scholarly journals TRIP13-deficient tubular epithelial cells are susceptible to apoptosis following acute kidney injury

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Jeffrey D. Pressly ◽  
Taketsugu Hama ◽  
Shannon O’ Brien ◽  
Kevin R. Regner ◽  
Frank Park
Keyword(s):  
Acute Kidney Injury ◽  
Epithelial Cells ◽  
Kidney Injury ◽  
Tubular Epithelial Cells

scholarly journals Proximal tubule-specific overexpression of netrin-1 suppresses acute kidney injury-induced interstitial fibrosis and glomerulosclerosis through suppression of IL-6/STAT3 signaling

2013 ◽  
Vol 304 (8) ◽  
pp. F1054-F1065 ◽  
Author(s):  
Punithavathi Ranganathan ◽  
Calpurnia Jayakumar ◽  
Ganesan Ramesh
Keyword(s):  
Acute Kidney Injury ◽  
Epithelial Cells ◽  
Interstitial Fibrosis ◽  
Kidney Injury ◽  
Transgenic Animals ◽  
Acute Injury ◽  
Tubular Epithelial Cells ◽  
Wild Type ◽  
Proximal Tubular Epithelial Cells ◽  
Proximal Tubular

Acute kidney injury-induced organ fibrosis is recognized as a major risk factor for the development of chronic kidney disease, which remains one of the leading causes of death in the developed world. However, knowledge on molecules that may suppress the fibrogenic response after injury is lacking. In ischemic models of acute kidney injury, we demonstrate a new function of netrin-1 in regulating interstitial fibrosis. Acute injury was promptly followed by a rise in serum creatinine in both wild-type and netrin-1 transgenic animals. However, the wild-type showed a slow recovery of kidney function compared with netrin-1 transgenic animals and reached baseline by 3 wk. Histological examination showed increased infiltration of interstitial macrophages, extensive fibrosis, reduction of capillary density, and glomerulosclerosis. Collagen IV and α-smooth muscle actin expression was absent in sham-operated kidneys; however, their expression was significantly increased at 2 wk and peaked at 3 wk after reperfusion. These changes were reduced in the transgenic mouse kidney, which overexpresses netrin-1 in proximal tubular epithelial cells. Fibrosis was associated with increased expression of IL-6 and extensive and chronic activation of STAT3. Administration of IL-6 exacerbated fibrosis in vivo in wild-type, but not in netrin-1 transgenic mice kidney and increased collagen I expression and STAT3 activation in vitro in renal epithelial cells subjected to hypoxia-reoxygenation, which was suppressed by netrin-1. Our data suggest that proximal tubular epithelial cells may play a prominent role in interstitial fibrosis and that netrin-1 could be a useful therapeutic agent for treating kidney fibrosis.

MO328ASYMPTOMATIC HYPERURICEMIA ACTS AS ANTIOXIDANT DURING ACUTE KIDNEY INJURY AND DISEASE*

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Qiuyue Ma ◽  
Viviane Gnemmi ◽  
Anders Hans-Joachim ◽  
Stefanie Steiger
Keyword(s):  
Acute Kidney Injury ◽  
Fatty Acid ◽  
Epithelial Cells ◽  
Kidney Function ◽  
Metabolic Activity ◽  
Mitochondrial Biogenesis ◽  
Kidney Injury ◽  
Acid Oxidation ◽  
Tubular Epithelial Cells ◽  
Tubular Injury

Abstract Background and Aims Acute kidney injury (AKI) and disease (AKD) are major causes of morbidity and mortality worldwide. Hyperuricemia (HU) is common in patients with impaired kidney function. While there is no doubt that crystalline uric acid (UA) causes acute and chronic UA nephropathy, urolithiasis and kidney stone disease, the pathogenesis of asymptomatic HU in AKI/AKD is incompletely understood. In animal studies, elevated serum UA levels may lead to endothelial dysfunction, renin-angiotensin system activation and oxidative stress. However, such models do not mimic human HU. To overcome this issue, we established a model of AKI/AKD with clinically relevant serum UA levels and hypothesized that asymptomatic HU improves the outcomes after AKI/AKD by restoring metabolic activity and mitochondrial biogenesis in macrophages and tubular epithelial cells. Method Alb-creERT2;Glut9lox/lox and Glut9lox/lox control mice were injected with tamoxifen and placed on a chow diet enriched with inosine. Hyperuricemic mice (serum UA ≥7 mg/dL) and mice without HU (serum UA 4-5 mg/dL) underwent uninephrectomy followed by unilateral ischemia-reperfusion (IR) to induce AKI/AKD. Serum and kidneys were collected on day 3 and 14 after AKI/AKD, and kidney function, tubular injury, inflammation, mitochondrial dysfunction, metabolic activity (fatty acid oxidation) and macrophage infiltration were quantified using GFR measurement, immunohistochemistry, colorimetric assays, electron microscopy, RT-PCR and flow cytometry. Results We observed an increase in serum UA levels from 7 to 10 mg/dL in hyperuricemic mice on day 3 after IR-induced AKI/AKD that returned to 7 mg/dL after 14 days (Figure left). While there was no difference in GFR between hyperuricemic and mice without HU with AKI/AKD on day 3, we found an improved kidney function in hyperuricemic mice on day 14 (Figure middle). This was associated with significantly less tubular injury and inflammation as well as an increase in the number of infiltrating anti-inflammatory M2-like macrophages as compared to mice without HU. Intrarenal mRNA expression level of the pro-oxidant heme-oxygenase-1 was reduced in hyperuricemic mice. However, the expression of anti-oxidant enzymes (Nrf-1 and Sod) and metabolic genes associated with fatty acid oxidation (Cpt1, Pparg, and Pgc1b) significantly increased as compared to mice without HU 14 days after AKI/AKD. In addition, HU increased the number of phospho-Histone-3 and intact proximal tubules and restored tubular mitochondrial morphology as indicated by an increased mitochondrial aspect ratio (Figure right). Conclusion Our data imply that asymptomatic HU improves kidney outcomes after IR-induced AKI/AKD because HU attenuates tubular injury and inflammation. In addition, we found that HU enhances the metabolic activity and anti-inflammatory M2-like macrophage polarization as well as restores mitochondrial biogenesis in tubular epithelial cells, suggesting that HU acts as antioxidant by improving kidney recovery after AKI/AKD.

How Reliable Is Automated Urinalysis in Acute Kidney Injury?

2020 ◽  
Author(s):  
Vani Chandrashekar ◽  
Anil Tarigopula ◽  
Vikram Prabhakar
Keyword(s):  
Acute Kidney Injury ◽  
Logistic Regression ◽  
Regression Analysis ◽  
Epithelial Cells ◽  
Logistic Regression Analysis ◽  
Blood Cells ◽  
White Blood Cells ◽  
Kidney Injury ◽  
Tubular Epithelial Cells ◽  
Spearman Test

Abstract Objective Examination of urine sediment is crucial in acute kidney injury (AKI). In such renal injury, tubular epithelial cells, epithelial cell casts, and dysmorphic red cells may provide clues to etiology. The aim of this study was to compare automated urinalysis findings with manual microscopic analysis in AKI. Methods Samples from patients diagnosed with AKI and control patients were included in the study. Red blood cells, white blood cells, renal tubular epithelial cells/small round cells, casts, and pathologic (path) cast counts obtained microscopically and by a UF1000i cytometer were compared by Spearman test. Logistic regression analysis was used to assess the ability to predict AKI from parameters obtained from the UF1000i. Results There was poor correlation between manual and automated analysis in AKI. None of the parameters could predict AKI using logistic regression analysis. However, the increment in the automated path cast count increased the odds of AKI 93 times. Conclusion Automated urinalysis parameters are poor predictors of AKI, and there is no agreement with manual microscopy.

scholarly journals Cell Death Patterns Due to Warm Ischemia or Reperfusion in Renal Tubular Epithelial Cells Originating from Human, Mouse, or the Native Hibernator Hamster

Biology ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 48 ◽  
Author(s):  
Theodoros Eleftheriadis ◽  
Georgios Pissas ◽  
Georgia Antoniadi ◽  
Vassilios Liakopoulos ◽  
Ioannis Stefanidis
Keyword(s):  
Lipid Peroxidation ◽  
Acute Kidney Injury ◽  
Cell Death ◽  
Epithelial Cells ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Human Cells ◽  
Tubular Epithelial Cells

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.

scholarly journals Bone Marrow-Derived Mesenchymal Stem Cells Ameliorate Sepsis-Induced Acute Kidney Injury by Promoting Mitophagy of Renal Tubular Epithelial Cells via the SIRT1/Parkin Axis

2021 ◽  
Vol 12 ◽  
Author(s):  
Jun Guo ◽  
Rong Wang ◽  
Donghai Liu
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Acute Kidney Injury ◽  
Mesenchymal Stem Cells ◽  
Epithelial Cells ◽  
Kidney Injury ◽  
Tubular Epithelial Cells ◽  
Renal Tubular Epithelial Cells ◽  
Differentiation Potential ◽  
Renal Tubular

Sepsis is a common risk factor for acute kidney injury (AKI). Bone marrow-derived mesenchymal stem cells (BMSCs) bear multi-directional differentiation potential. This study explored the role of BMSCs in sepsis-induced AKI (SI-AKI). A rat model of SI-AKI was established through cecal ligation and perforation. The SI-AKI rats were injected with CM-DiL-labeled BMSCs, followed by evaluation of pathological injury of kidney tissues and kidney injury-related indicators and inflammatory factors. HK-2 cells were treated with lipopolysaccharide (LPS) to establish SI-SKI model in vitro. Levels of mitochondrial proteins, autophagy-related proteins, NLRP3 inflammasome-related protein, and expressions of Parkin and SIRT1 in renal tubular epithelial cells (RTECs) of kidney tissues and HK-2 cells were detected. The results showed that BMSCs could reach rat kidney tissues and alleviate pathological injury of SI-SKI rats. BMSCs inhibited inflammation and promoted mitophagy of RTECs and HK-2 cells in rats with SI-AKI. BMSCs upregulated expressions of Parkin and SIRT1 in HK-2 cells. Parkin silencing or SIRT1 inhibitor reversed the promoting effect of BMSCs on mitophagy. BMSCs inhibited apoptosis and pyroptosis of RTECs in kidney tissues by upregulating SIRT1/Parkin. In conclusion, BMSCs promoted mitophagy and inhibited apoptosis and pyroptosis of RTECs in kidney tissues by upregulating SIRT1/Parkin, thereby ameliorating SI-AKI.

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