Role of mitochondria in the differential action of sodium deoxycholate and ursodeoxycholic acid on rat duodenum

2020 ◽  
pp. 1-8
Author(s):  
Adriana Pérez ◽  
María Angélica Rivoira ◽  
Valeria Rodríguez ◽  
Ana Marchionatti ◽  
Nori Tolosa de Talamoni
Keyword(s):  
Ursodeoxycholic Acid ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Dynamics ◽  
Krebs Cycle ◽  
Atp Synthesis ◽  
Sodium Deoxycholate ◽  
Inhibitory Effect ◽  
Transport Chain ◽  
Rat Duodenum ◽  
Krebs Cycle Enzymes

Sodium deoxycholate (NaDOC) inhibits the intestinal Ca2+ absorption and ursodeoxycholic acid (UDCA) stimulates it. The aim of this study was to determine whether NaDOC and UDCA produce differential effects on the redox state of duodenal mitochondria altering the Krebs cycle and the electron transport chain (ETC) functioning, which could lead to perturbations in the mitochondrial dynamics and biogenesis. Rat intestinal mitochondria were isolated from untreated and treated animals with either NaDOC, UDCA, or both. Krebs cycle enzymes, ETC components, ATP synthase, and mitochondrial dynamics and biogenesis markers were determined. NaDOC decreased isocitrate dehydrogenase (ICDH) and malate dehydrogenase activities affecting the ETC and ATP synthesis. NaDOC also induced oxidative stress and increased the superoxide dismutase activity and impaired the mitochondrial biogenesis and functionality. UDCA increased the activities of ICDH and complex II of ETC. The combination of both bile acids conserved the functional activities of Krebs cycle enzymes, ETC components, oxidative phosphorylation, and mitochondrial biogenesis. In conclusion, the inhibitory effect of NaDOC on intestinal Ca2+ absorption is mediated by mitochondrial dysfunction, which is avoided by UDCA. The stimulatory effect of UDCA alone is associated with amelioration of mitochondrial functioning. This knowledge could improve treatment of diseases that affect the intestinal Ca2+ absorption.

scholarly journals Complex II subunit SDHD is critical for cell growth and metabolism, which can be partially restored with a synthetic ubiquinone analog

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Aloka B. Bandara ◽  
Joshua C. Drake ◽  
David A. Brown
Keyword(s):  
Mammalian Cells ◽  
Krebs Cycle ◽  
Atp Synthesis ◽  
Hek293 Cells ◽  
Knockout Mutant ◽  
Complex Ii ◽  
Growth Defects ◽  
Transport Chain ◽  
Mutant Cells

Abstract Background Succinate dehydrogenase (Complex II) plays a dual role in respiration by catalyzing the oxidation of succinate to fumarate in the mitochondrial Krebs cycle and transferring electrons from succinate to ubiquinone in the mitochondrial electron transport chain (ETC). Mutations in Complex II are associated with a number of pathologies. SDHD, one of the four subunits of Complex II, serves by anchoring the complex to the inner-membrane and transferring electrons from the complex to ubiquinone. Thus, modeling SDHD dysfunction could be a valuable tool for understanding its importance in metabolism and developing novel therapeutics, however no suitable models exist. Results Via CRISPR/Cas9, we mutated SDHD in HEK293 cells and investigated the in vitro role of SDHD in metabolism. Compared to the parent HEK293, the knockout mutant HEK293ΔSDHD produced significantly less number of cells in culture. The mutant cells predictably had suppressed Complex II-mediated mitochondrial respiration, but also Complex I-mediated respiration. SDHD mutation also adversely affected glycolytic capacity and ATP synthesis. Mutant cells were more apoptotic and susceptible to necrosis. Treatment with the mitochondrial therapeutic idebenone partially improved oxygen consumption and growth of mutant cells. Conclusions Overall, our results suggest that SDHD is vital for growth and metabolism of mammalian cells, and that respiratory and growth defects can be partially restored with treatment of a ubiquinone analog. This is the first report to use CRISPR/Cas9 approach to construct a knockout SDHD cell line and evaluate the efficacy of an established mitochondrial therapeutic candidate to improve bioenergetic capacity.

Cellular metabolism

2021 ◽  
pp. 105-194
Keyword(s):  
Electron Transport Chain ◽  
Inborn Errors Of Metabolism ◽  
Krebs Cycle ◽  
Cellular Metabolism ◽  
Atp Synthesis ◽  
The Body ◽  
Clinical Aspects ◽  
Inborn Errors ◽  
Transport Chain ◽  
Cellular Compartments

‘Cellular metabolism’ addresses the major biochemical pathways and processes of the cells of the body. These include the central metabolic pathways involved in energy production: the tricarboxylic acid or Krebs cycle, and ATP synthesis through the electron transport chain and oxidative phosphorylation (chemiosmotic theory). Metabolism of each of the major fuel sources is considered: lipids, carbohydrates, and proteins, including energy storage as fat and glycogen, and excretion of nitrogen via the urea cycle. The different cellular compartments for metabolism are explored, as is the integration and regulation of the metabolic processes in a number of conditions such as fasting and starvation, exercise, pregnancy, and diabetes. Finally in this chapter the clinical aspects of metabolism are discussed, including energy balance and nutrition, obesity, and inborn errors of metabolism.

scholarly journals Complex II Subunit SDHD is Critical for Cell Growth and Metabolism, Which can be Partially Restored with A Synthetic Ubiquinone Analog

2020 ◽  
Author(s):  
Aloka B Bandara ◽  
David A Brown ◽  
Joshua Drake
Keyword(s):  
Mammalian Cells ◽  
Krebs Cycle ◽  
Atp Synthesis ◽  
Hek293 Cells ◽  
Knockout Mutant ◽  
Complex Ii ◽  
Growth Defects ◽  
Transport Chain ◽  
Mutant Cells

Abstract Background: Succinate dehydrogenase (Complex II) plays a dual role in respiration by catalyzing the oxidation of succinate to fumarate in the mitochondrial Krebs cycle and transferring electrons from succinate to ubiquinone in the mitochondrial electron transport chain (ETC). Mutations in Complex II are associated with a number of pathologies. SDHD, one of the four subunits of Complex II, serves by anchoring the complex to the inner-membrane and transferring electrons from the complex to ubiquinone. Thus, modeling SDHD dysfunction could be a valuable tool for understanding its importance in metabolism and developing novel therapeutics, however no suitable models exist. Results: Via CRISPR/Cas9, we mutated SDHD in HEK293 cells and investigated the in vitro role of SDHD in metabolism. Compared to the parent HEK293, the knockout mutant HEK293ΔSDHD produced significantly less number of cells in culture. The mutant cells predictably had suppressed Complex II-mediated mitochondrial respiration, but also Complex I-mediated respiration. SDHD mutation also adversely affected glycolytic capacity and ATP synthesis. Mutant cells were more apoptotic and susceptible to necrosis. Treatment with the mitochondrial therapeutic idebenone partially improved oxygen consumption and growth of mutant cells. Conclusions: Overall, our results suggest that SDHD is vital for growth and metabolism of mammalian cells, and that respiratory and growth defects can be partially restored with treatment of a ubiquinone analog. This is the first report to use CRISPR/Cas9 approach to construct a knockout SDHD cell line and evaluate the efficacy of an established mitochondrial therapeutic candidate to improve bioenergetic capacity.

scholarly journals Dietary Mg2+ Intake and the Na+/Mg2+ Exchanger SLC41A1 Influence Components of Mitochondrial Energetics in Murine Cardiomyocytes

2020 ◽  
Vol 21 (21) ◽  
pp. 8221
Author(s):  
Zuzana Tatarkova ◽  
Jeroen H. F. de Baaij ◽  
Marian Grendar ◽  
Jörg R. Aschenbach ◽  
Peter Racay ◽  
...  
Keyword(s):  
Krebs Cycle ◽  
Cell Types ◽  
Cardiac Mitochondria ◽  
Aconitate Hydratase ◽  
Transport Chain ◽  
Krebs Cycle Enzymes ◽  
Mg Content ◽  
Learning Analysis ◽  
Compensatory Effect

Cardiomyocytes are among the most energy-intensive cell types. Interplay between the components of cellular magnesium (Mg) homeostasis and energy metabolism in cardiomyocytes is poorly understood. We have investigated the effects of dietary Mg content and presence/functionality of the Na+/Mg2+ exchanger SLC41A1 on enzymatic functions of selected constituents of the Krebs cycle and complexes of the electron transport chain (ETC). The activities of aconitate hydratase (ACON), isocitrate dehydrogenase (ICDH), α-ketoglutarate dehydrogenase (KGDH), and ETC complexes CI–CV have been determined in vitro in mitochondria isolated from hearts of wild-type (WT) and Slc41a1−/− mice fed a diet with either normal or low Mg content. Our data demonstrate that both, the type of Mg diet and the Slc41a1 genotype largely impact on the activities of enzymes of the Krebs cycle and ETC. Moreover, a compensatory effect of Slc41a1−/− genotype on the effect of low Mg diet on activities of the tested Krebs cycle enzymes has been identified. A machine-learning analysis identified activities of ICDH, CI, CIV, and CV as common predictors of the type of Mg diet and of CII as suitable predictor of Slc41a1 genotype. Thus, our data delineate the effect of dietary Mg content and of SLC41A1 functionality on the energy-production in cardiac mitochondria.

Developmental regulation of mitochondrial biogenesis and function in the mouse mammary gland during a prolonged lactation cycle

2011 ◽  
Vol 43 (6) ◽  
pp. 271-285 ◽  
Author(s):  
Darryl L. Hadsell ◽  
Walter Olea ◽  
Jerry Wei ◽  
Marta L. Fiorotto ◽  
Risë K. Matsunami ◽  
...  
Keyword(s):  
Electron Transport ◽  
Mitochondrial Biogenesis ◽  
Electron Transport Chain ◽  
Atp Synthesis ◽  
Mammary Tissue ◽  
Early Lactation ◽  
Amp Kinase ◽  
Transport Chain ◽  
Mammary Cell ◽  
And Function

The regulation of mitochondrial biogenesis and function in the lactating mammary cell is poorly understood. The goal of this study was to use proteomics to relate temporal changes in mammary cell mitochondrial function during lactation to changes in the proteins that make up this organelle. The hypothesis tested was that changes in mammary cell mitochondrial biogenesis and function during lactation would be accounted for by coordinated changes in the proteins of the electron transport chain and that some of these proteins might be linked by their expression patterns to PPARGC1α and AMP kinase. The mitochondrial proteome was studied along with markers of mitochondrial biogenesis and function in mammary tissue collected from mice over the course of a single prolonged lactation cycle. Mammary tissue concentrations of AMP and ADP were increased ( P < 0.05) during early lactation and then declined with prolonged lactation. Similar changes were also observed for mitochondrial ATP synthesis activity, mitochondrial mass and DNA copy number. Analysis of the mammary cell mitochondrial proteome identified 244 unique proteins. Of these, only two proteins of the electron transport chain were found to increase during early lactation. In contrast, coordinated changes in numerous electron transport chain proteins were observed both during mid- and late lactation. There were six proteins that could be directly linked to PPARGC1α through network analysis. Abundance of PPARGC-1α and phosphorylation of AMP kinase was highest on day 2 postpartum. The results suggest that the increases in mammary mitochondria ATP synthesis activity during early lactation results from changes in only a limited number proteins. In addition, decreases in a handful of proteins linked to lipid oxidation could be temporally linked to decreases in PPARGC1α and phospho-AMP kinase suggesting potential roles for these proteins in coordinating mammary gland metabolism during early lactation.

Taurin-conjugated ursodeoxycholic acid has a reversible inhibitory effect on human keratinocyte growth

1998 ◽  
Vol 18 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Yuji Yamaguchi ◽  
Satoshi Itami ◽  
Kenju Nishida ◽  
Yumi Ando
Keyword(s):  
Ursodeoxycholic Acid ◽  
Inhibitory Effect ◽  
Human Keratinocyte

scholarly journals At the heart of mitochondrial quality control: many roads to the top

2021 ◽  
Author(s):  
Roberta A. Gottlieb ◽  
Honit Piplani ◽  
Jon Sin ◽  
Savannah Sawaged ◽  
Syed M. Hamid ◽  
...  
Keyword(s):  
Quality Control ◽  
Unfolded Protein Response ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Quality Control ◽  
Unfolded Protein ◽  
Selective Elimination ◽  
Protein Response ◽  
Mitochondrial Unfolded Protein Response

AbstractMitochondrial quality control depends upon selective elimination of damaged mitochondria, replacement by mitochondrial biogenesis, redistribution of mitochondrial components across the network by fusion, and segregation of damaged mitochondria by fission prior to mitophagy. In this review, we focus on mitochondrial dynamics (fusion/fission), mitophagy, and other mechanisms supporting mitochondrial quality control including maintenance of mtDNA and the mitochondrial unfolded protein response, particularly in the context of the heart.

Malic enzyme 2 connects the Krebs cycle intermediate fumarate to mitochondrial biogenesis

2021 ◽  
Author(s):  
Yi-Ping Wang ◽  
Azeem Sharda ◽  
Shuang-Nian Xu ◽  
Nick van Gastel ◽  
Cheuk Him Man ◽  
...  
Keyword(s):  
Mitochondrial Biogenesis ◽  
Malic Enzyme ◽  
Krebs Cycle

scholarly journals Primary and Secondary Drug Screening Assays for Friedreich Ataxia

2011 ◽  
Vol 17 (3) ◽  
pp. 303-313 ◽  
Author(s):  
M. Grazia Cotticelli ◽  
Lynn Rasmussen ◽  
Nicole L. Kushner ◽  
Sara McKellip ◽  
Melinda Ingrum Sosa ◽  
...  
Keyword(s):  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
High Throughput Screening ◽  
Mammalian Cells ◽  
Friedreich Ataxia ◽  
Krebs Cycle ◽  
C2c12 Cells ◽  
Transport Chain ◽  
Screening Assays ◽  
Yeast Mutants

Friedreich ataxia (FRDA) is an autosomal recessive neuro- and cardiodegenerative disorder for which there are no proven effective treatments. FRDA is caused by decreased expression and/or function of the protein frataxin. Frataxin chaperones iron in the mitochondrial matrix for the assembly of iron–sulfur clusters (ISCs), which are prosthetic groups critical for the function of the Krebs cycle and the mitochondrial electron transport chain (ETC). Decreased expression of frataxin or the yeast frataxin orthologue, Yfh1p, is associated with decreased ISC assembly, mitochondrial iron accumulation, and increased oxidative stress, all of which contribute to mitochondrial dysfunction. Using yeast depleted of Yfh1p, a high-throughput screening (HTS) assay was developed in which mitochondrial function was monitored by reduction of the tetrazolium dye WST-1 in a growth medium with a respiration-only carbon source. Of 101 200 compounds screened, 302 were identified that effectively rescue mitochondrial function. To confirm activities in mammalian cells and begin understanding mechanisms of action, secondary screening assays were developed using murine C2C12 cells and yeast mutants lacking specific complexes of the ETC, respectively. The compounds identified in this study have potential relevance for other neurodegenerative disorders associated with mitochondrial dysfunction, such as Parkinson disease.

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