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Identification of key uric acid synthesis pathway in a unique mutant silkworm Bombyx mori model of Parkinson's disease.

Tabunoki H, Ono H, Ode H, Ishikawa K, Kawana N, Banno Y, Shimada T, Nakamura Y, Yamamoto K, Satoh J, Bono H - PLoS ONE (2013)

Bottom Line: We found that the mRNA levels of genes in this pathway were significantly lower in B. mori op mutants, indicating that downstream events in the signal transduction cascade might be prevented.These results suggest that UA synthesis, transport, elimination and accumulation are decreased by environmental oxidative stress in the B. mori op mutant.In the case of B. mori op mutants, the relatively low availability of UA appears to be due both to the oxidation of DJ-1 and to its expenditure to mitigate the effects of environmental oxidative stress.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University, Tokyo, Japan. h_tabuno@cc.tuat.ac.jp

ABSTRACT
Plasma uric acid (UA) levels decrease following clinical progression and stage development of Parkinson's disease (PD). However, the molecular mechanisms underlying decreases in plasma UA levels remain unclear, and the potential to apply mutagenesis to a PD model has not previously been discovered. We identified a unique mutant of the silkworm Bombyx mori (B.mori) op. Initially, we investigated the causality of the phenotypic "op" by microarray analysis using our constructed KAIKO functional annotation pipeline. Consequently, we found a novel UA synthesis-modulating pathway, from DJ-1 to xanthine oxidase, and established methods for large-scale analysis of gene expression in B. mori. We found that the mRNA levels of genes in this pathway were significantly lower in B. mori op mutants, indicating that downstream events in the signal transduction cascade might be prevented. Additionally, levels of B.mori tyrosine hydroxylase (TH) and DJ-1 mRNA were significantly lower in the brain of B. mori op mutants. UA content was significantly lower in the B. mori op mutant tissues and hemolymph. The possibility that the B. mori op mutant might be due to loss of DJ-1 function was supported by the observed vulnerability to oxidative stress. These results suggest that UA synthesis, transport, elimination and accumulation are decreased by environmental oxidative stress in the B. mori op mutant. In the case of B. mori op mutants, the relatively low availability of UA appears to be due both to the oxidation of DJ-1 and to its expenditure to mitigate the effects of environmental oxidative stress. Our findings are expected to provide information needed to elucidate the molecular mechanism of decreased plasma UA levels in the clinical stage progression of PD.

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B.mori TH and DJ-1 mRNA expression in brain of wild-type and op mutant larvae by RT-PCR.(A) mRNA expression levels were measured by Image J ver. 1.37 c, and plotted to compare op and wild-type mRNA levels (TH; P<0.0001, DJ-1; P = 0.0017). (B) Lane 1, wild-type; lane 2, op mutant. (C) Immunohistochemical localization of tyrosine hydroxylase (TH) in op and wild-type brain. Tissue sections were prepared from day 5 to 7 fifth instar larvae. 1 (op) and 4 (wild-type) are negative controls. TH positive regions (2 and 3:op, 5 and 6:wild-type) are stained brown. Bar: 200 µm.
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pone-0069130-g003: B.mori TH and DJ-1 mRNA expression in brain of wild-type and op mutant larvae by RT-PCR.(A) mRNA expression levels were measured by Image J ver. 1.37 c, and plotted to compare op and wild-type mRNA levels (TH; P<0.0001, DJ-1; P = 0.0017). (B) Lane 1, wild-type; lane 2, op mutant. (C) Immunohistochemical localization of tyrosine hydroxylase (TH) in op and wild-type brain. Tissue sections were prepared from day 5 to 7 fifth instar larvae. 1 (op) and 4 (wild-type) are negative controls. TH positive regions (2 and 3:op, 5 and 6:wild-type) are stained brown. Bar: 200 µm.

Mentions: Tyrosine hydroxylase plays (TH) an important role in the biosynthesis of dopamine andproduction is reduced by a decrease in TH expression, leading to the onset of PD [18]. Thus, TH expression levels are used for diagnosis of PD. To investigate the expression levels of B. mori TH and DJ-1 mRNA in fifth instar op mutant and wild-type larval brain, we performed reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. B. mori TH and DJ-1 mRNA levels were found to be significantly lower in the brains of op larval mutants (Fig. 3A and B, Figure S2).


Identification of key uric acid synthesis pathway in a unique mutant silkworm Bombyx mori model of Parkinson's disease.

Tabunoki H, Ono H, Ode H, Ishikawa K, Kawana N, Banno Y, Shimada T, Nakamura Y, Yamamoto K, Satoh J, Bono H - PLoS ONE (2013)

B.mori TH and DJ-1 mRNA expression in brain of wild-type and op mutant larvae by RT-PCR.(A) mRNA expression levels were measured by Image J ver. 1.37 c, and plotted to compare op and wild-type mRNA levels (TH; P<0.0001, DJ-1; P = 0.0017). (B) Lane 1, wild-type; lane 2, op mutant. (C) Immunohistochemical localization of tyrosine hydroxylase (TH) in op and wild-type brain. Tissue sections were prepared from day 5 to 7 fifth instar larvae. 1 (op) and 4 (wild-type) are negative controls. TH positive regions (2 and 3:op, 5 and 6:wild-type) are stained brown. Bar: 200 µm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3722175&req=5

pone-0069130-g003: B.mori TH and DJ-1 mRNA expression in brain of wild-type and op mutant larvae by RT-PCR.(A) mRNA expression levels were measured by Image J ver. 1.37 c, and plotted to compare op and wild-type mRNA levels (TH; P<0.0001, DJ-1; P = 0.0017). (B) Lane 1, wild-type; lane 2, op mutant. (C) Immunohistochemical localization of tyrosine hydroxylase (TH) in op and wild-type brain. Tissue sections were prepared from day 5 to 7 fifth instar larvae. 1 (op) and 4 (wild-type) are negative controls. TH positive regions (2 and 3:op, 5 and 6:wild-type) are stained brown. Bar: 200 µm.
Mentions: Tyrosine hydroxylase plays (TH) an important role in the biosynthesis of dopamine andproduction is reduced by a decrease in TH expression, leading to the onset of PD [18]. Thus, TH expression levels are used for diagnosis of PD. To investigate the expression levels of B. mori TH and DJ-1 mRNA in fifth instar op mutant and wild-type larval brain, we performed reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. B. mori TH and DJ-1 mRNA levels were found to be significantly lower in the brains of op larval mutants (Fig. 3A and B, Figure S2).

Bottom Line: We found that the mRNA levels of genes in this pathway were significantly lower in B. mori op mutants, indicating that downstream events in the signal transduction cascade might be prevented.These results suggest that UA synthesis, transport, elimination and accumulation are decreased by environmental oxidative stress in the B. mori op mutant.In the case of B. mori op mutants, the relatively low availability of UA appears to be due both to the oxidation of DJ-1 and to its expenditure to mitigate the effects of environmental oxidative stress.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioinformatics and Molecular Neuropathology, Meiji Pharmaceutical University, Tokyo, Japan. h_tabuno@cc.tuat.ac.jp

ABSTRACT
Plasma uric acid (UA) levels decrease following clinical progression and stage development of Parkinson's disease (PD). However, the molecular mechanisms underlying decreases in plasma UA levels remain unclear, and the potential to apply mutagenesis to a PD model has not previously been discovered. We identified a unique mutant of the silkworm Bombyx mori (B.mori) op. Initially, we investigated the causality of the phenotypic "op" by microarray analysis using our constructed KAIKO functional annotation pipeline. Consequently, we found a novel UA synthesis-modulating pathway, from DJ-1 to xanthine oxidase, and established methods for large-scale analysis of gene expression in B. mori. We found that the mRNA levels of genes in this pathway were significantly lower in B. mori op mutants, indicating that downstream events in the signal transduction cascade might be prevented. Additionally, levels of B.mori tyrosine hydroxylase (TH) and DJ-1 mRNA were significantly lower in the brain of B. mori op mutants. UA content was significantly lower in the B. mori op mutant tissues and hemolymph. The possibility that the B. mori op mutant might be due to loss of DJ-1 function was supported by the observed vulnerability to oxidative stress. These results suggest that UA synthesis, transport, elimination and accumulation are decreased by environmental oxidative stress in the B. mori op mutant. In the case of B. mori op mutants, the relatively low availability of UA appears to be due both to the oxidation of DJ-1 and to its expenditure to mitigate the effects of environmental oxidative stress. Our findings are expected to provide information needed to elucidate the molecular mechanism of decreased plasma UA levels in the clinical stage progression of PD.

Show MeSH
Related in: MedlinePlus