scholarly journals Anti-tumor NAMPT inhibitor, KPT-9274, mediates gender-dependent murine anemia and nephrotoxicity by regulating SIRT3-mediated SOD deacetylation

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shaneice Mitchell ◽  
Pu Zhang ◽  
Matthew Cannon ◽  
Larry Beaver ◽  
Amy Lehman ◽  
...  
Keyword(s):  
Manganese Superoxide Dismutase ◽  
De Novo ◽  
Phase 1 ◽  
Kidney Injury ◽  
Manganese Superoxide ◽  
Mechanism Of Toxicity ◽  
Mechanistic Basis ◽  
Epo Deficiency ◽  
Rate Limiting ◽  
Sirt3 Expression

AbstractKPT-9274 is a phase 1 first-in-class dual PAK4/NAMPT inhibitor for solid tumor and non-Hodgkin’s lymphoma. It demonstrates pre-clinical efficacy toward a broad spectrum of acute myeloid leukemia (AML) subtypes by inhibiting NAMPT-dependent NAD+ production. NAMPT is the rate-limiting enzyme in the salvage metabolic pathway leading to NAD+ generation. Tumor cells which are deficient in de novo pathway enzyme NAPRT1 are addicted to NAMPT. In clinical trials, treatment with NAMPT inhibitors resulted in dose-limiting toxicities. In order to dissect the mechanism of toxicity, mice were treated with KPT-9274 and resulting toxicities were characterized histopathologically and biochemically. KPT-9274 treatment caused gender-dependent stomach and kidney injuries and anemia. Female mice treated with KPT-9274 had EPO deficiency and associated impaired erythropoiesis. KPT-9274 treatment suppressed SIRT3 expression and concomitantly upregulated acetyl-manganese superoxide dismutase (MnSOD) in IMCD3 cells, providing a mechanistic basis for observed kidney toxicity. Importantly, niacin supplementation mitigated KPT-9274-caused kidney injury and EPO deficiency without affecting its efficacy. Altogether, our study delineated the mechanism of KPT-9274-mediated toxicity and sheds light onto developing strategies to improve the tolerability of this important anti-AML inhibitor.

scholarly journals Genetic Polymorphisms of MnSOD Modify the Impacts of Environmental Melamine on Oxidative Stress and Early Kidney Injury in Calcium Urolithiasis Patients

Antioxidants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 152
Author(s):  
Chia-Chu Liu ◽  
Chia-Fang Wu ◽  
Yung-Chin Lee ◽  
Tsung-Yi Huang ◽  
Shih-Ting Huang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Manganese Superoxide Dismutase ◽  
Kidney Injury ◽  
Normal Function ◽  
Nucleotide Polymorphisms ◽  
Tubular Injury ◽  
Single Nucleotide ◽  
Manganese Superoxide ◽  
Calcium Urolithiasis ◽  
Renal Tubular

Environmental melamine exposure increases the risks of oxidative stress and early kidney injury. Manganese superoxide dismutase (MnSOD), glutathione peroxidase, and catalase can protect the kidneys against oxidative stress and maintain normal function. We evaluated whether their single-nucleotide polymorphisms (SNPs) could modify melamine’s effects. A total of 302 patients diagnosed with calcium urolithiasis were enrolled. All patients provided one-spot overnight urine samples to measure their melamine levels, urinary biomarkers of oxidative stress and renal tubular injury. Median values were used to dichotomize levels into high and low. Subjects carrying the T allele of rs4880 and high melamine levels had 3.60 times greater risk of high malondialdehyde levels than those carrying the C allele of rs4880 and low melamine levels after adjustment. Subjects carrying the G allele of rs5746136 and high melamine levels had 1.73 times greater risk of high N-Acetyl-β-d-glucosaminidase levels than those carrying the A allele of rs5746136 and low melamine levels. In conclusion, the SNPs of MnSOD, rs4880 and rs5746136, influence the risk of oxidative stress and renal tubular injury, respectively, in calcium urolithiasis patients. In the context of high urinary melamine levels, their effects on oxidative stress and renal tubular injury were further increased.

scholarly journals IκBα (inhibitory κBα) identified as labile repressor of MnSOD (manganese superoxide dismutase) expression

2004 ◽  
Vol 384 (3) ◽  
pp. 543-549 ◽  
Author(s):  
Kelley K. KININGHAM ◽  
Chotiros DAOSUKHO ◽  
Daret K. ST. CLAIR
Keyword(s):  
Superoxide Dismutase ◽  
Cell Line ◽  
Manganese Superoxide Dismutase ◽  
Phorbol Esters ◽  
De Novo ◽  
Nuclear Factor Κb ◽  
Binding Activity ◽  
Inhibitory Protein ◽  
Manganese Superoxide ◽  
Pre Treatment

Cytokines, phorbol esters, radiation and chemotherapeutic drugs up-regulate the expression of MnSOD (manganese superoxide dismutase). Using the VA-13 cell line, we studied the regulation of SOD2 upon treatment with PMA. Pre-treatment with CHX (cycloheximide) followed by PMA led to significantly higher levels of MnSOD mRNA compared with those with either agent alone, suggesting de novo synthesis of an inhibitory protein. PMA treatment modulates redox-sensitive transcription factors, therefore we evaluated the effects of this combination treatment upon AP-1 (activator protein 1) and NF-κB (nuclear factor κB), two trans-acting factors suggested to play a role in SOD2 regulation. Co-administration of CHX and PMA led to a time-dependent increase in the binding activity of NF-κB. Therefore we evaluated IκBα (inhibitory κBα) and found that co-administration decreased its steady-state level compared with either agent alone, suggesting that enhanced NF-κB activation is due to inhibition of IκBα synthesis. PMA activates PKC (protein kinase C) enzymes which phosphorylate IκBα, leading to its degradation, therefore we used GF109203X to inhibit PKC activity. Stable transfection utilizing a PMA-responsive element in the human SOD2 gene, showed a concentration-dependent decrease in luciferase and NF-κB-binding activity with GF109203X. Western blot analysis indicated the presence of several PKC isoforms in the VA-13 cell line; however, PMA pre-treatment specifically down-regulated α and βI, suggesting a role for one or more of these proteins in SOD2 induction. Taken together, these results indicate that the PKC pathway leading to SOD2 induction proceeds at least in part through NF-κB and that inhibition of IκBα synthesis might serve as a potential pharmacological approach to up-regulate MnSOD.

scholarly journals Inactivation of renal mitochondrial respiratory complexes and manganese superoxide dismutase during sepsis: mitochondria-targeted antioxidant mitigates injury

2014 ◽  
Vol 306 (7) ◽  
pp. F734-F743 ◽  
Author(s):  
Naeem K. Patil ◽  
Nirmala Parajuli ◽  
Lee Ann MacMillan-Crow ◽  
Philip R. Mayeux
Keyword(s):  
Superoxide Dismutase ◽  
Mitochondrial Dysfunction ◽  
Complex I ◽  
Animal Studies ◽  
Manganese Superoxide Dismutase ◽  
Cecal Ligation ◽  
Kidney Injury ◽  
Renal Microcirculation ◽  
Mitochondrial Superoxide ◽  
Manganese Superoxide

Acute kidney injury (AKI) is a complication of sepsis and leads to a high mortality rate. Human and animal studies suggest that mitochondrial dysfunction plays an important role in sepsis-induced multi-organ failure; however, the specific mitochondrial targets damaged during sepsis remain elusive. We used a clinically relevant cecal ligation and puncture (CLP) murine model of sepsis and assessed renal mitochondrial function using high-resolution respirometry, renal microcirculation using intravital microscopy, and renal function. CLP caused a time-dependent decrease in mitochondrial complex I and II/III respiration and reduced ATP. By 4 h after CLP, activity of manganese superoxide dismutase (MnSOD) was decreased by 50% and inhibition was sustained through 36 h. These events were associated with increased mitochondrial superoxide generation. We then evaluated whether the mitochondria-targeted antioxidant Mito-TEMPO could reverse renal mitochondrial dysfunction and attenuate sepsis-induced AKI. Mito-TEMPO (10 mg/kg) given at 6 h post-CLP decreased mitochondrial superoxide levels, protected complex I and II/III respiration, and restored MnSOD activity by 18 h. Mito-TEMPO also improved renal microcirculation and glomerular filtration rate. Importantly, even delayed therapy with a single dose of Mito-TEMPO significantly increased 96-h survival rate from 40% in untreated septic mice to 80%. Thus, sepsis causes sustained inactivation of three mitochondrial targets that can lead to increased mitochondrial superoxide. Importantly, even delayed therapy with Mito-TEMPO alleviated kidney injury, suggesting that it may be a promising approach to treat septic AKI.

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