scholarly journals Mitochondrial DNA alterations underlie an irreversible shift to aerobic glycolysis in fumarate hydratase–deficient renal cancer

2021 ◽  
Vol 14 (664) ◽  
pp. eabc4436
Author(s):  
Daniel R. Crooks ◽  
Nunziata Maio ◽  
Martin Lang ◽  
Christopher J. Ricketts ◽  
Cathy D. Vocke ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Respiratory Chain ◽  
Human Cancer ◽  
Aerobic Glycolysis ◽  
Krebs Cycle ◽  
Fumarate Hydratase ◽  
Mitochondrial Respiratory Chain ◽  
Respiratory Chain Complexes ◽  
Cycle Enzyme ◽  
Mtdna Mutations

Understanding the mechanisms of the Warburg shift to aerobic glycolysis is critical to defining the metabolic basis of cancer. Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an aggressive cancer characterized by biallelic inactivation of the gene encoding the Krebs cycle enzyme fumarate hydratase, an early shift to aerobic glycolysis, and rapid metastasis. We observed impairment of the mitochondrial respiratory chain in tumors from patients with HLRCC. Biochemical and transcriptomic analyses revealed that respiratory chain dysfunction in the tumors was due to loss of expression of mitochondrial DNA (mtDNA)–encoded subunits of respiratory chain complexes, caused by a marked decrease in mtDNA content and increased mtDNA mutations. We demonstrated that accumulation of fumarate in HLRCC tumors inactivated the core factors responsible for replication and proofreading of mtDNA, leading to loss of respiratory chain components, thereby promoting the shift to aerobic glycolysis and disease progression in this prototypic model of glucose-dependent human cancer.

scholarly journals Respiratory-deficient human fibroblasts exhibiting defective mitochondrial DNA replication

1995 ◽  
Vol 305 (3) ◽  
pp. 817-822 ◽  
Author(s):  
A G Bodnar ◽  
J M Cooper ◽  
J V Leonard ◽  
A H V Schapira
Keyword(s):  
Mitochondrial Dna ◽  
Respiratory Chain ◽  
Cultured Cells ◽  
Human Fibroblasts ◽  
Genetic Defect ◽  
Mitochondrial Protein ◽  
Mitochondrial Respiratory Chain ◽  
Human Cell Line ◽  
Respiratory Chain Complexes ◽  
Respiratory Deficient

We have characterized cultured skin fibroblasts from two siblings affected with a fatal mitochondrial disease caused by a nuclear genetic defect. Mitochondrial respiratory-chain function was severely decreased in these cells. Southern-blot analysis showed that the fibroblasts had reduced levels of mitochondrial DNA (mtDNA). The mtDNA was unstable and was eliminated from the cultured cells over many generations, generating the rho0 genotype. As the mtDNA level decreased, the cells became more dependent upon pyruvate and uridine for growth. Nuclear-encoded subunits of respiratory-chain complexes were synthesized and imported into the mitochondria of the mtDNA-depleted cells, albeit at reduced levels compared with the controls. Mitochondrial protein synthesis directed by the residual mtDNA indicated that the mtDNA was expressed and that the defect specifically involves the replication or maintenance of mtDNA. This is a unique example of a respiratory-deficient human cell line exhibiting defective mtDNA replication.

scholarly journals Dihydrorhodamine 123 identifies impaired mitochondrial respiratory chain function in cultured cells harboring mitochondrial DNA mutations.

1996 ◽  
Vol 44 (6) ◽  
pp. 571-579 ◽  
Author(s):  
C Sobreira ◽  
M Davidson ◽  
M P King ◽  
A F Miranda
Keyword(s):  
Mitochondrial Dna ◽  
Respiratory Chain ◽  
Mitochondrial Function ◽  
Cultured Cells ◽  
Mitochondrial Respiratory Chain ◽  
Mtdna Mutations ◽  
Dihydrorhodamine 123 ◽  
Very High ◽  
Mitochondrial Respiratory ◽  
In Cells

Several human diseases have been found to be caused by mitochondrial DNA (mtDNA) mutations. Pathogenic mutated (mut) mtDNAs are usually "heteroplasmic," coexisting intracellularly with wild-type (wt) mtDNAs. For some mtDNA mutations, cells have normal levels of respiratory chain function unless the percentage of mut-mtDNA is very high. Although progress in understanding the molecular basis of mitochondrial diseases has been remarkable, the heterogeneity of mut-mtDNA distribution, even among cells of the same tissue, makes it difficult to clearly delineate the relationships between mtDNA mutations, gene dosage, and clinical phenotypes. In a search for screening methods for identifying cultured cells with deficient mitochondrial function, we incubated living cells harboring mut-mtDNAs with dihydrorhodamine 123 (DHR123), an uncharged, nonfluorescent agent that can be converted by oxidation to the fluorescent laser dye rhodamine 123 (R123). Bright mitochondrial staining was observed in cells that respired normally. Fluorescence was significantly reduced in cells with mitochondrial respiratory chain dysfunction resulting from very high levels of mut-mtDNAs. The data show that DHR123 is useful for assessing mitochondrial function in single cells, and can be used for isolating viable, respiratory chain-deficient cells from heterogeneous cultures.

scholarly journals Protein Kinase A/CREB Signaling Prevents Adriamycin-Induced Podocyte Apoptosis via Upregulation of Mitochondrial Respiratory Chain Complexes

2017 ◽  
Vol 38 (1) ◽  
Author(s):  
Kewei Xie ◽  
Mingli Zhu ◽  
Peng Xiang ◽  
Xiaohuan Chen ◽  
Ayijiaken Kasimumali ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Respiratory Chain ◽  
Mitochondrial Respiratory Chain ◽  
Peroxisome Proliferator ◽  
Respiratory Chain Complexes ◽  
Peroxisome Proliferator Activated Receptor ◽  
Kinase A ◽  
Mitochondrial Respiratory

ABSTRACT Previous work showed that the activation of protein kinase A (PKA) signaling promoted mitochondrial fusion and prevented podocyte apoptosis. The cAMP response element binding protein (CREB) is the main downstream transcription factor of PKA signaling. Here we show that the PKA agonist 8-(4-chlorophenylthio)adenosine 3′,5′-cyclic monophosphate–cyclic AMP (pCPT-cAMP) prevented the production of adriamycin (ADR)-induced reactive oxygen species and apoptosis in podocytes, which were inhibited by CREB RNA interference (RNAi). The activation of PKA enhanced mitochondrial function and prevented the ADR-induced decrease of mitochondrial respiratory chain complex I subunits, NADH-ubiquinone oxidoreductase complex (ND) 1/3/4 genes, and protein expression. Inhibition of CREB expression alleviated pCPT-cAMP-induced ND3, but not the recovery of ND1/4 protein, in ADR-treated podocytes. In addition, CREB RNAi blocked the pCPT-cAMP-induced increase in ATP and the expression of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1-α). The chromatin immunoprecipitation assay showed enrichment of CREB on PGC1-α and ND3 promoters, suggesting that these promoters are CREB targets. In vivo, both an endogenous cAMP activator (isoproterenol) and pCPT-cAMP decreased the albumin/creatinine ratio in mice with ADR nephropathy, reduced glomerular oxidative stress, and retained Wilm's tumor suppressor gene 1 (WT-1)-positive cells in glomeruli. We conclude that the upregulation of mitochondrial respiratory chain proteins played a partial role in the protection of PKA/CREB signaling.

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