Abstract P544: Osteopontin Deficiency Decreases Autophagy and Exacerbates Tubular Injury in Acute Kidney Injury Induced by Folic Acid

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Tomoaki Nagao ◽  
Takafumi Okura ◽  
Akiko Tanino ◽  
Ken-ichi Miyoshi ◽  
Masayoshi Kukida ◽  
...  

Osteopontin (OPN), a secreted glycosylated phosphoprotein and pro-inflammatory cytokine, has been implicated in the pathology of several renal conditions, especially renal fibrosis in chronic kidney disease. OPN is slightly expressed in renal tubular cells in normal condition, but after acute tubular injury, OPN is highly induced in these cells. However, the role of induced OPN is still unclear. The aim of this study was to clarify the roles of OPN in acute kidney injury (AKI). AKI was induced in wild type (WT) and OPN knockout (KO) mice by using folic acid (FA) injection (0.35mg/kg). After 2days of injection, 34% of WT mice died, whereas 54% of KO died from renal failure. Kidneys from survived mice were removed and the renal histological changes, protein expression were examined. BUN and Creatinine levels were markedly elevated in WT-AKI and KO-AKI mice (BUN: WT-sham; 25.7±4.7mg/dl, WT-AKI; 315.0±173.2mg/dl, KO-AKI; 337.7±163.7mg/dl, Creatinine: WT-sham; 0.08±0.03 mg/dl, WT-AKI; 1.60±0.87 mg/dl, KO-AKI; 1.80±0.94 mg/dl). Renal OPN mRNA expression was increased in WT-AKI mice compared to WT-sham mice (p<0.05). High levels of OPN expression in renal tubular cells were induced in WT-AKI mice. TUNEL positive tubular cells were increased in KO-AKI mice compared to WT-AKI mice. In immunohistochemical analysis, Kidney injury molecules 1 (Kim-1) positive tubular cells were also highly increased in KO-AKI mice compared to WT-AKI mice. In contrast, LC3B (autophagy related protein) positive tubular cells were decreased in KO-AKI mice compared to WT-AKI mice. These results indicate that OPN deficiency exacerbates tubular injury via through the inhibiting autophagy in folic acid induced AKI mice.

2020 ◽  
Vol 21 (22) ◽  
pp. 8564
Author(s):  
Seok Jong Song ◽  
Su-mi Kim ◽  
Sang-ho Lee ◽  
Ju-Young Moon ◽  
Hyeon Seok Hwang ◽  
...  

Introduction: A recent study showed that early renal tubular injury is ameliorated in Nod-like receptor pyrin domain-containing protein 3 (NLRP3) KO mice with rhabdomyolysis-induced acute kidney injury (RIAKI). However, the precise mechanism has not been determined. Therefore, we investigated the role of NLRP3 in renal tubular cells in RIAKI. Methods: Glycerol-mediated RIAKI was induced in NLRP3 KO and wild-type (WT) mice. The mice were euthanized 24 h after glycerol injection, and both kidneys and plasma were collected. HKC-8 cells were treated with ferrous myoglobin to mimic a rhabdomyolytic environment. Results: Glycerol injection led to increase serum creatinine, aspartate aminotransferase (AST), and renal kidney injury molecule-1 (KIM-1) level; renal tubular necrosis; and apoptosis. Renal injury was attenuated in NLRP3 KO mice, while muscle damage and renal neutrophil recruitment did not differ between NLRP3 KO mice and WT mice. Following glycerin injection, increases in cleaved caspase-3, poly (ADP-ribose) polymerase (PARP), and a decrease in the glutathione peroxidase 4 (GPX-4) level were observed in the kidneys of mice with RIAKI, and these changes were alleviated in the kidneys of NLRP3 KO mice. NLRP3 was upregulated, and cell viability was suppressed in HKC-8 cells treated with ferrous myoglobin. Myoglobin-induced apoptosis and lipid peroxidation were significantly decreased in siNLRP3-treated HKC-8 cells compared to ferrous myoglobin-treated HKC-8 cells. Myoglobin reduced the mitochondrial membrane potential and increased mitochondrial fission and reactive oxygen species (ROS) and lipid peroxidation levels, which were restored to normal levels in NLRP3-depleted HKC-8 cells. Conclusions: NLRP3 depletion ameliorated renal tubular injury in a murine glycerol-induced acute kidney injury (AKI) model. A lack of NLRP3 improved tubular cell viability via attenuation of myoglobin-induced mitochondrial injury and lipid peroxidation, which might be the critical factor in protecting the kidney.


2013 ◽  
Vol 304 (4) ◽  
pp. F356-F366 ◽  
Author(s):  
Song He ◽  
Na Liu ◽  
George Bayliss ◽  
Shougang Zhuang

Proliferation of dedifferentiated intrinsic renal tubular cells has been recognized to be the major cellular event that contributes to renal repair after acute kidney injury (AKI). However, the underlying mechanism that initiates renal tubular dedifferentiation in vivo remains unexplored. Here we investigated whether epidermal growth factor receptor (EGFR) mediates this process in a murine model of folic acid (FA)-induced AKI using waved-2 mice that have reduced tyrosine kinase activity of EGFR and gefitinib, a specific EGFR inhibitor. Administration of FA for 48 h induced EGFR phosphorylation in the kidney of wild-type mice, but this was inhibited in waved-2 mice and wild-type mice given gefitinib. Compared with wild-type mice, waved-2 mice and wild-type mice treated with gefitinib had increased renal dysfunction, histologic damage, and tubular cell apoptosis after FA administration. PAX2, a dedifferentiation marker, and proliferating cell nuclear antigen, a proliferating marker, were highly expressed in renal tubular cells in wild-type mice; however, their expression was largely inhibited in the kidney of waved-2 mice. Inhibition of EGFR with gefitinib also blocked FA-induced expression of these two proteins in wild-type mice. Moreover, FA exposure resulted in phosphorylation of AKT, a downstream signaling molecule of the phosphatidylinositol 3-kinases pathway associated with renal epithelial proliferation in wild-type mice, and its phosphorylation was totally suppressed in waved-2 mice and wild-type mice given gefitinib. Taken together, these results suggest that EGFR activation is essential for initiation of renal tubular cell dedifferentiation and proliferation after AKI.


PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0126229 ◽  
Author(s):  
Tatsuki Matsumoto ◽  
Madoka Urushido ◽  
Haruna Ide ◽  
Masayuki Ishihara ◽  
Kazu Hamada-Ode ◽  
...  

2019 ◽  
Vol 20 (20) ◽  
pp. 5238 ◽  
Author(s):  
Daniela Maria Tanase ◽  
Evelina Maria Gosav ◽  
Smaranda Radu ◽  
Claudia Florida Costea ◽  
Manuela Ciocoiu ◽  
...  

Acute kidney injury (AKI) following platinum-based chemotherapeutics is a frequently reported serious side-effect. However, there are no approved biomarkers that can properly identify proximal tubular injury while routine assessments such as serum creatinine lack sensitivity. Kidney-injury-molecule 1 (KIM-1) is showing promise in identifying cisplatin-induced renal injury both in vitro and in vivo studies. In this review, we focus on describing the mechanisms of renal tubular cells cisplatin-induced apoptosis, the associated inflammatory response and oxidative stress and the role of KIM-1 as a possible biomarker used to predict cisplatin associated AKI.


2019 ◽  
Vol 44 (5) ◽  
pp. 1002-1013 ◽  
Author(s):  
Wen Zhang ◽  
Yunwen Yang ◽  
Huiping Gao ◽  
Yue Zhang ◽  
Zhanjun Jia ◽  
...  

Background: Some researches revealed that mitochondrial dysfunction is associated with various kidney injury. However, the role of mitochondrial dysfunction in the pathogenesis of acute kidney injury (AKI) still needs evidence. Methods: We evaluated the effect of mitochondrial complex I inhibitor rotenone on folic acid (FA)-induced AKI in mice. Results: Strikingly, the mice pretreated with rotenone at a dose of 200 ppm in food showed exacerbated kidney injury as shown by higher levels of blood urea nitrogen and creatinine compared with FA alone group. Meanwhile, both renal tubular injury score and the expression of renal tubular injury marker neutrophil gelatinase-associated lipocalin were further elevated in rotenone-pretreated mice, suggesting the deteriorated renal tubular injury. Moreover, the decrements of mitochondrial DNA copy number and the expressions of mitochondrial Cytochrome c oxidase subunit 1, mitochondrial NADH dehydrogenase subunit 1, and mitochondria-specific superoxide dismutase (SOD2) in the kidneys of FA-treated mice were further reduced in rotenone-pretreated mice, indicating the aggravated mitochondrial damage. In parallel with the SOD2 reduction, the oxidative stress markers of malondialdehyde and HO-1 displayed greater increment in AKI mice with rotenone pretreatment in line with the deteriorated apoptotic response and inflammation. Conclusion: Our results suggested that the inhibition of mitochondrial complex I activity aggravated renal tubular injury, mitochondrial damage, oxidative stress, cell apoptosis, and inflammation in FA-induced AKI.


2020 ◽  
Vol 9 (11) ◽  
pp. 3547
Author(s):  
Ti-I Chueh ◽  
Cai-Mei Zheng ◽  
Yi-Chou Hou ◽  
Kuo-Cheng Lu

The coronavirus 2019 (COVID-19) pandemic has caused a huge impact on health and economic issues. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes cellular damage by entry mediated by the angiotensin-converting enzyme 2 of the host cells and its conjugation with spike proteins of SARS-CoV-2. Beyond airway infection and acute respiratory distress syndrome, acute kidney injury is common in SARS-CoV-2-associated infection, and acute kidney injury (AKI) is predictive to multiorgan dysfunction in SARS-CoV-2 infection. Beyond the cytokine storm and hemodynamic instability, SARS-CoV-2 might directly induce kidney injury and cause histopathologic characteristics, including acute tubular necrosis, podocytopathy and microangiopathy. The expression of apparatus mediating SARS-CoV-2 entry, including angiotensin-converting enzyme 2, transmembrane protease serine 2 (TMPRSS2) and a disintegrin and metalloprotease 17 (ADAM17), within the renal tubular cells is highly associated with acute kidney injury mediated by SARS-CoV-2. Both entry from the luminal and basolateral sides of the renal tubular cells are the possible routes for COVID-19, and the microthrombi associated with severe sepsis and the dysregulated renin–angiotensin–aldosterone system worsen further renal injury in SARS-CoV-2-associated AKI. In the podocytes of the glomerulus, injured podocyte expressed CD147, which mediated the entry of SARS-CoV-2 and worsen further foot process effacement, which would worsen proteinuria, and the chronic hazard induced by SARS-CoV-2-mediated kidney injury is still unknown. Therefore, the aim of the review is to summarize current evidence on SARS-CoV-2-associated AKI and the possible pathogenesis directly by SARS-CoV-2.


2020 ◽  
Author(s):  
Yun Tang ◽  
Yanmei Wang ◽  
Chan Wang ◽  
Meidie Yu ◽  
Li Li ◽  
...  

Abstract Septic acute kidney injury (AKI) mainly results in life-threatening renal dysfunction involving renal tubular injury to bring heavy burden to patients in intensive care unit (ICU). However, there is still a lack of therapy to prevent septic AKI effectively and inexpensive. To observe the role and novel mechanism of isoliquiritigenin (ISL) which isolated from the roots of licorice in septic AKI, we used LPS to induce renal tubular injury upon septic AKI both in vitro and in vivo. 50mg/kg ISL and 5 mg/kg Ferrostatin-1 were once given to the male C57BL/6 mice one hour before 1 mg/kg LPS i.p injection. 50 μM and 100 μM ISL respectively pre-treat the human renal tubular cells 5 hrs before 2 μg/ml LPS stimulation. We found ISL pretreatment apparently reversed LPS-induced renal dysfunction and ameliorated murine renal tubular injury by suppression HMGB1 pathway. Furthermore, we observed that LPS induced autophagy and ferroptosis in renal tubular, whereas ISL pretreatment significantly suppress autophagy and ferroptosis of renal tubular both in vitro and in vivo. Mechanically, autophagy activated ferroptosis via NCOA4-mediated ferritinophagy. Moreover, HMGB1 is required for ferritinophagy in renal tubular. ISL treatment inhibited the expression of HMGB1. Taken together, these results suggest that ISL protects LPS-induced acute kidney injury through suppression of HMGB1 pathway in renal tubular against ferritinophagy.


2021 ◽  
Author(s):  
Woo Yeong Park ◽  
Sun-Ha Lim ◽  
Yaerim Kim ◽  
Jin Hyuk Paek ◽  
Kyubok Jin ◽  
...  

Abstract Renal tubular injury caused by oxidative stress and inflammation results in acute kidney injury. Recent research reported that antibiotics may restore deteriorated renal tubules, but the underlying mechanism remains unclear. Therefore, we investigated the efficacy and mechanism of action of antibiotics against renal tubular injury. We screened ciprofloxacin, ceftizoxime, minocycline, and netilmicin and selected ciprofloxacin to examine further because of its low toxicity towards renal tubular cells. We evaluated the effect of ciprofloxacin on cell survival by analyzing apoptosis and autophagy. TUNEL assay results showed that the ciprofloxacin group had less apoptotic cells than the control group. The ratio of cleaved caspase 3 to caspase 3, the final effector in the apoptosis process, was decreased, but the ratio of Bax to Bcl-2 located upstream of caspase 3 was not decreased in the ciprofloxacin group. Therefore, apoptosis inhibition does not occur via Bax/Bcl-2. Conversely, the levels of phosphorylated Bcl-2, and Beclin-1, an autophagy marker, were increased, and that of caspase-3 was decreased in the ciprofloxacin group. This indicates that ciprofloxacin enhanced autophagy, increasing the amount of free Beclin-1 via phosphorylated Bcl-2, and inhibited caspase activity. Therefore, ciprofloxacin might increase renal cell viability through the autophagy activation in acute kidney injury.


2019 ◽  
Vol 317 (3) ◽  
pp. F584-F592 ◽  
Author(s):  
Wen-Ting Zhao ◽  
Jun-Wen Huang ◽  
Ping-Ping Sun ◽  
Tao Su ◽  
Jia-Wei Tang ◽  
...  

Acute tubulointerstitial nephritis (ATIN) is a common cause of acute kidney injury characterized by inflammatory cells infiltrating in the interstitium. The present study aimed to explore noninvasive biomarkers that might indicate activity of pathological injuries and help direct treatment. Fifty-four patients with clinical-pathologically diagnosed ATIN from January 1, 2014, to June 30, 2016, at Peking University First Hospital were enrolled. Urine samples were collected on the morning of renal biopsy and assessed for urinary kidney injury molecule-1 (KIM-1) and urinary soluble C5b-9 (sC5b-9). Immunofluorescence staining for KIM-1 and C5b-9 was performed in biopsied kidney sections from ATIN cases. The clinical and pathological relevance of the two urinary biomarkers was analyzed. Both urinary KIM-1 and sC5b-9 values were significantly elevated in patients with ATIN compared with healthy controls. The urinary KIM-1 level positively correlated with urinary N-acetyl-β-d-glucosaminidase ( r = 0. 542, P = 0.001) and the pathological tubular injury score ( r = 0.469, P < 0.001), whereas the urinary sC5b-9 level was related to pathological activity scores for tubular injury ( r = 0.413, P = 0.002), interstitial inflammation ( r = 0.388, P = 0.004), and treatment response ( r = 0.564, P < 0.001). Urinary KIM-1 tended to have better diagnostic value for tubular injury than urinary sC5b-9, whereas only urinary sC5b-9 was able to demonstrate severe interstitial inflammation. A combination of urinary KIM-1 and sC5b-9 had an area under the receiver-operating characteristic curve of 0.864 (95% confidence interval: 0.766–0.963, P < 0.001, sensitivity: 75%, specificity: 88%) for acute tissue injury in ATIN. KIM-1 expression was markedly increased in renal tubular cells in both ATIN and acute tubular necrosis conditions, whereas a significant upregulation of C5b-9 was only detected in the tubular cells and interstitial cells in ATIN cases. Urinary KIM-1 is a specific biomarker for renal tubular injury in ATIN, whereas urinary sC5b-9 is valuable in demonstrating severe interstitial inflammation. The combination of these two biomarkers helps identify patients at an acute injury stage and, therefore, might facilitate clinical evaluation and guide immunosuppressive therapy.


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