MitoFit Open Seminars

MitoFit Preprints

MitoFit DOI Data Center

MitoPedia: Preprints

MitoFit Open Seminars

Time: Friday, 08:30 to 10:00

Location: Oroboros Instruments, Schöpfstr 18, MiPArt

2018-07-20 08:30 Friday MitoFit science meeting

• 08:30-09:15 Journal club: Bastos Sant'Anna Silva AC: Short-term starvation is a strategy to unravel the cellular capacity of oxidizing specific exogenous/endogenous substrates in mitochondria. Zeidler 2017 J Biol Chem
• 09:15-09:40 DatLab Protocol session: Timea Komlodi: Discussion of a DL-SUIT protocol for the MitoPedia: SUIT and DatLab 7.3.
• 09:40-10:00 Results of the week: Andras Meszaros: Side effects of the ATP synthase inhibitor, oligomycin

2018-07-13 08:30 Friday MitoFit science meeting

• 08:30-09:00 Gerhard Krumschnabel: Respiratory control in mitochondrial preparations: isolated mitochondria, tissue homogenate, and permeabilized fibres.

Abstract: The application of High-Resolution FluoRespirometry (HRFR) for assessing mitochondrial energy metabolism is well established. Experimental substrate-uncoupler-inhibitor protocols for OXPHOS analysis enable the dissection of functional modules of substrate utilization, converging branches of electron transfer and coupling control for elucidation of the pathways supporting mitochondrial performance and dysfunction. Here we applied substrate-uncoupler-inhibitor titration protocols to evaluate different mitochondrial preparations from two mammalian experimental models for their suitability in HRR. In mouse heart, a tissue homogenate micropreparation was compared to a permeabilized fiber preparation. In beef heart, with abundant tissue available, we extended this comparison to include the preparation of isolated mitochondria. The permeabilized fiber preparation has its advantages, but also has limitations, specifically the diffusion limitations imposed on mitochondria for oxygen and ADP, inorganic phosphate and energy substrates. To reduce these limitations, we evaluated a method for the preparation of cardiac homogenate which is based on low-shear mechanical homogenization using the PBI-Shredder, an auxiliary tool for HRFR. For mouse cardiac tissue, paired OXPHOS analysis on fibers and Shredder-samples indicated similar mitochondrial coupling control and respiratory capacities. Use of the PBI-Shredder reduced processing time of homogenate preparation compared to permeabilized fiber preparation and improved reproducibility within samples. Application of the PBI-Shredder with homogenates from mouse brain and liver yielded high-quality samples displaying tissue-specific OXPHOS fingerprints. In beef heart samples, Shredder homogenates did not reduce variability between preparations, but enhanced the coupling control ratio compared to both permeabilized fibers and isolated mitochondria. Overall, Shredder homogenates provide a valuable mitochondrial preparation, reducing preparation time and sample requirement while preserving the quality of the mitochondrial preparation.

• 09:00-09:20 ######: Discussion of a DL-SUIT protocol for the MitoPedia: SUIT and DatLab 7.3.
• 09:20-09:45 Erich Gnaiger: O2k-Publications in brief

• Scialo_2016_Cell Metab - ROS and RET
• Ignatenko_2018_Nat Commun - Neurodegeneration
• Smolkova_2010_J Bioenerg Biomembr - Cancer and O2-kinetics
• Kristiansen_2011_J Biol Chem - Cancer and O2-kinetics

2018-07-06 08:30 Friday MitoFit science meeting

• 08:30-09:00 Luiz Garcia e Souza: Comparison of protocols for platelet respirometry.

MitoEAGLE secondment report Lund

• 09:00-09:45 Erich Gnaiger: Mitochondrial pathway control of OXPHOS- and ET-capacity: Additivity of NADH- and succinate-linked pathways - N+S versus NS.

Abstract: Measuring the upper limit of mitochondrial performance

2018-06-15 08:30 Friday MitoFit science meeting

• Dr. Sabine Schmitt, Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München: Impact of tigecyclin on mitochondrial respiration, H2O2 production, ATP production and membrane potential.

Final report MtFOIE GRAS secondment

• Carolina Doerrier, Erich Gnaiger: Update on SUIT protocols and DL7