Template:BioblastAlert2021

Bioblast alert 2021(11) - Mitochondrial membrane potential: 2021-07-08

H'ow can you measure mt-membrane potential with O2k-FluoRespirometry?'

The extrinsic fluorophores safranin, TMRM or Rhodamine 123 can be used to measure mt-membrane potential in mitochondrial preparations.

- »Safranin«, »TMRM« and »Rhodamine 123«

Simultaneous measurement of O₂ flux and mt-membrane potential using safranin

from the O2k-Network »AT Innsbruck Oroboros«

Krumschnabel G, Eigentler A, Fasching M, Gnaiger E (2014) Use of safranin for the assessment of mitochondrial membrane potential by high-resolution respirometry and fluorometry. Methods Enzymol 542:163-81.- »Bioblast link«

TPP⁺ for potentiometric detection of mt-membrane potential (mtMP) or fluorometry with safranin?

Safranin enables measurement of the relationship between fluorescence intensity and mtMP, and if linear, the absolute mtMP can be calculated. TPP⁺ enables calibration for measurement of mtMP.
- »TPP⁺ vs safranin«

Mitoquinone does not alter respiration and mt-membrane potential in obese and diabetic rats.

from the O2k-Network »US IA Iowa City Sivitz WI«

Fink BD, Yu L, Coppey L, Obrosov A, Shevalye H, Kerns RJ, Yorek MA, Sivitz WI (2021) Effect of mitoquinone on liver metabolism and steatosis in obese and diabetic rats. Pharmacol Res Perspect 9:e00701. »Bioblast link«

Bioblast alert 2021(10) - Aging: 2021-07-02

Downregulation of mitoNEET causes cardiac impairment in aging

from the O2k-Network »JP Sapporo Yokota T«

Furihata T, Takada S, Kakutani N, Maekawa S, Tsuda M, Matsumoto J, Mizushima W, Fukushima A, Yokota T, Enzan N, Matsushima S, Handa H, Fumoto Y, Nio-Kobayashi J, Iwanaga T, Tanaka S, Tsutsui H, Sabe H, Kinugawa S (2021) Cardiac-specific loss of mitoNEET expression is linked with age-related heart failure. Commun Biol 4:138. - »Bioblast link«

Potential anti-aging therapeutic target: circadian regulation of mitochondrial uncoupling

from the O2k-Network »US FL Gainesville Hepple RT«

Ulgherait Matt, Chen Anna, McAllister Sophie F, Kim Han X, Delventhal Rebecca, Wayne Charlotte R, Garcia Christian J, Recinos Yocelyn, Oliva Miles, Canman Julie C, Picard Martin, Owusu-Ansah Edward, Shirasu-Hiza Mimi (2020) Circadian regulation of mitochondrial uncoupling and lifespan. Nat Commun 11:1927. - »Bioblast link«

Olive polyphenols - protection against mitochondrial dysfunction in Alzheimer's disease and brain aging

from the O2k-Network »DE Giessen Eckert GP«

Grewal R, Reutzel M, Dilberger B, Hein H, Zotzel J, Marx S, Tretzel J, Sarafeddinov A, Fuchs C, Eckert GP (2020) Purified oleocanthal and ligstroside protect against mitochondrial dysfunction in models of early Alzheimer's disease and brain ageing. Exp Neurol 328:113248. - »Bioblast link«

Sugar and fat effect on initial mitochondrial aging in the brain

from the O2k-Network »IT Naples Iossa S«

Crescenzo R, Spagnuolo MS, Cancelliere R, Iannotta L, Mazzoli A, Gatto C, Iossa S, Cigliano L (2019) Effect of initial aging and high-fat/high-fructose diet on mitochondrial bioenergetics and oxidative status in rat brain. Mol Neurobiol 56:7651-63. - »Bioblast link«

Bioblast alert 2021(09) - PhotoBiology: 2021-05-19

Photosynthesis and respiration -

measurement of oxygen dependence of oxygen flux with high time resolution:

Went N, Di Marcello M, Gnaiger E (2021) Oxygen dependence of photosynthesis and light-enhanced dark respiration studied by High-Resolution PhotoRespirometry. MitoFit Prep 2021.5. doi:10.26124/mitofit:2021-0005

Immediately after switching off the light, a sharp peak of light-enhanced dark respiration is observed in algae.

- »Light-enhanced dark respiration«

How can you monitor O₂ flux in response to light?

The PB-Module of the upcoming the NextGen-O2k enables experiments in PhotoBiology.
- »PB-Module« and »PhotoBiology«

7th Conference of the International Society for Applied Phycology - May 14 - August 13

May 20, 2021 at 11:00-11:30 am (GMT+2): Nora Went and Sabine Schmitt, Oroboros Instruments Q&A Session - »ISAP 2021 Virtual«

Bioblast alert 2021(08) - Cell-permeable succinate: 2021-05-07

A cell-permeable succinate prodrug can alleviate N-methyl carbamate-induced Complex I dysfunction

from the O2k-Network »US PA Philadelphia Kilbaugh T«, »US PA Philadelphia Jang DH« and »SE Lund Elmer E«

Janowska JI, Piel S, Saliba N, Kim CD, Jang DH, Karlsson M, Kilbaugh TJ, Ehinger JK (2020) Mitochondrial respiratory chain Complex I dysfunction induced by N-methyl carbamate ex vivo can be alleviated with a cell-permeable succinate prodrug carbamate toxicity and treatment. Toxicol In Vitro 65:104794. - »Bioblast link«

Cell-permeable succinate can restore statin-inhibited mitochondrial respiration

from the O2k-Network »RO Timisoara Muntean DM« and »SE Lund Elmer E«

Avram VF, Chamkha I, Åsander-Frostner E, Ehinger JK, Timar RZ, Hansson MJ, Muntean DM, Elmér E (2021) Cell-permeable succinate rescues mitochondrial respiration in cellular models of statin toxicity. Int J Mol Sci 22:424. - »Bioblast link«

Measuring succinate pathway (S-pathway) in living cells

Using MitoKit-CII – cell permeable succinate and malonate, the S-pathway can be measured
- »SUIT-003 O2 ce D060«

Bioblast alert 2021(07) - Diabetes: 2021-04-15

Diabetes, infarct size, mitochondrial respiration and succinate dehydrogenase inhibition - how do they relate?

from the O2k-Network »DK Aarhus Boetker HE«

Tonnesen PT, Hjortbak MV, Lassen TR, Seefeldt JM, Bøtker HE, Jespersen NR (2021) Myocardial salvage by succinate dehydrogenase inhibition in ischemia-reperfusion injury depends on diabetes stage in rats. Mol Cell Biochem [Epub ahead of print]. - »Bioblast link«

Gastric bypass surgery improves diabetic nephropathy in type 1 diabetic rats

from the O2k-Network »CN Chongqing Zhu Z«

Wei X, Lu Z, Li L, Zhang H, Sun F, Ma H, Wang L, Hu Y, Yan Z, Zheng H, Yang G, Liu D, Tepel M, Gao P, Zhu Z (2020) Reducing NADPH synthesis counteracts diabetic nephropathy through restoration of AMPK activity in type 1 diabetic rats. Cell Rep 32:108207. - »Bioblast link«

Skeletal muscle mitochondrial bioenergetics in men and women with type 1 diabetes

from the O2k-Network »CA Toronto Perry CG«

Monaco CMF, Bellissimo CA, Hughes MC, Ramos SV, Laham R, Perry CGR, Hawke TJ (2020) Sexual dimorphism in human skeletal muscle mitochondrial bioenergetics in response to type 1 diabetes. Am J Physiol Endocrinol Metab 318:E44-E51. - »Bioblast link«

Bioblast alert 2021(06) - Fatty acid oxidation (FAO): 2021-03-19

Approved FAO inhibitor Trimetazidine restricts tumor growth in oxidative lung carcinomas

from the O2k-Network »FR Bordeaux Rossignol R«

Amoedo ND, Sarlak S, Obre E, Esteves P, Bégueret H, Kieffer Y, Rousseau B, Dupis A, Izotte J, Bellance N, Dard L, Redonnet-Vernhet I, Punzi G, Rodrigues MF, Dumon E, Mafhouf W, Guyonnet-Dupérat V, Gales L, Palama T, Bellvert F, Dugot-Senan N, Claverol S, Baste JM, Lacombe D, Rezvani HR, Pierri CL, Mechta-Grigoriou F, Thumerel M, Rossignol R (2021) Targeting the mitochondrial trifunctional protein restrains tumor growth in oxidative lung carcinomas. J Clin Invest 131:e133081. - »Bioblast link«

CI inhibitors like rotenone inhibit FAO-linked respiration

Inhibition of CI leads to accumulation of NADH in the mt-matrix. The resultant lack of NAD⁺ blocks FAO.
- »Fatty acid oxidation pathway control state«

Measuring FAO-linked respiration requires a low concentration of malate

In the absence of malate, accumulation of acetyl-CoA inhibits FAO.
- »Gnaiger 2020 BEC MitoPathways - Chapter 5«

Quantifying FAO capacity (F-pathway) - avoid overestimation

Malate anaplerotic pathways are active in various tissues and cultured cells, which can lead to an overestimation of the F-pathway capacity. .
- Evaluate the malate anaplerotic pathway: »SUIT-027«

- Analyze F-pathway avoiding overestimation: »SUIT-002« and »SUIT-025«

Bioblast alert 2021(05) - Bioenerg Commun & MitoFit Preprints: 2021-03-04

Mitochondrial physiology in Parkinson’s disease (PD)

A COST Action MitoEAGLE contribution:

Krako Jakovljevic N, Ebanks B, Chakrabarti L, Markovic I, Moisoi N (2021) Mitochondrial homeostasis in cellular models of Parkinson’s Disease. MitoFit Preprints 2021.4 doi:10.26124/mitofit:2021-0004

Internal normalization of rate – what is the difference between flux control ratio and flux control efficiency?

A flux control ratio is the ratio of oxygen flux in a specific respiratory control state, normalized for maximum flux in a common reference state. Flux control efficiency expresses the control of respiration as a fractional change of oxygen flux or flow between protocol steps. Both values vary between theoretical lower and upper limits of 0 and 1.
- »Gnaiger 2020 BEC MitoPathways - Chapter 3«

Submit manuscripts simultaneously to MitoFit Preprints and Bioenergetics Communications via the BEC website

A seamless process for taking MitoFit preprints to living BEC communications with open and published peer review.

- »Bioenergetics Communications«

Bioblast alert 2021(04) - MitoFit Preprints: 2021-02-19

Exploring the Q-junction in real-time

Simultaneous measurement of coenzyme Q redox state and respiration in isolated mitochondria:

Komlodi T, Cardoso LHD, Doerrier C, Gnaiger E (2021) Coupling and pathway control of coenzyme Q redox state and respiration in isolated mitochondria. MitoFit Preprints 2021.2. doi:10.26124/mitofit:2021-0002

Diagnosis of mitochondrial disease in frozen samples

Measurement of respiratory function in cryopreserved muscle biopsies:

Zuccolotto-dos-Reis FH, Andriao-Escarso SH, Araujo JS, Espreafico EM, Alberici LC, Sobreira CFR (2021) Acetyl CoA driven respiration in frozen muscle contributes to the diagnosis of mitochondrial disease. MitoFit Preprints 2021.3. doi:10.26124/mitofit:2021-0003

Bioblast alert 2021(03) - ATP production P»: 2021-01-29

SUIT protocols with Magnesium Green™ (MgG) can be used to study respiration and ATP production P»

MgG dye does not affect respiration of cardiac isolated mitochondria.

Cardoso LHD, Doerrier C, Gnaiger E (2021) Magnesium Green for fluorometric measurement of ATP production does not interfere with mitochondrial respiration. MitoFit Preprints 2021.1. doi:10.26124/mitofit:2021-0001

Measuring ATP-ADP exchange using the fluorophore Magnesium Green

from the O2k-Network »HU Budapest Chinopoulos C«

Chinopoulos C, Kiss G, Kawamata H, Starkov AA (2014) Measurement of ADP-ATP exchange in relation to mitochondrial transmembrane potential and oxygen consumption. Methods Enzymol 542:333-48. »Bioblast link«

Magnesium Green and P» – which sample preparations work?

Magnesium Green (MgG) can be used with mitochondrial preparations: isolated mitochondria, tissue homogenates, and permeabilized cells and tissues.
- »MgG« and »Publications MgG«

Did you know that you can measure the respiratory capacity available for P» in living cells?

SUIT protocols from the SUIT-003 family guide you through the titrations to analyze R-L net ROUTINE capacity.
- »SUIT-003 O2 ce D009« and »SUIT-003 O2 ce-pce D020«

Bioblast alert 2021(02) - Permeabilized fibers: 2021-01-21

A quote from MitoPathways Chapter 3. Normalization:

Respiratory OXPHOS capacity P in human skeletal muscle ranges from 60 to 160 pmol∙s^-1∙mg^-1 based on wet muscle mass of permeabilized fibers. By comparison, mass-specific electron transfer capacity E is approximately 25 pmol∙s^-1∙mg^-1 in platelets and senescent fibroblasts and 40 to 80 pmol∙s^-1∙mg^-1 in PBMC, HEK, CEM, HUVEC, and young fibroblasts. ― Are these values comparable? - »Gnaiger 2020 BEC MitoPathways«.

Statistical evaluation on replica in high-resolution respirometry with permeabilized skeletal muscle fibers

from the O2k-Network »AU Melbourne Bishop DJ«

Jacques M, Kuang J, Bishop DJ, Yan X, Alvarez-Romero J, Munson F, Garnham A, Papadimitriou I, Voisin S, Eynon N (2019) Mitochondrial respiration variability and simulations in human skeletal muscle: The Gene SMART study. FASEB J 34:2978-86. - »Bioblast link«

Effect of temperature on mitochondrial respiratory capacity of cardiac permeabilized fibers

from the O2k-Network »AT Innsbruck Gnaiger E« , »CA Rimouski Blier PU« and »CA Edmonton Lemieux H«

Lemieux H, Blier PU, Gnaiger E (2017) Remodeling pathway control of mitochondrial respiratory capacity by temperature in mouse heart: electron flow through the Q-junction in permeabilized fibers. Sci Rep 7:2840. »Bioblast link«

What is the optimal ADP concentration to evaluate OXPHOS capacity in permeabilized muscle fibers (pfi)?

For the evaluation of OXPHOS capacity, the limitation of respiratory fluxes must be avoided by using a kinetically-saturating ADP concentration. In permeabilized muscle fibers, an ADP concentration of 5 mM or higher is needed to reach kinetically-saturating levels.
- »Optimum ADP concentration in pfi«

Bioblast alert 2021(01) - MitoPathways: the new BEC edition of the Blue Book: 2021-01-05

The 5^th edition of MitoPathways features new chapters on additivity of mitochondrial pathway capacities and protonmotive pressure – one step beyond ∆Ψ and the protonmotive force.

Gnaiger E (2020) Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis. 5th ed. Bioenerg Commun 2020.2: 112pp. doi:10.26124/bec:2020-0002. - »Open Access«