scholarly journals Mitochondrial DNA Depletion and Respiratory Chain Activity in Primary Human Subcutaneous Adipocytes Treated with Nucleoside Analogue Reverse Transcriptase Inhibitors

2009 ◽  
Vol 54 (1) ◽  
pp. 280-287 ◽  
Author(s):  
Metodi V. Stankov ◽  
Thomas Lücke ◽  
Anibh M. Das ◽  
Reinhold E. Schmidt ◽  
Georg M. N. Behrens
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Respiratory Chain ◽  
Mitochondrial Membrane ◽  
Reverse Transcriptase Inhibitors ◽  
Respiratory Chain Complexes ◽  
Mitochondrial Mass ◽  
Mtdna Depletion ◽  
Chain Complexes ◽  
Respiratory Chain Activity

ABSTRACT Mitochondrial dysfunction as a consequence of mitochondrial DNA (mtDNA) depletion due to therapy with nucleoside analogue reverse transcriptase inhibitors (NRTI) has been proposed as a pathogenic mechanism leading to lipoatrophy in HIV-infected patients. The aim of our study was to investigate the impact of NRTI treatment on mtDNA abundance and the activities of respiratory chain complexes in primary human subcutaneous preadipocytes (phsPA). We studied adipocyte phenotypes, viability, and differentiation (CCAAT/enhancer-binding protein α [C/EBPα] and peroxisome proliferator-activated receptor γ [PPARγ] expression) and adiponectin production, mtDNA content, mitochondrial membrane potential, mitochondrial mass, and respiratory chain enzyme and citrate synthase activities in both proliferating and differentiating phsPA. Cells were exposed to zidovudine (6 μM), stavudine (d4T; 3 μM), and zalcitabine (ddC; 0.1 μM) for 8 weeks. NRTI-induced mtDNA depletion occurred in proliferating and differentiating phsPA after exposure to therapeutic drug concentrations of d4T and ddC. At these concentrations, ddC and d4T led to an almost 50% decrease in the number of mtDNA copies per cell without major impact on adipocyte differentiation. Despite mtDNA depletion by NRTI, the activities of the respiratory chain complexes, the mitochondrial membrane potential, and the mitochondrial mass were found to be unaffected. Severe NRTI-mediated mtDNA depletion in phsPA is not inevitably associated with impaired respiratory chain activity or altered mitochondrial membrane potential.

Olfactomedin 4 Is Essential for Superoxide Production and Sensitizes Oxidative Stress-Induced Apoptosis in Neutrophils.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1356-1356
Author(s):  
Wenli Liu ◽  
Yueqin Liu ◽  
Ruihong Wang ◽  
Cuiling Li ◽  
Chuxia Deng ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Respiratory Chain ◽  
Complex I ◽  
Mitochondrial Membrane ◽  
Mitochondrial Respiratory Chain ◽  
H2o2 Production ◽  
Induced Apoptosis ◽  
Mitochondrial Respiratory

Abstract Abstract 1356 Poster Board I-378 Introduction Olfactomedin 4 (OLFM4), also called hGC-1, GW112 and pDP4, was first identified and specifically expressed in hematopoietic myeloid cells. OLFM4 expression in myeloid cells is regulated by transcription factors, PU1 and NF-κB. It has significant homology in its C-terminal domain with other olfactomedin-related proteins. OLFM4 encodes a 510 amino acid N-linked glycoprotein. The exact biological function of OLFM4, especially in neutrophils, is currently undefined. To characterize the in vivo function of OLFM4, we generated OLFM4 deficient mice (OLFM4-/-) and investigated its potential role in neutrophil functioins. Results 1) In this study, we showed that OLFM4 is a secreted glycoprotein and is also localized in the mitochondria, cytoplasm and cell membrane fractions of neutrophils. We demonstrated that OLFM4 interacts with GRIM-19 (Genes associated with Retinoid-IFN-induced Mortality-19), an apoptosis related protein, in the neutrophil mitochondria using co-immuoprecipitation assay. GRIM-19 is a subunit of complex I of mitochondrial respiratory chain and is essential for maintenance of mitochondrial membrane potential. Our result suggests that OLFM4 appears to be a novel component of complex I of mitochondrial respiratory chain and may be involved in regulation of mitochondrial membrane potential. 2) Mice heterozygous (OLFM4+/-) and homozygous (OLFM4-/-) for the null mutation in OLFM4 appeared to have normal development, fertility, and viability relative to wild-type (WT) mice. Whole blood analysis, differential leukocyte counts, blood chemistry and bone marrow smears were normal in OLFM4-/- mice, suggesting that OLFM4 is not essential for normal development and hematopoiesis in mice. 3) In response to LPS, fMLP and E.coli bacteria challenge, neutrophils from OLFM4-/- mice showed significantly reduced superoxide (O2−) and hydrogen peroxide (H2O2) production compared with WT mice. These results suggest that OLFM4 is an essential component to mediate O2− and H2O2 production in the neutrophil mitochondria under inflammation stimuli. 4) Exogenous H2O2 induced neutrophil apoptosis in a time and dose dependent manner in WT mice, but this induction of apoptosis was significantly reduced in OLFM4-/- mice. This result suggests that OLFM4 sensitizes and mediates H2O2-induced apoptosis in neutrophils. 5) Furthermore, we demonstrated that H2O2-stimulated mitochondrial membrane permeability reduction and caspase-3 and caspase-9 activation were inhibited in the neutrophils of OLFM4-/- mice. This result confirmed our hypothesis that OLFM4 may be involved in maintenance of mitochondrial membrane potential and suggests that OLFM4 may have opposite role as GRIM-19. 6) Moreover, Bax association with mitochondria and the cytoplasmic translocation of Omi/HtrA2 and Smac/DIABLO in response to H2O2 were inhibited in the neutrophils of OLFM4-/- mice. Conclusion Our results suggest: 1) OLFM4 has multiple subcellular localizations including mitochondria, cytoplasm, and cell membrane in neutrophils. The interaction of OLFM4 with GRIM-19 in the mitochondria suggests that OLFM4 is novel component of complex I of mitochondrial respiratory chain in the mitochondria of neutrophils, 2) OLFM4 is a novel mitochondrial molecule that is essential for O2− and H2O2 production in the neutrophils in the presence of inflammation stimuli, 3) Loss of OLFM4 in neutrophils does not trigger spontaneous apoptosis. However, OLFM4 sensitizes oxidative stress-induced apoptosis in mouse neutrophils. OLFM4 is involved in the regulation of mitochondria membrane potential and sensitizes cytoplasmic translocation of Omi/HtrA2 and Smac/DIABLO and caspases-3 and caspase-9 mediated apoptosis in the presence of oxidative stress. Disclosures No relevant conflicts of interest to declare.

Elevated Mitochondrial Membrane Potential in CLL Cells Is Associated with a more aggressive Natural History

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1765-1765
Author(s):  
Jeffrey R Gardner ◽  
Kristina Knapp ◽  
Mark G. Frattini ◽  
Nicole Lamanna ◽  
Renier Brentjens ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Natural History ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Doubling Time ◽  
Disease Course ◽  
Advisory Committees ◽  
Mitochondrial Mass ◽  
Cytogenetic Changes ◽  
Indolent Disease

Abstract Abstract 1765 Chronic lymphocytic leukemia (CLL) can be characterized by a variable natural history. While some patients have an aggressive disease course, others have an indolent course and never require treatment. Disease stage at diagnosis, cytogenetic changes, and mutation in the immunoglobulin hypervariable region, among other disease markers, have important prognostic contributions, but these prognostic markers do not reliably identify patients with an indolent natural history. We analyzed 174 individual patients with CLL and found that patients whose CLL cells retained a mitochondrial membrane potential (MMP) as measured by retention of the cyanine dye, JC-1, similar to normal B-lymphocytes had a particularly indolent disease course. While 73% of CLL patients had a substantial population of malignant lymphocytes with a higher mitochondrial membrane potential, 27% of patients had energetically normal CLL cells confirmed by co-immunostaining with anti-CD5 and anti-CD19. Elevated mitochondrial membrane potential is defined by the lymphocyte population having >50% of cells with a relative membrane potential (FL2/FL1=electrochemical potential/mitochondrial mass) > 2.0 (Figure 1). Patient samples from untreated patients were also organized into quintiles based upon the percentage of cells that populated the low mitochondrial membrane potential gate versus the percentage of cells that populated the high mitochondrial membrane potential gate (Figure 2). Patients in the lower quintile exhibited a predominance of cells in the low membrane potential gate across a broad range (.02%-42%) whereas patients in the upper quintile exhibited a predominance of cells in the high membrane potential gate across a much narrower range (88.6%-96.7%). With up to six years of follow up, no patient with normal MMP has required treatment or has advanced beyond Rai stage 0. Cytogenetic changes in this subgroup include normal cytogenetics, del13q, del11q, trisomy12, and del6q23. Of the 30 patients where immunoglobulin heavy chain variable gene mutations were measured, no patients with low MMP had a germline configuration. Lymphocyte doubling time was calculated for all patients for whom data is available and it is interesting to note that patients falling within the first quintile exhibited a median slope value of ∼1 with a median lymphocyte doubling time of ∼1.5 years, whereas patients in the upper quintile within the upper quintile exhibited a much steeper median slope value of 23 and an accelerated lymphocyte doubling time of approximately 7 months (see Figure 3 for patient examples). CLL cells with higher mitochondrial membrane potential have ultrastructural changes in the mitochondria typical of cells primarily utilizing glycolysis, but no difference in mitochondrial mass. CLL cells with a predominantly elevated MMP have increased lactate production and dramatically shortened survival when grown in media containing pyruvate as the primary energy substrate instead of glucose. These results indicate a significant difference in energy utilization and intracellular metabolism between malignant cells with normal and high MMP. Some patients with CLL cells that have elevated MMP appear to have an indolent disease course suggesting that elevated MMP does not necessarily portend an aggressive natural history, but to date, patients with CLL populations characterized by elevated MMP have encompassed the only patients in our study population who have required treatment directed at the CLL. The data indicate that analysis of the MMP in the CLL population can provide important prognostic information and may identify a population of patients with a benign course of disease. The prognostic significance of MMP in patients with CLL is independent of cytogenetics. The finding of low MMP appears to be confined to patients without a germline IGHV configuration. These results also indicate that the metabolic state of the malignant cell may play a central role in the clinical manifestation of disease and may point to the development of novel therapies that target mitochondrial respiration. Disclosures: Lamanna: Celgene Corporation:. Weiss:Celgene: Membership on an entity's Board of Directors or advisory committees. Scheinberg:Actinium Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

Effect of thyroid hormone on mitochondrial properties and oxidative stress in cells from patients with mtDNA defects

2009 ◽  
Vol 296 (2) ◽  
pp. C355-C362 ◽  
Author(s):  
Keir J. Menzies ◽  
Brian H. Robinson ◽  
David A. Hood
Keyword(s):  
Oxidative Stress ◽  
Membrane Potential ◽  
Thyroid Hormone ◽  
Protein Expression ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Membrane ◽  
Ros Production ◽  
Mitochondrial Mass ◽  
Mtdna Mutations

Mitochondrial (mt)DNA mutations contribute to various disease states characterized by low ATP production. In contrast, thyroid hormone [3,3′,5-triiodothyronine (T3)] induces mitochondrial biogenesis and enhances ATP generation within cells. To evaluate the role of T3-mediated mitochondrial biogenesis in patients with mtDNA mutations, three fibroblast cell lines with mtDNA mutations were evaluated, including two patients with Leigh's syndrome and one with hypertrophic cardiomyopathy. Compared with control cells, patient fibroblasts displayed similar levels of mitochondrial mass, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), mitochondrial transcription factor A (Tfam), and uncoupling protein 2 (UCP2) protein expression. However, patient cells exhibited a 1.6-fold elevation in ROS production, a 1.7-fold elevation in cytoplasmic Ca2+ levels, a 1.2-fold elevation in mitochondrial membrane potential, and 30% less complex V activity compared with control cells. Patient cells also displayed 20–25% reductions in both cytochrome c oxidase (COX) activity and MnSOD protein levels compared with control cells. After T3 treatment of patient cells, ROS production was decreased by 40%, cytoplasmic Ca2+ was reduced by 20%, COX activity was increased by 1.3-fold, and ATP levels were elevated by 1.6-fold, despite the absence of a change in mitochondrial mass. There were no significant alterations in the protein expression of PGC-1α, Tfam, or UCP2 in either T3-treated patient or control cells. However, T3 restored the mitochondrial membrane potential, complex V activity, and levels of MnSOD to normal values in patient cells and elevated MnSOD levels by 21% in control cells. These results suggest that T3 acts to reduce cellular oxidative stress, which may help attenuate ROS-mediated damage, along with improving mitochondrial function and energy status in cells with mtDNA defects.

AML Cells Have Increased Mitochondrial Mass but Less Reserve in Their Respiratory Chain Complexes Leading to Heightened Sensitivity to Inhibition of Mitochondrial Protein Translation,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3585-3585
Author(s):  
Shrivani Sriskanthadevan ◽  
Skrtic Marko ◽  
Bozhena Livak ◽  
Yulia Jitkova ◽  
Rose Hurren ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Respiratory Chain ◽  
Mitochondrial Biogenesis ◽  
Complex Iii ◽  
Reserve Capacity ◽  
Mitochondrial Translation ◽  
Respiratory Chain Complexes ◽  
Mitochondrial Mass ◽  
Respiratory Complexes ◽  
Chain Complexes

Abstract Abstract 3585 Recent studies suggest that dysregulated mitochondrial oxygen consumption promotes the growth of AML cells. Therefore, we characterized the structure and metabolic function of the mitochondria in AML and normal G-CSF-mobilized hematopoietic mononuclear cells (PBSCs). Compared to PBSCs, 1o AML cells had increased mitochondrial mass as demonstrated by an increased mitochondrial DNA copy number and increased activity of matrix enzyme citrate synthase. The increased mitochondrial mass observed in 1o AML cells may represent larger mitochondria and/or more numerous mitochondria. Therefore, we evaluated the mitochondria of 1o AML and normal CD34+ hematopoietic cells by electron microscopy. The mitochondria in 1o AML cells were larger in area, but fewer in number compared to normal CD34+ cells. Mitochondria contain the respiratory chain complexes that promote oxidative phosphorylation. Given the dysregulated mitochondrial biogenesis in 1o AML cells, we examined the levels and capacity of the respiratory complexes in 1o AML and normal PBSCs. When normalized for mitochondrial mass, 1o AML cells (n = 12) had reduced activity of respiratory complexes III and IV compared to PBSCs (n = 10) (Mean complex III activity AML vs PBSC: 0.32 ± 0.04 RU vs 0.66 ± 0.11 RU p = 0.0063; Mean complex IV activity AML vs PBSC: 0.13 ± 0.01 RU vs 0.24 ± 0.02 RU, p= 0.0003). We evaluated the capacity of the respiratory complexes in AML cells and PBSCs by treating with increasing concentrations of the complex III inhibitor antimycin, and measuring the changes in oxygen consumption. AML cells displayed heightened sensitivity to the complex III inhibitor and less reserve capacity in the respiratory complex compared to PBSCs (mean concentration of antimycin required to reduce oxygen consumption by 50%: AML (n = 11) vs PBSC (n = 3): 13.7 ± 1.6 nM vs 29.0 ± 2.4 nM; p = 0.0007). AML cell lines were similar to 1o AML cells with decreased basal respiratory complex activity and reserve capacity compared to PBSCs. Given the reduced levels and reserve in the respiratory chain complexes in AML cells, we evaluated the effects of inhibiting mitochondrial protein translation in AML cells and PBSCs. Chemical (tigecycline, and chloramphenicol) and genetic (RNAi knockdown of the EF-Tu) inhibition of mitochondrial translation reduced the levels and function of the respiratory complexes that contain proteins encoded by mitochondrial DNA. Consistent with the reduced reserve capacity, inhibiting mitochondrial translation preferentially reduced oxygen consumption and viability of 1o AML cells and AML cell lines over PBSCs and normal CD34+ cells. To understand the molecular basis for the abnormal mitochondrial biogenesis in 1o AML cells, we measured levels of the NRF-1, TFAM and EF-Tu, genes known to positively regulate mitochondrial biogenesis. Compared to PBSCs, AML samples showed at least a 3-fold increase in mRNA expression of these genes. Myc is a positive regulator of NRF-1, TFAM and EF-Tu. Therefore, we measured levels of myc in 1o AML cells and PBSCs by Q-RT-PCR. Compared to PBSCs, myc was increased in 1o AML cells and positively correlated with expression of NRF-1, TFAM and EF-Tu as well as with mitochondrial mass. To determine whether increased myc expression is functionally related to the increased mitochondrial biogenesis and decreased reserve in respiratory capacity, we employed P493 Burkitt's cells with inducible myc knockdown. P493 cells expressing myc had increased mitochondrial mass, larger mitochondria, and increased basal oxygen consumption compared to the myc knockdown cells. When normalized for mitochondrial mass, myc expressing cells had reduced activity of respiratory complexes III and IV compared to myc knockdown cells. In addition, myc expressing cells had less reserve in respiratory complex III (concentration of antimycin required to reduce oxygen consumption by 50% –+ myc P493 vs –myc P493: 6.580 ± 0.393 nM vs 12.87 ± 1.97 nM p =0.0352). Thus, compared to normal hematopoietic cells, AML cells have greater mitochondrial mass but reduced reserve in their respiratory complexes. As a result of this decreased reserve, AML cells have a heightened sensitivity to inhibition of mitochondrial translation which reduces respiratory chain complex levels and activity. Genetically, the abnormal mitochondrial structure and function appears related to dysregulated myc and its influence on genes promoting increased mitochondrial biogenesis. Disclosures: No relevant conflicts of interest to declare.

Interleukin-6 Reduces Erythroid Development and Mitochondrial Membrane Potential In Human Erythroleukemic Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3420-3420
Author(s):  
Bryan J. McCranor ◽  
MinJung Kim ◽  
Nicole M Cruz ◽  
Qian-Li Xue ◽  
Alan E. Berger ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Mitochondrial Mass ◽  
Hemoglobin Synthesis ◽  
Erythroid Maturation ◽  
Student’S T ◽  
Erythroid Development ◽  
Anemia Of Inflammation ◽  
Student’S T Test

Abstract Introduction Anemia of inflammation or chronic disease is common and is associated with diseases such as cancer, chronic kidney disease, autoimmune disease, and acute and chronic infections. Concentration of the inflammatory cytokine interleukin-6 (IL-6) is known to negatively correlate with hemoglobin concentration in many of these disease states. Whether IL-6 promotes anemia of inflammation outside of the IL-6-hepcidin antimicrobial peptide axis has not been extensively studied. We previously reported that chronic inflammation affected maturation of erythroid progenitors in a mouse model of chronic inflammation but over expression of hepcidin, alone, did not. We hypothesized that IL-6 may directly impair erythroid maturation, independent of iron restriction. Methods We utilized the human erythroleukemia TF-1 cell line, treated with recombinant human erythropoietin, to model erythroid maturation and exposed TF-1 cells to increasing doses (0, 1, 10, 100ng/ml) of IL-6 over six days. TF-1 erythroid maturation was determined by flow cytometry (based on CD44, CD71, and CD235a expression), and benzidine staining. In addition, expression levels of genes representing early [glycophorin A (GPA)], mid [aminolevulinic acid synthase 2 (ALAS2) and hemoglobin adult major beta chain (HBB)], and late [erythrocyte membrane protein Band 3 (SLC4A1)] stages of erythropoiesis were analyzed by qRT-PCR. Finally, mitochondrial mass, membrane potential, and oxidative stress were measured using fluorescent indicators. Results IL-6 significantly repressed erythropoietin-dependent TF-1 erythroid maturation at concentrations at or above 10 ng/ml (p=0.001, Cuzick test). We observed impaired hemoglobin synthesis as demonstrated by decreased benzidine staining (p=0.022, Cuzick test), but this did not correspond to detectable decreases in ALAS2 or HBB expression. However, IL-6 down regulated expression of SLCA4A1 which is expressed late in erythropoiesis (p=0.005, Welch t-tes). The mitochondrial membrane potential was decreased, at all IL-6 treatment doses (p=0.05, Student’s t-test), and mitochondrial mass was significantly decreased at the highest dose (p=0.05, Student’s t-test). Conclusions These data demonstrate that IL-6 can impair mitochondrial membrane potential, hemoglobin production, and erythroid maturation in an in vitro setting. Our findings suggest that IL-6 affects cells relatively late in erythropoiesis, after they are primed for hemoglobin synthesis. We hypothesize that the effect of IL-6 on the mitochondria of maturing erythroid cells could be a mechanism behind the impaired maturation phenotype that we observed. These results may indicate a novel pathway of action for IL-6 in the anemia of inflammation, and demonstrate potential for the opportunity to develop new therapeutic targets that affect late erythroid development. Disclosures: Roy: Celgene Corp.: Research Funding.

scholarly journals Porcine Circovirus 2 Induction of ROS Is Responsible for Mitophagy in PK-15 Cells via Activation of Drp1 Phosphorylation

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 289 ◽  
Author(s):  
Yikai Zhang ◽  
Renjie Sun ◽  
Xiaoliang Li ◽  
Weihuan Fang
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Rna Silencing ◽  
Mitochondrial Membrane ◽  
Mitochondrial Dynamics ◽  
Pcv2 Infection ◽  
Porcine Circovirus ◽  
Mitochondrial Mass ◽  
Mitochondrial Translocation ◽  
Porcine Circovirus 2

Mitochondrial dynamics is essential for the maintenance of cell homeostasis. Previous studies have shown that porcine circovirus 2 (PCV2) infection decreases the mitochondrial membrane potential and causes the elevation of reactive oxygen species (ROS), which may ultimately lead to mitochondrial apoptosis. However, whether PCV2 induce mitophagy remains unknown. Here we show that PCV2-induced mitophagy in PK-15 cells via Drp1 phosphorylation and PINK1/Parkin activation. PCV2 infection enhanced the phosphorylation of Drp1 and its subsequent translocation to mitochondria. PCV2-induced Drp1 phosphorylation could be suppressed by specific CDK1 inhibitor RO-3306, suggesting CDK1 as its possible upstream molecule. PCV2 infection increased the amount of ROS, up-regulated PINK1 expression, and stimulated recruitment of Parkin to mitochondria. N-acetyl-L-cysteine (NAC) markedly decreased PCV2-induced ROS, down-regulated Drp1 phosphorylation, and lessened PINK1 expression and mitochondrial accumulation of Parkin. Inhibition of Drp1 by mitochondrial division inhibitor-1 Mdivi-1 or RNA silencing not only resulted in the reduction of ROS and PINK1, improved mitochondrial mass and mitochondrial membrane potential, and decreased mitochondrial translocation of Parkin, but also led to reduced apoptotic responses. Together, our study shows that ROS induction due to PCV2 infection is responsible for the activation of Drp1 and the subsequent mitophagic and mitochondrial apoptotic responses.

scholarly journals UVRAG-Knockdown Regulates Mitochondrial Autophagy in Chronic Myeloid Leukaemia Cells by Targeting BNIP3L

2021 ◽  
Author(s):  
ChaoYong Liu ◽  
YanMin Ma ◽  
XiaoQin Zhang ◽  
Yang Liu ◽  
XiaoCheng Yin
Keyword(s):  
Flow Cytometry ◽  
Membrane Potential ◽  
Chronic Myeloid Leukaemia ◽  
Western Blot ◽  
Myeloid Leukaemia ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
K562 Cells ◽  
Mitochondrial Mass ◽  
Related Proteins

Abstract Objective: To explore whether UVRAG regulates mitochondrial autophagy via BNIP3L in K562 cellsMaterial and methods: We designed various assays to verify the relation between UVRAG and BNIP3L, we estabilished a mitochondrial autophagy model of K562 cells by CCCP, a mitochondrial autophagy inducer, and regulated the expression of UVRAG by cells transfection. Then we detected the expression of the BINP3L and autophagy-related proteins LC3-II/LC3-Ⅰ and P62 by Western blot. The changes of ROS, mitochondrial mass, and mitochondrial membrane potential (MMP) were detected by flow cytometry technology.Results: We found that CCCP could induce K562 cells mitochondrial autophagy, along with the change of MMP, mitochondrial mass and accumulation of ROS, also our experiment proved that UVRAG-Knockdown could reverse this phenomenon. Investigating the pathway of mitochondrial autophagy revealed UVRAG knockdown was accompanied by a decrease in BNIP3L and LC3 expression, a increase in P62 during mitochondrial autophagy. Conclusion: In our study, the results suggested that UVRAG may regulate mitochondrial autophagy of K562 cells via targeting BINP3L, which may be a potential target for the treatment of CML.

scholarly journals AML cells have low spare reserve capacity in their respiratory chain that renders them susceptible to oxidative metabolic stress

Blood ◽  
2015 ◽  
Vol 125 (13) ◽  
pp. 2120-2130 ◽  
Author(s):  
Shrivani Sriskanthadevan ◽  
Danny V. Jeyaraju ◽  
Timothy E. Chung ◽  
Swayam Prabha ◽  
Wei Xu ◽  
...  
Keyword(s):  
Respiratory Chain ◽  
Metabolic Stress ◽  
Chain Complex ◽  
Reserve Capacity ◽  
Respiratory Chain Complex ◽  
Respiratory Chain Complexes ◽  
Mitochondrial Mass ◽  
Chain Complexes ◽  
Key Points ◽  
Complex Activities

Key Points AML cells have increased mitochondrial mass, low respiratory chain complex activities, and low spare reserve capacity compared with normal cells. AML cells have heightened sensitivity to inhibitors of the respiratory chain complexes and oxidative stressors.

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