Detection of changes in mitochondrial hydrogen sulfide i n vivo in the fish model Poecilia mexicana (Poeciliidae)

Abstract

In this paper, we outline the use of a mitochondria-targeted ratiometric mass spectrometry probe, MitoA, to detect in vivo changes in mitochondrial hydrogen sulfide (H 2 S) in Poecilia mexicana (family Poeciliidae). MitoA is introduced via intraperitoneal injection into the animal and is taken up by mitochondria, where it reacts with H 2 S to form the product MitoN. The MitoN/MitoA ratio can be used to assess relative changes in the amounts of mitochondrial H 2 S produced over time. We describe the use of MitoA in the fish species P. mexicana to illustrate the steps for adopting the use of MitoA in a new organism, including extraction and purification of MitoA and MitoN from tissues followed by tandem mass spectrometry. In this proof-of-concept study we exposed H 2 S tolerant P. mexicana to 59 µM free H 2 S for 5 h, which resulted in increased MitoN/MitoA in brain and gills, but not in liver or muscle, demonstrating increased mitochondrial H 2 S levels in select tissues following whole-animal H 2 S exposure. This is the first time that accumulation of H 2 S has been observed in vivo during whole-animal exposure to free H 2 S using MitoA.

Convergent evolution of conserved mitochondrial pathways underlies repeated adaptation to extreme environments

“…Inside mitochondria, MitoA reacts with H 2 S and is converted to MitoN. The ratio of MitoN/MitoA can be quantified using liquid chromatography with tandem mass spectrometry and serve as a metric of mitochondrial H 2 S. We used a MitoA protocol specifically validated for P. mexicana (39). Fish injected with MitoA were exposed to different environmental H 2 S concentrations for 5 h. Gill, liver, brain, and muscle tissues were sampled from fish and used for the quantification of MitoN/MitoA ratios.…”

Strain-specificity in the hydrogen sulphide signalling network following dietary restriction in recombinant inbred mice

“…In addition, it will also be interesting to investigate precisely how H 2 S production varies in different tissues and in different cellular locations following DR. These approaches may be made more feasible with the advent of novel chemical probes to determine H 2 S in vivo (Arndt et al 2017;Lau et al 2019). However, irrespective of these caveats, we have shown that endogenous H 2 S levels and associated signalling pathways differ significantly depending on genetic background in mice under both AL and DR conditions.…”

First person – Gigi Lau and Nick Barts

“…ABSTRACTFirst Person is a series of interviews with the first authors of a selection of papers published in Biology Open, helping early-career researchers promote themselves alongside their papers. Gigi Lau and Nick Barts are co-first authors on ‘ Detection of changes in mitochondrial hydrogen sulfide in vivo in the fish model Poecilia mexicana (Poeciliidae)’, published in BiO. Gigi is a post-doctoral fellow in the lab of Dr Sjannie Lefevre at the University of Oslo, Norway, adaptive variation in mitochondrial function.…”