Volani 2016 Abstract MitoFit Science Camp 2016

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Effects of iron imbalances on mitochondrial activity in mouse liver homogenate and permabilized rat PBMCs.

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Volani C, Demetz E, Doerrier C, Gnaiger E, Weiss G (2016)

Event: MitoFit Science Camp 2016 Kuehtai AT

Iron is a fundamental co-factor for several cell processes, including oxidative phosphorylation, and mitochondria are the major sites of iron-utilization [1]. Besides being central part of mitochondrial complex I-IV enzymes of the electron transport system, iron also regulates citric acid cycle activity by modulating mitochondrial aconitase expression [2,3]. However, so far, little information is available on how mitochondrial function is affected by alterations of iron homeostasis, and how to best measure tissue mitochondrial activity and its interaction with iron metabolism in vivo; therefore we aimed at investigating the impact of tissue iron loading on mitochondria as well as the presence of mitochondrial blood markers, that might represent good surrogates for tissue iron imbalances.

To access the impact of iron on mitochondrial respiration we studied mitochondrial function in liver samples of 10-week old FVB mice and C57BL/6N mice, receiving either normal- or high iron (25 g/kg)-diet two weeks before being sacrificed. The liver was collected and stored in Custadiol prior to homogenization in MiR05. Mitochondrial LEAK respiration, Complex I and II maximal oxidative phosphorylation together with ET-pathway of the liver homogenates (2 mg) were assessed by means of high resolution respirometry (Oroboros Instruments, Austria).

Our ongoing experiments indicate that mitochondrial function testing can be successfully performed in mouse tissues as well as in isolated PBMCs from rats. Analysis of liver samples from mice indicate that dietary iron supplementation triggers changes in oxidative phosphorylation, having an impact on the activity of the electron transfer-pathway complexes. Analysis of mitochondrial PBMCs activity in rat samples is currently under investigation and might provide useful information on mitochondrial tissue activity.

Keywords: PBMC

O2k-Network Lab: AT Innsbruck Oroboros, AT Innsbruck Gnaiger E


Labels: MiParea: Respiration 


Organism: Mouse, Rat  Tissue;cell: Liver, Blood cells, Lymphocyte  Preparation: Homogenate 


Coupling state: LEAK, OXPHOS, ET  Pathway: N, S  HRR: Oxygraph-2k  Event: B2  MitoFit Science Camp 2016 

Affiliations

1-Dept Internal Med VI, Med Univ Innsbruck; 2-OROBOROS Instruments, Innsbruck; Austria. – c_volani@yahoo.com

References

  1. Martelli A, Schmucker S, Reutenauer L, Mathieu JR, Peyssonnaux C, Karim Z, Puy H, Galy B, Hentze MW, Puccio H (2015) Iron regulatory protein 1 sustains mitochondrial iron loading and function in frataxin deficiency. Cell Metab 21:311-22.
  2. Oexle H, Gnaiger E, Weiss G (1999) Iron-dependent changes in cellular energy metabolism: influence on citric acid cycle and oxidative phosphorylation. Biochim Biophys Acta 1413:99-107.
  3. Rouault TA (2016) Mitochondrial iron overload: causes and consequences. Curr Opin Genet Dev 38:31-7.