Comparison of urinary microRNA profiles from AKI patients with controls detected significant injury-specific increases in miR-21, miR-126 and miR-141 (p < 0.05) and decreases in miR-192 (p < 0.001) and miR-204 (p < 0.05). Expression of miR-141 increased in renal proximal tubular epithelial cells (PTECs) under oxidative stress in vitro and unilateral ischaemic reperfusion injury in vivo. Forced miR-141 expression in the presence of H2O2 increased PTEC death and decreased cell viability. Of nine messenger RNA targets with two or more miR-141 3’-untranslated region binding sites, we confirmed protein tyrosine phosphatase receptor type G (PTPRG) as a direct miR-141 target in PTECs. PTPRG-specific siRNA knockdown under oxidative stress increased PTEC death and decreased cell viability. In conclusion, we detected significant alterations in five urinary microRNAs following AKI, and identified proximal tubular cell PTPRG as a putative novel therapeutic target.

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PICK1 Deficiency Exacerbates Sepsis-Associated Acute Kidney Injury

BioMed Research International ◽

10.1155/2021/9884297 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Qian Dou ◽

Hang Tong ◽

Yichun Yang ◽

Han Zhang ◽

Hua Gan

Keyword(s):

Oxidative Stress ◽

Acute Kidney Injury ◽

Epithelial Cells ◽

Kidney Injury ◽

Tubular Epithelial Cells ◽

Renal Tubular Epithelial Cells ◽

Renal Tubular ◽

Induced Apoptosis

We performed in vitro and in vivo experiments to explore the role of protein kinase C-binding protein 1 (PICK1), an intracellular transporter involved in oxidative stress-related neuronal diseases, in sepsis-related acute kidney injury (AKI). Firstly, PCR, western blotting, and immunohistochemistry were used to observe the expression of PICK1 after lipopolysaccharide- (LPS-) induced AKI. Secondly, by inhibiting PICK1 in vivo and silencing PICK1 in vitro, we further explored the effect of PICK1 on AKI. Finally, the relationship between PICK1 and oxidative stress and the related mechanisms were explored. We found that the expression of PICK1 was increased in LPS-induced AKI models both in vitro and in vivo. PICK1 silencing significantly aggravated LPS-induced apoptosis, accompanied by ROS production in renal tubular epithelial cells. FSC231, a PICK1-specific inhibitor, aggravated LPS-induced kidney injury. Besides, NAC (N-acetylcysteine), a potent ROS scavenger, significantly inhibited the PICK1-silencing-induced apoptosis. In conclusion, PICK1 might protect renal tubular epithelial cells from LPS-induced apoptosis by reducing excessive ROS, making PICK1 a promising preventive target in LPS-induced AKI.

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Increased progression to kidney fibrosis after erythropoietin is used as a treatment for acute kidney injury

AJP Renal Physiology ◽

10.1152/ajprenal.00241.2013 ◽

2014 ◽

Vol 306 (6) ◽

pp. F681-F692 ◽

Cited By ~ 24

Author(s):

Glenda C. Gobe ◽

Nigel C. Bennett ◽

Malcolm West ◽

Paul Colditz ◽

Lindsay Brown ◽

...

Keyword(s):

Oxidative Stress ◽

Chronic Kidney Disease ◽

Acute Kidney Injury ◽

Renal Function ◽

Kidney Disease ◽

Kidney Injury ◽

Renal Ischemia ◽

Acute Injury

Treatment of renal ischemia-reperfusion (IR) injury with recombinant human erythropoietin (rhEPO) reduces acute kidney injury and improves function. We aimed to investigate whether progression to chronic kidney disease associated with acute injury was also reduced by rhEPO treatment, using in vivo and in vitro models. Rats were subjected to bilateral 40-min renal ischemia, and kidneys were studied at 4, 7, and 28 days postreperfusion for renal function, tubular injury and repair, inflammation, and fibrosis. Acute injury was modulated using rhEPO (1,000 or 5,000 IU/kg, intraperitoneally) at the time of reperfusion. Renal tubular epithelial cells or fibroblasts in culture were subjected to hypoxia or oxidative stress, with or without rhEPO (200 IU/ml), and fibrogenesis was studied. The results of the in vivo model confirmed functional and structural improvement with rhEPO at 4 days post-IR ( P < 0.05). At 7 days post-IR, fibrosis and myofibroblast stimulation were increased with IR with and without rhEPO ( P < 0.01). However, at 28 days post-IR, renal fibrosis and myofibroblast numbers were significantly greater with IR plus rhEPO ( P < 0.01) compared with IR only. Mechanistically, rhEPO stimulated profibrotic transforming growth factor-β, oxidative stress (marker 8-hydroxy-deoxyguanosine), and phosphorylation of the signal transduction protein extracellular signal-regulated kinase. In vitro, rhEPO protected tubular epithelium from apoptosis but stimulated epithelial-to-mesenchymal transition and also protected and activated fibroblasts, particularly with oxidative stress. In summary, although rhEPO was protective of renal function and structure in acute kidney injury, the supraphysiological dose needed for renoprotection contributed to fibrogenesis and stimulated chronic kidney disease in the long term.

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