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Zebrafish biosensor for toxicant induced muscle hyperactivity.

Shahid M, Takamiya M, Stegmaier J, Middel V, Gradl M, Klüver N, Mikut R, Dickmeis T, Scholz S, Rastegar S, Yang L, Strähle U - Sci Rep (2016)

Bottom Line: Exposure to substances that interfere with motor function induced a dose-dependent increase of GFP intensity beginning at sub-micromolar concentrations, while washout of the chemicals reduced the level of hspb11 transgene expression.Simultaneously, these toxicants induced muscle hyperactivity with increased calcium spike height and frequency.TgBAC(hspb11:GFP) zebrafish embryos provide a quantitative measure of muscle hyperactivity and represent a robust whole organism system for detecting chemicals that affect motor function.

View Article: PubMed Central - PubMed

Affiliation: Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Postfach 3640, D76021 Karlsruhe.

ABSTRACT
Robust and sensitive detection systems are a crucial asset for risk management of chemicals, which are produced in increasing number and diversity. To establish an in vivo biosensor system with quantitative readout for potential toxicant effects on motor function, we generated a transgenic zebrafish line TgBAC(hspb11:GFP) which expresses a GFP reporter under the control of regulatory elements of the small heat shock protein hspb11. Spatiotemporal hspb11 transgene expression in the musculature and the notochord matched closely that of endogenous hspb11 expression. Exposure to substances that interfere with motor function induced a dose-dependent increase of GFP intensity beginning at sub-micromolar concentrations, while washout of the chemicals reduced the level of hspb11 transgene expression. Simultaneously, these toxicants induced muscle hyperactivity with increased calcium spike height and frequency. The hspb11 transgene up-regulation induced by either chemicals or heat shock was eliminated after co-application of the anaesthetic MS-222. TgBAC(hspb11:GFP) zebrafish embryos provide a quantitative measure of muscle hyperactivity and represent a robust whole organism system for detecting chemicals that affect motor function.

No MeSH data available.


Related in: MedlinePlus

Reduced muscle integrity in correlation to hspb11 transgene up-regulation.Birefringence images from the trunk region of wildtype embryos, treated during 9–48 hpf with either azinphosmethyl (A, 3 μM), propoxur (B, 720 μM), galanthamine (C, 1 mM), chlorpyrifos (D, 20 μM), dibutylphthalate (E, 2.69 μM), veratridine (F, 120 μM), methylmercury (G, 0.119 μM), methoxychlor (H, 2.3 μM), esfenvalerate (I, 0.191 µM), flucythrinate (J, 0.055 µM), chlorophenol (K, 389 μM), dibromoethane (L, 2.1 mM), dimethylphenol (M, 327 μM) and chlorothalonil (N, 0.4 μM). Five representative examples are shown for each chemical. Scale bar: 500 μm.
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f4: Reduced muscle integrity in correlation to hspb11 transgene up-regulation.Birefringence images from the trunk region of wildtype embryos, treated during 9–48 hpf with either azinphosmethyl (A, 3 μM), propoxur (B, 720 μM), galanthamine (C, 1 mM), chlorpyrifos (D, 20 μM), dibutylphthalate (E, 2.69 μM), veratridine (F, 120 μM), methylmercury (G, 0.119 μM), methoxychlor (H, 2.3 μM), esfenvalerate (I, 0.191 µM), flucythrinate (J, 0.055 µM), chlorophenol (K, 389 μM), dibromoethane (L, 2.1 mM), dimethylphenol (M, 327 μM) and chlorothalonil (N, 0.4 μM). Five representative examples are shown for each chemical. Scale bar: 500 μm.

Mentions: Ion channels are often targets of medicines and toxicants. Normal motor function requires precise control of voltage-gated Na+ channel function for the transformation of focal membrane depolarization into a fibre-wide action potential and the ensuing release of intracellular calcium ions for actin-myosin interaction. We examined the effects of voltage-gated Na+ channel activators (veratridine, flucytrinate and esfenvalerate), of methylmercury that causes up-regulation of intracellular calcium levels, and of other channel modulators (methoxychlor and chlorophenol) (Fig. 3F–K). For all channel modulators, we observed dose-dependent up-regulation of hspb11 transgene expression, again in good dosage agreement with impaired motility (Fig. S1; Table S2). Channel modulator treatment led to reduced muscle integrity as well (Fig. 4F–K). Thus, hspb11 transgene up-regulation was again found to correlate with motor dysfunction, as we observed with AChE inhibitors.


Zebrafish biosensor for toxicant induced muscle hyperactivity.

Shahid M, Takamiya M, Stegmaier J, Middel V, Gradl M, Klüver N, Mikut R, Dickmeis T, Scholz S, Rastegar S, Yang L, Strähle U - Sci Rep (2016)

Reduced muscle integrity in correlation to hspb11 transgene up-regulation.Birefringence images from the trunk region of wildtype embryos, treated during 9–48 hpf with either azinphosmethyl (A, 3 μM), propoxur (B, 720 μM), galanthamine (C, 1 mM), chlorpyrifos (D, 20 μM), dibutylphthalate (E, 2.69 μM), veratridine (F, 120 μM), methylmercury (G, 0.119 μM), methoxychlor (H, 2.3 μM), esfenvalerate (I, 0.191 µM), flucythrinate (J, 0.055 µM), chlorophenol (K, 389 μM), dibromoethane (L, 2.1 mM), dimethylphenol (M, 327 μM) and chlorothalonil (N, 0.4 μM). Five representative examples are shown for each chemical. Scale bar: 500 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4815012&req=5

f4: Reduced muscle integrity in correlation to hspb11 transgene up-regulation.Birefringence images from the trunk region of wildtype embryos, treated during 9–48 hpf with either azinphosmethyl (A, 3 μM), propoxur (B, 720 μM), galanthamine (C, 1 mM), chlorpyrifos (D, 20 μM), dibutylphthalate (E, 2.69 μM), veratridine (F, 120 μM), methylmercury (G, 0.119 μM), methoxychlor (H, 2.3 μM), esfenvalerate (I, 0.191 µM), flucythrinate (J, 0.055 µM), chlorophenol (K, 389 μM), dibromoethane (L, 2.1 mM), dimethylphenol (M, 327 μM) and chlorothalonil (N, 0.4 μM). Five representative examples are shown for each chemical. Scale bar: 500 μm.
Mentions: Ion channels are often targets of medicines and toxicants. Normal motor function requires precise control of voltage-gated Na+ channel function for the transformation of focal membrane depolarization into a fibre-wide action potential and the ensuing release of intracellular calcium ions for actin-myosin interaction. We examined the effects of voltage-gated Na+ channel activators (veratridine, flucytrinate and esfenvalerate), of methylmercury that causes up-regulation of intracellular calcium levels, and of other channel modulators (methoxychlor and chlorophenol) (Fig. 3F–K). For all channel modulators, we observed dose-dependent up-regulation of hspb11 transgene expression, again in good dosage agreement with impaired motility (Fig. S1; Table S2). Channel modulator treatment led to reduced muscle integrity as well (Fig. 4F–K). Thus, hspb11 transgene up-regulation was again found to correlate with motor dysfunction, as we observed with AChE inhibitors.

Bottom Line: Exposure to substances that interfere with motor function induced a dose-dependent increase of GFP intensity beginning at sub-micromolar concentrations, while washout of the chemicals reduced the level of hspb11 transgene expression.Simultaneously, these toxicants induced muscle hyperactivity with increased calcium spike height and frequency.TgBAC(hspb11:GFP) zebrafish embryos provide a quantitative measure of muscle hyperactivity and represent a robust whole organism system for detecting chemicals that affect motor function.

View Article: PubMed Central - PubMed

Affiliation: Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Postfach 3640, D76021 Karlsruhe.

ABSTRACT
Robust and sensitive detection systems are a crucial asset for risk management of chemicals, which are produced in increasing number and diversity. To establish an in vivo biosensor system with quantitative readout for potential toxicant effects on motor function, we generated a transgenic zebrafish line TgBAC(hspb11:GFP) which expresses a GFP reporter under the control of regulatory elements of the small heat shock protein hspb11. Spatiotemporal hspb11 transgene expression in the musculature and the notochord matched closely that of endogenous hspb11 expression. Exposure to substances that interfere with motor function induced a dose-dependent increase of GFP intensity beginning at sub-micromolar concentrations, while washout of the chemicals reduced the level of hspb11 transgene expression. Simultaneously, these toxicants induced muscle hyperactivity with increased calcium spike height and frequency. The hspb11 transgene up-regulation induced by either chemicals or heat shock was eliminated after co-application of the anaesthetic MS-222. TgBAC(hspb11:GFP) zebrafish embryos provide a quantitative measure of muscle hyperactivity and represent a robust whole organism system for detecting chemicals that affect motor function.

No MeSH data available.


Related in: MedlinePlus