scholarly journals Ferrotoxicity and its amelioration by endogenous vitamin D in experimental acute kidney injury

2020 ◽  
Vol 245 (16) ◽  
pp. 1474-1489
Author(s):  
Chandrashekar Annamalai ◽  
Rajesh N Ganesh ◽  
Pragasam Viswanathan
Keyword(s):  
Gene Expression ◽  
Vitamin D ◽  
Acute Kidney Injury ◽  
Wistar Rats ◽  
Kidney Injury ◽  
Urinary Ngal ◽  
Tissue Lipid ◽  
Dihydroxyvitamin D3 ◽  
Tissue Lipid Peroxidation ◽  
Serum And Urine

Acute kidney injury causes significant morbidity and mortality. This experimental animal study investigated the simultaneous impact of iron and vitamin D on acute kidney injury induced by iohexol, an iodinated, non-ionic monomeric radiocontrast agent in Wistar rats. Out of 36 healthy male Wistar rats, saline was injected into six control rats (group 1) and iohexol into the remaining 30 experimental rats (groups 2 to 6 comprising six rats each). Biochemical, renal histological changes, and gene expression of iron-regulating proteins and 1 α-hydroxylase were analyzed. Urinary neutrophil gelatinase-associated lipocalin (NGAL), serum creatinine, urine protein, serum and urine catalytic iron, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and tissue lipid peroxidation were assayed. Rats injected with iohexol showed elevated urinary NGAL (11.94 ± 6.79 ng/mL), serum creatinine (2.92 ± 0.91 mg/dL), and urinary protein levels (11.03 ± 9.68 mg/mg creatinine) together with histological evidence of tubular injury and iron accumulation. Gene expression of iron-regulating proteins and 1 α-hydroxylase was altered. Serum and urine catalytic iron levels were elevated (0.57 ± 0.17; 48.95 ± 29.13 µmol/L) compared to controls (0.49 ± 0.04; 20.7 ± 2.62 µmol/L, P < 0.001). Urine catalytic iron positively correlated with tissue peroxidation (r = 0.469, CI 0.122 to 0.667, P = 0.004) and urinary NGAL (r = 0.788, CI 0.620 to 0.887, P < 0.001). 25-hydroxyvitamin D3 (61.58 ± 9.60 ng/mL) and 1,25-dihydroxyvitamin D3 (50.44 ± 19.76 pg/mL) levels increased simultaneously. In a multivariate linear regression analysis, serum iron, urine catalytic iron, and tissue lipid peroxidation independently and positively predicted urinary NGAL, an acute kidney injury biomarker. This study highlights the nephrotoxic potential of catalytic iron besides demonstrating a concurrent induction of vitamin D endogenously for possible renoprotection in acute kidney injury. Impact statement This work provides in-depth insights on catalytic iron-induced cytotoxicity and the resultant triggering of endogenous vitamin D synthesis in experimental acute kidney injury. Our results reveal significantly elevated levels of catalytic iron culminating in oxidant-mediated renal injury and a concomitant increase in 1,25-dihdyroxyvitamin D3 levels. Also, changes in other iron-related proteins including transferrin, ferritin, and hepcidin were observed both in the serum as well as in their mRNA expression. We consider all these findings vital since no connection between catalytic iron and vitamin D has been established so far. Furthermore, we believe that this work provides new and interesting results, with catalytic iron emerging as an important target in ameliorating renal cellular injury, possibly by timely administration of vitamin D. It also needs to be seen if these observations made in rats could be translated to humans by means of robust clinical trials.

NMR-Based Serum and Urine Metabolomic Profile Reveals Suppression of Mitochondrial Pathways in Experimental Sepsis-Associated Acute Kidney Injury

2021 ◽  
Author(s):  
Stephen Wade Standage ◽  
Shenyuan Xu ◽  
Lauren Brown ◽  
Qing Ma ◽  
Adeleine Koterba ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Kidney Injury ◽  
Kidney Function ◽  
Systemic Inflammation ◽  
Kidney Tissue ◽  
Kidney Injury ◽  
Acid Oxidation ◽  
Experimental Sepsis ◽  
Metabolic Derangement ◽  
Serum And Urine

Sepsis-associated acute kidney injury (SA-AKI) is a significant problem in the critically ill that causes increased death. Emerging understanding of this disease implicates metabolic dysfunction in its pathophysiology. This study sought to identify specific metabolic pathways amenable to potential therapeutic intervention. Using a murine model of sepsis, blood and tissue samples were collected for assessment of systemic inflammation, kidney function, and renal injury. Nuclear magnetic resonance (NMR)-based metabolomics quantified dozens of metabolites in serum and urine which were subsequently submitted to pathway analysis. Kidney tissue gene expression analysis confirmed implicated pathways. Septic mice had elevated circulating levels of inflammatory cytokines and increased levels of blood urea nitrogen and creatinine, indicating both systemic inflammation and poor kidney function. Renal tissue showed only mild histologic evidence of injury in sepsis. NMR metabolomic analysis identified the involvement of mitochondrial pathways associated with branched-chain amino acid (BCAA) metabolism, fatty acid oxidation, and de novo nicotinamide adenine dinucleotide (NAD+) biosynthesis in SA-AKI. Renal cortical gene expression of enzymes associated with those pathways was predominantly suppressed. Similar to humans, septic mice demonstrate renal dysfunction without significant tissue disruption, pointing to metabolic derangement as an important contributor to SA-AKI pathophysiology. Metabolism of BCAAs and fatty acids and NAD+ synthesis, which all center on mitochondrial function, appear to be suppressed. Developing interventions to activate these pathways may provide new therapeutic opportunities for SA-AKI.

Vitamin D in Acute Kidney Injury

2013 ◽  
Vol 12 (4) ◽  
pp. 262-272 ◽  
Author(s):  
Andrea Braun ◽  
Kenneth Christopher
Keyword(s):  
Vitamin D ◽  
Acute Kidney Injury ◽  
Kidney Injury

PO-0634 Factors Limiting Usefulness Of Serum And Urinary Ngal As A Marker Of Acute Kidney Injury In Preterm Newborns

2014 ◽  
Vol 99 (Suppl 2) ◽  
pp. A461.2-A461
Author(s):  
A Suchojad ◽  
M Smertka ◽  
A Tarko ◽  
M Majcherczyk ◽  
A Brzozowska ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Kidney Injury ◽  
Urinary Ngal ◽  
Preterm Newborns

scholarly journals Hyperbaric Oxygen Preconditioning Upregulates Heme OxyGenase-1 and Anti-Apoptotic Bcl-2 Protein Expression in Spontaneously Hypertensive Rats with Induced Postischemic Acute Kidney Injury

2021 ◽  
Vol 22 (3) ◽  
pp. 1382
Author(s):  
Jelena Nesovic Ostojic ◽  
Milan Ivanov ◽  
Nevena Mihailovic-Stanojevic ◽  
Danijela Karanovic ◽  
Sanjin Kovacevic ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Protein Expression ◽  
Hyperbaric Oxygen ◽  
Heme Oxygenase ◽  
Spontaneously Hypertensive Rats ◽  
Wistar Rats ◽  
Kidney Injury ◽  
Heme Oxygenase 1 ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive

Renal ischemia and reperfusion (I/R) injury is the most common cause of acute kidney injury (AKI). Pathogenesis of postischemic AKI involves hemodynamic changes, oxidative stress, inflammation process, calcium ion overloading, apoptosis and necrosis. Up to date, therapeutic approaches to treat AKI are extremely limited. Thus, the aim of this study was to evaluate the effects of hyperbaric oxygen (HBO) preconditioning on citoprotective enzyme, heme oxygenase-1 (HO-1), pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins expression, in postischemic AKI induced in normotensive Wistar and spontaneously hypertensive rats (SHR). The animals were randomly divided into six experimental groups: SHAM-operated Wistar rats (W-SHAM), Wistar rats with induced postischemic AKI (W-AKI) and Wistar group with HBO preconditioning before AKI induction (W-AKI + HBO). On the other hand, SHR rats were also divided into same three groups: SHR-SHAM, SHR-AKI and SHR-AKI + HBO. We demonstrated that HBO preconditioning upregulated HO-1 and anti-apoptotic Bcl-2 protein expression, in both Wistar and SH rats. In addition, HBO preconditioning improved glomerular filtration rate, supporting by significant increase in creatinine, urea and phosphate clearances in both rat strains. Considering our results, we can also say that even in hypertensive conditions, we can expect protective effects of HBO preconditioning in experimental model of AKI.

scholarly journals P0517RENAL STEM CELLS (ARPCS) AS A NEPHROPROTECTIVE APPROACH DURING CISPLATIN-INDUCED ACUTE KIDNEY INJURY: A DEFENSE MECHANISM BY EXTRACELLULAR VESICLES CARRYING THE CYP1B1 GENE

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
ROSSANA FRANZIN ◽  
Fabio Sallustio ◽  
Claudia Curci ◽  
Simona Simone ◽  
Angela Picerno ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Kidney Injury ◽  
Extracellular Vesicles ◽  
Caspase 3 ◽  
Defense Mechanism ◽  
Kidney Injury ◽  
The Body ◽  
Cell Culture Supernatant ◽  
Protective Agent ◽  
Cyp1b1 Gene

Abstract Background and Aims Cisplatin, is a nonspecific cytotoxic agent that primarily interferes with cellular DNA replication and the cell cycle, nevertheless it lacks tumor selectivity and acts also in normal cells. The most serious adverse reaction of cisplatin is Acute Kidney Injury (AKI), limiting its use and efficacy in chemotherapy. Cisplatin nephrotoxicity is observed in more than 30% of older patients, however the mechanism of nephrotoxicity remains unclear and specific preventive measures are not available. Today, there is an urgent need for specific nephroprotective strategies to be used during cisplatin chemotherapy. Recently, we found that tubular stem/progenitor cells (tARPC) are able to protect the tubular epithelial (RPTEC) from cisplatin induced injury, preserving their proliferation and inhibiting apoptosis. The aim of this study was to identify the molecular mechanisms involved in tARPC-mediated resistance to cisplatin. Method Co-cultures of RPTEC cells and tARPCs were exposed to cisplatin (2.5 µM) for 6 h and then kept in culture for 96 h. Gene expression profile was obtained from tARPCs and RPTECs by Agilent SurePrint G3 Human Gene Expression Microarrays. Genespring and R software were used for the analysis. Gene expression data were validated by Real-time PCR. Extracellular vesicles were isolated from cell culture supernatant by miRCURY Exosome Cell/Urine/CSF Kit (Qiagen) and RNA contained in extracellular vesicles was purified, analyzed in quality by Bioanalyzer (RNA nano) and evaluated by qPCR. The BrdU assay and caspase 3 were used to measure proliferation and apoptosis levels. Immunohistochemical expression of activated caspase-3 was used as a marker of apoptosis in RPTECs. Results By a whole-genome gene expression analysis, we found 107 genes specifically modulated by RPTECs in response to cisplatin and, among these, 30 genes induced by ARPCs following the cisplatin damage. In particular, we found a strong upregulation of the CYP1B1 gene (false discovery rate corrected p value &lt;0.05; fold change=4,1). The qPCR confirmed the increase in CYP1B1 levels in the co-cultures with respect to the respective basal conditions (p &lt;0.05). Interestingly, the CYP1B1 mRNA was also enveloped in Extracellular Vesicles released in the cell co-culture media by tARPC and RPTEC after cisplatin exposition. The CYP1B1 gene encodes a member of the cytochrome P450 superfamily of enzymes and the produced enzyme metabolizes procarcinogens, such as polycyclic aromatic hydrocarbons. CYP1B1 has been shown to be active within tumors and is also capable of metabolizing a structurally diverse range of anticancer drugs. It is responsible for the resistance to docetaxel, cisplatin, tamoxifen and nucleoside analogues. CYP1B1 is involved in the detoxification of the body by various exogenous toxic agents, including cisplatin. We found that CYP1B1 gene was expressed at low levels in RPTECs and in cisplatin-damaged RPTECs. Moreover, 96 h days after 2.5 μM exposure to cisplatin, RPTECs reduced the proliferation and underwent in apoptosis, as showed by caspase 3. However, in co-culture with ARPCs, ARPC cellular and extracellular vesicles CYP1B1 gene expression significantly increased, the apoptotic process was stopped and RPTECs increased their proliferation rate. These data support the hypothesis that ARPCs are sensor of cisplatin damaged-RPTEC and confers cisplatin resistance by transferring CYP1B1 gene in extracellular vesicles. Conclusion This is the first evidence of a cisplatin-induced overexpression of CYP1b1 in renal epithelial cells as a defense mechanism against cisplatin toxicity. This is consistent with our previous data showing that renal progenitors are resistant to cisplatin. The findings may have biological and clinical significance in terms of their implications in cellular communications and potential use of CYP1B1 as biomarkers for AKI induced by cisplatin or as protective agent.

scholarly journals Urinary NGAL incorporation into Renal Angina Index for early detection of acute kidney injury in critically ill children

2019 ◽  
Vol 3 (2) ◽  
pp. 093-099 ◽  
Author(s):  
Ali Mohammed Abu Zeid ◽  
Doaa Youssef Mohammed* ◽  
Amal Saeed AbdAlazeem ◽  
Anas Saad Elsayed Mohammed Seddeeq ◽  
Ashraf Mohamed Elnaany
Keyword(s):  
Acute Kidney Injury ◽  
Early Detection ◽  
Critically Ill ◽  
Kidney Injury ◽  
Critically Ill Children ◽  
Urinary Ngal ◽  
Renal Angina Index ◽  
Renal Angina

scholarly journals Bioinformatic analysis identifies potential biomarkers and therapeutic targets of septic-shock-associated acute kidney injury

Hereditas ◽  
2021 ◽  
Vol 158 (1) ◽  
Author(s):  
Yun Tang ◽  
Xiaobo Yang ◽  
Huaqing Shu ◽  
Yuan Yu ◽  
Shangwen Pan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Septic Shock ◽  
Acute Kidney Injury ◽  
Molecular Mechanisms ◽  
Therapeutic Targets ◽  
Kidney Injury ◽  
Enrichment Analysis ◽  
Pathway Enrichment Analysis ◽  
Blood Samples ◽  
Potential Biomarkers

Abstract Background Sepsis and septic shock are life-threatening diseases with high mortality rate in intensive care unit (ICU). Acute kidney injury (AKI) is a common complication of sepsis, and its occurrence is a poor prognostic sign to septic patients. We analyzed co-differentially expressed genes (co-DEGs) to explore relationships between septic shock and AKI and reveal potential biomarkers and therapeutic targets of septic-shock-associated AKI (SSAKI). Methods Two gene expression datasets (GSE30718 and GSE57065) were downloaded from the Gene Expression Omnibus (GEO). The GSE57065 dataset included 28 septic shock patients and 25 healthy volunteers and blood samples were collected within 0.5, 24 and 48 h after shock. Specimens of GSE30718 were collected from 26 patients with AKI and 11 control patents. AKI-DEGs and septic-shock-DEGs were identified using the two datasets. Subsequently, Gene Ontology (GO) functional analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and protein-protein interaction (PPI) network analysis were performed to elucidate molecular mechanisms of DEGs. We also evaluated co-DEGs and corresponding predicted miRNAs involved in septic shock and AKI. Results We identified 62 DEGs in AKI specimens and 888, 870, and 717 DEGs in septic shock blood samples within 0.5, 24 and 48 h, respectively. The hub genes of EGF and OLFM4 may be involved in AKI and QPCT, CKAP4, PRKCQ, PLAC8, PRC1, BCL9L, ATP11B, KLHL2, LDLRAP1, NDUFAF1, IFIT2, CSF1R, HGF, NRN1, GZMB, and STAT4 may be associated with septic shock. Besides, co-DEGs of VMP1, SLPI, PTX3, TIMP1, OLFM4, LCN2, and S100A9 coupled with corresponding predicted miRNAs, especially miR-29b-3p, miR-152-3p, and miR-223-3p may be regarded as promising targets for the diagnosis and treatment of SSAKI in the future. Conclusions Septic shock and AKI are related and VMP1, SLPI, PTX3, TIMP1, OLFM4, LCN2, and S100A9 genes are significantly associated with novel biomarkers involved in the occurrence and development of SSAKI.

miR-30e-5p regulates autophagy and apoptosis by targeting Beclin1 involved in contrast-induced acute kidney injury

2021 ◽  
Vol 28 ◽  
Author(s):  
Xiaoqin Liu ◽  
Qingzhao Li ◽  
Lixin Sun ◽  
Limei Chen ◽  
Yue Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acute Kidney Injury ◽  
Cell Apoptosis ◽  
Cell Injury ◽  
Cell Model ◽  
Kidney Injury ◽  
Cell Vitality ◽  
A Cell ◽  
Renal Tubular ◽  
Induced Apoptosis

Aims: This study aims to verify if miR-30e-5p targets Beclin1 (BECN1), a key regulator of autophagy, and investigate the function of miR-30e-5p and Beclin1 through mediating autophagy and apoptosis in contrast-induced acute kidney injury (CI-AKI). Methods: Human renal tubular epithelial HK-2 cells were treated with Urografin to construct a cell model of CI-AKI. Real-time reverse transcription–polymerase chain reaction was used to detect gene expression. The dual-luciferase reporting assay and endogenous validation were used to verify targeting and regulating function. The expressions of protein were detected using Western blot. Cell proliferation was detected using methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. Cell apoptosis was detected using terminal-deoxynucleoitidyl transferase mediated nick end labeling assay, and autophagy was detected using transmission electron microscopy. Results: HK-2 cells exposed to Urografin for 2 h induced a significant increase in miR-30e-5p. miR-30e-5p had a targeting effect on Beclin1. Moreover, Urografin exposure can enhance cell apoptosis by increasing caspase 3 gene expression and inhibiting autophagy, which was induced by decreased Beclin1 expression regulated by miR-30e-5p, thereby resulting in renal cell injury. Downregulation of miR-30e-5p or upregulation of Beclin1 restored cell vitality by promoting autophagy and suppressing apoptosis in Urografin-treated cells. Conclusions: Urografin increased the expression of miR-30e-5p in HK-2 cells and thus decreased Beclin1 levels to inhibit autophagy, but induced apoptosis, which may be the mechanism for CI-AKI.

The Renal System

2017 ◽  
Author(s):  
Jayme E. Locke ◽  
John T Killian Jr
Keyword(s):  
Vitamin D ◽  
Acute Kidney Injury ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Kidney Injury ◽  
Donor Nephrectomy ◽  
General Surgeon ◽  
Ureteral Injuries ◽  
Renal System

This updated review on the renal system provides a concise overview of the topics most important to the general surgeon. Anatomic topics have been expanded to also include variant anatomy and surgical approaches. There is a new focus on the accuracy and utility of equations for estimating the glomerular filtration rate, as well as supplementation and pharmacology for the general surgeon with discussions of vitamin D and erythropoietin. Acute kidney injury is defined; its pathophysiology is discussed; and its management is outlined, highlighting evidence-based practice. Finally, urologic surgery is addressed with a focus on donor nephrectomy and its consequences, as well as the management of iatrogenic ureteral injuries. Key words: acute kidney injury; contrast nephropathy; erythropoiesis-stimulating agents; estimated glomerular filtration rate; iatrogenic ureteral injury; laparoscopic donor nephrectomy; renal surgical anatomy; vitamin D supplementation

The Renal System

2017 ◽  
Author(s):  
Jayme E. Locke ◽  
John T Killian Jr
Keyword(s):  
Vitamin D ◽  
Acute Kidney Injury ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Kidney Injury ◽  
Donor Nephrectomy ◽  
General Surgeon ◽  
Ureteral Injuries ◽  
Renal System

This updated review on the renal system provides a concise overview of the topics most important to the general surgeon. Anatomic topics have been expanded to also include variant anatomy and surgical approaches. There is a new focus on the accuracy and utility of equations for estimating the glomerular filtration rate, as well as supplementation and pharmacology for the general surgeon with discussions of vitamin D and erythropoietin. Acute kidney injury is defined; its pathophysiology is discussed; and its management is outlined, highlighting evidence-based practice. Finally, urologic surgery is addressed with a focus on donor nephrectomy and its consequences, as well as the management of iatrogenic ureteral injuries. Key words: acute kidney injury; contrast nephropathy; erythropoiesis-stimulating agents; estimated glomerular filtration rate; iatrogenic ureteral injury; laparoscopic donor nephrectomy; renal surgical anatomy; vitamin D supplementation

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