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From omics to drug metabolism and high content screen of natural product in zebrafish: a new model for discovery of neuroactive compound.

Hung MW, Zhang ZJ, Li S, Lei B, Yuan S, Cui GZ, Man Hoi P, Chan K, Lee SM - Evid Based Complement Alternat Med (2012)

Bottom Line: Recent studies found a functional similarity of drug metabolism systems in zebrafish and mammals, providing a clue with why some compounds are active in zebrafish in vivo but not in vitro, as well as providing grounds for the rationales supporting the use of a zebrafish screen to identify prodrugs.Here, we discuss the advantages of the zebrafish model for evaluating drug metabolism and the mode of pharmacological action with the emerging omics approaches.Why this model is suitable for identifying lead compounds from natural products for therapy of disorders with multifactorial etiopathogenesis and imbalance of angiogenesis, such as Parkinson's disease, epilepsy, cardiotoxicity, cerebral hemorrhage, dyslipidemia, and hyperlipidemia, is addressed.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Quality Research in Chinese Medicine, University of Macau, Avenue Padre Tomás Pereira S.J., Taipa, Macau, China.

ABSTRACT
The zebrafish (Danio rerio) has recently become a common model in the fields of genetics, environmental science, toxicology, and especially drug screening. Zebrafish has emerged as a biomedically relevant model for in vivo high content drug screening and the simultaneous determination of multiple efficacy parameters, including behaviour, selectivity, and toxicity in the content of the whole organism. A zebrafish behavioural assay has been demonstrated as a novel, rapid, and high-throughput approach to the discovery of neuroactive, psychoactive, and memory-modulating compounds. Recent studies found a functional similarity of drug metabolism systems in zebrafish and mammals, providing a clue with why some compounds are active in zebrafish in vivo but not in vitro, as well as providing grounds for the rationales supporting the use of a zebrafish screen to identify prodrugs. Here, we discuss the advantages of the zebrafish model for evaluating drug metabolism and the mode of pharmacological action with the emerging omics approaches. Why this model is suitable for identifying lead compounds from natural products for therapy of disorders with multifactorial etiopathogenesis and imbalance of angiogenesis, such as Parkinson's disease, epilepsy, cardiotoxicity, cerebral hemorrhage, dyslipidemia, and hyperlipidemia, is addressed.

No MeSH data available.


Related in: MedlinePlus

MPTP induces DA neuron loss in zebrafish. (a) Representative picture of anti-TH whole mount immunostaining. TH+ neurons in diencephalic region were indicated by bracket, dorsal view. L-dep, L-deprenyl (selegiline), a selective MAO-B inhibitor, was used as positive control. (b) Counting of TH+ neuron. (c) Relative fold change of th gene expression as compared to control, MPTP downregulated th gene expression. #P < 0.05 and ##P < 0.01 compared with untreated control. *P < 0.05 and **P < 0.01 compared with MPTP treated alone.
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fig5: MPTP induces DA neuron loss in zebrafish. (a) Representative picture of anti-TH whole mount immunostaining. TH+ neurons in diencephalic region were indicated by bracket, dorsal view. L-dep, L-deprenyl (selegiline), a selective MAO-B inhibitor, was used as positive control. (b) Counting of TH+ neuron. (c) Relative fold change of th gene expression as compared to control, MPTP downregulated th gene expression. #P < 0.05 and ##P < 0.01 compared with untreated control. *P < 0.05 and **P < 0.01 compared with MPTP treated alone.

Mentions: The brain structure and function of the zebrafish are very similar to those of other vertebrates [70]. The anatomy of the zebrafish brain DA system was studied recently, and a region anatomically similar to the striatum was identified in the forebrain [71]. Neurotoxins, such as MPTP, 6-OHDA, and rotenone, are known to induce DA neuron loss in animal models. Among those neurotoxins, MPTP/MPP+ is the best characterized toxin to generate model of PD and has proved useful for studying the striatal circuitry involved in PD pathophysiology [72]. Exposure of zebrafish to MPTP caused profound loss of tyrosine hydroxylase-positive (TH+) neurons and downregulated TH mRNA expression in contrast to vehicle-treated healthy zebrafish (Figure 5) leading to a deficit in locomotor behaviour (Figure 6). Earlier studies revealed that 6-OHDA is taken up selectively by the plasma membrane dopamine transporter and subsequently accumulates in the mitochondria, resulting in the formation of ROS and RNS [73]. In addition, neuroinflammation plays a key role in 6-OHDA-induced DA neuron damage in vivo [74]. We measured the gene expression of proinflammatory mediators in 6-OHDA-treated zebrafish by quantitative real-time PCR and showed that 6-OHDA caused overexpression of IL-1β, TNF-α, and COX-2, several-fold higher than that of untreated control fish [75]. These proinflammatory genes play important roles in the etiology of PD [76]. It has been shown that the level of the COX-2 protein is upregulated in substantia nigra DA neurons in PD patients and in animal models [77]. The inhibition of COX-2 and TNF-α has provided neuroprotection in rats [76]. Our current iTRAQ-based shotgun proteomics study in a zebrafish model for PD suggested the potential involvement of both TNF-α/NF-κB and oxidative phosphorylation pathways in 6-OHDA-induced neurodegeneration in zebrafish (unpublished data). However, given that, all reported promising studies on this chemical induced PD experimental zebrafish model, more researches need to be done to differentiate systemic toxicity and selective neuronal toxicity of the neurotoxins. In addition, generation of transgenic zebrafish expressing fluorescent protein specifically in DA neuron, that allows tracking the kinetic change of living DA neurons in vivo, is a viable strategy to replace the postimmunochemical staining of TH-positive neurons.


From omics to drug metabolism and high content screen of natural product in zebrafish: a new model for discovery of neuroactive compound.

Hung MW, Zhang ZJ, Li S, Lei B, Yuan S, Cui GZ, Man Hoi P, Chan K, Lee SM - Evid Based Complement Alternat Med (2012)

MPTP induces DA neuron loss in zebrafish. (a) Representative picture of anti-TH whole mount immunostaining. TH+ neurons in diencephalic region were indicated by bracket, dorsal view. L-dep, L-deprenyl (selegiline), a selective MAO-B inhibitor, was used as positive control. (b) Counting of TH+ neuron. (c) Relative fold change of th gene expression as compared to control, MPTP downregulated th gene expression. #P < 0.05 and ##P < 0.01 compared with untreated control. *P < 0.05 and **P < 0.01 compared with MPTP treated alone.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3420231&req=5

fig5: MPTP induces DA neuron loss in zebrafish. (a) Representative picture of anti-TH whole mount immunostaining. TH+ neurons in diencephalic region were indicated by bracket, dorsal view. L-dep, L-deprenyl (selegiline), a selective MAO-B inhibitor, was used as positive control. (b) Counting of TH+ neuron. (c) Relative fold change of th gene expression as compared to control, MPTP downregulated th gene expression. #P < 0.05 and ##P < 0.01 compared with untreated control. *P < 0.05 and **P < 0.01 compared with MPTP treated alone.
Mentions: The brain structure and function of the zebrafish are very similar to those of other vertebrates [70]. The anatomy of the zebrafish brain DA system was studied recently, and a region anatomically similar to the striatum was identified in the forebrain [71]. Neurotoxins, such as MPTP, 6-OHDA, and rotenone, are known to induce DA neuron loss in animal models. Among those neurotoxins, MPTP/MPP+ is the best characterized toxin to generate model of PD and has proved useful for studying the striatal circuitry involved in PD pathophysiology [72]. Exposure of zebrafish to MPTP caused profound loss of tyrosine hydroxylase-positive (TH+) neurons and downregulated TH mRNA expression in contrast to vehicle-treated healthy zebrafish (Figure 5) leading to a deficit in locomotor behaviour (Figure 6). Earlier studies revealed that 6-OHDA is taken up selectively by the plasma membrane dopamine transporter and subsequently accumulates in the mitochondria, resulting in the formation of ROS and RNS [73]. In addition, neuroinflammation plays a key role in 6-OHDA-induced DA neuron damage in vivo [74]. We measured the gene expression of proinflammatory mediators in 6-OHDA-treated zebrafish by quantitative real-time PCR and showed that 6-OHDA caused overexpression of IL-1β, TNF-α, and COX-2, several-fold higher than that of untreated control fish [75]. These proinflammatory genes play important roles in the etiology of PD [76]. It has been shown that the level of the COX-2 protein is upregulated in substantia nigra DA neurons in PD patients and in animal models [77]. The inhibition of COX-2 and TNF-α has provided neuroprotection in rats [76]. Our current iTRAQ-based shotgun proteomics study in a zebrafish model for PD suggested the potential involvement of both TNF-α/NF-κB and oxidative phosphorylation pathways in 6-OHDA-induced neurodegeneration in zebrafish (unpublished data). However, given that, all reported promising studies on this chemical induced PD experimental zebrafish model, more researches need to be done to differentiate systemic toxicity and selective neuronal toxicity of the neurotoxins. In addition, generation of transgenic zebrafish expressing fluorescent protein specifically in DA neuron, that allows tracking the kinetic change of living DA neurons in vivo, is a viable strategy to replace the postimmunochemical staining of TH-positive neurons.

Bottom Line: Recent studies found a functional similarity of drug metabolism systems in zebrafish and mammals, providing a clue with why some compounds are active in zebrafish in vivo but not in vitro, as well as providing grounds for the rationales supporting the use of a zebrafish screen to identify prodrugs.Here, we discuss the advantages of the zebrafish model for evaluating drug metabolism and the mode of pharmacological action with the emerging omics approaches.Why this model is suitable for identifying lead compounds from natural products for therapy of disorders with multifactorial etiopathogenesis and imbalance of angiogenesis, such as Parkinson's disease, epilepsy, cardiotoxicity, cerebral hemorrhage, dyslipidemia, and hyperlipidemia, is addressed.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Quality Research in Chinese Medicine, University of Macau, Avenue Padre Tomás Pereira S.J., Taipa, Macau, China.

ABSTRACT
The zebrafish (Danio rerio) has recently become a common model in the fields of genetics, environmental science, toxicology, and especially drug screening. Zebrafish has emerged as a biomedically relevant model for in vivo high content drug screening and the simultaneous determination of multiple efficacy parameters, including behaviour, selectivity, and toxicity in the content of the whole organism. A zebrafish behavioural assay has been demonstrated as a novel, rapid, and high-throughput approach to the discovery of neuroactive, psychoactive, and memory-modulating compounds. Recent studies found a functional similarity of drug metabolism systems in zebrafish and mammals, providing a clue with why some compounds are active in zebrafish in vivo but not in vitro, as well as providing grounds for the rationales supporting the use of a zebrafish screen to identify prodrugs. Here, we discuss the advantages of the zebrafish model for evaluating drug metabolism and the mode of pharmacological action with the emerging omics approaches. Why this model is suitable for identifying lead compounds from natural products for therapy of disorders with multifactorial etiopathogenesis and imbalance of angiogenesis, such as Parkinson's disease, epilepsy, cardiotoxicity, cerebral hemorrhage, dyslipidemia, and hyperlipidemia, is addressed.

No MeSH data available.


Related in: MedlinePlus